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1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2  * All rights reserved.
3  *
4  * This package is an SSL implementation written
5  * by Eric Young (eay@cryptsoft.com).
6  * The implementation was written so as to conform with Netscapes SSL.
7  *
8  * This library is free for commercial and non-commercial use as long as
9  * the following conditions are aheared to.  The following conditions
10  * apply to all code found in this distribution, be it the RC4, RSA,
11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
12  * included with this distribution is covered by the same copyright terms
13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14  *
15  * Copyright remains Eric Young's, and as such any Copyright notices in
16  * the code are not to be removed.
17  * If this package is used in a product, Eric Young should be given attribution
18  * as the author of the parts of the library used.
19  * This can be in the form of a textual message at program startup or
20  * in documentation (online or textual) provided with the package.
21  *
22  * Redistribution and use in source and binary forms, with or without
23  * modification, are permitted provided that the following conditions
24  * are met:
25  * 1. Redistributions of source code must retain the copyright
26  *    notice, this list of conditions and the following disclaimer.
27  * 2. Redistributions in binary form must reproduce the above copyright
28  *    notice, this list of conditions and the following disclaimer in the
29  *    documentation and/or other materials provided with the distribution.
30  * 3. All advertising materials mentioning features or use of this software
31  *    must display the following acknowledgement:
32  *    "This product includes cryptographic software written by
33  *     Eric Young (eay@cryptsoft.com)"
34  *    The word 'cryptographic' can be left out if the rouines from the library
35  *    being used are not cryptographic related :-).
36  * 4. If you include any Windows specific code (or a derivative thereof) from
37  *    the apps directory (application code) you must include an acknowledgement:
38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39  *
40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE.
51  *
52  * The licence and distribution terms for any publically available version or
53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
54  * copied and put under another distribution licence
55  * [including the GNU Public Licence.]
56  */
57 /* ====================================================================
58  * Copyright (c) 1998-2007 The OpenSSL Project.  All rights reserved.
59  *
60  * Redistribution and use in source and binary forms, with or without
61  * modification, are permitted provided that the following conditions
62  * are met:
63  *
64  * 1. Redistributions of source code must retain the above copyright
65  *    notice, this list of conditions and the following disclaimer.
66  *
67  * 2. Redistributions in binary form must reproduce the above copyright
68  *    notice, this list of conditions and the following disclaimer in
69  *    the documentation and/or other materials provided with the
70  *    distribution.
71  *
72  * 3. All advertising materials mentioning features or use of this
73  *    software must display the following acknowledgment:
74  *    "This product includes software developed by the OpenSSL Project
75  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
76  *
77  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
78  *    endorse or promote products derived from this software without
79  *    prior written permission. For written permission, please contact
80  *    openssl-core@openssl.org.
81  *
82  * 5. Products derived from this software may not be called "OpenSSL"
83  *    nor may "OpenSSL" appear in their names without prior written
84  *    permission of the OpenSSL Project.
85  *
86  * 6. Redistributions of any form whatsoever must retain the following
87  *    acknowledgment:
88  *    "This product includes software developed by the OpenSSL Project
89  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
90  *
91  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
92  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
93  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
94  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
95  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
96  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
97  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
98  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
99  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
100  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
101  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
102  * OF THE POSSIBILITY OF SUCH DAMAGE.
103  * ====================================================================
104  *
105  * This product includes cryptographic software written by Eric Young
106  * (eay@cryptsoft.com).  This product includes software written by Tim
107  * Hudson (tjh@cryptsoft.com).
108  *
109  */
110 /* ====================================================================
111  * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
112  * ECC cipher suite support in OpenSSL originally developed by
113  * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
114  */
115 /* ====================================================================
116  * Copyright 2005 Nokia. All rights reserved.
117  *
118  * The portions of the attached software ("Contribution") is developed by
119  * Nokia Corporation and is licensed pursuant to the OpenSSL open source
120  * license.
121  *
122  * The Contribution, originally written by Mika Kousa and Pasi Eronen of
123  * Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites
124  * support (see RFC 4279) to OpenSSL.
125  *
126  * No patent licenses or other rights except those expressly stated in
127  * the OpenSSL open source license shall be deemed granted or received
128  * expressly, by implication, estoppel, or otherwise.
129  *
130  * No assurances are provided by Nokia that the Contribution does not
131  * infringe the patent or other intellectual property rights of any third
132  * party or that the license provides you with all the necessary rights
133  * to make use of the Contribution.
134  *
135  * THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN
136  * ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA
137  * SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY
138  * OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR
139  * OTHERWISE.
140  */
141 
142 #ifndef OPENSSL_HEADER_SSL_H
143 #define OPENSSL_HEADER_SSL_H
144 
145 #include <openssl/base.h>
146 
147 #include <openssl/bio.h>
148 #include <openssl/buf.h>
149 #include <openssl/pem.h>
150 #include <openssl/span.h>
151 #include <openssl/ssl3.h>
152 #include <openssl/thread.h>
153 #include <openssl/tls1.h>
154 #include <openssl/x509.h>
155 
156 #if !defined(OPENSSL_WINDOWS)
157 #include <sys/time.h>
158 #endif
159 
160 // Forward-declare struct timeval. On Windows, it is defined in winsock2.h and
161 // Windows headers define too many macros to be included in public headers.
162 // However, only a forward declaration is needed.
163 struct timeval;
164 
165 #if defined(__cplusplus)
166 extern "C" {
167 #endif
168 
169 
170 // SSL implementation.
171 
172 
173 // SSL contexts.
174 //
175 // |SSL_CTX| objects manage shared state and configuration between multiple TLS
176 // or DTLS connections. Whether the connections are TLS or DTLS is selected by
177 // an |SSL_METHOD| on creation.
178 //
179 // |SSL_CTX| are reference-counted and may be shared by connections across
180 // multiple threads. Once shared, functions which change the |SSL_CTX|'s
181 // configuration may not be used.
182 
183 // TLS_method is the |SSL_METHOD| used for TLS connections.
184 OPENSSL_EXPORT const SSL_METHOD *TLS_method(void);
185 
186 // DTLS_method is the |SSL_METHOD| used for DTLS connections.
187 OPENSSL_EXPORT const SSL_METHOD *DTLS_method(void);
188 
189 // TLS_with_buffers_method is like |TLS_method|, but avoids all use of
190 // crypto/x509. All client connections created with |TLS_with_buffers_method|
191 // will fail unless a certificate verifier is installed with
192 // |SSL_set_custom_verify| or |SSL_CTX_set_custom_verify|.
193 OPENSSL_EXPORT const SSL_METHOD *TLS_with_buffers_method(void);
194 
195 // DTLS_with_buffers_method is like |DTLS_method|, but avoids all use of
196 // crypto/x509.
197 OPENSSL_EXPORT const SSL_METHOD *DTLS_with_buffers_method(void);
198 
199 // SSL_CTX_new returns a newly-allocated |SSL_CTX| with default settings or NULL
200 // on error.
201 OPENSSL_EXPORT SSL_CTX *SSL_CTX_new(const SSL_METHOD *method);
202 
203 // SSL_CTX_up_ref increments the reference count of |ctx|. It returns one.
204 OPENSSL_EXPORT int SSL_CTX_up_ref(SSL_CTX *ctx);
205 
206 // SSL_CTX_free releases memory associated with |ctx|.
207 OPENSSL_EXPORT void SSL_CTX_free(SSL_CTX *ctx);
208 
209 
210 // SSL connections.
211 //
212 // An |SSL| object represents a single TLS or DTLS connection. Although the
213 // shared |SSL_CTX| is thread-safe, an |SSL| is not thread-safe and may only be
214 // used on one thread at a time.
215 
216 // SSL_new returns a newly-allocated |SSL| using |ctx| or NULL on error. The new
217 // connection inherits settings from |ctx| at the time of creation. Settings may
218 // also be individually configured on the connection.
219 //
220 // On creation, an |SSL| is not configured to be either a client or server. Call
221 // |SSL_set_connect_state| or |SSL_set_accept_state| to set this.
222 OPENSSL_EXPORT SSL *SSL_new(SSL_CTX *ctx);
223 
224 // SSL_free releases memory associated with |ssl|.
225 OPENSSL_EXPORT void SSL_free(SSL *ssl);
226 
227 // SSL_get_SSL_CTX returns the |SSL_CTX| associated with |ssl|. If
228 // |SSL_set_SSL_CTX| is called, it returns the new |SSL_CTX|, not the initial
229 // one.
230 OPENSSL_EXPORT SSL_CTX *SSL_get_SSL_CTX(const SSL *ssl);
231 
232 // SSL_set_connect_state configures |ssl| to be a client.
233 OPENSSL_EXPORT void SSL_set_connect_state(SSL *ssl);
234 
235 // SSL_set_accept_state configures |ssl| to be a server.
236 OPENSSL_EXPORT void SSL_set_accept_state(SSL *ssl);
237 
238 // SSL_is_server returns one if |ssl| is configured as a server and zero
239 // otherwise.
240 OPENSSL_EXPORT int SSL_is_server(const SSL *ssl);
241 
242 // SSL_is_dtls returns one if |ssl| is a DTLS connection and zero otherwise.
243 OPENSSL_EXPORT int SSL_is_dtls(const SSL *ssl);
244 
245 // SSL_set_bio configures |ssl| to read from |rbio| and write to |wbio|. |ssl|
246 // takes ownership of the two |BIO|s. If |rbio| and |wbio| are the same, |ssl|
247 // only takes ownership of one reference.
248 //
249 // In DTLS, |rbio| must be non-blocking to properly handle timeouts and
250 // retransmits.
251 //
252 // If |rbio| is the same as the currently configured |BIO| for reading, that
253 // side is left untouched and is not freed.
254 //
255 // If |wbio| is the same as the currently configured |BIO| for writing AND |ssl|
256 // is not currently configured to read from and write to the same |BIO|, that
257 // side is left untouched and is not freed. This asymmetry is present for
258 // historical reasons.
259 //
260 // Due to the very complex historical behavior of this function, calling this
261 // function if |ssl| already has |BIO|s configured is deprecated. Prefer
262 // |SSL_set0_rbio| and |SSL_set0_wbio| instead.
263 OPENSSL_EXPORT void SSL_set_bio(SSL *ssl, BIO *rbio, BIO *wbio);
264 
265 // SSL_set0_rbio configures |ssl| to read from |rbio|. It takes ownership of
266 // |rbio|.
267 //
268 // Note that, although this function and |SSL_set0_wbio| may be called on the
269 // same |BIO|, each call takes a reference. Use |BIO_up_ref| to balance this.
270 OPENSSL_EXPORT void SSL_set0_rbio(SSL *ssl, BIO *rbio);
271 
272 // SSL_set0_wbio configures |ssl| to write to |wbio|. It takes ownership of
273 // |wbio|.
274 //
275 // Note that, although this function and |SSL_set0_rbio| may be called on the
276 // same |BIO|, each call takes a reference. Use |BIO_up_ref| to balance this.
277 OPENSSL_EXPORT void SSL_set0_wbio(SSL *ssl, BIO *wbio);
278 
279 // SSL_get_rbio returns the |BIO| that |ssl| reads from.
280 OPENSSL_EXPORT BIO *SSL_get_rbio(const SSL *ssl);
281 
282 // SSL_get_wbio returns the |BIO| that |ssl| writes to.
283 OPENSSL_EXPORT BIO *SSL_get_wbio(const SSL *ssl);
284 
285 // SSL_get_fd calls |SSL_get_rfd|.
286 OPENSSL_EXPORT int SSL_get_fd(const SSL *ssl);
287 
288 // SSL_get_rfd returns the file descriptor that |ssl| is configured to read
289 // from. If |ssl|'s read |BIO| is not configured or doesn't wrap a file
290 // descriptor then it returns -1.
291 //
292 // Note: On Windows, this may return either a file descriptor or a socket (cast
293 // to int), depending on whether |ssl| was configured with a file descriptor or
294 // socket |BIO|.
295 OPENSSL_EXPORT int SSL_get_rfd(const SSL *ssl);
296 
297 // SSL_get_wfd returns the file descriptor that |ssl| is configured to write
298 // to. If |ssl|'s write |BIO| is not configured or doesn't wrap a file
299 // descriptor then it returns -1.
300 //
301 // Note: On Windows, this may return either a file descriptor or a socket (cast
302 // to int), depending on whether |ssl| was configured with a file descriptor or
303 // socket |BIO|.
304 OPENSSL_EXPORT int SSL_get_wfd(const SSL *ssl);
305 
306 // SSL_set_fd configures |ssl| to read from and write to |fd|. It returns one
307 // on success and zero on allocation error. The caller retains ownership of
308 // |fd|.
309 //
310 // On Windows, |fd| is cast to a |SOCKET| and used with Winsock APIs.
311 OPENSSL_EXPORT int SSL_set_fd(SSL *ssl, int fd);
312 
313 // SSL_set_rfd configures |ssl| to read from |fd|. It returns one on success and
314 // zero on allocation error. The caller retains ownership of |fd|.
315 //
316 // On Windows, |fd| is cast to a |SOCKET| and used with Winsock APIs.
317 OPENSSL_EXPORT int SSL_set_rfd(SSL *ssl, int fd);
318 
319 // SSL_set_wfd configures |ssl| to write to |fd|. It returns one on success and
320 // zero on allocation error. The caller retains ownership of |fd|.
321 //
322 // On Windows, |fd| is cast to a |SOCKET| and used with Winsock APIs.
323 OPENSSL_EXPORT int SSL_set_wfd(SSL *ssl, int fd);
324 
325 // SSL_do_handshake continues the current handshake. If there is none or the
326 // handshake has completed or False Started, it returns one. Otherwise, it
327 // returns <= 0. The caller should pass the value into |SSL_get_error| to
328 // determine how to proceed.
329 //
330 // In DTLS, the caller must drive retransmissions. Whenever |SSL_get_error|
331 // signals |SSL_ERROR_WANT_READ|, use |DTLSv1_get_timeout| to determine the
332 // current timeout. If it expires before the next retry, call
333 // |DTLSv1_handle_timeout|. Note that DTLS handshake retransmissions use fresh
334 // sequence numbers, so it is not sufficient to replay packets at the transport.
335 //
336 // TODO(davidben): Ensure 0 is only returned on transport EOF.
337 // https://crbug.com/466303.
338 OPENSSL_EXPORT int SSL_do_handshake(SSL *ssl);
339 
340 // SSL_connect configures |ssl| as a client, if unconfigured, and calls
341 // |SSL_do_handshake|.
342 OPENSSL_EXPORT int SSL_connect(SSL *ssl);
343 
344 // SSL_accept configures |ssl| as a server, if unconfigured, and calls
345 // |SSL_do_handshake|.
346 OPENSSL_EXPORT int SSL_accept(SSL *ssl);
347 
348 // SSL_read reads up to |num| bytes from |ssl| into |buf|. It implicitly runs
349 // any pending handshakes, including renegotiations when enabled. On success, it
350 // returns the number of bytes read. Otherwise, it returns <= 0. The caller
351 // should pass the value into |SSL_get_error| to determine how to proceed.
352 //
353 // TODO(davidben): Ensure 0 is only returned on transport EOF.
354 // https://crbug.com/466303.
355 OPENSSL_EXPORT int SSL_read(SSL *ssl, void *buf, int num);
356 
357 // SSL_peek behaves like |SSL_read| but does not consume any bytes returned.
358 OPENSSL_EXPORT int SSL_peek(SSL *ssl, void *buf, int num);
359 
360 // SSL_pending returns the number of buffered, decrypted bytes available for
361 // read in |ssl|. It does not read from the transport.
362 //
363 // In DTLS, it is possible for this function to return zero while there is
364 // buffered, undecrypted data from the transport in |ssl|. For example,
365 // |SSL_read| may read a datagram with two records, decrypt the first, and leave
366 // the second buffered for a subsequent call to |SSL_read|. Callers that wish to
367 // detect this case can use |SSL_has_pending|.
368 OPENSSL_EXPORT int SSL_pending(const SSL *ssl);
369 
370 // SSL_has_pending returns one if |ssl| has buffered, decrypted bytes available
371 // for read, or if |ssl| has buffered data from the transport that has not yet
372 // been decrypted. If |ssl| has neither, this function returns zero.
373 //
374 // In TLS, BoringSSL does not implement read-ahead, so this function returns one
375 // if and only if |SSL_pending| would return a non-zero value. In DTLS, it is
376 // possible for this function to return one while |SSL_pending| returns zero.
377 // For example, |SSL_read| may read a datagram with two records, decrypt the
378 // first, and leave the second buffered for a subsequent call to |SSL_read|.
379 //
380 // As a result, if this function returns one, the next call to |SSL_read| may
381 // still fail, read from the transport, or both. The buffered, undecrypted data
382 // may be invalid or incomplete.
383 OPENSSL_EXPORT int SSL_has_pending(const SSL *ssl);
384 
385 // SSL_write writes up to |num| bytes from |buf| into |ssl|. It implicitly runs
386 // any pending handshakes, including renegotiations when enabled. On success, it
387 // returns the number of bytes written. Otherwise, it returns <= 0. The caller
388 // should pass the value into |SSL_get_error| to determine how to proceed.
389 //
390 // In TLS, a non-blocking |SSL_write| differs from non-blocking |write| in that
391 // a failed |SSL_write| still commits to the data passed in. When retrying, the
392 // caller must supply the original write buffer (or a larger one containing the
393 // original as a prefix). By default, retries will fail if they also do not
394 // reuse the same |buf| pointer. This may be relaxed with
395 // |SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER|, but the buffer contents still must be
396 // unchanged.
397 //
398 // By default, in TLS, |SSL_write| will not return success until all |num| bytes
399 // are written. This may be relaxed with |SSL_MODE_ENABLE_PARTIAL_WRITE|. It
400 // allows |SSL_write| to complete with a partial result when only part of the
401 // input was written in a single record.
402 //
403 // In DTLS, neither |SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER| and
404 // |SSL_MODE_ENABLE_PARTIAL_WRITE| do anything. The caller may retry with a
405 // different buffer freely. A single call to |SSL_write| only ever writes a
406 // single record in a single packet, so |num| must be at most
407 // |SSL3_RT_MAX_PLAIN_LENGTH|.
408 //
409 // TODO(davidben): Ensure 0 is only returned on transport EOF.
410 // https://crbug.com/466303.
411 OPENSSL_EXPORT int SSL_write(SSL *ssl, const void *buf, int num);
412 
413 // SSL_KEY_UPDATE_REQUESTED indicates that the peer should reply to a KeyUpdate
414 // message with its own, thus updating traffic secrets for both directions on
415 // the connection.
416 #define SSL_KEY_UPDATE_REQUESTED 1
417 
418 // SSL_KEY_UPDATE_NOT_REQUESTED indicates that the peer should not reply with
419 // it's own KeyUpdate message.
420 #define SSL_KEY_UPDATE_NOT_REQUESTED 0
421 
422 // SSL_key_update queues a TLS 1.3 KeyUpdate message to be sent on |ssl|
423 // if one is not already queued. The |request_type| argument must one of the
424 // |SSL_KEY_UPDATE_*| values. This function requires that |ssl| have completed a
425 // TLS >= 1.3 handshake. It returns one on success or zero on error.
426 //
427 // Note that this function does not _send_ the message itself. The next call to
428 // |SSL_write| will cause the message to be sent. |SSL_write| may be called with
429 // a zero length to flush a KeyUpdate message when no application data is
430 // pending.
431 OPENSSL_EXPORT int SSL_key_update(SSL *ssl, int request_type);
432 
433 // SSL_shutdown shuts down |ssl|. It runs in two stages. First, it sends
434 // close_notify and returns zero or one on success or -1 on failure. Zero
435 // indicates that close_notify was sent, but not received, and one additionally
436 // indicates that the peer's close_notify had already been received.
437 //
438 // To then wait for the peer's close_notify, run |SSL_shutdown| to completion a
439 // second time. This returns 1 on success and -1 on failure. Application data
440 // is considered a fatal error at this point. To process or discard it, read
441 // until close_notify with |SSL_read| instead.
442 //
443 // In both cases, on failure, pass the return value into |SSL_get_error| to
444 // determine how to proceed.
445 //
446 // Most callers should stop at the first stage. Reading for close_notify is
447 // primarily used for uncommon protocols where the underlying transport is
448 // reused after TLS completes. Additionally, DTLS uses an unordered transport
449 // and is unordered, so the second stage is a no-op in DTLS.
450 OPENSSL_EXPORT int SSL_shutdown(SSL *ssl);
451 
452 // SSL_CTX_set_quiet_shutdown sets quiet shutdown on |ctx| to |mode|. If
453 // enabled, |SSL_shutdown| will not send a close_notify alert or wait for one
454 // from the peer. It will instead synchronously return one.
455 OPENSSL_EXPORT void SSL_CTX_set_quiet_shutdown(SSL_CTX *ctx, int mode);
456 
457 // SSL_CTX_get_quiet_shutdown returns whether quiet shutdown is enabled for
458 // |ctx|.
459 OPENSSL_EXPORT int SSL_CTX_get_quiet_shutdown(const SSL_CTX *ctx);
460 
461 // SSL_set_quiet_shutdown sets quiet shutdown on |ssl| to |mode|. If enabled,
462 // |SSL_shutdown| will not send a close_notify alert or wait for one from the
463 // peer. It will instead synchronously return one.
464 OPENSSL_EXPORT void SSL_set_quiet_shutdown(SSL *ssl, int mode);
465 
466 // SSL_get_quiet_shutdown returns whether quiet shutdown is enabled for
467 // |ssl|.
468 OPENSSL_EXPORT int SSL_get_quiet_shutdown(const SSL *ssl);
469 
470 // SSL_get_error returns a |SSL_ERROR_*| value for the most recent operation on
471 // |ssl|. It should be called after an operation failed to determine whether the
472 // error was fatal and, if not, when to retry.
473 OPENSSL_EXPORT int SSL_get_error(const SSL *ssl, int ret_code);
474 
475 // SSL_ERROR_NONE indicates the operation succeeded.
476 #define SSL_ERROR_NONE 0
477 
478 // SSL_ERROR_SSL indicates the operation failed within the library. The caller
479 // may inspect the error queue for more information.
480 #define SSL_ERROR_SSL 1
481 
482 // SSL_ERROR_WANT_READ indicates the operation failed attempting to read from
483 // the transport. The caller may retry the operation when the transport is ready
484 // for reading.
485 //
486 // If signaled by a DTLS handshake, the caller must also call
487 // |DTLSv1_get_timeout| and |DTLSv1_handle_timeout| as appropriate. See
488 // |SSL_do_handshake|.
489 #define SSL_ERROR_WANT_READ 2
490 
491 // SSL_ERROR_WANT_WRITE indicates the operation failed attempting to write to
492 // the transport. The caller may retry the operation when the transport is ready
493 // for writing.
494 #define SSL_ERROR_WANT_WRITE 3
495 
496 // SSL_ERROR_WANT_X509_LOOKUP indicates the operation failed in calling the
497 // |cert_cb| or |client_cert_cb|. The caller may retry the operation when the
498 // callback is ready to return a certificate or one has been configured
499 // externally.
500 //
501 // See also |SSL_CTX_set_cert_cb| and |SSL_CTX_set_client_cert_cb|.
502 #define SSL_ERROR_WANT_X509_LOOKUP 4
503 
504 // SSL_ERROR_SYSCALL indicates the operation failed externally to the library.
505 // The caller should consult the system-specific error mechanism. This is
506 // typically |errno| but may be something custom if using a custom |BIO|. It
507 // may also be signaled if the transport returned EOF, in which case the
508 // operation's return value will be zero.
509 #define SSL_ERROR_SYSCALL 5
510 
511 // SSL_ERROR_ZERO_RETURN indicates the operation failed because the connection
512 // was cleanly shut down with a close_notify alert.
513 #define SSL_ERROR_ZERO_RETURN 6
514 
515 // SSL_ERROR_WANT_CONNECT indicates the operation failed attempting to connect
516 // the transport (the |BIO| signaled |BIO_RR_CONNECT|). The caller may retry the
517 // operation when the transport is ready.
518 #define SSL_ERROR_WANT_CONNECT 7
519 
520 // SSL_ERROR_WANT_ACCEPT indicates the operation failed attempting to accept a
521 // connection from the transport (the |BIO| signaled |BIO_RR_ACCEPT|). The
522 // caller may retry the operation when the transport is ready.
523 //
524 // TODO(davidben): Remove this. It's used by accept BIOs which are bizarre.
525 #define SSL_ERROR_WANT_ACCEPT 8
526 
527 // SSL_ERROR_WANT_CHANNEL_ID_LOOKUP is never used.
528 //
529 // TODO(davidben): Remove this. Some callers reference it when stringifying
530 // errors. They should use |SSL_error_description| instead.
531 #define SSL_ERROR_WANT_CHANNEL_ID_LOOKUP 9
532 
533 // SSL_ERROR_PENDING_SESSION indicates the operation failed because the session
534 // lookup callback indicated the session was unavailable. The caller may retry
535 // the operation when lookup has completed.
536 //
537 // See also |SSL_CTX_sess_set_get_cb| and |SSL_magic_pending_session_ptr|.
538 #define SSL_ERROR_PENDING_SESSION 11
539 
540 // SSL_ERROR_PENDING_CERTIFICATE indicates the operation failed because the
541 // early callback indicated certificate lookup was incomplete. The caller may
542 // retry the operation when lookup has completed.
543 //
544 // See also |SSL_CTX_set_select_certificate_cb|.
545 #define SSL_ERROR_PENDING_CERTIFICATE 12
546 
547 // SSL_ERROR_WANT_PRIVATE_KEY_OPERATION indicates the operation failed because
548 // a private key operation was unfinished. The caller may retry the operation
549 // when the private key operation is complete.
550 //
551 // See also |SSL_set_private_key_method| and
552 // |SSL_CTX_set_private_key_method|.
553 #define SSL_ERROR_WANT_PRIVATE_KEY_OPERATION 13
554 
555 // SSL_ERROR_PENDING_TICKET indicates that a ticket decryption is pending. The
556 // caller may retry the operation when the decryption is ready.
557 //
558 // See also |SSL_CTX_set_ticket_aead_method|.
559 #define SSL_ERROR_PENDING_TICKET 14
560 
561 // SSL_ERROR_EARLY_DATA_REJECTED indicates that early data was rejected. The
562 // caller should treat this as a connection failure and retry any operations
563 // associated with the rejected early data. |SSL_reset_early_data_reject| may be
564 // used to reuse the underlying connection for the retry.
565 #define SSL_ERROR_EARLY_DATA_REJECTED 15
566 
567 // SSL_ERROR_WANT_CERTIFICATE_VERIFY indicates the operation failed because
568 // certificate verification was incomplete. The caller may retry the operation
569 // when certificate verification is complete.
570 //
571 // See also |SSL_CTX_set_custom_verify|.
572 #define SSL_ERROR_WANT_CERTIFICATE_VERIFY 16
573 
574 #define SSL_ERROR_HANDOFF 17
575 #define SSL_ERROR_HANDBACK 18
576 
577 // SSL_ERROR_WANT_RENEGOTIATE indicates the operation is pending a response to
578 // a renegotiation request from the server. The caller may call
579 // |SSL_renegotiate| to schedule a renegotiation and retry the operation.
580 //
581 // See also |ssl_renegotiate_explicit|.
582 #define SSL_ERROR_WANT_RENEGOTIATE 19
583 
584 // SSL_ERROR_HANDSHAKE_HINTS_READY indicates the handshake has progressed enough
585 // for |SSL_serialize_handshake_hints| to be called. See also
586 // |SSL_request_handshake_hints|.
587 #define SSL_ERROR_HANDSHAKE_HINTS_READY 20
588 
589 // SSL_error_description returns a string representation of |err|, where |err|
590 // is one of the |SSL_ERROR_*| constants returned by |SSL_get_error|, or NULL
591 // if the value is unrecognized.
592 OPENSSL_EXPORT const char *SSL_error_description(int err);
593 
594 // SSL_set_mtu sets the |ssl|'s MTU in DTLS to |mtu|. It returns one on success
595 // and zero on failure.
596 OPENSSL_EXPORT int SSL_set_mtu(SSL *ssl, unsigned mtu);
597 
598 // DTLSv1_set_initial_timeout_duration sets the initial duration for a DTLS
599 // handshake timeout.
600 //
601 // This duration overrides the default of 1 second, which is the strong
602 // recommendation of RFC 6347 (see section 4.2.4.1). However, there may exist
603 // situations where a shorter timeout would be beneficial, such as for
604 // time-sensitive applications.
605 OPENSSL_EXPORT void DTLSv1_set_initial_timeout_duration(SSL *ssl,
606                                                         unsigned duration_ms);
607 
608 // DTLSv1_get_timeout queries the next DTLS handshake timeout. If there is a
609 // timeout in progress, it sets |*out| to the time remaining and returns one.
610 // Otherwise, it returns zero.
611 //
612 // When the timeout expires, call |DTLSv1_handle_timeout| to handle the
613 // retransmit behavior.
614 //
615 // NOTE: This function must be queried again whenever the handshake state
616 // machine changes, including when |DTLSv1_handle_timeout| is called.
617 OPENSSL_EXPORT int DTLSv1_get_timeout(const SSL *ssl, struct timeval *out);
618 
619 // DTLSv1_handle_timeout is called when a DTLS handshake timeout expires. If no
620 // timeout had expired, it returns 0. Otherwise, it retransmits the previous
621 // flight of handshake messages and returns 1. If too many timeouts had expired
622 // without progress or an error occurs, it returns -1.
623 //
624 // The caller's external timer should be compatible with the one |ssl| queries
625 // within some fudge factor. Otherwise, the call will be a no-op, but
626 // |DTLSv1_get_timeout| will return an updated timeout.
627 //
628 // If the function returns -1, checking if |SSL_get_error| returns
629 // |SSL_ERROR_WANT_WRITE| may be used to determine if the retransmit failed due
630 // to a non-fatal error at the write |BIO|. However, the operation may not be
631 // retried until the next timeout fires.
632 //
633 // WARNING: This function breaks the usual return value convention.
634 //
635 // TODO(davidben): This |SSL_ERROR_WANT_WRITE| behavior is kind of bizarre.
636 OPENSSL_EXPORT int DTLSv1_handle_timeout(SSL *ssl);
637 
638 
639 // Protocol versions.
640 
641 #define DTLS1_VERSION_MAJOR 0xfe
642 #define SSL3_VERSION_MAJOR 0x03
643 
644 #define SSL3_VERSION 0x0300
645 #define TLS1_VERSION 0x0301
646 #define TLS1_1_VERSION 0x0302
647 #define TLS1_2_VERSION 0x0303
648 #define TLS1_3_VERSION 0x0304
649 
650 #define DTLS1_VERSION 0xfeff
651 #define DTLS1_2_VERSION 0xfefd
652 
653 // SSL_CTX_set_min_proto_version sets the minimum protocol version for |ctx| to
654 // |version|. If |version| is zero, the default minimum version is used. It
655 // returns one on success and zero if |version| is invalid.
656 OPENSSL_EXPORT int SSL_CTX_set_min_proto_version(SSL_CTX *ctx,
657                                                  uint16_t version);
658 
659 // SSL_CTX_set_max_proto_version sets the maximum protocol version for |ctx| to
660 // |version|. If |version| is zero, the default maximum version is used. It
661 // returns one on success and zero if |version| is invalid.
662 OPENSSL_EXPORT int SSL_CTX_set_max_proto_version(SSL_CTX *ctx,
663                                                  uint16_t version);
664 
665 // SSL_CTX_get_min_proto_version returns the minimum protocol version for |ctx|
666 OPENSSL_EXPORT uint16_t SSL_CTX_get_min_proto_version(const SSL_CTX *ctx);
667 
668 // SSL_CTX_get_max_proto_version returns the maximum protocol version for |ctx|
669 OPENSSL_EXPORT uint16_t SSL_CTX_get_max_proto_version(const SSL_CTX *ctx);
670 
671 // SSL_set_min_proto_version sets the minimum protocol version for |ssl| to
672 // |version|. If |version| is zero, the default minimum version is used. It
673 // returns one on success and zero if |version| is invalid.
674 OPENSSL_EXPORT int SSL_set_min_proto_version(SSL *ssl, uint16_t version);
675 
676 // SSL_set_max_proto_version sets the maximum protocol version for |ssl| to
677 // |version|. If |version| is zero, the default maximum version is used. It
678 // returns one on success and zero if |version| is invalid.
679 OPENSSL_EXPORT int SSL_set_max_proto_version(SSL *ssl, uint16_t version);
680 
681 // SSL_get_min_proto_version returns the minimum protocol version for |ssl|. If
682 // the connection's configuration has been shed, 0 is returned.
683 OPENSSL_EXPORT uint16_t SSL_get_min_proto_version(const SSL *ssl);
684 
685 // SSL_get_max_proto_version returns the maximum protocol version for |ssl|. If
686 // the connection's configuration has been shed, 0 is returned.
687 OPENSSL_EXPORT uint16_t SSL_get_max_proto_version(const SSL *ssl);
688 
689 // SSL_version returns the TLS or DTLS protocol version used by |ssl|, which is
690 // one of the |*_VERSION| values. (E.g. |TLS1_2_VERSION|.) Before the version
691 // is negotiated, the result is undefined.
692 OPENSSL_EXPORT int SSL_version(const SSL *ssl);
693 
694 
695 // Options.
696 //
697 // Options configure protocol behavior.
698 
699 // SSL_OP_NO_QUERY_MTU, in DTLS, disables querying the MTU from the underlying
700 // |BIO|. Instead, the MTU is configured with |SSL_set_mtu|.
701 #define SSL_OP_NO_QUERY_MTU 0x00001000L
702 
703 // SSL_OP_NO_TICKET disables session ticket support (RFC 5077).
704 #define SSL_OP_NO_TICKET 0x00004000L
705 
706 // SSL_OP_CIPHER_SERVER_PREFERENCE configures servers to select ciphers and
707 // ECDHE curves according to the server's preferences instead of the
708 // client's.
709 #define SSL_OP_CIPHER_SERVER_PREFERENCE 0x00400000L
710 
711 // The following flags toggle individual protocol versions. This is deprecated.
712 // Use |SSL_CTX_set_min_proto_version| and |SSL_CTX_set_max_proto_version|
713 // instead.
714 #define SSL_OP_NO_TLSv1 0x04000000L
715 #define SSL_OP_NO_TLSv1_2 0x08000000L
716 #define SSL_OP_NO_TLSv1_1 0x10000000L
717 #define SSL_OP_NO_TLSv1_3 0x20000000L
718 #define SSL_OP_NO_DTLSv1 SSL_OP_NO_TLSv1
719 #define SSL_OP_NO_DTLSv1_2 SSL_OP_NO_TLSv1_2
720 
721 // SSL_CTX_set_options enables all options set in |options| (which should be one
722 // or more of the |SSL_OP_*| values, ORed together) in |ctx|. It returns a
723 // bitmask representing the resulting enabled options.
724 OPENSSL_EXPORT uint32_t SSL_CTX_set_options(SSL_CTX *ctx, uint32_t options);
725 
726 // SSL_CTX_clear_options disables all options set in |options| (which should be
727 // one or more of the |SSL_OP_*| values, ORed together) in |ctx|. It returns a
728 // bitmask representing the resulting enabled options.
729 OPENSSL_EXPORT uint32_t SSL_CTX_clear_options(SSL_CTX *ctx, uint32_t options);
730 
731 // SSL_CTX_get_options returns a bitmask of |SSL_OP_*| values that represent all
732 // the options enabled for |ctx|.
733 OPENSSL_EXPORT uint32_t SSL_CTX_get_options(const SSL_CTX *ctx);
734 
735 // SSL_set_options enables all options set in |options| (which should be one or
736 // more of the |SSL_OP_*| values, ORed together) in |ssl|. It returns a bitmask
737 // representing the resulting enabled options.
738 OPENSSL_EXPORT uint32_t SSL_set_options(SSL *ssl, uint32_t options);
739 
740 // SSL_clear_options disables all options set in |options| (which should be one
741 // or more of the |SSL_OP_*| values, ORed together) in |ssl|. It returns a
742 // bitmask representing the resulting enabled options.
743 OPENSSL_EXPORT uint32_t SSL_clear_options(SSL *ssl, uint32_t options);
744 
745 // SSL_get_options returns a bitmask of |SSL_OP_*| values that represent all the
746 // options enabled for |ssl|.
747 OPENSSL_EXPORT uint32_t SSL_get_options(const SSL *ssl);
748 
749 
750 // Modes.
751 //
752 // Modes configure API behavior.
753 
754 // SSL_MODE_ENABLE_PARTIAL_WRITE, in TLS, allows |SSL_write| to complete with a
755 // partial result when the only part of the input was written in a single
756 // record. In DTLS, it does nothing.
757 #define SSL_MODE_ENABLE_PARTIAL_WRITE 0x00000001L
758 
759 // SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER, in TLS, allows retrying an incomplete
760 // |SSL_write| with a different buffer. However, |SSL_write| still assumes the
761 // buffer contents are unchanged. This is not the default to avoid the
762 // misconception that non-blocking |SSL_write| behaves like non-blocking
763 // |write|. In DTLS, it does nothing.
764 #define SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER 0x00000002L
765 
766 // SSL_MODE_NO_AUTO_CHAIN disables automatically building a certificate chain
767 // before sending certificates to the peer. This flag is set (and the feature
768 // disabled) by default.
769 // TODO(davidben): Remove this behavior. https://crbug.com/boringssl/42.
770 #define SSL_MODE_NO_AUTO_CHAIN 0x00000008L
771 
772 // SSL_MODE_ENABLE_FALSE_START allows clients to send application data before
773 // receipt of ChangeCipherSpec and Finished. This mode enables full handshakes
774 // to 'complete' in one RTT. See RFC 7918.
775 //
776 // When False Start is enabled, |SSL_do_handshake| may succeed before the
777 // handshake has completely finished. |SSL_write| will function at this point,
778 // and |SSL_read| will transparently wait for the final handshake leg before
779 // returning application data. To determine if False Start occurred or when the
780 // handshake is completely finished, see |SSL_in_false_start|, |SSL_in_init|,
781 // and |SSL_CB_HANDSHAKE_DONE| from |SSL_CTX_set_info_callback|.
782 #define SSL_MODE_ENABLE_FALSE_START 0x00000080L
783 
784 // SSL_MODE_CBC_RECORD_SPLITTING causes multi-byte CBC records in TLS 1.0 to be
785 // split in two: the first record will contain a single byte and the second will
786 // contain the remainder. This effectively randomises the IV and prevents BEAST
787 // attacks.
788 #define SSL_MODE_CBC_RECORD_SPLITTING 0x00000100L
789 
790 // SSL_MODE_NO_SESSION_CREATION will cause any attempts to create a session to
791 // fail with SSL_R_SESSION_MAY_NOT_BE_CREATED. This can be used to enforce that
792 // session resumption is used for a given SSL*.
793 #define SSL_MODE_NO_SESSION_CREATION 0x00000200L
794 
795 // SSL_MODE_SEND_FALLBACK_SCSV sends TLS_FALLBACK_SCSV in the ClientHello.
796 // To be set only by applications that reconnect with a downgraded protocol
797 // version; see RFC 7507 for details.
798 //
799 // DO NOT ENABLE THIS if your application attempts a normal handshake. Only use
800 // this in explicit fallback retries, following the guidance in RFC 7507.
801 #define SSL_MODE_SEND_FALLBACK_SCSV 0x00000400L
802 
803 // SSL_CTX_set_mode enables all modes set in |mode| (which should be one or more
804 // of the |SSL_MODE_*| values, ORed together) in |ctx|. It returns a bitmask
805 // representing the resulting enabled modes.
806 OPENSSL_EXPORT uint32_t SSL_CTX_set_mode(SSL_CTX *ctx, uint32_t mode);
807 
808 // SSL_CTX_clear_mode disables all modes set in |mode| (which should be one or
809 // more of the |SSL_MODE_*| values, ORed together) in |ctx|. It returns a
810 // bitmask representing the resulting enabled modes.
811 OPENSSL_EXPORT uint32_t SSL_CTX_clear_mode(SSL_CTX *ctx, uint32_t mode);
812 
813 // SSL_CTX_get_mode returns a bitmask of |SSL_MODE_*| values that represent all
814 // the modes enabled for |ssl|.
815 OPENSSL_EXPORT uint32_t SSL_CTX_get_mode(const SSL_CTX *ctx);
816 
817 // SSL_set_mode enables all modes set in |mode| (which should be one or more of
818 // the |SSL_MODE_*| values, ORed together) in |ssl|. It returns a bitmask
819 // representing the resulting enabled modes.
820 OPENSSL_EXPORT uint32_t SSL_set_mode(SSL *ssl, uint32_t mode);
821 
822 // SSL_clear_mode disables all modes set in |mode| (which should be one or more
823 // of the |SSL_MODE_*| values, ORed together) in |ssl|. It returns a bitmask
824 // representing the resulting enabled modes.
825 OPENSSL_EXPORT uint32_t SSL_clear_mode(SSL *ssl, uint32_t mode);
826 
827 // SSL_get_mode returns a bitmask of |SSL_MODE_*| values that represent all the
828 // modes enabled for |ssl|.
829 OPENSSL_EXPORT uint32_t SSL_get_mode(const SSL *ssl);
830 
831 // SSL_CTX_set0_buffer_pool sets a |CRYPTO_BUFFER_POOL| that will be used to
832 // store certificates. This can allow multiple connections to share
833 // certificates and thus save memory.
834 //
835 // The SSL_CTX does not take ownership of |pool| and the caller must ensure
836 // that |pool| outlives |ctx| and all objects linked to it, including |SSL|,
837 // |X509| and |SSL_SESSION| objects. Basically, don't ever free |pool|.
838 OPENSSL_EXPORT void SSL_CTX_set0_buffer_pool(SSL_CTX *ctx,
839                                              CRYPTO_BUFFER_POOL *pool);
840 
841 
842 // Configuring certificates and private keys.
843 //
844 // These functions configure the connection's leaf certificate, private key, and
845 // certificate chain. The certificate chain is ordered leaf to root (as sent on
846 // the wire) but does not include the leaf. Both client and server certificates
847 // use these functions.
848 //
849 // Certificates and keys may be configured before the handshake or dynamically
850 // in the early callback and certificate callback.
851 
852 // SSL_CTX_use_certificate sets |ctx|'s leaf certificate to |x509|. It returns
853 // one on success and zero on failure.
854 OPENSSL_EXPORT int SSL_CTX_use_certificate(SSL_CTX *ctx, X509 *x509);
855 
856 // SSL_use_certificate sets |ssl|'s leaf certificate to |x509|. It returns one
857 // on success and zero on failure.
858 OPENSSL_EXPORT int SSL_use_certificate(SSL *ssl, X509 *x509);
859 
860 // SSL_CTX_use_PrivateKey sets |ctx|'s private key to |pkey|. It returns one on
861 // success and zero on failure.
862 OPENSSL_EXPORT int SSL_CTX_use_PrivateKey(SSL_CTX *ctx, EVP_PKEY *pkey);
863 
864 // SSL_use_PrivateKey sets |ssl|'s private key to |pkey|. It returns one on
865 // success and zero on failure.
866 OPENSSL_EXPORT int SSL_use_PrivateKey(SSL *ssl, EVP_PKEY *pkey);
867 
868 // SSL_CTX_set0_chain sets |ctx|'s certificate chain, excluding the leaf, to
869 // |chain|. On success, it returns one and takes ownership of |chain|.
870 // Otherwise, it returns zero.
871 OPENSSL_EXPORT int SSL_CTX_set0_chain(SSL_CTX *ctx, STACK_OF(X509) *chain);
872 
873 // SSL_CTX_set1_chain sets |ctx|'s certificate chain, excluding the leaf, to
874 // |chain|. It returns one on success and zero on failure. The caller retains
875 // ownership of |chain| and may release it freely.
876 OPENSSL_EXPORT int SSL_CTX_set1_chain(SSL_CTX *ctx, STACK_OF(X509) *chain);
877 
878 // SSL_set0_chain sets |ssl|'s certificate chain, excluding the leaf, to
879 // |chain|. On success, it returns one and takes ownership of |chain|.
880 // Otherwise, it returns zero.
881 OPENSSL_EXPORT int SSL_set0_chain(SSL *ssl, STACK_OF(X509) *chain);
882 
883 // SSL_set1_chain sets |ssl|'s certificate chain, excluding the leaf, to
884 // |chain|. It returns one on success and zero on failure. The caller retains
885 // ownership of |chain| and may release it freely.
886 OPENSSL_EXPORT int SSL_set1_chain(SSL *ssl, STACK_OF(X509) *chain);
887 
888 // SSL_CTX_add0_chain_cert appends |x509| to |ctx|'s certificate chain. On
889 // success, it returns one and takes ownership of |x509|. Otherwise, it returns
890 // zero.
891 OPENSSL_EXPORT int SSL_CTX_add0_chain_cert(SSL_CTX *ctx, X509 *x509);
892 
893 // SSL_CTX_add1_chain_cert appends |x509| to |ctx|'s certificate chain. It
894 // returns one on success and zero on failure. The caller retains ownership of
895 // |x509| and may release it freely.
896 OPENSSL_EXPORT int SSL_CTX_add1_chain_cert(SSL_CTX *ctx, X509 *x509);
897 
898 // SSL_add0_chain_cert appends |x509| to |ctx|'s certificate chain. On success,
899 // it returns one and takes ownership of |x509|. Otherwise, it returns zero.
900 OPENSSL_EXPORT int SSL_add0_chain_cert(SSL *ssl, X509 *x509);
901 
902 // SSL_CTX_add_extra_chain_cert calls |SSL_CTX_add0_chain_cert|.
903 OPENSSL_EXPORT int SSL_CTX_add_extra_chain_cert(SSL_CTX *ctx, X509 *x509);
904 
905 // SSL_add1_chain_cert appends |x509| to |ctx|'s certificate chain. It returns
906 // one on success and zero on failure. The caller retains ownership of |x509|
907 // and may release it freely.
908 OPENSSL_EXPORT int SSL_add1_chain_cert(SSL *ssl, X509 *x509);
909 
910 // SSL_CTX_clear_chain_certs clears |ctx|'s certificate chain and returns
911 // one.
912 OPENSSL_EXPORT int SSL_CTX_clear_chain_certs(SSL_CTX *ctx);
913 
914 // SSL_CTX_clear_extra_chain_certs calls |SSL_CTX_clear_chain_certs|.
915 OPENSSL_EXPORT int SSL_CTX_clear_extra_chain_certs(SSL_CTX *ctx);
916 
917 // SSL_clear_chain_certs clears |ssl|'s certificate chain and returns one.
918 OPENSSL_EXPORT int SSL_clear_chain_certs(SSL *ssl);
919 
920 // SSL_CTX_set_cert_cb sets a callback that is called to select a certificate.
921 // The callback returns one on success, zero on internal error, and a negative
922 // number on failure or to pause the handshake. If the handshake is paused,
923 // |SSL_get_error| will return |SSL_ERROR_WANT_X509_LOOKUP|.
924 //
925 // On the client, the callback may call |SSL_get0_certificate_types| and
926 // |SSL_get_client_CA_list| for information on the server's certificate
927 // request.
928 //
929 // On the server, the callback will be called after extensions have been
930 // processed, but before the resumption decision has been made. This differs
931 // from OpenSSL which handles resumption before selecting the certificate.
932 OPENSSL_EXPORT void SSL_CTX_set_cert_cb(SSL_CTX *ctx,
933                                         int (*cb)(SSL *ssl, void *arg),
934                                         void *arg);
935 
936 // SSL_set_cert_cb sets a callback that is called to select a certificate. The
937 // callback returns one on success, zero on internal error, and a negative
938 // number on failure or to pause the handshake. If the handshake is paused,
939 // |SSL_get_error| will return |SSL_ERROR_WANT_X509_LOOKUP|.
940 //
941 // On the client, the callback may call |SSL_get0_certificate_types| and
942 // |SSL_get_client_CA_list| for information on the server's certificate
943 // request.
944 //
945 // On the server, the callback will be called after extensions have been
946 // processed, but before the resumption decision has been made. This differs
947 // from OpenSSL which handles resumption before selecting the certificate.
948 OPENSSL_EXPORT void SSL_set_cert_cb(SSL *ssl, int (*cb)(SSL *ssl, void *arg),
949                                     void *arg);
950 
951 // SSL_get0_certificate_types, for a client, sets |*out_types| to an array
952 // containing the client certificate types requested by a server. It returns the
953 // length of the array. Note this list is always empty in TLS 1.3. The server
954 // will instead send signature algorithms. See
955 // |SSL_get0_peer_verify_algorithms|.
956 //
957 // The behavior of this function is undefined except during the callbacks set by
958 // by |SSL_CTX_set_cert_cb| and |SSL_CTX_set_client_cert_cb| or when the
959 // handshake is paused because of them.
960 OPENSSL_EXPORT size_t SSL_get0_certificate_types(const SSL *ssl,
961                                                  const uint8_t **out_types);
962 
963 // SSL_get0_peer_verify_algorithms sets |*out_sigalgs| to an array containing
964 // the signature algorithms the peer is able to verify. It returns the length of
965 // the array. Note these values are only sent starting TLS 1.2 and only
966 // mandatory starting TLS 1.3. If not sent, the empty array is returned. For the
967 // historical client certificate types list, see |SSL_get0_certificate_types|.
968 //
969 // The behavior of this function is undefined except during the callbacks set by
970 // by |SSL_CTX_set_cert_cb| and |SSL_CTX_set_client_cert_cb| or when the
971 // handshake is paused because of them.
972 OPENSSL_EXPORT size_t
973 SSL_get0_peer_verify_algorithms(const SSL *ssl, const uint16_t **out_sigalgs);
974 
975 // SSL_get0_peer_delegation_algorithms sets |*out_sigalgs| to an array
976 // containing the signature algorithms the peer is willing to use with delegated
977 // credentials.  It returns the length of the array. If not sent, the empty
978 // array is returned.
979 //
980 // The behavior of this function is undefined except during the callbacks set by
981 // by |SSL_CTX_set_cert_cb| and |SSL_CTX_set_client_cert_cb| or when the
982 // handshake is paused because of them.
983 OPENSSL_EXPORT size_t
984 SSL_get0_peer_delegation_algorithms(const SSL *ssl,
985                                     const uint16_t **out_sigalgs);
986 
987 // SSL_certs_clear resets the private key, leaf certificate, and certificate
988 // chain of |ssl|.
989 OPENSSL_EXPORT void SSL_certs_clear(SSL *ssl);
990 
991 // SSL_CTX_check_private_key returns one if the certificate and private key
992 // configured in |ctx| are consistent and zero otherwise.
993 OPENSSL_EXPORT int SSL_CTX_check_private_key(const SSL_CTX *ctx);
994 
995 // SSL_check_private_key returns one if the certificate and private key
996 // configured in |ssl| are consistent and zero otherwise.
997 OPENSSL_EXPORT int SSL_check_private_key(const SSL *ssl);
998 
999 // SSL_CTX_get0_certificate returns |ctx|'s leaf certificate.
1000 OPENSSL_EXPORT X509 *SSL_CTX_get0_certificate(const SSL_CTX *ctx);
1001 
1002 // SSL_get_certificate returns |ssl|'s leaf certificate.
1003 OPENSSL_EXPORT X509 *SSL_get_certificate(const SSL *ssl);
1004 
1005 // SSL_CTX_get0_privatekey returns |ctx|'s private key.
1006 OPENSSL_EXPORT EVP_PKEY *SSL_CTX_get0_privatekey(const SSL_CTX *ctx);
1007 
1008 // SSL_get_privatekey returns |ssl|'s private key.
1009 OPENSSL_EXPORT EVP_PKEY *SSL_get_privatekey(const SSL *ssl);
1010 
1011 // SSL_CTX_get0_chain_certs sets |*out_chain| to |ctx|'s certificate chain and
1012 // returns one.
1013 OPENSSL_EXPORT int SSL_CTX_get0_chain_certs(const SSL_CTX *ctx,
1014                                             STACK_OF(X509) **out_chain);
1015 
1016 // SSL_CTX_get_extra_chain_certs calls |SSL_CTX_get0_chain_certs|.
1017 OPENSSL_EXPORT int SSL_CTX_get_extra_chain_certs(const SSL_CTX *ctx,
1018                                                  STACK_OF(X509) **out_chain);
1019 
1020 // SSL_get0_chain_certs sets |*out_chain| to |ssl|'s certificate chain and
1021 // returns one.
1022 OPENSSL_EXPORT int SSL_get0_chain_certs(const SSL *ssl,
1023                                         STACK_OF(X509) **out_chain);
1024 
1025 // SSL_CTX_set_signed_cert_timestamp_list sets the list of signed certificate
1026 // timestamps that is sent to clients that request it. The |list| argument must
1027 // contain one or more SCT structures serialised as a SignedCertificateTimestamp
1028 // List (see https://tools.ietf.org/html/rfc6962#section-3.3) – i.e. each SCT
1029 // is prefixed by a big-endian, uint16 length and the concatenation of one or
1030 // more such prefixed SCTs are themselves also prefixed by a uint16 length. It
1031 // returns one on success and zero on error. The caller retains ownership of
1032 // |list|.
1033 OPENSSL_EXPORT int SSL_CTX_set_signed_cert_timestamp_list(SSL_CTX *ctx,
1034                                                           const uint8_t *list,
1035                                                           size_t list_len);
1036 
1037 // SSL_set_signed_cert_timestamp_list sets the list of signed certificate
1038 // timestamps that is sent to clients that request is. The same format as the
1039 // one used for |SSL_CTX_set_signed_cert_timestamp_list| applies. The caller
1040 // retains ownership of |list|.
1041 OPENSSL_EXPORT int SSL_set_signed_cert_timestamp_list(SSL *ctx,
1042                                                       const uint8_t *list,
1043                                                       size_t list_len);
1044 
1045 // SSL_CTX_set_ocsp_response sets the OCSP response that is sent to clients
1046 // which request it. It returns one on success and zero on error. The caller
1047 // retains ownership of |response|.
1048 OPENSSL_EXPORT int SSL_CTX_set_ocsp_response(SSL_CTX *ctx,
1049                                              const uint8_t *response,
1050                                              size_t response_len);
1051 
1052 // SSL_set_ocsp_response sets the OCSP response that is sent to clients which
1053 // request it. It returns one on success and zero on error. The caller retains
1054 // ownership of |response|.
1055 OPENSSL_EXPORT int SSL_set_ocsp_response(SSL *ssl,
1056                                          const uint8_t *response,
1057                                          size_t response_len);
1058 
1059 // SSL_SIGN_* are signature algorithm values as defined in TLS 1.3.
1060 #define SSL_SIGN_RSA_PKCS1_SHA1 0x0201
1061 #define SSL_SIGN_RSA_PKCS1_SHA256 0x0401
1062 #define SSL_SIGN_RSA_PKCS1_SHA384 0x0501
1063 #define SSL_SIGN_RSA_PKCS1_SHA512 0x0601
1064 #define SSL_SIGN_ECDSA_SHA1 0x0203
1065 #define SSL_SIGN_ECDSA_SECP256R1_SHA256 0x0403
1066 #define SSL_SIGN_ECDSA_SECP384R1_SHA384 0x0503
1067 #define SSL_SIGN_ECDSA_SECP521R1_SHA512 0x0603
1068 #define SSL_SIGN_RSA_PSS_RSAE_SHA256 0x0804
1069 #define SSL_SIGN_RSA_PSS_RSAE_SHA384 0x0805
1070 #define SSL_SIGN_RSA_PSS_RSAE_SHA512 0x0806
1071 #define SSL_SIGN_ED25519 0x0807
1072 
1073 // SSL_SIGN_RSA_PKCS1_MD5_SHA1 is an internal signature algorithm used to
1074 // specify raw RSASSA-PKCS1-v1_5 with an MD5/SHA-1 concatenation, as used in TLS
1075 // before TLS 1.2.
1076 #define SSL_SIGN_RSA_PKCS1_MD5_SHA1 0xff01
1077 
1078 // SSL_get_signature_algorithm_name returns a human-readable name for |sigalg|,
1079 // or NULL if unknown. If |include_curve| is one, the curve for ECDSA algorithms
1080 // is included as in TLS 1.3. Otherwise, it is excluded as in TLS 1.2.
1081 OPENSSL_EXPORT const char *SSL_get_signature_algorithm_name(uint16_t sigalg,
1082                                                             int include_curve);
1083 
1084 // SSL_get_signature_algorithm_key_type returns the key type associated with
1085 // |sigalg| as an |EVP_PKEY_*| constant or |EVP_PKEY_NONE| if unknown.
1086 OPENSSL_EXPORT int SSL_get_signature_algorithm_key_type(uint16_t sigalg);
1087 
1088 // SSL_get_signature_algorithm_digest returns the digest function associated
1089 // with |sigalg| or |NULL| if |sigalg| has no prehash (Ed25519) or is unknown.
1090 OPENSSL_EXPORT const EVP_MD *SSL_get_signature_algorithm_digest(
1091     uint16_t sigalg);
1092 
1093 // SSL_is_signature_algorithm_rsa_pss returns one if |sigalg| is an RSA-PSS
1094 // signature algorithm and zero otherwise.
1095 OPENSSL_EXPORT int SSL_is_signature_algorithm_rsa_pss(uint16_t sigalg);
1096 
1097 // SSL_CTX_set_signing_algorithm_prefs configures |ctx| to use |prefs| as the
1098 // preference list when signing with |ctx|'s private key. It returns one on
1099 // success and zero on error. |prefs| should not include the internal-only value
1100 // |SSL_SIGN_RSA_PKCS1_MD5_SHA1|.
1101 OPENSSL_EXPORT int SSL_CTX_set_signing_algorithm_prefs(SSL_CTX *ctx,
1102                                                        const uint16_t *prefs,
1103                                                        size_t num_prefs);
1104 
1105 // SSL_set_signing_algorithm_prefs configures |ssl| to use |prefs| as the
1106 // preference list when signing with |ssl|'s private key. It returns one on
1107 // success and zero on error. |prefs| should not include the internal-only value
1108 // |SSL_SIGN_RSA_PKCS1_MD5_SHA1|.
1109 OPENSSL_EXPORT int SSL_set_signing_algorithm_prefs(SSL *ssl,
1110                                                    const uint16_t *prefs,
1111                                                    size_t num_prefs);
1112 
1113 
1114 // Certificate and private key convenience functions.
1115 
1116 // SSL_CTX_set_chain_and_key sets the certificate chain and private key for a
1117 // TLS client or server. References to the given |CRYPTO_BUFFER| and |EVP_PKEY|
1118 // objects are added as needed. Exactly one of |privkey| or |privkey_method|
1119 // may be non-NULL. Returns one on success and zero on error.
1120 OPENSSL_EXPORT int SSL_CTX_set_chain_and_key(
1121     SSL_CTX *ctx, CRYPTO_BUFFER *const *certs, size_t num_certs,
1122     EVP_PKEY *privkey, const SSL_PRIVATE_KEY_METHOD *privkey_method);
1123 
1124 // SSL_set_chain_and_key sets the certificate chain and private key for a TLS
1125 // client or server. References to the given |CRYPTO_BUFFER| and |EVP_PKEY|
1126 // objects are added as needed. Exactly one of |privkey| or |privkey_method|
1127 // may be non-NULL. Returns one on success and zero on error.
1128 OPENSSL_EXPORT int SSL_set_chain_and_key(
1129     SSL *ssl, CRYPTO_BUFFER *const *certs, size_t num_certs, EVP_PKEY *privkey,
1130     const SSL_PRIVATE_KEY_METHOD *privkey_method);
1131 
1132 // SSL_CTX_get0_chain returns the list of |CRYPTO_BUFFER|s that were set by
1133 // |SSL_CTX_set_chain_and_key|. Reference counts are not incremented by this
1134 // call. The return value may be |NULL| if no chain has been set.
1135 //
1136 // (Note: if a chain was configured by non-|CRYPTO_BUFFER|-based functions then
1137 // the return value is undefined and, even if not NULL, the stack itself may
1138 // contain nullptrs. Thus you shouldn't mix this function with
1139 // non-|CRYPTO_BUFFER| functions for manipulating the chain.)
1140 //
1141 // There is no |SSL*| version of this function because connections discard
1142 // configuration after handshaking, thus making it of questionable utility.
1143 OPENSSL_EXPORT const STACK_OF(CRYPTO_BUFFER)*
1144     SSL_CTX_get0_chain(const SSL_CTX *ctx);
1145 
1146 // SSL_CTX_use_RSAPrivateKey sets |ctx|'s private key to |rsa|. It returns one
1147 // on success and zero on failure.
1148 OPENSSL_EXPORT int SSL_CTX_use_RSAPrivateKey(SSL_CTX *ctx, RSA *rsa);
1149 
1150 // SSL_use_RSAPrivateKey sets |ctx|'s private key to |rsa|. It returns one on
1151 // success and zero on failure.
1152 OPENSSL_EXPORT int SSL_use_RSAPrivateKey(SSL *ssl, RSA *rsa);
1153 
1154 // The following functions configure certificates or private keys but take as
1155 // input DER-encoded structures. They return one on success and zero on
1156 // failure.
1157 
1158 OPENSSL_EXPORT int SSL_CTX_use_certificate_ASN1(SSL_CTX *ctx, size_t der_len,
1159                                                 const uint8_t *der);
1160 OPENSSL_EXPORT int SSL_use_certificate_ASN1(SSL *ssl, const uint8_t *der,
1161                                             size_t der_len);
1162 
1163 OPENSSL_EXPORT int SSL_CTX_use_PrivateKey_ASN1(int pk, SSL_CTX *ctx,
1164                                                const uint8_t *der,
1165                                                size_t der_len);
1166 OPENSSL_EXPORT int SSL_use_PrivateKey_ASN1(int type, SSL *ssl,
1167                                            const uint8_t *der, size_t der_len);
1168 
1169 OPENSSL_EXPORT int SSL_CTX_use_RSAPrivateKey_ASN1(SSL_CTX *ctx,
1170                                                   const uint8_t *der,
1171                                                   size_t der_len);
1172 OPENSSL_EXPORT int SSL_use_RSAPrivateKey_ASN1(SSL *ssl, const uint8_t *der,
1173                                               size_t der_len);
1174 
1175 // The following functions configure certificates or private keys but take as
1176 // input files to read from. They return one on success and zero on failure. The
1177 // |type| parameter is one of the |SSL_FILETYPE_*| values and determines whether
1178 // the file's contents are read as PEM or DER.
1179 
1180 #define SSL_FILETYPE_PEM 1
1181 #define SSL_FILETYPE_ASN1 2
1182 
1183 OPENSSL_EXPORT int SSL_CTX_use_RSAPrivateKey_file(SSL_CTX *ctx,
1184                                                   const char *file,
1185                                                   int type);
1186 OPENSSL_EXPORT int SSL_use_RSAPrivateKey_file(SSL *ssl, const char *file,
1187                                               int type);
1188 
1189 OPENSSL_EXPORT int SSL_CTX_use_certificate_file(SSL_CTX *ctx, const char *file,
1190                                                 int type);
1191 OPENSSL_EXPORT int SSL_use_certificate_file(SSL *ssl, const char *file,
1192                                             int type);
1193 
1194 OPENSSL_EXPORT int SSL_CTX_use_PrivateKey_file(SSL_CTX *ctx, const char *file,
1195                                                int type);
1196 OPENSSL_EXPORT int SSL_use_PrivateKey_file(SSL *ssl, const char *file,
1197                                            int type);
1198 
1199 // SSL_CTX_use_certificate_chain_file configures certificates for |ctx|. It
1200 // reads the contents of |file| as a PEM-encoded leaf certificate followed
1201 // optionally by the certificate chain to send to the peer. It returns one on
1202 // success and zero on failure.
1203 OPENSSL_EXPORT int SSL_CTX_use_certificate_chain_file(SSL_CTX *ctx,
1204                                                       const char *file);
1205 
1206 // SSL_CTX_set_default_passwd_cb sets the password callback for PEM-based
1207 // convenience functions called on |ctx|.
1208 OPENSSL_EXPORT void SSL_CTX_set_default_passwd_cb(SSL_CTX *ctx,
1209                                                   pem_password_cb *cb);
1210 
1211 // SSL_CTX_get_default_passwd_cb returns the callback set by
1212 // |SSL_CTX_set_default_passwd_cb|.
1213 OPENSSL_EXPORT pem_password_cb *SSL_CTX_get_default_passwd_cb(
1214     const SSL_CTX *ctx);
1215 
1216 // SSL_CTX_set_default_passwd_cb_userdata sets the userdata parameter for
1217 // |ctx|'s password callback.
1218 OPENSSL_EXPORT void SSL_CTX_set_default_passwd_cb_userdata(SSL_CTX *ctx,
1219                                                            void *data);
1220 
1221 // SSL_CTX_get_default_passwd_cb_userdata returns the userdata parameter set by
1222 // |SSL_CTX_set_default_passwd_cb_userdata|.
1223 OPENSSL_EXPORT void *SSL_CTX_get_default_passwd_cb_userdata(const SSL_CTX *ctx);
1224 
1225 
1226 // Custom private keys.
1227 
1228 enum ssl_private_key_result_t BORINGSSL_ENUM_INT {
1229   ssl_private_key_success,
1230   ssl_private_key_retry,
1231   ssl_private_key_failure,
1232 };
1233 
1234 // ssl_private_key_method_st (aka |SSL_PRIVATE_KEY_METHOD|) describes private
1235 // key hooks. This is used to off-load signing operations to a custom,
1236 // potentially asynchronous, backend. Metadata about the key such as the type
1237 // and size are parsed out of the certificate.
1238 //
1239 // Callers that use this structure should additionally call
1240 // |SSL_set_signing_algorithm_prefs| or |SSL_CTX_set_signing_algorithm_prefs|
1241 // with the private key's capabilities. This ensures BoringSSL will select a
1242 // suitable signature algorithm for the private key.
1243 struct ssl_private_key_method_st {
1244   // sign signs the message |in| in using the specified signature algorithm. On
1245   // success, it returns |ssl_private_key_success| and writes at most |max_out|
1246   // bytes of signature data to |out| and sets |*out_len| to the number of bytes
1247   // written. On failure, it returns |ssl_private_key_failure|. If the operation
1248   // has not completed, it returns |ssl_private_key_retry|. |sign| should
1249   // arrange for the high-level operation on |ssl| to be retried when the
1250   // operation is completed. This will result in a call to |complete|.
1251   //
1252   // |signature_algorithm| is one of the |SSL_SIGN_*| values, as defined in TLS
1253   // 1.3. Note that, in TLS 1.2, ECDSA algorithms do not require that curve
1254   // sizes match hash sizes, so the curve portion of |SSL_SIGN_ECDSA_*| values
1255   // must be ignored. BoringSSL will internally handle the curve matching logic
1256   // where appropriate.
1257   //
1258   // It is an error to call |sign| while another private key operation is in
1259   // progress on |ssl|.
1260   enum ssl_private_key_result_t (*sign)(SSL *ssl, uint8_t *out, size_t *out_len,
1261                                         size_t max_out,
1262                                         uint16_t signature_algorithm,
1263                                         const uint8_t *in, size_t in_len);
1264 
1265   // decrypt decrypts |in_len| bytes of encrypted data from |in|. On success it
1266   // returns |ssl_private_key_success|, writes at most |max_out| bytes of
1267   // decrypted data to |out| and sets |*out_len| to the actual number of bytes
1268   // written. On failure it returns |ssl_private_key_failure|. If the operation
1269   // has not completed, it returns |ssl_private_key_retry|. The caller should
1270   // arrange for the high-level operation on |ssl| to be retried when the
1271   // operation is completed, which will result in a call to |complete|. This
1272   // function only works with RSA keys and should perform a raw RSA decryption
1273   // operation with no padding.
1274   //
1275   // It is an error to call |decrypt| while another private key operation is in
1276   // progress on |ssl|.
1277   enum ssl_private_key_result_t (*decrypt)(SSL *ssl, uint8_t *out,
1278                                            size_t *out_len, size_t max_out,
1279                                            const uint8_t *in, size_t in_len);
1280 
1281   // complete completes a pending operation. If the operation has completed, it
1282   // returns |ssl_private_key_success| and writes the result to |out| as in
1283   // |sign|. Otherwise, it returns |ssl_private_key_failure| on failure and
1284   // |ssl_private_key_retry| if the operation is still in progress.
1285   //
1286   // |complete| may be called arbitrarily many times before completion, but it
1287   // is an error to call |complete| if there is no pending operation in progress
1288   // on |ssl|.
1289   enum ssl_private_key_result_t (*complete)(SSL *ssl, uint8_t *out,
1290                                             size_t *out_len, size_t max_out);
1291 };
1292 
1293 // SSL_set_private_key_method configures a custom private key on |ssl|.
1294 // |key_method| must remain valid for the lifetime of |ssl|.
1295 OPENSSL_EXPORT void SSL_set_private_key_method(
1296     SSL *ssl, const SSL_PRIVATE_KEY_METHOD *key_method);
1297 
1298 // SSL_CTX_set_private_key_method configures a custom private key on |ctx|.
1299 // |key_method| must remain valid for the lifetime of |ctx|.
1300 OPENSSL_EXPORT void SSL_CTX_set_private_key_method(
1301     SSL_CTX *ctx, const SSL_PRIVATE_KEY_METHOD *key_method);
1302 
1303 // SSL_can_release_private_key returns one if |ssl| will no longer call into the
1304 // private key and zero otherwise. If the function returns one, the caller can
1305 // release state associated with the private key.
1306 //
1307 // NOTE: This function assumes the caller does not use |SSL_clear| to reuse
1308 // |ssl| for a second connection. If |SSL_clear| is used, BoringSSL may still
1309 // use the private key on the second connection.
1310 OPENSSL_EXPORT int SSL_can_release_private_key(const SSL *ssl);
1311 
1312 
1313 // Cipher suites.
1314 //
1315 // |SSL_CIPHER| objects represent cipher suites.
1316 
1317 DEFINE_CONST_STACK_OF(SSL_CIPHER)
1318 
1319 // SSL_get_cipher_by_value returns the structure representing a TLS cipher
1320 // suite based on its assigned number, or NULL if unknown. See
1321 // https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-4.
1322 OPENSSL_EXPORT const SSL_CIPHER *SSL_get_cipher_by_value(uint16_t value);
1323 
1324 // SSL_CIPHER_get_id returns |cipher|'s non-IANA id. This is not its
1325 // IANA-assigned number, which is called the "value" here, although it may be
1326 // cast to a |uint16_t| to get it.
1327 OPENSSL_EXPORT uint32_t SSL_CIPHER_get_id(const SSL_CIPHER *cipher);
1328 
1329 // SSL_CIPHER_get_protocol_id returns |cipher|'s IANA-assigned number.
1330 OPENSSL_EXPORT uint16_t SSL_CIPHER_get_protocol_id(const SSL_CIPHER *cipher);
1331 
1332 // SSL_CIPHER_is_aead returns one if |cipher| uses an AEAD cipher.
1333 OPENSSL_EXPORT int SSL_CIPHER_is_aead(const SSL_CIPHER *cipher);
1334 
1335 // SSL_CIPHER_is_block_cipher returns one if |cipher| is a block cipher.
1336 OPENSSL_EXPORT int SSL_CIPHER_is_block_cipher(const SSL_CIPHER *cipher);
1337 
1338 // SSL_CIPHER_get_cipher_nid returns the NID for |cipher|'s bulk
1339 // cipher. Possible values are |NID_aes_128_gcm|, |NID_aes_256_gcm|,
1340 // |NID_chacha20_poly1305|, |NID_aes_128_cbc|, |NID_aes_256_cbc|, and
1341 // |NID_des_ede3_cbc|.
1342 OPENSSL_EXPORT int SSL_CIPHER_get_cipher_nid(const SSL_CIPHER *cipher);
1343 
1344 // SSL_CIPHER_get_digest_nid returns the NID for |cipher|'s HMAC if it is a
1345 // legacy cipher suite. For modern AEAD-based ciphers (see
1346 // |SSL_CIPHER_is_aead|), it returns |NID_undef|.
1347 //
1348 // Note this function only returns the legacy HMAC digest, not the PRF hash.
1349 OPENSSL_EXPORT int SSL_CIPHER_get_digest_nid(const SSL_CIPHER *cipher);
1350 
1351 // SSL_CIPHER_get_kx_nid returns the NID for |cipher|'s key exchange. This may
1352 // be |NID_kx_rsa|, |NID_kx_ecdhe|, or |NID_kx_psk| for TLS 1.2. In TLS 1.3,
1353 // cipher suites do not specify the key exchange, so this function returns
1354 // |NID_kx_any|.
1355 OPENSSL_EXPORT int SSL_CIPHER_get_kx_nid(const SSL_CIPHER *cipher);
1356 
1357 // SSL_CIPHER_get_auth_nid returns the NID for |cipher|'s authentication
1358 // type. This may be |NID_auth_rsa|, |NID_auth_ecdsa|, or |NID_auth_psk| for TLS
1359 // 1.2. In TLS 1.3, cipher suites do not specify authentication, so this
1360 // function returns |NID_auth_any|.
1361 OPENSSL_EXPORT int SSL_CIPHER_get_auth_nid(const SSL_CIPHER *cipher);
1362 
1363 // SSL_CIPHER_get_prf_nid retuns the NID for |cipher|'s PRF hash. If |cipher| is
1364 // a pre-TLS-1.2 cipher, it returns |NID_md5_sha1| but note these ciphers use
1365 // SHA-256 in TLS 1.2. Other return values may be treated uniformly in all
1366 // applicable versions.
1367 OPENSSL_EXPORT int SSL_CIPHER_get_prf_nid(const SSL_CIPHER *cipher);
1368 
1369 // SSL_CIPHER_get_min_version returns the minimum protocol version required
1370 // for |cipher|.
1371 OPENSSL_EXPORT uint16_t SSL_CIPHER_get_min_version(const SSL_CIPHER *cipher);
1372 
1373 // SSL_CIPHER_get_max_version returns the maximum protocol version that
1374 // supports |cipher|.
1375 OPENSSL_EXPORT uint16_t SSL_CIPHER_get_max_version(const SSL_CIPHER *cipher);
1376 
1377 // SSL_CIPHER_standard_name returns the standard IETF name for |cipher|. For
1378 // example, "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256".
1379 OPENSSL_EXPORT const char *SSL_CIPHER_standard_name(const SSL_CIPHER *cipher);
1380 
1381 // SSL_CIPHER_get_name returns the OpenSSL name of |cipher|. For example,
1382 // "ECDHE-RSA-AES128-GCM-SHA256". Callers are recommended to use
1383 // |SSL_CIPHER_standard_name| instead.
1384 OPENSSL_EXPORT const char *SSL_CIPHER_get_name(const SSL_CIPHER *cipher);
1385 
1386 // SSL_CIPHER_get_kx_name returns a string that describes the key-exchange
1387 // method used by |cipher|. For example, "ECDHE_ECDSA". TLS 1.3 AEAD-only
1388 // ciphers return the string "GENERIC".
1389 OPENSSL_EXPORT const char *SSL_CIPHER_get_kx_name(const SSL_CIPHER *cipher);
1390 
1391 // SSL_CIPHER_get_bits returns the strength, in bits, of |cipher|. If
1392 // |out_alg_bits| is not NULL, it writes the number of bits consumed by the
1393 // symmetric algorithm to |*out_alg_bits|.
1394 OPENSSL_EXPORT int SSL_CIPHER_get_bits(const SSL_CIPHER *cipher,
1395                                        int *out_alg_bits);
1396 
1397 
1398 // Cipher suite configuration.
1399 //
1400 // OpenSSL uses a mini-language to configure cipher suites. The language
1401 // maintains an ordered list of enabled ciphers, along with an ordered list of
1402 // disabled but available ciphers. Initially, all ciphers are disabled with a
1403 // default ordering. The cipher string is then interpreted as a sequence of
1404 // directives, separated by colons, each of which modifies this state.
1405 //
1406 // Most directives consist of a one character or empty opcode followed by a
1407 // selector which matches a subset of available ciphers.
1408 //
1409 // Available opcodes are:
1410 //
1411 //   The empty opcode enables and appends all matching disabled ciphers to the
1412 //   end of the enabled list. The newly appended ciphers are ordered relative to
1413 //   each other matching their order in the disabled list.
1414 //
1415 //   |-| disables all matching enabled ciphers and prepends them to the disabled
1416 //   list, with relative order from the enabled list preserved. This means the
1417 //   most recently disabled ciphers get highest preference relative to other
1418 //   disabled ciphers if re-enabled.
1419 //
1420 //   |+| moves all matching enabled ciphers to the end of the enabled list, with
1421 //   relative order preserved.
1422 //
1423 //   |!| deletes all matching ciphers, enabled or not, from either list. Deleted
1424 //   ciphers will not matched by future operations.
1425 //
1426 // A selector may be a specific cipher (using either the standard or OpenSSL
1427 // name for the cipher) or one or more rules separated by |+|. The final
1428 // selector matches the intersection of each rule. For instance, |AESGCM+aECDSA|
1429 // matches ECDSA-authenticated AES-GCM ciphers.
1430 //
1431 // Available cipher rules are:
1432 //
1433 //   |ALL| matches all ciphers.
1434 //
1435 //   |kRSA|, |kDHE|, |kECDHE|, and |kPSK| match ciphers using plain RSA, DHE,
1436 //   ECDHE, and plain PSK key exchanges, respectively. Note that ECDHE_PSK is
1437 //   matched by |kECDHE| and not |kPSK|.
1438 //
1439 //   |aRSA|, |aECDSA|, and |aPSK| match ciphers authenticated by RSA, ECDSA, and
1440 //   a pre-shared key, respectively.
1441 //
1442 //   |RSA|, |DHE|, |ECDHE|, |PSK|, |ECDSA|, and |PSK| are aliases for the
1443 //   corresponding |k*| or |a*| cipher rule. |RSA| is an alias for |kRSA|, not
1444 //   |aRSA|.
1445 //
1446 //   |3DES|, |AES128|, |AES256|, |AES|, |AESGCM|, |CHACHA20| match ciphers
1447 //   whose bulk cipher use the corresponding encryption scheme. Note that
1448 //   |AES|, |AES128|, and |AES256| match both CBC and GCM ciphers.
1449 //
1450 //   |SHA1|, and its alias |SHA|, match legacy cipher suites using HMAC-SHA1.
1451 //
1452 // Deprecated cipher rules:
1453 //
1454 //   |kEDH|, |EDH|, |kEECDH|, and |EECDH| are legacy aliases for |kDHE|, |DHE|,
1455 //   |kECDHE|, and |ECDHE|, respectively.
1456 //
1457 //   |HIGH| is an alias for |ALL|.
1458 //
1459 //   |FIPS| is an alias for |HIGH|.
1460 //
1461 //   |SSLv3| and |TLSv1| match ciphers available in TLS 1.1 or earlier.
1462 //   |TLSv1_2| matches ciphers new in TLS 1.2. This is confusing and should not
1463 //   be used.
1464 //
1465 // Unknown rules are silently ignored by legacy APIs, and rejected by APIs with
1466 // "strict" in the name, which should be preferred. Cipher lists can be long
1467 // and it's easy to commit typos. Strict functions will also reject the use of
1468 // spaces, semi-colons and commas as alternative separators.
1469 //
1470 // The special |@STRENGTH| directive will sort all enabled ciphers by strength.
1471 //
1472 // The |DEFAULT| directive, when appearing at the front of the string, expands
1473 // to the default ordering of available ciphers.
1474 //
1475 // If configuring a server, one may also configure equal-preference groups to
1476 // partially respect the client's preferences when
1477 // |SSL_OP_CIPHER_SERVER_PREFERENCE| is enabled. Ciphers in an equal-preference
1478 // group have equal priority and use the client order. This may be used to
1479 // enforce that AEADs are preferred but select AES-GCM vs. ChaCha20-Poly1305
1480 // based on client preferences. An equal-preference is specified with square
1481 // brackets, combining multiple selectors separated by |. For example:
1482 //
1483 //   [TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256|TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256]
1484 //
1485 // Once an equal-preference group is used, future directives must be
1486 // opcode-less. Inside an equal-preference group, spaces are not allowed.
1487 //
1488 // TLS 1.3 ciphers do not participate in this mechanism and instead have a
1489 // built-in preference order. Functions to set cipher lists do not affect TLS
1490 // 1.3, and functions to query the cipher list do not include TLS 1.3
1491 // ciphers.
1492 
1493 // SSL_DEFAULT_CIPHER_LIST is the default cipher suite configuration. It is
1494 // substituted when a cipher string starts with 'DEFAULT'.
1495 #define SSL_DEFAULT_CIPHER_LIST "ALL"
1496 
1497 // SSL_CTX_set_strict_cipher_list configures the cipher list for |ctx|,
1498 // evaluating |str| as a cipher string and returning error if |str| contains
1499 // anything meaningless. It returns one on success and zero on failure.
1500 OPENSSL_EXPORT int SSL_CTX_set_strict_cipher_list(SSL_CTX *ctx,
1501                                                   const char *str);
1502 
1503 // SSL_CTX_set_cipher_list configures the cipher list for |ctx|, evaluating
1504 // |str| as a cipher string. It returns one on success and zero on failure.
1505 //
1506 // Prefer to use |SSL_CTX_set_strict_cipher_list|. This function tolerates
1507 // garbage inputs, unless an empty cipher list results.
1508 OPENSSL_EXPORT int SSL_CTX_set_cipher_list(SSL_CTX *ctx, const char *str);
1509 
1510 // SSL_set_strict_cipher_list configures the cipher list for |ssl|, evaluating
1511 // |str| as a cipher string and returning error if |str| contains anything
1512 // meaningless. It returns one on success and zero on failure.
1513 OPENSSL_EXPORT int SSL_set_strict_cipher_list(SSL *ssl, const char *str);
1514 
1515 // SSL_set_cipher_list configures the cipher list for |ssl|, evaluating |str| as
1516 // a cipher string. It returns one on success and zero on failure.
1517 //
1518 // Prefer to use |SSL_set_strict_cipher_list|. This function tolerates garbage
1519 // inputs, unless an empty cipher list results.
1520 OPENSSL_EXPORT int SSL_set_cipher_list(SSL *ssl, const char *str);
1521 
1522 // SSL_CTX_get_ciphers returns the cipher list for |ctx|, in order of
1523 // preference.
1524 OPENSSL_EXPORT STACK_OF(SSL_CIPHER) *SSL_CTX_get_ciphers(const SSL_CTX *ctx);
1525 
1526 // SSL_CTX_cipher_in_group returns one if the |i|th cipher (see
1527 // |SSL_CTX_get_ciphers|) is in the same equipreference group as the one
1528 // following it and zero otherwise.
1529 OPENSSL_EXPORT int SSL_CTX_cipher_in_group(const SSL_CTX *ctx, size_t i);
1530 
1531 // SSL_get_ciphers returns the cipher list for |ssl|, in order of preference.
1532 OPENSSL_EXPORT STACK_OF(SSL_CIPHER) *SSL_get_ciphers(const SSL *ssl);
1533 
1534 
1535 // Connection information.
1536 
1537 // SSL_is_init_finished returns one if |ssl| has completed its initial handshake
1538 // and has no pending handshake. It returns zero otherwise.
1539 OPENSSL_EXPORT int SSL_is_init_finished(const SSL *ssl);
1540 
1541 // SSL_in_init returns one if |ssl| has a pending handshake and zero
1542 // otherwise.
1543 OPENSSL_EXPORT int SSL_in_init(const SSL *ssl);
1544 
1545 // SSL_in_false_start returns one if |ssl| has a pending handshake that is in
1546 // False Start. |SSL_write| may be called at this point without waiting for the
1547 // peer, but |SSL_read| will complete the handshake before accepting application
1548 // data.
1549 //
1550 // See also |SSL_MODE_ENABLE_FALSE_START|.
1551 OPENSSL_EXPORT int SSL_in_false_start(const SSL *ssl);
1552 
1553 // SSL_get_peer_certificate returns the peer's leaf certificate or NULL if the
1554 // peer did not use certificates. The caller must call |X509_free| on the
1555 // result to release it.
1556 OPENSSL_EXPORT X509 *SSL_get_peer_certificate(const SSL *ssl);
1557 
1558 // SSL_get_peer_cert_chain returns the peer's certificate chain or NULL if
1559 // unavailable or the peer did not use certificates. This is the unverified list
1560 // of certificates as sent by the peer, not the final chain built during
1561 // verification. The caller does not take ownership of the result.
1562 //
1563 // WARNING: This function behaves differently between client and server. If
1564 // |ssl| is a server, the returned chain does not include the leaf certificate.
1565 // If a client, it does.
1566 OPENSSL_EXPORT STACK_OF(X509) *SSL_get_peer_cert_chain(const SSL *ssl);
1567 
1568 // SSL_get_peer_full_cert_chain returns the peer's certificate chain, or NULL if
1569 // unavailable or the peer did not use certificates. This is the unverified list
1570 // of certificates as sent by the peer, not the final chain built during
1571 // verification. The caller does not take ownership of the result.
1572 //
1573 // This is the same as |SSL_get_peer_cert_chain| except that this function
1574 // always returns the full chain, i.e. the first element of the return value
1575 // (if any) will be the leaf certificate. In constrast,
1576 // |SSL_get_peer_cert_chain| returns only the intermediate certificates if the
1577 // |ssl| is a server.
1578 OPENSSL_EXPORT STACK_OF(X509) *SSL_get_peer_full_cert_chain(const SSL *ssl);
1579 
1580 // SSL_get0_peer_certificates returns the peer's certificate chain, or NULL if
1581 // unavailable or the peer did not use certificates. This is the unverified list
1582 // of certificates as sent by the peer, not the final chain built during
1583 // verification. The caller does not take ownership of the result.
1584 //
1585 // This is the |CRYPTO_BUFFER| variant of |SSL_get_peer_full_cert_chain|.
1586 OPENSSL_EXPORT const STACK_OF(CRYPTO_BUFFER) *
1587     SSL_get0_peer_certificates(const SSL *ssl);
1588 
1589 // SSL_get0_signed_cert_timestamp_list sets |*out| and |*out_len| to point to
1590 // |*out_len| bytes of SCT information from the server. This is only valid if
1591 // |ssl| is a client. The SCT information is a SignedCertificateTimestampList
1592 // (including the two leading length bytes).
1593 // See https://tools.ietf.org/html/rfc6962#section-3.3
1594 // If no SCT was received then |*out_len| will be zero on return.
1595 //
1596 // WARNING: the returned data is not guaranteed to be well formed.
1597 OPENSSL_EXPORT void SSL_get0_signed_cert_timestamp_list(const SSL *ssl,
1598                                                         const uint8_t **out,
1599                                                         size_t *out_len);
1600 
1601 // SSL_get0_ocsp_response sets |*out| and |*out_len| to point to |*out_len|
1602 // bytes of an OCSP response from the server. This is the DER encoding of an
1603 // OCSPResponse type as defined in RFC 2560.
1604 //
1605 // WARNING: the returned data is not guaranteed to be well formed.
1606 OPENSSL_EXPORT void SSL_get0_ocsp_response(const SSL *ssl, const uint8_t **out,
1607                                            size_t *out_len);
1608 
1609 // SSL_get_tls_unique writes at most |max_out| bytes of the tls-unique value
1610 // for |ssl| to |out| and sets |*out_len| to the number of bytes written. It
1611 // returns one on success or zero on error. In general |max_out| should be at
1612 // least 12.
1613 //
1614 // This function will always fail if the initial handshake has not completed.
1615 // The tls-unique value will change after a renegotiation but, since
1616 // renegotiations can be initiated by the server at any point, the higher-level
1617 // protocol must either leave them disabled or define states in which the
1618 // tls-unique value can be read.
1619 //
1620 // The tls-unique value is defined by
1621 // https://tools.ietf.org/html/rfc5929#section-3.1. Due to a weakness in the
1622 // TLS protocol, tls-unique is broken for resumed connections unless the
1623 // Extended Master Secret extension is negotiated. Thus this function will
1624 // return zero if |ssl| performed session resumption unless EMS was used when
1625 // negotiating the original session.
1626 OPENSSL_EXPORT int SSL_get_tls_unique(const SSL *ssl, uint8_t *out,
1627                                       size_t *out_len, size_t max_out);
1628 
1629 // SSL_get_extms_support returns one if the Extended Master Secret extension or
1630 // TLS 1.3 was negotiated. Otherwise, it returns zero.
1631 OPENSSL_EXPORT int SSL_get_extms_support(const SSL *ssl);
1632 
1633 // SSL_get_current_cipher returns cipher suite used by |ssl|, or NULL if it has
1634 // not been negotiated yet.
1635 OPENSSL_EXPORT const SSL_CIPHER *SSL_get_current_cipher(const SSL *ssl);
1636 
1637 // SSL_session_reused returns one if |ssl| performed an abbreviated handshake
1638 // and zero otherwise.
1639 //
1640 // TODO(davidben): Hammer down the semantics of this API while a handshake,
1641 // initial or renego, is in progress.
1642 OPENSSL_EXPORT int SSL_session_reused(const SSL *ssl);
1643 
1644 // SSL_get_secure_renegotiation_support returns one if the peer supports secure
1645 // renegotiation (RFC 5746) or TLS 1.3. Otherwise, it returns zero.
1646 OPENSSL_EXPORT int SSL_get_secure_renegotiation_support(const SSL *ssl);
1647 
1648 // SSL_export_keying_material exports a value derived from the master secret, as
1649 // specified in RFC 5705. It writes |out_len| bytes to |out| given a label and
1650 // optional context. (Since a zero length context is allowed, the |use_context|
1651 // flag controls whether a context is included.)
1652 //
1653 // It returns one on success and zero otherwise.
1654 OPENSSL_EXPORT int SSL_export_keying_material(
1655     SSL *ssl, uint8_t *out, size_t out_len, const char *label, size_t label_len,
1656     const uint8_t *context, size_t context_len, int use_context);
1657 
1658 
1659 // Sessions.
1660 //
1661 // An |SSL_SESSION| represents an SSL session that may be resumed in an
1662 // abbreviated handshake. It is reference-counted and immutable. Once
1663 // established, an |SSL_SESSION| may be shared by multiple |SSL| objects on
1664 // different threads and must not be modified.
1665 //
1666 // Note the TLS notion of "session" is not suitable for application-level
1667 // session state. It is an optional caching mechanism for the handshake. Not all
1668 // connections within an application-level session will reuse TLS sessions. TLS
1669 // sessions may be dropped by the client or ignored by the server at any time.
1670 
1671 DECLARE_PEM_rw(SSL_SESSION, SSL_SESSION)
1672 
1673 // SSL_SESSION_new returns a newly-allocated blank |SSL_SESSION| or NULL on
1674 // error. This may be useful when writing tests but should otherwise not be
1675 // used.
1676 OPENSSL_EXPORT SSL_SESSION *SSL_SESSION_new(const SSL_CTX *ctx);
1677 
1678 // SSL_SESSION_up_ref increments the reference count of |session| and returns
1679 // one.
1680 OPENSSL_EXPORT int SSL_SESSION_up_ref(SSL_SESSION *session);
1681 
1682 // SSL_SESSION_free decrements the reference count of |session|. If it reaches
1683 // zero, all data referenced by |session| and |session| itself are released.
1684 OPENSSL_EXPORT void SSL_SESSION_free(SSL_SESSION *session);
1685 
1686 // SSL_SESSION_to_bytes serializes |in| into a newly allocated buffer and sets
1687 // |*out_data| to that buffer and |*out_len| to its length. The caller takes
1688 // ownership of the buffer and must call |OPENSSL_free| when done. It returns
1689 // one on success and zero on error.
1690 OPENSSL_EXPORT int SSL_SESSION_to_bytes(const SSL_SESSION *in,
1691                                         uint8_t **out_data, size_t *out_len);
1692 
1693 // SSL_SESSION_to_bytes_for_ticket serializes |in|, but excludes the session
1694 // identification information, namely the session ID and ticket.
1695 OPENSSL_EXPORT int SSL_SESSION_to_bytes_for_ticket(const SSL_SESSION *in,
1696                                                    uint8_t **out_data,
1697                                                    size_t *out_len);
1698 
1699 // SSL_SESSION_from_bytes parses |in_len| bytes from |in| as an SSL_SESSION. It
1700 // returns a newly-allocated |SSL_SESSION| on success or NULL on error.
1701 OPENSSL_EXPORT SSL_SESSION *SSL_SESSION_from_bytes(
1702     const uint8_t *in, size_t in_len, const SSL_CTX *ctx);
1703 
1704 // SSL_SESSION_get_version returns a string describing the TLS or DTLS version
1705 // |session| was established at. For example, "TLSv1.2" or "DTLSv1".
1706 OPENSSL_EXPORT const char *SSL_SESSION_get_version(const SSL_SESSION *session);
1707 
1708 // SSL_SESSION_get_protocol_version returns the TLS or DTLS version |session|
1709 // was established at.
1710 OPENSSL_EXPORT uint16_t
1711 SSL_SESSION_get_protocol_version(const SSL_SESSION *session);
1712 
1713 // SSL_SESSION_set_protocol_version sets |session|'s TLS or DTLS version to
1714 // |version|. This may be useful when writing tests but should otherwise not be
1715 // used. It returns one on success and zero on error.
1716 OPENSSL_EXPORT int SSL_SESSION_set_protocol_version(SSL_SESSION *session,
1717                                                     uint16_t version);
1718 
1719 // SSL_MAX_SSL_SESSION_ID_LENGTH is the maximum length of an SSL session ID.
1720 #define SSL_MAX_SSL_SESSION_ID_LENGTH 32
1721 
1722 // SSL_SESSION_get_id returns a pointer to a buffer containing |session|'s
1723 // session ID and sets |*out_len| to its length.
1724 //
1725 // This function should only be used for implementing a TLS session cache. TLS
1726 // sessions are not suitable for application-level session state, and a session
1727 // ID is an implementation detail of the TLS resumption handshake mechanism. Not
1728 // all resumption flows use session IDs, and not all connections within an
1729 // application-level session will reuse TLS sessions.
1730 //
1731 // To determine if resumption occurred, use |SSL_session_reused| instead.
1732 // Comparing session IDs will not give the right result in all cases.
1733 //
1734 // As a workaround for some broken applications, BoringSSL sometimes synthesizes
1735 // arbitrary session IDs for non-ID-based sessions. This behavior may be
1736 // removed in the future.
1737 OPENSSL_EXPORT const uint8_t *SSL_SESSION_get_id(const SSL_SESSION *session,
1738                                                  unsigned *out_len);
1739 
1740 // SSL_SESSION_set1_id sets |session|'s session ID to |sid|, It returns one on
1741 // success and zero on error. This function may be useful in writing tests but
1742 // otherwise should not be used.
1743 OPENSSL_EXPORT int SSL_SESSION_set1_id(SSL_SESSION *session, const uint8_t *sid,
1744                                        size_t sid_len);
1745 
1746 // SSL_SESSION_get_time returns the time at which |session| was established in
1747 // seconds since the UNIX epoch.
1748 OPENSSL_EXPORT uint64_t SSL_SESSION_get_time(const SSL_SESSION *session);
1749 
1750 // SSL_SESSION_get_timeout returns the lifetime of |session| in seconds.
1751 OPENSSL_EXPORT uint32_t SSL_SESSION_get_timeout(const SSL_SESSION *session);
1752 
1753 // SSL_SESSION_get0_peer returns the peer leaf certificate stored in
1754 // |session|.
1755 //
1756 // TODO(davidben): This should return a const X509 *.
1757 OPENSSL_EXPORT X509 *SSL_SESSION_get0_peer(const SSL_SESSION *session);
1758 
1759 // SSL_SESSION_get0_peer_certificates returns the peer certificate chain stored
1760 // in |session|, or NULL if the peer did not use certificates. This is the
1761 // unverified list of certificates as sent by the peer, not the final chain
1762 // built during verification. The caller does not take ownership of the result.
1763 OPENSSL_EXPORT const STACK_OF(CRYPTO_BUFFER) *
1764     SSL_SESSION_get0_peer_certificates(const SSL_SESSION *session);
1765 
1766 // SSL_SESSION_get0_signed_cert_timestamp_list sets |*out| and |*out_len| to
1767 // point to |*out_len| bytes of SCT information stored in |session|. This is
1768 // only valid for client sessions. The SCT information is a
1769 // SignedCertificateTimestampList (including the two leading length bytes). See
1770 // https://tools.ietf.org/html/rfc6962#section-3.3 If no SCT was received then
1771 // |*out_len| will be zero on return.
1772 //
1773 // WARNING: the returned data is not guaranteed to be well formed.
1774 OPENSSL_EXPORT void SSL_SESSION_get0_signed_cert_timestamp_list(
1775     const SSL_SESSION *session, const uint8_t **out, size_t *out_len);
1776 
1777 // SSL_SESSION_get0_ocsp_response sets |*out| and |*out_len| to point to
1778 // |*out_len| bytes of an OCSP response from the server. This is the DER
1779 // encoding of an OCSPResponse type as defined in RFC 2560.
1780 //
1781 // WARNING: the returned data is not guaranteed to be well formed.
1782 OPENSSL_EXPORT void SSL_SESSION_get0_ocsp_response(const SSL_SESSION *session,
1783                                                    const uint8_t **out,
1784                                                    size_t *out_len);
1785 
1786 // SSL_MAX_MASTER_KEY_LENGTH is the maximum length of a master secret.
1787 #define SSL_MAX_MASTER_KEY_LENGTH 48
1788 
1789 // SSL_SESSION_get_master_key writes up to |max_out| bytes of |session|'s secret
1790 // to |out| and returns the number of bytes written. If |max_out| is zero, it
1791 // returns the size of the secret.
1792 OPENSSL_EXPORT size_t SSL_SESSION_get_master_key(const SSL_SESSION *session,
1793                                                  uint8_t *out, size_t max_out);
1794 
1795 // SSL_SESSION_set_time sets |session|'s creation time to |time| and returns
1796 // |time|. This function may be useful in writing tests but otherwise should not
1797 // be used.
1798 OPENSSL_EXPORT uint64_t SSL_SESSION_set_time(SSL_SESSION *session,
1799                                              uint64_t time);
1800 
1801 // SSL_SESSION_set_timeout sets |session|'s timeout to |timeout| and returns
1802 // one. This function may be useful in writing tests but otherwise should not
1803 // be used.
1804 OPENSSL_EXPORT uint32_t SSL_SESSION_set_timeout(SSL_SESSION *session,
1805                                                 uint32_t timeout);
1806 
1807 // SSL_SESSION_get0_id_context returns a pointer to a buffer containing
1808 // |session|'s session ID context (see |SSL_CTX_set_session_id_context|) and
1809 // sets |*out_len| to its length.
1810 OPENSSL_EXPORT const uint8_t *SSL_SESSION_get0_id_context(
1811     const SSL_SESSION *session, unsigned *out_len);
1812 
1813 // SSL_SESSION_set1_id_context sets |session|'s session ID context (see
1814 // |SSL_CTX_set_session_id_context|) to |sid_ctx|. It returns one on success and
1815 // zero on error. This function may be useful in writing tests but otherwise
1816 // should not be used.
1817 OPENSSL_EXPORT int SSL_SESSION_set1_id_context(SSL_SESSION *session,
1818                                                const uint8_t *sid_ctx,
1819                                                size_t sid_ctx_len);
1820 
1821 // SSL_SESSION_should_be_single_use returns one if |session| should be
1822 // single-use (TLS 1.3 and later) and zero otherwise.
1823 //
1824 // If this function returns one, clients retain multiple sessions and use each
1825 // only once. This prevents passive observers from correlating connections with
1826 // tickets. See RFC 8446, appendix C.4. If it returns zero, |session| cannot be
1827 // used without leaking a correlator.
1828 OPENSSL_EXPORT int SSL_SESSION_should_be_single_use(const SSL_SESSION *session);
1829 
1830 // SSL_SESSION_is_resumable returns one if |session| is complete and contains a
1831 // session ID or ticket. It returns zero otherwise. Note this function does not
1832 // ensure |session| will be resumed. It may be expired, dropped by the server,
1833 // or associated with incompatible parameters.
1834 OPENSSL_EXPORT int SSL_SESSION_is_resumable(const SSL_SESSION *session);
1835 
1836 // SSL_SESSION_has_ticket returns one if |session| has a ticket and zero
1837 // otherwise.
1838 OPENSSL_EXPORT int SSL_SESSION_has_ticket(const SSL_SESSION *session);
1839 
1840 // SSL_SESSION_get0_ticket sets |*out_ticket| and |*out_len| to |session|'s
1841 // ticket, or NULL and zero if it does not have one. |out_ticket| may be NULL
1842 // if only the ticket length is needed.
1843 OPENSSL_EXPORT void SSL_SESSION_get0_ticket(const SSL_SESSION *session,
1844                                             const uint8_t **out_ticket,
1845                                             size_t *out_len);
1846 
1847 // SSL_SESSION_set_ticket sets |session|'s ticket to |ticket|. It returns one on
1848 // success and zero on error. This function may be useful in writing tests but
1849 // otherwise should not be used.
1850 OPENSSL_EXPORT int SSL_SESSION_set_ticket(SSL_SESSION *session,
1851                                           const uint8_t *ticket,
1852                                           size_t ticket_len);
1853 
1854 // SSL_SESSION_get_ticket_lifetime_hint returns ticket lifetime hint of
1855 // |session| in seconds or zero if none was set.
1856 OPENSSL_EXPORT uint32_t
1857 SSL_SESSION_get_ticket_lifetime_hint(const SSL_SESSION *session);
1858 
1859 // SSL_SESSION_get0_cipher returns the cipher negotiated by the connection which
1860 // established |session|.
1861 //
1862 // Note that, in TLS 1.3, there is no guarantee that resumptions with |session|
1863 // will use that cipher. Prefer calling |SSL_get_current_cipher| on the |SSL|
1864 // instead.
1865 OPENSSL_EXPORT const SSL_CIPHER *SSL_SESSION_get0_cipher(
1866     const SSL_SESSION *session);
1867 
1868 // SSL_SESSION_has_peer_sha256 returns one if |session| has a SHA-256 hash of
1869 // the peer's certificate retained and zero if the peer did not present a
1870 // certificate or if this was not enabled when |session| was created. See also
1871 // |SSL_CTX_set_retain_only_sha256_of_client_certs|.
1872 OPENSSL_EXPORT int SSL_SESSION_has_peer_sha256(const SSL_SESSION *session);
1873 
1874 // SSL_SESSION_get0_peer_sha256 sets |*out_ptr| and |*out_len| to the SHA-256
1875 // hash of the peer certificate retained in |session|, or NULL and zero if it
1876 // does not have one. See also |SSL_CTX_set_retain_only_sha256_of_client_certs|.
1877 OPENSSL_EXPORT void SSL_SESSION_get0_peer_sha256(const SSL_SESSION *session,
1878                                                  const uint8_t **out_ptr,
1879                                                  size_t *out_len);
1880 
1881 
1882 // Session caching.
1883 //
1884 // Session caching allows connections to be established more efficiently based
1885 // on saved parameters from a previous connection, called a session (see
1886 // |SSL_SESSION|). The client offers a saved session, using an opaque identifier
1887 // from a previous connection. The server may accept the session, if it has the
1888 // parameters available. Otherwise, it will decline and continue with a full
1889 // handshake.
1890 //
1891 // This requires both the client and the server to retain session state. A
1892 // client does so with a stateful session cache. A server may do the same or, if
1893 // supported by both sides, statelessly using session tickets. For more
1894 // information on the latter, see the next section.
1895 //
1896 // For a server, the library implements a built-in internal session cache as an
1897 // in-memory hash table. Servers may also use |SSL_CTX_sess_set_get_cb| and
1898 // |SSL_CTX_sess_set_new_cb| to implement a custom external session cache. In
1899 // particular, this may be used to share a session cache between multiple
1900 // servers in a large deployment. An external cache may be used in addition to
1901 // or instead of the internal one. Use |SSL_CTX_set_session_cache_mode| to
1902 // toggle the internal cache.
1903 //
1904 // For a client, the only option is an external session cache. Clients may use
1905 // |SSL_CTX_sess_set_new_cb| to register a callback for when new sessions are
1906 // available. These may be cached and, in subsequent compatible connections,
1907 // configured with |SSL_set_session|.
1908 //
1909 // Note that offering or accepting a session short-circuits certificate
1910 // verification and most parameter negotiation. Resuming sessions across
1911 // different contexts may result in security failures and surprising
1912 // behavior. For a typical client, this means sessions for different hosts must
1913 // be cached under different keys. A client that connects to the same host with,
1914 // e.g., different cipher suite settings or client certificates should also use
1915 // separate session caches between those contexts. Servers should also partition
1916 // session caches between SNI hosts with |SSL_CTX_set_session_id_context|.
1917 //
1918 // Note also, in TLS 1.2 and earlier, offering sessions allows passive observers
1919 // to correlate different client connections. TLS 1.3 and later fix this,
1920 // provided clients use sessions at most once. Session caches are managed by the
1921 // caller in BoringSSL, so this must be implemented externally. See
1922 // |SSL_SESSION_should_be_single_use| for details.
1923 
1924 // SSL_SESS_CACHE_OFF disables all session caching.
1925 #define SSL_SESS_CACHE_OFF 0x0000
1926 
1927 // SSL_SESS_CACHE_CLIENT enables session caching for a client. The internal
1928 // cache is never used on a client, so this only enables the callbacks.
1929 #define SSL_SESS_CACHE_CLIENT 0x0001
1930 
1931 // SSL_SESS_CACHE_SERVER enables session caching for a server.
1932 #define SSL_SESS_CACHE_SERVER 0x0002
1933 
1934 // SSL_SESS_CACHE_BOTH enables session caching for both client and server.
1935 #define SSL_SESS_CACHE_BOTH (SSL_SESS_CACHE_CLIENT | SSL_SESS_CACHE_SERVER)
1936 
1937 // SSL_SESS_CACHE_NO_AUTO_CLEAR disables automatically calling
1938 // |SSL_CTX_flush_sessions| every 255 connections.
1939 #define SSL_SESS_CACHE_NO_AUTO_CLEAR 0x0080
1940 
1941 // SSL_SESS_CACHE_NO_INTERNAL_LOOKUP, on a server, disables looking up a session
1942 // from the internal session cache.
1943 #define SSL_SESS_CACHE_NO_INTERNAL_LOOKUP 0x0100
1944 
1945 // SSL_SESS_CACHE_NO_INTERNAL_STORE, on a server, disables storing sessions in
1946 // the internal session cache.
1947 #define SSL_SESS_CACHE_NO_INTERNAL_STORE 0x0200
1948 
1949 // SSL_SESS_CACHE_NO_INTERNAL, on a server, disables the internal session
1950 // cache.
1951 #define SSL_SESS_CACHE_NO_INTERNAL \
1952     (SSL_SESS_CACHE_NO_INTERNAL_LOOKUP | SSL_SESS_CACHE_NO_INTERNAL_STORE)
1953 
1954 // SSL_CTX_set_session_cache_mode sets the session cache mode bits for |ctx| to
1955 // |mode|. It returns the previous value.
1956 OPENSSL_EXPORT int SSL_CTX_set_session_cache_mode(SSL_CTX *ctx, int mode);
1957 
1958 // SSL_CTX_get_session_cache_mode returns the session cache mode bits for
1959 // |ctx|
1960 OPENSSL_EXPORT int SSL_CTX_get_session_cache_mode(const SSL_CTX *ctx);
1961 
1962 // SSL_set_session, for a client, configures |ssl| to offer to resume |session|
1963 // in the initial handshake and returns one. The caller retains ownership of
1964 // |session|. Note that configuring a session assumes the authentication in the
1965 // session is valid. For callers that wish to revalidate the session before
1966 // offering, see |SSL_SESSION_get0_peer_certificates|,
1967 // |SSL_SESSION_get0_signed_cert_timestamp_list|, and
1968 // |SSL_SESSION_get0_ocsp_response|.
1969 //
1970 // It is an error to call this function after the handshake has begun.
1971 OPENSSL_EXPORT int SSL_set_session(SSL *ssl, SSL_SESSION *session);
1972 
1973 // SSL_DEFAULT_SESSION_TIMEOUT is the default lifetime, in seconds, of a
1974 // session in TLS 1.2 or earlier. This is how long we are willing to use the
1975 // secret to encrypt traffic without fresh key material.
1976 #define SSL_DEFAULT_SESSION_TIMEOUT (2 * 60 * 60)
1977 
1978 // SSL_DEFAULT_SESSION_PSK_DHE_TIMEOUT is the default lifetime, in seconds, of a
1979 // session for TLS 1.3 psk_dhe_ke. This is how long we are willing to use the
1980 // secret as an authenticator.
1981 #define SSL_DEFAULT_SESSION_PSK_DHE_TIMEOUT (2 * 24 * 60 * 60)
1982 
1983 // SSL_DEFAULT_SESSION_AUTH_TIMEOUT is the default non-renewable lifetime, in
1984 // seconds, of a TLS 1.3 session. This is how long we are willing to trust the
1985 // signature in the initial handshake.
1986 #define SSL_DEFAULT_SESSION_AUTH_TIMEOUT (7 * 24 * 60 * 60)
1987 
1988 // SSL_CTX_set_timeout sets the lifetime, in seconds, of TLS 1.2 (or earlier)
1989 // sessions created in |ctx| to |timeout|.
1990 OPENSSL_EXPORT uint32_t SSL_CTX_set_timeout(SSL_CTX *ctx, uint32_t timeout);
1991 
1992 // SSL_CTX_set_session_psk_dhe_timeout sets the lifetime, in seconds, of TLS 1.3
1993 // sessions created in |ctx| to |timeout|.
1994 OPENSSL_EXPORT void SSL_CTX_set_session_psk_dhe_timeout(SSL_CTX *ctx,
1995                                                         uint32_t timeout);
1996 
1997 // SSL_CTX_get_timeout returns the lifetime, in seconds, of TLS 1.2 (or earlier)
1998 // sessions created in |ctx|.
1999 OPENSSL_EXPORT uint32_t SSL_CTX_get_timeout(const SSL_CTX *ctx);
2000 
2001 // SSL_MAX_SID_CTX_LENGTH is the maximum length of a session ID context.
2002 #define SSL_MAX_SID_CTX_LENGTH 32
2003 
2004 // SSL_CTX_set_session_id_context sets |ctx|'s session ID context to |sid_ctx|.
2005 // It returns one on success and zero on error. The session ID context is an
2006 // application-defined opaque byte string. A session will not be used in a
2007 // connection without a matching session ID context.
2008 //
2009 // For a server, if |SSL_VERIFY_PEER| is enabled, it is an error to not set a
2010 // session ID context.
2011 OPENSSL_EXPORT int SSL_CTX_set_session_id_context(SSL_CTX *ctx,
2012                                                   const uint8_t *sid_ctx,
2013                                                   size_t sid_ctx_len);
2014 
2015 // SSL_set_session_id_context sets |ssl|'s session ID context to |sid_ctx|. It
2016 // returns one on success and zero on error. See also
2017 // |SSL_CTX_set_session_id_context|.
2018 OPENSSL_EXPORT int SSL_set_session_id_context(SSL *ssl, const uint8_t *sid_ctx,
2019                                               size_t sid_ctx_len);
2020 
2021 // SSL_get0_session_id_context returns a pointer to |ssl|'s session ID context
2022 // and sets |*out_len| to its length.  It returns NULL on error.
2023 OPENSSL_EXPORT const uint8_t *SSL_get0_session_id_context(const SSL *ssl,
2024                                                           size_t *out_len);
2025 
2026 // SSL_SESSION_CACHE_MAX_SIZE_DEFAULT is the default maximum size of a session
2027 // cache.
2028 #define SSL_SESSION_CACHE_MAX_SIZE_DEFAULT (1024 * 20)
2029 
2030 // SSL_CTX_sess_set_cache_size sets the maximum size of |ctx|'s internal session
2031 // cache to |size|. It returns the previous value.
2032 OPENSSL_EXPORT unsigned long SSL_CTX_sess_set_cache_size(SSL_CTX *ctx,
2033                                                          unsigned long size);
2034 
2035 // SSL_CTX_sess_get_cache_size returns the maximum size of |ctx|'s internal
2036 // session cache.
2037 OPENSSL_EXPORT unsigned long SSL_CTX_sess_get_cache_size(const SSL_CTX *ctx);
2038 
2039 // SSL_CTX_sess_number returns the number of sessions in |ctx|'s internal
2040 // session cache.
2041 OPENSSL_EXPORT size_t SSL_CTX_sess_number(const SSL_CTX *ctx);
2042 
2043 // SSL_CTX_add_session inserts |session| into |ctx|'s internal session cache. It
2044 // returns one on success and zero on error or if |session| is already in the
2045 // cache. The caller retains its reference to |session|.
2046 OPENSSL_EXPORT int SSL_CTX_add_session(SSL_CTX *ctx, SSL_SESSION *session);
2047 
2048 // SSL_CTX_remove_session removes |session| from |ctx|'s internal session cache.
2049 // It returns one on success and zero if |session| was not in the cache.
2050 OPENSSL_EXPORT int SSL_CTX_remove_session(SSL_CTX *ctx, SSL_SESSION *session);
2051 
2052 // SSL_CTX_flush_sessions removes all sessions from |ctx| which have expired as
2053 // of time |time|. If |time| is zero, all sessions are removed.
2054 OPENSSL_EXPORT void SSL_CTX_flush_sessions(SSL_CTX *ctx, uint64_t time);
2055 
2056 // SSL_CTX_sess_set_new_cb sets the callback to be called when a new session is
2057 // established and ready to be cached. If the session cache is disabled (the
2058 // appropriate one of |SSL_SESS_CACHE_CLIENT| or |SSL_SESS_CACHE_SERVER| is
2059 // unset), the callback is not called.
2060 //
2061 // The callback is passed a reference to |session|. It returns one if it takes
2062 // ownership (and then calls |SSL_SESSION_free| when done) and zero otherwise. A
2063 // consumer which places |session| into an in-memory cache will likely return
2064 // one, with the cache calling |SSL_SESSION_free|. A consumer which serializes
2065 // |session| with |SSL_SESSION_to_bytes| may not need to retain |session| and
2066 // will likely return zero. Returning one is equivalent to calling
2067 // |SSL_SESSION_up_ref| and then returning zero.
2068 //
2069 // Note: For a client, the callback may be called on abbreviated handshakes if a
2070 // ticket is renewed. Further, it may not be called until some time after
2071 // |SSL_do_handshake| or |SSL_connect| completes if False Start is enabled. Thus
2072 // it's recommended to use this callback over calling |SSL_get_session| on
2073 // handshake completion.
2074 OPENSSL_EXPORT void SSL_CTX_sess_set_new_cb(
2075     SSL_CTX *ctx, int (*new_session_cb)(SSL *ssl, SSL_SESSION *session));
2076 
2077 // SSL_CTX_sess_get_new_cb returns the callback set by
2078 // |SSL_CTX_sess_set_new_cb|.
2079 OPENSSL_EXPORT int (*SSL_CTX_sess_get_new_cb(SSL_CTX *ctx))(
2080     SSL *ssl, SSL_SESSION *session);
2081 
2082 // SSL_CTX_sess_set_remove_cb sets a callback which is called when a session is
2083 // removed from the internal session cache.
2084 //
2085 // TODO(davidben): What is the point of this callback? It seems useless since it
2086 // only fires on sessions in the internal cache.
2087 OPENSSL_EXPORT void SSL_CTX_sess_set_remove_cb(
2088     SSL_CTX *ctx,
2089     void (*remove_session_cb)(SSL_CTX *ctx, SSL_SESSION *session));
2090 
2091 // SSL_CTX_sess_get_remove_cb returns the callback set by
2092 // |SSL_CTX_sess_set_remove_cb|.
2093 OPENSSL_EXPORT void (*SSL_CTX_sess_get_remove_cb(SSL_CTX *ctx))(
2094     SSL_CTX *ctx, SSL_SESSION *session);
2095 
2096 // SSL_CTX_sess_set_get_cb sets a callback to look up a session by ID for a
2097 // server. The callback is passed the session ID and should return a matching
2098 // |SSL_SESSION| or NULL if not found. It should set |*out_copy| to zero and
2099 // return a new reference to the session. This callback is not used for a
2100 // client.
2101 //
2102 // For historical reasons, if |*out_copy| is set to one (default), the SSL
2103 // library will take a new reference to the returned |SSL_SESSION|, expecting
2104 // the callback to return a non-owning pointer. This is not recommended. If
2105 // |ctx| and thus the callback is used on multiple threads, the session may be
2106 // removed and invalidated before the SSL library calls |SSL_SESSION_up_ref|,
2107 // whereas the callback may synchronize internally.
2108 //
2109 // To look up a session asynchronously, the callback may return
2110 // |SSL_magic_pending_session_ptr|. See the documentation for that function and
2111 // |SSL_ERROR_PENDING_SESSION|.
2112 //
2113 // If the internal session cache is enabled, the callback is only consulted if
2114 // the internal cache does not return a match.
2115 OPENSSL_EXPORT void SSL_CTX_sess_set_get_cb(
2116     SSL_CTX *ctx, SSL_SESSION *(*get_session_cb)(SSL *ssl, const uint8_t *id,
2117                                                  int id_len, int *out_copy));
2118 
2119 // SSL_CTX_sess_get_get_cb returns the callback set by
2120 // |SSL_CTX_sess_set_get_cb|.
2121 OPENSSL_EXPORT SSL_SESSION *(*SSL_CTX_sess_get_get_cb(SSL_CTX *ctx))(
2122     SSL *ssl, const uint8_t *id, int id_len, int *out_copy);
2123 
2124 // SSL_magic_pending_session_ptr returns a magic |SSL_SESSION|* which indicates
2125 // that the session isn't currently unavailable. |SSL_get_error| will then
2126 // return |SSL_ERROR_PENDING_SESSION| and the handshake can be retried later
2127 // when the lookup has completed.
2128 OPENSSL_EXPORT SSL_SESSION *SSL_magic_pending_session_ptr(void);
2129 
2130 
2131 // Session tickets.
2132 //
2133 // Session tickets, from RFC 5077, allow session resumption without server-side
2134 // state. The server maintains a secret ticket key and sends the client opaque
2135 // encrypted session parameters, called a ticket. When offering the session, the
2136 // client sends the ticket which the server decrypts to recover session state.
2137 // Session tickets are enabled by default but may be disabled with
2138 // |SSL_OP_NO_TICKET|.
2139 //
2140 // On the client, ticket-based sessions use the same APIs as ID-based tickets.
2141 // Callers do not need to handle them differently.
2142 //
2143 // On the server, tickets are encrypted and authenticated with a secret key.
2144 // By default, an |SSL_CTX| will manage session ticket encryption keys by
2145 // generating them internally and rotating every 48 hours. Tickets are minted
2146 // and processed transparently. The following functions may be used to configure
2147 // a persistent key or implement more custom behavior, including key rotation
2148 // and sharing keys between multiple servers in a large deployment. There are
2149 // three levels of customisation possible:
2150 //
2151 // 1) One can simply set the keys with |SSL_CTX_set_tlsext_ticket_keys|.
2152 // 2) One can configure an |EVP_CIPHER_CTX| and |HMAC_CTX| directly for
2153 //    encryption and authentication.
2154 // 3) One can configure an |SSL_TICKET_AEAD_METHOD| to have more control
2155 //    and the option of asynchronous decryption.
2156 //
2157 // An attacker that compromises a server's session ticket key can impersonate
2158 // the server and, prior to TLS 1.3, retroactively decrypt all application
2159 // traffic from sessions using that ticket key. Thus ticket keys must be
2160 // regularly rotated for forward secrecy. Note the default key is rotated
2161 // automatically once every 48 hours but manually configured keys are not.
2162 
2163 // SSL_DEFAULT_TICKET_KEY_ROTATION_INTERVAL is the interval with which the
2164 // default session ticket encryption key is rotated, if in use. If any
2165 // non-default ticket encryption mechanism is configured, automatic rotation is
2166 // disabled.
2167 #define SSL_DEFAULT_TICKET_KEY_ROTATION_INTERVAL (2 * 24 * 60 * 60)
2168 
2169 // SSL_CTX_get_tlsext_ticket_keys writes |ctx|'s session ticket key material to
2170 // |len| bytes of |out|. It returns one on success and zero if |len| is not
2171 // 48. If |out| is NULL, it returns 48 instead.
2172 OPENSSL_EXPORT int SSL_CTX_get_tlsext_ticket_keys(SSL_CTX *ctx, void *out,
2173                                                   size_t len);
2174 
2175 // SSL_CTX_set_tlsext_ticket_keys sets |ctx|'s session ticket key material to
2176 // |len| bytes of |in|. It returns one on success and zero if |len| is not
2177 // 48. If |in| is NULL, it returns 48 instead.
2178 OPENSSL_EXPORT int SSL_CTX_set_tlsext_ticket_keys(SSL_CTX *ctx, const void *in,
2179                                                   size_t len);
2180 
2181 // SSL_TICKET_KEY_NAME_LEN is the length of the key name prefix of a session
2182 // ticket.
2183 #define SSL_TICKET_KEY_NAME_LEN 16
2184 
2185 // SSL_CTX_set_tlsext_ticket_key_cb sets the ticket callback to |callback| and
2186 // returns one. |callback| will be called when encrypting a new ticket and when
2187 // decrypting a ticket from the client.
2188 //
2189 // In both modes, |ctx| and |hmac_ctx| will already have been initialized with
2190 // |EVP_CIPHER_CTX_init| and |HMAC_CTX_init|, respectively. |callback|
2191 // configures |hmac_ctx| with an HMAC digest and key, and configures |ctx|
2192 // for encryption or decryption, based on the mode.
2193 //
2194 // When encrypting a new ticket, |encrypt| will be one. It writes a public
2195 // 16-byte key name to |key_name| and a fresh IV to |iv|. The output IV length
2196 // must match |EVP_CIPHER_CTX_iv_length| of the cipher selected. In this mode,
2197 // |callback| returns 1 on success and -1 on error.
2198 //
2199 // When decrypting a ticket, |encrypt| will be zero. |key_name| will point to a
2200 // 16-byte key name and |iv| points to an IV. The length of the IV consumed must
2201 // match |EVP_CIPHER_CTX_iv_length| of the cipher selected. In this mode,
2202 // |callback| returns -1 to abort the handshake, 0 if decrypting the ticket
2203 // failed, and 1 or 2 on success. If it returns 2, the ticket will be renewed.
2204 // This may be used to re-key the ticket.
2205 //
2206 // WARNING: |callback| wildly breaks the usual return value convention and is
2207 // called in two different modes.
2208 OPENSSL_EXPORT int SSL_CTX_set_tlsext_ticket_key_cb(
2209     SSL_CTX *ctx, int (*callback)(SSL *ssl, uint8_t *key_name, uint8_t *iv,
2210                                   EVP_CIPHER_CTX *ctx, HMAC_CTX *hmac_ctx,
2211                                   int encrypt));
2212 
2213 // ssl_ticket_aead_result_t enumerates the possible results from decrypting a
2214 // ticket with an |SSL_TICKET_AEAD_METHOD|.
2215 enum ssl_ticket_aead_result_t BORINGSSL_ENUM_INT {
2216   // ssl_ticket_aead_success indicates that the ticket was successfully
2217   // decrypted.
2218   ssl_ticket_aead_success,
2219   // ssl_ticket_aead_retry indicates that the operation could not be
2220   // immediately completed and must be reattempted, via |open|, at a later
2221   // point.
2222   ssl_ticket_aead_retry,
2223   // ssl_ticket_aead_ignore_ticket indicates that the ticket should be ignored
2224   // (i.e. is corrupt or otherwise undecryptable).
2225   ssl_ticket_aead_ignore_ticket,
2226   // ssl_ticket_aead_error indicates that a fatal error occured and the
2227   // handshake should be terminated.
2228   ssl_ticket_aead_error,
2229 };
2230 
2231 // ssl_ticket_aead_method_st (aka |SSL_TICKET_AEAD_METHOD|) contains methods
2232 // for encrypting and decrypting session tickets.
2233 struct ssl_ticket_aead_method_st {
2234   // max_overhead returns the maximum number of bytes of overhead that |seal|
2235   // may add.
2236   size_t (*max_overhead)(SSL *ssl);
2237 
2238   // seal encrypts and authenticates |in_len| bytes from |in|, writes, at most,
2239   // |max_out_len| bytes to |out|, and puts the number of bytes written in
2240   // |*out_len|. The |in| and |out| buffers may be equal but will not otherwise
2241   // alias. It returns one on success or zero on error.
2242   int (*seal)(SSL *ssl, uint8_t *out, size_t *out_len, size_t max_out_len,
2243               const uint8_t *in, size_t in_len);
2244 
2245   // open authenticates and decrypts |in_len| bytes from |in|, writes, at most,
2246   // |max_out_len| bytes of plaintext to |out|, and puts the number of bytes
2247   // written in |*out_len|. The |in| and |out| buffers may be equal but will
2248   // not otherwise alias. See |ssl_ticket_aead_result_t| for details of the
2249   // return values. In the case that a retry is indicated, the caller should
2250   // arrange for the high-level operation on |ssl| to be retried when the
2251   // operation is completed, which will result in another call to |open|.
2252   enum ssl_ticket_aead_result_t (*open)(SSL *ssl, uint8_t *out, size_t *out_len,
2253                                         size_t max_out_len, const uint8_t *in,
2254                                         size_t in_len);
2255 };
2256 
2257 // SSL_CTX_set_ticket_aead_method configures a custom ticket AEAD method table
2258 // on |ctx|. |aead_method| must remain valid for the lifetime of |ctx|.
2259 OPENSSL_EXPORT void SSL_CTX_set_ticket_aead_method(
2260     SSL_CTX *ctx, const SSL_TICKET_AEAD_METHOD *aead_method);
2261 
2262 // SSL_process_tls13_new_session_ticket processes an unencrypted TLS 1.3
2263 // NewSessionTicket message from |buf| and returns a resumable |SSL_SESSION|,
2264 // or NULL on error. The caller takes ownership of the returned session and
2265 // must call |SSL_SESSION_free| to free it.
2266 //
2267 // |buf| contains |buf_len| bytes that represents a complete NewSessionTicket
2268 // message including its header, i.e., one byte for the type (0x04) and three
2269 // bytes for the length. |buf| must contain only one such message.
2270 //
2271 // This function may be used to process NewSessionTicket messages in TLS 1.3
2272 // clients that are handling the record layer externally.
2273 OPENSSL_EXPORT SSL_SESSION *SSL_process_tls13_new_session_ticket(
2274     SSL *ssl, const uint8_t *buf, size_t buf_len);
2275 
2276 // SSL_CTX_set_num_tickets configures |ctx| to send |num_tickets| immediately
2277 // after a successful TLS 1.3 handshake as a server. It returns one. Large
2278 // values of |num_tickets| will be capped within the library.
2279 //
2280 // By default, BoringSSL sends two tickets.
2281 OPENSSL_EXPORT int SSL_CTX_set_num_tickets(SSL_CTX *ctx, size_t num_tickets);
2282 
2283 // SSL_CTX_get_num_tickets returns the number of tickets |ctx| will send
2284 // immediately after a successful TLS 1.3 handshake as a server.
2285 OPENSSL_EXPORT size_t SSL_CTX_get_num_tickets(const SSL_CTX *ctx);
2286 
2287 
2288 // Elliptic curve Diffie-Hellman.
2289 //
2290 // Cipher suites using an ECDHE key exchange perform Diffie-Hellman over an
2291 // elliptic curve negotiated by both endpoints. See RFC 4492. Only named curves
2292 // are supported. ECDHE is always enabled, but the curve preferences may be
2293 // configured with these functions.
2294 //
2295 // Note that TLS 1.3 renames these from curves to groups. For consistency, we
2296 // currently use the TLS 1.2 name in the API.
2297 
2298 // SSL_CTX_set1_curves sets the preferred curves for |ctx| to be |curves|. Each
2299 // element of |curves| should be a curve nid. It returns one on success and
2300 // zero on failure.
2301 //
2302 // Note that this API uses nid values from nid.h and not the |SSL_CURVE_*|
2303 // values defined below.
2304 OPENSSL_EXPORT int SSL_CTX_set1_curves(SSL_CTX *ctx, const int *curves,
2305                                        size_t curves_len);
2306 
2307 // SSL_set1_curves sets the preferred curves for |ssl| to be |curves|. Each
2308 // element of |curves| should be a curve nid. It returns one on success and
2309 // zero on failure.
2310 //
2311 // Note that this API uses nid values from nid.h and not the |SSL_CURVE_*|
2312 // values defined below.
2313 OPENSSL_EXPORT int SSL_set1_curves(SSL *ssl, const int *curves,
2314                                    size_t curves_len);
2315 
2316 // SSL_CTX_set1_curves_list sets the preferred curves for |ctx| to be the
2317 // colon-separated list |curves|. Each element of |curves| should be a curve
2318 // name (e.g. P-256, X25519, ...). It returns one on success and zero on
2319 // failure.
2320 OPENSSL_EXPORT int SSL_CTX_set1_curves_list(SSL_CTX *ctx, const char *curves);
2321 
2322 // SSL_set1_curves_list sets the preferred curves for |ssl| to be the
2323 // colon-separated list |curves|. Each element of |curves| should be a curve
2324 // name (e.g. P-256, X25519, ...). It returns one on success and zero on
2325 // failure.
2326 OPENSSL_EXPORT int SSL_set1_curves_list(SSL *ssl, const char *curves);
2327 
2328 // SSL_CURVE_* define TLS curve IDs.
2329 #define SSL_CURVE_SECP224R1 21
2330 #define SSL_CURVE_SECP256R1 23
2331 #define SSL_CURVE_SECP384R1 24
2332 #define SSL_CURVE_SECP521R1 25
2333 #define SSL_CURVE_X25519 29
2334 #define SSL_CURVE_X25519KYBER768 0x6399
2335 #define SSL_CURVE_P256KYBER768 0xfe32
2336 
2337 // SSL_get_curve_id returns the ID of the curve used by |ssl|'s most recently
2338 // completed handshake or 0 if not applicable.
2339 //
2340 // TODO(davidben): This API currently does not work correctly if there is a
2341 // renegotiation in progress. Fix this.
2342 OPENSSL_EXPORT uint16_t SSL_get_curve_id(const SSL *ssl);
2343 
2344 // SSL_get_curve_name returns a human-readable name for the curve specified by
2345 // the given TLS curve id, or NULL if the curve is unknown.
2346 OPENSSL_EXPORT const char *SSL_get_curve_name(uint16_t curve_id);
2347 
2348 // SSL_CTX_set1_groups calls |SSL_CTX_set1_curves|.
2349 OPENSSL_EXPORT int SSL_CTX_set1_groups(SSL_CTX *ctx, const int *groups,
2350                                        size_t groups_len);
2351 
2352 // SSL_set1_groups calls |SSL_set1_curves|.
2353 OPENSSL_EXPORT int SSL_set1_groups(SSL *ssl, const int *groups,
2354                                    size_t groups_len);
2355 
2356 // SSL_CTX_set1_groups_list calls |SSL_CTX_set1_curves_list|.
2357 OPENSSL_EXPORT int SSL_CTX_set1_groups_list(SSL_CTX *ctx, const char *groups);
2358 
2359 // SSL_set1_groups_list calls |SSL_set1_curves_list|.
2360 OPENSSL_EXPORT int SSL_set1_groups_list(SSL *ssl, const char *groups);
2361 
2362 
2363 // Certificate verification.
2364 //
2365 // SSL may authenticate either endpoint with an X.509 certificate. Typically
2366 // this is used to authenticate the server to the client. These functions
2367 // configure certificate verification.
2368 //
2369 // WARNING: By default, certificate verification errors on a client are not
2370 // fatal. See |SSL_VERIFY_NONE| This may be configured with
2371 // |SSL_CTX_set_verify|.
2372 //
2373 // By default clients are anonymous but a server may request a certificate from
2374 // the client by setting |SSL_VERIFY_PEER|.
2375 //
2376 // Many of these functions use OpenSSL's legacy X.509 stack which is
2377 // underdocumented and deprecated, but the replacement isn't ready yet. For
2378 // now, consumers may use the existing stack or bypass it by performing
2379 // certificate verification externally. This may be done with
2380 // |SSL_CTX_set_cert_verify_callback| or by extracting the chain with
2381 // |SSL_get_peer_cert_chain| after the handshake. In the future, functions will
2382 // be added to use the SSL stack without dependency on any part of the legacy
2383 // X.509 and ASN.1 stack.
2384 //
2385 // To augment certificate verification, a client may also enable OCSP stapling
2386 // (RFC 6066) and Certificate Transparency (RFC 6962) extensions.
2387 
2388 // SSL_VERIFY_NONE, on a client, verifies the server certificate but does not
2389 // make errors fatal. The result may be checked with |SSL_get_verify_result|. On
2390 // a server it does not request a client certificate. This is the default.
2391 #define SSL_VERIFY_NONE 0x00
2392 
2393 // SSL_VERIFY_PEER, on a client, makes server certificate errors fatal. On a
2394 // server it requests a client certificate and makes errors fatal. However,
2395 // anonymous clients are still allowed. See
2396 // |SSL_VERIFY_FAIL_IF_NO_PEER_CERT|.
2397 #define SSL_VERIFY_PEER 0x01
2398 
2399 // SSL_VERIFY_FAIL_IF_NO_PEER_CERT configures a server to reject connections if
2400 // the client declines to send a certificate. This flag must be used together
2401 // with |SSL_VERIFY_PEER|, otherwise it won't work.
2402 #define SSL_VERIFY_FAIL_IF_NO_PEER_CERT 0x02
2403 
2404 // SSL_VERIFY_PEER_IF_NO_OBC configures a server to request a client certificate
2405 // if and only if Channel ID is not negotiated.
2406 #define SSL_VERIFY_PEER_IF_NO_OBC 0x04
2407 
2408 // SSL_CTX_set_verify configures certificate verification behavior. |mode| is
2409 // one of the |SSL_VERIFY_*| values defined above. |callback|, if not NULL, is
2410 // used to customize certificate verification, but is deprecated. See
2411 // |X509_STORE_CTX_set_verify_cb| for details.
2412 //
2413 // The callback may use |SSL_get_ex_data_X509_STORE_CTX_idx| with
2414 // |X509_STORE_CTX_get_ex_data| to look up the |SSL| from |store_ctx|.
2415 //
2416 // WARNING: |callback| should be NULL. This callback does not replace the
2417 // default certificate verification process and is, instead, called multiple
2418 // times in the course of that process. It is very difficult to implement this
2419 // callback safely, without inadvertently relying on implementation details or
2420 // making incorrect assumptions about when the callback is called.
2421 //
2422 // Instead, use |SSL_CTX_set_custom_verify| or
2423 // |SSL_CTX_set_cert_verify_callback| to customize certificate verification.
2424 // Those callbacks can inspect the peer-sent chain, call |X509_verify_cert| and
2425 // inspect the result, or perform other operations more straightforwardly.
2426 //
2427 // TODO(crbug.com/boringssl/426): We cite |X509_STORE_CTX_set_verify_cb| but
2428 // haven't documented it yet. Later that will have a more detailed warning about
2429 // why one should not use this callback.
2430 OPENSSL_EXPORT void SSL_CTX_set_verify(
2431     SSL_CTX *ctx, int mode, int (*callback)(int ok, X509_STORE_CTX *store_ctx));
2432 
2433 // SSL_set_verify configures certificate verification behavior. |mode| is one of
2434 // the |SSL_VERIFY_*| values defined above. |callback|, if not NULL, is used to
2435 // customize certificate verification, but is deprecated. See the behavior of
2436 // |X509_STORE_CTX_set_verify_cb|.
2437 //
2438 // The callback may use |SSL_get_ex_data_X509_STORE_CTX_idx| with
2439 // |X509_STORE_CTX_get_ex_data| to look up the |SSL| from |store_ctx|.
2440 //
2441 // WARNING: |callback| should be NULL. This callback does not replace the
2442 // default certificate verification process and is, instead, called multiple
2443 // times in the course of that process. It is very difficult to implement this
2444 // callback safely, without inadvertently relying on implementation details or
2445 // making incorrect assumptions about when the callback is called.
2446 //
2447 // Instead, use |SSL_set_custom_verify| or |SSL_CTX_set_cert_verify_callback| to
2448 // customize certificate verification. Those callbacks can inspect the peer-sent
2449 // chain, call |X509_verify_cert| and inspect the result, or perform other
2450 // operations more straightforwardly.
2451 //
2452 // TODO(crbug.com/boringssl/426): We cite |X509_STORE_CTX_set_verify_cb| but
2453 // haven't documented it yet. Later that will have a more detailed warning about
2454 // why one should not use this callback.
2455 OPENSSL_EXPORT void SSL_set_verify(SSL *ssl, int mode,
2456                                    int (*callback)(int ok,
2457                                                    X509_STORE_CTX *store_ctx));
2458 
2459 enum ssl_verify_result_t BORINGSSL_ENUM_INT {
2460   ssl_verify_ok,
2461   ssl_verify_invalid,
2462   ssl_verify_retry,
2463 };
2464 
2465 // SSL_CTX_set_custom_verify configures certificate verification. |mode| is one
2466 // of the |SSL_VERIFY_*| values defined above. |callback| performs the
2467 // certificate verification.
2468 //
2469 // The callback may call |SSL_get0_peer_certificates| for the certificate chain
2470 // to validate. The callback should return |ssl_verify_ok| if the certificate is
2471 // valid. If the certificate is invalid, the callback should return
2472 // |ssl_verify_invalid| and optionally set |*out_alert| to an alert to send to
2473 // the peer. Some useful alerts include |SSL_AD_CERTIFICATE_EXPIRED|,
2474 // |SSL_AD_CERTIFICATE_REVOKED|, |SSL_AD_UNKNOWN_CA|, |SSL_AD_BAD_CERTIFICATE|,
2475 // |SSL_AD_CERTIFICATE_UNKNOWN|, and |SSL_AD_INTERNAL_ERROR|. See RFC 5246
2476 // section 7.2.2 for their precise meanings. If unspecified,
2477 // |SSL_AD_CERTIFICATE_UNKNOWN| will be sent by default.
2478 //
2479 // To verify a certificate asynchronously, the callback may return
2480 // |ssl_verify_retry|. The handshake will then pause with |SSL_get_error|
2481 // returning |SSL_ERROR_WANT_CERTIFICATE_VERIFY|.
2482 OPENSSL_EXPORT void SSL_CTX_set_custom_verify(
2483     SSL_CTX *ctx, int mode,
2484     enum ssl_verify_result_t (*callback)(SSL *ssl, uint8_t *out_alert));
2485 
2486 // SSL_set_custom_verify behaves like |SSL_CTX_set_custom_verify| but configures
2487 // an individual |SSL|.
2488 OPENSSL_EXPORT void SSL_set_custom_verify(
2489     SSL *ssl, int mode,
2490     enum ssl_verify_result_t (*callback)(SSL *ssl, uint8_t *out_alert));
2491 
2492 // SSL_CTX_get_verify_mode returns |ctx|'s verify mode, set by
2493 // |SSL_CTX_set_verify|.
2494 OPENSSL_EXPORT int SSL_CTX_get_verify_mode(const SSL_CTX *ctx);
2495 
2496 // SSL_get_verify_mode returns |ssl|'s verify mode, set by |SSL_CTX_set_verify|
2497 // or |SSL_set_verify|.  It returns -1 on error.
2498 OPENSSL_EXPORT int SSL_get_verify_mode(const SSL *ssl);
2499 
2500 // SSL_CTX_get_verify_callback returns the callback set by
2501 // |SSL_CTX_set_verify|.
2502 OPENSSL_EXPORT int (*SSL_CTX_get_verify_callback(const SSL_CTX *ctx))(
2503     int ok, X509_STORE_CTX *store_ctx);
2504 
2505 // SSL_get_verify_callback returns the callback set by |SSL_CTX_set_verify| or
2506 // |SSL_set_verify|.
2507 OPENSSL_EXPORT int (*SSL_get_verify_callback(const SSL *ssl))(
2508     int ok, X509_STORE_CTX *store_ctx);
2509 
2510 // SSL_set1_host sets a DNS name that will be required to be present in the
2511 // verified leaf certificate. It returns one on success and zero on error.
2512 //
2513 // Note: unless _some_ name checking is performed, certificate validation is
2514 // ineffective. Simply checking that a host has some certificate from a CA is
2515 // rarely meaningful—you have to check that the CA believed that the host was
2516 // who you expect to be talking to.
2517 OPENSSL_EXPORT int SSL_set1_host(SSL *ssl, const char *hostname);
2518 
2519 // SSL_CTX_set_verify_depth sets the maximum depth of a certificate chain
2520 // accepted in verification. This number does not include the leaf, so a depth
2521 // of 1 allows the leaf and one CA certificate.
2522 OPENSSL_EXPORT void SSL_CTX_set_verify_depth(SSL_CTX *ctx, int depth);
2523 
2524 // SSL_set_verify_depth sets the maximum depth of a certificate chain accepted
2525 // in verification. This number does not include the leaf, so a depth of 1
2526 // allows the leaf and one CA certificate.
2527 OPENSSL_EXPORT void SSL_set_verify_depth(SSL *ssl, int depth);
2528 
2529 // SSL_CTX_get_verify_depth returns the maximum depth of a certificate accepted
2530 // in verification.
2531 OPENSSL_EXPORT int SSL_CTX_get_verify_depth(const SSL_CTX *ctx);
2532 
2533 // SSL_get_verify_depth returns the maximum depth of a certificate accepted in
2534 // verification.
2535 OPENSSL_EXPORT int SSL_get_verify_depth(const SSL *ssl);
2536 
2537 // SSL_CTX_set1_param sets verification parameters from |param|. It returns one
2538 // on success and zero on failure. The caller retains ownership of |param|.
2539 OPENSSL_EXPORT int SSL_CTX_set1_param(SSL_CTX *ctx,
2540                                       const X509_VERIFY_PARAM *param);
2541 
2542 // SSL_set1_param sets verification parameters from |param|. It returns one on
2543 // success and zero on failure. The caller retains ownership of |param|.
2544 OPENSSL_EXPORT int SSL_set1_param(SSL *ssl,
2545                                   const X509_VERIFY_PARAM *param);
2546 
2547 // SSL_CTX_get0_param returns |ctx|'s |X509_VERIFY_PARAM| for certificate
2548 // verification. The caller must not release the returned pointer but may call
2549 // functions on it to configure it.
2550 OPENSSL_EXPORT X509_VERIFY_PARAM *SSL_CTX_get0_param(SSL_CTX *ctx);
2551 
2552 // SSL_get0_param returns |ssl|'s |X509_VERIFY_PARAM| for certificate
2553 // verification. The caller must not release the returned pointer but may call
2554 // functions on it to configure it.
2555 OPENSSL_EXPORT X509_VERIFY_PARAM *SSL_get0_param(SSL *ssl);
2556 
2557 // SSL_CTX_set_purpose sets |ctx|'s |X509_VERIFY_PARAM|'s 'purpose' parameter to
2558 // |purpose|. It returns one on success and zero on error.
2559 OPENSSL_EXPORT int SSL_CTX_set_purpose(SSL_CTX *ctx, int purpose);
2560 
2561 // SSL_set_purpose sets |ssl|'s |X509_VERIFY_PARAM|'s 'purpose' parameter to
2562 // |purpose|. It returns one on success and zero on error.
2563 OPENSSL_EXPORT int SSL_set_purpose(SSL *ssl, int purpose);
2564 
2565 // SSL_CTX_set_trust sets |ctx|'s |X509_VERIFY_PARAM|'s 'trust' parameter to
2566 // |trust|. It returns one on success and zero on error.
2567 OPENSSL_EXPORT int SSL_CTX_set_trust(SSL_CTX *ctx, int trust);
2568 
2569 // SSL_set_trust sets |ssl|'s |X509_VERIFY_PARAM|'s 'trust' parameter to
2570 // |trust|. It returns one on success and zero on error.
2571 OPENSSL_EXPORT int SSL_set_trust(SSL *ssl, int trust);
2572 
2573 // SSL_CTX_set_cert_store sets |ctx|'s certificate store to |store|. It takes
2574 // ownership of |store|. The store is used for certificate verification.
2575 //
2576 // The store is also used for the auto-chaining feature, but this is deprecated.
2577 // See also |SSL_MODE_NO_AUTO_CHAIN|.
2578 OPENSSL_EXPORT void SSL_CTX_set_cert_store(SSL_CTX *ctx, X509_STORE *store);
2579 
2580 // SSL_CTX_get_cert_store returns |ctx|'s certificate store.
2581 OPENSSL_EXPORT X509_STORE *SSL_CTX_get_cert_store(const SSL_CTX *ctx);
2582 
2583 // SSL_CTX_set_default_verify_paths loads the OpenSSL system-default trust
2584 // anchors into |ctx|'s store. It returns one on success and zero on failure.
2585 OPENSSL_EXPORT int SSL_CTX_set_default_verify_paths(SSL_CTX *ctx);
2586 
2587 // SSL_CTX_load_verify_locations loads trust anchors into |ctx|'s store from
2588 // |ca_file| and |ca_dir|, either of which may be NULL. If |ca_file| is passed,
2589 // it is opened and PEM-encoded CA certificates are read. If |ca_dir| is passed,
2590 // it is treated as a directory in OpenSSL's hashed directory format. It returns
2591 // one on success and zero on failure.
2592 //
2593 // See
2594 // https://www.openssl.org/docs/man1.1.0/man3/SSL_CTX_load_verify_locations.html
2595 // for documentation on the directory format.
2596 OPENSSL_EXPORT int SSL_CTX_load_verify_locations(SSL_CTX *ctx,
2597                                                  const char *ca_file,
2598                                                  const char *ca_dir);
2599 
2600 // SSL_get_verify_result returns the result of certificate verification. It is
2601 // either |X509_V_OK| or a |X509_V_ERR_*| value.
2602 OPENSSL_EXPORT long SSL_get_verify_result(const SSL *ssl);
2603 
2604 // SSL_alert_from_verify_result returns the SSL alert code, such as
2605 // |SSL_AD_CERTIFICATE_EXPIRED|, that corresponds to an |X509_V_ERR_*| value.
2606 // The return value is always an alert, even when |result| is |X509_V_OK|.
2607 OPENSSL_EXPORT int SSL_alert_from_verify_result(long result);
2608 
2609 // SSL_get_ex_data_X509_STORE_CTX_idx returns the ex_data index used to look up
2610 // the |SSL| associated with an |X509_STORE_CTX| in the verify callback.
2611 OPENSSL_EXPORT int SSL_get_ex_data_X509_STORE_CTX_idx(void);
2612 
2613 // SSL_CTX_set_cert_verify_callback sets a custom callback to be called on
2614 // certificate verification rather than |X509_verify_cert|. |store_ctx| contains
2615 // the verification parameters. The callback should return one on success and
2616 // zero on fatal error. It may use |X509_STORE_CTX_set_error| to set a
2617 // verification result.
2618 //
2619 // The callback may use |SSL_get_ex_data_X509_STORE_CTX_idx| to recover the
2620 // |SSL| object from |store_ctx|.
2621 OPENSSL_EXPORT void SSL_CTX_set_cert_verify_callback(
2622     SSL_CTX *ctx, int (*callback)(X509_STORE_CTX *store_ctx, void *arg),
2623     void *arg);
2624 
2625 // SSL_enable_signed_cert_timestamps causes |ssl| (which must be the client end
2626 // of a connection) to request SCTs from the server. See
2627 // https://tools.ietf.org/html/rfc6962.
2628 //
2629 // Call |SSL_get0_signed_cert_timestamp_list| to recover the SCT after the
2630 // handshake.
2631 OPENSSL_EXPORT void SSL_enable_signed_cert_timestamps(SSL *ssl);
2632 
2633 // SSL_CTX_enable_signed_cert_timestamps enables SCT requests on all client SSL
2634 // objects created from |ctx|.
2635 //
2636 // Call |SSL_get0_signed_cert_timestamp_list| to recover the SCT after the
2637 // handshake.
2638 OPENSSL_EXPORT void SSL_CTX_enable_signed_cert_timestamps(SSL_CTX *ctx);
2639 
2640 // SSL_enable_ocsp_stapling causes |ssl| (which must be the client end of a
2641 // connection) to request a stapled OCSP response from the server.
2642 //
2643 // Call |SSL_get0_ocsp_response| to recover the OCSP response after the
2644 // handshake.
2645 OPENSSL_EXPORT void SSL_enable_ocsp_stapling(SSL *ssl);
2646 
2647 // SSL_CTX_enable_ocsp_stapling enables OCSP stapling on all client SSL objects
2648 // created from |ctx|.
2649 //
2650 // Call |SSL_get0_ocsp_response| to recover the OCSP response after the
2651 // handshake.
2652 OPENSSL_EXPORT void SSL_CTX_enable_ocsp_stapling(SSL_CTX *ctx);
2653 
2654 // SSL_CTX_set0_verify_cert_store sets an |X509_STORE| that will be used
2655 // exclusively for certificate verification and returns one. Ownership of
2656 // |store| is transferred to the |SSL_CTX|.
2657 OPENSSL_EXPORT int SSL_CTX_set0_verify_cert_store(SSL_CTX *ctx,
2658                                                   X509_STORE *store);
2659 
2660 // SSL_CTX_set1_verify_cert_store sets an |X509_STORE| that will be used
2661 // exclusively for certificate verification and returns one. An additional
2662 // reference to |store| will be taken.
2663 OPENSSL_EXPORT int SSL_CTX_set1_verify_cert_store(SSL_CTX *ctx,
2664                                                   X509_STORE *store);
2665 
2666 // SSL_set0_verify_cert_store sets an |X509_STORE| that will be used
2667 // exclusively for certificate verification and returns one. Ownership of
2668 // |store| is transferred to the |SSL|.
2669 OPENSSL_EXPORT int SSL_set0_verify_cert_store(SSL *ssl, X509_STORE *store);
2670 
2671 // SSL_set1_verify_cert_store sets an |X509_STORE| that will be used
2672 // exclusively for certificate verification and returns one. An additional
2673 // reference to |store| will be taken.
2674 OPENSSL_EXPORT int SSL_set1_verify_cert_store(SSL *ssl, X509_STORE *store);
2675 
2676 // SSL_CTX_set_verify_algorithm_prefs configures |ctx| to use |prefs| as the
2677 // preference list when verifying signatures from the peer's long-term key. It
2678 // returns one on zero on error. |prefs| should not include the internal-only
2679 // value |SSL_SIGN_RSA_PKCS1_MD5_SHA1|.
2680 OPENSSL_EXPORT int SSL_CTX_set_verify_algorithm_prefs(SSL_CTX *ctx,
2681                                                       const uint16_t *prefs,
2682                                                       size_t num_prefs);
2683 
2684 // SSL_set_verify_algorithm_prefs configures |ssl| to use |prefs| as the
2685 // preference list when verifying signatures from the peer's long-term key. It
2686 // returns one on zero on error. |prefs| should not include the internal-only
2687 // value |SSL_SIGN_RSA_PKCS1_MD5_SHA1|.
2688 OPENSSL_EXPORT int SSL_set_verify_algorithm_prefs(SSL *ssl,
2689                                                   const uint16_t *prefs,
2690                                                   size_t num_prefs);
2691 
2692 // SSL_set_hostflags calls |X509_VERIFY_PARAM_set_hostflags| on the
2693 // |X509_VERIFY_PARAM| associated with this |SSL*|. The |flags| argument
2694 // should be one of the |X509_CHECK_*| constants.
2695 OPENSSL_EXPORT void SSL_set_hostflags(SSL *ssl, unsigned flags);
2696 
2697 
2698 // Client certificate CA list.
2699 //
2700 // When requesting a client certificate, a server may advertise a list of
2701 // certificate authorities which are accepted. These functions may be used to
2702 // configure this list.
2703 
2704 // SSL_set_client_CA_list sets |ssl|'s client certificate CA list to
2705 // |name_list|. It takes ownership of |name_list|.
2706 OPENSSL_EXPORT void SSL_set_client_CA_list(SSL *ssl,
2707                                            STACK_OF(X509_NAME) *name_list);
2708 
2709 // SSL_CTX_set_client_CA_list sets |ctx|'s client certificate CA list to
2710 // |name_list|. It takes ownership of |name_list|.
2711 OPENSSL_EXPORT void SSL_CTX_set_client_CA_list(SSL_CTX *ctx,
2712                                                STACK_OF(X509_NAME) *name_list);
2713 
2714 // SSL_set0_client_CAs sets |ssl|'s client certificate CA list to |name_list|,
2715 // which should contain DER-encoded distinguished names (RFC 5280). It takes
2716 // ownership of |name_list|.
2717 OPENSSL_EXPORT void SSL_set0_client_CAs(SSL *ssl,
2718                                         STACK_OF(CRYPTO_BUFFER) *name_list);
2719 
2720 // SSL_CTX_set0_client_CAs sets |ctx|'s client certificate CA list to
2721 // |name_list|, which should contain DER-encoded distinguished names (RFC 5280).
2722 // It takes ownership of |name_list|.
2723 OPENSSL_EXPORT void SSL_CTX_set0_client_CAs(SSL_CTX *ctx,
2724                                             STACK_OF(CRYPTO_BUFFER) *name_list);
2725 
2726 // SSL_get_client_CA_list returns |ssl|'s client certificate CA list. If |ssl|
2727 // has not been configured as a client, this is the list configured by
2728 // |SSL_CTX_set_client_CA_list|.
2729 //
2730 // If configured as a client, it returns the client certificate CA list sent by
2731 // the server. In this mode, the behavior is undefined except during the
2732 // callbacks set by |SSL_CTX_set_cert_cb| and |SSL_CTX_set_client_cert_cb| or
2733 // when the handshake is paused because of them.
2734 OPENSSL_EXPORT STACK_OF(X509_NAME) *SSL_get_client_CA_list(const SSL *ssl);
2735 
2736 // SSL_get0_server_requested_CAs returns the CAs sent by a server to guide a
2737 // client in certificate selection. They are a series of DER-encoded X.509
2738 // names. This function may only be called during a callback set by
2739 // |SSL_CTX_set_cert_cb| or when the handshake is paused because of it.
2740 //
2741 // The returned stack is owned by |ssl|, as are its contents. It should not be
2742 // used past the point where the handshake is restarted after the callback.
2743 OPENSSL_EXPORT const STACK_OF(CRYPTO_BUFFER) *
2744     SSL_get0_server_requested_CAs(const SSL *ssl);
2745 
2746 // SSL_CTX_get_client_CA_list returns |ctx|'s client certificate CA list.
2747 OPENSSL_EXPORT STACK_OF(X509_NAME) *
2748     SSL_CTX_get_client_CA_list(const SSL_CTX *ctx);
2749 
2750 // SSL_add_client_CA appends |x509|'s subject to the client certificate CA list.
2751 // It returns one on success or zero on error. The caller retains ownership of
2752 // |x509|.
2753 OPENSSL_EXPORT int SSL_add_client_CA(SSL *ssl, X509 *x509);
2754 
2755 // SSL_CTX_add_client_CA appends |x509|'s subject to the client certificate CA
2756 // list. It returns one on success or zero on error. The caller retains
2757 // ownership of |x509|.
2758 OPENSSL_EXPORT int SSL_CTX_add_client_CA(SSL_CTX *ctx, X509 *x509);
2759 
2760 // SSL_load_client_CA_file opens |file| and reads PEM-encoded certificates from
2761 // it. It returns a newly-allocated stack of the certificate subjects or NULL
2762 // on error. Duplicates in |file| are ignored.
2763 OPENSSL_EXPORT STACK_OF(X509_NAME) *SSL_load_client_CA_file(const char *file);
2764 
2765 // SSL_dup_CA_list makes a deep copy of |list|. It returns the new list on
2766 // success or NULL on allocation error.
2767 OPENSSL_EXPORT STACK_OF(X509_NAME) *SSL_dup_CA_list(STACK_OF(X509_NAME) *list);
2768 
2769 // SSL_add_file_cert_subjects_to_stack behaves like |SSL_load_client_CA_file|
2770 // but appends the result to |out|. It returns one on success or zero on
2771 // error.
2772 OPENSSL_EXPORT int SSL_add_file_cert_subjects_to_stack(STACK_OF(X509_NAME) *out,
2773                                                        const char *file);
2774 
2775 // SSL_add_bio_cert_subjects_to_stack behaves like
2776 // |SSL_add_file_cert_subjects_to_stack| but reads from |bio|.
2777 OPENSSL_EXPORT int SSL_add_bio_cert_subjects_to_stack(STACK_OF(X509_NAME) *out,
2778                                                       BIO *bio);
2779 
2780 
2781 // Server name indication.
2782 //
2783 // The server_name extension (RFC 3546) allows the client to advertise the name
2784 // of the server it is connecting to. This is used in virtual hosting
2785 // deployments to select one of a several certificates on a single IP. Only the
2786 // host_name name type is supported.
2787 
2788 #define TLSEXT_NAMETYPE_host_name 0
2789 
2790 // SSL_set_tlsext_host_name, for a client, configures |ssl| to advertise |name|
2791 // in the server_name extension. It returns one on success and zero on error.
2792 OPENSSL_EXPORT int SSL_set_tlsext_host_name(SSL *ssl, const char *name);
2793 
2794 // SSL_get_servername, for a server, returns the hostname supplied by the
2795 // client or NULL if there was none. The |type| argument must be
2796 // |TLSEXT_NAMETYPE_host_name|.
2797 OPENSSL_EXPORT const char *SSL_get_servername(const SSL *ssl, const int type);
2798 
2799 // SSL_get_servername_type, for a server, returns |TLSEXT_NAMETYPE_host_name|
2800 // if the client sent a hostname and -1 otherwise.
2801 OPENSSL_EXPORT int SSL_get_servername_type(const SSL *ssl);
2802 
2803 // SSL_CTX_set_tlsext_servername_callback configures |callback| to be called on
2804 // the server after ClientHello extensions have been parsed and returns one.
2805 // The callback may use |SSL_get_servername| to examine the server_name
2806 // extension and returns a |SSL_TLSEXT_ERR_*| value. The value of |arg| may be
2807 // set by calling |SSL_CTX_set_tlsext_servername_arg|.
2808 //
2809 // If the callback returns |SSL_TLSEXT_ERR_NOACK|, the server_name extension is
2810 // not acknowledged in the ServerHello. If the return value is
2811 // |SSL_TLSEXT_ERR_ALERT_FATAL|, then |*out_alert| is the alert to send,
2812 // defaulting to |SSL_AD_UNRECOGNIZED_NAME|. |SSL_TLSEXT_ERR_ALERT_WARNING| is
2813 // ignored and treated as |SSL_TLSEXT_ERR_OK|.
2814 OPENSSL_EXPORT int SSL_CTX_set_tlsext_servername_callback(
2815     SSL_CTX *ctx, int (*callback)(SSL *ssl, int *out_alert, void *arg));
2816 
2817 // SSL_CTX_set_tlsext_servername_arg sets the argument to the servername
2818 // callback and returns one. See |SSL_CTX_set_tlsext_servername_callback|.
2819 OPENSSL_EXPORT int SSL_CTX_set_tlsext_servername_arg(SSL_CTX *ctx, void *arg);
2820 
2821 // SSL_TLSEXT_ERR_* are values returned by some extension-related callbacks.
2822 #define SSL_TLSEXT_ERR_OK 0
2823 #define SSL_TLSEXT_ERR_ALERT_WARNING 1
2824 #define SSL_TLSEXT_ERR_ALERT_FATAL 2
2825 #define SSL_TLSEXT_ERR_NOACK 3
2826 
2827 // SSL_set_SSL_CTX changes |ssl|'s |SSL_CTX|. |ssl| will use the
2828 // certificate-related settings from |ctx|, and |SSL_get_SSL_CTX| will report
2829 // |ctx|. This function may be used during the callbacks registered by
2830 // |SSL_CTX_set_select_certificate_cb|,
2831 // |SSL_CTX_set_tlsext_servername_callback|, and |SSL_CTX_set_cert_cb| or when
2832 // the handshake is paused from them. It is typically used to switch
2833 // certificates based on SNI.
2834 //
2835 // Note the session cache and related settings will continue to use the initial
2836 // |SSL_CTX|. Callers should use |SSL_CTX_set_session_id_context| to partition
2837 // the session cache between different domains.
2838 //
2839 // TODO(davidben): Should other settings change after this call?
2840 OPENSSL_EXPORT SSL_CTX *SSL_set_SSL_CTX(SSL *ssl, SSL_CTX *ctx);
2841 
2842 
2843 // Application-layer protocol negotiation.
2844 //
2845 // The ALPN extension (RFC 7301) allows negotiating different application-layer
2846 // protocols over a single port. This is used, for example, to negotiate
2847 // HTTP/2.
2848 
2849 // SSL_CTX_set_alpn_protos sets the client ALPN protocol list on |ctx| to
2850 // |protos|. |protos| must be in wire-format (i.e. a series of non-empty, 8-bit
2851 // length-prefixed strings), or the empty string to disable ALPN. It returns
2852 // zero on success and one on failure. Configuring a non-empty string enables
2853 // ALPN on a client.
2854 //
2855 // WARNING: this function is dangerous because it breaks the usual return value
2856 // convention.
2857 OPENSSL_EXPORT int SSL_CTX_set_alpn_protos(SSL_CTX *ctx, const uint8_t *protos,
2858                                            size_t protos_len);
2859 
2860 // SSL_set_alpn_protos sets the client ALPN protocol list on |ssl| to |protos|.
2861 // |protos| must be in wire-format (i.e. a series of non-empty, 8-bit
2862 // length-prefixed strings), or the empty string to disable ALPN. It returns
2863 // zero on success and one on failure. Configuring a non-empty string enables
2864 // ALPN on a client.
2865 //
2866 // WARNING: this function is dangerous because it breaks the usual return value
2867 // convention.
2868 OPENSSL_EXPORT int SSL_set_alpn_protos(SSL *ssl, const uint8_t *protos,
2869                                        size_t protos_len);
2870 
2871 // SSL_CTX_set_alpn_select_cb sets a callback function on |ctx| that is called
2872 // during ClientHello processing in order to select an ALPN protocol from the
2873 // client's list of offered protocols.
2874 //
2875 // The callback is passed a wire-format (i.e. a series of non-empty, 8-bit
2876 // length-prefixed strings) ALPN protocol list in |in|. To select a protocol,
2877 // the callback should set |*out| and |*out_len| to the selected protocol and
2878 // return |SSL_TLSEXT_ERR_OK| on success. It does not pass ownership of the
2879 // buffer, so |*out| should point to a static string, a buffer that outlives the
2880 // callback call, or the corresponding entry in |in|.
2881 //
2882 // If the server supports ALPN, but there are no protocols in common, the
2883 // callback should return |SSL_TLSEXT_ERR_ALERT_FATAL| to abort the connection
2884 // with a no_application_protocol alert.
2885 //
2886 // If the server does not support ALPN, it can return |SSL_TLSEXT_ERR_NOACK| to
2887 // continue the handshake without negotiating a protocol. This may be useful if
2888 // multiple server configurations share an |SSL_CTX|, only some of which have
2889 // ALPN protocols configured.
2890 //
2891 // |SSL_TLSEXT_ERR_ALERT_WARNING| is ignored and will be treated as
2892 // |SSL_TLSEXT_ERR_NOACK|.
2893 //
2894 // The callback will only be called if the client supports ALPN. Callers that
2895 // wish to require ALPN for all clients must check |SSL_get0_alpn_selected|
2896 // after the handshake. In QUIC connections, this is done automatically.
2897 //
2898 // The cipher suite is selected before negotiating ALPN. The callback may use
2899 // |SSL_get_pending_cipher| to query the cipher suite. This may be used to
2900 // implement HTTP/2's cipher suite constraints.
2901 OPENSSL_EXPORT void SSL_CTX_set_alpn_select_cb(
2902     SSL_CTX *ctx, int (*cb)(SSL *ssl, const uint8_t **out, uint8_t *out_len,
2903                             const uint8_t *in, unsigned in_len, void *arg),
2904     void *arg);
2905 
2906 // SSL_get0_alpn_selected gets the selected ALPN protocol (if any) from |ssl|.
2907 // On return it sets |*out_data| to point to |*out_len| bytes of protocol name
2908 // (not including the leading length-prefix byte). If the server didn't respond
2909 // with a negotiated protocol then |*out_len| will be zero.
2910 OPENSSL_EXPORT void SSL_get0_alpn_selected(const SSL *ssl,
2911                                            const uint8_t **out_data,
2912                                            unsigned *out_len);
2913 
2914 // SSL_CTX_set_allow_unknown_alpn_protos configures client connections on |ctx|
2915 // to allow unknown ALPN protocols from the server. Otherwise, by default, the
2916 // client will require that the protocol be advertised in
2917 // |SSL_CTX_set_alpn_protos|.
2918 OPENSSL_EXPORT void SSL_CTX_set_allow_unknown_alpn_protos(SSL_CTX *ctx,
2919                                                           int enabled);
2920 
2921 
2922 // Application-layer protocol settings
2923 //
2924 // The ALPS extension (draft-vvv-tls-alps) allows exchanging application-layer
2925 // settings in the TLS handshake for applications negotiated with ALPN. Note
2926 // that, when ALPS is negotiated, the client and server each advertise their own
2927 // settings, so there are functions to both configure setting to send and query
2928 // received settings.
2929 
2930 // SSL_add_application_settings configures |ssl| to enable ALPS with ALPN
2931 // protocol |proto|, sending an ALPS value of |settings|. It returns one on
2932 // success and zero on error. If |proto| is negotiated via ALPN and the peer
2933 // supports ALPS, |settings| will be sent to the peer. The peer's ALPS value can
2934 // be retrieved with |SSL_get0_peer_application_settings|.
2935 //
2936 // On the client, this function should be called before the handshake, once for
2937 // each supported ALPN protocol which uses ALPS. |proto| must be included in the
2938 // client's ALPN configuration (see |SSL_CTX_set_alpn_protos| and
2939 // |SSL_set_alpn_protos|). On the server, ALPS can be preconfigured for each
2940 // protocol as in the client, or configuration can be deferred to the ALPN
2941 // callback (see |SSL_CTX_set_alpn_select_cb|), in which case only the selected
2942 // protocol needs to be configured.
2943 //
2944 // ALPS can be independently configured from 0-RTT, however changes in protocol
2945 // settings will fallback to 1-RTT to negotiate the new value, so it is
2946 // recommended for |settings| to be relatively stable.
2947 OPENSSL_EXPORT int SSL_add_application_settings(SSL *ssl, const uint8_t *proto,
2948                                                 size_t proto_len,
2949                                                 const uint8_t *settings,
2950                                                 size_t settings_len);
2951 
2952 // SSL_get0_peer_application_settings sets |*out_data| and |*out_len| to a
2953 // buffer containing the peer's ALPS value, or the empty string if ALPS was not
2954 // negotiated. Note an empty string could also indicate the peer sent an empty
2955 // settings value. Use |SSL_has_application_settings| to check if ALPS was
2956 // negotiated. The output buffer is owned by |ssl| and is valid until the next
2957 // time |ssl| is modified.
2958 OPENSSL_EXPORT void SSL_get0_peer_application_settings(const SSL *ssl,
2959                                                        const uint8_t **out_data,
2960                                                        size_t *out_len);
2961 
2962 // SSL_has_application_settings returns one if ALPS was negotiated on this
2963 // connection and zero otherwise.
2964 OPENSSL_EXPORT int SSL_has_application_settings(const SSL *ssl);
2965 
2966 
2967 // Certificate compression.
2968 //
2969 // Certificates in TLS 1.3 can be compressed (RFC 8879). BoringSSL supports this
2970 // as both a client and a server, but does not link against any specific
2971 // compression libraries in order to keep dependencies to a minimum. Instead,
2972 // hooks for compression and decompression can be installed in an |SSL_CTX| to
2973 // enable support.
2974 
2975 // ssl_cert_compression_func_t is a pointer to a function that performs
2976 // compression. It must write the compressed representation of |in| to |out|,
2977 // returning one on success and zero on error. The results of compressing
2978 // certificates are not cached internally. Implementations may wish to implement
2979 // their own cache if they expect it to be useful given the certificates that
2980 // they serve.
2981 typedef int (*ssl_cert_compression_func_t)(SSL *ssl, CBB *out,
2982                                            const uint8_t *in, size_t in_len);
2983 
2984 // ssl_cert_decompression_func_t is a pointer to a function that performs
2985 // decompression. The compressed data from the peer is passed as |in| and the
2986 // decompressed result must be exactly |uncompressed_len| bytes long. It returns
2987 // one on success, in which case |*out| must be set to the result of
2988 // decompressing |in|, or zero on error. Setting |*out| transfers ownership,
2989 // i.e. |CRYPTO_BUFFER_free| will be called on |*out| at some point in the
2990 // future. The results of decompressions are not cached internally.
2991 // Implementations may wish to implement their own cache if they expect it to be
2992 // useful.
2993 typedef int (*ssl_cert_decompression_func_t)(SSL *ssl, CRYPTO_BUFFER **out,
2994                                              size_t uncompressed_len,
2995                                              const uint8_t *in, size_t in_len);
2996 
2997 // SSL_CTX_add_cert_compression_alg registers a certificate compression
2998 // algorithm on |ctx| with ID |alg_id|. (The value of |alg_id| should be an IANA
2999 // assigned value and each can only be registered once.)
3000 //
3001 // One of the function pointers may be NULL to avoid having to implement both
3002 // sides of a compression algorithm if you're only going to use it in one
3003 // direction. In this case, the unimplemented direction acts like it was never
3004 // configured.
3005 //
3006 // For a server, algorithms are registered in preference order with the most
3007 // preferable first. It returns one on success or zero on error.
3008 OPENSSL_EXPORT int SSL_CTX_add_cert_compression_alg(
3009     SSL_CTX *ctx, uint16_t alg_id, ssl_cert_compression_func_t compress,
3010     ssl_cert_decompression_func_t decompress);
3011 
3012 
3013 // Next protocol negotiation.
3014 //
3015 // The NPN extension (draft-agl-tls-nextprotoneg-03) is the predecessor to ALPN
3016 // and deprecated in favor of it.
3017 
3018 // SSL_CTX_set_next_protos_advertised_cb sets a callback that is called when a
3019 // TLS server needs a list of supported protocols for Next Protocol
3020 // Negotiation. The returned list must be in wire format. The list is returned
3021 // by setting |*out| to point to it and |*out_len| to its length. This memory
3022 // will not be modified, but one should assume that |ssl| keeps a reference to
3023 // it.
3024 //
3025 // The callback should return |SSL_TLSEXT_ERR_OK| if it wishes to advertise.
3026 // Otherwise, no such extension will be included in the ServerHello.
3027 OPENSSL_EXPORT void SSL_CTX_set_next_protos_advertised_cb(
3028     SSL_CTX *ctx,
3029     int (*cb)(SSL *ssl, const uint8_t **out, unsigned *out_len, void *arg),
3030     void *arg);
3031 
3032 // SSL_CTX_set_next_proto_select_cb sets a callback that is called when a client
3033 // needs to select a protocol from the server's provided list. |*out| must be
3034 // set to point to the selected protocol (which may be within |in|). The length
3035 // of the protocol name must be written into |*out_len|. The server's advertised
3036 // protocols are provided in |in| and |in_len|. The callback can assume that
3037 // |in| is syntactically valid.
3038 //
3039 // The client must select a protocol. It is fatal to the connection if this
3040 // callback returns a value other than |SSL_TLSEXT_ERR_OK|.
3041 //
3042 // Configuring this callback enables NPN on a client.
3043 OPENSSL_EXPORT void SSL_CTX_set_next_proto_select_cb(
3044     SSL_CTX *ctx, int (*cb)(SSL *ssl, uint8_t **out, uint8_t *out_len,
3045                             const uint8_t *in, unsigned in_len, void *arg),
3046     void *arg);
3047 
3048 // SSL_get0_next_proto_negotiated sets |*out_data| and |*out_len| to point to
3049 // the client's requested protocol for this connection. If the client didn't
3050 // request any protocol, then |*out_data| is set to NULL.
3051 //
3052 // Note that the client can request any protocol it chooses. The value returned
3053 // from this function need not be a member of the list of supported protocols
3054 // provided by the server.
3055 OPENSSL_EXPORT void SSL_get0_next_proto_negotiated(const SSL *ssl,
3056                                                    const uint8_t **out_data,
3057                                                    unsigned *out_len);
3058 
3059 // SSL_select_next_proto implements the standard protocol selection. It is
3060 // expected that this function is called from the callback set by
3061 // |SSL_CTX_set_next_proto_select_cb|.
3062 //
3063 // |peer| and |supported| must be vectors of 8-bit, length-prefixed byte strings
3064 // containing the peer and locally-configured protocols, respectively. The
3065 // length byte itself is not included in the length. A byte string of length 0
3066 // is invalid. No byte string may be truncated. |supported| is assumed to be
3067 // non-empty.
3068 //
3069 // This function finds the first protocol in |peer| which is also in
3070 // |supported|. If one was found, it sets |*out| and |*out_len| to point to it
3071 // and returns |OPENSSL_NPN_NEGOTIATED|. Otherwise, it returns
3072 // |OPENSSL_NPN_NO_OVERLAP| and sets |*out| and |*out_len| to the first
3073 // supported protocol.
3074 OPENSSL_EXPORT int SSL_select_next_proto(uint8_t **out, uint8_t *out_len,
3075                                          const uint8_t *peer, unsigned peer_len,
3076                                          const uint8_t *supported,
3077                                          unsigned supported_len);
3078 
3079 #define OPENSSL_NPN_UNSUPPORTED 0
3080 #define OPENSSL_NPN_NEGOTIATED 1
3081 #define OPENSSL_NPN_NO_OVERLAP 2
3082 
3083 
3084 // Channel ID.
3085 //
3086 // See draft-balfanz-tls-channelid-01. This is an old, experimental mechanism
3087 // and should not be used in new code.
3088 
3089 // SSL_CTX_set_tls_channel_id_enabled configures whether connections associated
3090 // with |ctx| should enable Channel ID as a server.
3091 OPENSSL_EXPORT void SSL_CTX_set_tls_channel_id_enabled(SSL_CTX *ctx,
3092                                                        int enabled);
3093 
3094 // SSL_set_tls_channel_id_enabled configures whether |ssl| should enable Channel
3095 // ID as a server.
3096 OPENSSL_EXPORT void SSL_set_tls_channel_id_enabled(SSL *ssl, int enabled);
3097 
3098 // SSL_CTX_set1_tls_channel_id configures a TLS client to send a TLS Channel ID
3099 // to compatible servers. |private_key| must be a P-256 EC key. It returns one
3100 // on success and zero on error.
3101 OPENSSL_EXPORT int SSL_CTX_set1_tls_channel_id(SSL_CTX *ctx,
3102                                                EVP_PKEY *private_key);
3103 
3104 // SSL_set1_tls_channel_id configures a TLS client to send a TLS Channel ID to
3105 // compatible servers. |private_key| must be a P-256 EC key. It returns one on
3106 // success and zero on error.
3107 OPENSSL_EXPORT int SSL_set1_tls_channel_id(SSL *ssl, EVP_PKEY *private_key);
3108 
3109 // SSL_get_tls_channel_id gets the client's TLS Channel ID from a server |SSL|
3110 // and copies up to the first |max_out| bytes into |out|. The Channel ID
3111 // consists of the client's P-256 public key as an (x,y) pair where each is a
3112 // 32-byte, big-endian field element. It returns 0 if the client didn't offer a
3113 // Channel ID and the length of the complete Channel ID otherwise. This function
3114 // always returns zero if |ssl| is a client.
3115 OPENSSL_EXPORT size_t SSL_get_tls_channel_id(SSL *ssl, uint8_t *out,
3116                                              size_t max_out);
3117 
3118 
3119 // DTLS-SRTP.
3120 //
3121 // See RFC 5764.
3122 
3123 // srtp_protection_profile_st (aka |SRTP_PROTECTION_PROFILE|) is an SRTP
3124 // profile for use with the use_srtp extension.
3125 struct srtp_protection_profile_st {
3126   const char *name;
3127   unsigned long id;
3128 } /* SRTP_PROTECTION_PROFILE */;
3129 
3130 DEFINE_CONST_STACK_OF(SRTP_PROTECTION_PROFILE)
3131 
3132 // SRTP_* define constants for SRTP profiles.
3133 #define SRTP_AES128_CM_SHA1_80 0x0001
3134 #define SRTP_AES128_CM_SHA1_32 0x0002
3135 #define SRTP_AES128_F8_SHA1_80 0x0003
3136 #define SRTP_AES128_F8_SHA1_32 0x0004
3137 #define SRTP_NULL_SHA1_80      0x0005
3138 #define SRTP_NULL_SHA1_32      0x0006
3139 #define SRTP_AEAD_AES_128_GCM  0x0007
3140 #define SRTP_AEAD_AES_256_GCM  0x0008
3141 
3142 // SSL_CTX_set_srtp_profiles enables SRTP for all SSL objects created from
3143 // |ctx|. |profile| contains a colon-separated list of profile names. It returns
3144 // one on success and zero on failure.
3145 OPENSSL_EXPORT int SSL_CTX_set_srtp_profiles(SSL_CTX *ctx,
3146                                              const char *profiles);
3147 
3148 // SSL_set_srtp_profiles enables SRTP for |ssl|.  |profile| contains a
3149 // colon-separated list of profile names. It returns one on success and zero on
3150 // failure.
3151 OPENSSL_EXPORT int SSL_set_srtp_profiles(SSL *ssl, const char *profiles);
3152 
3153 // SSL_get_srtp_profiles returns the SRTP profiles supported by |ssl|.
3154 OPENSSL_EXPORT const STACK_OF(SRTP_PROTECTION_PROFILE) *SSL_get_srtp_profiles(
3155     const SSL *ssl);
3156 
3157 // SSL_get_selected_srtp_profile returns the selected SRTP profile, or NULL if
3158 // SRTP was not negotiated.
3159 OPENSSL_EXPORT const SRTP_PROTECTION_PROFILE *SSL_get_selected_srtp_profile(
3160     SSL *ssl);
3161 
3162 
3163 // Pre-shared keys.
3164 //
3165 // Connections may be configured with PSK (Pre-Shared Key) cipher suites. These
3166 // authenticate using out-of-band pre-shared keys rather than certificates. See
3167 // RFC 4279.
3168 //
3169 // This implementation uses NUL-terminated C strings for identities and identity
3170 // hints, so values with a NUL character are not supported. (RFC 4279 does not
3171 // specify the format of an identity.)
3172 
3173 // PSK_MAX_IDENTITY_LEN is the maximum supported length of a PSK identity,
3174 // excluding the NUL terminator.
3175 #define PSK_MAX_IDENTITY_LEN 128
3176 
3177 // PSK_MAX_PSK_LEN is the maximum supported length of a pre-shared key.
3178 #define PSK_MAX_PSK_LEN 256
3179 
3180 // SSL_CTX_set_psk_client_callback sets the callback to be called when PSK is
3181 // negotiated on the client. This callback must be set to enable PSK cipher
3182 // suites on the client.
3183 //
3184 // The callback is passed the identity hint in |hint| or NULL if none was
3185 // provided. It should select a PSK identity and write the identity and the
3186 // corresponding PSK to |identity| and |psk|, respectively. The identity is
3187 // written as a NUL-terminated C string of length (excluding the NUL terminator)
3188 // at most |max_identity_len|. The PSK's length must be at most |max_psk_len|.
3189 // The callback returns the length of the PSK or 0 if no suitable identity was
3190 // found.
3191 OPENSSL_EXPORT void SSL_CTX_set_psk_client_callback(
3192     SSL_CTX *ctx, unsigned (*cb)(SSL *ssl, const char *hint, char *identity,
3193                                  unsigned max_identity_len, uint8_t *psk,
3194                                  unsigned max_psk_len));
3195 
3196 // SSL_set_psk_client_callback sets the callback to be called when PSK is
3197 // negotiated on the client. This callback must be set to enable PSK cipher
3198 // suites on the client. See also |SSL_CTX_set_psk_client_callback|.
3199 OPENSSL_EXPORT void SSL_set_psk_client_callback(
3200     SSL *ssl, unsigned (*cb)(SSL *ssl, const char *hint, char *identity,
3201                              unsigned max_identity_len, uint8_t *psk,
3202                              unsigned max_psk_len));
3203 
3204 // SSL_CTX_set_psk_server_callback sets the callback to be called when PSK is
3205 // negotiated on the server. This callback must be set to enable PSK cipher
3206 // suites on the server.
3207 //
3208 // The callback is passed the identity in |identity|. It should write a PSK of
3209 // length at most |max_psk_len| to |psk| and return the number of bytes written
3210 // or zero if the PSK identity is unknown.
3211 OPENSSL_EXPORT void SSL_CTX_set_psk_server_callback(
3212     SSL_CTX *ctx, unsigned (*cb)(SSL *ssl, const char *identity, uint8_t *psk,
3213                                  unsigned max_psk_len));
3214 
3215 // SSL_set_psk_server_callback sets the callback to be called when PSK is
3216 // negotiated on the server. This callback must be set to enable PSK cipher
3217 // suites on the server. See also |SSL_CTX_set_psk_server_callback|.
3218 OPENSSL_EXPORT void SSL_set_psk_server_callback(
3219     SSL *ssl, unsigned (*cb)(SSL *ssl, const char *identity, uint8_t *psk,
3220                              unsigned max_psk_len));
3221 
3222 // SSL_CTX_use_psk_identity_hint configures server connections to advertise an
3223 // identity hint of |identity_hint|. It returns one on success and zero on
3224 // error.
3225 OPENSSL_EXPORT int SSL_CTX_use_psk_identity_hint(SSL_CTX *ctx,
3226                                                  const char *identity_hint);
3227 
3228 // SSL_use_psk_identity_hint configures server connections to advertise an
3229 // identity hint of |identity_hint|. It returns one on success and zero on
3230 // error.
3231 OPENSSL_EXPORT int SSL_use_psk_identity_hint(SSL *ssl,
3232                                              const char *identity_hint);
3233 
3234 // SSL_get_psk_identity_hint returns the PSK identity hint advertised for |ssl|
3235 // or NULL if there is none.
3236 OPENSSL_EXPORT const char *SSL_get_psk_identity_hint(const SSL *ssl);
3237 
3238 // SSL_get_psk_identity, after the handshake completes, returns the PSK identity
3239 // that was negotiated by |ssl| or NULL if PSK was not used.
3240 OPENSSL_EXPORT const char *SSL_get_psk_identity(const SSL *ssl);
3241 
3242 
3243 // Delegated credentials.
3244 //
3245 // *** EXPERIMENTAL — PRONE TO CHANGE ***
3246 //
3247 // draft-ietf-tls-subcerts is a proposed extension for TLS 1.3 and above that
3248 // allows an end point to use its certificate to delegate credentials for
3249 // authentication. If the peer indicates support for this extension, then this
3250 // host may use a delegated credential to sign the handshake. Once issued,
3251 // credentials can't be revoked. In order to mitigate the damage in case the
3252 // credential secret key is compromised, the credential is only valid for a
3253 // short time (days, hours, or even minutes). This library implements draft-03
3254 // of the protocol spec.
3255 //
3256 // The extension ID has not been assigned; we're using 0xff02 for the time
3257 // being. Currently only the server side is implemented.
3258 //
3259 // Servers configure a DC for use in the handshake via
3260 // |SSL_set1_delegated_credential|. It must be signed by the host's end-entity
3261 // certificate as defined in draft-ietf-tls-subcerts-03.
3262 
3263 // SSL_set1_delegated_credential configures the delegated credential (DC) that
3264 // will be sent to the peer for the current connection. |dc| is the DC in wire
3265 // format, and |pkey| or |key_method| is the corresponding private key.
3266 // Currently (as of draft-03), only servers may configure a DC to use in the
3267 // handshake.
3268 //
3269 // The DC will only be used if the protocol version is correct and the signature
3270 // scheme is supported by the peer. If not, the DC will not be negotiated and
3271 // the handshake will use the private key (or private key method) associated
3272 // with the certificate.
3273 OPENSSL_EXPORT int SSL_set1_delegated_credential(
3274     SSL *ssl, CRYPTO_BUFFER *dc, EVP_PKEY *pkey,
3275     const SSL_PRIVATE_KEY_METHOD *key_method);
3276 
3277 // SSL_delegated_credential_used returns one if a delegated credential was used
3278 // and zero otherwise.
3279 OPENSSL_EXPORT int SSL_delegated_credential_used(const SSL *ssl);
3280 
3281 
3282 // QUIC integration.
3283 //
3284 // QUIC acts as an underlying transport for the TLS 1.3 handshake. The following
3285 // functions allow a QUIC implementation to serve as the underlying transport as
3286 // described in RFC 9001.
3287 //
3288 // When configured for QUIC, |SSL_do_handshake| will drive the handshake as
3289 // before, but it will not use the configured |BIO|. It will call functions on
3290 // |SSL_QUIC_METHOD| to configure secrets and send data. If data is needed from
3291 // the peer, it will return |SSL_ERROR_WANT_READ|. As the caller receives data
3292 // it can decrypt, it calls |SSL_provide_quic_data|. Subsequent
3293 // |SSL_do_handshake| calls will then consume that data and progress the
3294 // handshake. After the handshake is complete, the caller should continue to
3295 // call |SSL_provide_quic_data| for any post-handshake data, followed by
3296 // |SSL_process_quic_post_handshake| to process it. It is an error to call
3297 // |SSL_read| and |SSL_write| in QUIC.
3298 //
3299 // 0-RTT behaves similarly to |TLS_method|'s usual behavior. |SSL_do_handshake|
3300 // returns early as soon as the client (respectively, server) is allowed to send
3301 // 0-RTT (respectively, half-RTT) data. The caller should then call
3302 // |SSL_do_handshake| again to consume the remaining handshake messages and
3303 // confirm the handshake. As a client, |SSL_ERROR_EARLY_DATA_REJECTED| and
3304 // |SSL_reset_early_data_reject| behave as usual.
3305 //
3306 // See https://www.rfc-editor.org/rfc/rfc9001.html#section-4.1 for more details.
3307 //
3308 // To avoid DoS attacks, the QUIC implementation must limit the amount of data
3309 // being queued up. The implementation can call
3310 // |SSL_quic_max_handshake_flight_len| to get the maximum buffer length at each
3311 // encryption level.
3312 //
3313 // QUIC implementations must additionally configure transport parameters with
3314 // |SSL_set_quic_transport_params|. |SSL_get_peer_quic_transport_params| may be
3315 // used to query the value received from the peer. BoringSSL handles this
3316 // extension as an opaque byte string. The caller is responsible for serializing
3317 // and parsing them. See https://www.rfc-editor.org/rfc/rfc9000#section-7.4 for
3318 // details.
3319 //
3320 // QUIC additionally imposes restrictions on 0-RTT. In particular, the QUIC
3321 // transport layer requires that if a server accepts 0-RTT data, then the
3322 // transport parameters sent on the resumed connection must not lower any limits
3323 // compared to the transport parameters that the server sent on the connection
3324 // where the ticket for 0-RTT was issued. In effect, the server must remember
3325 // the transport parameters with the ticket. Application protocols running on
3326 // QUIC may impose similar restrictions, for example HTTP/3's restrictions on
3327 // SETTINGS frames.
3328 //
3329 // BoringSSL implements this check by doing a byte-for-byte comparison of an
3330 // opaque context passed in by the server. This context must be the same on the
3331 // connection where the ticket was issued and the connection where that ticket
3332 // is used for 0-RTT. If there is a mismatch, or the context was not set,
3333 // BoringSSL will reject early data (but not reject the resumption attempt).
3334 // This context is set via |SSL_set_quic_early_data_context| and should cover
3335 // both transport parameters and any application state.
3336 // |SSL_set_quic_early_data_context| must be called on the server with a
3337 // non-empty context if the server is to support 0-RTT in QUIC.
3338 //
3339 // BoringSSL does not perform any client-side checks on the transport
3340 // parameters received from a server that also accepted early data. It is up to
3341 // the caller to verify that the received transport parameters do not lower any
3342 // limits, and to close the QUIC connection if that is not the case. The same
3343 // holds for any application protocol state remembered for 0-RTT, e.g. HTTP/3
3344 // SETTINGS.
3345 
3346 // ssl_encryption_level_t represents a specific QUIC encryption level used to
3347 // transmit handshake messages.
3348 enum ssl_encryption_level_t BORINGSSL_ENUM_INT {
3349   ssl_encryption_initial = 0,
3350   ssl_encryption_early_data,
3351   ssl_encryption_handshake,
3352   ssl_encryption_application,
3353 };
3354 
3355 // ssl_quic_method_st (aka |SSL_QUIC_METHOD|) describes custom QUIC hooks.
3356 struct ssl_quic_method_st {
3357   // set_read_secret configures the read secret and cipher suite for the given
3358   // encryption level. It returns one on success and zero to terminate the
3359   // handshake with an error. It will be called at most once per encryption
3360   // level.
3361   //
3362   // BoringSSL will not release read keys before QUIC may use them. Once a level
3363   // has been initialized, QUIC may begin processing data from it. Handshake
3364   // data should be passed to |SSL_provide_quic_data| and application data (if
3365   // |level| is |ssl_encryption_early_data| or |ssl_encryption_application|) may
3366   // be processed according to the rules of the QUIC protocol.
3367   //
3368   // QUIC ACKs packets at the same encryption level they were received at,
3369   // except that client |ssl_encryption_early_data| (0-RTT) packets trigger
3370   // server |ssl_encryption_application| (1-RTT) ACKs. BoringSSL will always
3371   // install ACK-writing keys with |set_write_secret| before the packet-reading
3372   // keys with |set_read_secret|. This ensures the caller can always ACK any
3373   // packet it decrypts. Note this means the server installs 1-RTT write keys
3374   // before 0-RTT read keys.
3375   //
3376   // The converse is not true. An encryption level may be configured with write
3377   // secrets a roundtrip before the corresponding secrets for reading ACKs is
3378   // available.
3379   int (*set_read_secret)(SSL *ssl, enum ssl_encryption_level_t level,
3380                          const SSL_CIPHER *cipher, const uint8_t *secret,
3381                          size_t secret_len);
3382   // set_write_secret behaves like |set_read_secret| but configures the write
3383   // secret and cipher suite for the given encryption level. It will be called
3384   // at most once per encryption level.
3385   //
3386   // BoringSSL will not release write keys before QUIC may use them. If |level|
3387   // is |ssl_encryption_early_data| or |ssl_encryption_application|, QUIC may
3388   // begin sending application data at |level|. However, note that BoringSSL
3389   // configures server |ssl_encryption_application| write keys before the client
3390   // Finished. This allows QUIC to send half-RTT data, but the handshake is not
3391   // confirmed at this point and, if requesting client certificates, the client
3392   // is not yet authenticated.
3393   //
3394   // See |set_read_secret| for additional invariants between packets and their
3395   // ACKs.
3396   //
3397   // Note that, on 0-RTT reject, the |ssl_encryption_early_data| write secret
3398   // may use a different cipher suite from the other keys.
3399   int (*set_write_secret)(SSL *ssl, enum ssl_encryption_level_t level,
3400                           const SSL_CIPHER *cipher, const uint8_t *secret,
3401                           size_t secret_len);
3402   // add_handshake_data adds handshake data to the current flight at the given
3403   // encryption level. It returns one on success and zero on error.
3404   //
3405   // BoringSSL will pack data from a single encryption level together, but a
3406   // single handshake flight may include multiple encryption levels. Callers
3407   // should defer writing data to the network until |flush_flight| to better
3408   // pack QUIC packets into transport datagrams.
3409   //
3410   // If |level| is not |ssl_encryption_initial|, this function will not be
3411   // called before |level| is initialized with |set_write_secret|.
3412   int (*add_handshake_data)(SSL *ssl, enum ssl_encryption_level_t level,
3413                             const uint8_t *data, size_t len);
3414   // flush_flight is called when the current flight is complete and should be
3415   // written to the transport. Note a flight may contain data at several
3416   // encryption levels. It returns one on success and zero on error.
3417   int (*flush_flight)(SSL *ssl);
3418   // send_alert sends a fatal alert at the specified encryption level. It
3419   // returns one on success and zero on error.
3420   //
3421   // If |level| is not |ssl_encryption_initial|, this function will not be
3422   // called before |level| is initialized with |set_write_secret|.
3423   int (*send_alert)(SSL *ssl, enum ssl_encryption_level_t level, uint8_t alert);
3424 };
3425 
3426 // SSL_quic_max_handshake_flight_len returns returns the maximum number of bytes
3427 // that may be received at the given encryption level. This function should be
3428 // used to limit buffering in the QUIC implementation.
3429 //
3430 // See https://www.rfc-editor.org/rfc/rfc9000#section-7.5
3431 OPENSSL_EXPORT size_t SSL_quic_max_handshake_flight_len(
3432     const SSL *ssl, enum ssl_encryption_level_t level);
3433 
3434 // SSL_quic_read_level returns the current read encryption level.
3435 //
3436 // TODO(davidben): Is it still necessary to expose this function to callers?
3437 // QUICHE does not use it.
3438 OPENSSL_EXPORT enum ssl_encryption_level_t SSL_quic_read_level(const SSL *ssl);
3439 
3440 // SSL_quic_write_level returns the current write encryption level.
3441 //
3442 // TODO(davidben): Is it still necessary to expose this function to callers?
3443 // QUICHE does not use it.
3444 OPENSSL_EXPORT enum ssl_encryption_level_t SSL_quic_write_level(const SSL *ssl);
3445 
3446 // SSL_provide_quic_data provides data from QUIC at a particular encryption
3447 // level |level|. It returns one on success and zero on error. Note this
3448 // function will return zero if the handshake is not expecting data from |level|
3449 // at this time. The QUIC implementation should then close the connection with
3450 // an error.
3451 OPENSSL_EXPORT int SSL_provide_quic_data(SSL *ssl,
3452                                          enum ssl_encryption_level_t level,
3453                                          const uint8_t *data, size_t len);
3454 
3455 
3456 // SSL_process_quic_post_handshake processes any data that QUIC has provided
3457 // after the handshake has completed. This includes NewSessionTicket messages
3458 // sent by the server. It returns one on success and zero on error.
3459 OPENSSL_EXPORT int SSL_process_quic_post_handshake(SSL *ssl);
3460 
3461 // SSL_CTX_set_quic_method configures the QUIC hooks. This should only be
3462 // configured with a minimum version of TLS 1.3. |quic_method| must remain valid
3463 // for the lifetime of |ctx|. It returns one on success and zero on error.
3464 OPENSSL_EXPORT int SSL_CTX_set_quic_method(SSL_CTX *ctx,
3465                                            const SSL_QUIC_METHOD *quic_method);
3466 
3467 // SSL_set_quic_method configures the QUIC hooks. This should only be
3468 // configured with a minimum version of TLS 1.3. |quic_method| must remain valid
3469 // for the lifetime of |ssl|. It returns one on success and zero on error.
3470 OPENSSL_EXPORT int SSL_set_quic_method(SSL *ssl,
3471                                        const SSL_QUIC_METHOD *quic_method);
3472 
3473 // SSL_set_quic_transport_params configures |ssl| to send |params| (of length
3474 // |params_len|) in the quic_transport_parameters extension in either the
3475 // ClientHello or EncryptedExtensions handshake message. It is an error to set
3476 // transport parameters if |ssl| is not configured for QUIC. The buffer pointed
3477 // to by |params| only need be valid for the duration of the call to this
3478 // function. This function returns 1 on success and 0 on failure.
3479 OPENSSL_EXPORT int SSL_set_quic_transport_params(SSL *ssl,
3480                                                  const uint8_t *params,
3481                                                  size_t params_len);
3482 
3483 // SSL_get_peer_quic_transport_params provides the caller with the value of the
3484 // quic_transport_parameters extension sent by the peer. A pointer to the buffer
3485 // containing the TransportParameters will be put in |*out_params|, and its
3486 // length in |*params_len|. This buffer will be valid for the lifetime of the
3487 // |SSL|. If no params were received from the peer, |*out_params_len| will be 0.
3488 OPENSSL_EXPORT void SSL_get_peer_quic_transport_params(
3489     const SSL *ssl, const uint8_t **out_params, size_t *out_params_len);
3490 
3491 // SSL_set_quic_use_legacy_codepoint configures whether to use the legacy QUIC
3492 // extension codepoint 0xffa5 as opposed to the official value 57. Call with
3493 // |use_legacy| set to 1 to use 0xffa5 and call with 0 to use 57. By default,
3494 // the standard code point is used.
3495 OPENSSL_EXPORT void SSL_set_quic_use_legacy_codepoint(SSL *ssl, int use_legacy);
3496 
3497 // SSL_set_quic_early_data_context configures a context string in QUIC servers
3498 // for accepting early data. If a resumption connection offers early data, the
3499 // server will check if the value matches that of the connection which minted
3500 // the ticket. If not, resumption still succeeds but early data is rejected.
3501 // This should include all QUIC Transport Parameters except ones specified that
3502 // the client MUST NOT remember. This should also include any application
3503 // protocol-specific state. For HTTP/3, this should be the serialized server
3504 // SETTINGS frame and the QUIC Transport Parameters (except the stateless reset
3505 // token).
3506 //
3507 // This function may be called before |SSL_do_handshake| or during server
3508 // certificate selection. It returns 1 on success and 0 on failure.
3509 OPENSSL_EXPORT int SSL_set_quic_early_data_context(SSL *ssl,
3510                                                    const uint8_t *context,
3511                                                    size_t context_len);
3512 
3513 
3514 // Early data.
3515 //
3516 // WARNING: 0-RTT support in BoringSSL is currently experimental and not fully
3517 // implemented. It may cause interoperability or security failures when used.
3518 //
3519 // Early data, or 0-RTT, is a feature in TLS 1.3 which allows clients to send
3520 // data on the first flight during a resumption handshake. This can save a
3521 // round-trip in some application protocols.
3522 //
3523 // WARNING: A 0-RTT handshake has different security properties from normal
3524 // handshake, so it is off by default unless opted in. In particular, early data
3525 // is replayable by a network attacker. Callers must account for this when
3526 // sending or processing data before the handshake is confirmed. See RFC 8446
3527 // for more information.
3528 //
3529 // As a server, if early data is accepted, |SSL_do_handshake| will complete as
3530 // soon as the ClientHello is processed and server flight sent. |SSL_write| may
3531 // be used to send half-RTT data. |SSL_read| will consume early data and
3532 // transition to 1-RTT data as appropriate. Prior to the transition,
3533 // |SSL_in_init| will report the handshake is still in progress. Callers may use
3534 // it or |SSL_in_early_data| to defer or reject requests as needed.
3535 //
3536 // Early data as a client is more complex. If the offered session (see
3537 // |SSL_set_session|) is 0-RTT-capable, the handshake will return after sending
3538 // the ClientHello. The predicted peer certificates and ALPN protocol will be
3539 // available via the usual APIs. |SSL_write| will write early data, up to the
3540 // session's limit. Writes past this limit and |SSL_read| will complete the
3541 // handshake before continuing. Callers may also call |SSL_do_handshake| again
3542 // to complete the handshake sooner.
3543 //
3544 // If the server accepts early data, the handshake will succeed. |SSL_read| and
3545 // |SSL_write| will then act as in a 1-RTT handshake. The peer certificates and
3546 // ALPN protocol will be as predicted and need not be re-queried.
3547 //
3548 // If the server rejects early data, |SSL_do_handshake| (and thus |SSL_read| and
3549 // |SSL_write|) will then fail with |SSL_get_error| returning
3550 // |SSL_ERROR_EARLY_DATA_REJECTED|. The caller should treat this as a connection
3551 // error and most likely perform a high-level retry. Note the server may still
3552 // have processed the early data due to attacker replays.
3553 //
3554 // To then continue the handshake on the original connection, use
3555 // |SSL_reset_early_data_reject|. The connection will then behave as one which
3556 // had not yet completed the handshake. This allows a faster retry than making a
3557 // fresh connection. |SSL_do_handshake| will complete the full handshake,
3558 // possibly resulting in different peer certificates, ALPN protocol, and other
3559 // properties. The caller must disregard any values from before the reset and
3560 // query again.
3561 //
3562 // Finally, to implement the fallback described in RFC 8446 appendix D.3, retry
3563 // on a fresh connection without 0-RTT if the handshake fails with
3564 // |SSL_R_WRONG_VERSION_ON_EARLY_DATA|.
3565 
3566 // SSL_CTX_set_early_data_enabled sets whether early data is allowed to be used
3567 // with resumptions using |ctx|.
3568 OPENSSL_EXPORT void SSL_CTX_set_early_data_enabled(SSL_CTX *ctx, int enabled);
3569 
3570 // SSL_set_early_data_enabled sets whether early data is allowed to be used
3571 // with resumptions using |ssl|. See |SSL_CTX_set_early_data_enabled| for more
3572 // information.
3573 OPENSSL_EXPORT void SSL_set_early_data_enabled(SSL *ssl, int enabled);
3574 
3575 // SSL_in_early_data returns one if |ssl| has a pending handshake that has
3576 // progressed enough to send or receive early data. Clients may call |SSL_write|
3577 // to send early data, but |SSL_read| will complete the handshake before
3578 // accepting application data. Servers may call |SSL_read| to read early data
3579 // and |SSL_write| to send half-RTT data.
3580 OPENSSL_EXPORT int SSL_in_early_data(const SSL *ssl);
3581 
3582 // SSL_SESSION_early_data_capable returns whether early data would have been
3583 // attempted with |session| if enabled.
3584 OPENSSL_EXPORT int SSL_SESSION_early_data_capable(const SSL_SESSION *session);
3585 
3586 // SSL_SESSION_copy_without_early_data returns a copy of |session| with early
3587 // data disabled. If |session| already does not support early data, it returns
3588 // |session| with the reference count increased. The caller takes ownership of
3589 // the result and must release it with |SSL_SESSION_free|.
3590 //
3591 // This function may be used on the client to clear early data support from
3592 // existing sessions when the server rejects early data. In particular,
3593 // |SSL_R_WRONG_VERSION_ON_EARLY_DATA| requires a fresh connection to retry, and
3594 // the client would not want 0-RTT enabled for the next connection attempt.
3595 OPENSSL_EXPORT SSL_SESSION *SSL_SESSION_copy_without_early_data(
3596     SSL_SESSION *session);
3597 
3598 // SSL_early_data_accepted returns whether early data was accepted on the
3599 // handshake performed by |ssl|.
3600 OPENSSL_EXPORT int SSL_early_data_accepted(const SSL *ssl);
3601 
3602 // SSL_reset_early_data_reject resets |ssl| after an early data reject. All
3603 // 0-RTT state is discarded, including any pending |SSL_write| calls. The caller
3604 // should treat |ssl| as a logically fresh connection, usually by driving the
3605 // handshake to completion using |SSL_do_handshake|.
3606 //
3607 // It is an error to call this function on an |SSL| object that is not signaling
3608 // |SSL_ERROR_EARLY_DATA_REJECTED|.
3609 OPENSSL_EXPORT void SSL_reset_early_data_reject(SSL *ssl);
3610 
3611 // SSL_get_ticket_age_skew returns the difference, in seconds, between the
3612 // client-sent ticket age and the server-computed value in TLS 1.3 server
3613 // connections which resumed a session.
3614 OPENSSL_EXPORT int32_t SSL_get_ticket_age_skew(const SSL *ssl);
3615 
3616 // An ssl_early_data_reason_t describes why 0-RTT was accepted or rejected.
3617 // These values are persisted to logs. Entries should not be renumbered and
3618 // numeric values should never be reused.
3619 enum ssl_early_data_reason_t BORINGSSL_ENUM_INT {
3620   // The handshake has not progressed far enough for the 0-RTT status to be
3621   // known.
3622   ssl_early_data_unknown = 0,
3623   // 0-RTT is disabled for this connection.
3624   ssl_early_data_disabled = 1,
3625   // 0-RTT was accepted.
3626   ssl_early_data_accepted = 2,
3627   // The negotiated protocol version does not support 0-RTT.
3628   ssl_early_data_protocol_version = 3,
3629   // The peer declined to offer or accept 0-RTT for an unknown reason.
3630   ssl_early_data_peer_declined = 4,
3631   // The client did not offer a session.
3632   ssl_early_data_no_session_offered = 5,
3633   // The server declined to resume the session.
3634   ssl_early_data_session_not_resumed = 6,
3635   // The session does not support 0-RTT.
3636   ssl_early_data_unsupported_for_session = 7,
3637   // The server sent a HelloRetryRequest.
3638   ssl_early_data_hello_retry_request = 8,
3639   // The negotiated ALPN protocol did not match the session.
3640   ssl_early_data_alpn_mismatch = 9,
3641   // The connection negotiated Channel ID, which is incompatible with 0-RTT.
3642   ssl_early_data_channel_id = 10,
3643   // Value 11 is reserved. (It has historically |ssl_early_data_token_binding|.)
3644   // The client and server ticket age were too far apart.
3645   ssl_early_data_ticket_age_skew = 12,
3646   // QUIC parameters differ between this connection and the original.
3647   ssl_early_data_quic_parameter_mismatch = 13,
3648   // The application settings did not match the session.
3649   ssl_early_data_alps_mismatch = 14,
3650   // The value of the largest entry.
3651   ssl_early_data_reason_max_value = ssl_early_data_alps_mismatch,
3652 };
3653 
3654 // SSL_get_early_data_reason returns details why 0-RTT was accepted or rejected
3655 // on |ssl|. This is primarily useful on the server.
3656 OPENSSL_EXPORT enum ssl_early_data_reason_t SSL_get_early_data_reason(
3657     const SSL *ssl);
3658 
3659 // SSL_early_data_reason_string returns a string representation for |reason|, or
3660 // NULL if |reason| is unknown. This function may be used for logging.
3661 OPENSSL_EXPORT const char *SSL_early_data_reason_string(
3662     enum ssl_early_data_reason_t reason);
3663 
3664 
3665 // Encrypted ClientHello.
3666 //
3667 // ECH is a mechanism for encrypting the entire ClientHello message in TLS 1.3.
3668 // This can prevent observers from seeing cleartext information about the
3669 // connection, such as the server_name extension.
3670 //
3671 // By default, BoringSSL will treat the server name, session ticket, and client
3672 // certificate as secret, but most other parameters, such as the ALPN protocol
3673 // list will be treated as public and sent in the cleartext ClientHello. Other
3674 // APIs may be added for applications with different secrecy requirements.
3675 //
3676 // ECH support in BoringSSL is still experimental and under development.
3677 //
3678 // See https://tools.ietf.org/html/draft-ietf-tls-esni-13.
3679 
3680 // SSL_set_enable_ech_grease configures whether the client will send a GREASE
3681 // ECH extension when no supported ECHConfig is available.
3682 OPENSSL_EXPORT void SSL_set_enable_ech_grease(SSL *ssl, int enable);
3683 
3684 // SSL_set1_ech_config_list configures |ssl| to, as a client, offer ECH with the
3685 // specified configuration. |ech_config_list| should contain a serialized
3686 // ECHConfigList structure. It returns one on success and zero on error.
3687 //
3688 // This function returns an error if the input is malformed. If the input is
3689 // valid but none of the ECHConfigs implement supported parameters, it will
3690 // return success and proceed without ECH.
3691 //
3692 // If a supported ECHConfig is found, |ssl| will encrypt the true ClientHello
3693 // parameters. If the server cannot decrypt it, e.g. due to a key mismatch, ECH
3694 // has a recovery flow. |ssl| will handshake using the cleartext parameters,
3695 // including a public name in the ECHConfig. If using
3696 // |SSL_CTX_set_custom_verify|, callers should use |SSL_get0_ech_name_override|
3697 // to verify the certificate with the public name. If using the built-in
3698 // verifier, the |X509_STORE_CTX| will be configured automatically.
3699 //
3700 // If no other errors are found in this handshake, it will fail with
3701 // |SSL_R_ECH_REJECTED|. Since it didn't use the true parameters, the connection
3702 // cannot be used for application data. Instead, callers should handle this
3703 // error by calling |SSL_get0_ech_retry_configs| and retrying the connection
3704 // with updated ECH parameters. If the retry also fails with
3705 // |SSL_R_ECH_REJECTED|, the caller should report a connection failure.
3706 OPENSSL_EXPORT int SSL_set1_ech_config_list(SSL *ssl,
3707                                             const uint8_t *ech_config_list,
3708                                             size_t ech_config_list_len);
3709 
3710 // SSL_get0_ech_name_override, if |ssl| is a client and the server rejected ECH,
3711 // sets |*out_name| and |*out_name_len| to point to a buffer containing the ECH
3712 // public name. Otherwise, the buffer will be empty.
3713 //
3714 // When offering ECH as a client, this function should be called during the
3715 // certificate verification callback (see |SSL_CTX_set_custom_verify|). If
3716 // |*out_name_len| is non-zero, the caller should verify the certificate against
3717 // the result, interpreted as a DNS name, rather than the true server name. In
3718 // this case, the handshake will never succeed and is only used to authenticate
3719 // retry configs. See also |SSL_get0_ech_retry_configs|.
3720 OPENSSL_EXPORT void SSL_get0_ech_name_override(const SSL *ssl,
3721                                                const char **out_name,
3722                                                size_t *out_name_len);
3723 
3724 // SSL_get0_ech_retry_configs sets |*out_retry_configs| and
3725 // |*out_retry_configs_len| to a buffer containing a serialized ECHConfigList.
3726 // If the server did not provide an ECHConfigList, |*out_retry_configs_len| will
3727 // be zero.
3728 //
3729 // When handling an |SSL_R_ECH_REJECTED| error code as a client, callers should
3730 // use this function to recover from potential key mismatches. If the result is
3731 // non-empty, the caller should retry the connection, passing this buffer to
3732 // |SSL_set1_ech_config_list|. If the result is empty, the server has rolled
3733 // back ECH support, and the caller should retry without ECH.
3734 //
3735 // This function must only be called in response to an |SSL_R_ECH_REJECTED|
3736 // error code. Calling this function on |ssl|s that have not authenticated the
3737 // rejection handshake will assert in debug builds and otherwise return an
3738 // unparsable list.
3739 OPENSSL_EXPORT void SSL_get0_ech_retry_configs(
3740     const SSL *ssl, const uint8_t **out_retry_configs,
3741     size_t *out_retry_configs_len);
3742 
3743 // SSL_marshal_ech_config constructs a new serialized ECHConfig. On success, it
3744 // sets |*out| to a newly-allocated buffer containing the result and |*out_len|
3745 // to the size of the buffer. The caller must call |OPENSSL_free| on |*out| to
3746 // release the memory. On failure, it returns zero.
3747 //
3748 // The |config_id| field is a single byte identifer for the ECHConfig. Reusing
3749 // config IDs is allowed, but if multiple ECHConfigs with the same config ID are
3750 // active at a time, server load may increase. See
3751 // |SSL_ECH_KEYS_has_duplicate_config_id|.
3752 //
3753 // The public key and KEM algorithm are taken from |key|. |public_name| is the
3754 // DNS name used to authenticate the recovery flow. |max_name_len| should be the
3755 // length of the longest name in the ECHConfig's anonymity set and influences
3756 // client padding decisions.
3757 OPENSSL_EXPORT int SSL_marshal_ech_config(uint8_t **out, size_t *out_len,
3758                                           uint8_t config_id,
3759                                           const EVP_HPKE_KEY *key,
3760                                           const char *public_name,
3761                                           size_t max_name_len);
3762 
3763 // SSL_ECH_KEYS_new returns a newly-allocated |SSL_ECH_KEYS| or NULL on error.
3764 OPENSSL_EXPORT SSL_ECH_KEYS *SSL_ECH_KEYS_new(void);
3765 
3766 // SSL_ECH_KEYS_up_ref increments the reference count of |keys|.
3767 OPENSSL_EXPORT void SSL_ECH_KEYS_up_ref(SSL_ECH_KEYS *keys);
3768 
3769 // SSL_ECH_KEYS_free releases memory associated with |keys|.
3770 OPENSSL_EXPORT void SSL_ECH_KEYS_free(SSL_ECH_KEYS *keys);
3771 
3772 // SSL_ECH_KEYS_add decodes |ech_config| as an ECHConfig and appends it with
3773 // |key| to |keys|. If |is_retry_config| is non-zero, this config will be
3774 // returned to the client on configuration mismatch. It returns one on success
3775 // and zero on error.
3776 //
3777 // This function should be called successively to register each ECHConfig in
3778 // decreasing order of preference. This configuration must be completed before
3779 // setting |keys| on an |SSL_CTX| with |SSL_CTX_set1_ech_keys|. After that
3780 // point, |keys| is immutable; no more ECHConfig values may be added.
3781 //
3782 // See also |SSL_CTX_set1_ech_keys|.
3783 OPENSSL_EXPORT int SSL_ECH_KEYS_add(SSL_ECH_KEYS *keys, int is_retry_config,
3784                                     const uint8_t *ech_config,
3785                                     size_t ech_config_len,
3786                                     const EVP_HPKE_KEY *key);
3787 
3788 // SSL_ECH_KEYS_has_duplicate_config_id returns one if |keys| has duplicate
3789 // config IDs or zero otherwise. Duplicate config IDs still work, but may
3790 // increase server load due to trial decryption.
3791 OPENSSL_EXPORT int SSL_ECH_KEYS_has_duplicate_config_id(
3792     const SSL_ECH_KEYS *keys);
3793 
3794 // SSL_ECH_KEYS_marshal_retry_configs serializes the retry configs in |keys| as
3795 // an ECHConfigList. On success, it sets |*out| to a newly-allocated buffer
3796 // containing the result and |*out_len| to the size of the buffer. The caller
3797 // must call |OPENSSL_free| on |*out| to release the memory. On failure, it
3798 // returns zero.
3799 //
3800 // This output may be advertised to clients in DNS.
3801 OPENSSL_EXPORT int SSL_ECH_KEYS_marshal_retry_configs(const SSL_ECH_KEYS *keys,
3802                                                       uint8_t **out,
3803                                                       size_t *out_len);
3804 
3805 // SSL_CTX_set1_ech_keys configures |ctx| to use |keys| to decrypt encrypted
3806 // ClientHellos. It returns one on success, and zero on failure. If |keys| does
3807 // not contain any retry configs, this function will fail. Retry configs are
3808 // marked as such when they are added to |keys| with |SSL_ECH_KEYS_add|.
3809 //
3810 // Once |keys| has been passed to this function, it is immutable. Unlike most
3811 // |SSL_CTX| configuration functions, this function may be called even if |ctx|
3812 // already has associated connections on multiple threads. This may be used to
3813 // rotate keys in a long-lived server process.
3814 //
3815 // The configured ECHConfig values should also be advertised out-of-band via DNS
3816 // (see draft-ietf-dnsop-svcb-https). Before advertising an ECHConfig in DNS,
3817 // deployments should ensure all instances of the service are configured with
3818 // the ECHConfig and corresponding private key.
3819 //
3820 // Only the most recent fully-deployed ECHConfigs should be advertised in DNS.
3821 // |keys| may contain a newer set if those ECHConfigs are mid-deployment. It
3822 // should also contain older sets, until the DNS change has rolled out and the
3823 // old records have expired from caches.
3824 //
3825 // If there is a mismatch, |SSL| objects associated with |ctx| will complete the
3826 // handshake using the cleartext ClientHello and send updated ECHConfig values
3827 // to the client. The client will then retry to recover, but with a latency
3828 // penalty. This recovery flow depends on the public name in the ECHConfig.
3829 // Before advertising an ECHConfig in DNS, deployments must ensure all instances
3830 // of the service can present a valid certificate for the public name.
3831 //
3832 // BoringSSL negotiates ECH before certificate selection callbacks are called,
3833 // including |SSL_CTX_set_select_certificate_cb|. If ECH is negotiated, the
3834 // reported |SSL_CLIENT_HELLO| structure and |SSL_get_servername| function will
3835 // transparently reflect the inner ClientHello. Callers should select parameters
3836 // based on these values to correctly handle ECH as well as the recovery flow.
3837 OPENSSL_EXPORT int SSL_CTX_set1_ech_keys(SSL_CTX *ctx, SSL_ECH_KEYS *keys);
3838 
3839 // SSL_ech_accepted returns one if |ssl| negotiated ECH and zero otherwise.
3840 OPENSSL_EXPORT int SSL_ech_accepted(const SSL *ssl);
3841 
3842 
3843 // Alerts.
3844 //
3845 // TLS uses alerts to signal error conditions. Alerts have a type (warning or
3846 // fatal) and description. OpenSSL internally handles fatal alerts with
3847 // dedicated error codes (see |SSL_AD_REASON_OFFSET|). Except for close_notify,
3848 // warning alerts are silently ignored and may only be surfaced with
3849 // |SSL_CTX_set_info_callback|.
3850 
3851 // SSL_AD_REASON_OFFSET is the offset between error reasons and |SSL_AD_*|
3852 // values. Any error code under |ERR_LIB_SSL| with an error reason above this
3853 // value corresponds to an alert description. Consumers may add or subtract
3854 // |SSL_AD_REASON_OFFSET| to convert between them.
3855 //
3856 // make_errors.go reserves error codes above 1000 for manually-assigned errors.
3857 // This value must be kept in sync with reservedReasonCode in make_errors.h
3858 #define SSL_AD_REASON_OFFSET 1000
3859 
3860 // SSL_AD_* are alert descriptions.
3861 #define SSL_AD_CLOSE_NOTIFY SSL3_AD_CLOSE_NOTIFY
3862 #define SSL_AD_UNEXPECTED_MESSAGE SSL3_AD_UNEXPECTED_MESSAGE
3863 #define SSL_AD_BAD_RECORD_MAC SSL3_AD_BAD_RECORD_MAC
3864 #define SSL_AD_DECRYPTION_FAILED TLS1_AD_DECRYPTION_FAILED
3865 #define SSL_AD_RECORD_OVERFLOW TLS1_AD_RECORD_OVERFLOW
3866 #define SSL_AD_DECOMPRESSION_FAILURE SSL3_AD_DECOMPRESSION_FAILURE
3867 #define SSL_AD_HANDSHAKE_FAILURE SSL3_AD_HANDSHAKE_FAILURE
3868 #define SSL_AD_NO_CERTIFICATE SSL3_AD_NO_CERTIFICATE  // Legacy SSL 3.0 value
3869 #define SSL_AD_BAD_CERTIFICATE SSL3_AD_BAD_CERTIFICATE
3870 #define SSL_AD_UNSUPPORTED_CERTIFICATE SSL3_AD_UNSUPPORTED_CERTIFICATE
3871 #define SSL_AD_CERTIFICATE_REVOKED SSL3_AD_CERTIFICATE_REVOKED
3872 #define SSL_AD_CERTIFICATE_EXPIRED SSL3_AD_CERTIFICATE_EXPIRED
3873 #define SSL_AD_CERTIFICATE_UNKNOWN SSL3_AD_CERTIFICATE_UNKNOWN
3874 #define SSL_AD_ILLEGAL_PARAMETER SSL3_AD_ILLEGAL_PARAMETER
3875 #define SSL_AD_UNKNOWN_CA TLS1_AD_UNKNOWN_CA
3876 #define SSL_AD_ACCESS_DENIED TLS1_AD_ACCESS_DENIED
3877 #define SSL_AD_DECODE_ERROR TLS1_AD_DECODE_ERROR
3878 #define SSL_AD_DECRYPT_ERROR TLS1_AD_DECRYPT_ERROR
3879 #define SSL_AD_EXPORT_RESTRICTION TLS1_AD_EXPORT_RESTRICTION
3880 #define SSL_AD_PROTOCOL_VERSION TLS1_AD_PROTOCOL_VERSION
3881 #define SSL_AD_INSUFFICIENT_SECURITY TLS1_AD_INSUFFICIENT_SECURITY
3882 #define SSL_AD_INTERNAL_ERROR TLS1_AD_INTERNAL_ERROR
3883 #define SSL_AD_INAPPROPRIATE_FALLBACK SSL3_AD_INAPPROPRIATE_FALLBACK
3884 #define SSL_AD_USER_CANCELLED TLS1_AD_USER_CANCELLED
3885 #define SSL_AD_NO_RENEGOTIATION TLS1_AD_NO_RENEGOTIATION
3886 #define SSL_AD_MISSING_EXTENSION TLS1_AD_MISSING_EXTENSION
3887 #define SSL_AD_UNSUPPORTED_EXTENSION TLS1_AD_UNSUPPORTED_EXTENSION
3888 #define SSL_AD_CERTIFICATE_UNOBTAINABLE TLS1_AD_CERTIFICATE_UNOBTAINABLE
3889 #define SSL_AD_UNRECOGNIZED_NAME TLS1_AD_UNRECOGNIZED_NAME
3890 #define SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE \
3891   TLS1_AD_BAD_CERTIFICATE_STATUS_RESPONSE
3892 #define SSL_AD_BAD_CERTIFICATE_HASH_VALUE TLS1_AD_BAD_CERTIFICATE_HASH_VALUE
3893 #define SSL_AD_UNKNOWN_PSK_IDENTITY TLS1_AD_UNKNOWN_PSK_IDENTITY
3894 #define SSL_AD_CERTIFICATE_REQUIRED TLS1_AD_CERTIFICATE_REQUIRED
3895 #define SSL_AD_NO_APPLICATION_PROTOCOL TLS1_AD_NO_APPLICATION_PROTOCOL
3896 #define SSL_AD_ECH_REQUIRED TLS1_AD_ECH_REQUIRED
3897 
3898 // SSL_alert_type_string_long returns a string description of |value| as an
3899 // alert type (warning or fatal).
3900 OPENSSL_EXPORT const char *SSL_alert_type_string_long(int value);
3901 
3902 // SSL_alert_desc_string_long returns a string description of |value| as an
3903 // alert description or "unknown" if unknown.
3904 OPENSSL_EXPORT const char *SSL_alert_desc_string_long(int value);
3905 
3906 // SSL_send_fatal_alert sends a fatal alert over |ssl| of the specified type,
3907 // which should be one of the |SSL_AD_*| constants. It returns one on success
3908 // and <= 0 on error. The caller should pass the return value into
3909 // |SSL_get_error| to determine how to proceed. Once this function has been
3910 // called, future calls to |SSL_write| will fail.
3911 //
3912 // If retrying a failed operation due to |SSL_ERROR_WANT_WRITE|, subsequent
3913 // calls must use the same |alert| parameter.
3914 OPENSSL_EXPORT int SSL_send_fatal_alert(SSL *ssl, uint8_t alert);
3915 
3916 
3917 // ex_data functions.
3918 //
3919 // See |ex_data.h| for details.
3920 
3921 OPENSSL_EXPORT int SSL_set_ex_data(SSL *ssl, int idx, void *data);
3922 OPENSSL_EXPORT void *SSL_get_ex_data(const SSL *ssl, int idx);
3923 OPENSSL_EXPORT int SSL_get_ex_new_index(long argl, void *argp,
3924                                         CRYPTO_EX_unused *unused,
3925                                         CRYPTO_EX_dup *dup_unused,
3926                                         CRYPTO_EX_free *free_func);
3927 
3928 OPENSSL_EXPORT int SSL_SESSION_set_ex_data(SSL_SESSION *session, int idx,
3929                                            void *data);
3930 OPENSSL_EXPORT void *SSL_SESSION_get_ex_data(const SSL_SESSION *session,
3931                                              int idx);
3932 OPENSSL_EXPORT int SSL_SESSION_get_ex_new_index(long argl, void *argp,
3933                                                 CRYPTO_EX_unused *unused,
3934                                                 CRYPTO_EX_dup *dup_unused,
3935                                                 CRYPTO_EX_free *free_func);
3936 
3937 OPENSSL_EXPORT int SSL_CTX_set_ex_data(SSL_CTX *ctx, int idx, void *data);
3938 OPENSSL_EXPORT void *SSL_CTX_get_ex_data(const SSL_CTX *ctx, int idx);
3939 OPENSSL_EXPORT int SSL_CTX_get_ex_new_index(long argl, void *argp,
3940                                             CRYPTO_EX_unused *unused,
3941                                             CRYPTO_EX_dup *dup_unused,
3942                                             CRYPTO_EX_free *free_func);
3943 
3944 
3945 // Low-level record-layer state.
3946 
3947 // SSL_get_ivs sets |*out_iv_len| to the length of the IVs for the ciphers
3948 // underlying |ssl| and sets |*out_read_iv| and |*out_write_iv| to point to the
3949 // current IVs for the read and write directions. This is only meaningful for
3950 // connections with implicit IVs (i.e. CBC mode with TLS 1.0).
3951 //
3952 // It returns one on success or zero on error.
3953 OPENSSL_EXPORT int SSL_get_ivs(const SSL *ssl, const uint8_t **out_read_iv,
3954                                const uint8_t **out_write_iv,
3955                                size_t *out_iv_len);
3956 
3957 // SSL_get_key_block_len returns the length of |ssl|'s key block, for TLS 1.2
3958 // and below. It is an error to call this function during a handshake, or if
3959 // |ssl| negotiated TLS 1.3.
3960 OPENSSL_EXPORT size_t SSL_get_key_block_len(const SSL *ssl);
3961 
3962 // SSL_generate_key_block generates |out_len| bytes of key material for |ssl|'s
3963 // current connection state, for TLS 1.2 and below. It is an error to call this
3964 // function during a handshake, or if |ssl| negotiated TLS 1.3.
3965 OPENSSL_EXPORT int SSL_generate_key_block(const SSL *ssl, uint8_t *out,
3966                                           size_t out_len);
3967 
3968 // SSL_get_read_sequence returns, in TLS, the expected sequence number of the
3969 // next incoming record in the current epoch. In DTLS, it returns the maximum
3970 // sequence number received in the current epoch and includes the epoch number
3971 // in the two most significant bytes.
3972 OPENSSL_EXPORT uint64_t SSL_get_read_sequence(const SSL *ssl);
3973 
3974 // SSL_get_write_sequence returns the sequence number of the next outgoing
3975 // record in the current epoch. In DTLS, it includes the epoch number in the
3976 // two most significant bytes.
3977 OPENSSL_EXPORT uint64_t SSL_get_write_sequence(const SSL *ssl);
3978 
3979 // SSL_CTX_set_record_protocol_version returns whether |version| is zero.
3980 OPENSSL_EXPORT int SSL_CTX_set_record_protocol_version(SSL_CTX *ctx,
3981                                                        int version);
3982 
3983 
3984 // Handshake hints.
3985 //
3986 // *** EXPERIMENTAL — DO NOT USE WITHOUT CHECKING ***
3987 //
3988 // Some server deployments make asynchronous RPC calls in both ClientHello
3989 // dispatch and private key operations. In TLS handshakes where the private key
3990 // operation occurs in the first round-trip, this results in two consecutive RPC
3991 // round-trips. Handshake hints allow the RPC service to predicte a signature.
3992 // If correctly predicted, this can skip the second RPC call.
3993 //
3994 // First, the server installs a certificate selection callback (see
3995 // |SSL_CTX_set_select_certificate_cb|). When that is called, it performs the
3996 // RPC as before, but includes the ClientHello and a capabilities string from
3997 // |SSL_serialize_capabilities|.
3998 //
3999 // Next, the RPC service creates its own |SSL| object, applies the results of
4000 // certificate selection, calls |SSL_request_handshake_hints|, and runs the
4001 // handshake. If this successfully computes handshake hints (see
4002 // |SSL_serialize_handshake_hints|), the RPC server should send the hints
4003 // alongside any certificate selection results.
4004 //
4005 // Finally, the server calls |SSL_set_handshake_hints| and applies any
4006 // configuration from the RPC server. It then completes the handshake as before.
4007 // If the hints apply, BoringSSL will use the predicted signature and skip the
4008 // private key callbacks. Otherwise, BoringSSL will call private key callbacks
4009 // to generate a signature as before.
4010 //
4011 // Callers should synchronize configuration across the two services.
4012 // Configuration mismatches and some cases of version skew are not fatal, but
4013 // may result in the hints not applying. Additionally, some handshake flows use
4014 // the private key in later round-trips, such as TLS 1.3 HelloRetryRequest. In
4015 // those cases, BoringSSL will not predict a signature as there is no benefit.
4016 // Callers must allow for handshakes to complete without a predicted signature.
4017 //
4018 // Handshake hints are supported for TLS 1.3 and partially supported for
4019 // TLS 1.2. TLS 1.2 resumption handshakes are not yet fully hinted. They will
4020 // still work, but may not be as efficient.
4021 
4022 // SSL_serialize_capabilities writes an opaque byte string to |out| describing
4023 // some of |ssl|'s capabilities. It returns one on success and zero on error.
4024 //
4025 // This string is used by BoringSSL internally to reduce the impact of version
4026 // skew.
4027 OPENSSL_EXPORT int SSL_serialize_capabilities(const SSL *ssl, CBB *out);
4028 
4029 // SSL_request_handshake_hints configures |ssl| to generate a handshake hint for
4030 // |client_hello|. It returns one on success and zero on error. |client_hello|
4031 // should contain a serialized ClientHello structure, from the |client_hello|
4032 // and |client_hello_len| fields of the |SSL_CLIENT_HELLO| structure.
4033 // |capabilities| should contain the output of |SSL_serialize_capabilities|.
4034 //
4035 // When configured, |ssl| will perform no I/O (so there is no need to configure
4036 // |BIO|s). For QUIC, the caller should still configure an |SSL_QUIC_METHOD|,
4037 // but the callbacks themselves will never be called and may be left NULL or
4038 // report failure. |SSL_provide_quic_data| also should not be called.
4039 //
4040 // If hint generation is successful, |SSL_do_handshake| will stop the handshake
4041 // early with |SSL_get_error| returning |SSL_ERROR_HANDSHAKE_HINTS_READY|. At
4042 // this point, the caller should run |SSL_serialize_handshake_hints| to extract
4043 // the resulting hints.
4044 //
4045 // Hint generation may fail if, e.g., |ssl| was unable to process the
4046 // ClientHello. Callers should then complete the certificate selection RPC and
4047 // continue the original handshake with no hint. It will likely fail, but this
4048 // reports the correct alert to the client and is more robust in case of
4049 // mismatch.
4050 OPENSSL_EXPORT int SSL_request_handshake_hints(SSL *ssl,
4051                                                const uint8_t *client_hello,
4052                                                size_t client_hello_len,
4053                                                const uint8_t *capabilities,
4054                                                size_t capabilities_len);
4055 
4056 // SSL_serialize_handshake_hints writes an opaque byte string to |out|
4057 // containing the handshake hints computed by |out|. It returns one on success
4058 // and zero on error. This function should only be called if
4059 // |SSL_request_handshake_hints| was configured and the handshake terminated
4060 // with |SSL_ERROR_HANDSHAKE_HINTS_READY|.
4061 //
4062 // This string may be passed to |SSL_set_handshake_hints| on another |SSL| to
4063 // avoid an extra signature call.
4064 OPENSSL_EXPORT int SSL_serialize_handshake_hints(const SSL *ssl, CBB *out);
4065 
4066 // SSL_set_handshake_hints configures |ssl| to use |hints| as handshake hints.
4067 // It returns one on success and zero on error. The handshake will then continue
4068 // as before, but apply predicted values from |hints| where applicable.
4069 //
4070 // Hints may contain connection and session secrets, so they must not leak and
4071 // must come from a source trusted to terminate the connection. However, they
4072 // will not change |ssl|'s configuration. The caller is responsible for
4073 // serializing and applying options from the RPC server as needed. This ensures
4074 // |ssl|'s behavior is self-consistent and consistent with the caller's local
4075 // decisions.
4076 OPENSSL_EXPORT int SSL_set_handshake_hints(SSL *ssl, const uint8_t *hints,
4077                                            size_t hints_len);
4078 
4079 
4080 // Obscure functions.
4081 
4082 // SSL_CTX_set_msg_callback installs |cb| as the message callback for |ctx|.
4083 // This callback will be called when sending or receiving low-level record
4084 // headers, complete handshake messages, ChangeCipherSpec, and alerts.
4085 // |write_p| is one for outgoing messages and zero for incoming messages.
4086 //
4087 // For each record header, |cb| is called with |version| = 0 and |content_type|
4088 // = |SSL3_RT_HEADER|. The |len| bytes from |buf| contain the header. Note that
4089 // this does not include the record body. If the record is sealed, the length
4090 // in the header is the length of the ciphertext.
4091 //
4092 // For each handshake message, ChangeCipherSpec, and alert, |version| is the
4093 // protocol version and |content_type| is the corresponding record type. The
4094 // |len| bytes from |buf| contain the handshake message, one-byte
4095 // ChangeCipherSpec body, and two-byte alert, respectively.
4096 //
4097 // In connections that enable ECH, |cb| is additionally called with
4098 // |content_type| = |SSL3_RT_CLIENT_HELLO_INNER| for each ClientHelloInner that
4099 // is encrypted or decrypted. The |len| bytes from |buf| contain the
4100 // ClientHelloInner, including the reconstructed outer extensions and handshake
4101 // header.
4102 //
4103 // For a V2ClientHello, |version| is |SSL2_VERSION|, |content_type| is zero, and
4104 // the |len| bytes from |buf| contain the V2ClientHello structure.
4105 OPENSSL_EXPORT void SSL_CTX_set_msg_callback(
4106     SSL_CTX *ctx, void (*cb)(int is_write, int version, int content_type,
4107                              const void *buf, size_t len, SSL *ssl, void *arg));
4108 
4109 // SSL_CTX_set_msg_callback_arg sets the |arg| parameter of the message
4110 // callback.
4111 OPENSSL_EXPORT void SSL_CTX_set_msg_callback_arg(SSL_CTX *ctx, void *arg);
4112 
4113 // SSL_set_msg_callback installs |cb| as the message callback of |ssl|. See
4114 // |SSL_CTX_set_msg_callback| for when this callback is called.
4115 OPENSSL_EXPORT void SSL_set_msg_callback(
4116     SSL *ssl, void (*cb)(int write_p, int version, int content_type,
4117                          const void *buf, size_t len, SSL *ssl, void *arg));
4118 
4119 // SSL_set_msg_callback_arg sets the |arg| parameter of the message callback.
4120 OPENSSL_EXPORT void SSL_set_msg_callback_arg(SSL *ssl, void *arg);
4121 
4122 // SSL_CTX_set_keylog_callback configures a callback to log key material. This
4123 // is intended for debugging use with tools like Wireshark. The |cb| function
4124 // should log |line| followed by a newline, synchronizing with any concurrent
4125 // access to the log.
4126 //
4127 // The format is described in
4128 // https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/Key_Log_Format.
4129 OPENSSL_EXPORT void SSL_CTX_set_keylog_callback(
4130     SSL_CTX *ctx, void (*cb)(const SSL *ssl, const char *line));
4131 
4132 // SSL_CTX_get_keylog_callback returns the callback configured by
4133 // |SSL_CTX_set_keylog_callback|.
4134 OPENSSL_EXPORT void (*SSL_CTX_get_keylog_callback(const SSL_CTX *ctx))(
4135     const SSL *ssl, const char *line);
4136 
4137 // SSL_CTX_set_current_time_cb configures a callback to retrieve the current
4138 // time, which should be set in |*out_clock|. This can be used for testing
4139 // purposes; for example, a callback can be configured that returns a time
4140 // set explicitly by the test. The |ssl| pointer passed to |cb| is always null.
4141 OPENSSL_EXPORT void SSL_CTX_set_current_time_cb(
4142     SSL_CTX *ctx, void (*cb)(const SSL *ssl, struct timeval *out_clock));
4143 
4144 // SSL_set_shed_handshake_config allows some of the configuration of |ssl| to be
4145 // freed after its handshake completes.  Once configuration has been shed, APIs
4146 // that query it may fail.  "Configuration" in this context means anything that
4147 // was set by the caller, as distinct from information derived from the
4148 // handshake.  For example, |SSL_get_ciphers| queries how the |SSL| was
4149 // configured by the caller, and fails after configuration has been shed,
4150 // whereas |SSL_get_cipher| queries the result of the handshake, and is
4151 // unaffected by configuration shedding.
4152 //
4153 // If configuration shedding is enabled, it is an error to call |SSL_clear|.
4154 //
4155 // Note that configuration shedding as a client additionally depends on
4156 // renegotiation being disabled (see |SSL_set_renegotiate_mode|). If
4157 // renegotiation is possible, the configuration will be retained. If
4158 // configuration shedding is enabled and renegotiation later disabled after the
4159 // handshake, |SSL_set_renegotiate_mode| will shed configuration then. This may
4160 // be useful for clients which support renegotiation with some ALPN protocols,
4161 // such as HTTP/1.1, and not others, such as HTTP/2.
4162 OPENSSL_EXPORT void SSL_set_shed_handshake_config(SSL *ssl, int enable);
4163 
4164 enum ssl_renegotiate_mode_t BORINGSSL_ENUM_INT {
4165   ssl_renegotiate_never = 0,
4166   ssl_renegotiate_once,
4167   ssl_renegotiate_freely,
4168   ssl_renegotiate_ignore,
4169   ssl_renegotiate_explicit,
4170 };
4171 
4172 // SSL_set_renegotiate_mode configures how |ssl|, a client, reacts to
4173 // renegotiation attempts by a server. If |ssl| is a server, peer-initiated
4174 // renegotiations are *always* rejected and this function does nothing.
4175 //
4176 // WARNING: Renegotiation is error-prone, complicates TLS's security properties,
4177 // and increases its attack surface. When enabled, many common assumptions about
4178 // BoringSSL's behavior no longer hold, and the calling application must handle
4179 // more cases. Renegotiation is also incompatible with many application
4180 // protocols, e.g. section 9.2.1 of RFC 7540. Many functions behave in ambiguous
4181 // or undefined ways during a renegotiation.
4182 //
4183 // The renegotiation mode defaults to |ssl_renegotiate_never|, but may be set
4184 // at any point in a connection's lifetime. Set it to |ssl_renegotiate_once| to
4185 // allow one renegotiation, |ssl_renegotiate_freely| to allow all
4186 // renegotiations or |ssl_renegotiate_ignore| to ignore HelloRequest messages.
4187 // Note that ignoring HelloRequest messages may cause the connection to stall
4188 // if the server waits for the renegotiation to complete.
4189 //
4190 // If set to |ssl_renegotiate_explicit|, |SSL_read| and |SSL_peek| calls which
4191 // encounter a HelloRequest will pause with |SSL_ERROR_WANT_RENEGOTIATE|.
4192 // |SSL_write| will continue to work while paused. The caller may call
4193 // |SSL_renegotiate| to begin the renegotiation at a later point. This mode may
4194 // be used if callers wish to eagerly call |SSL_peek| without triggering a
4195 // renegotiation.
4196 //
4197 // If configuration shedding is enabled (see |SSL_set_shed_handshake_config|),
4198 // configuration is released if, at any point after the handshake, renegotiation
4199 // is disabled. It is not possible to switch from disabling renegotiation to
4200 // enabling it on a given connection. Callers that condition renegotiation on,
4201 // e.g., ALPN must enable renegotiation before the handshake and conditionally
4202 // disable it afterwards.
4203 //
4204 // When enabled, renegotiation can cause properties of |ssl|, such as the cipher
4205 // suite, to change during the lifetime of the connection. More over, during a
4206 // renegotiation, not all properties of the new handshake are available or fully
4207 // established. In BoringSSL, most functions, such as |SSL_get_current_cipher|,
4208 // report information from the most recently completed handshake, not the
4209 // pending one. However, renegotiation may rerun handshake callbacks, such as
4210 // |SSL_CTX_set_cert_cb|. Such callbacks must ensure they are acting on the
4211 // desired versions of each property.
4212 //
4213 // BoringSSL does not reverify peer certificates on renegotiation and instead
4214 // requires they match between handshakes, so certificate verification callbacks
4215 // (see |SSL_CTX_set_custom_verify|) may assume |ssl| is in the initial
4216 // handshake and use |SSL_get0_peer_certificates|, etc.
4217 //
4218 // There is no support in BoringSSL for initiating renegotiations as a client
4219 // or server.
4220 OPENSSL_EXPORT void SSL_set_renegotiate_mode(SSL *ssl,
4221                                              enum ssl_renegotiate_mode_t mode);
4222 
4223 // SSL_renegotiate starts a deferred renegotiation on |ssl| if it was configured
4224 // with |ssl_renegotiate_explicit| and has a pending HelloRequest. It returns
4225 // one on success and zero on error.
4226 //
4227 // This function does not do perform any I/O. On success, a subsequent
4228 // |SSL_do_handshake| call will run the handshake. |SSL_write| and
4229 // |SSL_read| will also complete the handshake before sending or receiving
4230 // application data.
4231 OPENSSL_EXPORT int SSL_renegotiate(SSL *ssl);
4232 
4233 // SSL_renegotiate_pending returns one if |ssl| is in the middle of a
4234 // renegotiation.
4235 OPENSSL_EXPORT int SSL_renegotiate_pending(SSL *ssl);
4236 
4237 // SSL_total_renegotiations returns the total number of renegotiation handshakes
4238 // performed by |ssl|. This includes the pending renegotiation, if any.
4239 OPENSSL_EXPORT int SSL_total_renegotiations(const SSL *ssl);
4240 
4241 // SSL_MAX_CERT_LIST_DEFAULT is the default maximum length, in bytes, of a peer
4242 // certificate chain.
4243 #define SSL_MAX_CERT_LIST_DEFAULT (1024 * 100)
4244 
4245 // SSL_CTX_get_max_cert_list returns the maximum length, in bytes, of a peer
4246 // certificate chain accepted by |ctx|.
4247 OPENSSL_EXPORT size_t SSL_CTX_get_max_cert_list(const SSL_CTX *ctx);
4248 
4249 // SSL_CTX_set_max_cert_list sets the maximum length, in bytes, of a peer
4250 // certificate chain to |max_cert_list|. This affects how much memory may be
4251 // consumed during the handshake.
4252 OPENSSL_EXPORT void SSL_CTX_set_max_cert_list(SSL_CTX *ctx,
4253                                               size_t max_cert_list);
4254 
4255 // SSL_get_max_cert_list returns the maximum length, in bytes, of a peer
4256 // certificate chain accepted by |ssl|.
4257 OPENSSL_EXPORT size_t SSL_get_max_cert_list(const SSL *ssl);
4258 
4259 // SSL_set_max_cert_list sets the maximum length, in bytes, of a peer
4260 // certificate chain to |max_cert_list|. This affects how much memory may be
4261 // consumed during the handshake.
4262 OPENSSL_EXPORT void SSL_set_max_cert_list(SSL *ssl, size_t max_cert_list);
4263 
4264 // SSL_CTX_set_max_send_fragment sets the maximum length, in bytes, of records
4265 // sent by |ctx|. Beyond this length, handshake messages and application data
4266 // will be split into multiple records. It returns one on success or zero on
4267 // error.
4268 OPENSSL_EXPORT int SSL_CTX_set_max_send_fragment(SSL_CTX *ctx,
4269                                                  size_t max_send_fragment);
4270 
4271 // SSL_set_max_send_fragment sets the maximum length, in bytes, of records sent
4272 // by |ssl|. Beyond this length, handshake messages and application data will
4273 // be split into multiple records. It returns one on success or zero on
4274 // error.
4275 OPENSSL_EXPORT int SSL_set_max_send_fragment(SSL *ssl,
4276                                              size_t max_send_fragment);
4277 
4278 // ssl_early_callback_ctx (aka |SSL_CLIENT_HELLO|) is passed to certain
4279 // callbacks that are called very early on during the server handshake. At this
4280 // point, much of the SSL* hasn't been filled out and only the ClientHello can
4281 // be depended on.
4282 struct ssl_early_callback_ctx {
4283   SSL *ssl;
4284   const uint8_t *client_hello;
4285   size_t client_hello_len;
4286   uint16_t version;
4287   const uint8_t *random;
4288   size_t random_len;
4289   const uint8_t *session_id;
4290   size_t session_id_len;
4291   const uint8_t *cipher_suites;
4292   size_t cipher_suites_len;
4293   const uint8_t *compression_methods;
4294   size_t compression_methods_len;
4295   const uint8_t *extensions;
4296   size_t extensions_len;
4297 } /* SSL_CLIENT_HELLO */;
4298 
4299 // ssl_select_cert_result_t enumerates the possible results from selecting a
4300 // certificate with |select_certificate_cb|.
4301 enum ssl_select_cert_result_t BORINGSSL_ENUM_INT {
4302   // ssl_select_cert_success indicates that the certificate selection was
4303   // successful.
4304   ssl_select_cert_success = 1,
4305   // ssl_select_cert_retry indicates that the operation could not be
4306   // immediately completed and must be reattempted at a later point.
4307   ssl_select_cert_retry = 0,
4308   // ssl_select_cert_error indicates that a fatal error occured and the
4309   // handshake should be terminated.
4310   ssl_select_cert_error = -1,
4311 };
4312 
4313 // SSL_early_callback_ctx_extension_get searches the extensions in
4314 // |client_hello| for an extension of the given type. If not found, it returns
4315 // zero. Otherwise it sets |out_data| to point to the extension contents (not
4316 // including the type and length bytes), sets |out_len| to the length of the
4317 // extension contents and returns one.
4318 OPENSSL_EXPORT int SSL_early_callback_ctx_extension_get(
4319     const SSL_CLIENT_HELLO *client_hello, uint16_t extension_type,
4320     const uint8_t **out_data, size_t *out_len);
4321 
4322 // SSL_CTX_set_select_certificate_cb sets a callback that is called before most
4323 // ClientHello processing and before the decision whether to resume a session
4324 // is made. The callback may inspect the ClientHello and configure the
4325 // connection. See |ssl_select_cert_result_t| for details of the return values.
4326 //
4327 // In the case that a retry is indicated, |SSL_get_error| will return
4328 // |SSL_ERROR_PENDING_CERTIFICATE| and the caller should arrange for the
4329 // high-level operation on |ssl| to be retried at a later time, which will
4330 // result in another call to |cb|.
4331 //
4332 // |SSL_get_servername| may be used during this callback.
4333 //
4334 // Note: The |SSL_CLIENT_HELLO| is only valid for the duration of the callback
4335 // and is not valid while the handshake is paused.
4336 OPENSSL_EXPORT void SSL_CTX_set_select_certificate_cb(
4337     SSL_CTX *ctx,
4338     enum ssl_select_cert_result_t (*cb)(const SSL_CLIENT_HELLO *));
4339 
4340 // SSL_CTX_set_dos_protection_cb sets a callback that is called once the
4341 // resumption decision for a ClientHello has been made. It can return one to
4342 // allow the handshake to continue or zero to cause the handshake to abort.
4343 OPENSSL_EXPORT void SSL_CTX_set_dos_protection_cb(
4344     SSL_CTX *ctx, int (*cb)(const SSL_CLIENT_HELLO *));
4345 
4346 // SSL_CTX_set_reverify_on_resume configures whether the certificate
4347 // verification callback will be used to reverify stored certificates
4348 // when resuming a session. This only works with |SSL_CTX_set_custom_verify|.
4349 // For now, this is incompatible with |SSL_VERIFY_NONE| mode, and is only
4350 // respected on clients.
4351 OPENSSL_EXPORT void SSL_CTX_set_reverify_on_resume(SSL_CTX *ctx, int enabled);
4352 
4353 // SSL_set_enforce_rsa_key_usage configures whether, when |ssl| is a client
4354 // negotiating TLS 1.2 or below, the keyUsage extension of RSA leaf server
4355 // certificates will be checked for consistency with the TLS usage. In all other
4356 // cases, this check is always enabled.
4357 //
4358 // This parameter may be set late; it will not be read until after the
4359 // certificate verification callback.
4360 OPENSSL_EXPORT void SSL_set_enforce_rsa_key_usage(SSL *ssl, int enabled);
4361 
4362 // SSL_was_key_usage_invalid returns one if |ssl|'s handshake succeeded despite
4363 // using TLS parameters which were incompatible with the leaf certificate's
4364 // keyUsage extension. Otherwise, it returns zero.
4365 //
4366 // If |SSL_set_enforce_rsa_key_usage| is enabled or not applicable, this
4367 // function will always return zero because key usages will be consistently
4368 // checked.
4369 OPENSSL_EXPORT int SSL_was_key_usage_invalid(const SSL *ssl);
4370 
4371 // SSL_ST_* are possible values for |SSL_state|, the bitmasks that make them up,
4372 // and some historical values for compatibility. Only |SSL_ST_INIT| and
4373 // |SSL_ST_OK| are ever returned.
4374 #define SSL_ST_CONNECT 0x1000
4375 #define SSL_ST_ACCEPT 0x2000
4376 #define SSL_ST_MASK 0x0FFF
4377 #define SSL_ST_INIT (SSL_ST_CONNECT | SSL_ST_ACCEPT)
4378 #define SSL_ST_OK 0x03
4379 #define SSL_ST_RENEGOTIATE (0x04 | SSL_ST_INIT)
4380 #define SSL_ST_BEFORE (0x05 | SSL_ST_INIT)
4381 
4382 // TLS_ST_* are aliases for |SSL_ST_*| for OpenSSL 1.1.0 compatibility.
4383 #define TLS_ST_OK SSL_ST_OK
4384 #define TLS_ST_BEFORE SSL_ST_BEFORE
4385 
4386 // SSL_CB_* are possible values for the |type| parameter in the info
4387 // callback and the bitmasks that make them up.
4388 #define SSL_CB_LOOP 0x01
4389 #define SSL_CB_EXIT 0x02
4390 #define SSL_CB_READ 0x04
4391 #define SSL_CB_WRITE 0x08
4392 #define SSL_CB_ALERT 0x4000
4393 #define SSL_CB_READ_ALERT (SSL_CB_ALERT | SSL_CB_READ)
4394 #define SSL_CB_WRITE_ALERT (SSL_CB_ALERT | SSL_CB_WRITE)
4395 #define SSL_CB_ACCEPT_LOOP (SSL_ST_ACCEPT | SSL_CB_LOOP)
4396 #define SSL_CB_ACCEPT_EXIT (SSL_ST_ACCEPT | SSL_CB_EXIT)
4397 #define SSL_CB_CONNECT_LOOP (SSL_ST_CONNECT | SSL_CB_LOOP)
4398 #define SSL_CB_CONNECT_EXIT (SSL_ST_CONNECT | SSL_CB_EXIT)
4399 #define SSL_CB_HANDSHAKE_START 0x10
4400 #define SSL_CB_HANDSHAKE_DONE 0x20
4401 
4402 // SSL_CTX_set_info_callback configures a callback to be run when various
4403 // events occur during a connection's lifetime. The |type| argument determines
4404 // the type of event and the meaning of the |value| argument. Callbacks must
4405 // ignore unexpected |type| values.
4406 //
4407 // |SSL_CB_READ_ALERT| is signaled for each alert received, warning or fatal.
4408 // The |value| argument is a 16-bit value where the alert level (either
4409 // |SSL3_AL_WARNING| or |SSL3_AL_FATAL|) is in the most-significant eight bits
4410 // and the alert type (one of |SSL_AD_*|) is in the least-significant eight.
4411 //
4412 // |SSL_CB_WRITE_ALERT| is signaled for each alert sent. The |value| argument
4413 // is constructed as with |SSL_CB_READ_ALERT|.
4414 //
4415 // |SSL_CB_HANDSHAKE_START| is signaled when a handshake begins. The |value|
4416 // argument is always one.
4417 //
4418 // |SSL_CB_HANDSHAKE_DONE| is signaled when a handshake completes successfully.
4419 // The |value| argument is always one. If a handshake False Starts, this event
4420 // may be used to determine when the Finished message is received.
4421 //
4422 // The following event types expose implementation details of the handshake
4423 // state machine. Consuming them is deprecated.
4424 //
4425 // |SSL_CB_ACCEPT_LOOP| (respectively, |SSL_CB_CONNECT_LOOP|) is signaled when
4426 // a server (respectively, client) handshake progresses. The |value| argument
4427 // is always one.
4428 //
4429 // |SSL_CB_ACCEPT_EXIT| (respectively, |SSL_CB_CONNECT_EXIT|) is signaled when
4430 // a server (respectively, client) handshake completes, fails, or is paused.
4431 // The |value| argument is one if the handshake succeeded and <= 0
4432 // otherwise.
4433 OPENSSL_EXPORT void SSL_CTX_set_info_callback(
4434     SSL_CTX *ctx, void (*cb)(const SSL *ssl, int type, int value));
4435 
4436 // SSL_CTX_get_info_callback returns the callback set by
4437 // |SSL_CTX_set_info_callback|.
4438 OPENSSL_EXPORT void (*SSL_CTX_get_info_callback(SSL_CTX *ctx))(const SSL *ssl,
4439                                                                int type,
4440                                                                int value);
4441 
4442 // SSL_set_info_callback configures a callback to be run at various events
4443 // during a connection's lifetime. See |SSL_CTX_set_info_callback|.
4444 OPENSSL_EXPORT void SSL_set_info_callback(
4445     SSL *ssl, void (*cb)(const SSL *ssl, int type, int value));
4446 
4447 // SSL_get_info_callback returns the callback set by |SSL_set_info_callback|.
4448 OPENSSL_EXPORT void (*SSL_get_info_callback(const SSL *ssl))(const SSL *ssl,
4449                                                              int type,
4450                                                              int value);
4451 
4452 // SSL_state_string_long returns the current state of the handshake state
4453 // machine as a string. This may be useful for debugging and logging.
4454 OPENSSL_EXPORT const char *SSL_state_string_long(const SSL *ssl);
4455 
4456 #define SSL_SENT_SHUTDOWN 1
4457 #define SSL_RECEIVED_SHUTDOWN 2
4458 
4459 // SSL_get_shutdown returns a bitmask with a subset of |SSL_SENT_SHUTDOWN| and
4460 // |SSL_RECEIVED_SHUTDOWN| to query whether close_notify was sent or received,
4461 // respectively.
4462 OPENSSL_EXPORT int SSL_get_shutdown(const SSL *ssl);
4463 
4464 // SSL_get_peer_signature_algorithm returns the signature algorithm used by the
4465 // peer. If not applicable, it returns zero.
4466 OPENSSL_EXPORT uint16_t SSL_get_peer_signature_algorithm(const SSL *ssl);
4467 
4468 // SSL_get_client_random writes up to |max_out| bytes of the most recent
4469 // handshake's client_random to |out| and returns the number of bytes written.
4470 // If |max_out| is zero, it returns the size of the client_random.
4471 OPENSSL_EXPORT size_t SSL_get_client_random(const SSL *ssl, uint8_t *out,
4472                                             size_t max_out);
4473 
4474 // SSL_get_server_random writes up to |max_out| bytes of the most recent
4475 // handshake's server_random to |out| and returns the number of bytes written.
4476 // If |max_out| is zero, it returns the size of the server_random.
4477 OPENSSL_EXPORT size_t SSL_get_server_random(const SSL *ssl, uint8_t *out,
4478                                             size_t max_out);
4479 
4480 // SSL_get_pending_cipher returns the cipher suite for the current handshake or
4481 // NULL if one has not been negotiated yet or there is no pending handshake.
4482 OPENSSL_EXPORT const SSL_CIPHER *SSL_get_pending_cipher(const SSL *ssl);
4483 
4484 // SSL_set_retain_only_sha256_of_client_certs, on a server, sets whether only
4485 // the SHA-256 hash of peer's certificate should be saved in memory and in the
4486 // session. This can save memory, ticket size and session cache space. If
4487 // enabled, |SSL_get_peer_certificate| will return NULL after the handshake
4488 // completes. See |SSL_SESSION_has_peer_sha256| and
4489 // |SSL_SESSION_get0_peer_sha256| to query the hash.
4490 OPENSSL_EXPORT void SSL_set_retain_only_sha256_of_client_certs(SSL *ssl,
4491                                                                int enable);
4492 
4493 // SSL_CTX_set_retain_only_sha256_of_client_certs, on a server, sets whether
4494 // only the SHA-256 hash of peer's certificate should be saved in memory and in
4495 // the session. This can save memory, ticket size and session cache space. If
4496 // enabled, |SSL_get_peer_certificate| will return NULL after the handshake
4497 // completes. See |SSL_SESSION_has_peer_sha256| and
4498 // |SSL_SESSION_get0_peer_sha256| to query the hash.
4499 OPENSSL_EXPORT void SSL_CTX_set_retain_only_sha256_of_client_certs(SSL_CTX *ctx,
4500                                                                    int enable);
4501 
4502 // SSL_CTX_set_grease_enabled configures whether sockets on |ctx| should enable
4503 // GREASE. See RFC 8701.
4504 OPENSSL_EXPORT void SSL_CTX_set_grease_enabled(SSL_CTX *ctx, int enabled);
4505 
4506 // SSL_CTX_set_permute_extensions configures whether sockets on |ctx| should
4507 // permute extensions. For now, this is only implemented for the ClientHello.
4508 OPENSSL_EXPORT void SSL_CTX_set_permute_extensions(SSL_CTX *ctx, int enabled);
4509 
4510 // SSL_set_permute_extensions configures whether sockets on |ssl| should
4511 // permute extensions. For now, this is only implemented for the ClientHello.
4512 OPENSSL_EXPORT void SSL_set_permute_extensions(SSL *ssl, int enabled);
4513 
4514 // SSL_max_seal_overhead returns the maximum overhead, in bytes, of sealing a
4515 // record with |ssl|.
4516 OPENSSL_EXPORT size_t SSL_max_seal_overhead(const SSL *ssl);
4517 
4518 // SSL_CTX_set_false_start_allowed_without_alpn configures whether connections
4519 // on |ctx| may use False Start (if |SSL_MODE_ENABLE_FALSE_START| is enabled)
4520 // without negotiating ALPN.
4521 OPENSSL_EXPORT void SSL_CTX_set_false_start_allowed_without_alpn(SSL_CTX *ctx,
4522                                                                  int allowed);
4523 
4524 // SSL_used_hello_retry_request returns one if the TLS 1.3 HelloRetryRequest
4525 // message has been either sent by the server or received by the client. It
4526 // returns zero otherwise.
4527 OPENSSL_EXPORT int SSL_used_hello_retry_request(const SSL *ssl);
4528 
4529 // SSL_set_jdk11_workaround configures whether to workaround various bugs in
4530 // JDK 11's TLS 1.3 implementation by disabling TLS 1.3 for such clients.
4531 //
4532 // https://bugs.openjdk.java.net/browse/JDK-8211806
4533 // https://bugs.openjdk.java.net/browse/JDK-8212885
4534 // https://bugs.openjdk.java.net/browse/JDK-8213202
4535 OPENSSL_EXPORT void SSL_set_jdk11_workaround(SSL *ssl, int enable);
4536 
4537 
4538 // Deprecated functions.
4539 
4540 // SSL_library_init calls |CRYPTO_library_init| and returns one.
4541 OPENSSL_EXPORT int SSL_library_init(void);
4542 
4543 // SSL_CIPHER_description writes a description of |cipher| into |buf| and
4544 // returns |buf|. If |buf| is NULL, it returns a newly allocated string, to be
4545 // freed with |OPENSSL_free|, or NULL on error.
4546 //
4547 // The description includes a trailing newline and has the form:
4548 // AES128-SHA              Kx=RSA      Au=RSA  Enc=AES(128)  Mac=SHA1
4549 //
4550 // Consider |SSL_CIPHER_standard_name| or |SSL_CIPHER_get_name| instead.
4551 OPENSSL_EXPORT const char *SSL_CIPHER_description(const SSL_CIPHER *cipher,
4552                                                   char *buf, int len);
4553 
4554 // SSL_CIPHER_get_version returns the string "TLSv1/SSLv3".
4555 OPENSSL_EXPORT const char *SSL_CIPHER_get_version(const SSL_CIPHER *cipher);
4556 
4557 typedef void COMP_METHOD;
4558 typedef struct ssl_comp_st SSL_COMP;
4559 
4560 // SSL_COMP_get_compression_methods returns NULL.
4561 OPENSSL_EXPORT STACK_OF(SSL_COMP) *SSL_COMP_get_compression_methods(void);
4562 
4563 // SSL_COMP_add_compression_method returns one.
4564 OPENSSL_EXPORT int SSL_COMP_add_compression_method(int id, COMP_METHOD *cm);
4565 
4566 // SSL_COMP_get_name returns NULL.
4567 OPENSSL_EXPORT const char *SSL_COMP_get_name(const COMP_METHOD *comp);
4568 
4569 // SSL_COMP_get0_name returns the |name| member of |comp|.
4570 OPENSSL_EXPORT const char *SSL_COMP_get0_name(const SSL_COMP *comp);
4571 
4572 // SSL_COMP_get_id returns the |id| member of |comp|.
4573 OPENSSL_EXPORT int SSL_COMP_get_id(const SSL_COMP *comp);
4574 
4575 // SSL_COMP_free_compression_methods does nothing.
4576 OPENSSL_EXPORT void SSL_COMP_free_compression_methods(void);
4577 
4578 // SSLv23_method calls |TLS_method|.
4579 OPENSSL_EXPORT const SSL_METHOD *SSLv23_method(void);
4580 
4581 // These version-specific methods behave exactly like |TLS_method| and
4582 // |DTLS_method| except they also call |SSL_CTX_set_min_proto_version| and
4583 // |SSL_CTX_set_max_proto_version| to lock connections to that protocol
4584 // version.
4585 OPENSSL_EXPORT const SSL_METHOD *TLSv1_method(void);
4586 OPENSSL_EXPORT const SSL_METHOD *TLSv1_1_method(void);
4587 OPENSSL_EXPORT const SSL_METHOD *TLSv1_2_method(void);
4588 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_method(void);
4589 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_2_method(void);
4590 
4591 // These client- and server-specific methods call their corresponding generic
4592 // methods.
4593 OPENSSL_EXPORT const SSL_METHOD *TLS_server_method(void);
4594 OPENSSL_EXPORT const SSL_METHOD *TLS_client_method(void);
4595 OPENSSL_EXPORT const SSL_METHOD *SSLv23_server_method(void);
4596 OPENSSL_EXPORT const SSL_METHOD *SSLv23_client_method(void);
4597 OPENSSL_EXPORT const SSL_METHOD *TLSv1_server_method(void);
4598 OPENSSL_EXPORT const SSL_METHOD *TLSv1_client_method(void);
4599 OPENSSL_EXPORT const SSL_METHOD *TLSv1_1_server_method(void);
4600 OPENSSL_EXPORT const SSL_METHOD *TLSv1_1_client_method(void);
4601 OPENSSL_EXPORT const SSL_METHOD *TLSv1_2_server_method(void);
4602 OPENSSL_EXPORT const SSL_METHOD *TLSv1_2_client_method(void);
4603 OPENSSL_EXPORT const SSL_METHOD *DTLS_server_method(void);
4604 OPENSSL_EXPORT const SSL_METHOD *DTLS_client_method(void);
4605 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_server_method(void);
4606 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_client_method(void);
4607 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_2_server_method(void);
4608 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_2_client_method(void);
4609 
4610 // SSL_clear resets |ssl| to allow another connection and returns one on success
4611 // or zero on failure. It returns most configuration state but releases memory
4612 // associated with the current connection.
4613 //
4614 // Free |ssl| and create a new one instead.
4615 OPENSSL_EXPORT int SSL_clear(SSL *ssl);
4616 
4617 // SSL_CTX_set_tmp_rsa_callback does nothing.
4618 OPENSSL_EXPORT void SSL_CTX_set_tmp_rsa_callback(
4619     SSL_CTX *ctx, RSA *(*cb)(SSL *ssl, int is_export, int keylength));
4620 
4621 // SSL_set_tmp_rsa_callback does nothing.
4622 OPENSSL_EXPORT void SSL_set_tmp_rsa_callback(SSL *ssl,
4623                                              RSA *(*cb)(SSL *ssl, int is_export,
4624                                                         int keylength));
4625 
4626 // SSL_CTX_sess_connect returns zero.
4627 OPENSSL_EXPORT int SSL_CTX_sess_connect(const SSL_CTX *ctx);
4628 
4629 // SSL_CTX_sess_connect_good returns zero.
4630 OPENSSL_EXPORT int SSL_CTX_sess_connect_good(const SSL_CTX *ctx);
4631 
4632 // SSL_CTX_sess_connect_renegotiate returns zero.
4633 OPENSSL_EXPORT int SSL_CTX_sess_connect_renegotiate(const SSL_CTX *ctx);
4634 
4635 // SSL_CTX_sess_accept returns zero.
4636 OPENSSL_EXPORT int SSL_CTX_sess_accept(const SSL_CTX *ctx);
4637 
4638 // SSL_CTX_sess_accept_renegotiate returns zero.
4639 OPENSSL_EXPORT int SSL_CTX_sess_accept_renegotiate(const SSL_CTX *ctx);
4640 
4641 // SSL_CTX_sess_accept_good returns zero.
4642 OPENSSL_EXPORT int SSL_CTX_sess_accept_good(const SSL_CTX *ctx);
4643 
4644 // SSL_CTX_sess_hits returns zero.
4645 OPENSSL_EXPORT int SSL_CTX_sess_hits(const SSL_CTX *ctx);
4646 
4647 // SSL_CTX_sess_cb_hits returns zero.
4648 OPENSSL_EXPORT int SSL_CTX_sess_cb_hits(const SSL_CTX *ctx);
4649 
4650 // SSL_CTX_sess_misses returns zero.
4651 OPENSSL_EXPORT int SSL_CTX_sess_misses(const SSL_CTX *ctx);
4652 
4653 // SSL_CTX_sess_timeouts returns zero.
4654 OPENSSL_EXPORT int SSL_CTX_sess_timeouts(const SSL_CTX *ctx);
4655 
4656 // SSL_CTX_sess_cache_full returns zero.
4657 OPENSSL_EXPORT int SSL_CTX_sess_cache_full(const SSL_CTX *ctx);
4658 
4659 // SSL_cutthrough_complete calls |SSL_in_false_start|.
4660 OPENSSL_EXPORT int SSL_cutthrough_complete(const SSL *ssl);
4661 
4662 // SSL_num_renegotiations calls |SSL_total_renegotiations|.
4663 OPENSSL_EXPORT int SSL_num_renegotiations(const SSL *ssl);
4664 
4665 // SSL_CTX_need_tmp_RSA returns zero.
4666 OPENSSL_EXPORT int SSL_CTX_need_tmp_RSA(const SSL_CTX *ctx);
4667 
4668 // SSL_need_tmp_RSA returns zero.
4669 OPENSSL_EXPORT int SSL_need_tmp_RSA(const SSL *ssl);
4670 
4671 // SSL_CTX_set_tmp_rsa returns one.
4672 OPENSSL_EXPORT int SSL_CTX_set_tmp_rsa(SSL_CTX *ctx, const RSA *rsa);
4673 
4674 // SSL_set_tmp_rsa returns one.
4675 OPENSSL_EXPORT int SSL_set_tmp_rsa(SSL *ssl, const RSA *rsa);
4676 
4677 // SSL_CTX_get_read_ahead returns zero.
4678 OPENSSL_EXPORT int SSL_CTX_get_read_ahead(const SSL_CTX *ctx);
4679 
4680 // SSL_CTX_set_read_ahead returns one.
4681 OPENSSL_EXPORT int SSL_CTX_set_read_ahead(SSL_CTX *ctx, int yes);
4682 
4683 // SSL_get_read_ahead returns zero.
4684 OPENSSL_EXPORT int SSL_get_read_ahead(const SSL *ssl);
4685 
4686 // SSL_set_read_ahead returns one.
4687 OPENSSL_EXPORT int SSL_set_read_ahead(SSL *ssl, int yes);
4688 
4689 // SSL_set_state does nothing.
4690 OPENSSL_EXPORT void SSL_set_state(SSL *ssl, int state);
4691 
4692 // SSL_get_shared_ciphers writes an empty string to |buf| and returns a
4693 // pointer to |buf|, or NULL if |len| is less than or equal to zero.
4694 OPENSSL_EXPORT char *SSL_get_shared_ciphers(const SSL *ssl, char *buf, int len);
4695 
4696 // SSL_get_shared_sigalgs returns zero.
4697 OPENSSL_EXPORT int SSL_get_shared_sigalgs(SSL *ssl, int idx, int *psign,
4698                                           int *phash, int *psignandhash,
4699                                           uint8_t *rsig, uint8_t *rhash);
4700 
4701 // SSL_MODE_HANDSHAKE_CUTTHROUGH is the same as SSL_MODE_ENABLE_FALSE_START.
4702 #define SSL_MODE_HANDSHAKE_CUTTHROUGH SSL_MODE_ENABLE_FALSE_START
4703 
4704 // i2d_SSL_SESSION serializes |in|, as described in |i2d_SAMPLE|.
4705 //
4706 // Use |SSL_SESSION_to_bytes| instead.
4707 OPENSSL_EXPORT int i2d_SSL_SESSION(SSL_SESSION *in, uint8_t **pp);
4708 
4709 // d2i_SSL_SESSION parses a serialized session from the |length| bytes pointed
4710 // to by |*pp|, as described in |d2i_SAMPLE|.
4711 //
4712 // Use |SSL_SESSION_from_bytes| instead.
4713 OPENSSL_EXPORT SSL_SESSION *d2i_SSL_SESSION(SSL_SESSION **a, const uint8_t **pp,
4714                                             long length);
4715 
4716 // i2d_SSL_SESSION_bio serializes |session| and writes the result to |bio|. It
4717 // returns the number of bytes written on success and <= 0 on error.
4718 OPENSSL_EXPORT int i2d_SSL_SESSION_bio(BIO *bio, const SSL_SESSION *session);
4719 
4720 // d2i_SSL_SESSION_bio reads a serialized |SSL_SESSION| from |bio| and returns a
4721 // newly-allocated |SSL_SESSION| or NULL on error. If |out| is not NULL, it also
4722 // frees |*out| and sets |*out| to the new |SSL_SESSION|.
4723 OPENSSL_EXPORT SSL_SESSION *d2i_SSL_SESSION_bio(BIO *bio, SSL_SESSION **out);
4724 
4725 // ERR_load_SSL_strings does nothing.
4726 OPENSSL_EXPORT void ERR_load_SSL_strings(void);
4727 
4728 // SSL_load_error_strings does nothing.
4729 OPENSSL_EXPORT void SSL_load_error_strings(void);
4730 
4731 // SSL_CTX_set_tlsext_use_srtp calls |SSL_CTX_set_srtp_profiles|. It returns
4732 // zero on success and one on failure.
4733 //
4734 // WARNING: this function is dangerous because it breaks the usual return value
4735 // convention. Use |SSL_CTX_set_srtp_profiles| instead.
4736 OPENSSL_EXPORT int SSL_CTX_set_tlsext_use_srtp(SSL_CTX *ctx,
4737                                                const char *profiles);
4738 
4739 // SSL_set_tlsext_use_srtp calls |SSL_set_srtp_profiles|. It returns zero on
4740 // success and one on failure.
4741 //
4742 // WARNING: this function is dangerous because it breaks the usual return value
4743 // convention. Use |SSL_set_srtp_profiles| instead.
4744 OPENSSL_EXPORT int SSL_set_tlsext_use_srtp(SSL *ssl, const char *profiles);
4745 
4746 // SSL_get_current_compression returns NULL.
4747 OPENSSL_EXPORT const COMP_METHOD *SSL_get_current_compression(SSL *ssl);
4748 
4749 // SSL_get_current_expansion returns NULL.
4750 OPENSSL_EXPORT const COMP_METHOD *SSL_get_current_expansion(SSL *ssl);
4751 
4752 // SSL_get_server_tmp_key returns zero.
4753 OPENSSL_EXPORT int SSL_get_server_tmp_key(SSL *ssl, EVP_PKEY **out_key);
4754 
4755 // SSL_CTX_set_tmp_dh returns 1.
4756 OPENSSL_EXPORT int SSL_CTX_set_tmp_dh(SSL_CTX *ctx, const DH *dh);
4757 
4758 // SSL_set_tmp_dh returns 1.
4759 OPENSSL_EXPORT int SSL_set_tmp_dh(SSL *ssl, const DH *dh);
4760 
4761 // SSL_CTX_set_tmp_dh_callback does nothing.
4762 OPENSSL_EXPORT void SSL_CTX_set_tmp_dh_callback(
4763     SSL_CTX *ctx, DH *(*cb)(SSL *ssl, int is_export, int keylength));
4764 
4765 // SSL_set_tmp_dh_callback does nothing.
4766 OPENSSL_EXPORT void SSL_set_tmp_dh_callback(SSL *ssl,
4767                                             DH *(*cb)(SSL *ssl, int is_export,
4768                                                       int keylength));
4769 
4770 // SSL_CTX_set1_sigalgs takes |num_values| ints and interprets them as pairs
4771 // where the first is the nid of a hash function and the second is an
4772 // |EVP_PKEY_*| value. It configures the signature algorithm preferences for
4773 // |ctx| based on them and returns one on success or zero on error.
4774 //
4775 // This API is compatible with OpenSSL. However, BoringSSL-specific code should
4776 // prefer |SSL_CTX_set_signing_algorithm_prefs| because it's clearer and it's
4777 // more convenient to codesearch for specific algorithm values.
4778 OPENSSL_EXPORT int SSL_CTX_set1_sigalgs(SSL_CTX *ctx, const int *values,
4779                                         size_t num_values);
4780 
4781 // SSL_set1_sigalgs takes |num_values| ints and interprets them as pairs where
4782 // the first is the nid of a hash function and the second is an |EVP_PKEY_*|
4783 // value. It configures the signature algorithm preferences for |ssl| based on
4784 // them and returns one on success or zero on error.
4785 //
4786 // This API is compatible with OpenSSL. However, BoringSSL-specific code should
4787 // prefer |SSL_CTX_set_signing_algorithm_prefs| because it's clearer and it's
4788 // more convenient to codesearch for specific algorithm values.
4789 OPENSSL_EXPORT int SSL_set1_sigalgs(SSL *ssl, const int *values,
4790                                     size_t num_values);
4791 
4792 // SSL_CTX_set1_sigalgs_list takes a textual specification of a set of signature
4793 // algorithms and configures them on |ctx|. It returns one on success and zero
4794 // on error. See
4795 // https://www.openssl.org/docs/man1.1.0/man3/SSL_CTX_set1_sigalgs_list.html for
4796 // a description of the text format. Also note that TLS 1.3 names (e.g.
4797 // "rsa_pkcs1_md5_sha1") can also be used (as in OpenSSL, although OpenSSL
4798 // doesn't document that).
4799 //
4800 // This API is compatible with OpenSSL. However, BoringSSL-specific code should
4801 // prefer |SSL_CTX_set_signing_algorithm_prefs| because it's clearer and it's
4802 // more convenient to codesearch for specific algorithm values.
4803 OPENSSL_EXPORT int SSL_CTX_set1_sigalgs_list(SSL_CTX *ctx, const char *str);
4804 
4805 // SSL_set1_sigalgs_list takes a textual specification of a set of signature
4806 // algorithms and configures them on |ssl|. It returns one on success and zero
4807 // on error. See
4808 // https://www.openssl.org/docs/man1.1.0/man3/SSL_CTX_set1_sigalgs_list.html for
4809 // a description of the text format. Also note that TLS 1.3 names (e.g.
4810 // "rsa_pkcs1_md5_sha1") can also be used (as in OpenSSL, although OpenSSL
4811 // doesn't document that).
4812 //
4813 // This API is compatible with OpenSSL. However, BoringSSL-specific code should
4814 // prefer |SSL_CTX_set_signing_algorithm_prefs| because it's clearer and it's
4815 // more convenient to codesearch for specific algorithm values.
4816 OPENSSL_EXPORT int SSL_set1_sigalgs_list(SSL *ssl, const char *str);
4817 
4818 #define SSL_set_app_data(s, arg) (SSL_set_ex_data(s, 0, (char *)(arg)))
4819 #define SSL_get_app_data(s) (SSL_get_ex_data(s, 0))
4820 #define SSL_SESSION_set_app_data(s, a) \
4821   (SSL_SESSION_set_ex_data(s, 0, (char *)(a)))
4822 #define SSL_SESSION_get_app_data(s) (SSL_SESSION_get_ex_data(s, 0))
4823 #define SSL_CTX_get_app_data(ctx) (SSL_CTX_get_ex_data(ctx, 0))
4824 #define SSL_CTX_set_app_data(ctx, arg) \
4825   (SSL_CTX_set_ex_data(ctx, 0, (char *)(arg)))
4826 
4827 #define OpenSSL_add_ssl_algorithms() SSL_library_init()
4828 #define SSLeay_add_ssl_algorithms() SSL_library_init()
4829 
4830 #define SSL_get_cipher(ssl) SSL_CIPHER_get_name(SSL_get_current_cipher(ssl))
4831 #define SSL_get_cipher_bits(ssl, out_alg_bits) \
4832     SSL_CIPHER_get_bits(SSL_get_current_cipher(ssl), out_alg_bits)
4833 #define SSL_get_cipher_version(ssl) \
4834     SSL_CIPHER_get_version(SSL_get_current_cipher(ssl))
4835 #define SSL_get_cipher_name(ssl) \
4836     SSL_CIPHER_get_name(SSL_get_current_cipher(ssl))
4837 #define SSL_get_time(session) SSL_SESSION_get_time(session)
4838 #define SSL_set_time(session, time) SSL_SESSION_set_time((session), (time))
4839 #define SSL_get_timeout(session) SSL_SESSION_get_timeout(session)
4840 #define SSL_set_timeout(session, timeout) \
4841     SSL_SESSION_set_timeout((session), (timeout))
4842 
4843 struct ssl_comp_st {
4844   int id;
4845   const char *name;
4846   char *method;
4847 };
4848 
4849 DEFINE_STACK_OF(SSL_COMP)
4850 
4851 // The following flags do nothing and are included only to make it easier to
4852 // compile code with BoringSSL.
4853 #define SSL_MODE_AUTO_RETRY 0
4854 #define SSL_MODE_RELEASE_BUFFERS 0
4855 #define SSL_MODE_SEND_CLIENTHELLO_TIME 0
4856 #define SSL_MODE_SEND_SERVERHELLO_TIME 0
4857 #define SSL_OP_ALL 0
4858 #define SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION 0
4859 #define SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS 0
4860 #define SSL_OP_EPHEMERAL_RSA 0
4861 #define SSL_OP_LEGACY_SERVER_CONNECT 0
4862 #define SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER 0
4863 #define SSL_OP_MICROSOFT_SESS_ID_BUG 0
4864 #define SSL_OP_MSIE_SSLV2_RSA_PADDING 0
4865 #define SSL_OP_NETSCAPE_CA_DN_BUG 0
4866 #define SSL_OP_NETSCAPE_CHALLENGE_BUG 0
4867 #define SSL_OP_NETSCAPE_DEMO_CIPHER_CHANGE_BUG 0
4868 #define SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG 0
4869 #define SSL_OP_NO_COMPRESSION 0
4870 #define SSL_OP_NO_RENEGOTIATION 0  // ssl_renegotiate_never is the default
4871 #define SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION 0
4872 #define SSL_OP_NO_SSLv2 0
4873 #define SSL_OP_NO_SSLv3 0
4874 #define SSL_OP_PKCS1_CHECK_1 0
4875 #define SSL_OP_PKCS1_CHECK_2 0
4876 #define SSL_OP_SINGLE_DH_USE 0
4877 #define SSL_OP_SINGLE_ECDH_USE 0
4878 #define SSL_OP_SSLEAY_080_CLIENT_DH_BUG 0
4879 #define SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG 0
4880 #define SSL_OP_TLS_BLOCK_PADDING_BUG 0
4881 #define SSL_OP_TLS_D5_BUG 0
4882 #define SSL_OP_TLS_ROLLBACK_BUG 0
4883 #define SSL_VERIFY_CLIENT_ONCE 0
4884 
4885 // SSL_cache_hit calls |SSL_session_reused|.
4886 OPENSSL_EXPORT int SSL_cache_hit(SSL *ssl);
4887 
4888 // SSL_get_default_timeout returns |SSL_DEFAULT_SESSION_TIMEOUT|.
4889 OPENSSL_EXPORT long SSL_get_default_timeout(const SSL *ssl);
4890 
4891 // SSL_get_version returns a string describing the TLS version used by |ssl|.
4892 // For example, "TLSv1.2" or "DTLSv1".
4893 OPENSSL_EXPORT const char *SSL_get_version(const SSL *ssl);
4894 
4895 // SSL_get_cipher_list returns the name of the |n|th cipher in the output of
4896 // |SSL_get_ciphers| or NULL if out of range. Use |SSL_get_ciphers| instead.
4897 OPENSSL_EXPORT const char *SSL_get_cipher_list(const SSL *ssl, int n);
4898 
4899 // SSL_CTX_set_client_cert_cb sets a callback which is called on the client if
4900 // the server requests a client certificate and none is configured. On success,
4901 // the callback should return one and set |*out_x509| to |*out_pkey| to a leaf
4902 // certificate and private key, respectively, passing ownership. It should
4903 // return zero to send no certificate and -1 to fail or pause the handshake. If
4904 // the handshake is paused, |SSL_get_error| will return
4905 // |SSL_ERROR_WANT_X509_LOOKUP|.
4906 //
4907 // The callback may call |SSL_get0_certificate_types| and
4908 // |SSL_get_client_CA_list| for information on the server's certificate request.
4909 //
4910 // Use |SSL_CTX_set_cert_cb| instead. Configuring intermediate certificates with
4911 // this function is confusing. This callback may not be registered concurrently
4912 // with |SSL_CTX_set_cert_cb| or |SSL_set_cert_cb|.
4913 OPENSSL_EXPORT void SSL_CTX_set_client_cert_cb(
4914     SSL_CTX *ctx, int (*cb)(SSL *ssl, X509 **out_x509, EVP_PKEY **out_pkey));
4915 
4916 #define SSL_NOTHING SSL_ERROR_NONE
4917 #define SSL_WRITING SSL_ERROR_WANT_WRITE
4918 #define SSL_READING SSL_ERROR_WANT_READ
4919 
4920 // SSL_want returns one of the above values to determine what the most recent
4921 // operation on |ssl| was blocked on. Use |SSL_get_error| instead.
4922 OPENSSL_EXPORT int SSL_want(const SSL *ssl);
4923 
4924 #define SSL_want_read(ssl) (SSL_want(ssl) == SSL_READING)
4925 #define SSL_want_write(ssl) (SSL_want(ssl) == SSL_WRITING)
4926 
4927  // SSL_get_finished writes up to |count| bytes of the Finished message sent by
4928  // |ssl| to |buf|. It returns the total untruncated length or zero if none has
4929  // been sent yet. At TLS 1.3 and later, it returns zero.
4930  //
4931  // Use |SSL_get_tls_unique| instead.
4932 OPENSSL_EXPORT size_t SSL_get_finished(const SSL *ssl, void *buf, size_t count);
4933 
4934  // SSL_get_peer_finished writes up to |count| bytes of the Finished message
4935  // received from |ssl|'s peer to |buf|. It returns the total untruncated length
4936  // or zero if none has been received yet. At TLS 1.3 and later, it returns
4937  // zero.
4938  //
4939  // Use |SSL_get_tls_unique| instead.
4940 OPENSSL_EXPORT size_t SSL_get_peer_finished(const SSL *ssl, void *buf,
4941                                             size_t count);
4942 
4943 // SSL_alert_type_string returns "!". Use |SSL_alert_type_string_long|
4944 // instead.
4945 OPENSSL_EXPORT const char *SSL_alert_type_string(int value);
4946 
4947 // SSL_alert_desc_string returns "!!". Use |SSL_alert_desc_string_long|
4948 // instead.
4949 OPENSSL_EXPORT const char *SSL_alert_desc_string(int value);
4950 
4951 // SSL_state_string returns "!!!!!!". Use |SSL_state_string_long| for a more
4952 // intelligible string.
4953 OPENSSL_EXPORT const char *SSL_state_string(const SSL *ssl);
4954 
4955 // SSL_TXT_* expand to strings.
4956 #define SSL_TXT_MEDIUM "MEDIUM"
4957 #define SSL_TXT_HIGH "HIGH"
4958 #define SSL_TXT_FIPS "FIPS"
4959 #define SSL_TXT_kRSA "kRSA"
4960 #define SSL_TXT_kDHE "kDHE"
4961 #define SSL_TXT_kEDH "kEDH"
4962 #define SSL_TXT_kECDHE "kECDHE"
4963 #define SSL_TXT_kEECDH "kEECDH"
4964 #define SSL_TXT_kPSK "kPSK"
4965 #define SSL_TXT_aRSA "aRSA"
4966 #define SSL_TXT_aECDSA "aECDSA"
4967 #define SSL_TXT_aPSK "aPSK"
4968 #define SSL_TXT_DH "DH"
4969 #define SSL_TXT_DHE "DHE"
4970 #define SSL_TXT_EDH "EDH"
4971 #define SSL_TXT_RSA "RSA"
4972 #define SSL_TXT_ECDH "ECDH"
4973 #define SSL_TXT_ECDHE "ECDHE"
4974 #define SSL_TXT_EECDH "EECDH"
4975 #define SSL_TXT_ECDSA "ECDSA"
4976 #define SSL_TXT_PSK "PSK"
4977 #define SSL_TXT_3DES "3DES"
4978 #define SSL_TXT_RC4 "RC4"
4979 #define SSL_TXT_AES128 "AES128"
4980 #define SSL_TXT_AES256 "AES256"
4981 #define SSL_TXT_AES "AES"
4982 #define SSL_TXT_AES_GCM "AESGCM"
4983 #define SSL_TXT_CHACHA20 "CHACHA20"
4984 #define SSL_TXT_MD5 "MD5"
4985 #define SSL_TXT_SHA1 "SHA1"
4986 #define SSL_TXT_SHA "SHA"
4987 #define SSL_TXT_SHA256 "SHA256"
4988 #define SSL_TXT_SHA384 "SHA384"
4989 #define SSL_TXT_SSLV3 "SSLv3"
4990 #define SSL_TXT_TLSV1 "TLSv1"
4991 #define SSL_TXT_TLSV1_1 "TLSv1.1"
4992 #define SSL_TXT_TLSV1_2 "TLSv1.2"
4993 #define SSL_TXT_TLSV1_3 "TLSv1.3"
4994 #define SSL_TXT_ALL "ALL"
4995 #define SSL_TXT_CMPDEF "COMPLEMENTOFDEFAULT"
4996 
4997 typedef struct ssl_conf_ctx_st SSL_CONF_CTX;
4998 
4999 // SSL_state returns |SSL_ST_INIT| if a handshake is in progress and |SSL_ST_OK|
5000 // otherwise.
5001 //
5002 // Use |SSL_is_init| instead.
5003 OPENSSL_EXPORT int SSL_state(const SSL *ssl);
5004 
5005 #define SSL_get_state(ssl) SSL_state(ssl)
5006 
5007 // SSL_set_shutdown causes |ssl| to behave as if the shutdown bitmask (see
5008 // |SSL_get_shutdown|) were |mode|. This may be used to skip sending or
5009 // receiving close_notify in |SSL_shutdown| by causing the implementation to
5010 // believe the events already happened.
5011 //
5012 // It is an error to use |SSL_set_shutdown| to unset a bit that has already been
5013 // set. Doing so will trigger an |assert| in debug builds and otherwise be
5014 // ignored.
5015 //
5016 // Use |SSL_CTX_set_quiet_shutdown| instead.
5017 OPENSSL_EXPORT void SSL_set_shutdown(SSL *ssl, int mode);
5018 
5019 // SSL_CTX_set_tmp_ecdh calls |SSL_CTX_set1_curves| with a one-element list
5020 // containing |ec_key|'s curve.
5021 OPENSSL_EXPORT int SSL_CTX_set_tmp_ecdh(SSL_CTX *ctx, const EC_KEY *ec_key);
5022 
5023 // SSL_set_tmp_ecdh calls |SSL_set1_curves| with a one-element list containing
5024 // |ec_key|'s curve.
5025 OPENSSL_EXPORT int SSL_set_tmp_ecdh(SSL *ssl, const EC_KEY *ec_key);
5026 
5027 // SSL_add_dir_cert_subjects_to_stack lists files in directory |dir|. It calls
5028 // |SSL_add_file_cert_subjects_to_stack| on each file and returns one on success
5029 // or zero on error. This function is only available from the libdecrepit
5030 // library.
5031 OPENSSL_EXPORT int SSL_add_dir_cert_subjects_to_stack(STACK_OF(X509_NAME) *out,
5032                                                       const char *dir);
5033 
5034 // SSL_CTX_enable_tls_channel_id calls |SSL_CTX_set_tls_channel_id_enabled|.
5035 OPENSSL_EXPORT int SSL_CTX_enable_tls_channel_id(SSL_CTX *ctx);
5036 
5037 // SSL_enable_tls_channel_id calls |SSL_set_tls_channel_id_enabled|.
5038 OPENSSL_EXPORT int SSL_enable_tls_channel_id(SSL *ssl);
5039 
5040 // BIO_f_ssl returns a |BIO_METHOD| that can wrap an |SSL*| in a |BIO*|. Note
5041 // that this has quite different behaviour from the version in OpenSSL (notably
5042 // that it doesn't try to auto renegotiate).
5043 //
5044 // IMPORTANT: if you are not curl, don't use this.
5045 OPENSSL_EXPORT const BIO_METHOD *BIO_f_ssl(void);
5046 
5047 // BIO_set_ssl sets |ssl| as the underlying connection for |bio|, which must
5048 // have been created using |BIO_f_ssl|. If |take_owership| is true, |bio| will
5049 // call |SSL_free| on |ssl| when closed. It returns one on success or something
5050 // other than one on error.
5051 OPENSSL_EXPORT long BIO_set_ssl(BIO *bio, SSL *ssl, int take_owership);
5052 
5053 // SSL_CTX_set_ecdh_auto returns one.
5054 #define SSL_CTX_set_ecdh_auto(ctx, onoff) 1
5055 
5056 // SSL_set_ecdh_auto returns one.
5057 #define SSL_set_ecdh_auto(ssl, onoff) 1
5058 
5059 // SSL_get_session returns a non-owning pointer to |ssl|'s session. For
5060 // historical reasons, which session it returns depends on |ssl|'s state.
5061 //
5062 // Prior to the start of the initial handshake, it returns the session the
5063 // caller set with |SSL_set_session|. After the initial handshake has finished
5064 // and if no additional handshakes are in progress, it returns the currently
5065 // active session. Its behavior is undefined while a handshake is in progress.
5066 //
5067 // If trying to add new sessions to an external session cache, use
5068 // |SSL_CTX_sess_set_new_cb| instead. In particular, using the callback is
5069 // required as of TLS 1.3. For compatibility, this function will return an
5070 // unresumable session which may be cached, but will never be resumed.
5071 //
5072 // If querying properties of the connection, use APIs on the |SSL| object.
5073 OPENSSL_EXPORT SSL_SESSION *SSL_get_session(const SSL *ssl);
5074 
5075 // SSL_get0_session is an alias for |SSL_get_session|.
5076 #define SSL_get0_session SSL_get_session
5077 
5078 // SSL_get1_session acts like |SSL_get_session| but returns a new reference to
5079 // the session.
5080 OPENSSL_EXPORT SSL_SESSION *SSL_get1_session(SSL *ssl);
5081 
5082 #define OPENSSL_INIT_NO_LOAD_SSL_STRINGS 0
5083 #define OPENSSL_INIT_LOAD_SSL_STRINGS 0
5084 #define OPENSSL_INIT_SSL_DEFAULT 0
5085 
5086 // OPENSSL_init_ssl calls |CRYPTO_library_init| and returns one.
5087 OPENSSL_EXPORT int OPENSSL_init_ssl(uint64_t opts,
5088                                     const OPENSSL_INIT_SETTINGS *settings);
5089 
5090 // The following constants are legacy aliases for RSA-PSS with rsaEncryption
5091 // keys. Use the new names instead.
5092 #define SSL_SIGN_RSA_PSS_SHA256 SSL_SIGN_RSA_PSS_RSAE_SHA256
5093 #define SSL_SIGN_RSA_PSS_SHA384 SSL_SIGN_RSA_PSS_RSAE_SHA384
5094 #define SSL_SIGN_RSA_PSS_SHA512 SSL_SIGN_RSA_PSS_RSAE_SHA512
5095 
5096 // SSL_set_tlsext_status_type configures a client to request OCSP stapling if
5097 // |type| is |TLSEXT_STATUSTYPE_ocsp| and disables it otherwise. It returns one
5098 // on success and zero if handshake configuration has already been shed.
5099 //
5100 // Use |SSL_enable_ocsp_stapling| instead.
5101 OPENSSL_EXPORT int SSL_set_tlsext_status_type(SSL *ssl, int type);
5102 
5103 // SSL_get_tlsext_status_type returns |TLSEXT_STATUSTYPE_ocsp| if the client
5104 // requested OCSP stapling and |TLSEXT_STATUSTYPE_nothing| otherwise. On the
5105 // client, this reflects whether OCSP stapling was enabled via, e.g.,
5106 // |SSL_set_tlsext_status_type|. On the server, this is determined during the
5107 // handshake. It may be queried in callbacks set by |SSL_CTX_set_cert_cb|. The
5108 // result is undefined after the handshake completes.
5109 OPENSSL_EXPORT int SSL_get_tlsext_status_type(const SSL *ssl);
5110 
5111 // SSL_set_tlsext_status_ocsp_resp sets the OCSP response. It returns one on
5112 // success and zero on error. On success, |ssl| takes ownership of |resp|, which
5113 // must have been allocated by |OPENSSL_malloc|.
5114 //
5115 // Use |SSL_set_ocsp_response| instead.
5116 OPENSSL_EXPORT int SSL_set_tlsext_status_ocsp_resp(SSL *ssl, uint8_t *resp,
5117                                                    size_t resp_len);
5118 
5119 // SSL_get_tlsext_status_ocsp_resp sets |*out| to point to the OCSP response
5120 // from the server. It returns the length of the response. If there was no
5121 // response, it sets |*out| to NULL and returns zero.
5122 //
5123 // Use |SSL_get0_ocsp_response| instead.
5124 //
5125 // WARNING: the returned data is not guaranteed to be well formed.
5126 OPENSSL_EXPORT size_t SSL_get_tlsext_status_ocsp_resp(const SSL *ssl,
5127                                                       const uint8_t **out);
5128 
5129 // SSL_CTX_set_tlsext_status_cb configures the legacy OpenSSL OCSP callback and
5130 // returns one. Though the type signature is the same, this callback has
5131 // different behavior for client and server connections:
5132 //
5133 // For clients, the callback is called after certificate verification. It should
5134 // return one for success, zero for a bad OCSP response, and a negative number
5135 // for internal error. Instead, handle this as part of certificate verification.
5136 // (Historically, OpenSSL verified certificates just before parsing stapled OCSP
5137 // responses, but BoringSSL fixes this ordering. All server credentials are
5138 // available during verification.)
5139 //
5140 // Do not use this callback as a server. It is provided for compatibility
5141 // purposes only. For servers, it is called to configure server credentials. It
5142 // should return |SSL_TLSEXT_ERR_OK| on success, |SSL_TLSEXT_ERR_NOACK| to
5143 // ignore OCSP requests, or |SSL_TLSEXT_ERR_ALERT_FATAL| on error. It is usually
5144 // used to fetch OCSP responses on demand, which is not ideal. Instead, treat
5145 // OCSP responses like other server credentials, such as certificates or SCT
5146 // lists. Configure, store, and refresh them eagerly. This avoids downtime if
5147 // the CA's OCSP responder is briefly offline.
5148 OPENSSL_EXPORT int SSL_CTX_set_tlsext_status_cb(SSL_CTX *ctx,
5149                                                 int (*callback)(SSL *ssl,
5150                                                                 void *arg));
5151 
5152 // SSL_CTX_set_tlsext_status_arg sets additional data for
5153 // |SSL_CTX_set_tlsext_status_cb|'s callback and returns one.
5154 OPENSSL_EXPORT int SSL_CTX_set_tlsext_status_arg(SSL_CTX *ctx, void *arg);
5155 
5156 // The following symbols are compatibility aliases for reason codes used when
5157 // receiving an alert from the peer. Use the other names instead, which fit the
5158 // naming convention.
5159 //
5160 // TODO(davidben): Fix references to |SSL_R_TLSV1_CERTIFICATE_REQUIRED| and
5161 // remove the compatibility value. The others come from OpenSSL.
5162 #define SSL_R_TLSV1_UNSUPPORTED_EXTENSION \
5163   SSL_R_TLSV1_ALERT_UNSUPPORTED_EXTENSION
5164 #define SSL_R_TLSV1_CERTIFICATE_UNOBTAINABLE \
5165   SSL_R_TLSV1_ALERT_CERTIFICATE_UNOBTAINABLE
5166 #define SSL_R_TLSV1_UNRECOGNIZED_NAME SSL_R_TLSV1_ALERT_UNRECOGNIZED_NAME
5167 #define SSL_R_TLSV1_BAD_CERTIFICATE_STATUS_RESPONSE \
5168   SSL_R_TLSV1_ALERT_BAD_CERTIFICATE_STATUS_RESPONSE
5169 #define SSL_R_TLSV1_BAD_CERTIFICATE_HASH_VALUE \
5170   SSL_R_TLSV1_ALERT_BAD_CERTIFICATE_HASH_VALUE
5171 #define SSL_R_TLSV1_CERTIFICATE_REQUIRED SSL_R_TLSV1_ALERT_CERTIFICATE_REQUIRED
5172 
5173 // SSL_CIPHER_get_value calls |SSL_CIPHER_get_protocol_id|.
5174 //
5175 // TODO(davidben): |SSL_CIPHER_get_value| was our name for this function, but
5176 // upstream added it as |SSL_CIPHER_get_protocol_id|. Switch callers to the new
5177 // name and remove this one.
5178 OPENSSL_EXPORT uint16_t SSL_CIPHER_get_value(const SSL_CIPHER *cipher);
5179 
5180 
5181 // Compliance policy configurations
5182 //
5183 // A TLS connection has a large number of different parameters. Some are well
5184 // known, like cipher suites, but many are obscure and configuration functions
5185 // for them may not exist. These policy controls allow broad configuration
5186 // goals to be specified so that they can flow down to all the different
5187 // parameters of a TLS connection.
5188 
5189 enum ssl_compliance_policy_t BORINGSSL_ENUM_INT {
5190   // ssl_policy_fips_202205 configures a TLS connection to use:
5191   //   * TLS 1.2 or 1.3
5192   //   * For TLS 1.2, only ECDHE_[RSA|ECDSA]_WITH_AES_*_GCM_SHA*.
5193   //   * For TLS 1.3, only AES-GCM
5194   //   * P-256 or P-384 for key agreement.
5195   //   * For server signatures, only PKCS#1/PSS with SHA256/384/512, or ECDSA
5196   //     with P-256 or P-384.
5197   //
5198   // Note: this policy can be configured even if BoringSSL has not been built in
5199   // FIPS mode. Call |FIPS_mode| to check that.
5200   //
5201   // Note: this setting aids with compliance with NIST requirements but does not
5202   // guarantee it. Careful reading of SP 800-52r2 is recommended.
5203   ssl_compliance_policy_fips_202205,
5204 };
5205 
5206 // SSL_CTX_set_compliance_policy configures various aspects of |ctx| based on
5207 // the given policy requirements. Subsequently calling other functions that
5208 // configure |ctx| may override |policy|, or may not. This should be the final
5209 // configuration function called in order to have defined behaviour.
5210 OPENSSL_EXPORT int SSL_CTX_set_compliance_policy(
5211     SSL_CTX *ctx, enum ssl_compliance_policy_t policy);
5212 
5213 // SSL_set_compliance_policy acts the same as |SSL_CTX_set_compliance_policy|,
5214 // but only configures a single |SSL*|.
5215 OPENSSL_EXPORT int SSL_set_compliance_policy(
5216     SSL *ssl, enum ssl_compliance_policy_t policy);
5217 
5218 
5219 // Nodejs compatibility section (hidden).
5220 //
5221 // These defines exist for node.js, with the hope that we can eliminate the
5222 // need for them over time.
5223 
5224 #define SSLerr(function, reason) \
5225   ERR_put_error(ERR_LIB_SSL, 0, reason, __FILE__, __LINE__)
5226 
5227 
5228 // Preprocessor compatibility section (hidden).
5229 //
5230 // Historically, a number of APIs were implemented in OpenSSL as macros and
5231 // constants to 'ctrl' functions. To avoid breaking #ifdefs in consumers, this
5232 // section defines a number of legacy macros.
5233 //
5234 // Although using either the CTRL values or their wrapper macros in #ifdefs is
5235 // still supported, the CTRL values may not be passed to |SSL_ctrl| and
5236 // |SSL_CTX_ctrl|. Call the functions (previously wrapper macros) instead.
5237 //
5238 // See PORTING.md in the BoringSSL source tree for a table of corresponding
5239 // functions.
5240 // https://boringssl.googlesource.com/boringssl/+/master/PORTING.md#Replacements-for-values
5241 
5242 #define DTLS_CTRL_GET_TIMEOUT doesnt_exist
5243 #define DTLS_CTRL_HANDLE_TIMEOUT doesnt_exist
5244 #define SSL_CTRL_CHAIN doesnt_exist
5245 #define SSL_CTRL_CHAIN_CERT doesnt_exist
5246 #define SSL_CTRL_CHANNEL_ID doesnt_exist
5247 #define SSL_CTRL_CLEAR_EXTRA_CHAIN_CERTS doesnt_exist
5248 #define SSL_CTRL_CLEAR_MODE doesnt_exist
5249 #define SSL_CTRL_CLEAR_OPTIONS doesnt_exist
5250 #define SSL_CTRL_EXTRA_CHAIN_CERT doesnt_exist
5251 #define SSL_CTRL_GET_CHAIN_CERTS doesnt_exist
5252 #define SSL_CTRL_GET_CHANNEL_ID doesnt_exist
5253 #define SSL_CTRL_GET_CLIENT_CERT_TYPES doesnt_exist
5254 #define SSL_CTRL_GET_EXTRA_CHAIN_CERTS doesnt_exist
5255 #define SSL_CTRL_GET_MAX_CERT_LIST doesnt_exist
5256 #define SSL_CTRL_GET_NUM_RENEGOTIATIONS doesnt_exist
5257 #define SSL_CTRL_GET_READ_AHEAD doesnt_exist
5258 #define SSL_CTRL_GET_RI_SUPPORT doesnt_exist
5259 #define SSL_CTRL_GET_SERVER_TMP_KEY doesnt_exist
5260 #define SSL_CTRL_GET_SESSION_REUSED doesnt_exist
5261 #define SSL_CTRL_GET_SESS_CACHE_MODE doesnt_exist
5262 #define SSL_CTRL_GET_SESS_CACHE_SIZE doesnt_exist
5263 #define SSL_CTRL_GET_TLSEXT_TICKET_KEYS doesnt_exist
5264 #define SSL_CTRL_GET_TOTAL_RENEGOTIATIONS doesnt_exist
5265 #define SSL_CTRL_MODE doesnt_exist
5266 #define SSL_CTRL_NEED_TMP_RSA doesnt_exist
5267 #define SSL_CTRL_OPTIONS doesnt_exist
5268 #define SSL_CTRL_SESS_NUMBER doesnt_exist
5269 #define SSL_CTRL_SET_CURVES doesnt_exist
5270 #define SSL_CTRL_SET_CURVES_LIST doesnt_exist
5271 #define SSL_CTRL_SET_ECDH_AUTO doesnt_exist
5272 #define SSL_CTRL_SET_MAX_CERT_LIST doesnt_exist
5273 #define SSL_CTRL_SET_MAX_SEND_FRAGMENT doesnt_exist
5274 #define SSL_CTRL_SET_MSG_CALLBACK doesnt_exist
5275 #define SSL_CTRL_SET_MSG_CALLBACK_ARG doesnt_exist
5276 #define SSL_CTRL_SET_MTU doesnt_exist
5277 #define SSL_CTRL_SET_READ_AHEAD doesnt_exist
5278 #define SSL_CTRL_SET_SESS_CACHE_MODE doesnt_exist
5279 #define SSL_CTRL_SET_SESS_CACHE_SIZE doesnt_exist
5280 #define SSL_CTRL_SET_TLSEXT_HOSTNAME doesnt_exist
5281 #define SSL_CTRL_SET_TLSEXT_SERVERNAME_ARG doesnt_exist
5282 #define SSL_CTRL_SET_TLSEXT_SERVERNAME_CB doesnt_exist
5283 #define SSL_CTRL_SET_TLSEXT_TICKET_KEYS doesnt_exist
5284 #define SSL_CTRL_SET_TLSEXT_TICKET_KEY_CB doesnt_exist
5285 #define SSL_CTRL_SET_TMP_DH doesnt_exist
5286 #define SSL_CTRL_SET_TMP_DH_CB doesnt_exist
5287 #define SSL_CTRL_SET_TMP_ECDH doesnt_exist
5288 #define SSL_CTRL_SET_TMP_ECDH_CB doesnt_exist
5289 #define SSL_CTRL_SET_TMP_RSA doesnt_exist
5290 #define SSL_CTRL_SET_TMP_RSA_CB doesnt_exist
5291 
5292 // |BORINGSSL_PREFIX| already makes each of these symbols into macros, so there
5293 // is no need to define conflicting macros.
5294 #if !defined(BORINGSSL_PREFIX)
5295 
5296 #define DTLSv1_get_timeout DTLSv1_get_timeout
5297 #define DTLSv1_handle_timeout DTLSv1_handle_timeout
5298 #define SSL_CTX_add0_chain_cert SSL_CTX_add0_chain_cert
5299 #define SSL_CTX_add1_chain_cert SSL_CTX_add1_chain_cert
5300 #define SSL_CTX_add_extra_chain_cert SSL_CTX_add_extra_chain_cert
5301 #define SSL_CTX_clear_extra_chain_certs SSL_CTX_clear_extra_chain_certs
5302 #define SSL_CTX_clear_chain_certs SSL_CTX_clear_chain_certs
5303 #define SSL_CTX_clear_mode SSL_CTX_clear_mode
5304 #define SSL_CTX_clear_options SSL_CTX_clear_options
5305 #define SSL_CTX_get0_chain_certs SSL_CTX_get0_chain_certs
5306 #define SSL_CTX_get_extra_chain_certs SSL_CTX_get_extra_chain_certs
5307 #define SSL_CTX_get_max_cert_list SSL_CTX_get_max_cert_list
5308 #define SSL_CTX_get_mode SSL_CTX_get_mode
5309 #define SSL_CTX_get_options SSL_CTX_get_options
5310 #define SSL_CTX_get_read_ahead SSL_CTX_get_read_ahead
5311 #define SSL_CTX_get_session_cache_mode SSL_CTX_get_session_cache_mode
5312 #define SSL_CTX_get_tlsext_ticket_keys SSL_CTX_get_tlsext_ticket_keys
5313 #define SSL_CTX_need_tmp_RSA SSL_CTX_need_tmp_RSA
5314 #define SSL_CTX_sess_get_cache_size SSL_CTX_sess_get_cache_size
5315 #define SSL_CTX_sess_number SSL_CTX_sess_number
5316 #define SSL_CTX_sess_set_cache_size SSL_CTX_sess_set_cache_size
5317 #define SSL_CTX_set0_chain SSL_CTX_set0_chain
5318 #define SSL_CTX_set1_chain SSL_CTX_set1_chain
5319 #define SSL_CTX_set1_curves SSL_CTX_set1_curves
5320 #define SSL_CTX_set_max_cert_list SSL_CTX_set_max_cert_list
5321 #define SSL_CTX_set_max_send_fragment SSL_CTX_set_max_send_fragment
5322 #define SSL_CTX_set_mode SSL_CTX_set_mode
5323 #define SSL_CTX_set_msg_callback_arg SSL_CTX_set_msg_callback_arg
5324 #define SSL_CTX_set_options SSL_CTX_set_options
5325 #define SSL_CTX_set_read_ahead SSL_CTX_set_read_ahead
5326 #define SSL_CTX_set_session_cache_mode SSL_CTX_set_session_cache_mode
5327 #define SSL_CTX_set_tlsext_servername_arg SSL_CTX_set_tlsext_servername_arg
5328 #define SSL_CTX_set_tlsext_servername_callback \
5329     SSL_CTX_set_tlsext_servername_callback
5330 #define SSL_CTX_set_tlsext_ticket_key_cb SSL_CTX_set_tlsext_ticket_key_cb
5331 #define SSL_CTX_set_tlsext_ticket_keys SSL_CTX_set_tlsext_ticket_keys
5332 #define SSL_CTX_set_tmp_dh SSL_CTX_set_tmp_dh
5333 #define SSL_CTX_set_tmp_ecdh SSL_CTX_set_tmp_ecdh
5334 #define SSL_CTX_set_tmp_rsa SSL_CTX_set_tmp_rsa
5335 #define SSL_add0_chain_cert SSL_add0_chain_cert
5336 #define SSL_add1_chain_cert SSL_add1_chain_cert
5337 #define SSL_clear_chain_certs SSL_clear_chain_certs
5338 #define SSL_clear_mode SSL_clear_mode
5339 #define SSL_clear_options SSL_clear_options
5340 #define SSL_get0_certificate_types SSL_get0_certificate_types
5341 #define SSL_get0_chain_certs SSL_get0_chain_certs
5342 #define SSL_get_max_cert_list SSL_get_max_cert_list
5343 #define SSL_get_mode SSL_get_mode
5344 #define SSL_get_options SSL_get_options
5345 #define SSL_get_secure_renegotiation_support \
5346     SSL_get_secure_renegotiation_support
5347 #define SSL_need_tmp_RSA SSL_need_tmp_RSA
5348 #define SSL_num_renegotiations SSL_num_renegotiations
5349 #define SSL_session_reused SSL_session_reused
5350 #define SSL_set0_chain SSL_set0_chain
5351 #define SSL_set1_chain SSL_set1_chain
5352 #define SSL_set1_curves SSL_set1_curves
5353 #define SSL_set_max_cert_list SSL_set_max_cert_list
5354 #define SSL_set_max_send_fragment SSL_set_max_send_fragment
5355 #define SSL_set_mode SSL_set_mode
5356 #define SSL_set_msg_callback_arg SSL_set_msg_callback_arg
5357 #define SSL_set_mtu SSL_set_mtu
5358 #define SSL_set_options SSL_set_options
5359 #define SSL_set_tlsext_host_name SSL_set_tlsext_host_name
5360 #define SSL_set_tmp_dh SSL_set_tmp_dh
5361 #define SSL_set_tmp_ecdh SSL_set_tmp_ecdh
5362 #define SSL_set_tmp_rsa SSL_set_tmp_rsa
5363 #define SSL_total_renegotiations SSL_total_renegotiations
5364 
5365 #endif // !defined(BORINGSSL_PREFIX)
5366 
5367 
5368 #if defined(__cplusplus)
5369 }  // extern C
5370 
5371 #if !defined(BORINGSSL_NO_CXX)
5372 
5373 extern "C++" {
5374 
5375 BSSL_NAMESPACE_BEGIN
5376 
5377 BORINGSSL_MAKE_DELETER(SSL, SSL_free)
5378 BORINGSSL_MAKE_DELETER(SSL_CTX, SSL_CTX_free)
5379 BORINGSSL_MAKE_UP_REF(SSL_CTX, SSL_CTX_up_ref)
5380 BORINGSSL_MAKE_DELETER(SSL_ECH_KEYS, SSL_ECH_KEYS_free)
5381 BORINGSSL_MAKE_UP_REF(SSL_ECH_KEYS, SSL_ECH_KEYS_up_ref)
5382 BORINGSSL_MAKE_DELETER(SSL_SESSION, SSL_SESSION_free)
5383 BORINGSSL_MAKE_UP_REF(SSL_SESSION, SSL_SESSION_up_ref)
5384 
5385 
5386 // *** EXPERIMENTAL — DO NOT USE WITHOUT CHECKING ***
5387 //
5388 // Split handshakes.
5389 //
5390 // Split handshakes allows the handshake part of a TLS connection to be
5391 // performed in a different process (or on a different machine) than the data
5392 // exchange. This only applies to servers.
5393 //
5394 // In the first part of a split handshake, an |SSL| (where the |SSL_CTX| has
5395 // been configured with |SSL_CTX_set_handoff_mode|) is used normally. Once the
5396 // ClientHello message has been received, the handshake will stop and
5397 // |SSL_get_error| will indicate |SSL_ERROR_HANDOFF|. At this point (and only
5398 // at this point), |SSL_serialize_handoff| can be called to write the “handoff”
5399 // state of the connection.
5400 //
5401 // Elsewhere, a fresh |SSL| can be used with |SSL_apply_handoff| to continue
5402 // the connection. The connection from the client is fed into this |SSL|, and
5403 // the handshake resumed. When the handshake stops again and |SSL_get_error|
5404 // indicates |SSL_ERROR_HANDBACK|, |SSL_serialize_handback| should be called to
5405 // serialize the state of the handshake again.
5406 //
5407 // Back at the first location, a fresh |SSL| can be used with
5408 // |SSL_apply_handback|. Then the client's connection can be processed mostly
5409 // as normal.
5410 //
5411 // Lastly, when a connection is in the handoff state, whether or not
5412 // |SSL_serialize_handoff| is called, |SSL_decline_handoff| will move it back
5413 // into a normal state where the connection can proceed without impact.
5414 //
5415 // WARNING: Currently only works with TLS 1.0–1.2.
5416 // WARNING: The serialisation formats are not yet stable: version skew may be
5417 //     fatal.
5418 // WARNING: The handback data contains sensitive key material and must be
5419 //     protected.
5420 // WARNING: Some calls on the final |SSL| will not work. Just as an example,
5421 //     calls like |SSL_get0_session_id_context| and |SSL_get_privatekey| won't
5422 //     work because the certificate used for handshaking isn't available.
5423 // WARNING: |SSL_apply_handoff| may trigger “msg” callback calls.
5424 
5425 OPENSSL_EXPORT void SSL_CTX_set_handoff_mode(SSL_CTX *ctx, bool on);
5426 OPENSSL_EXPORT void SSL_set_handoff_mode(SSL *SSL, bool on);
5427 OPENSSL_EXPORT bool SSL_serialize_handoff(const SSL *ssl, CBB *out,
5428                                           SSL_CLIENT_HELLO *out_hello);
5429 OPENSSL_EXPORT bool SSL_decline_handoff(SSL *ssl);
5430 OPENSSL_EXPORT bool SSL_apply_handoff(SSL *ssl, Span<const uint8_t> handoff);
5431 OPENSSL_EXPORT bool SSL_serialize_handback(const SSL *ssl, CBB *out);
5432 OPENSSL_EXPORT bool SSL_apply_handback(SSL *ssl, Span<const uint8_t> handback);
5433 
5434 // SSL_get_traffic_secrets sets |*out_read_traffic_secret| and
5435 // |*out_write_traffic_secret| to reference the TLS 1.3 traffic secrets for
5436 // |ssl|. This function is only valid on TLS 1.3 connections that have
5437 // completed the handshake. It returns true on success and false on error.
5438 OPENSSL_EXPORT bool SSL_get_traffic_secrets(
5439     const SSL *ssl, Span<const uint8_t> *out_read_traffic_secret,
5440     Span<const uint8_t> *out_write_traffic_secret);
5441 
5442 // SSL_CTX_set_aes_hw_override_for_testing sets |override_value| to
5443 // override checking for aes hardware support for testing. If |override_value|
5444 // is set to true, the library will behave as if aes hardware support is
5445 // present. If it is set to false, the library will behave as if aes hardware
5446 // support is not present.
5447 OPENSSL_EXPORT void SSL_CTX_set_aes_hw_override_for_testing(
5448     SSL_CTX *ctx, bool override_value);
5449 
5450 // SSL_set_aes_hw_override_for_testing acts the same as
5451 // |SSL_CTX_set_aes_override_for_testing| but only configures a single |SSL*|.
5452 OPENSSL_EXPORT void SSL_set_aes_hw_override_for_testing(SSL *ssl,
5453                                                         bool override_value);
5454 
5455 BSSL_NAMESPACE_END
5456 
5457 }  // extern C++
5458 
5459 #endif  // !defined(BORINGSSL_NO_CXX)
5460 
5461 #endif
5462 
5463 #define SSL_R_APP_DATA_IN_HANDSHAKE 100
5464 #define SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT 101
5465 #define SSL_R_BAD_ALERT 102
5466 #define SSL_R_BAD_CHANGE_CIPHER_SPEC 103
5467 #define SSL_R_BAD_DATA_RETURNED_BY_CALLBACK 104
5468 #define SSL_R_BAD_DH_P_LENGTH 105
5469 #define SSL_R_BAD_DIGEST_LENGTH 106
5470 #define SSL_R_BAD_ECC_CERT 107
5471 #define SSL_R_BAD_ECPOINT 108
5472 #define SSL_R_BAD_HANDSHAKE_RECORD 109
5473 #define SSL_R_BAD_HELLO_REQUEST 110
5474 #define SSL_R_BAD_LENGTH 111
5475 #define SSL_R_BAD_PACKET_LENGTH 112
5476 #define SSL_R_BAD_RSA_ENCRYPT 113
5477 #define SSL_R_BAD_SIGNATURE 114
5478 #define SSL_R_BAD_SRTP_MKI_VALUE 115
5479 #define SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST 116
5480 #define SSL_R_BAD_SSL_FILETYPE 117
5481 #define SSL_R_BAD_WRITE_RETRY 118
5482 #define SSL_R_BIO_NOT_SET 119
5483 #define SSL_R_BN_LIB 120
5484 #define SSL_R_BUFFER_TOO_SMALL 121
5485 #define SSL_R_CA_DN_LENGTH_MISMATCH 122
5486 #define SSL_R_CA_DN_TOO_LONG 123
5487 #define SSL_R_CCS_RECEIVED_EARLY 124
5488 #define SSL_R_CERTIFICATE_VERIFY_FAILED 125
5489 #define SSL_R_CERT_CB_ERROR 126
5490 #define SSL_R_CERT_LENGTH_MISMATCH 127
5491 #define SSL_R_CHANNEL_ID_NOT_P256 128
5492 #define SSL_R_CHANNEL_ID_SIGNATURE_INVALID 129
5493 #define SSL_R_CIPHER_OR_HASH_UNAVAILABLE 130
5494 #define SSL_R_CLIENTHELLO_PARSE_FAILED 131
5495 #define SSL_R_CLIENTHELLO_TLSEXT 132
5496 #define SSL_R_CONNECTION_REJECTED 133
5497 #define SSL_R_CONNECTION_TYPE_NOT_SET 134
5498 #define SSL_R_CUSTOM_EXTENSION_ERROR 135
5499 #define SSL_R_DATA_LENGTH_TOO_LONG 136
5500 #define SSL_R_DECODE_ERROR 137
5501 #define SSL_R_DECRYPTION_FAILED 138
5502 #define SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC 139
5503 #define SSL_R_DH_PUBLIC_VALUE_LENGTH_IS_WRONG 140
5504 #define SSL_R_DH_P_TOO_LONG 141
5505 #define SSL_R_DIGEST_CHECK_FAILED 142
5506 #define SSL_R_DTLS_MESSAGE_TOO_BIG 143
5507 #define SSL_R_ECC_CERT_NOT_FOR_SIGNING 144
5508 #define SSL_R_EMS_STATE_INCONSISTENT 145
5509 #define SSL_R_ENCRYPTED_LENGTH_TOO_LONG 146
5510 #define SSL_R_ERROR_ADDING_EXTENSION 147
5511 #define SSL_R_ERROR_IN_RECEIVED_CIPHER_LIST 148
5512 #define SSL_R_ERROR_PARSING_EXTENSION 149
5513 #define SSL_R_EXCESSIVE_MESSAGE_SIZE 150
5514 #define SSL_R_EXTRA_DATA_IN_MESSAGE 151
5515 #define SSL_R_FRAGMENT_MISMATCH 152
5516 #define SSL_R_GOT_NEXT_PROTO_WITHOUT_EXTENSION 153
5517 #define SSL_R_HANDSHAKE_FAILURE_ON_CLIENT_HELLO 154
5518 #define SSL_R_HTTPS_PROXY_REQUEST 155
5519 #define SSL_R_HTTP_REQUEST 156
5520 #define SSL_R_INAPPROPRIATE_FALLBACK 157
5521 #define SSL_R_INVALID_COMMAND 158
5522 #define SSL_R_INVALID_MESSAGE 159
5523 #define SSL_R_INVALID_SSL_SESSION 160
5524 #define SSL_R_INVALID_TICKET_KEYS_LENGTH 161
5525 #define SSL_R_LENGTH_MISMATCH 162
5526 #define SSL_R_MISSING_EXTENSION 164
5527 #define SSL_R_MISSING_RSA_CERTIFICATE 165
5528 #define SSL_R_MISSING_TMP_DH_KEY 166
5529 #define SSL_R_MISSING_TMP_ECDH_KEY 167
5530 #define SSL_R_MIXED_SPECIAL_OPERATOR_WITH_GROUPS 168
5531 #define SSL_R_MTU_TOO_SMALL 169
5532 #define SSL_R_NEGOTIATED_BOTH_NPN_AND_ALPN 170
5533 #define SSL_R_NESTED_GROUP 171
5534 #define SSL_R_NO_CERTIFICATES_RETURNED 172
5535 #define SSL_R_NO_CERTIFICATE_ASSIGNED 173
5536 #define SSL_R_NO_CERTIFICATE_SET 174
5537 #define SSL_R_NO_CIPHERS_AVAILABLE 175
5538 #define SSL_R_NO_CIPHERS_PASSED 176
5539 #define SSL_R_NO_CIPHER_MATCH 177
5540 #define SSL_R_NO_COMPRESSION_SPECIFIED 178
5541 #define SSL_R_NO_METHOD_SPECIFIED 179
5542 #define SSL_R_NO_P256_SUPPORT 180
5543 #define SSL_R_NO_PRIVATE_KEY_ASSIGNED 181
5544 #define SSL_R_NO_RENEGOTIATION 182
5545 #define SSL_R_NO_REQUIRED_DIGEST 183
5546 #define SSL_R_NO_SHARED_CIPHER 184
5547 #define SSL_R_NULL_SSL_CTX 185
5548 #define SSL_R_NULL_SSL_METHOD_PASSED 186
5549 #define SSL_R_OLD_SESSION_CIPHER_NOT_RETURNED 187
5550 #define SSL_R_OLD_SESSION_VERSION_NOT_RETURNED 188
5551 #define SSL_R_OUTPUT_ALIASES_INPUT 189
5552 #define SSL_R_PARSE_TLSEXT 190
5553 #define SSL_R_PATH_TOO_LONG 191
5554 #define SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE 192
5555 #define SSL_R_PEER_ERROR_UNSUPPORTED_CERTIFICATE_TYPE 193
5556 #define SSL_R_PROTOCOL_IS_SHUTDOWN 194
5557 #define SSL_R_PSK_IDENTITY_NOT_FOUND 195
5558 #define SSL_R_PSK_NO_CLIENT_CB 196
5559 #define SSL_R_PSK_NO_SERVER_CB 197
5560 #define SSL_R_READ_TIMEOUT_EXPIRED 198
5561 #define SSL_R_RECORD_LENGTH_MISMATCH 199
5562 #define SSL_R_RECORD_TOO_LARGE 200
5563 #define SSL_R_RENEGOTIATION_ENCODING_ERR 201
5564 #define SSL_R_RENEGOTIATION_MISMATCH 202
5565 #define SSL_R_REQUIRED_CIPHER_MISSING 203
5566 #define SSL_R_RESUMED_EMS_SESSION_WITHOUT_EMS_EXTENSION 204
5567 #define SSL_R_RESUMED_NON_EMS_SESSION_WITH_EMS_EXTENSION 205
5568 #define SSL_R_SCSV_RECEIVED_WHEN_RENEGOTIATING 206
5569 #define SSL_R_SERVERHELLO_TLSEXT 207
5570 #define SSL_R_SESSION_ID_CONTEXT_UNINITIALIZED 208
5571 #define SSL_R_SESSION_MAY_NOT_BE_CREATED 209
5572 #define SSL_R_SIGNATURE_ALGORITHMS_EXTENSION_SENT_BY_SERVER 210
5573 #define SSL_R_SRTP_COULD_NOT_ALLOCATE_PROFILES 211
5574 #define SSL_R_SRTP_UNKNOWN_PROTECTION_PROFILE 212
5575 #define SSL_R_SSL3_EXT_INVALID_SERVERNAME 213
5576 #define SSL_R_SSL_CTX_HAS_NO_DEFAULT_SSL_VERSION 214
5577 #define SSL_R_SSL_HANDSHAKE_FAILURE 215
5578 #define SSL_R_SSL_SESSION_ID_CONTEXT_TOO_LONG 216
5579 #define SSL_R_TLS_PEER_DID_NOT_RESPOND_WITH_CERTIFICATE_LIST 217
5580 #define SSL_R_TLS_RSA_ENCRYPTED_VALUE_LENGTH_IS_WRONG 218
5581 #define SSL_R_TOO_MANY_EMPTY_FRAGMENTS 219
5582 #define SSL_R_TOO_MANY_WARNING_ALERTS 220
5583 #define SSL_R_UNABLE_TO_FIND_ECDH_PARAMETERS 221
5584 #define SSL_R_UNEXPECTED_EXTENSION 222
5585 #define SSL_R_UNEXPECTED_MESSAGE 223
5586 #define SSL_R_UNEXPECTED_OPERATOR_IN_GROUP 224
5587 #define SSL_R_UNEXPECTED_RECORD 225
5588 #define SSL_R_UNINITIALIZED 226
5589 #define SSL_R_UNKNOWN_ALERT_TYPE 227
5590 #define SSL_R_UNKNOWN_CERTIFICATE_TYPE 228
5591 #define SSL_R_UNKNOWN_CIPHER_RETURNED 229
5592 #define SSL_R_UNKNOWN_CIPHER_TYPE 230
5593 #define SSL_R_UNKNOWN_DIGEST 231
5594 #define SSL_R_UNKNOWN_KEY_EXCHANGE_TYPE 232
5595 #define SSL_R_UNKNOWN_PROTOCOL 233
5596 #define SSL_R_UNKNOWN_SSL_VERSION 234
5597 #define SSL_R_UNKNOWN_STATE 235
5598 #define SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED 236
5599 #define SSL_R_UNSUPPORTED_CIPHER 237
5600 #define SSL_R_UNSUPPORTED_COMPRESSION_ALGORITHM 238
5601 #define SSL_R_UNSUPPORTED_ELLIPTIC_CURVE 239
5602 #define SSL_R_UNSUPPORTED_PROTOCOL 240
5603 #define SSL_R_WRONG_CERTIFICATE_TYPE 241
5604 #define SSL_R_WRONG_CIPHER_RETURNED 242
5605 #define SSL_R_WRONG_CURVE 243
5606 #define SSL_R_WRONG_MESSAGE_TYPE 244
5607 #define SSL_R_WRONG_SIGNATURE_TYPE 245
5608 #define SSL_R_WRONG_SSL_VERSION 246
5609 #define SSL_R_WRONG_VERSION_NUMBER 247
5610 #define SSL_R_X509_LIB 248
5611 #define SSL_R_X509_VERIFICATION_SETUP_PROBLEMS 249
5612 #define SSL_R_SHUTDOWN_WHILE_IN_INIT 250
5613 #define SSL_R_INVALID_OUTER_RECORD_TYPE 251
5614 #define SSL_R_UNSUPPORTED_PROTOCOL_FOR_CUSTOM_KEY 252
5615 #define SSL_R_NO_COMMON_SIGNATURE_ALGORITHMS 253
5616 #define SSL_R_DOWNGRADE_DETECTED 254
5617 #define SSL_R_EXCESS_HANDSHAKE_DATA 255
5618 #define SSL_R_INVALID_COMPRESSION_LIST 256
5619 #define SSL_R_DUPLICATE_EXTENSION 257
5620 #define SSL_R_MISSING_KEY_SHARE 258
5621 #define SSL_R_INVALID_ALPN_PROTOCOL 259
5622 #define SSL_R_TOO_MANY_KEY_UPDATES 260
5623 #define SSL_R_BLOCK_CIPHER_PAD_IS_WRONG 261
5624 #define SSL_R_NO_CIPHERS_SPECIFIED 262
5625 #define SSL_R_RENEGOTIATION_EMS_MISMATCH 263
5626 #define SSL_R_DUPLICATE_KEY_SHARE 264
5627 #define SSL_R_NO_GROUPS_SPECIFIED 265
5628 #define SSL_R_NO_SHARED_GROUP 266
5629 #define SSL_R_PRE_SHARED_KEY_MUST_BE_LAST 267
5630 #define SSL_R_OLD_SESSION_PRF_HASH_MISMATCH 268
5631 #define SSL_R_INVALID_SCT_LIST 269
5632 #define SSL_R_TOO_MUCH_SKIPPED_EARLY_DATA 270
5633 #define SSL_R_PSK_IDENTITY_BINDER_COUNT_MISMATCH 271
5634 #define SSL_R_CANNOT_PARSE_LEAF_CERT 272
5635 #define SSL_R_SERVER_CERT_CHANGED 273
5636 #define SSL_R_CERTIFICATE_AND_PRIVATE_KEY_MISMATCH 274
5637 #define SSL_R_CANNOT_HAVE_BOTH_PRIVKEY_AND_METHOD 275
5638 #define SSL_R_TICKET_ENCRYPTION_FAILED 276
5639 #define SSL_R_ALPN_MISMATCH_ON_EARLY_DATA 277
5640 #define SSL_R_WRONG_VERSION_ON_EARLY_DATA 278
5641 #define SSL_R_UNEXPECTED_EXTENSION_ON_EARLY_DATA 279
5642 #define SSL_R_NO_SUPPORTED_VERSIONS_ENABLED 280
5643 #define SSL_R_APPLICATION_DATA_INSTEAD_OF_HANDSHAKE 281
5644 #define SSL_R_EMPTY_HELLO_RETRY_REQUEST 282
5645 #define SSL_R_EARLY_DATA_NOT_IN_USE 283
5646 #define SSL_R_HANDSHAKE_NOT_COMPLETE 284
5647 #define SSL_R_NEGOTIATED_TB_WITHOUT_EMS_OR_RI 285
5648 #define SSL_R_SERVER_ECHOED_INVALID_SESSION_ID 286
5649 #define SSL_R_PRIVATE_KEY_OPERATION_FAILED 287
5650 #define SSL_R_SECOND_SERVERHELLO_VERSION_MISMATCH 288
5651 #define SSL_R_OCSP_CB_ERROR 289
5652 #define SSL_R_SSL_SESSION_ID_TOO_LONG 290
5653 #define SSL_R_APPLICATION_DATA_ON_SHUTDOWN 291
5654 #define SSL_R_CERT_DECOMPRESSION_FAILED 292
5655 #define SSL_R_UNCOMPRESSED_CERT_TOO_LARGE 293
5656 #define SSL_R_UNKNOWN_CERT_COMPRESSION_ALG 294
5657 #define SSL_R_INVALID_SIGNATURE_ALGORITHM 295
5658 #define SSL_R_DUPLICATE_SIGNATURE_ALGORITHM 296
5659 #define SSL_R_TLS13_DOWNGRADE 297
5660 #define SSL_R_QUIC_INTERNAL_ERROR 298
5661 #define SSL_R_WRONG_ENCRYPTION_LEVEL_RECEIVED 299
5662 #define SSL_R_TOO_MUCH_READ_EARLY_DATA 300
5663 #define SSL_R_INVALID_DELEGATED_CREDENTIAL 301
5664 #define SSL_R_KEY_USAGE_BIT_INCORRECT 302
5665 #define SSL_R_INCONSISTENT_CLIENT_HELLO 303
5666 #define SSL_R_CIPHER_MISMATCH_ON_EARLY_DATA 304
5667 #define SSL_R_QUIC_TRANSPORT_PARAMETERS_MISCONFIGURED 305
5668 #define SSL_R_UNEXPECTED_COMPATIBILITY_MODE 306
5669 #define SSL_R_NO_APPLICATION_PROTOCOL 307
5670 #define SSL_R_NEGOTIATED_ALPS_WITHOUT_ALPN 308
5671 #define SSL_R_ALPS_MISMATCH_ON_EARLY_DATA 309
5672 #define SSL_R_ECH_SERVER_CONFIG_AND_PRIVATE_KEY_MISMATCH 310
5673 #define SSL_R_ECH_SERVER_CONFIG_UNSUPPORTED_EXTENSION 311
5674 #define SSL_R_UNSUPPORTED_ECH_SERVER_CONFIG 312
5675 #define SSL_R_ECH_SERVER_WOULD_HAVE_NO_RETRY_CONFIGS 313
5676 #define SSL_R_INVALID_CLIENT_HELLO_INNER 314
5677 #define SSL_R_INVALID_ALPN_PROTOCOL_LIST 315
5678 #define SSL_R_COULD_NOT_PARSE_HINTS 316
5679 #define SSL_R_INVALID_ECH_PUBLIC_NAME 317
5680 #define SSL_R_INVALID_ECH_CONFIG_LIST 318
5681 #define SSL_R_ECH_REJECTED 319
5682 #define SSL_R_INVALID_OUTER_EXTENSION 320
5683 #define SSL_R_INCONSISTENT_ECH_NEGOTIATION 321
5684 #define SSL_R_SSLV3_ALERT_CLOSE_NOTIFY 1000
5685 #define SSL_R_SSLV3_ALERT_UNEXPECTED_MESSAGE 1010
5686 #define SSL_R_SSLV3_ALERT_BAD_RECORD_MAC 1020
5687 #define SSL_R_TLSV1_ALERT_DECRYPTION_FAILED 1021
5688 #define SSL_R_TLSV1_ALERT_RECORD_OVERFLOW 1022
5689 #define SSL_R_SSLV3_ALERT_DECOMPRESSION_FAILURE 1030
5690 #define SSL_R_SSLV3_ALERT_HANDSHAKE_FAILURE 1040
5691 #define SSL_R_SSLV3_ALERT_NO_CERTIFICATE 1041
5692 #define SSL_R_SSLV3_ALERT_BAD_CERTIFICATE 1042
5693 #define SSL_R_SSLV3_ALERT_UNSUPPORTED_CERTIFICATE 1043
5694 #define SSL_R_SSLV3_ALERT_CERTIFICATE_REVOKED 1044
5695 #define SSL_R_SSLV3_ALERT_CERTIFICATE_EXPIRED 1045
5696 #define SSL_R_SSLV3_ALERT_CERTIFICATE_UNKNOWN 1046
5697 #define SSL_R_SSLV3_ALERT_ILLEGAL_PARAMETER 1047
5698 #define SSL_R_TLSV1_ALERT_UNKNOWN_CA 1048
5699 #define SSL_R_TLSV1_ALERT_ACCESS_DENIED 1049
5700 #define SSL_R_TLSV1_ALERT_DECODE_ERROR 1050
5701 #define SSL_R_TLSV1_ALERT_DECRYPT_ERROR 1051
5702 #define SSL_R_TLSV1_ALERT_EXPORT_RESTRICTION 1060
5703 #define SSL_R_TLSV1_ALERT_PROTOCOL_VERSION 1070
5704 #define SSL_R_TLSV1_ALERT_INSUFFICIENT_SECURITY 1071
5705 #define SSL_R_TLSV1_ALERT_INTERNAL_ERROR 1080
5706 #define SSL_R_TLSV1_ALERT_INAPPROPRIATE_FALLBACK 1086
5707 #define SSL_R_TLSV1_ALERT_USER_CANCELLED 1090
5708 #define SSL_R_TLSV1_ALERT_NO_RENEGOTIATION 1100
5709 #define SSL_R_TLSV1_ALERT_UNSUPPORTED_EXTENSION 1110
5710 #define SSL_R_TLSV1_ALERT_CERTIFICATE_UNOBTAINABLE 1111
5711 #define SSL_R_TLSV1_ALERT_UNRECOGNIZED_NAME 1112
5712 #define SSL_R_TLSV1_ALERT_BAD_CERTIFICATE_STATUS_RESPONSE 1113
5713 #define SSL_R_TLSV1_ALERT_BAD_CERTIFICATE_HASH_VALUE 1114
5714 #define SSL_R_TLSV1_ALERT_UNKNOWN_PSK_IDENTITY 1115
5715 #define SSL_R_TLSV1_ALERT_CERTIFICATE_REQUIRED 1116
5716 #define SSL_R_TLSV1_ALERT_NO_APPLICATION_PROTOCOL 1120
5717 #define SSL_R_TLSV1_ALERT_ECH_REQUIRED 1121
5718 
5719 #endif  // OPENSSL_HEADER_SSL_H
5720