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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  *
113  * Portions of the attached software ("Contribution") are developed by
114  * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project.
115  *
116  * The Contribution is licensed pursuant to the OpenSSL open source
117  * license provided above.
118  *
119  * ECC cipher suite support in OpenSSL originally written by
120  * Vipul Gupta and Sumit Gupta of Sun Microsystems Laboratories.
121  *
122  */
123 /* ====================================================================
124  * Copyright 2005 Nokia. All rights reserved.
125  *
126  * The portions of the attached software ("Contribution") is developed by
127  * Nokia Corporation and is licensed pursuant to the OpenSSL open source
128  * license.
129  *
130  * The Contribution, originally written by Mika Kousa and Pasi Eronen of
131  * Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites
132  * support (see RFC 4279) to OpenSSL.
133  *
134  * No patent licenses or other rights except those expressly stated in
135  * the OpenSSL open source license shall be deemed granted or received
136  * expressly, by implication, estoppel, or otherwise.
137  *
138  * No assurances are provided by Nokia that the Contribution does not
139  * infringe the patent or other intellectual property rights of any third
140  * party or that the license provides you with all the necessary rights
141  * to make use of the Contribution.
142  *
143  * THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN
144  * ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA
145  * SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY
146  * OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR
147  * OTHERWISE. */
148 
149 #include <openssl/ssl.h>
150 
151 #include <assert.h>
152 #include <string.h>
153 
154 #include <openssl/bn.h>
155 #include <openssl/buf.h>
156 #include <openssl/bytestring.h>
157 #include <openssl/cipher.h>
158 #include <openssl/ec.h>
159 #include <openssl/ecdsa.h>
160 #include <openssl/err.h>
161 #include <openssl/evp.h>
162 #include <openssl/hmac.h>
163 #include <openssl/md5.h>
164 #include <openssl/mem.h>
165 #include <openssl/nid.h>
166 #include <openssl/rand.h>
167 #include <openssl/x509.h>
168 
169 #include "internal.h"
170 #include "../crypto/internal.h"
171 
172 
173 BSSL_NAMESPACE_BEGIN
174 
ssl_client_cipher_list_contains_cipher(const SSL_CLIENT_HELLO * client_hello,uint16_t id)175 bool ssl_client_cipher_list_contains_cipher(
176     const SSL_CLIENT_HELLO *client_hello, uint16_t id) {
177   CBS cipher_suites;
178   CBS_init(&cipher_suites, client_hello->cipher_suites,
179            client_hello->cipher_suites_len);
180 
181   while (CBS_len(&cipher_suites) > 0) {
182     uint16_t got_id;
183     if (!CBS_get_u16(&cipher_suites, &got_id)) {
184       return false;
185     }
186 
187     if (got_id == id) {
188       return true;
189     }
190   }
191 
192   return false;
193 }
194 
negotiate_version(SSL_HANDSHAKE * hs,uint8_t * out_alert,const SSL_CLIENT_HELLO * client_hello)195 static bool negotiate_version(SSL_HANDSHAKE *hs, uint8_t *out_alert,
196                               const SSL_CLIENT_HELLO *client_hello) {
197   SSL *const ssl = hs->ssl;
198   assert(!ssl->s3->have_version);
199   CBS supported_versions, versions;
200   if (ssl_client_hello_get_extension(client_hello, &supported_versions,
201                                      TLSEXT_TYPE_supported_versions)) {
202     if (!CBS_get_u8_length_prefixed(&supported_versions, &versions) ||
203         CBS_len(&supported_versions) != 0 ||
204         CBS_len(&versions) == 0) {
205       OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
206       *out_alert = SSL_AD_DECODE_ERROR;
207       return false;
208     }
209   } else {
210     // Convert the ClientHello version to an equivalent supported_versions
211     // extension.
212     static const uint8_t kTLSVersions[] = {
213         0x03, 0x03,  // TLS 1.2
214         0x03, 0x02,  // TLS 1.1
215         0x03, 0x01,  // TLS 1
216     };
217 
218     static const uint8_t kDTLSVersions[] = {
219         0xfe, 0xfd,  // DTLS 1.2
220         0xfe, 0xff,  // DTLS 1.0
221     };
222 
223     size_t versions_len = 0;
224     if (SSL_is_dtls(ssl)) {
225       if (client_hello->version <= DTLS1_2_VERSION) {
226         versions_len = 4;
227       } else if (client_hello->version <= DTLS1_VERSION) {
228         versions_len = 2;
229       }
230       CBS_init(&versions, kDTLSVersions + sizeof(kDTLSVersions) - versions_len,
231                versions_len);
232     } else {
233       if (client_hello->version >= TLS1_2_VERSION) {
234         versions_len = 6;
235       } else if (client_hello->version >= TLS1_1_VERSION) {
236         versions_len = 4;
237       } else if (client_hello->version >= TLS1_VERSION) {
238         versions_len = 2;
239       }
240       CBS_init(&versions, kTLSVersions + sizeof(kTLSVersions) - versions_len,
241                versions_len);
242     }
243   }
244 
245   if (!ssl_negotiate_version(hs, out_alert, &ssl->version, &versions)) {
246     return false;
247   }
248 
249   // At this point, the connection's version is known and |ssl->version| is
250   // fixed. Begin enforcing the record-layer version.
251   ssl->s3->have_version = true;
252   ssl->s3->aead_write_ctx->SetVersionIfNullCipher(ssl->version);
253 
254   // Handle FALLBACK_SCSV.
255   if (ssl_client_cipher_list_contains_cipher(client_hello,
256                                              SSL3_CK_FALLBACK_SCSV & 0xffff) &&
257       ssl_protocol_version(ssl) < hs->max_version) {
258     OPENSSL_PUT_ERROR(SSL, SSL_R_INAPPROPRIATE_FALLBACK);
259     *out_alert = SSL3_AD_INAPPROPRIATE_FALLBACK;
260     return false;
261   }
262 
263   return true;
264 }
265 
ssl_parse_client_cipher_list(const SSL_CLIENT_HELLO * client_hello)266 static UniquePtr<STACK_OF(SSL_CIPHER)> ssl_parse_client_cipher_list(
267     const SSL_CLIENT_HELLO *client_hello) {
268   CBS cipher_suites;
269   CBS_init(&cipher_suites, client_hello->cipher_suites,
270            client_hello->cipher_suites_len);
271 
272   UniquePtr<STACK_OF(SSL_CIPHER)> sk(sk_SSL_CIPHER_new_null());
273   if (!sk) {
274     OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
275     return nullptr;
276   }
277 
278   while (CBS_len(&cipher_suites) > 0) {
279     uint16_t cipher_suite;
280 
281     if (!CBS_get_u16(&cipher_suites, &cipher_suite)) {
282       OPENSSL_PUT_ERROR(SSL, SSL_R_ERROR_IN_RECEIVED_CIPHER_LIST);
283       return nullptr;
284     }
285 
286     const SSL_CIPHER *c = SSL_get_cipher_by_value(cipher_suite);
287     if (c != NULL && !sk_SSL_CIPHER_push(sk.get(), c)) {
288       OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
289       return nullptr;
290     }
291   }
292 
293   return sk;
294 }
295 
296 // ssl_get_compatible_server_ciphers determines the key exchange and
297 // authentication cipher suite masks compatible with the server configuration
298 // and current ClientHello parameters of |hs|. It sets |*out_mask_k| to the key
299 // exchange mask and |*out_mask_a| to the authentication mask.
ssl_get_compatible_server_ciphers(SSL_HANDSHAKE * hs,uint32_t * out_mask_k,uint32_t * out_mask_a)300 static void ssl_get_compatible_server_ciphers(SSL_HANDSHAKE *hs,
301                                               uint32_t *out_mask_k,
302                                               uint32_t *out_mask_a) {
303   uint32_t mask_k = 0;
304   uint32_t mask_a = 0;
305 
306   if (ssl_has_certificate(hs)) {
307     mask_a |= ssl_cipher_auth_mask_for_key(hs->local_pubkey.get());
308     if (EVP_PKEY_id(hs->local_pubkey.get()) == EVP_PKEY_RSA) {
309       mask_k |= SSL_kRSA;
310     }
311   }
312 
313   // Check for a shared group to consider ECDHE ciphers.
314   uint16_t unused;
315   if (tls1_get_shared_group(hs, &unused)) {
316     mask_k |= SSL_kECDHE;
317   }
318 
319   // PSK requires a server callback.
320   if (hs->config->psk_server_callback != NULL) {
321     mask_k |= SSL_kPSK;
322     mask_a |= SSL_aPSK;
323   }
324 
325   *out_mask_k = mask_k;
326   *out_mask_a = mask_a;
327 }
328 
ssl3_choose_cipher(SSL_HANDSHAKE * hs,const SSL_CLIENT_HELLO * client_hello,const SSLCipherPreferenceList * server_pref)329 static const SSL_CIPHER *ssl3_choose_cipher(
330     SSL_HANDSHAKE *hs, const SSL_CLIENT_HELLO *client_hello,
331     const SSLCipherPreferenceList *server_pref) {
332   SSL *const ssl = hs->ssl;
333   const STACK_OF(SSL_CIPHER) *prio, *allow;
334   // in_group_flags will either be NULL, or will point to an array of bytes
335   // which indicate equal-preference groups in the |prio| stack. See the
336   // comment about |in_group_flags| in the |SSLCipherPreferenceList|
337   // struct.
338   const bool *in_group_flags;
339   // group_min contains the minimal index so far found in a group, or -1 if no
340   // such value exists yet.
341   int group_min = -1;
342 
343   UniquePtr<STACK_OF(SSL_CIPHER)> client_pref =
344       ssl_parse_client_cipher_list(client_hello);
345   if (!client_pref) {
346     return nullptr;
347   }
348 
349   if (ssl->options & SSL_OP_CIPHER_SERVER_PREFERENCE) {
350     prio = server_pref->ciphers.get();
351     in_group_flags = server_pref->in_group_flags;
352     allow = client_pref.get();
353   } else {
354     prio = client_pref.get();
355     in_group_flags = NULL;
356     allow = server_pref->ciphers.get();
357   }
358 
359   uint32_t mask_k, mask_a;
360   ssl_get_compatible_server_ciphers(hs, &mask_k, &mask_a);
361 
362   for (size_t i = 0; i < sk_SSL_CIPHER_num(prio); i++) {
363     const SSL_CIPHER *c = sk_SSL_CIPHER_value(prio, i);
364 
365     size_t cipher_index;
366     if (// Check if the cipher is supported for the current version.
367         SSL_CIPHER_get_min_version(c) <= ssl_protocol_version(ssl) &&
368         ssl_protocol_version(ssl) <= SSL_CIPHER_get_max_version(c) &&
369         // Check the cipher is supported for the server configuration.
370         (c->algorithm_mkey & mask_k) &&
371         (c->algorithm_auth & mask_a) &&
372         // Check the cipher is in the |allow| list.
373         sk_SSL_CIPHER_find(allow, &cipher_index, c)) {
374       if (in_group_flags != NULL && in_group_flags[i]) {
375         // This element of |prio| is in a group. Update the minimum index found
376         // so far and continue looking.
377         if (group_min == -1 || (size_t)group_min > cipher_index) {
378           group_min = cipher_index;
379         }
380       } else {
381         if (group_min != -1 && (size_t)group_min < cipher_index) {
382           cipher_index = group_min;
383         }
384         return sk_SSL_CIPHER_value(allow, cipher_index);
385       }
386     }
387 
388     if (in_group_flags != NULL && !in_group_flags[i] && group_min != -1) {
389       // We are about to leave a group, but we found a match in it, so that's
390       // our answer.
391       return sk_SSL_CIPHER_value(allow, group_min);
392     }
393   }
394 
395   return nullptr;
396 }
397 
do_start_accept(SSL_HANDSHAKE * hs)398 static enum ssl_hs_wait_t do_start_accept(SSL_HANDSHAKE *hs) {
399   ssl_do_info_callback(hs->ssl, SSL_CB_HANDSHAKE_START, 1);
400   hs->state = state12_read_client_hello;
401   return ssl_hs_ok;
402 }
403 
404 // is_probably_jdk11_with_tls13 returns whether |client_hello| was probably sent
405 // from a JDK 11 client with both TLS 1.3 and a prior version enabled.
is_probably_jdk11_with_tls13(const SSL_CLIENT_HELLO * client_hello)406 static bool is_probably_jdk11_with_tls13(const SSL_CLIENT_HELLO *client_hello) {
407   // JDK 11 ClientHellos contain a number of unusual properties which should
408   // limit false positives.
409 
410   // JDK 11 does not support ChaCha20-Poly1305. This is unusual: many modern
411   // clients implement ChaCha20-Poly1305.
412   if (ssl_client_cipher_list_contains_cipher(
413           client_hello, TLS1_CK_CHACHA20_POLY1305_SHA256 & 0xffff)) {
414     return false;
415   }
416 
417   // JDK 11 always sends extensions in a particular order.
418   constexpr uint16_t kMaxFragmentLength = 0x0001;
419   constexpr uint16_t kStatusRequestV2 = 0x0011;
420   static CONSTEXPR_ARRAY struct {
421     uint16_t id;
422     bool required;
423   } kJavaExtensions[] = {
424       {TLSEXT_TYPE_server_name, false},
425       {kMaxFragmentLength, false},
426       {TLSEXT_TYPE_status_request, false},
427       {TLSEXT_TYPE_supported_groups, true},
428       {TLSEXT_TYPE_ec_point_formats, false},
429       {TLSEXT_TYPE_signature_algorithms, true},
430       // Java always sends signature_algorithms_cert.
431       {TLSEXT_TYPE_signature_algorithms_cert, true},
432       {TLSEXT_TYPE_application_layer_protocol_negotiation, false},
433       {kStatusRequestV2, false},
434       {TLSEXT_TYPE_extended_master_secret, false},
435       {TLSEXT_TYPE_supported_versions, true},
436       {TLSEXT_TYPE_cookie, false},
437       {TLSEXT_TYPE_psk_key_exchange_modes, true},
438       {TLSEXT_TYPE_key_share, true},
439       {TLSEXT_TYPE_renegotiate, false},
440       {TLSEXT_TYPE_pre_shared_key, false},
441   };
442   Span<const uint8_t> sigalgs, sigalgs_cert;
443   bool has_status_request = false, has_status_request_v2 = false;
444   CBS extensions, supported_groups;
445   CBS_init(&extensions, client_hello->extensions, client_hello->extensions_len);
446   for (const auto &java_extension : kJavaExtensions) {
447     CBS copy = extensions;
448     uint16_t id;
449     if (CBS_get_u16(&copy, &id) && id == java_extension.id) {
450       // The next extension is the one we expected.
451       extensions = copy;
452       CBS body;
453       if (!CBS_get_u16_length_prefixed(&extensions, &body)) {
454         return false;
455       }
456       switch (id) {
457         case TLSEXT_TYPE_status_request:
458           has_status_request = true;
459           break;
460         case kStatusRequestV2:
461           has_status_request_v2 = true;
462           break;
463         case TLSEXT_TYPE_signature_algorithms:
464           sigalgs = body;
465           break;
466         case TLSEXT_TYPE_signature_algorithms_cert:
467           sigalgs_cert = body;
468           break;
469         case TLSEXT_TYPE_supported_groups:
470           supported_groups = body;
471           break;
472       }
473     } else if (java_extension.required) {
474       return false;
475     }
476   }
477   if (CBS_len(&extensions) != 0) {
478     return false;
479   }
480 
481   // JDK 11 never advertises X25519. It is not offered by default, and
482   // -Djdk.tls.namedGroups=x25519 does not work. This is unusual: many modern
483   // clients implement X25519.
484   while (CBS_len(&supported_groups) > 0) {
485     uint16_t group;
486     if (!CBS_get_u16(&supported_groups, &group) ||
487         group == SSL_CURVE_X25519) {
488       return false;
489     }
490   }
491 
492   if (// JDK 11 always sends the same contents in signature_algorithms and
493       // signature_algorithms_cert. This is unusual: signature_algorithms_cert,
494       // if omitted, is treated as if it were signature_algorithms.
495       sigalgs != sigalgs_cert ||
496       // When TLS 1.2 or below is enabled, JDK 11 sends status_request_v2 iff it
497       // sends status_request. This is unusual: status_request_v2 is not widely
498       // implemented.
499       has_status_request != has_status_request_v2) {
500     return false;
501   }
502 
503   return true;
504 }
505 
do_read_client_hello(SSL_HANDSHAKE * hs)506 static enum ssl_hs_wait_t do_read_client_hello(SSL_HANDSHAKE *hs) {
507   SSL *const ssl = hs->ssl;
508 
509   SSLMessage msg;
510   if (!ssl->method->get_message(ssl, &msg)) {
511     return ssl_hs_read_message;
512   }
513 
514   if (!ssl_check_message_type(ssl, msg, SSL3_MT_CLIENT_HELLO)) {
515     return ssl_hs_error;
516   }
517 
518   if (hs->config->handoff) {
519     return ssl_hs_handoff;
520   }
521 
522   SSL_CLIENT_HELLO client_hello;
523   if (!ssl_client_hello_init(ssl, &client_hello, msg)) {
524     OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
525     ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
526     return ssl_hs_error;
527   }
528 
529   // Run the early callback.
530   if (ssl->ctx->select_certificate_cb != NULL) {
531     switch (ssl->ctx->select_certificate_cb(&client_hello)) {
532       case ssl_select_cert_retry:
533         return ssl_hs_certificate_selection_pending;
534 
535       case ssl_select_cert_error:
536         // Connection rejected.
537         OPENSSL_PUT_ERROR(SSL, SSL_R_CONNECTION_REJECTED);
538         ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
539         return ssl_hs_error;
540 
541       default:
542         /* fallthrough */;
543     }
544   }
545 
546   // Freeze the version range after the early callback.
547   if (!ssl_get_version_range(hs, &hs->min_version, &hs->max_version)) {
548     return ssl_hs_error;
549   }
550 
551   if (hs->config->jdk11_workaround &&
552       is_probably_jdk11_with_tls13(&client_hello)) {
553     hs->apply_jdk11_workaround = true;
554   }
555 
556   uint8_t alert = SSL_AD_DECODE_ERROR;
557   if (!negotiate_version(hs, &alert, &client_hello)) {
558     ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
559     return ssl_hs_error;
560   }
561 
562   hs->client_version = client_hello.version;
563   if (client_hello.random_len != SSL3_RANDOM_SIZE) {
564     OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
565     return ssl_hs_error;
566   }
567   OPENSSL_memcpy(ssl->s3->client_random, client_hello.random,
568                  client_hello.random_len);
569 
570   // Only null compression is supported. TLS 1.3 further requires the peer
571   // advertise no other compression.
572   if (OPENSSL_memchr(client_hello.compression_methods, 0,
573                      client_hello.compression_methods_len) == NULL ||
574       (ssl_protocol_version(ssl) >= TLS1_3_VERSION &&
575        client_hello.compression_methods_len != 1)) {
576     OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_COMPRESSION_LIST);
577     ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
578     return ssl_hs_error;
579   }
580 
581   // TLS extensions.
582   if (!ssl_parse_clienthello_tlsext(hs, &client_hello)) {
583     OPENSSL_PUT_ERROR(SSL, SSL_R_PARSE_TLSEXT);
584     return ssl_hs_error;
585   }
586 
587   hs->state = state12_select_certificate;
588   return ssl_hs_ok;
589 }
590 
do_select_certificate(SSL_HANDSHAKE * hs)591 static enum ssl_hs_wait_t do_select_certificate(SSL_HANDSHAKE *hs) {
592   SSL *const ssl = hs->ssl;
593 
594   SSLMessage msg;
595   if (!ssl->method->get_message(ssl, &msg)) {
596     return ssl_hs_read_message;
597   }
598 
599   // Call |cert_cb| to update server certificates if required.
600   if (hs->config->cert->cert_cb != NULL) {
601     int rv = hs->config->cert->cert_cb(ssl, hs->config->cert->cert_cb_arg);
602     if (rv == 0) {
603       OPENSSL_PUT_ERROR(SSL, SSL_R_CERT_CB_ERROR);
604       ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
605       return ssl_hs_error;
606     }
607     if (rv < 0) {
608       return ssl_hs_x509_lookup;
609     }
610   }
611 
612   if (!ssl_on_certificate_selected(hs)) {
613     return ssl_hs_error;
614   }
615 
616   if (hs->ocsp_stapling_requested &&
617       ssl->ctx->legacy_ocsp_callback != nullptr) {
618     switch (ssl->ctx->legacy_ocsp_callback(
619         ssl, ssl->ctx->legacy_ocsp_callback_arg)) {
620       case SSL_TLSEXT_ERR_OK:
621         break;
622       case SSL_TLSEXT_ERR_NOACK:
623         hs->ocsp_stapling_requested = false;
624         break;
625       default:
626         OPENSSL_PUT_ERROR(SSL, SSL_R_OCSP_CB_ERROR);
627         ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
628         return ssl_hs_error;
629     }
630   }
631 
632   if (ssl_protocol_version(ssl) >= TLS1_3_VERSION) {
633     // Jump to the TLS 1.3 state machine.
634     hs->state = state12_tls13;
635     return ssl_hs_ok;
636   }
637 
638   SSL_CLIENT_HELLO client_hello;
639   if (!ssl_client_hello_init(ssl, &client_hello, msg)) {
640     return ssl_hs_error;
641   }
642 
643   // Negotiate the cipher suite. This must be done after |cert_cb| so the
644   // certificate is finalized.
645   SSLCipherPreferenceList *prefs = hs->config->cipher_list
646                                        ? hs->config->cipher_list.get()
647                                        : ssl->ctx->cipher_list.get();
648   hs->new_cipher = ssl3_choose_cipher(hs, &client_hello, prefs);
649   if (hs->new_cipher == NULL) {
650     OPENSSL_PUT_ERROR(SSL, SSL_R_NO_SHARED_CIPHER);
651     ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
652     return ssl_hs_error;
653   }
654 
655   hs->state = state12_select_parameters;
656   return ssl_hs_ok;
657 }
658 
do_tls13(SSL_HANDSHAKE * hs)659 static enum ssl_hs_wait_t do_tls13(SSL_HANDSHAKE *hs) {
660   enum ssl_hs_wait_t wait = tls13_server_handshake(hs);
661   if (wait == ssl_hs_ok) {
662     hs->state = state12_finish_server_handshake;
663     return ssl_hs_ok;
664   }
665 
666   return wait;
667 }
668 
do_select_parameters(SSL_HANDSHAKE * hs)669 static enum ssl_hs_wait_t do_select_parameters(SSL_HANDSHAKE *hs) {
670   SSL *const ssl = hs->ssl;
671 
672   SSLMessage msg;
673   if (!ssl->method->get_message(ssl, &msg)) {
674     return ssl_hs_read_message;
675   }
676 
677   SSL_CLIENT_HELLO client_hello;
678   if (!ssl_client_hello_init(ssl, &client_hello, msg)) {
679     return ssl_hs_error;
680   }
681 
682   // Determine whether we are doing session resumption.
683   UniquePtr<SSL_SESSION> session;
684   bool tickets_supported = false, renew_ticket = false;
685   enum ssl_hs_wait_t wait = ssl_get_prev_session(
686       hs, &session, &tickets_supported, &renew_ticket, &client_hello);
687   if (wait != ssl_hs_ok) {
688     return wait;
689   }
690 
691   if (session) {
692     if (session->extended_master_secret && !hs->extended_master_secret) {
693       // A ClientHello without EMS that attempts to resume a session with EMS
694       // is fatal to the connection.
695       OPENSSL_PUT_ERROR(SSL, SSL_R_RESUMED_EMS_SESSION_WITHOUT_EMS_EXTENSION);
696       ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
697       return ssl_hs_error;
698     }
699 
700     if (!ssl_session_is_resumable(hs, session.get()) ||
701         // If the client offers the EMS extension, but the previous session
702         // didn't use it, then negotiate a new session.
703         hs->extended_master_secret != session->extended_master_secret) {
704       session.reset();
705     }
706   }
707 
708   if (session) {
709     // Use the old session.
710     hs->ticket_expected = renew_ticket;
711     ssl->session = std::move(session);
712     ssl->s3->session_reused = true;
713   } else {
714     hs->ticket_expected = tickets_supported;
715     ssl_set_session(ssl, NULL);
716     if (!ssl_get_new_session(hs, 1 /* server */)) {
717       return ssl_hs_error;
718     }
719 
720     // Clear the session ID if we want the session to be single-use.
721     if (!(ssl->ctx->session_cache_mode & SSL_SESS_CACHE_SERVER)) {
722       hs->new_session->session_id_length = 0;
723     }
724   }
725 
726   if (ssl->ctx->dos_protection_cb != NULL &&
727       ssl->ctx->dos_protection_cb(&client_hello) == 0) {
728     // Connection rejected for DOS reasons.
729     OPENSSL_PUT_ERROR(SSL, SSL_R_CONNECTION_REJECTED);
730     ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
731     return ssl_hs_error;
732   }
733 
734   if (ssl->session == NULL) {
735     hs->new_session->cipher = hs->new_cipher;
736 
737     // Determine whether to request a client certificate.
738     hs->cert_request = !!(hs->config->verify_mode & SSL_VERIFY_PEER);
739     // Only request a certificate if Channel ID isn't negotiated.
740     if ((hs->config->verify_mode & SSL_VERIFY_PEER_IF_NO_OBC) &&
741         ssl->s3->channel_id_valid) {
742       hs->cert_request = false;
743     }
744     // CertificateRequest may only be sent in certificate-based ciphers.
745     if (!ssl_cipher_uses_certificate_auth(hs->new_cipher)) {
746       hs->cert_request = false;
747     }
748 
749     if (!hs->cert_request) {
750       // OpenSSL returns X509_V_OK when no certificates are requested. This is
751       // classed by them as a bug, but it's assumed by at least NGINX.
752       hs->new_session->verify_result = X509_V_OK;
753     }
754   }
755 
756   // HTTP/2 negotiation depends on the cipher suite, so ALPN negotiation was
757   // deferred. Complete it now.
758   uint8_t alert = SSL_AD_DECODE_ERROR;
759   if (!ssl_negotiate_alpn(hs, &alert, &client_hello)) {
760     ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
761     return ssl_hs_error;
762   }
763 
764   // Now that all parameters are known, initialize the handshake hash and hash
765   // the ClientHello.
766   if (!hs->transcript.InitHash(ssl_protocol_version(ssl), hs->new_cipher) ||
767       !ssl_hash_message(hs, msg)) {
768     ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
769     return ssl_hs_error;
770   }
771 
772   // Handback includes the whole handshake transcript, so we cannot free the
773   // transcript buffer in the handback case.
774   if (!hs->cert_request && !hs->handback) {
775     hs->transcript.FreeBuffer();
776   }
777 
778   ssl->method->next_message(ssl);
779 
780   hs->state = state12_send_server_hello;
781   return ssl_hs_ok;
782 }
783 
copy_suffix(Span<uint8_t> out,Span<const uint8_t> in)784 static void copy_suffix(Span<uint8_t> out, Span<const uint8_t> in) {
785   out = out.subspan(out.size() - in.size());
786   assert(out.size() == in.size());
787   OPENSSL_memcpy(out.data(), in.data(), in.size());
788 }
789 
do_send_server_hello(SSL_HANDSHAKE * hs)790 static enum ssl_hs_wait_t do_send_server_hello(SSL_HANDSHAKE *hs) {
791   SSL *const ssl = hs->ssl;
792 
793   // We only accept ChannelIDs on connections with ECDHE in order to avoid a
794   // known attack while we fix ChannelID itself.
795   if (ssl->s3->channel_id_valid &&
796       (hs->new_cipher->algorithm_mkey & SSL_kECDHE) == 0) {
797     ssl->s3->channel_id_valid = false;
798   }
799 
800   // If this is a resumption and the original handshake didn't support
801   // ChannelID then we didn't record the original handshake hashes in the
802   // session and so cannot resume with ChannelIDs.
803   if (ssl->session != NULL &&
804       ssl->session->original_handshake_hash_len == 0) {
805     ssl->s3->channel_id_valid = false;
806   }
807 
808   struct OPENSSL_timeval now;
809   ssl_get_current_time(ssl, &now);
810   ssl->s3->server_random[0] = now.tv_sec >> 24;
811   ssl->s3->server_random[1] = now.tv_sec >> 16;
812   ssl->s3->server_random[2] = now.tv_sec >> 8;
813   ssl->s3->server_random[3] = now.tv_sec;
814   if (!RAND_bytes(ssl->s3->server_random + 4, SSL3_RANDOM_SIZE - 4)) {
815     return ssl_hs_error;
816   }
817 
818   // Implement the TLS 1.3 anti-downgrade feature.
819   if (ssl_supports_version(hs, TLS1_3_VERSION)) {
820     if (ssl_protocol_version(ssl) == TLS1_2_VERSION) {
821       if (hs->apply_jdk11_workaround) {
822         // JDK 11 implements the TLS 1.3 downgrade signal, so we cannot send it
823         // here. However, the signal is only effective if all TLS 1.2
824         // ServerHellos produced by the server are marked. Thus we send a
825         // different non-standard signal for the time being, until JDK 11.0.2 is
826         // released and clients have updated.
827         copy_suffix(ssl->s3->server_random, kJDK11DowngradeRandom);
828       } else {
829         copy_suffix(ssl->s3->server_random, kTLS13DowngradeRandom);
830       }
831     } else {
832       copy_suffix(ssl->s3->server_random, kTLS12DowngradeRandom);
833     }
834   }
835 
836   const SSL_SESSION *session = hs->new_session.get();
837   if (ssl->session != nullptr) {
838     session = ssl->session.get();
839   }
840 
841   ScopedCBB cbb;
842   CBB body, session_id;
843   if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_SERVER_HELLO) ||
844       !CBB_add_u16(&body, ssl->version) ||
845       !CBB_add_bytes(&body, ssl->s3->server_random, SSL3_RANDOM_SIZE) ||
846       !CBB_add_u8_length_prefixed(&body, &session_id) ||
847       !CBB_add_bytes(&session_id, session->session_id,
848                      session->session_id_length) ||
849       !CBB_add_u16(&body, ssl_cipher_get_value(hs->new_cipher)) ||
850       !CBB_add_u8(&body, 0 /* no compression */) ||
851       !ssl_add_serverhello_tlsext(hs, &body) ||
852       !ssl_add_message_cbb(ssl, cbb.get())) {
853     OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
854     return ssl_hs_error;
855   }
856 
857   if (ssl->session != NULL) {
858     hs->state = state12_send_server_finished;
859   } else {
860     hs->state = state12_send_server_certificate;
861   }
862   return ssl_hs_ok;
863 }
864 
do_send_server_certificate(SSL_HANDSHAKE * hs)865 static enum ssl_hs_wait_t do_send_server_certificate(SSL_HANDSHAKE *hs) {
866   SSL *const ssl = hs->ssl;
867   ScopedCBB cbb;
868 
869   if (ssl_cipher_uses_certificate_auth(hs->new_cipher)) {
870     if (!ssl_has_certificate(hs)) {
871       OPENSSL_PUT_ERROR(SSL, SSL_R_NO_CERTIFICATE_SET);
872       return ssl_hs_error;
873     }
874 
875     if (!ssl_output_cert_chain(hs)) {
876       return ssl_hs_error;
877     }
878 
879     if (hs->certificate_status_expected) {
880       CBB body, ocsp_response;
881       if (!ssl->method->init_message(ssl, cbb.get(), &body,
882                                      SSL3_MT_CERTIFICATE_STATUS) ||
883           !CBB_add_u8(&body, TLSEXT_STATUSTYPE_ocsp) ||
884           !CBB_add_u24_length_prefixed(&body, &ocsp_response) ||
885           !CBB_add_bytes(
886               &ocsp_response,
887               CRYPTO_BUFFER_data(hs->config->cert->ocsp_response.get()),
888               CRYPTO_BUFFER_len(hs->config->cert->ocsp_response.get())) ||
889           !ssl_add_message_cbb(ssl, cbb.get())) {
890         OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
891         return ssl_hs_error;
892       }
893     }
894   }
895 
896   // Assemble ServerKeyExchange parameters if needed.
897   uint32_t alg_k = hs->new_cipher->algorithm_mkey;
898   uint32_t alg_a = hs->new_cipher->algorithm_auth;
899   if (ssl_cipher_requires_server_key_exchange(hs->new_cipher) ||
900       ((alg_a & SSL_aPSK) && hs->config->psk_identity_hint)) {
901     // Pre-allocate enough room to comfortably fit an ECDHE public key. Prepend
902     // the client and server randoms for the signing transcript.
903     CBB child;
904     if (!CBB_init(cbb.get(), SSL3_RANDOM_SIZE * 2 + 128) ||
905         !CBB_add_bytes(cbb.get(), ssl->s3->client_random, SSL3_RANDOM_SIZE) ||
906         !CBB_add_bytes(cbb.get(), ssl->s3->server_random, SSL3_RANDOM_SIZE)) {
907       return ssl_hs_error;
908     }
909 
910     // PSK ciphers begin with an identity hint.
911     if (alg_a & SSL_aPSK) {
912       size_t len = hs->config->psk_identity_hint == nullptr
913                        ? 0
914                        : strlen(hs->config->psk_identity_hint.get());
915       if (!CBB_add_u16_length_prefixed(cbb.get(), &child) ||
916           !CBB_add_bytes(&child,
917                          (const uint8_t *)hs->config->psk_identity_hint.get(),
918                          len)) {
919         return ssl_hs_error;
920       }
921     }
922 
923     if (alg_k & SSL_kECDHE) {
924       // Determine the group to use.
925       uint16_t group_id;
926       if (!tls1_get_shared_group(hs, &group_id)) {
927         OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
928         ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
929         return ssl_hs_error;
930        }
931       hs->new_session->group_id = group_id;
932 
933       // Set up ECDH, generate a key, and emit the public half.
934       hs->key_shares[0] = SSLKeyShare::Create(group_id);
935       if (!hs->key_shares[0] ||
936           !CBB_add_u8(cbb.get(), NAMED_CURVE_TYPE) ||
937           !CBB_add_u16(cbb.get(), group_id) ||
938           !CBB_add_u8_length_prefixed(cbb.get(), &child) ||
939           !hs->key_shares[0]->Offer(&child)) {
940         return ssl_hs_error;
941       }
942     } else {
943       assert(alg_k & SSL_kPSK);
944     }
945 
946     if (!CBBFinishArray(cbb.get(), &hs->server_params)) {
947       return ssl_hs_error;
948     }
949   }
950 
951   hs->state = state12_send_server_key_exchange;
952   return ssl_hs_ok;
953 }
954 
do_send_server_key_exchange(SSL_HANDSHAKE * hs)955 static enum ssl_hs_wait_t do_send_server_key_exchange(SSL_HANDSHAKE *hs) {
956   SSL *const ssl = hs->ssl;
957 
958   if (hs->server_params.size() == 0) {
959     hs->state = state12_send_server_hello_done;
960     return ssl_hs_ok;
961   }
962 
963   ScopedCBB cbb;
964   CBB body, child;
965   if (!ssl->method->init_message(ssl, cbb.get(), &body,
966                                  SSL3_MT_SERVER_KEY_EXCHANGE) ||
967       // |hs->server_params| contains a prefix for signing.
968       hs->server_params.size() < 2 * SSL3_RANDOM_SIZE ||
969       !CBB_add_bytes(&body, hs->server_params.data() + 2 * SSL3_RANDOM_SIZE,
970                      hs->server_params.size() - 2 * SSL3_RANDOM_SIZE)) {
971     return ssl_hs_error;
972   }
973 
974   // Add a signature.
975   if (ssl_cipher_uses_certificate_auth(hs->new_cipher)) {
976     if (!ssl_has_private_key(hs)) {
977       ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
978       return ssl_hs_error;
979     }
980 
981     // Determine the signature algorithm.
982     uint16_t signature_algorithm;
983     if (!tls1_choose_signature_algorithm(hs, &signature_algorithm)) {
984       ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
985       return ssl_hs_error;
986     }
987     if (ssl_protocol_version(ssl) >= TLS1_2_VERSION) {
988       if (!CBB_add_u16(&body, signature_algorithm)) {
989         OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
990         ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
991         return ssl_hs_error;
992       }
993     }
994 
995     // Add space for the signature.
996     const size_t max_sig_len = EVP_PKEY_size(hs->local_pubkey.get());
997     uint8_t *ptr;
998     if (!CBB_add_u16_length_prefixed(&body, &child) ||
999         !CBB_reserve(&child, &ptr, max_sig_len)) {
1000       return ssl_hs_error;
1001     }
1002 
1003     size_t sig_len;
1004     switch (ssl_private_key_sign(hs, ptr, &sig_len, max_sig_len,
1005                                  signature_algorithm, hs->server_params)) {
1006       case ssl_private_key_success:
1007         if (!CBB_did_write(&child, sig_len)) {
1008           return ssl_hs_error;
1009         }
1010         break;
1011       case ssl_private_key_failure:
1012         return ssl_hs_error;
1013       case ssl_private_key_retry:
1014         return ssl_hs_private_key_operation;
1015     }
1016   }
1017 
1018   if (!ssl_add_message_cbb(ssl, cbb.get())) {
1019     return ssl_hs_error;
1020   }
1021 
1022   hs->server_params.Reset();
1023 
1024   hs->state = state12_send_server_hello_done;
1025   return ssl_hs_ok;
1026 }
1027 
do_send_server_hello_done(SSL_HANDSHAKE * hs)1028 static enum ssl_hs_wait_t do_send_server_hello_done(SSL_HANDSHAKE *hs) {
1029   SSL *const ssl = hs->ssl;
1030 
1031   ScopedCBB cbb;
1032   CBB body;
1033 
1034   if (hs->cert_request) {
1035     CBB cert_types, sigalgs_cbb;
1036     if (!ssl->method->init_message(ssl, cbb.get(), &body,
1037                                    SSL3_MT_CERTIFICATE_REQUEST) ||
1038         !CBB_add_u8_length_prefixed(&body, &cert_types) ||
1039         !CBB_add_u8(&cert_types, SSL3_CT_RSA_SIGN) ||
1040         !CBB_add_u8(&cert_types, TLS_CT_ECDSA_SIGN) ||
1041         // TLS 1.2 has no way to specify different signature algorithms for
1042         // certificates and the online signature, so emit the more restrictive
1043         // certificate list.
1044         (ssl_protocol_version(ssl) >= TLS1_2_VERSION &&
1045          (!CBB_add_u16_length_prefixed(&body, &sigalgs_cbb) ||
1046           !tls12_add_verify_sigalgs(ssl, &sigalgs_cbb, true /* certs */))) ||
1047         !ssl_add_client_CA_list(hs, &body) ||
1048         !ssl_add_message_cbb(ssl, cbb.get())) {
1049       OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
1050       return ssl_hs_error;
1051     }
1052   }
1053 
1054   if (!ssl->method->init_message(ssl, cbb.get(), &body,
1055                                  SSL3_MT_SERVER_HELLO_DONE) ||
1056       !ssl_add_message_cbb(ssl, cbb.get())) {
1057     OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
1058     return ssl_hs_error;
1059   }
1060 
1061   hs->state = state12_read_client_certificate;
1062   return ssl_hs_flush;
1063 }
1064 
do_read_client_certificate(SSL_HANDSHAKE * hs)1065 static enum ssl_hs_wait_t do_read_client_certificate(SSL_HANDSHAKE *hs) {
1066   SSL *const ssl = hs->ssl;
1067 
1068   if (hs->handback && hs->new_cipher->algorithm_mkey == SSL_kECDHE) {
1069     return ssl_hs_handback;
1070   }
1071   if (!hs->cert_request) {
1072     hs->state = state12_verify_client_certificate;
1073     return ssl_hs_ok;
1074   }
1075 
1076   SSLMessage msg;
1077   if (!ssl->method->get_message(ssl, &msg)) {
1078     return ssl_hs_read_message;
1079   }
1080 
1081   if (!ssl_check_message_type(ssl, msg, SSL3_MT_CERTIFICATE)) {
1082     return ssl_hs_error;
1083   }
1084 
1085   if (!ssl_hash_message(hs, msg)) {
1086     return ssl_hs_error;
1087   }
1088 
1089   CBS certificate_msg = msg.body;
1090   uint8_t alert = SSL_AD_DECODE_ERROR;
1091   if (!ssl_parse_cert_chain(&alert, &hs->new_session->certs, &hs->peer_pubkey,
1092                             hs->config->retain_only_sha256_of_client_certs
1093                                 ? hs->new_session->peer_sha256
1094                                 : nullptr,
1095                             &certificate_msg, ssl->ctx->pool)) {
1096     ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
1097     return ssl_hs_error;
1098   }
1099 
1100   if (CBS_len(&certificate_msg) != 0 ||
1101       !ssl->ctx->x509_method->session_cache_objects(hs->new_session.get())) {
1102     OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
1103     ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
1104     return ssl_hs_error;
1105   }
1106 
1107   if (sk_CRYPTO_BUFFER_num(hs->new_session->certs.get()) == 0) {
1108     // No client certificate so the handshake buffer may be discarded.
1109     hs->transcript.FreeBuffer();
1110 
1111     if (hs->config->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT) {
1112       // Fail for TLS only if we required a certificate
1113       OPENSSL_PUT_ERROR(SSL, SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE);
1114       ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
1115       return ssl_hs_error;
1116     }
1117 
1118     // OpenSSL returns X509_V_OK when no certificates are received. This is
1119     // classed by them as a bug, but it's assumed by at least NGINX.
1120     hs->new_session->verify_result = X509_V_OK;
1121   } else if (hs->config->retain_only_sha256_of_client_certs) {
1122     // The hash will have been filled in.
1123     hs->new_session->peer_sha256_valid = 1;
1124   }
1125 
1126   ssl->method->next_message(ssl);
1127   hs->state = state12_verify_client_certificate;
1128   return ssl_hs_ok;
1129 }
1130 
do_verify_client_certificate(SSL_HANDSHAKE * hs)1131 static enum ssl_hs_wait_t do_verify_client_certificate(SSL_HANDSHAKE *hs) {
1132   if (sk_CRYPTO_BUFFER_num(hs->new_session->certs.get()) > 0) {
1133     switch (ssl_verify_peer_cert(hs)) {
1134       case ssl_verify_ok:
1135         break;
1136       case ssl_verify_invalid:
1137         return ssl_hs_error;
1138       case ssl_verify_retry:
1139         return ssl_hs_certificate_verify;
1140     }
1141   }
1142 
1143   hs->state = state12_read_client_key_exchange;
1144   return ssl_hs_ok;
1145 }
1146 
do_read_client_key_exchange(SSL_HANDSHAKE * hs)1147 static enum ssl_hs_wait_t do_read_client_key_exchange(SSL_HANDSHAKE *hs) {
1148   SSL *const ssl = hs->ssl;
1149   SSLMessage msg;
1150   if (!ssl->method->get_message(ssl, &msg)) {
1151     return ssl_hs_read_message;
1152   }
1153 
1154   if (!ssl_check_message_type(ssl, msg, SSL3_MT_CLIENT_KEY_EXCHANGE)) {
1155     return ssl_hs_error;
1156   }
1157 
1158   CBS client_key_exchange = msg.body;
1159   uint32_t alg_k = hs->new_cipher->algorithm_mkey;
1160   uint32_t alg_a = hs->new_cipher->algorithm_auth;
1161 
1162   // If using a PSK key exchange, parse the PSK identity.
1163   if (alg_a & SSL_aPSK) {
1164     CBS psk_identity;
1165 
1166     // If using PSK, the ClientKeyExchange contains a psk_identity. If PSK,
1167     // then this is the only field in the message.
1168     if (!CBS_get_u16_length_prefixed(&client_key_exchange, &psk_identity) ||
1169         ((alg_k & SSL_kPSK) && CBS_len(&client_key_exchange) != 0)) {
1170       OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
1171       ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
1172       return ssl_hs_error;
1173     }
1174 
1175     if (CBS_len(&psk_identity) > PSK_MAX_IDENTITY_LEN ||
1176         CBS_contains_zero_byte(&psk_identity)) {
1177       OPENSSL_PUT_ERROR(SSL, SSL_R_DATA_LENGTH_TOO_LONG);
1178       ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
1179       return ssl_hs_error;
1180     }
1181     char *raw = nullptr;
1182     if (!CBS_strdup(&psk_identity, &raw)) {
1183       OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
1184       ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
1185       return ssl_hs_error;
1186     }
1187     hs->new_session->psk_identity.reset(raw);
1188   }
1189 
1190   // Depending on the key exchange method, compute |premaster_secret|.
1191   Array<uint8_t> premaster_secret;
1192   if (alg_k & SSL_kRSA) {
1193     CBS encrypted_premaster_secret;
1194     if (!CBS_get_u16_length_prefixed(&client_key_exchange,
1195                                      &encrypted_premaster_secret) ||
1196         CBS_len(&client_key_exchange) != 0) {
1197       OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
1198       ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
1199       return ssl_hs_error;
1200     }
1201 
1202     // Allocate a buffer large enough for an RSA decryption.
1203     Array<uint8_t> decrypt_buf;
1204     if (!decrypt_buf.Init(EVP_PKEY_size(hs->local_pubkey.get()))) {
1205       return ssl_hs_error;
1206     }
1207 
1208     // Decrypt with no padding. PKCS#1 padding will be removed as part of the
1209     // timing-sensitive code below.
1210     size_t decrypt_len;
1211     switch (ssl_private_key_decrypt(hs, decrypt_buf.data(), &decrypt_len,
1212                                     decrypt_buf.size(),
1213                                     encrypted_premaster_secret)) {
1214       case ssl_private_key_success:
1215         break;
1216       case ssl_private_key_failure:
1217         return ssl_hs_error;
1218       case ssl_private_key_retry:
1219         return ssl_hs_private_key_operation;
1220     }
1221 
1222     if (decrypt_len != decrypt_buf.size()) {
1223       OPENSSL_PUT_ERROR(SSL, SSL_R_DECRYPTION_FAILED);
1224       ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECRYPT_ERROR);
1225       return ssl_hs_error;
1226     }
1227 
1228     CONSTTIME_SECRET(decrypt_buf.data(), decrypt_len);
1229 
1230     // Prepare a random premaster, to be used on invalid padding. See RFC 5246,
1231     // section 7.4.7.1.
1232     if (!premaster_secret.Init(SSL_MAX_MASTER_KEY_LENGTH) ||
1233         !RAND_bytes(premaster_secret.data(), premaster_secret.size())) {
1234       return ssl_hs_error;
1235     }
1236 
1237     // The smallest padded premaster is 11 bytes of overhead. Small keys are
1238     // publicly invalid.
1239     if (decrypt_len < 11 + premaster_secret.size()) {
1240       OPENSSL_PUT_ERROR(SSL, SSL_R_DECRYPTION_FAILED);
1241       ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECRYPT_ERROR);
1242       return ssl_hs_error;
1243     }
1244 
1245     // Check the padding. See RFC 3447, section 7.2.2.
1246     size_t padding_len = decrypt_len - premaster_secret.size();
1247     uint8_t good = constant_time_eq_int_8(decrypt_buf[0], 0) &
1248                    constant_time_eq_int_8(decrypt_buf[1], 2);
1249     for (size_t i = 2; i < padding_len - 1; i++) {
1250       good &= ~constant_time_is_zero_8(decrypt_buf[i]);
1251     }
1252     good &= constant_time_is_zero_8(decrypt_buf[padding_len - 1]);
1253 
1254     // The premaster secret must begin with |client_version|. This too must be
1255     // checked in constant time (http://eprint.iacr.org/2003/052/).
1256     good &= constant_time_eq_8(decrypt_buf[padding_len],
1257                                (unsigned)(hs->client_version >> 8));
1258     good &= constant_time_eq_8(decrypt_buf[padding_len + 1],
1259                                (unsigned)(hs->client_version & 0xff));
1260 
1261     // Select, in constant time, either the decrypted premaster or the random
1262     // premaster based on |good|.
1263     for (size_t i = 0; i < premaster_secret.size(); i++) {
1264       premaster_secret[i] = constant_time_select_8(
1265           good, decrypt_buf[padding_len + i], premaster_secret[i]);
1266     }
1267   } else if (alg_k & SSL_kECDHE) {
1268     // Parse the ClientKeyExchange.
1269     CBS peer_key;
1270     if (!CBS_get_u8_length_prefixed(&client_key_exchange, &peer_key) ||
1271         CBS_len(&client_key_exchange) != 0) {
1272       OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
1273       ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
1274       return ssl_hs_error;
1275     }
1276 
1277     // Compute the premaster.
1278     uint8_t alert = SSL_AD_DECODE_ERROR;
1279     if (!hs->key_shares[0]->Finish(&premaster_secret, &alert, peer_key)) {
1280       ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
1281       return ssl_hs_error;
1282     }
1283 
1284     // The key exchange state may now be discarded.
1285     hs->key_shares[0].reset();
1286     hs->key_shares[1].reset();
1287   } else if (!(alg_k & SSL_kPSK)) {
1288     OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
1289     ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
1290     return ssl_hs_error;
1291   }
1292 
1293   // For a PSK cipher suite, the actual pre-master secret is combined with the
1294   // pre-shared key.
1295   if (alg_a & SSL_aPSK) {
1296     if (hs->config->psk_server_callback == NULL) {
1297       OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
1298       ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
1299       return ssl_hs_error;
1300     }
1301 
1302     // Look up the key for the identity.
1303     uint8_t psk[PSK_MAX_PSK_LEN];
1304     unsigned psk_len = hs->config->psk_server_callback(
1305         ssl, hs->new_session->psk_identity.get(), psk, sizeof(psk));
1306     if (psk_len > PSK_MAX_PSK_LEN) {
1307       OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
1308       ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
1309       return ssl_hs_error;
1310     } else if (psk_len == 0) {
1311       // PSK related to the given identity not found.
1312       OPENSSL_PUT_ERROR(SSL, SSL_R_PSK_IDENTITY_NOT_FOUND);
1313       ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNKNOWN_PSK_IDENTITY);
1314       return ssl_hs_error;
1315     }
1316 
1317     if (alg_k & SSL_kPSK) {
1318       // In plain PSK, other_secret is a block of 0s with the same length as the
1319       // pre-shared key.
1320       if (!premaster_secret.Init(psk_len)) {
1321         return ssl_hs_error;
1322       }
1323       OPENSSL_memset(premaster_secret.data(), 0, premaster_secret.size());
1324     }
1325 
1326     ScopedCBB new_premaster;
1327     CBB child;
1328     if (!CBB_init(new_premaster.get(),
1329                   2 + psk_len + 2 + premaster_secret.size()) ||
1330         !CBB_add_u16_length_prefixed(new_premaster.get(), &child) ||
1331         !CBB_add_bytes(&child, premaster_secret.data(),
1332                        premaster_secret.size()) ||
1333         !CBB_add_u16_length_prefixed(new_premaster.get(), &child) ||
1334         !CBB_add_bytes(&child, psk, psk_len) ||
1335         !CBBFinishArray(new_premaster.get(), &premaster_secret)) {
1336       OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
1337       return ssl_hs_error;
1338     }
1339   }
1340 
1341   if (!ssl_hash_message(hs, msg)) {
1342     return ssl_hs_error;
1343   }
1344 
1345   // Compute the master secret.
1346   hs->new_session->master_key_length = tls1_generate_master_secret(
1347       hs, hs->new_session->master_key, premaster_secret);
1348   if (hs->new_session->master_key_length == 0) {
1349     return ssl_hs_error;
1350   }
1351   hs->new_session->extended_master_secret = hs->extended_master_secret;
1352   CONSTTIME_DECLASSIFY(hs->new_session->master_key,
1353                        hs->new_session->master_key_length);
1354 
1355   ssl->method->next_message(ssl);
1356   hs->state = state12_read_client_certificate_verify;
1357   return ssl_hs_ok;
1358 }
1359 
do_read_client_certificate_verify(SSL_HANDSHAKE * hs)1360 static enum ssl_hs_wait_t do_read_client_certificate_verify(SSL_HANDSHAKE *hs) {
1361   SSL *const ssl = hs->ssl;
1362 
1363   // Only RSA and ECDSA client certificates are supported, so a
1364   // CertificateVerify is required if and only if there's a client certificate.
1365   if (!hs->peer_pubkey) {
1366     hs->transcript.FreeBuffer();
1367     hs->state = state12_read_change_cipher_spec;
1368     return ssl_hs_ok;
1369   }
1370 
1371   SSLMessage msg;
1372   if (!ssl->method->get_message(ssl, &msg)) {
1373     return ssl_hs_read_message;
1374   }
1375 
1376   if (!ssl_check_message_type(ssl, msg, SSL3_MT_CERTIFICATE_VERIFY)) {
1377     return ssl_hs_error;
1378   }
1379 
1380   CBS certificate_verify = msg.body, signature;
1381 
1382   // Determine the signature algorithm.
1383   uint16_t signature_algorithm = 0;
1384   if (ssl_protocol_version(ssl) >= TLS1_2_VERSION) {
1385     if (!CBS_get_u16(&certificate_verify, &signature_algorithm)) {
1386       OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
1387       ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
1388       return ssl_hs_error;
1389     }
1390     uint8_t alert = SSL_AD_DECODE_ERROR;
1391     if (!tls12_check_peer_sigalg(ssl, &alert, signature_algorithm)) {
1392       ssl_send_alert(ssl, SSL3_AL_FATAL, alert);
1393       return ssl_hs_error;
1394     }
1395     hs->new_session->peer_signature_algorithm = signature_algorithm;
1396   } else if (!tls1_get_legacy_signature_algorithm(&signature_algorithm,
1397                                                   hs->peer_pubkey.get())) {
1398     OPENSSL_PUT_ERROR(SSL, SSL_R_PEER_ERROR_UNSUPPORTED_CERTIFICATE_TYPE);
1399     ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNSUPPORTED_CERTIFICATE);
1400     return ssl_hs_error;
1401   }
1402 
1403   // Parse and verify the signature.
1404   if (!CBS_get_u16_length_prefixed(&certificate_verify, &signature) ||
1405       CBS_len(&certificate_verify) != 0) {
1406     OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
1407     ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
1408     return ssl_hs_error;
1409   }
1410 
1411   bool sig_ok =
1412       ssl_public_key_verify(ssl, signature, signature_algorithm,
1413                             hs->peer_pubkey.get(), hs->transcript.buffer());
1414 #if defined(BORINGSSL_UNSAFE_FUZZER_MODE)
1415   sig_ok = true;
1416   ERR_clear_error();
1417 #endif
1418   if (!sig_ok) {
1419     OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SIGNATURE);
1420     ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECRYPT_ERROR);
1421     return ssl_hs_error;
1422   }
1423 
1424   // The handshake buffer is no longer necessary, and we may hash the current
1425   // message.
1426   hs->transcript.FreeBuffer();
1427   if (!ssl_hash_message(hs, msg)) {
1428     return ssl_hs_error;
1429   }
1430 
1431   ssl->method->next_message(ssl);
1432   hs->state = state12_read_change_cipher_spec;
1433   return ssl_hs_ok;
1434 }
1435 
do_read_change_cipher_spec(SSL_HANDSHAKE * hs)1436 static enum ssl_hs_wait_t do_read_change_cipher_spec(SSL_HANDSHAKE *hs) {
1437   if (hs->handback && hs->ssl->session != NULL) {
1438     return ssl_hs_handback;
1439   }
1440   hs->state = state12_process_change_cipher_spec;
1441   return ssl_hs_read_change_cipher_spec;
1442 }
1443 
do_process_change_cipher_spec(SSL_HANDSHAKE * hs)1444 static enum ssl_hs_wait_t do_process_change_cipher_spec(SSL_HANDSHAKE *hs) {
1445   if (!tls1_change_cipher_state(hs, evp_aead_open)) {
1446     return ssl_hs_error;
1447   }
1448 
1449   hs->state = state12_read_next_proto;
1450   return ssl_hs_ok;
1451 }
1452 
do_read_next_proto(SSL_HANDSHAKE * hs)1453 static enum ssl_hs_wait_t do_read_next_proto(SSL_HANDSHAKE *hs) {
1454   SSL *const ssl = hs->ssl;
1455 
1456   if (!hs->next_proto_neg_seen) {
1457     hs->state = state12_read_channel_id;
1458     return ssl_hs_ok;
1459   }
1460 
1461   SSLMessage msg;
1462   if (!ssl->method->get_message(ssl, &msg)) {
1463     return ssl_hs_read_message;
1464   }
1465 
1466   if (!ssl_check_message_type(ssl, msg, SSL3_MT_NEXT_PROTO) ||
1467       !ssl_hash_message(hs, msg)) {
1468     return ssl_hs_error;
1469   }
1470 
1471   CBS next_protocol = msg.body, selected_protocol, padding;
1472   if (!CBS_get_u8_length_prefixed(&next_protocol, &selected_protocol) ||
1473       !CBS_get_u8_length_prefixed(&next_protocol, &padding) ||
1474       CBS_len(&next_protocol) != 0) {
1475     OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
1476     ssl_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
1477     return ssl_hs_error;
1478   }
1479 
1480   if (!ssl->s3->next_proto_negotiated.CopyFrom(selected_protocol)) {
1481     return ssl_hs_error;
1482   }
1483 
1484   ssl->method->next_message(ssl);
1485   hs->state = state12_read_channel_id;
1486   return ssl_hs_ok;
1487 }
1488 
do_read_channel_id(SSL_HANDSHAKE * hs)1489 static enum ssl_hs_wait_t do_read_channel_id(SSL_HANDSHAKE *hs) {
1490   SSL *const ssl = hs->ssl;
1491 
1492   if (!ssl->s3->channel_id_valid) {
1493     hs->state = state12_read_client_finished;
1494     return ssl_hs_ok;
1495   }
1496 
1497   SSLMessage msg;
1498   if (!ssl->method->get_message(ssl, &msg)) {
1499     return ssl_hs_read_message;
1500   }
1501 
1502   if (!ssl_check_message_type(ssl, msg, SSL3_MT_CHANNEL_ID) ||
1503       !tls1_verify_channel_id(hs, msg) ||
1504       !ssl_hash_message(hs, msg)) {
1505     return ssl_hs_error;
1506   }
1507 
1508   ssl->method->next_message(ssl);
1509   hs->state = state12_read_client_finished;
1510   return ssl_hs_ok;
1511 }
1512 
do_read_client_finished(SSL_HANDSHAKE * hs)1513 static enum ssl_hs_wait_t do_read_client_finished(SSL_HANDSHAKE *hs) {
1514   SSL *const ssl = hs->ssl;
1515   enum ssl_hs_wait_t wait = ssl_get_finished(hs);
1516   if (wait != ssl_hs_ok) {
1517     return wait;
1518   }
1519 
1520   if (ssl->session != NULL) {
1521     hs->state = state12_finish_server_handshake;
1522   } else {
1523     hs->state = state12_send_server_finished;
1524   }
1525 
1526   // If this is a full handshake with ChannelID then record the handshake
1527   // hashes in |hs->new_session| in case we need them to verify a
1528   // ChannelID signature on a resumption of this session in the future.
1529   if (ssl->session == NULL && ssl->s3->channel_id_valid &&
1530       !tls1_record_handshake_hashes_for_channel_id(hs)) {
1531     return ssl_hs_error;
1532   }
1533 
1534   return ssl_hs_ok;
1535 }
1536 
do_send_server_finished(SSL_HANDSHAKE * hs)1537 static enum ssl_hs_wait_t do_send_server_finished(SSL_HANDSHAKE *hs) {
1538   SSL *const ssl = hs->ssl;
1539 
1540   if (hs->ticket_expected) {
1541     const SSL_SESSION *session;
1542     UniquePtr<SSL_SESSION> session_copy;
1543     if (ssl->session == NULL) {
1544       // Fix the timeout to measure from the ticket issuance time.
1545       ssl_session_rebase_time(ssl, hs->new_session.get());
1546       session = hs->new_session.get();
1547     } else {
1548       // We are renewing an existing session. Duplicate the session to adjust
1549       // the timeout.
1550       session_copy =
1551           SSL_SESSION_dup(ssl->session.get(), SSL_SESSION_INCLUDE_NONAUTH);
1552       if (!session_copy) {
1553         return ssl_hs_error;
1554       }
1555 
1556       ssl_session_rebase_time(ssl, session_copy.get());
1557       session = session_copy.get();
1558     }
1559 
1560     ScopedCBB cbb;
1561     CBB body, ticket;
1562     if (!ssl->method->init_message(ssl, cbb.get(), &body,
1563                                    SSL3_MT_NEW_SESSION_TICKET) ||
1564         !CBB_add_u32(&body, session->timeout) ||
1565         !CBB_add_u16_length_prefixed(&body, &ticket) ||
1566         !ssl_encrypt_ticket(hs, &ticket, session) ||
1567         !ssl_add_message_cbb(ssl, cbb.get())) {
1568       return ssl_hs_error;
1569     }
1570   }
1571 
1572   if (!ssl->method->add_change_cipher_spec(ssl) ||
1573       !tls1_change_cipher_state(hs, evp_aead_seal) ||
1574       !ssl_send_finished(hs)) {
1575     return ssl_hs_error;
1576   }
1577 
1578   if (ssl->session != NULL) {
1579     hs->state = state12_read_change_cipher_spec;
1580   } else {
1581     hs->state = state12_finish_server_handshake;
1582   }
1583   return ssl_hs_flush;
1584 }
1585 
do_finish_server_handshake(SSL_HANDSHAKE * hs)1586 static enum ssl_hs_wait_t do_finish_server_handshake(SSL_HANDSHAKE *hs) {
1587   SSL *const ssl = hs->ssl;
1588 
1589   if (hs->handback) {
1590     return ssl_hs_handback;
1591   }
1592 
1593   ssl->method->on_handshake_complete(ssl);
1594 
1595   // If we aren't retaining peer certificates then we can discard it now.
1596   if (hs->new_session != NULL &&
1597       hs->config->retain_only_sha256_of_client_certs) {
1598     hs->new_session->certs.reset();
1599     ssl->ctx->x509_method->session_clear(hs->new_session.get());
1600   }
1601 
1602   if (ssl->session != NULL) {
1603     ssl->s3->established_session = UpRef(ssl->session);
1604   } else {
1605     ssl->s3->established_session = std::move(hs->new_session);
1606     ssl->s3->established_session->not_resumable = false;
1607   }
1608 
1609   hs->handshake_finalized = true;
1610   ssl->s3->initial_handshake_complete = true;
1611   ssl_update_cache(hs, SSL_SESS_CACHE_SERVER);
1612 
1613   hs->state = state12_done;
1614   return ssl_hs_ok;
1615 }
1616 
ssl_server_handshake(SSL_HANDSHAKE * hs)1617 enum ssl_hs_wait_t ssl_server_handshake(SSL_HANDSHAKE *hs) {
1618   while (hs->state != state12_done) {
1619     enum ssl_hs_wait_t ret = ssl_hs_error;
1620     enum tls12_server_hs_state_t state =
1621         static_cast<enum tls12_server_hs_state_t>(hs->state);
1622     switch (state) {
1623       case state12_start_accept:
1624         ret = do_start_accept(hs);
1625         break;
1626       case state12_read_client_hello:
1627         ret = do_read_client_hello(hs);
1628         break;
1629       case state12_select_certificate:
1630         ret = do_select_certificate(hs);
1631         break;
1632       case state12_tls13:
1633         ret = do_tls13(hs);
1634         break;
1635       case state12_select_parameters:
1636         ret = do_select_parameters(hs);
1637         break;
1638       case state12_send_server_hello:
1639         ret = do_send_server_hello(hs);
1640         break;
1641       case state12_send_server_certificate:
1642         ret = do_send_server_certificate(hs);
1643         break;
1644       case state12_send_server_key_exchange:
1645         ret = do_send_server_key_exchange(hs);
1646         break;
1647       case state12_send_server_hello_done:
1648         ret = do_send_server_hello_done(hs);
1649         break;
1650       case state12_read_client_certificate:
1651         ret = do_read_client_certificate(hs);
1652         break;
1653       case state12_verify_client_certificate:
1654         ret = do_verify_client_certificate(hs);
1655         break;
1656       case state12_read_client_key_exchange:
1657         ret = do_read_client_key_exchange(hs);
1658         break;
1659       case state12_read_client_certificate_verify:
1660         ret = do_read_client_certificate_verify(hs);
1661         break;
1662       case state12_read_change_cipher_spec:
1663         ret = do_read_change_cipher_spec(hs);
1664         break;
1665       case state12_process_change_cipher_spec:
1666         ret = do_process_change_cipher_spec(hs);
1667         break;
1668       case state12_read_next_proto:
1669         ret = do_read_next_proto(hs);
1670         break;
1671       case state12_read_channel_id:
1672         ret = do_read_channel_id(hs);
1673         break;
1674       case state12_read_client_finished:
1675         ret = do_read_client_finished(hs);
1676         break;
1677       case state12_send_server_finished:
1678         ret = do_send_server_finished(hs);
1679         break;
1680       case state12_finish_server_handshake:
1681         ret = do_finish_server_handshake(hs);
1682         break;
1683       case state12_done:
1684         ret = ssl_hs_ok;
1685         break;
1686     }
1687 
1688     if (hs->state != state) {
1689       ssl_do_info_callback(hs->ssl, SSL_CB_ACCEPT_LOOP, 1);
1690     }
1691 
1692     if (ret != ssl_hs_ok) {
1693       return ret;
1694     }
1695   }
1696 
1697   ssl_do_info_callback(hs->ssl, SSL_CB_HANDSHAKE_DONE, 1);
1698   return ssl_hs_ok;
1699 }
1700 
ssl_server_handshake_state(SSL_HANDSHAKE * hs)1701 const char *ssl_server_handshake_state(SSL_HANDSHAKE *hs) {
1702   enum tls12_server_hs_state_t state =
1703       static_cast<enum tls12_server_hs_state_t>(hs->state);
1704   switch (state) {
1705     case state12_start_accept:
1706       return "TLS server start_accept";
1707     case state12_read_client_hello:
1708       return "TLS server read_client_hello";
1709     case state12_select_certificate:
1710       return "TLS server select_certificate";
1711     case state12_tls13:
1712       return tls13_server_handshake_state(hs);
1713     case state12_select_parameters:
1714       return "TLS server select_parameters";
1715     case state12_send_server_hello:
1716       return "TLS server send_server_hello";
1717     case state12_send_server_certificate:
1718       return "TLS server send_server_certificate";
1719     case state12_send_server_key_exchange:
1720       return "TLS server send_server_key_exchange";
1721     case state12_send_server_hello_done:
1722       return "TLS server send_server_hello_done";
1723     case state12_read_client_certificate:
1724       return "TLS server read_client_certificate";
1725     case state12_verify_client_certificate:
1726       return "TLS server verify_client_certificate";
1727     case state12_read_client_key_exchange:
1728       return "TLS server read_client_key_exchange";
1729     case state12_read_client_certificate_verify:
1730       return "TLS server read_client_certificate_verify";
1731     case state12_read_change_cipher_spec:
1732       return "TLS server read_change_cipher_spec";
1733     case state12_process_change_cipher_spec:
1734       return "TLS server process_change_cipher_spec";
1735     case state12_read_next_proto:
1736       return "TLS server read_next_proto";
1737     case state12_read_channel_id:
1738       return "TLS server read_channel_id";
1739     case state12_read_client_finished:
1740       return "TLS server read_client_finished";
1741     case state12_send_server_finished:
1742       return "TLS server send_server_finished";
1743     case state12_finish_server_handshake:
1744       return "TLS server finish_server_handshake";
1745     case state12_done:
1746       return "TLS server done";
1747   }
1748 
1749   return "TLS server unknown";
1750 }
1751 
1752 BSSL_NAMESPACE_END
1753