• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /**
2  * \file ssl_misc.h
3  *
4  * \brief Internal functions shared by the SSL modules
5  */
6 /*
7  *  Copyright The Mbed TLS Contributors
8  *  SPDX-License-Identifier: Apache-2.0
9  *
10  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
11  *  not use this file except in compliance with the License.
12  *  You may obtain a copy of the License at
13  *
14  *  http://www.apache.org/licenses/LICENSE-2.0
15  *
16  *  Unless required by applicable law or agreed to in writing, software
17  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
18  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
19  *  See the License for the specific language governing permissions and
20  *  limitations under the License.
21  */
22 #ifndef MBEDTLS_SSL_MISC_H
23 #define MBEDTLS_SSL_MISC_H
24 
25 #include "mbedtls/build_info.h"
26 
27 #include "mbedtls/ssl.h"
28 #include "mbedtls/cipher.h"
29 
30 #if defined(MBEDTLS_USE_PSA_CRYPTO)
31 #include "psa/crypto.h"
32 #endif
33 
34 #if defined(MBEDTLS_MD5_C)
35 #include "mbedtls/md5.h"
36 #endif
37 
38 #if defined(MBEDTLS_SHA1_C)
39 #include "mbedtls/sha1.h"
40 #endif
41 
42 #if defined(MBEDTLS_SHA256_C)
43 #include "mbedtls/sha256.h"
44 #endif
45 
46 #if defined(MBEDTLS_SHA512_C)
47 #include "mbedtls/sha512.h"
48 #endif
49 
50 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
51 #include "mbedtls/ecjpake.h"
52 #endif
53 
54 #if defined(MBEDTLS_USE_PSA_CRYPTO)
55 #include "psa/crypto.h"
56 #include "mbedtls/psa_util.h"
57 #endif /* MBEDTLS_USE_PSA_CRYPTO */
58 
59 #if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
60     !defined(inline) && !defined(__cplusplus)
61 #define inline __inline
62 #endif
63 
64 /* Legacy minor version numbers as defined by:
65  * - RFC 2246: ProtocolVersion version = { 3, 1 };     // TLS v1.0
66  * - RFC 4346: ProtocolVersion version = { 3, 2 };     // TLS v1.1
67  *
68  * We no longer support these versions, but some code still references those
69  * constants as part of negotiating with the peer, so keep them available
70  * internally.
71  */
72 #define MBEDTLS_SSL_MINOR_VERSION_1             1
73 #define MBEDTLS_SSL_MINOR_VERSION_2             2
74 
75 /* Determine minimum supported version */
76 #define MBEDTLS_SSL_MIN_MAJOR_VERSION           MBEDTLS_SSL_MAJOR_VERSION_3
77 
78 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
79 #define MBEDTLS_SSL_MIN_MINOR_VERSION           MBEDTLS_SSL_MINOR_VERSION_3
80 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
81 
82 #define MBEDTLS_SSL_MIN_VALID_MINOR_VERSION MBEDTLS_SSL_MINOR_VERSION_3
83 #define MBEDTLS_SSL_MIN_VALID_MAJOR_VERSION MBEDTLS_SSL_MAJOR_VERSION_3
84 
85 /* Determine maximum supported version */
86 #define MBEDTLS_SSL_MAX_MAJOR_VERSION           MBEDTLS_SSL_MAJOR_VERSION_3
87 
88 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
89 #define MBEDTLS_SSL_MAX_MINOR_VERSION           MBEDTLS_SSL_MINOR_VERSION_3
90 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
91 
92 /* Shorthand for restartable ECC */
93 #if defined(MBEDTLS_ECP_RESTARTABLE) && \
94     defined(MBEDTLS_SSL_CLI_C) && \
95     defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
96     defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
97 #define MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED
98 #endif
99 
100 #define MBEDTLS_SSL_INITIAL_HANDSHAKE           0
101 #define MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS   1   /* In progress */
102 #define MBEDTLS_SSL_RENEGOTIATION_DONE          2   /* Done or aborted */
103 #define MBEDTLS_SSL_RENEGOTIATION_PENDING       3   /* Requested (server only) */
104 
105 /*
106  * Mask of TLS 1.3 handshake extensions used in extensions_present
107  * of mbedtls_ssl_handshake_params.
108  */
109 #define MBEDTLS_SSL_EXT_NONE                        0
110 
111 #define MBEDTLS_SSL_EXT_SERVERNAME                  ( 1 <<  0 )
112 #define MBEDTLS_SSL_EXT_MAX_FRAGMENT_LENGTH         ( 1 <<  1 )
113 #define MBEDTLS_SSL_EXT_STATUS_REQUEST              ( 1 <<  2 )
114 #define MBEDTLS_SSL_EXT_SUPPORTED_GROUPS            ( 1 <<  3 )
115 #define MBEDTLS_SSL_EXT_SIG_ALG                     ( 1 <<  4 )
116 #define MBEDTLS_SSL_EXT_USE_SRTP                    ( 1 <<  5 )
117 #define MBEDTLS_SSL_EXT_HEARTBEAT                   ( 1 <<  6 )
118 #define MBEDTLS_SSL_EXT_ALPN                        ( 1 <<  7 )
119 #define MBEDTLS_SSL_EXT_SCT                         ( 1 <<  8 )
120 #define MBEDTLS_SSL_EXT_CLI_CERT_TYPE               ( 1 <<  9 )
121 #define MBEDTLS_SSL_EXT_SERV_CERT_TYPE              ( 1 << 10 )
122 #define MBEDTLS_SSL_EXT_PADDING                     ( 1 << 11 )
123 #define MBEDTLS_SSL_EXT_PRE_SHARED_KEY              ( 1 << 12 )
124 #define MBEDTLS_SSL_EXT_EARLY_DATA                  ( 1 << 13 )
125 #define MBEDTLS_SSL_EXT_SUPPORTED_VERSIONS          ( 1 << 14 )
126 #define MBEDTLS_SSL_EXT_COOKIE                      ( 1 << 15 )
127 #define MBEDTLS_SSL_EXT_PSK_KEY_EXCHANGE_MODES      ( 1 << 16 )
128 #define MBEDTLS_SSL_EXT_CERT_AUTH                   ( 1 << 17 )
129 #define MBEDTLS_SSL_EXT_OID_FILTERS                 ( 1 << 18 )
130 #define MBEDTLS_SSL_EXT_POST_HANDSHAKE_AUTH         ( 1 << 19 )
131 #define MBEDTLS_SSL_EXT_SIG_ALG_CERT                ( 1 << 20 )
132 #define MBEDTLS_SSL_EXT_KEY_SHARE                   ( 1 << 21 )
133 
134 /*
135  * Helper macros for function call with return check.
136  */
137 /*
138  * Exit when return non-zero value
139  */
140 #define MBEDTLS_SSL_PROC_CHK( f )                               \
141     do {                                                        \
142         ret = ( f );                                            \
143         if( ret != 0 )                                          \
144         {                                                       \
145             goto cleanup;                                       \
146         }                                                       \
147     } while( 0 )
148 /*
149  * Exit when return negative value
150  */
151 #define MBEDTLS_SSL_PROC_CHK_NEG( f )                           \
152     do {                                                        \
153         ret = ( f );                                            \
154         if( ret < 0 )                                           \
155         {                                                       \
156             goto cleanup;                                       \
157         }                                                       \
158     } while( 0 )
159 
160 /*
161  * DTLS retransmission states, see RFC 6347 4.2.4
162  *
163  * The SENDING state is merged in PREPARING for initial sends,
164  * but is distinct for resends.
165  *
166  * Note: initial state is wrong for server, but is not used anyway.
167  */
168 #define MBEDTLS_SSL_RETRANS_PREPARING       0
169 #define MBEDTLS_SSL_RETRANS_SENDING         1
170 #define MBEDTLS_SSL_RETRANS_WAITING         2
171 #define MBEDTLS_SSL_RETRANS_FINISHED        3
172 
173 /*
174  * Allow extra bytes for record, authentication and encryption overhead:
175  * counter (8) + header (5) + IV(16) + MAC (16-48) + padding (0-256).
176  */
177 
178 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
179 
180 /* This macro determines whether CBC is supported. */
181 #if defined(MBEDTLS_CIPHER_MODE_CBC) &&                               \
182     ( defined(MBEDTLS_AES_C)      ||                                  \
183       defined(MBEDTLS_CAMELLIA_C) ||                                  \
184       defined(MBEDTLS_ARIA_C)     ||                                  \
185       defined(MBEDTLS_DES_C) )
186 #define MBEDTLS_SSL_SOME_SUITES_USE_CBC
187 #endif
188 
189 /* This macro determines whether a ciphersuite using a
190  * stream cipher can be used. */
191 #if defined(MBEDTLS_CIPHER_NULL_CIPHER)
192 #define MBEDTLS_SSL_SOME_SUITES_USE_STREAM
193 #endif
194 
195 /* This macro determines whether the CBC construct used in TLS 1.2 is supported. */
196 #if defined(MBEDTLS_SSL_SOME_SUITES_USE_CBC) && \
197       defined(MBEDTLS_SSL_PROTO_TLS1_2)
198 #define MBEDTLS_SSL_SOME_SUITES_USE_TLS_CBC
199 #endif
200 
201 #if defined(MBEDTLS_SSL_SOME_SUITES_USE_STREAM) || \
202     defined(MBEDTLS_SSL_SOME_SUITES_USE_CBC)
203 #define MBEDTLS_SSL_SOME_SUITES_USE_MAC
204 #endif
205 
206 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
207 
208 #if defined(MBEDTLS_SSL_SOME_SUITES_USE_MAC)
209 /* Ciphersuites using HMAC */
210 #if defined(MBEDTLS_SHA384_C)
211 #define MBEDTLS_SSL_MAC_ADD                 48  /* SHA-384 used for HMAC */
212 #elif defined(MBEDTLS_SHA256_C)
213 #define MBEDTLS_SSL_MAC_ADD                 32  /* SHA-256 used for HMAC */
214 #else
215 #define MBEDTLS_SSL_MAC_ADD                 20  /* SHA-1   used for HMAC */
216 #endif
217 #else /* MBEDTLS_SSL_SOME_SUITES_USE_MAC */
218 /* AEAD ciphersuites: GCM and CCM use a 128 bits tag */
219 #define MBEDTLS_SSL_MAC_ADD                 16
220 #endif
221 
222 #if defined(MBEDTLS_CIPHER_MODE_CBC)
223 #define MBEDTLS_SSL_PADDING_ADD            256
224 #else
225 #define MBEDTLS_SSL_PADDING_ADD              0
226 #endif
227 
228 #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
229 #define MBEDTLS_SSL_MAX_CID_EXPANSION      MBEDTLS_SSL_CID_TLS1_3_PADDING_GRANULARITY
230 #else
231 #define MBEDTLS_SSL_MAX_CID_EXPANSION        0
232 #endif
233 
234 #define MBEDTLS_SSL_PAYLOAD_OVERHEAD ( MBEDTLS_MAX_IV_LENGTH +          \
235                                        MBEDTLS_SSL_MAC_ADD +            \
236                                        MBEDTLS_SSL_PADDING_ADD +        \
237                                        MBEDTLS_SSL_MAX_CID_EXPANSION    \
238                                        )
239 
240 #define MBEDTLS_SSL_IN_PAYLOAD_LEN ( MBEDTLS_SSL_PAYLOAD_OVERHEAD + \
241                                      ( MBEDTLS_SSL_IN_CONTENT_LEN ) )
242 
243 #define MBEDTLS_SSL_OUT_PAYLOAD_LEN ( MBEDTLS_SSL_PAYLOAD_OVERHEAD + \
244                                       ( MBEDTLS_SSL_OUT_CONTENT_LEN ) )
245 
246 /* The maximum number of buffered handshake messages. */
247 #define MBEDTLS_SSL_MAX_BUFFERED_HS 4
248 
249 /* Maximum length we can advertise as our max content length for
250    RFC 6066 max_fragment_length extension negotiation purposes
251    (the lesser of both sizes, if they are unequal.)
252  */
253 #define MBEDTLS_TLS_EXT_ADV_CONTENT_LEN (                            \
254         (MBEDTLS_SSL_IN_CONTENT_LEN > MBEDTLS_SSL_OUT_CONTENT_LEN)   \
255         ? ( MBEDTLS_SSL_OUT_CONTENT_LEN )                            \
256         : ( MBEDTLS_SSL_IN_CONTENT_LEN )                             \
257         )
258 
259 /* Maximum size in bytes of list in sig-hash algorithm ext., RFC 5246 */
260 #define MBEDTLS_SSL_MAX_SIG_HASH_ALG_LIST_LEN  65534
261 
262 /* Maximum size in bytes of list in supported elliptic curve ext., RFC 4492 */
263 #define MBEDTLS_SSL_MAX_CURVE_LIST_LEN         65535
264 
265 /*
266  * Check that we obey the standard's message size bounds
267  */
268 
269 #if MBEDTLS_SSL_IN_CONTENT_LEN > 16384
270 #error "Bad configuration - incoming record content too large."
271 #endif
272 
273 #if MBEDTLS_SSL_OUT_CONTENT_LEN > 16384
274 #error "Bad configuration - outgoing record content too large."
275 #endif
276 
277 #if MBEDTLS_SSL_IN_PAYLOAD_LEN > MBEDTLS_SSL_IN_CONTENT_LEN + 2048
278 #error "Bad configuration - incoming protected record payload too large."
279 #endif
280 
281 #if MBEDTLS_SSL_OUT_PAYLOAD_LEN > MBEDTLS_SSL_OUT_CONTENT_LEN + 2048
282 #error "Bad configuration - outgoing protected record payload too large."
283 #endif
284 
285 /* Calculate buffer sizes */
286 
287 /* Note: Even though the TLS record header is only 5 bytes
288    long, we're internally using 8 bytes to store the
289    implicit sequence number. */
290 #define MBEDTLS_SSL_HEADER_LEN 13
291 
292 #if !defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
293 #define MBEDTLS_SSL_IN_BUFFER_LEN  \
294     ( ( MBEDTLS_SSL_HEADER_LEN ) + ( MBEDTLS_SSL_IN_PAYLOAD_LEN ) )
295 #else
296 #define MBEDTLS_SSL_IN_BUFFER_LEN  \
297     ( ( MBEDTLS_SSL_HEADER_LEN ) + ( MBEDTLS_SSL_IN_PAYLOAD_LEN ) \
298       + ( MBEDTLS_SSL_CID_IN_LEN_MAX ) )
299 #endif
300 
301 #if !defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
302 #define MBEDTLS_SSL_OUT_BUFFER_LEN  \
303     ( ( MBEDTLS_SSL_HEADER_LEN ) + ( MBEDTLS_SSL_OUT_PAYLOAD_LEN ) )
304 #else
305 #define MBEDTLS_SSL_OUT_BUFFER_LEN                               \
306     ( ( MBEDTLS_SSL_HEADER_LEN ) + ( MBEDTLS_SSL_OUT_PAYLOAD_LEN )    \
307       + ( MBEDTLS_SSL_CID_OUT_LEN_MAX ) )
308 #endif
309 
310 #define MBEDTLS_CLIENT_HELLO_RANDOM_LEN 32
311 #define MBEDTLS_SERVER_HELLO_RANDOM_LEN 32
312 
313 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
314 /**
315  * \brief          Return the maximum fragment length (payload, in bytes) for
316  *                 the output buffer. For the client, this is the configured
317  *                 value. For the server, it is the minimum of two - the
318  *                 configured value and the negotiated one.
319  *
320  * \sa             mbedtls_ssl_conf_max_frag_len()
321  * \sa             mbedtls_ssl_get_max_out_record_payload()
322  *
323  * \param ssl      SSL context
324  *
325  * \return         Current maximum fragment length for the output buffer.
326  */
327 size_t mbedtls_ssl_get_output_max_frag_len( const mbedtls_ssl_context *ssl );
328 
329 /**
330  * \brief          Return the maximum fragment length (payload, in bytes) for
331  *                 the input buffer. This is the negotiated maximum fragment
332  *                 length, or, if there is none, MBEDTLS_SSL_IN_CONTENT_LEN.
333  *                 If it is not defined either, the value is 2^14. This function
334  *                 works as its predecessor, \c mbedtls_ssl_get_max_frag_len().
335  *
336  * \sa             mbedtls_ssl_conf_max_frag_len()
337  * \sa             mbedtls_ssl_get_max_in_record_payload()
338  *
339  * \param ssl      SSL context
340  *
341  * \return         Current maximum fragment length for the output buffer.
342  */
343 size_t mbedtls_ssl_get_input_max_frag_len( const mbedtls_ssl_context *ssl );
344 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
345 
346 #if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
mbedtls_ssl_get_output_buflen(const mbedtls_ssl_context * ctx)347 static inline size_t mbedtls_ssl_get_output_buflen( const mbedtls_ssl_context *ctx )
348 {
349 #if defined (MBEDTLS_SSL_DTLS_CONNECTION_ID)
350     return mbedtls_ssl_get_output_max_frag_len( ctx )
351                + MBEDTLS_SSL_HEADER_LEN + MBEDTLS_SSL_PAYLOAD_OVERHEAD
352                + MBEDTLS_SSL_CID_OUT_LEN_MAX;
353 #else
354     return mbedtls_ssl_get_output_max_frag_len( ctx )
355                + MBEDTLS_SSL_HEADER_LEN + MBEDTLS_SSL_PAYLOAD_OVERHEAD;
356 #endif
357 }
358 
mbedtls_ssl_get_input_buflen(const mbedtls_ssl_context * ctx)359 static inline size_t mbedtls_ssl_get_input_buflen( const mbedtls_ssl_context *ctx )
360 {
361 #if defined (MBEDTLS_SSL_DTLS_CONNECTION_ID)
362     return mbedtls_ssl_get_input_max_frag_len( ctx )
363                + MBEDTLS_SSL_HEADER_LEN + MBEDTLS_SSL_PAYLOAD_OVERHEAD
364                + MBEDTLS_SSL_CID_IN_LEN_MAX;
365 #else
366     return mbedtls_ssl_get_input_max_frag_len( ctx )
367                + MBEDTLS_SSL_HEADER_LEN + MBEDTLS_SSL_PAYLOAD_OVERHEAD;
368 #endif
369 }
370 #endif
371 
372 /*
373  * TLS extension flags (for extensions with outgoing ServerHello content
374  * that need it (e.g. for RENEGOTIATION_INFO the server already knows because
375  * of state of the renegotiation flag, so no indicator is required)
376  */
377 #define MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS_PRESENT (1 << 0)
378 #define MBEDTLS_TLS_EXT_ECJPAKE_KKPP_OK                 (1 << 1)
379 
380 /**
381  * \brief        This function checks if the remaining size in a buffer is
382  *               greater or equal than a needed space.
383  *
384  * \param cur    Pointer to the current position in the buffer.
385  * \param end    Pointer to one past the end of the buffer.
386  * \param need   Needed space in bytes.
387  *
388  * \return       Zero if the needed space is available in the buffer, non-zero
389  *               otherwise.
390  */
mbedtls_ssl_chk_buf_ptr(const uint8_t * cur,const uint8_t * end,size_t need)391 static inline int mbedtls_ssl_chk_buf_ptr( const uint8_t *cur,
392                                            const uint8_t *end, size_t need )
393 {
394     return( ( cur > end ) || ( need > (size_t)( end - cur ) ) );
395 }
396 
397 /**
398  * \brief        This macro checks if the remaining size in a buffer is
399  *               greater or equal than a needed space. If it is not the case,
400  *               it returns an SSL_BUFFER_TOO_SMALL error.
401  *
402  * \param cur    Pointer to the current position in the buffer.
403  * \param end    Pointer to one past the end of the buffer.
404  * \param need   Needed space in bytes.
405  *
406  */
407 #define MBEDTLS_SSL_CHK_BUF_PTR( cur, end, need )                        \
408     do {                                                                 \
409         if( mbedtls_ssl_chk_buf_ptr( ( cur ), ( end ), ( need ) ) != 0 ) \
410         {                                                                \
411             return( MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL );                  \
412         }                                                                \
413     } while( 0 )
414 
415 /**
416  * \brief        This macro checks if the remaining length in an input buffer is
417  *               greater or equal than a needed length. If it is not the case, it
418  *               returns #MBEDTLS_ERR_SSL_DECODE_ERROR error and pends a
419  *               #MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR alert message.
420  *
421  *               This is a function-like macro. It is guaranteed to evaluate each
422  *               argument exactly once.
423  *
424  * \param cur    Pointer to the current position in the buffer.
425  * \param end    Pointer to one past the end of the buffer.
426  * \param need   Needed length in bytes.
427  *
428  */
429 #define MBEDTLS_SSL_CHK_BUF_READ_PTR( cur, end, need )                          \
430     do {                                                                        \
431         if( mbedtls_ssl_chk_buf_ptr( ( cur ), ( end ), ( need ) ) != 0 )        \
432         {                                                                       \
433             MBEDTLS_SSL_DEBUG_MSG( 1,                                           \
434                                    ( "missing input data in %s", __func__ ) );  \
435             MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR,   \
436                                           MBEDTLS_ERR_SSL_DECODE_ERROR );       \
437             return( MBEDTLS_ERR_SSL_DECODE_ERROR );                             \
438         }                                                                       \
439     } while( 0 )
440 
441 #ifdef __cplusplus
442 extern "C" {
443 #endif
444 
445 #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
446     defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
447 /*
448  * Abstraction for a grid of allowed signature-hash-algorithm pairs.
449  */
450 struct mbedtls_ssl_sig_hash_set_t
451 {
452     /* At the moment, we only need to remember a single suitable
453      * hash algorithm per signature algorithm. As long as that's
454      * the case - and we don't need a general lookup function -
455      * we can implement the sig-hash-set as a map from signatures
456      * to hash algorithms. */
457     mbedtls_md_type_t rsa;
458     mbedtls_md_type_t ecdsa;
459 };
460 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 &&
461           MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
462 
463 typedef int  mbedtls_ssl_tls_prf_cb( const unsigned char *secret, size_t slen,
464                                      const char *label,
465                                      const unsigned char *random, size_t rlen,
466                                      unsigned char *dstbuf, size_t dlen );
467 
468 /* cipher.h exports the maximum IV, key and block length from
469  * all ciphers enabled in the config, regardless of whether those
470  * ciphers are actually usable in SSL/TLS. Notably, XTS is enabled
471  * in the default configuration and uses 64 Byte keys, but it is
472  * not used for record protection in SSL/TLS.
473  *
474  * In order to prevent unnecessary inflation of key structures,
475  * we introduce SSL-specific variants of the max-{key,block,IV}
476  * macros here which are meant to only take those ciphers into
477  * account which can be negotiated in SSL/TLS.
478  *
479  * Since the current definitions of MBEDTLS_MAX_{KEY|BLOCK|IV}_LENGTH
480  * in cipher.h are rough overapproximations of the real maxima, here
481  * we content ourselves with replicating those overapproximations
482  * for the maximum block and IV length, and excluding XTS from the
483  * computation of the maximum key length. */
484 #define MBEDTLS_SSL_MAX_BLOCK_LENGTH 16
485 #define MBEDTLS_SSL_MAX_IV_LENGTH    16
486 #define MBEDTLS_SSL_MAX_KEY_LENGTH   32
487 
488 /**
489  * \brief   The data structure holding the cryptographic material (key and IV)
490  *          used for record protection in TLS 1.3.
491  */
492 struct mbedtls_ssl_key_set
493 {
494     /*! The key for client->server records. */
495     unsigned char client_write_key[ MBEDTLS_SSL_MAX_KEY_LENGTH ];
496     /*! The key for server->client records. */
497     unsigned char server_write_key[ MBEDTLS_SSL_MAX_KEY_LENGTH ];
498     /*! The IV  for client->server records. */
499     unsigned char client_write_iv[ MBEDTLS_SSL_MAX_IV_LENGTH ];
500     /*! The IV  for server->client records. */
501     unsigned char server_write_iv[ MBEDTLS_SSL_MAX_IV_LENGTH ];
502 
503     size_t key_len; /*!< The length of client_write_key and
504                      *   server_write_key, in Bytes. */
505     size_t iv_len;  /*!< The length of client_write_iv and
506                      *   server_write_iv, in Bytes. */
507 };
508 typedef struct mbedtls_ssl_key_set mbedtls_ssl_key_set;
509 
510 typedef struct
511 {
512     unsigned char binder_key                  [ MBEDTLS_TLS1_3_MD_MAX_SIZE ];
513     unsigned char client_early_traffic_secret [ MBEDTLS_TLS1_3_MD_MAX_SIZE ];
514     unsigned char early_exporter_master_secret[ MBEDTLS_TLS1_3_MD_MAX_SIZE ];
515 } mbedtls_ssl_tls13_early_secrets;
516 
517 typedef struct
518 {
519     unsigned char client_handshake_traffic_secret[ MBEDTLS_TLS1_3_MD_MAX_SIZE ];
520     unsigned char server_handshake_traffic_secret[ MBEDTLS_TLS1_3_MD_MAX_SIZE ];
521 } mbedtls_ssl_tls13_handshake_secrets;
522 
523 /*
524  * This structure contains the parameters only needed during handshake.
525  */
526 struct mbedtls_ssl_handshake_params
527 {
528     /* Frequently-used boolean or byte fields (placed early to take
529      * advantage of smaller code size for indirect access on Arm Thumb) */
530     uint8_t max_major_ver;              /*!< max. major version client*/
531     uint8_t max_minor_ver;              /*!< max. minor version client*/
532     uint8_t resume;                     /*!<  session resume indicator*/
533     uint8_t cli_exts;                   /*!< client extension presence*/
534 
535 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
536     uint8_t sni_authmode;               /*!< authmode from SNI callback     */
537 #endif
538 
539 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
540     uint8_t new_session_ticket;         /*!< use NewSessionTicket?    */
541 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
542 
543 #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
544     uint8_t extended_ms;                /*!< use Extended Master Secret? */
545 #endif
546 
547 #if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
548     uint8_t async_in_progress; /*!< an asynchronous operation is in progress */
549 #endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
550 
551 #if defined(MBEDTLS_SSL_PROTO_DTLS)
552     unsigned char retransmit_state;     /*!<  Retransmission state           */
553 #endif
554 
555 #if !defined(MBEDTLS_DEPRECATED_REMOVED)
556     unsigned char group_list_heap_allocated;
557 #endif
558 
559 #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED)
560     uint8_t ecrs_enabled;               /*!< Handshake supports EC restart? */
561     enum { /* this complements ssl->state with info on intra-state operations */
562         ssl_ecrs_none = 0,              /*!< nothing going on (yet)         */
563         ssl_ecrs_crt_verify,            /*!< Certificate: crt_verify()      */
564         ssl_ecrs_ske_start_processing,  /*!< ServerKeyExchange: pk_verify() */
565         ssl_ecrs_cke_ecdh_calc_secret,  /*!< ClientKeyExchange: ECDH step 2 */
566         ssl_ecrs_crt_vrfy_sign,         /*!< CertificateVerify: pk_sign()   */
567     } ecrs_state;                       /*!< current (or last) operation    */
568     mbedtls_x509_crt *ecrs_peer_cert;   /*!< The peer's CRT chain.          */
569     size_t ecrs_n;                      /*!< place for saving a length      */
570 #endif
571 
572     size_t pmslen;                      /*!<  premaster length        */
573 
574     mbedtls_ssl_ciphersuite_t const *ciphersuite_info;
575 
576     void (*update_checksum)(mbedtls_ssl_context *, const unsigned char *, size_t);
577     void (*calc_verify)(const mbedtls_ssl_context *, unsigned char *, size_t *);
578     void (*calc_finished)(mbedtls_ssl_context *, unsigned char *, int);
579     mbedtls_ssl_tls_prf_cb *tls_prf;
580 
581     /*
582      * Handshake specific crypto variables
583      */
584 #if defined(MBEDTLS_SSL_PROTO_TLS1_3)
585     int tls13_kex_modes; /*!< key exchange modes for TLS 1.3 */
586 #endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
587 
588 #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
589     defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
590     mbedtls_ssl_sig_hash_set_t hash_algs;             /*!<  Set of suitable sig-hash pairs */
591 #endif
592 
593 #if !defined(MBEDTLS_DEPRECATED_REMOVED)
594     const uint16_t *group_list;
595 #endif
596 
597 #if defined(MBEDTLS_DHM_C)
598     mbedtls_dhm_context dhm_ctx;                /*!<  DHM key exchange        */
599 #endif
600 
601 /* Adding guard for MBEDTLS_ECDSA_C to ensure no compile errors due
602  * to guards also being in ssl_srv.c and ssl_cli.c. There is a gap
603  * in functionality that access to ecdh_ctx structure is needed for
604  * MBEDTLS_ECDSA_C which does not seem correct.
605  */
606 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C)
607     mbedtls_ecdh_context ecdh_ctx;              /*!<  ECDH key exchange       */
608 
609 #if defined(MBEDTLS_USE_PSA_CRYPTO)
610     psa_key_type_t ecdh_psa_type;
611     uint16_t ecdh_bits;
612     psa_key_id_t ecdh_psa_privkey;
613     unsigned char ecdh_psa_peerkey[MBEDTLS_PSA_MAX_EC_PUBKEY_LENGTH];
614     size_t ecdh_psa_peerkey_len;
615 #endif /* MBEDTLS_USE_PSA_CRYPTO */
616 #endif /* MBEDTLS_ECDH_C || MBEDTLS_ECDSA_C */
617 
618 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
619     mbedtls_ecjpake_context ecjpake_ctx;        /*!< EC J-PAKE key exchange */
620 #if defined(MBEDTLS_SSL_CLI_C)
621     unsigned char *ecjpake_cache;               /*!< Cache for ClientHello ext */
622     size_t ecjpake_cache_len;                   /*!< Length of cached data */
623 #endif
624 #endif /* MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
625 
626 #if defined(MBEDTLS_ECDH_C) || defined(MBEDTLS_ECDSA_C) ||      \
627     defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
628     const mbedtls_ecp_curve_info **curves;      /*!<  Supported elliptic curves */
629 #endif
630 
631 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
632 #if defined(MBEDTLS_USE_PSA_CRYPTO)
633     psa_key_id_t psk_opaque;            /*!< Opaque PSK from the callback   */
634 #endif /* MBEDTLS_USE_PSA_CRYPTO */
635     unsigned char *psk;                 /*!<  PSK from the callback         */
636     size_t psk_len;                     /*!<  Length of PSK from callback   */
637 #endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */
638 
639 #if defined(MBEDTLS_SSL_ECP_RESTARTABLE_ENABLED)
640     mbedtls_x509_crt_restart_ctx ecrs_ctx;  /*!< restart context            */
641 #endif
642 
643 #if defined(MBEDTLS_X509_CRT_PARSE_C)
644     mbedtls_ssl_key_cert *key_cert;     /*!< chosen key/cert pair (server)  */
645 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
646     mbedtls_ssl_key_cert *sni_key_cert; /*!< key/cert list from SNI         */
647     mbedtls_x509_crt *sni_ca_chain;     /*!< trusted CAs from SNI callback  */
648     mbedtls_x509_crl *sni_ca_crl;       /*!< trusted CAs CRLs from SNI      */
649 #endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
650 #endif /* MBEDTLS_X509_CRT_PARSE_C */
651 
652 #if defined(MBEDTLS_X509_CRT_PARSE_C) &&        \
653     !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
654     mbedtls_pk_context peer_pubkey;     /*!< The public key from the peer.  */
655 #endif /* MBEDTLS_X509_CRT_PARSE_C && !MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
656 
657     struct
658     {
659         size_t total_bytes_buffered; /*!< Cumulative size of heap allocated
660                                       *   buffers used for message buffering. */
661 
662         uint8_t seen_ccs;               /*!< Indicates if a CCS message has
663                                          *   been seen in the current flight. */
664 
665         struct mbedtls_ssl_hs_buffer
666         {
667             unsigned is_valid      : 1;
668             unsigned is_fragmented : 1;
669             unsigned is_complete   : 1;
670             unsigned char *data;
671             size_t data_len;
672         } hs[MBEDTLS_SSL_MAX_BUFFERED_HS];
673 
674         struct
675         {
676             unsigned char *data;
677             size_t len;
678             unsigned epoch;
679         } future_record;
680 
681     } buffering;
682 
683 #if defined(MBEDTLS_SSL_PROTO_DTLS)
684     unsigned int out_msg_seq;           /*!<  Outgoing handshake sequence number */
685     unsigned int in_msg_seq;            /*!<  Incoming handshake sequence number */
686 
687     unsigned char *verify_cookie;       /*!<  Cli: HelloVerifyRequest cookie
688                                               Srv: unused                    */
689     unsigned char verify_cookie_len;    /*!<  Cli: cookie length
690                                               Srv: flag for sending a cookie */
691 
692     uint32_t retransmit_timeout;        /*!<  Current value of timeout       */
693     mbedtls_ssl_flight_item *flight;    /*!<  Current outgoing flight        */
694     mbedtls_ssl_flight_item *cur_msg;   /*!<  Current message in flight      */
695     unsigned char *cur_msg_p;           /*!<  Position in current message    */
696     unsigned int in_flight_start_seq;   /*!<  Minimum message sequence in the
697                                               flight being received          */
698     mbedtls_ssl_transform *alt_transform_out;   /*!<  Alternative transform for
699                                               resending messages             */
700     unsigned char alt_out_ctr[MBEDTLS_SSL_SEQUENCE_NUMBER_LEN]; /*!<  Alternative record epoch/counter
701                                                                       for resending messages         */
702 
703 #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
704     /* The state of CID configuration in this handshake. */
705 
706     uint8_t cid_in_use; /*!< This indicates whether the use of the CID extension
707                          *   has been negotiated. Possible values are
708                          *   #MBEDTLS_SSL_CID_ENABLED and
709                          *   #MBEDTLS_SSL_CID_DISABLED. */
710     unsigned char peer_cid[ MBEDTLS_SSL_CID_OUT_LEN_MAX ]; /*! The peer's CID */
711     uint8_t peer_cid_len;                                  /*!< The length of
712                                                             *   \c peer_cid.  */
713 #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
714 
715     uint16_t mtu;                       /*!<  Handshake mtu, used to fragment outgoing messages */
716 #endif /* MBEDTLS_SSL_PROTO_DTLS */
717 
718 #if defined(MBEDTLS_SSL_PROTO_TLS1_3)
719     /*! TLS 1.3 transforms for 0-RTT and encrypted handshake messages.
720      *  Those pointers own the transforms they reference. */
721     mbedtls_ssl_transform *transform_handshake;
722     mbedtls_ssl_transform *transform_earlydata;
723 #endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
724 
725     /*
726      * Checksum contexts
727      */
728 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
729 #if defined(MBEDTLS_SHA256_C)
730 #if defined(MBEDTLS_USE_PSA_CRYPTO)
731     psa_hash_operation_t fin_sha256_psa;
732 #else
733     mbedtls_sha256_context fin_sha256;
734 #endif
735 #endif
736 #if defined(MBEDTLS_SHA384_C)
737 #if defined(MBEDTLS_USE_PSA_CRYPTO)
738     psa_hash_operation_t fin_sha384_psa;
739 #else
740     mbedtls_sha512_context fin_sha512;
741 #endif
742 #endif
743 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
744 
745 #if defined(MBEDTLS_SSL_PROTO_TLS1_3)
746     uint16_t offered_group_id; /* The NamedGroup value for the group
747                                 * that is being used for ephemeral
748                                 * key exchange.
749                                 *
750                                 * On the client: Defaults to the first
751                                 * entry in the client's group list,
752                                 * but can be overwritten by the HRR. */
753 #endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
754 
755     /*
756      * State-local variables used during the processing
757      * of a specific handshake state.
758      */
759     union
760     {
761         /* Outgoing Finished message */
762         struct
763         {
764             uint8_t preparation_done;
765 
766             /* Buffer holding digest of the handshake up to
767              * but excluding the outgoing finished message. */
768             unsigned char digest[MBEDTLS_TLS1_3_MD_MAX_SIZE];
769             size_t digest_len;
770         } finished_out;
771 
772         /* Incoming Finished message */
773         struct
774         {
775             uint8_t preparation_done;
776 
777             /* Buffer holding digest of the handshake up to but
778              * excluding the peer's incoming finished message. */
779             unsigned char digest[MBEDTLS_TLS1_3_MD_MAX_SIZE];
780             size_t digest_len;
781         } finished_in;
782 
783     } state_local;
784 
785     /* End of state-local variables. */
786 
787     unsigned char randbytes[MBEDTLS_CLIENT_HELLO_RANDOM_LEN +
788                             MBEDTLS_SERVER_HELLO_RANDOM_LEN];
789                                         /*!<  random bytes            */
790     unsigned char premaster[MBEDTLS_PREMASTER_SIZE];
791                                         /*!<  premaster secret        */
792 
793 #if defined(MBEDTLS_SSL_PROTO_TLS1_3)
794     int extensions_present;             /*!< extension presence; Each bitfield
795                                              represents an extension and defined
796                                              as \c MBEDTLS_SSL_EXT_XXX */
797 
798     union
799     {
800         unsigned char early    [MBEDTLS_TLS1_3_MD_MAX_SIZE];
801         unsigned char handshake[MBEDTLS_TLS1_3_MD_MAX_SIZE];
802         unsigned char app      [MBEDTLS_TLS1_3_MD_MAX_SIZE];
803     } tls13_master_secrets;
804 
805     mbedtls_ssl_tls13_handshake_secrets tls13_hs_secrets;
806 #endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
807 
808 #if defined(MBEDTLS_SSL_ASYNC_PRIVATE)
809     /** Asynchronous operation context. This field is meant for use by the
810      * asynchronous operation callbacks (mbedtls_ssl_config::f_async_sign_start,
811      * mbedtls_ssl_config::f_async_decrypt_start,
812      * mbedtls_ssl_config::f_async_resume, mbedtls_ssl_config::f_async_cancel).
813      * The library does not use it internally. */
814     void *user_async_ctx;
815 #endif /* MBEDTLS_SSL_ASYNC_PRIVATE */
816 };
817 
818 typedef struct mbedtls_ssl_hs_buffer mbedtls_ssl_hs_buffer;
819 
820 /*
821  * Representation of decryption/encryption transformations on records
822  *
823  * There are the following general types of record transformations:
824  * - Stream transformations (TLS versions == 1.2 only)
825  *   Transformation adding a MAC and applying a stream-cipher
826  *   to the authenticated message.
827  * - CBC block cipher transformations ([D]TLS versions == 1.2 only)
828  *   For TLS 1.2, no IV is generated at key extraction time, but every
829  *   encrypted record is explicitly prefixed by the IV with which it was
830  *   encrypted.
831  * - AEAD transformations ([D]TLS versions == 1.2 only)
832  *   These come in two fundamentally different versions, the first one
833  *   used in TLS 1.2, excluding ChaChaPoly ciphersuites, and the second
834  *   one used for ChaChaPoly ciphersuites in TLS 1.2 as well as for TLS 1.3.
835  *   In the first transformation, the IV to be used for a record is obtained
836  *   as the concatenation of an explicit, static 4-byte IV and the 8-byte
837  *   record sequence number, and explicitly prepending this sequence number
838  *   to the encrypted record. In contrast, in the second transformation
839  *   the IV is obtained by XOR'ing a static IV obtained at key extraction
840  *   time with the 8-byte record sequence number, without prepending the
841  *   latter to the encrypted record.
842  *
843  * Additionally, DTLS 1.2 + CID as well as TLS 1.3 use an inner plaintext
844  * which allows to add flexible length padding and to hide a record's true
845  * content type.
846  *
847  * In addition to type and version, the following parameters are relevant:
848  * - The symmetric cipher algorithm to be used.
849  * - The (static) encryption/decryption keys for the cipher.
850  * - For stream/CBC, the type of message digest to be used.
851  * - For stream/CBC, (static) encryption/decryption keys for the digest.
852  * - For AEAD transformations, the size (potentially 0) of an explicit,
853  *   random initialization vector placed in encrypted records.
854  * - For some transformations (currently AEAD) an implicit IV. It is static
855  *   and (if present) is combined with the explicit IV in a transformation-
856  *   -dependent way (e.g. appending in TLS 1.2 and XOR'ing in TLS 1.3).
857  * - For stream/CBC, a flag determining the order of encryption and MAC.
858  * - The details of the transformation depend on the SSL/TLS version.
859  * - The length of the authentication tag.
860  *
861  * The struct below refines this abstract view as follows:
862  * - The cipher underlying the transformation is managed in
863  *   cipher contexts cipher_ctx_{enc/dec}, which must have the
864  *   same cipher type. The mode of these cipher contexts determines
865  *   the type of the transformation in the sense above: e.g., if
866  *   the type is MBEDTLS_CIPHER_AES_256_CBC resp. MBEDTLS_CIPHER_AES_192_GCM
867  *   then the transformation has type CBC resp. AEAD.
868  * - The cipher keys are never stored explicitly but
869  *   are maintained within cipher_ctx_{enc/dec}.
870  * - For stream/CBC transformations, the message digest contexts
871  *   used for the MAC's are stored in md_ctx_{enc/dec}. These contexts
872  *   are unused for AEAD transformations.
873  * - For stream/CBC transformations, the MAC keys are not stored explicitly
874  *   but maintained within md_ctx_{enc/dec}.
875  * - The mac_enc and mac_dec fields are unused for EAD transformations.
876  * - For transformations using an implicit IV maintained within
877  *   the transformation context, its contents are stored within
878  *   iv_{enc/dec}.
879  * - The value of ivlen indicates the length of the IV.
880  *   This is redundant in case of stream/CBC transformations
881  *   which always use 0 resp. the cipher's block length as the
882  *   IV length, but is needed for AEAD ciphers and may be
883  *   different from the underlying cipher's block length
884  *   in this case.
885  * - The field fixed_ivlen is nonzero for AEAD transformations only
886  *   and indicates the length of the static part of the IV which is
887  *   constant throughout the communication, and which is stored in
888  *   the first fixed_ivlen bytes of the iv_{enc/dec} arrays.
889  * - minor_ver denotes the SSL/TLS version
890  * - For stream/CBC transformations, maclen denotes the length of the
891  *   authentication tag, while taglen is unused and 0.
892  * - For AEAD transformations, taglen denotes the length of the
893  *   authentication tag, while maclen is unused and 0.
894  * - For CBC transformations, encrypt_then_mac determines the
895  *   order of encryption and authentication. This field is unused
896  *   in other transformations.
897  *
898  */
899 struct mbedtls_ssl_transform
900 {
901     /*
902      * Session specific crypto layer
903      */
904     size_t minlen;                      /*!<  min. ciphertext length  */
905     size_t ivlen;                       /*!<  IV length               */
906     size_t fixed_ivlen;                 /*!<  Fixed part of IV (AEAD) */
907     size_t maclen;                      /*!<  MAC(CBC) len            */
908     size_t taglen;                      /*!<  TAG(AEAD) len           */
909 
910     unsigned char iv_enc[16];           /*!<  IV (encryption)         */
911     unsigned char iv_dec[16];           /*!<  IV (decryption)         */
912 
913 #if defined(MBEDTLS_SSL_SOME_SUITES_USE_MAC)
914 
915     mbedtls_md_context_t md_ctx_enc;            /*!<  MAC (encryption)        */
916     mbedtls_md_context_t md_ctx_dec;            /*!<  MAC (decryption)        */
917 
918 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
919     int encrypt_then_mac;       /*!< flag for EtM activation                */
920 #endif
921 
922 #endif /* MBEDTLS_SSL_SOME_SUITES_USE_MAC */
923 
924     mbedtls_cipher_context_t cipher_ctx_enc;    /*!<  encryption context      */
925     mbedtls_cipher_context_t cipher_ctx_dec;    /*!<  decryption context      */
926     int minor_ver;
927 
928 #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
929     uint8_t in_cid_len;
930     uint8_t out_cid_len;
931     unsigned char in_cid [ MBEDTLS_SSL_CID_IN_LEN_MAX ];
932     unsigned char out_cid[ MBEDTLS_SSL_CID_OUT_LEN_MAX ];
933 #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
934 
935 #if defined(MBEDTLS_SSL_CONTEXT_SERIALIZATION)
936     /* We need the Hello random bytes in order to re-derive keys from the
937      * Master Secret and other session info,
938      * see ssl_tls12_populate_transform() */
939     unsigned char randbytes[MBEDTLS_SERVER_HELLO_RANDOM_LEN +
940                             MBEDTLS_CLIENT_HELLO_RANDOM_LEN];
941                             /*!< ServerHello.random+ClientHello.random */
942 #endif /* MBEDTLS_SSL_CONTEXT_SERIALIZATION */
943 };
944 
945 /*
946  * Return 1 if the transform uses an AEAD cipher, 0 otherwise.
947  * Equivalently, return 0 if a separate MAC is used, 1 otherwise.
948  */
mbedtls_ssl_transform_uses_aead(const mbedtls_ssl_transform * transform)949 static inline int mbedtls_ssl_transform_uses_aead(
950         const mbedtls_ssl_transform *transform )
951 {
952 #if defined(MBEDTLS_SSL_SOME_SUITES_USE_MAC)
953     return( transform->maclen == 0 && transform->taglen != 0 );
954 #else
955     (void) transform;
956     return( 1 );
957 #endif
958 }
959 
960 /*
961  * Internal representation of record frames
962  *
963  * Instances come in two flavors:
964  * (1) Encrypted
965  *     These always have data_offset = 0
966  * (2) Unencrypted
967  *     These have data_offset set to the amount of
968  *     pre-expansion during record protection. Concretely,
969  *     this is the length of the fixed part of the explicit IV
970  *     used for encryption, or 0 if no explicit IV is used
971  *     (e.g. for stream ciphers).
972  *
973  * The reason for the data_offset in the unencrypted case
974  * is to allow for in-place conversion of an unencrypted to
975  * an encrypted record. If the offset wasn't included, the
976  * encrypted content would need to be shifted afterwards to
977  * make space for the fixed IV.
978  *
979  */
980 #if MBEDTLS_SSL_CID_OUT_LEN_MAX > MBEDTLS_SSL_CID_IN_LEN_MAX
981 #define MBEDTLS_SSL_CID_LEN_MAX MBEDTLS_SSL_CID_OUT_LEN_MAX
982 #else
983 #define MBEDTLS_SSL_CID_LEN_MAX MBEDTLS_SSL_CID_IN_LEN_MAX
984 #endif
985 
986 typedef struct
987 {
988     uint8_t ctr[MBEDTLS_SSL_SEQUENCE_NUMBER_LEN];  /* In TLS:  The implicit record sequence number.
989                                                     * In DTLS: The 2-byte epoch followed by
990                                                     *          the 6-byte sequence number.
991                                                     * This is stored as a raw big endian byte array
992                                                     * as opposed to a uint64_t because we rarely
993                                                     * need to perform arithmetic on this, but do
994                                                     * need it as a Byte array for the purpose of
995                                                     * MAC computations.                             */
996     uint8_t type;           /* The record content type.                      */
997     uint8_t ver[2];         /* SSL/TLS version as present on the wire.
998                              * Convert to internal presentation of versions
999                              * using mbedtls_ssl_read_version() and
1000                              * mbedtls_ssl_write_version().
1001                              * Keep wire-format for MAC computations.        */
1002 
1003     unsigned char *buf;     /* Memory buffer enclosing the record content    */
1004     size_t buf_len;         /* Buffer length                                 */
1005     size_t data_offset;     /* Offset of record content                      */
1006     size_t data_len;        /* Length of record content                      */
1007 
1008 #if defined(MBEDTLS_SSL_DTLS_CONNECTION_ID)
1009     uint8_t cid_len;        /* Length of the CID (0 if not present)          */
1010     unsigned char cid[ MBEDTLS_SSL_CID_LEN_MAX ]; /* The CID                 */
1011 #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
1012 } mbedtls_record;
1013 
1014 #if defined(MBEDTLS_X509_CRT_PARSE_C)
1015 /*
1016  * List of certificate + private key pairs
1017  */
1018 struct mbedtls_ssl_key_cert
1019 {
1020     mbedtls_x509_crt *cert;                 /*!< cert                       */
1021     mbedtls_pk_context *key;                /*!< private key                */
1022     mbedtls_ssl_key_cert *next;             /*!< next key/cert pair         */
1023 };
1024 #endif /* MBEDTLS_X509_CRT_PARSE_C */
1025 
1026 #if defined(MBEDTLS_SSL_PROTO_DTLS)
1027 /*
1028  * List of handshake messages kept around for resending
1029  */
1030 struct mbedtls_ssl_flight_item
1031 {
1032     unsigned char *p;       /*!< message, including handshake headers   */
1033     size_t len;             /*!< length of p                            */
1034     unsigned char type;     /*!< type of the message: handshake or CCS  */
1035     mbedtls_ssl_flight_item *next;  /*!< next handshake message(s)              */
1036 };
1037 #endif /* MBEDTLS_SSL_PROTO_DTLS */
1038 
1039 #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
1040     defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
1041 
1042 /* Find an entry in a signature-hash set matching a given hash algorithm. */
1043 mbedtls_md_type_t mbedtls_ssl_sig_hash_set_find( mbedtls_ssl_sig_hash_set_t *set,
1044                                                  mbedtls_pk_type_t sig_alg );
1045 /* Add a signature-hash-pair to a signature-hash set */
1046 void mbedtls_ssl_sig_hash_set_add( mbedtls_ssl_sig_hash_set_t *set,
1047                                    mbedtls_pk_type_t sig_alg,
1048                                    mbedtls_md_type_t md_alg );
1049 /* Allow exactly one hash algorithm for each signature. */
1050 void mbedtls_ssl_sig_hash_set_const_hash( mbedtls_ssl_sig_hash_set_t *set,
1051                                           mbedtls_md_type_t md_alg );
1052 
1053 /* Setup an empty signature-hash set */
mbedtls_ssl_sig_hash_set_init(mbedtls_ssl_sig_hash_set_t * set)1054 static inline void mbedtls_ssl_sig_hash_set_init( mbedtls_ssl_sig_hash_set_t *set )
1055 {
1056     mbedtls_ssl_sig_hash_set_const_hash( set, MBEDTLS_MD_NONE );
1057 }
1058 
1059 #endif /* MBEDTLS_SSL_PROTO_TLS1_2) &&
1060           MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
1061 
1062 /**
1063  * \brief           Free referenced items in an SSL transform context and clear
1064  *                  memory
1065  *
1066  * \param transform SSL transform context
1067  */
1068 void mbedtls_ssl_transform_free( mbedtls_ssl_transform *transform );
1069 
1070 /**
1071  * \brief           Free referenced items in an SSL handshake context and clear
1072  *                  memory
1073  *
1074  * \param ssl       SSL context
1075  */
1076 void mbedtls_ssl_handshake_free( mbedtls_ssl_context *ssl );
1077 
1078 /* set inbound transform of ssl context */
1079 void mbedtls_ssl_set_inbound_transform( mbedtls_ssl_context *ssl,
1080                                         mbedtls_ssl_transform *transform );
1081 
1082 /* set outbound transform of ssl context */
1083 void mbedtls_ssl_set_outbound_transform( mbedtls_ssl_context *ssl,
1084                                          mbedtls_ssl_transform *transform );
1085 
1086 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
1087 int mbedtls_ssl_write_hostname_ext( mbedtls_ssl_context *ssl,
1088                                     unsigned char *buf,
1089                                     const unsigned char *end,
1090                                     size_t *olen );
1091 #endif
1092 
1093 int mbedtls_ssl_handshake_client_step( mbedtls_ssl_context *ssl );
1094 int mbedtls_ssl_handshake_server_step( mbedtls_ssl_context *ssl );
1095 void mbedtls_ssl_handshake_wrapup( mbedtls_ssl_context *ssl );
1096 
1097 int mbedtls_ssl_send_fatal_handshake_failure( mbedtls_ssl_context *ssl );
1098 
1099 void mbedtls_ssl_reset_checksum( mbedtls_ssl_context *ssl );
1100 int mbedtls_ssl_derive_keys( mbedtls_ssl_context *ssl );
1101 
1102 int mbedtls_ssl_handle_message_type( mbedtls_ssl_context *ssl );
1103 int mbedtls_ssl_prepare_handshake_record( mbedtls_ssl_context *ssl );
1104 void mbedtls_ssl_update_handshake_status( mbedtls_ssl_context *ssl );
1105 
1106 /**
1107  * \brief       Update record layer
1108  *
1109  *              This function roughly separates the implementation
1110  *              of the logic of (D)TLS from the implementation
1111  *              of the secure transport.
1112  *
1113  * \param  ssl              The SSL context to use.
1114  * \param  update_hs_digest This indicates if the handshake digest
1115  *                          should be automatically updated in case
1116  *                          a handshake message is found.
1117  *
1118  * \return      0 or non-zero error code.
1119  *
1120  * \note        A clarification on what is called 'record layer' here
1121  *              is in order, as many sensible definitions are possible:
1122  *
1123  *              The record layer takes as input an untrusted underlying
1124  *              transport (stream or datagram) and transforms it into
1125  *              a serially multiplexed, secure transport, which
1126  *              conceptually provides the following:
1127  *
1128  *              (1) Three datagram based, content-agnostic transports
1129  *                  for handshake, alert and CCS messages.
1130  *              (2) One stream- or datagram-based transport
1131  *                  for application data.
1132  *              (3) Functionality for changing the underlying transform
1133  *                  securing the contents.
1134  *
1135  *              The interface to this functionality is given as follows:
1136  *
1137  *              a Updating
1138  *                [Currently implemented by mbedtls_ssl_read_record]
1139  *
1140  *                Check if and on which of the four 'ports' data is pending:
1141  *                Nothing, a controlling datagram of type (1), or application
1142  *                data (2). In any case data is present, internal buffers
1143  *                provide access to the data for the user to process it.
1144  *                Consumption of type (1) datagrams is done automatically
1145  *                on the next update, invalidating that the internal buffers
1146  *                for previous datagrams, while consumption of application
1147  *                data (2) is user-controlled.
1148  *
1149  *              b Reading of application data
1150  *                [Currently manual adaption of ssl->in_offt pointer]
1151  *
1152  *                As mentioned in the last paragraph, consumption of data
1153  *                is different from the automatic consumption of control
1154  *                datagrams (1) because application data is treated as a stream.
1155  *
1156  *              c Tracking availability of application data
1157  *                [Currently manually through decreasing ssl->in_msglen]
1158  *
1159  *                For efficiency and to retain datagram semantics for
1160  *                application data in case of DTLS, the record layer
1161  *                provides functionality for checking how much application
1162  *                data is still available in the internal buffer.
1163  *
1164  *              d Changing the transformation securing the communication.
1165  *
1166  *              Given an opaque implementation of the record layer in the
1167  *              above sense, it should be possible to implement the logic
1168  *              of (D)TLS on top of it without the need to know anything
1169  *              about the record layer's internals. This is done e.g.
1170  *              in all the handshake handling functions, and in the
1171  *              application data reading function mbedtls_ssl_read.
1172  *
1173  * \note        The above tries to give a conceptual picture of the
1174  *              record layer, but the current implementation deviates
1175  *              from it in some places. For example, our implementation of
1176  *              the update functionality through mbedtls_ssl_read_record
1177  *              discards datagrams depending on the current state, which
1178  *              wouldn't fall under the record layer's responsibility
1179  *              following the above definition.
1180  *
1181  */
1182 int mbedtls_ssl_read_record( mbedtls_ssl_context *ssl,
1183                              unsigned update_hs_digest );
1184 int mbedtls_ssl_fetch_input( mbedtls_ssl_context *ssl, size_t nb_want );
1185 
1186 #ifdef ESCP_MBDTLS_CUSTOMIZATION
1187 int mbedtls_ssl_fetch_input_expand( mbedtls_ssl_context *ssl, size_t nb_want, int retry);
1188 #endif
1189 int mbedtls_ssl_write_handshake_msg_ext( mbedtls_ssl_context *ssl,
1190                                          int update_checksum );
mbedtls_ssl_write_handshake_msg(mbedtls_ssl_context * ssl)1191 static inline int mbedtls_ssl_write_handshake_msg( mbedtls_ssl_context *ssl )
1192 {
1193     return( mbedtls_ssl_write_handshake_msg_ext( ssl, 1 /* update checksum */ ) );
1194 }
1195 
1196 int mbedtls_ssl_write_record( mbedtls_ssl_context *ssl, uint8_t force_flush );
1197 int mbedtls_ssl_flush_output( mbedtls_ssl_context *ssl );
1198 
1199 int mbedtls_ssl_parse_certificate( mbedtls_ssl_context *ssl );
1200 int mbedtls_ssl_write_certificate( mbedtls_ssl_context *ssl );
1201 
1202 int mbedtls_ssl_parse_change_cipher_spec( mbedtls_ssl_context *ssl );
1203 int mbedtls_ssl_write_change_cipher_spec( mbedtls_ssl_context *ssl );
1204 
1205 int mbedtls_ssl_parse_finished( mbedtls_ssl_context *ssl );
1206 int mbedtls_ssl_write_finished( mbedtls_ssl_context *ssl );
1207 
1208 void mbedtls_ssl_optimize_checksum( mbedtls_ssl_context *ssl,
1209                             const mbedtls_ssl_ciphersuite_t *ciphersuite_info );
1210 
1211 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
1212 int mbedtls_ssl_psk_derive_premaster( mbedtls_ssl_context *ssl, mbedtls_key_exchange_type_t key_ex );
1213 
1214 /**
1215  * Get the first defined PSK by order of precedence:
1216  * 1. handshake PSK set by \c mbedtls_ssl_set_hs_psk() in the PSK callback
1217  * 2. static PSK configured by \c mbedtls_ssl_conf_psk()
1218  * Return a code and update the pair (PSK, PSK length) passed to this function
1219  */
mbedtls_ssl_get_psk(const mbedtls_ssl_context * ssl,const unsigned char ** psk,size_t * psk_len)1220 static inline int mbedtls_ssl_get_psk( const mbedtls_ssl_context *ssl,
1221     const unsigned char **psk, size_t *psk_len )
1222 {
1223     if( ssl->handshake->psk != NULL && ssl->handshake->psk_len > 0 )
1224     {
1225         *psk = ssl->handshake->psk;
1226         *psk_len = ssl->handshake->psk_len;
1227     }
1228 
1229     else if( ssl->conf->psk != NULL && ssl->conf->psk_len > 0 )
1230     {
1231         *psk = ssl->conf->psk;
1232         *psk_len = ssl->conf->psk_len;
1233     }
1234 
1235     else
1236     {
1237         *psk = NULL;
1238         *psk_len = 0;
1239         return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED );
1240     }
1241 
1242     return( 0 );
1243 }
1244 
1245 #if defined(MBEDTLS_USE_PSA_CRYPTO)
1246 /**
1247  * Get the first defined opaque PSK by order of precedence:
1248  * 1. handshake PSK set by \c mbedtls_ssl_set_hs_psk_opaque() in the PSK
1249  *    callback
1250  * 2. static PSK configured by \c mbedtls_ssl_conf_psk_opaque()
1251  * Return an opaque PSK
1252  */
mbedtls_ssl_get_opaque_psk(const mbedtls_ssl_context * ssl)1253 static inline psa_key_id_t mbedtls_ssl_get_opaque_psk(
1254     const mbedtls_ssl_context *ssl )
1255 {
1256     if( ! mbedtls_svc_key_id_is_null( ssl->handshake->psk_opaque ) )
1257         return( ssl->handshake->psk_opaque );
1258 
1259     if( ! mbedtls_svc_key_id_is_null( ssl->conf->psk_opaque ) )
1260         return( ssl->conf->psk_opaque );
1261 
1262     return( MBEDTLS_SVC_KEY_ID_INIT );
1263 }
1264 #endif /* MBEDTLS_USE_PSA_CRYPTO */
1265 
1266 #endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */
1267 
1268 #if defined(MBEDTLS_PK_C)
1269 unsigned char mbedtls_ssl_sig_from_pk( mbedtls_pk_context *pk );
1270 unsigned char mbedtls_ssl_sig_from_pk_alg( mbedtls_pk_type_t type );
1271 mbedtls_pk_type_t mbedtls_ssl_pk_alg_from_sig( unsigned char sig );
1272 #endif
1273 
1274 mbedtls_md_type_t mbedtls_ssl_md_alg_from_hash( unsigned char hash );
1275 unsigned char mbedtls_ssl_hash_from_md_alg( int md );
1276 int mbedtls_ssl_set_calc_verify_md( mbedtls_ssl_context *ssl, int md );
1277 
1278 #if defined(MBEDTLS_ECP_C)
1279 int mbedtls_ssl_check_curve( const mbedtls_ssl_context *ssl, mbedtls_ecp_group_id grp_id );
1280 #endif
1281 
1282 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
1283 int mbedtls_ssl_check_sig_hash( const mbedtls_ssl_context *ssl,
1284                                 mbedtls_md_type_t md );
1285 #endif
1286 
1287 #if defined(MBEDTLS_SSL_DTLS_SRTP)
mbedtls_ssl_check_srtp_profile_value(const uint16_t srtp_profile_value)1288 static inline mbedtls_ssl_srtp_profile mbedtls_ssl_check_srtp_profile_value
1289                                                     ( const uint16_t srtp_profile_value )
1290 {
1291     switch( srtp_profile_value )
1292     {
1293         case MBEDTLS_TLS_SRTP_AES128_CM_HMAC_SHA1_80:
1294         case MBEDTLS_TLS_SRTP_AES128_CM_HMAC_SHA1_32:
1295         case MBEDTLS_TLS_SRTP_NULL_HMAC_SHA1_80:
1296         case MBEDTLS_TLS_SRTP_NULL_HMAC_SHA1_32:
1297             return srtp_profile_value;
1298         default: break;
1299     }
1300     return( MBEDTLS_TLS_SRTP_UNSET );
1301 }
1302 #endif
1303 
1304 #if defined(MBEDTLS_X509_CRT_PARSE_C)
mbedtls_ssl_own_key(mbedtls_ssl_context * ssl)1305 static inline mbedtls_pk_context *mbedtls_ssl_own_key( mbedtls_ssl_context *ssl )
1306 {
1307     mbedtls_ssl_key_cert *key_cert;
1308 
1309     if( ssl->handshake != NULL && ssl->handshake->key_cert != NULL )
1310         key_cert = ssl->handshake->key_cert;
1311     else
1312         key_cert = ssl->conf->key_cert;
1313 
1314     return( key_cert == NULL ? NULL : key_cert->key );
1315 }
1316 
mbedtls_ssl_own_cert(mbedtls_ssl_context * ssl)1317 static inline mbedtls_x509_crt *mbedtls_ssl_own_cert( mbedtls_ssl_context *ssl )
1318 {
1319     mbedtls_ssl_key_cert *key_cert;
1320 
1321     if( ssl->handshake != NULL && ssl->handshake->key_cert != NULL )
1322         key_cert = ssl->handshake->key_cert;
1323     else
1324         key_cert = ssl->conf->key_cert;
1325 
1326     return( key_cert == NULL ? NULL : key_cert->cert );
1327 }
1328 
1329 /*
1330  * Check usage of a certificate wrt extensions:
1331  * keyUsage, extendedKeyUsage (later), and nSCertType (later).
1332  *
1333  * Warning: cert_endpoint is the endpoint of the cert (ie, of our peer when we
1334  * check a cert we received from them)!
1335  *
1336  * Return 0 if everything is OK, -1 if not.
1337  */
1338 int mbedtls_ssl_check_cert_usage( const mbedtls_x509_crt *cert,
1339                           const mbedtls_ssl_ciphersuite_t *ciphersuite,
1340                           int cert_endpoint,
1341                           uint32_t *flags );
1342 #endif /* MBEDTLS_X509_CRT_PARSE_C */
1343 
1344 void mbedtls_ssl_write_version( int major, int minor, int transport,
1345                         unsigned char ver[2] );
1346 void mbedtls_ssl_read_version( int *major, int *minor, int transport,
1347                        const unsigned char ver[2] );
1348 
mbedtls_ssl_in_hdr_len(const mbedtls_ssl_context * ssl)1349 static inline size_t mbedtls_ssl_in_hdr_len( const mbedtls_ssl_context *ssl )
1350 {
1351 #if !defined(MBEDTLS_SSL_PROTO_DTLS)
1352     ((void) ssl);
1353 #endif
1354 
1355 #if defined(MBEDTLS_SSL_PROTO_DTLS)
1356     if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
1357     {
1358         return( 13 );
1359     }
1360     else
1361 #endif /* MBEDTLS_SSL_PROTO_DTLS */
1362     {
1363         return( 5 );
1364     }
1365 }
1366 
mbedtls_ssl_out_hdr_len(const mbedtls_ssl_context * ssl)1367 static inline size_t mbedtls_ssl_out_hdr_len( const mbedtls_ssl_context *ssl )
1368 {
1369     return( (size_t) ( ssl->out_iv - ssl->out_hdr ) );
1370 }
1371 
mbedtls_ssl_hs_hdr_len(const mbedtls_ssl_context * ssl)1372 static inline size_t mbedtls_ssl_hs_hdr_len( const mbedtls_ssl_context *ssl )
1373 {
1374 #if defined(MBEDTLS_SSL_PROTO_DTLS)
1375     if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
1376         return( 12 );
1377 #else
1378     ((void) ssl);
1379 #endif
1380     return( 4 );
1381 }
1382 
1383 #if defined(MBEDTLS_SSL_PROTO_DTLS)
1384 void mbedtls_ssl_send_flight_completed( mbedtls_ssl_context *ssl );
1385 void mbedtls_ssl_recv_flight_completed( mbedtls_ssl_context *ssl );
1386 int mbedtls_ssl_resend( mbedtls_ssl_context *ssl );
1387 int mbedtls_ssl_flight_transmit( mbedtls_ssl_context *ssl );
1388 #endif
1389 
1390 /* Visible for testing purposes only */
1391 #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
1392 int mbedtls_ssl_dtls_replay_check( mbedtls_ssl_context const *ssl );
1393 void mbedtls_ssl_dtls_replay_update( mbedtls_ssl_context *ssl );
1394 #endif
1395 
1396 int mbedtls_ssl_session_copy( mbedtls_ssl_session *dst,
1397                               const mbedtls_ssl_session *src );
1398 
1399 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
1400 /* The hash buffer must have at least MBEDTLS_MD_MAX_SIZE bytes of length. */
1401 int mbedtls_ssl_get_key_exchange_md_tls1_2( mbedtls_ssl_context *ssl,
1402                                             unsigned char *hash, size_t *hashlen,
1403                                             unsigned char *data, size_t data_len,
1404                                             mbedtls_md_type_t md_alg );
1405 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
1406 
1407 #ifdef __cplusplus
1408 }
1409 #endif
1410 
1411 void mbedtls_ssl_transform_init( mbedtls_ssl_transform *transform );
1412 int mbedtls_ssl_encrypt_buf( mbedtls_ssl_context *ssl,
1413                              mbedtls_ssl_transform *transform,
1414                              mbedtls_record *rec,
1415                              int (*f_rng)(void *, unsigned char *, size_t),
1416                              void *p_rng );
1417 int mbedtls_ssl_decrypt_buf( mbedtls_ssl_context const *ssl,
1418                              mbedtls_ssl_transform *transform,
1419                              mbedtls_record *rec );
1420 
1421 /* Length of the "epoch" field in the record header */
mbedtls_ssl_ep_len(const mbedtls_ssl_context * ssl)1422 static inline size_t mbedtls_ssl_ep_len( const mbedtls_ssl_context *ssl )
1423 {
1424 #if defined(MBEDTLS_SSL_PROTO_DTLS)
1425     if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
1426         return( 2 );
1427 #else
1428     ((void) ssl);
1429 #endif
1430     return( 0 );
1431 }
1432 
1433 #if defined(MBEDTLS_SSL_PROTO_DTLS)
1434 int mbedtls_ssl_resend_hello_request( mbedtls_ssl_context *ssl );
1435 #endif /* MBEDTLS_SSL_PROTO_DTLS */
1436 
1437 void mbedtls_ssl_set_timer( mbedtls_ssl_context *ssl, uint32_t millisecs );
1438 int mbedtls_ssl_check_timer( mbedtls_ssl_context *ssl );
1439 
1440 void mbedtls_ssl_reset_in_out_pointers( mbedtls_ssl_context *ssl );
1441 void mbedtls_ssl_update_out_pointers( mbedtls_ssl_context *ssl,
1442                               mbedtls_ssl_transform *transform );
1443 void mbedtls_ssl_update_in_pointers( mbedtls_ssl_context *ssl );
1444 
1445 int mbedtls_ssl_session_reset_int( mbedtls_ssl_context *ssl, int partial );
1446 
1447 /*
1448  * Send pending alert
1449  */
1450 int mbedtls_ssl_handle_pending_alert( mbedtls_ssl_context *ssl );
1451 
1452 /*
1453  * Set pending fatal alert flag.
1454  */
1455 void mbedtls_ssl_pend_fatal_alert( mbedtls_ssl_context *ssl,
1456                                    unsigned char alert_type,
1457                                    int alert_reason );
1458 
1459 /* Alias of mbedtls_ssl_pend_fatal_alert */
1460 #define MBEDTLS_SSL_PEND_FATAL_ALERT( type, user_return_value )         \
1461             mbedtls_ssl_pend_fatal_alert( ssl, type, user_return_value )
1462 
1463 #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
1464 void mbedtls_ssl_dtls_replay_reset( mbedtls_ssl_context *ssl );
1465 #endif
1466 
1467 void mbedtls_ssl_handshake_wrapup_free_hs_transform( mbedtls_ssl_context *ssl );
1468 
1469 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1470 int mbedtls_ssl_start_renegotiation( mbedtls_ssl_context *ssl );
1471 #endif /* MBEDTLS_SSL_RENEGOTIATION */
1472 
1473 #if defined(MBEDTLS_SSL_PROTO_DTLS)
1474 size_t mbedtls_ssl_get_current_mtu( const mbedtls_ssl_context *ssl );
1475 void mbedtls_ssl_buffering_free( mbedtls_ssl_context *ssl );
1476 void mbedtls_ssl_flight_free( mbedtls_ssl_flight_item *flight );
1477 #endif /* MBEDTLS_SSL_PROTO_DTLS */
1478 
1479 /**
1480  * ssl utils functions for checking configuration.
1481  */
1482 
1483 #if defined(MBEDTLS_SSL_PROTO_TLS1_3)
mbedtls_ssl_conf_is_tls13_only(const mbedtls_ssl_config * conf)1484 static inline int mbedtls_ssl_conf_is_tls13_only( const mbedtls_ssl_config *conf )
1485 {
1486     if( conf->min_major_ver == MBEDTLS_SSL_MAJOR_VERSION_3 &&
1487         conf->max_major_ver == MBEDTLS_SSL_MAJOR_VERSION_3 &&
1488         conf->min_minor_ver == MBEDTLS_SSL_MINOR_VERSION_4 &&
1489         conf->max_minor_ver == MBEDTLS_SSL_MINOR_VERSION_4 )
1490     {
1491         return( 1 );
1492     }
1493     return( 0 );
1494 }
1495 #endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
1496 
1497 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
mbedtls_ssl_conf_is_tls12_only(const mbedtls_ssl_config * conf)1498 static inline int mbedtls_ssl_conf_is_tls12_only( const mbedtls_ssl_config *conf )
1499 {
1500     if( conf->min_major_ver == MBEDTLS_SSL_MAJOR_VERSION_3 &&
1501         conf->max_major_ver == MBEDTLS_SSL_MAJOR_VERSION_3 &&
1502         conf->min_minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 &&
1503         conf->max_minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 )
1504     {
1505         return( 1 );
1506     }
1507     return( 0 );
1508 }
1509 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
1510 
1511 #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && defined(MBEDTLS_SSL_PROTO_TLS1_3)
mbedtls_ssl_conf_is_hybrid_tls12_tls13(const mbedtls_ssl_config * conf)1512 static inline int mbedtls_ssl_conf_is_hybrid_tls12_tls13( const mbedtls_ssl_config *conf )
1513 {
1514     if( conf->min_major_ver == MBEDTLS_SSL_MAJOR_VERSION_3 &&
1515         conf->max_major_ver == MBEDTLS_SSL_MAJOR_VERSION_3 &&
1516         conf->min_minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 &&
1517         conf->max_minor_ver == MBEDTLS_SSL_MINOR_VERSION_4 )
1518     {
1519         return( 1 );
1520     }
1521     return( 0 );
1522 }
1523 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 && MBEDTLS_SSL_PROTO_TLS1_3 */
1524 
1525 #if defined(MBEDTLS_SSL_PROTO_TLS1_3)
1526 
1527 int mbedtls_ssl_tls13_process_finished_message( mbedtls_ssl_context *ssl );
1528 int mbedtls_ssl_tls13_write_finished_message( mbedtls_ssl_context *ssl );
1529 void mbedtls_ssl_tls13_handshake_wrapup( mbedtls_ssl_context *ssl );
1530 
1531 /**
1532  * \brief           TLS 1.3 client side state machine entry
1533  *
1534  * \param ssl       SSL context
1535  */
1536 int mbedtls_ssl_tls13_handshake_client_step( mbedtls_ssl_context *ssl );
1537 
1538 /**
1539  * \brief           TLS 1.3 server side state machine entry
1540  *
1541  * \param ssl       SSL context
1542  */
1543 int mbedtls_ssl_tls13_handshake_server_step( mbedtls_ssl_context *ssl );
1544 
1545 
1546 /*
1547  * Helper functions around key exchange modes.
1548  */
mbedtls_ssl_conf_tls13_check_kex_modes(mbedtls_ssl_context * ssl,int kex_mode_mask)1549 static inline unsigned mbedtls_ssl_conf_tls13_check_kex_modes( mbedtls_ssl_context *ssl,
1550                                                                int kex_mode_mask )
1551 {
1552     return( ( ssl->conf->tls13_kex_modes & kex_mode_mask ) != 0 );
1553 }
1554 
mbedtls_ssl_conf_tls13_psk_enabled(mbedtls_ssl_context * ssl)1555 static inline int mbedtls_ssl_conf_tls13_psk_enabled( mbedtls_ssl_context *ssl )
1556 {
1557     return( mbedtls_ssl_conf_tls13_check_kex_modes( ssl,
1558                    MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK ) );
1559 }
1560 
mbedtls_ssl_conf_tls13_psk_ephemeral_enabled(mbedtls_ssl_context * ssl)1561 static inline int mbedtls_ssl_conf_tls13_psk_ephemeral_enabled( mbedtls_ssl_context *ssl )
1562 {
1563     return( mbedtls_ssl_conf_tls13_check_kex_modes( ssl,
1564                    MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL ) );
1565 }
1566 
mbedtls_ssl_conf_tls13_ephemeral_enabled(mbedtls_ssl_context * ssl)1567 static inline int mbedtls_ssl_conf_tls13_ephemeral_enabled( mbedtls_ssl_context *ssl )
1568 {
1569     return( mbedtls_ssl_conf_tls13_check_kex_modes( ssl,
1570                    MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL ) );
1571 }
1572 
mbedtls_ssl_conf_tls13_some_ephemeral_enabled(mbedtls_ssl_context * ssl)1573 static inline int mbedtls_ssl_conf_tls13_some_ephemeral_enabled( mbedtls_ssl_context *ssl )
1574 {
1575     return( mbedtls_ssl_conf_tls13_check_kex_modes( ssl,
1576                    MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ALL ) );
1577 }
1578 
mbedtls_ssl_conf_tls13_some_psk_enabled(mbedtls_ssl_context * ssl)1579 static inline int mbedtls_ssl_conf_tls13_some_psk_enabled( mbedtls_ssl_context *ssl )
1580 {
1581     return( mbedtls_ssl_conf_tls13_check_kex_modes( ssl,
1582                    MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ALL ) );
1583 }
1584 
1585 /**
1586  * Given a list of key exchange modes, check if at least one of them is
1587  * supported.
1588  *
1589  * \param[in] ssl  SSL context
1590  * \param kex_modes_mask  Mask of the key exchange modes to check
1591  *
1592  * \return 0 if at least one of the key exchange modes is supported,
1593  *         !=0 otherwise.
1594  */
mbedtls_ssl_tls13_check_kex_modes(mbedtls_ssl_context * ssl,int kex_modes_mask)1595 static inline unsigned mbedtls_ssl_tls13_check_kex_modes( mbedtls_ssl_context *ssl,
1596                                                           int kex_modes_mask )
1597 {
1598     return( ( ssl->handshake->tls13_kex_modes & kex_modes_mask ) == 0 );
1599 }
1600 
mbedtls_ssl_tls13_psk_enabled(mbedtls_ssl_context * ssl)1601 static inline int mbedtls_ssl_tls13_psk_enabled( mbedtls_ssl_context *ssl )
1602 {
1603     return( ! mbedtls_ssl_tls13_check_kex_modes( ssl,
1604                    MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK ) );
1605 }
1606 
mbedtls_ssl_tls13_psk_ephemeral_enabled(mbedtls_ssl_context * ssl)1607 static inline int mbedtls_ssl_tls13_psk_ephemeral_enabled(
1608                                                     mbedtls_ssl_context *ssl )
1609 {
1610     return( ! mbedtls_ssl_tls13_check_kex_modes( ssl,
1611                    MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL ) );
1612 }
1613 
mbedtls_ssl_tls13_ephemeral_enabled(mbedtls_ssl_context * ssl)1614 static inline int mbedtls_ssl_tls13_ephemeral_enabled( mbedtls_ssl_context *ssl )
1615 {
1616     return( ! mbedtls_ssl_tls13_check_kex_modes( ssl,
1617                    MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL ) );
1618 }
1619 
mbedtls_ssl_tls13_some_ephemeral_enabled(mbedtls_ssl_context * ssl)1620 static inline int mbedtls_ssl_tls13_some_ephemeral_enabled( mbedtls_ssl_context *ssl )
1621 {
1622     return( ! mbedtls_ssl_tls13_check_kex_modes( ssl,
1623                    MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ALL ) );
1624 }
1625 
mbedtls_ssl_tls13_some_psk_enabled(mbedtls_ssl_context * ssl)1626 static inline int mbedtls_ssl_tls13_some_psk_enabled( mbedtls_ssl_context *ssl )
1627 {
1628     return( ! mbedtls_ssl_tls13_check_kex_modes( ssl,
1629                    MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ALL ) );
1630 }
1631 
1632 /*
1633  * Helper functions for NamedGroup.
1634  */
mbedtls_ssl_tls13_named_group_is_ecdhe(uint16_t named_group)1635 static inline int mbedtls_ssl_tls13_named_group_is_ecdhe( uint16_t named_group )
1636 {
1637     return( named_group == MBEDTLS_SSL_IANA_TLS_GROUP_SECP256R1 ||
1638             named_group == MBEDTLS_SSL_IANA_TLS_GROUP_SECP384R1 ||
1639             named_group == MBEDTLS_SSL_IANA_TLS_GROUP_SECP521R1 ||
1640             named_group == MBEDTLS_SSL_IANA_TLS_GROUP_X25519    ||
1641             named_group == MBEDTLS_SSL_IANA_TLS_GROUP_X448 );
1642 }
1643 
mbedtls_ssl_tls13_named_group_is_dhe(uint16_t named_group)1644 static inline int mbedtls_ssl_tls13_named_group_is_dhe( uint16_t named_group )
1645 {
1646     return( named_group >= MBEDTLS_SSL_IANA_TLS_GROUP_FFDHE2048 &&
1647             named_group <= MBEDTLS_SSL_IANA_TLS_GROUP_FFDHE8192 );
1648 }
1649 
mbedtls_ssl_handshake_set_state(mbedtls_ssl_context * ssl,mbedtls_ssl_states state)1650 static inline void mbedtls_ssl_handshake_set_state( mbedtls_ssl_context *ssl,
1651                                                     mbedtls_ssl_states state )
1652 {
1653     ssl->state = ( int ) state;
1654 }
1655 
1656 /*
1657  * Fetch TLS 1.3 handshake message header
1658  */
1659 int mbedtls_ssl_tls13_fetch_handshake_msg( mbedtls_ssl_context *ssl,
1660                                            unsigned hs_type,
1661                                            unsigned char **buf,
1662                                            size_t *buf_len );
1663 
1664 /*
1665  * Write TLS 1.3 handshake message header
1666  */
1667 int mbedtls_ssl_tls13_start_handshake_msg( mbedtls_ssl_context *ssl,
1668                                            unsigned hs_type,
1669                                            unsigned char **buf,
1670                                            size_t *buf_len );
1671 
1672 /*
1673  * Handler of TLS 1.3 server certificate message
1674  */
1675 int mbedtls_ssl_tls13_process_certificate( mbedtls_ssl_context *ssl );
1676 
1677 /*
1678  * Generic handler of Certificate Verify
1679  */
1680 int mbedtls_ssl_tls13_process_certificate_verify( mbedtls_ssl_context *ssl );
1681 
1682 /*
1683  * Write of dummy-CCS's for middlebox compatibility
1684  */
1685 int mbedtls_ssl_tls13_write_change_cipher_spec( mbedtls_ssl_context *ssl );
1686 
1687 /*
1688  * Write TLS 1.3 handshake message tail
1689  */
1690 int mbedtls_ssl_tls13_finish_handshake_msg( mbedtls_ssl_context *ssl,
1691                                             size_t buf_len,
1692                                             size_t msg_len );
1693 
1694 void mbedtls_ssl_tls13_add_hs_hdr_to_checksum( mbedtls_ssl_context *ssl,
1695                                                unsigned hs_type,
1696                                                size_t total_hs_len );
1697 
1698 /*
1699  * Update checksum of handshake messages.
1700  */
1701 void mbedtls_ssl_tls13_add_hs_msg_to_checksum( mbedtls_ssl_context *ssl,
1702                                                unsigned hs_type,
1703                                                unsigned char const *msg,
1704                                                size_t msg_len );
1705 
1706 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
1707 /*
1708  * Write TLS 1.3 Signature Algorithm extension
1709  */
1710 int mbedtls_ssl_tls13_write_sig_alg_ext( mbedtls_ssl_context *ssl,
1711                                          unsigned char *buf,
1712                                          unsigned char *end,
1713                                          size_t *out_len);
1714 
1715 #endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
1716 
1717 #endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
1718 
1719 /* Get handshake transcript */
1720 int mbedtls_ssl_get_handshake_transcript( mbedtls_ssl_context *ssl,
1721                                           const mbedtls_md_type_t md,
1722                                           unsigned char *dst,
1723                                           size_t dst_len,
1724                                           size_t *olen );
1725 
1726 /*
1727  * Return supported groups.
1728  *
1729  * In future, invocations can be changed to ssl->conf->group_list
1730  * when mbedtls_ssl_conf_curves() is deleted.
1731  *
1732  * ssl->handshake->group_list is either a translation of curve_list to IANA TLS group
1733  * identifiers when mbedtls_ssl_conf_curves() has been used, or a pointer to
1734  * ssl->conf->group_list when mbedtls_ssl_conf_groups() has been more recently invoked.
1735  *
1736  */
mbedtls_ssl_get_groups(const mbedtls_ssl_context * ssl)1737 static inline const void *mbedtls_ssl_get_groups( const mbedtls_ssl_context *ssl )
1738 {
1739     #if defined(MBEDTLS_DEPRECATED_REMOVED) || !defined(MBEDTLS_ECP_C)
1740     return( ssl->conf->group_list );
1741     #else
1742     if( ( ssl->handshake != NULL ) && ( ssl->handshake->group_list != NULL ) )
1743         return( ssl->handshake->group_list );
1744     else
1745         return( ssl->conf->group_list );
1746     #endif
1747 }
1748 
1749 #if defined(MBEDTLS_TEST_HOOKS)
1750 int mbedtls_ssl_check_dtls_clihlo_cookie(
1751                            mbedtls_ssl_context *ssl,
1752                            const unsigned char *cli_id, size_t cli_id_len,
1753                            const unsigned char *in, size_t in_len,
1754                            unsigned char *obuf, size_t buf_len, size_t *olen );
1755 #endif
1756 
1757 #endif /* ssl_misc.h */
1758