xref: /reactos/sdk/include/reactos/libs/mbedtls/ssl.h (revision 321bcc05)
1 /**
2  * \file ssl.h
3  *
4  * \brief SSL/TLS functions.
5  *
6  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
7  *  SPDX-License-Identifier: Apache-2.0
8  *
9  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
10  *  not use this file except in compliance with the License.
11  *  You may obtain a copy of the License at
12  *
13  *  http://www.apache.org/licenses/LICENSE-2.0
14  *
15  *  Unless required by applicable law or agreed to in writing, software
16  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
17  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
18  *  See the License for the specific language governing permissions and
19  *  limitations under the License.
20  *
21  *  This file is part of mbed TLS (https://tls.mbed.org)
22  */
23 #ifndef MBEDTLS_SSL_H
24 #define MBEDTLS_SSL_H
25 
26 #if !defined(MBEDTLS_CONFIG_FILE)
27 #include "config.h"
28 #else
29 #include MBEDTLS_CONFIG_FILE
30 #endif
31 
32 #include "bignum.h"
33 #include "ecp.h"
34 
35 #include "ssl_ciphersuites.h"
36 
37 #if defined(MBEDTLS_X509_CRT_PARSE_C)
38 #include "x509_crt.h"
39 #include "x509_crl.h"
40 #endif
41 
42 #if defined(MBEDTLS_DHM_C)
43 #include "dhm.h"
44 #endif
45 
46 #if defined(MBEDTLS_ECDH_C)
47 #include "ecdh.h"
48 #endif
49 
50 #if defined(MBEDTLS_ZLIB_SUPPORT)
51 #include "zlib.h"
52 #endif
53 
54 #if defined(MBEDTLS_HAVE_TIME)
55 #include <time.h>
56 #endif
57 
58 /*
59  * SSL Error codes
60  */
61 #define MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE               -0x7080  /**< The requested feature is not available. */
62 #define MBEDTLS_ERR_SSL_BAD_INPUT_DATA                    -0x7100  /**< Bad input parameters to function. */
63 #define MBEDTLS_ERR_SSL_INVALID_MAC                       -0x7180  /**< Verification of the message MAC failed. */
64 #define MBEDTLS_ERR_SSL_INVALID_RECORD                    -0x7200  /**< An invalid SSL record was received. */
65 #define MBEDTLS_ERR_SSL_CONN_EOF                          -0x7280  /**< The connection indicated an EOF. */
66 #define MBEDTLS_ERR_SSL_UNKNOWN_CIPHER                    -0x7300  /**< An unknown cipher was received. */
67 #define MBEDTLS_ERR_SSL_NO_CIPHER_CHOSEN                  -0x7380  /**< The server has no ciphersuites in common with the client. */
68 #define MBEDTLS_ERR_SSL_NO_RNG                            -0x7400  /**< No RNG was provided to the SSL module. */
69 #define MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE             -0x7480  /**< No client certification received from the client, but required by the authentication mode. */
70 #define MBEDTLS_ERR_SSL_CERTIFICATE_TOO_LARGE             -0x7500  /**< Our own certificate(s) is/are too large to send in an SSL message. */
71 #define MBEDTLS_ERR_SSL_CERTIFICATE_REQUIRED              -0x7580  /**< The own certificate is not set, but needed by the server. */
72 #define MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED              -0x7600  /**< The own private key or pre-shared key is not set, but needed. */
73 #define MBEDTLS_ERR_SSL_CA_CHAIN_REQUIRED                 -0x7680  /**< No CA Chain is set, but required to operate. */
74 #define MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE                -0x7700  /**< An unexpected message was received from our peer. */
75 #define MBEDTLS_ERR_SSL_FATAL_ALERT_MESSAGE               -0x7780  /**< A fatal alert message was received from our peer. */
76 #define MBEDTLS_ERR_SSL_PEER_VERIFY_FAILED                -0x7800  /**< Verification of our peer failed. */
77 #define MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY                 -0x7880  /**< The peer notified us that the connection is going to be closed. */
78 #define MBEDTLS_ERR_SSL_BAD_HS_CLIENT_HELLO               -0x7900  /**< Processing of the ClientHello handshake message failed. */
79 #define MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO               -0x7980  /**< Processing of the ServerHello handshake message failed. */
80 #define MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE                -0x7A00  /**< Processing of the Certificate handshake message failed. */
81 #define MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_REQUEST        -0x7A80  /**< Processing of the CertificateRequest handshake message failed. */
82 #define MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE        -0x7B00  /**< Processing of the ServerKeyExchange handshake message failed. */
83 #define MBEDTLS_ERR_SSL_BAD_HS_SERVER_HELLO_DONE          -0x7B80  /**< Processing of the ServerHelloDone handshake message failed. */
84 #define MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE        -0x7C00  /**< Processing of the ClientKeyExchange handshake message failed. */
85 #define MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_RP     -0x7C80  /**< Processing of the ClientKeyExchange handshake message failed in DHM / ECDH Read Public. */
86 #define MBEDTLS_ERR_SSL_BAD_HS_CLIENT_KEY_EXCHANGE_CS     -0x7D00  /**< Processing of the ClientKeyExchange handshake message failed in DHM / ECDH Calculate Secret. */
87 #define MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE_VERIFY         -0x7D80  /**< Processing of the CertificateVerify handshake message failed. */
88 #define MBEDTLS_ERR_SSL_BAD_HS_CHANGE_CIPHER_SPEC         -0x7E00  /**< Processing of the ChangeCipherSpec handshake message failed. */
89 #define MBEDTLS_ERR_SSL_BAD_HS_FINISHED                   -0x7E80  /**< Processing of the Finished handshake message failed. */
90 #define MBEDTLS_ERR_SSL_ALLOC_FAILED                      -0x7F00  /**< Memory allocation failed */
91 #define MBEDTLS_ERR_SSL_HW_ACCEL_FAILED                   -0x7F80  /**< Hardware acceleration function returned with error */
92 #define MBEDTLS_ERR_SSL_HW_ACCEL_FALLTHROUGH              -0x6F80  /**< Hardware acceleration function skipped / left alone data */
93 #define MBEDTLS_ERR_SSL_COMPRESSION_FAILED                -0x6F00  /**< Processing of the compression / decompression failed */
94 #define MBEDTLS_ERR_SSL_BAD_HS_PROTOCOL_VERSION           -0x6E80  /**< Handshake protocol not within min/max boundaries */
95 #define MBEDTLS_ERR_SSL_BAD_HS_NEW_SESSION_TICKET         -0x6E00  /**< Processing of the NewSessionTicket handshake message failed. */
96 #define MBEDTLS_ERR_SSL_SESSION_TICKET_EXPIRED            -0x6D80  /**< Session ticket has expired. */
97 #define MBEDTLS_ERR_SSL_PK_TYPE_MISMATCH                  -0x6D00  /**< Public key type mismatch (eg, asked for RSA key exchange and presented EC key) */
98 #define MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY                  -0x6C80  /**< Unknown identity received (eg, PSK identity) */
99 #define MBEDTLS_ERR_SSL_INTERNAL_ERROR                    -0x6C00  /**< Internal error (eg, unexpected failure in lower-level module) */
100 #define MBEDTLS_ERR_SSL_COUNTER_WRAPPING                  -0x6B80  /**< A counter would wrap (eg, too many messages exchanged). */
101 #define MBEDTLS_ERR_SSL_WAITING_SERVER_HELLO_RENEGO       -0x6B00  /**< Unexpected message at ServerHello in renegotiation. */
102 #define MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED             -0x6A80  /**< DTLS client must retry for hello verification */
103 #define MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL                  -0x6A00  /**< A buffer is too small to receive or write a message */
104 #define MBEDTLS_ERR_SSL_NO_USABLE_CIPHERSUITE             -0x6980  /**< None of the common ciphersuites is usable (eg, no suitable certificate, see debug messages). */
105 #define MBEDTLS_ERR_SSL_WANT_READ                         -0x6900  /**< Connection requires a read call. */
106 #define MBEDTLS_ERR_SSL_WANT_WRITE                        -0x6880  /**< Connection requires a write call. */
107 #define MBEDTLS_ERR_SSL_TIMEOUT                           -0x6800  /**< The operation timed out. */
108 #define MBEDTLS_ERR_SSL_CLIENT_RECONNECT                  -0x6780  /**< The client initiated a reconnect from the same port. */
109 #define MBEDTLS_ERR_SSL_UNEXPECTED_RECORD                 -0x6700  /**< Record header looks valid but is not expected. */
110 
111 /*
112  * Various constants
113  */
114 #define MBEDTLS_SSL_MAJOR_VERSION_3             3
115 #define MBEDTLS_SSL_MINOR_VERSION_0             0   /*!< SSL v3.0 */
116 #define MBEDTLS_SSL_MINOR_VERSION_1             1   /*!< TLS v1.0 */
117 #define MBEDTLS_SSL_MINOR_VERSION_2             2   /*!< TLS v1.1 */
118 #define MBEDTLS_SSL_MINOR_VERSION_3             3   /*!< TLS v1.2 */
119 
120 #define MBEDTLS_SSL_TRANSPORT_STREAM            0   /*!< TLS      */
121 #define MBEDTLS_SSL_TRANSPORT_DATAGRAM          1   /*!< DTLS     */
122 
123 #define MBEDTLS_SSL_MAX_HOST_NAME_LEN           255 /*!< Maximum host name defined in RFC 1035 */
124 
125 /* RFC 6066 section 4, see also mfl_code_to_length in ssl_tls.c
126  * NONE must be zero so that memset()ing structure to zero works */
127 #define MBEDTLS_SSL_MAX_FRAG_LEN_NONE           0   /*!< don't use this extension   */
128 #define MBEDTLS_SSL_MAX_FRAG_LEN_512            1   /*!< MaxFragmentLength 2^9      */
129 #define MBEDTLS_SSL_MAX_FRAG_LEN_1024           2   /*!< MaxFragmentLength 2^10     */
130 #define MBEDTLS_SSL_MAX_FRAG_LEN_2048           3   /*!< MaxFragmentLength 2^11     */
131 #define MBEDTLS_SSL_MAX_FRAG_LEN_4096           4   /*!< MaxFragmentLength 2^12     */
132 #define MBEDTLS_SSL_MAX_FRAG_LEN_INVALID        5   /*!< first invalid value        */
133 
134 #define MBEDTLS_SSL_IS_CLIENT                   0
135 #define MBEDTLS_SSL_IS_SERVER                   1
136 
137 #define MBEDTLS_SSL_IS_NOT_FALLBACK             0
138 #define MBEDTLS_SSL_IS_FALLBACK                 1
139 
140 #define MBEDTLS_SSL_EXTENDED_MS_DISABLED        0
141 #define MBEDTLS_SSL_EXTENDED_MS_ENABLED         1
142 
143 #define MBEDTLS_SSL_ETM_DISABLED                0
144 #define MBEDTLS_SSL_ETM_ENABLED                 1
145 
146 #define MBEDTLS_SSL_COMPRESS_NULL               0
147 #define MBEDTLS_SSL_COMPRESS_DEFLATE            1
148 
149 #define MBEDTLS_SSL_VERIFY_NONE                 0
150 #define MBEDTLS_SSL_VERIFY_OPTIONAL             1
151 #define MBEDTLS_SSL_VERIFY_REQUIRED             2
152 #define MBEDTLS_SSL_VERIFY_UNSET                3 /* Used only for sni_authmode */
153 
154 #define MBEDTLS_SSL_LEGACY_RENEGOTIATION        0
155 #define MBEDTLS_SSL_SECURE_RENEGOTIATION        1
156 
157 #define MBEDTLS_SSL_RENEGOTIATION_DISABLED      0
158 #define MBEDTLS_SSL_RENEGOTIATION_ENABLED       1
159 
160 #define MBEDTLS_SSL_ANTI_REPLAY_DISABLED        0
161 #define MBEDTLS_SSL_ANTI_REPLAY_ENABLED         1
162 
163 #define MBEDTLS_SSL_RENEGOTIATION_NOT_ENFORCED  -1
164 #define MBEDTLS_SSL_RENEGO_MAX_RECORDS_DEFAULT  16
165 
166 #define MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION     0
167 #define MBEDTLS_SSL_LEGACY_ALLOW_RENEGOTIATION  1
168 #define MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE      2
169 
170 #define MBEDTLS_SSL_TRUNC_HMAC_DISABLED         0
171 #define MBEDTLS_SSL_TRUNC_HMAC_ENABLED          1
172 #define MBEDTLS_SSL_TRUNCATED_HMAC_LEN          10  /* 80 bits, rfc 6066 section 7 */
173 
174 #define MBEDTLS_SSL_SESSION_TICKETS_DISABLED     0
175 #define MBEDTLS_SSL_SESSION_TICKETS_ENABLED      1
176 
177 #define MBEDTLS_SSL_CBC_RECORD_SPLITTING_DISABLED    0
178 #define MBEDTLS_SSL_CBC_RECORD_SPLITTING_ENABLED     1
179 
180 #define MBEDTLS_SSL_ARC4_ENABLED                0
181 #define MBEDTLS_SSL_ARC4_DISABLED               1
182 
183 #define MBEDTLS_SSL_PRESET_DEFAULT              0
184 #define MBEDTLS_SSL_PRESET_SUITEB               2
185 
186 /*
187  * Default range for DTLS retransmission timer value, in milliseconds.
188  * RFC 6347 4.2.4.1 says from 1 second to 60 seconds.
189  */
190 #define MBEDTLS_SSL_DTLS_TIMEOUT_DFL_MIN    1000
191 #define MBEDTLS_SSL_DTLS_TIMEOUT_DFL_MAX   60000
192 
193 /**
194  * \name SECTION: Module settings
195  *
196  * The configuration options you can set for this module are in this section.
197  * Either change them in config.h or define them on the compiler command line.
198  * \{
199  */
200 
201 #if !defined(MBEDTLS_SSL_DEFAULT_TICKET_LIFETIME)
202 #define MBEDTLS_SSL_DEFAULT_TICKET_LIFETIME     86400 /**< Lifetime of session tickets (if enabled) */
203 #endif
204 
205 /*
206  * Maxium fragment length in bytes,
207  * determines the size of each of the two internal I/O buffers.
208  *
209  * Note: the RFC defines the default size of SSL / TLS messages. If you
210  * change the value here, other clients / servers may not be able to
211  * communicate with you anymore. Only change this value if you control
212  * both sides of the connection and have it reduced at both sides, or
213  * if you're using the Max Fragment Length extension and you know all your
214  * peers are using it too!
215  */
216 #if !defined(MBEDTLS_SSL_MAX_CONTENT_LEN)
217 #define MBEDTLS_SSL_MAX_CONTENT_LEN         16384   /**< Size of the input / output buffer */
218 #endif
219 
220 /* \} name SECTION: Module settings */
221 
222 /*
223  * Length of the verify data for secure renegotiation
224  */
225 #if defined(MBEDTLS_SSL_PROTO_SSL3)
226 #define MBEDTLS_SSL_VERIFY_DATA_MAX_LEN 36
227 #else
228 #define MBEDTLS_SSL_VERIFY_DATA_MAX_LEN 12
229 #endif
230 
231 /*
232  * Signaling ciphersuite values (SCSV)
233  */
234 #define MBEDTLS_SSL_EMPTY_RENEGOTIATION_INFO    0xFF   /**< renegotiation info ext */
235 #define MBEDTLS_SSL_FALLBACK_SCSV_VALUE         0x5600 /**< draft-ietf-tls-downgrade-scsv-00 */
236 
237 /*
238  * Supported Signature and Hash algorithms (For TLS 1.2)
239  * RFC 5246 section 7.4.1.4.1
240  */
241 #define MBEDTLS_SSL_HASH_NONE                0
242 #define MBEDTLS_SSL_HASH_MD5                 1
243 #define MBEDTLS_SSL_HASH_SHA1                2
244 #define MBEDTLS_SSL_HASH_SHA224              3
245 #define MBEDTLS_SSL_HASH_SHA256              4
246 #define MBEDTLS_SSL_HASH_SHA384              5
247 #define MBEDTLS_SSL_HASH_SHA512              6
248 
249 #define MBEDTLS_SSL_SIG_ANON                 0
250 #define MBEDTLS_SSL_SIG_RSA                  1
251 #define MBEDTLS_SSL_SIG_ECDSA                3
252 
253 /*
254  * Client Certificate Types
255  * RFC 5246 section 7.4.4 plus RFC 4492 section 5.5
256  */
257 #define MBEDTLS_SSL_CERT_TYPE_RSA_SIGN       1
258 #define MBEDTLS_SSL_CERT_TYPE_ECDSA_SIGN    64
259 
260 /*
261  * Message, alert and handshake types
262  */
263 #define MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC     20
264 #define MBEDTLS_SSL_MSG_ALERT                  21
265 #define MBEDTLS_SSL_MSG_HANDSHAKE              22
266 #define MBEDTLS_SSL_MSG_APPLICATION_DATA       23
267 
268 #define MBEDTLS_SSL_ALERT_LEVEL_WARNING         1
269 #define MBEDTLS_SSL_ALERT_LEVEL_FATAL           2
270 
271 #define MBEDTLS_SSL_ALERT_MSG_CLOSE_NOTIFY           0  /* 0x00 */
272 #define MBEDTLS_SSL_ALERT_MSG_UNEXPECTED_MESSAGE    10  /* 0x0A */
273 #define MBEDTLS_SSL_ALERT_MSG_BAD_RECORD_MAC        20  /* 0x14 */
274 #define MBEDTLS_SSL_ALERT_MSG_DECRYPTION_FAILED     21  /* 0x15 */
275 #define MBEDTLS_SSL_ALERT_MSG_RECORD_OVERFLOW       22  /* 0x16 */
276 #define MBEDTLS_SSL_ALERT_MSG_DECOMPRESSION_FAILURE 30  /* 0x1E */
277 #define MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE     40  /* 0x28 */
278 #define MBEDTLS_SSL_ALERT_MSG_NO_CERT               41  /* 0x29 */
279 #define MBEDTLS_SSL_ALERT_MSG_BAD_CERT              42  /* 0x2A */
280 #define MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_CERT      43  /* 0x2B */
281 #define MBEDTLS_SSL_ALERT_MSG_CERT_REVOKED          44  /* 0x2C */
282 #define MBEDTLS_SSL_ALERT_MSG_CERT_EXPIRED          45  /* 0x2D */
283 #define MBEDTLS_SSL_ALERT_MSG_CERT_UNKNOWN          46  /* 0x2E */
284 #define MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER     47  /* 0x2F */
285 #define MBEDTLS_SSL_ALERT_MSG_UNKNOWN_CA            48  /* 0x30 */
286 #define MBEDTLS_SSL_ALERT_MSG_ACCESS_DENIED         49  /* 0x31 */
287 #define MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR          50  /* 0x32 */
288 #define MBEDTLS_SSL_ALERT_MSG_DECRYPT_ERROR         51  /* 0x33 */
289 #define MBEDTLS_SSL_ALERT_MSG_EXPORT_RESTRICTION    60  /* 0x3C */
290 #define MBEDTLS_SSL_ALERT_MSG_PROTOCOL_VERSION      70  /* 0x46 */
291 #define MBEDTLS_SSL_ALERT_MSG_INSUFFICIENT_SECURITY 71  /* 0x47 */
292 #define MBEDTLS_SSL_ALERT_MSG_INTERNAL_ERROR        80  /* 0x50 */
293 #define MBEDTLS_SSL_ALERT_MSG_INAPROPRIATE_FALLBACK 86  /* 0x56 */
294 #define MBEDTLS_SSL_ALERT_MSG_USER_CANCELED         90  /* 0x5A */
295 #define MBEDTLS_SSL_ALERT_MSG_NO_RENEGOTIATION     100  /* 0x64 */
296 #define MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT      110  /* 0x6E */
297 #define MBEDTLS_SSL_ALERT_MSG_UNRECOGNIZED_NAME    112  /* 0x70 */
298 #define MBEDTLS_SSL_ALERT_MSG_UNKNOWN_PSK_IDENTITY 115  /* 0x73 */
299 #define MBEDTLS_SSL_ALERT_MSG_NO_APPLICATION_PROTOCOL 120 /* 0x78 */
300 
301 #define MBEDTLS_SSL_HS_HELLO_REQUEST            0
302 #define MBEDTLS_SSL_HS_CLIENT_HELLO             1
303 #define MBEDTLS_SSL_HS_SERVER_HELLO             2
304 #define MBEDTLS_SSL_HS_HELLO_VERIFY_REQUEST     3
305 #define MBEDTLS_SSL_HS_NEW_SESSION_TICKET       4
306 #define MBEDTLS_SSL_HS_CERTIFICATE             11
307 #define MBEDTLS_SSL_HS_SERVER_KEY_EXCHANGE     12
308 #define MBEDTLS_SSL_HS_CERTIFICATE_REQUEST     13
309 #define MBEDTLS_SSL_HS_SERVER_HELLO_DONE       14
310 #define MBEDTLS_SSL_HS_CERTIFICATE_VERIFY      15
311 #define MBEDTLS_SSL_HS_CLIENT_KEY_EXCHANGE     16
312 #define MBEDTLS_SSL_HS_FINISHED                20
313 
314 /*
315  * TLS extensions
316  */
317 #define MBEDTLS_TLS_EXT_SERVERNAME                   0
318 #define MBEDTLS_TLS_EXT_SERVERNAME_HOSTNAME          0
319 
320 #define MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH          1
321 
322 #define MBEDTLS_TLS_EXT_TRUNCATED_HMAC               4
323 
324 #define MBEDTLS_TLS_EXT_SUPPORTED_ELLIPTIC_CURVES   10
325 #define MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS     11
326 
327 #define MBEDTLS_TLS_EXT_SIG_ALG                     13
328 
329 #define MBEDTLS_TLS_EXT_ALPN                        16
330 
331 #define MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC            22 /* 0x16 */
332 #define MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET  0x0017 /* 23 */
333 
334 #define MBEDTLS_TLS_EXT_SESSION_TICKET              35
335 
336 #define MBEDTLS_TLS_EXT_ECJPAKE_KKPP               256 /* experimental */
337 
338 #define MBEDTLS_TLS_EXT_RENEGOTIATION_INFO      0xFF01
339 
340 /*
341  * Size defines
342  */
343 #if !defined(MBEDTLS_PSK_MAX_LEN)
344 #define MBEDTLS_PSK_MAX_LEN            32 /* 256 bits */
345 #endif
346 
347 /* Dummy type used only for its size */
348 union mbedtls_ssl_premaster_secret
349 {
350 #if defined(MBEDTLS_KEY_EXCHANGE_RSA_ENABLED)
351     unsigned char _pms_rsa[48];                         /* RFC 5246 8.1.1 */
352 #endif
353 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED)
354     unsigned char _pms_dhm[MBEDTLS_MPI_MAX_SIZE];      /* RFC 5246 8.1.2 */
355 #endif
356 #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED)    || \
357     defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)  || \
358     defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED)     || \
359     defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
360     unsigned char _pms_ecdh[MBEDTLS_ECP_MAX_BYTES];    /* RFC 4492 5.10 */
361 #endif
362 #if defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED)
363     unsigned char _pms_psk[4 + 2 * MBEDTLS_PSK_MAX_LEN];       /* RFC 4279 2 */
364 #endif
365 #if defined(MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED)
366     unsigned char _pms_dhe_psk[4 + MBEDTLS_MPI_MAX_SIZE
367                                  + MBEDTLS_PSK_MAX_LEN];       /* RFC 4279 3 */
368 #endif
369 #if defined(MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED)
370     unsigned char _pms_rsa_psk[52 + MBEDTLS_PSK_MAX_LEN];      /* RFC 4279 4 */
371 #endif
372 #if defined(MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED)
373     unsigned char _pms_ecdhe_psk[4 + MBEDTLS_ECP_MAX_BYTES
374                                    + MBEDTLS_PSK_MAX_LEN];     /* RFC 5489 2 */
375 #endif
376 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
377     unsigned char _pms_ecjpake[32];     /* Thread spec: SHA-256 output */
378 #endif
379 };
380 
381 #define MBEDTLS_PREMASTER_SIZE     sizeof( union mbedtls_ssl_premaster_secret )
382 
383 #ifdef __cplusplus
384 extern "C" {
385 #endif
386 
387 /*
388  * SSL state machine
389  */
390 typedef enum
391 {
392     MBEDTLS_SSL_HELLO_REQUEST,
393     MBEDTLS_SSL_CLIENT_HELLO,
394     MBEDTLS_SSL_SERVER_HELLO,
395     MBEDTLS_SSL_SERVER_CERTIFICATE,
396     MBEDTLS_SSL_SERVER_KEY_EXCHANGE,
397     MBEDTLS_SSL_CERTIFICATE_REQUEST,
398     MBEDTLS_SSL_SERVER_HELLO_DONE,
399     MBEDTLS_SSL_CLIENT_CERTIFICATE,
400     MBEDTLS_SSL_CLIENT_KEY_EXCHANGE,
401     MBEDTLS_SSL_CERTIFICATE_VERIFY,
402     MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC,
403     MBEDTLS_SSL_CLIENT_FINISHED,
404     MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC,
405     MBEDTLS_SSL_SERVER_FINISHED,
406     MBEDTLS_SSL_FLUSH_BUFFERS,
407     MBEDTLS_SSL_HANDSHAKE_WRAPUP,
408     MBEDTLS_SSL_HANDSHAKE_OVER,
409     MBEDTLS_SSL_SERVER_NEW_SESSION_TICKET,
410     MBEDTLS_SSL_SERVER_HELLO_VERIFY_REQUEST_SENT,
411 }
412 mbedtls_ssl_states;
413 
414 /* Defined below */
415 typedef struct mbedtls_ssl_session mbedtls_ssl_session;
416 typedef struct mbedtls_ssl_context mbedtls_ssl_context;
417 typedef struct mbedtls_ssl_config  mbedtls_ssl_config;
418 
419 /* Defined in ssl_internal.h */
420 typedef struct mbedtls_ssl_transform mbedtls_ssl_transform;
421 typedef struct mbedtls_ssl_handshake_params mbedtls_ssl_handshake_params;
422 #if defined(MBEDTLS_X509_CRT_PARSE_C)
423 typedef struct mbedtls_ssl_key_cert mbedtls_ssl_key_cert;
424 #endif
425 #if defined(MBEDTLS_SSL_PROTO_DTLS)
426 typedef struct mbedtls_ssl_flight_item mbedtls_ssl_flight_item;
427 #endif
428 
429 /*
430  * This structure is used for storing current session data.
431  */
432 struct mbedtls_ssl_session
433 {
434 #if defined(MBEDTLS_HAVE_TIME)
435     time_t start;               /*!< starting time      */
436 #endif
437     int ciphersuite;            /*!< chosen ciphersuite */
438     int compression;            /*!< chosen compression */
439     size_t id_len;              /*!< session id length  */
440     unsigned char id[32];       /*!< session identifier */
441     unsigned char master[48];   /*!< the master secret  */
442 
443 #if defined(MBEDTLS_X509_CRT_PARSE_C)
444     mbedtls_x509_crt *peer_cert;        /*!< peer X.509 cert chain */
445 #endif /* MBEDTLS_X509_CRT_PARSE_C */
446     uint32_t verify_result;          /*!<  verification result     */
447 
448 #if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C)
449     unsigned char *ticket;      /*!< RFC 5077 session ticket */
450     size_t ticket_len;          /*!< session ticket length   */
451     uint32_t ticket_lifetime;   /*!< ticket lifetime hint    */
452 #endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_CLI_C */
453 
454 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
455     unsigned char mfl_code;     /*!< MaxFragmentLength negotiated by peer */
456 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
457 
458 #if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
459     int trunc_hmac;             /*!< flag for truncated hmac activation   */
460 #endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
461 
462 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
463     int encrypt_then_mac;       /*!< flag for EtM activation                */
464 #endif
465 };
466 
467 /**
468  * SSL/TLS configuration to be shared between mbedtls_ssl_context structures.
469  */
470 struct mbedtls_ssl_config
471 {
472     /* Group items by size (largest first) to minimize padding overhead */
473 
474     /*
475      * Pointers
476      */
477 
478     const int *ciphersuite_list[4]; /*!< allowed ciphersuites per version   */
479 
480     /** Callback for printing debug output                                  */
481     void (*f_dbg)(void *, int, const char *, int, const char *);
482     void *p_dbg;                    /*!< context for the debug function     */
483 
484     /** Callback for getting (pseudo-)random numbers                        */
485     int  (*f_rng)(void *, unsigned char *, size_t);
486     void *p_rng;                    /*!< context for the RNG function       */
487 
488     /** Callback to retrieve a session from the cache                       */
489     int (*f_get_cache)(void *, mbedtls_ssl_session *);
490     /** Callback to store a session into the cache                          */
491     int (*f_set_cache)(void *, const mbedtls_ssl_session *);
492     void *p_cache;                  /*!< context for cache callbacks        */
493 
494 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
495     /** Callback for setting cert according to SNI extension                */
496     int (*f_sni)(void *, mbedtls_ssl_context *, const unsigned char *, size_t);
497     void *p_sni;                    /*!< context for SNI callback           */
498 #endif
499 
500 #if defined(MBEDTLS_X509_CRT_PARSE_C)
501     /** Callback to customize X.509 certificate chain verification          */
502     int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *);
503     void *p_vrfy;                   /*!< context for X.509 verify calllback */
504 #endif
505 
506 #if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
507     /** Callback to retrieve PSK key from identity                          */
508     int (*f_psk)(void *, mbedtls_ssl_context *, const unsigned char *, size_t);
509     void *p_psk;                    /*!< context for PSK callback           */
510 #endif
511 
512 #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) && defined(MBEDTLS_SSL_SRV_C)
513     /** Callback to create & write a cookie for ClientHello veirifcation    */
514     int (*f_cookie_write)( void *, unsigned char **, unsigned char *,
515                            const unsigned char *, size_t );
516     /** Callback to verify validity of a ClientHello cookie                 */
517     int (*f_cookie_check)( void *, const unsigned char *, size_t,
518                            const unsigned char *, size_t );
519     void *p_cookie;                 /*!< context for the cookie callbacks   */
520 #endif
521 
522 #if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_SRV_C)
523     /** Callback to create & write a session ticket                         */
524     int (*f_ticket_write)( void *, const mbedtls_ssl_session *,
525             unsigned char *, const unsigned char *, size_t *, uint32_t * );
526     /** Callback to parse a session ticket into a session structure         */
527     int (*f_ticket_parse)( void *, mbedtls_ssl_session *, unsigned char *, size_t);
528     void *p_ticket;                 /*!< context for the ticket callbacks   */
529 #endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_SRV_C */
530 
531 #if defined(MBEDTLS_SSL_EXPORT_KEYS)
532     /** Callback to export key block and master secret                      */
533     int (*f_export_keys)( void *, const unsigned char *,
534             const unsigned char *, size_t, size_t, size_t );
535     void *p_export_keys;            /*!< context for key export callback    */
536 #endif
537 
538 #if defined(MBEDTLS_X509_CRT_PARSE_C)
539     const mbedtls_x509_crt_profile *cert_profile; /*!< verification profile */
540     mbedtls_ssl_key_cert *key_cert; /*!< own certificate/key pair(s)        */
541     mbedtls_x509_crt *ca_chain;     /*!< trusted CAs                        */
542     mbedtls_x509_crl *ca_crl;       /*!< trusted CAs CRLs                   */
543 #endif /* MBEDTLS_X509_CRT_PARSE_C */
544 
545 #if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
546     const int *sig_hashes;          /*!< allowed signature hashes           */
547 #endif
548 
549 #if defined(MBEDTLS_ECP_C)
550     const mbedtls_ecp_group_id *curve_list; /*!< allowed curves             */
551 #endif
552 
553 #if defined(MBEDTLS_DHM_C)
554     mbedtls_mpi dhm_P;              /*!< prime modulus for DHM              */
555     mbedtls_mpi dhm_G;              /*!< generator for DHM                  */
556 #endif
557 
558 #if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
559     unsigned char *psk;             /*!< pre-shared key                     */
560     size_t         psk_len;         /*!< length of the pre-shared key       */
561     unsigned char *psk_identity;    /*!< identity for PSK negotiation       */
562     size_t         psk_identity_len;/*!< length of identity                 */
563 #endif
564 
565 #if defined(MBEDTLS_SSL_ALPN)
566     const char **alpn_list;         /*!< ordered list of protocols          */
567 #endif
568 
569     /*
570      * Numerical settings (int then char)
571      */
572 
573     uint32_t read_timeout;          /*!< timeout for mbedtls_ssl_read (ms)  */
574 
575 #if defined(MBEDTLS_SSL_PROTO_DTLS)
576     uint32_t hs_timeout_min;        /*!< initial value of the handshake
577                                          retransmission timeout (ms)        */
578     uint32_t hs_timeout_max;        /*!< maximum value of the handshake
579                                          retransmission timeout (ms)        */
580 #endif
581 
582 #if defined(MBEDTLS_SSL_RENEGOTIATION)
583     int renego_max_records;         /*!< grace period for renegotiation     */
584     unsigned char renego_period[8]; /*!< value of the record counters
585                                          that triggers renegotiation        */
586 #endif
587 
588 #if defined(MBEDTLS_SSL_DTLS_BADMAC_LIMIT)
589     unsigned int badmac_limit;      /*!< limit of records with a bad MAC    */
590 #endif
591 
592 #if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_SSL_CLI_C)
593     unsigned int dhm_min_bitlen;    /*!< min. bit length of the DHM prime   */
594 #endif
595 
596     unsigned char max_major_ver;    /*!< max. major version used            */
597     unsigned char max_minor_ver;    /*!< max. minor version used            */
598     unsigned char min_major_ver;    /*!< min. major version used            */
599     unsigned char min_minor_ver;    /*!< min. minor version used            */
600 
601     /*
602      * Flags (bitfields)
603      */
604 
605     unsigned int endpoint : 1;      /*!< 0: client, 1: server               */
606     unsigned int transport : 1;     /*!< stream (TLS) or datagram (DTLS)    */
607     unsigned int authmode : 2;      /*!< MBEDTLS_SSL_VERIFY_XXX             */
608     /* needed even with renego disabled for LEGACY_BREAK_HANDSHAKE          */
609     unsigned int allow_legacy_renegotiation : 2 ; /*!< MBEDTLS_LEGACY_XXX   */
610 #if defined(MBEDTLS_ARC4_C)
611     unsigned int arc4_disabled : 1; /*!< blacklist RC4 ciphersuites?        */
612 #endif
613 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
614     unsigned int mfl_code : 3;      /*!< desired fragment length            */
615 #endif
616 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
617     unsigned int encrypt_then_mac : 1 ; /*!< negotiate encrypt-then-mac?    */
618 #endif
619 #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
620     unsigned int extended_ms : 1;   /*!< negotiate extended master secret?  */
621 #endif
622 #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
623     unsigned int anti_replay : 1;   /*!< detect and prevent replay?         */
624 #endif
625 #if defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING)
626     unsigned int cbc_record_splitting : 1;  /*!< do cbc record splitting    */
627 #endif
628 #if defined(MBEDTLS_SSL_RENEGOTIATION)
629     unsigned int disable_renegotiation : 1; /*!< disable renegotiation?     */
630 #endif
631 #if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
632     unsigned int trunc_hmac : 1;    /*!< negotiate truncated hmac?          */
633 #endif
634 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
635     unsigned int session_tickets : 1;   /*!< use session tickets?           */
636 #endif
637 #if defined(MBEDTLS_SSL_FALLBACK_SCSV) && defined(MBEDTLS_SSL_CLI_C)
638     unsigned int fallback : 1;      /*!< is this a fallback?                */
639 #endif
640 };
641 
642 
643 struct mbedtls_ssl_context
644 {
645     const mbedtls_ssl_config *conf; /*!< configuration information          */
646 
647     /*
648      * Miscellaneous
649      */
650     int state;                  /*!< SSL handshake: current state     */
651 #if defined(MBEDTLS_SSL_RENEGOTIATION)
652     int renego_status;          /*!< Initial, in progress, pending?   */
653     int renego_records_seen;    /*!< Records since renego request, or with DTLS,
654                                   number of retransmissions of request if
655                                   renego_max_records is < 0           */
656 #endif
657 
658     int major_ver;              /*!< equal to  MBEDTLS_SSL_MAJOR_VERSION_3    */
659     int minor_ver;              /*!< either 0 (SSL3) or 1 (TLS1.0)    */
660 
661 #if defined(MBEDTLS_SSL_DTLS_BADMAC_LIMIT)
662     unsigned badmac_seen;       /*!< records with a bad MAC received    */
663 #endif
664 
665     /*
666      * Callbacks
667      */
668     int (*f_send)(void *, const unsigned char *, size_t);
669     int (*f_recv)(void *, unsigned char *, size_t);
670     int (*f_recv_timeout)(void *, unsigned char *, size_t, uint32_t);
671     void *p_bio;                /*!< context for I/O operations   */
672 
673     /*
674      * Session layer
675      */
676     mbedtls_ssl_session *session_in;            /*!<  current session data (in)   */
677     mbedtls_ssl_session *session_out;           /*!<  current session data (out)  */
678     mbedtls_ssl_session *session;               /*!<  negotiated session data     */
679     mbedtls_ssl_session *session_negotiate;     /*!<  session data in negotiation */
680 
681     mbedtls_ssl_handshake_params *handshake;    /*!<  params required only during
682                                               the handshake process        */
683 
684     /*
685      * Record layer transformations
686      */
687     mbedtls_ssl_transform *transform_in;        /*!<  current transform params (in)   */
688     mbedtls_ssl_transform *transform_out;       /*!<  current transform params (in)   */
689     mbedtls_ssl_transform *transform;           /*!<  negotiated transform params     */
690     mbedtls_ssl_transform *transform_negotiate; /*!<  transform params in negotiation */
691 
692     /*
693      * Timers
694      */
695     void *p_timer;              /*!< context for the timer callbacks */
696     void (*f_set_timer)(void *, uint32_t, uint32_t); /*!< set timer callback */
697     int (*f_get_timer)(void *); /*!< get timer callback             */
698 
699     /*
700      * Record layer (incoming data)
701      */
702     unsigned char *in_buf;      /*!< input buffer                     */
703     unsigned char *in_ctr;      /*!< 64-bit incoming message counter
704                                      TLS: maintained by us
705                                      DTLS: read from peer             */
706     unsigned char *in_hdr;      /*!< start of record header           */
707     unsigned char *in_len;      /*!< two-bytes message length field   */
708     unsigned char *in_iv;       /*!< ivlen-byte IV                    */
709     unsigned char *in_msg;      /*!< message contents (in_iv+ivlen)   */
710     unsigned char *in_offt;     /*!< read offset in application data  */
711 
712     int in_msgtype;             /*!< record header: message type      */
713     size_t in_msglen;           /*!< record header: message length    */
714     size_t in_left;             /*!< amount of data read so far       */
715 #if defined(MBEDTLS_SSL_PROTO_DTLS)
716     uint16_t in_epoch;          /*!< DTLS epoch for incoming records  */
717     size_t next_record_offset;  /*!< offset of the next record in datagram
718                                      (equal to in_left if none)       */
719 #endif
720 #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
721     uint64_t in_window_top;     /*!< last validated record seq_num    */
722     uint64_t in_window;         /*!< bitmask for replay detection     */
723 #endif
724 
725     size_t in_hslen;            /*!< current handshake message length,
726                                      including the handshake header   */
727     int nb_zero;                /*!< # of 0-length encrypted messages */
728     int record_read;            /*!< record is already present        */
729 
730     /*
731      * Record layer (outgoing data)
732      */
733     unsigned char *out_buf;     /*!< output buffer                    */
734     unsigned char *out_ctr;     /*!< 64-bit outgoing message counter  */
735     unsigned char *out_hdr;     /*!< start of record header           */
736     unsigned char *out_len;     /*!< two-bytes message length field   */
737     unsigned char *out_iv;      /*!< ivlen-byte IV                    */
738     unsigned char *out_msg;     /*!< message contents (out_iv+ivlen)  */
739 
740     int out_msgtype;            /*!< record header: message type      */
741     size_t out_msglen;          /*!< record header: message length    */
742     size_t out_left;            /*!< amount of data not yet written   */
743 
744 #if defined(MBEDTLS_ZLIB_SUPPORT)
745     unsigned char *compress_buf;        /*!<  zlib data buffer        */
746 #endif
747 #if defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING)
748     signed char split_done;     /*!< current record already splitted? */
749 #endif
750 
751     /*
752      * PKI layer
753      */
754     int client_auth;                    /*!<  flag for client auth.   */
755 
756     /*
757      * User settings
758      */
759 #if defined(MBEDTLS_X509_CRT_PARSE_C)
760     char *hostname;             /*!< expected peer CN for verification
761                                      (and SNI if available)                 */
762 #endif
763 
764 #if defined(MBEDTLS_SSL_ALPN)
765     const char *alpn_chosen;    /*!<  negotiated protocol                   */
766 #endif
767 
768     /*
769      * Information for DTLS hello verify
770      */
771 #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) && defined(MBEDTLS_SSL_SRV_C)
772     unsigned char  *cli_id;         /*!<  transport-level ID of the client  */
773     size_t          cli_id_len;     /*!<  length of cli_id                  */
774 #endif
775 
776     /*
777      * Secure renegotiation
778      */
779     /* needed to know when to send extension on server */
780     int secure_renegotiation;           /*!<  does peer support legacy or
781                                               secure renegotiation           */
782 #if defined(MBEDTLS_SSL_RENEGOTIATION)
783     size_t verify_data_len;             /*!<  length of verify data stored   */
784     char own_verify_data[MBEDTLS_SSL_VERIFY_DATA_MAX_LEN]; /*!<  previous handshake verify data */
785     char peer_verify_data[MBEDTLS_SSL_VERIFY_DATA_MAX_LEN]; /*!<  previous handshake verify data */
786 #endif
787 };
788 
789 #if defined(MBEDTLS_SSL_HW_RECORD_ACCEL)
790 
791 #define MBEDTLS_SSL_CHANNEL_OUTBOUND    0
792 #define MBEDTLS_SSL_CHANNEL_INBOUND     1
793 
794 extern int (*mbedtls_ssl_hw_record_init)(mbedtls_ssl_context *ssl,
795                 const unsigned char *key_enc, const unsigned char *key_dec,
796                 size_t keylen,
797                 const unsigned char *iv_enc,  const unsigned char *iv_dec,
798                 size_t ivlen,
799                 const unsigned char *mac_enc, const unsigned char *mac_dec,
800                 size_t maclen);
801 extern int (*mbedtls_ssl_hw_record_activate)(mbedtls_ssl_context *ssl, int direction);
802 extern int (*mbedtls_ssl_hw_record_reset)(mbedtls_ssl_context *ssl);
803 extern int (*mbedtls_ssl_hw_record_write)(mbedtls_ssl_context *ssl);
804 extern int (*mbedtls_ssl_hw_record_read)(mbedtls_ssl_context *ssl);
805 extern int (*mbedtls_ssl_hw_record_finish)(mbedtls_ssl_context *ssl);
806 #endif /* MBEDTLS_SSL_HW_RECORD_ACCEL */
807 
808 /**
809  * \brief Returns the list of ciphersuites supported by the SSL/TLS module.
810  *
811  * \return              a statically allocated array of ciphersuites, the last
812  *                      entry is 0.
813  */
814 const int *mbedtls_ssl_list_ciphersuites( void );
815 
816 /**
817  * \brief               Return the name of the ciphersuite associated with the
818  *                      given ID
819  *
820  * \param ciphersuite_id SSL ciphersuite ID
821  *
822  * \return              a string containing the ciphersuite name
823  */
824 const char *mbedtls_ssl_get_ciphersuite_name( const int ciphersuite_id );
825 
826 /**
827  * \brief               Return the ID of the ciphersuite associated with the
828  *                      given name
829  *
830  * \param ciphersuite_name SSL ciphersuite name
831  *
832  * \return              the ID with the ciphersuite or 0 if not found
833  */
834 int mbedtls_ssl_get_ciphersuite_id( const char *ciphersuite_name );
835 
836 /**
837  * \brief          Initialize an SSL context
838  *                 Just makes the context ready for mbedtls_ssl_setup() or
839  *                 mbedtls_ssl_free()
840  *
841  * \param ssl      SSL context
842  */
843 void mbedtls_ssl_init( mbedtls_ssl_context *ssl );
844 
845 /**
846  * \brief          Set up an SSL context for use
847  *
848  * \note           No copy of the configuration context is made, it can be
849  *                 shared by many mbedtls_ssl_context structures.
850  *
851  * \warning        Modifying the conf structure after is has been used in this
852  *                 function is unsupported!
853  *
854  * \param ssl      SSL context
855  * \param conf     SSL configuration to use
856  *
857  * \return         0 if successful, or MBEDTLS_ERR_SSL_ALLOC_FAILED if
858  *                 memory allocation failed
859  */
860 int mbedtls_ssl_setup( mbedtls_ssl_context *ssl,
861                        const mbedtls_ssl_config *conf );
862 
863 /**
864  * \brief          Reset an already initialized SSL context for re-use
865  *                 while retaining application-set variables, function
866  *                 pointers and data.
867  *
868  * \param ssl      SSL context
869  * \return         0 if successful, or POLASSL_ERR_SSL_MALLOC_FAILED,
870                    MBEDTLS_ERR_SSL_HW_ACCEL_FAILED or
871  *                 MBEDTLS_ERR_SSL_COMPRESSION_FAILED
872  */
873 int mbedtls_ssl_session_reset( mbedtls_ssl_context *ssl );
874 
875 /**
876  * \brief          Set the current endpoint type
877  *
878  * \param conf     SSL configuration
879  * \param endpoint must be MBEDTLS_SSL_IS_CLIENT or MBEDTLS_SSL_IS_SERVER
880  */
881 void mbedtls_ssl_conf_endpoint( mbedtls_ssl_config *conf, int endpoint );
882 
883 /**
884  * \brief           Set the transport type (TLS or DTLS).
885  *                  Default: TLS
886  *
887  * \note            For DTLS, you must either provide a recv callback that
888  *                  doesn't block, or one that handles timeouts, see
889  *                  \c mbedtls_ssl_set_bio(). You also need to provide timer
890  *                  callbacks with \c mbedtls_ssl_set_timer_cb().
891  *
892  * \param conf      SSL configuration
893  * \param transport transport type:
894  *                  MBEDTLS_SSL_TRANSPORT_STREAM for TLS,
895  *                  MBEDTLS_SSL_TRANSPORT_DATAGRAM for DTLS.
896  */
897 void mbedtls_ssl_conf_transport( mbedtls_ssl_config *conf, int transport );
898 
899 /**
900  * \brief          Set the certificate verification mode
901  *                 Default: NONE on server, REQUIRED on client
902  *
903  * \param conf     SSL configuration
904  * \param authmode can be:
905  *
906  *  MBEDTLS_SSL_VERIFY_NONE:      peer certificate is not checked
907  *                        (default on server)
908  *                        (insecure on client)
909  *
910  *  MBEDTLS_SSL_VERIFY_OPTIONAL:  peer certificate is checked, however the
911  *                        handshake continues even if verification failed;
912  *                        mbedtls_ssl_get_verify_result() can be called after the
913  *                        handshake is complete.
914  *
915  *  MBEDTLS_SSL_VERIFY_REQUIRED:  peer *must* present a valid certificate,
916  *                        handshake is aborted if verification failed.
917  *
918  * \note On client, MBEDTLS_SSL_VERIFY_REQUIRED is the recommended mode.
919  * With MBEDTLS_SSL_VERIFY_OPTIONAL, the user needs to call mbedtls_ssl_get_verify_result() at
920  * the right time(s), which may not be obvious, while REQUIRED always perform
921  * the verification as soon as possible. For example, REQUIRED was protecting
922  * against the "triple handshake" attack even before it was found.
923  */
924 void mbedtls_ssl_conf_authmode( mbedtls_ssl_config *conf, int authmode );
925 
926 #if defined(MBEDTLS_X509_CRT_PARSE_C)
927 /**
928  * \brief          Set the verification callback (Optional).
929  *
930  *                 If set, the verify callback is called for each
931  *                 certificate in the chain. For implementation
932  *                 information, please see \c x509parse_verify()
933  *
934  * \param conf     SSL configuration
935  * \param f_vrfy   verification function
936  * \param p_vrfy   verification parameter
937  */
938 void mbedtls_ssl_conf_verify( mbedtls_ssl_config *conf,
939                      int (*f_vrfy)(void *, mbedtls_x509_crt *, int, uint32_t *),
940                      void *p_vrfy );
941 #endif /* MBEDTLS_X509_CRT_PARSE_C */
942 
943 /**
944  * \brief          Set the random number generator callback
945  *
946  * \param conf     SSL configuration
947  * \param f_rng    RNG function
948  * \param p_rng    RNG parameter
949  */
950 void mbedtls_ssl_conf_rng( mbedtls_ssl_config *conf,
951                   int (*f_rng)(void *, unsigned char *, size_t),
952                   void *p_rng );
953 
954 /**
955  * \brief          Set the debug callback
956  *
957  *                 The callback has the following argument:
958  *                 void *           opaque context for the callback
959  *                 int              debug level
960  *                 const char *     file name
961  *                 int              line number
962  *                 const char *     message
963  *
964  * \param conf     SSL configuration
965  * \param f_dbg    debug function
966  * \param p_dbg    debug parameter
967  */
968 void mbedtls_ssl_conf_dbg( mbedtls_ssl_config *conf,
969                   void (*f_dbg)(void *, int, const char *, int, const char *),
970                   void  *p_dbg );
971 
972 /**
973  * \brief          Set the underlying BIO callbacks for write, read and
974  *                 read-with-timeout.
975  *
976  * \param ssl      SSL context
977  * \param p_bio    parameter (context) shared by BIO callbacks
978  * \param f_send   write callback
979  * \param f_recv   read callback
980  * \param f_recv_timeout blocking read callback with timeout.
981  *                 The last argument is the timeout in milliseconds,
982  *                 0 means no timeout (block forever until a message comes)
983  *
984  * \note           One of f_recv or f_recv_timeout can be NULL, in which case
985  *                 the other is used. If both are non-NULL, f_recv_timeout is
986  *                 used and f_recv is ignored (as if it were NULL).
987  *
988  * \note           The two most common use cases are:
989  *                 - non-blocking I/O, f_recv != NULL, f_recv_timeout == NULL
990  *                 - blocking I/O, f_recv == NULL, f_recv_timout != NULL
991  *
992  * \note           For DTLS, you need to provide either a non-NULL
993  *                 f_recv_timeout callback, or a f_recv that doesn't block.
994  */
995 void mbedtls_ssl_set_bio( mbedtls_ssl_context *ssl,
996         void *p_bio,
997         int (*f_send)(void *, const unsigned char *, size_t),
998         int (*f_recv)(void *, unsigned char *, size_t),
999         int (*f_recv_timeout)(void *, unsigned char *, size_t, uint32_t) );
1000 
1001 /**
1002  * \brief          Set the timeout period for mbedtls_ssl_read()
1003  *                 (Default: no timeout.)
1004  *
1005  * \param conf     SSL configuration context
1006  * \param timeout  Timeout value in milliseconds.
1007  *                 Use 0 for no timeout (default).
1008  *
1009  * \note           With blocking I/O, this will only work if a non-NULL
1010  *                 \c f_recv_timeout was set with \c mbedtls_ssl_set_bio().
1011  *                 With non-blocking I/O, this will only work if timer
1012  *                 callbacks were set with \c mbedtls_ssl_set_timer_cb().
1013  *
1014  * \note           With non-blocking I/O, you may also skip this function
1015  *                 altogether and handle timeouts at the application layer.
1016  */
1017 void mbedtls_ssl_conf_read_timeout( mbedtls_ssl_config *conf, uint32_t timeout );
1018 
1019 /**
1020  * \brief          Set the timer callbacks
1021  *                 (Mandatory for DTLS.)
1022  *
1023  * \param ssl      SSL context
1024  * \param p_timer  parameter (context) shared by timer callback
1025  * \param f_set_timer   set timer callback
1026  *                 Accepts an intermediate and a final delay in milliseconcs
1027  *                 If the final delay is 0, cancels the running timer.
1028  * \param f_get_timer   get timer callback. Must return:
1029  *                 -1 if cancelled
1030  *                 0 if none of the delays is expired
1031  *                 1 if the intermediate delay only is expired
1032  *                 2 if the final delay is expired
1033  */
1034 void mbedtls_ssl_set_timer_cb( mbedtls_ssl_context *ssl,
1035                                void *p_timer,
1036                                void (*f_set_timer)(void *, uint32_t int_ms, uint32_t fin_ms),
1037                                int (*f_get_timer)(void *) );
1038 
1039 /**
1040  * \brief           Callback type: generate and write session ticket
1041  *
1042  * \note            This describes what a callback implementation should do.
1043  *                  This callback should generate and encrypted and
1044  *                  authenticated ticket for the session and write it to the
1045  *                  output buffer. Here, ticket means the opaque ticket part
1046  *                  of the NewSessionTicket structure of RFC 5077.
1047  *
1048  * \param p_ticket  Context for the callback
1049  * \param session   SSL session to bo written in the ticket
1050  * \param start     Start of the outpur buffer
1051  * \param end       End of the output buffer
1052  * \param tlen      On exit, holds the length written
1053  * \param lifetime  On exit, holds the lifetime of the ticket in seconds
1054  *
1055  * \return          0 if successful, or
1056  *                  a specific MBEDTLS_ERR_XXX code.
1057  */
1058 typedef int mbedtls_ssl_ticket_write_t( void *p_ticket,
1059                                         const mbedtls_ssl_session *session,
1060                                         unsigned char *start,
1061                                         const unsigned char *end,
1062                                         size_t *tlen,
1063                                         uint32_t *lifetime );
1064 
1065 #if defined(MBEDTLS_SSL_EXPORT_KEYS)
1066 /**
1067  * \brief           Callback type: Export key block and master secret
1068  *
1069  * \note            This is required for certain uses of TLS, e.g. EAP-TLS
1070  *                  (RFC 5216) and Thread. The key pointers are ephemeral and
1071  *                  therefore must not be stored. The master secret and keys
1072  *                  should not be used directly except as an input to a key
1073  *                  derivation function.
1074  *
1075  * \param p_expkey  Context for the callback
1076  * \param ms        Pointer to master secret (fixed length: 48 bytes)
1077  * \param kb        Pointer to key block, see RFC 5246 section 6.3
1078  *                  (variable length: 2 * maclen + 2 * keylen + 2 * ivlen).
1079  * \param maclen    MAC length
1080  * \param keylen    Key length
1081  * \param ivlen     IV length
1082  *
1083  * \return          0 if successful, or
1084  *                  a specific MBEDTLS_ERR_XXX code.
1085  */
1086 typedef int mbedtls_ssl_export_keys_t( void *p_expkey,
1087                                 const unsigned char *ms,
1088                                 const unsigned char *kb,
1089                                 size_t maclen,
1090                                 size_t keylen,
1091                                 size_t ivlen );
1092 #endif /* MBEDTLS_SSL_EXPORT_KEYS */
1093 
1094 /**
1095  * \brief           Callback type: parse and load session ticket
1096  *
1097  * \note            This describes what a callback implementation should do.
1098  *                  This callback should parse a session ticket as generated
1099  *                  by the corresponding mbedtls_ssl_ticket_write_t function,
1100  *                  and, if the ticket is authentic and valid, load the
1101  *                  session.
1102  *
1103  * \note            The implementation is allowed to modify the first len
1104  *                  bytes of the input buffer, eg to use it as a temporary
1105  *                  area for the decrypted ticket contents.
1106  *
1107  * \param p_ticket  Context for the callback
1108  * \param session   SSL session to be loaded
1109  * \param buf       Start of the buffer containing the ticket
1110  * \param len       Length of the ticket.
1111  *
1112  * \return          0 if successful, or
1113  *                  MBEDTLS_ERR_SSL_INVALID_MAC if not authentic, or
1114  *                  MBEDTLS_ERR_SSL_SESSION_TICKET_EXPIRED if expired, or
1115  *                  any other non-zero code for other failures.
1116  */
1117 typedef int mbedtls_ssl_ticket_parse_t( void *p_ticket,
1118                                         mbedtls_ssl_session *session,
1119                                         unsigned char *buf,
1120                                         size_t len );
1121 
1122 #if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_SRV_C)
1123 /**
1124  * \brief           Configure SSL session ticket callbacks (server only).
1125  *                  (Default: none.)
1126  *
1127  * \note            On server, session tickets are enabled by providing
1128  *                  non-NULL callbacks.
1129  *
1130  * \note            On client, use \c mbedtls_ssl_conf_session_tickets().
1131  *
1132  * \param conf      SSL configuration context
1133  * \param f_ticket_write    Callback for writing a ticket
1134  * \param f_ticket_parse    Callback for parsing a ticket
1135  * \param p_ticket          Context shared by the two callbacks
1136  */
1137 void mbedtls_ssl_conf_session_tickets_cb( mbedtls_ssl_config *conf,
1138         mbedtls_ssl_ticket_write_t *f_ticket_write,
1139         mbedtls_ssl_ticket_parse_t *f_ticket_parse,
1140         void *p_ticket );
1141 #endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_SRV_C */
1142 
1143 #if defined(MBEDTLS_SSL_EXPORT_KEYS)
1144 /**
1145  * \brief           Configure key export callback.
1146  *                  (Default: none.)
1147  *
1148  * \note            See \c mbedtls_ssl_export_keys_t.
1149  *
1150  * \param conf      SSL configuration context
1151  * \param f_export_keys     Callback for exporting keys
1152  * \param p_export_keys     Context for the callback
1153  */
1154 void mbedtls_ssl_conf_export_keys_cb( mbedtls_ssl_config *conf,
1155         mbedtls_ssl_export_keys_t *f_export_keys,
1156         void *p_export_keys );
1157 #endif /* MBEDTLS_SSL_EXPORT_KEYS */
1158 
1159 /**
1160  * \brief          Callback type: generate a cookie
1161  *
1162  * \param ctx      Context for the callback
1163  * \param p        Buffer to write to,
1164  *                 must be updated to point right after the cookie
1165  * \param end      Pointer to one past the end of the output buffer
1166  * \param info     Client ID info that was passed to
1167  *                 \c mbedtls_ssl_set_client_transport_id()
1168  * \param ilen     Length of info in bytes
1169  *
1170  * \return         The callback must return 0 on success,
1171  *                 or a negative error code.
1172  */
1173 typedef int mbedtls_ssl_cookie_write_t( void *ctx,
1174                                 unsigned char **p, unsigned char *end,
1175                                 const unsigned char *info, size_t ilen );
1176 
1177 /**
1178  * \brief          Callback type: verify a cookie
1179  *
1180  * \param ctx      Context for the callback
1181  * \param cookie   Cookie to verify
1182  * \param clen     Length of cookie
1183  * \param info     Client ID info that was passed to
1184  *                 \c mbedtls_ssl_set_client_transport_id()
1185  * \param ilen     Length of info in bytes
1186  *
1187  * \return         The callback must return 0 if cookie is valid,
1188  *                 or a negative error code.
1189  */
1190 typedef int mbedtls_ssl_cookie_check_t( void *ctx,
1191                                 const unsigned char *cookie, size_t clen,
1192                                 const unsigned char *info, size_t ilen );
1193 
1194 #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) && defined(MBEDTLS_SSL_SRV_C)
1195 /**
1196  * \brief           Register callbacks for DTLS cookies
1197  *                  (Server only. DTLS only.)
1198  *
1199  *                  Default: dummy callbacks that fail, in order to force you to
1200  *                  register working callbacks (and initialize their context).
1201  *
1202  *                  To disable HelloVerifyRequest, register NULL callbacks.
1203  *
1204  * \warning         Disabling hello verification allows your server to be used
1205  *                  for amplification in DoS attacks against other hosts.
1206  *                  Only disable if you known this can't happen in your
1207  *                  particular environment.
1208  *
1209  * \note            See comments on \c mbedtls_ssl_handshake() about handling
1210  *                  the MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED that is expected
1211  *                  on the first handshake attempt when this is enabled.
1212  *
1213  * \note            This is also necessary to handle client reconnection from
1214  *                  the same port as described in RFC 6347 section 4.2.8 (only
1215  *                  the variant with cookies is supported currently). See
1216  *                  comments on \c mbedtls_ssl_read() for details.
1217  *
1218  * \param conf              SSL configuration
1219  * \param f_cookie_write    Cookie write callback
1220  * \param f_cookie_check    Cookie check callback
1221  * \param p_cookie          Context for both callbacks
1222  */
1223 void mbedtls_ssl_conf_dtls_cookies( mbedtls_ssl_config *conf,
1224                            mbedtls_ssl_cookie_write_t *f_cookie_write,
1225                            mbedtls_ssl_cookie_check_t *f_cookie_check,
1226                            void *p_cookie );
1227 
1228 /**
1229  * \brief          Set client's transport-level identification info.
1230  *                 (Server only. DTLS only.)
1231  *
1232  *                 This is usually the IP address (and port), but could be
1233  *                 anything identify the client depending on the underlying
1234  *                 network stack. Used for HelloVerifyRequest with DTLS.
1235  *                 This is *not* used to route the actual packets.
1236  *
1237  * \param ssl      SSL context
1238  * \param info     Transport-level info identifying the client (eg IP + port)
1239  * \param ilen     Length of info in bytes
1240  *
1241  * \note           An internal copy is made, so the info buffer can be reused.
1242  *
1243  * \return         0 on success,
1244  *                 MBEDTLS_ERR_SSL_BAD_INPUT_DATA if used on client,
1245  *                 MBEDTLS_ERR_SSL_ALLOC_FAILED if out of memory.
1246  */
1247 int mbedtls_ssl_set_client_transport_id( mbedtls_ssl_context *ssl,
1248                                  const unsigned char *info,
1249                                  size_t ilen );
1250 
1251 #endif /* MBEDTLS_SSL_DTLS_HELLO_VERIFY && MBEDTLS_SSL_SRV_C */
1252 
1253 #if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
1254 /**
1255  * \brief          Enable or disable anti-replay protection for DTLS.
1256  *                 (DTLS only, no effect on TLS.)
1257  *                 Default: enabled.
1258  *
1259  * \param conf     SSL configuration
1260  * \param mode     MBEDTLS_SSL_ANTI_REPLAY_ENABLED or MBEDTLS_SSL_ANTI_REPLAY_DISABLED.
1261  *
1262  * \warning        Disabling this is a security risk unless the application
1263  *                 protocol handles duplicated packets in a safe way. You
1264  *                 should not disable this without careful consideration.
1265  *                 However, if your application already detects duplicated
1266  *                 packets and needs information about them to adjust its
1267  *                 transmission strategy, then you'll want to disable this.
1268  */
1269 void mbedtls_ssl_conf_dtls_anti_replay( mbedtls_ssl_config *conf, char mode );
1270 #endif /* MBEDTLS_SSL_DTLS_ANTI_REPLAY */
1271 
1272 #if defined(MBEDTLS_SSL_DTLS_BADMAC_LIMIT)
1273 /**
1274  * \brief          Set a limit on the number of records with a bad MAC
1275  *                 before terminating the connection.
1276  *                 (DTLS only, no effect on TLS.)
1277  *                 Default: 0 (disabled).
1278  *
1279  * \param conf     SSL configuration
1280  * \param limit    Limit, or 0 to disable.
1281  *
1282  * \note           If the limit is N, then the connection is terminated when
1283  *                 the Nth non-authentic record is seen.
1284  *
1285  * \note           Records with an invalid header are not counted, only the
1286  *                 ones going through the authentication-decryption phase.
1287  *
1288  * \note           This is a security trade-off related to the fact that it's
1289  *                 often relatively easy for an active attacker ot inject UDP
1290  *                 datagrams. On one hand, setting a low limit here makes it
1291  *                 easier for such an attacker to forcibly terminated a
1292  *                 connection. On the other hand, a high limit or no limit
1293  *                 might make us waste resources checking authentication on
1294  *                 many bogus packets.
1295  */
1296 void mbedtls_ssl_conf_dtls_badmac_limit( mbedtls_ssl_config *conf, unsigned limit );
1297 #endif /* MBEDTLS_SSL_DTLS_BADMAC_LIMIT */
1298 
1299 #if defined(MBEDTLS_SSL_PROTO_DTLS)
1300 /**
1301  * \brief          Set retransmit timeout values for the DTLS handshale.
1302  *                 (DTLS only, no effect on TLS.)
1303  *
1304  * \param conf     SSL configuration
1305  * \param min      Initial timeout value in milliseconds.
1306  *                 Default: 1000 (1 second).
1307  * \param max      Maximum timeout value in milliseconds.
1308  *                 Default: 60000 (60 seconds).
1309  *
1310  * \note           Default values are from RFC 6347 section 4.2.4.1.
1311  *
1312  * \note           Higher values for initial timeout may increase average
1313  *                 handshake latency. Lower values may increase the risk of
1314  *                 network congestion by causing more retransmissions.
1315  */
1316 void mbedtls_ssl_conf_handshake_timeout( mbedtls_ssl_config *conf, uint32_t min, uint32_t max );
1317 #endif /* MBEDTLS_SSL_PROTO_DTLS */
1318 
1319 #if defined(MBEDTLS_SSL_SRV_C)
1320 /**
1321  * \brief          Set the session cache callbacks (server-side only)
1322  *                 If not set, no session resuming is done (except if session
1323  *                 tickets are enabled too).
1324  *
1325  *                 The session cache has the responsibility to check for stale
1326  *                 entries based on timeout. See RFC 5246 for recommendations.
1327  *
1328  *                 Warning: session.peer_cert is cleared by the SSL/TLS layer on
1329  *                 connection shutdown, so do not cache the pointer! Either set
1330  *                 it to NULL or make a full copy of the certificate.
1331  *
1332  *                 The get callback is called once during the initial handshake
1333  *                 to enable session resuming. The get function has the
1334  *                 following parameters: (void *parameter, mbedtls_ssl_session *session)
1335  *                 If a valid entry is found, it should fill the master of
1336  *                 the session object with the cached values and return 0,
1337  *                 return 1 otherwise. Optionally peer_cert can be set as well
1338  *                 if it is properly present in cache entry.
1339  *
1340  *                 The set callback is called once during the initial handshake
1341  *                 to enable session resuming after the entire handshake has
1342  *                 been finished. The set function has the following parameters:
1343  *                 (void *parameter, const mbedtls_ssl_session *session). The function
1344  *                 should create a cache entry for future retrieval based on
1345  *                 the data in the session structure and should keep in mind
1346  *                 that the mbedtls_ssl_session object presented (and all its referenced
1347  *                 data) is cleared by the SSL/TLS layer when the connection is
1348  *                 terminated. It is recommended to add metadata to determine if
1349  *                 an entry is still valid in the future. Return 0 if
1350  *                 successfully cached, return 1 otherwise.
1351  *
1352  * \param conf           SSL configuration
1353  * \param p_cache        parmater (context) for both callbacks
1354  * \param f_get_cache    session get callback
1355  * \param f_set_cache    session set callback
1356  */
1357 void mbedtls_ssl_conf_session_cache( mbedtls_ssl_config *conf,
1358         void *p_cache,
1359         int (*f_get_cache)(void *, mbedtls_ssl_session *),
1360         int (*f_set_cache)(void *, const mbedtls_ssl_session *) );
1361 #endif /* MBEDTLS_SSL_SRV_C */
1362 
1363 #if defined(MBEDTLS_SSL_CLI_C)
1364 /**
1365  * \brief          Request resumption of session (client-side only)
1366  *                 Session data is copied from presented session structure.
1367  *
1368  * \param ssl      SSL context
1369  * \param session  session context
1370  *
1371  * \return         0 if successful,
1372  *                 MBEDTLS_ERR_SSL_ALLOC_FAILED if memory allocation failed,
1373  *                 MBEDTLS_ERR_SSL_BAD_INPUT_DATA if used server-side or
1374  *                 arguments are otherwise invalid
1375  *
1376  * \sa             mbedtls_ssl_get_session()
1377  */
1378 int mbedtls_ssl_set_session( mbedtls_ssl_context *ssl, const mbedtls_ssl_session *session );
1379 #endif /* MBEDTLS_SSL_CLI_C */
1380 
1381 /**
1382  * \brief               Set the list of allowed ciphersuites and the preference
1383  *                      order. First in the list has the highest preference.
1384  *                      (Overrides all version specific lists)
1385  *
1386  *                      The ciphersuites array is not copied, and must remain
1387  *                      valid for the lifetime of the ssl_config.
1388  *
1389  *                      Note: The server uses its own preferences
1390  *                      over the preference of the client unless
1391  *                      MBEDTLS_SSL_SRV_RESPECT_CLIENT_PREFERENCE is defined!
1392  *
1393  * \param conf          SSL configuration
1394  * \param ciphersuites  0-terminated list of allowed ciphersuites
1395  */
1396 void mbedtls_ssl_conf_ciphersuites( mbedtls_ssl_config *conf,
1397                                    const int *ciphersuites );
1398 
1399 /**
1400  * \brief               Set the list of allowed ciphersuites and the
1401  *                      preference order for a specific version of the protocol.
1402  *                      (Only useful on the server side)
1403  *
1404  *                      The ciphersuites array is not copied, and must remain
1405  *                      valid for the lifetime of the ssl_config.
1406  *
1407  * \param conf          SSL configuration
1408  * \param ciphersuites  0-terminated list of allowed ciphersuites
1409  * \param major         Major version number (only MBEDTLS_SSL_MAJOR_VERSION_3
1410  *                      supported)
1411  * \param minor         Minor version number (MBEDTLS_SSL_MINOR_VERSION_0,
1412  *                      MBEDTLS_SSL_MINOR_VERSION_1 and MBEDTLS_SSL_MINOR_VERSION_2,
1413  *                      MBEDTLS_SSL_MINOR_VERSION_3 supported)
1414  *
1415  * \note                With DTLS, use MBEDTLS_SSL_MINOR_VERSION_2 for DTLS 1.0
1416  *                      and MBEDTLS_SSL_MINOR_VERSION_3 for DTLS 1.2
1417  */
1418 void mbedtls_ssl_conf_ciphersuites_for_version( mbedtls_ssl_config *conf,
1419                                        const int *ciphersuites,
1420                                        int major, int minor );
1421 
1422 #if defined(MBEDTLS_X509_CRT_PARSE_C)
1423 /**
1424  * \brief          Set the X.509 security profile used for verification
1425  *
1426  * \note           The restrictions are enforced for all certificates in the
1427  *                 chain. However, signatures in the handshake are not covered
1428  *                 by this setting but by \b mbedtls_ssl_conf_sig_hashes().
1429  *
1430  * \param conf     SSL configuration
1431  * \param profile  Profile to use
1432  */
1433 void mbedtls_ssl_conf_cert_profile( mbedtls_ssl_config *conf,
1434                                     const mbedtls_x509_crt_profile *profile );
1435 
1436 /**
1437  * \brief          Set the data required to verify peer certificate
1438  *
1439  * \param conf     SSL configuration
1440  * \param ca_chain trusted CA chain (meaning all fully trusted top-level CAs)
1441  * \param ca_crl   trusted CA CRLs
1442  */
1443 void mbedtls_ssl_conf_ca_chain( mbedtls_ssl_config *conf,
1444                                mbedtls_x509_crt *ca_chain,
1445                                mbedtls_x509_crl *ca_crl );
1446 
1447 /**
1448  * \brief          Set own certificate chain and private key
1449  *
1450  * \note           own_cert should contain in order from the bottom up your
1451  *                 certificate chain. The top certificate (self-signed)
1452  *                 can be omitted.
1453  *
1454  * \note           On server, this function can be called multiple times to
1455  *                 provision more than one cert/key pair (eg one ECDSA, one
1456  *                 RSA with SHA-256, one RSA with SHA-1). An adequate
1457  *                 certificate will be selected according to the client's
1458  *                 advertised capabilities. In case mutliple certificates are
1459  *                 adequate, preference is given to the one set by the first
1460  *                 call to this function, then second, etc.
1461  *
1462  * \note           On client, only the first call has any effect.
1463  *
1464  * \param conf     SSL configuration
1465  * \param own_cert own public certificate chain
1466  * \param pk_key   own private key
1467  *
1468  * \return         0 on success or MBEDTLS_ERR_SSL_ALLOC_FAILED
1469  */
1470 int mbedtls_ssl_conf_own_cert( mbedtls_ssl_config *conf,
1471                               mbedtls_x509_crt *own_cert,
1472                               mbedtls_pk_context *pk_key );
1473 #endif /* MBEDTLS_X509_CRT_PARSE_C */
1474 
1475 #if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED)
1476 /**
1477  * \brief          Set the Pre Shared Key (PSK) and the expected identity name
1478  *
1479  * \note           This is mainly useful for clients. Servers will usually
1480  *                 want to use \c mbedtls_ssl_conf_psk_cb() instead.
1481  *
1482  * \param conf     SSL configuration
1483  * \param psk      pointer to the pre-shared key
1484  * \param psk_len  pre-shared key length
1485  * \param psk_identity      pointer to the pre-shared key identity
1486  * \param psk_identity_len  identity key length
1487  *
1488  * \return         0 if successful or MBEDTLS_ERR_SSL_ALLOC_FAILED
1489  */
1490 int mbedtls_ssl_conf_psk( mbedtls_ssl_config *conf,
1491                 const unsigned char *psk, size_t psk_len,
1492                 const unsigned char *psk_identity, size_t psk_identity_len );
1493 
1494 
1495 /**
1496  * \brief          Set the Pre Shared Key (PSK) for the current handshake
1497  *
1498  * \note           This should only be called inside the PSK callback,
1499  *                 ie the function passed to \c mbedtls_ssl_conf_psk_cb().
1500  *
1501  * \param ssl      SSL context
1502  * \param psk      pointer to the pre-shared key
1503  * \param psk_len  pre-shared key length
1504  *
1505  * \return         0 if successful or MBEDTLS_ERR_SSL_ALLOC_FAILED
1506  */
1507 int mbedtls_ssl_set_hs_psk( mbedtls_ssl_context *ssl,
1508                             const unsigned char *psk, size_t psk_len );
1509 
1510 /**
1511  * \brief          Set the PSK callback (server-side only).
1512  *
1513  *                 If set, the PSK callback is called for each
1514  *                 handshake where a PSK ciphersuite was negotiated.
1515  *                 The caller provides the identity received and wants to
1516  *                 receive the actual PSK data and length.
1517  *
1518  *                 The callback has the following parameters: (void *parameter,
1519  *                 mbedtls_ssl_context *ssl, const unsigned char *psk_identity,
1520  *                 size_t identity_len)
1521  *                 If a valid PSK identity is found, the callback should use
1522  *                 \c mbedtls_ssl_set_hs_psk() on the ssl context to set the
1523  *                 correct PSK and return 0.
1524  *                 Any other return value will result in a denied PSK identity.
1525  *
1526  * \note           If you set a PSK callback using this function, then you
1527  *                 don't need to set a PSK key and identity using
1528  *                 \c mbedtls_ssl_conf_psk().
1529  *
1530  * \param conf     SSL configuration
1531  * \param f_psk    PSK identity function
1532  * \param p_psk    PSK identity parameter
1533  */
1534 void mbedtls_ssl_conf_psk_cb( mbedtls_ssl_config *conf,
1535                      int (*f_psk)(void *, mbedtls_ssl_context *, const unsigned char *,
1536                                   size_t),
1537                      void *p_psk );
1538 #endif /* MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */
1539 
1540 #if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_SSL_SRV_C)
1541 /**
1542  * \brief          Set the Diffie-Hellman public P and G values,
1543  *                 read as hexadecimal strings (server-side only)
1544  *                 (Default: MBEDTLS_DHM_RFC5114_MODP_2048_[PG])
1545  *
1546  * \param conf     SSL configuration
1547  * \param dhm_P    Diffie-Hellman-Merkle modulus
1548  * \param dhm_G    Diffie-Hellman-Merkle generator
1549  *
1550  * \return         0 if successful
1551  */
1552 int mbedtls_ssl_conf_dh_param( mbedtls_ssl_config *conf, const char *dhm_P, const char *dhm_G );
1553 
1554 /**
1555  * \brief          Set the Diffie-Hellman public P and G values,
1556  *                 read from existing context (server-side only)
1557  *
1558  * \param conf     SSL configuration
1559  * \param dhm_ctx  Diffie-Hellman-Merkle context
1560  *
1561  * \return         0 if successful
1562  */
1563 int mbedtls_ssl_conf_dh_param_ctx( mbedtls_ssl_config *conf, mbedtls_dhm_context *dhm_ctx );
1564 #endif /* MBEDTLS_DHM_C && defined(MBEDTLS_SSL_SRV_C) */
1565 
1566 #if defined(MBEDTLS_DHM_C) && defined(MBEDTLS_SSL_CLI_C)
1567 /**
1568  * \brief          Set the minimum length for Diffie-Hellman parameters.
1569  *                 (Client-side only.)
1570  *                 (Default: 1024 bits.)
1571  *
1572  * \param conf     SSL configuration
1573  * \param bitlen   Minimum bit length of the DHM prime
1574  */
1575 void mbedtls_ssl_conf_dhm_min_bitlen( mbedtls_ssl_config *conf,
1576                                       unsigned int bitlen );
1577 #endif /* MBEDTLS_DHM_C && MBEDTLS_SSL_CLI_C */
1578 
1579 #if defined(MBEDTLS_ECP_C)
1580 /**
1581  * \brief          Set the allowed curves in order of preference.
1582  *                 (Default: all defined curves.)
1583  *
1584  *                 On server: this only affects selection of the ECDHE curve;
1585  *                 the curves used for ECDH and ECDSA are determined by the
1586  *                 list of available certificates instead.
1587  *
1588  *                 On client: this affects the list of curves offered for any
1589  *                 use. The server can override our preference order.
1590  *
1591  *                 Both sides: limits the set of curves accepted for use in
1592  *                 ECDHE and in the peer's end-entity certificate.
1593  *
1594  * \note           This has no influence on which curves are allowed inside the
1595  *                 certificate chains, see \c mbedtls_ssl_conf_cert_profile()
1596  *                 for that. For the end-entity certificate however, the key
1597  *                 will be accepted only if it is allowed both by this list
1598  *                 and by the cert profile.
1599  *
1600  * \note           This list should be ordered by decreasing preference
1601  *                 (preferred curve first).
1602  *
1603  * \param conf     SSL configuration
1604  * \param curves   Ordered list of allowed curves,
1605  *                 terminated by MBEDTLS_ECP_DP_NONE.
1606  */
1607 void mbedtls_ssl_conf_curves( mbedtls_ssl_config *conf,
1608                               const mbedtls_ecp_group_id *curves );
1609 #endif /* MBEDTLS_ECP_C */
1610 
1611 #if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
1612 /**
1613  * \brief          Set the allowed hashes for signatures during the handshake.
1614  *                 (Default: all available hashes except MD5.)
1615  *
1616  * \note           This only affects which hashes are offered and can be used
1617  *                 for signatures during the handshake. Hashes for message
1618  *                 authentication and the TLS PRF are controlled by the
1619  *                 ciphersuite, see \c mbedtls_ssl_conf_ciphersuites(). Hashes
1620  *                 used for certificate signature are controlled by the
1621  *                 verification profile, see \c mbedtls_ssl_conf_cert_profile().
1622  *
1623  * \note           This list should be ordered by decreasing preference
1624  *                 (preferred hash first).
1625  *
1626  * \param conf     SSL configuration
1627  * \param hashes   Ordered list of allowed signature hashes,
1628  *                 terminated by \c MBEDTLS_MD_NONE.
1629  */
1630 void mbedtls_ssl_conf_sig_hashes( mbedtls_ssl_config *conf,
1631                                   const int *hashes );
1632 #endif /* MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
1633 
1634 #if defined(MBEDTLS_X509_CRT_PARSE_C)
1635 /**
1636  * \brief          Set hostname for ServerName TLS extension
1637  *                 (client-side only)
1638  *
1639  *
1640  * \param ssl      SSL context
1641  * \param hostname the server hostname
1642  *
1643  * \return         0 if successful or MBEDTLS_ERR_SSL_ALLOC_FAILED
1644  */
1645 int mbedtls_ssl_set_hostname( mbedtls_ssl_context *ssl, const char *hostname );
1646 #endif /* MBEDTLS_X509_CRT_PARSE_C */
1647 
1648 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
1649 /**
1650  * \brief          Set own certificate and key for the current handshake
1651  *
1652  * \note           Same as \c mbedtls_ssl_conf_own_cert() but for use within
1653  *                 the SNI callback.
1654  *
1655  * \param ssl      SSL context
1656  * \param own_cert own public certificate chain
1657  * \param pk_key   own private key
1658  *
1659  * \return         0 on success or MBEDTLS_ERR_SSL_ALLOC_FAILED
1660  */
1661 int mbedtls_ssl_set_hs_own_cert( mbedtls_ssl_context *ssl,
1662                                  mbedtls_x509_crt *own_cert,
1663                                  mbedtls_pk_context *pk_key );
1664 
1665 /**
1666  * \brief          Set the data required to verify peer certificate for the
1667  *                 current handshake
1668  *
1669  * \note           Same as \c mbedtls_ssl_conf_ca_chain() but for use within
1670  *                 the SNI callback.
1671  *
1672  * \param ssl      SSL context
1673  * \param ca_chain trusted CA chain (meaning all fully trusted top-level CAs)
1674  * \param ca_crl   trusted CA CRLs
1675  */
1676 void mbedtls_ssl_set_hs_ca_chain( mbedtls_ssl_context *ssl,
1677                                   mbedtls_x509_crt *ca_chain,
1678                                   mbedtls_x509_crl *ca_crl );
1679 
1680 /**
1681  * \brief          Set authmode for the current handshake.
1682  *
1683  * \note           Same as \c mbedtls_ssl_conf_authmode() but for use within
1684  *                 the SNI callback.
1685  *
1686  * \param ssl      SSL context
1687  * \param authmode MBEDTLS_SSL_VERIFY_NONE, MBEDTLS_SSL_VERIFY_OPTIONAL or
1688  *                 MBEDTLS_SSL_VERIFY_REQUIRED
1689  */
1690 void mbedtls_ssl_set_hs_authmode( mbedtls_ssl_context *ssl,
1691                                   int authmode );
1692 
1693 /**
1694  * \brief          Set server side ServerName TLS extension callback
1695  *                 (optional, server-side only).
1696  *
1697  *                 If set, the ServerName callback is called whenever the
1698  *                 server receives a ServerName TLS extension from the client
1699  *                 during a handshake. The ServerName callback has the
1700  *                 following parameters: (void *parameter, mbedtls_ssl_context *ssl,
1701  *                 const unsigned char *hostname, size_t len). If a suitable
1702  *                 certificate is found, the callback must set the
1703  *                 certificate(s) and key(s) to use with \c
1704  *                 mbedtls_ssl_set_hs_own_cert() (can be called repeatedly),
1705  *                 and may optionally adjust the CA and associated CRL with \c
1706  *                 mbedtls_ssl_set_hs_ca_chain() as well as the client
1707  *                 authentication mode with \c mbedtls_ssl_set_hs_authmode(),
1708  *                 then must return 0. If no matching name is found, the
1709  *                 callback must either set a default cert, or
1710  *                 return non-zero to abort the handshake at this point.
1711  *
1712  * \param conf     SSL configuration
1713  * \param f_sni    verification function
1714  * \param p_sni    verification parameter
1715  */
1716 void mbedtls_ssl_conf_sni( mbedtls_ssl_config *conf,
1717                   int (*f_sni)(void *, mbedtls_ssl_context *, const unsigned char *,
1718                                size_t),
1719                   void *p_sni );
1720 #endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
1721 
1722 #if defined(MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED)
1723 /**
1724  * \brief          Set the EC J-PAKE password for current handshake.
1725  *
1726  * \note           An internal copy is made, and destroyed as soon as the
1727  *                 handshake is completed, or when the SSL context is reset or
1728  *                 freed.
1729  *
1730  * \note           The SSL context needs to be already set up. The right place
1731  *                 to call this function is between \c mbedtls_ssl_setup() or
1732  *                 \c mbedtls_ssl_reset() and \c mbedtls_ssl_handshake().
1733  *
1734  * \param ssl      SSL context
1735  * \param pw       EC J-PAKE password (pre-shared secret)
1736  * \param pw_len   length of pw in bytes
1737  *
1738  * \return         0 on success, or a negative error code.
1739  */
1740 int mbedtls_ssl_set_hs_ecjpake_password( mbedtls_ssl_context *ssl,
1741                                          const unsigned char *pw,
1742                                          size_t pw_len );
1743 #endif /*MBEDTLS_KEY_EXCHANGE_ECJPAKE_ENABLED */
1744 
1745 #if defined(MBEDTLS_SSL_ALPN)
1746 /**
1747  * \brief          Set the supported Application Layer Protocols.
1748  *
1749  * \param conf     SSL configuration
1750  * \param protos   NULL-terminated list of supported protocols,
1751  *                 in decreasing preference order.
1752  *
1753  * \return         0 on success, or MBEDTLS_ERR_SSL_BAD_INPUT_DATA.
1754  */
1755 int mbedtls_ssl_conf_alpn_protocols( mbedtls_ssl_config *conf, const char **protos );
1756 
1757 /**
1758  * \brief          Get the name of the negotiated Application Layer Protocol.
1759  *                 This function should be called after the handshake is
1760  *                 completed.
1761  *
1762  * \param ssl      SSL context
1763  *
1764  * \return         Protcol name, or NULL if no protocol was negotiated.
1765  */
1766 const char *mbedtls_ssl_get_alpn_protocol( const mbedtls_ssl_context *ssl );
1767 #endif /* MBEDTLS_SSL_ALPN */
1768 
1769 /**
1770  * \brief          Set the maximum supported version sent from the client side
1771  *                 and/or accepted at the server side
1772  *                 (Default: MBEDTLS_SSL_MAX_MAJOR_VERSION, MBEDTLS_SSL_MAX_MINOR_VERSION)
1773  *
1774  * \note           This ignores ciphersuites from higher versions.
1775  *
1776  * \note           With DTLS, use MBEDTLS_SSL_MINOR_VERSION_2 for DTLS 1.0 and
1777  *                 MBEDTLS_SSL_MINOR_VERSION_3 for DTLS 1.2
1778  *
1779  * \param conf     SSL configuration
1780  * \param major    Major version number (only MBEDTLS_SSL_MAJOR_VERSION_3 supported)
1781  * \param minor    Minor version number (MBEDTLS_SSL_MINOR_VERSION_0,
1782  *                 MBEDTLS_SSL_MINOR_VERSION_1 and MBEDTLS_SSL_MINOR_VERSION_2,
1783  *                 MBEDTLS_SSL_MINOR_VERSION_3 supported)
1784  */
1785 void mbedtls_ssl_conf_max_version( mbedtls_ssl_config *conf, int major, int minor );
1786 
1787 /**
1788  * \brief          Set the minimum accepted SSL/TLS protocol version
1789  *                 (Default: TLS 1.0)
1790  *
1791  * \note           Input outside of the SSL_MAX_XXXXX_VERSION and
1792  *                 SSL_MIN_XXXXX_VERSION range is ignored.
1793  *
1794  * \note           MBEDTLS_SSL_MINOR_VERSION_0 (SSL v3) should be avoided.
1795  *
1796  * \note           With DTLS, use MBEDTLS_SSL_MINOR_VERSION_2 for DTLS 1.0 and
1797  *                 MBEDTLS_SSL_MINOR_VERSION_3 for DTLS 1.2
1798  *
1799  * \param conf     SSL configuration
1800  * \param major    Major version number (only MBEDTLS_SSL_MAJOR_VERSION_3 supported)
1801  * \param minor    Minor version number (MBEDTLS_SSL_MINOR_VERSION_0,
1802  *                 MBEDTLS_SSL_MINOR_VERSION_1 and MBEDTLS_SSL_MINOR_VERSION_2,
1803  *                 MBEDTLS_SSL_MINOR_VERSION_3 supported)
1804  */
1805 void mbedtls_ssl_conf_min_version( mbedtls_ssl_config *conf, int major, int minor );
1806 
1807 #if defined(MBEDTLS_SSL_FALLBACK_SCSV) && defined(MBEDTLS_SSL_CLI_C)
1808 /**
1809  * \brief          Set the fallback flag (client-side only).
1810  *                 (Default: MBEDTLS_SSL_IS_NOT_FALLBACK).
1811  *
1812  * \note           Set to MBEDTLS_SSL_IS_FALLBACK when preparing a fallback
1813  *                 connection, that is a connection with max_version set to a
1814  *                 lower value than the value you're willing to use. Such
1815  *                 fallback connections are not recommended but are sometimes
1816  *                 necessary to interoperate with buggy (version-intolerant)
1817  *                 servers.
1818  *
1819  * \warning        You should NOT set this to MBEDTLS_SSL_IS_FALLBACK for
1820  *                 non-fallback connections! This would appear to work for a
1821  *                 while, then cause failures when the server is upgraded to
1822  *                 support a newer TLS version.
1823  *
1824  * \param conf     SSL configuration
1825  * \param fallback MBEDTLS_SSL_IS_NOT_FALLBACK or MBEDTLS_SSL_IS_FALLBACK
1826  */
1827 void mbedtls_ssl_conf_fallback( mbedtls_ssl_config *conf, char fallback );
1828 #endif /* MBEDTLS_SSL_FALLBACK_SCSV && MBEDTLS_SSL_CLI_C */
1829 
1830 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
1831 /**
1832  * \brief           Enable or disable Encrypt-then-MAC
1833  *                  (Default: MBEDTLS_SSL_ETM_ENABLED)
1834  *
1835  * \note            This should always be enabled, it is a security
1836  *                  improvement, and should not cause any interoperability
1837  *                  issue (used only if the peer supports it too).
1838  *
1839  * \param conf      SSL configuration
1840  * \param etm       MBEDTLS_SSL_ETM_ENABLED or MBEDTLS_SSL_ETM_DISABLED
1841  */
1842 void mbedtls_ssl_conf_encrypt_then_mac( mbedtls_ssl_config *conf, char etm );
1843 #endif /* MBEDTLS_SSL_ENCRYPT_THEN_MAC */
1844 
1845 #if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
1846 /**
1847  * \brief           Enable or disable Extended Master Secret negotiation.
1848  *                  (Default: MBEDTLS_SSL_EXTENDED_MS_ENABLED)
1849  *
1850  * \note            This should always be enabled, it is a security fix to the
1851  *                  protocol, and should not cause any interoperability issue
1852  *                  (used only if the peer supports it too).
1853  *
1854  * \param conf      SSL configuration
1855  * \param ems       MBEDTLS_SSL_EXTENDED_MS_ENABLED or MBEDTLS_SSL_EXTENDED_MS_DISABLED
1856  */
1857 void mbedtls_ssl_conf_extended_master_secret( mbedtls_ssl_config *conf, char ems );
1858 #endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
1859 
1860 #if defined(MBEDTLS_ARC4_C)
1861 /**
1862  * \brief          Disable or enable support for RC4
1863  *                 (Default: MBEDTLS_SSL_ARC4_DISABLED)
1864  *
1865  * \warning        Use of RC4 in (D)TLS has been prohibited by RFC ????
1866  *                 for security reasons. Use at your own risks.
1867  *
1868  * \note           This function will likely be removed in future versions as
1869  *                 RC4 will then be disabled by default at compile time.
1870  *
1871  * \param conf     SSL configuration
1872  * \param arc4     MBEDTLS_SSL_ARC4_ENABLED or MBEDTLS_SSL_ARC4_DISABLED
1873  */
1874 void mbedtls_ssl_conf_arc4_support( mbedtls_ssl_config *conf, char arc4 );
1875 #endif /* MBEDTLS_ARC4_C */
1876 
1877 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
1878 /**
1879  * \brief          Set the maximum fragment length to emit and/or negotiate
1880  *                 (Default: MBEDTLS_SSL_MAX_CONTENT_LEN, usually 2^14 bytes)
1881  *                 (Server: set maximum fragment length to emit,
1882  *                 usually negotiated by the client during handshake
1883  *                 (Client: set maximum fragment length to emit *and*
1884  *                 negotiate with the server during handshake)
1885  *
1886  * \param conf     SSL configuration
1887  * \param mfl_code Code for maximum fragment length (allowed values:
1888  *                 MBEDTLS_SSL_MAX_FRAG_LEN_512,  MBEDTLS_SSL_MAX_FRAG_LEN_1024,
1889  *                 MBEDTLS_SSL_MAX_FRAG_LEN_2048, MBEDTLS_SSL_MAX_FRAG_LEN_4096)
1890  *
1891  * \return         0 if successful or MBEDTLS_ERR_SSL_BAD_INPUT_DATA
1892  */
1893 int mbedtls_ssl_conf_max_frag_len( mbedtls_ssl_config *conf, unsigned char mfl_code );
1894 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
1895 
1896 #if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
1897 /**
1898  * \brief          Activate negotiation of truncated HMAC
1899  *                 (Default: MBEDTLS_SSL_TRUNC_HMAC_DISABLED)
1900  *
1901  * \param conf     SSL configuration
1902  * \param truncate Enable or disable (MBEDTLS_SSL_TRUNC_HMAC_ENABLED or
1903  *                                    MBEDTLS_SSL_TRUNC_HMAC_DISABLED)
1904  */
1905 void mbedtls_ssl_conf_truncated_hmac( mbedtls_ssl_config *conf, int truncate );
1906 #endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
1907 
1908 #if defined(MBEDTLS_SSL_CBC_RECORD_SPLITTING)
1909 /**
1910  * \brief          Enable / Disable 1/n-1 record splitting
1911  *                 (Default: MBEDTLS_SSL_CBC_RECORD_SPLITTING_ENABLED)
1912  *
1913  * \note           Only affects SSLv3 and TLS 1.0, not higher versions.
1914  *                 Does not affect non-CBC ciphersuites in any version.
1915  *
1916  * \param conf     SSL configuration
1917  * \param split    MBEDTLS_SSL_CBC_RECORD_SPLITTING_ENABLED or
1918  *                 MBEDTLS_SSL_CBC_RECORD_SPLITTING_DISABLED
1919  */
1920 void mbedtls_ssl_conf_cbc_record_splitting( mbedtls_ssl_config *conf, char split );
1921 #endif /* MBEDTLS_SSL_CBC_RECORD_SPLITTING */
1922 
1923 #if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C)
1924 /**
1925  * \brief          Enable / Disable session tickets (client only).
1926  *                 (Default: MBEDTLS_SSL_SESSION_TICKETS_ENABLED.)
1927  *
1928  * \note           On server, use \c mbedtls_ssl_conf_session_tickets_cb().
1929  *
1930  * \param conf     SSL configuration
1931  * \param use_tickets   Enable or disable (MBEDTLS_SSL_SESSION_TICKETS_ENABLED or
1932  *                                         MBEDTLS_SSL_SESSION_TICKETS_DISABLED)
1933  */
1934 void mbedtls_ssl_conf_session_tickets( mbedtls_ssl_config *conf, int use_tickets );
1935 #endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_CLI_C */
1936 
1937 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1938 /**
1939  * \brief          Enable / Disable renegotiation support for connection when
1940  *                 initiated by peer
1941  *                 (Default: MBEDTLS_SSL_RENEGOTIATION_DISABLED)
1942  *
1943  * \warning        It is recommended to always disable renegotation unless you
1944  *                 know you need it and you know what you're doing. In the
1945  *                 past, there has been several issues associated with
1946  *                 renegotiation or a poor understanding of its properties.
1947  *
1948  * \note           Server-side, enabling renegotiation also makes the server
1949  *                 susceptible to a resource DoS by a malicious client.
1950  *
1951  * \param conf    SSL configuration
1952  * \param renegotiation     Enable or disable (MBEDTLS_SSL_RENEGOTIATION_ENABLED or
1953  *                                             MBEDTLS_SSL_RENEGOTIATION_DISABLED)
1954  */
1955 void mbedtls_ssl_conf_renegotiation( mbedtls_ssl_config *conf, int renegotiation );
1956 #endif /* MBEDTLS_SSL_RENEGOTIATION */
1957 
1958 /**
1959  * \brief          Prevent or allow legacy renegotiation.
1960  *                 (Default: MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION)
1961  *
1962  *                 MBEDTLS_SSL_LEGACY_NO_RENEGOTIATION allows connections to
1963  *                 be established even if the peer does not support
1964  *                 secure renegotiation, but does not allow renegotiation
1965  *                 to take place if not secure.
1966  *                 (Interoperable and secure option)
1967  *
1968  *                 MBEDTLS_SSL_LEGACY_ALLOW_RENEGOTIATION allows renegotiations
1969  *                 with non-upgraded peers. Allowing legacy renegotiation
1970  *                 makes the connection vulnerable to specific man in the
1971  *                 middle attacks. (See RFC 5746)
1972  *                 (Most interoperable and least secure option)
1973  *
1974  *                 MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE breaks off connections
1975  *                 if peer does not support secure renegotiation. Results
1976  *                 in interoperability issues with non-upgraded peers
1977  *                 that do not support renegotiation altogether.
1978  *                 (Most secure option, interoperability issues)
1979  *
1980  * \param conf     SSL configuration
1981  * \param allow_legacy  Prevent or allow (SSL_NO_LEGACY_RENEGOTIATION,
1982  *                                        SSL_ALLOW_LEGACY_RENEGOTIATION or
1983  *                                        MBEDTLS_SSL_LEGACY_BREAK_HANDSHAKE)
1984  */
1985 void mbedtls_ssl_conf_legacy_renegotiation( mbedtls_ssl_config *conf, int allow_legacy );
1986 
1987 #if defined(MBEDTLS_SSL_RENEGOTIATION)
1988 /**
1989  * \brief          Enforce renegotiation requests.
1990  *                 (Default: enforced, max_records = 16)
1991  *
1992  *                 When we request a renegotiation, the peer can comply or
1993  *                 ignore the request. This function allows us to decide
1994  *                 whether to enforce our renegotiation requests by closing
1995  *                 the connection if the peer doesn't comply.
1996  *
1997  *                 However, records could already be in transit from the peer
1998  *                 when the request is emitted. In order to increase
1999  *                 reliability, we can accept a number of records before the
2000  *                 expected handshake records.
2001  *
2002  *                 The optimal value is highly dependent on the specific usage
2003  *                 scenario.
2004  *
2005  * \note           With DTLS and server-initiated renegotiation, the
2006  *                 HelloRequest is retransmited every time mbedtls_ssl_read() times
2007  *                 out or receives Application Data, until:
2008  *                 - max_records records have beens seen, if it is >= 0, or
2009  *                 - the number of retransmits that would happen during an
2010  *                 actual handshake has been reached.
2011  *                 Please remember the request might be lost a few times
2012  *                 if you consider setting max_records to a really low value.
2013  *
2014  * \warning        On client, the grace period can only happen during
2015  *                 mbedtls_ssl_read(), as opposed to mbedtls_ssl_write() and mbedtls_ssl_renegotiate()
2016  *                 which always behave as if max_record was 0. The reason is,
2017  *                 if we receive application data from the server, we need a
2018  *                 place to write it, which only happens during mbedtls_ssl_read().
2019  *
2020  * \param conf     SSL configuration
2021  * \param max_records Use MBEDTLS_SSL_RENEGOTIATION_NOT_ENFORCED if you don't want to
2022  *                 enforce renegotiation, or a non-negative value to enforce
2023  *                 it but allow for a grace period of max_records records.
2024  */
2025 void mbedtls_ssl_conf_renegotiation_enforced( mbedtls_ssl_config *conf, int max_records );
2026 
2027 /**
2028  * \brief          Set record counter threshold for periodic renegotiation.
2029  *                 (Default: 2^64 - 256.)
2030  *
2031  *                 Renegotiation is automatically triggered when a record
2032  *                 counter (outgoing or ingoing) crosses the defined
2033  *                 threshold. The default value is meant to prevent the
2034  *                 connection from being closed when the counter is about to
2035  *                 reached its maximal value (it is not allowed to wrap).
2036  *
2037  *                 Lower values can be used to enforce policies such as "keys
2038  *                 must be refreshed every N packets with cipher X".
2039  *
2040  * \param conf     SSL configuration
2041  * \param period   The threshold value: a big-endian 64-bit number.
2042  *                 Set to 2^64 - 1 to disable periodic renegotiation
2043  */
2044 void mbedtls_ssl_conf_renegotiation_period( mbedtls_ssl_config *conf,
2045                                    const unsigned char period[8] );
2046 #endif /* MBEDTLS_SSL_RENEGOTIATION */
2047 
2048 /**
2049  * \brief          Return the number of data bytes available to read
2050  *
2051  * \param ssl      SSL context
2052  *
2053  * \return         how many bytes are available in the read buffer
2054  */
2055 size_t mbedtls_ssl_get_bytes_avail( const mbedtls_ssl_context *ssl );
2056 
2057 /**
2058  * \brief          Return the result of the certificate verification
2059  *
2060  * \param ssl      SSL context
2061  *
2062  * \return         0 if successful,
2063  *                 -1 if result is not available (eg because the handshake was
2064  *                 aborted too early), or
2065  *                 a combination of BADCERT_xxx and BADCRL_xxx flags, see
2066  *                 x509.h
2067  */
2068 uint32_t mbedtls_ssl_get_verify_result( const mbedtls_ssl_context *ssl );
2069 
2070 /**
2071  * \brief          Return the name of the current ciphersuite
2072  *
2073  * \param ssl      SSL context
2074  *
2075  * \return         a string containing the ciphersuite name
2076  */
2077 const char *mbedtls_ssl_get_ciphersuite( const mbedtls_ssl_context *ssl );
2078 
2079 /**
2080  * \brief          Return the current SSL version (SSLv3/TLSv1/etc)
2081  *
2082  * \param ssl      SSL context
2083  *
2084  * \return         a string containing the SSL version
2085  */
2086 const char *mbedtls_ssl_get_version( const mbedtls_ssl_context *ssl );
2087 
2088 /**
2089  * \brief          Return the (maximum) number of bytes added by the record
2090  *                 layer: header + encryption/MAC overhead (inc. padding)
2091  *
2092  * \param ssl      SSL context
2093  *
2094  * \return         Current maximum record expansion in bytes, or
2095  *                 MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE if compression is
2096  *                 enabled, which makes expansion much less predictable
2097  */
2098 int mbedtls_ssl_get_record_expansion( const mbedtls_ssl_context *ssl );
2099 
2100 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
2101 /**
2102  * \brief          Return the maximum fragment length (payload, in bytes).
2103  *                 This is the value negotiated with peer if any,
2104  *                 or the locally configured value.
2105  *
2106  * \note           With DTLS, \c mbedtls_ssl_write() will return an error if
2107  *                 called with a larger length value.
2108  *                 With TLS, \c mbedtls_ssl_write() will fragment the input if
2109  *                 necessary and return the number of bytes written; it is up
2110  *                 to the caller to call \c mbedtls_ssl_write() again in
2111  *                 order to send the remaining bytes if any.
2112  *
2113  * \param ssl      SSL context
2114  *
2115  * \return         Current maximum fragment length.
2116  */
2117 size_t mbedtls_ssl_get_max_frag_len( const mbedtls_ssl_context *ssl );
2118 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
2119 
2120 #if defined(MBEDTLS_X509_CRT_PARSE_C)
2121 /**
2122  * \brief          Return the peer certificate from the current connection
2123  *
2124  *                 Note: Can be NULL in case no certificate was sent during
2125  *                 the handshake. Different calls for the same connection can
2126  *                 return the same or different pointers for the same
2127  *                 certificate and even a different certificate altogether.
2128  *                 The peer cert CAN change in a single connection if
2129  *                 renegotiation is performed.
2130  *
2131  * \param ssl      SSL context
2132  *
2133  * \return         the current peer certificate
2134  */
2135 const mbedtls_x509_crt *mbedtls_ssl_get_peer_cert( const mbedtls_ssl_context *ssl );
2136 #endif /* MBEDTLS_X509_CRT_PARSE_C */
2137 
2138 #if defined(MBEDTLS_SSL_CLI_C)
2139 /**
2140  * \brief          Save session in order to resume it later (client-side only)
2141  *                 Session data is copied to presented session structure.
2142  *
2143  * \warning        Currently, peer certificate is lost in the operation.
2144  *
2145  * \param ssl      SSL context
2146  * \param session  session context
2147  *
2148  * \return         0 if successful,
2149  *                 MBEDTLS_ERR_SSL_ALLOC_FAILED if memory allocation failed,
2150  *                 MBEDTLS_ERR_SSL_BAD_INPUT_DATA if used server-side or
2151  *                 arguments are otherwise invalid
2152  *
2153  * \sa             mbedtls_ssl_set_session()
2154  */
2155 int mbedtls_ssl_get_session( const mbedtls_ssl_context *ssl, mbedtls_ssl_session *session );
2156 #endif /* MBEDTLS_SSL_CLI_C */
2157 
2158 /**
2159  * \brief          Perform the SSL handshake
2160  *
2161  * \param ssl      SSL context
2162  *
2163  * \return         0 if successful, or
2164  *                 MBEDTLS_ERR_SSL_WANT_READ or MBEDTLS_ERR_SSL_WANT_WRITE, or
2165  *                 MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED (see below), or
2166  *                 a specific SSL error code.
2167  *
2168  * \note           If this function returns something other than 0 or
2169  *                 MBEDTLS_ERR_SSL_WANT_READ/WRITE, then the ssl context
2170  *                 becomes unusable, and you should either free it or call
2171  *                 \c mbedtls_ssl_session_reset() on it before re-using it for
2172  *                 a new connection; the current connection must be closed.
2173  *
2174  * \note           If DTLS is in use, then you may choose to handle
2175  *                 MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED specially for logging
2176  *                 purposes, as it is an expected return value rather than an
2177  *                 actual error, but you still need to reset/free the context.
2178  */
2179 int mbedtls_ssl_handshake( mbedtls_ssl_context *ssl );
2180 
2181 /**
2182  * \brief          Perform a single step of the SSL handshake
2183  *
2184  * \note           The state of the context (ssl->state) will be at
2185  *                 the following state after execution of this function.
2186  *                 Do not call this function if state is MBEDTLS_SSL_HANDSHAKE_OVER.
2187  *
2188  * \note           If this function returns something other than 0 or
2189  *                 MBEDTLS_ERR_SSL_WANT_READ/WRITE, then the ssl context
2190  *                 becomes unusable, and you should either free it or call
2191  *                 \c mbedtls_ssl_session_reset() on it before re-using it for
2192  *                 a new connection; the current connection must be closed.
2193  *
2194  * \param ssl      SSL context
2195  *
2196  * \return         0 if successful, or
2197  *                 MBEDTLS_ERR_SSL_WANT_READ or MBEDTLS_ERR_SSL_WANT_WRITE, or
2198  *                 a specific SSL error code.
2199  */
2200 int mbedtls_ssl_handshake_step( mbedtls_ssl_context *ssl );
2201 
2202 #if defined(MBEDTLS_SSL_RENEGOTIATION)
2203 /**
2204  * \brief          Initiate an SSL renegotiation on the running connection.
2205  *                 Client: perform the renegotiation right now.
2206  *                 Server: request renegotiation, which will be performed
2207  *                 during the next call to mbedtls_ssl_read() if honored by client.
2208  *
2209  * \param ssl      SSL context
2210  *
2211  * \return         0 if successful, or any mbedtls_ssl_handshake() return value.
2212  *
2213  * \note           If this function returns something other than 0 or
2214  *                 MBEDTLS_ERR_SSL_WANT_READ/WRITE, then the ssl context
2215  *                 becomes unusable, and you should either free it or call
2216  *                 \c mbedtls_ssl_session_reset() on it before re-using it for
2217  *                 a new connection; the current connection must be closed.
2218  */
2219 int mbedtls_ssl_renegotiate( mbedtls_ssl_context *ssl );
2220 #endif /* MBEDTLS_SSL_RENEGOTIATION */
2221 
2222 /**
2223  * \brief          Read at most 'len' application data bytes
2224  *
2225  * \param ssl      SSL context
2226  * \param buf      buffer that will hold the data
2227  * \param len      maximum number of bytes to read
2228  *
2229  * \return         the number of bytes read, or
2230  *                 0 for EOF, or
2231  *                 MBEDTLS_ERR_SSL_WANT_READ or MBEDTLS_ERR_SSL_WANT_WRITE, or
2232  *                 MBEDTLS_ERR_SSL_CLIENT_RECONNECT (see below), or
2233  *                 another negative error code.
2234  *
2235  * \note           If this function returns something other than a positive
2236  *                 value or MBEDTLS_ERR_SSL_WANT_READ/WRITE or
2237  *                 MBEDTLS_ERR_SSL_CLIENT_RECONNECT, then the ssl context
2238  *                 becomes unusable, and you should either free it or call
2239  *                 \c mbedtls_ssl_session_reset() on it before re-using it for
2240  *                 a new connection; the current connection must be closed.
2241  *
2242  * \note           When this function return MBEDTLS_ERR_SSL_CLIENT_RECONNECT
2243  *                 (which can only happen server-side), it means that a client
2244  *                 is initiating a new connection using the same source port.
2245  *                 You can either treat that as a connection close and wait
2246  *                 for the client to resend a ClientHello, or directly
2247  *                 continue with \c mbedtls_ssl_handshake() with the same
2248  *                 context (as it has beeen reset internally). Either way, you
2249  *                 should make sure this is seen by the application as a new
2250  *                 connection: application state, if any, should be reset, and
2251  *                 most importantly the identity of the client must be checked
2252  *                 again. WARNING: not validating the identity of the client
2253  *                 again, or not transmitting the new identity to the
2254  *                 application layer, would allow authentication bypass!
2255  */
2256 int mbedtls_ssl_read( mbedtls_ssl_context *ssl, unsigned char *buf, size_t len );
2257 
2258 /**
2259  * \brief          Try to write exactly 'len' application data bytes
2260  *
2261  * \warning        This function will do partial writes in some cases. If the
2262  *                 return value is non-negative but less than length, the
2263  *                 function must be called again with updated arguments:
2264  *                 buf + ret, len - ret (if ret is the return value) until
2265  *                 it returns a value equal to the last 'len' argument.
2266  *
2267  * \param ssl      SSL context
2268  * \param buf      buffer holding the data
2269  * \param len      how many bytes must be written
2270  *
2271  * \return         the number of bytes actually written (may be less than len),
2272  *                 or MBEDTLS_ERR_SSL_WANT_WRITE of MBEDTLS_ERR_SSL_WANT_READ,
2273  *                 or another negative error code.
2274  *
2275  * \note           If this function returns something other than a positive
2276  *                 value or MBEDTLS_ERR_SSL_WANT_READ/WRITE, the ssl context
2277  *                 becomes unusable, and you should either free it or call
2278  *                 \c mbedtls_ssl_session_reset() on it before re-using it for
2279  *                 a new connection; the current connection must be closed.
2280  *
2281  * \note           When this function returns MBEDTLS_ERR_SSL_WANT_WRITE/READ,
2282  *                 it must be called later with the *same* arguments,
2283  *                 until it returns a positive value.
2284  *
2285  * \note           If the requested length is greater than the maximum
2286  *                 fragment length (either the built-in limit or the one set
2287  *                 or negotiated with the peer), then:
2288  *                 - with TLS, less bytes than requested are written.
2289  *                 - with DTLS, MBEDTLS_ERR_SSL_BAD_INPUT_DATA is returned.
2290  *                 \c mbedtls_ssl_get_max_frag_len() may be used to query the
2291  *                 active maximum fragment length.
2292  */
2293 int mbedtls_ssl_write( mbedtls_ssl_context *ssl, const unsigned char *buf, size_t len );
2294 
2295 /**
2296  * \brief           Send an alert message
2297  *
2298  * \param ssl       SSL context
2299  * \param level     The alert level of the message
2300  *                  (MBEDTLS_SSL_ALERT_LEVEL_WARNING or MBEDTLS_SSL_ALERT_LEVEL_FATAL)
2301  * \param message   The alert message (SSL_ALERT_MSG_*)
2302  *
2303  * \return          0 if successful, or a specific SSL error code.
2304  *
2305  * \note           If this function returns something other than 0 or
2306  *                 MBEDTLS_ERR_SSL_WANT_READ/WRITE, then the ssl context
2307  *                 becomes unusable, and you should either free it or call
2308  *                 \c mbedtls_ssl_session_reset() on it before re-using it for
2309  *                 a new connection; the current connection must be closed.
2310  */
2311 int mbedtls_ssl_send_alert_message( mbedtls_ssl_context *ssl,
2312                             unsigned char level,
2313                             unsigned char message );
2314 /**
2315  * \brief          Notify the peer that the connection is being closed
2316  *
2317  * \param ssl      SSL context
2318  *
2319  * \return          0 if successful, or a specific SSL error code.
2320  *
2321  * \note           If this function returns something other than 0 or
2322  *                 MBEDTLS_ERR_SSL_WANT_READ/WRITE, then the ssl context
2323  *                 becomes unusable, and you should either free it or call
2324  *                 \c mbedtls_ssl_session_reset() on it before re-using it for
2325  *                 a new connection; the current connection must be closed.
2326  */
2327 int mbedtls_ssl_close_notify( mbedtls_ssl_context *ssl );
2328 
2329 /**
2330  * \brief          Free referenced items in an SSL context and clear memory
2331  *
2332  * \param ssl      SSL context
2333  */
2334 void mbedtls_ssl_free( mbedtls_ssl_context *ssl );
2335 
2336 /**
2337  * \brief          Initialize an SSL configuration context
2338  *                 Just makes the context ready for
2339  *                 mbedtls_ssl_config_defaults() or mbedtls_ssl_config_free().
2340  *
2341  * \note           You need to call mbedtls_ssl_config_defaults() unless you
2342  *                 manually set all of the relevent fields yourself.
2343  *
2344  * \param conf     SSL configuration context
2345  */
2346 void mbedtls_ssl_config_init( mbedtls_ssl_config *conf );
2347 
2348 /**
2349  * \brief          Load reasonnable default SSL configuration values.
2350  *                 (You need to call mbedtls_ssl_config_init() first.)
2351  *
2352  * \param conf     SSL configuration context
2353  * \param endpoint MBEDTLS_SSL_IS_CLIENT or MBEDTLS_SSL_IS_SERVER
2354  * \param transport MBEDTLS_SSL_TRANSPORT_STREAM for TLS, or
2355  *                  MBEDTLS_SSL_TRANSPORT_DATAGRAM for DTLS
2356  * \param preset   a MBEDTLS_SSL_PRESET_XXX value
2357  *                 (currently unused).
2358  *
2359  * \note           See \c mbedtls_ssl_conf_transport() for notes on DTLS.
2360  *
2361  * \return         0 if successful, or
2362  *                 MBEDTLS_ERR_XXX_ALLOC_FAILED on memory allocation error.
2363  */
2364 int mbedtls_ssl_config_defaults( mbedtls_ssl_config *conf,
2365                                  int endpoint, int transport, int preset );
2366 
2367 /**
2368  * \brief          Free an SSL configuration context
2369  *
2370  * \param conf     SSL configuration context
2371  */
2372 void mbedtls_ssl_config_free( mbedtls_ssl_config *conf );
2373 
2374 /**
2375  * \brief          Initialize SSL session structure
2376  *
2377  * \param session  SSL session
2378  */
2379 void mbedtls_ssl_session_init( mbedtls_ssl_session *session );
2380 
2381 /**
2382  * \brief          Free referenced items in an SSL session including the
2383  *                 peer certificate and clear memory
2384  *
2385  * \param session  SSL session
2386  */
2387 void mbedtls_ssl_session_free( mbedtls_ssl_session *session );
2388 
2389 #ifdef __cplusplus
2390 }
2391 #endif
2392 
2393 #endif /* ssl.h */
2394