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      1 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com)
      2  * All rights reserved.
      3  *
      4  * This package is an SSL implementation written
      5  * by Eric Young (eay (at) cryptsoft.com).
      6  * The implementation was written so as to conform with Netscapes SSL.
      7  *
      8  * This library is free for commercial and non-commercial use as long as
      9  * the following conditions are aheared to.  The following conditions
     10  * apply to all code found in this distribution, be it the RC4, RSA,
     11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
     12  * included with this distribution is covered by the same copyright terms
     13  * except that the holder is Tim Hudson (tjh (at) cryptsoft.com).
     14  *
     15  * Copyright remains Eric Young's, and as such any Copyright notices in
     16  * the code are not to be removed.
     17  * If this package is used in a product, Eric Young should be given attribution
     18  * as the author of the parts of the library used.
     19  * This can be in the form of a textual message at program startup or
     20  * in documentation (online or textual) provided with the package.
     21  *
     22  * Redistribution and use in source and binary forms, with or without
     23  * modification, are permitted provided that the following conditions
     24  * are met:
     25  * 1. Redistributions of source code must retain the copyright
     26  *    notice, this list of conditions and the following disclaimer.
     27  * 2. Redistributions in binary form must reproduce the above copyright
     28  *    notice, this list of conditions and the following disclaimer in the
     29  *    documentation and/or other materials provided with the distribution.
     30  * 3. All advertising materials mentioning features or use of this software
     31  *    must display the following acknowledgement:
     32  *    "This product includes cryptographic software written by
     33  *     Eric Young (eay (at) cryptsoft.com)"
     34  *    The word 'cryptographic' can be left out if the rouines from the library
     35  *    being used are not cryptographic related :-).
     36  * 4. If you include any Windows specific code (or a derivative thereof) from
     37  *    the apps directory (application code) you must include an acknowledgement:
     38  *    "This product includes software written by Tim Hudson (tjh (at) cryptsoft.com)"
     39  *
     40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
     41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     50  * SUCH DAMAGE.
     51  *
     52  * The licence and distribution terms for any publically available version or
     53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
     54  * copied and put under another distribution licence
     55  * [including the GNU Public Licence.]
     56  */
     57 /* ====================================================================
     58  * Copyright (c) 1998-2007 The OpenSSL Project.  All rights reserved.
     59  *
     60  * Redistribution and use in source and binary forms, with or without
     61  * modification, are permitted provided that the following conditions
     62  * are met:
     63  *
     64  * 1. Redistributions of source code must retain the above copyright
     65  *    notice, this list of conditions and the following disclaimer.
     66  *
     67  * 2. Redistributions in binary form must reproduce the above copyright
     68  *    notice, this list of conditions and the following disclaimer in
     69  *    the documentation and/or other materials provided with the
     70  *    distribution.
     71  *
     72  * 3. All advertising materials mentioning features or use of this
     73  *    software must display the following acknowledgment:
     74  *    "This product includes software developed by the OpenSSL Project
     75  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
     76  *
     77  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
     78  *    endorse or promote products derived from this software without
     79  *    prior written permission. For written permission, please contact
     80  *    openssl-core (at) openssl.org.
     81  *
     82  * 5. Products derived from this software may not be called "OpenSSL"
     83  *    nor may "OpenSSL" appear in their names without prior written
     84  *    permission of the OpenSSL Project.
     85  *
     86  * 6. Redistributions of any form whatsoever must retain the following
     87  *    acknowledgment:
     88  *    "This product includes software developed by the OpenSSL Project
     89  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
     90  *
     91  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
     92  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     93  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     94  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
     95  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     96  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     97  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     98  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     99  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
    100  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
    101  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
    102  * OF THE POSSIBILITY OF SUCH DAMAGE.
    103  * ====================================================================
    104  *
    105  * This product includes cryptographic software written by Eric Young
    106  * (eay (at) cryptsoft.com).  This product includes software written by Tim
    107  * Hudson (tjh (at) cryptsoft.com).
    108  *
    109  */
    110 /* ====================================================================
    111  * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
    112  * ECC cipher suite support in OpenSSL originally developed by
    113  * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
    114  */
    115 /* ====================================================================
    116  * Copyright 2005 Nokia. All rights reserved.
    117  *
    118  * The portions of the attached software ("Contribution") is developed by
    119  * Nokia Corporation and is licensed pursuant to the OpenSSL open source
    120  * license.
    121  *
    122  * The Contribution, originally written by Mika Kousa and Pasi Eronen of
    123  * Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites
    124  * support (see RFC 4279) to OpenSSL.
    125  *
    126  * No patent licenses or other rights except those expressly stated in
    127  * the OpenSSL open source license shall be deemed granted or received
    128  * expressly, by implication, estoppel, or otherwise.
    129  *
    130  * No assurances are provided by Nokia that the Contribution does not
    131  * infringe the patent or other intellectual property rights of any third
    132  * party or that the license provides you with all the necessary rights
    133  * to make use of the Contribution.
    134  *
    135  * THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN
    136  * ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA
    137  * SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY
    138  * OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR
    139  * OTHERWISE.
    140  */
    141 
    142 #ifndef OPENSSL_HEADER_SSL_INTERNAL_H
    143 #define OPENSSL_HEADER_SSL_INTERNAL_H
    144 
    145 #include <openssl/base.h>
    146 
    147 #include <openssl/aead.h>
    148 #include <openssl/pqueue.h>
    149 #include <openssl/ssl.h>
    150 #include <openssl/stack.h>
    151 
    152 #if defined(OPENSSL_WINDOWS)
    153 /* Windows defines struct timeval in winsock2.h. */
    154 #pragma warning(push, 3)
    155 #include <winsock2.h>
    156 #pragma warning(pop)
    157 #else
    158 #include <sys/time.h>
    159 #endif
    160 
    161 
    162 /* Cipher suites. */
    163 
    164 /* Bits for |algorithm_mkey| (key exchange algorithm). */
    165 #define SSL_kRSA 0x00000001L
    166 #define SSL_kDHE 0x00000002L
    167 #define SSL_kECDHE 0x00000004L
    168 /* SSL_kPSK is only set for plain PSK, not ECDHE_PSK. */
    169 #define SSL_kPSK 0x00000008L
    170 
    171 /* Bits for |algorithm_auth| (server authentication). */
    172 #define SSL_aRSA 0x00000001L
    173 #define SSL_aECDSA 0x00000002L
    174 /* SSL_aPSK is set for both PSK and ECDHE_PSK. */
    175 #define SSL_aPSK 0x00000004L
    176 
    177 /* Bits for |algorithm_enc| (symmetric encryption). */
    178 #define SSL_3DES 0x00000001L
    179 #define SSL_RC4 0x00000002L
    180 #define SSL_AES128 0x00000004L
    181 #define SSL_AES256 0x00000008L
    182 #define SSL_AES128GCM 0x00000010L
    183 #define SSL_AES256GCM 0x00000020L
    184 #define SSL_CHACHA20POLY1305_OLD 0x00000040L
    185 #define SSL_eNULL 0x00000080L
    186 #define SSL_CHACHA20POLY1305 0x00000100L
    187 
    188 #define SSL_AES (SSL_AES128 | SSL_AES256 | SSL_AES128GCM | SSL_AES256GCM)
    189 
    190 /* Bits for |algorithm_mac| (symmetric authentication). */
    191 #define SSL_MD5 0x00000001L
    192 #define SSL_SHA1 0x00000002L
    193 #define SSL_SHA256 0x00000004L
    194 #define SSL_SHA384 0x00000008L
    195 /* SSL_AEAD is set for all AEADs. */
    196 #define SSL_AEAD 0x00000010L
    197 
    198 /* Bits for |algorithm_prf| (handshake digest). */
    199 #define SSL_HANDSHAKE_MAC_DEFAULT 0x1
    200 #define SSL_HANDSHAKE_MAC_SHA256 0x2
    201 #define SSL_HANDSHAKE_MAC_SHA384 0x4
    202 
    203 /* SSL_MAX_DIGEST is the number of digest types which exist. When adding a new
    204  * one, update the table in ssl_cipher.c. */
    205 #define SSL_MAX_DIGEST 4
    206 
    207 /* ssl_cipher_get_evp_aead sets |*out_aead| to point to the correct EVP_AEAD
    208  * object for |cipher| protocol version |version|. It sets |*out_mac_secret_len|
    209  * and |*out_fixed_iv_len| to the MAC key length and fixed IV length,
    210  * respectively. The MAC key length is zero except for legacy block and stream
    211  * ciphers. It returns 1 on success and 0 on error. */
    212 int ssl_cipher_get_evp_aead(const EVP_AEAD **out_aead,
    213                             size_t *out_mac_secret_len,
    214                             size_t *out_fixed_iv_len,
    215                             const SSL_CIPHER *cipher, uint16_t version);
    216 
    217 /* ssl_get_handshake_digest returns the |EVP_MD| corresponding to
    218  * |algorithm_prf|. It returns SHA-1 for |SSL_HANDSHAKE_DEFAULT|. The caller is
    219  * responsible for maintaining the additional MD5 digest and switching to
    220  * SHA-256 in TLS 1.2. */
    221 const EVP_MD *ssl_get_handshake_digest(uint32_t algorithm_prf);
    222 
    223 /* ssl_create_cipher_list evaluates |rule_str| according to the ciphers in
    224  * |ssl_method|. It sets |*out_cipher_list| to a newly-allocated
    225  * |ssl_cipher_preference_list_st| containing the result.
    226  * |*out_cipher_list_by_id| is set to a list of selected ciphers sorted by
    227  * id. It returns |(*out_cipher_list)->ciphers| on success and NULL on
    228  * failure. */
    229 STACK_OF(SSL_CIPHER) *
    230 ssl_create_cipher_list(const SSL_PROTOCOL_METHOD *ssl_method,
    231                        struct ssl_cipher_preference_list_st **out_cipher_list,
    232                        STACK_OF(SSL_CIPHER) **out_cipher_list_by_id,
    233                        const char *rule_str);
    234 
    235 /* ssl_cipher_get_value returns the cipher suite id of |cipher|. */
    236 uint16_t ssl_cipher_get_value(const SSL_CIPHER *cipher);
    237 
    238 /* ssl_cipher_get_key_type returns the |EVP_PKEY_*| value corresponding to the
    239  * server key used in |cipher| or |EVP_PKEY_NONE| if there is none. */
    240 int ssl_cipher_get_key_type(const SSL_CIPHER *cipher);
    241 
    242 /* ssl_cipher_has_server_public_key returns 1 if |cipher| involves a server
    243  * public key in the key exchange, sent in a server Certificate message.
    244  * Otherwise it returns 0. */
    245 int ssl_cipher_has_server_public_key(const SSL_CIPHER *cipher);
    246 
    247 /* ssl_cipher_requires_server_key_exchange returns 1 if |cipher| requires a
    248  * ServerKeyExchange message. Otherwise it returns 0.
    249  *
    250  * Unlike |ssl_cipher_has_server_public_key|, this function may return zero
    251  * while still allowing |cipher| an optional ServerKeyExchange. This is the
    252  * case for plain PSK ciphers. */
    253 int ssl_cipher_requires_server_key_exchange(const SSL_CIPHER *cipher);
    254 
    255 /* ssl_cipher_get_record_split_len, for TLS 1.0 CBC mode ciphers, returns the
    256  * length of an encrypted 1-byte record, for use in record-splitting. Otherwise
    257  * it returns zero. */
    258 size_t ssl_cipher_get_record_split_len(const SSL_CIPHER *cipher);
    259 
    260 
    261 /* Encryption layer. */
    262 
    263 /* SSL_AEAD_CTX contains information about an AEAD that is being used to encrypt
    264  * an SSL connection. */
    265 struct ssl_aead_ctx_st {
    266   const SSL_CIPHER *cipher;
    267   EVP_AEAD_CTX ctx;
    268   /* fixed_nonce contains any bytes of the nonce that are fixed for all
    269    * records. */
    270   uint8_t fixed_nonce[12];
    271   uint8_t fixed_nonce_len, variable_nonce_len;
    272   /* variable_nonce_included_in_record is non-zero if the variable nonce
    273    * for a record is included as a prefix before the ciphertext. */
    274   char variable_nonce_included_in_record;
    275   /* random_variable_nonce is non-zero if the variable nonce is
    276    * randomly generated, rather than derived from the sequence
    277    * number. */
    278   char random_variable_nonce;
    279   /* omit_length_in_ad is non-zero if the length should be omitted in the
    280    * AEAD's ad parameter. */
    281   char omit_length_in_ad;
    282   /* omit_version_in_ad is non-zero if the version should be omitted
    283    * in the AEAD's ad parameter. */
    284   char omit_version_in_ad;
    285   /* xor_fixed_nonce is non-zero if the fixed nonce should be XOR'd into the
    286    * variable nonce rather than prepended. */
    287   char xor_fixed_nonce;
    288 } /* SSL_AEAD_CTX */;
    289 
    290 /* SSL_AEAD_CTX_new creates a newly-allocated |SSL_AEAD_CTX| using the supplied
    291  * key material. It returns NULL on error. Only one of |SSL_AEAD_CTX_open| or
    292  * |SSL_AEAD_CTX_seal| may be used with the resulting object, depending on
    293  * |direction|. |version| is the normalized protocol version, so DTLS 1.0 is
    294  * represented as 0x0301, not 0xffef. */
    295 SSL_AEAD_CTX *SSL_AEAD_CTX_new(enum evp_aead_direction_t direction,
    296                                uint16_t version, const SSL_CIPHER *cipher,
    297                                const uint8_t *enc_key, size_t enc_key_len,
    298                                const uint8_t *mac_key, size_t mac_key_len,
    299                                const uint8_t *fixed_iv, size_t fixed_iv_len);
    300 
    301 /* SSL_AEAD_CTX_free frees |ctx|. */
    302 void SSL_AEAD_CTX_free(SSL_AEAD_CTX *ctx);
    303 
    304 /* SSL_AEAD_CTX_explicit_nonce_len returns the length of the explicit nonce for
    305  * |ctx|, if any. |ctx| may be NULL to denote the null cipher. */
    306 size_t SSL_AEAD_CTX_explicit_nonce_len(SSL_AEAD_CTX *ctx);
    307 
    308 /* SSL_AEAD_CTX_max_overhead returns the maximum overhead of calling
    309  * |SSL_AEAD_CTX_seal|. |ctx| may be NULL to denote the null cipher. */
    310 size_t SSL_AEAD_CTX_max_overhead(SSL_AEAD_CTX *ctx);
    311 
    312 /* SSL_AEAD_CTX_open authenticates and decrypts |in_len| bytes from |in| and
    313  * writes the result to |out|. It returns one on success and zero on
    314  * error. |ctx| may be NULL to denote the null cipher.
    315  *
    316  * If |in| and |out| alias then |out| must be <= |in| + |explicit_nonce_len|. */
    317 int SSL_AEAD_CTX_open(SSL_AEAD_CTX *ctx, uint8_t *out, size_t *out_len,
    318                       size_t max_out, uint8_t type, uint16_t wire_version,
    319                       const uint8_t seqnum[8], const uint8_t *in,
    320                       size_t in_len);
    321 
    322 /* SSL_AEAD_CTX_seal encrypts and authenticates |in_len| bytes from |in| and
    323  * writes the result to |out|. It returns one on success and zero on
    324  * error. |ctx| may be NULL to denote the null cipher.
    325  *
    326  * If |in| and |out| alias then |out| + |explicit_nonce_len| must be <= |in| */
    327 int SSL_AEAD_CTX_seal(SSL_AEAD_CTX *ctx, uint8_t *out, size_t *out_len,
    328                       size_t max_out, uint8_t type, uint16_t wire_version,
    329                       const uint8_t seqnum[8], const uint8_t *in,
    330                       size_t in_len);
    331 
    332 
    333 /* DTLS replay bitmap. */
    334 
    335 /* DTLS1_BITMAP maintains a sliding window of 64 sequence numbers to detect
    336  * replayed packets. It should be initialized by zeroing every field. */
    337 typedef struct dtls1_bitmap_st {
    338   /* map is a bit mask of the last 64 sequence numbers. Bit
    339    * |1<<i| corresponds to |max_seq_num - i|. */
    340   uint64_t map;
    341   /* max_seq_num is the largest sequence number seen so far as a 64-bit
    342    * integer. */
    343   uint64_t max_seq_num;
    344 } DTLS1_BITMAP;
    345 
    346 
    347 /* Record layer. */
    348 
    349 /* ssl_record_prefix_len returns the length of the prefix before the ciphertext
    350  * of a record for |ssl|.
    351  *
    352  * TODO(davidben): Expose this as part of public API once the high-level
    353  * buffer-free APIs are available. */
    354 size_t ssl_record_prefix_len(const SSL *ssl);
    355 
    356 enum ssl_open_record_t {
    357   ssl_open_record_success,
    358   ssl_open_record_discard,
    359   ssl_open_record_partial,
    360   ssl_open_record_error,
    361 };
    362 
    363 /* tls_open_record decrypts a record from |in|.
    364  *
    365  * On success, it returns |ssl_open_record_success|. It sets |*out_type| to the
    366  * record type, |*out_len| to the plaintext length, and writes the record body
    367  * to |out|. It sets |*out_consumed| to the number of bytes of |in| consumed.
    368  * Note that |*out_len| may be zero.
    369  *
    370  * If a record was successfully processed but should be discarded, it returns
    371  * |ssl_open_record_discard| and sets |*out_consumed| to the number of bytes
    372  * consumed.
    373  *
    374  * If the input did not contain a complete record, it returns
    375  * |ssl_open_record_partial|. It sets |*out_consumed| to the total number of
    376  * bytes necessary. It is guaranteed that a successful call to |tls_open_record|
    377  * will consume at least that many bytes.
    378  *
    379  * On failure, it returns |ssl_open_record_error| and sets |*out_alert| to an
    380  * alert to emit.
    381  *
    382  * If |in| and |out| alias, |out| must be <= |in| + |ssl_record_prefix_len|. */
    383 enum ssl_open_record_t tls_open_record(
    384     SSL *ssl, uint8_t *out_type, uint8_t *out, size_t *out_len,
    385     size_t *out_consumed, uint8_t *out_alert, size_t max_out, const uint8_t *in,
    386     size_t in_len);
    387 
    388 /* dtls_open_record implements |tls_open_record| for DTLS. It never returns
    389  * |ssl_open_record_partial| but otherwise behaves analogously. */
    390 enum ssl_open_record_t dtls_open_record(
    391     SSL *ssl, uint8_t *out_type, uint8_t *out, size_t *out_len,
    392     size_t *out_consumed, uint8_t *out_alert, size_t max_out, const uint8_t *in,
    393     size_t in_len);
    394 
    395 /* ssl_seal_prefix_len returns the length of the prefix before the ciphertext
    396  * when sealing a record with |ssl|. Note that this value may differ from
    397  * |ssl_record_prefix_len| when TLS 1.0 CBC record-splitting is enabled. Sealing
    398  * a small record may also result in a smaller output than this value.
    399  *
    400  * TODO(davidben): Expose this as part of public API once the high-level
    401  * buffer-free APIs are available. */
    402 size_t ssl_seal_prefix_len(const SSL *ssl);
    403 
    404 /* ssl_max_seal_overhead returns the maximum overhead of sealing a record with
    405  * |ssl|. This includes |ssl_seal_prefix_len|.
    406  *
    407  * TODO(davidben): Expose this as part of public API once the high-level
    408  * buffer-free APIs are available. */
    409 size_t ssl_max_seal_overhead(const SSL *ssl);
    410 
    411 /* tls_seal_record seals a new record of type |type| and body |in| and writes it
    412  * to |out|. At most |max_out| bytes will be written. It returns one on success
    413  * and zero on error. If enabled, |tls_seal_record| implements TLS 1.0 CBC 1/n-1
    414  * record splitting and may write two records concatenated.
    415  *
    416  * For a large record, the ciphertext will begin |ssl_seal_prefix_len| bytes
    417  * into out. Aligning |out| appropriately may improve performance. It writes at
    418  * most |in_len| + |ssl_max_seal_overhead| bytes to |out|.
    419  *
    420  * If |in| and |out| alias, |out| + |ssl_seal_prefix_len| must be <= |in|. */
    421 int tls_seal_record(SSL *ssl, uint8_t *out, size_t *out_len, size_t max_out,
    422                     uint8_t type, const uint8_t *in, size_t in_len);
    423 
    424 enum dtls1_use_epoch_t {
    425   dtls1_use_previous_epoch,
    426   dtls1_use_current_epoch,
    427 };
    428 
    429 /* dtls_seal_record implements |tls_seal_record| for DTLS. |use_epoch| selects
    430  * which epoch's cipher state to use. */
    431 int dtls_seal_record(SSL *ssl, uint8_t *out, size_t *out_len, size_t max_out,
    432                      uint8_t type, const uint8_t *in, size_t in_len,
    433                      enum dtls1_use_epoch_t use_epoch);
    434 
    435 
    436 /* Private key operations. */
    437 
    438 /* ssl_has_private_key returns one if |ssl| has a private key
    439  * configured and zero otherwise. */
    440 int ssl_has_private_key(SSL *ssl);
    441 
    442 /* ssl_private_key_* call the corresponding function on the
    443  * |SSL_PRIVATE_KEY_METHOD| for |ssl|, if configured. Otherwise, they implement
    444  * the operation with |EVP_PKEY|. */
    445 
    446 int ssl_private_key_type(SSL *ssl);
    447 
    448 size_t ssl_private_key_max_signature_len(SSL *ssl);
    449 
    450 enum ssl_private_key_result_t ssl_private_key_sign(
    451     SSL *ssl, uint8_t *out, size_t *out_len, size_t max_out, const EVP_MD *md,
    452     const uint8_t *in, size_t in_len);
    453 
    454 enum ssl_private_key_result_t ssl_private_key_sign_complete(
    455     SSL *ssl, uint8_t *out, size_t *out_len, size_t max_out);
    456 
    457 enum ssl_private_key_result_t ssl_private_key_decrypt(
    458     SSL *ssl, uint8_t *out, size_t *out_len, size_t max_out,
    459     const uint8_t *in, size_t in_len);
    460 
    461 enum ssl_private_key_result_t ssl_private_key_decrypt_complete(
    462     SSL *ssl, uint8_t *out, size_t *out_len, size_t max_out);
    463 
    464 
    465 /* Custom extensions */
    466 
    467 /* ssl_custom_extension (a.k.a. SSL_CUSTOM_EXTENSION) is a structure that
    468  * contains information about custom-extension callbacks. */
    469 struct ssl_custom_extension {
    470   SSL_custom_ext_add_cb add_callback;
    471   void *add_arg;
    472   SSL_custom_ext_free_cb free_callback;
    473   SSL_custom_ext_parse_cb parse_callback;
    474   void *parse_arg;
    475   uint16_t value;
    476 };
    477 
    478 void SSL_CUSTOM_EXTENSION_free(SSL_CUSTOM_EXTENSION *custom_extension);
    479 
    480 int custom_ext_add_clienthello(SSL *ssl, CBB *extensions);
    481 int custom_ext_parse_serverhello(SSL *ssl, int *out_alert, uint16_t value,
    482                                  const CBS *extension);
    483 int custom_ext_parse_clienthello(SSL *ssl, int *out_alert, uint16_t value,
    484                                  const CBS *extension);
    485 int custom_ext_add_serverhello(SSL *ssl, CBB *extensions);
    486 
    487 
    488 /* Handshake hash.
    489  *
    490  * The TLS handshake maintains a transcript of all handshake messages. At
    491  * various points in the protocol, this is either a handshake buffer, a rolling
    492  * hash (selected by cipher suite) or both. */
    493 
    494 /* ssl3_init_handshake_buffer initializes the handshake buffer and resets the
    495  * handshake hash. It returns one success and zero on failure. */
    496 int ssl3_init_handshake_buffer(SSL *ssl);
    497 
    498 /* ssl3_init_handshake_hash initializes the handshake hash based on the pending
    499  * cipher and the contents of the handshake buffer. Subsequent calls to
    500  * |ssl3_update_handshake_hash| will update the rolling hash. It returns one on
    501  * success and zero on failure. It is an error to call this function after the
    502  * handshake buffer is released. */
    503 int ssl3_init_handshake_hash(SSL *ssl);
    504 
    505 /* ssl3_free_handshake_buffer releases the handshake buffer. Subsequent calls
    506  * to |ssl3_update_handshake_hash| will not update the handshake buffer. */
    507 void ssl3_free_handshake_buffer(SSL *ssl);
    508 
    509 /* ssl3_free_handshake_hash releases the handshake hash. */
    510 void ssl3_free_handshake_hash(SSL *ssl);
    511 
    512 /* ssl3_update_handshake_hash adds |in| to the handshake buffer and handshake
    513  * hash, whichever is enabled. It returns one on success and zero on failure. */
    514 int ssl3_update_handshake_hash(SSL *ssl, const uint8_t *in, size_t in_len);
    515 
    516 
    517 /* ECDH curves. */
    518 
    519 #define SSL_CURVE_SECP256R1 23
    520 #define SSL_CURVE_SECP384R1 24
    521 #define SSL_CURVE_SECP521R1 25
    522 #define SSL_CURVE_ECDH_X25519 29
    523 
    524 /* An SSL_ECDH_METHOD is an implementation of ECDH-like key exchanges for
    525  * TLS. */
    526 struct ssl_ecdh_method_st {
    527   int nid;
    528   uint16_t curve_id;
    529   const char name[8];
    530 
    531   /* cleanup releases state in |ctx|. */
    532   void (*cleanup)(SSL_ECDH_CTX *ctx);
    533 
    534   /* generate_keypair generates a keypair and writes the public value to
    535    * |out_public_key|. It returns one on success and zero on error. */
    536   int (*generate_keypair)(SSL_ECDH_CTX *ctx, CBB *out_public_key);
    537 
    538   /* compute_secret performs a key exchange against |peer_key| and, on
    539    * success, returns one and sets |*out_secret| and |*out_secret_len| to
    540    * a newly-allocated buffer containing the shared secret. The caller must
    541    * release this buffer with |OPENSSL_free|. Otherwise, it returns zero and
    542    * sets |*out_alert| to an alert to send to the peer. */
    543   int (*compute_secret)(SSL_ECDH_CTX *ctx, uint8_t **out_secret,
    544                         size_t *out_secret_len, uint8_t *out_alert,
    545                         const uint8_t *peer_key, size_t peer_key_len);
    546 } /* SSL_ECDH_METHOD */;
    547 
    548 /* ssl_nid_to_curve_id looks up the curve corresponding to |nid|. On success, it
    549  * sets |*out_curve_id| to the curve ID and returns one. Otherwise, it returns
    550  * zero. */
    551 int ssl_nid_to_curve_id(uint16_t *out_curve_id, int nid);
    552 
    553 /* SSL_ECDH_CTX_init sets up |ctx| for use with curve |curve_id|. It returns one
    554  * on success and zero on error. */
    555 int SSL_ECDH_CTX_init(SSL_ECDH_CTX *ctx, uint16_t curve_id);
    556 
    557 /* SSL_ECDH_CTX_init_for_dhe sets up |ctx| for use with legacy DHE-based ciphers
    558  * where the server specifies a group. It takes ownership of |params|. */
    559 void SSL_ECDH_CTX_init_for_dhe(SSL_ECDH_CTX *ctx, DH *params);
    560 
    561 /* SSL_ECDH_CTX_cleanup releases memory associated with |ctx|. It is legal to
    562  * call it in the zero state. */
    563 void SSL_ECDH_CTX_cleanup(SSL_ECDH_CTX *ctx);
    564 
    565 /* The following functions call the corresponding method of
    566  * |SSL_ECDH_METHOD|. */
    567 int SSL_ECDH_CTX_generate_keypair(SSL_ECDH_CTX *ctx, CBB *out_public_key);
    568 int SSL_ECDH_CTX_compute_secret(SSL_ECDH_CTX *ctx, uint8_t **out_secret,
    569                                 size_t *out_secret_len, uint8_t *out_alert,
    570                                 const uint8_t *peer_key, size_t peer_key_len);
    571 
    572 
    573 /* Transport buffers. */
    574 
    575 /* ssl_read_buffer returns a pointer to contents of the read buffer. */
    576 uint8_t *ssl_read_buffer(SSL *ssl);
    577 
    578 /* ssl_read_buffer_len returns the length of the read buffer. */
    579 size_t ssl_read_buffer_len(const SSL *ssl);
    580 
    581 /* ssl_read_buffer_extend_to extends the read buffer to the desired length. For
    582  * TLS, it reads to the end of the buffer until the buffer is |len| bytes
    583  * long. For DTLS, it reads a new packet and ignores |len|. It returns one on
    584  * success, zero on EOF, and a negative number on error.
    585  *
    586  * It is an error to call |ssl_read_buffer_extend_to| in DTLS when the buffer is
    587  * non-empty. */
    588 int ssl_read_buffer_extend_to(SSL *ssl, size_t len);
    589 
    590 /* ssl_read_buffer_consume consumes |len| bytes from the read buffer. It
    591  * advances the data pointer and decrements the length. The memory consumed will
    592  * remain valid until the next call to |ssl_read_buffer_extend| or it is
    593  * discarded with |ssl_read_buffer_discard|. */
    594 void ssl_read_buffer_consume(SSL *ssl, size_t len);
    595 
    596 /* ssl_read_buffer_discard discards the consumed bytes from the read buffer. If
    597  * the buffer is now empty, it releases memory used by it. */
    598 void ssl_read_buffer_discard(SSL *ssl);
    599 
    600 /* ssl_read_buffer_clear releases all memory associated with the read buffer and
    601  * zero-initializes it. */
    602 void ssl_read_buffer_clear(SSL *ssl);
    603 
    604 /* ssl_write_buffer_is_pending returns one if the write buffer has pending data
    605  * and zero if is empty. */
    606 int ssl_write_buffer_is_pending(const SSL *ssl);
    607 
    608 /* ssl_write_buffer_init initializes the write buffer. On success, it sets
    609  * |*out_ptr| to the start of the write buffer with space for up to |max_len|
    610  * bytes. It returns one on success and zero on failure. Call
    611  * |ssl_write_buffer_set_len| to complete initialization. */
    612 int ssl_write_buffer_init(SSL *ssl, uint8_t **out_ptr, size_t max_len);
    613 
    614 /* ssl_write_buffer_set_len is called after |ssl_write_buffer_init| to complete
    615  * initialization after |len| bytes are written to the buffer. */
    616 void ssl_write_buffer_set_len(SSL *ssl, size_t len);
    617 
    618 /* ssl_write_buffer_flush flushes the write buffer to the transport. It returns
    619  * one on success and <= 0 on error. For DTLS, whether or not the write
    620  * succeeds, the write buffer will be cleared. */
    621 int ssl_write_buffer_flush(SSL *ssl);
    622 
    623 /* ssl_write_buffer_clear releases all memory associated with the write buffer
    624  * and zero-initializes it. */
    625 void ssl_write_buffer_clear(SSL *ssl);
    626 
    627 
    628 /* Underdocumented functions.
    629  *
    630  * Functions below here haven't been touched up and may be underdocumented. */
    631 
    632 #define c2l(c, l)                                                            \
    633   (l = ((unsigned long)(*((c)++))), l |= (((unsigned long)(*((c)++))) << 8), \
    634    l |= (((unsigned long)(*((c)++))) << 16),                                 \
    635    l |= (((unsigned long)(*((c)++))) << 24))
    636 
    637 /* NOTE - c is not incremented as per c2l */
    638 #define c2ln(c, l1, l2, n)                       \
    639   {                                              \
    640     c += n;                                      \
    641     l1 = l2 = 0;                                 \
    642     switch (n) {                                 \
    643       case 8:                                    \
    644         l2 = ((unsigned long)(*(--(c)))) << 24;  \
    645       case 7:                                    \
    646         l2 |= ((unsigned long)(*(--(c)))) << 16; \
    647       case 6:                                    \
    648         l2 |= ((unsigned long)(*(--(c)))) << 8;  \
    649       case 5:                                    \
    650         l2 |= ((unsigned long)(*(--(c))));       \
    651       case 4:                                    \
    652         l1 = ((unsigned long)(*(--(c)))) << 24;  \
    653       case 3:                                    \
    654         l1 |= ((unsigned long)(*(--(c)))) << 16; \
    655       case 2:                                    \
    656         l1 |= ((unsigned long)(*(--(c)))) << 8;  \
    657       case 1:                                    \
    658         l1 |= ((unsigned long)(*(--(c))));       \
    659     }                                            \
    660   }
    661 
    662 #define l2c(l, c)                            \
    663   (*((c)++) = (uint8_t)(((l)) & 0xff),       \
    664    *((c)++) = (uint8_t)(((l) >> 8) & 0xff),  \
    665    *((c)++) = (uint8_t)(((l) >> 16) & 0xff), \
    666    *((c)++) = (uint8_t)(((l) >> 24) & 0xff))
    667 
    668 #define n2l(c, l)                          \
    669   (l = ((unsigned long)(*((c)++))) << 24,  \
    670    l |= ((unsigned long)(*((c)++))) << 16, \
    671    l |= ((unsigned long)(*((c)++))) << 8, l |= ((unsigned long)(*((c)++))))
    672 
    673 #define l2n(l, c)                            \
    674   (*((c)++) = (uint8_t)(((l) >> 24) & 0xff), \
    675    *((c)++) = (uint8_t)(((l) >> 16) & 0xff), \
    676    *((c)++) = (uint8_t)(((l) >> 8) & 0xff),  \
    677    *((c)++) = (uint8_t)(((l)) & 0xff))
    678 
    679 #define l2n8(l, c)                           \
    680   (*((c)++) = (uint8_t)(((l) >> 56) & 0xff), \
    681    *((c)++) = (uint8_t)(((l) >> 48) & 0xff), \
    682    *((c)++) = (uint8_t)(((l) >> 40) & 0xff), \
    683    *((c)++) = (uint8_t)(((l) >> 32) & 0xff), \
    684    *((c)++) = (uint8_t)(((l) >> 24) & 0xff), \
    685    *((c)++) = (uint8_t)(((l) >> 16) & 0xff), \
    686    *((c)++) = (uint8_t)(((l) >> 8) & 0xff),  \
    687    *((c)++) = (uint8_t)(((l)) & 0xff))
    688 
    689 /* NOTE - c is not incremented as per l2c */
    690 #define l2cn(l1, l2, c, n)                               \
    691   {                                                      \
    692     c += n;                                              \
    693     switch (n) {                                         \
    694       case 8:                                            \
    695         *(--(c)) = (uint8_t)(((l2) >> 24) & 0xff); \
    696       case 7:                                            \
    697         *(--(c)) = (uint8_t)(((l2) >> 16) & 0xff); \
    698       case 6:                                            \
    699         *(--(c)) = (uint8_t)(((l2) >> 8) & 0xff);  \
    700       case 5:                                            \
    701         *(--(c)) = (uint8_t)(((l2)) & 0xff);       \
    702       case 4:                                            \
    703         *(--(c)) = (uint8_t)(((l1) >> 24) & 0xff); \
    704       case 3:                                            \
    705         *(--(c)) = (uint8_t)(((l1) >> 16) & 0xff); \
    706       case 2:                                            \
    707         *(--(c)) = (uint8_t)(((l1) >> 8) & 0xff);  \
    708       case 1:                                            \
    709         *(--(c)) = (uint8_t)(((l1)) & 0xff);       \
    710     }                                                    \
    711   }
    712 
    713 #define n2s(c, s) \
    714   ((s = (((unsigned int)(c[0])) << 8) | (((unsigned int)(c[1])))), c += 2)
    715 
    716 #define s2n(s, c)                              \
    717   ((c[0] = (uint8_t)(((s) >> 8) & 0xff), \
    718     c[1] = (uint8_t)(((s)) & 0xff)),     \
    719    c += 2)
    720 
    721 #define n2l3(c, l)                                                         \
    722   ((l = (((unsigned long)(c[0])) << 16) | (((unsigned long)(c[1])) << 8) | \
    723         (((unsigned long)(c[2])))),                                        \
    724    c += 3)
    725 
    726 #define l2n3(l, c)                              \
    727   ((c[0] = (uint8_t)(((l) >> 16) & 0xff), \
    728     c[1] = (uint8_t)(((l) >> 8) & 0xff),  \
    729     c[2] = (uint8_t)(((l)) & 0xff)),      \
    730    c += 3)
    731 
    732 /* LOCAL STUFF */
    733 
    734 #define TLSEXT_CHANNEL_ID_SIZE 128
    735 
    736 /* Check if an SSL structure is using DTLS */
    737 #define SSL_IS_DTLS(ssl) (ssl->method->is_dtls)
    738 /* See if we need explicit IV */
    739 #define SSL_USE_EXPLICIT_IV(ssl) \
    740   (ssl->enc_method->enc_flags & SSL_ENC_FLAG_EXPLICIT_IV)
    741 /* See if we use signature algorithms extension and signature algorithm before
    742  * signatures. */
    743 #define SSL_USE_SIGALGS(ssl) (ssl->enc_method->enc_flags & SSL_ENC_FLAG_SIGALGS)
    744 
    745 /* From RFC4492, used in encoding the curve type in ECParameters */
    746 #define NAMED_CURVE_TYPE 3
    747 
    748 enum ssl_hash_message_t {
    749   ssl_dont_hash_message,
    750   ssl_hash_message,
    751 };
    752 
    753 /* Structure containing decoded values of signature algorithms extension */
    754 typedef struct tls_sigalgs_st {
    755   uint8_t rsign;
    756   uint8_t rhash;
    757 } TLS_SIGALGS;
    758 
    759 typedef struct cert_st {
    760   X509 *x509;
    761   EVP_PKEY *privatekey;
    762   /* Chain for this certificate */
    763   STACK_OF(X509) *chain;
    764 
    765   /* key_method, if non-NULL, is a set of callbacks to call for private key
    766    * operations. */
    767   const SSL_PRIVATE_KEY_METHOD *key_method;
    768 
    769   /* For clients the following masks are of *disabled* key and auth algorithms
    770    * based on the current configuration.
    771    *
    772    * TODO(davidben): Remove these. They get checked twice: when sending the
    773    * ClientHello and when processing the ServerHello. */
    774   uint32_t mask_k;
    775   uint32_t mask_a;
    776 
    777   DH *dh_tmp;
    778   DH *(*dh_tmp_cb)(SSL *ssl, int is_export, int keysize);
    779 
    780   /* peer_sigalgs are the algorithm/hash pairs that the peer supports. These
    781    * are taken from the contents of signature algorithms extension for a server
    782    * or from the CertificateRequest for a client. */
    783   TLS_SIGALGS *peer_sigalgs;
    784   /* peer_sigalgslen is the number of entries in |peer_sigalgs|. */
    785   size_t peer_sigalgslen;
    786 
    787   /* digest_nids, if non-NULL, is the set of digests supported by |privatekey|
    788    * in decreasing order of preference. */
    789   int *digest_nids;
    790   size_t num_digest_nids;
    791 
    792   /* Certificate setup callback: if set is called whenever a
    793    * certificate may be required (client or server). the callback
    794    * can then examine any appropriate parameters and setup any
    795    * certificates required. This allows advanced applications
    796    * to select certificates on the fly: for example based on
    797    * supported signature algorithms or curves. */
    798   int (*cert_cb)(SSL *ssl, void *arg);
    799   void *cert_cb_arg;
    800 } CERT;
    801 
    802 /* SSL_METHOD is a compatibility structure to support the legacy version-locked
    803  * methods. */
    804 struct ssl_method_st {
    805   /* version, if non-zero, is the only protocol version acceptable to an
    806    * SSL_CTX initialized from this method. */
    807   uint16_t version;
    808   /* method is the underlying SSL_PROTOCOL_METHOD that initializes the
    809    * SSL_CTX. */
    810   const SSL_PROTOCOL_METHOD *method;
    811 };
    812 
    813 /* Used to hold functions for SSLv2 or SSLv3/TLSv1 functions */
    814 struct ssl_protocol_method_st {
    815   /* is_dtls is one if the protocol is DTLS and zero otherwise. */
    816   char is_dtls;
    817   int (*ssl_new)(SSL *ssl);
    818   void (*ssl_free)(SSL *ssl);
    819   int (*ssl_accept)(SSL *ssl);
    820   int (*ssl_connect)(SSL *ssl);
    821   long (*ssl_get_message)(SSL *ssl, int header_state, int body_state,
    822                           int msg_type, long max,
    823                           enum ssl_hash_message_t hash_message, int *ok);
    824   int (*ssl_read_app_data)(SSL *ssl, uint8_t *buf, int len, int peek);
    825   int (*ssl_read_change_cipher_spec)(SSL *ssl);
    826   void (*ssl_read_close_notify)(SSL *ssl);
    827   int (*ssl_write_app_data)(SSL *ssl, const void *buf_, int len);
    828   int (*ssl_dispatch_alert)(SSL *ssl);
    829   /* supports_cipher returns one if |cipher| is supported by this protocol and
    830    * zero otherwise. */
    831   int (*supports_cipher)(const SSL_CIPHER *cipher);
    832   /* Handshake header length */
    833   unsigned int hhlen;
    834   /* Set the handshake header */
    835   int (*set_handshake_header)(SSL *ssl, int type, unsigned long len);
    836   /* Write out handshake message */
    837   int (*do_write)(SSL *ssl);
    838 };
    839 
    840 /* This is for the SSLv3/TLSv1.0 differences in crypto/hash stuff It is a bit
    841  * of a mess of functions, but hell, think of it as an opaque structure. */
    842 struct ssl3_enc_method {
    843   int (*prf)(SSL *, uint8_t *, size_t, const uint8_t *, size_t, const char *,
    844              size_t, const uint8_t *, size_t, const uint8_t *, size_t);
    845   int (*setup_key_block)(SSL *);
    846   int (*generate_master_secret)(SSL *, uint8_t *, const uint8_t *, size_t);
    847   int (*change_cipher_state)(SSL *, int);
    848   int (*final_finish_mac)(SSL *, const char *, int, uint8_t *);
    849   int (*cert_verify_mac)(SSL *, int, uint8_t *);
    850   const char *client_finished_label;
    851   int client_finished_label_len;
    852   const char *server_finished_label;
    853   int server_finished_label_len;
    854   int (*alert_value)(int);
    855   int (*export_keying_material)(SSL *, uint8_t *, size_t, const char *, size_t,
    856                                 const uint8_t *, size_t, int use_context);
    857   /* Various flags indicating protocol version requirements */
    858   unsigned int enc_flags;
    859 };
    860 
    861 #define SSL_HM_HEADER_LENGTH(ssl) ssl->method->hhlen
    862 #define ssl_handshake_start(ssl) \
    863   (((uint8_t *)ssl->init_buf->data) + ssl->method->hhlen)
    864 #define ssl_set_handshake_header(ssl, htype, len) \
    865   ssl->method->set_handshake_header(ssl, htype, len)
    866 #define ssl_do_write(ssl) ssl->method->do_write(ssl)
    867 
    868 /* Values for enc_flags */
    869 
    870 /* Uses explicit IV for CBC mode */
    871 #define SSL_ENC_FLAG_EXPLICIT_IV 0x1
    872 /* Uses signature algorithms extension */
    873 #define SSL_ENC_FLAG_SIGALGS 0x2
    874 /* Uses SHA256 default PRF */
    875 #define SSL_ENC_FLAG_SHA256_PRF 0x4
    876 
    877 /* lengths of messages */
    878 #define DTLS1_COOKIE_LENGTH 256
    879 
    880 #define DTLS1_RT_HEADER_LENGTH 13
    881 
    882 #define DTLS1_HM_HEADER_LENGTH 12
    883 
    884 #define DTLS1_CCS_HEADER_LENGTH 1
    885 
    886 #define DTLS1_AL_HEADER_LENGTH 2
    887 
    888 /* TODO(davidben): This structure is used for both incoming messages and
    889  * outgoing messages. |is_ccs| and |epoch| are only used in the latter and
    890  * should be moved elsewhere. */
    891 struct hm_header_st {
    892   uint8_t type;
    893   uint32_t msg_len;
    894   uint16_t seq;
    895   uint32_t frag_off;
    896   uint32_t frag_len;
    897   int is_ccs;
    898   /* epoch, for buffered outgoing messages, is the epoch the message was
    899    * originally sent in. */
    900   uint16_t epoch;
    901 };
    902 
    903 /* TODO(davidben): This structure is used for both incoming messages and
    904  * outgoing messages. |fragment| and |reassembly| are only used in the former
    905  * and should be moved elsewhere. */
    906 typedef struct hm_fragment_st {
    907   struct hm_header_st msg_header;
    908   uint8_t *fragment;
    909   uint8_t *reassembly;
    910 } hm_fragment;
    911 
    912 typedef struct dtls1_state_st {
    913   /* send_cookie is true if we are resending the ClientHello
    914    * with a cookie from a HelloVerifyRequest. */
    915   unsigned int send_cookie;
    916 
    917   uint8_t cookie[DTLS1_COOKIE_LENGTH];
    918   size_t cookie_len;
    919 
    920   /* The current data and handshake epoch.  This is initially undefined, and
    921    * starts at zero once the initial handshake is completed. */
    922   uint16_t r_epoch;
    923   uint16_t w_epoch;
    924 
    925   /* records being received in the current epoch */
    926   DTLS1_BITMAP bitmap;
    927 
    928   /* handshake message numbers.
    929    * TODO(davidben): It doesn't make much sense to store both of these. Only
    930    * store one. */
    931   uint16_t handshake_write_seq;
    932   uint16_t next_handshake_write_seq;
    933 
    934   uint16_t handshake_read_seq;
    935 
    936   /* save last sequence number for retransmissions */
    937   uint8_t last_write_sequence[8];
    938 
    939   /* buffered_messages is a priority queue of incoming handshake messages that
    940    * have yet to be processed.
    941    *
    942    * TODO(davidben): This data structure may as well be a ring buffer of fixed
    943    * size. */
    944   pqueue buffered_messages;
    945 
    946   /* send_messages is a priority queue of outgoing handshake messages sent in
    947    * the most recent handshake flight.
    948    *
    949    * TODO(davidben): This data structure may as well be a STACK_OF(T). */
    950   pqueue sent_messages;
    951 
    952   unsigned int mtu; /* max DTLS packet size */
    953 
    954   struct hm_header_st w_msg_hdr;
    955 
    956   /* num_timeouts is the number of times the retransmit timer has fired since
    957    * the last time it was reset. */
    958   unsigned int num_timeouts;
    959 
    960   /* Indicates when the last handshake msg or heartbeat sent will
    961    * timeout. */
    962   struct timeval next_timeout;
    963 
    964   /* Timeout duration */
    965   unsigned short timeout_duration;
    966 } DTLS1_STATE;
    967 
    968 extern const SSL3_ENC_METHOD TLSv1_enc_data;
    969 extern const SSL3_ENC_METHOD TLSv1_1_enc_data;
    970 extern const SSL3_ENC_METHOD TLSv1_2_enc_data;
    971 extern const SSL3_ENC_METHOD SSLv3_enc_data;
    972 extern const SRTP_PROTECTION_PROFILE kSRTPProfiles[];
    973 
    974 void ssl_clear_cipher_ctx(SSL *ssl);
    975 int ssl_clear_bad_session(SSL *ssl);
    976 CERT *ssl_cert_new(void);
    977 CERT *ssl_cert_dup(CERT *cert);
    978 void ssl_cert_clear_certs(CERT *c);
    979 void ssl_cert_free(CERT *c);
    980 int ssl_get_new_session(SSL *ssl, int is_server);
    981 
    982 enum ssl_session_result_t {
    983   ssl_session_success,
    984   ssl_session_error,
    985   ssl_session_retry,
    986 };
    987 
    988 /* ssl_get_prev_session looks up the previous session based on |ctx|. On
    989  * success, it sets |*out_session| to the session or NULL if none was found. It
    990  * sets |*out_send_ticket| to whether a ticket should be sent at the end of the
    991  * handshake. If the session could not be looked up synchronously, it returns
    992  * |ssl_session_retry| and should be called again. Otherwise, it returns
    993  * |ssl_session_error|.  */
    994 enum ssl_session_result_t ssl_get_prev_session(
    995     SSL *ssl, SSL_SESSION **out_session, int *out_send_ticket,
    996     const struct ssl_early_callback_ctx *ctx);
    997 
    998 STACK_OF(SSL_CIPHER) *ssl_bytes_to_cipher_list(SSL *ssl, const CBS *cbs);
    999 void ssl_cipher_preference_list_free(
   1000     struct ssl_cipher_preference_list_st *cipher_list);
   1001 struct ssl_cipher_preference_list_st *ssl_get_cipher_preferences(SSL *ssl);
   1002 
   1003 int ssl_cert_set0_chain(CERT *cert, STACK_OF(X509) *chain);
   1004 int ssl_cert_set1_chain(CERT *cert, STACK_OF(X509) *chain);
   1005 int ssl_cert_add0_chain_cert(CERT *cert, X509 *x509);
   1006 int ssl_cert_add1_chain_cert(CERT *cert, X509 *x509);
   1007 void ssl_cert_set_cert_cb(CERT *cert,
   1008                           int (*cb)(SSL *ssl, void *arg), void *arg);
   1009 
   1010 int ssl_verify_cert_chain(SSL *ssl, STACK_OF(X509) *cert_chain);
   1011 int ssl_add_cert_chain(SSL *ssl, unsigned long *l);
   1012 void ssl_update_cache(SSL *ssl, int mode);
   1013 
   1014 /* ssl_get_compatible_server_ciphers determines the key exchange and
   1015  * authentication cipher suite masks compatible with the server configuration
   1016  * and current ClientHello parameters of |ssl|. It sets |*out_mask_k| to the key
   1017  * exchange mask and |*out_mask_a| to the authentication mask. */
   1018 void ssl_get_compatible_server_ciphers(SSL *ssl, uint32_t *out_mask_k,
   1019                                        uint32_t *out_mask_a);
   1020 
   1021 STACK_OF(SSL_CIPHER) *ssl_get_ciphers_by_id(SSL *ssl);
   1022 int ssl_verify_alarm_type(long type);
   1023 
   1024 /* ssl_fill_hello_random fills a client_random or server_random field of length
   1025  * |len|. It returns one on success and zero on failure. */
   1026 int ssl_fill_hello_random(uint8_t *out, size_t len, int is_server);
   1027 
   1028 int ssl3_send_server_certificate(SSL *ssl);
   1029 int ssl3_send_new_session_ticket(SSL *ssl);
   1030 int ssl3_send_certificate_status(SSL *ssl);
   1031 int ssl3_get_finished(SSL *ssl, int state_a, int state_b);
   1032 int ssl3_send_change_cipher_spec(SSL *ssl, int state_a, int state_b);
   1033 int ssl3_prf(SSL *ssl, uint8_t *out, size_t out_len, const uint8_t *secret,
   1034              size_t secret_len, const char *label, size_t label_len,
   1035              const uint8_t *seed1, size_t seed1_len,
   1036              const uint8_t *seed2, size_t seed2_len);
   1037 void ssl3_cleanup_key_block(SSL *ssl);
   1038 int ssl3_do_write(SSL *ssl, int type);
   1039 int ssl3_send_alert(SSL *ssl, int level, int desc);
   1040 int ssl3_get_req_cert_type(SSL *ssl, uint8_t *p);
   1041 long ssl3_get_message(SSL *ssl, int header_state, int body_state, int msg_type,
   1042                       long max, enum ssl_hash_message_t hash_message, int *ok);
   1043 
   1044 /* ssl3_hash_current_message incorporates the current handshake message into the
   1045  * handshake hash. It returns one on success and zero on allocation failure. */
   1046 int ssl3_hash_current_message(SSL *ssl);
   1047 
   1048 /* ssl3_cert_verify_hash writes the CertificateVerify hash into the bytes
   1049  * pointed to by |out| and writes the number of bytes to |*out_len|. |out| must
   1050  * have room for EVP_MAX_MD_SIZE bytes. For TLS 1.2 and up, |*out_md| is used
   1051  * for the hash function, otherwise the hash function depends on |pkey_type|
   1052  * and is written to |*out_md|. It returns one on success and zero on
   1053  * failure. */
   1054 int ssl3_cert_verify_hash(SSL *ssl, uint8_t *out, size_t *out_len,
   1055                           const EVP_MD **out_md, int pkey_type);
   1056 
   1057 int ssl3_send_finished(SSL *ssl, int a, int b, const char *sender, int slen);
   1058 int ssl3_supports_cipher(const SSL_CIPHER *cipher);
   1059 int ssl3_dispatch_alert(SSL *ssl);
   1060 int ssl3_read_app_data(SSL *ssl, uint8_t *buf, int len, int peek);
   1061 int ssl3_read_change_cipher_spec(SSL *ssl);
   1062 void ssl3_read_close_notify(SSL *ssl);
   1063 int ssl3_read_bytes(SSL *ssl, int type, uint8_t *buf, int len, int peek);
   1064 int ssl3_write_app_data(SSL *ssl, const void *buf, int len);
   1065 int ssl3_write_bytes(SSL *ssl, int type, const void *buf, int len);
   1066 int ssl3_final_finish_mac(SSL *ssl, const char *sender, int slen, uint8_t *p);
   1067 int ssl3_cert_verify_mac(SSL *ssl, int md_nid, uint8_t *p);
   1068 int ssl3_output_cert_chain(SSL *ssl);
   1069 const SSL_CIPHER *ssl3_choose_cipher(
   1070     SSL *ssl, STACK_OF(SSL_CIPHER) *clnt,
   1071     struct ssl_cipher_preference_list_st *srvr);
   1072 
   1073 int ssl3_new(SSL *ssl);
   1074 void ssl3_free(SSL *ssl);
   1075 int ssl3_accept(SSL *ssl);
   1076 int ssl3_connect(SSL *ssl);
   1077 
   1078 /* ssl3_record_sequence_update increments the sequence number in |seq|. It
   1079  * returns one on success and zero on wraparound. */
   1080 int ssl3_record_sequence_update(uint8_t *seq, size_t seq_len);
   1081 
   1082 int ssl3_do_change_cipher_spec(SSL *ssl);
   1083 
   1084 int ssl3_set_handshake_header(SSL *ssl, int htype, unsigned long len);
   1085 int ssl3_handshake_write(SSL *ssl);
   1086 
   1087 int dtls1_do_handshake_write(SSL *ssl, enum dtls1_use_epoch_t use_epoch);
   1088 int dtls1_read_app_data(SSL *ssl, uint8_t *buf, int len, int peek);
   1089 int dtls1_read_change_cipher_spec(SSL *ssl);
   1090 void dtls1_read_close_notify(SSL *ssl);
   1091 int dtls1_read_bytes(SSL *ssl, int type, uint8_t *buf, int len, int peek);
   1092 void dtls1_set_message_header(SSL *ssl, uint8_t mt, unsigned long len,
   1093                               unsigned short seq_num, unsigned long frag_off,
   1094                               unsigned long frag_len);
   1095 
   1096 int dtls1_write_app_data(SSL *ssl, const void *buf, int len);
   1097 int dtls1_write_bytes(SSL *ssl, int type, const void *buf, int len,
   1098                       enum dtls1_use_epoch_t use_epoch);
   1099 
   1100 int dtls1_send_change_cipher_spec(SSL *ssl, int a, int b);
   1101 int dtls1_send_finished(SSL *ssl, int a, int b, const char *sender, int slen);
   1102 int dtls1_read_failed(SSL *ssl, int code);
   1103 int dtls1_buffer_message(SSL *ssl);
   1104 int dtls1_retransmit_buffered_messages(SSL *ssl);
   1105 void dtls1_clear_record_buffer(SSL *ssl);
   1106 void dtls1_get_message_header(uint8_t *data, struct hm_header_st *msg_hdr);
   1107 int dtls1_check_timeout_num(SSL *ssl);
   1108 int dtls1_set_handshake_header(SSL *ssl, int type, unsigned long len);
   1109 int dtls1_handshake_write(SSL *ssl);
   1110 
   1111 int dtls1_supports_cipher(const SSL_CIPHER *cipher);
   1112 void dtls1_start_timer(SSL *ssl);
   1113 void dtls1_stop_timer(SSL *ssl);
   1114 int dtls1_is_timer_expired(SSL *ssl);
   1115 void dtls1_double_timeout(SSL *ssl);
   1116 unsigned int dtls1_min_mtu(void);
   1117 void dtls1_hm_fragment_free(hm_fragment *frag);
   1118 
   1119 /* some client-only functions */
   1120 int ssl3_send_client_hello(SSL *ssl);
   1121 int ssl3_get_server_hello(SSL *ssl);
   1122 int ssl3_get_certificate_request(SSL *ssl);
   1123 int ssl3_get_new_session_ticket(SSL *ssl);
   1124 int ssl3_get_cert_status(SSL *ssl);
   1125 int ssl3_get_server_done(SSL *ssl);
   1126 int ssl3_send_cert_verify(SSL *ssl);
   1127 int ssl3_send_client_certificate(SSL *ssl);
   1128 int ssl_do_client_cert_cb(SSL *ssl, X509 **px509, EVP_PKEY **ppkey);
   1129 int ssl3_send_client_key_exchange(SSL *ssl);
   1130 int ssl3_get_server_key_exchange(SSL *ssl);
   1131 int ssl3_get_server_certificate(SSL *ssl);
   1132 int ssl3_send_next_proto(SSL *ssl);
   1133 int ssl3_send_channel_id(SSL *ssl);
   1134 int ssl3_verify_server_cert(SSL *ssl);
   1135 
   1136 /* some server-only functions */
   1137 int ssl3_get_initial_bytes(SSL *ssl);
   1138 int ssl3_get_v2_client_hello(SSL *ssl);
   1139 int ssl3_get_client_hello(SSL *ssl);
   1140 int ssl3_send_server_hello(SSL *ssl);
   1141 int ssl3_send_server_key_exchange(SSL *ssl);
   1142 int ssl3_send_certificate_request(SSL *ssl);
   1143 int ssl3_send_server_done(SSL *ssl);
   1144 int ssl3_get_client_certificate(SSL *ssl);
   1145 int ssl3_get_client_key_exchange(SSL *ssl);
   1146 int ssl3_get_cert_verify(SSL *ssl);
   1147 int ssl3_get_next_proto(SSL *ssl);
   1148 int ssl3_get_channel_id(SSL *ssl);
   1149 
   1150 int dtls1_new(SSL *ssl);
   1151 int dtls1_accept(SSL *ssl);
   1152 int dtls1_connect(SSL *ssl);
   1153 void dtls1_free(SSL *ssl);
   1154 
   1155 long dtls1_get_message(SSL *ssl, int st1, int stn, int mt, long max,
   1156                        enum ssl_hash_message_t hash_message, int *ok);
   1157 int dtls1_dispatch_alert(SSL *ssl);
   1158 
   1159 int ssl_init_wbio_buffer(SSL *ssl, int push);
   1160 void ssl_free_wbio_buffer(SSL *ssl);
   1161 
   1162 /* tls1_prf computes the TLS PRF function for |ssl| as described in RFC 5246,
   1163  * section 5 and RFC 2246 section 5. It writes |out_len| bytes to |out|, using
   1164  * |secret| as the secret and |label| as the label. |seed1| and |seed2| are
   1165  * concatenated to form the seed parameter. It returns one on success and zero
   1166  * on failure. */
   1167 int tls1_prf(SSL *ssl, uint8_t *out, size_t out_len, const uint8_t *secret,
   1168              size_t secret_len, const char *label, size_t label_len,
   1169              const uint8_t *seed1, size_t seed1_len,
   1170              const uint8_t *seed2, size_t seed2_len);
   1171 
   1172 int tls1_change_cipher_state(SSL *ssl, int which);
   1173 int tls1_setup_key_block(SSL *ssl);
   1174 int tls1_handshake_digest(SSL *ssl, uint8_t *out, size_t out_len);
   1175 int tls1_final_finish_mac(SSL *ssl, const char *str, int slen, uint8_t *p);
   1176 int tls1_cert_verify_mac(SSL *ssl, int md_nid, uint8_t *p);
   1177 int tls1_generate_master_secret(SSL *ssl, uint8_t *out, const uint8_t *premaster,
   1178                                 size_t premaster_len);
   1179 int tls1_export_keying_material(SSL *ssl, uint8_t *out, size_t out_len,
   1180                                 const char *label, size_t label_len,
   1181                                 const uint8_t *context, size_t context_len,
   1182                                 int use_context);
   1183 int tls1_alert_code(int code);
   1184 int ssl3_alert_code(int code);
   1185 
   1186 char ssl_early_callback_init(struct ssl_early_callback_ctx *ctx);
   1187 
   1188 /* tls1_check_curve_id returns one if |curve_id| is consistent with both our
   1189  * and the peer's curve preferences. Note: if called as the client, only our
   1190  * preferences are checked; the peer (the server) does not send preferences. */
   1191 int tls1_check_curve_id(SSL *ssl, uint16_t curve_id);
   1192 
   1193 /* tls1_get_shared_curve sets |*out_curve_id| to the first preferred shared
   1194  * curve between client and server preferences and returns one. If none may be
   1195  * found, it returns zero. */
   1196 int tls1_get_shared_curve(SSL *ssl, uint16_t *out_curve_id);
   1197 
   1198 /* tls1_set_curves converts the array of |ncurves| NIDs pointed to by |curves|
   1199  * into a newly allocated array of TLS curve IDs. On success, the function
   1200  * returns one and writes the array to |*out_curve_ids| and its size to
   1201  * |*out_curve_ids_len|. Otherwise, it returns zero. */
   1202 int tls1_set_curves(uint16_t **out_curve_ids, size_t *out_curve_ids_len,
   1203                     const int *curves, size_t ncurves);
   1204 
   1205 /* tls1_check_ec_cert returns one if |x| is an ECC certificate with curve and
   1206  * point format compatible with the client's preferences. Otherwise it returns
   1207  * zero. */
   1208 int tls1_check_ec_cert(SSL *ssl, X509 *x);
   1209 
   1210 /* ssl_add_clienthello_tlsext writes ClientHello extensions to |out|. It
   1211  * returns one on success and zero on failure. The |header_len| argument is the
   1212  * length of the ClientHello written so far and is used to compute the padding
   1213  * length. (It does not include the record header.) */
   1214 int ssl_add_clienthello_tlsext(SSL *ssl, CBB *out, size_t header_len);
   1215 
   1216 int ssl_add_serverhello_tlsext(SSL *ssl, CBB *out);
   1217 int ssl_parse_clienthello_tlsext(SSL *ssl, CBS *cbs);
   1218 int ssl_parse_serverhello_tlsext(SSL *ssl, CBS *cbs);
   1219 
   1220 #define tlsext_tick_md EVP_sha256
   1221 
   1222 /* tls_process_ticket processes the session ticket extension. On success, it
   1223  * sets |*out_session| to the decrypted session or NULL if the ticket was
   1224  * rejected. It sets |*out_send_ticket| to whether a new ticket should be sent
   1225  * at the end of the handshake. It returns one on success and zero on fatal
   1226  * error. */
   1227 int tls_process_ticket(SSL *ssl, SSL_SESSION **out_session,
   1228                        int *out_send_ticket, const uint8_t *ticket,
   1229                        size_t ticket_len, const uint8_t *session_id,
   1230                        size_t session_id_len);
   1231 
   1232 /* tls12_add_sigandhash assembles the SignatureAndHashAlgorithm corresponding to
   1233  * |ssl|'s private key and |md|. The two-byte value is written to |out|. It
   1234  * returns one on success and zero on failure. */
   1235 int tls12_add_sigandhash(SSL *ssl, CBB *out, const EVP_MD *md);
   1236 
   1237 int tls12_get_sigid(int pkey_type);
   1238 const EVP_MD *tls12_get_hash(uint8_t hash_alg);
   1239 
   1240 /* tls1_channel_id_hash computes the hash to be signed by Channel ID and writes
   1241  * it to |out|, which must contain at least |EVP_MAX_MD_SIZE| bytes. It returns
   1242  * one on success and zero on failure. */
   1243 int tls1_channel_id_hash(SSL *ssl, uint8_t *out, size_t *out_len);
   1244 
   1245 int tls1_record_handshake_hashes_for_channel_id(SSL *ssl);
   1246 
   1247 /* ssl_log_rsa_client_key_exchange logs |premaster|, if logging is enabled for
   1248  * |ssl|. It returns one on success and zero on failure. The entry is identified
   1249  * by the first 8 bytes of |encrypted_premaster|. */
   1250 int ssl_log_rsa_client_key_exchange(const SSL *ssl,
   1251                                     const uint8_t *encrypted_premaster,
   1252                                     size_t encrypted_premaster_len,
   1253                                     const uint8_t *premaster,
   1254                                     size_t premaster_len);
   1255 
   1256 /* ssl_log_master_secret logs |master|, if logging is enabled for |ssl|. It
   1257  * returns one on success and zero on failure. The entry is identified by
   1258  * |client_random|. */
   1259 int ssl_log_master_secret(const SSL *ssl, const uint8_t *client_random,
   1260                           size_t client_random_len, const uint8_t *master,
   1261                           size_t master_len);
   1262 
   1263 /* ssl3_can_false_start returns one if |ssl| is allowed to False Start and zero
   1264  * otherwise. */
   1265 int ssl3_can_false_start(const SSL *ssl);
   1266 
   1267 /* ssl3_get_enc_method returns the SSL3_ENC_METHOD corresponding to
   1268  * |version|. */
   1269 const SSL3_ENC_METHOD *ssl3_get_enc_method(uint16_t version);
   1270 
   1271 /* ssl3_get_max_server_version returns the maximum SSL/TLS version number
   1272  * supported by |ssl| as a server, or zero if all versions are disabled. */
   1273 uint16_t ssl3_get_max_server_version(const SSL *ssl);
   1274 
   1275 /* ssl3_get_mutual_version selects the protocol version on |ssl| for a client
   1276  * which advertises |client_version|. If no suitable version exists, it returns
   1277  * zero. */
   1278 uint16_t ssl3_get_mutual_version(SSL *ssl, uint16_t client_version);
   1279 
   1280 /* ssl3_get_max_client_version returns the maximum protocol version configured
   1281  * for the client. It is guaranteed that the set of allowed versions at or below
   1282  * this maximum version is contiguous. If all versions are disabled, it returns
   1283  * zero. */
   1284 uint16_t ssl3_get_max_client_version(SSL *ssl);
   1285 
   1286 /* ssl3_is_version_enabled returns one if |version| is an enabled protocol
   1287  * version for |ssl| and zero otherwise. */
   1288 int ssl3_is_version_enabled(SSL *ssl, uint16_t version);
   1289 
   1290 /* ssl3_version_from_wire maps |wire_version| to a protocol version. For
   1291  * SSLv3/TLS, the version is returned as-is. For DTLS, the corresponding TLS
   1292  * version is used. Note that this mapping is not injective but preserves
   1293  * comparisons.
   1294  *
   1295  * TODO(davidben): To normalize some DTLS-specific code, move away from using
   1296  * the wire version except at API boundaries. */
   1297 uint16_t ssl3_version_from_wire(SSL *ssl, uint16_t wire_version);
   1298 
   1299 uint32_t ssl_get_algorithm_prf(SSL *ssl);
   1300 int tls1_parse_peer_sigalgs(SSL *ssl, const CBS *sigalgs);
   1301 
   1302 /* tls1_choose_signing_digest returns a digest for use with |ssl|'s private key
   1303  * based on the peer's preferences the digests supported. */
   1304 const EVP_MD *tls1_choose_signing_digest(SSL *ssl);
   1305 
   1306 size_t tls12_get_psigalgs(SSL *ssl, const uint8_t **psigs);
   1307 
   1308 /* tls12_check_peer_sigalg checks that |hash| and |signature| are consistent
   1309  * with |pkey| and |ssl|'s sent, supported signature algorithms and, if so,
   1310  * writes the relevant digest into |*out_md| and returns 1. Otherwise it
   1311  * returns 0 and writes an alert into |*out_alert|. */
   1312 int tls12_check_peer_sigalg(SSL *ssl, const EVP_MD **out_md, int *out_alert,
   1313                             uint8_t hash, uint8_t signature, EVP_PKEY *pkey);
   1314 void ssl_set_client_disabled(SSL *ssl);
   1315 
   1316 #endif /* OPENSSL_HEADER_SSL_INTERNAL_H */
   1317