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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_H
    143 #define OPENSSL_HEADER_SSL_H
    144 
    145 #include <openssl/base.h>
    146 
    147 #include <openssl/bio.h>
    148 #include <openssl/buf.h>
    149 #include <openssl/hmac.h>
    150 #include <openssl/lhash.h>
    151 #include <openssl/pem.h>
    152 #include <openssl/ssl3.h>
    153 #include <openssl/thread.h>
    154 #include <openssl/tls1.h>
    155 #include <openssl/x509.h>
    156 
    157 #if !defined(OPENSSL_WINDOWS)
    158 #include <sys/time.h>
    159 #endif
    160 
    161 /* wpa_supplicant expects to get the version functions from ssl.h */
    162 #include <openssl/crypto.h>
    163 
    164 /* Forward-declare struct timeval. On Windows, it is defined in winsock2.h and
    165  * Windows headers define too many macros to be included in public headers.
    166  * However, only a forward declaration is needed. */
    167 struct timeval;
    168 
    169 #if defined(__cplusplus)
    170 extern "C" {
    171 #endif
    172 
    173 
    174 /* SSL implementation. */
    175 
    176 
    177 /* SSL contexts.
    178  *
    179  * |SSL_CTX| objects manage shared state and configuration between multiple TLS
    180  * or DTLS connections. Whether the connections are TLS or DTLS is selected by
    181  * an |SSL_METHOD| on creation.
    182  *
    183  * |SSL_CTX| are reference-counted and may be shared by connections across
    184  * multiple threads. Once shared, functions which change the |SSL_CTX|'s
    185  * configuration may not be used. */
    186 
    187 /* TLS_method is the |SSL_METHOD| used for TLS (and SSLv3) connections. */
    188 OPENSSL_EXPORT const SSL_METHOD *TLS_method(void);
    189 
    190 /* DTLS_method is the |SSL_METHOD| used for DTLS connections. */
    191 OPENSSL_EXPORT const SSL_METHOD *DTLS_method(void);
    192 
    193 /* SSL_CTX_new returns a newly-allocated |SSL_CTX| with default settings or NULL
    194  * on error. */
    195 OPENSSL_EXPORT SSL_CTX *SSL_CTX_new(const SSL_METHOD *method);
    196 
    197 /* SSL_CTX_free releases memory associated with |ctx|. */
    198 OPENSSL_EXPORT void SSL_CTX_free(SSL_CTX *ctx);
    199 
    200 
    201 /* SSL connections.
    202  *
    203  * An |SSL| object represents a single TLS or DTLS connection. Although the
    204  * shared |SSL_CTX| is thread-safe, an |SSL| is not thread-safe and may only be
    205  * used on one thread at a time. */
    206 
    207 /* SSL_new returns a newly-allocated |SSL| using |ctx| or NULL on error. The new
    208  * connection inherits settings from |ctx| at the time of creation. Settings may
    209  * also be individually configured on the connection.
    210  *
    211  * On creation, an |SSL| is not configured to be either a client or server. Call
    212  * |SSL_set_connect_state| or |SSL_set_accept_state| to set this. */
    213 OPENSSL_EXPORT SSL *SSL_new(SSL_CTX *ctx);
    214 
    215 /* SSL_free releases memory associated with |ssl|. */
    216 OPENSSL_EXPORT void SSL_free(SSL *ssl);
    217 
    218 /* SSL_get_SSL_CTX returns the |SSL_CTX| associated with |ssl|. If
    219  * |SSL_set_SSL_CTX| is called, it returns the new |SSL_CTX|, not the initial
    220  * one. */
    221 OPENSSL_EXPORT SSL_CTX *SSL_get_SSL_CTX(const SSL *ssl);
    222 
    223 /* SSL_set_connect_state configures |ssl| to be a client. */
    224 OPENSSL_EXPORT void SSL_set_connect_state(SSL *ssl);
    225 
    226 /* SSL_set_accept_state configures |ssl| to be a server. */
    227 OPENSSL_EXPORT void SSL_set_accept_state(SSL *ssl);
    228 
    229 /* SSL_is_server returns one if |ssl| is configured as a server and zero
    230  * otherwise. */
    231 OPENSSL_EXPORT int SSL_is_server(SSL *ssl);
    232 
    233 /* SSL_set_bio configures |ssl| to read from |rbio| and write to |wbio|. |ssl|
    234  * takes ownership of the two |BIO|s. If |rbio| and |wbio| are the same, |ssl|
    235  * only takes ownership of one reference.
    236  *
    237  * In DTLS, if |rbio| is blocking, it must handle
    238  * |BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT| control requests to set read timeouts.
    239  *
    240  * Calling this function on an already-configured |ssl| is deprecated. */
    241 OPENSSL_EXPORT void SSL_set_bio(SSL *ssl, BIO *rbio, BIO *wbio);
    242 
    243 /* SSL_get_rbio returns the |BIO| that |ssl| reads from. */
    244 OPENSSL_EXPORT BIO *SSL_get_rbio(const SSL *ssl);
    245 
    246 /* SSL_get_wbio returns the |BIO| that |ssl| writes to. */
    247 OPENSSL_EXPORT BIO *SSL_get_wbio(const SSL *ssl);
    248 
    249 /* SSL_get_fd calls |SSL_get_rfd|. */
    250 OPENSSL_EXPORT int SSL_get_fd(const SSL *ssl);
    251 
    252 /* SSL_get_rfd returns the file descriptor that |ssl| is configured to read
    253  * from. If |ssl|'s read |BIO| is not configured or doesn't wrap a file
    254  * descriptor then it returns -1. */
    255 OPENSSL_EXPORT int SSL_get_rfd(const SSL *ssl);
    256 
    257 /* SSL_get_wfd returns the file descriptor that |ssl| is configured to write
    258  * to. If |ssl|'s write |BIO| is not configured or doesn't wrap a file
    259  * descriptor then it returns -1. */
    260 OPENSSL_EXPORT int SSL_get_wfd(const SSL *ssl);
    261 
    262 /* SSL_set_fd configures |ssl| to read from and write to |fd|. It returns one
    263  * on success and zero on allocation error. The caller retains ownership of
    264  * |fd|. */
    265 OPENSSL_EXPORT int SSL_set_fd(SSL *ssl, int fd);
    266 
    267 /* SSL_set_rfd configures |ssl| to read from |fd|. It returns one on success and
    268  * zero on allocation error. The caller retains ownership of |fd|. */
    269 OPENSSL_EXPORT int SSL_set_rfd(SSL *ssl, int fd);
    270 
    271 /* SSL_set_wfd configures |ssl| to write to |fd|. It returns one on success and
    272  * zero on allocation error. The caller retains ownership of |fd|. */
    273 OPENSSL_EXPORT int SSL_set_wfd(SSL *ssl, int fd);
    274 
    275 /* SSL_do_handshake continues the current handshake. If there is none or the
    276  * handshake has completed or False Started, it returns one. Otherwise, it
    277  * returns <= 0. The caller should pass the value into |SSL_get_error| to
    278  * determine how to proceed.
    279  *
    280  * In DTLS, if the read |BIO| is non-blocking, the caller must drive
    281  * retransmissions. Whenever |SSL_get_error| signals |SSL_ERROR_WANT_READ|, use
    282  * |DTLSv1_get_timeout| to determine the current timeout. If it expires before
    283  * the next retry, call |DTLSv1_handle_timeout|. Note that DTLS handshake
    284  * retransmissions use fresh sequence numbers, so it is not sufficient to replay
    285  * packets at the transport.
    286  *
    287  * TODO(davidben): Ensure 0 is only returned on transport EOF.
    288  * https://crbug.com/466303. */
    289 OPENSSL_EXPORT int SSL_do_handshake(SSL *ssl);
    290 
    291 /* SSL_connect configures |ssl| as a client, if unconfigured, and calls
    292  * |SSL_do_handshake|. */
    293 OPENSSL_EXPORT int SSL_connect(SSL *ssl);
    294 
    295 /* SSL_accept configures |ssl| as a server, if unconfigured, and calls
    296  * |SSL_do_handshake|. */
    297 OPENSSL_EXPORT int SSL_accept(SSL *ssl);
    298 
    299 /* SSL_read reads up to |num| bytes from |ssl| into |buf|. It implicitly runs
    300  * any pending handshakes, including renegotiations when enabled. On success, it
    301  * returns the number of bytes read. Otherwise, it returns <= 0. The caller
    302  * should pass the value into |SSL_get_error| to determine how to proceed.
    303  *
    304  * TODO(davidben): Ensure 0 is only returned on transport EOF.
    305  * https://crbug.com/466303. */
    306 OPENSSL_EXPORT int SSL_read(SSL *ssl, void *buf, int num);
    307 
    308 /* SSL_peek behaves like |SSL_read| but does not consume any bytes returned. */
    309 OPENSSL_EXPORT int SSL_peek(SSL *ssl, void *buf, int num);
    310 
    311 /* SSL_pending returns the number of bytes available in |ssl|. It does not read
    312  * from the transport. */
    313 OPENSSL_EXPORT int SSL_pending(const SSL *ssl);
    314 
    315 /* SSL_write writes up to |num| bytes from |buf| into |ssl|. It implicitly runs
    316  * any pending handshakes, including renegotiations when enabled. On success, it
    317  * returns the number of bytes read. Otherwise, it returns <= 0. The caller
    318  * should pass the value into |SSL_get_error| to determine how to proceed.
    319  *
    320  * In TLS, a non-blocking |SSL_write| differs from non-blocking |write| in that
    321  * a failed |SSL_write| still commits to the data passed in. When retrying, the
    322  * caller must supply the original write buffer (or a larger one containing the
    323  * original as a prefix). By default, retries will fail if they also do not
    324  * reuse the same |buf| pointer. This may be relaxed with
    325  * |SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER|, but the buffer contents still must be
    326  * unchanged.
    327  *
    328  * By default, in TLS, |SSL_write| will not return success until all |num| bytes
    329  * are written. This may be relaxed with |SSL_MODE_ENABLE_PARTIAL_WRITE|. It
    330  * allows |SSL_write| to complete with a partial result when only part of the
    331  * input was written in a single record.
    332  *
    333  * In DTLS, neither |SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER| and
    334  * |SSL_MODE_ENABLE_PARTIAL_WRITE| do anything. The caller may retry with a
    335  * different buffer freely. A single call to |SSL_write| only ever writes a
    336  * single record in a single packet, so |num| must be at most
    337  * |SSL3_RT_MAX_PLAIN_LENGTH|.
    338  *
    339  * TODO(davidben): Ensure 0 is only returned on transport EOF.
    340  * https://crbug.com/466303. */
    341 OPENSSL_EXPORT int SSL_write(SSL *ssl, const void *buf, int num);
    342 
    343 /* SSL_shutdown shuts down |ssl|. On success, it completes in two stages. First,
    344  * it returns 0 if |ssl| completed uni-directional shutdown; close_notify has
    345  * been sent, but the peer's close_notify has not been received. Most callers
    346  * may stop at this point. For bi-directional shutdown, call |SSL_shutdown|
    347  * again. It returns 1 if close_notify has been both sent and received.
    348  *
    349  * If the peer's close_notify arrived first, the first stage is skipped.
    350  * |SSL_shutdown| will return 1 once close_notify is sent and skip 0. Callers
    351  * only interested in uni-directional shutdown must therefore allow for the
    352  * first stage returning either 0 or 1.
    353  *
    354  * |SSL_shutdown| returns -1 on failure. The caller should pass the return value
    355  * into |SSL_get_error| to determine how to proceed. If the underlying |BIO| is
    356  * non-blocking, both stages may require retry.
    357  *
    358  * |SSL_shutdown| must be called to retain |ssl|'s session in the session
    359  * cache. Use |SSL_CTX_set_quiet_shutdown| to configure |SSL_shutdown| to
    360  * neither send nor wait for close_notify but still retain the session.
    361  *
    362  * TODO(davidben): Is there any point in the session cache interaction? Remove
    363  * it? */
    364 OPENSSL_EXPORT int SSL_shutdown(SSL *ssl);
    365 
    366 /* SSL_CTX_set_quiet_shutdown sets quiet shutdown on |ctx| to |mode|. If
    367  * enabled, |SSL_shutdown| will not send a close_notify alert or wait for one
    368  * from the peer. It will instead synchronously return one. */
    369 OPENSSL_EXPORT void SSL_CTX_set_quiet_shutdown(SSL_CTX *ctx, int mode);
    370 
    371 /* SSL_CTX_get_quiet_shutdown returns whether quiet shutdown is enabled for
    372  * |ctx|. */
    373 OPENSSL_EXPORT int SSL_CTX_get_quiet_shutdown(const SSL_CTX *ctx);
    374 
    375 /* SSL_set_quiet_shutdown sets quiet shutdown on |ssl| to |mode|. If enabled,
    376  * |SSL_shutdown| will not send a close_notify alert or wait for one from the
    377  * peer. It will instead synchronously return one. */
    378 OPENSSL_EXPORT void SSL_set_quiet_shutdown(SSL *ssl, int mode);
    379 
    380 /* SSL_get_quiet_shutdown returns whether quiet shutdown is enabled for
    381  * |ssl|. */
    382 OPENSSL_EXPORT int SSL_get_quiet_shutdown(const SSL *ssl);
    383 
    384 /* SSL_get_error returns a |SSL_ERROR_*| value for the most recent operation on
    385  * |ssl|. It should be called after an operation failed to determine whether the
    386  * error was fatal and, if not, when to retry. */
    387 OPENSSL_EXPORT int SSL_get_error(const SSL *ssl, int ret_code);
    388 
    389 /* SSL_ERROR_NONE indicates the operation succeeded. */
    390 #define SSL_ERROR_NONE 0
    391 
    392 /* SSL_ERROR_SSL indicates the operation failed within the library. The caller
    393  * may inspect the error queue for more information. */
    394 #define SSL_ERROR_SSL 1
    395 
    396 /* SSL_ERROR_WANT_READ indicates the operation failed attempting to read from
    397  * the transport. The caller may retry the operation when the transport is ready
    398  * for reading.
    399  *
    400  * If signaled by a DTLS handshake, the caller must also call
    401  * |DTLSv1_get_timeout| and |DTLSv1_handle_timeout| as appropriate. See
    402  * |SSL_do_handshake|. */
    403 #define SSL_ERROR_WANT_READ 2
    404 
    405 /* SSL_ERROR_WANT_WRITE indicates the operation failed attempting to write to
    406  * the transport. The caller may retry the operation when the transport is ready
    407  * for writing. */
    408 #define SSL_ERROR_WANT_WRITE 3
    409 
    410 /* SSL_ERROR_WANT_X509_LOOKUP indicates the operation failed in calling the
    411  * |cert_cb| or |client_cert_cb|. The caller may retry the operation when the
    412  * callback is ready to return a certificate or one has been configured
    413  * externally.
    414  *
    415  * See also |SSL_CTX_set_cert_cb| and |SSL_CTX_set_client_cert_cb|. */
    416 #define SSL_ERROR_WANT_X509_LOOKUP 4
    417 
    418 /* SSL_ERROR_WANT_SYSCALL indicates the operation failed externally to the
    419  * library. The caller should consult the system-specific error mechanism. This
    420  * is typically |errno| but may be something custom if using a custom |BIO|. It
    421  * may also be signaled if the transport returned EOF, in which case the
    422  * operation's return value will be zero. */
    423 #define SSL_ERROR_SYSCALL 5
    424 
    425 /* SSL_ERROR_ZERO_RETURN indicates the operation failed because the connection
    426  * was cleanly shut down with a close_notify alert. */
    427 #define SSL_ERROR_ZERO_RETURN 6
    428 
    429 /* SSL_ERROR_WANT_CONNECT indicates the operation failed attempting to connect
    430  * the transport (the |BIO| signaled |BIO_RR_CONNECT|). The caller may retry the
    431  * operation when the transport is ready. */
    432 #define SSL_ERROR_WANT_CONNECT 7
    433 
    434 /* SSL_ERROR_WANT_ACCEPT indicates the operation failed attempting to accept a
    435  * connection from the transport (the |BIO| signaled |BIO_RR_ACCEPT|). The
    436  * caller may retry the operation when the transport is ready.
    437  *
    438  * TODO(davidben): Remove this. It's used by accept BIOs which are bizarre. */
    439 #define SSL_ERROR_WANT_ACCEPT 8
    440 
    441 /* SSL_ERROR_WANT_CHANNEL_ID_LOOKUP indicates the operation failed looking up
    442  * the Channel ID key. The caller may retry the operation when |channel_id_cb|
    443  * is ready to return a key or one has been configured with
    444  * |SSL_set1_tls_channel_id|.
    445  *
    446  * See also |SSL_CTX_set_channel_id_cb|. */
    447 #define SSL_ERROR_WANT_CHANNEL_ID_LOOKUP 9
    448 
    449 /* SSL_ERROR_PENDING_SESSION indicates the operation failed because the session
    450  * lookup callback indicated the session was unavailable. The caller may retry
    451  * the operation when lookup has completed.
    452  *
    453  * See also |SSL_CTX_sess_set_get_cb| and |SSL_magic_pending_session_ptr|. */
    454 #define SSL_ERROR_PENDING_SESSION 11
    455 
    456 /* SSL_ERROR_PENDING_CERTIFICATE indicates the operation failed because the
    457  * early callback indicated certificate lookup was incomplete. The caller may
    458  * retry the operation when lookup has completed. Note: when the operation is
    459  * retried, the early callback will not be called a second time.
    460  *
    461  * See also |SSL_CTX_set_select_certificate_cb|. */
    462 #define SSL_ERROR_PENDING_CERTIFICATE 12
    463 
    464 /* SSL_ERROR_WANT_PRIVATE_KEY_OPERATION indicates the operation failed because
    465  * a private key operation was unfinished. The caller may retry the operation
    466  * when the private key operation is complete.
    467  *
    468  * See also |SSL_set_private_key_method|. */
    469 #define SSL_ERROR_WANT_PRIVATE_KEY_OPERATION 13
    470 
    471 /* SSL_set_mtu sets the |ssl|'s MTU in DTLS to |mtu|. It returns one on success
    472  * and zero on failure. */
    473 OPENSSL_EXPORT int SSL_set_mtu(SSL *ssl, unsigned mtu);
    474 
    475 /* DTLSv1_get_timeout queries the next DTLS handshake timeout. If there is a
    476  * timeout in progress, it sets |*out| to the time remaining and returns one.
    477  * Otherwise, it returns zero.
    478  *
    479  * When the timeout expires, call |DTLSv1_handle_timeout| to handle the
    480  * retransmit behavior.
    481  *
    482  * NOTE: This function must be queried again whenever the handshake state
    483  * machine changes, including when |DTLSv1_handle_timeout| is called. */
    484 OPENSSL_EXPORT int DTLSv1_get_timeout(const SSL *ssl, struct timeval *out);
    485 
    486 /* DTLSv1_handle_timeout is called when a DTLS handshake timeout expires. If no
    487  * timeout had expired, it returns 0. Otherwise, it retransmits the previous
    488  * flight of handshake messages and returns 1. If too many timeouts had expired
    489  * without progress or an error occurs, it returns -1.
    490  *
    491  * The caller's external timer should be compatible with the one |ssl| queries
    492  * within some fudge factor. Otherwise, the call will be a no-op, but
    493  * |DTLSv1_get_timeout| will return an updated timeout.
    494  *
    495  * If the function returns -1, checking if |SSL_get_error| returns
    496  * |SSL_ERROR_WANT_WRITE| may be used to determine if the retransmit failed due
    497  * to a non-fatal error at the write |BIO|. However, the operation may not be
    498  * retried until the next timeout fires.
    499  *
    500  * WARNING: This function breaks the usual return value convention.
    501  *
    502  * TODO(davidben): This |SSL_ERROR_WANT_WRITE| behavior is kind of bizarre. */
    503 OPENSSL_EXPORT int DTLSv1_handle_timeout(SSL *ssl);
    504 
    505 
    506 /* Protocol versions. */
    507 
    508 #define DTLS1_VERSION_MAJOR 0xfe
    509 #define SSL3_VERSION_MAJOR 0x03
    510 
    511 #define SSL3_VERSION 0x0300
    512 #define TLS1_VERSION 0x0301
    513 #define TLS1_1_VERSION 0x0302
    514 #define TLS1_2_VERSION 0x0303
    515 
    516 #define DTLS1_VERSION 0xfeff
    517 #define DTLS1_2_VERSION 0xfefd
    518 
    519 /* SSL_CTX_set_min_version sets the minimum protocol version for |ctx| to
    520  * |version|. */
    521 OPENSSL_EXPORT void SSL_CTX_set_min_version(SSL_CTX *ctx, uint16_t version);
    522 
    523 /* SSL_CTX_set_max_version sets the maximum protocol version for |ctx| to
    524  * |version|. */
    525 OPENSSL_EXPORT void SSL_CTX_set_max_version(SSL_CTX *ctx, uint16_t version);
    526 
    527 /* SSL_set_min_version sets the minimum protocol version for |ssl| to
    528  * |version|. */
    529 OPENSSL_EXPORT void SSL_set_min_version(SSL *ssl, uint16_t version);
    530 
    531 /* SSL_set_max_version sets the maximum protocol version for |ssl| to
    532  * |version|. */
    533 OPENSSL_EXPORT void SSL_set_max_version(SSL *ssl, uint16_t version);
    534 
    535 /* SSL_version returns the TLS or DTLS protocol version used by |ssl|, which is
    536  * one of the |*_VERSION| values. (E.g. |TLS1_2_VERSION|.) Before the version
    537  * is negotiated, the result is undefined. */
    538 OPENSSL_EXPORT int SSL_version(const SSL *ssl);
    539 
    540 
    541 /* Options.
    542  *
    543  * Options configure protocol behavior. */
    544 
    545 /* SSL_OP_NO_QUERY_MTU, in DTLS, disables querying the MTU from the underlying
    546  * |BIO|. Instead, the MTU is configured with |SSL_set_mtu|. */
    547 #define SSL_OP_NO_QUERY_MTU 0x00001000L
    548 
    549 /* SSL_OP_NO_TICKET disables session ticket support (RFC 5077). */
    550 #define SSL_OP_NO_TICKET 0x00004000L
    551 
    552 /* SSL_OP_CIPHER_SERVER_PREFERENCE configures servers to select ciphers and
    553  * ECDHE curves according to the server's preferences instead of the
    554  * client's. */
    555 #define SSL_OP_CIPHER_SERVER_PREFERENCE 0x00400000L
    556 
    557 /* SSL_OP_DISABLE_NPN configures an individual |SSL| to not advertise NPN,
    558  * despite |SSL_CTX_set_next_proto_select_cb| being configured on the
    559  * |SSL_CTX|. */
    560 #define SSL_OP_DISABLE_NPN 0x00800000L
    561 
    562 /* SSL_CTX_set_options enables all options set in |options| (which should be one
    563  * or more of the |SSL_OP_*| values, ORed together) in |ctx|. It returns a
    564  * bitmask representing the resulting enabled options. */
    565 OPENSSL_EXPORT uint32_t SSL_CTX_set_options(SSL_CTX *ctx, uint32_t options);
    566 
    567 /* SSL_CTX_clear_options disables all options set in |options| (which should be
    568  * one or more of the |SSL_OP_*| values, ORed together) in |ctx|. It returns a
    569  * bitmask representing the resulting enabled options. */
    570 OPENSSL_EXPORT uint32_t SSL_CTX_clear_options(SSL_CTX *ctx, uint32_t options);
    571 
    572 /* SSL_CTX_get_options returns a bitmask of |SSL_OP_*| values that represent all
    573  * the options enabled for |ctx|. */
    574 OPENSSL_EXPORT uint32_t SSL_CTX_get_options(const SSL_CTX *ctx);
    575 
    576 /* SSL_set_options enables all options set in |options| (which should be one or
    577  * more of the |SSL_OP_*| values, ORed together) in |ssl|. It returns a bitmask
    578  * representing the resulting enabled options. */
    579 OPENSSL_EXPORT uint32_t SSL_set_options(SSL *ssl, uint32_t options);
    580 
    581 /* SSL_clear_options disables all options set in |options| (which should be one
    582  * or more of the |SSL_OP_*| values, ORed together) in |ssl|. It returns a
    583  * bitmask representing the resulting enabled options. */
    584 OPENSSL_EXPORT uint32_t SSL_clear_options(SSL *ssl, uint32_t options);
    585 
    586 /* SSL_get_options returns a bitmask of |SSL_OP_*| values that represent all the
    587  * options enabled for |ssl|. */
    588 OPENSSL_EXPORT uint32_t SSL_get_options(const SSL *ssl);
    589 
    590 
    591 /* Modes.
    592  *
    593  * Modes configure API behavior. */
    594 
    595 /* SSL_MODE_ENABLE_PARTIAL_WRITE, in TLS, allows |SSL_write| to complete with a
    596  * partial result when the only part of the input was written in a single
    597  * record. In DTLS, it does nothing. */
    598 #define SSL_MODE_ENABLE_PARTIAL_WRITE 0x00000001L
    599 
    600 /* SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER, in TLS, allows retrying an incomplete
    601  * |SSL_write| with a different buffer. However, |SSL_write| still assumes the
    602  * buffer contents are unchanged. This is not the default to avoid the
    603  * misconception that non-blocking |SSL_write| behaves like non-blocking
    604  * |write|. In DTLS, it does nothing. */
    605 #define SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER 0x00000002L
    606 
    607 /* SSL_MODE_NO_AUTO_CHAIN disables automatically building a certificate chain
    608  * before sending certificates to the peer.
    609  * TODO(davidben): Remove this behavior. https://crbug.com/486295. */
    610 #define SSL_MODE_NO_AUTO_CHAIN 0x00000008L
    611 
    612 /* SSL_MODE_ENABLE_FALSE_START allows clients to send application data before
    613  * receipt of ChangeCipherSpec and Finished. This mode enables full-handshakes
    614  * to 'complete' in one RTT. See draft-bmoeller-tls-falsestart-01.
    615  *
    616  * When False Start is enabled, |SSL_do_handshake| may succeed before the
    617  * handshake has completely finished. |SSL_write| will function at this point,
    618  * and |SSL_read| will transparently wait for the final handshake leg before
    619  * returning application data. To determine if False Start occurred or when the
    620  * handshake is completely finished, see |SSL_in_false_start|, |SSL_in_init|,
    621  * and |SSL_CB_HANDSHAKE_DONE| from |SSL_CTX_set_info_callback|. */
    622 #define SSL_MODE_ENABLE_FALSE_START 0x00000080L
    623 
    624 /* SSL_MODE_CBC_RECORD_SPLITTING causes multi-byte CBC records in SSL 3.0 and
    625  * TLS 1.0 to be split in two: the first record will contain a single byte and
    626  * the second will contain the remainder. This effectively randomises the IV and
    627  * prevents BEAST attacks. */
    628 #define SSL_MODE_CBC_RECORD_SPLITTING 0x00000100L
    629 
    630 /* SSL_MODE_NO_SESSION_CREATION will cause any attempts to create a session to
    631  * fail with SSL_R_SESSION_MAY_NOT_BE_CREATED. This can be used to enforce that
    632  * session resumption is used for a given SSL*. */
    633 #define SSL_MODE_NO_SESSION_CREATION 0x00000200L
    634 
    635 /* SSL_MODE_SEND_FALLBACK_SCSV sends TLS_FALLBACK_SCSV in the ClientHello.
    636  * To be set only by applications that reconnect with a downgraded protocol
    637  * version; see RFC 7507 for details.
    638  *
    639  * DO NOT ENABLE THIS if your application attempts a normal handshake. Only use
    640  * this in explicit fallback retries, following the guidance in RFC 7507. */
    641 #define SSL_MODE_SEND_FALLBACK_SCSV 0x00000400L
    642 
    643 /* SSL_CTX_set_mode enables all modes set in |mode| (which should be one or more
    644  * of the |SSL_MODE_*| values, ORed together) in |ctx|. It returns a bitmask
    645  * representing the resulting enabled modes. */
    646 OPENSSL_EXPORT uint32_t SSL_CTX_set_mode(SSL_CTX *ctx, uint32_t mode);
    647 
    648 /* SSL_CTX_clear_mode disables all modes set in |mode| (which should be one or
    649  * more of the |SSL_MODE_*| values, ORed together) in |ctx|. It returns a
    650  * bitmask representing the resulting enabled modes. */
    651 OPENSSL_EXPORT uint32_t SSL_CTX_clear_mode(SSL_CTX *ctx, uint32_t mode);
    652 
    653 /* SSL_CTX_get_mode returns a bitmask of |SSL_MODE_*| values that represent all
    654  * the modes enabled for |ssl|. */
    655 OPENSSL_EXPORT uint32_t SSL_CTX_get_mode(const SSL_CTX *ctx);
    656 
    657 /* SSL_set_mode enables all modes set in |mode| (which should be one or more of
    658  * the |SSL_MODE_*| values, ORed together) in |ssl|. It returns a bitmask
    659  * representing the resulting enabled modes. */
    660 OPENSSL_EXPORT uint32_t SSL_set_mode(SSL *ssl, uint32_t mode);
    661 
    662 /* SSL_clear_mode disables all modes set in |mode| (which should be one or more
    663  * of the |SSL_MODE_*| values, ORed together) in |ssl|. It returns a bitmask
    664  * representing the resulting enabled modes. */
    665 OPENSSL_EXPORT uint32_t SSL_clear_mode(SSL *ssl, uint32_t mode);
    666 
    667 /* SSL_get_mode returns a bitmask of |SSL_MODE_*| values that represent all the
    668  * modes enabled for |ssl|. */
    669 OPENSSL_EXPORT uint32_t SSL_get_mode(const SSL *ssl);
    670 
    671 
    672 /* Configuring certificates and private keys.
    673  *
    674  * These functions configure the connection's leaf certificate, private key, and
    675  * certificate chain. The certificate chain is ordered leaf to root (as sent on
    676  * the wire) but does not include the leaf. Both client and server certificates
    677  * use these functions.
    678  *
    679  * Certificates and keys may be configured before the handshake or dynamically
    680  * in the early callback and certificate callback. */
    681 
    682 /* SSL_CTX_use_certificate sets |ctx|'s leaf certificate to |x509|. It returns
    683  * one on success and zero on failure. */
    684 OPENSSL_EXPORT int SSL_CTX_use_certificate(SSL_CTX *ctx, X509 *x509);
    685 
    686 /* SSL_use_certificate sets |ssl|'s leaf certificate to |x509|. It returns one
    687  * on success and zero on failure. */
    688 OPENSSL_EXPORT int SSL_use_certificate(SSL *ssl, X509 *x509);
    689 
    690 /* SSL_CTX_use_PrivateKey sets |ctx|'s private key to |pkey|. It returns one on
    691  * success and zero on failure. */
    692 OPENSSL_EXPORT int SSL_CTX_use_PrivateKey(SSL_CTX *ctx, EVP_PKEY *pkey);
    693 
    694 /* SSL_use_PrivateKey sets |ssl|'s private key to |pkey|. It returns one on
    695  * success and zero on failure. */
    696 OPENSSL_EXPORT int SSL_use_PrivateKey(SSL *ssl, EVP_PKEY *pkey);
    697 
    698 /* SSL_CTX_set0_chain sets |ctx|'s certificate chain, excluding the leaf, to
    699  * |chain|. On success, it returns one and takes ownership of |chain|.
    700  * Otherwise, it returns zero. */
    701 OPENSSL_EXPORT int SSL_CTX_set0_chain(SSL_CTX *ctx, STACK_OF(X509) *chain);
    702 
    703 /* SSL_CTX_set1_chain sets |ctx|'s certificate chain, excluding the leaf, to
    704  * |chain|. It returns one on success and zero on failure. The caller retains
    705  * ownership of |chain| and may release it freely. */
    706 OPENSSL_EXPORT int SSL_CTX_set1_chain(SSL_CTX *ctx, STACK_OF(X509) *chain);
    707 
    708 /* SSL_set0_chain sets |ssl|'s certificate chain, excluding the leaf, to
    709  * |chain|. On success, it returns one and takes ownership of |chain|.
    710  * Otherwise, it returns zero. */
    711 OPENSSL_EXPORT int SSL_set0_chain(SSL *ssl, STACK_OF(X509) *chain);
    712 
    713 /* SSL_set1_chain sets |ssl|'s certificate chain, excluding the leaf, to
    714  * |chain|. It returns one on success and zero on failure. The caller retains
    715  * ownership of |chain| and may release it freely. */
    716 OPENSSL_EXPORT int SSL_set1_chain(SSL *ssl, STACK_OF(X509) *chain);
    717 
    718 /* SSL_CTX_add0_chain_cert appends |x509| to |ctx|'s certificate chain. On
    719  * success, it returns one and takes ownership of |x509|. Otherwise, it returns
    720  * zero. */
    721 OPENSSL_EXPORT int SSL_CTX_add0_chain_cert(SSL_CTX *ctx, X509 *x509);
    722 
    723 /* SSL_CTX_add1_chain_cert appends |x509| to |ctx|'s certificate chain. It
    724  * returns one on success and zero on failure. The caller retains ownership of
    725  * |x509| and may release it freely. */
    726 OPENSSL_EXPORT int SSL_CTX_add1_chain_cert(SSL_CTX *ctx, X509 *x509);
    727 
    728 /* SSL_add0_chain_cert appends |x509| to |ctx|'s certificate chain. On success,
    729  * it returns one and takes ownership of |x509|. Otherwise, it returns zero. */
    730 OPENSSL_EXPORT int SSL_add0_chain_cert(SSL *ssl, X509 *x509);
    731 
    732 /* SSL_CTX_add_extra_chain_cert calls |SSL_CTX_add0_chain_cert|. */
    733 OPENSSL_EXPORT int SSL_CTX_add_extra_chain_cert(SSL_CTX *ctx, X509 *x509);
    734 
    735 /* SSL_add1_chain_cert appends |x509| to |ctx|'s certificate chain. It returns
    736  * one on success and zero on failure. The caller retains ownership of |x509|
    737  * and may release it freely. */
    738 OPENSSL_EXPORT int SSL_add1_chain_cert(SSL *ssl, X509 *x509);
    739 
    740 /* SSL_CTX_clear_chain_certs clears |ctx|'s certificate chain and returns
    741  * one. */
    742 OPENSSL_EXPORT int SSL_CTX_clear_chain_certs(SSL_CTX *ctx);
    743 
    744 /* SSL_CTX_clear_extra_chain_certs calls |SSL_CTX_clear_chain_certs|. */
    745 OPENSSL_EXPORT int SSL_CTX_clear_extra_chain_certs(SSL_CTX *ctx);
    746 
    747 /* SSL_clear_chain_certs clears |ssl|'s certificate chain and returns one. */
    748 OPENSSL_EXPORT int SSL_clear_chain_certs(SSL *ssl);
    749 
    750 /* SSL_CTX_set_cert_cb sets a callback that is called to select a certificate.
    751  * The callback returns one on success, zero on internal error, and a negative
    752  * number on failure or to pause the handshake. If the handshake is paused,
    753  * |SSL_get_error| will return |SSL_ERROR_WANT_X509_LOOKUP|.
    754  *
    755  * On the client, the callback may call |SSL_get0_certificate_types| and
    756  * |SSL_get_client_CA_list| for information on the server's certificate
    757  * request. */
    758 OPENSSL_EXPORT void SSL_CTX_set_cert_cb(SSL_CTX *ctx,
    759                                         int (*cb)(SSL *ssl, void *arg),
    760                                         void *arg);
    761 
    762 /* SSL_set_cert_cb sets a callback that is called to select a certificate. The
    763  * callback returns one on success, zero on internal error, and a negative
    764  * number on failure or to pause the handshake. If the handshake is paused,
    765  * |SSL_get_error| will return |SSL_ERROR_WANT_X509_LOOKUP|.
    766  *
    767  * On the client, the callback may call |SSL_get0_certificate_types| and
    768  * |SSL_get_client_CA_list| for information on the server's certificate
    769  * request. */
    770 OPENSSL_EXPORT void SSL_set_cert_cb(SSL *ssl, int (*cb)(SSL *ssl, void *arg),
    771                                     void *arg);
    772 
    773 /* SSL_get0_certificate_types, for a client, sets |*out_types| to an array
    774  * containing the client certificate types requested by a server. It returns the
    775  * length of the array.
    776  *
    777  * The behavior of this function is undefined except during the callbacks set by
    778  * by |SSL_CTX_set_cert_cb| and |SSL_CTX_set_client_cert_cb| or when the
    779  * handshake is paused because of them. */
    780 OPENSSL_EXPORT size_t SSL_get0_certificate_types(SSL *ssl,
    781                                                  const uint8_t **out_types);
    782 
    783 /* SSL_certs_clear resets the private key, leaf certificate, and certificate
    784  * chain of |ssl|. */
    785 OPENSSL_EXPORT void SSL_certs_clear(SSL *ssl);
    786 
    787 /* SSL_CTX_check_private_key returns one if the certificate and private key
    788  * configured in |ctx| are consistent and zero otherwise. */
    789 OPENSSL_EXPORT int SSL_CTX_check_private_key(const SSL_CTX *ctx);
    790 
    791 /* SSL_check_private_key returns one if the certificate and private key
    792  * configured in |ssl| are consistent and zero otherwise. */
    793 OPENSSL_EXPORT int SSL_check_private_key(const SSL *ssl);
    794 
    795 /* SSL_CTX_get0_certificate returns |ctx|'s leaf certificate. */
    796 OPENSSL_EXPORT X509 *SSL_CTX_get0_certificate(const SSL_CTX *ctx);
    797 
    798 /* SSL_get_certificate returns |ssl|'s leaf certificate. */
    799 OPENSSL_EXPORT X509 *SSL_get_certificate(const SSL *ssl);
    800 
    801 /* SSL_CTX_get0_privatekey returns |ctx|'s private key. */
    802 OPENSSL_EXPORT EVP_PKEY *SSL_CTX_get0_privatekey(const SSL_CTX *ctx);
    803 
    804 /* SSL_get_privatekey returns |ssl|'s private key. */
    805 OPENSSL_EXPORT EVP_PKEY *SSL_get_privatekey(const SSL *ssl);
    806 
    807 /* SSL_CTX_get0_chain_certs sets |*out_chain| to |ctx|'s certificate chain and
    808  * returns one. */
    809 OPENSSL_EXPORT int SSL_CTX_get0_chain_certs(const SSL_CTX *ctx,
    810                                             STACK_OF(X509) **out_chain);
    811 
    812 /* SSL_CTX_get_extra_chain_certs calls |SSL_CTX_get0_chain_certs|. */
    813 OPENSSL_EXPORT int SSL_CTX_get_extra_chain_certs(const SSL_CTX *ctx,
    814                                                  STACK_OF(X509) **out_chain);
    815 
    816 /* SSL_get0_chain_certs sets |*out_chain| to |ssl|'s certificate chain and
    817  * returns one. */
    818 OPENSSL_EXPORT int SSL_get0_chain_certs(const SSL *ssl,
    819                                         STACK_OF(X509) **out_chain);
    820 
    821 /* SSL_CTX_set_signed_cert_timestamp_list sets the list of signed certificate
    822  * timestamps that is sent to clients that request it. The |list| argument must
    823  * contain one or more SCT structures serialised as a SignedCertificateTimestamp
    824  * List (see https://tools.ietf.org/html/rfc6962#section-3.3)  i.e. each SCT
    825  * is prefixed by a big-endian, uint16 length and the concatenation of one or
    826  * more such prefixed SCTs are themselves also prefixed by a uint16 length. It
    827  * returns one on success and zero on error. The caller retains ownership of
    828  * |list|. */
    829 OPENSSL_EXPORT int SSL_CTX_set_signed_cert_timestamp_list(SSL_CTX *ctx,
    830                                                           const uint8_t *list,
    831                                                           size_t list_len);
    832 
    833 /* SSL_CTX_set_ocsp_response sets the OCSP reponse that is sent to clients
    834  * which request it. It returns one on success and zero on error. The caller
    835  * retains ownership of |response|. */
    836 OPENSSL_EXPORT int SSL_CTX_set_ocsp_response(SSL_CTX *ctx,
    837                                              const uint8_t *response,
    838                                              size_t response_len);
    839 
    840 /* SSL_set_private_key_digest_prefs copies |num_digests| NIDs from |digest_nids|
    841  * into |ssl|. These digests will be used, in decreasing order of preference,
    842  * when signing with |ssl|'s private key. It returns one on success and zero on
    843  * error. */
    844 OPENSSL_EXPORT int SSL_set_private_key_digest_prefs(SSL *ssl,
    845                                                     const int *digest_nids,
    846                                                     size_t num_digests);
    847 
    848 
    849 /* Certificate and private key convenience functions. */
    850 
    851 /* SSL_CTX_use_RSAPrivateKey sets |ctx|'s private key to |rsa|. It returns one
    852  * on success and zero on failure. */
    853 OPENSSL_EXPORT int SSL_CTX_use_RSAPrivateKey(SSL_CTX *ctx, RSA *rsa);
    854 
    855 /* SSL_use_RSAPrivateKey sets |ctx|'s private key to |rsa|. It returns one on
    856  * success and zero on failure. */
    857 OPENSSL_EXPORT int SSL_use_RSAPrivateKey(SSL *ssl, RSA *rsa);
    858 
    859 /* The following functions configure certificates or private keys but take as
    860  * input DER-encoded structures. They return one on success and zero on
    861  * failure. */
    862 
    863 OPENSSL_EXPORT int SSL_CTX_use_certificate_ASN1(SSL_CTX *ctx, size_t der_len,
    864                                                 const uint8_t *der);
    865 OPENSSL_EXPORT int SSL_use_certificate_ASN1(SSL *ssl, const uint8_t *der,
    866                                             size_t der_len);
    867 
    868 OPENSSL_EXPORT int SSL_CTX_use_PrivateKey_ASN1(int pk, SSL_CTX *ctx,
    869                                                const uint8_t *der,
    870                                                size_t der_len);
    871 OPENSSL_EXPORT int SSL_use_PrivateKey_ASN1(int type, SSL *ssl,
    872                                            const uint8_t *der, size_t der_len);
    873 
    874 OPENSSL_EXPORT int SSL_CTX_use_RSAPrivateKey_ASN1(SSL_CTX *ctx,
    875                                                   const uint8_t *der,
    876                                                   size_t der_len);
    877 OPENSSL_EXPORT int SSL_use_RSAPrivateKey_ASN1(SSL *ssl, const uint8_t *der,
    878                                               size_t der_len);
    879 
    880 /* The following functions configure certificates or private keys but take as
    881  * input files to read from. They return one on success and zero on failure. The
    882  * |type| parameter is one of the |SSL_FILETYPE_*| values and determines whether
    883  * the file's contents are read as PEM or DER. */
    884 
    885 #define SSL_FILETYPE_ASN1 X509_FILETYPE_ASN1
    886 #define SSL_FILETYPE_PEM X509_FILETYPE_PEM
    887 
    888 OPENSSL_EXPORT int SSL_CTX_use_RSAPrivateKey_file(SSL_CTX *ctx,
    889                                                   const char *file,
    890                                                   int type);
    891 OPENSSL_EXPORT int SSL_use_RSAPrivateKey_file(SSL *ssl, const char *file,
    892                                               int type);
    893 
    894 OPENSSL_EXPORT int SSL_CTX_use_certificate_file(SSL_CTX *ctx, const char *file,
    895                                                 int type);
    896 OPENSSL_EXPORT int SSL_use_certificate_file(SSL *ssl, const char *file,
    897                                             int type);
    898 
    899 OPENSSL_EXPORT int SSL_CTX_use_PrivateKey_file(SSL_CTX *ctx, const char *file,
    900                                                int type);
    901 OPENSSL_EXPORT int SSL_use_PrivateKey_file(SSL *ssl, const char *file,
    902                                            int type);
    903 
    904 /* SSL_CTX_use_certificate_chain_file configures certificates for |ctx|. It
    905  * reads the contents of |file| as a PEM-encoded leaf certificate followed
    906  * optionally by the certificate chain to send to the peer. It returns one on
    907  * success and zero on failure. */
    908 OPENSSL_EXPORT int SSL_CTX_use_certificate_chain_file(SSL_CTX *ctx,
    909                                                       const char *file);
    910 
    911 /* SSL_CTX_set_default_passwd_cb sets the password callback for PEM-based
    912  * convenience functions called on |ctx|. */
    913 OPENSSL_EXPORT void SSL_CTX_set_default_passwd_cb(SSL_CTX *ctx,
    914                                                   pem_password_cb *cb);
    915 
    916 /* SSL_CTX_set_default_passwd_cb_userdata sets the userdata parameter for
    917  * |ctx|'s password callback. */
    918 OPENSSL_EXPORT void SSL_CTX_set_default_passwd_cb_userdata(SSL_CTX *ctx,
    919                                                            void *data);
    920 
    921 
    922 /* Custom private keys. */
    923 
    924 enum ssl_private_key_result_t {
    925   ssl_private_key_success,
    926   ssl_private_key_retry,
    927   ssl_private_key_failure,
    928 };
    929 
    930 /* SSL_PRIVATE_KEY_METHOD describes private key hooks. This is used to off-load
    931  * signing operations to a custom, potentially asynchronous, backend. */
    932 typedef struct ssl_private_key_method_st {
    933   /* type returns either |EVP_PKEY_RSA| or |EVP_PKEY_EC| to denote the type of
    934    * key used by |ssl|. */
    935   int (*type)(SSL *ssl);
    936 
    937   /* max_signature_len returns the maximum length of a signature signed by the
    938    * key used by |ssl|. This must be a constant value for a given |ssl|. */
    939   size_t (*max_signature_len)(SSL *ssl);
    940 
    941   /* sign signs |in_len| bytes of digest from |in|. |md| is the hash function
    942    * used to calculate |in|. On success, it returns |ssl_private_key_success|
    943    * and writes at most |max_out| bytes of signature data to |out|. On failure,
    944    * it returns |ssl_private_key_failure|. If the operation has not completed,
    945    * it returns |ssl_private_key_retry|. |sign| should arrange for the
    946    * high-level operation on |ssl| to be retried when the operation is
    947    * completed. This will result in a call to |sign_complete|.
    948    *
    949    * If the key is an RSA key, implementations must use PKCS#1 padding. |in| is
    950    * the digest itself, so the DigestInfo prefix, if any, must be prepended by
    951    * |sign|. If |md| is |EVP_md5_sha1|, there is no prefix.
    952    *
    953    * It is an error to call |sign| while another private key operation is in
    954    * progress on |ssl|. */
    955   enum ssl_private_key_result_t (*sign)(SSL *ssl, uint8_t *out, size_t *out_len,
    956                                         size_t max_out, const EVP_MD *md,
    957                                         const uint8_t *in, size_t in_len);
    958 
    959   /* sign_complete completes a pending |sign| operation. If the operation has
    960    * completed, it returns |ssl_private_key_success| and writes the result to
    961    * |out| as in |sign|. Otherwise, it returns |ssl_private_key_failure| on
    962    * failure and |ssl_private_key_retry| if the operation is still in progress.
    963    *
    964    * |sign_complete| may be called arbitrarily many times before completion, but
    965    * it is an error to call |sign_complete| if there is no pending |sign|
    966    * operation in progress on |ssl|. */
    967   enum ssl_private_key_result_t (*sign_complete)(SSL *ssl, uint8_t *out,
    968                                                  size_t *out_len,
    969                                                  size_t max_out);
    970 
    971   /* decrypt decrypts |in_len| bytes of encrypted data from |in|. On success it
    972    * returns |ssl_private_key_success|, writes at most |max_out| bytes of
    973    * decrypted data to |out| and sets |*out_len| to the actual number of bytes
    974    * written. On failure it returns |ssl_private_key_failure|. If the operation
    975    * has not completed, it returns |ssl_private_key_retry|. The caller should
    976    * arrange for the high-level operation on |ssl| to be retried when the
    977    * operation is completed, which will result in a call to |decrypt_complete|.
    978    * This function only works with RSA keys and should perform a raw RSA
    979    * decryption operation with no padding.
    980    *
    981    * It is an error to call |decrypt| while another private key operation is in
    982    * progress on |ssl|. */
    983   enum ssl_private_key_result_t (*decrypt)(SSL *ssl, uint8_t *out,
    984                                            size_t *out_len, size_t max_out,
    985                                            const uint8_t *in, size_t in_len);
    986 
    987   /* decrypt_complete completes a pending |decrypt| operation. If the operation
    988    * has completed, it returns |ssl_private_key_success| and writes the result
    989    * to |out| as in |decrypt|. Otherwise, it returns |ssl_private_key_failure|
    990    * on failure and |ssl_private_key_retry| if the operation is still in
    991    * progress.
    992    *
    993    * |decrypt_complete| may be called arbitrarily many times before completion,
    994    * but it is an error to call |decrypt_complete| if there is no pending
    995    * |decrypt| operation in progress on |ssl|. */
    996   enum ssl_private_key_result_t (*decrypt_complete)(SSL *ssl, uint8_t *out,
    997                                                     size_t *out_len,
    998                                                     size_t max_out);
    999 } SSL_PRIVATE_KEY_METHOD;
   1000 
   1001 /* SSL_set_private_key_method configures a custom private key on |ssl|.
   1002  * |key_method| must remain valid for the lifetime of |ssl|. */
   1003 OPENSSL_EXPORT void SSL_set_private_key_method(
   1004     SSL *ssl, const SSL_PRIVATE_KEY_METHOD *key_method);
   1005 
   1006 
   1007 /* Cipher suites.
   1008  *
   1009  * |SSL_CIPHER| objects represent cipher suites. */
   1010 
   1011 DECLARE_STACK_OF(SSL_CIPHER)
   1012 
   1013 /* SSL_get_cipher_by_value returns the structure representing a TLS cipher
   1014  * suite based on its assigned number, or NULL if unknown. See
   1015  * https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-4. */
   1016 OPENSSL_EXPORT const SSL_CIPHER *SSL_get_cipher_by_value(uint16_t value);
   1017 
   1018 /* SSL_CIPHER_get_id returns |cipher|'s id. It may be cast to a |uint16_t| to
   1019  * get the cipher suite value. */
   1020 OPENSSL_EXPORT uint32_t SSL_CIPHER_get_id(const SSL_CIPHER *cipher);
   1021 
   1022 /* SSL_CIPHER_is_AES returns one if |cipher| uses AES (either GCM or CBC
   1023  * mode). */
   1024 OPENSSL_EXPORT int SSL_CIPHER_is_AES(const SSL_CIPHER *cipher);
   1025 
   1026 /* SSL_CIPHER_has_MD5_HMAC returns one if |cipher| uses HMAC-MD5. */
   1027 OPENSSL_EXPORT int SSL_CIPHER_has_MD5_HMAC(const SSL_CIPHER *cipher);
   1028 
   1029 /* SSL_CIPHER_has_SHA1_HMAC returns one if |cipher| uses HMAC-SHA1. */
   1030 OPENSSL_EXPORT int SSL_CIPHER_has_SHA1_HMAC(const SSL_CIPHER *cipher);
   1031 
   1032 /* SSL_CIPHER_is_AESGCM returns one if |cipher| uses AES-GCM. */
   1033 OPENSSL_EXPORT int SSL_CIPHER_is_AESGCM(const SSL_CIPHER *cipher);
   1034 
   1035 /* SSL_CIPHER_is_AES128GCM returns one if |cipher| uses 128-bit AES-GCM. */
   1036 OPENSSL_EXPORT int SSL_CIPHER_is_AES128GCM(const SSL_CIPHER *cipher);
   1037 
   1038 /* SSL_CIPHER_is_AES128CBC returns one if |cipher| uses 128-bit AES in CBC
   1039  * mode. */
   1040 OPENSSL_EXPORT int SSL_CIPHER_is_AES128CBC(const SSL_CIPHER *cipher);
   1041 
   1042 /* SSL_CIPHER_is_AES256CBC returns one if |cipher| uses 256-bit AES in CBC
   1043  * mode. */
   1044 OPENSSL_EXPORT int SSL_CIPHER_is_AES256CBC(const SSL_CIPHER *cipher);
   1045 
   1046 /* SSL_CIPHER_is_CHACHA20POLY1305 returns one if |cipher| uses
   1047  * CHACHA20_POLY1305. Note this includes both the
   1048  * draft-ietf-tls-chacha20-poly1305-04 and draft-agl-tls-chacha20poly1305-04
   1049  * versions. */
   1050 OPENSSL_EXPORT int SSL_CIPHER_is_CHACHA20POLY1305(const SSL_CIPHER *cipher);
   1051 
   1052 /* SSL_CIPHER_is_NULL returns one if |cipher| does not encrypt. */
   1053 OPENSSL_EXPORT int SSL_CIPHER_is_NULL(const SSL_CIPHER *cipher);
   1054 
   1055 /* SSL_CIPHER_is_RC4 returns one if |cipher| uses RC4. */
   1056 OPENSSL_EXPORT int SSL_CIPHER_is_RC4(const SSL_CIPHER *cipher);
   1057 
   1058 /* SSL_CIPHER_is_block_cipher returns one if |cipher| is a block cipher. */
   1059 OPENSSL_EXPORT int SSL_CIPHER_is_block_cipher(const SSL_CIPHER *cipher);
   1060 
   1061 /* SSL_CIPHER_is_ECDSA returns one if |cipher| uses ECDSA. */
   1062 OPENSSL_EXPORT int SSL_CIPHER_is_ECDSA(const SSL_CIPHER *cipher);
   1063 
   1064 /* SSL_CIPHER_is_ECDHE returns one if |cipher| uses ECDHE. */
   1065 OPENSSL_EXPORT int SSL_CIPHER_is_ECDHE(const SSL_CIPHER *cipher);
   1066 
   1067 /* SSL_CIPHER_get_min_version returns the minimum protocol version required
   1068  * for |cipher|. */
   1069 OPENSSL_EXPORT uint16_t SSL_CIPHER_get_min_version(const SSL_CIPHER *cipher);
   1070 
   1071 /* SSL_CIPHER_get_name returns the OpenSSL name of |cipher|. */
   1072 OPENSSL_EXPORT const char *SSL_CIPHER_get_name(const SSL_CIPHER *cipher);
   1073 
   1074 /* SSL_CIPHER_get_kx_name returns a string that describes the key-exchange
   1075  * method used by |cipher|. For example, "ECDHE_ECDSA". */
   1076 OPENSSL_EXPORT const char *SSL_CIPHER_get_kx_name(const SSL_CIPHER *cipher);
   1077 
   1078 /* SSL_CIPHER_get_rfc_name returns a newly-allocated string with the standard
   1079  * name for |cipher| or NULL on error. For example,
   1080  * "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256". The caller is responsible for
   1081  * calling |OPENSSL_free| on the result. */
   1082 OPENSSL_EXPORT char *SSL_CIPHER_get_rfc_name(const SSL_CIPHER *cipher);
   1083 
   1084 /* SSL_CIPHER_get_bits returns the strength, in bits, of |cipher|. If
   1085  * |out_alg_bits| is not NULL, it writes the number of bits consumed by the
   1086  * symmetric algorithm to |*out_alg_bits|. */
   1087 OPENSSL_EXPORT int SSL_CIPHER_get_bits(const SSL_CIPHER *cipher,
   1088                                        int *out_alg_bits);
   1089 
   1090 
   1091 /* Cipher suite configuration.
   1092  *
   1093  * OpenSSL uses a mini-language to configure cipher suites. The language
   1094  * maintains an ordered list of enabled ciphers, along with an ordered list of
   1095  * disabled but available ciphers. Initially, all ciphers are disabled with a
   1096  * default ordering. The cipher string is then interpreted as a sequence of
   1097  * directives, separated by colons, each of which modifies this state.
   1098  *
   1099  * Most directives consist of a one character or empty opcode followed by a
   1100  * selector which matches a subset of available ciphers.
   1101  *
   1102  * Available opcodes are:
   1103  *
   1104  *   The empty opcode enables and appends all matching disabled ciphers to the
   1105  *   end of the enabled list. The newly appended ciphers are ordered relative to
   1106  *   each other matching their order in the disabled list.
   1107  *
   1108  *   |-| disables all matching enabled ciphers and prepends them to the disabled
   1109  *   list, with relative order from the enabled list preserved. This means the
   1110  *   most recently disabled ciphers get highest preference relative to other
   1111  *   disabled ciphers if re-enabled.
   1112  *
   1113  *   |+| moves all matching enabled ciphers to the end of the enabled list, with
   1114  *   relative order preserved.
   1115  *
   1116  *   |!| deletes all matching ciphers, enabled or not, from either list. Deleted
   1117  *   ciphers will not matched by future operations.
   1118  *
   1119  * A selector may be a specific cipher (using the OpenSSL name for the cipher)
   1120  * or one or more rules separated by |+|. The final selector matches the
   1121  * intersection of each rule. For instance, |AESGCM+aECDSA| matches
   1122  * ECDSA-authenticated AES-GCM ciphers.
   1123  *
   1124  * Available cipher rules are:
   1125  *
   1126  *   |ALL| matches all ciphers.
   1127  *
   1128  *   |kRSA|, |kDHE|, |kECDHE|, and |kPSK| match ciphers using plain RSA, DHE,
   1129  *   ECDHE, and plain PSK key exchanges, respectively. Note that ECDHE_PSK is
   1130  *   matched by |kECDHE| and not |kPSK|.
   1131  *
   1132  *   |aRSA|, |aECDSA|, and |aPSK| match ciphers authenticated by RSA, ECDSA, and
   1133  *   a pre-shared key, respectively.
   1134  *
   1135  *   |RSA|, |DHE|, |ECDHE|, |PSK|, |ECDSA|, and |PSK| are aliases for the
   1136  *   corresponding |k*| or |a*| cipher rule. |RSA| is an alias for |kRSA|, not
   1137  *   |aRSA|.
   1138  *
   1139  *   |3DES|, |RC4|, |AES128|, |AES256|, |AES|, |AESGCM|, |CHACHA20| match
   1140  *   ciphers whose bulk cipher use the corresponding encryption scheme. Note
   1141  *   that |AES|, |AES128|, and |AES256| match both CBC and GCM ciphers.
   1142  *
   1143  *   |MD5|, |SHA1|, |SHA256|, and |SHA384| match legacy cipher suites using the
   1144  *   corresponding hash function in their MAC. AEADs are matched by none of
   1145  *   these.
   1146  *
   1147  *   |SHA| is an alias for |SHA1|.
   1148  *
   1149  * Although implemented, authentication-only ciphers match no rules and must be
   1150  * explicitly selected by name.
   1151  *
   1152  * Deprecated cipher rules:
   1153  *
   1154  *   |kEDH|, |EDH|, |kEECDH|, and |EECDH| are legacy aliases for |kDHE|, |DHE|,
   1155  *   |kECDHE|, and |ECDHE|, respectively.
   1156  *
   1157  *   |MEDIUM| and |HIGH| match RC4-based ciphers and all others, respectively.
   1158  *
   1159  *   |FIPS| is an alias for |HIGH|.
   1160  *
   1161  *   |SSLv3| and |TLSv1| match ciphers available in TLS 1.1 or earlier.
   1162  *   |TLSv1_2| matches ciphers new in TLS 1.2. This is confusing and should not
   1163  *   be used.
   1164  *
   1165  * Unknown rules silently match nothing.
   1166  *
   1167  * The special |@STRENGTH| directive will sort all enabled ciphers by strength.
   1168  *
   1169  * The |DEFAULT| directive, when appearing at the front of the string, expands
   1170  * to the default ordering of available ciphers.
   1171  *
   1172  * If configuring a server, one may also configure equal-preference groups to
   1173  * partially respect the client's preferences when
   1174  * |SSL_OP_CIPHER_SERVER_PREFERENCE| is enabled. Ciphers in an equal-preference
   1175  * group have equal priority and use the client order. This may be used to
   1176  * enforce that AEADs are preferred but select AES-GCM vs. ChaCha20-Poly1305
   1177  * based on client preferences. An equal-preference is specified with square
   1178  * brackets, combining multiple selectors separated by |. For example:
   1179  *
   1180  *   [ECDHE-ECDSA-CHACHA20-POLY1305|ECDHE-ECDSA-AES128-GCM-SHA256]
   1181  *
   1182  * Once an equal-preference group is used, future directives must be
   1183  * opcode-less. */
   1184 
   1185 /* SSL_DEFAULT_CIPHER_LIST is the default cipher suite configuration. It is
   1186  * substituted when a cipher string starts with 'DEFAULT'. */
   1187 #define SSL_DEFAULT_CIPHER_LIST "ALL"
   1188 
   1189 /* SSL_CTX_set_cipher_list configures the cipher list for |ctx|, evaluating
   1190  * |str| as a cipher string. It returns one on success and zero on failure. */
   1191 OPENSSL_EXPORT int SSL_CTX_set_cipher_list(SSL_CTX *ctx, const char *str);
   1192 
   1193 /* SSL_CTX_set_cipher_list_tls10 configures the TLS 1.0+ cipher list for |ctx|,
   1194  * evaluating |str| as a cipher string. It returns one on success and zero on
   1195  * failure. If set, servers will use this cipher suite list for TLS 1.0 or
   1196  * higher. */
   1197 OPENSSL_EXPORT int SSL_CTX_set_cipher_list_tls10(SSL_CTX *ctx, const char *str);
   1198 
   1199 /* SSL_CTX_set_cipher_list_tls11 configures the TLS 1.1+ cipher list for |ctx|,
   1200  * evaluating |str| as a cipher string. It returns one on success and zero on
   1201  * failure. If set, servers will use this cipher suite list for TLS 1.1 or
   1202  * higher. */
   1203 OPENSSL_EXPORT int SSL_CTX_set_cipher_list_tls11(SSL_CTX *ctx, const char *str);
   1204 
   1205 /* SSL_set_cipher_list configures the cipher list for |ssl|, evaluating |str| as
   1206  * a cipher string. It returns one on success and zero on failure. */
   1207 OPENSSL_EXPORT int SSL_set_cipher_list(SSL *ssl, const char *str);
   1208 
   1209 /* SSL_get_ciphers returns the cipher list for |ssl|, in order of preference. If
   1210  * |SSL_CTX_set_cipher_list_tls10| or |SSL_CTX_set_cipher_list_tls11| has been
   1211  * used, the corresponding list for the current version is returned. */
   1212 OPENSSL_EXPORT STACK_OF(SSL_CIPHER) *SSL_get_ciphers(const SSL *ssl);
   1213 
   1214 
   1215 /* Connection information. */
   1216 
   1217 /* SSL_is_init_finished returns one if |ssl| has completed its initial handshake
   1218  * and has no pending handshake. It returns zero otherwise. */
   1219 OPENSSL_EXPORT int SSL_is_init_finished(const SSL *ssl);
   1220 
   1221 /* SSL_in_init returns one if |ssl| has a pending handshake and zero
   1222  * otherwise. */
   1223 OPENSSL_EXPORT int SSL_in_init(const SSL *ssl);
   1224 
   1225 /* SSL_in_false_start returns one if |ssl| has a pending handshake that is in
   1226  * False Start. |SSL_write| may be called at this point without waiting for the
   1227  * peer, but |SSL_read| will complete the handshake before accepting application
   1228  * data.
   1229  *
   1230  * See also |SSL_MODE_ENABLE_FALSE_START|. */
   1231 OPENSSL_EXPORT int SSL_in_false_start(const SSL *ssl);
   1232 
   1233 /* SSL_get_peer_certificate returns the peer's leaf certificate or NULL if the
   1234  * peer did not use certificates. The caller must call |X509_free| on the
   1235  * result to release it. */
   1236 OPENSSL_EXPORT X509 *SSL_get_peer_certificate(const SSL *ssl);
   1237 
   1238 /* SSL_get_peer_cert_chain returns the peer's certificate chain or NULL if
   1239  * unavailable or the peer did not use certificates. This is the unverified
   1240  * list of certificates as sent by the peer, not the final chain built during
   1241  * verification. For historical reasons, this value may not be available if
   1242  * resuming a serialized |SSL_SESSION|. The caller does not take ownership of
   1243  * the result.
   1244  *
   1245  * WARNING: This function behaves differently between client and server. If
   1246  * |ssl| is a server, the returned chain does not include the leaf certificate.
   1247  * If a client, it does. */
   1248 OPENSSL_EXPORT STACK_OF(X509) *SSL_get_peer_cert_chain(const SSL *ssl);
   1249 
   1250 /* SSL_get0_signed_cert_timestamp_list sets |*out| and |*out_len| to point to
   1251  * |*out_len| bytes of SCT information from the server. This is only valid if
   1252  * |ssl| is a client. The SCT information is a SignedCertificateTimestampList
   1253  * (including the two leading length bytes).
   1254  * See https://tools.ietf.org/html/rfc6962#section-3.3
   1255  * If no SCT was received then |*out_len| will be zero on return.
   1256  *
   1257  * WARNING: the returned data is not guaranteed to be well formed. */
   1258 OPENSSL_EXPORT void SSL_get0_signed_cert_timestamp_list(const SSL *ssl,
   1259                                                         const uint8_t **out,
   1260                                                         size_t *out_len);
   1261 
   1262 /* SSL_get0_ocsp_response sets |*out| and |*out_len| to point to |*out_len|
   1263  * bytes of an OCSP response from the server. This is the DER encoding of an
   1264  * OCSPResponse type as defined in RFC 2560.
   1265  *
   1266  * WARNING: the returned data is not guaranteed to be well formed. */
   1267 OPENSSL_EXPORT void SSL_get0_ocsp_response(const SSL *ssl, const uint8_t **out,
   1268                                            size_t *out_len);
   1269 
   1270 /* SSL_get_tls_unique writes at most |max_out| bytes of the tls-unique value
   1271  * for |ssl| to |out| and sets |*out_len| to the number of bytes written. It
   1272  * returns one on success or zero on error. In general |max_out| should be at
   1273  * least 12.
   1274  *
   1275  * This function will always fail if the initial handshake has not completed.
   1276  * The tls-unique value will change after a renegotiation but, since
   1277  * renegotiations can be initiated by the server at any point, the higher-level
   1278  * protocol must either leave them disabled or define states in which the
   1279  * tls-unique value can be read.
   1280  *
   1281  * The tls-unique value is defined by
   1282  * https://tools.ietf.org/html/rfc5929#section-3.1. Due to a weakness in the
   1283  * TLS protocol, tls-unique is broken for resumed connections unless the
   1284  * Extended Master Secret extension is negotiated. Thus this function will
   1285  * return zero if |ssl| performed session resumption unless EMS was used when
   1286  * negotiating the original session. */
   1287 OPENSSL_EXPORT int SSL_get_tls_unique(const SSL *ssl, uint8_t *out,
   1288                                       size_t *out_len, size_t max_out);
   1289 
   1290 /* SSL_get_extms_support returns one if the Extended Master Secret
   1291  * extension was negotiated. Otherwise, it returns zero. */
   1292 OPENSSL_EXPORT int SSL_get_extms_support(const SSL *ssl);
   1293 
   1294 /* SSL_get_current_cipher returns the cipher used in the current outgoing
   1295  * connection state, or NULL if the null cipher is active. */
   1296 OPENSSL_EXPORT const SSL_CIPHER *SSL_get_current_cipher(const SSL *ssl);
   1297 
   1298 /* SSL_session_reused returns one if |ssl| performed an abbreviated handshake
   1299  * and zero otherwise.
   1300  *
   1301  * TODO(davidben): Hammer down the semantics of this API while a handshake,
   1302  * initial or renego, is in progress. */
   1303 OPENSSL_EXPORT int SSL_session_reused(const SSL *ssl);
   1304 
   1305 /* SSL_get_secure_renegotiation_support returns one if the peer supports secure
   1306  * renegotiation (RFC 5746) and zero otherwise. */
   1307 OPENSSL_EXPORT int SSL_get_secure_renegotiation_support(const SSL *ssl);
   1308 
   1309 /* SSL_export_keying_material exports a value derived from the master secret, as
   1310  * specified in RFC 5705. It writes |out_len| bytes to |out| given a label and
   1311  * optional context. (Since a zero length context is allowed, the |use_context|
   1312  * flag controls whether a context is included.)
   1313  *
   1314  * It returns one on success and zero otherwise. */
   1315 OPENSSL_EXPORT int SSL_export_keying_material(
   1316     SSL *ssl, uint8_t *out, size_t out_len, const char *label, size_t label_len,
   1317     const uint8_t *context, size_t context_len, int use_context);
   1318 
   1319 
   1320 /* Custom extensions.
   1321  *
   1322  * The custom extension functions allow TLS extensions to be added to
   1323  * ClientHello and ServerHello messages. */
   1324 
   1325 /* SSL_custom_ext_add_cb is a callback function that is called when the
   1326  * ClientHello (for clients) or ServerHello (for servers) is constructed. In
   1327  * the case of a server, this callback will only be called for a given
   1328  * extension if the ClientHello contained that extension  it's not possible to
   1329  * inject extensions into a ServerHello that the client didn't request.
   1330  *
   1331  * When called, |extension_value| will contain the extension number that is
   1332  * being considered for addition (so that a single callback can handle multiple
   1333  * extensions). If the callback wishes to include the extension, it must set
   1334  * |*out| to point to |*out_len| bytes of extension contents and return one. In
   1335  * this case, the corresponding |SSL_custom_ext_free_cb| callback will later be
   1336  * called with the value of |*out| once that data has been copied.
   1337  *
   1338  * If the callback does not wish to add an extension it must return zero.
   1339  *
   1340  * Alternatively, the callback can abort the connection by setting
   1341  * |*out_alert_value| to a TLS alert number and returning -1. */
   1342 typedef int (*SSL_custom_ext_add_cb)(SSL *ssl, unsigned extension_value,
   1343                                      const uint8_t **out, size_t *out_len,
   1344                                      int *out_alert_value, void *add_arg);
   1345 
   1346 /* SSL_custom_ext_free_cb is a callback function that is called by OpenSSL iff
   1347  * an |SSL_custom_ext_add_cb| callback previously returned one. In that case,
   1348  * this callback is called and passed the |out| pointer that was returned by
   1349  * the add callback. This is to free any dynamically allocated data created by
   1350  * the add callback. */
   1351 typedef void (*SSL_custom_ext_free_cb)(SSL *ssl, unsigned extension_value,
   1352                                        const uint8_t *out, void *add_arg);
   1353 
   1354 /* SSL_custom_ext_parse_cb is a callback function that is called by OpenSSL to
   1355  * parse an extension from the peer: that is from the ServerHello for a client
   1356  * and from the ClientHello for a server.
   1357  *
   1358  * When called, |extension_value| will contain the extension number and the
   1359  * contents of the extension are |contents_len| bytes at |contents|.
   1360  *
   1361  * The callback must return one to continue the handshake. Otherwise, if it
   1362  * returns zero, a fatal alert with value |*out_alert_value| is sent and the
   1363  * handshake is aborted. */
   1364 typedef int (*SSL_custom_ext_parse_cb)(SSL *ssl, unsigned extension_value,
   1365                                        const uint8_t *contents,
   1366                                        size_t contents_len,
   1367                                        int *out_alert_value, void *parse_arg);
   1368 
   1369 /* SSL_extension_supported returns one iff OpenSSL internally handles
   1370  * extensions of type |extension_value|. This can be used to avoid registering
   1371  * custom extension handlers for extensions that a future version of OpenSSL
   1372  * may handle internally. */
   1373 OPENSSL_EXPORT int SSL_extension_supported(unsigned extension_value);
   1374 
   1375 /* SSL_CTX_add_client_custom_ext registers callback functions for handling
   1376  * custom TLS extensions for client connections.
   1377  *
   1378  * If |add_cb| is NULL then an empty extension will be added in each
   1379  * ClientHello. Otherwise, see the comment for |SSL_custom_ext_add_cb| about
   1380  * this callback.
   1381  *
   1382  * The |free_cb| may be NULL if |add_cb| doesn't dynamically allocate data that
   1383  * needs to be freed.
   1384  *
   1385  * It returns one on success or zero on error. It's always an error to register
   1386  * callbacks for the same extension twice, or to register callbacks for an
   1387  * extension that OpenSSL handles internally. See |SSL_extension_supported| to
   1388  * discover, at runtime, which extensions OpenSSL handles internally. */
   1389 OPENSSL_EXPORT int SSL_CTX_add_client_custom_ext(
   1390     SSL_CTX *ctx, unsigned extension_value, SSL_custom_ext_add_cb add_cb,
   1391     SSL_custom_ext_free_cb free_cb, void *add_arg,
   1392     SSL_custom_ext_parse_cb parse_cb, void *parse_arg);
   1393 
   1394 /* SSL_CTX_add_server_custom_ext is the same as
   1395  * |SSL_CTX_add_client_custom_ext|, but for server connections.
   1396  *
   1397  * Unlike on the client side, if |add_cb| is NULL no extension will be added.
   1398  * The |add_cb|, if any, will only be called if the ClientHello contained a
   1399  * matching extension. */
   1400 OPENSSL_EXPORT int SSL_CTX_add_server_custom_ext(
   1401     SSL_CTX *ctx, unsigned extension_value, SSL_custom_ext_add_cb add_cb,
   1402     SSL_custom_ext_free_cb free_cb, void *add_arg,
   1403     SSL_custom_ext_parse_cb parse_cb, void *parse_arg);
   1404 
   1405 
   1406 /* Sessions.
   1407  *
   1408  * An |SSL_SESSION| represents an SSL session that may be resumed in an
   1409  * abbreviated handshake. It is reference-counted and immutable. Once
   1410  * established, an |SSL_SESSION| may be shared by multiple |SSL| objects on
   1411  * different threads and must not be modified. */
   1412 
   1413 DECLARE_LHASH_OF(SSL_SESSION)
   1414 DECLARE_PEM_rw(SSL_SESSION, SSL_SESSION)
   1415 
   1416 /* SSL_SESSION_new returns a newly-allocated blank |SSL_SESSION| or NULL on
   1417  * error. This may be useful in writing tests but otherwise should not be
   1418  * used outside the library. */
   1419 OPENSSL_EXPORT SSL_SESSION *SSL_SESSION_new(void);
   1420 
   1421 /* SSL_SESSION_up_ref, if |session| is not NULL, increments the reference count
   1422  * of |session|. It then returns |session|. */
   1423 OPENSSL_EXPORT SSL_SESSION *SSL_SESSION_up_ref(SSL_SESSION *session);
   1424 
   1425 /* SSL_SESSION_free decrements the reference count of |session|. If it reaches
   1426  * zero, all data referenced by |session| and |session| itself are released. */
   1427 OPENSSL_EXPORT void SSL_SESSION_free(SSL_SESSION *session);
   1428 
   1429 /* SSL_SESSION_to_bytes serializes |in| into a newly allocated buffer and sets
   1430  * |*out_data| to that buffer and |*out_len| to its length. The caller takes
   1431  * ownership of the buffer and must call |OPENSSL_free| when done. It returns
   1432  * one on success and zero on error. */
   1433 OPENSSL_EXPORT int SSL_SESSION_to_bytes(const SSL_SESSION *in,
   1434                                         uint8_t **out_data, size_t *out_len);
   1435 
   1436 /* SSL_SESSION_to_bytes_for_ticket serializes |in|, but excludes the session
   1437  * identification information, namely the session ID and ticket. */
   1438 OPENSSL_EXPORT int SSL_SESSION_to_bytes_for_ticket(const SSL_SESSION *in,
   1439                                                    uint8_t **out_data,
   1440                                                    size_t *out_len);
   1441 
   1442 /* SSL_SESSION_from_bytes parses |in_len| bytes from |in| as an SSL_SESSION. It
   1443  * returns a newly-allocated |SSL_SESSION| on success or NULL on error. */
   1444 OPENSSL_EXPORT SSL_SESSION *SSL_SESSION_from_bytes(const uint8_t *in,
   1445                                                    size_t in_len);
   1446 
   1447 /* SSL_SESSION_get_version returns a string describing the TLS version |session|
   1448  * was established at. For example, "TLSv1.2" or "SSLv3". */
   1449 OPENSSL_EXPORT const char *SSL_SESSION_get_version(const SSL_SESSION *session);
   1450 
   1451 /* SSL_SESSION_get_id returns a pointer to a buffer containg |session|'s session
   1452  * ID and sets |*out_len| to its length. */
   1453 OPENSSL_EXPORT const uint8_t *SSL_SESSION_get_id(const SSL_SESSION *session,
   1454                                                  unsigned *out_len);
   1455 
   1456 /* SSL_SESSION_get_time returns the time at which |session| was established in
   1457  * seconds since the UNIX epoch. */
   1458 OPENSSL_EXPORT long SSL_SESSION_get_time(const SSL_SESSION *session);
   1459 
   1460 /* SSL_SESSION_get_timeout returns the lifetime of |session| in seconds. */
   1461 OPENSSL_EXPORT long SSL_SESSION_get_timeout(const SSL_SESSION *session);
   1462 
   1463 /* SSL_SESSION_get_key_exchange_info returns a value that describes the
   1464  * strength of the asymmetric operation that provides confidentiality to
   1465  * |session|. Its interpretation depends on the operation used. See the
   1466  * documentation for this value in the |SSL_SESSION| structure. */
   1467 OPENSSL_EXPORT uint32_t SSL_SESSION_get_key_exchange_info(
   1468     const SSL_SESSION *session);
   1469 
   1470 /* SSL_SESSION_get0_peer return's the peer leaf certificate stored in
   1471  * |session|.
   1472  *
   1473  * TODO(davidben): This should return a const X509 *. */
   1474 OPENSSL_EXPORT X509 *SSL_SESSION_get0_peer(const SSL_SESSION *session);
   1475 
   1476 /* SSL_SESSION_set_time sets |session|'s creation time to |time| and returns
   1477  * |time|. This function may be useful in writing tests but otherwise should not
   1478  * be used. */
   1479 OPENSSL_EXPORT long SSL_SESSION_set_time(SSL_SESSION *session, long time);
   1480 
   1481 /* SSL_SESSION_set_timeout sets |session|'s timeout to |timeout| and returns
   1482  * one. This function may be useful in writing tests but otherwise should not
   1483  * be used. */
   1484 OPENSSL_EXPORT long SSL_SESSION_set_timeout(SSL_SESSION *session, long timeout);
   1485 
   1486 /* SSL_SESSION_set1_id_context sets |session|'s session ID context (see
   1487  * |SSL_CTX_set_session_id_context|) to |sid_ctx|. It returns one on success and
   1488  * zero on error. This function may be useful in writing tests but otherwise
   1489  * should not be used. */
   1490 OPENSSL_EXPORT int SSL_SESSION_set1_id_context(SSL_SESSION *session,
   1491                                                const uint8_t *sid_ctx,
   1492                                                unsigned sid_ctx_len);
   1493 
   1494 
   1495 /* Session caching.
   1496  *
   1497  * Session caching allows clients to reconnect to a server based on saved
   1498  * parameters from a previous connection.
   1499  *
   1500  * For a server, the library implements a built-in internal session cache as an
   1501  * in-memory hash table. One may also register callbacks to implement a custom
   1502  * external session cache. An external cache may be used in addition to or
   1503  * instead of the internal one. Use |SSL_CTX_set_session_cache_mode| to toggle
   1504  * the internal cache.
   1505  *
   1506  * For a client, the only option is an external session cache. Prior to
   1507  * handshaking, the consumer should look up a session externally (keyed, for
   1508  * instance, by hostname) and use |SSL_set_session| to configure which session
   1509  * to offer. The callbacks may be used to determine when new sessions are
   1510  * available.
   1511  *
   1512  * Note that offering or accepting a session short-circuits most parameter
   1513  * negotiation. Resuming sessions across different configurations may result in
   1514  * surprising behavor. So, for instance, a client implementing a version
   1515  * fallback should shard its session cache by maximum protocol version. */
   1516 
   1517 /* SSL_SESS_CACHE_OFF disables all session caching. */
   1518 #define SSL_SESS_CACHE_OFF 0x0000
   1519 
   1520 /* SSL_SESS_CACHE_CLIENT enables session caching for a client. The internal
   1521  * cache is never used on a client, so this only enables the callbacks. */
   1522 #define SSL_SESS_CACHE_CLIENT 0x0001
   1523 
   1524 /* SSL_SESS_CACHE_SERVER enables session caching for a server. */
   1525 #define SSL_SESS_CACHE_SERVER 0x0002
   1526 
   1527 /* SSL_SESS_CACHE_SERVER enables session caching for both client and server. */
   1528 #define SSL_SESS_CACHE_BOTH (SSL_SESS_CACHE_CLIENT | SSL_SESS_CACHE_SERVER)
   1529 
   1530 /* SSL_SESS_CACHE_NO_AUTO_CLEAR disables automatically calling
   1531  * |SSL_CTX_flush_sessions| every 255 connections. */
   1532 #define SSL_SESS_CACHE_NO_AUTO_CLEAR 0x0080
   1533 
   1534 /* SSL_SESS_CACHE_NO_INTERNAL_LOOKUP, on a server, disables looking up a session
   1535  * from the internal session cache. */
   1536 #define SSL_SESS_CACHE_NO_INTERNAL_LOOKUP 0x0100
   1537 
   1538 /* SSL_SESS_CACHE_NO_INTERNAL_STORE, on a server, disables storing sessions in
   1539  * the internal session cache. */
   1540 #define SSL_SESS_CACHE_NO_INTERNAL_STORE 0x0200
   1541 
   1542 /* SSL_SESS_CACHE_NO_INTERNAL, on a server, disables the internal session
   1543  * cache. */
   1544 #define SSL_SESS_CACHE_NO_INTERNAL \
   1545     (SSL_SESS_CACHE_NO_INTERNAL_LOOKUP | SSL_SESS_CACHE_NO_INTERNAL_STORE)
   1546 
   1547 /* SSL_CTX_set_session_cache_mode sets the session cache mode bits for |ctx| to
   1548  * |mode|. It returns the previous value. */
   1549 OPENSSL_EXPORT int SSL_CTX_set_session_cache_mode(SSL_CTX *ctx, int mode);
   1550 
   1551 /* SSL_CTX_get_session_cache_mode returns the session cache mode bits for
   1552  * |ctx| */
   1553 OPENSSL_EXPORT int SSL_CTX_get_session_cache_mode(const SSL_CTX *ctx);
   1554 
   1555 /* SSL_set_session, for a client, configures |ssl| to offer to resume |session|
   1556  * in the initial handshake and returns one. The caller retains ownership of
   1557  * |session|. */
   1558 OPENSSL_EXPORT int SSL_set_session(SSL *ssl, SSL_SESSION *session);
   1559 
   1560 /* SSL_get_session returns a non-owning pointer to |ssl|'s session. Prior to the
   1561  * initial handshake beginning, this is the session to be offered, set by
   1562  * |SSL_set_session|. After a handshake has finished, this is the currently
   1563  * active session. Its behavior is undefined while a handshake is progress. */
   1564 OPENSSL_EXPORT SSL_SESSION *SSL_get_session(const SSL *ssl);
   1565 
   1566 /* SSL_get0_session is an alias for |SSL_get_session|. */
   1567 #define SSL_get0_session SSL_get_session
   1568 
   1569 /* SSL_get1_session acts like |SSL_get_session| but returns a new reference to
   1570  * the session. */
   1571 OPENSSL_EXPORT SSL_SESSION *SSL_get1_session(SSL *ssl);
   1572 
   1573 /* SSL_DEFAULT_SESSION_TIMEOUT is the default lifetime, in seconds, of a
   1574  * session. */
   1575 #define SSL_DEFAULT_SESSION_TIMEOUT (2 * 60 * 60)
   1576 
   1577 /* SSL_CTX_set_timeout sets the lifetime, in seconds, of sessions created in
   1578  * |ctx| to |timeout|. */
   1579 OPENSSL_EXPORT long SSL_CTX_set_timeout(SSL_CTX *ctx, long timeout);
   1580 
   1581 /* SSL_CTX_get_timeout returns the lifetime, in seconds, of sessions created in
   1582  * |ctx|. */
   1583 OPENSSL_EXPORT long SSL_CTX_get_timeout(const SSL_CTX *ctx);
   1584 
   1585 /* SSL_CTX_set_session_id_context sets |ctx|'s session ID context to |sid_ctx|.
   1586  * It returns one on success and zero on error. The session ID context is an
   1587  * application-defined opaque byte string. A session will not be used in a
   1588  * connection without a matching session ID context.
   1589  *
   1590  * For a server, if |SSL_VERIFY_PEER| is enabled, it is an error to not set a
   1591  * session ID context.
   1592  *
   1593  * TODO(davidben): Is that check needed? That seems a special case of taking
   1594  * care not to cross-resume across configuration changes, and this is only
   1595  * relevant if a server requires client auth. */
   1596 OPENSSL_EXPORT int SSL_CTX_set_session_id_context(SSL_CTX *ctx,
   1597                                                   const uint8_t *sid_ctx,
   1598                                                   unsigned sid_ctx_len);
   1599 
   1600 /* SSL_set_session_id_context sets |ssl|'s session ID context to |sid_ctx|. It
   1601  * returns one on success and zero on error. See also
   1602  * |SSL_CTX_set_session_id_context|. */
   1603 OPENSSL_EXPORT int SSL_set_session_id_context(SSL *ssl, const uint8_t *sid_ctx,
   1604                                               unsigned sid_ctx_len);
   1605 
   1606 /* SSL_SESSION_CACHE_MAX_SIZE_DEFAULT is the default maximum size of a session
   1607  * cache. */
   1608 #define SSL_SESSION_CACHE_MAX_SIZE_DEFAULT (1024 * 20)
   1609 
   1610 /* SSL_CTX_sess_set_cache_size sets the maximum size of |ctx|'s internal session
   1611  * cache to |size|. It returns the previous value. */
   1612 OPENSSL_EXPORT unsigned long SSL_CTX_sess_set_cache_size(SSL_CTX *ctx,
   1613                                                          unsigned long size);
   1614 
   1615 /* SSL_CTX_sess_get_cache_size returns the maximum size of |ctx|'s internal
   1616  * session cache. */
   1617 OPENSSL_EXPORT unsigned long SSL_CTX_sess_get_cache_size(const SSL_CTX *ctx);
   1618 
   1619 /* SSL_CTX_sessions returns |ctx|'s internal session cache. */
   1620 OPENSSL_EXPORT LHASH_OF(SSL_SESSION) *SSL_CTX_sessions(SSL_CTX *ctx);
   1621 
   1622 /* SSL_CTX_sess_number returns the number of sessions in |ctx|'s internal
   1623  * session cache. */
   1624 OPENSSL_EXPORT size_t SSL_CTX_sess_number(const SSL_CTX *ctx);
   1625 
   1626 /* SSL_CTX_add_session inserts |session| into |ctx|'s internal session cache. It
   1627  * returns one on success and zero on error or if |session| is already in the
   1628  * cache. The caller retains its reference to |session|. */
   1629 OPENSSL_EXPORT int SSL_CTX_add_session(SSL_CTX *ctx, SSL_SESSION *session);
   1630 
   1631 /* SSL_CTX_remove_session removes |session| from |ctx|'s internal session cache.
   1632  * It returns one on success and zero if |session| was not in the cache. */
   1633 OPENSSL_EXPORT int SSL_CTX_remove_session(SSL_CTX *ctx, SSL_SESSION *session);
   1634 
   1635 /* SSL_CTX_flush_sessions removes all sessions from |ctx| which have expired as
   1636  * of time |time|. If |time| is zero, all sessions are removed. */
   1637 OPENSSL_EXPORT void SSL_CTX_flush_sessions(SSL_CTX *ctx, long time);
   1638 
   1639 /* SSL_CTX_sess_set_new_cb sets the callback to be called when a new session is
   1640  * established and ready to be cached. If the session cache is disabled (the
   1641  * appropriate one of |SSL_SESS_CACHE_CLIENT| or |SSL_SESS_CACHE_SERVER| is
   1642  * unset), the callback is not called.
   1643  *
   1644  * The callback is passed a reference to |session|. It returns one if it takes
   1645  * ownership and zero otherwise.
   1646  *
   1647  * Note: For a client, the callback may be called on abbreviated handshakes if a
   1648  * ticket is renewed. Further, it may not be called until some time after
   1649  * |SSL_do_handshake| or |SSL_connect| completes if False Start is enabled. Thus
   1650  * it's recommended to use this callback over checking |SSL_session_reused| on
   1651  * handshake completion.
   1652  *
   1653  * TODO(davidben): Conditioning callbacks on |SSL_SESS_CACHE_CLIENT| or
   1654  * |SSL_SESS_CACHE_SERVER| doesn't make any sense when one could just as easily
   1655  * not supply the callbacks. Removing that condition and the client internal
   1656  * cache would simplify things. */
   1657 OPENSSL_EXPORT void SSL_CTX_sess_set_new_cb(
   1658     SSL_CTX *ctx, int (*new_session_cb)(SSL *ssl, SSL_SESSION *session));
   1659 
   1660 /* SSL_CTX_sess_get_new_cb returns the callback set by
   1661  * |SSL_CTX_sess_set_new_cb|. */
   1662 OPENSSL_EXPORT int (*SSL_CTX_sess_get_new_cb(SSL_CTX *ctx))(
   1663     SSL *ssl, SSL_SESSION *session);
   1664 
   1665 /* SSL_CTX_sess_set_remove_cb sets a callback which is called when a session is
   1666  * removed from the internal session cache.
   1667  *
   1668  * TODO(davidben): What is the point of this callback? It seems useless since it
   1669  * only fires on sessions in the internal cache. */
   1670 OPENSSL_EXPORT void SSL_CTX_sess_set_remove_cb(
   1671     SSL_CTX *ctx,
   1672     void (*remove_session_cb)(SSL_CTX *ctx, SSL_SESSION *session));
   1673 
   1674 /* SSL_CTX_sess_get_remove_cb returns the callback set by
   1675  * |SSL_CTX_sess_set_remove_cb|. */
   1676 OPENSSL_EXPORT void (*SSL_CTX_sess_get_remove_cb(SSL_CTX *ctx))(
   1677     SSL_CTX *ctx, SSL_SESSION *session);
   1678 
   1679 /* SSL_CTX_sess_set_get_cb sets a callback to look up a session by ID for a
   1680  * server. The callback is passed the session ID and should return a matching
   1681  * |SSL_SESSION| or NULL if not found. It should set |*out_copy| to zero and
   1682  * return a new reference to the session. This callback is not used for a
   1683  * client.
   1684  *
   1685  * For historical reasons, if |*out_copy| is set to one (default), the SSL
   1686  * library will take a new reference to the returned |SSL_SESSION|, expecting
   1687  * the callback to return a non-owning pointer. This is not recommended. If
   1688  * |ctx| and thus the callback is used on multiple threads, the session may be
   1689  * removed and invalidated before the SSL library calls |SSL_SESSION_up_ref|,
   1690  * whereas the callback may synchronize internally.
   1691  *
   1692  * To look up a session asynchronously, the callback may return
   1693  * |SSL_magic_pending_session_ptr|. See the documentation for that function and
   1694  * |SSL_ERROR_PENDING_SESSION|.
   1695  *
   1696  * If the internal session cache is enabled, the callback is only consulted if
   1697  * the internal cache does not return a match.
   1698  *
   1699  * The callback's |id| parameter is not const for historical reasons, but the
   1700  * contents may not be modified. */
   1701 OPENSSL_EXPORT void SSL_CTX_sess_set_get_cb(
   1702     SSL_CTX *ctx,
   1703     SSL_SESSION *(*get_session_cb)(SSL *ssl, uint8_t *id, int id_len,
   1704                                    int *out_copy));
   1705 
   1706 /* SSL_CTX_sess_get_get_cb returns the callback set by
   1707  * |SSL_CTX_sess_set_get_cb|. */
   1708 OPENSSL_EXPORT SSL_SESSION *(*SSL_CTX_sess_get_get_cb(SSL_CTX *ctx))(
   1709     SSL *ssl, uint8_t *id, int id_len, int *out_copy);
   1710 
   1711 /* SSL_magic_pending_session_ptr returns a magic |SSL_SESSION|* which indicates
   1712  * that the session isn't currently unavailable. |SSL_get_error| will then
   1713  * return |SSL_ERROR_PENDING_SESSION| and the handshake can be retried later
   1714  * when the lookup has completed. */
   1715 OPENSSL_EXPORT SSL_SESSION *SSL_magic_pending_session_ptr(void);
   1716 
   1717 
   1718 /* Session tickets.
   1719  *
   1720  * Session tickets, from RFC 5077, allow session resumption without server-side
   1721  * state. Session tickets are supported in by default but may be disabled with
   1722  * |SSL_OP_NO_TICKET|.
   1723  *
   1724  * On the client, ticket-based sessions use the same APIs as ID-based tickets.
   1725  * Callers do not need to handle them differently.
   1726  *
   1727  * On the server, tickets are encrypted and authenticated with a secret key. By
   1728  * default, an |SSL_CTX| generates a key on creation. Tickets are minted and
   1729  * processed transparently. The following functions may be used to configure a
   1730  * persistent key or implement more custom behavior. */
   1731 
   1732 /* SSL_CTX_get_tlsext_ticket_keys writes |ctx|'s session ticket key material to
   1733  * |len| bytes of |out|. It returns one on success and zero if |len| is not
   1734  * 48. If |out| is NULL, it returns 48 instead. */
   1735 OPENSSL_EXPORT int SSL_CTX_get_tlsext_ticket_keys(SSL_CTX *ctx, void *out,
   1736                                                   size_t len);
   1737 
   1738 /* SSL_CTX_set_tlsext_ticket_keys sets |ctx|'s session ticket key material to
   1739  * |len| bytes of |in|. It returns one on success and zero if |len| is not
   1740  * 48. If |in| is NULL, it returns 48 instead. */
   1741 OPENSSL_EXPORT int SSL_CTX_set_tlsext_ticket_keys(SSL_CTX *ctx, const void *in,
   1742                                                   size_t len);
   1743 
   1744 /* SSL_TICKET_KEY_NAME_LEN is the length of the key name prefix of a session
   1745  * ticket. */
   1746 #define SSL_TICKET_KEY_NAME_LEN 16
   1747 
   1748 /* SSL_CTX_set_tlsext_ticket_key_cb sets the ticket callback to |callback| and
   1749  * returns one. |callback| will be called when encrypting a new ticket and when
   1750  * decrypting a ticket from the client.
   1751  *
   1752  * In both modes, |ctx| and |hmac_ctx| will already have been initialized with
   1753  * |EVP_CIPHER_CTX_init| and |HMAC_CTX_init|, respectively. |callback|
   1754  * configures |hmac_ctx| with an HMAC digest and key, and configures |ctx|
   1755  * for encryption or decryption, based on the mode.
   1756  *
   1757  * When encrypting a new ticket, |encrypt| will be one. It writes a public
   1758  * 16-byte key name to |key_name| and a fresh IV to |iv|. The output IV length
   1759  * must match |EVP_CIPHER_CTX_iv_length| of the cipher selected. In this mode,
   1760  * |callback| returns 1 on success and -1 on error.
   1761  *
   1762  * When decrypting a ticket, |encrypt| will be zero. |key_name| will point to a
   1763  * 16-byte key name and |iv| points to an IV. The length of the IV consumed must
   1764  * match |EVP_CIPHER_CTX_iv_length| of the cipher selected. In this mode,
   1765  * |callback| returns -1 to abort the handshake, 0 if decrypting the ticket
   1766  * failed, and 1 or 2 on success. If it returns 2, the ticket will be renewed.
   1767  * This may be used to re-key the ticket.
   1768  *
   1769  * WARNING: |callback| wildly breaks the usual return value convention and is
   1770  * called in two different modes. */
   1771 OPENSSL_EXPORT int SSL_CTX_set_tlsext_ticket_key_cb(
   1772     SSL_CTX *ctx, int (*callback)(SSL *ssl, uint8_t *key_name, uint8_t *iv,
   1773                                   EVP_CIPHER_CTX *ctx, HMAC_CTX *hmac_ctx,
   1774                                   int encrypt));
   1775 
   1776 
   1777 /* Elliptic curve Diffie-Hellman.
   1778  *
   1779  * Cipher suites using an ECDHE key exchange perform Diffie-Hellman over an
   1780  * elliptic curve negotiated by both endpoints. See RFC 4492. Only named curves
   1781  * are supported. ECDHE is always enabled, but the curve preferences may be
   1782  * configured with these functions.
   1783  *
   1784  * A client may use |SSL_SESSION_get_key_exchange_info| to determine the curve
   1785  * selected. */
   1786 
   1787 /* SSL_CTX_set1_curves sets the preferred curves for |ctx| to be |curves|. Each
   1788  * element of |curves| should be a curve nid. It returns one on success and
   1789  * zero on failure. */
   1790 OPENSSL_EXPORT int SSL_CTX_set1_curves(SSL_CTX *ctx, const int *curves,
   1791                                        size_t curves_len);
   1792 
   1793 /* SSL_set1_curves sets the preferred curves for |ssl| to be |curves|. Each
   1794  * element of |curves| should be a curve nid. It returns one on success and
   1795  * zero on failure. */
   1796 OPENSSL_EXPORT int SSL_set1_curves(SSL *ssl, const int *curves,
   1797                                    size_t curves_len);
   1798 
   1799 /* SSL_get_curve_name returns a human-readable name for the elliptic curve
   1800  * specified by the given TLS curve id, or NULL if the curve if unknown. */
   1801 OPENSSL_EXPORT const char *SSL_get_curve_name(uint16_t curve_id);
   1802 
   1803 
   1804 /* Multiplicative Diffie-Hellman.
   1805  *
   1806  * Cipher suites using a DHE key exchange perform Diffie-Hellman over a
   1807  * multiplicative group selected by the server. These ciphers are disabled for a
   1808  * server unless a group is chosen with one of these functions.
   1809  *
   1810  * A client may use |SSL_SESSION_get_key_exchange_info| to determine the size of
   1811  * the selected group's prime, but note that servers may select degenerate
   1812  * groups. */
   1813 
   1814 /* SSL_CTX_set_tmp_dh configures |ctx| to use the group from |dh| as the group
   1815  * for DHE. Only the group is used, so |dh| needn't have a keypair. It returns
   1816  * one on success and zero on error. */
   1817 OPENSSL_EXPORT int SSL_CTX_set_tmp_dh(SSL_CTX *ctx, const DH *dh);
   1818 
   1819 /* SSL_set_tmp_dh configures |ssl| to use the group from |dh| as the group for
   1820  * DHE. Only the group is used, so |dh| needn't have a keypair. It returns one
   1821  * on success and zero on error. */
   1822 OPENSSL_EXPORT int SSL_set_tmp_dh(SSL *ssl, const DH *dh);
   1823 
   1824 /* SSL_CTX_set_tmp_dh_callback configures |ctx| to use |callback| to determine
   1825  * the group for DHE ciphers. |callback| should ignore |is_export| and
   1826  * |keylength| and return a |DH| of the selected group or NULL on error. Only
   1827  * the parameters are used, so the |DH| needn't have a generated keypair.
   1828  *
   1829  * WARNING: The caller does not take ownership of the resulting |DH|, so
   1830  * |callback| must save and release the object elsewhere. */
   1831 OPENSSL_EXPORT void SSL_CTX_set_tmp_dh_callback(
   1832     SSL_CTX *ctx, DH *(*callback)(SSL *ssl, int is_export, int keylength));
   1833 
   1834 /* SSL_set_tmp_dh_callback configures |ssl| to use |callback| to determine the
   1835  * group for DHE ciphers. |callback| should ignore |is_export| and |keylength|
   1836  * and return a |DH| of the selected group or NULL on error. Only the
   1837  * parameters are used, so the |DH| needn't have a generated keypair.
   1838  *
   1839  * WARNING: The caller does not take ownership of the resulting |DH|, so
   1840  * |callback| must save and release the object elsewhere. */
   1841 OPENSSL_EXPORT void SSL_set_tmp_dh_callback(SSL *ssl,
   1842                                             DH *(*dh)(SSL *ssl, int is_export,
   1843                                                       int keylength));
   1844 
   1845 
   1846 /* Certificate verification.
   1847  *
   1848  * SSL may authenticate either endpoint with an X.509 certificate. Typically
   1849  * this is used to authenticate the server to the client. These functions
   1850  * configure certificate verification.
   1851  *
   1852  * WARNING: By default, certificate verification errors on a client are not
   1853  * fatal. See |SSL_VERIFY_NONE| This may be configured with
   1854  * |SSL_CTX_set_verify|.
   1855  *
   1856  * By default clients are anonymous but a server may request a certificate from
   1857  * the client by setting |SSL_VERIFY_PEER|.
   1858  *
   1859  * Many of these functions use OpenSSL's legacy X.509 stack which is
   1860  * underdocumented and deprecated, but the replacement isn't ready yet. For
   1861  * now, consumers may use the existing stack or bypass it by performing
   1862  * certificate verification externally. This may be done with
   1863  * |SSL_CTX_set_cert_verify_callback| or by extracting the chain with
   1864  * |SSL_get_peer_cert_chain| after the handshake. In the future, functions will
   1865  * be added to use the SSL stack without dependency on any part of the legacy
   1866  * X.509 and ASN.1 stack.
   1867  *
   1868  * To augment certificate verification, a client may also enable OCSP stapling
   1869  * (RFC 6066) and Certificate Transparency (RFC 6962) extensions. */
   1870 
   1871 /* SSL_VERIFY_NONE, on a client, verifies the server certificate but does not
   1872  * make errors fatal. The result may be checked with |SSL_get_verify_result|. On
   1873  * a server it does not request a client certificate. This is the default. */
   1874 #define SSL_VERIFY_NONE 0x00
   1875 
   1876 /* SSL_VERIFY_PEER, on a client, makes server certificate errors fatal. On a
   1877  * server it requests a client certificate and makes errors fatal. However,
   1878  * anonymous clients are still allowed. See
   1879  * |SSL_VERIFY_FAIL_IF_NO_PEER_CERT|. */
   1880 #define SSL_VERIFY_PEER 0x01
   1881 
   1882 /* SSL_VERIFY_FAIL_IF_NO_PEER_CERT configures a server to reject connections if
   1883  * the client declines to send a certificate. Otherwise |SSL_VERIFY_PEER| still
   1884  * allows anonymous clients. */
   1885 #define SSL_VERIFY_FAIL_IF_NO_PEER_CERT 0x02
   1886 
   1887 /* SSL_VERIFY_PEER_IF_NO_OBC configures a server to request a client certificate
   1888  * if and only if Channel ID is not negotiated. */
   1889 #define SSL_VERIFY_PEER_IF_NO_OBC 0x04
   1890 
   1891 /* SSL_CTX_set_verify configures certificate verification behavior. |mode| is
   1892  * one of the |SSL_VERIFY_*| values defined above. |callback|, if not NULL, is
   1893  * used to customize certificate verification. See the behavior of
   1894  * |X509_STORE_CTX_set_verify_cb|.
   1895  *
   1896  * The callback may use |SSL_get_ex_data_X509_STORE_CTX_idx| with
   1897  * |X509_STORE_CTX_get_ex_data| to look up the |SSL| from |store_ctx|. */
   1898 OPENSSL_EXPORT void SSL_CTX_set_verify(
   1899     SSL_CTX *ctx, int mode, int (*callback)(int ok, X509_STORE_CTX *store_ctx));
   1900 
   1901 /* SSL_set_verify configures certificate verification behavior. |mode| is one of
   1902  * the |SSL_VERIFY_*| values defined above. |callback|, if not NULL, is used to
   1903  * customize certificate verification. See the behavior of
   1904  * |X509_STORE_CTX_set_verify_cb|.
   1905  *
   1906  * The callback may use |SSL_get_ex_data_X509_STORE_CTX_idx| with
   1907  * |X509_STORE_CTX_get_ex_data| to look up the |SSL| from |store_ctx|. */
   1908 OPENSSL_EXPORT void SSL_set_verify(SSL *ssl, int mode,
   1909                                    int (*callback)(int ok,
   1910                                                    X509_STORE_CTX *store_ctx));
   1911 
   1912 /* SSL_CTX_get_verify_mode returns |ctx|'s verify mode, set by
   1913  * |SSL_CTX_set_verify|. */
   1914 OPENSSL_EXPORT int SSL_CTX_get_verify_mode(const SSL_CTX *ctx);
   1915 
   1916 /* SSL_get_verify_mode returns |ssl|'s verify mode, set by |SSL_CTX_set_verify|
   1917  * or |SSL_set_verify|. */
   1918 OPENSSL_EXPORT int SSL_get_verify_mode(const SSL *ssl);
   1919 
   1920 /* SSL_CTX_get_verify_callback returns the callback set by
   1921  * |SSL_CTX_set_verify|. */
   1922 OPENSSL_EXPORT int (*SSL_CTX_get_verify_callback(const SSL_CTX *ctx))(
   1923     int ok, X509_STORE_CTX *store_ctx);
   1924 
   1925 /* SSL_get_verify_callback returns the callback set by |SSL_CTX_set_verify| or
   1926  * |SSL_set_verify|. */
   1927 OPENSSL_EXPORT int (*SSL_get_verify_callback(const SSL *ssl))(
   1928     int ok, X509_STORE_CTX *store_ctx);
   1929 
   1930 /* SSL_CTX_set_verify_depth sets the maximum depth of a certificate chain
   1931  * accepted in verification. This number does not include the leaf, so a depth
   1932  * of 1 allows the leaf and one CA certificate. */
   1933 OPENSSL_EXPORT void SSL_CTX_set_verify_depth(SSL_CTX *ctx, int depth);
   1934 
   1935 /* SSL_set_verify_depth sets the maximum depth of a certificate chain accepted
   1936  * in verification. This number does not include the leaf, so a depth of 1
   1937  * allows the leaf and one CA certificate. */
   1938 OPENSSL_EXPORT void SSL_set_verify_depth(SSL *ssl, int depth);
   1939 
   1940 /* SSL_CTX_get_verify_depth returns the maximum depth of a certificate accepted
   1941  * in verification. */
   1942 OPENSSL_EXPORT int SSL_CTX_get_verify_depth(const SSL_CTX *ctx);
   1943 
   1944 /* SSL_get_verify_depth returns the maximum depth of a certificate accepted in
   1945  * verification. */
   1946 OPENSSL_EXPORT int SSL_get_verify_depth(const SSL *ssl);
   1947 
   1948 /* SSL_CTX_set1_param sets verification parameters from |param|. It returns one
   1949  * on success and zero on failure. The caller retains ownership of |param|. */
   1950 OPENSSL_EXPORT int SSL_CTX_set1_param(SSL_CTX *ctx,
   1951                                       const X509_VERIFY_PARAM *param);
   1952 
   1953 /* SSL_set1_param sets verification parameters from |param|. It returns one on
   1954  * success and zero on failure. The caller retains ownership of |param|. */
   1955 OPENSSL_EXPORT int SSL_set1_param(SSL *ssl,
   1956                                   const X509_VERIFY_PARAM *param);
   1957 
   1958 /* SSL_CTX_get0_param returns |ctx|'s |X509_VERIFY_PARAM| for certificate
   1959  * verification. The caller must not release the returned pointer but may call
   1960  * functions on it to configure it. */
   1961 OPENSSL_EXPORT X509_VERIFY_PARAM *SSL_CTX_get0_param(SSL_CTX *ctx);
   1962 
   1963 /* SSL_get0_param returns |ssl|'s |X509_VERIFY_PARAM| for certificate
   1964  * verification. The caller must not release the returned pointer but may call
   1965  * functions on it to configure it. */
   1966 OPENSSL_EXPORT X509_VERIFY_PARAM *SSL_get0_param(SSL *ssl);
   1967 
   1968 /* SSL_CTX_set_purpose sets |ctx|'s |X509_VERIFY_PARAM|'s 'purpose' parameter to
   1969  * |purpose|. It returns one on success and zero on error. */
   1970 OPENSSL_EXPORT int SSL_CTX_set_purpose(SSL_CTX *ctx, int purpose);
   1971 
   1972 /* SSL_set_purpose sets |ssl|'s |X509_VERIFY_PARAM|'s 'purpose' parameter to
   1973  * |purpose|. It returns one on success and zero on error. */
   1974 OPENSSL_EXPORT int SSL_set_purpose(SSL *ssl, int purpose);
   1975 
   1976 /* SSL_CTX_set_trust sets |ctx|'s |X509_VERIFY_PARAM|'s 'trust' parameter to
   1977  * |trust|. It returns one on success and zero on error. */
   1978 OPENSSL_EXPORT int SSL_CTX_set_trust(SSL_CTX *ctx, int trust);
   1979 
   1980 /* SSL_set_trust sets |ssl|'s |X509_VERIFY_PARAM|'s 'trust' parameter to
   1981  * |trust|. It returns one on success and zero on error. */
   1982 OPENSSL_EXPORT int SSL_set_trust(SSL *ssl, int trust);
   1983 
   1984 /* SSL_CTX_set_cert_store sets |ctx|'s certificate store to |store|. It takes
   1985  * ownership of |store|. The store is used for certificate verification.
   1986  *
   1987  * The store is also used for the auto-chaining feature, but this is deprecated.
   1988  * See also |SSL_MODE_NO_AUTO_CHAIN|. */
   1989 OPENSSL_EXPORT void SSL_CTX_set_cert_store(SSL_CTX *ctx, X509_STORE *store);
   1990 
   1991 /* SSL_CTX_get_cert_store returns |ctx|'s certificate store. */
   1992 OPENSSL_EXPORT X509_STORE *SSL_CTX_get_cert_store(const SSL_CTX *ctx);
   1993 
   1994 /* SSL_CTX_set_default_verify_paths loads the OpenSSL system-default trust
   1995  * anchors into |ctx|'s store. It returns one on success and zero on failure. */
   1996 OPENSSL_EXPORT int SSL_CTX_set_default_verify_paths(SSL_CTX *ctx);
   1997 
   1998 /* SSL_CTX_load_verify_locations loads trust anchors into |ctx|'s store from
   1999  * |ca_file| and |ca_dir|, either of which may be NULL. If |ca_file| is passed,
   2000  * it is opened and PEM-encoded CA certificates are read. If |ca_dir| is passed,
   2001  * it is treated as a directory in OpenSSL's hashed directory format. It returns
   2002  * one on success and zero on failure.
   2003  *
   2004  * See
   2005  * https://www.openssl.org/docs/manmaster/ssl/SSL_CTX_load_verify_locations.html
   2006  * for documentation on the directory format. */
   2007 OPENSSL_EXPORT int SSL_CTX_load_verify_locations(SSL_CTX *ctx,
   2008                                                  const char *ca_file,
   2009                                                  const char *ca_dir);
   2010 
   2011 /* SSL_get_verify_result returns the result of certificate verification. It is
   2012  * either |X509_V_OK| or a |X509_V_ERR_*| value. */
   2013 OPENSSL_EXPORT long SSL_get_verify_result(const SSL *ssl);
   2014 
   2015 /* SSL_set_verify_result overrides the result of certificate verification. */
   2016 OPENSSL_EXPORT void SSL_set_verify_result(SSL *ssl, long result);
   2017 
   2018 /* SSL_get_ex_data_X509_STORE_CTX_idx returns the ex_data index used to look up
   2019  * the |SSL| associated with an |X509_STORE_CTX| in the verify callback. */
   2020 OPENSSL_EXPORT int SSL_get_ex_data_X509_STORE_CTX_idx(void);
   2021 
   2022 /* SSL_CTX_set_cert_verify_callback sets a custom callback to be called on
   2023  * certificate verification rather than |X509_verify_cert|. |store_ctx| contains
   2024  * the verification parameters. The callback should return one on success and
   2025  * zero on fatal error. It may use |X509_STORE_CTX_set_error| to set a
   2026  * verification result.
   2027  *
   2028  * The callback may use either the |arg| parameter or
   2029  * |SSL_get_ex_data_X509_STORE_CTX_idx| to recover the associated |SSL|
   2030  * object. */
   2031 OPENSSL_EXPORT void SSL_CTX_set_cert_verify_callback(
   2032     SSL_CTX *ctx, int (*callback)(X509_STORE_CTX *store_ctx, void *arg),
   2033     void *arg);
   2034 
   2035 /* SSL_enable_signed_cert_timestamps causes |ssl| (which must be the client end
   2036  * of a connection) to request SCTs from the server. See
   2037  * https://tools.ietf.org/html/rfc6962. It returns one.
   2038  *
   2039  * Call |SSL_get0_signed_cert_timestamp_list| to recover the SCT after the
   2040  * handshake. */
   2041 OPENSSL_EXPORT int SSL_enable_signed_cert_timestamps(SSL *ssl);
   2042 
   2043 /* SSL_CTX_enable_signed_cert_timestamps enables SCT requests on all client SSL
   2044  * objects created from |ctx|.
   2045  *
   2046  * Call |SSL_get0_signed_cert_timestamp_list| to recover the SCT after the
   2047  * handshake. */
   2048 OPENSSL_EXPORT void SSL_CTX_enable_signed_cert_timestamps(SSL_CTX *ctx);
   2049 
   2050 /* SSL_enable_ocsp_stapling causes |ssl| (which must be the client end of a
   2051  * connection) to request a stapled OCSP response from the server. It returns
   2052  * one.
   2053  *
   2054  * Call |SSL_get0_ocsp_response| to recover the OCSP response after the
   2055  * handshake. */
   2056 OPENSSL_EXPORT int SSL_enable_ocsp_stapling(SSL *ssl);
   2057 
   2058 /* SSL_CTX_enable_ocsp_stapling enables OCSP stapling on all client SSL objects
   2059  * created from |ctx|.
   2060  *
   2061  * Call |SSL_get0_ocsp_response| to recover the OCSP response after the
   2062  * handshake. */
   2063 OPENSSL_EXPORT void SSL_CTX_enable_ocsp_stapling(SSL_CTX *ctx);
   2064 
   2065 
   2066 /* Client certificate CA list.
   2067  *
   2068  * When requesting a client certificate, a server may advertise a list of
   2069  * certificate authorities which are accepted. These functions may be used to
   2070  * configure this list. */
   2071 
   2072 /* SSL_set_client_CA_list sets |ssl|'s client certificate CA list to
   2073  * |name_list|. It takes ownership of |name_list|. */
   2074 OPENSSL_EXPORT void SSL_set_client_CA_list(SSL *ssl,
   2075                                            STACK_OF(X509_NAME) *name_list);
   2076 
   2077 /* SSL_CTX_set_client_CA_list sets |ctx|'s client certificate CA list to
   2078  * |name_list|. It takes ownership of |name_list|. */
   2079 OPENSSL_EXPORT void SSL_CTX_set_client_CA_list(SSL_CTX *ctx,
   2080                                                STACK_OF(X509_NAME) *name_list);
   2081 
   2082 /* SSL_get_client_CA_list returns |ssl|'s client certificate CA list. If |ssl|
   2083  * has not been configured as a client, this is the list configured by
   2084  * |SSL_CTX_set_client_CA_list|.
   2085  *
   2086  * If configured as a client, it returns the client certificate CA list sent by
   2087  * the server. In this mode, the behavior is undefined except during the
   2088  * callbacks set by |SSL_CTX_set_cert_cb| and |SSL_CTX_set_client_cert_cb| or
   2089  * when the handshake is paused because of them. */
   2090 OPENSSL_EXPORT STACK_OF(X509_NAME) *SSL_get_client_CA_list(const SSL *ssl);
   2091 
   2092 /* SSL_CTX_get_client_CA_list returns |ctx|'s client certificate CA list. */
   2093 OPENSSL_EXPORT STACK_OF(X509_NAME) *
   2094     SSL_CTX_get_client_CA_list(const SSL_CTX *ctx);
   2095 
   2096 /* SSL_add_client_CA appends |x509|'s subject to the client certificate CA list.
   2097  * It returns one on success or zero on error. The caller retains ownership of
   2098  * |x509|. */
   2099 OPENSSL_EXPORT int SSL_add_client_CA(SSL *ssl, X509 *x509);
   2100 
   2101 /* SSL_CTX_add_client_CA appends |x509|'s subject to the client certificate CA
   2102  * list. It returns one on success or zero on error. The caller retains
   2103  * ownership of |x509|. */
   2104 OPENSSL_EXPORT int SSL_CTX_add_client_CA(SSL_CTX *ctx, X509 *x509);
   2105 
   2106 /* SSL_load_client_CA_file opens |file| and reads PEM-encoded certificates from
   2107  * it. It returns a newly-allocated stack of the certificate subjects or NULL
   2108  * on error. */
   2109 OPENSSL_EXPORT STACK_OF(X509_NAME) *SSL_load_client_CA_file(const char *file);
   2110 
   2111 /* SSL_dup_CA_list makes a deep copy of |list|. It returns the new list on
   2112  * success or NULL on allocation error. */
   2113 OPENSSL_EXPORT STACK_OF(X509_NAME) *SSL_dup_CA_list(STACK_OF(X509_NAME) *list);
   2114 
   2115 /* SSL_add_file_cert_subjects_to_stack behaves like |SSL_load_client_CA_file|
   2116  * but appends the result to |out|. It returns one on success or zero on
   2117  * error. */
   2118 OPENSSL_EXPORT int SSL_add_file_cert_subjects_to_stack(STACK_OF(X509_NAME) *out,
   2119                                                        const char *file);
   2120 
   2121 /* SSL_add_dir_cert_subjects_to_stack lists files in directory |dir|. It calls
   2122  * |SSL_add_file_cert_subjects_to_stack| on each file and returns one on success
   2123  * or zero on error. */
   2124 OPENSSL_EXPORT int SSL_add_dir_cert_subjects_to_stack(STACK_OF(X509_NAME) *out,
   2125                                                       const char *dir);
   2126 
   2127 
   2128 /* Server name indication.
   2129  *
   2130  * The server_name extension (RFC 3546) allows the client to advertise the name
   2131  * of the server it is connecting to. This is used in virtual hosting
   2132  * deployments to select one of a several certificates on a single IP. Only the
   2133  * host_name name type is supported. */
   2134 
   2135 #define TLSEXT_NAMETYPE_host_name 0
   2136 
   2137 /* SSL_set_tlsext_host_name, for a client, configures |ssl| to advertise |name|
   2138  * in the server_name extension. It returns one on success and zero on error. */
   2139 OPENSSL_EXPORT int SSL_set_tlsext_host_name(SSL *ssl, const char *name);
   2140 
   2141 /* SSL_get_servername, for a server, returns the hostname supplied by the
   2142  * client or NULL if there was none. The |type| argument must be
   2143  * |TLSEXT_NAMETYPE_host_name|. */
   2144 OPENSSL_EXPORT const char *SSL_get_servername(const SSL *ssl, const int type);
   2145 
   2146 /* SSL_get_servername_type, for a server, returns |TLSEXT_NAMETYPE_host_name|
   2147  * if the client sent a hostname and -1 otherwise. */
   2148 OPENSSL_EXPORT int SSL_get_servername_type(const SSL *ssl);
   2149 
   2150 /* SSL_CTX_set_tlsext_servername_callback configures |callback| to be called on
   2151  * the server after ClientHello extensions have been parsed and returns one.
   2152  * The callback may use |SSL_get_servername| to examine the server_name extension
   2153  * and returns a |SSL_TLSEXT_ERR_*| value. The value of |arg| may be set by
   2154  * calling |SSL_CTX_set_tlsext_servername_arg|.
   2155  *
   2156  * If the callback returns |SSL_TLSEXT_ERR_NOACK|, the server_name extension is
   2157  * not acknowledged in the ServerHello. If the return value is
   2158  * |SSL_TLSEXT_ERR_ALERT_FATAL| or |SSL_TLSEXT_ERR_ALERT_WARNING| then
   2159  * |*out_alert| must be set to the alert value to send. */
   2160 OPENSSL_EXPORT int SSL_CTX_set_tlsext_servername_callback(
   2161     SSL_CTX *ctx, int (*callback)(SSL *ssl, int *out_alert, void *arg));
   2162 
   2163 /* SSL_CTX_set_tlsext_servername_arg sets the argument to the servername
   2164  * callback and returns one. See |SSL_CTX_set_tlsext_servername_callback|. */
   2165 OPENSSL_EXPORT int SSL_CTX_set_tlsext_servername_arg(SSL_CTX *ctx, void *arg);
   2166 
   2167 /* SSL_TLSEXT_ERR_* are values returned by some extension-related callbacks. */
   2168 #define SSL_TLSEXT_ERR_OK 0
   2169 #define SSL_TLSEXT_ERR_ALERT_WARNING 1
   2170 #define SSL_TLSEXT_ERR_ALERT_FATAL 2
   2171 #define SSL_TLSEXT_ERR_NOACK 3
   2172 
   2173 
   2174 /* Application-layer protocol negotation.
   2175  *
   2176  * The ALPN extension (RFC 7301) allows negotiating different application-layer
   2177  * protocols over a single port. This is used, for example, to negotiate
   2178  * HTTP/2. */
   2179 
   2180 /* SSL_CTX_set_alpn_protos sets the client ALPN protocol list on |ctx| to
   2181  * |protos|. |protos| must be in wire-format (i.e. a series of non-empty, 8-bit
   2182  * length-prefixed strings). It returns zero on success and one on failure.
   2183  * Configuring this list enables ALPN on a client.
   2184  *
   2185  * WARNING: this function is dangerous because it breaks the usual return value
   2186  * convention. */
   2187 OPENSSL_EXPORT int SSL_CTX_set_alpn_protos(SSL_CTX *ctx, const uint8_t *protos,
   2188                                            unsigned protos_len);
   2189 
   2190 /* SSL_set_alpn_protos sets the client ALPN protocol list on |ssl| to |protos|.
   2191  * |protos| must be in wire-format (i.e. a series of non-empty, 8-bit
   2192  * length-prefixed strings). It returns zero on success and one on failure.
   2193  * Configuring this list enables ALPN on a client.
   2194  *
   2195  * WARNING: this function is dangerous because it breaks the usual return value
   2196  * convention. */
   2197 OPENSSL_EXPORT int SSL_set_alpn_protos(SSL *ssl, const uint8_t *protos,
   2198                                        unsigned protos_len);
   2199 
   2200 /* SSL_CTX_set_alpn_select_cb sets a callback function on |ctx| that is called
   2201  * during ClientHello processing in order to select an ALPN protocol from the
   2202  * client's list of offered protocols. Configuring this callback enables ALPN on
   2203  * a server.
   2204  *
   2205  * The callback is passed a wire-format (i.e. a series of non-empty, 8-bit
   2206  * length-prefixed strings) ALPN protocol list in |in|. It should set |*out| and
   2207  * |*out_len| to the selected protocol and return |SSL_TLSEXT_ERR_OK| on
   2208  * success. It does not pass ownership of the buffer. Otherwise, it should
   2209  * return |SSL_TLSEXT_ERR_NOACK|. Other |SSL_TLSEXT_ERR_*| values are
   2210  * unimplemented and will be treated as |SSL_TLSEXT_ERR_NOACK|. */
   2211 OPENSSL_EXPORT void SSL_CTX_set_alpn_select_cb(
   2212     SSL_CTX *ctx, int (*cb)(SSL *ssl, const uint8_t **out, uint8_t *out_len,
   2213                             const uint8_t *in, unsigned in_len, void *arg),
   2214     void *arg);
   2215 
   2216 /* SSL_get0_alpn_selected gets the selected ALPN protocol (if any) from |ssl|.
   2217  * On return it sets |*out_data| to point to |*out_len| bytes of protocol name
   2218  * (not including the leading length-prefix byte). If the server didn't respond
   2219  * with a negotiated protocol then |*out_len| will be zero. */
   2220 OPENSSL_EXPORT void SSL_get0_alpn_selected(const SSL *ssl,
   2221                                            const uint8_t **out_data,
   2222                                            unsigned *out_len);
   2223 
   2224 
   2225 /* Next protocol negotiation.
   2226  *
   2227  * The NPN extension (draft-agl-tls-nextprotoneg-03) is the predecessor to ALPN
   2228  * and deprecated in favor of it. */
   2229 
   2230 /* SSL_CTX_set_next_protos_advertised_cb sets a callback that is called when a
   2231  * TLS server needs a list of supported protocols for Next Protocol
   2232  * Negotiation. The returned list must be in wire format. The list is returned
   2233  * by setting |*out| to point to it and |*out_len| to its length. This memory
   2234  * will not be modified, but one should assume that |ssl| keeps a reference to
   2235  * it.
   2236  *
   2237  * The callback should return |SSL_TLSEXT_ERR_OK| if it wishes to advertise.
   2238  * Otherwise, no such extension will be included in the ServerHello. */
   2239 OPENSSL_EXPORT void SSL_CTX_set_next_protos_advertised_cb(
   2240     SSL_CTX *ctx,
   2241     int (*cb)(SSL *ssl, const uint8_t **out, unsigned *out_len, void *arg),
   2242     void *arg);
   2243 
   2244 /* SSL_CTX_set_next_proto_select_cb sets a callback that is called when a client
   2245  * needs to select a protocol from the server's provided list. |*out| must be
   2246  * set to point to the selected protocol (which may be within |in|). The length
   2247  * of the protocol name must be written into |*out_len|. The server's advertised
   2248  * protocols are provided in |in| and |in_len|. The callback can assume that
   2249  * |in| is syntactically valid.
   2250  *
   2251  * The client must select a protocol. It is fatal to the connection if this
   2252  * callback returns a value other than |SSL_TLSEXT_ERR_OK|.
   2253  *
   2254  * Configuring this callback enables NPN on a client. */
   2255 OPENSSL_EXPORT void SSL_CTX_set_next_proto_select_cb(
   2256     SSL_CTX *ctx, int (*cb)(SSL *ssl, uint8_t **out, uint8_t *out_len,
   2257                             const uint8_t *in, unsigned in_len, void *arg),
   2258     void *arg);
   2259 
   2260 /* SSL_get0_next_proto_negotiated sets |*out_data| and |*out_len| to point to
   2261  * the client's requested protocol for this connection. If the client didn't
   2262  * request any protocol, then |*out_data| is set to NULL.
   2263  *
   2264  * Note that the client can request any protocol it chooses. The value returned
   2265  * from this function need not be a member of the list of supported protocols
   2266  * provided by the server. */
   2267 OPENSSL_EXPORT void SSL_get0_next_proto_negotiated(const SSL *ssl,
   2268                                                    const uint8_t **out_data,
   2269                                                    unsigned *out_len);
   2270 
   2271 /* SSL_select_next_proto implements the standard protocol selection. It is
   2272  * expected that this function is called from the callback set by
   2273  * |SSL_CTX_set_next_proto_select_cb|.
   2274  *
   2275  * The protocol data is assumed to be a vector of 8-bit, length prefixed byte
   2276  * strings. The length byte itself is not included in the length. A byte
   2277  * string of length 0 is invalid. No byte string may be truncated.
   2278  *
   2279  * The current, but experimental algorithm for selecting the protocol is:
   2280  *
   2281  * 1) If the server doesn't support NPN then this is indicated to the
   2282  * callback. In this case, the client application has to abort the connection
   2283  * or have a default application level protocol.
   2284  *
   2285  * 2) If the server supports NPN, but advertises an empty list then the
   2286  * client selects the first protcol in its list, but indicates via the
   2287  * API that this fallback case was enacted.
   2288  *
   2289  * 3) Otherwise, the client finds the first protocol in the server's list
   2290  * that it supports and selects this protocol. This is because it's
   2291  * assumed that the server has better information about which protocol
   2292  * a client should use.
   2293  *
   2294  * 4) If the client doesn't support any of the server's advertised
   2295  * protocols, then this is treated the same as case 2.
   2296  *
   2297  * It returns either |OPENSSL_NPN_NEGOTIATED| if a common protocol was found, or
   2298  * |OPENSSL_NPN_NO_OVERLAP| if the fallback case was reached. */
   2299 OPENSSL_EXPORT int SSL_select_next_proto(uint8_t **out, uint8_t *out_len,
   2300                                          const uint8_t *server,
   2301                                          unsigned server_len,
   2302                                          const uint8_t *client,
   2303                                          unsigned client_len);
   2304 
   2305 #define OPENSSL_NPN_UNSUPPORTED 0
   2306 #define OPENSSL_NPN_NEGOTIATED 1
   2307 #define OPENSSL_NPN_NO_OVERLAP 2
   2308 
   2309 
   2310 /* Channel ID.
   2311  *
   2312  * See draft-balfanz-tls-channelid-01. */
   2313 
   2314 /* SSL_CTX_enable_tls_channel_id either configures a TLS server to accept TLS
   2315  * Channel IDs from clients, or configures a client to send TLS Channel IDs to
   2316  * a server. It returns one. */
   2317 OPENSSL_EXPORT int SSL_CTX_enable_tls_channel_id(SSL_CTX *ctx);
   2318 
   2319 /* SSL_enable_tls_channel_id either configures a TLS server to accept TLS
   2320  * Channel IDs from clients, or configures a client to send TLS Channel IDs to
   2321  * server. It returns one. */
   2322 OPENSSL_EXPORT int SSL_enable_tls_channel_id(SSL *ssl);
   2323 
   2324 /* SSL_CTX_set1_tls_channel_id configures a TLS client to send a TLS Channel ID
   2325  * to compatible servers. |private_key| must be a P-256 EC key. It returns one
   2326  * on success and zero on error. */
   2327 OPENSSL_EXPORT int SSL_CTX_set1_tls_channel_id(SSL_CTX *ctx,
   2328                                                EVP_PKEY *private_key);
   2329 
   2330 /* SSL_set1_tls_channel_id configures a TLS client to send a TLS Channel ID to
   2331  * compatible servers. |private_key| must be a P-256 EC key. It returns one on
   2332  * success and zero on error. */
   2333 OPENSSL_EXPORT int SSL_set1_tls_channel_id(SSL *ssl, EVP_PKEY *private_key);
   2334 
   2335 /* SSL_get_tls_channel_id gets the client's TLS Channel ID from a server |SSL*|
   2336  * and copies up to the first |max_out| bytes into |out|. The Channel ID
   2337  * consists of the client's P-256 public key as an (x,y) pair where each is a
   2338  * 32-byte, big-endian field element. It returns 0 if the client didn't offer a
   2339  * Channel ID and the length of the complete Channel ID otherwise. */
   2340 OPENSSL_EXPORT size_t SSL_get_tls_channel_id(SSL *ssl, uint8_t *out,
   2341                                              size_t max_out);
   2342 
   2343 /* SSL_CTX_set_channel_id_cb sets a callback to be called when a TLS Channel ID
   2344  * is requested. The callback may set |*out_pkey| to a key, passing a reference
   2345  * to the caller. If none is returned, the handshake will pause and
   2346  * |SSL_get_error| will return |SSL_ERROR_WANT_CHANNEL_ID_LOOKUP|.
   2347  *
   2348  * See also |SSL_ERROR_WANT_CHANNEL_ID_LOOKUP|. */
   2349 OPENSSL_EXPORT void SSL_CTX_set_channel_id_cb(
   2350     SSL_CTX *ctx, void (*channel_id_cb)(SSL *ssl, EVP_PKEY **out_pkey));
   2351 
   2352 /* SSL_CTX_get_channel_id_cb returns the callback set by
   2353  * |SSL_CTX_set_channel_id_cb|. */
   2354 OPENSSL_EXPORT void (*SSL_CTX_get_channel_id_cb(SSL_CTX *ctx))(
   2355     SSL *ssl, EVP_PKEY **out_pkey);
   2356 
   2357 
   2358 /* DTLS-SRTP.
   2359  *
   2360  * See RFC 5764. */
   2361 
   2362 /* An SRTP_PROTECTION_PROFILE is an SRTP profile for use with the use_srtp
   2363  * extension. */
   2364 struct srtp_protection_profile_st {
   2365   const char *name;
   2366   unsigned long id;
   2367 } /* SRTP_PROTECTION_PROFILE */;
   2368 
   2369 DECLARE_STACK_OF(SRTP_PROTECTION_PROFILE)
   2370 
   2371 /* SRTP_* define constants for SRTP profiles. */
   2372 #define SRTP_AES128_CM_SHA1_80 0x0001
   2373 #define SRTP_AES128_CM_SHA1_32 0x0002
   2374 #define SRTP_AES128_F8_SHA1_80 0x0003
   2375 #define SRTP_AES128_F8_SHA1_32 0x0004
   2376 #define SRTP_NULL_SHA1_80      0x0005
   2377 #define SRTP_NULL_SHA1_32      0x0006
   2378 #define SRTP_AEAD_AES_128_GCM  0x0007
   2379 #define SRTP_AEAD_AES_256_GCM  0x0008
   2380 
   2381 /* SSL_CTX_set_srtp_profiles enables SRTP for all SSL objects created from
   2382  * |ctx|. |profile| contains a colon-separated list of profile names. It returns
   2383  * one on success and zero on failure. */
   2384 OPENSSL_EXPORT int SSL_CTX_set_srtp_profiles(SSL_CTX *ctx,
   2385                                              const char *profiles);
   2386 
   2387 /* SSL_set_srtp_profiles enables SRTP for |ssl|.  |profile| contains a
   2388  * colon-separated list of profile names. It returns one on success and zero on
   2389  * failure. */
   2390 OPENSSL_EXPORT int SSL_set_srtp_profiles(SSL *ssl, const char *profiles);
   2391 
   2392 /* SSL_get_srtp_profiles returns the SRTP profiles supported by |ssl|. */
   2393 OPENSSL_EXPORT STACK_OF(SRTP_PROTECTION_PROFILE) *SSL_get_srtp_profiles(
   2394     SSL *ssl);
   2395 
   2396 /* SSL_get_selected_srtp_profile returns the selected SRTP profile, or NULL if
   2397  * SRTP was not negotiated. */
   2398 OPENSSL_EXPORT const SRTP_PROTECTION_PROFILE *SSL_get_selected_srtp_profile(
   2399     SSL *ssl);
   2400 
   2401 
   2402 /* Pre-shared keys.
   2403  *
   2404  * Connections may be configured with PSK (Pre-Shared Key) cipher suites. These
   2405  * authenticate using out-of-band pre-shared keys rather than certificates. See
   2406  * RFC 4279.
   2407  *
   2408  * This implementation uses NUL-terminated C strings for identities and identity
   2409  * hints, so values with a NUL character are not supported. (RFC 4279 does not
   2410  * specify the format of an identity.) */
   2411 
   2412 /* PSK_MAX_IDENTITY_LEN is the maximum supported length of a PSK identity,
   2413  * excluding the NUL terminator. */
   2414 #define PSK_MAX_IDENTITY_LEN 128
   2415 
   2416 /* PSK_MAX_PSK_LEN is the maximum supported length of a pre-shared key. */
   2417 #define PSK_MAX_PSK_LEN 256
   2418 
   2419 /* SSL_CTX_set_psk_client_callback sets the callback to be called when PSK is
   2420  * negotiated on the client. This callback must be set to enable PSK cipher
   2421  * suites on the client.
   2422  *
   2423  * The callback is passed the identity hint in |hint| or NULL if none was
   2424  * provided. It should select a PSK identity and write the identity and the
   2425  * corresponding PSK to |identity| and |psk|, respectively. The identity is
   2426  * written as a NUL-terminated C string of length (excluding the NUL terminator)
   2427  * at most |max_identity_len|. The PSK's length must be at most |max_psk_len|.
   2428  * The callback returns the length of the PSK or 0 if no suitable identity was
   2429  * found. */
   2430 OPENSSL_EXPORT void SSL_CTX_set_psk_client_callback(
   2431     SSL_CTX *ctx,
   2432     unsigned (*psk_client_callback)(
   2433         SSL *ssl, const char *hint, char *identity,
   2434         unsigned max_identity_len, uint8_t *psk, unsigned max_psk_len));
   2435 
   2436 /* SSL_set_psk_client_callback sets the callback to be called when PSK is
   2437  * negotiated on the client. This callback must be set to enable PSK cipher
   2438  * suites on the client. See also |SSL_CTX_set_psk_client_callback|. */
   2439 OPENSSL_EXPORT void SSL_set_psk_client_callback(
   2440     SSL *ssl, unsigned (*psk_client_callback)(SSL *ssl, const char *hint,
   2441                                               char *identity,
   2442                                               unsigned max_identity_len,
   2443                                               uint8_t *psk,
   2444                                               unsigned max_psk_len));
   2445 
   2446 /* SSL_CTX_set_psk_server_callback sets the callback to be called when PSK is
   2447  * negotiated on the server. This callback must be set to enable PSK cipher
   2448  * suites on the server.
   2449  *
   2450  * The callback is passed the identity in |identity|. It should write a PSK of
   2451  * length at most |max_psk_len| to |psk| and return the number of bytes written
   2452  * or zero if the PSK identity is unknown. */
   2453 OPENSSL_EXPORT void SSL_CTX_set_psk_server_callback(
   2454     SSL_CTX *ctx,
   2455     unsigned (*psk_server_callback)(SSL *ssl, const char *identity,
   2456                                     uint8_t *psk,
   2457                                     unsigned max_psk_len));
   2458 
   2459 /* SSL_set_psk_server_callback sets the callback to be called when PSK is
   2460  * negotiated on the server. This callback must be set to enable PSK cipher
   2461  * suites on the server. See also |SSL_CTX_set_psk_server_callback|. */
   2462 OPENSSL_EXPORT void SSL_set_psk_server_callback(
   2463     SSL *ssl,
   2464     unsigned (*psk_server_callback)(SSL *ssl, const char *identity,
   2465                                     uint8_t *psk,
   2466                                     unsigned max_psk_len));
   2467 
   2468 /* SSL_CTX_use_psk_identity_hint configures server connections to advertise an
   2469  * identity hint of |identity_hint|. It returns one on success and zero on
   2470  * error. */
   2471 OPENSSL_EXPORT int SSL_CTX_use_psk_identity_hint(SSL_CTX *ctx,
   2472                                                  const char *identity_hint);
   2473 
   2474 /* SSL_use_psk_identity_hint configures server connections to advertise an
   2475  * identity hint of |identity_hint|. It returns one on success and zero on
   2476  * error. */
   2477 OPENSSL_EXPORT int SSL_use_psk_identity_hint(SSL *ssl,
   2478                                              const char *identity_hint);
   2479 
   2480 /* SSL_get_psk_identity_hint returns the PSK identity hint advertised for |ssl|
   2481  * or NULL if there is none. */
   2482 OPENSSL_EXPORT const char *SSL_get_psk_identity_hint(const SSL *ssl);
   2483 
   2484 /* SSL_get_psk_identity, after the handshake completes, returns the PSK identity
   2485  * that was negotiated by |ssl| or NULL if PSK was not used. */
   2486 OPENSSL_EXPORT const char *SSL_get_psk_identity(const SSL *ssl);
   2487 
   2488 
   2489 /* Alerts.
   2490  *
   2491  * TLS and SSL 3.0 use alerts to signal error conditions. Alerts have a type
   2492  * (warning or fatal) and description. OpenSSL internally handles fatal alerts
   2493  * with dedicated error codes (see |SSL_AD_REASON_OFFSET|). Except for
   2494  * close_notify, warning alerts are silently ignored and may only be surfaced
   2495  * with |SSL_CTX_set_info_callback|. */
   2496 
   2497 /* SSL_AD_REASON_OFFSET is the offset between error reasons and |SSL_AD_*|
   2498  * values. Any error code under |ERR_LIB_SSL| with an error reason above this
   2499  * value corresponds to an alert description. Consumers may add or subtract
   2500  * |SSL_AD_REASON_OFFSET| to convert between them.
   2501  *
   2502  * make_errors.go reserves error codes above 1000 for manually-assigned errors.
   2503  * This value must be kept in sync with reservedReasonCode in make_errors.h */
   2504 #define SSL_AD_REASON_OFFSET 1000
   2505 
   2506 /* SSL_AD_* are alert descriptions for SSL 3.0 and TLS. */
   2507 #define SSL_AD_CLOSE_NOTIFY SSL3_AD_CLOSE_NOTIFY
   2508 #define SSL_AD_UNEXPECTED_MESSAGE SSL3_AD_UNEXPECTED_MESSAGE
   2509 #define SSL_AD_BAD_RECORD_MAC SSL3_AD_BAD_RECORD_MAC
   2510 #define SSL_AD_DECRYPTION_FAILED TLS1_AD_DECRYPTION_FAILED
   2511 #define SSL_AD_RECORD_OVERFLOW TLS1_AD_RECORD_OVERFLOW
   2512 #define SSL_AD_DECOMPRESSION_FAILURE SSL3_AD_DECOMPRESSION_FAILURE
   2513 #define SSL_AD_HANDSHAKE_FAILURE SSL3_AD_HANDSHAKE_FAILURE
   2514 #define SSL_AD_NO_CERTIFICATE SSL3_AD_NO_CERTIFICATE /* Not used in TLS */
   2515 #define SSL_AD_BAD_CERTIFICATE SSL3_AD_BAD_CERTIFICATE
   2516 #define SSL_AD_UNSUPPORTED_CERTIFICATE SSL3_AD_UNSUPPORTED_CERTIFICATE
   2517 #define SSL_AD_CERTIFICATE_REVOKED SSL3_AD_CERTIFICATE_REVOKED
   2518 #define SSL_AD_CERTIFICATE_EXPIRED SSL3_AD_CERTIFICATE_EXPIRED
   2519 #define SSL_AD_CERTIFICATE_UNKNOWN SSL3_AD_CERTIFICATE_UNKNOWN
   2520 #define SSL_AD_ILLEGAL_PARAMETER SSL3_AD_ILLEGAL_PARAMETER
   2521 #define SSL_AD_UNKNOWN_CA TLS1_AD_UNKNOWN_CA
   2522 #define SSL_AD_ACCESS_DENIED TLS1_AD_ACCESS_DENIED
   2523 #define SSL_AD_DECODE_ERROR TLS1_AD_DECODE_ERROR
   2524 #define SSL_AD_DECRYPT_ERROR TLS1_AD_DECRYPT_ERROR
   2525 #define SSL_AD_EXPORT_RESTRICTION TLS1_AD_EXPORT_RESTRICTION
   2526 #define SSL_AD_PROTOCOL_VERSION TLS1_AD_PROTOCOL_VERSION
   2527 #define SSL_AD_INSUFFICIENT_SECURITY TLS1_AD_INSUFFICIENT_SECURITY
   2528 #define SSL_AD_INTERNAL_ERROR TLS1_AD_INTERNAL_ERROR
   2529 #define SSL_AD_USER_CANCELLED TLS1_AD_USER_CANCELLED
   2530 #define SSL_AD_NO_RENEGOTIATION TLS1_AD_NO_RENEGOTIATION
   2531 #define SSL_AD_UNSUPPORTED_EXTENSION TLS1_AD_UNSUPPORTED_EXTENSION
   2532 #define SSL_AD_CERTIFICATE_UNOBTAINABLE TLS1_AD_CERTIFICATE_UNOBTAINABLE
   2533 #define SSL_AD_UNRECOGNIZED_NAME TLS1_AD_UNRECOGNIZED_NAME
   2534 #define SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE \
   2535   TLS1_AD_BAD_CERTIFICATE_STATUS_RESPONSE
   2536 #define SSL_AD_BAD_CERTIFICATE_HASH_VALUE TLS1_AD_BAD_CERTIFICATE_HASH_VALUE
   2537 #define SSL_AD_UNKNOWN_PSK_IDENTITY TLS1_AD_UNKNOWN_PSK_IDENTITY
   2538 #define SSL_AD_INAPPROPRIATE_FALLBACK SSL3_AD_INAPPROPRIATE_FALLBACK
   2539 
   2540 /* SSL_alert_type_string_long returns a string description of |value| as an
   2541  * alert type (warning or fatal). */
   2542 OPENSSL_EXPORT const char *SSL_alert_type_string_long(int value);
   2543 
   2544 /* SSL_alert_desc_string_long returns a string description of |value| as an
   2545  * alert description or "unknown" if unknown. */
   2546 OPENSSL_EXPORT const char *SSL_alert_desc_string_long(int value);
   2547 
   2548 
   2549 /* ex_data functions.
   2550  *
   2551  * See |ex_data.h| for details. */
   2552 
   2553 OPENSSL_EXPORT int SSL_set_ex_data(SSL *ssl, int idx, void *data);
   2554 OPENSSL_EXPORT void *SSL_get_ex_data(const SSL *ssl, int idx);
   2555 OPENSSL_EXPORT int SSL_get_ex_new_index(long argl, void *argp,
   2556                                         CRYPTO_EX_unused *unused,
   2557                                         CRYPTO_EX_dup *dup_func,
   2558                                         CRYPTO_EX_free *free_func);
   2559 
   2560 OPENSSL_EXPORT int SSL_SESSION_set_ex_data(SSL_SESSION *session, int idx,
   2561                                            void *data);
   2562 OPENSSL_EXPORT void *SSL_SESSION_get_ex_data(const SSL_SESSION *session,
   2563                                              int idx);
   2564 OPENSSL_EXPORT int SSL_SESSION_get_ex_new_index(long argl, void *argp,
   2565                                                 CRYPTO_EX_unused *unused,
   2566                                                 CRYPTO_EX_dup *dup_func,
   2567                                                 CRYPTO_EX_free *free_func);
   2568 
   2569 OPENSSL_EXPORT int SSL_CTX_set_ex_data(SSL_CTX *ctx, int idx, void *data);
   2570 OPENSSL_EXPORT void *SSL_CTX_get_ex_data(const SSL_CTX *ctx, int idx);
   2571 OPENSSL_EXPORT int SSL_CTX_get_ex_new_index(long argl, void *argp,
   2572                                             CRYPTO_EX_unused *unused,
   2573                                             CRYPTO_EX_dup *dup_func,
   2574                                             CRYPTO_EX_free *free_func);
   2575 
   2576 
   2577 /* Obscure functions. */
   2578 
   2579 /* SSL_get_rc4_state sets |*read_key| and |*write_key| to the RC4 states for
   2580  * the read and write directions. It returns one on success or zero if |ssl|
   2581  * isn't using an RC4-based cipher suite. */
   2582 OPENSSL_EXPORT int SSL_get_rc4_state(const SSL *ssl, const RC4_KEY **read_key,
   2583                                      const RC4_KEY **write_key);
   2584 
   2585 /* SSL_get_ivs sets |*out_iv_len| to the length of the IVs for the ciphers
   2586  * underlying |ssl| and sets |*out_read_iv| and |*out_write_iv| to point to the
   2587  * current IVs for the read and write directions. This is only meaningful for
   2588  * connections with implicit IVs (i.e. CBC mode with SSLv3 or TLS 1.0).
   2589  *
   2590  * It returns one on success or zero on error. */
   2591 OPENSSL_EXPORT int SSL_get_ivs(const SSL *ssl, const uint8_t **out_read_iv,
   2592                                const uint8_t **out_write_iv,
   2593                                size_t *out_iv_len);
   2594 
   2595 /* SSL_get_structure_sizes returns the sizes of the SSL, SSL_CTX and
   2596  * SSL_SESSION structures so that a test can ensure that outside code agrees on
   2597  * these values. */
   2598 OPENSSL_EXPORT void SSL_get_structure_sizes(size_t *ssl_size,
   2599                                             size_t *ssl_ctx_size,
   2600                                             size_t *ssl_session_size);
   2601 
   2602 /* SSL_CTX_set_msg_callback installs |cb| as the message callback for |ctx|.
   2603  * This callback will be called when sending or receiving low-level record
   2604  * headers, complete handshake messages, ChangeCipherSpec, and alerts.
   2605  * |write_p| is one for outgoing messages and zero for incoming messages.
   2606  *
   2607  * For each record header, |cb| is called with |version| = 0 and |content_type|
   2608  * = |SSL3_RT_HEADER|. The |len| bytes from |buf| contain the header. Note that
   2609  * this does not include the record body. If the record is sealed, the length
   2610  * in the header is the length of the ciphertext.
   2611  *
   2612  * For each handshake message, ChangeCipherSpec, and alert, |version| is the
   2613  * protocol version and |content_type| is the corresponding record type. The
   2614  * |len| bytes from |buf| contain the handshake message, one-byte
   2615  * ChangeCipherSpec body, and two-byte alert, respectively. */
   2616 OPENSSL_EXPORT void SSL_CTX_set_msg_callback(
   2617     SSL_CTX *ctx, void (*cb)(int write_p, int version, int content_type,
   2618                              const void *buf, size_t len, SSL *ssl, void *arg));
   2619 
   2620 /* SSL_CTX_set_msg_callback_arg sets the |arg| parameter of the message
   2621  * callback. */
   2622 OPENSSL_EXPORT void SSL_CTX_set_msg_callback_arg(SSL_CTX *ctx, void *arg);
   2623 
   2624 /* SSL_set_msg_callback installs |cb| as the message callback of |ssl|. See
   2625  * |SSL_CTX_set_msg_callback| for when this callback is called. */
   2626 OPENSSL_EXPORT void SSL_set_msg_callback(
   2627     SSL *ssl, void (*cb)(int write_p, int version, int content_type,
   2628                          const void *buf, size_t len, SSL *ssl, void *arg));
   2629 
   2630 /* SSL_set_msg_callback_arg sets the |arg| parameter of the message callback. */
   2631 OPENSSL_EXPORT void SSL_set_msg_callback_arg(SSL *ssl, void *arg);
   2632 
   2633 /* SSL_CTX_set_keylog_callback configures a callback to log key material. This
   2634  * is intended for debugging use with tools like Wireshark. The |cb| function
   2635  * should log |line| followed by a newline, synchronizing with any concurrent
   2636  * access to the log.
   2637  *
   2638  * The format is described in
   2639  * https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/Key_Log_Format. */
   2640 OPENSSL_EXPORT void SSL_CTX_set_keylog_callback(
   2641     SSL_CTX *ctx, void (*cb)(const SSL *ssl, const char *line));
   2642 
   2643 enum ssl_renegotiate_mode_t {
   2644   ssl_renegotiate_never = 0,
   2645   ssl_renegotiate_once,
   2646   ssl_renegotiate_freely,
   2647   ssl_renegotiate_ignore,
   2648 };
   2649 
   2650 /* SSL_set_renegotiate_mode configures how |ssl|, a client, reacts to
   2651  * renegotiation attempts by a server. If |ssl| is a server, peer-initiated
   2652  * renegotiations are *always* rejected and this function does nothing.
   2653  *
   2654  * The renegotiation mode defaults to |ssl_renegotiate_never|, but may be set
   2655  * at any point in a connection's lifetime. Set it to |ssl_renegotiate_once| to
   2656  * allow one renegotiation, |ssl_renegotiate_freely| to allow all
   2657  * renegotiations or |ssl_renegotiate_ignore| to ignore HelloRequest messages.
   2658  * Note that ignoring HelloRequest messages may cause the connection to stall
   2659  * if the server waits for the renegotiation to complete.
   2660  *
   2661  * There is no support in BoringSSL for initiating renegotiations as a client
   2662  * or server. */
   2663 OPENSSL_EXPORT void SSL_set_renegotiate_mode(SSL *ssl,
   2664                                              enum ssl_renegotiate_mode_t mode);
   2665 
   2666 /* SSL_renegotiate_pending returns one if |ssl| is in the middle of a
   2667  * renegotiation. */
   2668 OPENSSL_EXPORT int SSL_renegotiate_pending(SSL *ssl);
   2669 
   2670 /* SSL_total_renegotiations returns the total number of renegotiation handshakes
   2671  * peformed by |ssl|. This includes the pending renegotiation, if any. */
   2672 OPENSSL_EXPORT int SSL_total_renegotiations(const SSL *ssl);
   2673 
   2674 /* SSL_MAX_CERT_LIST_DEFAULT is the default maximum length, in bytes, of a peer
   2675  * certificate chain. */
   2676 #define SSL_MAX_CERT_LIST_DEFAULT 1024 * 100
   2677 
   2678 /* SSL_CTX_get_max_cert_list returns the maximum length, in bytes, of a peer
   2679  * certificate chain accepted by |ctx|. */
   2680 OPENSSL_EXPORT size_t SSL_CTX_get_max_cert_list(const SSL_CTX *ctx);
   2681 
   2682 /* SSL_CTX_set_max_cert_list sets the maximum length, in bytes, of a peer
   2683  * certificate chain to |max_cert_list|. This affects how much memory may be
   2684  * consumed during the handshake. */
   2685 OPENSSL_EXPORT void SSL_CTX_set_max_cert_list(SSL_CTX *ctx,
   2686                                               size_t max_cert_list);
   2687 
   2688 /* SSL_get_max_cert_list returns the maximum length, in bytes, of a peer
   2689  * certificate chain accepted by |ssl|. */
   2690 OPENSSL_EXPORT size_t SSL_get_max_cert_list(const SSL *ssl);
   2691 
   2692 /* SSL_set_max_cert_list sets the maximum length, in bytes, of a peer
   2693  * certificate chain to |max_cert_list|. This affects how much memory may be
   2694  * consumed during the handshake. */
   2695 OPENSSL_EXPORT void SSL_set_max_cert_list(SSL *ssl, size_t max_cert_list);
   2696 
   2697 /* SSL_CTX_set_max_send_fragment sets the maximum length, in bytes, of records
   2698  * sent by |ctx|. Beyond this length, handshake messages and application data
   2699  * will be split into multiple records. */
   2700 OPENSSL_EXPORT void SSL_CTX_set_max_send_fragment(SSL_CTX *ctx,
   2701                                                   size_t max_send_fragment);
   2702 
   2703 /* SSL_set_max_send_fragment sets the maximum length, in bytes, of records
   2704  * sent by |ssl|. Beyond this length, handshake messages and application data
   2705  * will be split into multiple records. */
   2706 OPENSSL_EXPORT void SSL_set_max_send_fragment(SSL *ssl,
   2707                                               size_t max_send_fragment);
   2708 
   2709 /* ssl_early_callback_ctx is passed to certain callbacks that are called very
   2710  * early on during the server handshake. At this point, much of the SSL* hasn't
   2711  * been filled out and only the ClientHello can be depended on. */
   2712 struct ssl_early_callback_ctx {
   2713   SSL *ssl;
   2714   const uint8_t *client_hello;
   2715   size_t client_hello_len;
   2716   const uint8_t *session_id;
   2717   size_t session_id_len;
   2718   const uint8_t *cipher_suites;
   2719   size_t cipher_suites_len;
   2720   const uint8_t *compression_methods;
   2721   size_t compression_methods_len;
   2722   const uint8_t *extensions;
   2723   size_t extensions_len;
   2724 };
   2725 
   2726 /* SSL_early_callback_ctx_extension_get searches the extensions in |ctx| for an
   2727  * extension of the given type. If not found, it returns zero. Otherwise it
   2728  * sets |out_data| to point to the extension contents (not including the type
   2729  * and length bytes), sets |out_len| to the length of the extension contents
   2730  * and returns one. */
   2731 OPENSSL_EXPORT int SSL_early_callback_ctx_extension_get(
   2732     const struct ssl_early_callback_ctx *ctx, uint16_t extension_type,
   2733     const uint8_t **out_data, size_t *out_len);
   2734 
   2735 /* SSL_CTX_set_select_certificate_cb sets a callback that is called before most
   2736  * ClientHello processing and before the decision whether to resume a session
   2737  * is made. The callback may inspect the ClientHello and configure the
   2738  * connection. It may then return one to continue the handshake or zero to
   2739  * pause the handshake to perform an asynchronous operation. If paused,
   2740  * |SSL_get_error| will return |SSL_ERROR_PENDING_CERTIFICATE|.
   2741  *
   2742  * Note: The |ssl_early_callback_ctx| is only valid for the duration of the
   2743  * callback and is not valid while the handshake is paused. Further, unlike with
   2744  * most callbacks, when the handshake loop is resumed, it will not call the
   2745  * callback a second time. The caller must finish reconfiguring the connection
   2746  * before resuming the handshake. */
   2747 OPENSSL_EXPORT void SSL_CTX_set_select_certificate_cb(
   2748     SSL_CTX *ctx, int (*cb)(const struct ssl_early_callback_ctx *));
   2749 
   2750 /* SSL_CTX_set_dos_protection_cb sets a callback that is called once the
   2751  * resumption decision for a ClientHello has been made. It can return one to
   2752  * allow the handshake to continue or zero to cause the handshake to abort. */
   2753 OPENSSL_EXPORT void SSL_CTX_set_dos_protection_cb(
   2754     SSL_CTX *ctx, int (*cb)(const struct ssl_early_callback_ctx *));
   2755 
   2756 /* SSL_ST_* are possible values for |SSL_state| and the bitmasks that make them
   2757  * up. */
   2758 #define SSL_ST_CONNECT 0x1000
   2759 #define SSL_ST_ACCEPT 0x2000
   2760 #define SSL_ST_MASK 0x0FFF
   2761 #define SSL_ST_INIT (SSL_ST_CONNECT | SSL_ST_ACCEPT)
   2762 #define SSL_ST_OK 0x03
   2763 #define SSL_ST_RENEGOTIATE (0x04 | SSL_ST_INIT)
   2764 
   2765 /* SSL_CB_* are possible values for the |type| parameter in the info
   2766  * callback and the bitmasks that make them up. */
   2767 #define SSL_CB_LOOP 0x01
   2768 #define SSL_CB_EXIT 0x02
   2769 #define SSL_CB_READ 0x04
   2770 #define SSL_CB_WRITE 0x08
   2771 #define SSL_CB_ALERT 0x4000
   2772 #define SSL_CB_READ_ALERT (SSL_CB_ALERT | SSL_CB_READ)
   2773 #define SSL_CB_WRITE_ALERT (SSL_CB_ALERT | SSL_CB_WRITE)
   2774 #define SSL_CB_ACCEPT_LOOP (SSL_ST_ACCEPT | SSL_CB_LOOP)
   2775 #define SSL_CB_ACCEPT_EXIT (SSL_ST_ACCEPT | SSL_CB_EXIT)
   2776 #define SSL_CB_CONNECT_LOOP (SSL_ST_CONNECT | SSL_CB_LOOP)
   2777 #define SSL_CB_CONNECT_EXIT (SSL_ST_CONNECT | SSL_CB_EXIT)
   2778 #define SSL_CB_HANDSHAKE_START 0x10
   2779 #define SSL_CB_HANDSHAKE_DONE 0x20
   2780 
   2781 /* SSL_CTX_set_info_callback configures a callback to be run when various
   2782  * events occur during a connection's lifetime. The |type| argumentj determines
   2783  * the type of event and the meaning of the |value| argument. Callbacks must
   2784  * ignore unexpected |type| values.
   2785  *
   2786  * |SSL_CB_READ_ALERT| is signaled for each alert received, warning or fatal.
   2787  * The |value| argument is a 16-bit value where the alert level (either
   2788  * |SSL3_AL_WARNING| or |SSL3_AL_FATAL|) is in the most-significant eight bits and
   2789  * the alert type (one of |SSL_AD_*|) is in the least-significant eight.
   2790  *
   2791  * |SSL_CB_WRITE_ALERT| is signaled for each alert sent. The |value| argument
   2792  * is constructed as with |SSL_CB_READ_ALERT|.
   2793  *
   2794  * |SSL_CB_HANDSHAKE_START| is signaled when a handshake begins. The |value|
   2795  * argument is always one.
   2796  *
   2797  * |SSL_CB_HANDSHAKE_DONE| is signaled when a handshake completes successfully.
   2798  * The |value| argument is always one. If a handshake False Starts, this event
   2799  * may be used to determine when the Finished message is received.
   2800  *
   2801  * The following event types expose implementation details of the handshake
   2802  * state machine. Consuming them is deprecated.
   2803  *
   2804  * |SSL_CB_ACCEPT_LOOP| (respectively, |SSL_CB_CONNECT_LOOP|) is signaled when
   2805  * a server (respectively, client) handshake progresses. The |value| argument
   2806  * is always one. For the duration of the callback, |SSL_state| will return the
   2807  * previous state.
   2808  *
   2809  * |SSL_CB_ACCEPT_EXIT| (respectively, |SSL_CB_CONNECT_EXIT|) is signaled when
   2810  * a server (respectively, client) handshake completes, fails, or is paused.
   2811  * The |value| argument is one if the handshake succeeded and <= 0
   2812  * otherwise. */
   2813 OPENSSL_EXPORT void SSL_CTX_set_info_callback(
   2814     SSL_CTX *ctx, void (*cb)(const SSL *ssl, int type, int value));
   2815 
   2816 /* SSL_CTX_get_info_callback returns the callback set by
   2817  * |SSL_CTX_set_info_callback|. */
   2818 OPENSSL_EXPORT void (*SSL_CTX_get_info_callback(SSL_CTX *ctx))(const SSL *ssl,
   2819                                                                int type,
   2820                                                                int value);
   2821 
   2822 /* SSL_set_info_callback configures a callback to be run at various events
   2823  * during a connection's lifetime. See |SSL_CTX_set_info_callback|. */
   2824 OPENSSL_EXPORT void SSL_set_info_callback(
   2825     SSL *ssl, void (*cb)(const SSL *ssl, int type, int value));
   2826 
   2827 /* SSL_get_info_callback returns the callback set by |SSL_set_info_callback|. */
   2828 OPENSSL_EXPORT void (*SSL_get_info_callback(const SSL *ssl))(const SSL *ssl,
   2829                                                              int type,
   2830                                                              int value);
   2831 
   2832 /* SSL_state_string_long returns the current state of the handshake state
   2833  * machine as a string. This may be useful for debugging and logging. */
   2834 OPENSSL_EXPORT const char *SSL_state_string_long(const SSL *ssl);
   2835 
   2836 /* SSL_set_SSL_CTX partially changes |ssl|'s |SSL_CTX|. |ssl| will use the
   2837  * certificate and session_id_context from |ctx|, and |SSL_get_SSL_CTX| will
   2838  * report |ctx|. However most settings and the session cache itself will
   2839  * continue to use the initial |SSL_CTX|. It is often used as part of SNI.
   2840  *
   2841  * TODO(davidben): Make a better story here and get rid of this API. Also
   2842  * determine if there's anything else affected by |SSL_set_SSL_CTX| that
   2843  * matters. Not as many values are affected as one might initially think. The
   2844  * session cache explicitly selects the initial |SSL_CTX|. Most settings are
   2845  * copied at |SSL_new| so |ctx|'s versions don't apply. This, notably, has some
   2846  * consequences for any plans to make |SSL| copy-on-write most of its
   2847  * configuration. */
   2848 OPENSSL_EXPORT SSL_CTX *SSL_set_SSL_CTX(SSL *ssl, SSL_CTX *ctx);
   2849 
   2850 #define SSL_SENT_SHUTDOWN 1
   2851 #define SSL_RECEIVED_SHUTDOWN 2
   2852 
   2853 /* SSL_get_shutdown returns a bitmask with a subset of |SSL_SENT_SHUTDOWN| and
   2854  * |SSL_RECEIVED_SHUTDOWN| to query whether close_notify was sent or received,
   2855  * respectively. */
   2856 OPENSSL_EXPORT int SSL_get_shutdown(const SSL *ssl);
   2857 
   2858 /* SSL_get_server_key_exchange_hash, on a client, returns the hash the server
   2859  * used to sign the ServerKeyExchange in TLS 1.2. If not applicable, it returns
   2860  * |TLSEXT_hash_none|. */
   2861 OPENSSL_EXPORT uint8_t SSL_get_server_key_exchange_hash(const SSL *ssl);
   2862 
   2863 
   2864 /* Deprecated functions. */
   2865 
   2866 /* SSL_library_init calls |CRYPTO_library_init| and returns one. */
   2867 OPENSSL_EXPORT int SSL_library_init(void);
   2868 
   2869 /* SSL_set_reject_peer_renegotiations calls |SSL_set_renegotiate_mode| with
   2870  * |ssl_never_renegotiate| if |reject| is one and |ssl_renegotiate_freely| if
   2871  * zero. */
   2872 OPENSSL_EXPORT void SSL_set_reject_peer_renegotiations(SSL *ssl, int reject);
   2873 
   2874 /* SSL_CIPHER_description writes a description of |cipher| into |buf| and
   2875  * returns |buf|. If |buf| is NULL, it returns a newly allocated string, to be
   2876  * freed with |OPENSSL_free|, or NULL on error.
   2877  *
   2878  * The description includes a trailing newline and has the form:
   2879  * AES128-SHA              Kx=RSA      Au=RSA  Enc=AES(128)  Mac=SHA1
   2880  *
   2881  * Consider |SSL_CIPHER_get_name| or |SSL_CIPHER_get_rfc_name| instead. */
   2882 OPENSSL_EXPORT const char *SSL_CIPHER_description(const SSL_CIPHER *cipher,
   2883                                                   char *buf, int len);
   2884 
   2885 /* SSL_CIPHER_get_version returns the string "TLSv1/SSLv3". */
   2886 OPENSSL_EXPORT const char *SSL_CIPHER_get_version(const SSL_CIPHER *cipher);
   2887 
   2888 typedef void COMP_METHOD;
   2889 
   2890 /* SSL_COMP_get_compression_methods returns NULL. */
   2891 OPENSSL_EXPORT COMP_METHOD *SSL_COMP_get_compression_methods(void);
   2892 
   2893 /* SSL_COMP_add_compression_method returns one. */
   2894 OPENSSL_EXPORT int SSL_COMP_add_compression_method(int id, COMP_METHOD *cm);
   2895 
   2896 /* SSL_COMP_get_name returns NULL. */
   2897 OPENSSL_EXPORT const char *SSL_COMP_get_name(const COMP_METHOD *comp);
   2898 
   2899 /* SSLv23_method calls |TLS_method|. */
   2900 OPENSSL_EXPORT const SSL_METHOD *SSLv23_method(void);
   2901 
   2902 /* These version-specific methods behave exactly like |TLS_method| and
   2903  * |DTLS_method| except they also call |SSL_CTX_set_min_version| and
   2904  * |SSL_CTX_set_max_version| to lock connections to that protocol version. */
   2905 OPENSSL_EXPORT const SSL_METHOD *SSLv3_method(void);
   2906 OPENSSL_EXPORT const SSL_METHOD *TLSv1_method(void);
   2907 OPENSSL_EXPORT const SSL_METHOD *TLSv1_1_method(void);
   2908 OPENSSL_EXPORT const SSL_METHOD *TLSv1_2_method(void);
   2909 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_method(void);
   2910 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_2_method(void);
   2911 
   2912 /* These client- and server-specific methods call their corresponding generic
   2913  * methods. */
   2914 OPENSSL_EXPORT const SSL_METHOD *SSLv23_server_method(void);
   2915 OPENSSL_EXPORT const SSL_METHOD *SSLv23_client_method(void);
   2916 OPENSSL_EXPORT const SSL_METHOD *SSLv3_server_method(void);
   2917 OPENSSL_EXPORT const SSL_METHOD *SSLv3_client_method(void);
   2918 OPENSSL_EXPORT const SSL_METHOD *TLSv1_server_method(void);
   2919 OPENSSL_EXPORT const SSL_METHOD *TLSv1_client_method(void);
   2920 OPENSSL_EXPORT const SSL_METHOD *TLSv1_1_server_method(void);
   2921 OPENSSL_EXPORT const SSL_METHOD *TLSv1_1_client_method(void);
   2922 OPENSSL_EXPORT const SSL_METHOD *TLSv1_2_server_method(void);
   2923 OPENSSL_EXPORT const SSL_METHOD *TLSv1_2_client_method(void);
   2924 OPENSSL_EXPORT const SSL_METHOD *DTLS_server_method(void);
   2925 OPENSSL_EXPORT const SSL_METHOD *DTLS_client_method(void);
   2926 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_server_method(void);
   2927 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_client_method(void);
   2928 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_2_server_method(void);
   2929 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_2_client_method(void);
   2930 
   2931 /* SSL_clear resets |ssl| to allow another connection and returns one on success
   2932  * or zero on failure. It returns most configuration state but releases memory
   2933  * associated with the current connection.
   2934  *
   2935  * Free |ssl| and create a new one instead. */
   2936 OPENSSL_EXPORT int SSL_clear(SSL *ssl);
   2937 
   2938 /* SSL_CTX_set_tmp_rsa_callback does nothing. */
   2939 OPENSSL_EXPORT void SSL_CTX_set_tmp_rsa_callback(
   2940     SSL_CTX *ctx, RSA *(*cb)(SSL *ssl, int is_export, int keylength));
   2941 
   2942 /* SSL_set_tmp_rsa_callback does nothing. */
   2943 OPENSSL_EXPORT void SSL_set_tmp_rsa_callback(SSL *ssl,
   2944                                              RSA *(*cb)(SSL *ssl, int is_export,
   2945                                                         int keylength));
   2946 
   2947 /* SSL_CTX_sess_connect returns zero. */
   2948 OPENSSL_EXPORT int SSL_CTX_sess_connect(const SSL_CTX *ctx);
   2949 
   2950 /* SSL_CTX_sess_connect_good returns zero. */
   2951 OPENSSL_EXPORT int SSL_CTX_sess_connect_good(const SSL_CTX *ctx);
   2952 
   2953 /* SSL_CTX_sess_connect_renegotiate returns zero. */
   2954 OPENSSL_EXPORT int SSL_CTX_sess_connect_renegotiate(const SSL_CTX *ctx);
   2955 
   2956 /* SSL_CTX_sess_accept returns zero. */
   2957 OPENSSL_EXPORT int SSL_CTX_sess_accept(const SSL_CTX *ctx);
   2958 
   2959 /* SSL_CTX_sess_accept_renegotiate returns zero. */
   2960 OPENSSL_EXPORT int SSL_CTX_sess_accept_renegotiate(const SSL_CTX *ctx);
   2961 
   2962 /* SSL_CTX_sess_accept_good returns zero. */
   2963 OPENSSL_EXPORT int SSL_CTX_sess_accept_good(const SSL_CTX *ctx);
   2964 
   2965 /* SSL_CTX_sess_hits returns zero. */
   2966 OPENSSL_EXPORT int SSL_CTX_sess_hits(const SSL_CTX *ctx);
   2967 
   2968 /* SSL_CTX_sess_cb_hits returns zero. */
   2969 OPENSSL_EXPORT int SSL_CTX_sess_cb_hits(const SSL_CTX *ctx);
   2970 
   2971 /* SSL_CTX_sess_misses returns zero. */
   2972 OPENSSL_EXPORT int SSL_CTX_sess_misses(const SSL_CTX *ctx);
   2973 
   2974 /* SSL_CTX_sess_timeouts returns zero. */
   2975 OPENSSL_EXPORT int SSL_CTX_sess_timeouts(const SSL_CTX *ctx);
   2976 
   2977 /* SSL_CTX_sess_cache_full returns zero. */
   2978 OPENSSL_EXPORT int SSL_CTX_sess_cache_full(const SSL_CTX *ctx);
   2979 
   2980 /* SSL_cutthrough_complete calls |SSL_in_false_start|. */
   2981 OPENSSL_EXPORT int SSL_cutthrough_complete(const SSL *s);
   2982 
   2983 /* SSL_num_renegotiations calls |SSL_total_renegotiations|. */
   2984 OPENSSL_EXPORT int SSL_num_renegotiations(const SSL *ssl);
   2985 
   2986 /* SSL_CTX_need_tmp_RSA returns zero. */
   2987 OPENSSL_EXPORT int SSL_CTX_need_tmp_RSA(const SSL_CTX *ctx);
   2988 
   2989 /* SSL_need_tmp_RSA returns zero. */
   2990 OPENSSL_EXPORT int SSL_need_tmp_RSA(const SSL *ssl);
   2991 
   2992 /* SSL_CTX_set_tmp_rsa returns one. */
   2993 OPENSSL_EXPORT int SSL_CTX_set_tmp_rsa(SSL_CTX *ctx, const RSA *rsa);
   2994 
   2995 /* SSL_set_tmp_rsa returns one. */
   2996 OPENSSL_EXPORT int SSL_set_tmp_rsa(SSL *ssl, const RSA *rsa);
   2997 
   2998 /* SSL_CTX_get_read_ahead returns zero. */
   2999 OPENSSL_EXPORT int SSL_CTX_get_read_ahead(const SSL_CTX *ctx);
   3000 
   3001 /* SSL_CTX_set_read_ahead does nothing. */
   3002 OPENSSL_EXPORT void SSL_CTX_set_read_ahead(SSL_CTX *ctx, int yes);
   3003 
   3004 /* SSL_get_read_ahead returns zero. */
   3005 OPENSSL_EXPORT int SSL_get_read_ahead(const SSL *s);
   3006 
   3007 /* SSL_set_read_ahead does nothing. */
   3008 OPENSSL_EXPORT void SSL_set_read_ahead(SSL *s, int yes);
   3009 
   3010 /* SSL_renegotiate put an error on the error queue and returns zero. */
   3011 OPENSSL_EXPORT int SSL_renegotiate(SSL *ssl);
   3012 
   3013 /* SSL_set_state does nothing. */
   3014 OPENSSL_EXPORT void SSL_set_state(SSL *ssl, int state);
   3015 
   3016 /* SSL_MODE_HANDSHAKE_CUTTHROUGH is the same as SSL_MODE_ENABLE_FALSE_START. */
   3017 #define SSL_MODE_HANDSHAKE_CUTTHROUGH SSL_MODE_ENABLE_FALSE_START
   3018 
   3019 /* i2d_SSL_SESSION serializes |in| to the bytes pointed to by |*pp|. On success,
   3020  * it returns the number of bytes written and advances |*pp| by that many bytes.
   3021  * On failure, it returns -1. If |pp| is NULL, no bytes are written and only the
   3022  * length is returned.
   3023  *
   3024  * Use |SSL_SESSION_to_bytes| instead. */
   3025 OPENSSL_EXPORT int i2d_SSL_SESSION(SSL_SESSION *in, uint8_t **pp);
   3026 
   3027 /* d2i_SSL_SESSION parses a serialized session from the |length| bytes pointed
   3028  * to by |*pp|. It returns the new |SSL_SESSION| and advances |*pp| by the
   3029  * number of bytes consumed on success and NULL on failure. The caller takes
   3030  * ownership of the new session and must call |SSL_SESSION_free| when done.
   3031  *
   3032  * If |a| is non-NULL, |*a| is released and set the new |SSL_SESSION|.
   3033  *
   3034  * Use |SSL_SESSION_from_bytes| instead. */
   3035 OPENSSL_EXPORT SSL_SESSION *d2i_SSL_SESSION(SSL_SESSION **a, const uint8_t **pp,
   3036                                             long length);
   3037 
   3038 /* i2d_SSL_SESSION_bio serializes |session| and writes the result to |bio|. It
   3039  * returns the number of bytes written on success and <= 0 on error. */
   3040 OPENSSL_EXPORT int i2d_SSL_SESSION_bio(BIO *bio, const SSL_SESSION *session);
   3041 
   3042 /* d2i_SSL_SESSION_bio reads a serialized |SSL_SESSION| from |bio| and returns a
   3043  * newly-allocated |SSL_SESSION| or NULL on error. If |out| is not NULL, it also
   3044  * frees |*out| and sets |*out| to the new |SSL_SESSION|.  */
   3045 OPENSSL_EXPORT SSL_SESSION *d2i_SSL_SESSION_bio(BIO *bio, SSL_SESSION **out);
   3046 
   3047 /* ERR_load_SSL_strings does nothing. */
   3048 OPENSSL_EXPORT void ERR_load_SSL_strings(void);
   3049 
   3050 /* SSL_load_error_strings does nothing. */
   3051 OPENSSL_EXPORT void SSL_load_error_strings(void);
   3052 
   3053 /* SSL_CTX_set_tlsext_use_srtp calls |SSL_CTX_set_srtp_profiles|. It returns
   3054  * zero on success and one on failure.
   3055  *
   3056  * WARNING: this function is dangerous because it breaks the usual return value
   3057  * convention. Use |SSL_CTX_set_srtp_profiles| instead. */
   3058 OPENSSL_EXPORT int SSL_CTX_set_tlsext_use_srtp(SSL_CTX *ctx,
   3059                                                const char *profiles);
   3060 
   3061 /* SSL_set_tlsext_use_srtp calls |SSL_set_srtp_profiles|. It returns zero on
   3062  * success and one on failure.
   3063  *
   3064  * WARNING: this function is dangerous because it breaks the usual return value
   3065  * convention. Use |SSL_set_srtp_profiles| instead. */
   3066 OPENSSL_EXPORT int SSL_set_tlsext_use_srtp(SSL *ssl, const char *profiles);
   3067 
   3068 /* SSL_get_current_compression returns NULL. */
   3069 OPENSSL_EXPORT const COMP_METHOD *SSL_get_current_compression(SSL *s);
   3070 
   3071 /* SSL_get_current_expansion returns NULL. */
   3072 OPENSSL_EXPORT const COMP_METHOD *SSL_get_current_expansion(SSL *s);
   3073 
   3074 #define SSL_set_app_data(s, arg) (SSL_set_ex_data(s, 0, (char *)arg))
   3075 #define SSL_get_app_data(s) (SSL_get_ex_data(s, 0))
   3076 #define SSL_SESSION_set_app_data(s, a) \
   3077   (SSL_SESSION_set_ex_data(s, 0, (char *)a))
   3078 #define SSL_SESSION_get_app_data(s) (SSL_SESSION_get_ex_data(s, 0))
   3079 #define SSL_CTX_get_app_data(ctx) (SSL_CTX_get_ex_data(ctx, 0))
   3080 #define SSL_CTX_set_app_data(ctx, arg) \
   3081   (SSL_CTX_set_ex_data(ctx, 0, (char *)arg))
   3082 
   3083 #define OpenSSL_add_ssl_algorithms() SSL_library_init()
   3084 #define SSLeay_add_ssl_algorithms() SSL_library_init()
   3085 
   3086 #define SSL_get_cipher(ssl) SSL_CIPHER_get_name(SSL_get_current_cipher(ssl))
   3087 #define SSL_get_cipher_bits(ssl, out_alg_bits) \
   3088 	  SSL_CIPHER_get_bits(SSL_get_current_cipher(ssl), out_alg_bits)
   3089 #define SSL_get_cipher_version(ssl) \
   3090 	  SSL_CIPHER_get_version(SSL_get_current_cipher(ssl))
   3091 #define SSL_get_cipher_name(ssl) \
   3092 	  SSL_CIPHER_get_name(SSL_get_current_cipher(ssl))
   3093 #define SSL_get_time(session) SSL_SESSION_get_time(session)
   3094 #define SSL_set_time(session, time) SSL_SESSION_set_time((session), (time))
   3095 #define SSL_get_timeout(session) SSL_SESSION_get_timeout(session)
   3096 #define SSL_set_timeout(session, timeout) \
   3097 		SSL_SESSION_set_timeout((session), (timeout))
   3098 
   3099 typedef struct ssl_comp_st SSL_COMP;
   3100 
   3101 struct ssl_comp_st {
   3102   int id;
   3103   const char *name;
   3104   char *method;
   3105 };
   3106 
   3107 DECLARE_STACK_OF(SSL_COMP)
   3108 
   3109 /* The following flags toggle individual protocol versions. This is deprecated.
   3110  * Use |SSL_CTX_set_min_version| and |SSL_CTX_set_max_version| instead. */
   3111 #define SSL_OP_NO_SSLv3 0x02000000L
   3112 #define SSL_OP_NO_TLSv1 0x04000000L
   3113 #define SSL_OP_NO_TLSv1_2 0x08000000L
   3114 #define SSL_OP_NO_TLSv1_1 0x10000000L
   3115 #define SSL_OP_NO_DTLSv1 SSL_OP_NO_TLSv1
   3116 #define SSL_OP_NO_DTLSv1_2 SSL_OP_NO_TLSv1_2
   3117 
   3118 /* The following flags do nothing and are included only to make it easier to
   3119  * compile code with BoringSSL. */
   3120 #define SSL_MODE_AUTO_RETRY 0
   3121 #define SSL_MODE_RELEASE_BUFFERS 0
   3122 #define SSL_MODE_SEND_CLIENTHELLO_TIME 0
   3123 #define SSL_MODE_SEND_SERVERHELLO_TIME 0
   3124 #define SSL_OP_ALL 0
   3125 #define SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION 0
   3126 #define SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS 0
   3127 #define SSL_OP_EPHEMERAL_RSA 0
   3128 #define SSL_OP_LEGACY_SERVER_CONNECT 0
   3129 #define SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER 0
   3130 #define SSL_OP_MICROSOFT_SESS_ID_BUG 0
   3131 #define SSL_OP_MSIE_SSLV2_RSA_PADDING 0
   3132 #define SSL_OP_NETSCAPE_CA_DN_BUG 0
   3133 #define SSL_OP_NETSCAPE_CHALLENGE_BUG 0
   3134 #define SSL_OP_NETSCAPE_DEMO_CIPHER_CHANGE_BUG 0
   3135 #define SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG 0
   3136 #define SSL_OP_NO_COMPRESSION 0
   3137 #define SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION 0
   3138 #define SSL_OP_NO_SSLv2 0
   3139 #define SSL_OP_PKCS1_CHECK_1 0
   3140 #define SSL_OP_PKCS1_CHECK_2 0
   3141 #define SSL_OP_SINGLE_DH_USE 0
   3142 #define SSL_OP_SINGLE_ECDH_USE 0
   3143 #define SSL_OP_SSLEAY_080_CLIENT_DH_BUG 0
   3144 #define SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG 0
   3145 #define SSL_OP_TLS_BLOCK_PADDING_BUG 0
   3146 #define SSL_OP_TLS_D5_BUG 0
   3147 #define SSL_OP_TLS_ROLLBACK_BUG 0
   3148 #define SSL_VERIFY_CLIENT_ONCE 0
   3149 
   3150 /* SSL_cache_hit calls |SSL_session_resumed|. */
   3151 OPENSSL_EXPORT int SSL_cache_hit(SSL *ssl);
   3152 
   3153 /* SSL_get_default_timeout returns |SSL_DEFAULT_SESSION_TIMEOUT|. */
   3154 OPENSSL_EXPORT long SSL_get_default_timeout(const SSL *ssl);
   3155 
   3156 /* SSL_get_version returns a string describing the TLS version used by |ssl|.
   3157  * For example, "TLSv1.2" or "SSLv3". */
   3158 OPENSSL_EXPORT const char *SSL_get_version(const SSL *ssl);
   3159 
   3160 /* SSL_get_cipher_list returns the name of the |n|th cipher in the output of
   3161  * |SSL_get_ciphers| or NULL if out of range. Use |SSL_get_ciphers| insteads. */
   3162 OPENSSL_EXPORT const char *SSL_get_cipher_list(const SSL *ssl, int n);
   3163 
   3164 /* SSL_CTX_set_client_cert_cb sets a callback which is called on the client if
   3165  * the server requests a client certificate and none is configured. On success,
   3166  * the callback should return one and set |*out_x509| to |*out_pkey| to a leaf
   3167  * certificate and private key, respectively, passing ownership. It should
   3168  * return zero to send no certificate and -1 to fail or pause the handshake. If
   3169  * the handshake is paused, |SSL_get_error| will return
   3170  * |SSL_ERROR_WANT_X509_LOOKUP|.
   3171  *
   3172  * The callback may call |SSL_get0_certificate_types| and
   3173  * |SSL_get_client_CA_list| for information on the server's certificate request.
   3174  *
   3175  * Use |SSL_CTX_set_cert_cb| instead. Configuring intermediate certificates with
   3176  * this function is confusing. */
   3177 OPENSSL_EXPORT void SSL_CTX_set_client_cert_cb(
   3178     SSL_CTX *ctx,
   3179     int (*client_cert_cb)(SSL *ssl, X509 **out_x509, EVP_PKEY **out_pkey));
   3180 
   3181 /* SSL_CTX_get_client_cert_cb returns the callback set by
   3182  * |SSL_CTX_set_client_cert_cb|. */
   3183 OPENSSL_EXPORT int (*SSL_CTX_get_client_cert_cb(SSL_CTX *ctx))(
   3184       SSL *ssl, X509 **out_x509, EVP_PKEY **out_pkey);
   3185 
   3186 #define SSL_NOTHING 1
   3187 #define SSL_WRITING 2
   3188 #define SSL_READING 3
   3189 #define SSL_X509_LOOKUP 4
   3190 #define SSL_CHANNEL_ID_LOOKUP 5
   3191 #define SSL_PENDING_SESSION 7
   3192 #define SSL_CERTIFICATE_SELECTION_PENDING 8
   3193 #define SSL_PRIVATE_KEY_OPERATION 9
   3194 
   3195 /* SSL_want returns one of the above values to determine what the most recent
   3196  * operation on |ssl| was blocked on. Use |SSL_get_error| instead. */
   3197 OPENSSL_EXPORT int SSL_want(const SSL *ssl);
   3198 
   3199 #define SSL_want_nothing(ssl) (SSL_want(ssl) == SSL_NOTHING)
   3200 #define SSL_want_read(ssl) (SSL_want(ssl) == SSL_READING)
   3201 #define SSL_want_write(ssl) (SSL_want(ssl) == SSL_WRITING)
   3202 #define SSL_want_x509_lookup(ssl) (SSL_want(ssl) == SSL_X509_LOOKUP)
   3203 #define SSL_want_channel_id_lookup(ssl) (SSL_want(ssl) == SSL_CHANNEL_ID_LOOKUP)
   3204 #define SSL_want_session(ssl) (SSL_want(ssl) == SSL_PENDING_SESSION)
   3205 #define SSL_want_certificate(ssl) \
   3206   (SSL_want(ssl) == SSL_CERTIFICATE_SELECTION_PENDING)
   3207 #define SSL_want_private_key_operation(ssl) \
   3208   (SSL_want(ssl) == SSL_PRIVATE_KEY_OPERATION)
   3209 
   3210  /* SSL_get_finished writes up to |count| bytes of the Finished message sent by
   3211   * |ssl| to |buf|. It returns the total untruncated length or zero if none has
   3212   * been sent yet.
   3213   *
   3214   * Use |SSL_get_tls_unique| instead. */
   3215 OPENSSL_EXPORT size_t SSL_get_finished(const SSL *ssl, void *buf, size_t count);
   3216 
   3217  /* SSL_get_peer_finished writes up to |count| bytes of the Finished message
   3218   * received from |ssl|'s peer to |buf|. It returns the total untruncated length
   3219   * or zero if none has been received yet.
   3220   *
   3221   * Use |SSL_get_tls_unique| instead. */
   3222 OPENSSL_EXPORT size_t SSL_get_peer_finished(const SSL *ssl, void *buf,
   3223                                             size_t count);
   3224 
   3225 /* SSL_alert_type_string returns "!". Use |SSL_alert_type_string_long|
   3226  * instead. */
   3227 OPENSSL_EXPORT const char *SSL_alert_type_string(int value);
   3228 
   3229 /* SSL_alert_desc_string returns "!!". Use |SSL_alert_desc_string_long|
   3230  * instead. */
   3231 OPENSSL_EXPORT const char *SSL_alert_desc_string(int value);
   3232 
   3233 /* SSL_TXT_* expand to strings. */
   3234 #define SSL_TXT_MEDIUM "MEDIUM"
   3235 #define SSL_TXT_HIGH "HIGH"
   3236 #define SSL_TXT_FIPS "FIPS"
   3237 #define SSL_TXT_kRSA "kRSA"
   3238 #define SSL_TXT_kDHE "kDHE"
   3239 #define SSL_TXT_kEDH "kEDH"
   3240 #define SSL_TXT_kECDHE "kECDHE"
   3241 #define SSL_TXT_kEECDH "kEECDH"
   3242 #define SSL_TXT_kPSK "kPSK"
   3243 #define SSL_TXT_aRSA "aRSA"
   3244 #define SSL_TXT_aECDSA "aECDSA"
   3245 #define SSL_TXT_aPSK "aPSK"
   3246 #define SSL_TXT_DH "DH"
   3247 #define SSL_TXT_DHE "DHE"
   3248 #define SSL_TXT_EDH "EDH"
   3249 #define SSL_TXT_RSA "RSA"
   3250 #define SSL_TXT_ECDH "ECDH"
   3251 #define SSL_TXT_ECDHE "ECDHE"
   3252 #define SSL_TXT_EECDH "EECDH"
   3253 #define SSL_TXT_ECDSA "ECDSA"
   3254 #define SSL_TXT_PSK "PSK"
   3255 #define SSL_TXT_3DES "3DES"
   3256 #define SSL_TXT_RC4 "RC4"
   3257 #define SSL_TXT_AES128 "AES128"
   3258 #define SSL_TXT_AES256 "AES256"
   3259 #define SSL_TXT_AES "AES"
   3260 #define SSL_TXT_AES_GCM "AESGCM"
   3261 #define SSL_TXT_CHACHA20 "CHACHA20"
   3262 #define SSL_TXT_MD5 "MD5"
   3263 #define SSL_TXT_SHA1 "SHA1"
   3264 #define SSL_TXT_SHA "SHA"
   3265 #define SSL_TXT_SHA256 "SHA256"
   3266 #define SSL_TXT_SHA384 "SHA384"
   3267 #define SSL_TXT_SSLV3 "SSLv3"
   3268 #define SSL_TXT_TLSV1 "TLSv1"
   3269 #define SSL_TXT_TLSV1_1 "TLSv1.1"
   3270 #define SSL_TXT_TLSV1_2 "TLSv1.2"
   3271 #define SSL_TXT_ALL "ALL"
   3272 #define SSL_TXT_CMPDEF "COMPLEMENTOFDEFAULT"
   3273 
   3274 typedef struct ssl_conf_ctx_st SSL_CONF_CTX;
   3275 
   3276 /* SSL_state returns the current state of the handshake state machine. */
   3277 OPENSSL_EXPORT int SSL_state(const SSL *ssl);
   3278 
   3279 #define SSL_get_state(ssl) SSL_state(ssl)
   3280 
   3281 /* SSL_state_string returns the current state of the handshake state machine as
   3282  * a six-letter string. Use |SSL_state_string_long| for a more intelligible
   3283  * string. */
   3284 OPENSSL_EXPORT const char *SSL_state_string(const SSL *ssl);
   3285 
   3286 /* SSL_set_shutdown causes |ssl| to behave as if the shutdown bitmask (see
   3287  * |SSL_get_shutdown|) were |mode|. This may be used to skip sending or
   3288  * receiving close_notify in |SSL_shutdown| by causing the implementation to
   3289  * believe the events already happened.
   3290  *
   3291  * It is an error to use |SSL_set_shutdown| to unset a bit that has already been
   3292  * set. Doing so will trigger an |assert| in debug builds and otherwise be
   3293  * ignored.
   3294  *
   3295  * Use |SSL_CTX_set_quiet_shutdown| instead. */
   3296 OPENSSL_EXPORT void SSL_set_shutdown(SSL *ssl, int mode);
   3297 
   3298 /* SSL_CTX_set_tmp_ecdh calls |SSL_CTX_set1_curves| with a one-element list
   3299  * containing |ec_key|'s curve. */
   3300 OPENSSL_EXPORT int SSL_CTX_set_tmp_ecdh(SSL_CTX *ctx, const EC_KEY *ec_key);
   3301 
   3302 /* SSL_set_tmp_ecdh calls |SSL_set1_curves| with a one-element list containing
   3303  * |ec_key|'s curve. */
   3304 OPENSSL_EXPORT int SSL_set_tmp_ecdh(SSL *ssl, const EC_KEY *ec_key);
   3305 
   3306 
   3307 /* Private structures.
   3308  *
   3309  * This structures are exposed for historical reasons, but access to them is
   3310  * deprecated. */
   3311 
   3312 typedef struct ssl_protocol_method_st SSL_PROTOCOL_METHOD;
   3313 typedef struct ssl3_enc_method SSL3_ENC_METHOD;
   3314 typedef struct ssl_aead_ctx_st SSL_AEAD_CTX;
   3315 
   3316 struct ssl_cipher_st {
   3317   /* name is the OpenSSL name for the cipher. */
   3318   const char *name;
   3319   /* id is the cipher suite value bitwise OR-d with 0x03000000. */
   3320   uint32_t id;
   3321 
   3322   /* algorithm_* are internal fields. See ssl/internal.h for their values. */
   3323   uint32_t algorithm_mkey;
   3324   uint32_t algorithm_auth;
   3325   uint32_t algorithm_enc;
   3326   uint32_t algorithm_mac;
   3327   uint32_t algorithm_prf;
   3328 };
   3329 
   3330 typedef struct ssl_ecdh_method_st SSL_ECDH_METHOD;
   3331 typedef struct ssl_ecdh_ctx_st {
   3332   const SSL_ECDH_METHOD *method;
   3333   void *data;
   3334 } SSL_ECDH_CTX;
   3335 
   3336 #define SSL_MAX_SSL_SESSION_ID_LENGTH 32
   3337 #define SSL_MAX_SID_CTX_LENGTH 32
   3338 #define SSL_MAX_MASTER_KEY_LENGTH 48
   3339 
   3340 struct ssl_session_st {
   3341   CRYPTO_refcount_t references;
   3342   int ssl_version; /* what ssl version session info is being kept in here? */
   3343 
   3344   /* key_exchange_info contains an indication of the size of the asymmetric
   3345    * primitive used in the handshake that created this session. In the event
   3346    * that two asymmetric operations are used, this value applies to the one
   3347    * that controls the confidentiality of the connection. Its interpretation
   3348    * depends on the primitive that was used; as specified by the cipher suite:
   3349    *   DHE: the size, in bits, of the multiplicative group.
   3350    *   RSA: the size, in bits, of the modulus.
   3351    *   ECDHE: the TLS id for the curve.
   3352    *
   3353    * A zero indicates that the value is unknown. */
   3354   uint32_t key_exchange_info;
   3355 
   3356   int master_key_length;
   3357   uint8_t master_key[SSL_MAX_MASTER_KEY_LENGTH];
   3358 
   3359   /* session_id - valid? */
   3360   unsigned int session_id_length;
   3361   uint8_t session_id[SSL_MAX_SSL_SESSION_ID_LENGTH];
   3362   /* this is used to determine whether the session is being reused in
   3363    * the appropriate context. It is up to the application to set this,
   3364    * via SSL_new */
   3365   unsigned int sid_ctx_length;
   3366   uint8_t sid_ctx[SSL_MAX_SID_CTX_LENGTH];
   3367 
   3368   char *psk_identity;
   3369   /* peer is the peer's certificate. */
   3370   X509 *peer;
   3371 
   3372   /* cert_chain is the certificate chain sent by the peer. NOTE: for historical
   3373    * reasons, when a client (so the peer is a server), the chain includes
   3374    * |peer|, but when a server it does not. */
   3375   STACK_OF(X509) *cert_chain;
   3376 
   3377   /* when app_verify_callback accepts a session where the peer's certificate is
   3378    * not ok, we must remember the error for session reuse: */
   3379   long verify_result; /* only for servers */
   3380 
   3381   long timeout;
   3382   long time;
   3383 
   3384   const SSL_CIPHER *cipher;
   3385 
   3386   CRYPTO_EX_DATA ex_data; /* application specific data */
   3387 
   3388   /* These are used to make removal of session-ids more efficient and to
   3389    * implement a maximum cache size. */
   3390   SSL_SESSION *prev, *next;
   3391   char *tlsext_hostname;
   3392 
   3393   /* RFC4507 info */
   3394   uint8_t *tlsext_tick;               /* Session ticket */
   3395   size_t tlsext_ticklen;              /* Session ticket length */
   3396 
   3397   size_t tlsext_signed_cert_timestamp_list_length;
   3398   uint8_t *tlsext_signed_cert_timestamp_list; /* Server's list. */
   3399 
   3400   /* The OCSP response that came with the session. */
   3401   size_t ocsp_response_length;
   3402   uint8_t *ocsp_response;
   3403 
   3404   /* peer_sha256 contains the SHA-256 hash of the peer's certificate if
   3405    * |peer_sha256_valid| is true. */
   3406   uint8_t peer_sha256[SHA256_DIGEST_LENGTH];
   3407 
   3408   /* original_handshake_hash contains the handshake hash (either SHA-1+MD5 or
   3409    * SHA-2, depending on TLS version) for the original, full handshake that
   3410    * created a session. This is used by Channel IDs during resumption. */
   3411   uint8_t original_handshake_hash[EVP_MAX_MD_SIZE];
   3412   unsigned original_handshake_hash_len;
   3413 
   3414   uint32_t tlsext_tick_lifetime_hint; /* Session lifetime hint in seconds */
   3415 
   3416   /* extended_master_secret is true if the master secret in this session was
   3417    * generated using EMS and thus isn't vulnerable to the Triple Handshake
   3418    * attack. */
   3419   unsigned extended_master_secret:1;
   3420 
   3421   /* peer_sha256_valid is non-zero if |peer_sha256| is valid. */
   3422   unsigned peer_sha256_valid:1; /* Non-zero if peer_sha256 is valid */
   3423 
   3424   /* not_resumable is used to indicate that session resumption is not allowed.
   3425    * Applications can also set this bit for a new session via
   3426    * not_resumable_session_cb to disable session caching and tickets. */
   3427   unsigned not_resumable:1;
   3428 };
   3429 
   3430 /* ssl_cipher_preference_list_st contains a list of SSL_CIPHERs with
   3431  * equal-preference groups. For TLS clients, the groups are moot because the
   3432  * server picks the cipher and groups cannot be expressed on the wire. However,
   3433  * for servers, the equal-preference groups allow the client's preferences to
   3434  * be partially respected. (This only has an effect with
   3435  * SSL_OP_CIPHER_SERVER_PREFERENCE).
   3436  *
   3437  * The equal-preference groups are expressed by grouping SSL_CIPHERs together.
   3438  * All elements of a group have the same priority: no ordering is expressed
   3439  * within a group.
   3440  *
   3441  * The values in |ciphers| are in one-to-one correspondence with
   3442  * |in_group_flags|. (That is, sk_SSL_CIPHER_num(ciphers) is the number of
   3443  * bytes in |in_group_flags|.) The bytes in |in_group_flags| are either 1, to
   3444  * indicate that the corresponding SSL_CIPHER is not the last element of a
   3445  * group, or 0 to indicate that it is.
   3446  *
   3447  * For example, if |in_group_flags| contains all zeros then that indicates a
   3448  * traditional, fully-ordered preference. Every SSL_CIPHER is the last element
   3449  * of the group (i.e. they are all in a one-element group).
   3450  *
   3451  * For a more complex example, consider:
   3452  *   ciphers:        A  B  C  D  E  F
   3453  *   in_group_flags: 1  1  0  0  1  0
   3454  *
   3455  * That would express the following, order:
   3456  *
   3457  *    A         E
   3458  *    B -> D -> F
   3459  *    C
   3460  */
   3461 struct ssl_cipher_preference_list_st {
   3462   STACK_OF(SSL_CIPHER) *ciphers;
   3463   uint8_t *in_group_flags;
   3464 };
   3465 
   3466 struct ssl_ctx_st {
   3467   const SSL_PROTOCOL_METHOD *method;
   3468 
   3469   /* lock is used to protect various operations on this object. */
   3470   CRYPTO_MUTEX lock;
   3471 
   3472   /* max_version is the maximum acceptable protocol version. If zero, the
   3473    * maximum supported version, currently (D)TLS 1.2, is used. */
   3474   uint16_t max_version;
   3475 
   3476   /* min_version is the minimum acceptable protocl version. If zero, the
   3477    * minimum supported version, currently SSL 3.0 and DTLS 1.0, is used */
   3478   uint16_t min_version;
   3479 
   3480   struct ssl_cipher_preference_list_st *cipher_list;
   3481   /* same as above but sorted for lookup */
   3482   STACK_OF(SSL_CIPHER) *cipher_list_by_id;
   3483 
   3484   /* cipher_list_tls10 is the list of ciphers when TLS 1.0 or greater is in
   3485    * use. This only applies to server connections as, for clients, the version
   3486    * number is known at connect time and so the cipher list can be set then. If
   3487    * |cipher_list_tls11| is non-NULL then this applies only to TLS 1.0
   3488    * connections.
   3489    *
   3490    * TODO(agl): this exists to assist in the death of SSLv3. It can hopefully
   3491    * be removed after that. */
   3492   struct ssl_cipher_preference_list_st *cipher_list_tls10;
   3493 
   3494   /* cipher_list_tls11 is the list of ciphers when TLS 1.1 or greater is in
   3495    * use. This only applies to server connections as, for clients, the version
   3496    * number is known at connect time and so the cipher list can be set then. */
   3497   struct ssl_cipher_preference_list_st *cipher_list_tls11;
   3498 
   3499   X509_STORE *cert_store;
   3500   LHASH_OF(SSL_SESSION) *sessions;
   3501   /* Most session-ids that will be cached, default is
   3502    * SSL_SESSION_CACHE_MAX_SIZE_DEFAULT. 0 is unlimited. */
   3503   unsigned long session_cache_size;
   3504   SSL_SESSION *session_cache_head;
   3505   SSL_SESSION *session_cache_tail;
   3506 
   3507   /* handshakes_since_cache_flush is the number of successful handshakes since
   3508    * the last cache flush. */
   3509   int handshakes_since_cache_flush;
   3510 
   3511   /* This can have one of 2 values, ored together,
   3512    * SSL_SESS_CACHE_CLIENT,
   3513    * SSL_SESS_CACHE_SERVER,
   3514    * Default is SSL_SESSION_CACHE_SERVER, which means only
   3515    * SSL_accept which cache SSL_SESSIONS. */
   3516   int session_cache_mode;
   3517 
   3518   /* If timeout is not 0, it is the default timeout value set when SSL_new() is
   3519    * called.  This has been put in to make life easier to set things up */
   3520   long session_timeout;
   3521 
   3522   /* If this callback is not null, it will be called each time a session id is
   3523    * added to the cache.  If this function returns 1, it means that the
   3524    * callback will do a SSL_SESSION_free() when it has finished using it.
   3525    * Otherwise, on 0, it means the callback has finished with it. If
   3526    * remove_session_cb is not null, it will be called when a session-id is
   3527    * removed from the cache.  After the call, OpenSSL will SSL_SESSION_free()
   3528    * it. */
   3529   int (*new_session_cb)(SSL *ssl, SSL_SESSION *sess);
   3530   void (*remove_session_cb)(SSL_CTX *ctx, SSL_SESSION *sess);
   3531   SSL_SESSION *(*get_session_cb)(SSL *ssl, uint8_t *data, int len,
   3532                                  int *copy);
   3533 
   3534   CRYPTO_refcount_t references;
   3535 
   3536   /* if defined, these override the X509_verify_cert() calls */
   3537   int (*app_verify_callback)(X509_STORE_CTX *store_ctx, void *arg);
   3538   void *app_verify_arg;
   3539 
   3540   /* Default password callback. */
   3541   pem_password_cb *default_passwd_callback;
   3542 
   3543   /* Default password callback user data. */
   3544   void *default_passwd_callback_userdata;
   3545 
   3546   /* get client cert callback */
   3547   int (*client_cert_cb)(SSL *ssl, X509 **out_x509, EVP_PKEY **out_pkey);
   3548 
   3549   /* get channel id callback */
   3550   void (*channel_id_cb)(SSL *ssl, EVP_PKEY **out_pkey);
   3551 
   3552   CRYPTO_EX_DATA ex_data;
   3553 
   3554   /* custom_*_extensions stores any callback sets for custom extensions. Note
   3555    * that these pointers will be NULL if the stack would otherwise be empty. */
   3556   STACK_OF(SSL_CUSTOM_EXTENSION) *client_custom_extensions;
   3557   STACK_OF(SSL_CUSTOM_EXTENSION) *server_custom_extensions;
   3558 
   3559   /* Default values used when no per-SSL value is defined follow */
   3560 
   3561   void (*info_callback)(const SSL *ssl, int type, int value);
   3562 
   3563   /* what we put in client cert requests */
   3564   STACK_OF(X509_NAME) *client_CA;
   3565 
   3566 
   3567   /* Default values to use in SSL structures follow (these are copied by
   3568    * SSL_new) */
   3569 
   3570   uint32_t options;
   3571   uint32_t mode;
   3572   uint32_t max_cert_list;
   3573 
   3574   struct cert_st /* CERT */ *cert;
   3575 
   3576   /* callback that allows applications to peek at protocol messages */
   3577   void (*msg_callback)(int write_p, int version, int content_type,
   3578                        const void *buf, size_t len, SSL *ssl, void *arg);
   3579   void *msg_callback_arg;
   3580 
   3581   int verify_mode;
   3582   unsigned int sid_ctx_length;
   3583   uint8_t sid_ctx[SSL_MAX_SID_CTX_LENGTH];
   3584   int (*default_verify_callback)(
   3585       int ok, X509_STORE_CTX *ctx); /* called 'verify_callback' in the SSL */
   3586 
   3587   X509_VERIFY_PARAM *param;
   3588 
   3589   /* select_certificate_cb is called before most ClientHello processing and
   3590    * before the decision whether to resume a session is made. It may return one
   3591    * to continue the handshake or zero to cause the handshake loop to return
   3592    * with an error and cause SSL_get_error to return
   3593    * SSL_ERROR_PENDING_CERTIFICATE. Note: when the handshake loop is resumed, it
   3594    * will not call the callback a second time. */
   3595   int (*select_certificate_cb)(const struct ssl_early_callback_ctx *);
   3596 
   3597   /* dos_protection_cb is called once the resumption decision for a ClientHello
   3598    * has been made. It returns one to continue the handshake or zero to
   3599    * abort. */
   3600   int (*dos_protection_cb) (const struct ssl_early_callback_ctx *);
   3601 
   3602   /* Maximum amount of data to send in one fragment. actual record size can be
   3603    * more than this due to padding and MAC overheads. */
   3604   uint16_t max_send_fragment;
   3605 
   3606   /* TLS extensions servername callback */
   3607   int (*tlsext_servername_callback)(SSL *, int *, void *);
   3608   void *tlsext_servername_arg;
   3609   /* RFC 4507 session ticket keys */
   3610   uint8_t tlsext_tick_key_name[SSL_TICKET_KEY_NAME_LEN];
   3611   uint8_t tlsext_tick_hmac_key[16];
   3612   uint8_t tlsext_tick_aes_key[16];
   3613   /* Callback to support customisation of ticket key setting */
   3614   int (*tlsext_ticket_key_cb)(SSL *ssl, uint8_t *name, uint8_t *iv,
   3615                               EVP_CIPHER_CTX *ectx, HMAC_CTX *hctx, int enc);
   3616 
   3617   /* Server-only: psk_identity_hint is the default identity hint to send in
   3618    * PSK-based key exchanges. */
   3619   char *psk_identity_hint;
   3620 
   3621   unsigned int (*psk_client_callback)(SSL *ssl, const char *hint,
   3622                                       char *identity,
   3623                                       unsigned int max_identity_len,
   3624                                       uint8_t *psk, unsigned int max_psk_len);
   3625   unsigned int (*psk_server_callback)(SSL *ssl, const char *identity,
   3626                                       uint8_t *psk, unsigned int max_psk_len);
   3627 
   3628 
   3629   /* retain_only_sha256_of_client_certs is true if we should compute the SHA256
   3630    * hash of the peer's certifiate and then discard it to save memory and
   3631    * session space. Only effective on the server side. */
   3632   char retain_only_sha256_of_client_certs;
   3633 
   3634   /* Next protocol negotiation information */
   3635   /* (for experimental NPN extension). */
   3636 
   3637   /* For a server, this contains a callback function by which the set of
   3638    * advertised protocols can be provided. */
   3639   int (*next_protos_advertised_cb)(SSL *ssl, const uint8_t **out,
   3640                                    unsigned *out_len, void *arg);
   3641   void *next_protos_advertised_cb_arg;
   3642   /* For a client, this contains a callback function that selects the
   3643    * next protocol from the list provided by the server. */
   3644   int (*next_proto_select_cb)(SSL *ssl, uint8_t **out, uint8_t *out_len,
   3645                               const uint8_t *in, unsigned in_len, void *arg);
   3646   void *next_proto_select_cb_arg;
   3647 
   3648   /* ALPN information
   3649    * (we are in the process of transitioning from NPN to ALPN.) */
   3650 
   3651   /* For a server, this contains a callback function that allows the
   3652    * server to select the protocol for the connection.
   3653    *   out: on successful return, this must point to the raw protocol
   3654    *        name (without the length prefix).
   3655    *   outlen: on successful return, this contains the length of |*out|.
   3656    *   in: points to the client's list of supported protocols in
   3657    *       wire-format.
   3658    *   inlen: the length of |in|. */
   3659   int (*alpn_select_cb)(SSL *s, const uint8_t **out, uint8_t *out_len,
   3660                         const uint8_t *in, unsigned in_len, void *arg);
   3661   void *alpn_select_cb_arg;
   3662 
   3663   /* For a client, this contains the list of supported protocols in wire
   3664    * format. */
   3665   uint8_t *alpn_client_proto_list;
   3666   unsigned alpn_client_proto_list_len;
   3667 
   3668   /* SRTP profiles we are willing to do from RFC 5764 */
   3669   STACK_OF(SRTP_PROTECTION_PROFILE) *srtp_profiles;
   3670 
   3671   /* EC extension values inherited by SSL structure */
   3672   size_t tlsext_ellipticcurvelist_length;
   3673   uint16_t *tlsext_ellipticcurvelist;
   3674 
   3675   /* The client's Channel ID private key. */
   3676   EVP_PKEY *tlsext_channel_id_private;
   3677 
   3678   /* Signed certificate timestamp list to be sent to the client, if requested */
   3679   uint8_t *signed_cert_timestamp_list;
   3680   size_t signed_cert_timestamp_list_length;
   3681 
   3682   /* OCSP response to be sent to the client, if requested. */
   3683   uint8_t *ocsp_response;
   3684   size_t ocsp_response_length;
   3685 
   3686   /* keylog_callback, if not NULL, is the key logging callback. See
   3687    * |SSL_CTX_set_keylog_callback|. */
   3688   void (*keylog_callback)(const SSL *ssl, const char *line);
   3689 
   3690   /* current_time_cb, if not NULL, is the function to use to get the current
   3691    * time. It sets |*out_clock| to the current time. */
   3692   void (*current_time_cb)(const SSL *ssl, struct timeval *out_clock);
   3693 
   3694   /* quiet_shutdown is true if the connection should not send a close_notify on
   3695    * shutdown. */
   3696   unsigned quiet_shutdown:1;
   3697 
   3698   /* ocsp_stapling_enabled is only used by client connections and indicates
   3699    * whether OCSP stapling will be requested. */
   3700   unsigned ocsp_stapling_enabled:1;
   3701 
   3702   /* If true, a client will request certificate timestamps. */
   3703   unsigned signed_cert_timestamps_enabled:1;
   3704 
   3705   /* tlsext_channel_id_enabled is copied from the |SSL_CTX|. For a server,
   3706    * means that we'll accept Channel IDs from clients. For a client, means that
   3707    * we'll advertise support. */
   3708   unsigned tlsext_channel_id_enabled:1;
   3709 };
   3710 
   3711 struct ssl_st {
   3712   /* version is the protocol version. */
   3713   int version;
   3714 
   3715   /* max_version is the maximum acceptable protocol version. If zero, the
   3716    * maximum supported version, currently (D)TLS 1.2, is used. */
   3717   uint16_t max_version;
   3718 
   3719   /* min_version is the minimum acceptable protocl version. If zero, the
   3720    * minimum supported version, currently SSL 3.0 and DTLS 1.0, is used */
   3721   uint16_t min_version;
   3722 
   3723   /* method is the method table corresponding to the current protocol (DTLS or
   3724    * TLS). */
   3725   const SSL_PROTOCOL_METHOD *method;
   3726 
   3727   /* enc_method is the method table corresponding to the current protocol
   3728    * version. */
   3729   const SSL3_ENC_METHOD *enc_method;
   3730 
   3731   /* There are 2 BIO's even though they are normally both the same. This is so
   3732    * data can be read and written to different handlers */
   3733 
   3734   BIO *rbio; /* used by SSL_read */
   3735   BIO *wbio; /* used by SSL_write */
   3736 
   3737   /* bbio, if non-NULL, is a buffer placed in front of |wbio| to pack handshake
   3738    * messages within one flight into a single |BIO_write|.
   3739    *
   3740    * TODO(davidben): This does not work right for DTLS. It assumes the MTU is
   3741    * smaller than the buffer size so that the buffer's internal flushing never
   3742    * kicks in. It also doesn't kick in for DTLS retransmission. Replace this
   3743    * with a better mechanism. */
   3744   BIO *bbio;
   3745 
   3746   int (*handshake_func)(SSL *);
   3747 
   3748   /* Imagine that here's a boolean member "init" that is switched as soon as
   3749    * SSL_set_{accept/connect}_state is called for the first time, so that
   3750    * "state" and "handshake_func" are properly initialized.  But as
   3751    * handshake_func is == 0 until then, we use this test instead of an "init"
   3752    * member. */
   3753 
   3754   int shutdown; /* we have shut things down, 0x01 sent, 0x02
   3755                  * for received */
   3756   int state;    /* where we are */
   3757 
   3758   BUF_MEM *init_buf; /* buffer used during init */
   3759   uint8_t *init_msg; /* pointer to handshake message body, set by
   3760                         ssl3_get_message() */
   3761   int init_num;      /* amount read/written */
   3762   int init_off;      /* amount read/written */
   3763 
   3764   struct ssl3_state_st *s3;  /* SSLv3 variables */
   3765   struct dtls1_state_st *d1; /* DTLSv1 variables */
   3766 
   3767   /* callback that allows applications to peek at protocol messages */
   3768   void (*msg_callback)(int write_p, int version, int content_type,
   3769                        const void *buf, size_t len, SSL *ssl, void *arg);
   3770   void *msg_callback_arg;
   3771 
   3772   X509_VERIFY_PARAM *param;
   3773 
   3774   /* crypto */
   3775   struct ssl_cipher_preference_list_st *cipher_list;
   3776   STACK_OF(SSL_CIPHER) *cipher_list_by_id;
   3777 
   3778   SSL_AEAD_CTX *aead_read_ctx;
   3779   SSL_AEAD_CTX *aead_write_ctx;
   3780 
   3781   /* session info */
   3782 
   3783   /* client cert? */
   3784   /* This is used to hold the server certificate used */
   3785   struct cert_st /* CERT */ *cert;
   3786 
   3787   /* This holds a variable that indicates what we were doing when a 0 or -1 is
   3788    * returned.  This is needed for non-blocking IO so we know what request
   3789    * needs re-doing when in SSL_accept or SSL_connect */
   3790   int rwstate;
   3791 
   3792   /* the session_id_context is used to ensure sessions are only reused
   3793    * in the appropriate context */
   3794   unsigned int sid_ctx_length;
   3795   uint8_t sid_ctx[SSL_MAX_SID_CTX_LENGTH];
   3796 
   3797   /* This can also be in the session once a session is established */
   3798   SSL_SESSION *session;
   3799 
   3800   int (*verify_callback)(int ok,
   3801                          X509_STORE_CTX *ctx); /* fail if callback returns 0 */
   3802 
   3803   void (*info_callback)(const SSL *ssl, int type, int value);
   3804 
   3805   /* Server-only: psk_identity_hint is the identity hint to send in
   3806    * PSK-based key exchanges. */
   3807   char *psk_identity_hint;
   3808 
   3809   unsigned int (*psk_client_callback)(SSL *ssl, const char *hint,
   3810                                       char *identity,
   3811                                       unsigned int max_identity_len,
   3812                                       uint8_t *psk, unsigned int max_psk_len);
   3813   unsigned int (*psk_server_callback)(SSL *ssl, const char *identity,
   3814                                       uint8_t *psk, unsigned int max_psk_len);
   3815 
   3816   SSL_CTX *ctx;
   3817 
   3818   /* extra application data */
   3819   long verify_result;
   3820   CRYPTO_EX_DATA ex_data;
   3821 
   3822   /* for server side, keep the list of CA_dn we can use */
   3823   STACK_OF(X509_NAME) *client_CA;
   3824 
   3825   uint32_t options; /* protocol behaviour */
   3826   uint32_t mode;    /* API behaviour */
   3827   uint32_t max_cert_list;
   3828   int client_version; /* what was passed, used for
   3829                        * SSLv3/TLS rollback check */
   3830   uint16_t max_send_fragment;
   3831   char *tlsext_hostname;
   3832   /* RFC4507 session ticket expected to be received or sent */
   3833   int tlsext_ticket_expected;
   3834   size_t tlsext_ellipticcurvelist_length;
   3835   uint16_t *tlsext_ellipticcurvelist; /* our list */
   3836 
   3837   SSL_CTX *initial_ctx; /* initial ctx, used to store sessions */
   3838 
   3839   /* Next protocol negotiation. For the client, this is the protocol that we
   3840    * sent in NextProtocol and is set when handling ServerHello extensions.
   3841    *
   3842    * For a server, this is the client's selected_protocol from NextProtocol and
   3843    * is set when handling the NextProtocol message, before the Finished
   3844    * message. */
   3845   uint8_t *next_proto_negotiated;
   3846   size_t next_proto_negotiated_len;
   3847 
   3848   /* srtp_profiles is the list of configured SRTP protection profiles for
   3849    * DTLS-SRTP. */
   3850   STACK_OF(SRTP_PROTECTION_PROFILE) *srtp_profiles;
   3851 
   3852   /* srtp_profile is the selected SRTP protection profile for
   3853    * DTLS-SRTP. */
   3854   const SRTP_PROTECTION_PROFILE *srtp_profile;
   3855 
   3856   /* The client's Channel ID private key. */
   3857   EVP_PKEY *tlsext_channel_id_private;
   3858 
   3859   /* For a client, this contains the list of supported protocols in wire
   3860    * format. */
   3861   uint8_t *alpn_client_proto_list;
   3862   unsigned alpn_client_proto_list_len;
   3863 
   3864   /* renegotiate_mode controls how peer renegotiation attempts are handled. */
   3865   enum ssl_renegotiate_mode_t renegotiate_mode;
   3866 
   3867   /* These fields are always NULL and exist only to keep wpa_supplicant happy
   3868    * about the change to EVP_AEAD. They are only needed for EAP-FAST, which we
   3869    * don't support. */
   3870   EVP_CIPHER_CTX *enc_read_ctx;
   3871   EVP_MD_CTX *read_hash;
   3872 
   3873   /* in_handshake is non-zero when we are actually in SSL_accept() or
   3874    * SSL_connect() */
   3875   int in_handshake;
   3876 
   3877   /* verify_mode is a bitmask of |SSL_VERIFY_*| values. */
   3878   uint8_t verify_mode;
   3879 
   3880   /* hit is true if this connection is resuming a previous session. */
   3881   unsigned hit:1;
   3882 
   3883   /* server is true iff the this SSL* is the server half. Note: before the SSL*
   3884    * is initialized by either SSL_set_accept_state or SSL_set_connect_state,
   3885    * the side is not determined. In this state, server is always false. */
   3886   unsigned server:1;
   3887 
   3888   /* quiet_shutdown is true if the connection should not send a close_notify on
   3889    * shutdown. */
   3890   unsigned quiet_shutdown:1;
   3891 
   3892   /* Enable signed certificate time stamps. Currently client only. */
   3893   unsigned signed_cert_timestamps_enabled:1;
   3894 
   3895   /* ocsp_stapling_enabled is only used by client connections and indicates
   3896    * whether OCSP stapling will be requested. */
   3897   unsigned ocsp_stapling_enabled:1;
   3898 
   3899   /* tlsext_channel_id_enabled is copied from the |SSL_CTX|. For a server,
   3900    * means that we'll accept Channel IDs from clients. For a client, means that
   3901    * we'll advertise support. */
   3902   unsigned tlsext_channel_id_enabled:1;
   3903 };
   3904 
   3905 typedef struct ssl3_record_st {
   3906   /* type is the record type. */
   3907   uint8_t type;
   3908   /* length is the number of unconsumed bytes in the record. */
   3909   uint16_t length;
   3910   /* data is a non-owning pointer to the first unconsumed byte of the record. */
   3911   uint8_t *data;
   3912 } SSL3_RECORD;
   3913 
   3914 typedef struct ssl3_buffer_st {
   3915   /* buf is the memory allocated for this buffer. */
   3916   uint8_t *buf;
   3917   /* offset is the offset into |buf| which the buffer contents start at. */
   3918   uint16_t offset;
   3919   /* len is the length of the buffer contents from |buf| + |offset|. */
   3920   uint16_t len;
   3921   /* cap is how much memory beyond |buf| + |offset| is available. */
   3922   uint16_t cap;
   3923 } SSL3_BUFFER;
   3924 
   3925 typedef struct ssl3_state_st {
   3926   uint8_t read_sequence[8];
   3927   uint8_t write_sequence[8];
   3928 
   3929   uint8_t server_random[SSL3_RANDOM_SIZE];
   3930   uint8_t client_random[SSL3_RANDOM_SIZE];
   3931 
   3932   /* have_version is true if the connection's final version is known. Otherwise
   3933    * the version has not been negotiated yet. */
   3934   char have_version;
   3935 
   3936   /* initial_handshake_complete is true if the initial handshake has
   3937    * completed. */
   3938   char initial_handshake_complete;
   3939 
   3940   /* read_buffer holds data from the transport to be processed. */
   3941   SSL3_BUFFER read_buffer;
   3942   /* write_buffer holds data to be written to the transport. */
   3943   SSL3_BUFFER write_buffer;
   3944 
   3945   SSL3_RECORD rrec; /* each decoded record goes in here */
   3946 
   3947   /* hello_request_len is the number of bytes of HelloRequest received, possibly
   3948    * split over multiple records. */
   3949   uint8_t hello_request_len;
   3950 
   3951   /* partial write - check the numbers match */
   3952   unsigned int wnum; /* number of bytes sent so far */
   3953   int wpend_tot;     /* number bytes written */
   3954   int wpend_type;
   3955   int wpend_ret; /* number of bytes submitted */
   3956   const uint8_t *wpend_buf;
   3957 
   3958   /* handshake_buffer, if non-NULL, contains the handshake transcript. */
   3959   BUF_MEM *handshake_buffer;
   3960   /* handshake_hash, if initialized with an |EVP_MD|, maintains the handshake
   3961    * hash. For TLS 1.1 and below, it is the SHA-1 half. */
   3962   EVP_MD_CTX handshake_hash;
   3963   /* handshake_md5, if initialized with an |EVP_MD|, maintains the MD5 half of
   3964    * the handshake hash for TLS 1.1 and below. */
   3965   EVP_MD_CTX handshake_md5;
   3966 
   3967   int warn_alert;
   3968   int fatal_alert;
   3969   /* we allow one fatal and one warning alert to be outstanding, send close
   3970    * alert via the warning alert */
   3971   int alert_dispatch;
   3972   uint8_t send_alert[2];
   3973 
   3974   int total_renegotiations;
   3975 
   3976   /* empty_record_count is the number of consecutive empty records received. */
   3977   uint8_t empty_record_count;
   3978 
   3979   /* warning_alert_count is the number of consecutive warning alerts
   3980    * received. */
   3981   uint8_t warning_alert_count;
   3982 
   3983   /* State pertaining to the pending handshake.
   3984    *
   3985    * TODO(davidben): State is current spread all over the place. Move
   3986    * pending handshake state here so it can be managed separately from
   3987    * established connection state in case of renegotiations. */
   3988   struct {
   3989     uint8_t finish_md[EVP_MAX_MD_SIZE];
   3990     int finish_md_len;
   3991     uint8_t peer_finish_md[EVP_MAX_MD_SIZE];
   3992     int peer_finish_md_len;
   3993 
   3994     unsigned long message_size;
   3995     int message_type;
   3996 
   3997     /* used to hold the new cipher we are going to use */
   3998     const SSL_CIPHER *new_cipher;
   3999 
   4000     /* used when SSL_ST_FLUSH_DATA is entered */
   4001     int next_state;
   4002 
   4003     int reuse_message;
   4004 
   4005     union {
   4006       /* sent is a bitset where the bits correspond to elements of kExtensions
   4007        * in t1_lib.c. Each bit is set if that extension was sent in a
   4008        * ClientHello. It's not used by servers. */
   4009       uint32_t sent;
   4010       /* received is a bitset, like |sent|, but is used by servers to record
   4011        * which extensions were received from a client. */
   4012       uint32_t received;
   4013     } extensions;
   4014 
   4015     union {
   4016       /* sent is a bitset where the bits correspond to elements of
   4017        * |client_custom_extensions| in the |SSL_CTX|. Each bit is set if that
   4018        * extension was sent in a ClientHello. It's not used by servers. */
   4019       uint16_t sent;
   4020       /* received is a bitset, like |sent|, but is used by servers to record
   4021        * which custom extensions were received from a client. The bits here
   4022        * correspond to |server_custom_extensions|. */
   4023       uint16_t received;
   4024     } custom_extensions;
   4025 
   4026     /* SNI extension */
   4027 
   4028     /* should_ack_sni is used by a server and indicates that the SNI extension
   4029      * should be echoed in the ServerHello. */
   4030     unsigned should_ack_sni:1;
   4031 
   4032 
   4033     /* Client-only: cert_req determines if a client certificate is to be sent.
   4034      * This is 0 if no client Certificate message is to be sent, 1 if there is
   4035      * a client certificate, and 2 to send an empty client Certificate
   4036      * message. */
   4037     int cert_req;
   4038 
   4039     /* Client-only: ca_names contains the list of CAs received in a
   4040      * CertificateRequest message. */
   4041     STACK_OF(X509_NAME) *ca_names;
   4042 
   4043     /* Client-only: certificate_types contains the set of certificate types
   4044      * received in a CertificateRequest message. */
   4045     uint8_t *certificate_types;
   4046     size_t num_certificate_types;
   4047 
   4048     int key_block_length;
   4049     uint8_t *key_block;
   4050 
   4051     const EVP_AEAD *new_aead;
   4052     uint8_t new_mac_secret_len;
   4053     uint8_t new_fixed_iv_len;
   4054     uint8_t new_variable_iv_len;
   4055 
   4056     /* Server-only: cert_request is true if a client certificate was
   4057      * requested. */
   4058     int cert_request;
   4059 
   4060     /* certificate_status_expected is true if OCSP stapling was negotiated and
   4061      * the server is expected to send a CertificateStatus message. (This is
   4062      * used on both the client and server sides.) */
   4063     unsigned certificate_status_expected:1;
   4064 
   4065     /* ocsp_stapling_requested is true if a client requested OCSP stapling. */
   4066     unsigned ocsp_stapling_requested:1;
   4067 
   4068     /* Server-only: peer_ellipticcurvelist contains the EC curve IDs advertised
   4069      * by the peer. This is only set on the server's end. The server does not
   4070      * advertise this extension to the client. */
   4071     uint16_t *peer_ellipticcurvelist;
   4072     size_t peer_ellipticcurvelist_length;
   4073 
   4074     /* extended_master_secret indicates whether the extended master secret
   4075      * computation is used in this handshake. Note that this is different from
   4076      * whether it was used for the current session. If this is a resumption
   4077      * handshake then EMS might be negotiated in the client and server hello
   4078      * messages, but it doesn't matter if the session that's being resumed
   4079      * didn't use it to create the master secret initially. */
   4080     char extended_master_secret;
   4081 
   4082     /* Client-only: peer_psk_identity_hint is the psk_identity_hint sent by the
   4083      * server when using a PSK key exchange. */
   4084     char *peer_psk_identity_hint;
   4085 
   4086     /* new_mac_secret_size is unused and exists only until wpa_supplicant can
   4087      * be updated. It is only needed for EAP-FAST, which we don't support. */
   4088     uint8_t new_mac_secret_size;
   4089 
   4090     /* Client-only: in_false_start is one if there is a pending handshake in
   4091      * False Start. The client may write data at this point. */
   4092     char in_false_start;
   4093 
   4094     /* server_key_exchange_hash, on a client, is the hash the server used to
   4095      * sign the ServerKeyExchange in TLS 1.2. If not applicable, it is
   4096      * |TLSEXT_hash_none|. */
   4097     uint8_t server_key_exchange_hash;
   4098 
   4099     /* ecdh_ctx is the current ECDH instance. */
   4100     SSL_ECDH_CTX ecdh_ctx;
   4101 
   4102     /* peer_key is the peer's ECDH key. */
   4103     uint8_t *peer_key;
   4104     uint16_t peer_key_len;
   4105   } tmp;
   4106 
   4107   /* Connection binding to prevent renegotiation attacks */
   4108   uint8_t previous_client_finished[EVP_MAX_MD_SIZE];
   4109   uint8_t previous_client_finished_len;
   4110   uint8_t previous_server_finished[EVP_MAX_MD_SIZE];
   4111   uint8_t previous_server_finished_len;
   4112   int send_connection_binding; /* TODOEKR */
   4113 
   4114   /* Set if we saw the Next Protocol Negotiation extension from our peer. */
   4115   int next_proto_neg_seen;
   4116 
   4117   /* ALPN information
   4118    * (we are in the process of transitioning from NPN to ALPN.) */
   4119 
   4120   /* In a server these point to the selected ALPN protocol after the
   4121    * ClientHello has been processed. In a client these contain the protocol
   4122    * that the server selected once the ServerHello has been processed. */
   4123   uint8_t *alpn_selected;
   4124   size_t alpn_selected_len;
   4125 
   4126   /* In a client, this means that the server supported Channel ID and that a
   4127    * Channel ID was sent. In a server it means that we echoed support for
   4128    * Channel IDs and that tlsext_channel_id will be valid after the
   4129    * handshake. */
   4130   char tlsext_channel_id_valid;
   4131   /* For a server:
   4132    *     If |tlsext_channel_id_valid| is true, then this contains the
   4133    *     verified Channel ID from the client: a P256 point, (x,y), where
   4134    *     each are big-endian values. */
   4135   uint8_t tlsext_channel_id[64];
   4136 } SSL3_STATE;
   4137 
   4138 
   4139 /* Android compatibility section (hidden).
   4140  *
   4141  * These functions are declared, temporarily, for Android because
   4142  * wpa_supplicant will take a little time to sync with upstream. Outside of
   4143  * Android they'll have no definition. */
   4144 
   4145 #define SSL_F_SSL_SET_SESSION_TICKET_EXT doesnt_exist
   4146 
   4147 OPENSSL_EXPORT int SSL_set_session_ticket_ext(SSL *s, void *ext_data,
   4148                                               int ext_len);
   4149 OPENSSL_EXPORT int SSL_set_session_secret_cb(SSL *s, void *cb, void *arg);
   4150 OPENSSL_EXPORT int SSL_set_session_ticket_ext_cb(SSL *s, void *cb, void *arg);
   4151 OPENSSL_EXPORT int SSL_set_ssl_method(SSL *s, const SSL_METHOD *method);
   4152 
   4153 
   4154 /* Preprocessor compatibility section (hidden).
   4155  *
   4156  * Historically, a number of APIs were implemented in OpenSSL as macros and
   4157  * constants to 'ctrl' functions. To avoid breaking #ifdefs in consumers, this
   4158  * section defines a number of legacy macros.
   4159  *
   4160  * Although using either the CTRL values or their wrapper macros in #ifdefs is
   4161  * still supported, the CTRL values may not be passed to |SSL_ctrl| and
   4162  * |SSL_CTX_ctrl|. Call the functions (previously wrapper macros) instead. */
   4163 
   4164 #define DTLS_CTRL_GET_TIMEOUT doesnt_exist
   4165 #define DTLS_CTRL_HANDLE_TIMEOUT doesnt_exist
   4166 #define SSL_CTRL_CHAIN doesnt_exist
   4167 #define SSL_CTRL_CHAIN_CERT doesnt_exist
   4168 #define SSL_CTRL_CHANNEL_ID doesnt_exist
   4169 #define SSL_CTRL_CLEAR_EXTRA_CHAIN_CERTS doesnt_exist
   4170 #define SSL_CTRL_CLEAR_MODE doesnt_exist
   4171 #define SSL_CTRL_CLEAR_OPTIONS doesnt_exist
   4172 #define SSL_CTRL_EXTRA_CHAIN_CERT doesnt_exist
   4173 #define SSL_CTRL_GET_CHAIN_CERTS doesnt_exist
   4174 #define SSL_CTRL_GET_CHANNEL_ID doesnt_exist
   4175 #define SSL_CTRL_GET_CLIENT_CERT_TYPES doesnt_exist
   4176 #define SSL_CTRL_GET_EXTRA_CHAIN_CERTS doesnt_exist
   4177 #define SSL_CTRL_GET_MAX_CERT_LIST doesnt_exist
   4178 #define SSL_CTRL_GET_NUM_RENEGOTIATIONS doesnt_exist
   4179 #define SSL_CTRL_GET_READ_AHEAD doesnt_exist
   4180 #define SSL_CTRL_GET_RI_SUPPORT doesnt_exist
   4181 #define SSL_CTRL_GET_SESSION_REUSED doesnt_exist
   4182 #define SSL_CTRL_GET_SESS_CACHE_MODE doesnt_exist
   4183 #define SSL_CTRL_GET_SESS_CACHE_SIZE doesnt_exist
   4184 #define SSL_CTRL_GET_TLSEXT_TICKET_KEYS doesnt_exist
   4185 #define SSL_CTRL_GET_TOTAL_RENEGOTIATIONS doesnt_exist
   4186 #define SSL_CTRL_MODE doesnt_exist
   4187 #define SSL_CTRL_NEED_TMP_RSA doesnt_exist
   4188 #define SSL_CTRL_OPTIONS doesnt_exist
   4189 #define SSL_CTRL_SESS_NUMBER doesnt_exist
   4190 #define SSL_CTRL_SET_CHANNEL_ID doesnt_exist
   4191 #define SSL_CTRL_SET_CURVES doesnt_exist
   4192 #define SSL_CTRL_SET_MAX_CERT_LIST doesnt_exist
   4193 #define SSL_CTRL_SET_MAX_SEND_FRAGMENT doesnt_exist
   4194 #define SSL_CTRL_SET_MSG_CALLBACK doesnt_exist
   4195 #define SSL_CTRL_SET_MSG_CALLBACK_ARG doesnt_exist
   4196 #define SSL_CTRL_SET_MTU doesnt_exist
   4197 #define SSL_CTRL_SET_READ_AHEAD doesnt_exist
   4198 #define SSL_CTRL_SET_SESS_CACHE_MODE doesnt_exist
   4199 #define SSL_CTRL_SET_SESS_CACHE_SIZE doesnt_exist
   4200 #define SSL_CTRL_SET_TLSEXT_HOSTNAME doesnt_exist
   4201 #define SSL_CTRL_SET_TLSEXT_SERVERNAME_ARG doesnt_exist
   4202 #define SSL_CTRL_SET_TLSEXT_SERVERNAME_CB doesnt_exist
   4203 #define SSL_CTRL_SET_TLSEXT_TICKET_KEYS doesnt_exist
   4204 #define SSL_CTRL_SET_TLSEXT_TICKET_KEY_CB doesnt_exist
   4205 #define SSL_CTRL_SET_TMP_DH doesnt_exist
   4206 #define SSL_CTRL_SET_TMP_DH_CB doesnt_exist
   4207 #define SSL_CTRL_SET_TMP_ECDH doesnt_exist
   4208 #define SSL_CTRL_SET_TMP_ECDH_CB doesnt_exist
   4209 #define SSL_CTRL_SET_TMP_RSA doesnt_exist
   4210 #define SSL_CTRL_SET_TMP_RSA_CB doesnt_exist
   4211 
   4212 #define DTLSv1_get_timeout DTLSv1_get_timeout
   4213 #define DTLSv1_handle_timeout DTLSv1_handle_timeout
   4214 #define SSL_CTX_add0_chain_cert SSL_CTX_add0_chain_cert
   4215 #define SSL_CTX_add1_chain_cert SSL_CTX_add1_chain_cert
   4216 #define SSL_CTX_add_extra_chain_cert SSL_CTX_add_extra_chain_cert
   4217 #define SSL_CTX_clear_extra_chain_certs SSL_CTX_clear_extra_chain_certs
   4218 #define SSL_CTX_clear_chain_certs SSL_CTX_clear_chain_certs
   4219 #define SSL_CTX_clear_mode SSL_CTX_clear_mode
   4220 #define SSL_CTX_clear_options SSL_CTX_clear_options
   4221 #define SSL_CTX_enable_tls_channel_id SSL_CTX_enable_tls_channel_id
   4222 #define SSL_CTX_get0_chain_certs SSL_CTX_get0_chain_certs
   4223 #define SSL_CTX_get_extra_chain_certs SSL_CTX_get_extra_chain_certs
   4224 #define SSL_CTX_get_max_cert_list SSL_CTX_get_max_cert_list
   4225 #define SSL_CTX_get_mode SSL_CTX_get_mode
   4226 #define SSL_CTX_get_options SSL_CTX_get_options
   4227 #define SSL_CTX_get_read_ahead SSL_CTX_get_read_ahead
   4228 #define SSL_CTX_get_session_cache_mode SSL_CTX_get_session_cache_mode
   4229 #define SSL_CTX_get_tlsext_ticket_keys SSL_CTX_get_tlsext_ticket_keys
   4230 #define SSL_CTX_need_tmp_RSA SSL_CTX_need_tmp_RSA
   4231 #define SSL_CTX_sess_get_cache_size SSL_CTX_sess_get_cache_size
   4232 #define SSL_CTX_sess_number SSL_CTX_sess_number
   4233 #define SSL_CTX_sess_set_cache_size SSL_CTX_sess_set_cache_size
   4234 #define SSL_CTX_set0_chain SSL_CTX_set0_chain
   4235 #define SSL_CTX_set1_chain SSL_CTX_set1_chain
   4236 #define SSL_CTX_set1_curves SSL_CTX_set1_curves
   4237 #define SSL_CTX_set1_tls_channel_id SSL_CTX_set1_tls_channel_id
   4238 #define SSL_CTX_set_max_cert_list SSL_CTX_set_max_cert_list
   4239 #define SSL_CTX_set_max_send_fragment SSL_CTX_set_max_send_fragment
   4240 #define SSL_CTX_set_mode SSL_CTX_set_mode
   4241 #define SSL_CTX_set_msg_callback_arg SSL_CTX_set_msg_callback_arg
   4242 #define SSL_CTX_set_options SSL_CTX_set_options
   4243 #define SSL_CTX_set_read_ahead SSL_CTX_set_read_ahead
   4244 #define SSL_CTX_set_session_cache_mode SSL_CTX_set_session_cache_mode
   4245 #define SSL_CTX_set_tlsext_servername_arg SSL_CTX_set_tlsext_servername_arg
   4246 #define SSL_CTX_set_tlsext_servername_callback \
   4247     SSL_CTX_set_tlsext_servername_callback
   4248 #define SSL_CTX_set_tlsext_ticket_key_cb SSL_CTX_set_tlsext_ticket_key_cb
   4249 #define SSL_CTX_set_tlsext_ticket_keys SSL_CTX_set_tlsext_ticket_keys
   4250 #define SSL_CTX_set_tmp_dh SSL_CTX_set_tmp_dh
   4251 #define SSL_CTX_set_tmp_ecdh SSL_CTX_set_tmp_ecdh
   4252 #define SSL_CTX_set_tmp_rsa SSL_CTX_set_tmp_rsa
   4253 #define SSL_add0_chain_cert SSL_add0_chain_cert
   4254 #define SSL_add1_chain_cert SSL_add1_chain_cert
   4255 #define SSL_clear_chain_certs SSL_clear_chain_certs
   4256 #define SSL_clear_mode SSL_clear_mode
   4257 #define SSL_clear_options SSL_clear_options
   4258 #define SSL_enable_tls_channel_id SSL_enable_tls_channel_id
   4259 #define SSL_get0_certificate_types SSL_get0_certificate_types
   4260 #define SSL_get0_chain_certs SSL_get0_chain_certs
   4261 #define SSL_get_max_cert_list SSL_get_max_cert_list
   4262 #define SSL_get_mode SSL_get_mode
   4263 #define SSL_get_options SSL_get_options
   4264 #define SSL_get_secure_renegotiation_support \
   4265     SSL_get_secure_renegotiation_support
   4266 #define SSL_get_tls_channel_id SSL_get_tls_channel_id
   4267 #define SSL_need_tmp_RSA SSL_need_tmp_RSA
   4268 #define SSL_num_renegotiations SSL_num_renegotiations
   4269 #define SSL_session_reused SSL_session_reused
   4270 #define SSL_set0_chain SSL_set0_chain
   4271 #define SSL_set1_chain SSL_set1_chain
   4272 #define SSL_set1_curves SSL_set1_curves
   4273 #define SSL_set1_tls_channel_id SSL_set1_tls_channel_id
   4274 #define SSL_set_max_cert_list SSL_set_max_cert_list
   4275 #define SSL_set_max_send_fragment SSL_set_max_send_fragment
   4276 #define SSL_set_mode SSL_set_mode
   4277 #define SSL_set_msg_callback_arg SSL_set_msg_callback_arg
   4278 #define SSL_set_mtu SSL_set_mtu
   4279 #define SSL_set_options SSL_set_options
   4280 #define SSL_set_tlsext_host_name SSL_set_tlsext_host_name
   4281 #define SSL_set_tmp_dh SSL_set_tmp_dh
   4282 #define SSL_set_tmp_ecdh SSL_set_tmp_ecdh
   4283 #define SSL_set_tmp_rsa SSL_set_tmp_rsa
   4284 #define SSL_total_renegotiations SSL_total_renegotiations
   4285 
   4286 
   4287 #if defined(__cplusplus)
   4288 } /* extern C */
   4289 #endif
   4290 
   4291 #define SSL_R_APP_DATA_IN_HANDSHAKE 100
   4292 #define SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT 101
   4293 #define SSL_R_BAD_ALERT 102
   4294 #define SSL_R_BAD_CHANGE_CIPHER_SPEC 103
   4295 #define SSL_R_BAD_DATA_RETURNED_BY_CALLBACK 104
   4296 #define SSL_R_BAD_DH_P_LENGTH 105
   4297 #define SSL_R_BAD_DIGEST_LENGTH 106
   4298 #define SSL_R_BAD_ECC_CERT 107
   4299 #define SSL_R_BAD_ECPOINT 108
   4300 #define SSL_R_BAD_HANDSHAKE_RECORD 109
   4301 #define SSL_R_BAD_HELLO_REQUEST 110
   4302 #define SSL_R_BAD_LENGTH 111
   4303 #define SSL_R_BAD_PACKET_LENGTH 112
   4304 #define SSL_R_BAD_RSA_ENCRYPT 113
   4305 #define SSL_R_BAD_SIGNATURE 114
   4306 #define SSL_R_BAD_SRTP_MKI_VALUE 115
   4307 #define SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST 116
   4308 #define SSL_R_BAD_SSL_FILETYPE 117
   4309 #define SSL_R_BAD_WRITE_RETRY 118
   4310 #define SSL_R_BIO_NOT_SET 119
   4311 #define SSL_R_BN_LIB 120
   4312 #define SSL_R_BUFFER_TOO_SMALL 121
   4313 #define SSL_R_CA_DN_LENGTH_MISMATCH 122
   4314 #define SSL_R_CA_DN_TOO_LONG 123
   4315 #define SSL_R_CCS_RECEIVED_EARLY 124
   4316 #define SSL_R_CERTIFICATE_VERIFY_FAILED 125
   4317 #define SSL_R_CERT_CB_ERROR 126
   4318 #define SSL_R_CERT_LENGTH_MISMATCH 127
   4319 #define SSL_R_CHANNEL_ID_NOT_P256 128
   4320 #define SSL_R_CHANNEL_ID_SIGNATURE_INVALID 129
   4321 #define SSL_R_CIPHER_OR_HASH_UNAVAILABLE 130
   4322 #define SSL_R_CLIENTHELLO_PARSE_FAILED 131
   4323 #define SSL_R_CLIENTHELLO_TLSEXT 132
   4324 #define SSL_R_CONNECTION_REJECTED 133
   4325 #define SSL_R_CONNECTION_TYPE_NOT_SET 134
   4326 #define SSL_R_CUSTOM_EXTENSION_ERROR 135
   4327 #define SSL_R_DATA_LENGTH_TOO_LONG 136
   4328 #define SSL_R_DECODE_ERROR 137
   4329 #define SSL_R_DECRYPTION_FAILED 138
   4330 #define SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC 139
   4331 #define SSL_R_DH_PUBLIC_VALUE_LENGTH_IS_WRONG 140
   4332 #define SSL_R_DH_P_TOO_LONG 141
   4333 #define SSL_R_DIGEST_CHECK_FAILED 142
   4334 #define SSL_R_DTLS_MESSAGE_TOO_BIG 143
   4335 #define SSL_R_ECC_CERT_NOT_FOR_SIGNING 144
   4336 #define SSL_R_EMS_STATE_INCONSISTENT 145
   4337 #define SSL_R_ENCRYPTED_LENGTH_TOO_LONG 146
   4338 #define SSL_R_ERROR_ADDING_EXTENSION 147
   4339 #define SSL_R_ERROR_IN_RECEIVED_CIPHER_LIST 148
   4340 #define SSL_R_ERROR_PARSING_EXTENSION 149
   4341 #define SSL_R_EXCESSIVE_MESSAGE_SIZE 150
   4342 #define SSL_R_EXTRA_DATA_IN_MESSAGE 151
   4343 #define SSL_R_FRAGMENT_MISMATCH 152
   4344 #define SSL_R_GOT_NEXT_PROTO_WITHOUT_EXTENSION 153
   4345 #define SSL_R_HANDSHAKE_FAILURE_ON_CLIENT_HELLO 154
   4346 #define SSL_R_HTTPS_PROXY_REQUEST 155
   4347 #define SSL_R_HTTP_REQUEST 156
   4348 #define SSL_R_INAPPROPRIATE_FALLBACK 157
   4349 #define SSL_R_INVALID_COMMAND 158
   4350 #define SSL_R_INVALID_MESSAGE 159
   4351 #define SSL_R_INVALID_SSL_SESSION 160
   4352 #define SSL_R_INVALID_TICKET_KEYS_LENGTH 161
   4353 #define SSL_R_LENGTH_MISMATCH 162
   4354 #define SSL_R_LIBRARY_HAS_NO_CIPHERS 163
   4355 #define SSL_R_MISSING_EXTENSION 164
   4356 #define SSL_R_MISSING_RSA_CERTIFICATE 165
   4357 #define SSL_R_MISSING_TMP_DH_KEY 166
   4358 #define SSL_R_MISSING_TMP_ECDH_KEY 167
   4359 #define SSL_R_MIXED_SPECIAL_OPERATOR_WITH_GROUPS 168
   4360 #define SSL_R_MTU_TOO_SMALL 169
   4361 #define SSL_R_NEGOTIATED_BOTH_NPN_AND_ALPN 170
   4362 #define SSL_R_NESTED_GROUP 171
   4363 #define SSL_R_NO_CERTIFICATES_RETURNED 172
   4364 #define SSL_R_NO_CERTIFICATE_ASSIGNED 173
   4365 #define SSL_R_NO_CERTIFICATE_SET 174
   4366 #define SSL_R_NO_CIPHERS_AVAILABLE 175
   4367 #define SSL_R_NO_CIPHERS_PASSED 176
   4368 #define SSL_R_NO_CIPHER_MATCH 177
   4369 #define SSL_R_NO_COMPRESSION_SPECIFIED 178
   4370 #define SSL_R_NO_METHOD_SPECIFIED 179
   4371 #define SSL_R_NO_P256_SUPPORT 180
   4372 #define SSL_R_NO_PRIVATE_KEY_ASSIGNED 181
   4373 #define SSL_R_NO_RENEGOTIATION 182
   4374 #define SSL_R_NO_REQUIRED_DIGEST 183
   4375 #define SSL_R_NO_SHARED_CIPHER 184
   4376 #define SSL_R_NULL_SSL_CTX 185
   4377 #define SSL_R_NULL_SSL_METHOD_PASSED 186
   4378 #define SSL_R_OLD_SESSION_CIPHER_NOT_RETURNED 187
   4379 #define SSL_R_OLD_SESSION_VERSION_NOT_RETURNED 188
   4380 #define SSL_R_OUTPUT_ALIASES_INPUT 189
   4381 #define SSL_R_PARSE_TLSEXT 190
   4382 #define SSL_R_PATH_TOO_LONG 191
   4383 #define SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE 192
   4384 #define SSL_R_PEER_ERROR_UNSUPPORTED_CERTIFICATE_TYPE 193
   4385 #define SSL_R_PROTOCOL_IS_SHUTDOWN 194
   4386 #define SSL_R_PSK_IDENTITY_NOT_FOUND 195
   4387 #define SSL_R_PSK_NO_CLIENT_CB 196
   4388 #define SSL_R_PSK_NO_SERVER_CB 197
   4389 #define SSL_R_READ_TIMEOUT_EXPIRED 198
   4390 #define SSL_R_RECORD_LENGTH_MISMATCH 199
   4391 #define SSL_R_RECORD_TOO_LARGE 200
   4392 #define SSL_R_RENEGOTIATION_ENCODING_ERR 201
   4393 #define SSL_R_RENEGOTIATION_MISMATCH 202
   4394 #define SSL_R_REQUIRED_CIPHER_MISSING 203
   4395 #define SSL_R_RESUMED_EMS_SESSION_WITHOUT_EMS_EXTENSION 204
   4396 #define SSL_R_RESUMED_NON_EMS_SESSION_WITH_EMS_EXTENSION 205
   4397 #define SSL_R_SCSV_RECEIVED_WHEN_RENEGOTIATING 206
   4398 #define SSL_R_SERVERHELLO_TLSEXT 207
   4399 #define SSL_R_SESSION_ID_CONTEXT_UNINITIALIZED 208
   4400 #define SSL_R_SESSION_MAY_NOT_BE_CREATED 209
   4401 #define SSL_R_SIGNATURE_ALGORITHMS_EXTENSION_SENT_BY_SERVER 210
   4402 #define SSL_R_SRTP_COULD_NOT_ALLOCATE_PROFILES 211
   4403 #define SSL_R_SRTP_UNKNOWN_PROTECTION_PROFILE 212
   4404 #define SSL_R_SSL3_EXT_INVALID_SERVERNAME 213
   4405 #define SSL_R_SSL_CTX_HAS_NO_DEFAULT_SSL_VERSION 214
   4406 #define SSL_R_SSL_HANDSHAKE_FAILURE 215
   4407 #define SSL_R_SSL_SESSION_ID_CONTEXT_TOO_LONG 216
   4408 #define SSL_R_TLS_PEER_DID_NOT_RESPOND_WITH_CERTIFICATE_LIST 217
   4409 #define SSL_R_TLS_RSA_ENCRYPTED_VALUE_LENGTH_IS_WRONG 218
   4410 #define SSL_R_TOO_MANY_EMPTY_FRAGMENTS 219
   4411 #define SSL_R_TOO_MANY_WARNING_ALERTS 220
   4412 #define SSL_R_UNABLE_TO_FIND_ECDH_PARAMETERS 221
   4413 #define SSL_R_UNEXPECTED_EXTENSION 222
   4414 #define SSL_R_UNEXPECTED_MESSAGE 223
   4415 #define SSL_R_UNEXPECTED_OPERATOR_IN_GROUP 224
   4416 #define SSL_R_UNEXPECTED_RECORD 225
   4417 #define SSL_R_UNINITIALIZED 226
   4418 #define SSL_R_UNKNOWN_ALERT_TYPE 227
   4419 #define SSL_R_UNKNOWN_CERTIFICATE_TYPE 228
   4420 #define SSL_R_UNKNOWN_CIPHER_RETURNED 229
   4421 #define SSL_R_UNKNOWN_CIPHER_TYPE 230
   4422 #define SSL_R_UNKNOWN_DIGEST 231
   4423 #define SSL_R_UNKNOWN_KEY_EXCHANGE_TYPE 232
   4424 #define SSL_R_UNKNOWN_PROTOCOL 233
   4425 #define SSL_R_UNKNOWN_SSL_VERSION 234
   4426 #define SSL_R_UNKNOWN_STATE 235
   4427 #define SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED 236
   4428 #define SSL_R_UNSUPPORTED_CIPHER 237
   4429 #define SSL_R_UNSUPPORTED_COMPRESSION_ALGORITHM 238
   4430 #define SSL_R_UNSUPPORTED_ELLIPTIC_CURVE 239
   4431 #define SSL_R_UNSUPPORTED_PROTOCOL 240
   4432 #define SSL_R_WRONG_CERTIFICATE_TYPE 241
   4433 #define SSL_R_WRONG_CIPHER_RETURNED 242
   4434 #define SSL_R_WRONG_CURVE 243
   4435 #define SSL_R_WRONG_MESSAGE_TYPE 244
   4436 #define SSL_R_WRONG_SIGNATURE_TYPE 245
   4437 #define SSL_R_WRONG_SSL_VERSION 246
   4438 #define SSL_R_WRONG_VERSION_NUMBER 247
   4439 #define SSL_R_X509_LIB 248
   4440 #define SSL_R_X509_VERIFICATION_SETUP_PROBLEMS 249
   4441 #define SSL_R_SSLV3_ALERT_CLOSE_NOTIFY 1000
   4442 #define SSL_R_SSLV3_ALERT_UNEXPECTED_MESSAGE 1010
   4443 #define SSL_R_SSLV3_ALERT_BAD_RECORD_MAC 1020
   4444 #define SSL_R_TLSV1_ALERT_DECRYPTION_FAILED 1021
   4445 #define SSL_R_TLSV1_ALERT_RECORD_OVERFLOW 1022
   4446 #define SSL_R_SSLV3_ALERT_DECOMPRESSION_FAILURE 1030
   4447 #define SSL_R_SSLV3_ALERT_HANDSHAKE_FAILURE 1040
   4448 #define SSL_R_SSLV3_ALERT_NO_CERTIFICATE 1041
   4449 #define SSL_R_SSLV3_ALERT_BAD_CERTIFICATE 1042
   4450 #define SSL_R_SSLV3_ALERT_UNSUPPORTED_CERTIFICATE 1043
   4451 #define SSL_R_SSLV3_ALERT_CERTIFICATE_REVOKED 1044
   4452 #define SSL_R_SSLV3_ALERT_CERTIFICATE_EXPIRED 1045
   4453 #define SSL_R_SSLV3_ALERT_CERTIFICATE_UNKNOWN 1046
   4454 #define SSL_R_SSLV3_ALERT_ILLEGAL_PARAMETER 1047
   4455 #define SSL_R_TLSV1_ALERT_UNKNOWN_CA 1048
   4456 #define SSL_R_TLSV1_ALERT_ACCESS_DENIED 1049
   4457 #define SSL_R_TLSV1_ALERT_DECODE_ERROR 1050
   4458 #define SSL_R_TLSV1_ALERT_DECRYPT_ERROR 1051
   4459 #define SSL_R_TLSV1_ALERT_EXPORT_RESTRICTION 1060
   4460 #define SSL_R_TLSV1_ALERT_PROTOCOL_VERSION 1070
   4461 #define SSL_R_TLSV1_ALERT_INSUFFICIENT_SECURITY 1071
   4462 #define SSL_R_TLSV1_ALERT_INTERNAL_ERROR 1080
   4463 #define SSL_R_TLSV1_ALERT_INAPPROPRIATE_FALLBACK 1086
   4464 #define SSL_R_TLSV1_ALERT_USER_CANCELLED 1090
   4465 #define SSL_R_TLSV1_ALERT_NO_RENEGOTIATION 1100
   4466 #define SSL_R_TLSV1_UNSUPPORTED_EXTENSION 1110
   4467 #define SSL_R_TLSV1_CERTIFICATE_UNOBTAINABLE 1111
   4468 #define SSL_R_TLSV1_UNRECOGNIZED_NAME 1112
   4469 #define SSL_R_TLSV1_BAD_CERTIFICATE_STATUS_RESPONSE 1113
   4470 #define SSL_R_TLSV1_BAD_CERTIFICATE_HASH_VALUE 1114
   4471 
   4472 #endif /* OPENSSL_HEADER_SSL_H */
   4473