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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 /* Forward-declare struct timeval. On Windows, it is defined in winsock2.h and
    162  * Windows headers define too many macros to be included in public headers.
    163  * However, only a forward declaration is needed. */
    164 struct timeval;
    165 
    166 #if defined(__cplusplus)
    167 extern "C" {
    168 #endif
    169 
    170 
    171 /* SSL implementation. */
    172 
    173 
    174 /* SSL contexts.
    175  *
    176  * |SSL_CTX| objects manage shared state and configuration between multiple TLS
    177  * or DTLS connections. Whether the connections are TLS or DTLS is selected by
    178  * an |SSL_METHOD| on creation.
    179  *
    180  * |SSL_CTX| are reference-counted and may be shared by connections across
    181  * multiple threads. Once shared, functions which change the |SSL_CTX|'s
    182  * configuration may not be used. */
    183 
    184 /* TLS_method is the |SSL_METHOD| used for TLS (and SSLv3) connections. */
    185 OPENSSL_EXPORT const SSL_METHOD *TLS_method(void);
    186 
    187 /* DTLS_method is the |SSL_METHOD| used for DTLS connections. */
    188 OPENSSL_EXPORT const SSL_METHOD *DTLS_method(void);
    189 
    190 /* TLS_with_buffers_method is like |TLS_method|, but avoids all use of
    191  * crypto/x509. */
    192 OPENSSL_EXPORT const SSL_METHOD *TLS_with_buffers_method(void);
    193 
    194 /* SSL_CTX_new returns a newly-allocated |SSL_CTX| with default settings or NULL
    195  * on error. */
    196 OPENSSL_EXPORT SSL_CTX *SSL_CTX_new(const SSL_METHOD *method);
    197 
    198 /* SSL_CTX_up_ref increments the reference count of |ctx|. It returns one. */
    199 OPENSSL_EXPORT int SSL_CTX_up_ref(SSL_CTX *ctx);
    200 
    201 /* SSL_CTX_free releases memory associated with |ctx|. */
    202 OPENSSL_EXPORT void SSL_CTX_free(SSL_CTX *ctx);
    203 
    204 
    205 /* SSL connections.
    206  *
    207  * An |SSL| object represents a single TLS or DTLS connection. Although the
    208  * shared |SSL_CTX| is thread-safe, an |SSL| is not thread-safe and may only be
    209  * used on one thread at a time. */
    210 
    211 /* SSL_new returns a newly-allocated |SSL| using |ctx| or NULL on error. The new
    212  * connection inherits settings from |ctx| at the time of creation. Settings may
    213  * also be individually configured on the connection.
    214  *
    215  * On creation, an |SSL| is not configured to be either a client or server. Call
    216  * |SSL_set_connect_state| or |SSL_set_accept_state| to set this. */
    217 OPENSSL_EXPORT SSL *SSL_new(SSL_CTX *ctx);
    218 
    219 /* SSL_free releases memory associated with |ssl|. */
    220 OPENSSL_EXPORT void SSL_free(SSL *ssl);
    221 
    222 /* SSL_get_SSL_CTX returns the |SSL_CTX| associated with |ssl|. If
    223  * |SSL_set_SSL_CTX| is called, it returns the new |SSL_CTX|, not the initial
    224  * one. */
    225 OPENSSL_EXPORT SSL_CTX *SSL_get_SSL_CTX(const SSL *ssl);
    226 
    227 /* SSL_set_connect_state configures |ssl| to be a client. */
    228 OPENSSL_EXPORT void SSL_set_connect_state(SSL *ssl);
    229 
    230 /* SSL_set_accept_state configures |ssl| to be a server. */
    231 OPENSSL_EXPORT void SSL_set_accept_state(SSL *ssl);
    232 
    233 /* SSL_is_server returns one if |ssl| is configured as a server and zero
    234  * otherwise. */
    235 OPENSSL_EXPORT int SSL_is_server(const SSL *ssl);
    236 
    237 /* SSL_is_dtls returns one if |ssl| is a DTLS connection and zero otherwise. */
    238 OPENSSL_EXPORT int SSL_is_dtls(const SSL *ssl);
    239 
    240 /* SSL_set_bio configures |ssl| to read from |rbio| and write to |wbio|. |ssl|
    241  * takes ownership of the two |BIO|s. If |rbio| and |wbio| are the same, |ssl|
    242  * only takes ownership of one reference.
    243  *
    244  * In DTLS, |rbio| must be non-blocking to properly handle timeouts and
    245  * retransmits.
    246  *
    247  * If |rbio| is the same as the currently configured |BIO| for reading, that
    248  * side is left untouched and is not freed.
    249  *
    250  * If |wbio| is the same as the currently configured |BIO| for writing AND |ssl|
    251  * is not currently configured to read from and write to the same |BIO|, that
    252  * side is left untouched and is not freed. This asymmetry is present for
    253  * historical reasons.
    254  *
    255  * Due to the very complex historical behavior of this function, calling this
    256  * function if |ssl| already has |BIO|s configured is deprecated. Prefer
    257  * |SSL_set0_rbio| and |SSL_set0_wbio| instead. */
    258 OPENSSL_EXPORT void SSL_set_bio(SSL *ssl, BIO *rbio, BIO *wbio);
    259 
    260 /* SSL_set0_rbio configures |ssl| to write to |rbio|. It takes ownership of
    261  * |rbio|.
    262  *
    263  * Note that, although this function and |SSL_set0_wbio| may be called on the
    264  * same |BIO|, each call takes a reference. Use |BIO_up_ref| to balance this. */
    265 OPENSSL_EXPORT void SSL_set0_rbio(SSL *ssl, BIO *rbio);
    266 
    267 /* SSL_set0_wbio configures |ssl| to write to |wbio|. It takes ownership of
    268  * |wbio|.
    269  *
    270  * Note that, although this function and |SSL_set0_rbio| may be called on the
    271  * same |BIO|, each call takes a reference. Use |BIO_up_ref| to balance this. */
    272 OPENSSL_EXPORT void SSL_set0_wbio(SSL *ssl, BIO *wbio);
    273 
    274 /* SSL_get_rbio returns the |BIO| that |ssl| reads from. */
    275 OPENSSL_EXPORT BIO *SSL_get_rbio(const SSL *ssl);
    276 
    277 /* SSL_get_wbio returns the |BIO| that |ssl| writes to. */
    278 OPENSSL_EXPORT BIO *SSL_get_wbio(const SSL *ssl);
    279 
    280 /* SSL_get_fd calls |SSL_get_rfd|. */
    281 OPENSSL_EXPORT int SSL_get_fd(const SSL *ssl);
    282 
    283 /* SSL_get_rfd returns the file descriptor that |ssl| is configured to read
    284  * from. If |ssl|'s read |BIO| is not configured or doesn't wrap a file
    285  * descriptor then it returns -1.
    286  *
    287  * Note: On Windows, this may return either a file descriptor or a socket (cast
    288  * to int), depending on whether |ssl| was configured with a file descriptor or
    289  * socket |BIO|. */
    290 OPENSSL_EXPORT int SSL_get_rfd(const SSL *ssl);
    291 
    292 /* SSL_get_wfd returns the file descriptor that |ssl| is configured to write
    293  * to. If |ssl|'s write |BIO| is not configured or doesn't wrap a file
    294  * descriptor then it returns -1.
    295  *
    296  * Note: On Windows, this may return either a file descriptor or a socket (cast
    297  * to int), depending on whether |ssl| was configured with a file descriptor or
    298  * socket |BIO|. */
    299 OPENSSL_EXPORT int SSL_get_wfd(const SSL *ssl);
    300 
    301 /* SSL_set_fd configures |ssl| to read from and write to |fd|. It returns one
    302  * on success and zero on allocation error. The caller retains ownership of
    303  * |fd|.
    304  *
    305  * On Windows, |fd| is cast to a |SOCKET| and used with Winsock APIs. */
    306 OPENSSL_EXPORT int SSL_set_fd(SSL *ssl, int fd);
    307 
    308 /* SSL_set_rfd configures |ssl| to read from |fd|. It returns one on success and
    309  * zero on allocation error. The caller retains ownership of |fd|.
    310  *
    311  * On Windows, |fd| is cast to a |SOCKET| and used with Winsock APIs. */
    312 OPENSSL_EXPORT int SSL_set_rfd(SSL *ssl, int fd);
    313 
    314 /* SSL_set_wfd configures |ssl| to write to |fd|. It returns one on success and
    315  * zero on allocation error. The caller retains ownership of |fd|.
    316  *
    317  * On Windows, |fd| is cast to a |SOCKET| and used with Winsock APIs. */
    318 OPENSSL_EXPORT int SSL_set_wfd(SSL *ssl, int fd);
    319 
    320 /* SSL_do_handshake continues the current handshake. If there is none or the
    321  * handshake has completed or False Started, it returns one. Otherwise, it
    322  * returns <= 0. The caller should pass the value into |SSL_get_error| to
    323  * determine how to proceed.
    324  *
    325  * In DTLS, the caller must drive retransmissions. Whenever |SSL_get_error|
    326  * signals |SSL_ERROR_WANT_READ|, use |DTLSv1_get_timeout| to determine the
    327  * current timeout. If it expires before the next retry, call
    328  * |DTLSv1_handle_timeout|. Note that DTLS handshake retransmissions use fresh
    329  * sequence numbers, so it is not sufficient to replay packets at the transport.
    330  *
    331  * TODO(davidben): Ensure 0 is only returned on transport EOF.
    332  * https://crbug.com/466303. */
    333 OPENSSL_EXPORT int SSL_do_handshake(SSL *ssl);
    334 
    335 /* SSL_connect configures |ssl| as a client, if unconfigured, and calls
    336  * |SSL_do_handshake|. */
    337 OPENSSL_EXPORT int SSL_connect(SSL *ssl);
    338 
    339 /* SSL_accept configures |ssl| as a server, if unconfigured, and calls
    340  * |SSL_do_handshake|. */
    341 OPENSSL_EXPORT int SSL_accept(SSL *ssl);
    342 
    343 /* SSL_read reads up to |num| bytes from |ssl| into |buf|. It implicitly runs
    344  * any pending handshakes, including renegotiations when enabled. On success, it
    345  * returns the number of bytes read. Otherwise, it returns <= 0. The caller
    346  * should pass the value into |SSL_get_error| to determine how to proceed.
    347  *
    348  * TODO(davidben): Ensure 0 is only returned on transport EOF.
    349  * https://crbug.com/466303. */
    350 OPENSSL_EXPORT int SSL_read(SSL *ssl, void *buf, int num);
    351 
    352 /* SSL_peek behaves like |SSL_read| but does not consume any bytes returned. */
    353 OPENSSL_EXPORT int SSL_peek(SSL *ssl, void *buf, int num);
    354 
    355 /* SSL_pending returns the number of bytes available in |ssl|. It does not read
    356  * from the transport. */
    357 OPENSSL_EXPORT int SSL_pending(const SSL *ssl);
    358 
    359 /* SSL_write writes up to |num| bytes from |buf| into |ssl|. It implicitly runs
    360  * any pending handshakes, including renegotiations when enabled. On success, it
    361  * returns the number of bytes written. Otherwise, it returns <= 0. The caller
    362  * should pass the value into |SSL_get_error| to determine how to proceed.
    363  *
    364  * In TLS, a non-blocking |SSL_write| differs from non-blocking |write| in that
    365  * a failed |SSL_write| still commits to the data passed in. When retrying, the
    366  * caller must supply the original write buffer (or a larger one containing the
    367  * original as a prefix). By default, retries will fail if they also do not
    368  * reuse the same |buf| pointer. This may be relaxed with
    369  * |SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER|, but the buffer contents still must be
    370  * unchanged.
    371  *
    372  * By default, in TLS, |SSL_write| will not return success until all |num| bytes
    373  * are written. This may be relaxed with |SSL_MODE_ENABLE_PARTIAL_WRITE|. It
    374  * allows |SSL_write| to complete with a partial result when only part of the
    375  * input was written in a single record.
    376  *
    377  * In DTLS, neither |SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER| and
    378  * |SSL_MODE_ENABLE_PARTIAL_WRITE| do anything. The caller may retry with a
    379  * different buffer freely. A single call to |SSL_write| only ever writes a
    380  * single record in a single packet, so |num| must be at most
    381  * |SSL3_RT_MAX_PLAIN_LENGTH|.
    382  *
    383  * TODO(davidben): Ensure 0 is only returned on transport EOF.
    384  * https://crbug.com/466303. */
    385 OPENSSL_EXPORT int SSL_write(SSL *ssl, const void *buf, int num);
    386 
    387 /* SSL_shutdown shuts down |ssl|. On success, it completes in two stages. First,
    388  * it returns 0 if |ssl| completed uni-directional shutdown; close_notify has
    389  * been sent, but the peer's close_notify has not been received. Most callers
    390  * may stop at this point. For bi-directional shutdown, call |SSL_shutdown|
    391  * again. It returns 1 if close_notify has been both sent and received.
    392  *
    393  * If the peer's close_notify arrived first, the first stage is skipped.
    394  * |SSL_shutdown| will return 1 once close_notify is sent and skip 0. Callers
    395  * only interested in uni-directional shutdown must therefore allow for the
    396  * first stage returning either 0 or 1.
    397  *
    398  * |SSL_shutdown| returns -1 on failure. The caller should pass the return value
    399  * into |SSL_get_error| to determine how to proceed. If the underlying |BIO| is
    400  * non-blocking, both stages may require retry. */
    401 OPENSSL_EXPORT int SSL_shutdown(SSL *ssl);
    402 
    403 /* SSL_CTX_set_quiet_shutdown sets quiet shutdown on |ctx| to |mode|. If
    404  * enabled, |SSL_shutdown| will not send a close_notify alert or wait for one
    405  * from the peer. It will instead synchronously return one. */
    406 OPENSSL_EXPORT void SSL_CTX_set_quiet_shutdown(SSL_CTX *ctx, int mode);
    407 
    408 /* SSL_CTX_get_quiet_shutdown returns whether quiet shutdown is enabled for
    409  * |ctx|. */
    410 OPENSSL_EXPORT int SSL_CTX_get_quiet_shutdown(const SSL_CTX *ctx);
    411 
    412 /* SSL_set_quiet_shutdown sets quiet shutdown on |ssl| to |mode|. If enabled,
    413  * |SSL_shutdown| will not send a close_notify alert or wait for one from the
    414  * peer. It will instead synchronously return one. */
    415 OPENSSL_EXPORT void SSL_set_quiet_shutdown(SSL *ssl, int mode);
    416 
    417 /* SSL_get_quiet_shutdown returns whether quiet shutdown is enabled for
    418  * |ssl|. */
    419 OPENSSL_EXPORT int SSL_get_quiet_shutdown(const SSL *ssl);
    420 
    421 /* SSL_get_error returns a |SSL_ERROR_*| value for the most recent operation on
    422  * |ssl|. It should be called after an operation failed to determine whether the
    423  * error was fatal and, if not, when to retry. */
    424 OPENSSL_EXPORT int SSL_get_error(const SSL *ssl, int ret_code);
    425 
    426 /* SSL_ERROR_NONE indicates the operation succeeded. */
    427 #define SSL_ERROR_NONE 0
    428 
    429 /* SSL_ERROR_SSL indicates the operation failed within the library. The caller
    430  * may inspect the error queue for more information. */
    431 #define SSL_ERROR_SSL 1
    432 
    433 /* SSL_ERROR_WANT_READ indicates the operation failed attempting to read from
    434  * the transport. The caller may retry the operation when the transport is ready
    435  * for reading.
    436  *
    437  * If signaled by a DTLS handshake, the caller must also call
    438  * |DTLSv1_get_timeout| and |DTLSv1_handle_timeout| as appropriate. See
    439  * |SSL_do_handshake|. */
    440 #define SSL_ERROR_WANT_READ 2
    441 
    442 /* SSL_ERROR_WANT_WRITE indicates the operation failed attempting to write to
    443  * the transport. The caller may retry the operation when the transport is ready
    444  * for writing. */
    445 #define SSL_ERROR_WANT_WRITE 3
    446 
    447 /* SSL_ERROR_WANT_X509_LOOKUP indicates the operation failed in calling the
    448  * |cert_cb| or |client_cert_cb|. The caller may retry the operation when the
    449  * callback is ready to return a certificate or one has been configured
    450  * externally.
    451  *
    452  * See also |SSL_CTX_set_cert_cb| and |SSL_CTX_set_client_cert_cb|. */
    453 #define SSL_ERROR_WANT_X509_LOOKUP 4
    454 
    455 /* SSL_ERROR_SYSCALL indicates the operation failed externally to the library.
    456  * The caller should consult the system-specific error mechanism. This is
    457  * typically |errno| but may be something custom if using a custom |BIO|. It
    458  * may also be signaled if the transport returned EOF, in which case the
    459  * operation's return value will be zero. */
    460 #define SSL_ERROR_SYSCALL 5
    461 
    462 /* SSL_ERROR_ZERO_RETURN indicates the operation failed because the connection
    463  * was cleanly shut down with a close_notify alert. */
    464 #define SSL_ERROR_ZERO_RETURN 6
    465 
    466 /* SSL_ERROR_WANT_CONNECT indicates the operation failed attempting to connect
    467  * the transport (the |BIO| signaled |BIO_RR_CONNECT|). The caller may retry the
    468  * operation when the transport is ready. */
    469 #define SSL_ERROR_WANT_CONNECT 7
    470 
    471 /* SSL_ERROR_WANT_ACCEPT indicates the operation failed attempting to accept a
    472  * connection from the transport (the |BIO| signaled |BIO_RR_ACCEPT|). The
    473  * caller may retry the operation when the transport is ready.
    474  *
    475  * TODO(davidben): Remove this. It's used by accept BIOs which are bizarre. */
    476 #define SSL_ERROR_WANT_ACCEPT 8
    477 
    478 /* SSL_ERROR_WANT_CHANNEL_ID_LOOKUP indicates the operation failed looking up
    479  * the Channel ID key. The caller may retry the operation when |channel_id_cb|
    480  * is ready to return a key or one has been configured with
    481  * |SSL_set1_tls_channel_id|.
    482  *
    483  * See also |SSL_CTX_set_channel_id_cb|. */
    484 #define SSL_ERROR_WANT_CHANNEL_ID_LOOKUP 9
    485 
    486 /* SSL_ERROR_PENDING_SESSION indicates the operation failed because the session
    487  * lookup callback indicated the session was unavailable. The caller may retry
    488  * the operation when lookup has completed.
    489  *
    490  * See also |SSL_CTX_sess_set_get_cb| and |SSL_magic_pending_session_ptr|. */
    491 #define SSL_ERROR_PENDING_SESSION 11
    492 
    493 /* SSL_ERROR_PENDING_CERTIFICATE indicates the operation failed because the
    494  * early callback indicated certificate lookup was incomplete. The caller may
    495  * retry the operation when lookup has completed. Note: when the operation is
    496  * retried, the early callback will not be called a second time.
    497  *
    498  * See also |SSL_CTX_set_select_certificate_cb|. */
    499 #define SSL_ERROR_PENDING_CERTIFICATE 12
    500 
    501 /* SSL_ERROR_WANT_PRIVATE_KEY_OPERATION indicates the operation failed because
    502  * a private key operation was unfinished. The caller may retry the operation
    503  * when the private key operation is complete.
    504  *
    505  * See also |SSL_set_private_key_method| and
    506  * |SSL_CTX_set_private_key_method|. */
    507 #define SSL_ERROR_WANT_PRIVATE_KEY_OPERATION 13
    508 
    509 /* SSL_ERROR_PENDING_TICKET indicates that a ticket decryption is pending. The
    510  * caller may retry the operation when the decryption is ready.
    511  *
    512  * See also |SSL_CTX_set_ticket_aead_method|. */
    513 #define SSL_ERROR_PENDING_TICKET 14
    514 
    515 /* SSL_set_mtu sets the |ssl|'s MTU in DTLS to |mtu|. It returns one on success
    516  * and zero on failure. */
    517 OPENSSL_EXPORT int SSL_set_mtu(SSL *ssl, unsigned mtu);
    518 
    519 /* DTLSv1_set_initial_timeout_duration sets the initial duration for a DTLS
    520  * handshake timeout.
    521  *
    522  * This duration overrides the default of 1 second, which is the strong
    523  * recommendation of RFC 6347 (see section 4.2.4.1). However, there may exist
    524  * situations where a shorter timeout would be beneficial, such as for
    525  * time-sensitive applications. */
    526 OPENSSL_EXPORT void DTLSv1_set_initial_timeout_duration(SSL *ssl,
    527                                                         unsigned duration_ms);
    528 
    529 /* DTLSv1_get_timeout queries the next DTLS handshake timeout. If there is a
    530  * timeout in progress, it sets |*out| to the time remaining and returns one.
    531  * Otherwise, it returns zero.
    532  *
    533  * When the timeout expires, call |DTLSv1_handle_timeout| to handle the
    534  * retransmit behavior.
    535  *
    536  * NOTE: This function must be queried again whenever the handshake state
    537  * machine changes, including when |DTLSv1_handle_timeout| is called. */
    538 OPENSSL_EXPORT int DTLSv1_get_timeout(const SSL *ssl, struct timeval *out);
    539 
    540 /* DTLSv1_handle_timeout is called when a DTLS handshake timeout expires. If no
    541  * timeout had expired, it returns 0. Otherwise, it retransmits the previous
    542  * flight of handshake messages and returns 1. If too many timeouts had expired
    543  * without progress or an error occurs, it returns -1.
    544  *
    545  * The caller's external timer should be compatible with the one |ssl| queries
    546  * within some fudge factor. Otherwise, the call will be a no-op, but
    547  * |DTLSv1_get_timeout| will return an updated timeout.
    548  *
    549  * If the function returns -1, checking if |SSL_get_error| returns
    550  * |SSL_ERROR_WANT_WRITE| may be used to determine if the retransmit failed due
    551  * to a non-fatal error at the write |BIO|. However, the operation may not be
    552  * retried until the next timeout fires.
    553  *
    554  * WARNING: This function breaks the usual return value convention.
    555  *
    556  * TODO(davidben): This |SSL_ERROR_WANT_WRITE| behavior is kind of bizarre. */
    557 OPENSSL_EXPORT int DTLSv1_handle_timeout(SSL *ssl);
    558 
    559 
    560 /* Protocol versions. */
    561 
    562 #define DTLS1_VERSION_MAJOR 0xfe
    563 #define SSL3_VERSION_MAJOR 0x03
    564 
    565 #define SSL3_VERSION 0x0300
    566 #define TLS1_VERSION 0x0301
    567 #define TLS1_1_VERSION 0x0302
    568 #define TLS1_2_VERSION 0x0303
    569 #define TLS1_3_VERSION 0x0304
    570 
    571 #define DTLS1_VERSION 0xfeff
    572 #define DTLS1_2_VERSION 0xfefd
    573 
    574 #define TLS1_3_DRAFT_VERSION 0x7f12
    575 
    576 /* SSL_CTX_set_min_proto_version sets the minimum protocol version for |ctx| to
    577  * |version|. If |version| is zero, the default minimum version is used. It
    578  * returns one on success and zero if |version| is invalid. */
    579 OPENSSL_EXPORT int SSL_CTX_set_min_proto_version(SSL_CTX *ctx,
    580                                                  uint16_t version);
    581 
    582 /* SSL_CTX_set_max_proto_version sets the maximum protocol version for |ctx| to
    583  * |version|. If |version| is zero, the default maximum version is used. It
    584  * returns one on success and zero if |version| is invalid. */
    585 OPENSSL_EXPORT int SSL_CTX_set_max_proto_version(SSL_CTX *ctx,
    586                                                  uint16_t version);
    587 
    588 /* SSL_set_min_proto_version sets the minimum protocol version for |ssl| to
    589  * |version|. If |version| is zero, the default minimum version is used. It
    590  * returns one on success and zero if |version| is invalid. */
    591 OPENSSL_EXPORT int SSL_set_min_proto_version(SSL *ssl, uint16_t version);
    592 
    593 /* SSL_set_max_proto_version sets the maximum protocol version for |ssl| to
    594  * |version|. If |version| is zero, the default maximum version is used. It
    595  * returns one on success and zero if |version| is invalid. */
    596 OPENSSL_EXPORT int SSL_set_max_proto_version(SSL *ssl, uint16_t version);
    597 
    598 /* SSL_version returns the TLS or DTLS protocol version used by |ssl|, which is
    599  * one of the |*_VERSION| values. (E.g. |TLS1_2_VERSION|.) Before the version
    600  * is negotiated, the result is undefined. */
    601 OPENSSL_EXPORT int SSL_version(const SSL *ssl);
    602 
    603 
    604 /* Options.
    605  *
    606  * Options configure protocol behavior. */
    607 
    608 /* SSL_OP_NO_QUERY_MTU, in DTLS, disables querying the MTU from the underlying
    609  * |BIO|. Instead, the MTU is configured with |SSL_set_mtu|. */
    610 #define SSL_OP_NO_QUERY_MTU 0x00001000L
    611 
    612 /* SSL_OP_NO_TICKET disables session ticket support (RFC 5077). */
    613 #define SSL_OP_NO_TICKET 0x00004000L
    614 
    615 /* SSL_OP_CIPHER_SERVER_PREFERENCE configures servers to select ciphers and
    616  * ECDHE curves according to the server's preferences instead of the
    617  * client's. */
    618 #define SSL_OP_CIPHER_SERVER_PREFERENCE 0x00400000L
    619 
    620 /* The following flags toggle individual protocol versions. This is deprecated.
    621  * Use |SSL_CTX_set_min_proto_version| and |SSL_CTX_set_max_proto_version|
    622  * instead. */
    623 #define SSL_OP_NO_SSLv3 0x02000000L
    624 #define SSL_OP_NO_TLSv1 0x04000000L
    625 #define SSL_OP_NO_TLSv1_2 0x08000000L
    626 #define SSL_OP_NO_TLSv1_1 0x10000000L
    627 #define SSL_OP_NO_TLSv1_3 0x20000000L
    628 #define SSL_OP_NO_DTLSv1 SSL_OP_NO_TLSv1
    629 #define SSL_OP_NO_DTLSv1_2 SSL_OP_NO_TLSv1_2
    630 
    631 /* SSL_CTX_set_options enables all options set in |options| (which should be one
    632  * or more of the |SSL_OP_*| values, ORed together) in |ctx|. It returns a
    633  * bitmask representing the resulting enabled options. */
    634 OPENSSL_EXPORT uint32_t SSL_CTX_set_options(SSL_CTX *ctx, uint32_t options);
    635 
    636 /* SSL_CTX_clear_options disables all options set in |options| (which should be
    637  * one or more of the |SSL_OP_*| values, ORed together) in |ctx|. It returns a
    638  * bitmask representing the resulting enabled options. */
    639 OPENSSL_EXPORT uint32_t SSL_CTX_clear_options(SSL_CTX *ctx, uint32_t options);
    640 
    641 /* SSL_CTX_get_options returns a bitmask of |SSL_OP_*| values that represent all
    642  * the options enabled for |ctx|. */
    643 OPENSSL_EXPORT uint32_t SSL_CTX_get_options(const SSL_CTX *ctx);
    644 
    645 /* SSL_set_options enables all options set in |options| (which should be one or
    646  * more of the |SSL_OP_*| values, ORed together) in |ssl|. It returns a bitmask
    647  * representing the resulting enabled options. */
    648 OPENSSL_EXPORT uint32_t SSL_set_options(SSL *ssl, uint32_t options);
    649 
    650 /* SSL_clear_options disables all options set in |options| (which should be one
    651  * or more of the |SSL_OP_*| values, ORed together) in |ssl|. It returns a
    652  * bitmask representing the resulting enabled options. */
    653 OPENSSL_EXPORT uint32_t SSL_clear_options(SSL *ssl, uint32_t options);
    654 
    655 /* SSL_get_options returns a bitmask of |SSL_OP_*| values that represent all the
    656  * options enabled for |ssl|. */
    657 OPENSSL_EXPORT uint32_t SSL_get_options(const SSL *ssl);
    658 
    659 
    660 /* Modes.
    661  *
    662  * Modes configure API behavior. */
    663 
    664 /* SSL_MODE_ENABLE_PARTIAL_WRITE, in TLS, allows |SSL_write| to complete with a
    665  * partial result when the only part of the input was written in a single
    666  * record. In DTLS, it does nothing. */
    667 #define SSL_MODE_ENABLE_PARTIAL_WRITE 0x00000001L
    668 
    669 /* SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER, in TLS, allows retrying an incomplete
    670  * |SSL_write| with a different buffer. However, |SSL_write| still assumes the
    671  * buffer contents are unchanged. This is not the default to avoid the
    672  * misconception that non-blocking |SSL_write| behaves like non-blocking
    673  * |write|. In DTLS, it does nothing. */
    674 #define SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER 0x00000002L
    675 
    676 /* SSL_MODE_NO_AUTO_CHAIN disables automatically building a certificate chain
    677  * before sending certificates to the peer. This flag is set (and the feature
    678  * disabled) by default.
    679  * TODO(davidben): Remove this behavior. https://crbug.com/boringssl/42. */
    680 #define SSL_MODE_NO_AUTO_CHAIN 0x00000008L
    681 
    682 /* SSL_MODE_ENABLE_FALSE_START allows clients to send application data before
    683  * receipt of ChangeCipherSpec and Finished. This mode enables full handshakes
    684  * to 'complete' in one RTT. See RFC 7918.
    685  *
    686  * When False Start is enabled, |SSL_do_handshake| may succeed before the
    687  * handshake has completely finished. |SSL_write| will function at this point,
    688  * and |SSL_read| will transparently wait for the final handshake leg before
    689  * returning application data. To determine if False Start occurred or when the
    690  * handshake is completely finished, see |SSL_in_false_start|, |SSL_in_init|,
    691  * and |SSL_CB_HANDSHAKE_DONE| from |SSL_CTX_set_info_callback|. */
    692 #define SSL_MODE_ENABLE_FALSE_START 0x00000080L
    693 
    694 /* SSL_MODE_CBC_RECORD_SPLITTING causes multi-byte CBC records in SSL 3.0 and
    695  * TLS 1.0 to be split in two: the first record will contain a single byte and
    696  * the second will contain the remainder. This effectively randomises the IV and
    697  * prevents BEAST attacks. */
    698 #define SSL_MODE_CBC_RECORD_SPLITTING 0x00000100L
    699 
    700 /* SSL_MODE_NO_SESSION_CREATION will cause any attempts to create a session to
    701  * fail with SSL_R_SESSION_MAY_NOT_BE_CREATED. This can be used to enforce that
    702  * session resumption is used for a given SSL*. */
    703 #define SSL_MODE_NO_SESSION_CREATION 0x00000200L
    704 
    705 /* SSL_MODE_SEND_FALLBACK_SCSV sends TLS_FALLBACK_SCSV in the ClientHello.
    706  * To be set only by applications that reconnect with a downgraded protocol
    707  * version; see RFC 7507 for details.
    708  *
    709  * DO NOT ENABLE THIS if your application attempts a normal handshake. Only use
    710  * this in explicit fallback retries, following the guidance in RFC 7507. */
    711 #define SSL_MODE_SEND_FALLBACK_SCSV 0x00000400L
    712 
    713 /* SSL_CTX_set_mode enables all modes set in |mode| (which should be one or more
    714  * of the |SSL_MODE_*| values, ORed together) in |ctx|. It returns a bitmask
    715  * representing the resulting enabled modes. */
    716 OPENSSL_EXPORT uint32_t SSL_CTX_set_mode(SSL_CTX *ctx, uint32_t mode);
    717 
    718 /* SSL_CTX_clear_mode disables all modes set in |mode| (which should be one or
    719  * more of the |SSL_MODE_*| values, ORed together) in |ctx|. It returns a
    720  * bitmask representing the resulting enabled modes. */
    721 OPENSSL_EXPORT uint32_t SSL_CTX_clear_mode(SSL_CTX *ctx, uint32_t mode);
    722 
    723 /* SSL_CTX_get_mode returns a bitmask of |SSL_MODE_*| values that represent all
    724  * the modes enabled for |ssl|. */
    725 OPENSSL_EXPORT uint32_t SSL_CTX_get_mode(const SSL_CTX *ctx);
    726 
    727 /* SSL_set_mode enables all modes set in |mode| (which should be one or more of
    728  * the |SSL_MODE_*| values, ORed together) in |ssl|. It returns a bitmask
    729  * representing the resulting enabled modes. */
    730 OPENSSL_EXPORT uint32_t SSL_set_mode(SSL *ssl, uint32_t mode);
    731 
    732 /* SSL_clear_mode disables all modes set in |mode| (which should be one or more
    733  * of the |SSL_MODE_*| values, ORed together) in |ssl|. It returns a bitmask
    734  * representing the resulting enabled modes. */
    735 OPENSSL_EXPORT uint32_t SSL_clear_mode(SSL *ssl, uint32_t mode);
    736 
    737 /* SSL_get_mode returns a bitmask of |SSL_MODE_*| values that represent all the
    738  * modes enabled for |ssl|. */
    739 OPENSSL_EXPORT uint32_t SSL_get_mode(const SSL *ssl);
    740 
    741 /* SSL_CTX_set0_buffer_pool sets a |CRYPTO_BUFFER_POOL| that will be used to
    742  * store certificates. This can allow multiple connections to share
    743  * certificates and thus save memory.
    744  *
    745  * The SSL_CTX does not take ownership of |pool| and the caller must ensure
    746  * that |pool| outlives |ctx| and all objects linked to it, including |SSL|,
    747  * |X509| and |SSL_SESSION| objects. Basically, don't ever free |pool|. */
    748 OPENSSL_EXPORT void SSL_CTX_set0_buffer_pool(SSL_CTX *ctx,
    749                                              CRYPTO_BUFFER_POOL *pool);
    750 
    751 
    752 /* Configuring certificates and private keys.
    753  *
    754  * These functions configure the connection's leaf certificate, private key, and
    755  * certificate chain. The certificate chain is ordered leaf to root (as sent on
    756  * the wire) but does not include the leaf. Both client and server certificates
    757  * use these functions.
    758  *
    759  * Certificates and keys may be configured before the handshake or dynamically
    760  * in the early callback and certificate callback. */
    761 
    762 /* SSL_CTX_use_certificate sets |ctx|'s leaf certificate to |x509|. It returns
    763  * one on success and zero on failure. */
    764 OPENSSL_EXPORT int SSL_CTX_use_certificate(SSL_CTX *ctx, X509 *x509);
    765 
    766 /* SSL_use_certificate sets |ssl|'s leaf certificate to |x509|. It returns one
    767  * on success and zero on failure. */
    768 OPENSSL_EXPORT int SSL_use_certificate(SSL *ssl, X509 *x509);
    769 
    770 /* SSL_CTX_use_PrivateKey sets |ctx|'s private key to |pkey|. It returns one on
    771  * success and zero on failure. */
    772 OPENSSL_EXPORT int SSL_CTX_use_PrivateKey(SSL_CTX *ctx, EVP_PKEY *pkey);
    773 
    774 /* SSL_use_PrivateKey sets |ssl|'s private key to |pkey|. It returns one on
    775  * success and zero on failure. */
    776 OPENSSL_EXPORT int SSL_use_PrivateKey(SSL *ssl, EVP_PKEY *pkey);
    777 
    778 /* SSL_CTX_set0_chain sets |ctx|'s certificate chain, excluding the leaf, to
    779  * |chain|. On success, it returns one and takes ownership of |chain|.
    780  * Otherwise, it returns zero. */
    781 OPENSSL_EXPORT int SSL_CTX_set0_chain(SSL_CTX *ctx, STACK_OF(X509) *chain);
    782 
    783 /* SSL_CTX_set1_chain sets |ctx|'s certificate chain, excluding the leaf, to
    784  * |chain|. It returns one on success and zero on failure. The caller retains
    785  * ownership of |chain| and may release it freely. */
    786 OPENSSL_EXPORT int SSL_CTX_set1_chain(SSL_CTX *ctx, STACK_OF(X509) *chain);
    787 
    788 /* SSL_set0_chain sets |ssl|'s certificate chain, excluding the leaf, to
    789  * |chain|. On success, it returns one and takes ownership of |chain|.
    790  * Otherwise, it returns zero. */
    791 OPENSSL_EXPORT int SSL_set0_chain(SSL *ssl, STACK_OF(X509) *chain);
    792 
    793 /* SSL_set1_chain sets |ssl|'s certificate chain, excluding the leaf, to
    794  * |chain|. It returns one on success and zero on failure. The caller retains
    795  * ownership of |chain| and may release it freely. */
    796 OPENSSL_EXPORT int SSL_set1_chain(SSL *ssl, STACK_OF(X509) *chain);
    797 
    798 /* SSL_CTX_add0_chain_cert appends |x509| to |ctx|'s certificate chain. On
    799  * success, it returns one and takes ownership of |x509|. Otherwise, it returns
    800  * zero. */
    801 OPENSSL_EXPORT int SSL_CTX_add0_chain_cert(SSL_CTX *ctx, X509 *x509);
    802 
    803 /* SSL_CTX_add1_chain_cert appends |x509| to |ctx|'s certificate chain. It
    804  * returns one on success and zero on failure. The caller retains ownership of
    805  * |x509| and may release it freely. */
    806 OPENSSL_EXPORT int SSL_CTX_add1_chain_cert(SSL_CTX *ctx, X509 *x509);
    807 
    808 /* SSL_add0_chain_cert appends |x509| to |ctx|'s certificate chain. On success,
    809  * it returns one and takes ownership of |x509|. Otherwise, it returns zero. */
    810 OPENSSL_EXPORT int SSL_add0_chain_cert(SSL *ssl, X509 *x509);
    811 
    812 /* SSL_CTX_add_extra_chain_cert calls |SSL_CTX_add0_chain_cert|. */
    813 OPENSSL_EXPORT int SSL_CTX_add_extra_chain_cert(SSL_CTX *ctx, X509 *x509);
    814 
    815 /* SSL_add1_chain_cert appends |x509| to |ctx|'s certificate chain. It returns
    816  * one on success and zero on failure. The caller retains ownership of |x509|
    817  * and may release it freely. */
    818 OPENSSL_EXPORT int SSL_add1_chain_cert(SSL *ssl, X509 *x509);
    819 
    820 /* SSL_CTX_clear_chain_certs clears |ctx|'s certificate chain and returns
    821  * one. */
    822 OPENSSL_EXPORT int SSL_CTX_clear_chain_certs(SSL_CTX *ctx);
    823 
    824 /* SSL_CTX_clear_extra_chain_certs calls |SSL_CTX_clear_chain_certs|. */
    825 OPENSSL_EXPORT int SSL_CTX_clear_extra_chain_certs(SSL_CTX *ctx);
    826 
    827 /* SSL_clear_chain_certs clears |ssl|'s certificate chain and returns one. */
    828 OPENSSL_EXPORT int SSL_clear_chain_certs(SSL *ssl);
    829 
    830 /* SSL_CTX_set_cert_cb sets a callback that is called to select a certificate.
    831  * The callback returns one on success, zero on internal error, and a negative
    832  * number on failure or to pause the handshake. If the handshake is paused,
    833  * |SSL_get_error| will return |SSL_ERROR_WANT_X509_LOOKUP|.
    834  *
    835  * On the client, the callback may call |SSL_get0_certificate_types| and
    836  * |SSL_get_client_CA_list| for information on the server's certificate
    837  * request.
    838  *
    839  * On the server, the callback will be called on non-resumption handshakes,
    840  * after extensions have been processed. */
    841 OPENSSL_EXPORT void SSL_CTX_set_cert_cb(SSL_CTX *ctx,
    842                                         int (*cb)(SSL *ssl, void *arg),
    843                                         void *arg);
    844 
    845 /* SSL_set_cert_cb sets a callback that is called to select a certificate. The
    846  * callback returns one on success, zero on internal error, and a negative
    847  * number on failure or to pause the handshake. If the handshake is paused,
    848  * |SSL_get_error| will return |SSL_ERROR_WANT_X509_LOOKUP|.
    849  *
    850  * On the client, the callback may call |SSL_get0_certificate_types| and
    851  * |SSL_get_client_CA_list| for information on the server's certificate
    852  * request. */
    853 OPENSSL_EXPORT void SSL_set_cert_cb(SSL *ssl, int (*cb)(SSL *ssl, void *arg),
    854                                     void *arg);
    855 
    856 /* SSL_get0_certificate_types, for a client, sets |*out_types| to an array
    857  * containing the client certificate types requested by a server. It returns the
    858  * length of the array.
    859  *
    860  * The behavior of this function is undefined except during the callbacks set by
    861  * by |SSL_CTX_set_cert_cb| and |SSL_CTX_set_client_cert_cb| or when the
    862  * handshake is paused because of them. */
    863 OPENSSL_EXPORT size_t SSL_get0_certificate_types(SSL *ssl,
    864                                                  const uint8_t **out_types);
    865 
    866 /* SSL_certs_clear resets the private key, leaf certificate, and certificate
    867  * chain of |ssl|. */
    868 OPENSSL_EXPORT void SSL_certs_clear(SSL *ssl);
    869 
    870 /* SSL_CTX_check_private_key returns one if the certificate and private key
    871  * configured in |ctx| are consistent and zero otherwise. */
    872 OPENSSL_EXPORT int SSL_CTX_check_private_key(const SSL_CTX *ctx);
    873 
    874 /* SSL_check_private_key returns one if the certificate and private key
    875  * configured in |ssl| are consistent and zero otherwise. */
    876 OPENSSL_EXPORT int SSL_check_private_key(const SSL *ssl);
    877 
    878 /* SSL_CTX_get0_certificate returns |ctx|'s leaf certificate. */
    879 OPENSSL_EXPORT X509 *SSL_CTX_get0_certificate(const SSL_CTX *ctx);
    880 
    881 /* SSL_get_certificate returns |ssl|'s leaf certificate. */
    882 OPENSSL_EXPORT X509 *SSL_get_certificate(const SSL *ssl);
    883 
    884 /* SSL_CTX_get0_privatekey returns |ctx|'s private key. */
    885 OPENSSL_EXPORT EVP_PKEY *SSL_CTX_get0_privatekey(const SSL_CTX *ctx);
    886 
    887 /* SSL_get_privatekey returns |ssl|'s private key. */
    888 OPENSSL_EXPORT EVP_PKEY *SSL_get_privatekey(const SSL *ssl);
    889 
    890 /* SSL_CTX_get0_chain_certs sets |*out_chain| to |ctx|'s certificate chain and
    891  * returns one. */
    892 OPENSSL_EXPORT int SSL_CTX_get0_chain_certs(const SSL_CTX *ctx,
    893                                             STACK_OF(X509) **out_chain);
    894 
    895 /* SSL_CTX_get_extra_chain_certs calls |SSL_CTX_get0_chain_certs|. */
    896 OPENSSL_EXPORT int SSL_CTX_get_extra_chain_certs(const SSL_CTX *ctx,
    897                                                  STACK_OF(X509) **out_chain);
    898 
    899 /* SSL_get0_chain_certs sets |*out_chain| to |ssl|'s certificate chain and
    900  * returns one. */
    901 OPENSSL_EXPORT int SSL_get0_chain_certs(const SSL *ssl,
    902                                         STACK_OF(X509) **out_chain);
    903 
    904 /* SSL_CTX_set_signed_cert_timestamp_list sets the list of signed certificate
    905  * timestamps that is sent to clients that request it. The |list| argument must
    906  * contain one or more SCT structures serialised as a SignedCertificateTimestamp
    907  * List (see https://tools.ietf.org/html/rfc6962#section-3.3)  i.e. each SCT
    908  * is prefixed by a big-endian, uint16 length and the concatenation of one or
    909  * more such prefixed SCTs are themselves also prefixed by a uint16 length. It
    910  * returns one on success and zero on error. The caller retains ownership of
    911  * |list|. */
    912 OPENSSL_EXPORT int SSL_CTX_set_signed_cert_timestamp_list(SSL_CTX *ctx,
    913                                                           const uint8_t *list,
    914                                                           size_t list_len);
    915 
    916 /* SSL_set_signed_cert_timestamp_list sets the list of signed certificate
    917  * timestamps that is sent to clients that request is. The same format as the
    918  * one used for |SSL_CTX_set_signed_cert_timestamp_list| applies. The caller
    919  * retains ownership of |list|. */
    920 OPENSSL_EXPORT int SSL_set_signed_cert_timestamp_list(SSL *ctx,
    921                                                       const uint8_t *list,
    922                                                       size_t list_len);
    923 
    924 /* SSL_CTX_set_ocsp_response sets the OCSP response that is sent to clients
    925  * which request it. It returns one on success and zero on error. The caller
    926  * retains ownership of |response|. */
    927 OPENSSL_EXPORT int SSL_CTX_set_ocsp_response(SSL_CTX *ctx,
    928                                              const uint8_t *response,
    929                                              size_t response_len);
    930 
    931 /* SSL_set_ocsp_response sets the OCSP response that is sent to clients which
    932  * request it. It returns one on success and zero on error. The caller retains
    933  * ownership of |response|. */
    934 OPENSSL_EXPORT int SSL_set_ocsp_response(SSL *ssl,
    935                                          const uint8_t *response,
    936                                          size_t response_len);
    937 
    938 /* SSL_SIGN_* are signature algorithm values as defined in TLS 1.3. */
    939 #define SSL_SIGN_RSA_PKCS1_SHA1 0x0201
    940 #define SSL_SIGN_RSA_PKCS1_SHA256 0x0401
    941 #define SSL_SIGN_RSA_PKCS1_SHA384 0x0501
    942 #define SSL_SIGN_RSA_PKCS1_SHA512 0x0601
    943 #define SSL_SIGN_ECDSA_SHA1 0x0203
    944 #define SSL_SIGN_ECDSA_SECP256R1_SHA256 0x0403
    945 #define SSL_SIGN_ECDSA_SECP384R1_SHA384 0x0503
    946 #define SSL_SIGN_ECDSA_SECP521R1_SHA512 0x0603
    947 #define SSL_SIGN_RSA_PSS_SHA256 0x0804
    948 #define SSL_SIGN_RSA_PSS_SHA384 0x0805
    949 #define SSL_SIGN_RSA_PSS_SHA512 0x0806
    950 
    951 /* SSL_SIGN_RSA_PKCS1_MD5_SHA1 is an internal signature algorithm used to
    952  * specify raw RSASSA-PKCS1-v1_5 with an MD5/SHA-1 concatenation, as used in TLS
    953  * before TLS 1.2. */
    954 #define SSL_SIGN_RSA_PKCS1_MD5_SHA1 0xff01
    955 
    956 /* SSL_CTX_set_signing_algorithm_prefs configures |ctx| to use |prefs| as the
    957  * preference list when signing with |ctx|'s private key. It returns one on
    958  * success and zero on error. |prefs| should not include the internal-only value
    959  * |SSL_SIGN_RSA_PKCS1_MD5_SHA1|. */
    960 OPENSSL_EXPORT int SSL_CTX_set_signing_algorithm_prefs(SSL_CTX *ctx,
    961                                                        const uint16_t *prefs,
    962                                                        size_t num_prefs);
    963 
    964 /* SSL_set_signing_algorithm_prefs configures |ssl| to use |prefs| as the
    965  * preference list when signing with |ssl|'s private key. It returns one on
    966  * success and zero on error. |prefs| should not include the internal-only value
    967  * |SSL_SIGN_RSA_PKCS1_MD5_SHA1|. */
    968 OPENSSL_EXPORT int SSL_set_signing_algorithm_prefs(SSL *ssl,
    969                                                    const uint16_t *prefs,
    970                                                    size_t num_prefs);
    971 
    972 
    973 /* Certificate and private key convenience functions. */
    974 
    975 /* SSL_CTX_set_chain_and_key sets the certificate chain and private key for a
    976  * TLS client or server. References to the given |CRYPTO_BUFFER| and |EVP_PKEY|
    977  * objects are added as needed. Exactly one of |privkey| or |privkey_method|
    978  * may be non-NULL. Returns one on success and zero on error. */
    979 OPENSSL_EXPORT int SSL_CTX_set_chain_and_key(
    980     SSL_CTX *ctx, CRYPTO_BUFFER *const *certs, size_t num_certs,
    981     EVP_PKEY *privkey, const SSL_PRIVATE_KEY_METHOD *privkey_method);
    982 
    983 /* SSL_set_chain_and_key sets the certificate chain and private key for a TLS
    984  * client or server. References to the given |CRYPTO_BUFFER| and |EVP_PKEY|
    985  * objects are added as needed. Exactly one of |privkey| or |privkey_method|
    986  * may be non-NULL. Returns one on success and zero on error. */
    987 OPENSSL_EXPORT int SSL_set_chain_and_key(
    988     SSL *ssl, CRYPTO_BUFFER *const *certs, size_t num_certs, EVP_PKEY *privkey,
    989     const SSL_PRIVATE_KEY_METHOD *privkey_method);
    990 
    991 /* SSL_CTX_use_RSAPrivateKey sets |ctx|'s private key to |rsa|. It returns one
    992  * on success and zero on failure. */
    993 OPENSSL_EXPORT int SSL_CTX_use_RSAPrivateKey(SSL_CTX *ctx, RSA *rsa);
    994 
    995 /* SSL_use_RSAPrivateKey sets |ctx|'s private key to |rsa|. It returns one on
    996  * success and zero on failure. */
    997 OPENSSL_EXPORT int SSL_use_RSAPrivateKey(SSL *ssl, RSA *rsa);
    998 
    999 /* The following functions configure certificates or private keys but take as
   1000  * input DER-encoded structures. They return one on success and zero on
   1001  * failure. */
   1002 
   1003 OPENSSL_EXPORT int SSL_CTX_use_certificate_ASN1(SSL_CTX *ctx, size_t der_len,
   1004                                                 const uint8_t *der);
   1005 OPENSSL_EXPORT int SSL_use_certificate_ASN1(SSL *ssl, const uint8_t *der,
   1006                                             size_t der_len);
   1007 
   1008 OPENSSL_EXPORT int SSL_CTX_use_PrivateKey_ASN1(int pk, SSL_CTX *ctx,
   1009                                                const uint8_t *der,
   1010                                                size_t der_len);
   1011 OPENSSL_EXPORT int SSL_use_PrivateKey_ASN1(int type, SSL *ssl,
   1012                                            const uint8_t *der, size_t der_len);
   1013 
   1014 OPENSSL_EXPORT int SSL_CTX_use_RSAPrivateKey_ASN1(SSL_CTX *ctx,
   1015                                                   const uint8_t *der,
   1016                                                   size_t der_len);
   1017 OPENSSL_EXPORT int SSL_use_RSAPrivateKey_ASN1(SSL *ssl, const uint8_t *der,
   1018                                               size_t der_len);
   1019 
   1020 /* The following functions configure certificates or private keys but take as
   1021  * input files to read from. They return one on success and zero on failure. The
   1022  * |type| parameter is one of the |SSL_FILETYPE_*| values and determines whether
   1023  * the file's contents are read as PEM or DER. */
   1024 
   1025 #define SSL_FILETYPE_ASN1 X509_FILETYPE_ASN1
   1026 #define SSL_FILETYPE_PEM X509_FILETYPE_PEM
   1027 
   1028 OPENSSL_EXPORT int SSL_CTX_use_RSAPrivateKey_file(SSL_CTX *ctx,
   1029                                                   const char *file,
   1030                                                   int type);
   1031 OPENSSL_EXPORT int SSL_use_RSAPrivateKey_file(SSL *ssl, const char *file,
   1032                                               int type);
   1033 
   1034 OPENSSL_EXPORT int SSL_CTX_use_certificate_file(SSL_CTX *ctx, const char *file,
   1035                                                 int type);
   1036 OPENSSL_EXPORT int SSL_use_certificate_file(SSL *ssl, const char *file,
   1037                                             int type);
   1038 
   1039 OPENSSL_EXPORT int SSL_CTX_use_PrivateKey_file(SSL_CTX *ctx, const char *file,
   1040                                                int type);
   1041 OPENSSL_EXPORT int SSL_use_PrivateKey_file(SSL *ssl, const char *file,
   1042                                            int type);
   1043 
   1044 /* SSL_CTX_use_certificate_chain_file configures certificates for |ctx|. It
   1045  * reads the contents of |file| as a PEM-encoded leaf certificate followed
   1046  * optionally by the certificate chain to send to the peer. It returns one on
   1047  * success and zero on failure. */
   1048 OPENSSL_EXPORT int SSL_CTX_use_certificate_chain_file(SSL_CTX *ctx,
   1049                                                       const char *file);
   1050 
   1051 /* SSL_CTX_set_default_passwd_cb sets the password callback for PEM-based
   1052  * convenience functions called on |ctx|. */
   1053 OPENSSL_EXPORT void SSL_CTX_set_default_passwd_cb(SSL_CTX *ctx,
   1054                                                   pem_password_cb *cb);
   1055 
   1056 /* SSL_CTX_set_default_passwd_cb_userdata sets the userdata parameter for
   1057  * |ctx|'s password callback. */
   1058 OPENSSL_EXPORT void SSL_CTX_set_default_passwd_cb_userdata(SSL_CTX *ctx,
   1059                                                            void *data);
   1060 
   1061 
   1062 /* Custom private keys. */
   1063 
   1064 enum ssl_private_key_result_t {
   1065   ssl_private_key_success,
   1066   ssl_private_key_retry,
   1067   ssl_private_key_failure,
   1068 };
   1069 
   1070 /* ssl_private_key_method_st (aka |SSL_PRIVATE_KEY_METHOD|) describes private
   1071  * key hooks. This is used to off-load signing operations to a custom,
   1072  * potentially asynchronous, backend. */
   1073 struct ssl_private_key_method_st {
   1074   /* type returns the type of the key used by |ssl|. For RSA keys, return
   1075    * |NID_rsaEncryption|. For ECDSA keys, return |NID_X9_62_prime256v1|,
   1076    * |NID_secp384r1|, or |NID_secp521r1|, depending on the curve. */
   1077   int (*type)(SSL *ssl);
   1078 
   1079   /* max_signature_len returns the maximum length of a signature signed by the
   1080    * key used by |ssl|. This must be a constant value for a given |ssl|. */
   1081   size_t (*max_signature_len)(SSL *ssl);
   1082 
   1083   /* sign signs the message |in| in using the specified signature algorithm. On
   1084    * success, it returns |ssl_private_key_success| and writes at most |max_out|
   1085    * bytes of signature data to |out| and sets |*out_len| to the number of bytes
   1086    * written. On failure, it returns |ssl_private_key_failure|. If the operation
   1087    * has not completed, it returns |ssl_private_key_retry|. |sign| should
   1088    * arrange for the high-level operation on |ssl| to be retried when the
   1089    * operation is completed. This will result in a call to |complete|.
   1090    *
   1091    * |signature_algorithm| is one of the |SSL_SIGN_*| values, as defined in TLS
   1092    * 1.3. Note that, in TLS 1.2, ECDSA algorithms do not require that curve
   1093    * sizes match hash sizes, so the curve portion of |SSL_SIGN_ECDSA_*| values
   1094    * must be ignored. BoringSSL will internally handle the curve matching logic
   1095    * where appropriate.
   1096    *
   1097    * It is an error to call |sign| while another private key operation is in
   1098    * progress on |ssl|. */
   1099   enum ssl_private_key_result_t (*sign)(SSL *ssl, uint8_t *out, size_t *out_len,
   1100                                         size_t max_out,
   1101                                         uint16_t signature_algorithm,
   1102                                         const uint8_t *in, size_t in_len);
   1103 
   1104   /* sign_digest signs |in_len| bytes of digest from |in|. |md| is the hash
   1105    * function used to calculate |in|. On success, it returns
   1106    * |ssl_private_key_success| and writes at most |max_out| bytes of signature
   1107    * data to |out|. On failure, it returns |ssl_private_key_failure|. If the
   1108    * operation has not completed, it returns |ssl_private_key_retry|. |sign|
   1109    * should arrange for the high-level operation on |ssl| to be retried when the
   1110    * operation is completed. This will result in a call to |complete|.
   1111    *
   1112    * If the key is an RSA key, implementations must use PKCS#1 padding. |in| is
   1113    * the digest itself, so the DigestInfo prefix, if any, must be prepended by
   1114    * |sign|. If |md| is |EVP_md5_sha1|, there is no prefix.
   1115    *
   1116    * It is an error to call |sign_digest| while another private key operation is
   1117    * in progress on |ssl|.
   1118    *
   1119    * This function is deprecated. Implement |sign| instead.
   1120    *
   1121    * TODO(davidben): Remove this function. */
   1122   enum ssl_private_key_result_t (*sign_digest)(SSL *ssl, uint8_t *out,
   1123                                                size_t *out_len, size_t max_out,
   1124                                                const EVP_MD *md,
   1125                                                const uint8_t *in,
   1126                                                size_t in_len);
   1127 
   1128   /* decrypt decrypts |in_len| bytes of encrypted data from |in|. On success it
   1129    * returns |ssl_private_key_success|, writes at most |max_out| bytes of
   1130    * decrypted data to |out| and sets |*out_len| to the actual number of bytes
   1131    * written. On failure it returns |ssl_private_key_failure|. If the operation
   1132    * has not completed, it returns |ssl_private_key_retry|. The caller should
   1133    * arrange for the high-level operation on |ssl| to be retried when the
   1134    * operation is completed, which will result in a call to |complete|. This
   1135    * function only works with RSA keys and should perform a raw RSA decryption
   1136    * operation with no padding.
   1137    *
   1138    * It is an error to call |decrypt| while another private key operation is in
   1139    * progress on |ssl|. */
   1140   enum ssl_private_key_result_t (*decrypt)(SSL *ssl, uint8_t *out,
   1141                                            size_t *out_len, size_t max_out,
   1142                                            const uint8_t *in, size_t in_len);
   1143 
   1144   /* complete completes a pending operation. If the operation has completed, it
   1145    * returns |ssl_private_key_success| and writes the result to |out| as in
   1146    * |sign|. Otherwise, it returns |ssl_private_key_failure| on failure and
   1147    * |ssl_private_key_retry| if the operation is still in progress.
   1148    *
   1149    * |complete| may be called arbitrarily many times before completion, but it
   1150    * is an error to call |complete| if there is no pending operation in progress
   1151    * on |ssl|. */
   1152   enum ssl_private_key_result_t (*complete)(SSL *ssl, uint8_t *out,
   1153                                             size_t *out_len, size_t max_out);
   1154 };
   1155 
   1156 /* SSL_set_private_key_method configures a custom private key on |ssl|.
   1157  * |key_method| must remain valid for the lifetime of |ssl|. */
   1158 OPENSSL_EXPORT void SSL_set_private_key_method(
   1159     SSL *ssl, const SSL_PRIVATE_KEY_METHOD *key_method);
   1160 
   1161 /* SSL_CTX_set_private_key_method configures a custom private key on |ctx|.
   1162  * |key_method| must remain valid for the lifetime of |ctx|. */
   1163 OPENSSL_EXPORT void SSL_CTX_set_private_key_method(
   1164     SSL_CTX *ctx, const SSL_PRIVATE_KEY_METHOD *key_method);
   1165 
   1166 
   1167 /* Cipher suites.
   1168  *
   1169  * |SSL_CIPHER| objects represent cipher suites. */
   1170 
   1171 DECLARE_STACK_OF(SSL_CIPHER)
   1172 
   1173 /* SSL_get_cipher_by_value returns the structure representing a TLS cipher
   1174  * suite based on its assigned number, or NULL if unknown. See
   1175  * https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-4. */
   1176 OPENSSL_EXPORT const SSL_CIPHER *SSL_get_cipher_by_value(uint16_t value);
   1177 
   1178 /* SSL_CIPHER_get_id returns |cipher|'s id. It may be cast to a |uint16_t| to
   1179  * get the cipher suite value. */
   1180 OPENSSL_EXPORT uint32_t SSL_CIPHER_get_id(const SSL_CIPHER *cipher);
   1181 
   1182 /* SSL_CIPHER_is_AES returns one if |cipher| uses AES (either GCM or CBC
   1183  * mode). */
   1184 OPENSSL_EXPORT int SSL_CIPHER_is_AES(const SSL_CIPHER *cipher);
   1185 
   1186 /* SSL_CIPHER_has_SHA1_HMAC returns one if |cipher| uses HMAC-SHA1. */
   1187 OPENSSL_EXPORT int SSL_CIPHER_has_SHA1_HMAC(const SSL_CIPHER *cipher);
   1188 
   1189 /* SSL_CIPHER_has_SHA256_HMAC returns one if |cipher| uses HMAC-SHA256. */
   1190 OPENSSL_EXPORT int SSL_CIPHER_has_SHA256_HMAC(const SSL_CIPHER *cipher);
   1191 
   1192 /* SSL_CIPHER_is_AEAD returns one if |cipher| uses an AEAD cipher. */
   1193 OPENSSL_EXPORT int SSL_CIPHER_is_AEAD(const SSL_CIPHER *cipher);
   1194 
   1195 /* SSL_CIPHER_is_AESGCM returns one if |cipher| uses AES-GCM. */
   1196 OPENSSL_EXPORT int SSL_CIPHER_is_AESGCM(const SSL_CIPHER *cipher);
   1197 
   1198 /* SSL_CIPHER_is_AES128GCM returns one if |cipher| uses 128-bit AES-GCM. */
   1199 OPENSSL_EXPORT int SSL_CIPHER_is_AES128GCM(const SSL_CIPHER *cipher);
   1200 
   1201 /* SSL_CIPHER_is_AES128CBC returns one if |cipher| uses 128-bit AES in CBC
   1202  * mode. */
   1203 OPENSSL_EXPORT int SSL_CIPHER_is_AES128CBC(const SSL_CIPHER *cipher);
   1204 
   1205 /* SSL_CIPHER_is_AES256CBC returns one if |cipher| uses 256-bit AES in CBC
   1206  * mode. */
   1207 OPENSSL_EXPORT int SSL_CIPHER_is_AES256CBC(const SSL_CIPHER *cipher);
   1208 
   1209 /* SSL_CIPHER_is_CHACHA20POLY1305 returns one if |cipher| uses
   1210  * CHACHA20_POLY1305. Note this includes both the RFC 7905 and
   1211  * draft-agl-tls-chacha20poly1305-04 versions. */
   1212 OPENSSL_EXPORT int SSL_CIPHER_is_CHACHA20POLY1305(const SSL_CIPHER *cipher);
   1213 
   1214 /* SSL_CIPHER_is_NULL returns one if |cipher| does not encrypt. */
   1215 OPENSSL_EXPORT int SSL_CIPHER_is_NULL(const SSL_CIPHER *cipher);
   1216 
   1217 /* SSL_CIPHER_is_block_cipher returns one if |cipher| is a block cipher. */
   1218 OPENSSL_EXPORT int SSL_CIPHER_is_block_cipher(const SSL_CIPHER *cipher);
   1219 
   1220 /* SSL_CIPHER_is_ECDSA returns one if |cipher| uses ECDSA. */
   1221 OPENSSL_EXPORT int SSL_CIPHER_is_ECDSA(const SSL_CIPHER *cipher);
   1222 
   1223 /* SSL_CIPHER_is_DHE returns one if |cipher| uses DHE. */
   1224 OPENSSL_EXPORT int SSL_CIPHER_is_DHE(const SSL_CIPHER *cipher);
   1225 
   1226 /* SSL_CIPHER_is_ECDHE returns one if |cipher| uses ECDHE. */
   1227 OPENSSL_EXPORT int SSL_CIPHER_is_ECDHE(const SSL_CIPHER *cipher);
   1228 
   1229 /* SSL_CIPHER_is_static_RSA returns one if |cipher| uses the static RSA key
   1230  * exchange. */
   1231 OPENSSL_EXPORT int SSL_CIPHER_is_static_RSA(const SSL_CIPHER *cipher);
   1232 
   1233 /* SSL_CIPHER_get_min_version returns the minimum protocol version required
   1234  * for |cipher|. */
   1235 OPENSSL_EXPORT uint16_t SSL_CIPHER_get_min_version(const SSL_CIPHER *cipher);
   1236 
   1237 /* SSL_CIPHER_get_max_version returns the maximum protocol version that
   1238  * supports |cipher|. */
   1239 OPENSSL_EXPORT uint16_t SSL_CIPHER_get_max_version(const SSL_CIPHER *cipher);
   1240 
   1241 /* SSL_CIPHER_get_name returns the OpenSSL name of |cipher|. */
   1242 OPENSSL_EXPORT const char *SSL_CIPHER_get_name(const SSL_CIPHER *cipher);
   1243 
   1244 /* SSL_CIPHER_get_kx_name returns a string that describes the key-exchange
   1245  * method used by |cipher|. For example, "ECDHE_ECDSA". TLS 1.3 AEAD-only
   1246  * ciphers return the string "GENERIC". */
   1247 OPENSSL_EXPORT const char *SSL_CIPHER_get_kx_name(const SSL_CIPHER *cipher);
   1248 
   1249 /* SSL_CIPHER_get_rfc_name returns a newly-allocated string with the standard
   1250  * name for |cipher| or NULL on error. For example,
   1251  * "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256". The caller is responsible for
   1252  * calling |OPENSSL_free| on the result. */
   1253 OPENSSL_EXPORT char *SSL_CIPHER_get_rfc_name(const SSL_CIPHER *cipher);
   1254 
   1255 /* SSL_CIPHER_get_bits returns the strength, in bits, of |cipher|. If
   1256  * |out_alg_bits| is not NULL, it writes the number of bits consumed by the
   1257  * symmetric algorithm to |*out_alg_bits|. */
   1258 OPENSSL_EXPORT int SSL_CIPHER_get_bits(const SSL_CIPHER *cipher,
   1259                                        int *out_alg_bits);
   1260 
   1261 
   1262 /* Cipher suite configuration.
   1263  *
   1264  * OpenSSL uses a mini-language to configure cipher suites. The language
   1265  * maintains an ordered list of enabled ciphers, along with an ordered list of
   1266  * disabled but available ciphers. Initially, all ciphers are disabled with a
   1267  * default ordering. The cipher string is then interpreted as a sequence of
   1268  * directives, separated by colons, each of which modifies this state.
   1269  *
   1270  * Most directives consist of a one character or empty opcode followed by a
   1271  * selector which matches a subset of available ciphers.
   1272  *
   1273  * Available opcodes are:
   1274  *
   1275  *   The empty opcode enables and appends all matching disabled ciphers to the
   1276  *   end of the enabled list. The newly appended ciphers are ordered relative to
   1277  *   each other matching their order in the disabled list.
   1278  *
   1279  *   |-| disables all matching enabled ciphers and prepends them to the disabled
   1280  *   list, with relative order from the enabled list preserved. This means the
   1281  *   most recently disabled ciphers get highest preference relative to other
   1282  *   disabled ciphers if re-enabled.
   1283  *
   1284  *   |+| moves all matching enabled ciphers to the end of the enabled list, with
   1285  *   relative order preserved.
   1286  *
   1287  *   |!| deletes all matching ciphers, enabled or not, from either list. Deleted
   1288  *   ciphers will not matched by future operations.
   1289  *
   1290  * A selector may be a specific cipher (using the OpenSSL name for the cipher)
   1291  * or one or more rules separated by |+|. The final selector matches the
   1292  * intersection of each rule. For instance, |AESGCM+aECDSA| matches
   1293  * ECDSA-authenticated AES-GCM ciphers.
   1294  *
   1295  * Available cipher rules are:
   1296  *
   1297  *   |ALL| matches all ciphers.
   1298  *
   1299  *   |kRSA|, |kDHE|, |kECDHE|, and |kPSK| match ciphers using plain RSA, DHE,
   1300  *   ECDHE, and plain PSK key exchanges, respectively. Note that ECDHE_PSK is
   1301  *   matched by |kECDHE| and not |kPSK|.
   1302  *
   1303  *   |aRSA|, |aECDSA|, and |aPSK| match ciphers authenticated by RSA, ECDSA, and
   1304  *   a pre-shared key, respectively.
   1305  *
   1306  *   |RSA|, |DHE|, |ECDHE|, |PSK|, |ECDSA|, and |PSK| are aliases for the
   1307  *   corresponding |k*| or |a*| cipher rule. |RSA| is an alias for |kRSA|, not
   1308  *   |aRSA|.
   1309  *
   1310  *   |3DES|, |AES128|, |AES256|, |AES|, |AESGCM|, |CHACHA20| match ciphers
   1311  *   whose bulk cipher use the corresponding encryption scheme. Note that
   1312  *   |AES|, |AES128|, and |AES256| match both CBC and GCM ciphers.
   1313  *
   1314  *   |SHA1|, |SHA256|, and |SHA384| match legacy cipher suites using the
   1315  *   corresponding hash function in their MAC. AEADs are matched by none of
   1316  *   these.
   1317  *
   1318  *   |SHA| is an alias for |SHA1|.
   1319  *
   1320  * Although implemented, authentication-only ciphers match no rules and must be
   1321  * explicitly selected by name.
   1322  *
   1323  * Deprecated cipher rules:
   1324  *
   1325  *   |kEDH|, |EDH|, |kEECDH|, and |EECDH| are legacy aliases for |kDHE|, |DHE|,
   1326  *   |kECDHE|, and |ECDHE|, respectively.
   1327  *
   1328  *   |HIGH| is an alias for |ALL|.
   1329  *
   1330  *   |FIPS| is an alias for |HIGH|.
   1331  *
   1332  *   |SSLv3| and |TLSv1| match ciphers available in TLS 1.1 or earlier.
   1333  *   |TLSv1_2| matches ciphers new in TLS 1.2. This is confusing and should not
   1334  *   be used.
   1335  *
   1336  * Unknown rules are silently ignored by legacy APIs, and rejected by APIs with
   1337  * "strict" in the name, which should be preferred. Cipher lists can be long and
   1338  * it's easy to commit typos.
   1339  *
   1340  * The special |@STRENGTH| directive will sort all enabled ciphers by strength.
   1341  *
   1342  * The |DEFAULT| directive, when appearing at the front of the string, expands
   1343  * to the default ordering of available ciphers.
   1344  *
   1345  * If configuring a server, one may also configure equal-preference groups to
   1346  * partially respect the client's preferences when
   1347  * |SSL_OP_CIPHER_SERVER_PREFERENCE| is enabled. Ciphers in an equal-preference
   1348  * group have equal priority and use the client order. This may be used to
   1349  * enforce that AEADs are preferred but select AES-GCM vs. ChaCha20-Poly1305
   1350  * based on client preferences. An equal-preference is specified with square
   1351  * brackets, combining multiple selectors separated by |. For example:
   1352  *
   1353  *   [ECDHE-ECDSA-CHACHA20-POLY1305|ECDHE-ECDSA-AES128-GCM-SHA256]
   1354  *
   1355  * Once an equal-preference group is used, future directives must be
   1356  * opcode-less.
   1357  *
   1358  * TLS 1.3 ciphers do not participate in this mechanism and instead have a
   1359  * built-in preference order. Functions to set cipher lists do not affect TLS
   1360  * 1.3, and functions to query the cipher list do not include TLS 1.3
   1361  * ciphers. */
   1362 
   1363 /* SSL_DEFAULT_CIPHER_LIST is the default cipher suite configuration. It is
   1364  * substituted when a cipher string starts with 'DEFAULT'. */
   1365 #define SSL_DEFAULT_CIPHER_LIST "ALL"
   1366 
   1367 /* SSL_CTX_set_strict_cipher_list configures the cipher list for |ctx|,
   1368  * evaluating |str| as a cipher string and returning error if |str| contains
   1369  * anything meaningless. It returns one on success and zero on failure. */
   1370 OPENSSL_EXPORT int SSL_CTX_set_strict_cipher_list(SSL_CTX *ctx,
   1371                                                   const char *str);
   1372 
   1373 /* SSL_CTX_set_cipher_list configures the cipher list for |ctx|, evaluating
   1374  * |str| as a cipher string. It returns one on success and zero on failure.
   1375  *
   1376  * Prefer to use |SSL_CTX_set_strict_cipher_list|. This function tolerates
   1377  * garbage inputs, unless an empty cipher list results. */
   1378 OPENSSL_EXPORT int SSL_CTX_set_cipher_list(SSL_CTX *ctx, const char *str);
   1379 
   1380 /* SSL_set_strict_cipher_list configures the cipher list for |ssl|, evaluating
   1381  * |str| as a cipher string and returning error if |str| contains anything
   1382  * meaningless. It returns one on success and zero on failure. */
   1383 OPENSSL_EXPORT int SSL_set_strict_cipher_list(SSL *ssl, const char *str);
   1384 
   1385 /* SSL_set_cipher_list configures the cipher list for |ssl|, evaluating |str| as
   1386  * a cipher string. It returns one on success and zero on failure.
   1387  *
   1388  * Prefer to use |SSL_set_strict_cipher_list|. This function tolerates garbage
   1389  * inputs, unless an empty cipher list results. */
   1390 OPENSSL_EXPORT int SSL_set_cipher_list(SSL *ssl, const char *str);
   1391 
   1392 /* SSL_CTX_get_ciphers returns the cipher list for |ctx|, in order of
   1393  * preference. */
   1394 OPENSSL_EXPORT STACK_OF(SSL_CIPHER) *SSL_CTX_get_ciphers(const SSL_CTX *ctx);
   1395 
   1396 /* SSL_get_ciphers returns the cipher list for |ssl|, in order of preference. */
   1397 OPENSSL_EXPORT STACK_OF(SSL_CIPHER) *SSL_get_ciphers(const SSL *ssl);
   1398 
   1399 
   1400 /* Connection information. */
   1401 
   1402 /* SSL_is_init_finished returns one if |ssl| has completed its initial handshake
   1403  * and has no pending handshake. It returns zero otherwise. */
   1404 OPENSSL_EXPORT int SSL_is_init_finished(const SSL *ssl);
   1405 
   1406 /* SSL_in_init returns one if |ssl| has a pending handshake and zero
   1407  * otherwise. */
   1408 OPENSSL_EXPORT int SSL_in_init(const SSL *ssl);
   1409 
   1410 /* SSL_in_false_start returns one if |ssl| has a pending handshake that is in
   1411  * False Start. |SSL_write| may be called at this point without waiting for the
   1412  * peer, but |SSL_read| will complete the handshake before accepting application
   1413  * data.
   1414  *
   1415  * See also |SSL_MODE_ENABLE_FALSE_START|. */
   1416 OPENSSL_EXPORT int SSL_in_false_start(const SSL *ssl);
   1417 
   1418 /* SSL_get_peer_certificate returns the peer's leaf certificate or NULL if the
   1419  * peer did not use certificates. The caller must call |X509_free| on the
   1420  * result to release it. */
   1421 OPENSSL_EXPORT X509 *SSL_get_peer_certificate(const SSL *ssl);
   1422 
   1423 /* SSL_get_peer_cert_chain returns the peer's certificate chain or NULL if
   1424  * unavailable or the peer did not use certificates. This is the unverified list
   1425  * of certificates as sent by the peer, not the final chain built during
   1426  * verification. The caller does not take ownership of the result.
   1427  *
   1428  * WARNING: This function behaves differently between client and server. If
   1429  * |ssl| is a server, the returned chain does not include the leaf certificate.
   1430  * If a client, it does. */
   1431 OPENSSL_EXPORT STACK_OF(X509) *SSL_get_peer_cert_chain(const SSL *ssl);
   1432 
   1433 /* SSL_get_peer_full_cert_chain returns the peer's certificate chain, or NULL if
   1434  * unavailable or the peer did not use certificates. This is the unverified list
   1435  * of certificates as sent by the peer, not the final chain built during
   1436  * verification. The caller does not take ownership of the result.
   1437  *
   1438  * This is the same as |SSL_get_peer_cert_chain| except that this function
   1439  * always returns the full chain, i.e. the first element of the return value
   1440  * (if any) will be the leaf certificate. In constrast,
   1441  * |SSL_get_peer_cert_chain| returns only the intermediate certificates if the
   1442  * |ssl| is a server. */
   1443 OPENSSL_EXPORT STACK_OF(X509) *SSL_get_peer_full_cert_chain(const SSL *ssl);
   1444 
   1445 /* SSL_get0_peer_certificates returns the peer's certificate chain, or NULL if
   1446  * unavailable or the peer did not use certificates. This is the unverified list
   1447  * of certificates as sent by the peer, not the final chain built during
   1448  * verification. The caller does not take ownership of the result.
   1449  *
   1450  * This is the |CRYPTO_BUFFER| variant of |SSL_get_peer_full_cert_chain|. */
   1451 OPENSSL_EXPORT STACK_OF(CRYPTO_BUFFER) *
   1452     SSL_get0_peer_certificates(const SSL *ssl);
   1453 
   1454 /* SSL_get0_signed_cert_timestamp_list sets |*out| and |*out_len| to point to
   1455  * |*out_len| bytes of SCT information from the server. This is only valid if
   1456  * |ssl| is a client. The SCT information is a SignedCertificateTimestampList
   1457  * (including the two leading length bytes).
   1458  * See https://tools.ietf.org/html/rfc6962#section-3.3
   1459  * If no SCT was received then |*out_len| will be zero on return.
   1460  *
   1461  * WARNING: the returned data is not guaranteed to be well formed. */
   1462 OPENSSL_EXPORT void SSL_get0_signed_cert_timestamp_list(const SSL *ssl,
   1463                                                         const uint8_t **out,
   1464                                                         size_t *out_len);
   1465 
   1466 /* SSL_get0_ocsp_response sets |*out| and |*out_len| to point to |*out_len|
   1467  * bytes of an OCSP response from the server. This is the DER encoding of an
   1468  * OCSPResponse type as defined in RFC 2560.
   1469  *
   1470  * WARNING: the returned data is not guaranteed to be well formed. */
   1471 OPENSSL_EXPORT void SSL_get0_ocsp_response(const SSL *ssl, const uint8_t **out,
   1472                                            size_t *out_len);
   1473 
   1474 /* SSL_get_tls_unique writes at most |max_out| bytes of the tls-unique value
   1475  * for |ssl| to |out| and sets |*out_len| to the number of bytes written. It
   1476  * returns one on success or zero on error. In general |max_out| should be at
   1477  * least 12.
   1478  *
   1479  * This function will always fail if the initial handshake has not completed.
   1480  * The tls-unique value will change after a renegotiation but, since
   1481  * renegotiations can be initiated by the server at any point, the higher-level
   1482  * protocol must either leave them disabled or define states in which the
   1483  * tls-unique value can be read.
   1484  *
   1485  * The tls-unique value is defined by
   1486  * https://tools.ietf.org/html/rfc5929#section-3.1. Due to a weakness in the
   1487  * TLS protocol, tls-unique is broken for resumed connections unless the
   1488  * Extended Master Secret extension is negotiated. Thus this function will
   1489  * return zero if |ssl| performed session resumption unless EMS was used when
   1490  * negotiating the original session. */
   1491 OPENSSL_EXPORT int SSL_get_tls_unique(const SSL *ssl, uint8_t *out,
   1492                                       size_t *out_len, size_t max_out);
   1493 
   1494 /* SSL_get_extms_support returns one if the Extended Master Secret extension or
   1495  * TLS 1.3 was negotiated. Otherwise, it returns zero. */
   1496 OPENSSL_EXPORT int SSL_get_extms_support(const SSL *ssl);
   1497 
   1498 /* SSL_get_current_cipher returns the cipher used in the current outgoing
   1499  * connection state, or NULL if the null cipher is active. */
   1500 OPENSSL_EXPORT const SSL_CIPHER *SSL_get_current_cipher(const SSL *ssl);
   1501 
   1502 /* SSL_session_reused returns one if |ssl| performed an abbreviated handshake
   1503  * and zero otherwise.
   1504  *
   1505  * TODO(davidben): Hammer down the semantics of this API while a handshake,
   1506  * initial or renego, is in progress. */
   1507 OPENSSL_EXPORT int SSL_session_reused(const SSL *ssl);
   1508 
   1509 /* SSL_get_secure_renegotiation_support returns one if the peer supports secure
   1510  * renegotiation (RFC 5746) or TLS 1.3. Otherwise, it returns zero. */
   1511 OPENSSL_EXPORT int SSL_get_secure_renegotiation_support(const SSL *ssl);
   1512 
   1513 /* SSL_export_keying_material exports a value derived from the master secret, as
   1514  * specified in RFC 5705. It writes |out_len| bytes to |out| given a label and
   1515  * optional context. (Since a zero length context is allowed, the |use_context|
   1516  * flag controls whether a context is included.)
   1517  *
   1518  * It returns one on success and zero otherwise. */
   1519 OPENSSL_EXPORT int SSL_export_keying_material(
   1520     SSL *ssl, uint8_t *out, size_t out_len, const char *label, size_t label_len,
   1521     const uint8_t *context, size_t context_len, int use_context);
   1522 
   1523 
   1524 /* Custom extensions.
   1525  *
   1526  * The custom extension functions allow TLS extensions to be added to
   1527  * ClientHello and ServerHello messages. */
   1528 
   1529 /* SSL_custom_ext_add_cb is a callback function that is called when the
   1530  * ClientHello (for clients) or ServerHello (for servers) is constructed. In
   1531  * the case of a server, this callback will only be called for a given
   1532  * extension if the ClientHello contained that extension  it's not possible to
   1533  * inject extensions into a ServerHello that the client didn't request.
   1534  *
   1535  * When called, |extension_value| will contain the extension number that is
   1536  * being considered for addition (so that a single callback can handle multiple
   1537  * extensions). If the callback wishes to include the extension, it must set
   1538  * |*out| to point to |*out_len| bytes of extension contents and return one. In
   1539  * this case, the corresponding |SSL_custom_ext_free_cb| callback will later be
   1540  * called with the value of |*out| once that data has been copied.
   1541  *
   1542  * If the callback does not wish to add an extension it must return zero.
   1543  *
   1544  * Alternatively, the callback can abort the connection by setting
   1545  * |*out_alert_value| to a TLS alert number and returning -1. */
   1546 typedef int (*SSL_custom_ext_add_cb)(SSL *ssl, unsigned extension_value,
   1547                                      const uint8_t **out, size_t *out_len,
   1548                                      int *out_alert_value, void *add_arg);
   1549 
   1550 /* SSL_custom_ext_free_cb is a callback function that is called by OpenSSL iff
   1551  * an |SSL_custom_ext_add_cb| callback previously returned one. In that case,
   1552  * this callback is called and passed the |out| pointer that was returned by
   1553  * the add callback. This is to free any dynamically allocated data created by
   1554  * the add callback. */
   1555 typedef void (*SSL_custom_ext_free_cb)(SSL *ssl, unsigned extension_value,
   1556                                        const uint8_t *out, void *add_arg);
   1557 
   1558 /* SSL_custom_ext_parse_cb is a callback function that is called by OpenSSL to
   1559  * parse an extension from the peer: that is from the ServerHello for a client
   1560  * and from the ClientHello for a server.
   1561  *
   1562  * When called, |extension_value| will contain the extension number and the
   1563  * contents of the extension are |contents_len| bytes at |contents|.
   1564  *
   1565  * The callback must return one to continue the handshake. Otherwise, if it
   1566  * returns zero, a fatal alert with value |*out_alert_value| is sent and the
   1567  * handshake is aborted. */
   1568 typedef int (*SSL_custom_ext_parse_cb)(SSL *ssl, unsigned extension_value,
   1569                                        const uint8_t *contents,
   1570                                        size_t contents_len,
   1571                                        int *out_alert_value, void *parse_arg);
   1572 
   1573 /* SSL_extension_supported returns one iff OpenSSL internally handles
   1574  * extensions of type |extension_value|. This can be used to avoid registering
   1575  * custom extension handlers for extensions that a future version of OpenSSL
   1576  * may handle internally. */
   1577 OPENSSL_EXPORT int SSL_extension_supported(unsigned extension_value);
   1578 
   1579 /* SSL_CTX_add_client_custom_ext registers callback functions for handling
   1580  * custom TLS extensions for client connections.
   1581  *
   1582  * If |add_cb| is NULL then an empty extension will be added in each
   1583  * ClientHello. Otherwise, see the comment for |SSL_custom_ext_add_cb| about
   1584  * this callback.
   1585  *
   1586  * The |free_cb| may be NULL if |add_cb| doesn't dynamically allocate data that
   1587  * needs to be freed.
   1588  *
   1589  * It returns one on success or zero on error. It's always an error to register
   1590  * callbacks for the same extension twice, or to register callbacks for an
   1591  * extension that OpenSSL handles internally. See |SSL_extension_supported| to
   1592  * discover, at runtime, which extensions OpenSSL handles internally. */
   1593 OPENSSL_EXPORT int SSL_CTX_add_client_custom_ext(
   1594     SSL_CTX *ctx, unsigned extension_value, SSL_custom_ext_add_cb add_cb,
   1595     SSL_custom_ext_free_cb free_cb, void *add_arg,
   1596     SSL_custom_ext_parse_cb parse_cb, void *parse_arg);
   1597 
   1598 /* SSL_CTX_add_server_custom_ext is the same as
   1599  * |SSL_CTX_add_client_custom_ext|, but for server connections.
   1600  *
   1601  * Unlike on the client side, if |add_cb| is NULL no extension will be added.
   1602  * The |add_cb|, if any, will only be called if the ClientHello contained a
   1603  * matching extension. */
   1604 OPENSSL_EXPORT int SSL_CTX_add_server_custom_ext(
   1605     SSL_CTX *ctx, unsigned extension_value, SSL_custom_ext_add_cb add_cb,
   1606     SSL_custom_ext_free_cb free_cb, void *add_arg,
   1607     SSL_custom_ext_parse_cb parse_cb, void *parse_arg);
   1608 
   1609 
   1610 /* Sessions.
   1611  *
   1612  * An |SSL_SESSION| represents an SSL session that may be resumed in an
   1613  * abbreviated handshake. It is reference-counted and immutable. Once
   1614  * established, an |SSL_SESSION| may be shared by multiple |SSL| objects on
   1615  * different threads and must not be modified. */
   1616 
   1617 DECLARE_LHASH_OF(SSL_SESSION)
   1618 DECLARE_PEM_rw(SSL_SESSION, SSL_SESSION)
   1619 
   1620 /* SSL_SESSION_new returns a newly-allocated blank |SSL_SESSION| or NULL on
   1621  * error. This may be useful when writing tests but should otherwise not be
   1622  * used. */
   1623 OPENSSL_EXPORT SSL_SESSION *SSL_SESSION_new(const SSL_CTX *ctx);
   1624 
   1625 /* SSL_SESSION_up_ref increments the reference count of |session| and returns
   1626  * one. */
   1627 OPENSSL_EXPORT int SSL_SESSION_up_ref(SSL_SESSION *session);
   1628 
   1629 /* SSL_SESSION_free decrements the reference count of |session|. If it reaches
   1630  * zero, all data referenced by |session| and |session| itself are released. */
   1631 OPENSSL_EXPORT void SSL_SESSION_free(SSL_SESSION *session);
   1632 
   1633 /* SSL_SESSION_to_bytes serializes |in| into a newly allocated buffer and sets
   1634  * |*out_data| to that buffer and |*out_len| to its length. The caller takes
   1635  * ownership of the buffer and must call |OPENSSL_free| when done. It returns
   1636  * one on success and zero on error. */
   1637 OPENSSL_EXPORT int SSL_SESSION_to_bytes(const SSL_SESSION *in,
   1638                                         uint8_t **out_data, size_t *out_len);
   1639 
   1640 /* SSL_SESSION_to_bytes_for_ticket serializes |in|, but excludes the session
   1641  * identification information, namely the session ID and ticket. */
   1642 OPENSSL_EXPORT int SSL_SESSION_to_bytes_for_ticket(const SSL_SESSION *in,
   1643                                                    uint8_t **out_data,
   1644                                                    size_t *out_len);
   1645 
   1646 /* SSL_SESSION_from_bytes parses |in_len| bytes from |in| as an SSL_SESSION. It
   1647  * returns a newly-allocated |SSL_SESSION| on success or NULL on error. */
   1648 OPENSSL_EXPORT SSL_SESSION *SSL_SESSION_from_bytes(
   1649     const uint8_t *in, size_t in_len, const SSL_CTX *ctx);
   1650 
   1651 /* SSL_SESSION_get_version returns a string describing the TLS version |session|
   1652  * was established at. For example, "TLSv1.2" or "SSLv3". */
   1653 OPENSSL_EXPORT const char *SSL_SESSION_get_version(const SSL_SESSION *session);
   1654 
   1655 /* SSL_SESSION_get_id returns a pointer to a buffer containing |session|'s
   1656  * session ID and sets |*out_len| to its length. */
   1657 OPENSSL_EXPORT const uint8_t *SSL_SESSION_get_id(const SSL_SESSION *session,
   1658                                                  unsigned *out_len);
   1659 
   1660 /* SSL_SESSION_get_time returns the time at which |session| was established in
   1661  * seconds since the UNIX epoch. */
   1662 OPENSSL_EXPORT uint64_t SSL_SESSION_get_time(const SSL_SESSION *session);
   1663 
   1664 /* SSL_SESSION_get_timeout returns the lifetime of |session| in seconds. */
   1665 OPENSSL_EXPORT uint32_t SSL_SESSION_get_timeout(const SSL_SESSION *session);
   1666 
   1667 /* SSL_SESSION_get0_peer returns the peer leaf certificate stored in
   1668  * |session|.
   1669  *
   1670  * TODO(davidben): This should return a const X509 *. */
   1671 OPENSSL_EXPORT X509 *SSL_SESSION_get0_peer(const SSL_SESSION *session);
   1672 
   1673 /* SSL_SESSION_get_master_key writes up to |max_out| bytes of |session|'s master
   1674  * secret to |out| and returns the number of bytes written. If |max_out| is
   1675  * zero, it returns the size of the master secret. */
   1676 OPENSSL_EXPORT size_t SSL_SESSION_get_master_key(const SSL_SESSION *session,
   1677                                                  uint8_t *out, size_t max_out);
   1678 
   1679 /* SSL_SESSION_set_time sets |session|'s creation time to |time| and returns
   1680  * |time|. This function may be useful in writing tests but otherwise should not
   1681  * be used. */
   1682 OPENSSL_EXPORT uint64_t SSL_SESSION_set_time(SSL_SESSION *session,
   1683                                              uint64_t time);
   1684 
   1685 /* SSL_SESSION_set_timeout sets |session|'s timeout to |timeout| and returns
   1686  * one. This function may be useful in writing tests but otherwise should not
   1687  * be used. */
   1688 OPENSSL_EXPORT uint32_t SSL_SESSION_set_timeout(SSL_SESSION *session,
   1689                                                 uint32_t timeout);
   1690 
   1691 /* SSL_SESSION_set1_id_context sets |session|'s session ID context (see
   1692  * |SSL_CTX_set_session_id_context|) to |sid_ctx|. It returns one on success and
   1693  * zero on error. This function may be useful in writing tests but otherwise
   1694  * should not be used. */
   1695 OPENSSL_EXPORT int SSL_SESSION_set1_id_context(SSL_SESSION *session,
   1696                                                const uint8_t *sid_ctx,
   1697                                                size_t sid_ctx_len);
   1698 
   1699 
   1700 /* Session caching.
   1701  *
   1702  * Session caching allows clients to reconnect to a server based on saved
   1703  * parameters from a previous connection.
   1704  *
   1705  * For a server, the library implements a built-in internal session cache as an
   1706  * in-memory hash table. One may also register callbacks to implement a custom
   1707  * external session cache. An external cache may be used in addition to or
   1708  * instead of the internal one. Use |SSL_CTX_set_session_cache_mode| to toggle
   1709  * the internal cache.
   1710  *
   1711  * For a client, the only option is an external session cache. Prior to
   1712  * handshaking, the consumer should look up a session externally (keyed, for
   1713  * instance, by hostname) and use |SSL_set_session| to configure which session
   1714  * to offer. The callbacks may be used to determine when new sessions are
   1715  * available.
   1716  *
   1717  * Note that offering or accepting a session short-circuits most parameter
   1718  * negotiation. Resuming sessions across different configurations may result in
   1719  * surprising behavior. So, for instance, a client implementing a version
   1720  * fallback should shard its session cache by maximum protocol version. */
   1721 
   1722 /* SSL_SESS_CACHE_OFF disables all session caching. */
   1723 #define SSL_SESS_CACHE_OFF 0x0000
   1724 
   1725 /* SSL_SESS_CACHE_CLIENT enables session caching for a client. The internal
   1726  * cache is never used on a client, so this only enables the callbacks. */
   1727 #define SSL_SESS_CACHE_CLIENT 0x0001
   1728 
   1729 /* SSL_SESS_CACHE_SERVER enables session caching for a server. */
   1730 #define SSL_SESS_CACHE_SERVER 0x0002
   1731 
   1732 /* SSL_SESS_CACHE_BOTH enables session caching for both client and server. */
   1733 #define SSL_SESS_CACHE_BOTH (SSL_SESS_CACHE_CLIENT | SSL_SESS_CACHE_SERVER)
   1734 
   1735 /* SSL_SESS_CACHE_NO_AUTO_CLEAR disables automatically calling
   1736  * |SSL_CTX_flush_sessions| every 255 connections. */
   1737 #define SSL_SESS_CACHE_NO_AUTO_CLEAR 0x0080
   1738 
   1739 /* SSL_SESS_CACHE_NO_INTERNAL_LOOKUP, on a server, disables looking up a session
   1740  * from the internal session cache. */
   1741 #define SSL_SESS_CACHE_NO_INTERNAL_LOOKUP 0x0100
   1742 
   1743 /* SSL_SESS_CACHE_NO_INTERNAL_STORE, on a server, disables storing sessions in
   1744  * the internal session cache. */
   1745 #define SSL_SESS_CACHE_NO_INTERNAL_STORE 0x0200
   1746 
   1747 /* SSL_SESS_CACHE_NO_INTERNAL, on a server, disables the internal session
   1748  * cache. */
   1749 #define SSL_SESS_CACHE_NO_INTERNAL \
   1750     (SSL_SESS_CACHE_NO_INTERNAL_LOOKUP | SSL_SESS_CACHE_NO_INTERNAL_STORE)
   1751 
   1752 /* SSL_CTX_set_session_cache_mode sets the session cache mode bits for |ctx| to
   1753  * |mode|. It returns the previous value. */
   1754 OPENSSL_EXPORT int SSL_CTX_set_session_cache_mode(SSL_CTX *ctx, int mode);
   1755 
   1756 /* SSL_CTX_get_session_cache_mode returns the session cache mode bits for
   1757  * |ctx| */
   1758 OPENSSL_EXPORT int SSL_CTX_get_session_cache_mode(const SSL_CTX *ctx);
   1759 
   1760 /* SSL_set_session, for a client, configures |ssl| to offer to resume |session|
   1761  * in the initial handshake and returns one. The caller retains ownership of
   1762  * |session|.
   1763  *
   1764  * It is an error to call this function after the handshake has begun. */
   1765 OPENSSL_EXPORT int SSL_set_session(SSL *ssl, SSL_SESSION *session);
   1766 
   1767 /* SSL_get_session returns a non-owning pointer to |ssl|'s session. For
   1768  * historical reasons, which session it returns depends on |ssl|'s state.
   1769  *
   1770  * Prior to the start of the initial handshake, it returns the session the
   1771  * caller set with |SSL_set_session|. After the initial handshake has finished
   1772  * and if no additional handshakes are in progress, it returns the currently
   1773  * active session. Its behavior is undefined while a handshake is in progress.
   1774  *
   1775  * Using this function to add new sessions to an external session cache is
   1776  * deprecated. Use |SSL_CTX_sess_set_new_cb| instead. */
   1777 OPENSSL_EXPORT SSL_SESSION *SSL_get_session(const SSL *ssl);
   1778 
   1779 /* SSL_get0_session is an alias for |SSL_get_session|. */
   1780 #define SSL_get0_session SSL_get_session
   1781 
   1782 /* SSL_get1_session acts like |SSL_get_session| but returns a new reference to
   1783  * the session. */
   1784 OPENSSL_EXPORT SSL_SESSION *SSL_get1_session(SSL *ssl);
   1785 
   1786 /* SSL_DEFAULT_SESSION_TIMEOUT is the default lifetime, in seconds, of a
   1787  * session in TLS 1.2 or earlier. This is how long we are willing to use the
   1788  * secret to encrypt traffic without fresh key material. */
   1789 #define SSL_DEFAULT_SESSION_TIMEOUT (2 * 60 * 60)
   1790 
   1791 /* SSL_DEFAULT_SESSION_PSK_DHE_TIMEOUT is the default lifetime, in seconds, of a
   1792  * session for TLS 1.3 psk_dhe_ke. This is how long we are willing to use the
   1793  * secret as an authenticator. */
   1794 #define SSL_DEFAULT_SESSION_PSK_DHE_TIMEOUT (2 * 24 * 60 * 60)
   1795 
   1796 /* SSL_DEFAULT_SESSION_AUTH_TIMEOUT is the default non-renewable lifetime, in
   1797  * seconds, of a TLS 1.3 session. This is how long we are willing to trust the
   1798  * signature in the initial handshake. */
   1799 #define SSL_DEFAULT_SESSION_AUTH_TIMEOUT (7 * 24 * 60 * 60)
   1800 
   1801 /* SSL_CTX_set_timeout sets the lifetime, in seconds, of TLS 1.2 (or earlier)
   1802  * sessions created in |ctx| to |timeout|. */
   1803 OPENSSL_EXPORT uint32_t SSL_CTX_set_timeout(SSL_CTX *ctx, uint32_t timeout);
   1804 
   1805 /* SSL_CTX_set_session_psk_dhe_timeout sets the lifetime, in seconds, of TLS 1.3
   1806  * sessions created in |ctx| to |timeout|. */
   1807 OPENSSL_EXPORT void SSL_CTX_set_session_psk_dhe_timeout(SSL_CTX *ctx,
   1808                                                         uint32_t timeout);
   1809 
   1810 /* SSL_CTX_get_timeout returns the lifetime, in seconds, of TLS 1.2 (or earlier)
   1811  * sessions created in |ctx|. */
   1812 OPENSSL_EXPORT uint32_t SSL_CTX_get_timeout(const SSL_CTX *ctx);
   1813 
   1814 /* SSL_CTX_set_session_id_context sets |ctx|'s session ID context to |sid_ctx|.
   1815  * It returns one on success and zero on error. The session ID context is an
   1816  * application-defined opaque byte string. A session will not be used in a
   1817  * connection without a matching session ID context.
   1818  *
   1819  * For a server, if |SSL_VERIFY_PEER| is enabled, it is an error to not set a
   1820  * session ID context.
   1821  *
   1822  * TODO(davidben): Is that check needed? That seems a special case of taking
   1823  * care not to cross-resume across configuration changes, and this is only
   1824  * relevant if a server requires client auth. */
   1825 OPENSSL_EXPORT int SSL_CTX_set_session_id_context(SSL_CTX *ctx,
   1826                                                   const uint8_t *sid_ctx,
   1827                                                   size_t sid_ctx_len);
   1828 
   1829 /* SSL_set_session_id_context sets |ssl|'s session ID context to |sid_ctx|. It
   1830  * returns one on success and zero on error. See also
   1831  * |SSL_CTX_set_session_id_context|. */
   1832 OPENSSL_EXPORT int SSL_set_session_id_context(SSL *ssl, const uint8_t *sid_ctx,
   1833                                               size_t sid_ctx_len);
   1834 
   1835 /* SSL_get0_session_id_context returns a pointer to |ssl|'s session ID context
   1836  * and sets |*out_len| to its length. */
   1837 OPENSSL_EXPORT const uint8_t *SSL_get0_session_id_context(const SSL *ssl,
   1838                                                           size_t *out_len);
   1839 
   1840 /* SSL_SESSION_CACHE_MAX_SIZE_DEFAULT is the default maximum size of a session
   1841  * cache. */
   1842 #define SSL_SESSION_CACHE_MAX_SIZE_DEFAULT (1024 * 20)
   1843 
   1844 /* SSL_CTX_sess_set_cache_size sets the maximum size of |ctx|'s internal session
   1845  * cache to |size|. It returns the previous value. */
   1846 OPENSSL_EXPORT unsigned long SSL_CTX_sess_set_cache_size(SSL_CTX *ctx,
   1847                                                          unsigned long size);
   1848 
   1849 /* SSL_CTX_sess_get_cache_size returns the maximum size of |ctx|'s internal
   1850  * session cache. */
   1851 OPENSSL_EXPORT unsigned long SSL_CTX_sess_get_cache_size(const SSL_CTX *ctx);
   1852 
   1853 /* SSL_CTX_sessions returns |ctx|'s internal session cache. */
   1854 OPENSSL_EXPORT LHASH_OF(SSL_SESSION) *SSL_CTX_sessions(SSL_CTX *ctx);
   1855 
   1856 /* SSL_CTX_sess_number returns the number of sessions in |ctx|'s internal
   1857  * session cache. */
   1858 OPENSSL_EXPORT size_t SSL_CTX_sess_number(const SSL_CTX *ctx);
   1859 
   1860 /* SSL_CTX_add_session inserts |session| into |ctx|'s internal session cache. It
   1861  * returns one on success and zero on error or if |session| is already in the
   1862  * cache. The caller retains its reference to |session|. */
   1863 OPENSSL_EXPORT int SSL_CTX_add_session(SSL_CTX *ctx, SSL_SESSION *session);
   1864 
   1865 /* SSL_CTX_remove_session removes |session| from |ctx|'s internal session cache.
   1866  * It returns one on success and zero if |session| was not in the cache. */
   1867 OPENSSL_EXPORT int SSL_CTX_remove_session(SSL_CTX *ctx, SSL_SESSION *session);
   1868 
   1869 /* SSL_CTX_flush_sessions removes all sessions from |ctx| which have expired as
   1870  * of time |time|. If |time| is zero, all sessions are removed. */
   1871 OPENSSL_EXPORT void SSL_CTX_flush_sessions(SSL_CTX *ctx, uint64_t time);
   1872 
   1873 /* SSL_CTX_sess_set_new_cb sets the callback to be called when a new session is
   1874  * established and ready to be cached. If the session cache is disabled (the
   1875  * appropriate one of |SSL_SESS_CACHE_CLIENT| or |SSL_SESS_CACHE_SERVER| is
   1876  * unset), the callback is not called.
   1877  *
   1878  * The callback is passed a reference to |session|. It returns one if it takes
   1879  * ownership and zero otherwise.
   1880  *
   1881  * Note: For a client, the callback may be called on abbreviated handshakes if a
   1882  * ticket is renewed. Further, it may not be called until some time after
   1883  * |SSL_do_handshake| or |SSL_connect| completes if False Start is enabled. Thus
   1884  * it's recommended to use this callback over checking |SSL_session_reused| on
   1885  * handshake completion.
   1886  *
   1887  * TODO(davidben): Conditioning callbacks on |SSL_SESS_CACHE_CLIENT| or
   1888  * |SSL_SESS_CACHE_SERVER| doesn't make any sense when one could just as easily
   1889  * not supply the callbacks. Removing that condition and the client internal
   1890  * cache would simplify things. */
   1891 OPENSSL_EXPORT void SSL_CTX_sess_set_new_cb(
   1892     SSL_CTX *ctx, int (*new_session_cb)(SSL *ssl, SSL_SESSION *session));
   1893 
   1894 /* SSL_CTX_sess_get_new_cb returns the callback set by
   1895  * |SSL_CTX_sess_set_new_cb|. */
   1896 OPENSSL_EXPORT int (*SSL_CTX_sess_get_new_cb(SSL_CTX *ctx))(
   1897     SSL *ssl, SSL_SESSION *session);
   1898 
   1899 /* SSL_CTX_sess_set_remove_cb sets a callback which is called when a session is
   1900  * removed from the internal session cache.
   1901  *
   1902  * TODO(davidben): What is the point of this callback? It seems useless since it
   1903  * only fires on sessions in the internal cache. */
   1904 OPENSSL_EXPORT void SSL_CTX_sess_set_remove_cb(
   1905     SSL_CTX *ctx,
   1906     void (*remove_session_cb)(SSL_CTX *ctx, SSL_SESSION *session));
   1907 
   1908 /* SSL_CTX_sess_get_remove_cb returns the callback set by
   1909  * |SSL_CTX_sess_set_remove_cb|. */
   1910 OPENSSL_EXPORT void (*SSL_CTX_sess_get_remove_cb(SSL_CTX *ctx))(
   1911     SSL_CTX *ctx, SSL_SESSION *session);
   1912 
   1913 /* SSL_CTX_sess_set_get_cb sets a callback to look up a session by ID for a
   1914  * server. The callback is passed the session ID and should return a matching
   1915  * |SSL_SESSION| or NULL if not found. It should set |*out_copy| to zero and
   1916  * return a new reference to the session. This callback is not used for a
   1917  * client.
   1918  *
   1919  * For historical reasons, if |*out_copy| is set to one (default), the SSL
   1920  * library will take a new reference to the returned |SSL_SESSION|, expecting
   1921  * the callback to return a non-owning pointer. This is not recommended. If
   1922  * |ctx| and thus the callback is used on multiple threads, the session may be
   1923  * removed and invalidated before the SSL library calls |SSL_SESSION_up_ref|,
   1924  * whereas the callback may synchronize internally.
   1925  *
   1926  * To look up a session asynchronously, the callback may return
   1927  * |SSL_magic_pending_session_ptr|. See the documentation for that function and
   1928  * |SSL_ERROR_PENDING_SESSION|.
   1929  *
   1930  * If the internal session cache is enabled, the callback is only consulted if
   1931  * the internal cache does not return a match.
   1932  *
   1933  * The callback's |id| parameter is not const for historical reasons, but the
   1934  * contents may not be modified. */
   1935 OPENSSL_EXPORT void SSL_CTX_sess_set_get_cb(
   1936     SSL_CTX *ctx,
   1937     SSL_SESSION *(*get_session_cb)(SSL *ssl, uint8_t *id, int id_len,
   1938                                    int *out_copy));
   1939 
   1940 /* SSL_CTX_sess_get_get_cb returns the callback set by
   1941  * |SSL_CTX_sess_set_get_cb|. */
   1942 OPENSSL_EXPORT SSL_SESSION *(*SSL_CTX_sess_get_get_cb(SSL_CTX *ctx))(
   1943     SSL *ssl, uint8_t *id, int id_len, int *out_copy);
   1944 
   1945 /* SSL_magic_pending_session_ptr returns a magic |SSL_SESSION|* which indicates
   1946  * that the session isn't currently unavailable. |SSL_get_error| will then
   1947  * return |SSL_ERROR_PENDING_SESSION| and the handshake can be retried later
   1948  * when the lookup has completed. */
   1949 OPENSSL_EXPORT SSL_SESSION *SSL_magic_pending_session_ptr(void);
   1950 
   1951 
   1952 /* Session tickets.
   1953  *
   1954  * Session tickets, from RFC 5077, allow session resumption without server-side
   1955  * state. Session tickets are supported in by default but may be disabled with
   1956  * |SSL_OP_NO_TICKET|.
   1957  *
   1958  * On the client, ticket-based sessions use the same APIs as ID-based tickets.
   1959  * Callers do not need to handle them differently.
   1960  *
   1961  * On the server, tickets are encrypted and authenticated with a secret key. By
   1962  * default, an |SSL_CTX| generates a key on creation. Tickets are minted and
   1963  * processed transparently. The following functions may be used to configure a
   1964  * persistent key or implement more custom behavior. There are three levels of
   1965  * customisation possible:
   1966  *
   1967  * 1) One can simply set the keys with |SSL_CTX_set_tlsext_ticket_keys|.
   1968  * 2) One can configure an |EVP_CIPHER_CTX| and |HMAC_CTX| directly for
   1969  *    encryption and authentication.
   1970  * 3) One can configure an |SSL_TICKET_ENCRYPTION_METHOD| to have more control
   1971  *    and the option of asynchronous decryption. */
   1972 
   1973 /* SSL_CTX_get_tlsext_ticket_keys writes |ctx|'s session ticket key material to
   1974  * |len| bytes of |out|. It returns one on success and zero if |len| is not
   1975  * 48. If |out| is NULL, it returns 48 instead. */
   1976 OPENSSL_EXPORT int SSL_CTX_get_tlsext_ticket_keys(SSL_CTX *ctx, void *out,
   1977                                                   size_t len);
   1978 
   1979 /* SSL_CTX_set_tlsext_ticket_keys sets |ctx|'s session ticket key material to
   1980  * |len| bytes of |in|. It returns one on success and zero if |len| is not
   1981  * 48. If |in| is NULL, it returns 48 instead. */
   1982 OPENSSL_EXPORT int SSL_CTX_set_tlsext_ticket_keys(SSL_CTX *ctx, const void *in,
   1983                                                   size_t len);
   1984 
   1985 /* SSL_TICKET_KEY_NAME_LEN is the length of the key name prefix of a session
   1986  * ticket. */
   1987 #define SSL_TICKET_KEY_NAME_LEN 16
   1988 
   1989 /* SSL_CTX_set_tlsext_ticket_key_cb sets the ticket callback to |callback| and
   1990  * returns one. |callback| will be called when encrypting a new ticket and when
   1991  * decrypting a ticket from the client.
   1992  *
   1993  * In both modes, |ctx| and |hmac_ctx| will already have been initialized with
   1994  * |EVP_CIPHER_CTX_init| and |HMAC_CTX_init|, respectively. |callback|
   1995  * configures |hmac_ctx| with an HMAC digest and key, and configures |ctx|
   1996  * for encryption or decryption, based on the mode.
   1997  *
   1998  * When encrypting a new ticket, |encrypt| will be one. It writes a public
   1999  * 16-byte key name to |key_name| and a fresh IV to |iv|. The output IV length
   2000  * must match |EVP_CIPHER_CTX_iv_length| of the cipher selected. In this mode,
   2001  * |callback| returns 1 on success and -1 on error.
   2002  *
   2003  * When decrypting a ticket, |encrypt| will be zero. |key_name| will point to a
   2004  * 16-byte key name and |iv| points to an IV. The length of the IV consumed must
   2005  * match |EVP_CIPHER_CTX_iv_length| of the cipher selected. In this mode,
   2006  * |callback| returns -1 to abort the handshake, 0 if decrypting the ticket
   2007  * failed, and 1 or 2 on success. If it returns 2, the ticket will be renewed.
   2008  * This may be used to re-key the ticket.
   2009  *
   2010  * WARNING: |callback| wildly breaks the usual return value convention and is
   2011  * called in two different modes. */
   2012 OPENSSL_EXPORT int SSL_CTX_set_tlsext_ticket_key_cb(
   2013     SSL_CTX *ctx, int (*callback)(SSL *ssl, uint8_t *key_name, uint8_t *iv,
   2014                                   EVP_CIPHER_CTX *ctx, HMAC_CTX *hmac_ctx,
   2015                                   int encrypt));
   2016 
   2017 /* ssl_ticket_aead_result_t enumerates the possible results from decrypting a
   2018  * ticket with an |SSL_TICKET_AEAD_METHOD|. */
   2019 enum ssl_ticket_aead_result_t {
   2020   /* ssl_ticket_aead_success indicates that the ticket was successfully
   2021    * decrypted. */
   2022   ssl_ticket_aead_success,
   2023   /* ssl_ticket_aead_retry indicates that the operation could not be
   2024    * immediately completed and must be reattempted, via |open|, at a later
   2025    * point. */
   2026   ssl_ticket_aead_retry,
   2027   /* ssl_ticket_aead_ignore_ticket indicates that the ticket should be ignored
   2028    * (i.e. is corrupt or otherwise undecryptable). */
   2029   ssl_ticket_aead_ignore_ticket,
   2030   /* ssl_ticket_aead_error indicates that a fatal error occured and the
   2031    * handshake should be terminated. */
   2032   ssl_ticket_aead_error,
   2033 };
   2034 
   2035 /* ssl_ticket_aead_method_st (aka |SSL_TICKET_ENCRYPTION_METHOD|) contains
   2036  * methods for encrypting and decrypting session tickets. */
   2037 struct ssl_ticket_aead_method_st {
   2038   /* max_overhead returns the maximum number of bytes of overhead that |seal|
   2039    * may add. */
   2040   size_t (*max_overhead)(SSL *ssl);
   2041 
   2042   /* seal encrypts and authenticates |in_len| bytes from |in|, writes, at most,
   2043    * |max_out_len| bytes to |out|, and puts the number of bytes written in
   2044    * |*out_len|. The |in| and |out| buffers may be equal but will not otherwise
   2045    * alias. It returns one on success or zero on error. */
   2046   int (*seal)(SSL *ssl, uint8_t *out, size_t *out_len, size_t max_out_len,
   2047               const uint8_t *in, size_t in_len);
   2048 
   2049   /* open authenticates and decrypts |in_len| bytes from |in|, writes, at most,
   2050    * |max_out_len| bytes of plaintext to |out|, and puts the number of bytes
   2051    * written in |*out_len|. The |in| and |out| buffers may be equal but will
   2052    * not otherwise alias. See |ssl_ticket_aead_result_t| for details of the
   2053    * return values. In the case that a retry is indicated, the caller should
   2054    * arrange for the high-level operation on |ssl| to be retried when the
   2055    * operation is completed, which will result in another call to |open|. */
   2056   enum ssl_ticket_aead_result_t (*open)(SSL *ssl, uint8_t *out, size_t *out_len,
   2057                                         size_t max_out_len, const uint8_t *in,
   2058                                         size_t in_len);
   2059 };
   2060 
   2061 /* SSL_CTX_set_ticket_aead_method configures a custom ticket AEAD method table
   2062  * on |ctx|. |aead_method| must remain valid for the lifetime of |ctx|. */
   2063 OPENSSL_EXPORT void SSL_CTX_set_ticket_aead_method(
   2064     SSL_CTX *ctx, const SSL_TICKET_AEAD_METHOD *aead_method);
   2065 
   2066 
   2067 /* Elliptic curve Diffie-Hellman.
   2068  *
   2069  * Cipher suites using an ECDHE key exchange perform Diffie-Hellman over an
   2070  * elliptic curve negotiated by both endpoints. See RFC 4492. Only named curves
   2071  * are supported. ECDHE is always enabled, but the curve preferences may be
   2072  * configured with these functions.
   2073  *
   2074  * Note that TLS 1.3 renames these from curves to groups. For consistency, we
   2075  * currently use the TLS 1.2 name in the API. */
   2076 
   2077 /* SSL_CTX_set1_curves sets the preferred curves for |ctx| to be |curves|. Each
   2078  * element of |curves| should be a curve nid. It returns one on success and
   2079  * zero on failure.
   2080  *
   2081  * Note that this API uses nid values from nid.h and not the |SSL_CURVE_*|
   2082  * values defined below. */
   2083 OPENSSL_EXPORT int SSL_CTX_set1_curves(SSL_CTX *ctx, const int *curves,
   2084                                        size_t curves_len);
   2085 
   2086 /* SSL_set1_curves sets the preferred curves for |ssl| to be |curves|. Each
   2087  * element of |curves| should be a curve nid. It returns one on success and
   2088  * zero on failure.
   2089  *
   2090  * Note that this API uses nid values from nid.h and not the |SSL_CURVE_*|
   2091  * values defined below. */
   2092 OPENSSL_EXPORT int SSL_set1_curves(SSL *ssl, const int *curves,
   2093                                    size_t curves_len);
   2094 
   2095 /* SSL_CTX_set1_curves_list sets the preferred curves for |ctx| to be the
   2096  * colon-separated list |curves|. Each element of |curves| should be a curve
   2097  * name (e.g. P-256, X25519, ...). It returns one on success and zero on
   2098  * failure. */
   2099 OPENSSL_EXPORT int SSL_CTX_set1_curves_list(SSL_CTX *ctx, const char *curves);
   2100 
   2101 /* SSL_set1_curves_list sets the preferred curves for |ssl| to be the
   2102  * colon-separated list |curves|. Each element of |curves| should be a curve
   2103  * name (e.g. P-256, X25519, ...). It returns one on success and zero on
   2104  * failure. */
   2105 OPENSSL_EXPORT int SSL_set1_curves_list(SSL *ssl, const char *curves);
   2106 
   2107 /* SSL_CURVE_* define TLS curve IDs. */
   2108 #define SSL_CURVE_SECP256R1 23
   2109 #define SSL_CURVE_SECP384R1 24
   2110 #define SSL_CURVE_SECP521R1 25
   2111 #define SSL_CURVE_X25519 29
   2112 
   2113 /* SSL_get_curve_id returns the ID of the curve used by |ssl|'s most recently
   2114  * completed handshake or 0 if not applicable.
   2115  *
   2116  * TODO(davidben): This API currently does not work correctly if there is a
   2117  * renegotiation in progress. Fix this. */
   2118 OPENSSL_EXPORT uint16_t SSL_get_curve_id(const SSL *ssl);
   2119 
   2120 /* SSL_get_curve_name returns a human-readable name for the curve specified by
   2121  * the given TLS curve id, or NULL if the curve is unknown. */
   2122 OPENSSL_EXPORT const char *SSL_get_curve_name(uint16_t curve_id);
   2123 
   2124 
   2125 /* Multiplicative Diffie-Hellman.
   2126  *
   2127  * Cipher suites using a DHE key exchange perform Diffie-Hellman over a
   2128  * multiplicative group selected by the server. These ciphers are disabled for a
   2129  * server unless a group is chosen with one of these functions. */
   2130 
   2131 /* SSL_CTX_set_tmp_dh configures |ctx| to use the group from |dh| as the group
   2132  * for DHE. Only the group is used, so |dh| needn't have a keypair. It returns
   2133  * one on success and zero on error. */
   2134 OPENSSL_EXPORT int SSL_CTX_set_tmp_dh(SSL_CTX *ctx, const DH *dh);
   2135 
   2136 /* SSL_set_tmp_dh configures |ssl| to use the group from |dh| as the group for
   2137  * DHE. Only the group is used, so |dh| needn't have a keypair. It returns one
   2138  * on success and zero on error. */
   2139 OPENSSL_EXPORT int SSL_set_tmp_dh(SSL *ssl, const DH *dh);
   2140 
   2141 /* SSL_CTX_set_tmp_dh_callback configures |ctx| to use |callback| to determine
   2142  * the group for DHE ciphers. |callback| should ignore |is_export| and
   2143  * |keylength| and return a |DH| of the selected group or NULL on error. Only
   2144  * the parameters are used, so the |DH| needn't have a generated keypair.
   2145  *
   2146  * WARNING: The caller does not take ownership of the resulting |DH|, so
   2147  * |callback| must save and release the object elsewhere. */
   2148 OPENSSL_EXPORT void SSL_CTX_set_tmp_dh_callback(
   2149     SSL_CTX *ctx, DH *(*callback)(SSL *ssl, int is_export, int keylength));
   2150 
   2151 /* SSL_set_tmp_dh_callback configures |ssl| to use |callback| to determine the
   2152  * group for DHE ciphers. |callback| should ignore |is_export| and |keylength|
   2153  * and return a |DH| of the selected group or NULL on error. Only the
   2154  * parameters are used, so the |DH| needn't have a generated keypair.
   2155  *
   2156  * WARNING: The caller does not take ownership of the resulting |DH|, so
   2157  * |callback| must save and release the object elsewhere. */
   2158 OPENSSL_EXPORT void SSL_set_tmp_dh_callback(SSL *ssl,
   2159                                             DH *(*dh)(SSL *ssl, int is_export,
   2160                                                       int keylength));
   2161 
   2162 
   2163 /* Certificate verification.
   2164  *
   2165  * SSL may authenticate either endpoint with an X.509 certificate. Typically
   2166  * this is used to authenticate the server to the client. These functions
   2167  * configure certificate verification.
   2168  *
   2169  * WARNING: By default, certificate verification errors on a client are not
   2170  * fatal. See |SSL_VERIFY_NONE| This may be configured with
   2171  * |SSL_CTX_set_verify|.
   2172  *
   2173  * By default clients are anonymous but a server may request a certificate from
   2174  * the client by setting |SSL_VERIFY_PEER|.
   2175  *
   2176  * Many of these functions use OpenSSL's legacy X.509 stack which is
   2177  * underdocumented and deprecated, but the replacement isn't ready yet. For
   2178  * now, consumers may use the existing stack or bypass it by performing
   2179  * certificate verification externally. This may be done with
   2180  * |SSL_CTX_set_cert_verify_callback| or by extracting the chain with
   2181  * |SSL_get_peer_cert_chain| after the handshake. In the future, functions will
   2182  * be added to use the SSL stack without dependency on any part of the legacy
   2183  * X.509 and ASN.1 stack.
   2184  *
   2185  * To augment certificate verification, a client may also enable OCSP stapling
   2186  * (RFC 6066) and Certificate Transparency (RFC 6962) extensions. */
   2187 
   2188 /* SSL_VERIFY_NONE, on a client, verifies the server certificate but does not
   2189  * make errors fatal. The result may be checked with |SSL_get_verify_result|. On
   2190  * a server it does not request a client certificate. This is the default. */
   2191 #define SSL_VERIFY_NONE 0x00
   2192 
   2193 /* SSL_VERIFY_PEER, on a client, makes server certificate errors fatal. On a
   2194  * server it requests a client certificate and makes errors fatal. However,
   2195  * anonymous clients are still allowed. See
   2196  * |SSL_VERIFY_FAIL_IF_NO_PEER_CERT|. */
   2197 #define SSL_VERIFY_PEER 0x01
   2198 
   2199 /* SSL_VERIFY_FAIL_IF_NO_PEER_CERT configures a server to reject connections if
   2200  * the client declines to send a certificate. Otherwise |SSL_VERIFY_PEER| still
   2201  * allows anonymous clients. */
   2202 #define SSL_VERIFY_FAIL_IF_NO_PEER_CERT 0x02
   2203 
   2204 /* SSL_VERIFY_PEER_IF_NO_OBC configures a server to request a client certificate
   2205  * if and only if Channel ID is not negotiated. */
   2206 #define SSL_VERIFY_PEER_IF_NO_OBC 0x04
   2207 
   2208 /* SSL_CTX_set_verify configures certificate verification behavior. |mode| is
   2209  * one of the |SSL_VERIFY_*| values defined above. |callback|, if not NULL, is
   2210  * used to customize certificate verification. See the behavior of
   2211  * |X509_STORE_CTX_set_verify_cb|.
   2212  *
   2213  * The callback may use |SSL_get_ex_data_X509_STORE_CTX_idx| with
   2214  * |X509_STORE_CTX_get_ex_data| to look up the |SSL| from |store_ctx|. */
   2215 OPENSSL_EXPORT void SSL_CTX_set_verify(
   2216     SSL_CTX *ctx, int mode, int (*callback)(int ok, X509_STORE_CTX *store_ctx));
   2217 
   2218 /* SSL_set_verify configures certificate verification behavior. |mode| is one of
   2219  * the |SSL_VERIFY_*| values defined above. |callback|, if not NULL, is used to
   2220  * customize certificate verification. See the behavior of
   2221  * |X509_STORE_CTX_set_verify_cb|.
   2222  *
   2223  * The callback may use |SSL_get_ex_data_X509_STORE_CTX_idx| with
   2224  * |X509_STORE_CTX_get_ex_data| to look up the |SSL| from |store_ctx|. */
   2225 OPENSSL_EXPORT void SSL_set_verify(SSL *ssl, int mode,
   2226                                    int (*callback)(int ok,
   2227                                                    X509_STORE_CTX *store_ctx));
   2228 
   2229 /* SSL_CTX_get_verify_mode returns |ctx|'s verify mode, set by
   2230  * |SSL_CTX_set_verify|. */
   2231 OPENSSL_EXPORT int SSL_CTX_get_verify_mode(const SSL_CTX *ctx);
   2232 
   2233 /* SSL_get_verify_mode returns |ssl|'s verify mode, set by |SSL_CTX_set_verify|
   2234  * or |SSL_set_verify|. */
   2235 OPENSSL_EXPORT int SSL_get_verify_mode(const SSL *ssl);
   2236 
   2237 /* SSL_CTX_get_verify_callback returns the callback set by
   2238  * |SSL_CTX_set_verify|. */
   2239 OPENSSL_EXPORT int (*SSL_CTX_get_verify_callback(const SSL_CTX *ctx))(
   2240     int ok, X509_STORE_CTX *store_ctx);
   2241 
   2242 /* SSL_get_verify_callback returns the callback set by |SSL_CTX_set_verify| or
   2243  * |SSL_set_verify|. */
   2244 OPENSSL_EXPORT int (*SSL_get_verify_callback(const SSL *ssl))(
   2245     int ok, X509_STORE_CTX *store_ctx);
   2246 
   2247 /* SSL_CTX_set_verify_depth sets the maximum depth of a certificate chain
   2248  * accepted in verification. This number does not include the leaf, so a depth
   2249  * of 1 allows the leaf and one CA certificate. */
   2250 OPENSSL_EXPORT void SSL_CTX_set_verify_depth(SSL_CTX *ctx, int depth);
   2251 
   2252 /* SSL_set_verify_depth sets the maximum depth of a certificate chain accepted
   2253  * in verification. This number does not include the leaf, so a depth of 1
   2254  * allows the leaf and one CA certificate. */
   2255 OPENSSL_EXPORT void SSL_set_verify_depth(SSL *ssl, int depth);
   2256 
   2257 /* SSL_CTX_get_verify_depth returns the maximum depth of a certificate accepted
   2258  * in verification. */
   2259 OPENSSL_EXPORT int SSL_CTX_get_verify_depth(const SSL_CTX *ctx);
   2260 
   2261 /* SSL_get_verify_depth returns the maximum depth of a certificate accepted in
   2262  * verification. */
   2263 OPENSSL_EXPORT int SSL_get_verify_depth(const SSL *ssl);
   2264 
   2265 /* SSL_CTX_set1_param sets verification parameters from |param|. It returns one
   2266  * on success and zero on failure. The caller retains ownership of |param|. */
   2267 OPENSSL_EXPORT int SSL_CTX_set1_param(SSL_CTX *ctx,
   2268                                       const X509_VERIFY_PARAM *param);
   2269 
   2270 /* SSL_set1_param sets verification parameters from |param|. It returns one on
   2271  * success and zero on failure. The caller retains ownership of |param|. */
   2272 OPENSSL_EXPORT int SSL_set1_param(SSL *ssl,
   2273                                   const X509_VERIFY_PARAM *param);
   2274 
   2275 /* SSL_CTX_get0_param returns |ctx|'s |X509_VERIFY_PARAM| for certificate
   2276  * verification. The caller must not release the returned pointer but may call
   2277  * functions on it to configure it. */
   2278 OPENSSL_EXPORT X509_VERIFY_PARAM *SSL_CTX_get0_param(SSL_CTX *ctx);
   2279 
   2280 /* SSL_get0_param returns |ssl|'s |X509_VERIFY_PARAM| for certificate
   2281  * verification. The caller must not release the returned pointer but may call
   2282  * functions on it to configure it. */
   2283 OPENSSL_EXPORT X509_VERIFY_PARAM *SSL_get0_param(SSL *ssl);
   2284 
   2285 /* SSL_CTX_set_purpose sets |ctx|'s |X509_VERIFY_PARAM|'s 'purpose' parameter to
   2286  * |purpose|. It returns one on success and zero on error. */
   2287 OPENSSL_EXPORT int SSL_CTX_set_purpose(SSL_CTX *ctx, int purpose);
   2288 
   2289 /* SSL_set_purpose sets |ssl|'s |X509_VERIFY_PARAM|'s 'purpose' parameter to
   2290  * |purpose|. It returns one on success and zero on error. */
   2291 OPENSSL_EXPORT int SSL_set_purpose(SSL *ssl, int purpose);
   2292 
   2293 /* SSL_CTX_set_trust sets |ctx|'s |X509_VERIFY_PARAM|'s 'trust' parameter to
   2294  * |trust|. It returns one on success and zero on error. */
   2295 OPENSSL_EXPORT int SSL_CTX_set_trust(SSL_CTX *ctx, int trust);
   2296 
   2297 /* SSL_set_trust sets |ssl|'s |X509_VERIFY_PARAM|'s 'trust' parameter to
   2298  * |trust|. It returns one on success and zero on error. */
   2299 OPENSSL_EXPORT int SSL_set_trust(SSL *ssl, int trust);
   2300 
   2301 /* SSL_CTX_set_cert_store sets |ctx|'s certificate store to |store|. It takes
   2302  * ownership of |store|. The store is used for certificate verification.
   2303  *
   2304  * The store is also used for the auto-chaining feature, but this is deprecated.
   2305  * See also |SSL_MODE_NO_AUTO_CHAIN|. */
   2306 OPENSSL_EXPORT void SSL_CTX_set_cert_store(SSL_CTX *ctx, X509_STORE *store);
   2307 
   2308 /* SSL_CTX_get_cert_store returns |ctx|'s certificate store. */
   2309 OPENSSL_EXPORT X509_STORE *SSL_CTX_get_cert_store(const SSL_CTX *ctx);
   2310 
   2311 /* SSL_CTX_set_default_verify_paths loads the OpenSSL system-default trust
   2312  * anchors into |ctx|'s store. It returns one on success and zero on failure. */
   2313 OPENSSL_EXPORT int SSL_CTX_set_default_verify_paths(SSL_CTX *ctx);
   2314 
   2315 /* SSL_CTX_load_verify_locations loads trust anchors into |ctx|'s store from
   2316  * |ca_file| and |ca_dir|, either of which may be NULL. If |ca_file| is passed,
   2317  * it is opened and PEM-encoded CA certificates are read. If |ca_dir| is passed,
   2318  * it is treated as a directory in OpenSSL's hashed directory format. It returns
   2319  * one on success and zero on failure.
   2320  *
   2321  * See
   2322  * https://www.openssl.org/docs/manmaster/ssl/SSL_CTX_load_verify_locations.html
   2323  * for documentation on the directory format. */
   2324 OPENSSL_EXPORT int SSL_CTX_load_verify_locations(SSL_CTX *ctx,
   2325                                                  const char *ca_file,
   2326                                                  const char *ca_dir);
   2327 
   2328 /* SSL_get_verify_result returns the result of certificate verification. It is
   2329  * either |X509_V_OK| or a |X509_V_ERR_*| value. */
   2330 OPENSSL_EXPORT long SSL_get_verify_result(const SSL *ssl);
   2331 
   2332 /* SSL_get_ex_data_X509_STORE_CTX_idx returns the ex_data index used to look up
   2333  * the |SSL| associated with an |X509_STORE_CTX| in the verify callback. */
   2334 OPENSSL_EXPORT int SSL_get_ex_data_X509_STORE_CTX_idx(void);
   2335 
   2336 /* SSL_CTX_set_cert_verify_callback sets a custom callback to be called on
   2337  * certificate verification rather than |X509_verify_cert|. |store_ctx| contains
   2338  * the verification parameters. The callback should return one on success and
   2339  * zero on fatal error. It may use |X509_STORE_CTX_set_error| to set a
   2340  * verification result.
   2341  *
   2342  * The callback may use |SSL_get_ex_data_X509_STORE_CTX_idx| to recover the
   2343  * |SSL| object from |store_ctx|. */
   2344 OPENSSL_EXPORT void SSL_CTX_set_cert_verify_callback(
   2345     SSL_CTX *ctx, int (*callback)(X509_STORE_CTX *store_ctx, void *arg),
   2346     void *arg);
   2347 
   2348 /* SSL_CTX_i_promise_to_verify_certs_after_the_handshake indicates that the
   2349  * caller understands that the |CRYPTO_BUFFER|-based methods currently require
   2350  * post-handshake verification of certificates and thus it's ok to accept any
   2351  * certificates during the handshake. */
   2352 OPENSSL_EXPORT void SSL_CTX_i_promise_to_verify_certs_after_the_handshake(
   2353     SSL_CTX *ctx);
   2354 
   2355 /* SSL_enable_signed_cert_timestamps causes |ssl| (which must be the client end
   2356  * of a connection) to request SCTs from the server. See
   2357  * https://tools.ietf.org/html/rfc6962.
   2358  *
   2359  * Call |SSL_get0_signed_cert_timestamp_list| to recover the SCT after the
   2360  * handshake. */
   2361 OPENSSL_EXPORT void SSL_enable_signed_cert_timestamps(SSL *ssl);
   2362 
   2363 /* SSL_CTX_enable_signed_cert_timestamps enables SCT requests on all client SSL
   2364  * objects created from |ctx|.
   2365  *
   2366  * Call |SSL_get0_signed_cert_timestamp_list| to recover the SCT after the
   2367  * handshake. */
   2368 OPENSSL_EXPORT void SSL_CTX_enable_signed_cert_timestamps(SSL_CTX *ctx);
   2369 
   2370 /* SSL_enable_ocsp_stapling causes |ssl| (which must be the client end of a
   2371  * connection) to request a stapled OCSP response from the server.
   2372  *
   2373  * Call |SSL_get0_ocsp_response| to recover the OCSP response after the
   2374  * handshake. */
   2375 OPENSSL_EXPORT void SSL_enable_ocsp_stapling(SSL *ssl);
   2376 
   2377 /* SSL_CTX_enable_ocsp_stapling enables OCSP stapling on all client SSL objects
   2378  * created from |ctx|.
   2379  *
   2380  * Call |SSL_get0_ocsp_response| to recover the OCSP response after the
   2381  * handshake. */
   2382 OPENSSL_EXPORT void SSL_CTX_enable_ocsp_stapling(SSL_CTX *ctx);
   2383 
   2384 /* SSL_CTX_set0_verify_cert_store sets an |X509_STORE| that will be used
   2385  * exclusively for certificate verification and returns one. Ownership of
   2386  * |store| is transferred to the |SSL_CTX|. */
   2387 OPENSSL_EXPORT int SSL_CTX_set0_verify_cert_store(SSL_CTX *ctx,
   2388                                                   X509_STORE *store);
   2389 
   2390 /* SSL_CTX_set1_verify_cert_store sets an |X509_STORE| that will be used
   2391  * exclusively for certificate verification and returns one. An additional
   2392  * reference to |store| will be taken. */
   2393 OPENSSL_EXPORT int SSL_CTX_set1_verify_cert_store(SSL_CTX *ctx,
   2394                                                   X509_STORE *store);
   2395 
   2396 /* SSL_set0_verify_cert_store sets an |X509_STORE| that will be used
   2397  * exclusively for certificate verification and returns one. Ownership of
   2398  * |store| is transferred to the |SSL|. */
   2399 OPENSSL_EXPORT int SSL_set0_verify_cert_store(SSL *ssl, X509_STORE *store);
   2400 
   2401 /* SSL_set1_verify_cert_store sets an |X509_STORE| that will be used
   2402  * exclusively for certificate verification and returns one. An additional
   2403  * reference to |store| will be taken. */
   2404 OPENSSL_EXPORT int SSL_set1_verify_cert_store(SSL *ssl, X509_STORE *store);
   2405 
   2406 
   2407 /* Client certificate CA list.
   2408  *
   2409  * When requesting a client certificate, a server may advertise a list of
   2410  * certificate authorities which are accepted. These functions may be used to
   2411  * configure this list. */
   2412 
   2413 /* SSL_set_client_CA_list sets |ssl|'s client certificate CA list to
   2414  * |name_list|. It takes ownership of |name_list|. */
   2415 OPENSSL_EXPORT void SSL_set_client_CA_list(SSL *ssl,
   2416                                            STACK_OF(X509_NAME) *name_list);
   2417 
   2418 /* SSL_CTX_set_client_CA_list sets |ctx|'s client certificate CA list to
   2419  * |name_list|. It takes ownership of |name_list|. */
   2420 OPENSSL_EXPORT void SSL_CTX_set_client_CA_list(SSL_CTX *ctx,
   2421                                                STACK_OF(X509_NAME) *name_list);
   2422 
   2423 /* SSL_get_client_CA_list returns |ssl|'s client certificate CA list. If |ssl|
   2424  * has not been configured as a client, this is the list configured by
   2425  * |SSL_CTX_set_client_CA_list|.
   2426  *
   2427  * If configured as a client, it returns the client certificate CA list sent by
   2428  * the server. In this mode, the behavior is undefined except during the
   2429  * callbacks set by |SSL_CTX_set_cert_cb| and |SSL_CTX_set_client_cert_cb| or
   2430  * when the handshake is paused because of them. */
   2431 OPENSSL_EXPORT STACK_OF(X509_NAME) *SSL_get_client_CA_list(const SSL *ssl);
   2432 
   2433 /* SSL_get0_server_requested_CAs returns the CAs sent by a server to guide a
   2434  * client in certificate selection. They are a series of DER-encoded X.509
   2435  * names. This function may only be called during a callback set by
   2436  * |SSL_CTX_set_cert_cb| or when the handshake is paused because of it.
   2437  *
   2438  * The returned stack is owned by |ssl|, as are its contents. It should not be
   2439  * used past the point where the handshake is restarted after the callback. */
   2440 OPENSSL_EXPORT STACK_OF(CRYPTO_BUFFER) *SSL_get0_server_requested_CAs(
   2441     const SSL *ssl);
   2442 
   2443 /* SSL_CTX_get_client_CA_list returns |ctx|'s client certificate CA list. */
   2444 OPENSSL_EXPORT STACK_OF(X509_NAME) *
   2445     SSL_CTX_get_client_CA_list(const SSL_CTX *ctx);
   2446 
   2447 /* SSL_add_client_CA appends |x509|'s subject to the client certificate CA list.
   2448  * It returns one on success or zero on error. The caller retains ownership of
   2449  * |x509|. */
   2450 OPENSSL_EXPORT int SSL_add_client_CA(SSL *ssl, X509 *x509);
   2451 
   2452 /* SSL_CTX_add_client_CA appends |x509|'s subject to the client certificate CA
   2453  * list. It returns one on success or zero on error. The caller retains
   2454  * ownership of |x509|. */
   2455 OPENSSL_EXPORT int SSL_CTX_add_client_CA(SSL_CTX *ctx, X509 *x509);
   2456 
   2457 /* SSL_load_client_CA_file opens |file| and reads PEM-encoded certificates from
   2458  * it. It returns a newly-allocated stack of the certificate subjects or NULL
   2459  * on error. */
   2460 OPENSSL_EXPORT STACK_OF(X509_NAME) *SSL_load_client_CA_file(const char *file);
   2461 
   2462 /* SSL_dup_CA_list makes a deep copy of |list|. It returns the new list on
   2463  * success or NULL on allocation error. */
   2464 OPENSSL_EXPORT STACK_OF(X509_NAME) *SSL_dup_CA_list(STACK_OF(X509_NAME) *list);
   2465 
   2466 /* SSL_add_file_cert_subjects_to_stack behaves like |SSL_load_client_CA_file|
   2467  * but appends the result to |out|. It returns one on success or zero on
   2468  * error. */
   2469 OPENSSL_EXPORT int SSL_add_file_cert_subjects_to_stack(STACK_OF(X509_NAME) *out,
   2470                                                        const char *file);
   2471 
   2472 
   2473 /* Server name indication.
   2474  *
   2475  * The server_name extension (RFC 3546) allows the client to advertise the name
   2476  * of the server it is connecting to. This is used in virtual hosting
   2477  * deployments to select one of a several certificates on a single IP. Only the
   2478  * host_name name type is supported. */
   2479 
   2480 #define TLSEXT_NAMETYPE_host_name 0
   2481 
   2482 /* SSL_set_tlsext_host_name, for a client, configures |ssl| to advertise |name|
   2483  * in the server_name extension. It returns one on success and zero on error. */
   2484 OPENSSL_EXPORT int SSL_set_tlsext_host_name(SSL *ssl, const char *name);
   2485 
   2486 /* SSL_get_servername, for a server, returns the hostname supplied by the
   2487  * client or NULL if there was none. The |type| argument must be
   2488  * |TLSEXT_NAMETYPE_host_name|. */
   2489 OPENSSL_EXPORT const char *SSL_get_servername(const SSL *ssl, const int type);
   2490 
   2491 /* SSL_get_servername_type, for a server, returns |TLSEXT_NAMETYPE_host_name|
   2492  * if the client sent a hostname and -1 otherwise. */
   2493 OPENSSL_EXPORT int SSL_get_servername_type(const SSL *ssl);
   2494 
   2495 /* SSL_CTX_set_tlsext_servername_callback configures |callback| to be called on
   2496  * the server after ClientHello extensions have been parsed and returns one.
   2497  * The callback may use |SSL_get_servername| to examine the server_name
   2498  * extension and returns a |SSL_TLSEXT_ERR_*| value. The value of |arg| may be
   2499  * set by calling |SSL_CTX_set_tlsext_servername_arg|.
   2500  *
   2501  * If the callback returns |SSL_TLSEXT_ERR_NOACK|, the server_name extension is
   2502  * not acknowledged in the ServerHello. If the return value is
   2503  * |SSL_TLSEXT_ERR_ALERT_FATAL|, then |*out_alert| is the alert to send,
   2504  * defaulting to |SSL_AD_UNRECOGNIZED_NAME|. |SSL_TLSEXT_ERR_ALERT_WARNING| is
   2505  * ignored and treated as |SSL_TLSEXT_ERR_OK|. */
   2506 OPENSSL_EXPORT int SSL_CTX_set_tlsext_servername_callback(
   2507     SSL_CTX *ctx, int (*callback)(SSL *ssl, int *out_alert, void *arg));
   2508 
   2509 /* SSL_CTX_set_tlsext_servername_arg sets the argument to the servername
   2510  * callback and returns one. See |SSL_CTX_set_tlsext_servername_callback|. */
   2511 OPENSSL_EXPORT int SSL_CTX_set_tlsext_servername_arg(SSL_CTX *ctx, void *arg);
   2512 
   2513 /* SSL_TLSEXT_ERR_* are values returned by some extension-related callbacks. */
   2514 #define SSL_TLSEXT_ERR_OK 0
   2515 #define SSL_TLSEXT_ERR_ALERT_WARNING 1
   2516 #define SSL_TLSEXT_ERR_ALERT_FATAL 2
   2517 #define SSL_TLSEXT_ERR_NOACK 3
   2518 
   2519 /* SSL_set_SSL_CTX changes |ssl|'s |SSL_CTX|. |ssl| will use the
   2520  * certificate-related settings from |ctx|, and |SSL_get_SSL_CTX| will report
   2521  * |ctx|. This function may be used during the callbacks registered by
   2522  * |SSL_CTX_set_select_certificate_cb|,
   2523  * |SSL_CTX_set_tlsext_servername_callback|, and |SSL_CTX_set_cert_cb| or when
   2524  * the handshake is paused from them. It is typically used to switch
   2525  * certificates based on SNI.
   2526  *
   2527  * Note the session cache and related settings will continue to use the initial
   2528  * |SSL_CTX|. Callers should use |SSL_CTX_set_session_id_context| to partition
   2529  * the session cache between different domains.
   2530  *
   2531  * TODO(davidben): Should other settings change after this call? */
   2532 OPENSSL_EXPORT SSL_CTX *SSL_set_SSL_CTX(SSL *ssl, SSL_CTX *ctx);
   2533 
   2534 
   2535 /* Application-layer protocol negotiation.
   2536  *
   2537  * The ALPN extension (RFC 7301) allows negotiating different application-layer
   2538  * protocols over a single port. This is used, for example, to negotiate
   2539  * HTTP/2. */
   2540 
   2541 /* SSL_CTX_set_alpn_protos sets the client ALPN protocol list on |ctx| to
   2542  * |protos|. |protos| must be in wire-format (i.e. a series of non-empty, 8-bit
   2543  * length-prefixed strings). It returns zero on success and one on failure.
   2544  * Configuring this list enables ALPN on a client.
   2545  *
   2546  * WARNING: this function is dangerous because it breaks the usual return value
   2547  * convention. */
   2548 OPENSSL_EXPORT int SSL_CTX_set_alpn_protos(SSL_CTX *ctx, const uint8_t *protos,
   2549                                            unsigned protos_len);
   2550 
   2551 /* SSL_set_alpn_protos sets the client ALPN protocol list on |ssl| to |protos|.
   2552  * |protos| must be in wire-format (i.e. a series of non-empty, 8-bit
   2553  * length-prefixed strings). It returns zero on success and one on failure.
   2554  * Configuring this list enables ALPN on a client.
   2555  *
   2556  * WARNING: this function is dangerous because it breaks the usual return value
   2557  * convention. */
   2558 OPENSSL_EXPORT int SSL_set_alpn_protos(SSL *ssl, const uint8_t *protos,
   2559                                        unsigned protos_len);
   2560 
   2561 /* SSL_CTX_set_alpn_select_cb sets a callback function on |ctx| that is called
   2562  * during ClientHello processing in order to select an ALPN protocol from the
   2563  * client's list of offered protocols. Configuring this callback enables ALPN on
   2564  * a server.
   2565  *
   2566  * The callback is passed a wire-format (i.e. a series of non-empty, 8-bit
   2567  * length-prefixed strings) ALPN protocol list in |in|. It should set |*out| and
   2568  * |*out_len| to the selected protocol and return |SSL_TLSEXT_ERR_OK| on
   2569  * success. It does not pass ownership of the buffer. Otherwise, it should
   2570  * return |SSL_TLSEXT_ERR_NOACK|. Other |SSL_TLSEXT_ERR_*| values are
   2571  * unimplemented and will be treated as |SSL_TLSEXT_ERR_NOACK|.
   2572  *
   2573  * The cipher suite is selected before negotiating ALPN. The callback may use
   2574  * |SSL_get_pending_cipher| to query the cipher suite. */
   2575 OPENSSL_EXPORT void SSL_CTX_set_alpn_select_cb(
   2576     SSL_CTX *ctx, int (*cb)(SSL *ssl, const uint8_t **out, uint8_t *out_len,
   2577                             const uint8_t *in, unsigned in_len, void *arg),
   2578     void *arg);
   2579 
   2580 /* SSL_get0_alpn_selected gets the selected ALPN protocol (if any) from |ssl|.
   2581  * On return it sets |*out_data| to point to |*out_len| bytes of protocol name
   2582  * (not including the leading length-prefix byte). If the server didn't respond
   2583  * with a negotiated protocol then |*out_len| will be zero. */
   2584 OPENSSL_EXPORT void SSL_get0_alpn_selected(const SSL *ssl,
   2585                                            const uint8_t **out_data,
   2586                                            unsigned *out_len);
   2587 
   2588 
   2589 /* Next protocol negotiation.
   2590  *
   2591  * The NPN extension (draft-agl-tls-nextprotoneg-03) is the predecessor to ALPN
   2592  * and deprecated in favor of it. */
   2593 
   2594 /* SSL_CTX_set_next_protos_advertised_cb sets a callback that is called when a
   2595  * TLS server needs a list of supported protocols for Next Protocol
   2596  * Negotiation. The returned list must be in wire format. The list is returned
   2597  * by setting |*out| to point to it and |*out_len| to its length. This memory
   2598  * will not be modified, but one should assume that |ssl| keeps a reference to
   2599  * it.
   2600  *
   2601  * The callback should return |SSL_TLSEXT_ERR_OK| if it wishes to advertise.
   2602  * Otherwise, no such extension will be included in the ServerHello. */
   2603 OPENSSL_EXPORT void SSL_CTX_set_next_protos_advertised_cb(
   2604     SSL_CTX *ctx,
   2605     int (*cb)(SSL *ssl, const uint8_t **out, unsigned *out_len, void *arg),
   2606     void *arg);
   2607 
   2608 /* SSL_CTX_set_next_proto_select_cb sets a callback that is called when a client
   2609  * needs to select a protocol from the server's provided list. |*out| must be
   2610  * set to point to the selected protocol (which may be within |in|). The length
   2611  * of the protocol name must be written into |*out_len|. The server's advertised
   2612  * protocols are provided in |in| and |in_len|. The callback can assume that
   2613  * |in| is syntactically valid.
   2614  *
   2615  * The client must select a protocol. It is fatal to the connection if this
   2616  * callback returns a value other than |SSL_TLSEXT_ERR_OK|.
   2617  *
   2618  * Configuring this callback enables NPN on a client. */
   2619 OPENSSL_EXPORT void SSL_CTX_set_next_proto_select_cb(
   2620     SSL_CTX *ctx, int (*cb)(SSL *ssl, uint8_t **out, uint8_t *out_len,
   2621                             const uint8_t *in, unsigned in_len, void *arg),
   2622     void *arg);
   2623 
   2624 /* SSL_get0_next_proto_negotiated sets |*out_data| and |*out_len| to point to
   2625  * the client's requested protocol for this connection. If the client didn't
   2626  * request any protocol, then |*out_data| is set to NULL.
   2627  *
   2628  * Note that the client can request any protocol it chooses. The value returned
   2629  * from this function need not be a member of the list of supported protocols
   2630  * provided by the server. */
   2631 OPENSSL_EXPORT void SSL_get0_next_proto_negotiated(const SSL *ssl,
   2632                                                    const uint8_t **out_data,
   2633                                                    unsigned *out_len);
   2634 
   2635 /* SSL_select_next_proto implements the standard protocol selection. It is
   2636  * expected that this function is called from the callback set by
   2637  * |SSL_CTX_set_next_proto_select_cb|.
   2638  *
   2639  * The protocol data is assumed to be a vector of 8-bit, length prefixed byte
   2640  * strings. The length byte itself is not included in the length. A byte
   2641  * string of length 0 is invalid. No byte string may be truncated.
   2642  *
   2643  * The current, but experimental algorithm for selecting the protocol is:
   2644  *
   2645  * 1) If the server doesn't support NPN then this is indicated to the
   2646  * callback. In this case, the client application has to abort the connection
   2647  * or have a default application level protocol.
   2648  *
   2649  * 2) If the server supports NPN, but advertises an empty list then the
   2650  * client selects the first protocol in its list, but indicates via the
   2651  * API that this fallback case was enacted.
   2652  *
   2653  * 3) Otherwise, the client finds the first protocol in the server's list
   2654  * that it supports and selects this protocol. This is because it's
   2655  * assumed that the server has better information about which protocol
   2656  * a client should use.
   2657  *
   2658  * 4) If the client doesn't support any of the server's advertised
   2659  * protocols, then this is treated the same as case 2.
   2660  *
   2661  * It returns either |OPENSSL_NPN_NEGOTIATED| if a common protocol was found, or
   2662  * |OPENSSL_NPN_NO_OVERLAP| if the fallback case was reached. */
   2663 OPENSSL_EXPORT int SSL_select_next_proto(uint8_t **out, uint8_t *out_len,
   2664                                          const uint8_t *server,
   2665                                          unsigned server_len,
   2666                                          const uint8_t *client,
   2667                                          unsigned client_len);
   2668 
   2669 #define OPENSSL_NPN_UNSUPPORTED 0
   2670 #define OPENSSL_NPN_NEGOTIATED 1
   2671 #define OPENSSL_NPN_NO_OVERLAP 2
   2672 
   2673 
   2674 /* Channel ID.
   2675  *
   2676  * See draft-balfanz-tls-channelid-01. */
   2677 
   2678 /* SSL_CTX_set_tls_channel_id_enabled configures whether connections associated
   2679  * with |ctx| should enable Channel ID. */
   2680 OPENSSL_EXPORT void SSL_CTX_set_tls_channel_id_enabled(SSL_CTX *ctx,
   2681                                                        int enabled);
   2682 
   2683 /* SSL_set_tls_channel_id_enabled configures whether |ssl| should enable Channel
   2684  * ID. */
   2685 OPENSSL_EXPORT void SSL_set_tls_channel_id_enabled(SSL *ssl, int enabled);
   2686 
   2687 /* SSL_CTX_set1_tls_channel_id configures a TLS client to send a TLS Channel ID
   2688  * to compatible servers. |private_key| must be a P-256 EC key. It returns one
   2689  * on success and zero on error. */
   2690 OPENSSL_EXPORT int SSL_CTX_set1_tls_channel_id(SSL_CTX *ctx,
   2691                                                EVP_PKEY *private_key);
   2692 
   2693 /* SSL_set1_tls_channel_id configures a TLS client to send a TLS Channel ID to
   2694  * compatible servers. |private_key| must be a P-256 EC key. It returns one on
   2695  * success and zero on error. */
   2696 OPENSSL_EXPORT int SSL_set1_tls_channel_id(SSL *ssl, EVP_PKEY *private_key);
   2697 
   2698 /* SSL_get_tls_channel_id gets the client's TLS Channel ID from a server |SSL*|
   2699  * and copies up to the first |max_out| bytes into |out|. The Channel ID
   2700  * consists of the client's P-256 public key as an (x,y) pair where each is a
   2701  * 32-byte, big-endian field element. It returns 0 if the client didn't offer a
   2702  * Channel ID and the length of the complete Channel ID otherwise. */
   2703 OPENSSL_EXPORT size_t SSL_get_tls_channel_id(SSL *ssl, uint8_t *out,
   2704                                              size_t max_out);
   2705 
   2706 /* SSL_CTX_set_channel_id_cb sets a callback to be called when a TLS Channel ID
   2707  * is requested. The callback may set |*out_pkey| to a key, passing a reference
   2708  * to the caller. If none is returned, the handshake will pause and
   2709  * |SSL_get_error| will return |SSL_ERROR_WANT_CHANNEL_ID_LOOKUP|.
   2710  *
   2711  * See also |SSL_ERROR_WANT_CHANNEL_ID_LOOKUP|. */
   2712 OPENSSL_EXPORT void SSL_CTX_set_channel_id_cb(
   2713     SSL_CTX *ctx, void (*channel_id_cb)(SSL *ssl, EVP_PKEY **out_pkey));
   2714 
   2715 /* SSL_CTX_get_channel_id_cb returns the callback set by
   2716  * |SSL_CTX_set_channel_id_cb|. */
   2717 OPENSSL_EXPORT void (*SSL_CTX_get_channel_id_cb(SSL_CTX *ctx))(
   2718     SSL *ssl, EVP_PKEY **out_pkey);
   2719 
   2720 
   2721 /* DTLS-SRTP.
   2722  *
   2723  * See RFC 5764. */
   2724 
   2725 /* srtp_protection_profile_st (aka |SRTP_PROTECTION_PROFILE|) is an SRTP
   2726  * profile for use with the use_srtp extension. */
   2727 struct srtp_protection_profile_st {
   2728   const char *name;
   2729   unsigned long id;
   2730 } /* SRTP_PROTECTION_PROFILE */;
   2731 
   2732 DECLARE_STACK_OF(SRTP_PROTECTION_PROFILE)
   2733 
   2734 /* SRTP_* define constants for SRTP profiles. */
   2735 #define SRTP_AES128_CM_SHA1_80 0x0001
   2736 #define SRTP_AES128_CM_SHA1_32 0x0002
   2737 #define SRTP_AES128_F8_SHA1_80 0x0003
   2738 #define SRTP_AES128_F8_SHA1_32 0x0004
   2739 #define SRTP_NULL_SHA1_80      0x0005
   2740 #define SRTP_NULL_SHA1_32      0x0006
   2741 #define SRTP_AEAD_AES_128_GCM  0x0007
   2742 #define SRTP_AEAD_AES_256_GCM  0x0008
   2743 
   2744 /* SSL_CTX_set_srtp_profiles enables SRTP for all SSL objects created from
   2745  * |ctx|. |profile| contains a colon-separated list of profile names. It returns
   2746  * one on success and zero on failure. */
   2747 OPENSSL_EXPORT int SSL_CTX_set_srtp_profiles(SSL_CTX *ctx,
   2748                                              const char *profiles);
   2749 
   2750 /* SSL_set_srtp_profiles enables SRTP for |ssl|.  |profile| contains a
   2751  * colon-separated list of profile names. It returns one on success and zero on
   2752  * failure. */
   2753 OPENSSL_EXPORT int SSL_set_srtp_profiles(SSL *ssl, const char *profiles);
   2754 
   2755 /* SSL_get_srtp_profiles returns the SRTP profiles supported by |ssl|. */
   2756 OPENSSL_EXPORT STACK_OF(SRTP_PROTECTION_PROFILE) *SSL_get_srtp_profiles(
   2757     SSL *ssl);
   2758 
   2759 /* SSL_get_selected_srtp_profile returns the selected SRTP profile, or NULL if
   2760  * SRTP was not negotiated. */
   2761 OPENSSL_EXPORT const SRTP_PROTECTION_PROFILE *SSL_get_selected_srtp_profile(
   2762     SSL *ssl);
   2763 
   2764 
   2765 /* Pre-shared keys.
   2766  *
   2767  * Connections may be configured with PSK (Pre-Shared Key) cipher suites. These
   2768  * authenticate using out-of-band pre-shared keys rather than certificates. See
   2769  * RFC 4279.
   2770  *
   2771  * This implementation uses NUL-terminated C strings for identities and identity
   2772  * hints, so values with a NUL character are not supported. (RFC 4279 does not
   2773  * specify the format of an identity.) */
   2774 
   2775 /* PSK_MAX_IDENTITY_LEN is the maximum supported length of a PSK identity,
   2776  * excluding the NUL terminator. */
   2777 #define PSK_MAX_IDENTITY_LEN 128
   2778 
   2779 /* PSK_MAX_PSK_LEN is the maximum supported length of a pre-shared key. */
   2780 #define PSK_MAX_PSK_LEN 256
   2781 
   2782 /* SSL_CTX_set_psk_client_callback sets the callback to be called when PSK is
   2783  * negotiated on the client. This callback must be set to enable PSK cipher
   2784  * suites on the client.
   2785  *
   2786  * The callback is passed the identity hint in |hint| or NULL if none was
   2787  * provided. It should select a PSK identity and write the identity and the
   2788  * corresponding PSK to |identity| and |psk|, respectively. The identity is
   2789  * written as a NUL-terminated C string of length (excluding the NUL terminator)
   2790  * at most |max_identity_len|. The PSK's length must be at most |max_psk_len|.
   2791  * The callback returns the length of the PSK or 0 if no suitable identity was
   2792  * found. */
   2793 OPENSSL_EXPORT void SSL_CTX_set_psk_client_callback(
   2794     SSL_CTX *ctx,
   2795     unsigned (*psk_client_callback)(
   2796         SSL *ssl, const char *hint, char *identity,
   2797         unsigned max_identity_len, uint8_t *psk, unsigned max_psk_len));
   2798 
   2799 /* SSL_set_psk_client_callback sets the callback to be called when PSK is
   2800  * negotiated on the client. This callback must be set to enable PSK cipher
   2801  * suites on the client. See also |SSL_CTX_set_psk_client_callback|. */
   2802 OPENSSL_EXPORT void SSL_set_psk_client_callback(
   2803     SSL *ssl, unsigned (*psk_client_callback)(SSL *ssl, const char *hint,
   2804                                               char *identity,
   2805                                               unsigned max_identity_len,
   2806                                               uint8_t *psk,
   2807                                               unsigned max_psk_len));
   2808 
   2809 /* SSL_CTX_set_psk_server_callback sets the callback to be called when PSK is
   2810  * negotiated on the server. This callback must be set to enable PSK cipher
   2811  * suites on the server.
   2812  *
   2813  * The callback is passed the identity in |identity|. It should write a PSK of
   2814  * length at most |max_psk_len| to |psk| and return the number of bytes written
   2815  * or zero if the PSK identity is unknown. */
   2816 OPENSSL_EXPORT void SSL_CTX_set_psk_server_callback(
   2817     SSL_CTX *ctx,
   2818     unsigned (*psk_server_callback)(SSL *ssl, const char *identity,
   2819                                     uint8_t *psk,
   2820                                     unsigned max_psk_len));
   2821 
   2822 /* SSL_set_psk_server_callback sets the callback to be called when PSK is
   2823  * negotiated on the server. This callback must be set to enable PSK cipher
   2824  * suites on the server. See also |SSL_CTX_set_psk_server_callback|. */
   2825 OPENSSL_EXPORT void SSL_set_psk_server_callback(
   2826     SSL *ssl,
   2827     unsigned (*psk_server_callback)(SSL *ssl, const char *identity,
   2828                                     uint8_t *psk,
   2829                                     unsigned max_psk_len));
   2830 
   2831 /* SSL_CTX_use_psk_identity_hint configures server connections to advertise an
   2832  * identity hint of |identity_hint|. It returns one on success and zero on
   2833  * error. */
   2834 OPENSSL_EXPORT int SSL_CTX_use_psk_identity_hint(SSL_CTX *ctx,
   2835                                                  const char *identity_hint);
   2836 
   2837 /* SSL_use_psk_identity_hint configures server connections to advertise an
   2838  * identity hint of |identity_hint|. It returns one on success and zero on
   2839  * error. */
   2840 OPENSSL_EXPORT int SSL_use_psk_identity_hint(SSL *ssl,
   2841                                              const char *identity_hint);
   2842 
   2843 /* SSL_get_psk_identity_hint returns the PSK identity hint advertised for |ssl|
   2844  * or NULL if there is none. */
   2845 OPENSSL_EXPORT const char *SSL_get_psk_identity_hint(const SSL *ssl);
   2846 
   2847 /* SSL_get_psk_identity, after the handshake completes, returns the PSK identity
   2848  * that was negotiated by |ssl| or NULL if PSK was not used. */
   2849 OPENSSL_EXPORT const char *SSL_get_psk_identity(const SSL *ssl);
   2850 
   2851 
   2852 /* Alerts.
   2853  *
   2854  * TLS and SSL 3.0 use alerts to signal error conditions. Alerts have a type
   2855  * (warning or fatal) and description. OpenSSL internally handles fatal alerts
   2856  * with dedicated error codes (see |SSL_AD_REASON_OFFSET|). Except for
   2857  * close_notify, warning alerts are silently ignored and may only be surfaced
   2858  * with |SSL_CTX_set_info_callback|. */
   2859 
   2860 /* SSL_AD_REASON_OFFSET is the offset between error reasons and |SSL_AD_*|
   2861  * values. Any error code under |ERR_LIB_SSL| with an error reason above this
   2862  * value corresponds to an alert description. Consumers may add or subtract
   2863  * |SSL_AD_REASON_OFFSET| to convert between them.
   2864  *
   2865  * make_errors.go reserves error codes above 1000 for manually-assigned errors.
   2866  * This value must be kept in sync with reservedReasonCode in make_errors.h */
   2867 #define SSL_AD_REASON_OFFSET 1000
   2868 
   2869 /* SSL_AD_* are alert descriptions for SSL 3.0 and TLS. */
   2870 #define SSL_AD_CLOSE_NOTIFY SSL3_AD_CLOSE_NOTIFY
   2871 #define SSL_AD_UNEXPECTED_MESSAGE SSL3_AD_UNEXPECTED_MESSAGE
   2872 #define SSL_AD_BAD_RECORD_MAC SSL3_AD_BAD_RECORD_MAC
   2873 #define SSL_AD_DECRYPTION_FAILED TLS1_AD_DECRYPTION_FAILED
   2874 #define SSL_AD_RECORD_OVERFLOW TLS1_AD_RECORD_OVERFLOW
   2875 #define SSL_AD_DECOMPRESSION_FAILURE SSL3_AD_DECOMPRESSION_FAILURE
   2876 #define SSL_AD_HANDSHAKE_FAILURE SSL3_AD_HANDSHAKE_FAILURE
   2877 #define SSL_AD_NO_CERTIFICATE SSL3_AD_NO_CERTIFICATE /* Not used in TLS */
   2878 #define SSL_AD_BAD_CERTIFICATE SSL3_AD_BAD_CERTIFICATE
   2879 #define SSL_AD_UNSUPPORTED_CERTIFICATE SSL3_AD_UNSUPPORTED_CERTIFICATE
   2880 #define SSL_AD_CERTIFICATE_REVOKED SSL3_AD_CERTIFICATE_REVOKED
   2881 #define SSL_AD_CERTIFICATE_EXPIRED SSL3_AD_CERTIFICATE_EXPIRED
   2882 #define SSL_AD_CERTIFICATE_UNKNOWN SSL3_AD_CERTIFICATE_UNKNOWN
   2883 #define SSL_AD_ILLEGAL_PARAMETER SSL3_AD_ILLEGAL_PARAMETER
   2884 #define SSL_AD_UNKNOWN_CA TLS1_AD_UNKNOWN_CA
   2885 #define SSL_AD_ACCESS_DENIED TLS1_AD_ACCESS_DENIED
   2886 #define SSL_AD_DECODE_ERROR TLS1_AD_DECODE_ERROR
   2887 #define SSL_AD_DECRYPT_ERROR TLS1_AD_DECRYPT_ERROR
   2888 #define SSL_AD_EXPORT_RESTRICTION TLS1_AD_EXPORT_RESTRICTION
   2889 #define SSL_AD_PROTOCOL_VERSION TLS1_AD_PROTOCOL_VERSION
   2890 #define SSL_AD_INSUFFICIENT_SECURITY TLS1_AD_INSUFFICIENT_SECURITY
   2891 #define SSL_AD_INTERNAL_ERROR TLS1_AD_INTERNAL_ERROR
   2892 #define SSL_AD_INAPPROPRIATE_FALLBACK SSL3_AD_INAPPROPRIATE_FALLBACK
   2893 #define SSL_AD_USER_CANCELLED TLS1_AD_USER_CANCELLED
   2894 #define SSL_AD_NO_RENEGOTIATION TLS1_AD_NO_RENEGOTIATION
   2895 #define SSL_AD_MISSING_EXTENSION TLS1_AD_MISSING_EXTENSION
   2896 #define SSL_AD_UNSUPPORTED_EXTENSION TLS1_AD_UNSUPPORTED_EXTENSION
   2897 #define SSL_AD_CERTIFICATE_UNOBTAINABLE TLS1_AD_CERTIFICATE_UNOBTAINABLE
   2898 #define SSL_AD_UNRECOGNIZED_NAME TLS1_AD_UNRECOGNIZED_NAME
   2899 #define SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE \
   2900   TLS1_AD_BAD_CERTIFICATE_STATUS_RESPONSE
   2901 #define SSL_AD_BAD_CERTIFICATE_HASH_VALUE TLS1_AD_BAD_CERTIFICATE_HASH_VALUE
   2902 #define SSL_AD_UNKNOWN_PSK_IDENTITY TLS1_AD_UNKNOWN_PSK_IDENTITY
   2903 #define SSL_AD_CERTIFICATE_REQUIRED TLS1_AD_CERTIFICATE_REQUIRED
   2904 
   2905 /* SSL_alert_type_string_long returns a string description of |value| as an
   2906  * alert type (warning or fatal). */
   2907 OPENSSL_EXPORT const char *SSL_alert_type_string_long(int value);
   2908 
   2909 /* SSL_alert_desc_string_long returns a string description of |value| as an
   2910  * alert description or "unknown" if unknown. */
   2911 OPENSSL_EXPORT const char *SSL_alert_desc_string_long(int value);
   2912 
   2913 /* SSL_send_fatal_alert sends a fatal alert over |ssl| of the specified type,
   2914  * which should be one of the |SSL_AD_*| constants. It returns one on success
   2915  * and <= 0 on error. The caller should pass the return value into
   2916  * |SSL_get_error| to determine how to proceed. Once this function has been
   2917  * called, future calls to |SSL_write| will fail.
   2918  *
   2919  * If retrying a failed operation due to |SSL_ERROR_WANT_WRITE|, subsequent
   2920  * calls must use the same |alert| parameter. */
   2921 OPENSSL_EXPORT int SSL_send_fatal_alert(SSL *ssl, uint8_t alert);
   2922 
   2923 
   2924 /* ex_data functions.
   2925  *
   2926  * See |ex_data.h| for details. */
   2927 
   2928 OPENSSL_EXPORT int SSL_set_ex_data(SSL *ssl, int idx, void *data);
   2929 OPENSSL_EXPORT void *SSL_get_ex_data(const SSL *ssl, int idx);
   2930 OPENSSL_EXPORT int SSL_get_ex_new_index(long argl, void *argp,
   2931                                         CRYPTO_EX_unused *unused,
   2932                                         CRYPTO_EX_dup *dup_func,
   2933                                         CRYPTO_EX_free *free_func);
   2934 
   2935 OPENSSL_EXPORT int SSL_SESSION_set_ex_data(SSL_SESSION *session, int idx,
   2936                                            void *data);
   2937 OPENSSL_EXPORT void *SSL_SESSION_get_ex_data(const SSL_SESSION *session,
   2938                                              int idx);
   2939 OPENSSL_EXPORT int SSL_SESSION_get_ex_new_index(long argl, void *argp,
   2940                                                 CRYPTO_EX_unused *unused,
   2941                                                 CRYPTO_EX_dup *dup_func,
   2942                                                 CRYPTO_EX_free *free_func);
   2943 
   2944 OPENSSL_EXPORT int SSL_CTX_set_ex_data(SSL_CTX *ctx, int idx, void *data);
   2945 OPENSSL_EXPORT void *SSL_CTX_get_ex_data(const SSL_CTX *ctx, int idx);
   2946 OPENSSL_EXPORT int SSL_CTX_get_ex_new_index(long argl, void *argp,
   2947                                             CRYPTO_EX_unused *unused,
   2948                                             CRYPTO_EX_dup *dup_func,
   2949                                             CRYPTO_EX_free *free_func);
   2950 
   2951 
   2952 /* Low-level record-layer state. */
   2953 
   2954 /* SSL_get_ivs sets |*out_iv_len| to the length of the IVs for the ciphers
   2955  * underlying |ssl| and sets |*out_read_iv| and |*out_write_iv| to point to the
   2956  * current IVs for the read and write directions. This is only meaningful for
   2957  * connections with implicit IVs (i.e. CBC mode with SSLv3 or TLS 1.0).
   2958  *
   2959  * It returns one on success or zero on error. */
   2960 OPENSSL_EXPORT int SSL_get_ivs(const SSL *ssl, const uint8_t **out_read_iv,
   2961                                const uint8_t **out_write_iv,
   2962                                size_t *out_iv_len);
   2963 
   2964 /* SSL_get_key_block_len returns the length of |ssl|'s key block. */
   2965 OPENSSL_EXPORT size_t SSL_get_key_block_len(const SSL *ssl);
   2966 
   2967 /* SSL_generate_key_block generates |out_len| bytes of key material for |ssl|'s
   2968  * current connection state. */
   2969 OPENSSL_EXPORT int SSL_generate_key_block(const SSL *ssl, uint8_t *out,
   2970                                           size_t out_len);
   2971 
   2972 /* SSL_get_read_sequence returns, in TLS, the expected sequence number of the
   2973  * next incoming record in the current epoch. In DTLS, it returns the maximum
   2974  * sequence number received in the current epoch and includes the epoch number
   2975  * in the two most significant bytes. */
   2976 OPENSSL_EXPORT uint64_t SSL_get_read_sequence(const SSL *ssl);
   2977 
   2978 /* SSL_get_write_sequence returns the sequence number of the next outgoing
   2979  * record in the current epoch. In DTLS, it includes the epoch number in the
   2980  * two most significant bytes. */
   2981 OPENSSL_EXPORT uint64_t SSL_get_write_sequence(const SSL *ssl);
   2982 
   2983 
   2984 /* Obscure functions. */
   2985 
   2986 /* SSL_get_structure_sizes returns the sizes of the SSL, SSL_CTX and
   2987  * SSL_SESSION structures so that a test can ensure that outside code agrees on
   2988  * these values. */
   2989 OPENSSL_EXPORT void SSL_get_structure_sizes(size_t *ssl_size,
   2990                                             size_t *ssl_ctx_size,
   2991                                             size_t *ssl_session_size);
   2992 
   2993 /* SSL_CTX_set_msg_callback installs |cb| as the message callback for |ctx|.
   2994  * This callback will be called when sending or receiving low-level record
   2995  * headers, complete handshake messages, ChangeCipherSpec, and alerts.
   2996  * |write_p| is one for outgoing messages and zero for incoming messages.
   2997  *
   2998  * For each record header, |cb| is called with |version| = 0 and |content_type|
   2999  * = |SSL3_RT_HEADER|. The |len| bytes from |buf| contain the header. Note that
   3000  * this does not include the record body. If the record is sealed, the length
   3001  * in the header is the length of the ciphertext.
   3002  *
   3003  * For each handshake message, ChangeCipherSpec, and alert, |version| is the
   3004  * protocol version and |content_type| is the corresponding record type. The
   3005  * |len| bytes from |buf| contain the handshake message, one-byte
   3006  * ChangeCipherSpec body, and two-byte alert, respectively.
   3007  *
   3008  * For a V2ClientHello, |version| is |SSL2_VERSION|, |content_type| is zero, and
   3009  * the |len| bytes from |buf| contain the V2ClientHello structure. */
   3010 OPENSSL_EXPORT void SSL_CTX_set_msg_callback(
   3011     SSL_CTX *ctx, void (*cb)(int write_p, int version, int content_type,
   3012                              const void *buf, size_t len, SSL *ssl, void *arg));
   3013 
   3014 /* SSL_CTX_set_msg_callback_arg sets the |arg| parameter of the message
   3015  * callback. */
   3016 OPENSSL_EXPORT void SSL_CTX_set_msg_callback_arg(SSL_CTX *ctx, void *arg);
   3017 
   3018 /* SSL_set_msg_callback installs |cb| as the message callback of |ssl|. See
   3019  * |SSL_CTX_set_msg_callback| for when this callback is called. */
   3020 OPENSSL_EXPORT void SSL_set_msg_callback(
   3021     SSL *ssl, void (*cb)(int write_p, int version, int content_type,
   3022                          const void *buf, size_t len, SSL *ssl, void *arg));
   3023 
   3024 /* SSL_set_msg_callback_arg sets the |arg| parameter of the message callback. */
   3025 OPENSSL_EXPORT void SSL_set_msg_callback_arg(SSL *ssl, void *arg);
   3026 
   3027 /* SSL_CTX_set_keylog_callback configures a callback to log key material. This
   3028  * is intended for debugging use with tools like Wireshark. The |cb| function
   3029  * should log |line| followed by a newline, synchronizing with any concurrent
   3030  * access to the log.
   3031  *
   3032  * The format is described in
   3033  * https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/Key_Log_Format. */
   3034 OPENSSL_EXPORT void SSL_CTX_set_keylog_callback(
   3035     SSL_CTX *ctx, void (*cb)(const SSL *ssl, const char *line));
   3036 
   3037 /* SSL_CTX_get_keylog_callback returns the callback configured by
   3038  * |SSL_CTX_set_keylog_callback|. */
   3039 OPENSSL_EXPORT void (*SSL_CTX_get_keylog_callback(const SSL_CTX *ctx))(
   3040     const SSL *ssl, const char *line);
   3041 
   3042 /* SSL_CTX_set_current_time_cb configures a callback to retrieve the current
   3043  * time, which should be set in |*out_clock|. This can be used for testing
   3044  * purposes; for example, a callback can be configured that returns a time
   3045  * set explicitly by the test. */
   3046 OPENSSL_EXPORT void SSL_CTX_set_current_time_cb(
   3047     SSL_CTX *ctx, void (*cb)(const SSL *ssl, struct timeval *out_clock));
   3048 
   3049 enum ssl_renegotiate_mode_t {
   3050   ssl_renegotiate_never = 0,
   3051   ssl_renegotiate_once,
   3052   ssl_renegotiate_freely,
   3053   ssl_renegotiate_ignore,
   3054 };
   3055 
   3056 /* SSL_set_renegotiate_mode configures how |ssl|, a client, reacts to
   3057  * renegotiation attempts by a server. If |ssl| is a server, peer-initiated
   3058  * renegotiations are *always* rejected and this function does nothing.
   3059  *
   3060  * The renegotiation mode defaults to |ssl_renegotiate_never|, but may be set
   3061  * at any point in a connection's lifetime. Set it to |ssl_renegotiate_once| to
   3062  * allow one renegotiation, |ssl_renegotiate_freely| to allow all
   3063  * renegotiations or |ssl_renegotiate_ignore| to ignore HelloRequest messages.
   3064  * Note that ignoring HelloRequest messages may cause the connection to stall
   3065  * if the server waits for the renegotiation to complete.
   3066  *
   3067  * There is no support in BoringSSL for initiating renegotiations as a client
   3068  * or server. */
   3069 OPENSSL_EXPORT void SSL_set_renegotiate_mode(SSL *ssl,
   3070                                              enum ssl_renegotiate_mode_t mode);
   3071 
   3072 /* SSL_renegotiate_pending returns one if |ssl| is in the middle of a
   3073  * renegotiation. */
   3074 OPENSSL_EXPORT int SSL_renegotiate_pending(SSL *ssl);
   3075 
   3076 /* SSL_total_renegotiations returns the total number of renegotiation handshakes
   3077  * performed by |ssl|. This includes the pending renegotiation, if any. */
   3078 OPENSSL_EXPORT int SSL_total_renegotiations(const SSL *ssl);
   3079 
   3080 /* SSL_CTX_set_early_data_enabled sets whether early data is allowed to be used
   3081  * with resumptions using |ctx|.
   3082  *
   3083  * As a server, if the client's early data is accepted, |SSL_do_handshake| will
   3084  * complete as soon as the ClientHello is processed and server flight sent.
   3085  * |SSL_write| may be used to send half-RTT data. |SSL_read| will consume early
   3086  * data and transition to 1-RTT data as appropriate.
   3087  *
   3088  * Note early data is replayable by a network attacker. |SSL_in_init| and
   3089  * |SSL_is_init_finished| will report the handshake is still in progress until
   3090  * the client's Finished message is received. Callers may use these functions
   3091  * to defer some processing if desired.
   3092  *
   3093  * WARNING: This is experimental and may cause interoperability failures until
   3094  * fully implemented. */
   3095 OPENSSL_EXPORT void SSL_CTX_set_early_data_enabled(SSL_CTX *ctx, int enabled);
   3096 
   3097 /* SSL_early_data_accepted returns whether early data was accepted on the
   3098  * handshake performed by |ssl|. */
   3099 OPENSSL_EXPORT int SSL_early_data_accepted(const SSL *ssl);
   3100 
   3101 /* SSL_MAX_CERT_LIST_DEFAULT is the default maximum length, in bytes, of a peer
   3102  * certificate chain. */
   3103 #define SSL_MAX_CERT_LIST_DEFAULT (1024 * 100)
   3104 
   3105 /* SSL_CTX_get_max_cert_list returns the maximum length, in bytes, of a peer
   3106  * certificate chain accepted by |ctx|. */
   3107 OPENSSL_EXPORT size_t SSL_CTX_get_max_cert_list(const SSL_CTX *ctx);
   3108 
   3109 /* SSL_CTX_set_max_cert_list sets the maximum length, in bytes, of a peer
   3110  * certificate chain to |max_cert_list|. This affects how much memory may be
   3111  * consumed during the handshake. */
   3112 OPENSSL_EXPORT void SSL_CTX_set_max_cert_list(SSL_CTX *ctx,
   3113                                               size_t max_cert_list);
   3114 
   3115 /* SSL_get_max_cert_list returns the maximum length, in bytes, of a peer
   3116  * certificate chain accepted by |ssl|. */
   3117 OPENSSL_EXPORT size_t SSL_get_max_cert_list(const SSL *ssl);
   3118 
   3119 /* SSL_set_max_cert_list sets the maximum length, in bytes, of a peer
   3120  * certificate chain to |max_cert_list|. This affects how much memory may be
   3121  * consumed during the handshake. */
   3122 OPENSSL_EXPORT void SSL_set_max_cert_list(SSL *ssl, size_t max_cert_list);
   3123 
   3124 /* SSL_CTX_set_max_send_fragment sets the maximum length, in bytes, of records
   3125  * sent by |ctx|. Beyond this length, handshake messages and application data
   3126  * will be split into multiple records. It returns one on success or zero on
   3127  * error. */
   3128 OPENSSL_EXPORT int SSL_CTX_set_max_send_fragment(SSL_CTX *ctx,
   3129                                                  size_t max_send_fragment);
   3130 
   3131 /* SSL_set_max_send_fragment sets the maximum length, in bytes, of records sent
   3132  * by |ssl|. Beyond this length, handshake messages and application data will
   3133  * be split into multiple records. It returns one on success or zero on
   3134  * error. */
   3135 OPENSSL_EXPORT int SSL_set_max_send_fragment(SSL *ssl,
   3136                                              size_t max_send_fragment);
   3137 
   3138 /* SSL_get_v2clienthello_count returns the total number of V2ClientHellos that
   3139  * are accepted. */
   3140 OPENSSL_EXPORT uint64_t SSL_get_v2clienthello_count(void);
   3141 
   3142 /* ssl_early_callback_ctx (aka |SSL_CLIENT_HELLO|) is passed to certain
   3143  * callbacks that are called very early on during the server handshake. At this
   3144  * point, much of the SSL* hasn't been filled out and only the ClientHello can
   3145  * be depended on. */
   3146 typedef struct ssl_early_callback_ctx {
   3147   SSL *ssl;
   3148   const uint8_t *client_hello;
   3149   size_t client_hello_len;
   3150   uint16_t version;
   3151   const uint8_t *random;
   3152   size_t random_len;
   3153   const uint8_t *session_id;
   3154   size_t session_id_len;
   3155   const uint8_t *cipher_suites;
   3156   size_t cipher_suites_len;
   3157   const uint8_t *compression_methods;
   3158   size_t compression_methods_len;
   3159   const uint8_t *extensions;
   3160   size_t extensions_len;
   3161 } SSL_CLIENT_HELLO;
   3162 
   3163 /* ssl_select_cert_result_t enumerates the possible results from selecting a
   3164  * certificate with |select_certificate_cb|. */
   3165 enum ssl_select_cert_result_t {
   3166   /* ssl_select_cert_success indicates that the certificate selection was
   3167    * successful. */
   3168   ssl_select_cert_success = 1,
   3169   /* ssl_select_cert_retry indicates that the operation could not be
   3170    * immediately completed and must be reattempted at a later point. */
   3171   ssl_select_cert_retry = 0,
   3172   /* ssl_select_cert_error indicates that a fatal error occured and the
   3173    * handshake should be terminated. */
   3174   ssl_select_cert_error = -1,
   3175 };
   3176 
   3177 /* SSL_early_callback_ctx_extension_get searches the extensions in
   3178  * |client_hello| for an extension of the given type. If not found, it returns
   3179  * zero. Otherwise it sets |out_data| to point to the extension contents (not
   3180  * including the type and length bytes), sets |out_len| to the length of the
   3181  * extension contents and returns one. */
   3182 OPENSSL_EXPORT int SSL_early_callback_ctx_extension_get(
   3183     const SSL_CLIENT_HELLO *client_hello, uint16_t extension_type,
   3184     const uint8_t **out_data, size_t *out_len);
   3185 
   3186 /* SSL_CTX_set_select_certificate_cb sets a callback that is called before most
   3187  * ClientHello processing and before the decision whether to resume a session
   3188  * is made. The callback may inspect the ClientHello and configure the
   3189  * connection. See |ssl_select_cert_result_t| for details of the return values.
   3190  *
   3191  * In the case that a retry is indicated, |SSL_get_error| will return
   3192  * |SSL_ERROR_PENDING_CERTIFICATE| and the caller should arrange for the
   3193  * high-level operation on |ssl| to be retried at a later time, which will
   3194  * result in another call to |cb|.
   3195  *
   3196  * Note: The |SSL_CLIENT_HELLO| is only valid for the duration of the callback
   3197  * and is not valid while the handshake is paused. */
   3198 OPENSSL_EXPORT void SSL_CTX_set_select_certificate_cb(
   3199     SSL_CTX *ctx,
   3200     enum ssl_select_cert_result_t (*cb)(const SSL_CLIENT_HELLO *));
   3201 
   3202 /* SSL_CTX_set_dos_protection_cb sets a callback that is called once the
   3203  * resumption decision for a ClientHello has been made. It can return one to
   3204  * allow the handshake to continue or zero to cause the handshake to abort. */
   3205 OPENSSL_EXPORT void SSL_CTX_set_dos_protection_cb(
   3206     SSL_CTX *ctx, int (*cb)(const SSL_CLIENT_HELLO *));
   3207 
   3208 /* SSL_ST_* are possible values for |SSL_state| and the bitmasks that make them
   3209  * up. */
   3210 #define SSL_ST_CONNECT 0x1000
   3211 #define SSL_ST_ACCEPT 0x2000
   3212 #define SSL_ST_MASK 0x0FFF
   3213 #define SSL_ST_INIT (SSL_ST_CONNECT | SSL_ST_ACCEPT)
   3214 #define SSL_ST_OK 0x03
   3215 #define SSL_ST_RENEGOTIATE (0x04 | SSL_ST_INIT)
   3216 #define SSL_ST_TLS13 (0x05 | SSL_ST_INIT)
   3217 
   3218 /* SSL_CB_* are possible values for the |type| parameter in the info
   3219  * callback and the bitmasks that make them up. */
   3220 #define SSL_CB_LOOP 0x01
   3221 #define SSL_CB_EXIT 0x02
   3222 #define SSL_CB_READ 0x04
   3223 #define SSL_CB_WRITE 0x08
   3224 #define SSL_CB_ALERT 0x4000
   3225 #define SSL_CB_READ_ALERT (SSL_CB_ALERT | SSL_CB_READ)
   3226 #define SSL_CB_WRITE_ALERT (SSL_CB_ALERT | SSL_CB_WRITE)
   3227 #define SSL_CB_ACCEPT_LOOP (SSL_ST_ACCEPT | SSL_CB_LOOP)
   3228 #define SSL_CB_ACCEPT_EXIT (SSL_ST_ACCEPT | SSL_CB_EXIT)
   3229 #define SSL_CB_CONNECT_LOOP (SSL_ST_CONNECT | SSL_CB_LOOP)
   3230 #define SSL_CB_CONNECT_EXIT (SSL_ST_CONNECT | SSL_CB_EXIT)
   3231 #define SSL_CB_HANDSHAKE_START 0x10
   3232 #define SSL_CB_HANDSHAKE_DONE 0x20
   3233 
   3234 /* SSL_CTX_set_info_callback configures a callback to be run when various
   3235  * events occur during a connection's lifetime. The |type| argument determines
   3236  * the type of event and the meaning of the |value| argument. Callbacks must
   3237  * ignore unexpected |type| values.
   3238  *
   3239  * |SSL_CB_READ_ALERT| is signaled for each alert received, warning or fatal.
   3240  * The |value| argument is a 16-bit value where the alert level (either
   3241  * |SSL3_AL_WARNING| or |SSL3_AL_FATAL|) is in the most-significant eight bits
   3242  * and the alert type (one of |SSL_AD_*|) is in the least-significant eight.
   3243  *
   3244  * |SSL_CB_WRITE_ALERT| is signaled for each alert sent. The |value| argument
   3245  * is constructed as with |SSL_CB_READ_ALERT|.
   3246  *
   3247  * |SSL_CB_HANDSHAKE_START| is signaled when a handshake begins. The |value|
   3248  * argument is always one.
   3249  *
   3250  * |SSL_CB_HANDSHAKE_DONE| is signaled when a handshake completes successfully.
   3251  * The |value| argument is always one. If a handshake False Starts, this event
   3252  * may be used to determine when the Finished message is received.
   3253  *
   3254  * The following event types expose implementation details of the handshake
   3255  * state machine. Consuming them is deprecated.
   3256  *
   3257  * |SSL_CB_ACCEPT_LOOP| (respectively, |SSL_CB_CONNECT_LOOP|) is signaled when
   3258  * a server (respectively, client) handshake progresses. The |value| argument
   3259  * is always one.
   3260  *
   3261  * |SSL_CB_ACCEPT_EXIT| (respectively, |SSL_CB_CONNECT_EXIT|) is signaled when
   3262  * a server (respectively, client) handshake completes, fails, or is paused.
   3263  * The |value| argument is one if the handshake succeeded and <= 0
   3264  * otherwise. */
   3265 OPENSSL_EXPORT void SSL_CTX_set_info_callback(
   3266     SSL_CTX *ctx, void (*cb)(const SSL *ssl, int type, int value));
   3267 
   3268 /* SSL_CTX_get_info_callback returns the callback set by
   3269  * |SSL_CTX_set_info_callback|. */
   3270 OPENSSL_EXPORT void (*SSL_CTX_get_info_callback(SSL_CTX *ctx))(const SSL *ssl,
   3271                                                                int type,
   3272                                                                int value);
   3273 
   3274 /* SSL_set_info_callback configures a callback to be run at various events
   3275  * during a connection's lifetime. See |SSL_CTX_set_info_callback|. */
   3276 OPENSSL_EXPORT void SSL_set_info_callback(
   3277     SSL *ssl, void (*cb)(const SSL *ssl, int type, int value));
   3278 
   3279 /* SSL_get_info_callback returns the callback set by |SSL_set_info_callback|. */
   3280 OPENSSL_EXPORT void (*SSL_get_info_callback(const SSL *ssl))(const SSL *ssl,
   3281                                                              int type,
   3282                                                              int value);
   3283 
   3284 /* SSL_state_string_long returns the current state of the handshake state
   3285  * machine as a string. This may be useful for debugging and logging. */
   3286 OPENSSL_EXPORT const char *SSL_state_string_long(const SSL *ssl);
   3287 
   3288 #define SSL_SENT_SHUTDOWN 1
   3289 #define SSL_RECEIVED_SHUTDOWN 2
   3290 
   3291 /* SSL_get_shutdown returns a bitmask with a subset of |SSL_SENT_SHUTDOWN| and
   3292  * |SSL_RECEIVED_SHUTDOWN| to query whether close_notify was sent or received,
   3293  * respectively. */
   3294 OPENSSL_EXPORT int SSL_get_shutdown(const SSL *ssl);
   3295 
   3296 /* SSL_get_peer_signature_algorithm returns the signature algorithm used by the
   3297  * peer. If not applicable, it returns zero. */
   3298 OPENSSL_EXPORT uint16_t SSL_get_peer_signature_algorithm(const SSL *ssl);
   3299 
   3300 /* SSL_get_client_random writes up to |max_out| bytes of the most recent
   3301  * handshake's client_random to |out| and returns the number of bytes written.
   3302  * If |max_out| is zero, it returns the size of the client_random. */
   3303 OPENSSL_EXPORT size_t SSL_get_client_random(const SSL *ssl, uint8_t *out,
   3304                                             size_t max_out);
   3305 
   3306 /* SSL_get_server_random writes up to |max_out| bytes of the most recent
   3307  * handshake's server_random to |out| and returns the number of bytes written.
   3308  * If |max_out| is zero, it returns the size of the server_random. */
   3309 OPENSSL_EXPORT size_t SSL_get_server_random(const SSL *ssl, uint8_t *out,
   3310                                             size_t max_out);
   3311 
   3312 /* SSL_get_pending_cipher returns the cipher suite for the current handshake or
   3313  * NULL if one has not been negotiated yet or there is no pending handshake. */
   3314 OPENSSL_EXPORT const SSL_CIPHER *SSL_get_pending_cipher(const SSL *ssl);
   3315 
   3316 /* SSL_set_retain_only_sha256_of_client_certs, on a server, sets whether only
   3317  * the SHA-256 hash of peer's certificate should be saved in memory and in the
   3318  * session. This can save memory, ticket size and session cache space. If
   3319  * enabled, |SSL_get_peer_certificate| will return NULL after the handshake
   3320  * completes. See the |peer_sha256| field of |SSL_SESSION| for the hash. */
   3321 OPENSSL_EXPORT void SSL_set_retain_only_sha256_of_client_certs(SSL *ssl,
   3322                                                                int enable);
   3323 
   3324 /* SSL_CTX_set_retain_only_sha256_of_client_certs, on a server, sets whether
   3325  * only the SHA-256 hash of peer's certificate should be saved in memory and in
   3326  * the session. This can save memory, ticket size and session cache space. If
   3327  * enabled, |SSL_get_peer_certificate| will return NULL after the handshake
   3328  * completes. See the |peer_sha256| field of |SSL_SESSION| for the hash. */
   3329 OPENSSL_EXPORT void SSL_CTX_set_retain_only_sha256_of_client_certs(SSL_CTX *ctx,
   3330                                                                    int enable);
   3331 
   3332 /* SSL_CTX_set_grease_enabled configures whether sockets on |ctx| should enable
   3333  * GREASE. See draft-davidben-tls-grease-01. */
   3334 OPENSSL_EXPORT void SSL_CTX_set_grease_enabled(SSL_CTX *ctx, int enabled);
   3335 
   3336 /* SSL_max_seal_overhead returns the maximum overhead, in bytes, of sealing a
   3337  * record with |ssl|. */
   3338 OPENSSL_EXPORT size_t SSL_max_seal_overhead(const SSL *ssl);
   3339 
   3340 /* SSL_get_ticket_age_skew returns the difference, in seconds, between the
   3341  * client-sent ticket age and the server-computed value in TLS 1.3 server
   3342  * connections which resumed a session. */
   3343 OPENSSL_EXPORT int32_t SSL_get_ticket_age_skew(const SSL *ssl);
   3344 
   3345 
   3346 /* Deprecated functions. */
   3347 
   3348 /* SSL_library_init calls |CRYPTO_library_init| and returns one. */
   3349 OPENSSL_EXPORT int SSL_library_init(void);
   3350 
   3351 /* SSL_CIPHER_description writes a description of |cipher| into |buf| and
   3352  * returns |buf|. If |buf| is NULL, it returns a newly allocated string, to be
   3353  * freed with |OPENSSL_free|, or NULL on error.
   3354  *
   3355  * The description includes a trailing newline and has the form:
   3356  * AES128-SHA              Kx=RSA      Au=RSA  Enc=AES(128)  Mac=SHA1
   3357  *
   3358  * Consider |SSL_CIPHER_get_name| or |SSL_CIPHER_get_rfc_name| instead. */
   3359 OPENSSL_EXPORT const char *SSL_CIPHER_description(const SSL_CIPHER *cipher,
   3360                                                   char *buf, int len);
   3361 
   3362 /* SSL_CIPHER_get_version returns the string "TLSv1/SSLv3". */
   3363 OPENSSL_EXPORT const char *SSL_CIPHER_get_version(const SSL_CIPHER *cipher);
   3364 
   3365 typedef void COMP_METHOD;
   3366 
   3367 /* SSL_COMP_get_compression_methods returns NULL. */
   3368 OPENSSL_EXPORT COMP_METHOD *SSL_COMP_get_compression_methods(void);
   3369 
   3370 /* SSL_COMP_add_compression_method returns one. */
   3371 OPENSSL_EXPORT int SSL_COMP_add_compression_method(int id, COMP_METHOD *cm);
   3372 
   3373 /* SSL_COMP_get_name returns NULL. */
   3374 OPENSSL_EXPORT const char *SSL_COMP_get_name(const COMP_METHOD *comp);
   3375 
   3376 /* SSL_COMP_free_compression_methods does nothing. */
   3377 OPENSSL_EXPORT void SSL_COMP_free_compression_methods(void);
   3378 
   3379 /* SSLv23_method calls |TLS_method|. */
   3380 OPENSSL_EXPORT const SSL_METHOD *SSLv23_method(void);
   3381 
   3382 /* These version-specific methods behave exactly like |TLS_method| and
   3383  * |DTLS_method| except they also call |SSL_CTX_set_min_proto_version| and
   3384  * |SSL_CTX_set_max_proto_version| to lock connections to that protocol
   3385  * version. */
   3386 OPENSSL_EXPORT const SSL_METHOD *SSLv3_method(void);
   3387 OPENSSL_EXPORT const SSL_METHOD *TLSv1_method(void);
   3388 OPENSSL_EXPORT const SSL_METHOD *TLSv1_1_method(void);
   3389 OPENSSL_EXPORT const SSL_METHOD *TLSv1_2_method(void);
   3390 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_method(void);
   3391 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_2_method(void);
   3392 
   3393 /* These client- and server-specific methods call their corresponding generic
   3394  * methods. */
   3395 OPENSSL_EXPORT const SSL_METHOD *TLS_server_method(void);
   3396 OPENSSL_EXPORT const SSL_METHOD *TLS_client_method(void);
   3397 OPENSSL_EXPORT const SSL_METHOD *SSLv23_server_method(void);
   3398 OPENSSL_EXPORT const SSL_METHOD *SSLv23_client_method(void);
   3399 OPENSSL_EXPORT const SSL_METHOD *SSLv3_server_method(void);
   3400 OPENSSL_EXPORT const SSL_METHOD *SSLv3_client_method(void);
   3401 OPENSSL_EXPORT const SSL_METHOD *TLSv1_server_method(void);
   3402 OPENSSL_EXPORT const SSL_METHOD *TLSv1_client_method(void);
   3403 OPENSSL_EXPORT const SSL_METHOD *TLSv1_1_server_method(void);
   3404 OPENSSL_EXPORT const SSL_METHOD *TLSv1_1_client_method(void);
   3405 OPENSSL_EXPORT const SSL_METHOD *TLSv1_2_server_method(void);
   3406 OPENSSL_EXPORT const SSL_METHOD *TLSv1_2_client_method(void);
   3407 OPENSSL_EXPORT const SSL_METHOD *DTLS_server_method(void);
   3408 OPENSSL_EXPORT const SSL_METHOD *DTLS_client_method(void);
   3409 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_server_method(void);
   3410 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_client_method(void);
   3411 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_2_server_method(void);
   3412 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_2_client_method(void);
   3413 
   3414 /* SSL_clear resets |ssl| to allow another connection and returns one on success
   3415  * or zero on failure. It returns most configuration state but releases memory
   3416  * associated with the current connection.
   3417  *
   3418  * Free |ssl| and create a new one instead. */
   3419 OPENSSL_EXPORT int SSL_clear(SSL *ssl);
   3420 
   3421 /* SSL_CTX_set_tmp_rsa_callback does nothing. */
   3422 OPENSSL_EXPORT void SSL_CTX_set_tmp_rsa_callback(
   3423     SSL_CTX *ctx, RSA *(*cb)(SSL *ssl, int is_export, int keylength));
   3424 
   3425 /* SSL_set_tmp_rsa_callback does nothing. */
   3426 OPENSSL_EXPORT void SSL_set_tmp_rsa_callback(SSL *ssl,
   3427                                              RSA *(*cb)(SSL *ssl, int is_export,
   3428                                                         int keylength));
   3429 
   3430 /* SSL_CTX_sess_connect returns zero. */
   3431 OPENSSL_EXPORT int SSL_CTX_sess_connect(const SSL_CTX *ctx);
   3432 
   3433 /* SSL_CTX_sess_connect_good returns zero. */
   3434 OPENSSL_EXPORT int SSL_CTX_sess_connect_good(const SSL_CTX *ctx);
   3435 
   3436 /* SSL_CTX_sess_connect_renegotiate returns zero. */
   3437 OPENSSL_EXPORT int SSL_CTX_sess_connect_renegotiate(const SSL_CTX *ctx);
   3438 
   3439 /* SSL_CTX_sess_accept returns zero. */
   3440 OPENSSL_EXPORT int SSL_CTX_sess_accept(const SSL_CTX *ctx);
   3441 
   3442 /* SSL_CTX_sess_accept_renegotiate returns zero. */
   3443 OPENSSL_EXPORT int SSL_CTX_sess_accept_renegotiate(const SSL_CTX *ctx);
   3444 
   3445 /* SSL_CTX_sess_accept_good returns zero. */
   3446 OPENSSL_EXPORT int SSL_CTX_sess_accept_good(const SSL_CTX *ctx);
   3447 
   3448 /* SSL_CTX_sess_hits returns zero. */
   3449 OPENSSL_EXPORT int SSL_CTX_sess_hits(const SSL_CTX *ctx);
   3450 
   3451 /* SSL_CTX_sess_cb_hits returns zero. */
   3452 OPENSSL_EXPORT int SSL_CTX_sess_cb_hits(const SSL_CTX *ctx);
   3453 
   3454 /* SSL_CTX_sess_misses returns zero. */
   3455 OPENSSL_EXPORT int SSL_CTX_sess_misses(const SSL_CTX *ctx);
   3456 
   3457 /* SSL_CTX_sess_timeouts returns zero. */
   3458 OPENSSL_EXPORT int SSL_CTX_sess_timeouts(const SSL_CTX *ctx);
   3459 
   3460 /* SSL_CTX_sess_cache_full returns zero. */
   3461 OPENSSL_EXPORT int SSL_CTX_sess_cache_full(const SSL_CTX *ctx);
   3462 
   3463 /* SSL_cutthrough_complete calls |SSL_in_false_start|. */
   3464 OPENSSL_EXPORT int SSL_cutthrough_complete(const SSL *s);
   3465 
   3466 /* SSL_num_renegotiations calls |SSL_total_renegotiations|. */
   3467 OPENSSL_EXPORT int SSL_num_renegotiations(const SSL *ssl);
   3468 
   3469 /* SSL_CTX_need_tmp_RSA returns zero. */
   3470 OPENSSL_EXPORT int SSL_CTX_need_tmp_RSA(const SSL_CTX *ctx);
   3471 
   3472 /* SSL_need_tmp_RSA returns zero. */
   3473 OPENSSL_EXPORT int SSL_need_tmp_RSA(const SSL *ssl);
   3474 
   3475 /* SSL_CTX_set_tmp_rsa returns one. */
   3476 OPENSSL_EXPORT int SSL_CTX_set_tmp_rsa(SSL_CTX *ctx, const RSA *rsa);
   3477 
   3478 /* SSL_set_tmp_rsa returns one. */
   3479 OPENSSL_EXPORT int SSL_set_tmp_rsa(SSL *ssl, const RSA *rsa);
   3480 
   3481 /* SSL_CTX_get_read_ahead returns zero. */
   3482 OPENSSL_EXPORT int SSL_CTX_get_read_ahead(const SSL_CTX *ctx);
   3483 
   3484 /* SSL_CTX_set_read_ahead does nothing. */
   3485 OPENSSL_EXPORT void SSL_CTX_set_read_ahead(SSL_CTX *ctx, int yes);
   3486 
   3487 /* SSL_get_read_ahead returns zero. */
   3488 OPENSSL_EXPORT int SSL_get_read_ahead(const SSL *s);
   3489 
   3490 /* SSL_set_read_ahead does nothing. */
   3491 OPENSSL_EXPORT void SSL_set_read_ahead(SSL *s, int yes);
   3492 
   3493 /* SSL_renegotiate put an error on the error queue and returns zero. */
   3494 OPENSSL_EXPORT int SSL_renegotiate(SSL *ssl);
   3495 
   3496 /* SSL_set_state does nothing. */
   3497 OPENSSL_EXPORT void SSL_set_state(SSL *ssl, int state);
   3498 
   3499 /* SSL_get_shared_ciphers writes an empty string to |buf| and returns a
   3500  * pointer to |buf|, or NULL if |len| is less than or equal to zero. */
   3501 OPENSSL_EXPORT char *SSL_get_shared_ciphers(const SSL *ssl, char *buf, int len);
   3502 
   3503 /* SSL_MODE_HANDSHAKE_CUTTHROUGH is the same as SSL_MODE_ENABLE_FALSE_START. */
   3504 #define SSL_MODE_HANDSHAKE_CUTTHROUGH SSL_MODE_ENABLE_FALSE_START
   3505 
   3506 /* i2d_SSL_SESSION serializes |in| to the bytes pointed to by |*pp|. On success,
   3507  * it returns the number of bytes written and advances |*pp| by that many bytes.
   3508  * On failure, it returns -1. If |pp| is NULL, no bytes are written and only the
   3509  * length is returned.
   3510  *
   3511  * Use |SSL_SESSION_to_bytes| instead. */
   3512 OPENSSL_EXPORT int i2d_SSL_SESSION(SSL_SESSION *in, uint8_t **pp);
   3513 
   3514 /* d2i_SSL_SESSION parses a serialized session from the |length| bytes pointed
   3515  * to by |*pp|. It returns the new |SSL_SESSION| and advances |*pp| by the
   3516  * number of bytes consumed on success and NULL on failure. The caller takes
   3517  * ownership of the new session and must call |SSL_SESSION_free| when done.
   3518  *
   3519  * If |a| is non-NULL, |*a| is released and set the new |SSL_SESSION|.
   3520  *
   3521  * Use |SSL_SESSION_from_bytes| instead. */
   3522 OPENSSL_EXPORT SSL_SESSION *d2i_SSL_SESSION(SSL_SESSION **a, const uint8_t **pp,
   3523                                             long length);
   3524 
   3525 /* i2d_SSL_SESSION_bio serializes |session| and writes the result to |bio|. It
   3526  * returns the number of bytes written on success and <= 0 on error. */
   3527 OPENSSL_EXPORT int i2d_SSL_SESSION_bio(BIO *bio, const SSL_SESSION *session);
   3528 
   3529 /* d2i_SSL_SESSION_bio reads a serialized |SSL_SESSION| from |bio| and returns a
   3530  * newly-allocated |SSL_SESSION| or NULL on error. If |out| is not NULL, it also
   3531  * frees |*out| and sets |*out| to the new |SSL_SESSION|.  */
   3532 OPENSSL_EXPORT SSL_SESSION *d2i_SSL_SESSION_bio(BIO *bio, SSL_SESSION **out);
   3533 
   3534 /* ERR_load_SSL_strings does nothing. */
   3535 OPENSSL_EXPORT void ERR_load_SSL_strings(void);
   3536 
   3537 /* SSL_load_error_strings does nothing. */
   3538 OPENSSL_EXPORT void SSL_load_error_strings(void);
   3539 
   3540 /* SSL_CTX_set_tlsext_use_srtp calls |SSL_CTX_set_srtp_profiles|. It returns
   3541  * zero on success and one on failure.
   3542  *
   3543  * WARNING: this function is dangerous because it breaks the usual return value
   3544  * convention. Use |SSL_CTX_set_srtp_profiles| instead. */
   3545 OPENSSL_EXPORT int SSL_CTX_set_tlsext_use_srtp(SSL_CTX *ctx,
   3546                                                const char *profiles);
   3547 
   3548 /* SSL_set_tlsext_use_srtp calls |SSL_set_srtp_profiles|. It returns zero on
   3549  * success and one on failure.
   3550  *
   3551  * WARNING: this function is dangerous because it breaks the usual return value
   3552  * convention. Use |SSL_set_srtp_profiles| instead. */
   3553 OPENSSL_EXPORT int SSL_set_tlsext_use_srtp(SSL *ssl, const char *profiles);
   3554 
   3555 /* SSL_get_current_compression returns NULL. */
   3556 OPENSSL_EXPORT const COMP_METHOD *SSL_get_current_compression(SSL *s);
   3557 
   3558 /* SSL_get_current_expansion returns NULL. */
   3559 OPENSSL_EXPORT const COMP_METHOD *SSL_get_current_expansion(SSL *s);
   3560 
   3561 /* SSL_get_server_tmp_key returns zero. */
   3562 OPENSSL_EXPORT int *SSL_get_server_tmp_key(SSL *ssl, EVP_PKEY **out_key);
   3563 
   3564 #define SSL_set_app_data(s, arg) (SSL_set_ex_data(s, 0, (char *)(arg)))
   3565 #define SSL_get_app_data(s) (SSL_get_ex_data(s, 0))
   3566 #define SSL_SESSION_set_app_data(s, a) \
   3567   (SSL_SESSION_set_ex_data(s, 0, (char *)(a)))
   3568 #define SSL_SESSION_get_app_data(s) (SSL_SESSION_get_ex_data(s, 0))
   3569 #define SSL_CTX_get_app_data(ctx) (SSL_CTX_get_ex_data(ctx, 0))
   3570 #define SSL_CTX_set_app_data(ctx, arg) \
   3571   (SSL_CTX_set_ex_data(ctx, 0, (char *)(arg)))
   3572 
   3573 #define OpenSSL_add_ssl_algorithms() SSL_library_init()
   3574 #define SSLeay_add_ssl_algorithms() SSL_library_init()
   3575 
   3576 #define SSL_get_cipher(ssl) SSL_CIPHER_get_name(SSL_get_current_cipher(ssl))
   3577 #define SSL_get_cipher_bits(ssl, out_alg_bits) \
   3578     SSL_CIPHER_get_bits(SSL_get_current_cipher(ssl), out_alg_bits)
   3579 #define SSL_get_cipher_version(ssl) \
   3580     SSL_CIPHER_get_version(SSL_get_current_cipher(ssl))
   3581 #define SSL_get_cipher_name(ssl) \
   3582     SSL_CIPHER_get_name(SSL_get_current_cipher(ssl))
   3583 #define SSL_get_time(session) SSL_SESSION_get_time(session)
   3584 #define SSL_set_time(session, time) SSL_SESSION_set_time((session), (time))
   3585 #define SSL_get_timeout(session) SSL_SESSION_get_timeout(session)
   3586 #define SSL_set_timeout(session, timeout) \
   3587     SSL_SESSION_set_timeout((session), (timeout))
   3588 
   3589 typedef struct ssl_comp_st SSL_COMP;
   3590 
   3591 struct ssl_comp_st {
   3592   int id;
   3593   const char *name;
   3594   char *method;
   3595 };
   3596 
   3597 DECLARE_STACK_OF(SSL_COMP)
   3598 
   3599 /* The following flags do nothing and are included only to make it easier to
   3600  * compile code with BoringSSL. */
   3601 #define SSL_MODE_AUTO_RETRY 0
   3602 #define SSL_MODE_RELEASE_BUFFERS 0
   3603 #define SSL_MODE_SEND_CLIENTHELLO_TIME 0
   3604 #define SSL_MODE_SEND_SERVERHELLO_TIME 0
   3605 #define SSL_OP_ALL 0
   3606 #define SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION 0
   3607 #define SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS 0
   3608 #define SSL_OP_EPHEMERAL_RSA 0
   3609 #define SSL_OP_LEGACY_SERVER_CONNECT 0
   3610 #define SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER 0
   3611 #define SSL_OP_MICROSOFT_SESS_ID_BUG 0
   3612 #define SSL_OP_MSIE_SSLV2_RSA_PADDING 0
   3613 #define SSL_OP_NETSCAPE_CA_DN_BUG 0
   3614 #define SSL_OP_NETSCAPE_CHALLENGE_BUG 0
   3615 #define SSL_OP_NETSCAPE_DEMO_CIPHER_CHANGE_BUG 0
   3616 #define SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG 0
   3617 #define SSL_OP_NO_COMPRESSION 0
   3618 #define SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION 0
   3619 #define SSL_OP_NO_SSLv2 0
   3620 #define SSL_OP_PKCS1_CHECK_1 0
   3621 #define SSL_OP_PKCS1_CHECK_2 0
   3622 #define SSL_OP_SINGLE_DH_USE 0
   3623 #define SSL_OP_SINGLE_ECDH_USE 0
   3624 #define SSL_OP_SSLEAY_080_CLIENT_DH_BUG 0
   3625 #define SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG 0
   3626 #define SSL_OP_TLS_BLOCK_PADDING_BUG 0
   3627 #define SSL_OP_TLS_D5_BUG 0
   3628 #define SSL_OP_TLS_ROLLBACK_BUG 0
   3629 #define SSL_VERIFY_CLIENT_ONCE 0
   3630 
   3631 /* SSL_cache_hit calls |SSL_session_reused|. */
   3632 OPENSSL_EXPORT int SSL_cache_hit(SSL *ssl);
   3633 
   3634 /* SSL_get_default_timeout returns |SSL_DEFAULT_SESSION_TIMEOUT|. */
   3635 OPENSSL_EXPORT long SSL_get_default_timeout(const SSL *ssl);
   3636 
   3637 /* SSL_get_version returns a string describing the TLS version used by |ssl|.
   3638  * For example, "TLSv1.2" or "SSLv3". */
   3639 OPENSSL_EXPORT const char *SSL_get_version(const SSL *ssl);
   3640 
   3641 /* SSL_get_cipher_list returns the name of the |n|th cipher in the output of
   3642  * |SSL_get_ciphers| or NULL if out of range. Use |SSL_get_ciphers| instead. */
   3643 OPENSSL_EXPORT const char *SSL_get_cipher_list(const SSL *ssl, int n);
   3644 
   3645 /* SSL_CTX_set_client_cert_cb sets a callback which is called on the client if
   3646  * the server requests a client certificate and none is configured. On success,
   3647  * the callback should return one and set |*out_x509| to |*out_pkey| to a leaf
   3648  * certificate and private key, respectively, passing ownership. It should
   3649  * return zero to send no certificate and -1 to fail or pause the handshake. If
   3650  * the handshake is paused, |SSL_get_error| will return
   3651  * |SSL_ERROR_WANT_X509_LOOKUP|.
   3652  *
   3653  * The callback may call |SSL_get0_certificate_types| and
   3654  * |SSL_get_client_CA_list| for information on the server's certificate request.
   3655  *
   3656  * Use |SSL_CTX_set_cert_cb| instead. Configuring intermediate certificates with
   3657  * this function is confusing. This callback may not be registered concurrently
   3658  * with |SSL_CTX_set_cert_cb| or |SSL_set_cert_cb|. */
   3659 OPENSSL_EXPORT void SSL_CTX_set_client_cert_cb(
   3660     SSL_CTX *ctx,
   3661     int (*client_cert_cb)(SSL *ssl, X509 **out_x509, EVP_PKEY **out_pkey));
   3662 
   3663 #define SSL_NOTHING 1
   3664 #define SSL_WRITING 2
   3665 #define SSL_READING 3
   3666 #define SSL_X509_LOOKUP 4
   3667 #define SSL_CHANNEL_ID_LOOKUP 5
   3668 #define SSL_PENDING_SESSION 7
   3669 #define SSL_CERTIFICATE_SELECTION_PENDING 8
   3670 #define SSL_PRIVATE_KEY_OPERATION 9
   3671 #define SSL_PENDING_TICKET 10
   3672 
   3673 /* SSL_want returns one of the above values to determine what the most recent
   3674  * operation on |ssl| was blocked on. Use |SSL_get_error| instead. */
   3675 OPENSSL_EXPORT int SSL_want(const SSL *ssl);
   3676 
   3677 #define SSL_want_read(ssl) (SSL_want(ssl) == SSL_READING)
   3678 #define SSL_want_write(ssl) (SSL_want(ssl) == SSL_WRITING)
   3679 
   3680  /* SSL_get_finished writes up to |count| bytes of the Finished message sent by
   3681   * |ssl| to |buf|. It returns the total untruncated length or zero if none has
   3682   * been sent yet. At SSL 3.0 or TLS 1.3 and later, it returns zero.
   3683   *
   3684   * Use |SSL_get_tls_unique| instead. */
   3685 OPENSSL_EXPORT size_t SSL_get_finished(const SSL *ssl, void *buf, size_t count);
   3686 
   3687  /* SSL_get_peer_finished writes up to |count| bytes of the Finished message
   3688   * received from |ssl|'s peer to |buf|. It returns the total untruncated length
   3689   * or zero if none has been received yet. At SSL 3.0 or TLS 1.3 and later, it
   3690   * returns zero.
   3691   *
   3692   * Use |SSL_get_tls_unique| instead. */
   3693 OPENSSL_EXPORT size_t SSL_get_peer_finished(const SSL *ssl, void *buf,
   3694                                             size_t count);
   3695 
   3696 /* SSL_alert_type_string returns "!". Use |SSL_alert_type_string_long|
   3697  * instead. */
   3698 OPENSSL_EXPORT const char *SSL_alert_type_string(int value);
   3699 
   3700 /* SSL_alert_desc_string returns "!!". Use |SSL_alert_desc_string_long|
   3701  * instead. */
   3702 OPENSSL_EXPORT const char *SSL_alert_desc_string(int value);
   3703 
   3704 /* SSL_TXT_* expand to strings. */
   3705 #define SSL_TXT_MEDIUM "MEDIUM"
   3706 #define SSL_TXT_HIGH "HIGH"
   3707 #define SSL_TXT_FIPS "FIPS"
   3708 #define SSL_TXT_kRSA "kRSA"
   3709 #define SSL_TXT_kDHE "kDHE"
   3710 #define SSL_TXT_kEDH "kEDH"
   3711 #define SSL_TXT_kECDHE "kECDHE"
   3712 #define SSL_TXT_kEECDH "kEECDH"
   3713 #define SSL_TXT_kPSK "kPSK"
   3714 #define SSL_TXT_aRSA "aRSA"
   3715 #define SSL_TXT_aECDSA "aECDSA"
   3716 #define SSL_TXT_aPSK "aPSK"
   3717 #define SSL_TXT_DH "DH"
   3718 #define SSL_TXT_DHE "DHE"
   3719 #define SSL_TXT_EDH "EDH"
   3720 #define SSL_TXT_RSA "RSA"
   3721 #define SSL_TXT_ECDH "ECDH"
   3722 #define SSL_TXT_ECDHE "ECDHE"
   3723 #define SSL_TXT_EECDH "EECDH"
   3724 #define SSL_TXT_ECDSA "ECDSA"
   3725 #define SSL_TXT_PSK "PSK"
   3726 #define SSL_TXT_3DES "3DES"
   3727 #define SSL_TXT_RC4 "RC4"
   3728 #define SSL_TXT_AES128 "AES128"
   3729 #define SSL_TXT_AES256 "AES256"
   3730 #define SSL_TXT_AES "AES"
   3731 #define SSL_TXT_AES_GCM "AESGCM"
   3732 #define SSL_TXT_CHACHA20 "CHACHA20"
   3733 #define SSL_TXT_MD5 "MD5"
   3734 #define SSL_TXT_SHA1 "SHA1"
   3735 #define SSL_TXT_SHA "SHA"
   3736 #define SSL_TXT_SHA256 "SHA256"
   3737 #define SSL_TXT_SHA384 "SHA384"
   3738 #define SSL_TXT_SSLV3 "SSLv3"
   3739 #define SSL_TXT_TLSV1 "TLSv1"
   3740 #define SSL_TXT_TLSV1_1 "TLSv1.1"
   3741 #define SSL_TXT_TLSV1_2 "TLSv1.2"
   3742 #define SSL_TXT_TLSV1_3 "TLSv1.3"
   3743 #define SSL_TXT_ALL "ALL"
   3744 #define SSL_TXT_CMPDEF "COMPLEMENTOFDEFAULT"
   3745 
   3746 typedef struct ssl_conf_ctx_st SSL_CONF_CTX;
   3747 
   3748 /* SSL_state returns |SSL_ST_INIT| if a handshake is in progress and |SSL_ST_OK|
   3749  * otherwise.
   3750  *
   3751  * Use |SSL_is_init| instead. */
   3752 OPENSSL_EXPORT int SSL_state(const SSL *ssl);
   3753 
   3754 #define SSL_get_state(ssl) SSL_state(ssl)
   3755 
   3756 /* SSL_state_string returns the current state of the handshake state machine as
   3757  * a six-letter string. Use |SSL_state_string_long| for a more intelligible
   3758  * string. */
   3759 OPENSSL_EXPORT const char *SSL_state_string(const SSL *ssl);
   3760 
   3761 /* SSL_set_shutdown causes |ssl| to behave as if the shutdown bitmask (see
   3762  * |SSL_get_shutdown|) were |mode|. This may be used to skip sending or
   3763  * receiving close_notify in |SSL_shutdown| by causing the implementation to
   3764  * believe the events already happened.
   3765  *
   3766  * It is an error to use |SSL_set_shutdown| to unset a bit that has already been
   3767  * set. Doing so will trigger an |assert| in debug builds and otherwise be
   3768  * ignored.
   3769  *
   3770  * Use |SSL_CTX_set_quiet_shutdown| instead. */
   3771 OPENSSL_EXPORT void SSL_set_shutdown(SSL *ssl, int mode);
   3772 
   3773 /* SSL_CTX_set_tmp_ecdh calls |SSL_CTX_set1_curves| with a one-element list
   3774  * containing |ec_key|'s curve. */
   3775 OPENSSL_EXPORT int SSL_CTX_set_tmp_ecdh(SSL_CTX *ctx, const EC_KEY *ec_key);
   3776 
   3777 /* SSL_set_tmp_ecdh calls |SSL_set1_curves| with a one-element list containing
   3778  * |ec_key|'s curve. */
   3779 OPENSSL_EXPORT int SSL_set_tmp_ecdh(SSL *ssl, const EC_KEY *ec_key);
   3780 
   3781 /* SSL_add_dir_cert_subjects_to_stack lists files in directory |dir|. It calls
   3782  * |SSL_add_file_cert_subjects_to_stack| on each file and returns one on success
   3783  * or zero on error. This function is only available from the libdecrepit
   3784  * library. */
   3785 OPENSSL_EXPORT int SSL_add_dir_cert_subjects_to_stack(STACK_OF(X509_NAME) *out,
   3786                                                       const char *dir);
   3787 
   3788 /* SSL_set_private_key_digest_prefs copies |num_digests| NIDs from |digest_nids|
   3789  * into |ssl|. These digests will be used, in decreasing order of preference,
   3790  * when signing with |ssl|'s private key. It returns one on success and zero on
   3791  * error.
   3792  *
   3793  * Use |SSL_set_signing_algorithm_prefs| instead.
   3794  *
   3795  * TODO(davidben): Remove this API when callers have been updated. */
   3796 OPENSSL_EXPORT int SSL_set_private_key_digest_prefs(SSL *ssl,
   3797                                                     const int *digest_nids,
   3798                                                     size_t num_digests);
   3799 
   3800 /* SSL_set_verify_result calls |abort| unless |result| is |X509_V_OK|.
   3801  *
   3802  * TODO(davidben): Remove this function once it has been removed from
   3803  * netty-tcnative. */
   3804 OPENSSL_EXPORT void SSL_set_verify_result(SSL *ssl, long result);
   3805 
   3806 /* SSL_CTX_set_min_version calls |SSL_CTX_set_min_proto_version|. */
   3807 OPENSSL_EXPORT int SSL_CTX_set_min_version(SSL_CTX *ctx, uint16_t version);
   3808 
   3809 /* SSL_CTX_set_max_version calls |SSL_CTX_set_max_proto_version|. */
   3810 OPENSSL_EXPORT int SSL_CTX_set_max_version(SSL_CTX *ctx, uint16_t version);
   3811 
   3812 /* SSL_set_min_version calls |SSL_set_min_proto_version|. */
   3813 OPENSSL_EXPORT int SSL_set_min_version(SSL *ssl, uint16_t version);
   3814 
   3815 /* SSL_set_max_version calls |SSL_set_max_proto_version|. */
   3816 OPENSSL_EXPORT int SSL_set_max_version(SSL *ssl, uint16_t version);
   3817 
   3818 /* SSL_CTX_enable_tls_channel_id calls |SSL_CTX_set_tls_channel_id_enabled|. */
   3819 OPENSSL_EXPORT int SSL_CTX_enable_tls_channel_id(SSL_CTX *ctx);
   3820 
   3821 /* SSL_enable_tls_channel_id calls |SSL_set_tls_channel_id_enabled|. */
   3822 OPENSSL_EXPORT int SSL_enable_tls_channel_id(SSL *ssl);
   3823 
   3824 /* BIO_f_ssl returns a |BIO_METHOD| that can wrap an |SSL*| in a |BIO*|. Note
   3825  * that this has quite different behaviour from the version in OpenSSL (notably
   3826  * that it doesn't try to auto renegotiate).
   3827  *
   3828  * IMPORTANT: if you are not curl, don't use this. */
   3829 OPENSSL_EXPORT const BIO_METHOD *BIO_f_ssl(void);
   3830 
   3831 /* BIO_set_ssl sets |ssl| as the underlying connection for |bio|, which must
   3832  * have been created using |BIO_f_ssl|. If |take_owership| is true, |bio| will
   3833  * call |SSL_free| on |ssl| when closed. It returns one on success or something
   3834  * other than one on error. */
   3835 OPENSSL_EXPORT long BIO_set_ssl(BIO *bio, SSL *ssl, int take_owership);
   3836 
   3837 /* SSL_CTX_set_ecdh_auto returns one. */
   3838 #define SSL_CTX_set_ecdh_auto(ctx, onoff) 1
   3839 
   3840 /* SSL_set_ecdh_auto returns one. */
   3841 #define SSL_set_ecdh_auto(ssl, onoff) 1
   3842 
   3843 
   3844 /* Private structures.
   3845  *
   3846  * This structures are exposed for historical reasons, but access to them is
   3847  * deprecated. */
   3848 
   3849 typedef struct ssl_protocol_method_st SSL_PROTOCOL_METHOD;
   3850 typedef struct ssl_x509_method_st SSL_X509_METHOD;
   3851 
   3852 struct ssl_cipher_st {
   3853   /* name is the OpenSSL name for the cipher. */
   3854   const char *name;
   3855   /* id is the cipher suite value bitwise OR-d with 0x03000000. */
   3856   uint32_t id;
   3857 
   3858   /* algorithm_* are internal fields. See ssl/internal.h for their values. */
   3859   uint32_t algorithm_mkey;
   3860   uint32_t algorithm_auth;
   3861   uint32_t algorithm_enc;
   3862   uint32_t algorithm_mac;
   3863   uint32_t algorithm_prf;
   3864 };
   3865 
   3866 #define SSL_MAX_SSL_SESSION_ID_LENGTH 32
   3867 #define SSL_MAX_SID_CTX_LENGTH 32
   3868 #define SSL_MAX_MASTER_KEY_LENGTH 48
   3869 
   3870 struct ssl_session_st {
   3871   CRYPTO_refcount_t references;
   3872   int ssl_version; /* what ssl version session info is being kept in here? */
   3873 
   3874   /* group_id is the ID of the ECDH group used to establish this session or zero
   3875    * if not applicable or unknown. */
   3876   uint16_t group_id;
   3877 
   3878   /* peer_signature_algorithm is the signature algorithm used to authenticate
   3879    * the peer, or zero if not applicable or unknown. */
   3880   uint16_t peer_signature_algorithm;
   3881 
   3882   /* master_key, in TLS 1.2 and below, is the master secret associated with the
   3883    * session. In TLS 1.3 and up, it is the resumption secret. */
   3884   int master_key_length;
   3885   uint8_t master_key[SSL_MAX_MASTER_KEY_LENGTH];
   3886 
   3887   /* session_id - valid? */
   3888   unsigned int session_id_length;
   3889   uint8_t session_id[SSL_MAX_SSL_SESSION_ID_LENGTH];
   3890   /* this is used to determine whether the session is being reused in
   3891    * the appropriate context. It is up to the application to set this,
   3892    * via SSL_new */
   3893   uint8_t sid_ctx_length;
   3894   uint8_t sid_ctx[SSL_MAX_SID_CTX_LENGTH];
   3895 
   3896   char *psk_identity;
   3897 
   3898   /* certs contains the certificate chain from the peer, starting with the leaf
   3899    * certificate. */
   3900   STACK_OF(CRYPTO_BUFFER) *certs;
   3901 
   3902   const SSL_X509_METHOD *x509_method;
   3903 
   3904   /* x509_peer is the peer's certificate. */
   3905   X509 *x509_peer;
   3906 
   3907   /* x509_chain is the certificate chain sent by the peer. NOTE: for historical
   3908    * reasons, when a client (so the peer is a server), the chain includes
   3909    * |peer|, but when a server it does not. */
   3910   STACK_OF(X509) *x509_chain;
   3911 
   3912   /* x509_chain_without_leaf is a lazily constructed copy of |x509_chain| that
   3913    * omits the leaf certificate. This exists because OpenSSL, historically,
   3914    * didn't include the leaf certificate in the chain for a server, but did for
   3915    * a client. The |x509_chain| always includes it and, if an API call requires
   3916    * a chain without, it is stored here. */
   3917   STACK_OF(X509) *x509_chain_without_leaf;
   3918 
   3919   /* verify_result is the result of certificate verification in the case of
   3920    * non-fatal certificate errors. */
   3921   long verify_result;
   3922 
   3923   /* timeout is the lifetime of the session in seconds, measured from |time|.
   3924    * This is renewable up to |auth_timeout|. */
   3925   uint32_t timeout;
   3926 
   3927   /* auth_timeout is the non-renewable lifetime of the session in seconds,
   3928    * measured from |time|. */
   3929   uint32_t auth_timeout;
   3930 
   3931   /* time is the time the session was issued, measured in seconds from the UNIX
   3932    * epoch. */
   3933   uint64_t time;
   3934 
   3935   const SSL_CIPHER *cipher;
   3936 
   3937   CRYPTO_EX_DATA ex_data; /* application specific data */
   3938 
   3939   /* These are used to make removal of session-ids more efficient and to
   3940    * implement a maximum cache size. */
   3941   SSL_SESSION *prev, *next;
   3942   char *tlsext_hostname;
   3943 
   3944   /* RFC4507 info */
   3945   uint8_t *tlsext_tick;               /* Session ticket */
   3946   size_t tlsext_ticklen;              /* Session ticket length */
   3947 
   3948   size_t tlsext_signed_cert_timestamp_list_length;
   3949   uint8_t *tlsext_signed_cert_timestamp_list; /* Server's list. */
   3950 
   3951   /* The OCSP response that came with the session. */
   3952   size_t ocsp_response_length;
   3953   uint8_t *ocsp_response;
   3954 
   3955   /* peer_sha256 contains the SHA-256 hash of the peer's certificate if
   3956    * |peer_sha256_valid| is true. */
   3957   uint8_t peer_sha256[SHA256_DIGEST_LENGTH];
   3958 
   3959   /* original_handshake_hash contains the handshake hash (either SHA-1+MD5 or
   3960    * SHA-2, depending on TLS version) for the original, full handshake that
   3961    * created a session. This is used by Channel IDs during resumption. */
   3962   uint8_t original_handshake_hash[EVP_MAX_MD_SIZE];
   3963   uint8_t original_handshake_hash_len;
   3964 
   3965   uint32_t tlsext_tick_lifetime_hint; /* Session lifetime hint in seconds */
   3966 
   3967   uint32_t ticket_age_add;
   3968 
   3969   /* ticket_max_early_data is the maximum amount of data allowed to be sent as
   3970    * early data. If zero, 0-RTT is disallowed. */
   3971   uint32_t ticket_max_early_data;
   3972 
   3973   /* early_alpn is the ALPN protocol from the initial handshake. This is only
   3974    * stored for TLS 1.3 and above in order to enforce ALPN matching for 0-RTT
   3975    * resumptions. */
   3976   uint8_t *early_alpn;
   3977   size_t early_alpn_len;
   3978 
   3979   /* extended_master_secret is true if the master secret in this session was
   3980    * generated using EMS and thus isn't vulnerable to the Triple Handshake
   3981    * attack. */
   3982   unsigned extended_master_secret:1;
   3983 
   3984   /* peer_sha256_valid is non-zero if |peer_sha256| is valid. */
   3985   unsigned peer_sha256_valid:1; /* Non-zero if peer_sha256 is valid */
   3986 
   3987   /* not_resumable is used to indicate that session resumption is disallowed. */
   3988   unsigned not_resumable:1;
   3989 
   3990   /* ticket_age_add_valid is non-zero if |ticket_age_add| is valid. */
   3991   unsigned ticket_age_add_valid:1;
   3992 
   3993   /* is_server is true if this session was created by a server. */
   3994   unsigned is_server:1;
   3995 };
   3996 
   3997 /* ssl_cipher_preference_list_st contains a list of SSL_CIPHERs with
   3998  * equal-preference groups. For TLS clients, the groups are moot because the
   3999  * server picks the cipher and groups cannot be expressed on the wire. However,
   4000  * for servers, the equal-preference groups allow the client's preferences to
   4001  * be partially respected. (This only has an effect with
   4002  * SSL_OP_CIPHER_SERVER_PREFERENCE).
   4003  *
   4004  * The equal-preference groups are expressed by grouping SSL_CIPHERs together.
   4005  * All elements of a group have the same priority: no ordering is expressed
   4006  * within a group.
   4007  *
   4008  * The values in |ciphers| are in one-to-one correspondence with
   4009  * |in_group_flags|. (That is, sk_SSL_CIPHER_num(ciphers) is the number of
   4010  * bytes in |in_group_flags|.) The bytes in |in_group_flags| are either 1, to
   4011  * indicate that the corresponding SSL_CIPHER is not the last element of a
   4012  * group, or 0 to indicate that it is.
   4013  *
   4014  * For example, if |in_group_flags| contains all zeros then that indicates a
   4015  * traditional, fully-ordered preference. Every SSL_CIPHER is the last element
   4016  * of the group (i.e. they are all in a one-element group).
   4017  *
   4018  * For a more complex example, consider:
   4019  *   ciphers:        A  B  C  D  E  F
   4020  *   in_group_flags: 1  1  0  0  1  0
   4021  *
   4022  * That would express the following, order:
   4023  *
   4024  *    A         E
   4025  *    B -> D -> F
   4026  *    C
   4027  */
   4028 struct ssl_cipher_preference_list_st {
   4029   STACK_OF(SSL_CIPHER) *ciphers;
   4030   uint8_t *in_group_flags;
   4031 };
   4032 
   4033 /* ssl_ctx_st (aka |SSL_CTX|) contains configuration common to several SSL
   4034  * connections. */
   4035 struct ssl_ctx_st {
   4036   const SSL_PROTOCOL_METHOD *method;
   4037   const SSL_X509_METHOD *x509_method;
   4038 
   4039   /* lock is used to protect various operations on this object. */
   4040   CRYPTO_MUTEX lock;
   4041 
   4042   /* max_version is the maximum acceptable protocol version. Note this version
   4043    * is normalized in DTLS. */
   4044   uint16_t max_version;
   4045 
   4046   /* min_version is the minimum acceptable protocol version. Note this version
   4047    * is normalized in DTLS. */
   4048   uint16_t min_version;
   4049 
   4050   struct ssl_cipher_preference_list_st *cipher_list;
   4051 
   4052   X509_STORE *cert_store;
   4053   LHASH_OF(SSL_SESSION) *sessions;
   4054   /* Most session-ids that will be cached, default is
   4055    * SSL_SESSION_CACHE_MAX_SIZE_DEFAULT. 0 is unlimited. */
   4056   unsigned long session_cache_size;
   4057   SSL_SESSION *session_cache_head;
   4058   SSL_SESSION *session_cache_tail;
   4059 
   4060   /* handshakes_since_cache_flush is the number of successful handshakes since
   4061    * the last cache flush. */
   4062   int handshakes_since_cache_flush;
   4063 
   4064   /* This can have one of 2 values, ored together,
   4065    * SSL_SESS_CACHE_CLIENT,
   4066    * SSL_SESS_CACHE_SERVER,
   4067    * Default is SSL_SESSION_CACHE_SERVER, which means only
   4068    * SSL_accept which cache SSL_SESSIONS. */
   4069   int session_cache_mode;
   4070 
   4071   /* session_timeout is the default lifetime for new sessions in TLS 1.2 and
   4072    * earlier, in seconds. */
   4073   uint32_t session_timeout;
   4074 
   4075   /* session_psk_dhe_timeout is the default lifetime for new sessions in TLS
   4076    * 1.3, in seconds. */
   4077   uint32_t session_psk_dhe_timeout;
   4078 
   4079   /* If this callback is not null, it will be called each time a session id is
   4080    * added to the cache.  If this function returns 1, it means that the
   4081    * callback will do a SSL_SESSION_free() when it has finished using it.
   4082    * Otherwise, on 0, it means the callback has finished with it. If
   4083    * remove_session_cb is not null, it will be called when a session-id is
   4084    * removed from the cache.  After the call, OpenSSL will SSL_SESSION_free()
   4085    * it. */
   4086   int (*new_session_cb)(SSL *ssl, SSL_SESSION *sess);
   4087   void (*remove_session_cb)(SSL_CTX *ctx, SSL_SESSION *sess);
   4088   SSL_SESSION *(*get_session_cb)(SSL *ssl, uint8_t *data, int len,
   4089                                  int *copy);
   4090 
   4091   CRYPTO_refcount_t references;
   4092 
   4093   /* if defined, these override the X509_verify_cert() calls */
   4094   int (*app_verify_callback)(X509_STORE_CTX *store_ctx, void *arg);
   4095   void *app_verify_arg;
   4096 
   4097   /* Default password callback. */
   4098   pem_password_cb *default_passwd_callback;
   4099 
   4100   /* Default password callback user data. */
   4101   void *default_passwd_callback_userdata;
   4102 
   4103   /* get client cert callback */
   4104   int (*client_cert_cb)(SSL *ssl, X509 **out_x509, EVP_PKEY **out_pkey);
   4105 
   4106   /* get channel id callback */
   4107   void (*channel_id_cb)(SSL *ssl, EVP_PKEY **out_pkey);
   4108 
   4109   CRYPTO_EX_DATA ex_data;
   4110 
   4111   /* custom_*_extensions stores any callback sets for custom extensions. Note
   4112    * that these pointers will be NULL if the stack would otherwise be empty. */
   4113   STACK_OF(SSL_CUSTOM_EXTENSION) *client_custom_extensions;
   4114   STACK_OF(SSL_CUSTOM_EXTENSION) *server_custom_extensions;
   4115 
   4116   /* Default values used when no per-SSL value is defined follow */
   4117 
   4118   void (*info_callback)(const SSL *ssl, int type, int value);
   4119 
   4120   /* what we put in client cert requests */
   4121   STACK_OF(CRYPTO_BUFFER) *client_CA;
   4122 
   4123   /* cached_x509_client_CA is a cache of parsed versions of the elements of
   4124    * |client_CA|. */
   4125   STACK_OF(X509_NAME) *cached_x509_client_CA;
   4126 
   4127 
   4128   /* Default values to use in SSL structures follow (these are copied by
   4129    * SSL_new) */
   4130 
   4131   uint32_t options;
   4132   uint32_t mode;
   4133   uint32_t max_cert_list;
   4134 
   4135   struct cert_st /* CERT */ *cert;
   4136 
   4137   /* callback that allows applications to peek at protocol messages */
   4138   void (*msg_callback)(int write_p, int version, int content_type,
   4139                        const void *buf, size_t len, SSL *ssl, void *arg);
   4140   void *msg_callback_arg;
   4141 
   4142   int verify_mode;
   4143   int (*default_verify_callback)(
   4144       int ok, X509_STORE_CTX *ctx); /* called 'verify_callback' in the SSL */
   4145 
   4146   X509_VERIFY_PARAM *param;
   4147 
   4148   /* select_certificate_cb is called before most ClientHello processing and
   4149    * before the decision whether to resume a session is made. See
   4150    * |ssl_select_cert_result_t| for details of the return values. */
   4151   enum ssl_select_cert_result_t (*select_certificate_cb)(
   4152       const SSL_CLIENT_HELLO *);
   4153 
   4154   /* dos_protection_cb is called once the resumption decision for a ClientHello
   4155    * has been made. It returns one to continue the handshake or zero to
   4156    * abort. */
   4157   int (*dos_protection_cb) (const SSL_CLIENT_HELLO *);
   4158 
   4159   /* Maximum amount of data to send in one fragment. actual record size can be
   4160    * more than this due to padding and MAC overheads. */
   4161   uint16_t max_send_fragment;
   4162 
   4163   /* TLS extensions servername callback */
   4164   int (*tlsext_servername_callback)(SSL *, int *, void *);
   4165   void *tlsext_servername_arg;
   4166   /* RFC 4507 session ticket keys */
   4167   uint8_t tlsext_tick_key_name[SSL_TICKET_KEY_NAME_LEN];
   4168   uint8_t tlsext_tick_hmac_key[16];
   4169   uint8_t tlsext_tick_aes_key[16];
   4170   /* Callback to support customisation of ticket key setting */
   4171   int (*tlsext_ticket_key_cb)(SSL *ssl, uint8_t *name, uint8_t *iv,
   4172                               EVP_CIPHER_CTX *ectx, HMAC_CTX *hctx, int enc);
   4173 
   4174   /* Server-only: psk_identity_hint is the default identity hint to send in
   4175    * PSK-based key exchanges. */
   4176   char *psk_identity_hint;
   4177 
   4178   unsigned int (*psk_client_callback)(SSL *ssl, const char *hint,
   4179                                       char *identity,
   4180                                       unsigned int max_identity_len,
   4181                                       uint8_t *psk, unsigned int max_psk_len);
   4182   unsigned int (*psk_server_callback)(SSL *ssl, const char *identity,
   4183                                       uint8_t *psk, unsigned int max_psk_len);
   4184 
   4185 
   4186   /* retain_only_sha256_of_client_certs is true if we should compute the SHA256
   4187    * hash of the peer's certificate and then discard it to save memory and
   4188    * session space. Only effective on the server side. */
   4189   char retain_only_sha256_of_client_certs;
   4190 
   4191   /* Next protocol negotiation information */
   4192   /* (for experimental NPN extension). */
   4193 
   4194   /* For a server, this contains a callback function by which the set of
   4195    * advertised protocols can be provided. */
   4196   int (*next_protos_advertised_cb)(SSL *ssl, const uint8_t **out,
   4197                                    unsigned *out_len, void *arg);
   4198   void *next_protos_advertised_cb_arg;
   4199   /* For a client, this contains a callback function that selects the
   4200    * next protocol from the list provided by the server. */
   4201   int (*next_proto_select_cb)(SSL *ssl, uint8_t **out, uint8_t *out_len,
   4202                               const uint8_t *in, unsigned in_len, void *arg);
   4203   void *next_proto_select_cb_arg;
   4204 
   4205   /* ALPN information
   4206    * (we are in the process of transitioning from NPN to ALPN.) */
   4207 
   4208   /* For a server, this contains a callback function that allows the
   4209    * server to select the protocol for the connection.
   4210    *   out: on successful return, this must point to the raw protocol
   4211    *        name (without the length prefix).
   4212    *   outlen: on successful return, this contains the length of |*out|.
   4213    *   in: points to the client's list of supported protocols in
   4214    *       wire-format.
   4215    *   inlen: the length of |in|. */
   4216   int (*alpn_select_cb)(SSL *s, const uint8_t **out, uint8_t *out_len,
   4217                         const uint8_t *in, unsigned in_len, void *arg);
   4218   void *alpn_select_cb_arg;
   4219 
   4220   /* For a client, this contains the list of supported protocols in wire
   4221    * format. */
   4222   uint8_t *alpn_client_proto_list;
   4223   unsigned alpn_client_proto_list_len;
   4224 
   4225   /* SRTP profiles we are willing to do from RFC 5764 */
   4226   STACK_OF(SRTP_PROTECTION_PROFILE) *srtp_profiles;
   4227 
   4228   /* Supported group values inherited by SSL structure */
   4229   size_t supported_group_list_len;
   4230   uint16_t *supported_group_list;
   4231 
   4232   /* The client's Channel ID private key. */
   4233   EVP_PKEY *tlsext_channel_id_private;
   4234 
   4235   /* keylog_callback, if not NULL, is the key logging callback. See
   4236    * |SSL_CTX_set_keylog_callback|. */
   4237   void (*keylog_callback)(const SSL *ssl, const char *line);
   4238 
   4239   /* current_time_cb, if not NULL, is the function to use to get the current
   4240    * time. It sets |*out_clock| to the current time. See
   4241    * |SSL_CTX_set_current_time_cb|. */
   4242   void (*current_time_cb)(const SSL *ssl, struct timeval *out_clock);
   4243 
   4244   /* pool is used for all |CRYPTO_BUFFER|s in case we wish to share certificate
   4245    * memory. */
   4246   CRYPTO_BUFFER_POOL *pool;
   4247 
   4248   /* ticket_aead_method contains function pointers for opening and sealing
   4249    * session tickets. */
   4250   const SSL_TICKET_AEAD_METHOD *ticket_aead_method;
   4251 
   4252   /* quiet_shutdown is true if the connection should not send a close_notify on
   4253    * shutdown. */
   4254   unsigned quiet_shutdown:1;
   4255 
   4256   /* If enable_early_data is non-zero, early data can be sent and accepted over
   4257    * new connections. */
   4258   unsigned enable_early_data:1;
   4259 
   4260   /* ocsp_stapling_enabled is only used by client connections and indicates
   4261    * whether OCSP stapling will be requested. */
   4262   unsigned ocsp_stapling_enabled:1;
   4263 
   4264   /* If true, a client will request certificate timestamps. */
   4265   unsigned signed_cert_timestamps_enabled:1;
   4266 
   4267   /* tlsext_channel_id_enabled is one if Channel ID is enabled and zero
   4268    * otherwise. For a server, means that we'll accept Channel IDs from clients.
   4269    * For a client, means that we'll advertise support. */
   4270   unsigned tlsext_channel_id_enabled:1;
   4271 
   4272   /* grease_enabled is one if draft-davidben-tls-grease-01 is enabled and zero
   4273    * otherwise. */
   4274   unsigned grease_enabled:1;
   4275 
   4276   /* i_promise_to_verify_certs_after_the_handshake indicates that the
   4277    * application is using the |CRYPTO_BUFFER|-based methods and understands
   4278    * that this currently requires post-handshake verification of
   4279    * certificates. */
   4280   unsigned i_promise_to_verify_certs_after_the_handshake:1;
   4281 };
   4282 
   4283 
   4284 /* Nodejs compatibility section (hidden).
   4285  *
   4286  * These defines exist for node.js, with the hope that we can eliminate the
   4287  * need for them over time. */
   4288 #define SSLerr(function, reason) \
   4289   ERR_put_error(ERR_LIB_SSL, 0, reason, __FILE__, __LINE__)
   4290 
   4291 
   4292 /* Preprocessor compatibility section (hidden).
   4293  *
   4294  * Historically, a number of APIs were implemented in OpenSSL as macros and
   4295  * constants to 'ctrl' functions. To avoid breaking #ifdefs in consumers, this
   4296  * section defines a number of legacy macros.
   4297  *
   4298  * Although using either the CTRL values or their wrapper macros in #ifdefs is
   4299  * still supported, the CTRL values may not be passed to |SSL_ctrl| and
   4300  * |SSL_CTX_ctrl|. Call the functions (previously wrapper macros) instead.
   4301  *
   4302  * See PORTING.md in the BoringSSL source tree for a table of corresponding
   4303  * functions.
   4304  * https://boringssl.googlesource.com/boringssl/+/master/PORTING.md#Replacements-for-values
   4305  */
   4306 
   4307 #define DTLS_CTRL_GET_TIMEOUT doesnt_exist
   4308 #define DTLS_CTRL_HANDLE_TIMEOUT doesnt_exist
   4309 #define SSL_CTRL_CHAIN doesnt_exist
   4310 #define SSL_CTRL_CHAIN_CERT doesnt_exist
   4311 #define SSL_CTRL_CHANNEL_ID doesnt_exist
   4312 #define SSL_CTRL_CLEAR_EXTRA_CHAIN_CERTS doesnt_exist
   4313 #define SSL_CTRL_CLEAR_MODE doesnt_exist
   4314 #define SSL_CTRL_CLEAR_OPTIONS doesnt_exist
   4315 #define SSL_CTRL_EXTRA_CHAIN_CERT doesnt_exist
   4316 #define SSL_CTRL_GET_CHAIN_CERTS doesnt_exist
   4317 #define SSL_CTRL_GET_CHANNEL_ID doesnt_exist
   4318 #define SSL_CTRL_GET_CLIENT_CERT_TYPES doesnt_exist
   4319 #define SSL_CTRL_GET_EXTRA_CHAIN_CERTS doesnt_exist
   4320 #define SSL_CTRL_GET_MAX_CERT_LIST doesnt_exist
   4321 #define SSL_CTRL_GET_NUM_RENEGOTIATIONS doesnt_exist
   4322 #define SSL_CTRL_GET_READ_AHEAD doesnt_exist
   4323 #define SSL_CTRL_GET_RI_SUPPORT doesnt_exist
   4324 #define SSL_CTRL_GET_SESSION_REUSED doesnt_exist
   4325 #define SSL_CTRL_GET_SESS_CACHE_MODE doesnt_exist
   4326 #define SSL_CTRL_GET_SESS_CACHE_SIZE doesnt_exist
   4327 #define SSL_CTRL_GET_TLSEXT_TICKET_KEYS doesnt_exist
   4328 #define SSL_CTRL_GET_TOTAL_RENEGOTIATIONS doesnt_exist
   4329 #define SSL_CTRL_MODE doesnt_exist
   4330 #define SSL_CTRL_NEED_TMP_RSA doesnt_exist
   4331 #define SSL_CTRL_OPTIONS doesnt_exist
   4332 #define SSL_CTRL_SESS_NUMBER doesnt_exist
   4333 #define SSL_CTRL_SET_CURVES doesnt_exist
   4334 #define SSL_CTRL_SET_CURVES_LIST doesnt_exist
   4335 #define SSL_CTRL_SET_ECDH_AUTO doesnt_exist
   4336 #define SSL_CTRL_SET_MAX_CERT_LIST doesnt_exist
   4337 #define SSL_CTRL_SET_MAX_SEND_FRAGMENT doesnt_exist
   4338 #define SSL_CTRL_SET_MSG_CALLBACK doesnt_exist
   4339 #define SSL_CTRL_SET_MSG_CALLBACK_ARG doesnt_exist
   4340 #define SSL_CTRL_SET_MTU doesnt_exist
   4341 #define SSL_CTRL_SET_READ_AHEAD doesnt_exist
   4342 #define SSL_CTRL_SET_SESS_CACHE_MODE doesnt_exist
   4343 #define SSL_CTRL_SET_SESS_CACHE_SIZE doesnt_exist
   4344 #define SSL_CTRL_SET_TLSEXT_HOSTNAME doesnt_exist
   4345 #define SSL_CTRL_SET_TLSEXT_SERVERNAME_ARG doesnt_exist
   4346 #define SSL_CTRL_SET_TLSEXT_SERVERNAME_CB doesnt_exist
   4347 #define SSL_CTRL_SET_TLSEXT_TICKET_KEYS doesnt_exist
   4348 #define SSL_CTRL_SET_TLSEXT_TICKET_KEY_CB doesnt_exist
   4349 #define SSL_CTRL_SET_TMP_DH doesnt_exist
   4350 #define SSL_CTRL_SET_TMP_DH_CB doesnt_exist
   4351 #define SSL_CTRL_SET_TMP_ECDH doesnt_exist
   4352 #define SSL_CTRL_SET_TMP_ECDH_CB doesnt_exist
   4353 #define SSL_CTRL_SET_TMP_RSA doesnt_exist
   4354 #define SSL_CTRL_SET_TMP_RSA_CB doesnt_exist
   4355 
   4356 #define DTLSv1_get_timeout DTLSv1_get_timeout
   4357 #define DTLSv1_handle_timeout DTLSv1_handle_timeout
   4358 #define SSL_CTX_add0_chain_cert SSL_CTX_add0_chain_cert
   4359 #define SSL_CTX_add1_chain_cert SSL_CTX_add1_chain_cert
   4360 #define SSL_CTX_add_extra_chain_cert SSL_CTX_add_extra_chain_cert
   4361 #define SSL_CTX_clear_extra_chain_certs SSL_CTX_clear_extra_chain_certs
   4362 #define SSL_CTX_clear_chain_certs SSL_CTX_clear_chain_certs
   4363 #define SSL_CTX_clear_mode SSL_CTX_clear_mode
   4364 #define SSL_CTX_clear_options SSL_CTX_clear_options
   4365 #define SSL_CTX_get0_chain_certs SSL_CTX_get0_chain_certs
   4366 #define SSL_CTX_get_extra_chain_certs SSL_CTX_get_extra_chain_certs
   4367 #define SSL_CTX_get_max_cert_list SSL_CTX_get_max_cert_list
   4368 #define SSL_CTX_get_mode SSL_CTX_get_mode
   4369 #define SSL_CTX_get_options SSL_CTX_get_options
   4370 #define SSL_CTX_get_read_ahead SSL_CTX_get_read_ahead
   4371 #define SSL_CTX_get_session_cache_mode SSL_CTX_get_session_cache_mode
   4372 #define SSL_CTX_get_tlsext_ticket_keys SSL_CTX_get_tlsext_ticket_keys
   4373 #define SSL_CTX_need_tmp_RSA SSL_CTX_need_tmp_RSA
   4374 #define SSL_CTX_sess_get_cache_size SSL_CTX_sess_get_cache_size
   4375 #define SSL_CTX_sess_number SSL_CTX_sess_number
   4376 #define SSL_CTX_sess_set_cache_size SSL_CTX_sess_set_cache_size
   4377 #define SSL_CTX_set0_chain SSL_CTX_set0_chain
   4378 #define SSL_CTX_set1_chain SSL_CTX_set1_chain
   4379 #define SSL_CTX_set1_curves SSL_CTX_set1_curves
   4380 #define SSL_CTX_set_max_cert_list SSL_CTX_set_max_cert_list
   4381 #define SSL_CTX_set_max_send_fragment SSL_CTX_set_max_send_fragment
   4382 #define SSL_CTX_set_mode SSL_CTX_set_mode
   4383 #define SSL_CTX_set_msg_callback_arg SSL_CTX_set_msg_callback_arg
   4384 #define SSL_CTX_set_options SSL_CTX_set_options
   4385 #define SSL_CTX_set_read_ahead SSL_CTX_set_read_ahead
   4386 #define SSL_CTX_set_session_cache_mode SSL_CTX_set_session_cache_mode
   4387 #define SSL_CTX_set_tlsext_servername_arg SSL_CTX_set_tlsext_servername_arg
   4388 #define SSL_CTX_set_tlsext_servername_callback \
   4389     SSL_CTX_set_tlsext_servername_callback
   4390 #define SSL_CTX_set_tlsext_ticket_key_cb SSL_CTX_set_tlsext_ticket_key_cb
   4391 #define SSL_CTX_set_tlsext_ticket_keys SSL_CTX_set_tlsext_ticket_keys
   4392 #define SSL_CTX_set_tmp_dh SSL_CTX_set_tmp_dh
   4393 #define SSL_CTX_set_tmp_ecdh SSL_CTX_set_tmp_ecdh
   4394 #define SSL_CTX_set_tmp_rsa SSL_CTX_set_tmp_rsa
   4395 #define SSL_add0_chain_cert SSL_add0_chain_cert
   4396 #define SSL_add1_chain_cert SSL_add1_chain_cert
   4397 #define SSL_clear_chain_certs SSL_clear_chain_certs
   4398 #define SSL_clear_mode SSL_clear_mode
   4399 #define SSL_clear_options SSL_clear_options
   4400 #define SSL_get0_certificate_types SSL_get0_certificate_types
   4401 #define SSL_get0_chain_certs SSL_get0_chain_certs
   4402 #define SSL_get_max_cert_list SSL_get_max_cert_list
   4403 #define SSL_get_mode SSL_get_mode
   4404 #define SSL_get_options SSL_get_options
   4405 #define SSL_get_secure_renegotiation_support \
   4406     SSL_get_secure_renegotiation_support
   4407 #define SSL_need_tmp_RSA SSL_need_tmp_RSA
   4408 #define SSL_num_renegotiations SSL_num_renegotiations
   4409 #define SSL_session_reused SSL_session_reused
   4410 #define SSL_set0_chain SSL_set0_chain
   4411 #define SSL_set1_chain SSL_set1_chain
   4412 #define SSL_set1_curves SSL_set1_curves
   4413 #define SSL_set_max_cert_list SSL_set_max_cert_list
   4414 #define SSL_set_max_send_fragment SSL_set_max_send_fragment
   4415 #define SSL_set_mode SSL_set_mode
   4416 #define SSL_set_msg_callback_arg SSL_set_msg_callback_arg
   4417 #define SSL_set_mtu SSL_set_mtu
   4418 #define SSL_set_options SSL_set_options
   4419 #define SSL_set_tlsext_host_name SSL_set_tlsext_host_name
   4420 #define SSL_set_tmp_dh SSL_set_tmp_dh
   4421 #define SSL_set_tmp_ecdh SSL_set_tmp_ecdh
   4422 #define SSL_set_tmp_rsa SSL_set_tmp_rsa
   4423 #define SSL_total_renegotiations SSL_total_renegotiations
   4424 
   4425 
   4426 #if defined(__cplusplus)
   4427 } /* extern C */
   4428 
   4429 extern "C++" {
   4430 
   4431 namespace bssl {
   4432 
   4433 BORINGSSL_MAKE_DELETER(SSL, SSL_free)
   4434 BORINGSSL_MAKE_DELETER(SSL_CTX, SSL_CTX_free)
   4435 BORINGSSL_MAKE_DELETER(SSL_SESSION, SSL_SESSION_free)
   4436 
   4437 }  // namespace bssl
   4438 
   4439 }  /* extern C++ */
   4440 
   4441 #endif
   4442 
   4443 #define SSL_R_APP_DATA_IN_HANDSHAKE 100
   4444 #define SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT 101
   4445 #define SSL_R_BAD_ALERT 102
   4446 #define SSL_R_BAD_CHANGE_CIPHER_SPEC 103
   4447 #define SSL_R_BAD_DATA_RETURNED_BY_CALLBACK 104
   4448 #define SSL_R_BAD_DH_P_LENGTH 105
   4449 #define SSL_R_BAD_DIGEST_LENGTH 106
   4450 #define SSL_R_BAD_ECC_CERT 107
   4451 #define SSL_R_BAD_ECPOINT 108
   4452 #define SSL_R_BAD_HANDSHAKE_RECORD 109
   4453 #define SSL_R_BAD_HELLO_REQUEST 110
   4454 #define SSL_R_BAD_LENGTH 111
   4455 #define SSL_R_BAD_PACKET_LENGTH 112
   4456 #define SSL_R_BAD_RSA_ENCRYPT 113
   4457 #define SSL_R_BAD_SIGNATURE 114
   4458 #define SSL_R_BAD_SRTP_MKI_VALUE 115
   4459 #define SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST 116
   4460 #define SSL_R_BAD_SSL_FILETYPE 117
   4461 #define SSL_R_BAD_WRITE_RETRY 118
   4462 #define SSL_R_BIO_NOT_SET 119
   4463 #define SSL_R_BN_LIB 120
   4464 #define SSL_R_BUFFER_TOO_SMALL 121
   4465 #define SSL_R_CA_DN_LENGTH_MISMATCH 122
   4466 #define SSL_R_CA_DN_TOO_LONG 123
   4467 #define SSL_R_CCS_RECEIVED_EARLY 124
   4468 #define SSL_R_CERTIFICATE_VERIFY_FAILED 125
   4469 #define SSL_R_CERT_CB_ERROR 126
   4470 #define SSL_R_CERT_LENGTH_MISMATCH 127
   4471 #define SSL_R_CHANNEL_ID_NOT_P256 128
   4472 #define SSL_R_CHANNEL_ID_SIGNATURE_INVALID 129
   4473 #define SSL_R_CIPHER_OR_HASH_UNAVAILABLE 130
   4474 #define SSL_R_CLIENTHELLO_PARSE_FAILED 131
   4475 #define SSL_R_CLIENTHELLO_TLSEXT 132
   4476 #define SSL_R_CONNECTION_REJECTED 133
   4477 #define SSL_R_CONNECTION_TYPE_NOT_SET 134
   4478 #define SSL_R_CUSTOM_EXTENSION_ERROR 135
   4479 #define SSL_R_DATA_LENGTH_TOO_LONG 136
   4480 #define SSL_R_DECODE_ERROR 137
   4481 #define SSL_R_DECRYPTION_FAILED 138
   4482 #define SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC 139
   4483 #define SSL_R_DH_PUBLIC_VALUE_LENGTH_IS_WRONG 140
   4484 #define SSL_R_DH_P_TOO_LONG 141
   4485 #define SSL_R_DIGEST_CHECK_FAILED 142
   4486 #define SSL_R_DTLS_MESSAGE_TOO_BIG 143
   4487 #define SSL_R_ECC_CERT_NOT_FOR_SIGNING 144
   4488 #define SSL_R_EMS_STATE_INCONSISTENT 145
   4489 #define SSL_R_ENCRYPTED_LENGTH_TOO_LONG 146
   4490 #define SSL_R_ERROR_ADDING_EXTENSION 147
   4491 #define SSL_R_ERROR_IN_RECEIVED_CIPHER_LIST 148
   4492 #define SSL_R_ERROR_PARSING_EXTENSION 149
   4493 #define SSL_R_EXCESSIVE_MESSAGE_SIZE 150
   4494 #define SSL_R_EXTRA_DATA_IN_MESSAGE 151
   4495 #define SSL_R_FRAGMENT_MISMATCH 152
   4496 #define SSL_R_GOT_NEXT_PROTO_WITHOUT_EXTENSION 153
   4497 #define SSL_R_HANDSHAKE_FAILURE_ON_CLIENT_HELLO 154
   4498 #define SSL_R_HTTPS_PROXY_REQUEST 155
   4499 #define SSL_R_HTTP_REQUEST 156
   4500 #define SSL_R_INAPPROPRIATE_FALLBACK 157
   4501 #define SSL_R_INVALID_COMMAND 158
   4502 #define SSL_R_INVALID_MESSAGE 159
   4503 #define SSL_R_INVALID_SSL_SESSION 160
   4504 #define SSL_R_INVALID_TICKET_KEYS_LENGTH 161
   4505 #define SSL_R_LENGTH_MISMATCH 162
   4506 #define SSL_R_MISSING_EXTENSION 164
   4507 #define SSL_R_MISSING_RSA_CERTIFICATE 165
   4508 #define SSL_R_MISSING_TMP_DH_KEY 166
   4509 #define SSL_R_MISSING_TMP_ECDH_KEY 167
   4510 #define SSL_R_MIXED_SPECIAL_OPERATOR_WITH_GROUPS 168
   4511 #define SSL_R_MTU_TOO_SMALL 169
   4512 #define SSL_R_NEGOTIATED_BOTH_NPN_AND_ALPN 170
   4513 #define SSL_R_NESTED_GROUP 171
   4514 #define SSL_R_NO_CERTIFICATES_RETURNED 172
   4515 #define SSL_R_NO_CERTIFICATE_ASSIGNED 173
   4516 #define SSL_R_NO_CERTIFICATE_SET 174
   4517 #define SSL_R_NO_CIPHERS_AVAILABLE 175
   4518 #define SSL_R_NO_CIPHERS_PASSED 176
   4519 #define SSL_R_NO_CIPHER_MATCH 177
   4520 #define SSL_R_NO_COMPRESSION_SPECIFIED 178
   4521 #define SSL_R_NO_METHOD_SPECIFIED 179
   4522 #define SSL_R_NO_P256_SUPPORT 180
   4523 #define SSL_R_NO_PRIVATE_KEY_ASSIGNED 181
   4524 #define SSL_R_NO_RENEGOTIATION 182
   4525 #define SSL_R_NO_REQUIRED_DIGEST 183
   4526 #define SSL_R_NO_SHARED_CIPHER 184
   4527 #define SSL_R_NULL_SSL_CTX 185
   4528 #define SSL_R_NULL_SSL_METHOD_PASSED 186
   4529 #define SSL_R_OLD_SESSION_CIPHER_NOT_RETURNED 187
   4530 #define SSL_R_OLD_SESSION_VERSION_NOT_RETURNED 188
   4531 #define SSL_R_OUTPUT_ALIASES_INPUT 189
   4532 #define SSL_R_PARSE_TLSEXT 190
   4533 #define SSL_R_PATH_TOO_LONG 191
   4534 #define SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE 192
   4535 #define SSL_R_PEER_ERROR_UNSUPPORTED_CERTIFICATE_TYPE 193
   4536 #define SSL_R_PROTOCOL_IS_SHUTDOWN 194
   4537 #define SSL_R_PSK_IDENTITY_NOT_FOUND 195
   4538 #define SSL_R_PSK_NO_CLIENT_CB 196
   4539 #define SSL_R_PSK_NO_SERVER_CB 197
   4540 #define SSL_R_READ_TIMEOUT_EXPIRED 198
   4541 #define SSL_R_RECORD_LENGTH_MISMATCH 199
   4542 #define SSL_R_RECORD_TOO_LARGE 200
   4543 #define SSL_R_RENEGOTIATION_ENCODING_ERR 201
   4544 #define SSL_R_RENEGOTIATION_MISMATCH 202
   4545 #define SSL_R_REQUIRED_CIPHER_MISSING 203
   4546 #define SSL_R_RESUMED_EMS_SESSION_WITHOUT_EMS_EXTENSION 204
   4547 #define SSL_R_RESUMED_NON_EMS_SESSION_WITH_EMS_EXTENSION 205
   4548 #define SSL_R_SCSV_RECEIVED_WHEN_RENEGOTIATING 206
   4549 #define SSL_R_SERVERHELLO_TLSEXT 207
   4550 #define SSL_R_SESSION_ID_CONTEXT_UNINITIALIZED 208
   4551 #define SSL_R_SESSION_MAY_NOT_BE_CREATED 209
   4552 #define SSL_R_SIGNATURE_ALGORITHMS_EXTENSION_SENT_BY_SERVER 210
   4553 #define SSL_R_SRTP_COULD_NOT_ALLOCATE_PROFILES 211
   4554 #define SSL_R_SRTP_UNKNOWN_PROTECTION_PROFILE 212
   4555 #define SSL_R_SSL3_EXT_INVALID_SERVERNAME 213
   4556 #define SSL_R_SSL_CTX_HAS_NO_DEFAULT_SSL_VERSION 214
   4557 #define SSL_R_SSL_HANDSHAKE_FAILURE 215
   4558 #define SSL_R_SSL_SESSION_ID_CONTEXT_TOO_LONG 216
   4559 #define SSL_R_TLS_PEER_DID_NOT_RESPOND_WITH_CERTIFICATE_LIST 217
   4560 #define SSL_R_TLS_RSA_ENCRYPTED_VALUE_LENGTH_IS_WRONG 218
   4561 #define SSL_R_TOO_MANY_EMPTY_FRAGMENTS 219
   4562 #define SSL_R_TOO_MANY_WARNING_ALERTS 220
   4563 #define SSL_R_UNABLE_TO_FIND_ECDH_PARAMETERS 221
   4564 #define SSL_R_UNEXPECTED_EXTENSION 222
   4565 #define SSL_R_UNEXPECTED_MESSAGE 223
   4566 #define SSL_R_UNEXPECTED_OPERATOR_IN_GROUP 224
   4567 #define SSL_R_UNEXPECTED_RECORD 225
   4568 #define SSL_R_UNINITIALIZED 226
   4569 #define SSL_R_UNKNOWN_ALERT_TYPE 227
   4570 #define SSL_R_UNKNOWN_CERTIFICATE_TYPE 228
   4571 #define SSL_R_UNKNOWN_CIPHER_RETURNED 229
   4572 #define SSL_R_UNKNOWN_CIPHER_TYPE 230
   4573 #define SSL_R_UNKNOWN_DIGEST 231
   4574 #define SSL_R_UNKNOWN_KEY_EXCHANGE_TYPE 232
   4575 #define SSL_R_UNKNOWN_PROTOCOL 233
   4576 #define SSL_R_UNKNOWN_SSL_VERSION 234
   4577 #define SSL_R_UNKNOWN_STATE 235
   4578 #define SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED 236
   4579 #define SSL_R_UNSUPPORTED_CIPHER 237
   4580 #define SSL_R_UNSUPPORTED_COMPRESSION_ALGORITHM 238
   4581 #define SSL_R_UNSUPPORTED_ELLIPTIC_CURVE 239
   4582 #define SSL_R_UNSUPPORTED_PROTOCOL 240
   4583 #define SSL_R_WRONG_CERTIFICATE_TYPE 241
   4584 #define SSL_R_WRONG_CIPHER_RETURNED 242
   4585 #define SSL_R_WRONG_CURVE 243
   4586 #define SSL_R_WRONG_MESSAGE_TYPE 244
   4587 #define SSL_R_WRONG_SIGNATURE_TYPE 245
   4588 #define SSL_R_WRONG_SSL_VERSION 246
   4589 #define SSL_R_WRONG_VERSION_NUMBER 247
   4590 #define SSL_R_X509_LIB 248
   4591 #define SSL_R_X509_VERIFICATION_SETUP_PROBLEMS 249
   4592 #define SSL_R_SHUTDOWN_WHILE_IN_INIT 250
   4593 #define SSL_R_INVALID_OUTER_RECORD_TYPE 251
   4594 #define SSL_R_UNSUPPORTED_PROTOCOL_FOR_CUSTOM_KEY 252
   4595 #define SSL_R_NO_COMMON_SIGNATURE_ALGORITHMS 253
   4596 #define SSL_R_DOWNGRADE_DETECTED 254
   4597 #define SSL_R_BUFFERED_MESSAGES_ON_CIPHER_CHANGE 255
   4598 #define SSL_R_INVALID_COMPRESSION_LIST 256
   4599 #define SSL_R_DUPLICATE_EXTENSION 257
   4600 #define SSL_R_MISSING_KEY_SHARE 258
   4601 #define SSL_R_INVALID_ALPN_PROTOCOL 259
   4602 #define SSL_R_TOO_MANY_KEY_UPDATES 260
   4603 #define SSL_R_BLOCK_CIPHER_PAD_IS_WRONG 261
   4604 #define SSL_R_NO_CIPHERS_SPECIFIED 262
   4605 #define SSL_R_RENEGOTIATION_EMS_MISMATCH 263
   4606 #define SSL_R_DUPLICATE_KEY_SHARE 264
   4607 #define SSL_R_NO_GROUPS_SPECIFIED 265
   4608 #define SSL_R_NO_SHARED_GROUP 266
   4609 #define SSL_R_PRE_SHARED_KEY_MUST_BE_LAST 267
   4610 #define SSL_R_OLD_SESSION_PRF_HASH_MISMATCH 268
   4611 #define SSL_R_INVALID_SCT_LIST 269
   4612 #define SSL_R_TOO_MUCH_SKIPPED_EARLY_DATA 270
   4613 #define SSL_R_PSK_IDENTITY_BINDER_COUNT_MISMATCH 271
   4614 #define SSL_R_CANNOT_PARSE_LEAF_CERT 272
   4615 #define SSL_R_SERVER_CERT_CHANGED 273
   4616 #define SSL_R_CERTIFICATE_AND_PRIVATE_KEY_MISMATCH 274
   4617 #define SSL_R_CANNOT_HAVE_BOTH_PRIVKEY_AND_METHOD 275
   4618 #define SSL_R_TICKET_ENCRYPTION_FAILED 276
   4619 #define SSL_R_ALPN_MISMATCH_ON_EARLY_DATA 277
   4620 #define SSL_R_WRONG_VERSION_ON_EARLY_DATA 278
   4621 #define SSL_R_CHANNEL_ID_ON_EARLY_DATA 279
   4622 #define SSL_R_SSLV3_ALERT_CLOSE_NOTIFY 1000
   4623 #define SSL_R_SSLV3_ALERT_UNEXPECTED_MESSAGE 1010
   4624 #define SSL_R_SSLV3_ALERT_BAD_RECORD_MAC 1020
   4625 #define SSL_R_TLSV1_ALERT_DECRYPTION_FAILED 1021
   4626 #define SSL_R_TLSV1_ALERT_RECORD_OVERFLOW 1022
   4627 #define SSL_R_SSLV3_ALERT_DECOMPRESSION_FAILURE 1030
   4628 #define SSL_R_SSLV3_ALERT_HANDSHAKE_FAILURE 1040
   4629 #define SSL_R_SSLV3_ALERT_NO_CERTIFICATE 1041
   4630 #define SSL_R_SSLV3_ALERT_BAD_CERTIFICATE 1042
   4631 #define SSL_R_SSLV3_ALERT_UNSUPPORTED_CERTIFICATE 1043
   4632 #define SSL_R_SSLV3_ALERT_CERTIFICATE_REVOKED 1044
   4633 #define SSL_R_SSLV3_ALERT_CERTIFICATE_EXPIRED 1045
   4634 #define SSL_R_SSLV3_ALERT_CERTIFICATE_UNKNOWN 1046
   4635 #define SSL_R_SSLV3_ALERT_ILLEGAL_PARAMETER 1047
   4636 #define SSL_R_TLSV1_ALERT_UNKNOWN_CA 1048
   4637 #define SSL_R_TLSV1_ALERT_ACCESS_DENIED 1049
   4638 #define SSL_R_TLSV1_ALERT_DECODE_ERROR 1050
   4639 #define SSL_R_TLSV1_ALERT_DECRYPT_ERROR 1051
   4640 #define SSL_R_TLSV1_ALERT_EXPORT_RESTRICTION 1060
   4641 #define SSL_R_TLSV1_ALERT_PROTOCOL_VERSION 1070
   4642 #define SSL_R_TLSV1_ALERT_INSUFFICIENT_SECURITY 1071
   4643 #define SSL_R_TLSV1_ALERT_INTERNAL_ERROR 1080
   4644 #define SSL_R_TLSV1_ALERT_INAPPROPRIATE_FALLBACK 1086
   4645 #define SSL_R_TLSV1_ALERT_USER_CANCELLED 1090
   4646 #define SSL_R_TLSV1_ALERT_NO_RENEGOTIATION 1100
   4647 #define SSL_R_TLSV1_UNSUPPORTED_EXTENSION 1110
   4648 #define SSL_R_TLSV1_CERTIFICATE_UNOBTAINABLE 1111
   4649 #define SSL_R_TLSV1_UNRECOGNIZED_NAME 1112
   4650 #define SSL_R_TLSV1_BAD_CERTIFICATE_STATUS_RESPONSE 1113
   4651 #define SSL_R_TLSV1_BAD_CERTIFICATE_HASH_VALUE 1114
   4652 #define SSL_R_TLSV1_UNKNOWN_PSK_IDENTITY 1115
   4653 #define SSL_R_TLSV1_CERTIFICATE_REQUIRED 1116
   4654 
   4655 #endif /* OPENSSL_HEADER_SSL_H */
   4656