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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.
    496  *
    497  * See also |SSL_CTX_set_select_certificate_cb|. */
    498 #define SSL_ERROR_PENDING_CERTIFICATE 12
    499 
    500 /* SSL_ERROR_WANT_PRIVATE_KEY_OPERATION indicates the operation failed because
    501  * a private key operation was unfinished. The caller may retry the operation
    502  * when the private key operation is complete.
    503  *
    504  * See also |SSL_set_private_key_method| and
    505  * |SSL_CTX_set_private_key_method|. */
    506 #define SSL_ERROR_WANT_PRIVATE_KEY_OPERATION 13
    507 
    508 /* SSL_ERROR_PENDING_TICKET indicates that a ticket decryption is pending. The
    509  * caller may retry the operation when the decryption is ready.
    510  *
    511  * See also |SSL_CTX_set_ticket_aead_method|. */
    512 #define SSL_ERROR_PENDING_TICKET 14
    513 
    514 /* SSL_ERROR_EARLY_DATA_REJECTED indicates that early data was rejected. The
    515  * caller should treat this as a connection failure and retry any operations
    516  * associated with the rejected early data. |SSL_reset_early_data_reject| may be
    517  * used to reuse the underlying connection for the retry. */
    518 #define SSL_ERROR_EARLY_DATA_REJECTED 15
    519 
    520 /* SSL_set_mtu sets the |ssl|'s MTU in DTLS to |mtu|. It returns one on success
    521  * and zero on failure. */
    522 OPENSSL_EXPORT int SSL_set_mtu(SSL *ssl, unsigned mtu);
    523 
    524 /* DTLSv1_set_initial_timeout_duration sets the initial duration for a DTLS
    525  * handshake timeout.
    526  *
    527  * This duration overrides the default of 1 second, which is the strong
    528  * recommendation of RFC 6347 (see section 4.2.4.1). However, there may exist
    529  * situations where a shorter timeout would be beneficial, such as for
    530  * time-sensitive applications. */
    531 OPENSSL_EXPORT void DTLSv1_set_initial_timeout_duration(SSL *ssl,
    532                                                         unsigned duration_ms);
    533 
    534 /* DTLSv1_get_timeout queries the next DTLS handshake timeout. If there is a
    535  * timeout in progress, it sets |*out| to the time remaining and returns one.
    536  * Otherwise, it returns zero.
    537  *
    538  * When the timeout expires, call |DTLSv1_handle_timeout| to handle the
    539  * retransmit behavior.
    540  *
    541  * NOTE: This function must be queried again whenever the handshake state
    542  * machine changes, including when |DTLSv1_handle_timeout| is called. */
    543 OPENSSL_EXPORT int DTLSv1_get_timeout(const SSL *ssl, struct timeval *out);
    544 
    545 /* DTLSv1_handle_timeout is called when a DTLS handshake timeout expires. If no
    546  * timeout had expired, it returns 0. Otherwise, it retransmits the previous
    547  * flight of handshake messages and returns 1. If too many timeouts had expired
    548  * without progress or an error occurs, it returns -1.
    549  *
    550  * The caller's external timer should be compatible with the one |ssl| queries
    551  * within some fudge factor. Otherwise, the call will be a no-op, but
    552  * |DTLSv1_get_timeout| will return an updated timeout.
    553  *
    554  * If the function returns -1, checking if |SSL_get_error| returns
    555  * |SSL_ERROR_WANT_WRITE| may be used to determine if the retransmit failed due
    556  * to a non-fatal error at the write |BIO|. However, the operation may not be
    557  * retried until the next timeout fires.
    558  *
    559  * WARNING: This function breaks the usual return value convention.
    560  *
    561  * TODO(davidben): This |SSL_ERROR_WANT_WRITE| behavior is kind of bizarre. */
    562 OPENSSL_EXPORT int DTLSv1_handle_timeout(SSL *ssl);
    563 
    564 
    565 /* Protocol versions. */
    566 
    567 #define DTLS1_VERSION_MAJOR 0xfe
    568 #define SSL3_VERSION_MAJOR 0x03
    569 
    570 #define SSL3_VERSION 0x0300
    571 #define TLS1_VERSION 0x0301
    572 #define TLS1_1_VERSION 0x0302
    573 #define TLS1_2_VERSION 0x0303
    574 #define TLS1_3_VERSION 0x0304
    575 
    576 #define DTLS1_VERSION 0xfeff
    577 #define DTLS1_2_VERSION 0xfefd
    578 
    579 #define TLS1_3_DRAFT_VERSION 0x7f12
    580 #define TLS1_3_EXPERIMENT_VERSION 0x7e01
    581 #define TLS1_3_RECORD_TYPE_EXPERIMENT_VERSION 0x7a12
    582 
    583 /* SSL_CTX_set_min_proto_version sets the minimum protocol version for |ctx| to
    584  * |version|. If |version| is zero, the default minimum version is used. It
    585  * returns one on success and zero if |version| is invalid. */
    586 OPENSSL_EXPORT int SSL_CTX_set_min_proto_version(SSL_CTX *ctx,
    587                                                  uint16_t version);
    588 
    589 /* SSL_CTX_set_max_proto_version sets the maximum protocol version for |ctx| to
    590  * |version|. If |version| is zero, the default maximum version is used. It
    591  * returns one on success and zero if |version| is invalid. */
    592 OPENSSL_EXPORT int SSL_CTX_set_max_proto_version(SSL_CTX *ctx,
    593                                                  uint16_t version);
    594 
    595 /* SSL_set_min_proto_version sets the minimum protocol version for |ssl| to
    596  * |version|. If |version| is zero, the default minimum version is used. It
    597  * returns one on success and zero if |version| is invalid. */
    598 OPENSSL_EXPORT int SSL_set_min_proto_version(SSL *ssl, uint16_t version);
    599 
    600 /* SSL_set_max_proto_version sets the maximum protocol version for |ssl| to
    601  * |version|. If |version| is zero, the default maximum version is used. It
    602  * returns one on success and zero if |version| is invalid. */
    603 OPENSSL_EXPORT int SSL_set_max_proto_version(SSL *ssl, uint16_t version);
    604 
    605 /* SSL_version returns the TLS or DTLS protocol version used by |ssl|, which is
    606  * one of the |*_VERSION| values. (E.g. |TLS1_2_VERSION|.) Before the version
    607  * is negotiated, the result is undefined. */
    608 OPENSSL_EXPORT int SSL_version(const SSL *ssl);
    609 
    610 
    611 /* Options.
    612  *
    613  * Options configure protocol behavior. */
    614 
    615 /* SSL_OP_NO_QUERY_MTU, in DTLS, disables querying the MTU from the underlying
    616  * |BIO|. Instead, the MTU is configured with |SSL_set_mtu|. */
    617 #define SSL_OP_NO_QUERY_MTU 0x00001000L
    618 
    619 /* SSL_OP_NO_TICKET disables session ticket support (RFC 5077). */
    620 #define SSL_OP_NO_TICKET 0x00004000L
    621 
    622 /* SSL_OP_CIPHER_SERVER_PREFERENCE configures servers to select ciphers and
    623  * ECDHE curves according to the server's preferences instead of the
    624  * client's. */
    625 #define SSL_OP_CIPHER_SERVER_PREFERENCE 0x00400000L
    626 
    627 /* The following flags toggle individual protocol versions. This is deprecated.
    628  * Use |SSL_CTX_set_min_proto_version| and |SSL_CTX_set_max_proto_version|
    629  * instead. */
    630 #define SSL_OP_NO_SSLv3 0x02000000L
    631 #define SSL_OP_NO_TLSv1 0x04000000L
    632 #define SSL_OP_NO_TLSv1_2 0x08000000L
    633 #define SSL_OP_NO_TLSv1_1 0x10000000L
    634 #define SSL_OP_NO_TLSv1_3 0x20000000L
    635 #define SSL_OP_NO_DTLSv1 SSL_OP_NO_TLSv1
    636 #define SSL_OP_NO_DTLSv1_2 SSL_OP_NO_TLSv1_2
    637 
    638 /* SSL_CTX_set_options enables all options set in |options| (which should be one
    639  * or more of the |SSL_OP_*| values, ORed together) in |ctx|. It returns a
    640  * bitmask representing the resulting enabled options. */
    641 OPENSSL_EXPORT uint32_t SSL_CTX_set_options(SSL_CTX *ctx, uint32_t options);
    642 
    643 /* SSL_CTX_clear_options disables all options set in |options| (which should be
    644  * one or more of the |SSL_OP_*| values, ORed together) in |ctx|. It returns a
    645  * bitmask representing the resulting enabled options. */
    646 OPENSSL_EXPORT uint32_t SSL_CTX_clear_options(SSL_CTX *ctx, uint32_t options);
    647 
    648 /* SSL_CTX_get_options returns a bitmask of |SSL_OP_*| values that represent all
    649  * the options enabled for |ctx|. */
    650 OPENSSL_EXPORT uint32_t SSL_CTX_get_options(const SSL_CTX *ctx);
    651 
    652 /* SSL_set_options enables all options set in |options| (which should be one or
    653  * more of the |SSL_OP_*| values, ORed together) in |ssl|. It returns a bitmask
    654  * representing the resulting enabled options. */
    655 OPENSSL_EXPORT uint32_t SSL_set_options(SSL *ssl, uint32_t options);
    656 
    657 /* SSL_clear_options disables all options set in |options| (which should be one
    658  * or more of the |SSL_OP_*| values, ORed together) in |ssl|. It returns a
    659  * bitmask representing the resulting enabled options. */
    660 OPENSSL_EXPORT uint32_t SSL_clear_options(SSL *ssl, uint32_t options);
    661 
    662 /* SSL_get_options returns a bitmask of |SSL_OP_*| values that represent all the
    663  * options enabled for |ssl|. */
    664 OPENSSL_EXPORT uint32_t SSL_get_options(const SSL *ssl);
    665 
    666 
    667 /* Modes.
    668  *
    669  * Modes configure API behavior. */
    670 
    671 /* SSL_MODE_ENABLE_PARTIAL_WRITE, in TLS, allows |SSL_write| to complete with a
    672  * partial result when the only part of the input was written in a single
    673  * record. In DTLS, it does nothing. */
    674 #define SSL_MODE_ENABLE_PARTIAL_WRITE 0x00000001L
    675 
    676 /* SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER, in TLS, allows retrying an incomplete
    677  * |SSL_write| with a different buffer. However, |SSL_write| still assumes the
    678  * buffer contents are unchanged. This is not the default to avoid the
    679  * misconception that non-blocking |SSL_write| behaves like non-blocking
    680  * |write|. In DTLS, it does nothing. */
    681 #define SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER 0x00000002L
    682 
    683 /* SSL_MODE_NO_AUTO_CHAIN disables automatically building a certificate chain
    684  * before sending certificates to the peer. This flag is set (and the feature
    685  * disabled) by default.
    686  * TODO(davidben): Remove this behavior. https://crbug.com/boringssl/42. */
    687 #define SSL_MODE_NO_AUTO_CHAIN 0x00000008L
    688 
    689 /* SSL_MODE_ENABLE_FALSE_START allows clients to send application data before
    690  * receipt of ChangeCipherSpec and Finished. This mode enables full handshakes
    691  * to 'complete' in one RTT. See RFC 7918.
    692  *
    693  * When False Start is enabled, |SSL_do_handshake| may succeed before the
    694  * handshake has completely finished. |SSL_write| will function at this point,
    695  * and |SSL_read| will transparently wait for the final handshake leg before
    696  * returning application data. To determine if False Start occurred or when the
    697  * handshake is completely finished, see |SSL_in_false_start|, |SSL_in_init|,
    698  * and |SSL_CB_HANDSHAKE_DONE| from |SSL_CTX_set_info_callback|. */
    699 #define SSL_MODE_ENABLE_FALSE_START 0x00000080L
    700 
    701 /* SSL_MODE_CBC_RECORD_SPLITTING causes multi-byte CBC records in SSL 3.0 and
    702  * TLS 1.0 to be split in two: the first record will contain a single byte and
    703  * the second will contain the remainder. This effectively randomises the IV and
    704  * prevents BEAST attacks. */
    705 #define SSL_MODE_CBC_RECORD_SPLITTING 0x00000100L
    706 
    707 /* SSL_MODE_NO_SESSION_CREATION will cause any attempts to create a session to
    708  * fail with SSL_R_SESSION_MAY_NOT_BE_CREATED. This can be used to enforce that
    709  * session resumption is used for a given SSL*. */
    710 #define SSL_MODE_NO_SESSION_CREATION 0x00000200L
    711 
    712 /* SSL_MODE_SEND_FALLBACK_SCSV sends TLS_FALLBACK_SCSV in the ClientHello.
    713  * To be set only by applications that reconnect with a downgraded protocol
    714  * version; see RFC 7507 for details.
    715  *
    716  * DO NOT ENABLE THIS if your application attempts a normal handshake. Only use
    717  * this in explicit fallback retries, following the guidance in RFC 7507. */
    718 #define SSL_MODE_SEND_FALLBACK_SCSV 0x00000400L
    719 
    720 /* SSL_CTX_set_mode enables all modes set in |mode| (which should be one or more
    721  * of the |SSL_MODE_*| values, ORed together) in |ctx|. It returns a bitmask
    722  * representing the resulting enabled modes. */
    723 OPENSSL_EXPORT uint32_t SSL_CTX_set_mode(SSL_CTX *ctx, uint32_t mode);
    724 
    725 /* SSL_CTX_clear_mode disables all modes set in |mode| (which should be one or
    726  * more of the |SSL_MODE_*| values, ORed together) in |ctx|. It returns a
    727  * bitmask representing the resulting enabled modes. */
    728 OPENSSL_EXPORT uint32_t SSL_CTX_clear_mode(SSL_CTX *ctx, uint32_t mode);
    729 
    730 /* SSL_CTX_get_mode returns a bitmask of |SSL_MODE_*| values that represent all
    731  * the modes enabled for |ssl|. */
    732 OPENSSL_EXPORT uint32_t SSL_CTX_get_mode(const SSL_CTX *ctx);
    733 
    734 /* SSL_set_mode enables all modes set in |mode| (which should be one or more of
    735  * the |SSL_MODE_*| values, ORed together) in |ssl|. It returns a bitmask
    736  * representing the resulting enabled modes. */
    737 OPENSSL_EXPORT uint32_t SSL_set_mode(SSL *ssl, uint32_t mode);
    738 
    739 /* SSL_clear_mode disables all modes set in |mode| (which should be one or more
    740  * of the |SSL_MODE_*| values, ORed together) in |ssl|. It returns a bitmask
    741  * representing the resulting enabled modes. */
    742 OPENSSL_EXPORT uint32_t SSL_clear_mode(SSL *ssl, uint32_t mode);
    743 
    744 /* SSL_get_mode returns a bitmask of |SSL_MODE_*| values that represent all the
    745  * modes enabled for |ssl|. */
    746 OPENSSL_EXPORT uint32_t SSL_get_mode(const SSL *ssl);
    747 
    748 /* SSL_CTX_set0_buffer_pool sets a |CRYPTO_BUFFER_POOL| that will be used to
    749  * store certificates. This can allow multiple connections to share
    750  * certificates and thus save memory.
    751  *
    752  * The SSL_CTX does not take ownership of |pool| and the caller must ensure
    753  * that |pool| outlives |ctx| and all objects linked to it, including |SSL|,
    754  * |X509| and |SSL_SESSION| objects. Basically, don't ever free |pool|. */
    755 OPENSSL_EXPORT void SSL_CTX_set0_buffer_pool(SSL_CTX *ctx,
    756                                              CRYPTO_BUFFER_POOL *pool);
    757 
    758 
    759 /* Configuring certificates and private keys.
    760  *
    761  * These functions configure the connection's leaf certificate, private key, and
    762  * certificate chain. The certificate chain is ordered leaf to root (as sent on
    763  * the wire) but does not include the leaf. Both client and server certificates
    764  * use these functions.
    765  *
    766  * Certificates and keys may be configured before the handshake or dynamically
    767  * in the early callback and certificate callback. */
    768 
    769 /* SSL_CTX_use_certificate sets |ctx|'s leaf certificate to |x509|. It returns
    770  * one on success and zero on failure. */
    771 OPENSSL_EXPORT int SSL_CTX_use_certificate(SSL_CTX *ctx, X509 *x509);
    772 
    773 /* SSL_use_certificate sets |ssl|'s leaf certificate to |x509|. It returns one
    774  * on success and zero on failure. */
    775 OPENSSL_EXPORT int SSL_use_certificate(SSL *ssl, X509 *x509);
    776 
    777 /* SSL_CTX_use_PrivateKey sets |ctx|'s private key to |pkey|. It returns one on
    778  * success and zero on failure. */
    779 OPENSSL_EXPORT int SSL_CTX_use_PrivateKey(SSL_CTX *ctx, EVP_PKEY *pkey);
    780 
    781 /* SSL_use_PrivateKey sets |ssl|'s private key to |pkey|. It returns one on
    782  * success and zero on failure. */
    783 OPENSSL_EXPORT int SSL_use_PrivateKey(SSL *ssl, EVP_PKEY *pkey);
    784 
    785 /* SSL_CTX_set0_chain sets |ctx|'s certificate chain, excluding the leaf, to
    786  * |chain|. On success, it returns one and takes ownership of |chain|.
    787  * Otherwise, it returns zero. */
    788 OPENSSL_EXPORT int SSL_CTX_set0_chain(SSL_CTX *ctx, STACK_OF(X509) *chain);
    789 
    790 /* SSL_CTX_set1_chain sets |ctx|'s certificate chain, excluding the leaf, to
    791  * |chain|. It returns one on success and zero on failure. The caller retains
    792  * ownership of |chain| and may release it freely. */
    793 OPENSSL_EXPORT int SSL_CTX_set1_chain(SSL_CTX *ctx, STACK_OF(X509) *chain);
    794 
    795 /* SSL_set0_chain sets |ssl|'s certificate chain, excluding the leaf, to
    796  * |chain|. On success, it returns one and takes ownership of |chain|.
    797  * Otherwise, it returns zero. */
    798 OPENSSL_EXPORT int SSL_set0_chain(SSL *ssl, STACK_OF(X509) *chain);
    799 
    800 /* SSL_set1_chain sets |ssl|'s certificate chain, excluding the leaf, to
    801  * |chain|. It returns one on success and zero on failure. The caller retains
    802  * ownership of |chain| and may release it freely. */
    803 OPENSSL_EXPORT int SSL_set1_chain(SSL *ssl, STACK_OF(X509) *chain);
    804 
    805 /* SSL_CTX_add0_chain_cert appends |x509| to |ctx|'s certificate chain. On
    806  * success, it returns one and takes ownership of |x509|. Otherwise, it returns
    807  * zero. */
    808 OPENSSL_EXPORT int SSL_CTX_add0_chain_cert(SSL_CTX *ctx, X509 *x509);
    809 
    810 /* SSL_CTX_add1_chain_cert appends |x509| to |ctx|'s certificate chain. It
    811  * returns one on success and zero on failure. The caller retains ownership of
    812  * |x509| and may release it freely. */
    813 OPENSSL_EXPORT int SSL_CTX_add1_chain_cert(SSL_CTX *ctx, X509 *x509);
    814 
    815 /* SSL_add0_chain_cert appends |x509| to |ctx|'s certificate chain. On success,
    816  * it returns one and takes ownership of |x509|. Otherwise, it returns zero. */
    817 OPENSSL_EXPORT int SSL_add0_chain_cert(SSL *ssl, X509 *x509);
    818 
    819 /* SSL_CTX_add_extra_chain_cert calls |SSL_CTX_add0_chain_cert|. */
    820 OPENSSL_EXPORT int SSL_CTX_add_extra_chain_cert(SSL_CTX *ctx, X509 *x509);
    821 
    822 /* SSL_add1_chain_cert appends |x509| to |ctx|'s certificate chain. It returns
    823  * one on success and zero on failure. The caller retains ownership of |x509|
    824  * and may release it freely. */
    825 OPENSSL_EXPORT int SSL_add1_chain_cert(SSL *ssl, X509 *x509);
    826 
    827 /* SSL_CTX_clear_chain_certs clears |ctx|'s certificate chain and returns
    828  * one. */
    829 OPENSSL_EXPORT int SSL_CTX_clear_chain_certs(SSL_CTX *ctx);
    830 
    831 /* SSL_CTX_clear_extra_chain_certs calls |SSL_CTX_clear_chain_certs|. */
    832 OPENSSL_EXPORT int SSL_CTX_clear_extra_chain_certs(SSL_CTX *ctx);
    833 
    834 /* SSL_clear_chain_certs clears |ssl|'s certificate chain and returns one. */
    835 OPENSSL_EXPORT int SSL_clear_chain_certs(SSL *ssl);
    836 
    837 /* SSL_CTX_set_cert_cb sets a callback that is called to select a certificate.
    838  * The callback returns one on success, zero on internal error, and a negative
    839  * number on failure or to pause the handshake. If the handshake is paused,
    840  * |SSL_get_error| will return |SSL_ERROR_WANT_X509_LOOKUP|.
    841  *
    842  * On the client, the callback may call |SSL_get0_certificate_types| and
    843  * |SSL_get_client_CA_list| for information on the server's certificate
    844  * request.
    845  *
    846  * On the server, the callback will be called on non-resumption handshakes,
    847  * after extensions have been processed. */
    848 OPENSSL_EXPORT void SSL_CTX_set_cert_cb(SSL_CTX *ctx,
    849                                         int (*cb)(SSL *ssl, void *arg),
    850                                         void *arg);
    851 
    852 /* SSL_set_cert_cb sets a callback that is called to select a certificate. The
    853  * callback returns one on success, zero on internal error, and a negative
    854  * number on failure or to pause the handshake. If the handshake is paused,
    855  * |SSL_get_error| will return |SSL_ERROR_WANT_X509_LOOKUP|.
    856  *
    857  * On the client, the callback may call |SSL_get0_certificate_types| and
    858  * |SSL_get_client_CA_list| for information on the server's certificate
    859  * request. */
    860 OPENSSL_EXPORT void SSL_set_cert_cb(SSL *ssl, int (*cb)(SSL *ssl, void *arg),
    861                                     void *arg);
    862 
    863 /* SSL_get0_certificate_types, for a client, sets |*out_types| to an array
    864  * containing the client certificate types requested by a server. It returns the
    865  * length of the array.
    866  *
    867  * The behavior of this function is undefined except during the callbacks set by
    868  * by |SSL_CTX_set_cert_cb| and |SSL_CTX_set_client_cert_cb| or when the
    869  * handshake is paused because of them. */
    870 OPENSSL_EXPORT size_t SSL_get0_certificate_types(SSL *ssl,
    871                                                  const uint8_t **out_types);
    872 
    873 /* SSL_certs_clear resets the private key, leaf certificate, and certificate
    874  * chain of |ssl|. */
    875 OPENSSL_EXPORT void SSL_certs_clear(SSL *ssl);
    876 
    877 /* SSL_CTX_check_private_key returns one if the certificate and private key
    878  * configured in |ctx| are consistent and zero otherwise. */
    879 OPENSSL_EXPORT int SSL_CTX_check_private_key(const SSL_CTX *ctx);
    880 
    881 /* SSL_check_private_key returns one if the certificate and private key
    882  * configured in |ssl| are consistent and zero otherwise. */
    883 OPENSSL_EXPORT int SSL_check_private_key(const SSL *ssl);
    884 
    885 /* SSL_CTX_get0_certificate returns |ctx|'s leaf certificate. */
    886 OPENSSL_EXPORT X509 *SSL_CTX_get0_certificate(const SSL_CTX *ctx);
    887 
    888 /* SSL_get_certificate returns |ssl|'s leaf certificate. */
    889 OPENSSL_EXPORT X509 *SSL_get_certificate(const SSL *ssl);
    890 
    891 /* SSL_CTX_get0_privatekey returns |ctx|'s private key. */
    892 OPENSSL_EXPORT EVP_PKEY *SSL_CTX_get0_privatekey(const SSL_CTX *ctx);
    893 
    894 /* SSL_get_privatekey returns |ssl|'s private key. */
    895 OPENSSL_EXPORT EVP_PKEY *SSL_get_privatekey(const SSL *ssl);
    896 
    897 /* SSL_CTX_get0_chain_certs sets |*out_chain| to |ctx|'s certificate chain and
    898  * returns one. */
    899 OPENSSL_EXPORT int SSL_CTX_get0_chain_certs(const SSL_CTX *ctx,
    900                                             STACK_OF(X509) **out_chain);
    901 
    902 /* SSL_CTX_get_extra_chain_certs calls |SSL_CTX_get0_chain_certs|. */
    903 OPENSSL_EXPORT int SSL_CTX_get_extra_chain_certs(const SSL_CTX *ctx,
    904                                                  STACK_OF(X509) **out_chain);
    905 
    906 /* SSL_get0_chain_certs sets |*out_chain| to |ssl|'s certificate chain and
    907  * returns one. */
    908 OPENSSL_EXPORT int SSL_get0_chain_certs(const SSL *ssl,
    909                                         STACK_OF(X509) **out_chain);
    910 
    911 /* SSL_CTX_set_signed_cert_timestamp_list sets the list of signed certificate
    912  * timestamps that is sent to clients that request it. The |list| argument must
    913  * contain one or more SCT structures serialised as a SignedCertificateTimestamp
    914  * List (see https://tools.ietf.org/html/rfc6962#section-3.3)  i.e. each SCT
    915  * is prefixed by a big-endian, uint16 length and the concatenation of one or
    916  * more such prefixed SCTs are themselves also prefixed by a uint16 length. It
    917  * returns one on success and zero on error. The caller retains ownership of
    918  * |list|. */
    919 OPENSSL_EXPORT int SSL_CTX_set_signed_cert_timestamp_list(SSL_CTX *ctx,
    920                                                           const uint8_t *list,
    921                                                           size_t list_len);
    922 
    923 /* SSL_set_signed_cert_timestamp_list sets the list of signed certificate
    924  * timestamps that is sent to clients that request is. The same format as the
    925  * one used for |SSL_CTX_set_signed_cert_timestamp_list| applies. The caller
    926  * retains ownership of |list|. */
    927 OPENSSL_EXPORT int SSL_set_signed_cert_timestamp_list(SSL *ctx,
    928                                                       const uint8_t *list,
    929                                                       size_t list_len);
    930 
    931 /* SSL_CTX_set_ocsp_response sets the OCSP response that is sent to clients
    932  * which request it. It returns one on success and zero on error. The caller
    933  * retains ownership of |response|. */
    934 OPENSSL_EXPORT int SSL_CTX_set_ocsp_response(SSL_CTX *ctx,
    935                                              const uint8_t *response,
    936                                              size_t response_len);
    937 
    938 /* SSL_set_ocsp_response sets the OCSP response that is sent to clients which
    939  * request it. It returns one on success and zero on error. The caller retains
    940  * ownership of |response|. */
    941 OPENSSL_EXPORT int SSL_set_ocsp_response(SSL *ssl,
    942                                          const uint8_t *response,
    943                                          size_t response_len);
    944 
    945 /* SSL_SIGN_* are signature algorithm values as defined in TLS 1.3. */
    946 #define SSL_SIGN_RSA_PKCS1_SHA1 0x0201
    947 #define SSL_SIGN_RSA_PKCS1_SHA256 0x0401
    948 #define SSL_SIGN_RSA_PKCS1_SHA384 0x0501
    949 #define SSL_SIGN_RSA_PKCS1_SHA512 0x0601
    950 #define SSL_SIGN_ECDSA_SHA1 0x0203
    951 #define SSL_SIGN_ECDSA_SECP256R1_SHA256 0x0403
    952 #define SSL_SIGN_ECDSA_SECP384R1_SHA384 0x0503
    953 #define SSL_SIGN_ECDSA_SECP521R1_SHA512 0x0603
    954 #define SSL_SIGN_RSA_PSS_SHA256 0x0804
    955 #define SSL_SIGN_RSA_PSS_SHA384 0x0805
    956 #define SSL_SIGN_RSA_PSS_SHA512 0x0806
    957 #define SSL_SIGN_ED25519 0x0807
    958 
    959 /* SSL_SIGN_RSA_PKCS1_MD5_SHA1 is an internal signature algorithm used to
    960  * specify raw RSASSA-PKCS1-v1_5 with an MD5/SHA-1 concatenation, as used in TLS
    961  * before TLS 1.2. */
    962 #define SSL_SIGN_RSA_PKCS1_MD5_SHA1 0xff01
    963 
    964 /* SSL_CTX_set_signing_algorithm_prefs configures |ctx| to use |prefs| as the
    965  * preference list when signing with |ctx|'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_CTX_set_signing_algorithm_prefs(SSL_CTX *ctx,
    969                                                        const uint16_t *prefs,
    970                                                        size_t num_prefs);
    971 
    972 /* SSL_set_signing_algorithm_prefs configures |ssl| to use |prefs| as the
    973  * preference list when signing with |ssl|'s private key. It returns one on
    974  * success and zero on error. |prefs| should not include the internal-only value
    975  * |SSL_SIGN_RSA_PKCS1_MD5_SHA1|. */
    976 OPENSSL_EXPORT int SSL_set_signing_algorithm_prefs(SSL *ssl,
    977                                                    const uint16_t *prefs,
    978                                                    size_t num_prefs);
    979 
    980 
    981 /* Certificate and private key convenience functions. */
    982 
    983 /* SSL_CTX_set_chain_and_key sets the certificate chain and private key for a
    984  * TLS 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_CTX_set_chain_and_key(
    988     SSL_CTX *ctx, CRYPTO_BUFFER *const *certs, size_t num_certs,
    989     EVP_PKEY *privkey, const SSL_PRIVATE_KEY_METHOD *privkey_method);
    990 
    991 /* SSL_set_chain_and_key sets the certificate chain and private key for a TLS
    992  * client or server. References to the given |CRYPTO_BUFFER| and |EVP_PKEY|
    993  * objects are added as needed. Exactly one of |privkey| or |privkey_method|
    994  * may be non-NULL. Returns one on success and zero on error. */
    995 OPENSSL_EXPORT int SSL_set_chain_and_key(
    996     SSL *ssl, CRYPTO_BUFFER *const *certs, size_t num_certs, EVP_PKEY *privkey,
    997     const SSL_PRIVATE_KEY_METHOD *privkey_method);
    998 
    999 /* SSL_CTX_use_RSAPrivateKey sets |ctx|'s private key to |rsa|. It returns one
   1000  * on success and zero on failure. */
   1001 OPENSSL_EXPORT int SSL_CTX_use_RSAPrivateKey(SSL_CTX *ctx, RSA *rsa);
   1002 
   1003 /* SSL_use_RSAPrivateKey sets |ctx|'s private key to |rsa|. It returns one on
   1004  * success and zero on failure. */
   1005 OPENSSL_EXPORT int SSL_use_RSAPrivateKey(SSL *ssl, RSA *rsa);
   1006 
   1007 /* The following functions configure certificates or private keys but take as
   1008  * input DER-encoded structures. They return one on success and zero on
   1009  * failure. */
   1010 
   1011 OPENSSL_EXPORT int SSL_CTX_use_certificate_ASN1(SSL_CTX *ctx, size_t der_len,
   1012                                                 const uint8_t *der);
   1013 OPENSSL_EXPORT int SSL_use_certificate_ASN1(SSL *ssl, const uint8_t *der,
   1014                                             size_t der_len);
   1015 
   1016 OPENSSL_EXPORT int SSL_CTX_use_PrivateKey_ASN1(int pk, SSL_CTX *ctx,
   1017                                                const uint8_t *der,
   1018                                                size_t der_len);
   1019 OPENSSL_EXPORT int SSL_use_PrivateKey_ASN1(int type, SSL *ssl,
   1020                                            const uint8_t *der, size_t der_len);
   1021 
   1022 OPENSSL_EXPORT int SSL_CTX_use_RSAPrivateKey_ASN1(SSL_CTX *ctx,
   1023                                                   const uint8_t *der,
   1024                                                   size_t der_len);
   1025 OPENSSL_EXPORT int SSL_use_RSAPrivateKey_ASN1(SSL *ssl, const uint8_t *der,
   1026                                               size_t der_len);
   1027 
   1028 /* The following functions configure certificates or private keys but take as
   1029  * input files to read from. They return one on success and zero on failure. The
   1030  * |type| parameter is one of the |SSL_FILETYPE_*| values and determines whether
   1031  * the file's contents are read as PEM or DER. */
   1032 
   1033 #define SSL_FILETYPE_ASN1 X509_FILETYPE_ASN1
   1034 #define SSL_FILETYPE_PEM X509_FILETYPE_PEM
   1035 
   1036 OPENSSL_EXPORT int SSL_CTX_use_RSAPrivateKey_file(SSL_CTX *ctx,
   1037                                                   const char *file,
   1038                                                   int type);
   1039 OPENSSL_EXPORT int SSL_use_RSAPrivateKey_file(SSL *ssl, const char *file,
   1040                                               int type);
   1041 
   1042 OPENSSL_EXPORT int SSL_CTX_use_certificate_file(SSL_CTX *ctx, const char *file,
   1043                                                 int type);
   1044 OPENSSL_EXPORT int SSL_use_certificate_file(SSL *ssl, const char *file,
   1045                                             int type);
   1046 
   1047 OPENSSL_EXPORT int SSL_CTX_use_PrivateKey_file(SSL_CTX *ctx, const char *file,
   1048                                                int type);
   1049 OPENSSL_EXPORT int SSL_use_PrivateKey_file(SSL *ssl, const char *file,
   1050                                            int type);
   1051 
   1052 /* SSL_CTX_use_certificate_chain_file configures certificates for |ctx|. It
   1053  * reads the contents of |file| as a PEM-encoded leaf certificate followed
   1054  * optionally by the certificate chain to send to the peer. It returns one on
   1055  * success and zero on failure. */
   1056 OPENSSL_EXPORT int SSL_CTX_use_certificate_chain_file(SSL_CTX *ctx,
   1057                                                       const char *file);
   1058 
   1059 /* SSL_CTX_set_default_passwd_cb sets the password callback for PEM-based
   1060  * convenience functions called on |ctx|. */
   1061 OPENSSL_EXPORT void SSL_CTX_set_default_passwd_cb(SSL_CTX *ctx,
   1062                                                   pem_password_cb *cb);
   1063 
   1064 /* SSL_CTX_set_default_passwd_cb_userdata sets the userdata parameter for
   1065  * |ctx|'s password callback. */
   1066 OPENSSL_EXPORT void SSL_CTX_set_default_passwd_cb_userdata(SSL_CTX *ctx,
   1067                                                            void *data);
   1068 
   1069 
   1070 /* Custom private keys. */
   1071 
   1072 enum ssl_private_key_result_t {
   1073   ssl_private_key_success,
   1074   ssl_private_key_retry,
   1075   ssl_private_key_failure,
   1076 };
   1077 
   1078 /* ssl_private_key_method_st (aka |SSL_PRIVATE_KEY_METHOD|) describes private
   1079  * key hooks. This is used to off-load signing operations to a custom,
   1080  * potentially asynchronous, backend. Metadata about the key such as the type
   1081  * and size are parsed out of the certificate.
   1082  *
   1083  * TODO(davidben): This API has a number of legacy hooks. Remove the last
   1084  * consumer of |sign_digest| and trim it. */
   1085 struct ssl_private_key_method_st {
   1086   /* type is ignored and should be NULL. */
   1087   int (*type)(SSL *ssl);
   1088 
   1089   /* max_signature_len is ignored and should be NULL. */
   1090   size_t (*max_signature_len)(SSL *ssl);
   1091 
   1092   /* sign signs the message |in| in using the specified signature algorithm. On
   1093    * success, it returns |ssl_private_key_success| and writes at most |max_out|
   1094    * bytes of signature data to |out| and sets |*out_len| to the number of bytes
   1095    * written. On failure, it returns |ssl_private_key_failure|. If the operation
   1096    * has not completed, it returns |ssl_private_key_retry|. |sign| should
   1097    * arrange for the high-level operation on |ssl| to be retried when the
   1098    * operation is completed. This will result in a call to |complete|.
   1099    *
   1100    * |signature_algorithm| is one of the |SSL_SIGN_*| values, as defined in TLS
   1101    * 1.3. Note that, in TLS 1.2, ECDSA algorithms do not require that curve
   1102    * sizes match hash sizes, so the curve portion of |SSL_SIGN_ECDSA_*| values
   1103    * must be ignored. BoringSSL will internally handle the curve matching logic
   1104    * where appropriate.
   1105    *
   1106    * It is an error to call |sign| while another private key operation is in
   1107    * progress on |ssl|. */
   1108   enum ssl_private_key_result_t (*sign)(SSL *ssl, uint8_t *out, size_t *out_len,
   1109                                         size_t max_out,
   1110                                         uint16_t signature_algorithm,
   1111                                         const uint8_t *in, size_t in_len);
   1112 
   1113   /* sign_digest signs |in_len| bytes of digest from |in|. |md| is the hash
   1114    * function used to calculate |in|. On success, it returns
   1115    * |ssl_private_key_success| and writes at most |max_out| bytes of signature
   1116    * data to |out|. On failure, it returns |ssl_private_key_failure|. If the
   1117    * operation has not completed, it returns |ssl_private_key_retry|. |sign|
   1118    * should arrange for the high-level operation on |ssl| to be retried when the
   1119    * operation is completed. This will result in a call to |complete|.
   1120    *
   1121    * If the key is an RSA key, implementations must use PKCS#1 padding. |in| is
   1122    * the digest itself, so the DigestInfo prefix, if any, must be prepended by
   1123    * |sign|. If |md| is |EVP_md5_sha1|, there is no prefix.
   1124    *
   1125    * It is an error to call |sign_digest| while another private key operation is
   1126    * in progress on |ssl|.
   1127    *
   1128    * This function is deprecated. Implement |sign| instead.
   1129    *
   1130    * TODO(davidben): Remove this function. */
   1131   enum ssl_private_key_result_t (*sign_digest)(SSL *ssl, uint8_t *out,
   1132                                                size_t *out_len, size_t max_out,
   1133                                                const EVP_MD *md,
   1134                                                const uint8_t *in,
   1135                                                size_t in_len);
   1136 
   1137   /* decrypt decrypts |in_len| bytes of encrypted data from |in|. On success it
   1138    * returns |ssl_private_key_success|, writes at most |max_out| bytes of
   1139    * decrypted data to |out| and sets |*out_len| to the actual number of bytes
   1140    * written. On failure it returns |ssl_private_key_failure|. If the operation
   1141    * has not completed, it returns |ssl_private_key_retry|. The caller should
   1142    * arrange for the high-level operation on |ssl| to be retried when the
   1143    * operation is completed, which will result in a call to |complete|. This
   1144    * function only works with RSA keys and should perform a raw RSA decryption
   1145    * operation with no padding.
   1146    *
   1147    * It is an error to call |decrypt| while another private key operation is in
   1148    * progress on |ssl|. */
   1149   enum ssl_private_key_result_t (*decrypt)(SSL *ssl, uint8_t *out,
   1150                                            size_t *out_len, size_t max_out,
   1151                                            const uint8_t *in, size_t in_len);
   1152 
   1153   /* complete completes a pending operation. If the operation has completed, it
   1154    * returns |ssl_private_key_success| and writes the result to |out| as in
   1155    * |sign|. Otherwise, it returns |ssl_private_key_failure| on failure and
   1156    * |ssl_private_key_retry| if the operation is still in progress.
   1157    *
   1158    * |complete| may be called arbitrarily many times before completion, but it
   1159    * is an error to call |complete| if there is no pending operation in progress
   1160    * on |ssl|. */
   1161   enum ssl_private_key_result_t (*complete)(SSL *ssl, uint8_t *out,
   1162                                             size_t *out_len, size_t max_out);
   1163 };
   1164 
   1165 /* SSL_set_private_key_method configures a custom private key on |ssl|.
   1166  * |key_method| must remain valid for the lifetime of |ssl|. */
   1167 OPENSSL_EXPORT void SSL_set_private_key_method(
   1168     SSL *ssl, const SSL_PRIVATE_KEY_METHOD *key_method);
   1169 
   1170 /* SSL_CTX_set_private_key_method configures a custom private key on |ctx|.
   1171  * |key_method| must remain valid for the lifetime of |ctx|. */
   1172 OPENSSL_EXPORT void SSL_CTX_set_private_key_method(
   1173     SSL_CTX *ctx, const SSL_PRIVATE_KEY_METHOD *key_method);
   1174 
   1175 
   1176 /* Cipher suites.
   1177  *
   1178  * |SSL_CIPHER| objects represent cipher suites. */
   1179 
   1180 DEFINE_CONST_STACK_OF(SSL_CIPHER)
   1181 
   1182 /* SSL_get_cipher_by_value returns the structure representing a TLS cipher
   1183  * suite based on its assigned number, or NULL if unknown. See
   1184  * https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-4. */
   1185 OPENSSL_EXPORT const SSL_CIPHER *SSL_get_cipher_by_value(uint16_t value);
   1186 
   1187 /* SSL_CIPHER_get_id returns |cipher|'s id. It may be cast to a |uint16_t| to
   1188  * get the cipher suite value. */
   1189 OPENSSL_EXPORT uint32_t SSL_CIPHER_get_id(const SSL_CIPHER *cipher);
   1190 
   1191 /* SSL_CIPHER_is_AES returns one if |cipher| uses AES (either GCM or CBC
   1192  * mode). */
   1193 OPENSSL_EXPORT int SSL_CIPHER_is_AES(const SSL_CIPHER *cipher);
   1194 
   1195 /* SSL_CIPHER_has_SHA1_HMAC returns one if |cipher| uses HMAC-SHA1. */
   1196 OPENSSL_EXPORT int SSL_CIPHER_has_SHA1_HMAC(const SSL_CIPHER *cipher);
   1197 
   1198 /* SSL_CIPHER_has_SHA256_HMAC returns one if |cipher| uses HMAC-SHA256. */
   1199 OPENSSL_EXPORT int SSL_CIPHER_has_SHA256_HMAC(const SSL_CIPHER *cipher);
   1200 
   1201 /* SSL_CIPHER_has_SHA384_HMAC returns one if |cipher| uses HMAC-SHA384. */
   1202 OPENSSL_EXPORT int SSL_CIPHER_has_SHA384_HMAC(const SSL_CIPHER *cipher);
   1203 
   1204 /* SSL_CIPHER_is_AEAD returns one if |cipher| uses an AEAD cipher. */
   1205 OPENSSL_EXPORT int SSL_CIPHER_is_AEAD(const SSL_CIPHER *cipher);
   1206 
   1207 /* SSL_CIPHER_is_AESGCM returns one if |cipher| uses AES-GCM. */
   1208 OPENSSL_EXPORT int SSL_CIPHER_is_AESGCM(const SSL_CIPHER *cipher);
   1209 
   1210 /* SSL_CIPHER_is_AES128GCM returns one if |cipher| uses 128-bit AES-GCM. */
   1211 OPENSSL_EXPORT int SSL_CIPHER_is_AES128GCM(const SSL_CIPHER *cipher);
   1212 
   1213 /* SSL_CIPHER_is_AES128CBC returns one if |cipher| uses 128-bit AES in CBC
   1214  * mode. */
   1215 OPENSSL_EXPORT int SSL_CIPHER_is_AES128CBC(const SSL_CIPHER *cipher);
   1216 
   1217 /* SSL_CIPHER_is_AES256CBC returns one if |cipher| uses 256-bit AES in CBC
   1218  * mode. */
   1219 OPENSSL_EXPORT int SSL_CIPHER_is_AES256CBC(const SSL_CIPHER *cipher);
   1220 
   1221 /* SSL_CIPHER_is_CHACHA20POLY1305 returns one if |cipher| uses
   1222  * CHACHA20_POLY1305. Note this includes both the RFC 7905 and
   1223  * draft-agl-tls-chacha20poly1305-04 versions. */
   1224 OPENSSL_EXPORT int SSL_CIPHER_is_CHACHA20POLY1305(const SSL_CIPHER *cipher);
   1225 
   1226 /* SSL_CIPHER_is_NULL returns one if |cipher| does not encrypt. */
   1227 OPENSSL_EXPORT int SSL_CIPHER_is_NULL(const SSL_CIPHER *cipher);
   1228 
   1229 /* SSL_CIPHER_is_block_cipher returns one if |cipher| is a block cipher. */
   1230 OPENSSL_EXPORT int SSL_CIPHER_is_block_cipher(const SSL_CIPHER *cipher);
   1231 
   1232 /* SSL_CIPHER_is_ECDSA returns one if |cipher| uses ECDSA. */
   1233 OPENSSL_EXPORT int SSL_CIPHER_is_ECDSA(const SSL_CIPHER *cipher);
   1234 
   1235 /* SSL_CIPHER_is_ECDHE returns one if |cipher| uses ECDHE. */
   1236 OPENSSL_EXPORT int SSL_CIPHER_is_ECDHE(const SSL_CIPHER *cipher);
   1237 
   1238 /* SSL_CIPHER_is_static_RSA returns one if |cipher| uses the static RSA key
   1239  * exchange. */
   1240 OPENSSL_EXPORT int SSL_CIPHER_is_static_RSA(const SSL_CIPHER *cipher);
   1241 
   1242 /* SSL_CIPHER_get_min_version returns the minimum protocol version required
   1243  * for |cipher|. */
   1244 OPENSSL_EXPORT uint16_t SSL_CIPHER_get_min_version(const SSL_CIPHER *cipher);
   1245 
   1246 /* SSL_CIPHER_get_max_version returns the maximum protocol version that
   1247  * supports |cipher|. */
   1248 OPENSSL_EXPORT uint16_t SSL_CIPHER_get_max_version(const SSL_CIPHER *cipher);
   1249 
   1250 /* SSL_CIPHER_standard_name returns the standard IETF name for |cipher|. For
   1251  * example, "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256". */
   1252 OPENSSL_EXPORT const char *SSL_CIPHER_standard_name(const SSL_CIPHER *cipher);
   1253 
   1254 /* SSL_CIPHER_get_name returns the OpenSSL name of |cipher|. For example,
   1255  * "ECDHE-RSA-AES128-GCM-SHA256". */
   1256 OPENSSL_EXPORT const char *SSL_CIPHER_get_name(const SSL_CIPHER *cipher);
   1257 
   1258 /* SSL_CIPHER_get_kx_name returns a string that describes the key-exchange
   1259  * method used by |cipher|. For example, "ECDHE_ECDSA". TLS 1.3 AEAD-only
   1260  * ciphers return the string "GENERIC". */
   1261 OPENSSL_EXPORT const char *SSL_CIPHER_get_kx_name(const SSL_CIPHER *cipher);
   1262 
   1263 /* SSL_CIPHER_get_bits returns the strength, in bits, of |cipher|. If
   1264  * |out_alg_bits| is not NULL, it writes the number of bits consumed by the
   1265  * symmetric algorithm to |*out_alg_bits|. */
   1266 OPENSSL_EXPORT int SSL_CIPHER_get_bits(const SSL_CIPHER *cipher,
   1267                                        int *out_alg_bits);
   1268 
   1269 
   1270 /* Cipher suite configuration.
   1271  *
   1272  * OpenSSL uses a mini-language to configure cipher suites. The language
   1273  * maintains an ordered list of enabled ciphers, along with an ordered list of
   1274  * disabled but available ciphers. Initially, all ciphers are disabled with a
   1275  * default ordering. The cipher string is then interpreted as a sequence of
   1276  * directives, separated by colons, each of which modifies this state.
   1277  *
   1278  * Most directives consist of a one character or empty opcode followed by a
   1279  * selector which matches a subset of available ciphers.
   1280  *
   1281  * Available opcodes are:
   1282  *
   1283  *   The empty opcode enables and appends all matching disabled ciphers to the
   1284  *   end of the enabled list. The newly appended ciphers are ordered relative to
   1285  *   each other matching their order in the disabled list.
   1286  *
   1287  *   |-| disables all matching enabled ciphers and prepends them to the disabled
   1288  *   list, with relative order from the enabled list preserved. This means the
   1289  *   most recently disabled ciphers get highest preference relative to other
   1290  *   disabled ciphers if re-enabled.
   1291  *
   1292  *   |+| moves all matching enabled ciphers to the end of the enabled list, with
   1293  *   relative order preserved.
   1294  *
   1295  *   |!| deletes all matching ciphers, enabled or not, from either list. Deleted
   1296  *   ciphers will not matched by future operations.
   1297  *
   1298  * A selector may be a specific cipher (using either the standard or OpenSSL
   1299  * name for the cipher) or one or more rules separated by |+|. The final
   1300  * selector matches the intersection of each rule. For instance, |AESGCM+aECDSA|
   1301  * matches ECDSA-authenticated AES-GCM ciphers.
   1302  *
   1303  * Available cipher rules are:
   1304  *
   1305  *   |ALL| matches all ciphers.
   1306  *
   1307  *   |kRSA|, |kDHE|, |kECDHE|, and |kPSK| match ciphers using plain RSA, DHE,
   1308  *   ECDHE, and plain PSK key exchanges, respectively. Note that ECDHE_PSK is
   1309  *   matched by |kECDHE| and not |kPSK|.
   1310  *
   1311  *   |aRSA|, |aECDSA|, and |aPSK| match ciphers authenticated by RSA, ECDSA, and
   1312  *   a pre-shared key, respectively.
   1313  *
   1314  *   |RSA|, |DHE|, |ECDHE|, |PSK|, |ECDSA|, and |PSK| are aliases for the
   1315  *   corresponding |k*| or |a*| cipher rule. |RSA| is an alias for |kRSA|, not
   1316  *   |aRSA|.
   1317  *
   1318  *   |3DES|, |AES128|, |AES256|, |AES|, |AESGCM|, |CHACHA20| match ciphers
   1319  *   whose bulk cipher use the corresponding encryption scheme. Note that
   1320  *   |AES|, |AES128|, and |AES256| match both CBC and GCM ciphers.
   1321  *
   1322  *   |SHA1|, |SHA256|, and |SHA384| match legacy cipher suites using the
   1323  *   corresponding hash function in their MAC. AEADs are matched by none of
   1324  *   these.
   1325  *
   1326  *   |SHA| is an alias for |SHA1|.
   1327  *
   1328  * Although implemented, authentication-only ciphers match no rules and must be
   1329  * explicitly selected by name.
   1330  *
   1331  * Deprecated cipher rules:
   1332  *
   1333  *   |kEDH|, |EDH|, |kEECDH|, and |EECDH| are legacy aliases for |kDHE|, |DHE|,
   1334  *   |kECDHE|, and |ECDHE|, respectively.
   1335  *
   1336  *   |HIGH| is an alias for |ALL|.
   1337  *
   1338  *   |FIPS| is an alias for |HIGH|.
   1339  *
   1340  *   |SSLv3| and |TLSv1| match ciphers available in TLS 1.1 or earlier.
   1341  *   |TLSv1_2| matches ciphers new in TLS 1.2. This is confusing and should not
   1342  *   be used.
   1343  *
   1344  * Unknown rules are silently ignored by legacy APIs, and rejected by APIs with
   1345  * "strict" in the name, which should be preferred. Cipher lists can be long and
   1346  * it's easy to commit typos.
   1347  *
   1348  * The special |@STRENGTH| directive will sort all enabled ciphers by strength.
   1349  *
   1350  * The |DEFAULT| directive, when appearing at the front of the string, expands
   1351  * to the default ordering of available ciphers.
   1352  *
   1353  * If configuring a server, one may also configure equal-preference groups to
   1354  * partially respect the client's preferences when
   1355  * |SSL_OP_CIPHER_SERVER_PREFERENCE| is enabled. Ciphers in an equal-preference
   1356  * group have equal priority and use the client order. This may be used to
   1357  * enforce that AEADs are preferred but select AES-GCM vs. ChaCha20-Poly1305
   1358  * based on client preferences. An equal-preference is specified with square
   1359  * brackets, combining multiple selectors separated by |. For example:
   1360  *
   1361  *   [ECDHE-ECDSA-CHACHA20-POLY1305|ECDHE-ECDSA-AES128-GCM-SHA256]
   1362  *
   1363  * Once an equal-preference group is used, future directives must be
   1364  * opcode-less.
   1365  *
   1366  * TLS 1.3 ciphers do not participate in this mechanism and instead have a
   1367  * built-in preference order. Functions to set cipher lists do not affect TLS
   1368  * 1.3, and functions to query the cipher list do not include TLS 1.3
   1369  * ciphers. */
   1370 
   1371 /* SSL_DEFAULT_CIPHER_LIST is the default cipher suite configuration. It is
   1372  * substituted when a cipher string starts with 'DEFAULT'. */
   1373 #define SSL_DEFAULT_CIPHER_LIST "ALL"
   1374 
   1375 /* SSL_CTX_set_strict_cipher_list configures the cipher list for |ctx|,
   1376  * evaluating |str| as a cipher string and returning error if |str| contains
   1377  * anything meaningless. It returns one on success and zero on failure. */
   1378 OPENSSL_EXPORT int SSL_CTX_set_strict_cipher_list(SSL_CTX *ctx,
   1379                                                   const char *str);
   1380 
   1381 /* SSL_CTX_set_cipher_list configures the cipher list for |ctx|, evaluating
   1382  * |str| as a cipher string. It returns one on success and zero on failure.
   1383  *
   1384  * Prefer to use |SSL_CTX_set_strict_cipher_list|. This function tolerates
   1385  * garbage inputs, unless an empty cipher list results. */
   1386 OPENSSL_EXPORT int SSL_CTX_set_cipher_list(SSL_CTX *ctx, const char *str);
   1387 
   1388 /* SSL_set_strict_cipher_list configures the cipher list for |ssl|, evaluating
   1389  * |str| as a cipher string and returning error if |str| contains anything
   1390  * meaningless. It returns one on success and zero on failure. */
   1391 OPENSSL_EXPORT int SSL_set_strict_cipher_list(SSL *ssl, const char *str);
   1392 
   1393 /* SSL_set_cipher_list configures the cipher list for |ssl|, evaluating |str| as
   1394  * a cipher string. It returns one on success and zero on failure.
   1395  *
   1396  * Prefer to use |SSL_set_strict_cipher_list|. This function tolerates garbage
   1397  * inputs, unless an empty cipher list results. */
   1398 OPENSSL_EXPORT int SSL_set_cipher_list(SSL *ssl, const char *str);
   1399 
   1400 /* SSL_CTX_get_ciphers returns the cipher list for |ctx|, in order of
   1401  * preference. */
   1402 OPENSSL_EXPORT STACK_OF(SSL_CIPHER) *SSL_CTX_get_ciphers(const SSL_CTX *ctx);
   1403 
   1404 /* SSL_get_ciphers returns the cipher list for |ssl|, in order of preference. */
   1405 OPENSSL_EXPORT STACK_OF(SSL_CIPHER) *SSL_get_ciphers(const SSL *ssl);
   1406 
   1407 
   1408 /* Connection information. */
   1409 
   1410 /* SSL_is_init_finished returns one if |ssl| has completed its initial handshake
   1411  * and has no pending handshake. It returns zero otherwise. */
   1412 OPENSSL_EXPORT int SSL_is_init_finished(const SSL *ssl);
   1413 
   1414 /* SSL_in_init returns one if |ssl| has a pending handshake and zero
   1415  * otherwise. */
   1416 OPENSSL_EXPORT int SSL_in_init(const SSL *ssl);
   1417 
   1418 /* SSL_in_false_start returns one if |ssl| has a pending handshake that is in
   1419  * False Start. |SSL_write| may be called at this point without waiting for the
   1420  * peer, but |SSL_read| will complete the handshake before accepting application
   1421  * data.
   1422  *
   1423  * See also |SSL_MODE_ENABLE_FALSE_START|. */
   1424 OPENSSL_EXPORT int SSL_in_false_start(const SSL *ssl);
   1425 
   1426 /* SSL_get_peer_certificate returns the peer's leaf certificate or NULL if the
   1427  * peer did not use certificates. The caller must call |X509_free| on the
   1428  * result to release it. */
   1429 OPENSSL_EXPORT X509 *SSL_get_peer_certificate(const SSL *ssl);
   1430 
   1431 /* SSL_get_peer_cert_chain returns the peer's certificate chain or NULL if
   1432  * unavailable or the peer did not use certificates. This is the unverified list
   1433  * of certificates as sent by the peer, not the final chain built during
   1434  * verification. The caller does not take ownership of the result.
   1435  *
   1436  * WARNING: This function behaves differently between client and server. If
   1437  * |ssl| is a server, the returned chain does not include the leaf certificate.
   1438  * If a client, it does. */
   1439 OPENSSL_EXPORT STACK_OF(X509) *SSL_get_peer_cert_chain(const SSL *ssl);
   1440 
   1441 /* SSL_get_peer_full_cert_chain returns the peer's certificate chain, or NULL if
   1442  * unavailable or the peer did not use certificates. This is the unverified list
   1443  * of certificates as sent by the peer, not the final chain built during
   1444  * verification. The caller does not take ownership of the result.
   1445  *
   1446  * This is the same as |SSL_get_peer_cert_chain| except that this function
   1447  * always returns the full chain, i.e. the first element of the return value
   1448  * (if any) will be the leaf certificate. In constrast,
   1449  * |SSL_get_peer_cert_chain| returns only the intermediate certificates if the
   1450  * |ssl| is a server. */
   1451 OPENSSL_EXPORT STACK_OF(X509) *SSL_get_peer_full_cert_chain(const SSL *ssl);
   1452 
   1453 /* SSL_get0_peer_certificates returns the peer's certificate chain, or NULL if
   1454  * unavailable or the peer did not use certificates. This is the unverified list
   1455  * of certificates as sent by the peer, not the final chain built during
   1456  * verification. The caller does not take ownership of the result.
   1457  *
   1458  * This is the |CRYPTO_BUFFER| variant of |SSL_get_peer_full_cert_chain|. */
   1459 OPENSSL_EXPORT STACK_OF(CRYPTO_BUFFER) *
   1460     SSL_get0_peer_certificates(const SSL *ssl);
   1461 
   1462 /* SSL_get0_signed_cert_timestamp_list sets |*out| and |*out_len| to point to
   1463  * |*out_len| bytes of SCT information from the server. This is only valid if
   1464  * |ssl| is a client. The SCT information is a SignedCertificateTimestampList
   1465  * (including the two leading length bytes).
   1466  * See https://tools.ietf.org/html/rfc6962#section-3.3
   1467  * If no SCT was received then |*out_len| will be zero on return.
   1468  *
   1469  * WARNING: the returned data is not guaranteed to be well formed. */
   1470 OPENSSL_EXPORT void SSL_get0_signed_cert_timestamp_list(const SSL *ssl,
   1471                                                         const uint8_t **out,
   1472                                                         size_t *out_len);
   1473 
   1474 /* SSL_get0_ocsp_response sets |*out| and |*out_len| to point to |*out_len|
   1475  * bytes of an OCSP response from the server. This is the DER encoding of an
   1476  * OCSPResponse type as defined in RFC 2560.
   1477  *
   1478  * WARNING: the returned data is not guaranteed to be well formed. */
   1479 OPENSSL_EXPORT void SSL_get0_ocsp_response(const SSL *ssl, const uint8_t **out,
   1480                                            size_t *out_len);
   1481 
   1482 /* SSL_get_tls_unique writes at most |max_out| bytes of the tls-unique value
   1483  * for |ssl| to |out| and sets |*out_len| to the number of bytes written. It
   1484  * returns one on success or zero on error. In general |max_out| should be at
   1485  * least 12.
   1486  *
   1487  * This function will always fail if the initial handshake has not completed.
   1488  * The tls-unique value will change after a renegotiation but, since
   1489  * renegotiations can be initiated by the server at any point, the higher-level
   1490  * protocol must either leave them disabled or define states in which the
   1491  * tls-unique value can be read.
   1492  *
   1493  * The tls-unique value is defined by
   1494  * https://tools.ietf.org/html/rfc5929#section-3.1. Due to a weakness in the
   1495  * TLS protocol, tls-unique is broken for resumed connections unless the
   1496  * Extended Master Secret extension is negotiated. Thus this function will
   1497  * return zero if |ssl| performed session resumption unless EMS was used when
   1498  * negotiating the original session. */
   1499 OPENSSL_EXPORT int SSL_get_tls_unique(const SSL *ssl, uint8_t *out,
   1500                                       size_t *out_len, size_t max_out);
   1501 
   1502 /* SSL_get_extms_support returns one if the Extended Master Secret extension or
   1503  * TLS 1.3 was negotiated. Otherwise, it returns zero. */
   1504 OPENSSL_EXPORT int SSL_get_extms_support(const SSL *ssl);
   1505 
   1506 /* SSL_get_current_cipher returns the cipher used in the current outgoing
   1507  * connection state, or NULL if the null cipher is active. */
   1508 OPENSSL_EXPORT const SSL_CIPHER *SSL_get_current_cipher(const SSL *ssl);
   1509 
   1510 /* SSL_session_reused returns one if |ssl| performed an abbreviated handshake
   1511  * and zero otherwise.
   1512  *
   1513  * TODO(davidben): Hammer down the semantics of this API while a handshake,
   1514  * initial or renego, is in progress. */
   1515 OPENSSL_EXPORT int SSL_session_reused(const SSL *ssl);
   1516 
   1517 /* SSL_get_secure_renegotiation_support returns one if the peer supports secure
   1518  * renegotiation (RFC 5746) or TLS 1.3. Otherwise, it returns zero. */
   1519 OPENSSL_EXPORT int SSL_get_secure_renegotiation_support(const SSL *ssl);
   1520 
   1521 /* SSL_export_keying_material exports a value derived from the master secret, as
   1522  * specified in RFC 5705. It writes |out_len| bytes to |out| given a label and
   1523  * optional context. (Since a zero length context is allowed, the |use_context|
   1524  * flag controls whether a context is included.)
   1525  *
   1526  * It returns one on success and zero otherwise. */
   1527 OPENSSL_EXPORT int SSL_export_keying_material(
   1528     SSL *ssl, uint8_t *out, size_t out_len, const char *label, size_t label_len,
   1529     const uint8_t *context, size_t context_len, int use_context);
   1530 
   1531 
   1532 /* Custom extensions.
   1533  *
   1534  * The custom extension functions allow TLS extensions to be added to
   1535  * ClientHello and ServerHello messages. */
   1536 
   1537 /* SSL_custom_ext_add_cb is a callback function that is called when the
   1538  * ClientHello (for clients) or ServerHello (for servers) is constructed. In
   1539  * the case of a server, this callback will only be called for a given
   1540  * extension if the ClientHello contained that extension  it's not possible to
   1541  * inject extensions into a ServerHello that the client didn't request.
   1542  *
   1543  * When called, |extension_value| will contain the extension number that is
   1544  * being considered for addition (so that a single callback can handle multiple
   1545  * extensions). If the callback wishes to include the extension, it must set
   1546  * |*out| to point to |*out_len| bytes of extension contents and return one. In
   1547  * this case, the corresponding |SSL_custom_ext_free_cb| callback will later be
   1548  * called with the value of |*out| once that data has been copied.
   1549  *
   1550  * If the callback does not wish to add an extension it must return zero.
   1551  *
   1552  * Alternatively, the callback can abort the connection by setting
   1553  * |*out_alert_value| to a TLS alert number and returning -1. */
   1554 typedef int (*SSL_custom_ext_add_cb)(SSL *ssl, unsigned extension_value,
   1555                                      const uint8_t **out, size_t *out_len,
   1556                                      int *out_alert_value, void *add_arg);
   1557 
   1558 /* SSL_custom_ext_free_cb is a callback function that is called by OpenSSL iff
   1559  * an |SSL_custom_ext_add_cb| callback previously returned one. In that case,
   1560  * this callback is called and passed the |out| pointer that was returned by
   1561  * the add callback. This is to free any dynamically allocated data created by
   1562  * the add callback. */
   1563 typedef void (*SSL_custom_ext_free_cb)(SSL *ssl, unsigned extension_value,
   1564                                        const uint8_t *out, void *add_arg);
   1565 
   1566 /* SSL_custom_ext_parse_cb is a callback function that is called by OpenSSL to
   1567  * parse an extension from the peer: that is from the ServerHello for a client
   1568  * and from the ClientHello for a server.
   1569  *
   1570  * When called, |extension_value| will contain the extension number and the
   1571  * contents of the extension are |contents_len| bytes at |contents|.
   1572  *
   1573  * The callback must return one to continue the handshake. Otherwise, if it
   1574  * returns zero, a fatal alert with value |*out_alert_value| is sent and the
   1575  * handshake is aborted. */
   1576 typedef int (*SSL_custom_ext_parse_cb)(SSL *ssl, unsigned extension_value,
   1577                                        const uint8_t *contents,
   1578                                        size_t contents_len,
   1579                                        int *out_alert_value, void *parse_arg);
   1580 
   1581 /* SSL_extension_supported returns one iff OpenSSL internally handles
   1582  * extensions of type |extension_value|. This can be used to avoid registering
   1583  * custom extension handlers for extensions that a future version of OpenSSL
   1584  * may handle internally. */
   1585 OPENSSL_EXPORT int SSL_extension_supported(unsigned extension_value);
   1586 
   1587 /* SSL_CTX_add_client_custom_ext registers callback functions for handling
   1588  * custom TLS extensions for client connections.
   1589  *
   1590  * If |add_cb| is NULL then an empty extension will be added in each
   1591  * ClientHello. Otherwise, see the comment for |SSL_custom_ext_add_cb| about
   1592  * this callback.
   1593  *
   1594  * The |free_cb| may be NULL if |add_cb| doesn't dynamically allocate data that
   1595  * needs to be freed.
   1596  *
   1597  * It returns one on success or zero on error. It's always an error to register
   1598  * callbacks for the same extension twice, or to register callbacks for an
   1599  * extension that OpenSSL handles internally. See |SSL_extension_supported| to
   1600  * discover, at runtime, which extensions OpenSSL handles internally. */
   1601 OPENSSL_EXPORT int SSL_CTX_add_client_custom_ext(
   1602     SSL_CTX *ctx, unsigned extension_value, SSL_custom_ext_add_cb add_cb,
   1603     SSL_custom_ext_free_cb free_cb, void *add_arg,
   1604     SSL_custom_ext_parse_cb parse_cb, void *parse_arg);
   1605 
   1606 /* SSL_CTX_add_server_custom_ext is the same as
   1607  * |SSL_CTX_add_client_custom_ext|, but for server connections.
   1608  *
   1609  * Unlike on the client side, if |add_cb| is NULL no extension will be added.
   1610  * The |add_cb|, if any, will only be called if the ClientHello contained a
   1611  * matching extension. */
   1612 OPENSSL_EXPORT int SSL_CTX_add_server_custom_ext(
   1613     SSL_CTX *ctx, unsigned extension_value, SSL_custom_ext_add_cb add_cb,
   1614     SSL_custom_ext_free_cb free_cb, void *add_arg,
   1615     SSL_custom_ext_parse_cb parse_cb, void *parse_arg);
   1616 
   1617 
   1618 /* Sessions.
   1619  *
   1620  * An |SSL_SESSION| represents an SSL session that may be resumed in an
   1621  * abbreviated handshake. It is reference-counted and immutable. Once
   1622  * established, an |SSL_SESSION| may be shared by multiple |SSL| objects on
   1623  * different threads and must not be modified. */
   1624 
   1625 DECLARE_LHASH_OF(SSL_SESSION)
   1626 DECLARE_PEM_rw(SSL_SESSION, SSL_SESSION)
   1627 
   1628 /* SSL_SESSION_new returns a newly-allocated blank |SSL_SESSION| or NULL on
   1629  * error. This may be useful when writing tests but should otherwise not be
   1630  * used. */
   1631 OPENSSL_EXPORT SSL_SESSION *SSL_SESSION_new(const SSL_CTX *ctx);
   1632 
   1633 /* SSL_SESSION_up_ref increments the reference count of |session| and returns
   1634  * one. */
   1635 OPENSSL_EXPORT int SSL_SESSION_up_ref(SSL_SESSION *session);
   1636 
   1637 /* SSL_SESSION_free decrements the reference count of |session|. If it reaches
   1638  * zero, all data referenced by |session| and |session| itself are released. */
   1639 OPENSSL_EXPORT void SSL_SESSION_free(SSL_SESSION *session);
   1640 
   1641 /* SSL_SESSION_to_bytes serializes |in| into a newly allocated buffer and sets
   1642  * |*out_data| to that buffer and |*out_len| to its length. The caller takes
   1643  * ownership of the buffer and must call |OPENSSL_free| when done. It returns
   1644  * one on success and zero on error. */
   1645 OPENSSL_EXPORT int SSL_SESSION_to_bytes(const SSL_SESSION *in,
   1646                                         uint8_t **out_data, size_t *out_len);
   1647 
   1648 /* SSL_SESSION_to_bytes_for_ticket serializes |in|, but excludes the session
   1649  * identification information, namely the session ID and ticket. */
   1650 OPENSSL_EXPORT int SSL_SESSION_to_bytes_for_ticket(const SSL_SESSION *in,
   1651                                                    uint8_t **out_data,
   1652                                                    size_t *out_len);
   1653 
   1654 /* SSL_SESSION_from_bytes parses |in_len| bytes from |in| as an SSL_SESSION. It
   1655  * returns a newly-allocated |SSL_SESSION| on success or NULL on error. */
   1656 OPENSSL_EXPORT SSL_SESSION *SSL_SESSION_from_bytes(
   1657     const uint8_t *in, size_t in_len, const SSL_CTX *ctx);
   1658 
   1659 /* SSL_SESSION_get_version returns a string describing the TLS version |session|
   1660  * was established at. For example, "TLSv1.2" or "SSLv3". */
   1661 OPENSSL_EXPORT const char *SSL_SESSION_get_version(const SSL_SESSION *session);
   1662 
   1663 /* SSL_SESSION_get_id returns a pointer to a buffer containing |session|'s
   1664  * session ID and sets |*out_len| to its length. */
   1665 OPENSSL_EXPORT const uint8_t *SSL_SESSION_get_id(const SSL_SESSION *session,
   1666                                                  unsigned *out_len);
   1667 
   1668 /* SSL_SESSION_get_time returns the time at which |session| was established in
   1669  * seconds since the UNIX epoch. */
   1670 OPENSSL_EXPORT uint64_t SSL_SESSION_get_time(const SSL_SESSION *session);
   1671 
   1672 /* SSL_SESSION_get_timeout returns the lifetime of |session| in seconds. */
   1673 OPENSSL_EXPORT uint32_t SSL_SESSION_get_timeout(const SSL_SESSION *session);
   1674 
   1675 /* SSL_SESSION_get0_peer returns the peer leaf certificate stored in
   1676  * |session|.
   1677  *
   1678  * TODO(davidben): This should return a const X509 *. */
   1679 OPENSSL_EXPORT X509 *SSL_SESSION_get0_peer(const SSL_SESSION *session);
   1680 
   1681 /* SSL_SESSION_get_master_key writes up to |max_out| bytes of |session|'s master
   1682  * secret to |out| and returns the number of bytes written. If |max_out| is
   1683  * zero, it returns the size of the master secret. */
   1684 OPENSSL_EXPORT size_t SSL_SESSION_get_master_key(const SSL_SESSION *session,
   1685                                                  uint8_t *out, size_t max_out);
   1686 
   1687 /* SSL_SESSION_set_time sets |session|'s creation time to |time| and returns
   1688  * |time|. This function may be useful in writing tests but otherwise should not
   1689  * be used. */
   1690 OPENSSL_EXPORT uint64_t SSL_SESSION_set_time(SSL_SESSION *session,
   1691                                              uint64_t time);
   1692 
   1693 /* SSL_SESSION_set_timeout sets |session|'s timeout to |timeout| and returns
   1694  * one. This function may be useful in writing tests but otherwise should not
   1695  * be used. */
   1696 OPENSSL_EXPORT uint32_t SSL_SESSION_set_timeout(SSL_SESSION *session,
   1697                                                 uint32_t timeout);
   1698 
   1699 /* SSL_SESSION_set1_id_context sets |session|'s session ID context (see
   1700  * |SSL_CTX_set_session_id_context|) to |sid_ctx|. It returns one on success and
   1701  * zero on error. This function may be useful in writing tests but otherwise
   1702  * should not be used. */
   1703 OPENSSL_EXPORT int SSL_SESSION_set1_id_context(SSL_SESSION *session,
   1704                                                const uint8_t *sid_ctx,
   1705                                                size_t sid_ctx_len);
   1706 
   1707 
   1708 /* Session caching.
   1709  *
   1710  * Session caching allows connections to be established more efficiently based
   1711  * on saved parameters from a previous connection, called a session (see
   1712  * |SSL_SESSION|). The client offers a saved session, using an opaque identifier
   1713  * from a previous connection. The server may accept the session, if it has the
   1714  * parameters available. Otherwise, it will decline and continue with a full
   1715  * handshake.
   1716  *
   1717  * This requires both the client and the server to retain session state. A
   1718  * client does so with a stateful session cache. A server may do the same or, if
   1719  * supported by both sides, statelessly using session tickets. For more
   1720  * information on the latter, see the next section.
   1721  *
   1722  * For a server, the library implements a built-in internal session cache as an
   1723  * in-memory hash table. Servers may also use |SSL_CTX_sess_set_get_cb| and
   1724  * |SSL_CTX_sess_set_new_cb| to implement a custom external session cache. In
   1725  * particular, this may be used to share a session cache between multiple
   1726  * servers in a large deployment. An external cache may be used in addition to
   1727  * or instead of the internal one. Use |SSL_CTX_set_session_cache_mode| to
   1728  * toggle the internal cache.
   1729  *
   1730  * For a client, the only option is an external session cache. Clients may use
   1731  * |SSL_CTX_sess_set_new_cb| to register a callback for when new sessions are
   1732  * available. These may be cached and, in subsequent compatible connections,
   1733  * configured with |SSL_set_session|.
   1734  *
   1735  * Note that offering or accepting a session short-circuits certificate
   1736  * verification and most parameter negotiation. Resuming sessions across
   1737  * different contexts may result in security failures and surprising
   1738  * behavior. For a typical client, this means sessions for different hosts must
   1739  * be cached under different keys. A client that connects to the same host with,
   1740  * e.g., different cipher suite settings or client certificates should also use
   1741  * separate session caches between those contexts. Servers should also partition
   1742  * session caches between SNI hosts with |SSL_CTX_set_session_id_context|.  */
   1743 
   1744 /* SSL_SESS_CACHE_OFF disables all session caching. */
   1745 #define SSL_SESS_CACHE_OFF 0x0000
   1746 
   1747 /* SSL_SESS_CACHE_CLIENT enables session caching for a client. The internal
   1748  * cache is never used on a client, so this only enables the callbacks. */
   1749 #define SSL_SESS_CACHE_CLIENT 0x0001
   1750 
   1751 /* SSL_SESS_CACHE_SERVER enables session caching for a server. */
   1752 #define SSL_SESS_CACHE_SERVER 0x0002
   1753 
   1754 /* SSL_SESS_CACHE_BOTH enables session caching for both client and server. */
   1755 #define SSL_SESS_CACHE_BOTH (SSL_SESS_CACHE_CLIENT | SSL_SESS_CACHE_SERVER)
   1756 
   1757 /* SSL_SESS_CACHE_NO_AUTO_CLEAR disables automatically calling
   1758  * |SSL_CTX_flush_sessions| every 255 connections. */
   1759 #define SSL_SESS_CACHE_NO_AUTO_CLEAR 0x0080
   1760 
   1761 /* SSL_SESS_CACHE_NO_INTERNAL_LOOKUP, on a server, disables looking up a session
   1762  * from the internal session cache. */
   1763 #define SSL_SESS_CACHE_NO_INTERNAL_LOOKUP 0x0100
   1764 
   1765 /* SSL_SESS_CACHE_NO_INTERNAL_STORE, on a server, disables storing sessions in
   1766  * the internal session cache. */
   1767 #define SSL_SESS_CACHE_NO_INTERNAL_STORE 0x0200
   1768 
   1769 /* SSL_SESS_CACHE_NO_INTERNAL, on a server, disables the internal session
   1770  * cache. */
   1771 #define SSL_SESS_CACHE_NO_INTERNAL \
   1772     (SSL_SESS_CACHE_NO_INTERNAL_LOOKUP | SSL_SESS_CACHE_NO_INTERNAL_STORE)
   1773 
   1774 /* SSL_CTX_set_session_cache_mode sets the session cache mode bits for |ctx| to
   1775  * |mode|. It returns the previous value. */
   1776 OPENSSL_EXPORT int SSL_CTX_set_session_cache_mode(SSL_CTX *ctx, int mode);
   1777 
   1778 /* SSL_CTX_get_session_cache_mode returns the session cache mode bits for
   1779  * |ctx| */
   1780 OPENSSL_EXPORT int SSL_CTX_get_session_cache_mode(const SSL_CTX *ctx);
   1781 
   1782 /* SSL_set_session, for a client, configures |ssl| to offer to resume |session|
   1783  * in the initial handshake and returns one. The caller retains ownership of
   1784  * |session|.
   1785  *
   1786  * It is an error to call this function after the handshake has begun. */
   1787 OPENSSL_EXPORT int SSL_set_session(SSL *ssl, SSL_SESSION *session);
   1788 
   1789 /* SSL_DEFAULT_SESSION_TIMEOUT is the default lifetime, in seconds, of a
   1790  * session in TLS 1.2 or earlier. This is how long we are willing to use the
   1791  * secret to encrypt traffic without fresh key material. */
   1792 #define SSL_DEFAULT_SESSION_TIMEOUT (2 * 60 * 60)
   1793 
   1794 /* SSL_DEFAULT_SESSION_PSK_DHE_TIMEOUT is the default lifetime, in seconds, of a
   1795  * session for TLS 1.3 psk_dhe_ke. This is how long we are willing to use the
   1796  * secret as an authenticator. */
   1797 #define SSL_DEFAULT_SESSION_PSK_DHE_TIMEOUT (2 * 24 * 60 * 60)
   1798 
   1799 /* SSL_DEFAULT_SESSION_AUTH_TIMEOUT is the default non-renewable lifetime, in
   1800  * seconds, of a TLS 1.3 session. This is how long we are willing to trust the
   1801  * signature in the initial handshake. */
   1802 #define SSL_DEFAULT_SESSION_AUTH_TIMEOUT (7 * 24 * 60 * 60)
   1803 
   1804 /* SSL_CTX_set_timeout sets the lifetime, in seconds, of TLS 1.2 (or earlier)
   1805  * sessions created in |ctx| to |timeout|. */
   1806 OPENSSL_EXPORT uint32_t SSL_CTX_set_timeout(SSL_CTX *ctx, uint32_t timeout);
   1807 
   1808 /* SSL_CTX_set_session_psk_dhe_timeout sets the lifetime, in seconds, of TLS 1.3
   1809  * sessions created in |ctx| to |timeout|. */
   1810 OPENSSL_EXPORT void SSL_CTX_set_session_psk_dhe_timeout(SSL_CTX *ctx,
   1811                                                         uint32_t timeout);
   1812 
   1813 /* SSL_CTX_get_timeout returns the lifetime, in seconds, of TLS 1.2 (or earlier)
   1814  * sessions created in |ctx|. */
   1815 OPENSSL_EXPORT uint32_t SSL_CTX_get_timeout(const SSL_CTX *ctx);
   1816 
   1817 /* SSL_CTX_set_session_id_context sets |ctx|'s session ID context to |sid_ctx|.
   1818  * It returns one on success and zero on error. The session ID context is an
   1819  * application-defined opaque byte string. A session will not be used in a
   1820  * connection without a matching session ID context.
   1821  *
   1822  * For a server, if |SSL_VERIFY_PEER| is enabled, it is an error to not set a
   1823  * session ID context. */
   1824 OPENSSL_EXPORT int SSL_CTX_set_session_id_context(SSL_CTX *ctx,
   1825                                                   const uint8_t *sid_ctx,
   1826                                                   size_t sid_ctx_len);
   1827 
   1828 /* SSL_set_session_id_context sets |ssl|'s session ID context to |sid_ctx|. It
   1829  * returns one on success and zero on error. See also
   1830  * |SSL_CTX_set_session_id_context|. */
   1831 OPENSSL_EXPORT int SSL_set_session_id_context(SSL *ssl, const uint8_t *sid_ctx,
   1832                                               size_t sid_ctx_len);
   1833 
   1834 /* SSL_get0_session_id_context returns a pointer to |ssl|'s session ID context
   1835  * and sets |*out_len| to its length. */
   1836 OPENSSL_EXPORT const uint8_t *SSL_get0_session_id_context(const SSL *ssl,
   1837                                                           size_t *out_len);
   1838 
   1839 /* SSL_SESSION_CACHE_MAX_SIZE_DEFAULT is the default maximum size of a session
   1840  * cache. */
   1841 #define SSL_SESSION_CACHE_MAX_SIZE_DEFAULT (1024 * 20)
   1842 
   1843 /* SSL_CTX_sess_set_cache_size sets the maximum size of |ctx|'s internal session
   1844  * cache to |size|. It returns the previous value. */
   1845 OPENSSL_EXPORT unsigned long SSL_CTX_sess_set_cache_size(SSL_CTX *ctx,
   1846                                                          unsigned long size);
   1847 
   1848 /* SSL_CTX_sess_get_cache_size returns the maximum size of |ctx|'s internal
   1849  * session cache. */
   1850 OPENSSL_EXPORT unsigned long SSL_CTX_sess_get_cache_size(const SSL_CTX *ctx);
   1851 
   1852 /* SSL_CTX_sessions returns |ctx|'s internal session cache. */
   1853 OPENSSL_EXPORT LHASH_OF(SSL_SESSION) *SSL_CTX_sessions(SSL_CTX *ctx);
   1854 
   1855 /* SSL_CTX_sess_number returns the number of sessions in |ctx|'s internal
   1856  * session cache. */
   1857 OPENSSL_EXPORT size_t SSL_CTX_sess_number(const SSL_CTX *ctx);
   1858 
   1859 /* SSL_CTX_add_session inserts |session| into |ctx|'s internal session cache. It
   1860  * returns one on success and zero on error or if |session| is already in the
   1861  * cache. The caller retains its reference to |session|. */
   1862 OPENSSL_EXPORT int SSL_CTX_add_session(SSL_CTX *ctx, SSL_SESSION *session);
   1863 
   1864 /* SSL_CTX_remove_session removes |session| from |ctx|'s internal session cache.
   1865  * It returns one on success and zero if |session| was not in the cache. */
   1866 OPENSSL_EXPORT int SSL_CTX_remove_session(SSL_CTX *ctx, SSL_SESSION *session);
   1867 
   1868 /* SSL_CTX_flush_sessions removes all sessions from |ctx| which have expired as
   1869  * of time |time|. If |time| is zero, all sessions are removed. */
   1870 OPENSSL_EXPORT void SSL_CTX_flush_sessions(SSL_CTX *ctx, uint64_t time);
   1871 
   1872 /* SSL_CTX_sess_set_new_cb sets the callback to be called when a new session is
   1873  * established and ready to be cached. If the session cache is disabled (the
   1874  * appropriate one of |SSL_SESS_CACHE_CLIENT| or |SSL_SESS_CACHE_SERVER| is
   1875  * unset), the callback is not called.
   1876  *
   1877  * The callback is passed a reference to |session|. It returns one if it takes
   1878  * ownership (and then calls |SSL_SESSION_free| when done) and zero otherwise. A
   1879  * consumer which places |session| into an in-memory cache will likely return
   1880  * one, with the cache calling |SSL_SESSION_free|. A consumer which serializes
   1881  * |session| with |SSL_SESSION_to_bytes| may not need to retain |session| and
   1882  * will likely return zero. Returning one is equivalent to calling
   1883  * |SSL_SESSION_up_ref| and then returning zero.
   1884  *
   1885  * Note: For a client, the callback may be called on abbreviated handshakes if a
   1886  * ticket is renewed. Further, it may not be called until some time after
   1887  * |SSL_do_handshake| or |SSL_connect| completes if False Start is enabled. Thus
   1888  * it's recommended to use this callback over calling |SSL_get_session| on
   1889  * handshake completion. */
   1890 OPENSSL_EXPORT void SSL_CTX_sess_set_new_cb(
   1891     SSL_CTX *ctx, int (*new_session_cb)(SSL *ssl, SSL_SESSION *session));
   1892 
   1893 /* SSL_CTX_sess_get_new_cb returns the callback set by
   1894  * |SSL_CTX_sess_set_new_cb|. */
   1895 OPENSSL_EXPORT int (*SSL_CTX_sess_get_new_cb(SSL_CTX *ctx))(
   1896     SSL *ssl, SSL_SESSION *session);
   1897 
   1898 /* SSL_CTX_sess_set_remove_cb sets a callback which is called when a session is
   1899  * removed from the internal session cache.
   1900  *
   1901  * TODO(davidben): What is the point of this callback? It seems useless since it
   1902  * only fires on sessions in the internal cache. */
   1903 OPENSSL_EXPORT void SSL_CTX_sess_set_remove_cb(
   1904     SSL_CTX *ctx,
   1905     void (*remove_session_cb)(SSL_CTX *ctx, SSL_SESSION *session));
   1906 
   1907 /* SSL_CTX_sess_get_remove_cb returns the callback set by
   1908  * |SSL_CTX_sess_set_remove_cb|. */
   1909 OPENSSL_EXPORT void (*SSL_CTX_sess_get_remove_cb(SSL_CTX *ctx))(
   1910     SSL_CTX *ctx, SSL_SESSION *session);
   1911 
   1912 /* SSL_CTX_sess_set_get_cb sets a callback to look up a session by ID for a
   1913  * server. The callback is passed the session ID and should return a matching
   1914  * |SSL_SESSION| or NULL if not found. It should set |*out_copy| to zero and
   1915  * return a new reference to the session. This callback is not used for a
   1916  * client.
   1917  *
   1918  * For historical reasons, if |*out_copy| is set to one (default), the SSL
   1919  * library will take a new reference to the returned |SSL_SESSION|, expecting
   1920  * the callback to return a non-owning pointer. This is not recommended. If
   1921  * |ctx| and thus the callback is used on multiple threads, the session may be
   1922  * removed and invalidated before the SSL library calls |SSL_SESSION_up_ref|,
   1923  * whereas the callback may synchronize internally.
   1924  *
   1925  * To look up a session asynchronously, the callback may return
   1926  * |SSL_magic_pending_session_ptr|. See the documentation for that function and
   1927  * |SSL_ERROR_PENDING_SESSION|.
   1928  *
   1929  * If the internal session cache is enabled, the callback is only consulted if
   1930  * the internal cache does not return a match.
   1931  *
   1932  * The callback's |id| parameter is not const for historical reasons, but the
   1933  * contents may not be modified. */
   1934 OPENSSL_EXPORT void SSL_CTX_sess_set_get_cb(
   1935     SSL_CTX *ctx,
   1936     SSL_SESSION *(*get_session_cb)(SSL *ssl, uint8_t *id, int id_len,
   1937                                    int *out_copy));
   1938 
   1939 /* SSL_CTX_sess_get_get_cb returns the callback set by
   1940  * |SSL_CTX_sess_set_get_cb|. */
   1941 OPENSSL_EXPORT SSL_SESSION *(*SSL_CTX_sess_get_get_cb(SSL_CTX *ctx))(
   1942     SSL *ssl, uint8_t *id, int id_len, int *out_copy);
   1943 
   1944 /* SSL_magic_pending_session_ptr returns a magic |SSL_SESSION|* which indicates
   1945  * that the session isn't currently unavailable. |SSL_get_error| will then
   1946  * return |SSL_ERROR_PENDING_SESSION| and the handshake can be retried later
   1947  * when the lookup has completed. */
   1948 OPENSSL_EXPORT SSL_SESSION *SSL_magic_pending_session_ptr(void);
   1949 
   1950 
   1951 /* Session tickets.
   1952  *
   1953  * Session tickets, from RFC 5077, allow session resumption without server-side
   1954  * state. The server maintains a secret ticket key and sends the client opaque
   1955  * encrypted session parameters, called a ticket. When offering the session, the
   1956  * client sends the ticket which the server decrypts to recover session state.
   1957  * Session tickets are enabled by default but may be disabled with
   1958  * |SSL_OP_NO_TICKET|.
   1959  *
   1960  * On the client, ticket-based sessions use the same APIs as ID-based tickets.
   1961  * Callers do not need to handle them differently.
   1962  *
   1963  * On the server, tickets are encrypted and authenticated with a secret key. By
   1964  * default, an |SSL_CTX| generates a key on creation and uses it for the
   1965  * lifetime of the |SSL_CTX|. Tickets are minted and processed
   1966  * transparently. The following functions may be used to configure a persistent
   1967  * key or implement more custom behavior, including key rotation and sharing
   1968  * keys between multiple servers in a large deployment. There are three levels
   1969  * of customisation possible:
   1970  *
   1971  * 1) One can simply set the keys with |SSL_CTX_set_tlsext_ticket_keys|.
   1972  * 2) One can configure an |EVP_CIPHER_CTX| and |HMAC_CTX| directly for
   1973  *    encryption and authentication.
   1974  * 3) One can configure an |SSL_TICKET_ENCRYPTION_METHOD| to have more control
   1975  *    and the option of asynchronous decryption.
   1976  *
   1977  * An attacker that compromises a server's session ticket key can impersonate
   1978  * the server and, prior to TLS 1.3, retroactively decrypt all application
   1979  * traffic from sessions using that ticket key. Thus ticket keys must be
   1980  * regularly rotated for forward secrecy. Note the default key is currently not
   1981  * rotated.
   1982  *
   1983  * TODO(davidben): This is silly. Rotate the default key automatically. */
   1984 
   1985 /* SSL_CTX_get_tlsext_ticket_keys writes |ctx|'s session ticket key material to
   1986  * |len| bytes of |out|. It returns one on success and zero if |len| is not
   1987  * 48. If |out| is NULL, it returns 48 instead. */
   1988 OPENSSL_EXPORT int SSL_CTX_get_tlsext_ticket_keys(SSL_CTX *ctx, void *out,
   1989                                                   size_t len);
   1990 
   1991 /* SSL_CTX_set_tlsext_ticket_keys sets |ctx|'s session ticket key material to
   1992  * |len| bytes of |in|. It returns one on success and zero if |len| is not
   1993  * 48. If |in| is NULL, it returns 48 instead. */
   1994 OPENSSL_EXPORT int SSL_CTX_set_tlsext_ticket_keys(SSL_CTX *ctx, const void *in,
   1995                                                   size_t len);
   1996 
   1997 /* SSL_TICKET_KEY_NAME_LEN is the length of the key name prefix of a session
   1998  * ticket. */
   1999 #define SSL_TICKET_KEY_NAME_LEN 16
   2000 
   2001 /* SSL_CTX_set_tlsext_ticket_key_cb sets the ticket callback to |callback| and
   2002  * returns one. |callback| will be called when encrypting a new ticket and when
   2003  * decrypting a ticket from the client.
   2004  *
   2005  * In both modes, |ctx| and |hmac_ctx| will already have been initialized with
   2006  * |EVP_CIPHER_CTX_init| and |HMAC_CTX_init|, respectively. |callback|
   2007  * configures |hmac_ctx| with an HMAC digest and key, and configures |ctx|
   2008  * for encryption or decryption, based on the mode.
   2009  *
   2010  * When encrypting a new ticket, |encrypt| will be one. It writes a public
   2011  * 16-byte key name to |key_name| and a fresh IV to |iv|. The output IV length
   2012  * must match |EVP_CIPHER_CTX_iv_length| of the cipher selected. In this mode,
   2013  * |callback| returns 1 on success and -1 on error.
   2014  *
   2015  * When decrypting a ticket, |encrypt| will be zero. |key_name| will point to a
   2016  * 16-byte key name and |iv| points to an IV. The length of the IV consumed must
   2017  * match |EVP_CIPHER_CTX_iv_length| of the cipher selected. In this mode,
   2018  * |callback| returns -1 to abort the handshake, 0 if decrypting the ticket
   2019  * failed, and 1 or 2 on success. If it returns 2, the ticket will be renewed.
   2020  * This may be used to re-key the ticket.
   2021  *
   2022  * WARNING: |callback| wildly breaks the usual return value convention and is
   2023  * called in two different modes. */
   2024 OPENSSL_EXPORT int SSL_CTX_set_tlsext_ticket_key_cb(
   2025     SSL_CTX *ctx, int (*callback)(SSL *ssl, uint8_t *key_name, uint8_t *iv,
   2026                                   EVP_CIPHER_CTX *ctx, HMAC_CTX *hmac_ctx,
   2027                                   int encrypt));
   2028 
   2029 /* ssl_ticket_aead_result_t enumerates the possible results from decrypting a
   2030  * ticket with an |SSL_TICKET_AEAD_METHOD|. */
   2031 enum ssl_ticket_aead_result_t {
   2032   /* ssl_ticket_aead_success indicates that the ticket was successfully
   2033    * decrypted. */
   2034   ssl_ticket_aead_success,
   2035   /* ssl_ticket_aead_retry indicates that the operation could not be
   2036    * immediately completed and must be reattempted, via |open|, at a later
   2037    * point. */
   2038   ssl_ticket_aead_retry,
   2039   /* ssl_ticket_aead_ignore_ticket indicates that the ticket should be ignored
   2040    * (i.e. is corrupt or otherwise undecryptable). */
   2041   ssl_ticket_aead_ignore_ticket,
   2042   /* ssl_ticket_aead_error indicates that a fatal error occured and the
   2043    * handshake should be terminated. */
   2044   ssl_ticket_aead_error,
   2045 };
   2046 
   2047 /* ssl_ticket_aead_method_st (aka |SSL_TICKET_ENCRYPTION_METHOD|) contains
   2048  * methods for encrypting and decrypting session tickets. */
   2049 struct ssl_ticket_aead_method_st {
   2050   /* max_overhead returns the maximum number of bytes of overhead that |seal|
   2051    * may add. */
   2052   size_t (*max_overhead)(SSL *ssl);
   2053 
   2054   /* seal encrypts and authenticates |in_len| bytes from |in|, writes, at most,
   2055    * |max_out_len| bytes to |out|, and puts the number of bytes written in
   2056    * |*out_len|. The |in| and |out| buffers may be equal but will not otherwise
   2057    * alias. It returns one on success or zero on error. */
   2058   int (*seal)(SSL *ssl, uint8_t *out, size_t *out_len, size_t max_out_len,
   2059               const uint8_t *in, size_t in_len);
   2060 
   2061   /* open authenticates and decrypts |in_len| bytes from |in|, writes, at most,
   2062    * |max_out_len| bytes of plaintext to |out|, and puts the number of bytes
   2063    * written in |*out_len|. The |in| and |out| buffers may be equal but will
   2064    * not otherwise alias. See |ssl_ticket_aead_result_t| for details of the
   2065    * return values. In the case that a retry is indicated, the caller should
   2066    * arrange for the high-level operation on |ssl| to be retried when the
   2067    * operation is completed, which will result in another call to |open|. */
   2068   enum ssl_ticket_aead_result_t (*open)(SSL *ssl, uint8_t *out, size_t *out_len,
   2069                                         size_t max_out_len, const uint8_t *in,
   2070                                         size_t in_len);
   2071 };
   2072 
   2073 /* SSL_CTX_set_ticket_aead_method configures a custom ticket AEAD method table
   2074  * on |ctx|. |aead_method| must remain valid for the lifetime of |ctx|. */
   2075 OPENSSL_EXPORT void SSL_CTX_set_ticket_aead_method(
   2076     SSL_CTX *ctx, const SSL_TICKET_AEAD_METHOD *aead_method);
   2077 
   2078 
   2079 /* Elliptic curve Diffie-Hellman.
   2080  *
   2081  * Cipher suites using an ECDHE key exchange perform Diffie-Hellman over an
   2082  * elliptic curve negotiated by both endpoints. See RFC 4492. Only named curves
   2083  * are supported. ECDHE is always enabled, but the curve preferences may be
   2084  * configured with these functions.
   2085  *
   2086  * Note that TLS 1.3 renames these from curves to groups. For consistency, we
   2087  * currently use the TLS 1.2 name in the API. */
   2088 
   2089 /* SSL_CTX_set1_curves sets the preferred curves for |ctx| to be |curves|. Each
   2090  * element of |curves| should be a curve nid. It returns one on success and
   2091  * zero on failure.
   2092  *
   2093  * Note that this API uses nid values from nid.h and not the |SSL_CURVE_*|
   2094  * values defined below. */
   2095 OPENSSL_EXPORT int SSL_CTX_set1_curves(SSL_CTX *ctx, const int *curves,
   2096                                        size_t curves_len);
   2097 
   2098 /* SSL_set1_curves sets the preferred curves for |ssl| to be |curves|. Each
   2099  * element of |curves| should be a curve nid. It returns one on success and
   2100  * zero on failure.
   2101  *
   2102  * Note that this API uses nid values from nid.h and not the |SSL_CURVE_*|
   2103  * values defined below. */
   2104 OPENSSL_EXPORT int SSL_set1_curves(SSL *ssl, const int *curves,
   2105                                    size_t curves_len);
   2106 
   2107 /* SSL_CTX_set1_curves_list sets the preferred curves for |ctx| to be the
   2108  * colon-separated list |curves|. Each element of |curves| should be a curve
   2109  * name (e.g. P-256, X25519, ...). It returns one on success and zero on
   2110  * failure. */
   2111 OPENSSL_EXPORT int SSL_CTX_set1_curves_list(SSL_CTX *ctx, const char *curves);
   2112 
   2113 /* SSL_set1_curves_list sets the preferred curves for |ssl| to be the
   2114  * colon-separated list |curves|. Each element of |curves| should be a curve
   2115  * name (e.g. P-256, X25519, ...). It returns one on success and zero on
   2116  * failure. */
   2117 OPENSSL_EXPORT int SSL_set1_curves_list(SSL *ssl, const char *curves);
   2118 
   2119 /* SSL_CURVE_* define TLS curve IDs. */
   2120 #define SSL_CURVE_SECP224R1 21
   2121 #define SSL_CURVE_SECP256R1 23
   2122 #define SSL_CURVE_SECP384R1 24
   2123 #define SSL_CURVE_SECP521R1 25
   2124 #define SSL_CURVE_X25519 29
   2125 
   2126 /* SSL_get_curve_id returns the ID of the curve used by |ssl|'s most recently
   2127  * completed handshake or 0 if not applicable.
   2128  *
   2129  * TODO(davidben): This API currently does not work correctly if there is a
   2130  * renegotiation in progress. Fix this. */
   2131 OPENSSL_EXPORT uint16_t SSL_get_curve_id(const SSL *ssl);
   2132 
   2133 /* SSL_get_curve_name returns a human-readable name for the curve specified by
   2134  * the given TLS curve id, or NULL if the curve is unknown. */
   2135 OPENSSL_EXPORT const char *SSL_get_curve_name(uint16_t curve_id);
   2136 
   2137 
   2138 /* Certificate verification.
   2139  *
   2140  * SSL may authenticate either endpoint with an X.509 certificate. Typically
   2141  * this is used to authenticate the server to the client. These functions
   2142  * configure certificate verification.
   2143  *
   2144  * WARNING: By default, certificate verification errors on a client are not
   2145  * fatal. See |SSL_VERIFY_NONE| This may be configured with
   2146  * |SSL_CTX_set_verify|.
   2147  *
   2148  * By default clients are anonymous but a server may request a certificate from
   2149  * the client by setting |SSL_VERIFY_PEER|.
   2150  *
   2151  * Many of these functions use OpenSSL's legacy X.509 stack which is
   2152  * underdocumented and deprecated, but the replacement isn't ready yet. For
   2153  * now, consumers may use the existing stack or bypass it by performing
   2154  * certificate verification externally. This may be done with
   2155  * |SSL_CTX_set_cert_verify_callback| or by extracting the chain with
   2156  * |SSL_get_peer_cert_chain| after the handshake. In the future, functions will
   2157  * be added to use the SSL stack without dependency on any part of the legacy
   2158  * X.509 and ASN.1 stack.
   2159  *
   2160  * To augment certificate verification, a client may also enable OCSP stapling
   2161  * (RFC 6066) and Certificate Transparency (RFC 6962) extensions. */
   2162 
   2163 /* SSL_VERIFY_NONE, on a client, verifies the server certificate but does not
   2164  * make errors fatal. The result may be checked with |SSL_get_verify_result|. On
   2165  * a server it does not request a client certificate. This is the default. */
   2166 #define SSL_VERIFY_NONE 0x00
   2167 
   2168 /* SSL_VERIFY_PEER, on a client, makes server certificate errors fatal. On a
   2169  * server it requests a client certificate and makes errors fatal. However,
   2170  * anonymous clients are still allowed. See
   2171  * |SSL_VERIFY_FAIL_IF_NO_PEER_CERT|. */
   2172 #define SSL_VERIFY_PEER 0x01
   2173 
   2174 /* SSL_VERIFY_FAIL_IF_NO_PEER_CERT configures a server to reject connections if
   2175  * the client declines to send a certificate. This flag must be used together
   2176  * with |SSL_VERIFY_PEER|, otherwise it won't work. */
   2177 #define SSL_VERIFY_FAIL_IF_NO_PEER_CERT 0x02
   2178 
   2179 /* SSL_VERIFY_PEER_IF_NO_OBC configures a server to request a client certificate
   2180  * if and only if Channel ID is not negotiated. */
   2181 #define SSL_VERIFY_PEER_IF_NO_OBC 0x04
   2182 
   2183 /* SSL_CTX_set_verify configures certificate verification behavior. |mode| is
   2184  * one of the |SSL_VERIFY_*| values defined above. |callback|, if not NULL, is
   2185  * used to customize certificate verification. See the behavior of
   2186  * |X509_STORE_CTX_set_verify_cb|.
   2187  *
   2188  * The callback may use |SSL_get_ex_data_X509_STORE_CTX_idx| with
   2189  * |X509_STORE_CTX_get_ex_data| to look up the |SSL| from |store_ctx|. */
   2190 OPENSSL_EXPORT void SSL_CTX_set_verify(
   2191     SSL_CTX *ctx, int mode, int (*callback)(int ok, X509_STORE_CTX *store_ctx));
   2192 
   2193 /* SSL_set_verify configures certificate verification behavior. |mode| is one of
   2194  * the |SSL_VERIFY_*| values defined above. |callback|, if not NULL, is used to
   2195  * customize certificate verification. See the behavior of
   2196  * |X509_STORE_CTX_set_verify_cb|.
   2197  *
   2198  * The callback may use |SSL_get_ex_data_X509_STORE_CTX_idx| with
   2199  * |X509_STORE_CTX_get_ex_data| to look up the |SSL| from |store_ctx|. */
   2200 OPENSSL_EXPORT void SSL_set_verify(SSL *ssl, int mode,
   2201                                    int (*callback)(int ok,
   2202                                                    X509_STORE_CTX *store_ctx));
   2203 
   2204 /* SSL_CTX_get_verify_mode returns |ctx|'s verify mode, set by
   2205  * |SSL_CTX_set_verify|. */
   2206 OPENSSL_EXPORT int SSL_CTX_get_verify_mode(const SSL_CTX *ctx);
   2207 
   2208 /* SSL_get_verify_mode returns |ssl|'s verify mode, set by |SSL_CTX_set_verify|
   2209  * or |SSL_set_verify|. */
   2210 OPENSSL_EXPORT int SSL_get_verify_mode(const SSL *ssl);
   2211 
   2212 /* SSL_CTX_get_verify_callback returns the callback set by
   2213  * |SSL_CTX_set_verify|. */
   2214 OPENSSL_EXPORT int (*SSL_CTX_get_verify_callback(const SSL_CTX *ctx))(
   2215     int ok, X509_STORE_CTX *store_ctx);
   2216 
   2217 /* SSL_get_verify_callback returns the callback set by |SSL_CTX_set_verify| or
   2218  * |SSL_set_verify|. */
   2219 OPENSSL_EXPORT int (*SSL_get_verify_callback(const SSL *ssl))(
   2220     int ok, X509_STORE_CTX *store_ctx);
   2221 
   2222 /* SSL_CTX_set_verify_depth sets the maximum depth of a certificate chain
   2223  * accepted in verification. This number does not include the leaf, so a depth
   2224  * of 1 allows the leaf and one CA certificate. */
   2225 OPENSSL_EXPORT void SSL_CTX_set_verify_depth(SSL_CTX *ctx, int depth);
   2226 
   2227 /* SSL_set_verify_depth sets the maximum depth of a certificate chain accepted
   2228  * in verification. This number does not include the leaf, so a depth of 1
   2229  * allows the leaf and one CA certificate. */
   2230 OPENSSL_EXPORT void SSL_set_verify_depth(SSL *ssl, int depth);
   2231 
   2232 /* SSL_CTX_get_verify_depth returns the maximum depth of a certificate accepted
   2233  * in verification. */
   2234 OPENSSL_EXPORT int SSL_CTX_get_verify_depth(const SSL_CTX *ctx);
   2235 
   2236 /* SSL_get_verify_depth returns the maximum depth of a certificate accepted in
   2237  * verification. */
   2238 OPENSSL_EXPORT int SSL_get_verify_depth(const SSL *ssl);
   2239 
   2240 /* SSL_CTX_set1_param sets verification parameters from |param|. It returns one
   2241  * on success and zero on failure. The caller retains ownership of |param|. */
   2242 OPENSSL_EXPORT int SSL_CTX_set1_param(SSL_CTX *ctx,
   2243                                       const X509_VERIFY_PARAM *param);
   2244 
   2245 /* SSL_set1_param sets verification parameters from |param|. It returns one on
   2246  * success and zero on failure. The caller retains ownership of |param|. */
   2247 OPENSSL_EXPORT int SSL_set1_param(SSL *ssl,
   2248                                   const X509_VERIFY_PARAM *param);
   2249 
   2250 /* SSL_CTX_get0_param returns |ctx|'s |X509_VERIFY_PARAM| for certificate
   2251  * verification. The caller must not release the returned pointer but may call
   2252  * functions on it to configure it. */
   2253 OPENSSL_EXPORT X509_VERIFY_PARAM *SSL_CTX_get0_param(SSL_CTX *ctx);
   2254 
   2255 /* SSL_get0_param returns |ssl|'s |X509_VERIFY_PARAM| for certificate
   2256  * verification. The caller must not release the returned pointer but may call
   2257  * functions on it to configure it. */
   2258 OPENSSL_EXPORT X509_VERIFY_PARAM *SSL_get0_param(SSL *ssl);
   2259 
   2260 /* SSL_CTX_set_purpose sets |ctx|'s |X509_VERIFY_PARAM|'s 'purpose' parameter to
   2261  * |purpose|. It returns one on success and zero on error. */
   2262 OPENSSL_EXPORT int SSL_CTX_set_purpose(SSL_CTX *ctx, int purpose);
   2263 
   2264 /* SSL_set_purpose sets |ssl|'s |X509_VERIFY_PARAM|'s 'purpose' parameter to
   2265  * |purpose|. It returns one on success and zero on error. */
   2266 OPENSSL_EXPORT int SSL_set_purpose(SSL *ssl, int purpose);
   2267 
   2268 /* SSL_CTX_set_trust sets |ctx|'s |X509_VERIFY_PARAM|'s 'trust' parameter to
   2269  * |trust|. It returns one on success and zero on error. */
   2270 OPENSSL_EXPORT int SSL_CTX_set_trust(SSL_CTX *ctx, int trust);
   2271 
   2272 /* SSL_set_trust sets |ssl|'s |X509_VERIFY_PARAM|'s 'trust' parameter to
   2273  * |trust|. It returns one on success and zero on error. */
   2274 OPENSSL_EXPORT int SSL_set_trust(SSL *ssl, int trust);
   2275 
   2276 /* SSL_CTX_set_cert_store sets |ctx|'s certificate store to |store|. It takes
   2277  * ownership of |store|. The store is used for certificate verification.
   2278  *
   2279  * The store is also used for the auto-chaining feature, but this is deprecated.
   2280  * See also |SSL_MODE_NO_AUTO_CHAIN|. */
   2281 OPENSSL_EXPORT void SSL_CTX_set_cert_store(SSL_CTX *ctx, X509_STORE *store);
   2282 
   2283 /* SSL_CTX_get_cert_store returns |ctx|'s certificate store. */
   2284 OPENSSL_EXPORT X509_STORE *SSL_CTX_get_cert_store(const SSL_CTX *ctx);
   2285 
   2286 /* SSL_CTX_set_default_verify_paths loads the OpenSSL system-default trust
   2287  * anchors into |ctx|'s store. It returns one on success and zero on failure. */
   2288 OPENSSL_EXPORT int SSL_CTX_set_default_verify_paths(SSL_CTX *ctx);
   2289 
   2290 /* SSL_CTX_load_verify_locations loads trust anchors into |ctx|'s store from
   2291  * |ca_file| and |ca_dir|, either of which may be NULL. If |ca_file| is passed,
   2292  * it is opened and PEM-encoded CA certificates are read. If |ca_dir| is passed,
   2293  * it is treated as a directory in OpenSSL's hashed directory format. It returns
   2294  * one on success and zero on failure.
   2295  *
   2296  * See
   2297  * https://www.openssl.org/docs/manmaster/ssl/SSL_CTX_load_verify_locations.html
   2298  * for documentation on the directory format. */
   2299 OPENSSL_EXPORT int SSL_CTX_load_verify_locations(SSL_CTX *ctx,
   2300                                                  const char *ca_file,
   2301                                                  const char *ca_dir);
   2302 
   2303 /* SSL_get_verify_result returns the result of certificate verification. It is
   2304  * either |X509_V_OK| or a |X509_V_ERR_*| value. */
   2305 OPENSSL_EXPORT long SSL_get_verify_result(const SSL *ssl);
   2306 
   2307 /* SSL_get_ex_data_X509_STORE_CTX_idx returns the ex_data index used to look up
   2308  * the |SSL| associated with an |X509_STORE_CTX| in the verify callback. */
   2309 OPENSSL_EXPORT int SSL_get_ex_data_X509_STORE_CTX_idx(void);
   2310 
   2311 /* SSL_CTX_set_cert_verify_callback sets a custom callback to be called on
   2312  * certificate verification rather than |X509_verify_cert|. |store_ctx| contains
   2313  * the verification parameters. The callback should return one on success and
   2314  * zero on fatal error. It may use |X509_STORE_CTX_set_error| to set a
   2315  * verification result.
   2316  *
   2317  * The callback may use |SSL_get_ex_data_X509_STORE_CTX_idx| to recover the
   2318  * |SSL| object from |store_ctx|. */
   2319 OPENSSL_EXPORT void SSL_CTX_set_cert_verify_callback(
   2320     SSL_CTX *ctx, int (*callback)(X509_STORE_CTX *store_ctx, void *arg),
   2321     void *arg);
   2322 
   2323 /* SSL_CTX_i_promise_to_verify_certs_after_the_handshake indicates that the
   2324  * caller understands that the |CRYPTO_BUFFER|-based methods currently require
   2325  * post-handshake verification of certificates and thus it's ok to accept any
   2326  * certificates during the handshake. */
   2327 OPENSSL_EXPORT void SSL_CTX_i_promise_to_verify_certs_after_the_handshake(
   2328     SSL_CTX *ctx);
   2329 
   2330 /* SSL_enable_signed_cert_timestamps causes |ssl| (which must be the client end
   2331  * of a connection) to request SCTs from the server. See
   2332  * https://tools.ietf.org/html/rfc6962.
   2333  *
   2334  * Call |SSL_get0_signed_cert_timestamp_list| to recover the SCT after the
   2335  * handshake. */
   2336 OPENSSL_EXPORT void SSL_enable_signed_cert_timestamps(SSL *ssl);
   2337 
   2338 /* SSL_CTX_enable_signed_cert_timestamps enables SCT requests on all client SSL
   2339  * objects created from |ctx|.
   2340  *
   2341  * Call |SSL_get0_signed_cert_timestamp_list| to recover the SCT after the
   2342  * handshake. */
   2343 OPENSSL_EXPORT void SSL_CTX_enable_signed_cert_timestamps(SSL_CTX *ctx);
   2344 
   2345 /* SSL_enable_ocsp_stapling causes |ssl| (which must be the client end of a
   2346  * connection) to request a stapled OCSP response from the server.
   2347  *
   2348  * Call |SSL_get0_ocsp_response| to recover the OCSP response after the
   2349  * handshake. */
   2350 OPENSSL_EXPORT void SSL_enable_ocsp_stapling(SSL *ssl);
   2351 
   2352 /* SSL_CTX_enable_ocsp_stapling enables OCSP stapling on all client SSL objects
   2353  * created from |ctx|.
   2354  *
   2355  * Call |SSL_get0_ocsp_response| to recover the OCSP response after the
   2356  * handshake. */
   2357 OPENSSL_EXPORT void SSL_CTX_enable_ocsp_stapling(SSL_CTX *ctx);
   2358 
   2359 /* SSL_CTX_set0_verify_cert_store sets an |X509_STORE| that will be used
   2360  * exclusively for certificate verification and returns one. Ownership of
   2361  * |store| is transferred to the |SSL_CTX|. */
   2362 OPENSSL_EXPORT int SSL_CTX_set0_verify_cert_store(SSL_CTX *ctx,
   2363                                                   X509_STORE *store);
   2364 
   2365 /* SSL_CTX_set1_verify_cert_store sets an |X509_STORE| that will be used
   2366  * exclusively for certificate verification and returns one. An additional
   2367  * reference to |store| will be taken. */
   2368 OPENSSL_EXPORT int SSL_CTX_set1_verify_cert_store(SSL_CTX *ctx,
   2369                                                   X509_STORE *store);
   2370 
   2371 /* SSL_set0_verify_cert_store sets an |X509_STORE| that will be used
   2372  * exclusively for certificate verification and returns one. Ownership of
   2373  * |store| is transferred to the |SSL|. */
   2374 OPENSSL_EXPORT int SSL_set0_verify_cert_store(SSL *ssl, X509_STORE *store);
   2375 
   2376 /* SSL_set1_verify_cert_store sets an |X509_STORE| that will be used
   2377  * exclusively for certificate verification and returns one. An additional
   2378  * reference to |store| will be taken. */
   2379 OPENSSL_EXPORT int SSL_set1_verify_cert_store(SSL *ssl, X509_STORE *store);
   2380 
   2381 /* SSL_CTX_set_ed25519_enabled configures whether |ctx| advertises support for
   2382  * the Ed25519 signature algorithm when using the default preference list. */
   2383 OPENSSL_EXPORT void SSL_CTX_set_ed25519_enabled(SSL_CTX *ctx, int enabled);
   2384 
   2385 /* SSL_CTX_set_verify_algorithm_prefs confingures |ctx| to use |prefs| as the
   2386  * preference list when verifying signature's from the peer's long-term key. It
   2387  * returns one on zero on error. |prefs| should not include the internal-only
   2388  * value |SSL_SIGN_RSA_PKCS1_MD5_SHA1|. */
   2389 OPENSSL_EXPORT int SSL_CTX_set_verify_algorithm_prefs(SSL_CTX *ctx,
   2390                                                       const uint16_t *prefs,
   2391                                                       size_t num_prefs);
   2392 
   2393 
   2394 /* Client certificate CA list.
   2395  *
   2396  * When requesting a client certificate, a server may advertise a list of
   2397  * certificate authorities which are accepted. These functions may be used to
   2398  * configure this list. */
   2399 
   2400 /* SSL_set_client_CA_list sets |ssl|'s client certificate CA list to
   2401  * |name_list|. It takes ownership of |name_list|. */
   2402 OPENSSL_EXPORT void SSL_set_client_CA_list(SSL *ssl,
   2403                                            STACK_OF(X509_NAME) *name_list);
   2404 
   2405 /* SSL_CTX_set_client_CA_list sets |ctx|'s client certificate CA list to
   2406  * |name_list|. It takes ownership of |name_list|. */
   2407 OPENSSL_EXPORT void SSL_CTX_set_client_CA_list(SSL_CTX *ctx,
   2408                                                STACK_OF(X509_NAME) *name_list);
   2409 
   2410 /* SSL_get_client_CA_list returns |ssl|'s client certificate CA list. If |ssl|
   2411  * has not been configured as a client, this is the list configured by
   2412  * |SSL_CTX_set_client_CA_list|.
   2413  *
   2414  * If configured as a client, it returns the client certificate CA list sent by
   2415  * the server. In this mode, the behavior is undefined except during the
   2416  * callbacks set by |SSL_CTX_set_cert_cb| and |SSL_CTX_set_client_cert_cb| or
   2417  * when the handshake is paused because of them. */
   2418 OPENSSL_EXPORT STACK_OF(X509_NAME) *SSL_get_client_CA_list(const SSL *ssl);
   2419 
   2420 /* SSL_get0_server_requested_CAs returns the CAs sent by a server to guide a
   2421  * client in certificate selection. They are a series of DER-encoded X.509
   2422  * names. This function may only be called during a callback set by
   2423  * |SSL_CTX_set_cert_cb| or when the handshake is paused because of it.
   2424  *
   2425  * The returned stack is owned by |ssl|, as are its contents. It should not be
   2426  * used past the point where the handshake is restarted after the callback. */
   2427 OPENSSL_EXPORT STACK_OF(CRYPTO_BUFFER) *SSL_get0_server_requested_CAs(
   2428     const SSL *ssl);
   2429 
   2430 /* SSL_CTX_get_client_CA_list returns |ctx|'s client certificate CA list. */
   2431 OPENSSL_EXPORT STACK_OF(X509_NAME) *
   2432     SSL_CTX_get_client_CA_list(const SSL_CTX *ctx);
   2433 
   2434 /* SSL_add_client_CA appends |x509|'s subject to the client certificate CA list.
   2435  * It returns one on success or zero on error. The caller retains ownership of
   2436  * |x509|. */
   2437 OPENSSL_EXPORT int SSL_add_client_CA(SSL *ssl, X509 *x509);
   2438 
   2439 /* SSL_CTX_add_client_CA appends |x509|'s subject to the client certificate CA
   2440  * list. It returns one on success or zero on error. The caller retains
   2441  * ownership of |x509|. */
   2442 OPENSSL_EXPORT int SSL_CTX_add_client_CA(SSL_CTX *ctx, X509 *x509);
   2443 
   2444 /* SSL_load_client_CA_file opens |file| and reads PEM-encoded certificates from
   2445  * it. It returns a newly-allocated stack of the certificate subjects or NULL
   2446  * on error. */
   2447 OPENSSL_EXPORT STACK_OF(X509_NAME) *SSL_load_client_CA_file(const char *file);
   2448 
   2449 /* SSL_dup_CA_list makes a deep copy of |list|. It returns the new list on
   2450  * success or NULL on allocation error. */
   2451 OPENSSL_EXPORT STACK_OF(X509_NAME) *SSL_dup_CA_list(STACK_OF(X509_NAME) *list);
   2452 
   2453 /* SSL_add_file_cert_subjects_to_stack behaves like |SSL_load_client_CA_file|
   2454  * but appends the result to |out|. It returns one on success or zero on
   2455  * error. */
   2456 OPENSSL_EXPORT int SSL_add_file_cert_subjects_to_stack(STACK_OF(X509_NAME) *out,
   2457                                                        const char *file);
   2458 
   2459 
   2460 /* Server name indication.
   2461  *
   2462  * The server_name extension (RFC 3546) allows the client to advertise the name
   2463  * of the server it is connecting to. This is used in virtual hosting
   2464  * deployments to select one of a several certificates on a single IP. Only the
   2465  * host_name name type is supported. */
   2466 
   2467 #define TLSEXT_NAMETYPE_host_name 0
   2468 
   2469 /* SSL_set_tlsext_host_name, for a client, configures |ssl| to advertise |name|
   2470  * in the server_name extension. It returns one on success and zero on error. */
   2471 OPENSSL_EXPORT int SSL_set_tlsext_host_name(SSL *ssl, const char *name);
   2472 
   2473 /* SSL_get_servername, for a server, returns the hostname supplied by the
   2474  * client or NULL if there was none. The |type| argument must be
   2475  * |TLSEXT_NAMETYPE_host_name|. */
   2476 OPENSSL_EXPORT const char *SSL_get_servername(const SSL *ssl, const int type);
   2477 
   2478 /* SSL_get_servername_type, for a server, returns |TLSEXT_NAMETYPE_host_name|
   2479  * if the client sent a hostname and -1 otherwise. */
   2480 OPENSSL_EXPORT int SSL_get_servername_type(const SSL *ssl);
   2481 
   2482 /* SSL_CTX_set_tlsext_servername_callback configures |callback| to be called on
   2483  * the server after ClientHello extensions have been parsed and returns one.
   2484  * The callback may use |SSL_get_servername| to examine the server_name
   2485  * extension and returns a |SSL_TLSEXT_ERR_*| value. The value of |arg| may be
   2486  * set by calling |SSL_CTX_set_tlsext_servername_arg|.
   2487  *
   2488  * If the callback returns |SSL_TLSEXT_ERR_NOACK|, the server_name extension is
   2489  * not acknowledged in the ServerHello. If the return value is
   2490  * |SSL_TLSEXT_ERR_ALERT_FATAL|, then |*out_alert| is the alert to send,
   2491  * defaulting to |SSL_AD_UNRECOGNIZED_NAME|. |SSL_TLSEXT_ERR_ALERT_WARNING| is
   2492  * ignored and treated as |SSL_TLSEXT_ERR_OK|. */
   2493 OPENSSL_EXPORT int SSL_CTX_set_tlsext_servername_callback(
   2494     SSL_CTX *ctx, int (*callback)(SSL *ssl, int *out_alert, void *arg));
   2495 
   2496 /* SSL_CTX_set_tlsext_servername_arg sets the argument to the servername
   2497  * callback and returns one. See |SSL_CTX_set_tlsext_servername_callback|. */
   2498 OPENSSL_EXPORT int SSL_CTX_set_tlsext_servername_arg(SSL_CTX *ctx, void *arg);
   2499 
   2500 /* SSL_TLSEXT_ERR_* are values returned by some extension-related callbacks. */
   2501 #define SSL_TLSEXT_ERR_OK 0
   2502 #define SSL_TLSEXT_ERR_ALERT_WARNING 1
   2503 #define SSL_TLSEXT_ERR_ALERT_FATAL 2
   2504 #define SSL_TLSEXT_ERR_NOACK 3
   2505 
   2506 /* SSL_set_SSL_CTX changes |ssl|'s |SSL_CTX|. |ssl| will use the
   2507  * certificate-related settings from |ctx|, and |SSL_get_SSL_CTX| will report
   2508  * |ctx|. This function may be used during the callbacks registered by
   2509  * |SSL_CTX_set_select_certificate_cb|,
   2510  * |SSL_CTX_set_tlsext_servername_callback|, and |SSL_CTX_set_cert_cb| or when
   2511  * the handshake is paused from them. It is typically used to switch
   2512  * certificates based on SNI.
   2513  *
   2514  * Note the session cache and related settings will continue to use the initial
   2515  * |SSL_CTX|. Callers should use |SSL_CTX_set_session_id_context| to partition
   2516  * the session cache between different domains.
   2517  *
   2518  * TODO(davidben): Should other settings change after this call? */
   2519 OPENSSL_EXPORT SSL_CTX *SSL_set_SSL_CTX(SSL *ssl, SSL_CTX *ctx);
   2520 
   2521 
   2522 /* Application-layer protocol negotiation.
   2523  *
   2524  * The ALPN extension (RFC 7301) allows negotiating different application-layer
   2525  * protocols over a single port. This is used, for example, to negotiate
   2526  * HTTP/2. */
   2527 
   2528 /* SSL_CTX_set_alpn_protos sets the client ALPN protocol list on |ctx| to
   2529  * |protos|. |protos| must be in wire-format (i.e. a series of non-empty, 8-bit
   2530  * length-prefixed strings). It returns zero on success and one on failure.
   2531  * Configuring this list enables ALPN on a client.
   2532  *
   2533  * WARNING: this function is dangerous because it breaks the usual return value
   2534  * convention. */
   2535 OPENSSL_EXPORT int SSL_CTX_set_alpn_protos(SSL_CTX *ctx, const uint8_t *protos,
   2536                                            unsigned protos_len);
   2537 
   2538 /* SSL_set_alpn_protos sets the client ALPN protocol list on |ssl| to |protos|.
   2539  * |protos| must be in wire-format (i.e. a series of non-empty, 8-bit
   2540  * length-prefixed strings). It returns zero on success and one on failure.
   2541  * Configuring this list enables ALPN on a client.
   2542  *
   2543  * WARNING: this function is dangerous because it breaks the usual return value
   2544  * convention. */
   2545 OPENSSL_EXPORT int SSL_set_alpn_protos(SSL *ssl, const uint8_t *protos,
   2546                                        unsigned protos_len);
   2547 
   2548 /* SSL_CTX_set_alpn_select_cb sets a callback function on |ctx| that is called
   2549  * during ClientHello processing in order to select an ALPN protocol from the
   2550  * client's list of offered protocols. Configuring this callback enables ALPN on
   2551  * a server.
   2552  *
   2553  * The callback is passed a wire-format (i.e. a series of non-empty, 8-bit
   2554  * length-prefixed strings) ALPN protocol list in |in|. It should set |*out| and
   2555  * |*out_len| to the selected protocol and return |SSL_TLSEXT_ERR_OK| on
   2556  * success. It does not pass ownership of the buffer. Otherwise, it should
   2557  * return |SSL_TLSEXT_ERR_NOACK|. Other |SSL_TLSEXT_ERR_*| values are
   2558  * unimplemented and will be treated as |SSL_TLSEXT_ERR_NOACK|.
   2559  *
   2560  * The cipher suite is selected before negotiating ALPN. The callback may use
   2561  * |SSL_get_pending_cipher| to query the cipher suite. */
   2562 OPENSSL_EXPORT void SSL_CTX_set_alpn_select_cb(
   2563     SSL_CTX *ctx, int (*cb)(SSL *ssl, const uint8_t **out, uint8_t *out_len,
   2564                             const uint8_t *in, unsigned in_len, void *arg),
   2565     void *arg);
   2566 
   2567 /* SSL_get0_alpn_selected gets the selected ALPN protocol (if any) from |ssl|.
   2568  * On return it sets |*out_data| to point to |*out_len| bytes of protocol name
   2569  * (not including the leading length-prefix byte). If the server didn't respond
   2570  * with a negotiated protocol then |*out_len| will be zero. */
   2571 OPENSSL_EXPORT void SSL_get0_alpn_selected(const SSL *ssl,
   2572                                            const uint8_t **out_data,
   2573                                            unsigned *out_len);
   2574 
   2575 /* SSL_CTX_set_allow_unknown_alpn_protos configures client connections on |ctx|
   2576  * to allow unknown ALPN protocols from the server. Otherwise, by default, the
   2577  * client will require that the protocol be advertised in
   2578  * |SSL_CTX_set_alpn_protos|. */
   2579 OPENSSL_EXPORT void SSL_CTX_set_allow_unknown_alpn_protos(SSL_CTX *ctx,
   2580                                                           int enabled);
   2581 
   2582 
   2583 /* Next protocol negotiation.
   2584  *
   2585  * The NPN extension (draft-agl-tls-nextprotoneg-03) is the predecessor to ALPN
   2586  * and deprecated in favor of it. */
   2587 
   2588 /* SSL_CTX_set_next_protos_advertised_cb sets a callback that is called when a
   2589  * TLS server needs a list of supported protocols for Next Protocol
   2590  * Negotiation. The returned list must be in wire format. The list is returned
   2591  * by setting |*out| to point to it and |*out_len| to its length. This memory
   2592  * will not be modified, but one should assume that |ssl| keeps a reference to
   2593  * it.
   2594  *
   2595  * The callback should return |SSL_TLSEXT_ERR_OK| if it wishes to advertise.
   2596  * Otherwise, no such extension will be included in the ServerHello. */
   2597 OPENSSL_EXPORT void SSL_CTX_set_next_protos_advertised_cb(
   2598     SSL_CTX *ctx,
   2599     int (*cb)(SSL *ssl, const uint8_t **out, unsigned *out_len, void *arg),
   2600     void *arg);
   2601 
   2602 /* SSL_CTX_set_next_proto_select_cb sets a callback that is called when a client
   2603  * needs to select a protocol from the server's provided list. |*out| must be
   2604  * set to point to the selected protocol (which may be within |in|). The length
   2605  * of the protocol name must be written into |*out_len|. The server's advertised
   2606  * protocols are provided in |in| and |in_len|. The callback can assume that
   2607  * |in| is syntactically valid.
   2608  *
   2609  * The client must select a protocol. It is fatal to the connection if this
   2610  * callback returns a value other than |SSL_TLSEXT_ERR_OK|.
   2611  *
   2612  * Configuring this callback enables NPN on a client. */
   2613 OPENSSL_EXPORT void SSL_CTX_set_next_proto_select_cb(
   2614     SSL_CTX *ctx, int (*cb)(SSL *ssl, uint8_t **out, uint8_t *out_len,
   2615                             const uint8_t *in, unsigned in_len, void *arg),
   2616     void *arg);
   2617 
   2618 /* SSL_get0_next_proto_negotiated sets |*out_data| and |*out_len| to point to
   2619  * the client's requested protocol for this connection. If the client didn't
   2620  * request any protocol, then |*out_data| is set to NULL.
   2621  *
   2622  * Note that the client can request any protocol it chooses. The value returned
   2623  * from this function need not be a member of the list of supported protocols
   2624  * provided by the server. */
   2625 OPENSSL_EXPORT void SSL_get0_next_proto_negotiated(const SSL *ssl,
   2626                                                    const uint8_t **out_data,
   2627                                                    unsigned *out_len);
   2628 
   2629 /* SSL_select_next_proto implements the standard protocol selection. It is
   2630  * expected that this function is called from the callback set by
   2631  * |SSL_CTX_set_next_proto_select_cb|.
   2632  *
   2633  * |peer| and |supported| must be vectors of 8-bit, length-prefixed byte strings
   2634  * containing the peer and locally-configured protocols, respectively. The
   2635  * length byte itself is not included in the length. A byte string of length 0
   2636  * is invalid. No byte string may be truncated. |supported| is assumed to be
   2637  * non-empty.
   2638  *
   2639  * This function finds the first protocol in |peer| which is also in
   2640  * |supported|. If one was found, it sets |*out| and |*out_len| to point to it
   2641  * and returns |OPENSSL_NPN_NEGOTIATED|. Otherwise, it returns
   2642  * |OPENSSL_NPN_NO_OVERLAP| and sets |*out| and |*out_len| to the first
   2643  * supported protocol. */
   2644 OPENSSL_EXPORT int SSL_select_next_proto(uint8_t **out, uint8_t *out_len,
   2645                                          const uint8_t *peer, unsigned peer_len,
   2646                                          const uint8_t *supported,
   2647                                          unsigned supported_len);
   2648 
   2649 #define OPENSSL_NPN_UNSUPPORTED 0
   2650 #define OPENSSL_NPN_NEGOTIATED 1
   2651 #define OPENSSL_NPN_NO_OVERLAP 2
   2652 
   2653 
   2654 /* Channel ID.
   2655  *
   2656  * See draft-balfanz-tls-channelid-01. */
   2657 
   2658 /* SSL_CTX_set_tls_channel_id_enabled configures whether connections associated
   2659  * with |ctx| should enable Channel ID. */
   2660 OPENSSL_EXPORT void SSL_CTX_set_tls_channel_id_enabled(SSL_CTX *ctx,
   2661                                                        int enabled);
   2662 
   2663 /* SSL_set_tls_channel_id_enabled configures whether |ssl| should enable Channel
   2664  * ID. */
   2665 OPENSSL_EXPORT void SSL_set_tls_channel_id_enabled(SSL *ssl, int enabled);
   2666 
   2667 /* SSL_CTX_set1_tls_channel_id configures a TLS client to send a TLS Channel ID
   2668  * to compatible servers. |private_key| must be a P-256 EC key. It returns one
   2669  * on success and zero on error. */
   2670 OPENSSL_EXPORT int SSL_CTX_set1_tls_channel_id(SSL_CTX *ctx,
   2671                                                EVP_PKEY *private_key);
   2672 
   2673 /* SSL_set1_tls_channel_id configures a TLS client to send a TLS Channel ID to
   2674  * compatible servers. |private_key| must be a P-256 EC key. It returns one on
   2675  * success and zero on error. */
   2676 OPENSSL_EXPORT int SSL_set1_tls_channel_id(SSL *ssl, EVP_PKEY *private_key);
   2677 
   2678 /* SSL_get_tls_channel_id gets the client's TLS Channel ID from a server |SSL*|
   2679  * and copies up to the first |max_out| bytes into |out|. The Channel ID
   2680  * consists of the client's P-256 public key as an (x,y) pair where each is a
   2681  * 32-byte, big-endian field element. It returns 0 if the client didn't offer a
   2682  * Channel ID and the length of the complete Channel ID otherwise. */
   2683 OPENSSL_EXPORT size_t SSL_get_tls_channel_id(SSL *ssl, uint8_t *out,
   2684                                              size_t max_out);
   2685 
   2686 /* SSL_CTX_set_channel_id_cb sets a callback to be called when a TLS Channel ID
   2687  * is requested. The callback may set |*out_pkey| to a key, passing a reference
   2688  * to the caller. If none is returned, the handshake will pause and
   2689  * |SSL_get_error| will return |SSL_ERROR_WANT_CHANNEL_ID_LOOKUP|.
   2690  *
   2691  * See also |SSL_ERROR_WANT_CHANNEL_ID_LOOKUP|. */
   2692 OPENSSL_EXPORT void SSL_CTX_set_channel_id_cb(
   2693     SSL_CTX *ctx, void (*channel_id_cb)(SSL *ssl, EVP_PKEY **out_pkey));
   2694 
   2695 /* SSL_CTX_get_channel_id_cb returns the callback set by
   2696  * |SSL_CTX_set_channel_id_cb|. */
   2697 OPENSSL_EXPORT void (*SSL_CTX_get_channel_id_cb(SSL_CTX *ctx))(
   2698     SSL *ssl, EVP_PKEY **out_pkey);
   2699 
   2700 
   2701 /* DTLS-SRTP.
   2702  *
   2703  * See RFC 5764. */
   2704 
   2705 /* srtp_protection_profile_st (aka |SRTP_PROTECTION_PROFILE|) is an SRTP
   2706  * profile for use with the use_srtp extension. */
   2707 struct srtp_protection_profile_st {
   2708   const char *name;
   2709   unsigned long id;
   2710 } /* SRTP_PROTECTION_PROFILE */;
   2711 
   2712 DEFINE_CONST_STACK_OF(SRTP_PROTECTION_PROFILE)
   2713 
   2714 /* SRTP_* define constants for SRTP profiles. */
   2715 #define SRTP_AES128_CM_SHA1_80 0x0001
   2716 #define SRTP_AES128_CM_SHA1_32 0x0002
   2717 #define SRTP_AES128_F8_SHA1_80 0x0003
   2718 #define SRTP_AES128_F8_SHA1_32 0x0004
   2719 #define SRTP_NULL_SHA1_80      0x0005
   2720 #define SRTP_NULL_SHA1_32      0x0006
   2721 #define SRTP_AEAD_AES_128_GCM  0x0007
   2722 #define SRTP_AEAD_AES_256_GCM  0x0008
   2723 
   2724 /* SSL_CTX_set_srtp_profiles enables SRTP for all SSL objects created from
   2725  * |ctx|. |profile| contains a colon-separated list of profile names. It returns
   2726  * one on success and zero on failure. */
   2727 OPENSSL_EXPORT int SSL_CTX_set_srtp_profiles(SSL_CTX *ctx,
   2728                                              const char *profiles);
   2729 
   2730 /* SSL_set_srtp_profiles enables SRTP for |ssl|.  |profile| contains a
   2731  * colon-separated list of profile names. It returns one on success and zero on
   2732  * failure. */
   2733 OPENSSL_EXPORT int SSL_set_srtp_profiles(SSL *ssl, const char *profiles);
   2734 
   2735 /* SSL_get_srtp_profiles returns the SRTP profiles supported by |ssl|. */
   2736 OPENSSL_EXPORT STACK_OF(SRTP_PROTECTION_PROFILE) *SSL_get_srtp_profiles(
   2737     SSL *ssl);
   2738 
   2739 /* SSL_get_selected_srtp_profile returns the selected SRTP profile, or NULL if
   2740  * SRTP was not negotiated. */
   2741 OPENSSL_EXPORT const SRTP_PROTECTION_PROFILE *SSL_get_selected_srtp_profile(
   2742     SSL *ssl);
   2743 
   2744 
   2745 /* Pre-shared keys.
   2746  *
   2747  * Connections may be configured with PSK (Pre-Shared Key) cipher suites. These
   2748  * authenticate using out-of-band pre-shared keys rather than certificates. See
   2749  * RFC 4279.
   2750  *
   2751  * This implementation uses NUL-terminated C strings for identities and identity
   2752  * hints, so values with a NUL character are not supported. (RFC 4279 does not
   2753  * specify the format of an identity.) */
   2754 
   2755 /* PSK_MAX_IDENTITY_LEN is the maximum supported length of a PSK identity,
   2756  * excluding the NUL terminator. */
   2757 #define PSK_MAX_IDENTITY_LEN 128
   2758 
   2759 /* PSK_MAX_PSK_LEN is the maximum supported length of a pre-shared key. */
   2760 #define PSK_MAX_PSK_LEN 256
   2761 
   2762 /* SSL_CTX_set_psk_client_callback sets the callback to be called when PSK is
   2763  * negotiated on the client. This callback must be set to enable PSK cipher
   2764  * suites on the client.
   2765  *
   2766  * The callback is passed the identity hint in |hint| or NULL if none was
   2767  * provided. It should select a PSK identity and write the identity and the
   2768  * corresponding PSK to |identity| and |psk|, respectively. The identity is
   2769  * written as a NUL-terminated C string of length (excluding the NUL terminator)
   2770  * at most |max_identity_len|. The PSK's length must be at most |max_psk_len|.
   2771  * The callback returns the length of the PSK or 0 if no suitable identity was
   2772  * found. */
   2773 OPENSSL_EXPORT void SSL_CTX_set_psk_client_callback(
   2774     SSL_CTX *ctx,
   2775     unsigned (*psk_client_callback)(
   2776         SSL *ssl, const char *hint, char *identity,
   2777         unsigned max_identity_len, uint8_t *psk, unsigned max_psk_len));
   2778 
   2779 /* SSL_set_psk_client_callback sets the callback to be called when PSK is
   2780  * negotiated on the client. This callback must be set to enable PSK cipher
   2781  * suites on the client. See also |SSL_CTX_set_psk_client_callback|. */
   2782 OPENSSL_EXPORT void SSL_set_psk_client_callback(
   2783     SSL *ssl, unsigned (*psk_client_callback)(SSL *ssl, const char *hint,
   2784                                               char *identity,
   2785                                               unsigned max_identity_len,
   2786                                               uint8_t *psk,
   2787                                               unsigned max_psk_len));
   2788 
   2789 /* SSL_CTX_set_psk_server_callback sets the callback to be called when PSK is
   2790  * negotiated on the server. This callback must be set to enable PSK cipher
   2791  * suites on the server.
   2792  *
   2793  * The callback is passed the identity in |identity|. It should write a PSK of
   2794  * length at most |max_psk_len| to |psk| and return the number of bytes written
   2795  * or zero if the PSK identity is unknown. */
   2796 OPENSSL_EXPORT void SSL_CTX_set_psk_server_callback(
   2797     SSL_CTX *ctx,
   2798     unsigned (*psk_server_callback)(SSL *ssl, const char *identity,
   2799                                     uint8_t *psk,
   2800                                     unsigned max_psk_len));
   2801 
   2802 /* SSL_set_psk_server_callback sets the callback to be called when PSK is
   2803  * negotiated on the server. This callback must be set to enable PSK cipher
   2804  * suites on the server. See also |SSL_CTX_set_psk_server_callback|. */
   2805 OPENSSL_EXPORT void SSL_set_psk_server_callback(
   2806     SSL *ssl,
   2807     unsigned (*psk_server_callback)(SSL *ssl, const char *identity,
   2808                                     uint8_t *psk,
   2809                                     unsigned max_psk_len));
   2810 
   2811 /* SSL_CTX_use_psk_identity_hint configures server connections to advertise an
   2812  * identity hint of |identity_hint|. It returns one on success and zero on
   2813  * error. */
   2814 OPENSSL_EXPORT int SSL_CTX_use_psk_identity_hint(SSL_CTX *ctx,
   2815                                                  const char *identity_hint);
   2816 
   2817 /* SSL_use_psk_identity_hint configures server connections to advertise an
   2818  * identity hint of |identity_hint|. It returns one on success and zero on
   2819  * error. */
   2820 OPENSSL_EXPORT int SSL_use_psk_identity_hint(SSL *ssl,
   2821                                              const char *identity_hint);
   2822 
   2823 /* SSL_get_psk_identity_hint returns the PSK identity hint advertised for |ssl|
   2824  * or NULL if there is none. */
   2825 OPENSSL_EXPORT const char *SSL_get_psk_identity_hint(const SSL *ssl);
   2826 
   2827 /* SSL_get_psk_identity, after the handshake completes, returns the PSK identity
   2828  * that was negotiated by |ssl| or NULL if PSK was not used. */
   2829 OPENSSL_EXPORT const char *SSL_get_psk_identity(const SSL *ssl);
   2830 
   2831 
   2832 /* Early data.
   2833  *
   2834  * WARNING: 0-RTT support in BoringSSL is currently experimental and not fully
   2835  * implemented. It may cause interoperability or security failures when used.
   2836  *
   2837  * Early data, or 0-RTT, is a feature in TLS 1.3 which allows clients to send
   2838  * data on the first flight during a resumption handshake. This can save a
   2839  * round-trip in some application protocols.
   2840  *
   2841  * WARNING: A 0-RTT handshake has different security properties from normal
   2842  * handshake, so it is off by default unless opted in. In particular, early data
   2843  * is replayable by a network attacker. Callers must account for this when
   2844  * sending or processing data before the handshake is confirmed. See
   2845  * draft-ietf-tls-tls13-18 for more information.
   2846  *
   2847  * As a server, if early data is accepted, |SSL_do_handshake| will complete as
   2848  * soon as the ClientHello is processed and server flight sent. |SSL_write| may
   2849  * be used to send half-RTT data. |SSL_read| will consume early data and
   2850  * transition to 1-RTT data as appropriate. Prior to the transition,
   2851  * |SSL_in_init| will report the handshake is still in progress. Callers may use
   2852  * it or |SSL_in_early_data| to defer or reject requests as needed.
   2853  *
   2854  * Early data as a client is more complex. If the offered session (see
   2855  * |SSL_set_session|) is 0-RTT-capable, the handshake will return after sending
   2856  * the ClientHello. The predicted peer certificate and ALPN protocol will be
   2857  * available via the usual APIs. |SSL_write| will write early data, up to the
   2858  * session's limit. Writes past this limit and |SSL_read| will complete the
   2859  * handshake before continuing. Callers may also call |SSL_do_handshake| again
   2860  * to complete the handshake sooner.
   2861  *
   2862  * If the server accepts early data, the handshake will succeed. |SSL_read| and
   2863  * |SSL_write| will then act as in a 1-RTT handshake. The peer certificate and
   2864  * ALPN protocol will be as predicted and need not be re-queried.
   2865  *
   2866  * If the server rejects early data, |SSL_do_handshake| (and thus |SSL_read| and
   2867  * |SSL_write|) will then fail with |SSL_get_error| returning
   2868  * |SSL_ERROR_EARLY_DATA_REJECTED|. The caller should treat this as a connection
   2869  * error and most likely perform a high-level retry. Note the server may still
   2870  * have processed the early data due to attacker replays.
   2871  *
   2872  * To then continue the handshake on the original connection, use
   2873  * |SSL_reset_early_data_reject|. This allows a faster retry than making a fresh
   2874  * connection. |SSL_do_handshake| will the complete the full handshake as in a
   2875  * fresh connection. Once reset, the peer certificate, ALPN protocol, and other
   2876  * properties may change so the caller must query them again.
   2877  *
   2878  * Finally, to implement the fallback described in draft-ietf-tls-tls13-18
   2879  * appendix C.3, retry on a fresh connection without 0-RTT if the handshake
   2880  * fails with |SSL_R_WRONG_VERSION_ON_EARLY_DATA|. */
   2881 
   2882 /* SSL_CTX_set_early_data_enabled sets whether early data is allowed to be used
   2883  * with resumptions using |ctx|. */
   2884 OPENSSL_EXPORT void SSL_CTX_set_early_data_enabled(SSL_CTX *ctx, int enabled);
   2885 
   2886 /* SSL_set_early_data_enabled sets whether early data is allowed to be used
   2887  * with resumptions using |ssl|. See |SSL_CTX_set_early_data_enabled| for more
   2888  * information. */
   2889 OPENSSL_EXPORT void SSL_set_early_data_enabled(SSL *ssl, int enabled);
   2890 
   2891 /* SSL_in_early_data returns one if |ssl| has a pending handshake that has
   2892  * progressed enough to send or receive early data. Clients may call |SSL_write|
   2893  * to send early data, but |SSL_read| will complete the handshake before
   2894  * accepting application data. Servers may call |SSL_read| to read early data
   2895  * and |SSL_write| to send half-RTT data. */
   2896 OPENSSL_EXPORT int SSL_in_early_data(const SSL *ssl);
   2897 
   2898 /* SSL_early_data_accepted returns whether early data was accepted on the
   2899  * handshake performed by |ssl|. */
   2900 OPENSSL_EXPORT int SSL_early_data_accepted(const SSL *ssl);
   2901 
   2902 /* SSL_reset_early_data_reject resets |ssl| after an early data reject. All
   2903  * 0-RTT state is discarded, including any pending |SSL_write| calls. The caller
   2904  * should treat |ssl| as a logically fresh connection, usually by driving the
   2905  * handshake to completion using |SSL_do_handshake|.
   2906  *
   2907  * It is an error to call this function on an |SSL| object that is not signaling
   2908  * |SSL_ERROR_EARLY_DATA_REJECTED|. */
   2909 OPENSSL_EXPORT void SSL_reset_early_data_reject(SSL *ssl);
   2910 
   2911 
   2912 /* Alerts.
   2913  *
   2914  * TLS and SSL 3.0 use alerts to signal error conditions. Alerts have a type
   2915  * (warning or fatal) and description. OpenSSL internally handles fatal alerts
   2916  * with dedicated error codes (see |SSL_AD_REASON_OFFSET|). Except for
   2917  * close_notify, warning alerts are silently ignored and may only be surfaced
   2918  * with |SSL_CTX_set_info_callback|. */
   2919 
   2920 /* SSL_AD_REASON_OFFSET is the offset between error reasons and |SSL_AD_*|
   2921  * values. Any error code under |ERR_LIB_SSL| with an error reason above this
   2922  * value corresponds to an alert description. Consumers may add or subtract
   2923  * |SSL_AD_REASON_OFFSET| to convert between them.
   2924  *
   2925  * make_errors.go reserves error codes above 1000 for manually-assigned errors.
   2926  * This value must be kept in sync with reservedReasonCode in make_errors.h */
   2927 #define SSL_AD_REASON_OFFSET 1000
   2928 
   2929 /* SSL_AD_* are alert descriptions for SSL 3.0 and TLS. */
   2930 #define SSL_AD_CLOSE_NOTIFY SSL3_AD_CLOSE_NOTIFY
   2931 #define SSL_AD_UNEXPECTED_MESSAGE SSL3_AD_UNEXPECTED_MESSAGE
   2932 #define SSL_AD_BAD_RECORD_MAC SSL3_AD_BAD_RECORD_MAC
   2933 #define SSL_AD_DECRYPTION_FAILED TLS1_AD_DECRYPTION_FAILED
   2934 #define SSL_AD_RECORD_OVERFLOW TLS1_AD_RECORD_OVERFLOW
   2935 #define SSL_AD_DECOMPRESSION_FAILURE SSL3_AD_DECOMPRESSION_FAILURE
   2936 #define SSL_AD_HANDSHAKE_FAILURE SSL3_AD_HANDSHAKE_FAILURE
   2937 #define SSL_AD_NO_CERTIFICATE SSL3_AD_NO_CERTIFICATE /* Not used in TLS */
   2938 #define SSL_AD_BAD_CERTIFICATE SSL3_AD_BAD_CERTIFICATE
   2939 #define SSL_AD_UNSUPPORTED_CERTIFICATE SSL3_AD_UNSUPPORTED_CERTIFICATE
   2940 #define SSL_AD_CERTIFICATE_REVOKED SSL3_AD_CERTIFICATE_REVOKED
   2941 #define SSL_AD_CERTIFICATE_EXPIRED SSL3_AD_CERTIFICATE_EXPIRED
   2942 #define SSL_AD_CERTIFICATE_UNKNOWN SSL3_AD_CERTIFICATE_UNKNOWN
   2943 #define SSL_AD_ILLEGAL_PARAMETER SSL3_AD_ILLEGAL_PARAMETER
   2944 #define SSL_AD_UNKNOWN_CA TLS1_AD_UNKNOWN_CA
   2945 #define SSL_AD_ACCESS_DENIED TLS1_AD_ACCESS_DENIED
   2946 #define SSL_AD_DECODE_ERROR TLS1_AD_DECODE_ERROR
   2947 #define SSL_AD_DECRYPT_ERROR TLS1_AD_DECRYPT_ERROR
   2948 #define SSL_AD_EXPORT_RESTRICTION TLS1_AD_EXPORT_RESTRICTION
   2949 #define SSL_AD_PROTOCOL_VERSION TLS1_AD_PROTOCOL_VERSION
   2950 #define SSL_AD_INSUFFICIENT_SECURITY TLS1_AD_INSUFFICIENT_SECURITY
   2951 #define SSL_AD_INTERNAL_ERROR TLS1_AD_INTERNAL_ERROR
   2952 #define SSL_AD_INAPPROPRIATE_FALLBACK SSL3_AD_INAPPROPRIATE_FALLBACK
   2953 #define SSL_AD_USER_CANCELLED TLS1_AD_USER_CANCELLED
   2954 #define SSL_AD_NO_RENEGOTIATION TLS1_AD_NO_RENEGOTIATION
   2955 #define SSL_AD_MISSING_EXTENSION TLS1_AD_MISSING_EXTENSION
   2956 #define SSL_AD_UNSUPPORTED_EXTENSION TLS1_AD_UNSUPPORTED_EXTENSION
   2957 #define SSL_AD_CERTIFICATE_UNOBTAINABLE TLS1_AD_CERTIFICATE_UNOBTAINABLE
   2958 #define SSL_AD_UNRECOGNIZED_NAME TLS1_AD_UNRECOGNIZED_NAME
   2959 #define SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE \
   2960   TLS1_AD_BAD_CERTIFICATE_STATUS_RESPONSE
   2961 #define SSL_AD_BAD_CERTIFICATE_HASH_VALUE TLS1_AD_BAD_CERTIFICATE_HASH_VALUE
   2962 #define SSL_AD_UNKNOWN_PSK_IDENTITY TLS1_AD_UNKNOWN_PSK_IDENTITY
   2963 #define SSL_AD_CERTIFICATE_REQUIRED TLS1_AD_CERTIFICATE_REQUIRED
   2964 
   2965 /* SSL_alert_type_string_long returns a string description of |value| as an
   2966  * alert type (warning or fatal). */
   2967 OPENSSL_EXPORT const char *SSL_alert_type_string_long(int value);
   2968 
   2969 /* SSL_alert_desc_string_long returns a string description of |value| as an
   2970  * alert description or "unknown" if unknown. */
   2971 OPENSSL_EXPORT const char *SSL_alert_desc_string_long(int value);
   2972 
   2973 /* SSL_send_fatal_alert sends a fatal alert over |ssl| of the specified type,
   2974  * which should be one of the |SSL_AD_*| constants. It returns one on success
   2975  * and <= 0 on error. The caller should pass the return value into
   2976  * |SSL_get_error| to determine how to proceed. Once this function has been
   2977  * called, future calls to |SSL_write| will fail.
   2978  *
   2979  * If retrying a failed operation due to |SSL_ERROR_WANT_WRITE|, subsequent
   2980  * calls must use the same |alert| parameter. */
   2981 OPENSSL_EXPORT int SSL_send_fatal_alert(SSL *ssl, uint8_t alert);
   2982 
   2983 
   2984 /* ex_data functions.
   2985  *
   2986  * See |ex_data.h| for details. */
   2987 
   2988 OPENSSL_EXPORT int SSL_set_ex_data(SSL *ssl, int idx, void *data);
   2989 OPENSSL_EXPORT void *SSL_get_ex_data(const SSL *ssl, int idx);
   2990 OPENSSL_EXPORT int SSL_get_ex_new_index(long argl, void *argp,
   2991                                         CRYPTO_EX_unused *unused,
   2992                                         CRYPTO_EX_dup *dup_unused,
   2993                                         CRYPTO_EX_free *free_func);
   2994 
   2995 OPENSSL_EXPORT int SSL_SESSION_set_ex_data(SSL_SESSION *session, int idx,
   2996                                            void *data);
   2997 OPENSSL_EXPORT void *SSL_SESSION_get_ex_data(const SSL_SESSION *session,
   2998                                              int idx);
   2999 OPENSSL_EXPORT int SSL_SESSION_get_ex_new_index(long argl, void *argp,
   3000                                                 CRYPTO_EX_unused *unused,
   3001                                                 CRYPTO_EX_dup *dup_unused,
   3002                                                 CRYPTO_EX_free *free_func);
   3003 
   3004 OPENSSL_EXPORT int SSL_CTX_set_ex_data(SSL_CTX *ctx, int idx, void *data);
   3005 OPENSSL_EXPORT void *SSL_CTX_get_ex_data(const SSL_CTX *ctx, int idx);
   3006 OPENSSL_EXPORT int SSL_CTX_get_ex_new_index(long argl, void *argp,
   3007                                             CRYPTO_EX_unused *unused,
   3008                                             CRYPTO_EX_dup *dup_unused,
   3009                                             CRYPTO_EX_free *free_func);
   3010 
   3011 
   3012 /* Low-level record-layer state. */
   3013 
   3014 /* SSL_get_ivs sets |*out_iv_len| to the length of the IVs for the ciphers
   3015  * underlying |ssl| and sets |*out_read_iv| and |*out_write_iv| to point to the
   3016  * current IVs for the read and write directions. This is only meaningful for
   3017  * connections with implicit IVs (i.e. CBC mode with SSLv3 or TLS 1.0).
   3018  *
   3019  * It returns one on success or zero on error. */
   3020 OPENSSL_EXPORT int SSL_get_ivs(const SSL *ssl, const uint8_t **out_read_iv,
   3021                                const uint8_t **out_write_iv,
   3022                                size_t *out_iv_len);
   3023 
   3024 /* SSL_get_key_block_len returns the length of |ssl|'s key block. */
   3025 OPENSSL_EXPORT size_t SSL_get_key_block_len(const SSL *ssl);
   3026 
   3027 /* SSL_generate_key_block generates |out_len| bytes of key material for |ssl|'s
   3028  * current connection state. */
   3029 OPENSSL_EXPORT int SSL_generate_key_block(const SSL *ssl, uint8_t *out,
   3030                                           size_t out_len);
   3031 
   3032 /* SSL_get_read_sequence returns, in TLS, the expected sequence number of the
   3033  * next incoming record in the current epoch. In DTLS, it returns the maximum
   3034  * sequence number received in the current epoch and includes the epoch number
   3035  * in the two most significant bytes. */
   3036 OPENSSL_EXPORT uint64_t SSL_get_read_sequence(const SSL *ssl);
   3037 
   3038 /* SSL_get_write_sequence returns the sequence number of the next outgoing
   3039  * record in the current epoch. In DTLS, it includes the epoch number in the
   3040  * two most significant bytes. */
   3041 OPENSSL_EXPORT uint64_t SSL_get_write_sequence(const SSL *ssl);
   3042 
   3043 
   3044 /* Obscure functions. */
   3045 
   3046 /* SSL_get_structure_sizes returns the sizes of the SSL, SSL_CTX and
   3047  * SSL_SESSION structures so that a test can ensure that outside code agrees on
   3048  * these values. */
   3049 OPENSSL_EXPORT void SSL_get_structure_sizes(size_t *ssl_size,
   3050                                             size_t *ssl_ctx_size,
   3051                                             size_t *ssl_session_size);
   3052 
   3053 /* SSL_CTX_set_msg_callback installs |cb| as the message callback for |ctx|.
   3054  * This callback will be called when sending or receiving low-level record
   3055  * headers, complete handshake messages, ChangeCipherSpec, and alerts.
   3056  * |write_p| is one for outgoing messages and zero for incoming messages.
   3057  *
   3058  * For each record header, |cb| is called with |version| = 0 and |content_type|
   3059  * = |SSL3_RT_HEADER|. The |len| bytes from |buf| contain the header. Note that
   3060  * this does not include the record body. If the record is sealed, the length
   3061  * in the header is the length of the ciphertext.
   3062  *
   3063  * For each handshake message, ChangeCipherSpec, and alert, |version| is the
   3064  * protocol version and |content_type| is the corresponding record type. The
   3065  * |len| bytes from |buf| contain the handshake message, one-byte
   3066  * ChangeCipherSpec body, and two-byte alert, respectively.
   3067  *
   3068  * For a V2ClientHello, |version| is |SSL2_VERSION|, |content_type| is zero, and
   3069  * the |len| bytes from |buf| contain the V2ClientHello structure. */
   3070 OPENSSL_EXPORT void SSL_CTX_set_msg_callback(
   3071     SSL_CTX *ctx, void (*cb)(int write_p, int version, int content_type,
   3072                              const void *buf, size_t len, SSL *ssl, void *arg));
   3073 
   3074 /* SSL_CTX_set_msg_callback_arg sets the |arg| parameter of the message
   3075  * callback. */
   3076 OPENSSL_EXPORT void SSL_CTX_set_msg_callback_arg(SSL_CTX *ctx, void *arg);
   3077 
   3078 /* SSL_set_msg_callback installs |cb| as the message callback of |ssl|. See
   3079  * |SSL_CTX_set_msg_callback| for when this callback is called. */
   3080 OPENSSL_EXPORT void SSL_set_msg_callback(
   3081     SSL *ssl, void (*cb)(int write_p, int version, int content_type,
   3082                          const void *buf, size_t len, SSL *ssl, void *arg));
   3083 
   3084 /* SSL_set_msg_callback_arg sets the |arg| parameter of the message callback. */
   3085 OPENSSL_EXPORT void SSL_set_msg_callback_arg(SSL *ssl, void *arg);
   3086 
   3087 /* SSL_CTX_set_keylog_callback configures a callback to log key material. This
   3088  * is intended for debugging use with tools like Wireshark. The |cb| function
   3089  * should log |line| followed by a newline, synchronizing with any concurrent
   3090  * access to the log.
   3091  *
   3092  * The format is described in
   3093  * https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSS/Key_Log_Format. */
   3094 OPENSSL_EXPORT void SSL_CTX_set_keylog_callback(
   3095     SSL_CTX *ctx, void (*cb)(const SSL *ssl, const char *line));
   3096 
   3097 /* SSL_CTX_get_keylog_callback returns the callback configured by
   3098  * |SSL_CTX_set_keylog_callback|. */
   3099 OPENSSL_EXPORT void (*SSL_CTX_get_keylog_callback(const SSL_CTX *ctx))(
   3100     const SSL *ssl, const char *line);
   3101 
   3102 /* SSL_CTX_set_current_time_cb configures a callback to retrieve the current
   3103  * time, which should be set in |*out_clock|. This can be used for testing
   3104  * purposes; for example, a callback can be configured that returns a time
   3105  * set explicitly by the test. */
   3106 OPENSSL_EXPORT void SSL_CTX_set_current_time_cb(
   3107     SSL_CTX *ctx, void (*cb)(const SSL *ssl, struct timeval *out_clock));
   3108 
   3109 enum ssl_renegotiate_mode_t {
   3110   ssl_renegotiate_never = 0,
   3111   ssl_renegotiate_once,
   3112   ssl_renegotiate_freely,
   3113   ssl_renegotiate_ignore,
   3114 };
   3115 
   3116 /* SSL_set_renegotiate_mode configures how |ssl|, a client, reacts to
   3117  * renegotiation attempts by a server. If |ssl| is a server, peer-initiated
   3118  * renegotiations are *always* rejected and this function does nothing.
   3119  *
   3120  * The renegotiation mode defaults to |ssl_renegotiate_never|, but may be set
   3121  * at any point in a connection's lifetime. Set it to |ssl_renegotiate_once| to
   3122  * allow one renegotiation, |ssl_renegotiate_freely| to allow all
   3123  * renegotiations or |ssl_renegotiate_ignore| to ignore HelloRequest messages.
   3124  * Note that ignoring HelloRequest messages may cause the connection to stall
   3125  * if the server waits for the renegotiation to complete.
   3126  *
   3127  * There is no support in BoringSSL for initiating renegotiations as a client
   3128  * or server. */
   3129 OPENSSL_EXPORT void SSL_set_renegotiate_mode(SSL *ssl,
   3130                                              enum ssl_renegotiate_mode_t mode);
   3131 
   3132 /* SSL_renegotiate_pending returns one if |ssl| is in the middle of a
   3133  * renegotiation. */
   3134 OPENSSL_EXPORT int SSL_renegotiate_pending(SSL *ssl);
   3135 
   3136 /* SSL_total_renegotiations returns the total number of renegotiation handshakes
   3137  * performed by |ssl|. This includes the pending renegotiation, if any. */
   3138 OPENSSL_EXPORT int SSL_total_renegotiations(const SSL *ssl);
   3139 
   3140 enum tls13_variant_t {
   3141   tls13_default = 0,
   3142   tls13_experiment = 1,
   3143   tls13_record_type_experiment = 2,
   3144 };
   3145 
   3146 /* SSL_CTX_set_tls13_variant sets which variant of TLS 1.3 we negotiate. On the
   3147  * server, if |variant| is not |tls13_default|, all variants are enabled. On the
   3148  * client, only the configured variant is enabled. */
   3149 OPENSSL_EXPORT void SSL_CTX_set_tls13_variant(SSL_CTX *ctx,
   3150                                               enum tls13_variant_t variant);
   3151 
   3152 /* SSL_set_tls13_variant sets which variant of TLS 1.3 we negotiate. On the
   3153  * server, if |variant| is not |tls13_default|, all variants are enabled. On the
   3154  * client, only the configured variant is enabled. */
   3155 OPENSSL_EXPORT void SSL_set_tls13_variant(SSL *ssl,
   3156                                           enum tls13_variant_t variant);
   3157 
   3158 /* SSL_MAX_CERT_LIST_DEFAULT is the default maximum length, in bytes, of a peer
   3159  * certificate chain. */
   3160 #define SSL_MAX_CERT_LIST_DEFAULT (1024 * 100)
   3161 
   3162 /* SSL_CTX_get_max_cert_list returns the maximum length, in bytes, of a peer
   3163  * certificate chain accepted by |ctx|. */
   3164 OPENSSL_EXPORT size_t SSL_CTX_get_max_cert_list(const SSL_CTX *ctx);
   3165 
   3166 /* SSL_CTX_set_max_cert_list sets the maximum length, in bytes, of a peer
   3167  * certificate chain to |max_cert_list|. This affects how much memory may be
   3168  * consumed during the handshake. */
   3169 OPENSSL_EXPORT void SSL_CTX_set_max_cert_list(SSL_CTX *ctx,
   3170                                               size_t max_cert_list);
   3171 
   3172 /* SSL_get_max_cert_list returns the maximum length, in bytes, of a peer
   3173  * certificate chain accepted by |ssl|. */
   3174 OPENSSL_EXPORT size_t SSL_get_max_cert_list(const SSL *ssl);
   3175 
   3176 /* SSL_set_max_cert_list sets the maximum length, in bytes, of a peer
   3177  * certificate chain to |max_cert_list|. This affects how much memory may be
   3178  * consumed during the handshake. */
   3179 OPENSSL_EXPORT void SSL_set_max_cert_list(SSL *ssl, size_t max_cert_list);
   3180 
   3181 /* SSL_CTX_set_max_send_fragment sets the maximum length, in bytes, of records
   3182  * sent by |ctx|. Beyond this length, handshake messages and application data
   3183  * will be split into multiple records. It returns one on success or zero on
   3184  * error. */
   3185 OPENSSL_EXPORT int SSL_CTX_set_max_send_fragment(SSL_CTX *ctx,
   3186                                                  size_t max_send_fragment);
   3187 
   3188 /* SSL_set_max_send_fragment sets the maximum length, in bytes, of records sent
   3189  * by |ssl|. Beyond this length, handshake messages and application data will
   3190  * be split into multiple records. It returns one on success or zero on
   3191  * error. */
   3192 OPENSSL_EXPORT int SSL_set_max_send_fragment(SSL *ssl,
   3193                                              size_t max_send_fragment);
   3194 
   3195 /* ssl_early_callback_ctx (aka |SSL_CLIENT_HELLO|) is passed to certain
   3196  * callbacks that are called very early on during the server handshake. At this
   3197  * point, much of the SSL* hasn't been filled out and only the ClientHello can
   3198  * be depended on. */
   3199 typedef struct ssl_early_callback_ctx {
   3200   SSL *ssl;
   3201   const uint8_t *client_hello;
   3202   size_t client_hello_len;
   3203   uint16_t version;
   3204   const uint8_t *random;
   3205   size_t random_len;
   3206   const uint8_t *session_id;
   3207   size_t session_id_len;
   3208   const uint8_t *cipher_suites;
   3209   size_t cipher_suites_len;
   3210   const uint8_t *compression_methods;
   3211   size_t compression_methods_len;
   3212   const uint8_t *extensions;
   3213   size_t extensions_len;
   3214 } SSL_CLIENT_HELLO;
   3215 
   3216 /* ssl_select_cert_result_t enumerates the possible results from selecting a
   3217  * certificate with |select_certificate_cb|. */
   3218 enum ssl_select_cert_result_t {
   3219   /* ssl_select_cert_success indicates that the certificate selection was
   3220    * successful. */
   3221   ssl_select_cert_success = 1,
   3222   /* ssl_select_cert_retry indicates that the operation could not be
   3223    * immediately completed and must be reattempted at a later point. */
   3224   ssl_select_cert_retry = 0,
   3225   /* ssl_select_cert_error indicates that a fatal error occured and the
   3226    * handshake should be terminated. */
   3227   ssl_select_cert_error = -1,
   3228 };
   3229 
   3230 /* SSL_early_callback_ctx_extension_get searches the extensions in
   3231  * |client_hello| for an extension of the given type. If not found, it returns
   3232  * zero. Otherwise it sets |out_data| to point to the extension contents (not
   3233  * including the type and length bytes), sets |out_len| to the length of the
   3234  * extension contents and returns one. */
   3235 OPENSSL_EXPORT int SSL_early_callback_ctx_extension_get(
   3236     const SSL_CLIENT_HELLO *client_hello, uint16_t extension_type,
   3237     const uint8_t **out_data, size_t *out_len);
   3238 
   3239 /* SSL_CTX_set_select_certificate_cb sets a callback that is called before most
   3240  * ClientHello processing and before the decision whether to resume a session
   3241  * is made. The callback may inspect the ClientHello and configure the
   3242  * connection. See |ssl_select_cert_result_t| for details of the return values.
   3243  *
   3244  * In the case that a retry is indicated, |SSL_get_error| will return
   3245  * |SSL_ERROR_PENDING_CERTIFICATE| and the caller should arrange for the
   3246  * high-level operation on |ssl| to be retried at a later time, which will
   3247  * result in another call to |cb|.
   3248  *
   3249  * Note: The |SSL_CLIENT_HELLO| is only valid for the duration of the callback
   3250  * and is not valid while the handshake is paused. */
   3251 OPENSSL_EXPORT void SSL_CTX_set_select_certificate_cb(
   3252     SSL_CTX *ctx,
   3253     enum ssl_select_cert_result_t (*cb)(const SSL_CLIENT_HELLO *));
   3254 
   3255 /* SSL_CTX_set_dos_protection_cb sets a callback that is called once the
   3256  * resumption decision for a ClientHello has been made. It can return one to
   3257  * allow the handshake to continue or zero to cause the handshake to abort. */
   3258 OPENSSL_EXPORT void SSL_CTX_set_dos_protection_cb(
   3259     SSL_CTX *ctx, int (*cb)(const SSL_CLIENT_HELLO *));
   3260 
   3261 /* SSL_ST_* are possible values for |SSL_state| and the bitmasks that make them
   3262  * up. */
   3263 #define SSL_ST_CONNECT 0x1000
   3264 #define SSL_ST_ACCEPT 0x2000
   3265 #define SSL_ST_MASK 0x0FFF
   3266 #define SSL_ST_INIT (SSL_ST_CONNECT | SSL_ST_ACCEPT)
   3267 #define SSL_ST_OK 0x03
   3268 #define SSL_ST_RENEGOTIATE (0x04 | SSL_ST_INIT)
   3269 #define SSL_ST_TLS13 (0x05 | SSL_ST_INIT)
   3270 
   3271 /* SSL_CB_* are possible values for the |type| parameter in the info
   3272  * callback and the bitmasks that make them up. */
   3273 #define SSL_CB_LOOP 0x01
   3274 #define SSL_CB_EXIT 0x02
   3275 #define SSL_CB_READ 0x04
   3276 #define SSL_CB_WRITE 0x08
   3277 #define SSL_CB_ALERT 0x4000
   3278 #define SSL_CB_READ_ALERT (SSL_CB_ALERT | SSL_CB_READ)
   3279 #define SSL_CB_WRITE_ALERT (SSL_CB_ALERT | SSL_CB_WRITE)
   3280 #define SSL_CB_ACCEPT_LOOP (SSL_ST_ACCEPT | SSL_CB_LOOP)
   3281 #define SSL_CB_ACCEPT_EXIT (SSL_ST_ACCEPT | SSL_CB_EXIT)
   3282 #define SSL_CB_CONNECT_LOOP (SSL_ST_CONNECT | SSL_CB_LOOP)
   3283 #define SSL_CB_CONNECT_EXIT (SSL_ST_CONNECT | SSL_CB_EXIT)
   3284 #define SSL_CB_HANDSHAKE_START 0x10
   3285 #define SSL_CB_HANDSHAKE_DONE 0x20
   3286 
   3287 /* SSL_CTX_set_info_callback configures a callback to be run when various
   3288  * events occur during a connection's lifetime. The |type| argument determines
   3289  * the type of event and the meaning of the |value| argument. Callbacks must
   3290  * ignore unexpected |type| values.
   3291  *
   3292  * |SSL_CB_READ_ALERT| is signaled for each alert received, warning or fatal.
   3293  * The |value| argument is a 16-bit value where the alert level (either
   3294  * |SSL3_AL_WARNING| or |SSL3_AL_FATAL|) is in the most-significant eight bits
   3295  * and the alert type (one of |SSL_AD_*|) is in the least-significant eight.
   3296  *
   3297  * |SSL_CB_WRITE_ALERT| is signaled for each alert sent. The |value| argument
   3298  * is constructed as with |SSL_CB_READ_ALERT|.
   3299  *
   3300  * |SSL_CB_HANDSHAKE_START| is signaled when a handshake begins. The |value|
   3301  * argument is always one.
   3302  *
   3303  * |SSL_CB_HANDSHAKE_DONE| is signaled when a handshake completes successfully.
   3304  * The |value| argument is always one. If a handshake False Starts, this event
   3305  * may be used to determine when the Finished message is received.
   3306  *
   3307  * The following event types expose implementation details of the handshake
   3308  * state machine. Consuming them is deprecated.
   3309  *
   3310  * |SSL_CB_ACCEPT_LOOP| (respectively, |SSL_CB_CONNECT_LOOP|) is signaled when
   3311  * a server (respectively, client) handshake progresses. The |value| argument
   3312  * is always one.
   3313  *
   3314  * |SSL_CB_ACCEPT_EXIT| (respectively, |SSL_CB_CONNECT_EXIT|) is signaled when
   3315  * a server (respectively, client) handshake completes, fails, or is paused.
   3316  * The |value| argument is one if the handshake succeeded and <= 0
   3317  * otherwise. */
   3318 OPENSSL_EXPORT void SSL_CTX_set_info_callback(
   3319     SSL_CTX *ctx, void (*cb)(const SSL *ssl, int type, int value));
   3320 
   3321 /* SSL_CTX_get_info_callback returns the callback set by
   3322  * |SSL_CTX_set_info_callback|. */
   3323 OPENSSL_EXPORT void (*SSL_CTX_get_info_callback(SSL_CTX *ctx))(const SSL *ssl,
   3324                                                                int type,
   3325                                                                int value);
   3326 
   3327 /* SSL_set_info_callback configures a callback to be run at various events
   3328  * during a connection's lifetime. See |SSL_CTX_set_info_callback|. */
   3329 OPENSSL_EXPORT void SSL_set_info_callback(
   3330     SSL *ssl, void (*cb)(const SSL *ssl, int type, int value));
   3331 
   3332 /* SSL_get_info_callback returns the callback set by |SSL_set_info_callback|. */
   3333 OPENSSL_EXPORT void (*SSL_get_info_callback(const SSL *ssl))(const SSL *ssl,
   3334                                                              int type,
   3335                                                              int value);
   3336 
   3337 /* SSL_state_string_long returns the current state of the handshake state
   3338  * machine as a string. This may be useful for debugging and logging. */
   3339 OPENSSL_EXPORT const char *SSL_state_string_long(const SSL *ssl);
   3340 
   3341 #define SSL_SENT_SHUTDOWN 1
   3342 #define SSL_RECEIVED_SHUTDOWN 2
   3343 
   3344 /* SSL_get_shutdown returns a bitmask with a subset of |SSL_SENT_SHUTDOWN| and
   3345  * |SSL_RECEIVED_SHUTDOWN| to query whether close_notify was sent or received,
   3346  * respectively. */
   3347 OPENSSL_EXPORT int SSL_get_shutdown(const SSL *ssl);
   3348 
   3349 /* SSL_get_peer_signature_algorithm returns the signature algorithm used by the
   3350  * peer. If not applicable, it returns zero. */
   3351 OPENSSL_EXPORT uint16_t SSL_get_peer_signature_algorithm(const SSL *ssl);
   3352 
   3353 /* SSL_get_client_random writes up to |max_out| bytes of the most recent
   3354  * handshake's client_random to |out| and returns the number of bytes written.
   3355  * If |max_out| is zero, it returns the size of the client_random. */
   3356 OPENSSL_EXPORT size_t SSL_get_client_random(const SSL *ssl, uint8_t *out,
   3357                                             size_t max_out);
   3358 
   3359 /* SSL_get_server_random writes up to |max_out| bytes of the most recent
   3360  * handshake's server_random to |out| and returns the number of bytes written.
   3361  * If |max_out| is zero, it returns the size of the server_random. */
   3362 OPENSSL_EXPORT size_t SSL_get_server_random(const SSL *ssl, uint8_t *out,
   3363                                             size_t max_out);
   3364 
   3365 /* SSL_get_pending_cipher returns the cipher suite for the current handshake or
   3366  * NULL if one has not been negotiated yet or there is no pending handshake. */
   3367 OPENSSL_EXPORT const SSL_CIPHER *SSL_get_pending_cipher(const SSL *ssl);
   3368 
   3369 /* SSL_set_retain_only_sha256_of_client_certs, on a server, sets whether only
   3370  * the SHA-256 hash of peer's certificate should be saved in memory and in the
   3371  * session. This can save memory, ticket size and session cache space. If
   3372  * enabled, |SSL_get_peer_certificate| will return NULL after the handshake
   3373  * completes. See the |peer_sha256| field of |SSL_SESSION| for the hash. */
   3374 OPENSSL_EXPORT void SSL_set_retain_only_sha256_of_client_certs(SSL *ssl,
   3375                                                                int enable);
   3376 
   3377 /* SSL_CTX_set_retain_only_sha256_of_client_certs, on a server, sets whether
   3378  * only the SHA-256 hash of peer's certificate should be saved in memory and in
   3379  * the session. This can save memory, ticket size and session cache space. If
   3380  * enabled, |SSL_get_peer_certificate| will return NULL after the handshake
   3381  * completes. See the |peer_sha256| field of |SSL_SESSION| for the hash. */
   3382 OPENSSL_EXPORT void SSL_CTX_set_retain_only_sha256_of_client_certs(SSL_CTX *ctx,
   3383                                                                    int enable);
   3384 
   3385 /* SSL_CTX_set_grease_enabled configures whether sockets on |ctx| should enable
   3386  * GREASE. See draft-davidben-tls-grease-01. */
   3387 OPENSSL_EXPORT void SSL_CTX_set_grease_enabled(SSL_CTX *ctx, int enabled);
   3388 
   3389 /* SSL_max_seal_overhead returns the maximum overhead, in bytes, of sealing a
   3390  * record with |ssl|. */
   3391 OPENSSL_EXPORT size_t SSL_max_seal_overhead(const SSL *ssl);
   3392 
   3393 /* SSL_get_ticket_age_skew returns the difference, in seconds, between the
   3394  * client-sent ticket age and the server-computed value in TLS 1.3 server
   3395  * connections which resumed a session. */
   3396 OPENSSL_EXPORT int32_t SSL_get_ticket_age_skew(const SSL *ssl);
   3397 
   3398 
   3399 /* Deprecated functions. */
   3400 
   3401 /* SSL_library_init calls |CRYPTO_library_init| and returns one. */
   3402 OPENSSL_EXPORT int SSL_library_init(void);
   3403 
   3404 /* SSL_CIPHER_description writes a description of |cipher| into |buf| and
   3405  * returns |buf|. If |buf| is NULL, it returns a newly allocated string, to be
   3406  * freed with |OPENSSL_free|, or NULL on error.
   3407  *
   3408  * The description includes a trailing newline and has the form:
   3409  * AES128-SHA              Kx=RSA      Au=RSA  Enc=AES(128)  Mac=SHA1
   3410  *
   3411  * Consider |SSL_CIPHER_standard_name| or |SSL_CIPHER_get_name| instead. */
   3412 OPENSSL_EXPORT const char *SSL_CIPHER_description(const SSL_CIPHER *cipher,
   3413                                                   char *buf, int len);
   3414 
   3415 /* SSL_CIPHER_get_version returns the string "TLSv1/SSLv3". */
   3416 OPENSSL_EXPORT const char *SSL_CIPHER_get_version(const SSL_CIPHER *cipher);
   3417 
   3418 /* SSL_CIPHER_get_rfc_name returns a newly-allocated string containing the
   3419  * result of |SSL_CIPHER_standard_name| or NULL on error. The caller is
   3420  * responsible for calling |OPENSSL_free| on the result.
   3421  *
   3422  * Use |SSL_CIPHER_standard_name| instead. */
   3423 OPENSSL_EXPORT char *SSL_CIPHER_get_rfc_name(const SSL_CIPHER *cipher);
   3424 
   3425 typedef void COMP_METHOD;
   3426 
   3427 /* SSL_COMP_get_compression_methods returns NULL. */
   3428 OPENSSL_EXPORT STACK_OF(SSL_COMP) *SSL_COMP_get_compression_methods(void);
   3429 
   3430 /* SSL_COMP_add_compression_method returns one. */
   3431 OPENSSL_EXPORT int SSL_COMP_add_compression_method(int id, COMP_METHOD *cm);
   3432 
   3433 /* SSL_COMP_get_name returns NULL. */
   3434 OPENSSL_EXPORT const char *SSL_COMP_get_name(const COMP_METHOD *comp);
   3435 
   3436 /* SSL_COMP_free_compression_methods does nothing. */
   3437 OPENSSL_EXPORT void SSL_COMP_free_compression_methods(void);
   3438 
   3439 /* SSLv23_method calls |TLS_method|. */
   3440 OPENSSL_EXPORT const SSL_METHOD *SSLv23_method(void);
   3441 
   3442 /* These version-specific methods behave exactly like |TLS_method| and
   3443  * |DTLS_method| except they also call |SSL_CTX_set_min_proto_version| and
   3444  * |SSL_CTX_set_max_proto_version| to lock connections to that protocol
   3445  * version. */
   3446 OPENSSL_EXPORT const SSL_METHOD *TLSv1_method(void);
   3447 OPENSSL_EXPORT const SSL_METHOD *TLSv1_1_method(void);
   3448 OPENSSL_EXPORT const SSL_METHOD *TLSv1_2_method(void);
   3449 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_method(void);
   3450 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_2_method(void);
   3451 
   3452 /* SSLv3_method returns an |SSL_METHOD| with no versions enabled. */
   3453 OPENSSL_EXPORT const SSL_METHOD *SSLv3_method(void);
   3454 
   3455 /* These client- and server-specific methods call their corresponding generic
   3456  * methods. */
   3457 OPENSSL_EXPORT const SSL_METHOD *TLS_server_method(void);
   3458 OPENSSL_EXPORT const SSL_METHOD *TLS_client_method(void);
   3459 OPENSSL_EXPORT const SSL_METHOD *SSLv23_server_method(void);
   3460 OPENSSL_EXPORT const SSL_METHOD *SSLv23_client_method(void);
   3461 OPENSSL_EXPORT const SSL_METHOD *SSLv3_server_method(void);
   3462 OPENSSL_EXPORT const SSL_METHOD *SSLv3_client_method(void);
   3463 OPENSSL_EXPORT const SSL_METHOD *TLSv1_server_method(void);
   3464 OPENSSL_EXPORT const SSL_METHOD *TLSv1_client_method(void);
   3465 OPENSSL_EXPORT const SSL_METHOD *TLSv1_1_server_method(void);
   3466 OPENSSL_EXPORT const SSL_METHOD *TLSv1_1_client_method(void);
   3467 OPENSSL_EXPORT const SSL_METHOD *TLSv1_2_server_method(void);
   3468 OPENSSL_EXPORT const SSL_METHOD *TLSv1_2_client_method(void);
   3469 OPENSSL_EXPORT const SSL_METHOD *DTLS_server_method(void);
   3470 OPENSSL_EXPORT const SSL_METHOD *DTLS_client_method(void);
   3471 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_server_method(void);
   3472 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_client_method(void);
   3473 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_2_server_method(void);
   3474 OPENSSL_EXPORT const SSL_METHOD *DTLSv1_2_client_method(void);
   3475 
   3476 /* SSL_clear resets |ssl| to allow another connection and returns one on success
   3477  * or zero on failure. It returns most configuration state but releases memory
   3478  * associated with the current connection.
   3479  *
   3480  * Free |ssl| and create a new one instead. */
   3481 OPENSSL_EXPORT int SSL_clear(SSL *ssl);
   3482 
   3483 /* SSL_CTX_set_tmp_rsa_callback does nothing. */
   3484 OPENSSL_EXPORT void SSL_CTX_set_tmp_rsa_callback(
   3485     SSL_CTX *ctx, RSA *(*cb)(SSL *ssl, int is_export, int keylength));
   3486 
   3487 /* SSL_set_tmp_rsa_callback does nothing. */
   3488 OPENSSL_EXPORT void SSL_set_tmp_rsa_callback(SSL *ssl,
   3489                                              RSA *(*cb)(SSL *ssl, int is_export,
   3490                                                         int keylength));
   3491 
   3492 /* SSL_CTX_sess_connect returns zero. */
   3493 OPENSSL_EXPORT int SSL_CTX_sess_connect(const SSL_CTX *ctx);
   3494 
   3495 /* SSL_CTX_sess_connect_good returns zero. */
   3496 OPENSSL_EXPORT int SSL_CTX_sess_connect_good(const SSL_CTX *ctx);
   3497 
   3498 /* SSL_CTX_sess_connect_renegotiate returns zero. */
   3499 OPENSSL_EXPORT int SSL_CTX_sess_connect_renegotiate(const SSL_CTX *ctx);
   3500 
   3501 /* SSL_CTX_sess_accept returns zero. */
   3502 OPENSSL_EXPORT int SSL_CTX_sess_accept(const SSL_CTX *ctx);
   3503 
   3504 /* SSL_CTX_sess_accept_renegotiate returns zero. */
   3505 OPENSSL_EXPORT int SSL_CTX_sess_accept_renegotiate(const SSL_CTX *ctx);
   3506 
   3507 /* SSL_CTX_sess_accept_good returns zero. */
   3508 OPENSSL_EXPORT int SSL_CTX_sess_accept_good(const SSL_CTX *ctx);
   3509 
   3510 /* SSL_CTX_sess_hits returns zero. */
   3511 OPENSSL_EXPORT int SSL_CTX_sess_hits(const SSL_CTX *ctx);
   3512 
   3513 /* SSL_CTX_sess_cb_hits returns zero. */
   3514 OPENSSL_EXPORT int SSL_CTX_sess_cb_hits(const SSL_CTX *ctx);
   3515 
   3516 /* SSL_CTX_sess_misses returns zero. */
   3517 OPENSSL_EXPORT int SSL_CTX_sess_misses(const SSL_CTX *ctx);
   3518 
   3519 /* SSL_CTX_sess_timeouts returns zero. */
   3520 OPENSSL_EXPORT int SSL_CTX_sess_timeouts(const SSL_CTX *ctx);
   3521 
   3522 /* SSL_CTX_sess_cache_full returns zero. */
   3523 OPENSSL_EXPORT int SSL_CTX_sess_cache_full(const SSL_CTX *ctx);
   3524 
   3525 /* SSL_cutthrough_complete calls |SSL_in_false_start|. */
   3526 OPENSSL_EXPORT int SSL_cutthrough_complete(const SSL *s);
   3527 
   3528 /* SSL_num_renegotiations calls |SSL_total_renegotiations|. */
   3529 OPENSSL_EXPORT int SSL_num_renegotiations(const SSL *ssl);
   3530 
   3531 /* SSL_CTX_need_tmp_RSA returns zero. */
   3532 OPENSSL_EXPORT int SSL_CTX_need_tmp_RSA(const SSL_CTX *ctx);
   3533 
   3534 /* SSL_need_tmp_RSA returns zero. */
   3535 OPENSSL_EXPORT int SSL_need_tmp_RSA(const SSL *ssl);
   3536 
   3537 /* SSL_CTX_set_tmp_rsa returns one. */
   3538 OPENSSL_EXPORT int SSL_CTX_set_tmp_rsa(SSL_CTX *ctx, const RSA *rsa);
   3539 
   3540 /* SSL_set_tmp_rsa returns one. */
   3541 OPENSSL_EXPORT int SSL_set_tmp_rsa(SSL *ssl, const RSA *rsa);
   3542 
   3543 /* SSL_CTX_get_read_ahead returns zero. */
   3544 OPENSSL_EXPORT int SSL_CTX_get_read_ahead(const SSL_CTX *ctx);
   3545 
   3546 /* SSL_CTX_set_read_ahead does nothing. */
   3547 OPENSSL_EXPORT void SSL_CTX_set_read_ahead(SSL_CTX *ctx, int yes);
   3548 
   3549 /* SSL_get_read_ahead returns zero. */
   3550 OPENSSL_EXPORT int SSL_get_read_ahead(const SSL *s);
   3551 
   3552 /* SSL_set_read_ahead does nothing. */
   3553 OPENSSL_EXPORT void SSL_set_read_ahead(SSL *s, int yes);
   3554 
   3555 /* SSL_renegotiate put an error on the error queue and returns zero. */
   3556 OPENSSL_EXPORT int SSL_renegotiate(SSL *ssl);
   3557 
   3558 /* SSL_set_state does nothing. */
   3559 OPENSSL_EXPORT void SSL_set_state(SSL *ssl, int state);
   3560 
   3561 /* SSL_get_shared_ciphers writes an empty string to |buf| and returns a
   3562  * pointer to |buf|, or NULL if |len| is less than or equal to zero. */
   3563 OPENSSL_EXPORT char *SSL_get_shared_ciphers(const SSL *ssl, char *buf, int len);
   3564 
   3565 /* SSL_MODE_HANDSHAKE_CUTTHROUGH is the same as SSL_MODE_ENABLE_FALSE_START. */
   3566 #define SSL_MODE_HANDSHAKE_CUTTHROUGH SSL_MODE_ENABLE_FALSE_START
   3567 
   3568 /* i2d_SSL_SESSION serializes |in| to the bytes pointed to by |*pp|. On success,
   3569  * it returns the number of bytes written and advances |*pp| by that many bytes.
   3570  * On failure, it returns -1. If |pp| is NULL, no bytes are written and only the
   3571  * length is returned.
   3572  *
   3573  * Use |SSL_SESSION_to_bytes| instead. */
   3574 OPENSSL_EXPORT int i2d_SSL_SESSION(SSL_SESSION *in, uint8_t **pp);
   3575 
   3576 /* d2i_SSL_SESSION parses a serialized session from the |length| bytes pointed
   3577  * to by |*pp|. It returns the new |SSL_SESSION| and advances |*pp| by the
   3578  * number of bytes consumed on success and NULL on failure. The caller takes
   3579  * ownership of the new session and must call |SSL_SESSION_free| when done.
   3580  *
   3581  * If |a| is non-NULL, |*a| is released and set the new |SSL_SESSION|.
   3582  *
   3583  * Use |SSL_SESSION_from_bytes| instead. */
   3584 OPENSSL_EXPORT SSL_SESSION *d2i_SSL_SESSION(SSL_SESSION **a, const uint8_t **pp,
   3585                                             long length);
   3586 
   3587 /* i2d_SSL_SESSION_bio serializes |session| and writes the result to |bio|. It
   3588  * returns the number of bytes written on success and <= 0 on error. */
   3589 OPENSSL_EXPORT int i2d_SSL_SESSION_bio(BIO *bio, const SSL_SESSION *session);
   3590 
   3591 /* d2i_SSL_SESSION_bio reads a serialized |SSL_SESSION| from |bio| and returns a
   3592  * newly-allocated |SSL_SESSION| or NULL on error. If |out| is not NULL, it also
   3593  * frees |*out| and sets |*out| to the new |SSL_SESSION|.  */
   3594 OPENSSL_EXPORT SSL_SESSION *d2i_SSL_SESSION_bio(BIO *bio, SSL_SESSION **out);
   3595 
   3596 /* ERR_load_SSL_strings does nothing. */
   3597 OPENSSL_EXPORT void ERR_load_SSL_strings(void);
   3598 
   3599 /* SSL_load_error_strings does nothing. */
   3600 OPENSSL_EXPORT void SSL_load_error_strings(void);
   3601 
   3602 /* SSL_CTX_set_tlsext_use_srtp calls |SSL_CTX_set_srtp_profiles|. It returns
   3603  * zero on success and one on failure.
   3604  *
   3605  * WARNING: this function is dangerous because it breaks the usual return value
   3606  * convention. Use |SSL_CTX_set_srtp_profiles| instead. */
   3607 OPENSSL_EXPORT int SSL_CTX_set_tlsext_use_srtp(SSL_CTX *ctx,
   3608                                                const char *profiles);
   3609 
   3610 /* SSL_set_tlsext_use_srtp calls |SSL_set_srtp_profiles|. It returns zero on
   3611  * success and one on failure.
   3612  *
   3613  * WARNING: this function is dangerous because it breaks the usual return value
   3614  * convention. Use |SSL_set_srtp_profiles| instead. */
   3615 OPENSSL_EXPORT int SSL_set_tlsext_use_srtp(SSL *ssl, const char *profiles);
   3616 
   3617 /* SSL_get_current_compression returns NULL. */
   3618 OPENSSL_EXPORT const COMP_METHOD *SSL_get_current_compression(SSL *s);
   3619 
   3620 /* SSL_get_current_expansion returns NULL. */
   3621 OPENSSL_EXPORT const COMP_METHOD *SSL_get_current_expansion(SSL *s);
   3622 
   3623 /* SSL_get_server_tmp_key returns zero. */
   3624 OPENSSL_EXPORT int *SSL_get_server_tmp_key(SSL *ssl, EVP_PKEY **out_key);
   3625 
   3626 /* SSL_CTX_set_tmp_dh returns 1. */
   3627 OPENSSL_EXPORT int SSL_CTX_set_tmp_dh(SSL_CTX *ctx, const DH *dh);
   3628 
   3629 /* SSL_set_tmp_dh returns 1. */
   3630 OPENSSL_EXPORT int SSL_set_tmp_dh(SSL *ssl, const DH *dh);
   3631 
   3632 /* SSL_CTX_set_tmp_dh_callback does nothing. */
   3633 OPENSSL_EXPORT void SSL_CTX_set_tmp_dh_callback(
   3634     SSL_CTX *ctx, DH *(*callback)(SSL *ssl, int is_export, int keylength));
   3635 
   3636 /* SSL_set_tmp_dh_callback does nothing. */
   3637 OPENSSL_EXPORT void SSL_set_tmp_dh_callback(SSL *ssl,
   3638                                             DH *(*dh)(SSL *ssl, int is_export,
   3639                                                       int keylength));
   3640 
   3641 
   3642 #define SSL_set_app_data(s, arg) (SSL_set_ex_data(s, 0, (char *)(arg)))
   3643 #define SSL_get_app_data(s) (SSL_get_ex_data(s, 0))
   3644 #define SSL_SESSION_set_app_data(s, a) \
   3645   (SSL_SESSION_set_ex_data(s, 0, (char *)(a)))
   3646 #define SSL_SESSION_get_app_data(s) (SSL_SESSION_get_ex_data(s, 0))
   3647 #define SSL_CTX_get_app_data(ctx) (SSL_CTX_get_ex_data(ctx, 0))
   3648 #define SSL_CTX_set_app_data(ctx, arg) \
   3649   (SSL_CTX_set_ex_data(ctx, 0, (char *)(arg)))
   3650 
   3651 #define OpenSSL_add_ssl_algorithms() SSL_library_init()
   3652 #define SSLeay_add_ssl_algorithms() SSL_library_init()
   3653 
   3654 #define SSL_get_cipher(ssl) SSL_CIPHER_get_name(SSL_get_current_cipher(ssl))
   3655 #define SSL_get_cipher_bits(ssl, out_alg_bits) \
   3656     SSL_CIPHER_get_bits(SSL_get_current_cipher(ssl), out_alg_bits)
   3657 #define SSL_get_cipher_version(ssl) \
   3658     SSL_CIPHER_get_version(SSL_get_current_cipher(ssl))
   3659 #define SSL_get_cipher_name(ssl) \
   3660     SSL_CIPHER_get_name(SSL_get_current_cipher(ssl))
   3661 #define SSL_get_time(session) SSL_SESSION_get_time(session)
   3662 #define SSL_set_time(session, time) SSL_SESSION_set_time((session), (time))
   3663 #define SSL_get_timeout(session) SSL_SESSION_get_timeout(session)
   3664 #define SSL_set_timeout(session, timeout) \
   3665     SSL_SESSION_set_timeout((session), (timeout))
   3666 
   3667 typedef struct ssl_comp_st SSL_COMP;
   3668 
   3669 struct ssl_comp_st {
   3670   int id;
   3671   const char *name;
   3672   char *method;
   3673 };
   3674 
   3675 DEFINE_STACK_OF(SSL_COMP)
   3676 
   3677 /* The following flags do nothing and are included only to make it easier to
   3678  * compile code with BoringSSL. */
   3679 #define SSL_MODE_AUTO_RETRY 0
   3680 #define SSL_MODE_RELEASE_BUFFERS 0
   3681 #define SSL_MODE_SEND_CLIENTHELLO_TIME 0
   3682 #define SSL_MODE_SEND_SERVERHELLO_TIME 0
   3683 #define SSL_OP_ALL 0
   3684 #define SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION 0
   3685 #define SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS 0
   3686 #define SSL_OP_EPHEMERAL_RSA 0
   3687 #define SSL_OP_LEGACY_SERVER_CONNECT 0
   3688 #define SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER 0
   3689 #define SSL_OP_MICROSOFT_SESS_ID_BUG 0
   3690 #define SSL_OP_MSIE_SSLV2_RSA_PADDING 0
   3691 #define SSL_OP_NETSCAPE_CA_DN_BUG 0
   3692 #define SSL_OP_NETSCAPE_CHALLENGE_BUG 0
   3693 #define SSL_OP_NETSCAPE_DEMO_CIPHER_CHANGE_BUG 0
   3694 #define SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG 0
   3695 #define SSL_OP_NO_COMPRESSION 0
   3696 #define SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION 0
   3697 #define SSL_OP_NO_SSLv2 0
   3698 #define SSL_OP_PKCS1_CHECK_1 0
   3699 #define SSL_OP_PKCS1_CHECK_2 0
   3700 #define SSL_OP_SINGLE_DH_USE 0
   3701 #define SSL_OP_SINGLE_ECDH_USE 0
   3702 #define SSL_OP_SSLEAY_080_CLIENT_DH_BUG 0
   3703 #define SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG 0
   3704 #define SSL_OP_TLS_BLOCK_PADDING_BUG 0
   3705 #define SSL_OP_TLS_D5_BUG 0
   3706 #define SSL_OP_TLS_ROLLBACK_BUG 0
   3707 #define SSL_VERIFY_CLIENT_ONCE 0
   3708 
   3709 /* SSL_cache_hit calls |SSL_session_reused|. */
   3710 OPENSSL_EXPORT int SSL_cache_hit(SSL *ssl);
   3711 
   3712 /* SSL_get_default_timeout returns |SSL_DEFAULT_SESSION_TIMEOUT|. */
   3713 OPENSSL_EXPORT long SSL_get_default_timeout(const SSL *ssl);
   3714 
   3715 /* SSL_get_version returns a string describing the TLS version used by |ssl|.
   3716  * For example, "TLSv1.2" or "SSLv3". */
   3717 OPENSSL_EXPORT const char *SSL_get_version(const SSL *ssl);
   3718 
   3719 /* SSL_get_cipher_list returns the name of the |n|th cipher in the output of
   3720  * |SSL_get_ciphers| or NULL if out of range. Use |SSL_get_ciphers| instead. */
   3721 OPENSSL_EXPORT const char *SSL_get_cipher_list(const SSL *ssl, int n);
   3722 
   3723 /* SSL_CTX_set_client_cert_cb sets a callback which is called on the client if
   3724  * the server requests a client certificate and none is configured. On success,
   3725  * the callback should return one and set |*out_x509| to |*out_pkey| to a leaf
   3726  * certificate and private key, respectively, passing ownership. It should
   3727  * return zero to send no certificate and -1 to fail or pause the handshake. If
   3728  * the handshake is paused, |SSL_get_error| will return
   3729  * |SSL_ERROR_WANT_X509_LOOKUP|.
   3730  *
   3731  * The callback may call |SSL_get0_certificate_types| and
   3732  * |SSL_get_client_CA_list| for information on the server's certificate request.
   3733  *
   3734  * Use |SSL_CTX_set_cert_cb| instead. Configuring intermediate certificates with
   3735  * this function is confusing. This callback may not be registered concurrently
   3736  * with |SSL_CTX_set_cert_cb| or |SSL_set_cert_cb|. */
   3737 OPENSSL_EXPORT void SSL_CTX_set_client_cert_cb(
   3738     SSL_CTX *ctx,
   3739     int (*client_cert_cb)(SSL *ssl, X509 **out_x509, EVP_PKEY **out_pkey));
   3740 
   3741 #define SSL_NOTHING 1
   3742 #define SSL_WRITING 2
   3743 #define SSL_READING 3
   3744 #define SSL_X509_LOOKUP 4
   3745 #define SSL_CHANNEL_ID_LOOKUP 5
   3746 #define SSL_PENDING_SESSION 7
   3747 #define SSL_CERTIFICATE_SELECTION_PENDING 8
   3748 #define SSL_PRIVATE_KEY_OPERATION 9
   3749 #define SSL_PENDING_TICKET 10
   3750 #define SSL_EARLY_DATA_REJECTED 11
   3751 
   3752 /* SSL_want returns one of the above values to determine what the most recent
   3753  * operation on |ssl| was blocked on. Use |SSL_get_error| instead. */
   3754 OPENSSL_EXPORT int SSL_want(const SSL *ssl);
   3755 
   3756 #define SSL_want_read(ssl) (SSL_want(ssl) == SSL_READING)
   3757 #define SSL_want_write(ssl) (SSL_want(ssl) == SSL_WRITING)
   3758 
   3759  /* SSL_get_finished writes up to |count| bytes of the Finished message sent by
   3760   * |ssl| to |buf|. It returns the total untruncated length or zero if none has
   3761   * been sent yet. At SSL 3.0 or TLS 1.3 and later, it returns zero.
   3762   *
   3763   * Use |SSL_get_tls_unique| instead. */
   3764 OPENSSL_EXPORT size_t SSL_get_finished(const SSL *ssl, void *buf, size_t count);
   3765 
   3766  /* SSL_get_peer_finished writes up to |count| bytes of the Finished message
   3767   * received from |ssl|'s peer to |buf|. It returns the total untruncated length
   3768   * or zero if none has been received yet. At SSL 3.0 or TLS 1.3 and later, it
   3769   * returns zero.
   3770   *
   3771   * Use |SSL_get_tls_unique| instead. */
   3772 OPENSSL_EXPORT size_t SSL_get_peer_finished(const SSL *ssl, void *buf,
   3773                                             size_t count);
   3774 
   3775 /* SSL_alert_type_string returns "!". Use |SSL_alert_type_string_long|
   3776  * instead. */
   3777 OPENSSL_EXPORT const char *SSL_alert_type_string(int value);
   3778 
   3779 /* SSL_alert_desc_string returns "!!". Use |SSL_alert_desc_string_long|
   3780  * instead. */
   3781 OPENSSL_EXPORT const char *SSL_alert_desc_string(int value);
   3782 
   3783 /* SSL_TXT_* expand to strings. */
   3784 #define SSL_TXT_MEDIUM "MEDIUM"
   3785 #define SSL_TXT_HIGH "HIGH"
   3786 #define SSL_TXT_FIPS "FIPS"
   3787 #define SSL_TXT_kRSA "kRSA"
   3788 #define SSL_TXT_kDHE "kDHE"
   3789 #define SSL_TXT_kEDH "kEDH"
   3790 #define SSL_TXT_kECDHE "kECDHE"
   3791 #define SSL_TXT_kEECDH "kEECDH"
   3792 #define SSL_TXT_kPSK "kPSK"
   3793 #define SSL_TXT_aRSA "aRSA"
   3794 #define SSL_TXT_aECDSA "aECDSA"
   3795 #define SSL_TXT_aPSK "aPSK"
   3796 #define SSL_TXT_DH "DH"
   3797 #define SSL_TXT_DHE "DHE"
   3798 #define SSL_TXT_EDH "EDH"
   3799 #define SSL_TXT_RSA "RSA"
   3800 #define SSL_TXT_ECDH "ECDH"
   3801 #define SSL_TXT_ECDHE "ECDHE"
   3802 #define SSL_TXT_EECDH "EECDH"
   3803 #define SSL_TXT_ECDSA "ECDSA"
   3804 #define SSL_TXT_PSK "PSK"
   3805 #define SSL_TXT_3DES "3DES"
   3806 #define SSL_TXT_RC4 "RC4"
   3807 #define SSL_TXT_AES128 "AES128"
   3808 #define SSL_TXT_AES256 "AES256"
   3809 #define SSL_TXT_AES "AES"
   3810 #define SSL_TXT_AES_GCM "AESGCM"
   3811 #define SSL_TXT_CHACHA20 "CHACHA20"
   3812 #define SSL_TXT_MD5 "MD5"
   3813 #define SSL_TXT_SHA1 "SHA1"
   3814 #define SSL_TXT_SHA "SHA"
   3815 #define SSL_TXT_SHA256 "SHA256"
   3816 #define SSL_TXT_SHA384 "SHA384"
   3817 #define SSL_TXT_SSLV3 "SSLv3"
   3818 #define SSL_TXT_TLSV1 "TLSv1"
   3819 #define SSL_TXT_TLSV1_1 "TLSv1.1"
   3820 #define SSL_TXT_TLSV1_2 "TLSv1.2"
   3821 #define SSL_TXT_TLSV1_3 "TLSv1.3"
   3822 #define SSL_TXT_ALL "ALL"
   3823 #define SSL_TXT_CMPDEF "COMPLEMENTOFDEFAULT"
   3824 
   3825 typedef struct ssl_conf_ctx_st SSL_CONF_CTX;
   3826 
   3827 /* SSL_state returns |SSL_ST_INIT| if a handshake is in progress and |SSL_ST_OK|
   3828  * otherwise.
   3829  *
   3830  * Use |SSL_is_init| instead. */
   3831 OPENSSL_EXPORT int SSL_state(const SSL *ssl);
   3832 
   3833 #define SSL_get_state(ssl) SSL_state(ssl)
   3834 
   3835 /* SSL_state_string returns the current state of the handshake state machine as
   3836  * a six-letter string. Use |SSL_state_string_long| for a more intelligible
   3837  * string. */
   3838 OPENSSL_EXPORT const char *SSL_state_string(const SSL *ssl);
   3839 
   3840 /* SSL_set_shutdown causes |ssl| to behave as if the shutdown bitmask (see
   3841  * |SSL_get_shutdown|) were |mode|. This may be used to skip sending or
   3842  * receiving close_notify in |SSL_shutdown| by causing the implementation to
   3843  * believe the events already happened.
   3844  *
   3845  * It is an error to use |SSL_set_shutdown| to unset a bit that has already been
   3846  * set. Doing so will trigger an |assert| in debug builds and otherwise be
   3847  * ignored.
   3848  *
   3849  * Use |SSL_CTX_set_quiet_shutdown| instead. */
   3850 OPENSSL_EXPORT void SSL_set_shutdown(SSL *ssl, int mode);
   3851 
   3852 /* SSL_CTX_set_tmp_ecdh calls |SSL_CTX_set1_curves| with a one-element list
   3853  * containing |ec_key|'s curve. */
   3854 OPENSSL_EXPORT int SSL_CTX_set_tmp_ecdh(SSL_CTX *ctx, const EC_KEY *ec_key);
   3855 
   3856 /* SSL_set_tmp_ecdh calls |SSL_set1_curves| with a one-element list containing
   3857  * |ec_key|'s curve. */
   3858 OPENSSL_EXPORT int SSL_set_tmp_ecdh(SSL *ssl, const EC_KEY *ec_key);
   3859 
   3860 /* SSL_add_dir_cert_subjects_to_stack lists files in directory |dir|. It calls
   3861  * |SSL_add_file_cert_subjects_to_stack| on each file and returns one on success
   3862  * or zero on error. This function is only available from the libdecrepit
   3863  * library. */
   3864 OPENSSL_EXPORT int SSL_add_dir_cert_subjects_to_stack(STACK_OF(X509_NAME) *out,
   3865                                                       const char *dir);
   3866 
   3867 /* SSL_set_private_key_digest_prefs copies |num_digests| NIDs from |digest_nids|
   3868  * into |ssl|. These digests will be used, in decreasing order of preference,
   3869  * when signing with |ssl|'s private key. It returns one on success and zero on
   3870  * error.
   3871  *
   3872  * Use |SSL_set_signing_algorithm_prefs| instead.
   3873  *
   3874  * TODO(davidben): Remove this API when callers have been updated. */
   3875 OPENSSL_EXPORT int SSL_set_private_key_digest_prefs(SSL *ssl,
   3876                                                     const int *digest_nids,
   3877                                                     size_t num_digests);
   3878 
   3879 /* SSL_set_verify_result calls |abort| unless |result| is |X509_V_OK|.
   3880  *
   3881  * TODO(davidben): Remove this function once it has been removed from
   3882  * netty-tcnative. */
   3883 OPENSSL_EXPORT void SSL_set_verify_result(SSL *ssl, long result);
   3884 
   3885 /* SSL_CTX_enable_tls_channel_id calls |SSL_CTX_set_tls_channel_id_enabled|. */
   3886 OPENSSL_EXPORT int SSL_CTX_enable_tls_channel_id(SSL_CTX *ctx);
   3887 
   3888 /* SSL_enable_tls_channel_id calls |SSL_set_tls_channel_id_enabled|. */
   3889 OPENSSL_EXPORT int SSL_enable_tls_channel_id(SSL *ssl);
   3890 
   3891 /* BIO_f_ssl returns a |BIO_METHOD| that can wrap an |SSL*| in a |BIO*|. Note
   3892  * that this has quite different behaviour from the version in OpenSSL (notably
   3893  * that it doesn't try to auto renegotiate).
   3894  *
   3895  * IMPORTANT: if you are not curl, don't use this. */
   3896 OPENSSL_EXPORT const BIO_METHOD *BIO_f_ssl(void);
   3897 
   3898 /* BIO_set_ssl sets |ssl| as the underlying connection for |bio|, which must
   3899  * have been created using |BIO_f_ssl|. If |take_owership| is true, |bio| will
   3900  * call |SSL_free| on |ssl| when closed. It returns one on success or something
   3901  * other than one on error. */
   3902 OPENSSL_EXPORT long BIO_set_ssl(BIO *bio, SSL *ssl, int take_owership);
   3903 
   3904 /* SSL_CTX_set_ecdh_auto returns one. */
   3905 #define SSL_CTX_set_ecdh_auto(ctx, onoff) 1
   3906 
   3907 /* SSL_set_ecdh_auto returns one. */
   3908 #define SSL_set_ecdh_auto(ssl, onoff) 1
   3909 
   3910 /* SSL_get_session returns a non-owning pointer to |ssl|'s session. For
   3911  * historical reasons, which session it returns depends on |ssl|'s state.
   3912  *
   3913  * Prior to the start of the initial handshake, it returns the session the
   3914  * caller set with |SSL_set_session|. After the initial handshake has finished
   3915  * and if no additional handshakes are in progress, it returns the currently
   3916  * active session. Its behavior is undefined while a handshake is in progress.
   3917  *
   3918  * If trying to add new sessions to an external session cache, use
   3919  * |SSL_CTX_sess_set_new_cb| instead. In particular, using the callback is
   3920  * required as of TLS 1.3. For compatibility, this function will return an
   3921  * unresumable session which may be cached, but will never be resumed.
   3922  *
   3923  * If querying properties of the connection, use APIs on the |SSL| object. */
   3924 OPENSSL_EXPORT SSL_SESSION *SSL_get_session(const SSL *ssl);
   3925 
   3926 /* SSL_get0_session is an alias for |SSL_get_session|. */
   3927 #define SSL_get0_session SSL_get_session
   3928 
   3929 /* SSL_get1_session acts like |SSL_get_session| but returns a new reference to
   3930  * the session. */
   3931 OPENSSL_EXPORT SSL_SESSION *SSL_get1_session(SSL *ssl);
   3932 
   3933 
   3934 /* Private structures.
   3935  *
   3936  * This structures are exposed for historical reasons, but access to them is
   3937  * deprecated. */
   3938 
   3939 typedef struct ssl_protocol_method_st SSL_PROTOCOL_METHOD;
   3940 typedef struct ssl_x509_method_st SSL_X509_METHOD;
   3941 
   3942 struct ssl_cipher_st {
   3943   /* name is the OpenSSL name for the cipher. */
   3944   const char *name;
   3945   /* standard_name is the IETF name for the cipher. */
   3946   const char *standard_name;
   3947   /* id is the cipher suite value bitwise OR-d with 0x03000000. */
   3948   uint32_t id;
   3949 
   3950   /* algorithm_* are internal fields. See ssl/internal.h for their values. */
   3951   uint32_t algorithm_mkey;
   3952   uint32_t algorithm_auth;
   3953   uint32_t algorithm_enc;
   3954   uint32_t algorithm_mac;
   3955   uint32_t algorithm_prf;
   3956 };
   3957 
   3958 #define SSL_MAX_SSL_SESSION_ID_LENGTH 32
   3959 #define SSL_MAX_SID_CTX_LENGTH 32
   3960 #define SSL_MAX_MASTER_KEY_LENGTH 48
   3961 
   3962 struct ssl_session_st {
   3963   CRYPTO_refcount_t references;
   3964   int ssl_version; /* what ssl version session info is being kept in here? */
   3965 
   3966   /* group_id is the ID of the ECDH group used to establish this session or zero
   3967    * if not applicable or unknown. */
   3968   uint16_t group_id;
   3969 
   3970   /* peer_signature_algorithm is the signature algorithm used to authenticate
   3971    * the peer, or zero if not applicable or unknown. */
   3972   uint16_t peer_signature_algorithm;
   3973 
   3974   /* master_key, in TLS 1.2 and below, is the master secret associated with the
   3975    * session. In TLS 1.3 and up, it is the resumption secret. */
   3976   int master_key_length;
   3977   uint8_t master_key[SSL_MAX_MASTER_KEY_LENGTH];
   3978 
   3979   /* session_id - valid? */
   3980   unsigned int session_id_length;
   3981   uint8_t session_id[SSL_MAX_SSL_SESSION_ID_LENGTH];
   3982   /* this is used to determine whether the session is being reused in
   3983    * the appropriate context. It is up to the application to set this,
   3984    * via SSL_new */
   3985   uint8_t sid_ctx_length;
   3986   uint8_t sid_ctx[SSL_MAX_SID_CTX_LENGTH];
   3987 
   3988   char *psk_identity;
   3989 
   3990   /* certs contains the certificate chain from the peer, starting with the leaf
   3991    * certificate. */
   3992   STACK_OF(CRYPTO_BUFFER) *certs;
   3993 
   3994   const SSL_X509_METHOD *x509_method;
   3995 
   3996   /* x509_peer is the peer's certificate. */
   3997   X509 *x509_peer;
   3998 
   3999   /* x509_chain is the certificate chain sent by the peer. NOTE: for historical
   4000    * reasons, when a client (so the peer is a server), the chain includes
   4001    * |peer|, but when a server it does not. */
   4002   STACK_OF(X509) *x509_chain;
   4003 
   4004   /* x509_chain_without_leaf is a lazily constructed copy of |x509_chain| that
   4005    * omits the leaf certificate. This exists because OpenSSL, historically,
   4006    * didn't include the leaf certificate in the chain for a server, but did for
   4007    * a client. The |x509_chain| always includes it and, if an API call requires
   4008    * a chain without, it is stored here. */
   4009   STACK_OF(X509) *x509_chain_without_leaf;
   4010 
   4011   /* verify_result is the result of certificate verification in the case of
   4012    * non-fatal certificate errors. */
   4013   long verify_result;
   4014 
   4015   /* timeout is the lifetime of the session in seconds, measured from |time|.
   4016    * This is renewable up to |auth_timeout|. */
   4017   uint32_t timeout;
   4018 
   4019   /* auth_timeout is the non-renewable lifetime of the session in seconds,
   4020    * measured from |time|. */
   4021   uint32_t auth_timeout;
   4022 
   4023   /* time is the time the session was issued, measured in seconds from the UNIX
   4024    * epoch. */
   4025   uint64_t time;
   4026 
   4027   const SSL_CIPHER *cipher;
   4028 
   4029   CRYPTO_EX_DATA ex_data; /* application specific data */
   4030 
   4031   /* These are used to make removal of session-ids more efficient and to
   4032    * implement a maximum cache size. */
   4033   SSL_SESSION *prev, *next;
   4034   char *tlsext_hostname;
   4035 
   4036   /* RFC4507 info */
   4037   uint8_t *tlsext_tick;               /* Session ticket */
   4038   size_t tlsext_ticklen;              /* Session ticket length */
   4039 
   4040   size_t tlsext_signed_cert_timestamp_list_length;
   4041   uint8_t *tlsext_signed_cert_timestamp_list; /* Server's list. */
   4042 
   4043   /* The OCSP response that came with the session. */
   4044   size_t ocsp_response_length;
   4045   uint8_t *ocsp_response;
   4046 
   4047   /* peer_sha256 contains the SHA-256 hash of the peer's certificate if
   4048    * |peer_sha256_valid| is true. */
   4049   uint8_t peer_sha256[SHA256_DIGEST_LENGTH];
   4050 
   4051   /* original_handshake_hash contains the handshake hash (either SHA-1+MD5 or
   4052    * SHA-2, depending on TLS version) for the original, full handshake that
   4053    * created a session. This is used by Channel IDs during resumption. */
   4054   uint8_t original_handshake_hash[EVP_MAX_MD_SIZE];
   4055   uint8_t original_handshake_hash_len;
   4056 
   4057   uint32_t tlsext_tick_lifetime_hint; /* Session lifetime hint in seconds */
   4058 
   4059   uint32_t ticket_age_add;
   4060 
   4061   /* ticket_max_early_data is the maximum amount of data allowed to be sent as
   4062    * early data. If zero, 0-RTT is disallowed. */
   4063   uint32_t ticket_max_early_data;
   4064 
   4065   /* early_alpn is the ALPN protocol from the initial handshake. This is only
   4066    * stored for TLS 1.3 and above in order to enforce ALPN matching for 0-RTT
   4067    * resumptions. */
   4068   uint8_t *early_alpn;
   4069   size_t early_alpn_len;
   4070 
   4071   /* extended_master_secret is true if the master secret in this session was
   4072    * generated using EMS and thus isn't vulnerable to the Triple Handshake
   4073    * attack. */
   4074   unsigned extended_master_secret:1;
   4075 
   4076   /* peer_sha256_valid is non-zero if |peer_sha256| is valid. */
   4077   unsigned peer_sha256_valid:1; /* Non-zero if peer_sha256 is valid */
   4078 
   4079   /* not_resumable is used to indicate that session resumption is disallowed. */
   4080   unsigned not_resumable:1;
   4081 
   4082   /* ticket_age_add_valid is non-zero if |ticket_age_add| is valid. */
   4083   unsigned ticket_age_add_valid:1;
   4084 
   4085   /* is_server is true if this session was created by a server. */
   4086   unsigned is_server:1;
   4087 };
   4088 
   4089 /* ssl_cipher_preference_list_st contains a list of SSL_CIPHERs with
   4090  * equal-preference groups. For TLS clients, the groups are moot because the
   4091  * server picks the cipher and groups cannot be expressed on the wire. However,
   4092  * for servers, the equal-preference groups allow the client's preferences to
   4093  * be partially respected. (This only has an effect with
   4094  * SSL_OP_CIPHER_SERVER_PREFERENCE).
   4095  *
   4096  * The equal-preference groups are expressed by grouping SSL_CIPHERs together.
   4097  * All elements of a group have the same priority: no ordering is expressed
   4098  * within a group.
   4099  *
   4100  * The values in |ciphers| are in one-to-one correspondence with
   4101  * |in_group_flags|. (That is, sk_SSL_CIPHER_num(ciphers) is the number of
   4102  * bytes in |in_group_flags|.) The bytes in |in_group_flags| are either 1, to
   4103  * indicate that the corresponding SSL_CIPHER is not the last element of a
   4104  * group, or 0 to indicate that it is.
   4105  *
   4106  * For example, if |in_group_flags| contains all zeros then that indicates a
   4107  * traditional, fully-ordered preference. Every SSL_CIPHER is the last element
   4108  * of the group (i.e. they are all in a one-element group).
   4109  *
   4110  * For a more complex example, consider:
   4111  *   ciphers:        A  B  C  D  E  F
   4112  *   in_group_flags: 1  1  0  0  1  0
   4113  *
   4114  * That would express the following, order:
   4115  *
   4116  *    A         E
   4117  *    B -> D -> F
   4118  *    C
   4119  */
   4120 struct ssl_cipher_preference_list_st {
   4121   STACK_OF(SSL_CIPHER) *ciphers;
   4122   uint8_t *in_group_flags;
   4123 };
   4124 
   4125 DECLARE_STACK_OF(SSL_CUSTOM_EXTENSION)
   4126 
   4127 /* ssl_ctx_st (aka |SSL_CTX|) contains configuration common to several SSL
   4128  * connections. */
   4129 struct ssl_ctx_st {
   4130   const SSL_PROTOCOL_METHOD *method;
   4131   const SSL_X509_METHOD *x509_method;
   4132 
   4133   /* lock is used to protect various operations on this object. */
   4134   CRYPTO_MUTEX lock;
   4135 
   4136   /* conf_max_version is the maximum acceptable protocol version configured by
   4137    * |SSL_CTX_set_max_proto_version|. Note this version is normalized in DTLS
   4138    * and is further constrainted by |SSL_OP_NO_*|. */
   4139   uint16_t conf_max_version;
   4140 
   4141   /* conf_min_version is the minimum acceptable protocol version configured by
   4142    * |SSL_CTX_set_min_proto_version|. Note this version is normalized in DTLS
   4143    * and is further constrainted by |SSL_OP_NO_*|. */
   4144   uint16_t conf_min_version;
   4145 
   4146   /* tls13_variant is the variant of TLS 1.3 we are using for this
   4147    * configuration. */
   4148   enum tls13_variant_t tls13_variant;
   4149 
   4150   struct ssl_cipher_preference_list_st *cipher_list;
   4151 
   4152   X509_STORE *cert_store;
   4153   LHASH_OF(SSL_SESSION) *sessions;
   4154   /* Most session-ids that will be cached, default is
   4155    * SSL_SESSION_CACHE_MAX_SIZE_DEFAULT. 0 is unlimited. */
   4156   unsigned long session_cache_size;
   4157   SSL_SESSION *session_cache_head;
   4158   SSL_SESSION *session_cache_tail;
   4159 
   4160   /* handshakes_since_cache_flush is the number of successful handshakes since
   4161    * the last cache flush. */
   4162   int handshakes_since_cache_flush;
   4163 
   4164   /* This can have one of 2 values, ored together,
   4165    * SSL_SESS_CACHE_CLIENT,
   4166    * SSL_SESS_CACHE_SERVER,
   4167    * Default is SSL_SESSION_CACHE_SERVER, which means only
   4168    * SSL_accept which cache SSL_SESSIONS. */
   4169   int session_cache_mode;
   4170 
   4171   /* session_timeout is the default lifetime for new sessions in TLS 1.2 and
   4172    * earlier, in seconds. */
   4173   uint32_t session_timeout;
   4174 
   4175   /* session_psk_dhe_timeout is the default lifetime for new sessions in TLS
   4176    * 1.3, in seconds. */
   4177   uint32_t session_psk_dhe_timeout;
   4178 
   4179   /* If this callback is not null, it will be called each time a session id is
   4180    * added to the cache.  If this function returns 1, it means that the
   4181    * callback will do a SSL_SESSION_free() when it has finished using it.
   4182    * Otherwise, on 0, it means the callback has finished with it. If
   4183    * remove_session_cb is not null, it will be called when a session-id is
   4184    * removed from the cache.  After the call, OpenSSL will SSL_SESSION_free()
   4185    * it. */
   4186   int (*new_session_cb)(SSL *ssl, SSL_SESSION *sess);
   4187   void (*remove_session_cb)(SSL_CTX *ctx, SSL_SESSION *sess);
   4188   SSL_SESSION *(*get_session_cb)(SSL *ssl, uint8_t *data, int len,
   4189                                  int *copy);
   4190 
   4191   CRYPTO_refcount_t references;
   4192 
   4193   /* if defined, these override the X509_verify_cert() calls */
   4194   int (*app_verify_callback)(X509_STORE_CTX *store_ctx, void *arg);
   4195   void *app_verify_arg;
   4196 
   4197   /* Default password callback. */
   4198   pem_password_cb *default_passwd_callback;
   4199 
   4200   /* Default password callback user data. */
   4201   void *default_passwd_callback_userdata;
   4202 
   4203   /* get client cert callback */
   4204   int (*client_cert_cb)(SSL *ssl, X509 **out_x509, EVP_PKEY **out_pkey);
   4205 
   4206   /* get channel id callback */
   4207   void (*channel_id_cb)(SSL *ssl, EVP_PKEY **out_pkey);
   4208 
   4209   CRYPTO_EX_DATA ex_data;
   4210 
   4211   /* custom_*_extensions stores any callback sets for custom extensions. Note
   4212    * that these pointers will be NULL if the stack would otherwise be empty. */
   4213   STACK_OF(SSL_CUSTOM_EXTENSION) *client_custom_extensions;
   4214   STACK_OF(SSL_CUSTOM_EXTENSION) *server_custom_extensions;
   4215 
   4216   /* Default values used when no per-SSL value is defined follow */
   4217 
   4218   void (*info_callback)(const SSL *ssl, int type, int value);
   4219 
   4220   /* what we put in client cert requests */
   4221   STACK_OF(CRYPTO_BUFFER) *client_CA;
   4222 
   4223   /* cached_x509_client_CA is a cache of parsed versions of the elements of
   4224    * |client_CA|. */
   4225   STACK_OF(X509_NAME) *cached_x509_client_CA;
   4226 
   4227 
   4228   /* Default values to use in SSL structures follow (these are copied by
   4229    * SSL_new) */
   4230 
   4231   uint32_t options;
   4232   uint32_t mode;
   4233   uint32_t max_cert_list;
   4234 
   4235   struct cert_st /* CERT */ *cert;
   4236 
   4237   /* callback that allows applications to peek at protocol messages */
   4238   void (*msg_callback)(int write_p, int version, int content_type,
   4239                        const void *buf, size_t len, SSL *ssl, void *arg);
   4240   void *msg_callback_arg;
   4241 
   4242   int verify_mode;
   4243   int (*default_verify_callback)(
   4244       int ok, X509_STORE_CTX *ctx); /* called 'verify_callback' in the SSL */
   4245 
   4246   X509_VERIFY_PARAM *param;
   4247 
   4248   /* select_certificate_cb is called before most ClientHello processing and
   4249    * before the decision whether to resume a session is made. See
   4250    * |ssl_select_cert_result_t| for details of the return values. */
   4251   enum ssl_select_cert_result_t (*select_certificate_cb)(
   4252       const SSL_CLIENT_HELLO *);
   4253 
   4254   /* dos_protection_cb is called once the resumption decision for a ClientHello
   4255    * has been made. It returns one to continue the handshake or zero to
   4256    * abort. */
   4257   int (*dos_protection_cb) (const SSL_CLIENT_HELLO *);
   4258 
   4259   /* Maximum amount of data to send in one fragment. actual record size can be
   4260    * more than this due to padding and MAC overheads. */
   4261   uint16_t max_send_fragment;
   4262 
   4263   /* TLS extensions servername callback */
   4264   int (*tlsext_servername_callback)(SSL *, int *, void *);
   4265   void *tlsext_servername_arg;
   4266   /* RFC 4507 session ticket keys */
   4267   uint8_t tlsext_tick_key_name[SSL_TICKET_KEY_NAME_LEN];
   4268   uint8_t tlsext_tick_hmac_key[16];
   4269   uint8_t tlsext_tick_aes_key[16];
   4270   /* Callback to support customisation of ticket key setting */
   4271   int (*tlsext_ticket_key_cb)(SSL *ssl, uint8_t *name, uint8_t *iv,
   4272                               EVP_CIPHER_CTX *ectx, HMAC_CTX *hctx, int enc);
   4273 
   4274   /* Server-only: psk_identity_hint is the default identity hint to send in
   4275    * PSK-based key exchanges. */
   4276   char *psk_identity_hint;
   4277 
   4278   unsigned int (*psk_client_callback)(SSL *ssl, const char *hint,
   4279                                       char *identity,
   4280                                       unsigned int max_identity_len,
   4281                                       uint8_t *psk, unsigned int max_psk_len);
   4282   unsigned int (*psk_server_callback)(SSL *ssl, const char *identity,
   4283                                       uint8_t *psk, unsigned int max_psk_len);
   4284 
   4285 
   4286   /* retain_only_sha256_of_client_certs is true if we should compute the SHA256
   4287    * hash of the peer's certificate and then discard it to save memory and
   4288    * session space. Only effective on the server side. */
   4289   char retain_only_sha256_of_client_certs;
   4290 
   4291   /* Next protocol negotiation information */
   4292   /* (for experimental NPN extension). */
   4293 
   4294   /* For a server, this contains a callback function by which the set of
   4295    * advertised protocols can be provided. */
   4296   int (*next_protos_advertised_cb)(SSL *ssl, const uint8_t **out,
   4297                                    unsigned *out_len, void *arg);
   4298   void *next_protos_advertised_cb_arg;
   4299   /* For a client, this contains a callback function that selects the
   4300    * next protocol from the list provided by the server. */
   4301   int (*next_proto_select_cb)(SSL *ssl, uint8_t **out, uint8_t *out_len,
   4302                               const uint8_t *in, unsigned in_len, void *arg);
   4303   void *next_proto_select_cb_arg;
   4304 
   4305   /* ALPN information
   4306    * (we are in the process of transitioning from NPN to ALPN.) */
   4307 
   4308   /* For a server, this contains a callback function that allows the
   4309    * server to select the protocol for the connection.
   4310    *   out: on successful return, this must point to the raw protocol
   4311    *        name (without the length prefix).
   4312    *   outlen: on successful return, this contains the length of |*out|.
   4313    *   in: points to the client's list of supported protocols in
   4314    *       wire-format.
   4315    *   inlen: the length of |in|. */
   4316   int (*alpn_select_cb)(SSL *s, const uint8_t **out, uint8_t *out_len,
   4317                         const uint8_t *in, unsigned in_len, void *arg);
   4318   void *alpn_select_cb_arg;
   4319 
   4320   /* For a client, this contains the list of supported protocols in wire
   4321    * format. */
   4322   uint8_t *alpn_client_proto_list;
   4323   unsigned alpn_client_proto_list_len;
   4324 
   4325   /* SRTP profiles we are willing to do from RFC 5764 */
   4326   STACK_OF(SRTP_PROTECTION_PROFILE) *srtp_profiles;
   4327 
   4328   /* Supported group values inherited by SSL structure */
   4329   size_t supported_group_list_len;
   4330   uint16_t *supported_group_list;
   4331 
   4332   /* The client's Channel ID private key. */
   4333   EVP_PKEY *tlsext_channel_id_private;
   4334 
   4335   /* keylog_callback, if not NULL, is the key logging callback. See
   4336    * |SSL_CTX_set_keylog_callback|. */
   4337   void (*keylog_callback)(const SSL *ssl, const char *line);
   4338 
   4339   /* current_time_cb, if not NULL, is the function to use to get the current
   4340    * time. It sets |*out_clock| to the current time. See
   4341    * |SSL_CTX_set_current_time_cb|. */
   4342   void (*current_time_cb)(const SSL *ssl, struct timeval *out_clock);
   4343 
   4344   /* pool is used for all |CRYPTO_BUFFER|s in case we wish to share certificate
   4345    * memory. */
   4346   CRYPTO_BUFFER_POOL *pool;
   4347 
   4348   /* ticket_aead_method contains function pointers for opening and sealing
   4349    * session tickets. */
   4350   const SSL_TICKET_AEAD_METHOD *ticket_aead_method;
   4351 
   4352   /* verify_sigalgs, if not empty, is the set of signature algorithms
   4353    * accepted from the peer in decreasing order of preference. */
   4354   uint16_t *verify_sigalgs;
   4355   size_t num_verify_sigalgs;
   4356 
   4357   /* quiet_shutdown is true if the connection should not send a close_notify on
   4358    * shutdown. */
   4359   unsigned quiet_shutdown:1;
   4360 
   4361   /* ocsp_stapling_enabled is only used by client connections and indicates
   4362    * whether OCSP stapling will be requested. */
   4363   unsigned ocsp_stapling_enabled:1;
   4364 
   4365   /* If true, a client will request certificate timestamps. */
   4366   unsigned signed_cert_timestamps_enabled:1;
   4367 
   4368   /* tlsext_channel_id_enabled is one if Channel ID is enabled and zero
   4369    * otherwise. For a server, means that we'll accept Channel IDs from clients.
   4370    * For a client, means that we'll advertise support. */
   4371   unsigned tlsext_channel_id_enabled:1;
   4372 
   4373   /* grease_enabled is one if draft-davidben-tls-grease-01 is enabled and zero
   4374    * otherwise. */
   4375   unsigned grease_enabled:1;
   4376 
   4377   /* i_promise_to_verify_certs_after_the_handshake indicates that the
   4378    * application is using the |CRYPTO_BUFFER|-based methods and understands
   4379    * that this currently requires post-handshake verification of
   4380    * certificates. */
   4381   unsigned i_promise_to_verify_certs_after_the_handshake:1;
   4382 
   4383   /* allow_unknown_alpn_protos is one if the client allows unsolicited ALPN
   4384    * protocols from the peer. */
   4385   unsigned allow_unknown_alpn_protos:1;
   4386 
   4387   /* ed25519_enabled is one if Ed25519 is advertised in the handshake. */
   4388   unsigned ed25519_enabled:1;
   4389 };
   4390 
   4391 
   4392 /* Nodejs compatibility section (hidden).
   4393  *
   4394  * These defines exist for node.js, with the hope that we can eliminate the
   4395  * need for them over time. */
   4396 #define SSLerr(function, reason) \
   4397   ERR_put_error(ERR_LIB_SSL, 0, reason, __FILE__, __LINE__)
   4398 
   4399 
   4400 /* Preprocessor compatibility section (hidden).
   4401  *
   4402  * Historically, a number of APIs were implemented in OpenSSL as macros and
   4403  * constants to 'ctrl' functions. To avoid breaking #ifdefs in consumers, this
   4404  * section defines a number of legacy macros.
   4405  *
   4406  * Although using either the CTRL values or their wrapper macros in #ifdefs is
   4407  * still supported, the CTRL values may not be passed to |SSL_ctrl| and
   4408  * |SSL_CTX_ctrl|. Call the functions (previously wrapper macros) instead.
   4409  *
   4410  * See PORTING.md in the BoringSSL source tree for a table of corresponding
   4411  * functions.
   4412  * https://boringssl.googlesource.com/boringssl/+/master/PORTING.md#Replacements-for-values
   4413  */
   4414 
   4415 #define DTLS_CTRL_GET_TIMEOUT doesnt_exist
   4416 #define DTLS_CTRL_HANDLE_TIMEOUT doesnt_exist
   4417 #define SSL_CTRL_CHAIN doesnt_exist
   4418 #define SSL_CTRL_CHAIN_CERT doesnt_exist
   4419 #define SSL_CTRL_CHANNEL_ID doesnt_exist
   4420 #define SSL_CTRL_CLEAR_EXTRA_CHAIN_CERTS doesnt_exist
   4421 #define SSL_CTRL_CLEAR_MODE doesnt_exist
   4422 #define SSL_CTRL_CLEAR_OPTIONS doesnt_exist
   4423 #define SSL_CTRL_EXTRA_CHAIN_CERT doesnt_exist
   4424 #define SSL_CTRL_GET_CHAIN_CERTS doesnt_exist
   4425 #define SSL_CTRL_GET_CHANNEL_ID doesnt_exist
   4426 #define SSL_CTRL_GET_CLIENT_CERT_TYPES doesnt_exist
   4427 #define SSL_CTRL_GET_EXTRA_CHAIN_CERTS doesnt_exist
   4428 #define SSL_CTRL_GET_MAX_CERT_LIST doesnt_exist
   4429 #define SSL_CTRL_GET_NUM_RENEGOTIATIONS doesnt_exist
   4430 #define SSL_CTRL_GET_READ_AHEAD doesnt_exist
   4431 #define SSL_CTRL_GET_RI_SUPPORT doesnt_exist
   4432 #define SSL_CTRL_GET_SESSION_REUSED doesnt_exist
   4433 #define SSL_CTRL_GET_SESS_CACHE_MODE doesnt_exist
   4434 #define SSL_CTRL_GET_SESS_CACHE_SIZE doesnt_exist
   4435 #define SSL_CTRL_GET_TLSEXT_TICKET_KEYS doesnt_exist
   4436 #define SSL_CTRL_GET_TOTAL_RENEGOTIATIONS doesnt_exist
   4437 #define SSL_CTRL_MODE doesnt_exist
   4438 #define SSL_CTRL_NEED_TMP_RSA doesnt_exist
   4439 #define SSL_CTRL_OPTIONS doesnt_exist
   4440 #define SSL_CTRL_SESS_NUMBER doesnt_exist
   4441 #define SSL_CTRL_SET_CURVES doesnt_exist
   4442 #define SSL_CTRL_SET_CURVES_LIST doesnt_exist
   4443 #define SSL_CTRL_SET_ECDH_AUTO doesnt_exist
   4444 #define SSL_CTRL_SET_MAX_CERT_LIST doesnt_exist
   4445 #define SSL_CTRL_SET_MAX_SEND_FRAGMENT doesnt_exist
   4446 #define SSL_CTRL_SET_MSG_CALLBACK doesnt_exist
   4447 #define SSL_CTRL_SET_MSG_CALLBACK_ARG doesnt_exist
   4448 #define SSL_CTRL_SET_MTU doesnt_exist
   4449 #define SSL_CTRL_SET_READ_AHEAD doesnt_exist
   4450 #define SSL_CTRL_SET_SESS_CACHE_MODE doesnt_exist
   4451 #define SSL_CTRL_SET_SESS_CACHE_SIZE doesnt_exist
   4452 #define SSL_CTRL_SET_TLSEXT_HOSTNAME doesnt_exist
   4453 #define SSL_CTRL_SET_TLSEXT_SERVERNAME_ARG doesnt_exist
   4454 #define SSL_CTRL_SET_TLSEXT_SERVERNAME_CB doesnt_exist
   4455 #define SSL_CTRL_SET_TLSEXT_TICKET_KEYS doesnt_exist
   4456 #define SSL_CTRL_SET_TLSEXT_TICKET_KEY_CB doesnt_exist
   4457 #define SSL_CTRL_SET_TMP_DH doesnt_exist
   4458 #define SSL_CTRL_SET_TMP_DH_CB doesnt_exist
   4459 #define SSL_CTRL_SET_TMP_ECDH doesnt_exist
   4460 #define SSL_CTRL_SET_TMP_ECDH_CB doesnt_exist
   4461 #define SSL_CTRL_SET_TMP_RSA doesnt_exist
   4462 #define SSL_CTRL_SET_TMP_RSA_CB doesnt_exist
   4463 
   4464 #define DTLSv1_get_timeout DTLSv1_get_timeout
   4465 #define DTLSv1_handle_timeout DTLSv1_handle_timeout
   4466 #define SSL_CTX_add0_chain_cert SSL_CTX_add0_chain_cert
   4467 #define SSL_CTX_add1_chain_cert SSL_CTX_add1_chain_cert
   4468 #define SSL_CTX_add_extra_chain_cert SSL_CTX_add_extra_chain_cert
   4469 #define SSL_CTX_clear_extra_chain_certs SSL_CTX_clear_extra_chain_certs
   4470 #define SSL_CTX_clear_chain_certs SSL_CTX_clear_chain_certs
   4471 #define SSL_CTX_clear_mode SSL_CTX_clear_mode
   4472 #define SSL_CTX_clear_options SSL_CTX_clear_options
   4473 #define SSL_CTX_get0_chain_certs SSL_CTX_get0_chain_certs
   4474 #define SSL_CTX_get_extra_chain_certs SSL_CTX_get_extra_chain_certs
   4475 #define SSL_CTX_get_max_cert_list SSL_CTX_get_max_cert_list
   4476 #define SSL_CTX_get_mode SSL_CTX_get_mode
   4477 #define SSL_CTX_get_options SSL_CTX_get_options
   4478 #define SSL_CTX_get_read_ahead SSL_CTX_get_read_ahead
   4479 #define SSL_CTX_get_session_cache_mode SSL_CTX_get_session_cache_mode
   4480 #define SSL_CTX_get_tlsext_ticket_keys SSL_CTX_get_tlsext_ticket_keys
   4481 #define SSL_CTX_need_tmp_RSA SSL_CTX_need_tmp_RSA
   4482 #define SSL_CTX_sess_get_cache_size SSL_CTX_sess_get_cache_size
   4483 #define SSL_CTX_sess_number SSL_CTX_sess_number
   4484 #define SSL_CTX_sess_set_cache_size SSL_CTX_sess_set_cache_size
   4485 #define SSL_CTX_set0_chain SSL_CTX_set0_chain
   4486 #define SSL_CTX_set1_chain SSL_CTX_set1_chain
   4487 #define SSL_CTX_set1_curves SSL_CTX_set1_curves
   4488 #define SSL_CTX_set_max_cert_list SSL_CTX_set_max_cert_list
   4489 #define SSL_CTX_set_max_send_fragment SSL_CTX_set_max_send_fragment
   4490 #define SSL_CTX_set_mode SSL_CTX_set_mode
   4491 #define SSL_CTX_set_msg_callback_arg SSL_CTX_set_msg_callback_arg
   4492 #define SSL_CTX_set_options SSL_CTX_set_options
   4493 #define SSL_CTX_set_read_ahead SSL_CTX_set_read_ahead
   4494 #define SSL_CTX_set_session_cache_mode SSL_CTX_set_session_cache_mode
   4495 #define SSL_CTX_set_tlsext_servername_arg SSL_CTX_set_tlsext_servername_arg
   4496 #define SSL_CTX_set_tlsext_servername_callback \
   4497     SSL_CTX_set_tlsext_servername_callback
   4498 #define SSL_CTX_set_tlsext_ticket_key_cb SSL_CTX_set_tlsext_ticket_key_cb
   4499 #define SSL_CTX_set_tlsext_ticket_keys SSL_CTX_set_tlsext_ticket_keys
   4500 #define SSL_CTX_set_tmp_dh SSL_CTX_set_tmp_dh
   4501 #define SSL_CTX_set_tmp_ecdh SSL_CTX_set_tmp_ecdh
   4502 #define SSL_CTX_set_tmp_rsa SSL_CTX_set_tmp_rsa
   4503 #define SSL_add0_chain_cert SSL_add0_chain_cert
   4504 #define SSL_add1_chain_cert SSL_add1_chain_cert
   4505 #define SSL_clear_chain_certs SSL_clear_chain_certs
   4506 #define SSL_clear_mode SSL_clear_mode
   4507 #define SSL_clear_options SSL_clear_options
   4508 #define SSL_get0_certificate_types SSL_get0_certificate_types
   4509 #define SSL_get0_chain_certs SSL_get0_chain_certs
   4510 #define SSL_get_max_cert_list SSL_get_max_cert_list
   4511 #define SSL_get_mode SSL_get_mode
   4512 #define SSL_get_options SSL_get_options
   4513 #define SSL_get_secure_renegotiation_support \
   4514     SSL_get_secure_renegotiation_support
   4515 #define SSL_need_tmp_RSA SSL_need_tmp_RSA
   4516 #define SSL_num_renegotiations SSL_num_renegotiations
   4517 #define SSL_session_reused SSL_session_reused
   4518 #define SSL_set0_chain SSL_set0_chain
   4519 #define SSL_set1_chain SSL_set1_chain
   4520 #define SSL_set1_curves SSL_set1_curves
   4521 #define SSL_set_max_cert_list SSL_set_max_cert_list
   4522 #define SSL_set_max_send_fragment SSL_set_max_send_fragment
   4523 #define SSL_set_mode SSL_set_mode
   4524 #define SSL_set_msg_callback_arg SSL_set_msg_callback_arg
   4525 #define SSL_set_mtu SSL_set_mtu
   4526 #define SSL_set_options SSL_set_options
   4527 #define SSL_set_tlsext_host_name SSL_set_tlsext_host_name
   4528 #define SSL_set_tmp_dh SSL_set_tmp_dh
   4529 #define SSL_set_tmp_ecdh SSL_set_tmp_ecdh
   4530 #define SSL_set_tmp_rsa SSL_set_tmp_rsa
   4531 #define SSL_total_renegotiations SSL_total_renegotiations
   4532 
   4533 
   4534 #if defined(__cplusplus)
   4535 } /* extern C */
   4536 
   4537 extern "C++" {
   4538 
   4539 namespace bssl {
   4540 
   4541 BORINGSSL_MAKE_DELETER(SSL, SSL_free)
   4542 BORINGSSL_MAKE_DELETER(SSL_CTX, SSL_CTX_free)
   4543 BORINGSSL_MAKE_DELETER(SSL_SESSION, SSL_SESSION_free)
   4544 
   4545 }  // namespace bssl
   4546 
   4547 }  /* extern C++ */
   4548 
   4549 #endif
   4550 
   4551 #define SSL_R_APP_DATA_IN_HANDSHAKE 100
   4552 #define SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT 101
   4553 #define SSL_R_BAD_ALERT 102
   4554 #define SSL_R_BAD_CHANGE_CIPHER_SPEC 103
   4555 #define SSL_R_BAD_DATA_RETURNED_BY_CALLBACK 104
   4556 #define SSL_R_BAD_DH_P_LENGTH 105
   4557 #define SSL_R_BAD_DIGEST_LENGTH 106
   4558 #define SSL_R_BAD_ECC_CERT 107
   4559 #define SSL_R_BAD_ECPOINT 108
   4560 #define SSL_R_BAD_HANDSHAKE_RECORD 109
   4561 #define SSL_R_BAD_HELLO_REQUEST 110
   4562 #define SSL_R_BAD_LENGTH 111
   4563 #define SSL_R_BAD_PACKET_LENGTH 112
   4564 #define SSL_R_BAD_RSA_ENCRYPT 113
   4565 #define SSL_R_BAD_SIGNATURE 114
   4566 #define SSL_R_BAD_SRTP_MKI_VALUE 115
   4567 #define SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST 116
   4568 #define SSL_R_BAD_SSL_FILETYPE 117
   4569 #define SSL_R_BAD_WRITE_RETRY 118
   4570 #define SSL_R_BIO_NOT_SET 119
   4571 #define SSL_R_BN_LIB 120
   4572 #define SSL_R_BUFFER_TOO_SMALL 121
   4573 #define SSL_R_CA_DN_LENGTH_MISMATCH 122
   4574 #define SSL_R_CA_DN_TOO_LONG 123
   4575 #define SSL_R_CCS_RECEIVED_EARLY 124
   4576 #define SSL_R_CERTIFICATE_VERIFY_FAILED 125
   4577 #define SSL_R_CERT_CB_ERROR 126
   4578 #define SSL_R_CERT_LENGTH_MISMATCH 127
   4579 #define SSL_R_CHANNEL_ID_NOT_P256 128
   4580 #define SSL_R_CHANNEL_ID_SIGNATURE_INVALID 129
   4581 #define SSL_R_CIPHER_OR_HASH_UNAVAILABLE 130
   4582 #define SSL_R_CLIENTHELLO_PARSE_FAILED 131
   4583 #define SSL_R_CLIENTHELLO_TLSEXT 132
   4584 #define SSL_R_CONNECTION_REJECTED 133
   4585 #define SSL_R_CONNECTION_TYPE_NOT_SET 134
   4586 #define SSL_R_CUSTOM_EXTENSION_ERROR 135
   4587 #define SSL_R_DATA_LENGTH_TOO_LONG 136
   4588 #define SSL_R_DECODE_ERROR 137
   4589 #define SSL_R_DECRYPTION_FAILED 138
   4590 #define SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC 139
   4591 #define SSL_R_DH_PUBLIC_VALUE_LENGTH_IS_WRONG 140
   4592 #define SSL_R_DH_P_TOO_LONG 141
   4593 #define SSL_R_DIGEST_CHECK_FAILED 142
   4594 #define SSL_R_DTLS_MESSAGE_TOO_BIG 143
   4595 #define SSL_R_ECC_CERT_NOT_FOR_SIGNING 144
   4596 #define SSL_R_EMS_STATE_INCONSISTENT 145
   4597 #define SSL_R_ENCRYPTED_LENGTH_TOO_LONG 146
   4598 #define SSL_R_ERROR_ADDING_EXTENSION 147
   4599 #define SSL_R_ERROR_IN_RECEIVED_CIPHER_LIST 148
   4600 #define SSL_R_ERROR_PARSING_EXTENSION 149
   4601 #define SSL_R_EXCESSIVE_MESSAGE_SIZE 150
   4602 #define SSL_R_EXTRA_DATA_IN_MESSAGE 151
   4603 #define SSL_R_FRAGMENT_MISMATCH 152
   4604 #define SSL_R_GOT_NEXT_PROTO_WITHOUT_EXTENSION 153
   4605 #define SSL_R_HANDSHAKE_FAILURE_ON_CLIENT_HELLO 154
   4606 #define SSL_R_HTTPS_PROXY_REQUEST 155
   4607 #define SSL_R_HTTP_REQUEST 156
   4608 #define SSL_R_INAPPROPRIATE_FALLBACK 157
   4609 #define SSL_R_INVALID_COMMAND 158
   4610 #define SSL_R_INVALID_MESSAGE 159
   4611 #define SSL_R_INVALID_SSL_SESSION 160
   4612 #define SSL_R_INVALID_TICKET_KEYS_LENGTH 161
   4613 #define SSL_R_LENGTH_MISMATCH 162
   4614 #define SSL_R_MISSING_EXTENSION 164
   4615 #define SSL_R_MISSING_RSA_CERTIFICATE 165
   4616 #define SSL_R_MISSING_TMP_DH_KEY 166
   4617 #define SSL_R_MISSING_TMP_ECDH_KEY 167
   4618 #define SSL_R_MIXED_SPECIAL_OPERATOR_WITH_GROUPS 168
   4619 #define SSL_R_MTU_TOO_SMALL 169
   4620 #define SSL_R_NEGOTIATED_BOTH_NPN_AND_ALPN 170
   4621 #define SSL_R_NESTED_GROUP 171
   4622 #define SSL_R_NO_CERTIFICATES_RETURNED 172
   4623 #define SSL_R_NO_CERTIFICATE_ASSIGNED 173
   4624 #define SSL_R_NO_CERTIFICATE_SET 174
   4625 #define SSL_R_NO_CIPHERS_AVAILABLE 175
   4626 #define SSL_R_NO_CIPHERS_PASSED 176
   4627 #define SSL_R_NO_CIPHER_MATCH 177
   4628 #define SSL_R_NO_COMPRESSION_SPECIFIED 178
   4629 #define SSL_R_NO_METHOD_SPECIFIED 179
   4630 #define SSL_R_NO_P256_SUPPORT 180
   4631 #define SSL_R_NO_PRIVATE_KEY_ASSIGNED 181
   4632 #define SSL_R_NO_RENEGOTIATION 182
   4633 #define SSL_R_NO_REQUIRED_DIGEST 183
   4634 #define SSL_R_NO_SHARED_CIPHER 184
   4635 #define SSL_R_NULL_SSL_CTX 185
   4636 #define SSL_R_NULL_SSL_METHOD_PASSED 186
   4637 #define SSL_R_OLD_SESSION_CIPHER_NOT_RETURNED 187
   4638 #define SSL_R_OLD_SESSION_VERSION_NOT_RETURNED 188
   4639 #define SSL_R_OUTPUT_ALIASES_INPUT 189
   4640 #define SSL_R_PARSE_TLSEXT 190
   4641 #define SSL_R_PATH_TOO_LONG 191
   4642 #define SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE 192
   4643 #define SSL_R_PEER_ERROR_UNSUPPORTED_CERTIFICATE_TYPE 193
   4644 #define SSL_R_PROTOCOL_IS_SHUTDOWN 194
   4645 #define SSL_R_PSK_IDENTITY_NOT_FOUND 195
   4646 #define SSL_R_PSK_NO_CLIENT_CB 196
   4647 #define SSL_R_PSK_NO_SERVER_CB 197
   4648 #define SSL_R_READ_TIMEOUT_EXPIRED 198
   4649 #define SSL_R_RECORD_LENGTH_MISMATCH 199
   4650 #define SSL_R_RECORD_TOO_LARGE 200
   4651 #define SSL_R_RENEGOTIATION_ENCODING_ERR 201
   4652 #define SSL_R_RENEGOTIATION_MISMATCH 202
   4653 #define SSL_R_REQUIRED_CIPHER_MISSING 203
   4654 #define SSL_R_RESUMED_EMS_SESSION_WITHOUT_EMS_EXTENSION 204
   4655 #define SSL_R_RESUMED_NON_EMS_SESSION_WITH_EMS_EXTENSION 205
   4656 #define SSL_R_SCSV_RECEIVED_WHEN_RENEGOTIATING 206
   4657 #define SSL_R_SERVERHELLO_TLSEXT 207
   4658 #define SSL_R_SESSION_ID_CONTEXT_UNINITIALIZED 208
   4659 #define SSL_R_SESSION_MAY_NOT_BE_CREATED 209
   4660 #define SSL_R_SIGNATURE_ALGORITHMS_EXTENSION_SENT_BY_SERVER 210
   4661 #define SSL_R_SRTP_COULD_NOT_ALLOCATE_PROFILES 211
   4662 #define SSL_R_SRTP_UNKNOWN_PROTECTION_PROFILE 212
   4663 #define SSL_R_SSL3_EXT_INVALID_SERVERNAME 213
   4664 #define SSL_R_SSL_CTX_HAS_NO_DEFAULT_SSL_VERSION 214
   4665 #define SSL_R_SSL_HANDSHAKE_FAILURE 215
   4666 #define SSL_R_SSL_SESSION_ID_CONTEXT_TOO_LONG 216
   4667 #define SSL_R_TLS_PEER_DID_NOT_RESPOND_WITH_CERTIFICATE_LIST 217
   4668 #define SSL_R_TLS_RSA_ENCRYPTED_VALUE_LENGTH_IS_WRONG 218
   4669 #define SSL_R_TOO_MANY_EMPTY_FRAGMENTS 219
   4670 #define SSL_R_TOO_MANY_WARNING_ALERTS 220
   4671 #define SSL_R_UNABLE_TO_FIND_ECDH_PARAMETERS 221
   4672 #define SSL_R_UNEXPECTED_EXTENSION 222
   4673 #define SSL_R_UNEXPECTED_MESSAGE 223
   4674 #define SSL_R_UNEXPECTED_OPERATOR_IN_GROUP 224
   4675 #define SSL_R_UNEXPECTED_RECORD 225
   4676 #define SSL_R_UNINITIALIZED 226
   4677 #define SSL_R_UNKNOWN_ALERT_TYPE 227
   4678 #define SSL_R_UNKNOWN_CERTIFICATE_TYPE 228
   4679 #define SSL_R_UNKNOWN_CIPHER_RETURNED 229
   4680 #define SSL_R_UNKNOWN_CIPHER_TYPE 230
   4681 #define SSL_R_UNKNOWN_DIGEST 231
   4682 #define SSL_R_UNKNOWN_KEY_EXCHANGE_TYPE 232
   4683 #define SSL_R_UNKNOWN_PROTOCOL 233
   4684 #define SSL_R_UNKNOWN_SSL_VERSION 234
   4685 #define SSL_R_UNKNOWN_STATE 235
   4686 #define SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED 236
   4687 #define SSL_R_UNSUPPORTED_CIPHER 237
   4688 #define SSL_R_UNSUPPORTED_COMPRESSION_ALGORITHM 238
   4689 #define SSL_R_UNSUPPORTED_ELLIPTIC_CURVE 239
   4690 #define SSL_R_UNSUPPORTED_PROTOCOL 240
   4691 #define SSL_R_WRONG_CERTIFICATE_TYPE 241
   4692 #define SSL_R_WRONG_CIPHER_RETURNED 242
   4693 #define SSL_R_WRONG_CURVE 243
   4694 #define SSL_R_WRONG_MESSAGE_TYPE 244
   4695 #define SSL_R_WRONG_SIGNATURE_TYPE 245
   4696 #define SSL_R_WRONG_SSL_VERSION 246
   4697 #define SSL_R_WRONG_VERSION_NUMBER 247
   4698 #define SSL_R_X509_LIB 248
   4699 #define SSL_R_X509_VERIFICATION_SETUP_PROBLEMS 249
   4700 #define SSL_R_SHUTDOWN_WHILE_IN_INIT 250
   4701 #define SSL_R_INVALID_OUTER_RECORD_TYPE 251
   4702 #define SSL_R_UNSUPPORTED_PROTOCOL_FOR_CUSTOM_KEY 252
   4703 #define SSL_R_NO_COMMON_SIGNATURE_ALGORITHMS 253
   4704 #define SSL_R_DOWNGRADE_DETECTED 254
   4705 #define SSL_R_BUFFERED_MESSAGES_ON_CIPHER_CHANGE 255
   4706 #define SSL_R_INVALID_COMPRESSION_LIST 256
   4707 #define SSL_R_DUPLICATE_EXTENSION 257
   4708 #define SSL_R_MISSING_KEY_SHARE 258
   4709 #define SSL_R_INVALID_ALPN_PROTOCOL 259
   4710 #define SSL_R_TOO_MANY_KEY_UPDATES 260
   4711 #define SSL_R_BLOCK_CIPHER_PAD_IS_WRONG 261
   4712 #define SSL_R_NO_CIPHERS_SPECIFIED 262
   4713 #define SSL_R_RENEGOTIATION_EMS_MISMATCH 263
   4714 #define SSL_R_DUPLICATE_KEY_SHARE 264
   4715 #define SSL_R_NO_GROUPS_SPECIFIED 265
   4716 #define SSL_R_NO_SHARED_GROUP 266
   4717 #define SSL_R_PRE_SHARED_KEY_MUST_BE_LAST 267
   4718 #define SSL_R_OLD_SESSION_PRF_HASH_MISMATCH 268
   4719 #define SSL_R_INVALID_SCT_LIST 269
   4720 #define SSL_R_TOO_MUCH_SKIPPED_EARLY_DATA 270
   4721 #define SSL_R_PSK_IDENTITY_BINDER_COUNT_MISMATCH 271
   4722 #define SSL_R_CANNOT_PARSE_LEAF_CERT 272
   4723 #define SSL_R_SERVER_CERT_CHANGED 273
   4724 #define SSL_R_CERTIFICATE_AND_PRIVATE_KEY_MISMATCH 274
   4725 #define SSL_R_CANNOT_HAVE_BOTH_PRIVKEY_AND_METHOD 275
   4726 #define SSL_R_TICKET_ENCRYPTION_FAILED 276
   4727 #define SSL_R_ALPN_MISMATCH_ON_EARLY_DATA 277
   4728 #define SSL_R_WRONG_VERSION_ON_EARLY_DATA 278
   4729 #define SSL_R_CHANNEL_ID_ON_EARLY_DATA 279
   4730 #define SSL_R_NO_SUPPORTED_VERSIONS_ENABLED 280
   4731 #define SSL_R_APPLICATION_DATA_INSTEAD_OF_HANDSHAKE 281
   4732 #define SSL_R_SSLV3_ALERT_CLOSE_NOTIFY 1000
   4733 #define SSL_R_SSLV3_ALERT_UNEXPECTED_MESSAGE 1010
   4734 #define SSL_R_SSLV3_ALERT_BAD_RECORD_MAC 1020
   4735 #define SSL_R_TLSV1_ALERT_DECRYPTION_FAILED 1021
   4736 #define SSL_R_TLSV1_ALERT_RECORD_OVERFLOW 1022
   4737 #define SSL_R_SSLV3_ALERT_DECOMPRESSION_FAILURE 1030
   4738 #define SSL_R_SSLV3_ALERT_HANDSHAKE_FAILURE 1040
   4739 #define SSL_R_SSLV3_ALERT_NO_CERTIFICATE 1041
   4740 #define SSL_R_SSLV3_ALERT_BAD_CERTIFICATE 1042
   4741 #define SSL_R_SSLV3_ALERT_UNSUPPORTED_CERTIFICATE 1043
   4742 #define SSL_R_SSLV3_ALERT_CERTIFICATE_REVOKED 1044
   4743 #define SSL_R_SSLV3_ALERT_CERTIFICATE_EXPIRED 1045
   4744 #define SSL_R_SSLV3_ALERT_CERTIFICATE_UNKNOWN 1046
   4745 #define SSL_R_SSLV3_ALERT_ILLEGAL_PARAMETER 1047
   4746 #define SSL_R_TLSV1_ALERT_UNKNOWN_CA 1048
   4747 #define SSL_R_TLSV1_ALERT_ACCESS_DENIED 1049
   4748 #define SSL_R_TLSV1_ALERT_DECODE_ERROR 1050
   4749 #define SSL_R_TLSV1_ALERT_DECRYPT_ERROR 1051
   4750 #define SSL_R_TLSV1_ALERT_EXPORT_RESTRICTION 1060
   4751 #define SSL_R_TLSV1_ALERT_PROTOCOL_VERSION 1070
   4752 #define SSL_R_TLSV1_ALERT_INSUFFICIENT_SECURITY 1071
   4753 #define SSL_R_TLSV1_ALERT_INTERNAL_ERROR 1080
   4754 #define SSL_R_TLSV1_ALERT_INAPPROPRIATE_FALLBACK 1086
   4755 #define SSL_R_TLSV1_ALERT_USER_CANCELLED 1090
   4756 #define SSL_R_TLSV1_ALERT_NO_RENEGOTIATION 1100
   4757 #define SSL_R_TLSV1_UNSUPPORTED_EXTENSION 1110
   4758 #define SSL_R_TLSV1_CERTIFICATE_UNOBTAINABLE 1111
   4759 #define SSL_R_TLSV1_UNRECOGNIZED_NAME 1112
   4760 #define SSL_R_TLSV1_BAD_CERTIFICATE_STATUS_RESPONSE 1113
   4761 #define SSL_R_TLSV1_BAD_CERTIFICATE_HASH_VALUE 1114
   4762 #define SSL_R_TLSV1_UNKNOWN_PSK_IDENTITY 1115
   4763 #define SSL_R_TLSV1_CERTIFICATE_REQUIRED 1116
   4764 #define SSL_R_TOO_MUCH_READ_EARLY_DATA 1117
   4765 
   4766 #endif /* OPENSSL_HEADER_SSL_H */
   4767