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