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/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
/* ====================================================================
* Copyright (c) 1998-2007 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* openssl-core@openssl.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com).
*
*/
/* ====================================================================
* Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
* ECC cipher suite support in OpenSSL originally developed by
* SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
*/
/* ====================================================================
* Copyright 2005 Nokia. All rights reserved.
*
* The portions of the attached software ("Contribution") is developed by
* Nokia Corporation and is licensed pursuant to the OpenSSL open source
* license.
*
* The Contribution, originally written by Mika Kousa and Pasi Eronen of
* Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites
* support (see RFC 4279) to OpenSSL.
*
* No patent licenses or other rights except those expressly stated in
* the OpenSSL open source license shall be deemed granted or received
* expressly, by implication, estoppel, or otherwise.
*
* No assurances are provided by Nokia that the Contribution does not
* infringe the patent or other intellectual property rights of any third
* party or that the license provides you with all the necessary rights
* to make use of the Contribution.
*
* THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN
* ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA
* SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY
* OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR
* OTHERWISE.
*/
#ifndef OPENSSL_HEADER_SSL_H
#define OPENSSL_HEADER_SSL_H
#include <openssl/base.h>
#include <openssl/bio.h>
#include <openssl/buf.h>
#include <openssl/pem.h>
#include <openssl/span.h>
#include <openssl/ssl3.h>
#include <openssl/thread.h>
#include <openssl/tls1.h>
#include <openssl/x509.h>
#if !defined(OPENSSL_WINDOWS)
#include <sys/time.h>
#endif
// NGINX needs this #include. Consider revisiting this after NGINX 1.14.0 has
// been out for a year or so (assuming that they fix it in that release.) See
// https://boringssl-review.googlesource.com/c/boringssl/+/21664.
#include <openssl/hmac.h>
// Forward-declare struct timeval. On Windows, it is defined in winsock2.h and
// Windows headers define too many macros to be included in public headers.
// However, only a forward declaration is needed.
struct timeval;
#if defined(__cplusplus)
extern "C" {
#endif
// SSL implementation.
// SSL contexts.
//
// |SSL_CTX| objects manage shared state and configuration between multiple TLS
// or DTLS connections. Whether the connections are TLS or DTLS is selected by
// an |SSL_METHOD| on creation.
//
// |SSL_CTX| are reference-counted and may be shared by connections across
// multiple threads. Once shared, functions which change the |SSL_CTX|'s
// configuration may not be used.
// TLS_method is the |SSL_METHOD| used for TLS (and SSLv3) connections.
OPENSSL_EXPORT const SSL_METHOD *TLS_method(void);
// DTLS_method is the |SSL_METHOD| used for DTLS connections.
OPENSSL_EXPORT const SSL_METHOD *DTLS_method(void);
// TLS_with_buffers_method is like |TLS_method|, but avoids all use of
// crypto/x509.
OPENSSL_EXPORT const SSL_METHOD *TLS_with_buffers_method(void);
// DTLS_with_buffers_method is like |DTLS_method|, but avoids all use of
// crypto/x509.
OPENSSL_EXPORT const SSL_METHOD *DTLS_with_buffers_method(void);
// SSL_CTX_new returns a newly-allocated |SSL_CTX| with default settings or NULL
// on error.
OPENSSL_EXPORT SSL_CTX *SSL_CTX_new(const SSL_METHOD *method);
// SSL_CTX_up_ref increments the reference count of |ctx|. It returns one.
OPENSSL_EXPORT int SSL_CTX_up_ref(SSL_CTX *ctx);
// SSL_CTX_free releases memory associated with |ctx|.
OPENSSL_EXPORT void SSL_CTX_free(SSL_CTX *ctx);
// SSL connections.
//
// An |SSL| object represents a single TLS or DTLS connection. Although the
// shared |SSL_CTX| is thread-safe, an |SSL| is not thread-safe and may only be
// used on one thread at a time.
// SSL_new returns a newly-allocated |SSL| using |ctx| or NULL on error. The new
// connection inherits settings from |ctx| at the time of creation. Settings may
// also be individually configured on the connection.
//
// On creation, an |SSL| is not configured to be either a client or server. Call
// |SSL_set_connect_state| or |SSL_set_accept_state| to set this.
OPENSSL_EXPORT SSL *SSL_new(SSL_CTX *ctx);
// SSL_free releases memory associated with |ssl|.
OPENSSL_EXPORT void SSL_free(SSL *ssl);
// SSL_get_SSL_CTX returns the |SSL_CTX| associated with |ssl|. If
// |SSL_set_SSL_CTX| is called, it returns the new |SSL_CTX|, not the initial
// one.
OPENSSL_EXPORT SSL_CTX *SSL_get_SSL_CTX(const SSL *ssl);
// SSL_set_connect_state configures |ssl| to be a client.
OPENSSL_EXPORT void SSL_set_connect_state(SSL *ssl);
// SSL_set_accept_state configures |ssl| to be a server.
OPENSSL_EXPORT void SSL_set_accept_state(SSL *ssl);
// SSL_is_server returns one if |ssl| is configured as a server and zero
// otherwise.
OPENSSL_EXPORT int SSL_is_server(const SSL *ssl);
// SSL_is_dtls returns one if |ssl| is a DTLS connection and zero otherwise.
OPENSSL_EXPORT int SSL_is_dtls(const SSL *ssl);
// SSL_set_bio configures |ssl| to read from |rbio| and write to |wbio|. |ssl|
// takes ownership of the two |BIO|s. If |rbio| and |wbio| are the same, |ssl|
// only takes ownership of one reference.
//
// In DTLS, |rbio| must be non-blocking to properly handle timeouts and
// retransmits.
//
// If |rbio| is the same as the currently configured |BIO| for reading, that
// side is left untouched and is not freed.
//
// If |wbio| is the same as the currently configured |BIO| for writing AND |ssl|
// is not currently configured to read from and write to the same |BIO|, that
// side is left untouched and is not freed. This asymmetry is present for
// historical reasons.
//
// Due to the very complex historical behavior of this function, calling this
// function if |ssl| already has |BIO|s configured is deprecated. Prefer
// |SSL_set0_rbio| and |SSL_set0_wbio| instead.
OPENSSL_EXPORT void SSL_set_bio(SSL *ssl, BIO *rbio, BIO *wbio);
// SSL_set0_rbio configures |ssl| to write to |rbio|. It takes ownership of
// |rbio|.
//
// Note that, although this function and |SSL_set0_wbio| may be called on the
// same |BIO|, each call takes a reference. Use |BIO_up_ref| to balance this.
OPENSSL_EXPORT void SSL_set0_rbio(SSL *ssl, BIO *rbio);
// SSL_set0_wbio configures |ssl| to write to |wbio|. It takes ownership of
// |wbio|.
//
// Note that, although this function and |SSL_set0_rbio| may be called on the
// same |BIO|, each call takes a reference. Use |BIO_up_ref| to balance this.
OPENSSL_EXPORT void SSL_set0_wbio(SSL *ssl, BIO *wbio);
// SSL_get_rbio returns the |BIO| that |ssl| reads from.
OPENSSL_EXPORT BIO *SSL_get_rbio(const SSL *ssl);
// SSL_get_wbio returns the |BIO| that |ssl| writes to.
OPENSSL_EXPORT BIO *SSL_get_wbio(const SSL *ssl);
// SSL_get_fd calls |SSL_get_rfd|.
OPENSSL_EXPORT int SSL_get_fd(const SSL *ssl);
// SSL_get_rfd returns the file descriptor that |ssl| is configured to read
// from. If |ssl|'s read |BIO| is not configured or doesn't wrap a file
// descriptor then it returns -1.
//
// Note: On Windows, this may return either a file descriptor or a socket (cast
// to int), depending on whether |ssl| was configured with a file descriptor or
// socket |BIO|.
OPENSSL_EXPORT int SSL_get_rfd(const SSL *ssl);
// SSL_get_wfd returns the file descriptor that |ssl| is configured to write
// to. If |ssl|'s write |BIO| is not configured or doesn't wrap a file
// descriptor then it returns -1.
//
// Note: On Windows, this may return either a file descriptor or a socket (cast
// to int), depending on whether |ssl| was configured with a file descriptor or
// socket |BIO|.
OPENSSL_EXPORT int SSL_get_wfd(const SSL *ssl);
// SSL_set_fd configures |ssl| to read from and write to |fd|. It returns one
// on success and zero on allocation error. The caller retains ownership of
// |fd|.
//
// On Windows, |fd| is cast to a |SOCKET| and used with Winsock APIs.
OPENSSL_EXPORT int SSL_set_fd(SSL *ssl, int fd);
// SSL_set_rfd configures |ssl| to read from |fd|. It returns one on success and
// zero on allocation error. The caller retains ownership of |fd|.
//
// On Windows, |fd| is cast to a |SOCKET| and used with Winsock APIs.
OPENSSL_EXPORT int SSL_set_rfd(SSL *ssl, int fd);
// SSL_set_wfd configures |ssl| to write to |fd|. It returns one on success and
// zero on allocation error. The caller retains ownership of |fd|.
//
// On Windows, |fd| is cast to a |SOCKET| and used with Winsock APIs.
OPENSSL_EXPORT int SSL_set_wfd(SSL *ssl, int fd);
// SSL_do_handshake continues the current handshake. If there is none or the
// handshake has completed or False Started, it returns one. Otherwise, it
// returns <= 0. The caller should pass the value into |SSL_get_error| to
// determine how to proceed.
//
// In DTLS, the caller must drive retransmissions. Whenever |SSL_get_error|
// signals |SSL_ERROR_WANT_READ|, use |DTLSv1_get_timeout| to determine the
// current timeout. If it expires before the next retry, call
// |DTLSv1_handle_timeout|. Note that DTLS handshake retransmissions use fresh
// sequence numbers, so it is not sufficient to replay packets at the transport.
//
// TODO(davidben): Ensure 0 is only returned on transport EOF.
// https://crbug.com/466303.
OPENSSL_EXPORT int SSL_do_handshake(SSL *ssl);
// SSL_connect configures |ssl| as a client, if unconfigured, and calls
// |SSL_do_handshake|.
OPENSSL_EXPORT int SSL_connect(SSL *ssl);
// SSL_accept configures |ssl| as a server, if unconfigured, and calls
// |SSL_do_handshake|.
OPENSSL_EXPORT int SSL_accept(SSL *ssl);
// SSL_read reads up to |num| bytes from |ssl| into |buf|. It implicitly runs
// any pending handshakes, including renegotiations when enabled. On success, it
// returns the number of bytes read. Otherwise, it returns <= 0. The caller
// should pass the value into |SSL_get_error| to determine how to proceed.
//
// TODO(davidben): Ensure 0 is only returned on transport EOF.
// https://crbug.com/466303.
OPENSSL_EXPORT int SSL_read(SSL *ssl, void *buf, int num);
// SSL_peek behaves like |SSL_read| but does not consume any bytes returned.
OPENSSL_EXPORT int SSL_peek(SSL *ssl, void *buf, int num);
// SSL_pending returns the number of bytes available in |ssl|. It does not read
// from the transport.
OPENSSL_EXPORT int SSL_pending(const SSL *ssl);
// SSL_write writes up to |num| bytes from |buf| into |ssl|. It implicitly runs
// any pending handshakes, including renegotiations when enabled. On success, it
// returns the number of bytes written. Otherwise, it returns <= 0. The caller
// should pass the value into |SSL_get_error| to determine how to proceed.
//
// In TLS, a non-blocking |SSL_write| differs from non-blocking |write| in that
// a failed |SSL_write| still commits to the data passed in. When retrying, the
// caller must supply the original write buffer (or a larger one containing the
// original as a prefix). By default, retries will fail if they also do not
// reuse the same |buf| pointer. This may be relaxed with
// |SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER|, but the buffer contents still must be
// unchanged.
//
// By default, in TLS, |SSL_write| will not return success until all |num| bytes
// are written. This may be relaxed with |SSL_MODE_ENABLE_PARTIAL_WRITE|. It
// allows |SSL_write| to complete with a partial result when only part of the
// input was written in a single record.
//
// In DTLS, neither |SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER| and
// |SSL_MODE_ENABLE_PARTIAL_WRITE| do anything. The caller may retry with a
// different buffer freely. A single call to |SSL_write| only ever writes a
// single record in a single packet, so |num| must be at most
// |SSL3_RT_MAX_PLAIN_LENGTH|.
//
// TODO(davidben): Ensure 0 is only returned on transport EOF.
// https://crbug.com/466303.
OPENSSL_EXPORT int SSL_write(SSL *ssl, const void *buf, int num);
// SSL_shutdown shuts down |ssl|. On success, it completes in two stages. First,
// it returns 0 if |ssl| completed uni-directional shutdown; close_notify has
// been sent, but the peer's close_notify has not been received. Most callers
// may stop at this point. For bi-directional shutdown, call |SSL_shutdown|
// again. It returns 1 if close_notify has been both sent and received.
//
// If the peer's close_notify arrived first, the first stage is skipped.
// |SSL_shutdown| will return 1 once close_notify is sent and skip 0. Callers
// only interested in uni-directional shutdown must therefore allow for the
// first stage returning either 0 or 1.
//
// |SSL_shutdown| returns -1 on failure. The caller should pass the return value
// into |SSL_get_error| to determine how to proceed. If the underlying |BIO| is
// non-blocking, both stages may require retry.
OPENSSL_EXPORT int SSL_shutdown(SSL *ssl);
// SSL_CTX_set_quiet_shutdown sets quiet shutdown on |ctx| to |mode|. If
// enabled, |SSL_shutdown| will not send a close_notify alert or wait for one
// from the peer. It will instead synchronously return one.
OPENSSL_EXPORT void SSL_CTX_set_quiet_shutdown(SSL_CTX *ctx, int mode);
// SSL_CTX_get_quiet_shutdown returns whether quiet shutdown is enabled for
// |ctx|.
OPENSSL_EXPORT int SSL_CTX_get_quiet_shutdown(const SSL_CTX *ctx);
// SSL_set_quiet_shutdown sets quiet shutdown on |ssl| to |mode|. If enabled,
// |SSL_shutdown| will not send a close_notify alert or wait for one from the
// peer. It will instead synchronously return one.
OPENSSL_EXPORT void SSL_set_quiet_shutdown(SSL *ssl, int mode);
// SSL_get_quiet_shutdown returns whether quiet shutdown is enabled for
// |ssl|.
OPENSSL_EXPORT int SSL_get_quiet_shutdown(const SSL *ssl);
// SSL_get_error returns a |SSL_ERROR_*| value for the most recent operation on
// |ssl|. It should be called after an operation failed to determine whether the
// error was fatal and, if not, when to retry.
OPENSSL_EXPORT int SSL_get_error(const SSL *ssl, int ret_code);
// SSL_ERROR_NONE indicates the operation succeeded.
#define SSL_ERROR_NONE 0
// SSL_ERROR_SSL indicates the operation failed within the library. The caller
// may inspect the error queue for more information.
#define SSL_ERROR_SSL 1
// SSL_ERROR_WANT_READ indicates the operation failed attempting to read from
// the transport. The caller may retry the operation when the transport is ready
// for reading.
//
// If signaled by a DTLS handshake, the caller must also call
// |DTLSv1_get_timeout| and |DTLSv1_handle_timeout| as appropriate. See
// |SSL_do_handshake|.
#define SSL_ERROR_WANT_READ 2
// SSL_ERROR_WANT_WRITE indicates the operation failed attempting to write to
// the transport. The caller may retry the operation when the transport is ready
// for writing.
#define SSL_ERROR_WANT_WRITE 3
// SSL_ERROR_WANT_X509_LOOKUP indicates the operation failed in calling the
// |cert_cb| or |client_cert_cb|. The caller may retry the operation when the
// callback is ready to return a certificate or one has been configured
// externally.
//
// See also |SSL_CTX_set_cert_cb| and |SSL_CTX_set_client_cert_cb|.
#define SSL_ERROR_WANT_X509_LOOKUP 4
// SSL_ERROR_SYSCALL indicates the operation failed externally to the library.
// The caller should consult the system-specific error mechanism. This is
// typically |errno| but may be something custom if using a custom |BIO|. It
// may also be signaled if the transport returned EOF, in which case the
// operation's return value will be zero.
#define SSL_ERROR_SYSCALL 5
// SSL_ERROR_ZERO_RETURN indicates the operation failed because the connection
// was cleanly shut down with a close_notify alert.
#define SSL_ERROR_ZERO_RETURN 6
// SSL_ERROR_WANT_CONNECT indicates the operation failed attempting to connect
// the transport (the |BIO| signaled |BIO_RR_CONNECT|). The caller may retry the
// operation when the transport is ready.
#define SSL_ERROR_WANT_CONNECT 7
// SSL_ERROR_WANT_ACCEPT indicates the operation failed attempting to accept a
// connection from the transport (the |BIO| signaled |BIO_RR_ACCEPT|). The
// caller may retry the operation when the transport is ready.
//
// TODO(davidben): Remove this. It's used by accept BIOs which are bizarre.
#define SSL_ERROR_WANT_ACCEPT 8
// SSL_ERROR_WANT_CHANNEL_ID_LOOKUP indicates the operation failed looking up
// the Channel ID key. The caller may retry the operation when |channel_id_cb|
// is ready to return a key or one has been configured with
// |SSL_set1_tls_channel_id|.
//
// See also |SSL_CTX_set_channel_id_cb|.
#define SSL_ERROR_WANT_CHANNEL_ID_LOOKUP 9
// SSL_ERROR_PENDING_SESSION indicates the operation failed because the session
// lookup callback indicated the session was unavailable. The caller may retry
// the operation when lookup has completed.
//
// See also |SSL_CTX_sess_set_get_cb| and |SSL_magic_pending_session_ptr|.
#define SSL_ERROR_PENDING_SESSION 11
// SSL_ERROR_PENDING_CERTIFICATE indicates the operation failed because the
// early callback indicated certificate lookup was incomplete. The caller may
// retry the operation when lookup has completed.
//
// See also |SSL_CTX_set_select_certificate_cb|.
#define SSL_ERROR_PENDING_CERTIFICATE 12
// SSL_ERROR_WANT_PRIVATE_KEY_OPERATION indicates the operation failed because
// a private key operation was unfinished. The caller may retry the operation
// when the private key operation is complete.
//
// See also |SSL_set_private_key_method| and
// |SSL_CTX_set_private_key_method|.
#define SSL_ERROR_WANT_PRIVATE_KEY_OPERATION 13
// SSL_ERROR_PENDING_TICKET indicates that a ticket decryption is pending. The
// caller may retry the operation when the decryption is ready.
//
// See also |SSL_CTX_set_ticket_aead_method|.
#define SSL_ERROR_PENDING_TICKET 14
// SSL_ERROR_EARLY_DATA_REJECTED indicates that early data was rejected. The
// caller should treat this as a connection failure and retry any operations
// associated with the rejected early data. |SSL_reset_early_data_reject| may be
// used to reuse the underlying connection for the retry.
#define SSL_ERROR_EARLY_DATA_REJECTED 15
// SSL_ERROR_WANT_CERTIFICATE_VERIFY indicates the operation failed because
// certificate verification was incomplete. The caller may retry the operation
// when certificate verification is complete.
//
// See also |SSL_CTX_set_custom_verify|.
#define SSL_ERROR_WANT_CERTIFICATE_VERIFY 16
// SSL_set_mtu sets the |ssl|'s MTU in DTLS to |mtu|. It returns one on success
// and zero on failure.
OPENSSL_EXPORT int SSL_set_mtu(SSL *ssl, unsigned mtu);
// DTLSv1_set_initial_timeout_duration sets the initial duration for a DTLS
// handshake timeout.
//
// This duration overrides the default of 1 second, which is the strong
// recommendation of RFC 6347 (see section 4.2.4.1). However, there may exist
// situations where a shorter timeout would be beneficial, such as for
// time-sensitive applications.
OPENSSL_EXPORT void DTLSv1_set_initial_timeout_duration(SSL *ssl,
unsigned duration_ms);
// DTLSv1_get_timeout queries the next DTLS handshake timeout. If there is a
// timeout in progress, it sets |*out| to the time remaining and returns one.
// Otherwise, it returns zero.
//
// When the timeout expires, call |DTLSv1_handle_timeout| to handle the
// retransmit behavior.
//
// NOTE: This function must be queried again whenever the handshake state
// machine changes, including when |DTLSv1_handle_timeout| is called.
OPENSSL_EXPORT int DTLSv1_get_timeout(const SSL *ssl, struct timeval *out);
// DTLSv1_handle_timeout is called when a DTLS handshake timeout expires. If no
// timeout had expired, it returns 0. Otherwise, it retransmits the previous
// flight of handshake messages and returns 1. If too many timeouts had expired
// without progress or an error occurs, it returns -1.
//
// The caller's external timer should be compatible with the one |ssl| queries
// within some fudge factor. Otherwise, the call will be a no-op, but
// |DTLSv1_get_timeout| will return an updated timeout.
//
// If the function returns -1, checking if |SSL_get_error| returns
// |SSL_ERROR_WANT_WRITE| may be used to determine if the retransmit failed due
// to a non-fatal error at the write |BIO|. However, the operation may not be
// retried until the next timeout fires.
//
// WARNING: This function breaks the usual return value convention.
//
// TODO(davidben): This |SSL_ERROR_WANT_WRITE| behavior is kind of bizarre.
OPENSSL_EXPORT int DTLSv1_handle_timeout(SSL *ssl);
// Protocol versions.
#define DTLS1_VERSION_MAJOR 0xfe
#define SSL3_VERSION_MAJOR 0x03
#define SSL3_VERSION 0x0300
#define TLS1_VERSION 0x0301
#define TLS1_1_VERSION 0x0302
#define TLS1_2_VERSION 0x0303
#define TLS1_3_VERSION 0x0304
#define DTLS1_VERSION 0xfeff
#define DTLS1_2_VERSION 0xfefd
#define TLS1_3_DRAFT_VERSION 0x7f12
#define TLS1_3_DRAFT21_VERSION 0x7f15
#define TLS1_3_DRAFT22_VERSION 0x7e04
#define TLS1_3_EXPERIMENT_VERSION 0x7e01
#define TLS1_3_EXPERIMENT2_VERSION 0x7e02
#define TLS1_3_EXPERIMENT3_VERSION 0x7e03
// SSL_CTX_set_min_proto_version sets the minimum protocol version for |ctx| to
// |version|. If |version| is zero, the default minimum version is used. It
// returns one on success and zero if |version| is invalid.
OPENSSL_EXPORT int SSL_CTX_set_min_proto_version(SSL_CTX *ctx,
uint16_t version);
// SSL_CTX_set_max_proto_version sets the maximum protocol version for |ctx| to
// |version|. If |version| is zero, the default maximum version is used. It
// returns one on success and zero if |version| is invalid.
OPENSSL_EXPORT int SSL_CTX_set_max_proto_version(SSL_CTX *ctx,
uint16_t version);
// SSL_set_min_proto_version sets the minimum protocol version for |ssl| to
// |version|. If |version| is zero, the default minimum version is used. It
// returns one on success and zero if |version| is invalid.
OPENSSL_EXPORT int SSL_set_min_proto_version(SSL *ssl, uint16_t version);
// SSL_set_max_proto_version sets the maximum protocol version for |ssl| to
// |version|. If |version| is zero, the default maximum version is used. It
// returns one on success and zero if |version| is invalid.
OPENSSL_EXPORT int SSL_set_max_proto_version(SSL *ssl, uint16_t version);
// SSL_version returns the TLS or DTLS protocol version used by |ssl|, which is
// one of the |*_VERSION| values. (E.g. |TLS1_2_VERSION|.) Before the version
// is negotiated, the result is undefined.
OPENSSL_EXPORT int SSL_version(const SSL *ssl);
// Options.
//
// Options configure protocol behavior.
// SSL_OP_NO_QUERY_MTU, in DTLS, disables querying the MTU from the underlying
// |BIO|. Instead, the MTU is configured with |SSL_set_mtu|.
#define SSL_OP_NO_QUERY_MTU 0x00001000L
// SSL_OP_NO_TICKET disables session ticket support (RFC 5077).
#define SSL_OP_NO_TICKET 0x00004000L
// SSL_OP_CIPHER_SERVER_PREFERENCE configures servers to select ciphers and
// ECDHE curves according to the server's preferences instead of the
// client's.
#define SSL_OP_CIPHER_SERVER_PREFERENCE 0x00400000L
// The following flags toggle individual protocol versions. This is deprecated.
// Use |SSL_CTX_set_min_proto_version| and |SSL_CTX_set_max_proto_version|
// instead.
#define SSL_OP_NO_SSLv3 0x02000000L
#define SSL_OP_NO_TLSv1 0x04000000L
#define SSL_OP_NO_TLSv1_2 0x08000000L
#define SSL_OP_NO_TLSv1_1 0x10000000L
#define SSL_OP_NO_TLSv1_3 0x20000000L
#define SSL_OP_NO_DTLSv1 SSL_OP_NO_TLSv1
#define SSL_OP_NO_DTLSv1_2 SSL_OP_NO_TLSv1_2
// SSL_CTX_set_options enables all options set in |options| (which should be one
// or more of the |SSL_OP_*| values, ORed together) in |ctx|. It returns a
// bitmask representing the resulting enabled options.
OPENSSL_EXPORT uint32_t SSL_CTX_set_options(SSL_CTX *ctx, uint32_t options);
// SSL_CTX_clear_options disables all options set in |options| (which should be
// one or more of the |SSL_OP_*| values, ORed together) in |ctx|. It returns a
// bitmask representing the resulting enabled options.
OPENSSL_EXPORT uint32_t SSL_CTX_clear_options(SSL_CTX *ctx, uint32_t options);
// SSL_CTX_get_options returns a bitmask of |SSL_OP_*| values that represent all
// the options enabled for |ctx|.
OPENSSL_EXPORT uint32_t SSL_CTX_get_options(const SSL_CTX *ctx);
// SSL_set_options enables all options set in |options| (which should be one or
// more of the |SSL_OP_*| values, ORed together) in |ssl|. It returns a bitmask
// representing the resulting enabled options.
OPENSSL_EXPORT uint32_t SSL_set_options(SSL *ssl, uint32_t options);
// SSL_clear_options disables all options set in |options| (which should be one
// or more of the |SSL_OP_*| values, ORed together) in |ssl|. It returns a
// bitmask representing the resulting enabled options.
OPENSSL_EXPORT uint32_t SSL_clear_options(SSL *ssl, uint32_t options);
// SSL_get_options returns a bitmask of |SSL_OP_*| values that represent all the
// options enabled for |ssl|.
OPENSSL_EXPORT uint32_t SSL_get_options(const SSL *ssl);
// Modes.
//
// Modes configure API behavior.
// SSL_MODE_ENABLE_PARTIAL_WRITE, in TLS, allows |SSL_write| to complete with a
// partial result when the only part of the input was written in a single
// record. In DTLS, it does nothing.
#define SSL_MODE_ENABLE_PARTIAL_WRITE 0x00000001L
// SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER, in TLS, allows retrying an incomplete
// |SSL_write| with a different buffer. However, |SSL_write| still assumes the
// buffer contents are unchanged. This is not the default to avoid the
// misconception that non-blocking |SSL_write| behaves like non-blocking
// |write|. In DTLS, it does nothing.
#define SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER 0x00000002L
// SSL_MODE_NO_AUTO_CHAIN disables automatically building a certificate chain
// before sending certificates to the peer. This flag is set (and the feature
// disabled) by default.
// TODO(davidben): Remove this behavior. https://crbug.com/boringssl/42.
#define SSL_MODE_NO_AUTO_CHAIN 0x00000008L
// SSL_MODE_ENABLE_FALSE_START allows clients to send application data before
// receipt of ChangeCipherSpec and Finished. This mode enables full handshakes
// to 'complete' in one RTT. See RFC 7918.
//
// When False Start is enabled, |SSL_do_handshake| may succeed before the
// handshake has completely finished. |SSL_write| will function at this point,
// and |SSL_read| will transparently wait for the final handshake leg before
// returning application data. To determine if False Start occurred or when the
// handshake is completely finished, see |SSL_in_false_start|, |SSL_in_init|,
// and |SSL_CB_HANDSHAKE_DONE| from |SSL_CTX_set_info_callback|.
#define SSL_MODE_ENABLE_FALSE_START 0x00000080L
// SSL_MODE_CBC_RECORD_SPLITTING causes multi-byte CBC records in SSL 3.0 and
// TLS 1.0 to be split in two: the first record will contain a single byte and
// the second will contain the remainder. This effectively randomises the IV and
// prevents BEAST attacks.
#define SSL_MODE_CBC_RECORD_SPLITTING 0x00000100L
// SSL_MODE_NO_SESSION_CREATION will cause any attempts to create a session to
// fail with SSL_R_SESSION_MAY_NOT_BE_CREATED. This can be used to enforce that
// session resumption is used for a given SSL*.
#define SSL_MODE_NO_SESSION_CREATION 0x00000200L
// SSL_MODE_SEND_FALLBACK_SCSV sends TLS_FALLBACK_SCSV in the ClientHello.
// To be set only by applications that reconnect with a downgraded protocol
// version; see RFC 7507 for details.
//
// DO NOT ENABLE THIS if your application attempts a normal handshake. Only use
// this in explicit fallback retries, following the guidance in RFC 7507.
#define SSL_MODE_SEND_FALLBACK_SCSV 0x00000400L
// SSL_CTX_set_mode enables all modes set in |mode| (which should be one or more
// of the |SSL_MODE_*| values, ORed together) in |ctx|. It returns a bitmask
// representing the resulting enabled modes.
OPENSSL_EXPORT uint32_t SSL_CTX_set_mode(SSL_CTX *ctx, uint32_t mode);
// SSL_CTX_clear_mode disables all modes set in |mode| (which should be one or
// more of the |SSL_MODE_*| values, ORed together) in |ctx|. It returns a
// bitmask representing the resulting enabled modes.
OPENSSL_EXPORT uint32_t SSL_CTX_clear_mode(SSL_CTX *ctx, uint32_t mode);
// SSL_CTX_get_mode returns a bitmask of |SSL_MODE_*| values that represent all
// the modes enabled for |ssl|.
OPENSSL_EXPORT uint32_t SSL_CTX_get_mode(const SSL_CTX *ctx);
// SSL_set_mode enables all modes set in |mode| (which should be one or more of
// the |SSL_MODE_*| values, ORed together) in |ssl|. It returns a bitmask
// representing the resulting enabled modes.
OPENSSL_EXPORT uint32_t SSL_set_mode(SSL *ssl, uint32_t mode);
// SSL_clear_mode disables all modes set in |mode| (which should be one or more
// of the |SSL_MODE_*| values, ORed together) in |ssl|. It returns a bitmask
// representing the resulting enabled modes.
OPENSSL_EXPORT uint32_t SSL_clear_mode(SSL *ssl, uint32_t mode);
// SSL_get_mode returns a bitmask of |SSL_MODE_*| values that represent all the
// modes enabled for |ssl|.
OPENSSL_EXPORT uint32_t SSL_get_mode(const SSL *ssl);
// SSL_CTX_set0_buffer_pool sets a |CRYPTO_BUFFER_POOL| that will be used to
// store certificates. This can allow multiple connections to share
// certificates and thus save memory.
//
// The SSL_CTX does not take ownership of |pool| and the caller must ensure
// that |pool| outlives |ctx| and all objects linked to it, including |SSL|,
// |X509| and |SSL_SESSION| objects. Basically, don't ever free |pool|.
OPENSSL_EXPORT void SSL_CTX_set0_buffer_pool(SSL_CTX *ctx,
CRYPTO_BUFFER_POOL *pool);
// Configuring certificates and private keys.
//
// These functions configure the connection's leaf certificate, private key, and
// certificate chain. The certificate chain is ordered leaf to root (as sent on
// the wire) but does not include the leaf. Both client and server certificates
// use these functions.
//
// Certificates and keys may be configured before the handshake or dynamically
// in the early callback and certificate callback.
// SSL_CTX_use_certificate sets |ctx|'s leaf certificate to |x509|. It returns
// one on success and zero on failure.
OPENSSL_EXPORT int SSL_CTX_use_certificate(SSL_CTX *ctx, X509 *x509);
// SSL_use_certificate sets |ssl|'s leaf certificate to |x509|. It returns one
// on success and zero on failure.
OPENSSL_EXPORT int SSL_use_certificate(SSL *ssl, X509 *x509);
// SSL_CTX_use_PrivateKey sets |ctx|'s private key to |pkey|. It returns one on
// success and zero on failure.
OPENSSL_EXPORT int SSL_CTX_use_PrivateKey(SSL_CTX *ctx, EVP_PKEY *pkey);
// SSL_use_PrivateKey sets |ssl|'s private key to |pkey|. It returns one on
// success and zero on failure.
OPENSSL_EXPORT int SSL_use_PrivateKey(SSL *ssl, EVP_PKEY *pkey);
// SSL_CTX_set0_chain sets |ctx|'s certificate chain, excluding the leaf, to
// |chain|. On success, it returns one and takes ownership of |chain|.
// Otherwise, it returns zero.
OPENSSL_EXPORT int SSL_CTX_set0_chain(SSL_CTX *ctx, STACK_OF(X509) *chain);
// SSL_CTX_set1_chain sets |ctx|'s certificate chain, excluding the leaf, to
// |chain|. It returns one on success and zero on failure. The caller retains
// ownership of |chain| and may release it freely.
OPENSSL_EXPORT int SSL_CTX_set1_chain(SSL_CTX *ctx, STACK_OF(X509) *chain);
// SSL_set0_chain sets |ssl|'s certificate chain, excluding the leaf, to
// |chain|. On success, it returns one and takes ownership of |chain|.
// Otherwise, it returns zero.
OPENSSL_EXPORT int SSL_set0_chain(SSL *ssl, STACK_OF(X509) *chain);
// SSL_set1_chain sets |ssl|'s certificate chain, excluding the leaf, to
// |chain|. It returns one on success and zero on failure. The caller retains
// ownership of |chain| and may release it freely.
OPENSSL_EXPORT int SSL_set1_chain(SSL *ssl, STACK_OF(X509) *chain);
// SSL_CTX_add0_chain_cert appends |x509| to |ctx|'s certificate chain. On
// success, it returns one and takes ownership of |x509|. Otherwise, it returns
// zero.
OPENSSL_EXPORT int SSL_CTX_add0_chain_cert(SSL_CTX *ctx, X509 *x509);
// SSL_CTX_add1_chain_cert appends |x509| to |ctx|'s certificate chain. It
// returns one on success and zero on failure. The caller retains ownership of
// |x509| and may release it freely.
OPENSSL_EXPORT int SSL_CTX_add1_chain_cert(SSL_CTX *ctx, X509 *x509);
// SSL_add0_chain_cert appends |x509| to |ctx|'s certificate chain. On success,
// it returns one and takes ownership of |x509|. Otherwise, it returns zero.
OPENSSL_EXPORT int SSL_add0_chain_cert(SSL *ssl, X509 *x509);
// SSL_CTX_add_extra_chain_cert calls |SSL_CTX_add0_chain_cert|.
OPENSSL_EXPORT int SSL_CTX_add_extra_chain_cert(SSL_CTX *ctx, X509 *x509);
// SSL_add1_chain_cert appends |x509| to |ctx|'s certificate chain. It returns
// one on success and zero on failure. The caller retains ownership of |x509|
// and may release it freely.
OPENSSL_EXPORT int SSL_add1_chain_cert(SSL *ssl, X509 *x509);
// SSL_CTX_clear_chain_certs clears |ctx|'s certificate chain and returns
// one.
OPENSSL_EXPORT int SSL_CTX_clear_chain_certs(SSL_CTX *ctx);
// SSL_CTX_clear_extra_chain_certs calls |SSL_CTX_clear_chain_certs|.
OPENSSL_EXPORT int SSL_CTX_clear_extra_chain_certs(SSL_CTX *ctx);
// SSL_clear_chain_certs clears |ssl|'s certificate chain and returns one.
OPENSSL_EXPORT int SSL_clear_chain_certs(SSL *ssl);
// SSL_CTX_set_cert_cb sets a callback that is called to select a certificate.
// The callback returns one on success, zero on internal error, and a negative
// number on failure or to pause the handshake. If the handshake is paused,
// |SSL_get_error| will return |SSL_ERROR_WANT_X509_LOOKUP|.
//
// On the client, the callback may call |SSL_get0_certificate_types| and
// |SSL_get_client_CA_list| for information on the server's certificate
// request.
//
// On the server, the callback will be called on non-resumption handshakes,
// after extensions have been processed.
OPENSSL_EXPORT void SSL_CTX_set_cert_cb(SSL_CTX *ctx,
int (*cb)(SSL *ssl, void *arg),
void *arg);
// SSL_set_cert_cb sets a callback that is called to select a certificate. The
// callback returns one on success, zero on internal error, and a negative
// number on failure or to pause the handshake. If the handshake is paused,
// |SSL_get_error| will return |SSL_ERROR_WANT_X509_LOOKUP|.
//
// On the client, the callback may call |SSL_get0_certificate_types| and
// |SSL_get_client_CA_list| for information on the server's certificate
// request.
OPENSSL_EXPORT void SSL_set_cert_cb(SSL *ssl, int (*cb)(SSL *ssl, void *arg),
void *arg);
// SSL_get0_certificate_types, for a client, sets |*out_types| to an array
// containing the client certificate types requested by a server. It returns the
// length of the array.
//
// The behavior of this function is undefined except during the callbacks set by
// by |SSL_CTX_set_cert_cb| and |SSL_CTX_set_client_cert_cb| or when the
// handshake is paused because of them.
OPENSSL_EXPORT size_t SSL_get0_certificate_types(SSL *ssl,
const uint8_t **out_types);
// SSL_certs_clear resets the private key, leaf certificate, and certificate
// chain of |ssl|.
OPENSSL_EXPORT void SSL_certs_clear(SSL *ssl);
// SSL_CTX_check_private_key returns one if the certificate and private key
// configured in |ctx| are consistent and zero otherwise.
OPENSSL_EXPORT int SSL_CTX_check_private_key(const SSL_CTX *ctx);
// SSL_check_private_key returns one if the certificate and private key
// configured in |ssl| are consistent and zero otherwise.
OPENSSL_EXPORT int SSL_check_private_key(const SSL *ssl);
// SSL_CTX_get0_certificate returns |ctx|'s leaf certificate.
OPENSSL_EXPORT X509 *SSL_CTX_get0_certificate(const SSL_CTX *ctx);
// SSL_get_certificate returns |ssl|'s leaf certificate.
OPENSSL_EXPORT X509 *SSL_get_certificate(const SSL *ssl);
// SSL_CTX_get0_privatekey returns |ctx|'s private key.
OPENSSL_EXPORT EVP_PKEY *SSL_CTX_get0_privatekey(const SSL_CTX *ctx);
// SSL_get_privatekey returns |ssl|'s private key.
OPENSSL_EXPORT EVP_PKEY *SSL_get_privatekey(const SSL *ssl);
// SSL_CTX_get0_chain_certs sets |*out_chain| to |ctx|'s certificate chain and
// returns one.
OPENSSL_EXPORT int SSL_CTX_get0_chain_certs(const SSL_CTX *ctx,
STACK_OF(X509) **out_chain);
// SSL_CTX_get_extra_chain_certs calls |SSL_CTX_get0_chain_certs|.
OPENSSL_EXPORT int SSL_CTX_get_extra_chain_certs(const SSL_CTX *ctx,
STACK_OF(X509) **out_chain);
// SSL_get0_chain_certs sets |*out_chain| to |ssl|'s certificate chain and
// returns one.
OPENSSL_EXPORT int SSL_get0_chain_certs(const SSL *ssl,
STACK_OF(X509) **out_chain);
// SSL_CTX_set_signed_cert_timestamp_list sets the list of signed certificate
// timestamps that is sent to clients that request it. The |list| argument must
// contain one or more SCT structures serialised as a SignedCertificateTimestamp
// List (see https://tools.ietf.org/html/rfc6962#section-3.3) – i.e. each SCT
// is prefixed by a big-endian, uint16 length and the concatenation of one or
// more such prefixed SCTs are themselves also prefixed by a uint16 length. It
// returns one on success and zero on error. The caller retains ownership of
// |list|.
OPENSSL_EXPORT int SSL_CTX_set_signed_cert_timestamp_list(SSL_CTX *ctx,
const uint8_t *list,
size_t list_len);
// SSL_set_signed_cert_timestamp_list sets the list of signed certificate
// timestamps that is sent to clients that request is. The same format as the
// one used for |SSL_CTX_set_signed_cert_timestamp_list| applies. The caller
// retains ownership of |list|.
OPENSSL_EXPORT int SSL_set_signed_cert_timestamp_list(SSL *ctx,
const uint8_t *list,
size_t list_len);
// SSL_CTX_set_ocsp_response sets the OCSP response that is sent to clients
// which request it. It returns one on success and zero on error. The caller
// retains ownership of |response|.
OPENSSL_EXPORT int SSL_CTX_set_ocsp_response(SSL_CTX *ctx,
const uint8_t *response,
size_t response_len);
// SSL_set_ocsp_response sets the OCSP response that is sent to clients which
// request it. It returns one on success and zero on error. The caller retains
// ownership of |response|.
OPENSSL_EXPORT int SSL_set_ocsp_response(SSL *ssl,
const uint8_t *response,
size_t response_len);
// SSL_SIGN_* are signature algorithm values as defined in TLS 1.3.
#define SSL_SIGN_RSA_PKCS1_SHA1 0x0201
#define SSL_SIGN_RSA_PKCS1_SHA256 0x0401
#define SSL_SIGN_RSA_PKCS1_SHA384 0x0501
#define SSL_SIGN_RSA_PKCS1_SHA512 0x0601
#define SSL_SIGN_ECDSA_SHA1 0x0203
#define SSL_SIGN_ECDSA_SECP256R1_SHA256 0x0403
#define SSL_SIGN_ECDSA_SECP384R1_SHA384 0x0503
#define SSL_SIGN_ECDSA_SECP521R1_SHA512 0x0603
#define SSL_SIGN_RSA_PSS_SHA256 0x0804
#define SSL_SIGN_RSA_PSS_SHA384 0x0805
#define SSL_SIGN_RSA_PSS_SHA512 0x0806
#define SSL_SIGN_ED25519 0x0807
// SSL_SIGN_RSA_PKCS1_MD5_SHA1 is an internal signature algorithm used to
// specify raw RSASSA-PKCS1-v1_5 with an MD5/SHA-1 concatenation, as used in TLS
// before TLS 1.2.
#define SSL_SIGN_RSA_PKCS1_MD5_SHA1 0xff01
// SSL_get_signature_algorithm_name returns a human-readable name for |sigalg|,
// or NULL if unknown. If |include_curve| is one, the curve for ECDSA algorithms
// is included as in TLS 1.3. Otherwise, it is excluded as in TLS 1.2.
OPENSSL_EXPORT const char *SSL_get_signature_algorithm_name(uint16_t sigalg,
int include_curve);
// SSL_get_signature_algorithm_key_type returns the key type associated with
// |sigalg| as an |EVP_PKEY_*| constant or |EVP_PKEY_NONE| if unknown.
OPENSSL_EXPORT int SSL_get_signature_algorithm_key_type(uint16_t sigalg);
// SSL_get_signature_algorithm_digest returns the digest function associated
// with |sigalg| or |NULL| if |sigalg| has no prehash (Ed25519) or is unknown.
OPENSSL_EXPORT const EVP_MD *SSL_get_signature_algorithm_digest(
uint16_t sigalg);
// SSL_is_signature_algorithm_rsa_pss returns one if |sigalg| is an RSA-PSS
// signature algorithm and zero otherwise.
OPENSSL_EXPORT int SSL_is_signature_algorithm_rsa_pss(uint16_t sigalg);
// SSL_CTX_set_signing_algorithm_prefs configures |ctx| to use |prefs| as the
// preference list when signing with |ctx|'s private key. It returns one on
// success and zero on error. |prefs| should not include the internal-only value
// |SSL_SIGN_RSA_PKCS1_MD5_SHA1|.
OPENSSL_EXPORT int SSL_CTX_set_signing_algorithm_prefs(SSL_CTX *ctx,
const uint16_t *prefs,
size_t num_prefs);
// SSL_set_signing_algorithm_prefs configures |ssl| to use |prefs| as the
// preference list when signing with |ssl|'s private key. It returns one on
// success and zero on error. |prefs| should not include the internal-only value
// |SSL_SIGN_RSA_PKCS1_MD5_SHA1|.
OPENSSL_EXPORT int SSL_set_signing_algorithm_prefs(SSL *ssl,
const uint16_t *prefs,
size_t num_prefs);
// Certificate and private key convenience functions.
// SSL_CTX_set_chain_and_key sets the certificate chain and private key for a
// TLS client or server. References to the given |CRYPTO_BUFFER| and |EVP_PKEY|
// objects are added as needed. Exactly one of |privkey| or |privkey_method|
// may be non-NULL. Returns one on success and zero on error.
OPENSSL_EXPORT int SSL_CTX_set_chain_and_key(
SSL_CTX *ctx, CRYPTO_BUFFER *const *certs, size_t num_certs,
EVP_PKEY *privkey, const SSL_PRIVATE_KEY_METHOD *privkey_method);
// SSL_set_chain_and_key sets the certificate chain and private key for a TLS
// client or server. References to the given |CRYPTO_BUFFER| and |EVP_PKEY|
// objects are added as needed. Exactly one of |privkey| or |privkey_method|
// may be non-NULL. Returns one on success and zero on error.
OPENSSL_EXPORT int SSL_set_chain_and_key(
SSL *ssl, CRYPTO_BUFFER *const *certs, size_t num_certs, EVP_PKEY *privkey,
const SSL_PRIVATE_KEY_METHOD *privkey_method);
// SSL_CTX_use_RSAPrivateKey sets |ctx|'s private key to |rsa|. It returns one
// on success and zero on failure.
OPENSSL_EXPORT int SSL_CTX_use_RSAPrivateKey(SSL_CTX *ctx, RSA *rsa);
// SSL_use_RSAPrivateKey sets |ctx|'s private key to |rsa|. It returns one on
// success and zero on failure.
OPENSSL_EXPORT int SSL_use_RSAPrivateKey(SSL *ssl, RSA *rsa);
// The following functions configure certificates or private keys but take as
// input DER-encoded structures. They return one on success and zero on
// failure.
OPENSSL_EXPORT int SSL_CTX_use_certificate_ASN1(SSL_CTX *ctx, size_t der_len,
const uint8_t *der);
OPENSSL_EXPORT int SSL_use_certificate_ASN1(SSL *ssl, const uint8_t *der,
size_t der_len);
OPENSSL_EXPORT int SSL_CTX_use_PrivateKey_ASN1(int pk, SSL_CTX *ctx,
const uint8_t *der,
size_t der_len);
OPENSSL_EXPORT int SSL_use_PrivateKey_ASN1(int type, SSL *ssl,
const uint8_t *der, size_t der_len);
OPENSSL_EXPORT int SSL_CTX_use_RSAPrivateKey_ASN1(SSL_CTX *ctx,
const uint8_t *der,
size_t der_len);
OPENSSL_EXPORT int SSL_use_RSAPrivateKey_ASN1(SSL *ssl, const uint8_t *der,
size_t der_len);
// The following functions configure certificates or private keys but take as
// input files to read from. They return one on success and zero on failure. The
// |type| parameter is one of the |SSL_FILETYPE_*| values and determines whether
// the file's contents are read as PEM or DER.
#define SSL_FILETYPE_PEM 1
#define SSL_FILETYPE_ASN1 2
OPENSSL_EXPORT int SSL_CTX_use_RSAPrivateKey_file(SSL_CTX *ctx,
const char *file,
int type);
OPENSSL_EXPORT int SSL_use_RSAPrivateKey_file(SSL *ssl, const char *file,
int type);
OPENSSL_EXPORT int SSL_CTX_use_certificate_file(SSL_CTX *ctx, const char *file,
int type);
OPENSSL_EXPORT int SSL_use_certificate_file(SSL *ssl, const char *file,
int type);
OPENSSL_EXPORT int SSL_CTX_use_PrivateKey_file(SSL_CTX *ctx, const char *file,
int type);
OPENSSL_EXPORT int SSL_use_PrivateKey_file(SSL *ssl, const char *file,
int type);
// SSL_CTX_use_certificate_chain_file configures certificates for |ctx|. It
// reads the contents of |file| as a PEM-encoded leaf certificate followed
// optionally by the certificate chain to send to the peer. It returns one on
// success and zero on failure.
OPENSSL_EXPORT int SSL_CTX_use_certificate_chain_file(SSL_CTX *ctx,
const char *file);
// SSL_CTX_set_default_passwd_cb sets the password callback for PEM-based
// convenience functions called on |ctx|.
OPENSSL_EXPORT void SSL_CTX_set_default_passwd_cb(SSL_CTX *ctx,
pem_password_cb *cb);
// SSL_CTX_get_default_passwd_cb returns the callback set by
// |SSL_CTX_set_default_passwd_cb|.
OPENSSL_EXPORT pem_password_cb *SSL_CTX_get_default_passwd_cb(
const SSL_CTX *ctx);
// SSL_CTX_set_default_passwd_cb_userdata sets the userdata parameter for
// |ctx|'s password callback.
OPENSSL_EXPORT void SSL_CTX_set_default_passwd_cb_userdata(SSL_CTX *ctx,
void *data);
// SSL_CTX_get_default_passwd_cb_userdata returns the userdata parameter set by
// |SSL_CTX_set_default_passwd_cb_userdata|.
OPENSSL_EXPORT void *SSL_CTX_get_default_passwd_cb_userdata(const SSL_CTX *ctx);
// Custom private keys.
enum ssl_private_key_result_t {
ssl_private_key_success,
ssl_private_key_retry,
ssl_private_key_failure,
};
// ssl_private_key_method_st (aka |SSL_PRIVATE_KEY_METHOD|) describes private
// key hooks. This is used to off-load signing operations to a custom,
// potentially asynchronous, backend. Metadata about the key such as the type
// and size are parsed out of the certificate.
//
// TODO(davidben): This API has a number of legacy hooks. Remove the last
// consumer of |sign_digest| and trim it.
struct ssl_private_key_method_st {
// type is ignored and should be NULL.
int (*type)(SSL *ssl);
// max_signature_len is ignored and should be NULL.
size_t (*max_signature_len)(SSL *ssl);
// sign signs the message |in| in using the specified signature algorithm. On
// success, it returns |ssl_private_key_success| and writes at most |max_out|
// bytes of signature data to |out| and sets |*out_len| to the number of bytes
// written. On failure, it returns |ssl_private_key_failure|. If the operation
// has not completed, it returns |ssl_private_key_retry|. |sign| should
// arrange for the high-level operation on |ssl| to be retried when the
// operation is completed. This will result in a call to |complete|.
//
// |signature_algorithm| is one of the |SSL_SIGN_*| values, as defined in TLS
// 1.3. Note that, in TLS 1.2, ECDSA algorithms do not require that curve
// sizes match hash sizes, so the curve portion of |SSL_SIGN_ECDSA_*| values
// must be ignored. BoringSSL will internally handle the curve matching logic
// where appropriate.
//
// It is an error to call |sign| while another private key operation is in
// progress on |ssl|.
enum ssl_private_key_result_t (*sign)(SSL *ssl, uint8_t *out, size_t *out_len,
size_t max_out,
uint16_t signature_algorithm,
const uint8_t *in, size_t in_len);
// sign_digest signs |in_len| bytes of digest from |in|. |md| is the hash
// function used to calculate |in|. On success, it returns
// |ssl_private_key_success| and writes at most |max_out| bytes of signature
// data to |out|. On failure, it returns |ssl_private_key_failure|. If the
// operation has not completed, it returns |ssl_private_key_retry|. |sign|
// should arrange for the high-level operation on |ssl| to be retried when the
// operation is completed. This will result in a call to |complete|.
//
// If the key is an RSA key, implementations must use PKCS#1 padding. |in| is
// the digest itself, so the DigestInfo prefix, if any, must be prepended by
// |sign|. If |md| is |EVP_md5_sha1|, there is no prefix.
//
// It is an error to call |sign_digest| while another private key operation is
// in progress on |ssl|.
//
// This function is deprecated. Implement |sign| instead.
//
// TODO(davidben): Remove this function.
enum ssl_private_key_result_t (*sign_digest)(SSL *ssl, uint8_t *out,
size_t *out_len, size_t max_out,
const EVP_MD *md,
const uint8_t *in,
size_t in_len);
// decrypt decrypts |in_len| bytes of encrypted data from |in|. On success it
// returns |ssl_private_key_success|, writes at most |max_out| bytes of
// decrypted data to |out| and sets |*out_len| to the actual number of bytes
// written. On failure it returns |ssl_private_key_failure|. If the operation
// has not completed, it returns |ssl_private_key_retry|. The caller should
// arrange for the high-level operation on |ssl| to be retried when the
// operation is completed, which will result in a call to |complete|. This
// function only works with RSA keys and should perform a raw RSA decryption
// operation with no padding.
//
// It is an error to call |decrypt| while another private key operation is in
// progress on |ssl|.
enum ssl_private_key_result_t (*decrypt)(SSL *ssl, uint8_t *out,
size_t *out_len, size_t max_out,
const uint8_t *in, size_t in_len);
// complete completes a pending operation. If the operation has completed, it
// returns |ssl_private_key_success| and writes the result to |out| as in
// |sign|. Otherwise, it returns |ssl_private_key_failure| on failure and
// |ssl_private_key_retry| if the operation is still in progress.
//
// |complete| may be called arbitrarily many times before completion, but it
// is an error to call |complete| if there is no pending operation in progress
// on |ssl|.
enum ssl_private_key_result_t (*complete)(SSL *ssl, uint8_t *out,
size_t *out_len, size_t max_out);
};
// SSL_set_private_key_method configures a custom private key on |ssl|.
// |key_method| must remain valid for the lifetime of |ssl|.
OPENSSL_EXPORT void SSL_set_private_key_method(
SSL *ssl, const SSL_PRIVATE_KEY_METHOD *key_method);
// SSL_CTX_set_private_key_method configures a custom private key on |ctx|.
// |key_method| must remain valid for the lifetime of |ctx|.
OPENSSL_EXPORT void SSL_CTX_set_private_key_method(
SSL_CTX *ctx, const SSL_PRIVATE_KEY_METHOD *key_method);
// Cipher suites.
//
// |SSL_CIPHER| objects represent cipher suites.
DEFINE_CONST_STACK_OF(SSL_CIPHER)
// SSL_get_cipher_by_value returns the structure representing a TLS cipher
// suite based on its assigned number, or NULL if unknown. See
// https://www.iana.org/assignments/tls-parameters/tls-parameters.xhtml#tls-parameters-4.
OPENSSL_EXPORT const SSL_CIPHER *SSL_get_cipher_by_value(uint16_t value);
// SSL_CIPHER_get_id returns |cipher|'s id. It may be cast to a |uint16_t| to
// get the cipher suite value.
OPENSSL_EXPORT uint32_t SSL_CIPHER_get_id(const SSL_CIPHER *cipher);
// SSL_CIPHER_is_aead returns one if |cipher| uses an AEAD cipher.
OPENSSL_EXPORT int SSL_CIPHER_is_aead(const SSL_CIPHER *cipher);
// SSL_CIPHER_is_block_cipher returns one if |cipher| is a block cipher.
OPENSSL_EXPORT int SSL_CIPHER_is_block_cipher(const SSL_CIPHER *cipher);
// SSL_CIPHER_get_cipher_nid returns the NID for |cipher|'s bulk
// cipher. Possible values are |NID_aes_128_gcm|, |NID_aes_256_gcm|,
// |NID_chacha20_poly1305|, |NID_aes_128_cbc|, |NID_aes_256_cbc|, and
// |NID_des_ede3_cbc|.
OPENSSL_EXPORT int SSL_CIPHER_get_cipher_nid(const SSL_CIPHER *cipher);
// SSL_CIPHER_get_digest_nid returns the NID for |cipher|'s HMAC if it is a
// legacy cipher suite. For modern AEAD-based ciphers (see
// |SSL_CIPHER_is_aead|), it returns |NID_undef|.
//
// Note this function only returns the legacy HMAC digest, not the PRF hash.
OPENSSL_EXPORT int SSL_CIPHER_get_digest_nid(const SSL_CIPHER *cipher);
// SSL_CIPHER_get_kx_nid returns the NID for |cipher|'s key exchange. This may
// be |NID_kx_rsa|, |NID_kx_ecdhe|, or |NID_kx_psk| for TLS 1.2. In TLS 1.3,
// cipher suites do not specify the key exchange, so this function returns
// |NID_kx_any|.
OPENSSL_EXPORT int SSL_CIPHER_get_kx_nid(const SSL_CIPHER *cipher);
// SSL_CIPHER_get_auth_nid returns the NID for |cipher|'s authentication
// type. This may be |NID_auth_rsa|, |NID_auth_ecdsa|, or |NID_auth_psk| for TLS
// 1.2. In TLS 1.3, cipher suites do not specify authentication, so this
// function returns |NID_auth_any|.
OPENSSL_EXPORT int SSL_CIPHER_get_auth_nid(const SSL_CIPHER *cipher);
// SSL_CIPHER_get_prf_nid retuns the NID for |cipher|'s PRF hash. If |cipher| is
// a pre-TLS-1.2 cipher, it returns |NID_md5_sha1| but note these ciphers use
// SHA-256 in TLS 1.2. Other return values may be treated uniformly in all
// applicable versions.
OPENSSL_EXPORT int SSL_CIPHER_get_prf_nid(const SSL_CIPHER *cipher);
// SSL_CIPHER_get_min_version returns the minimum protocol version required
// for |cipher|.
OPENSSL_EXPORT uint16_t SSL_CIPHER_get_min_version(const SSL_CIPHER *cipher);
// SSL_CIPHER_get_max_version returns the maximum protocol version that
// supports |cipher|.
OPENSSL_EXPORT uint16_t SSL_CIPHER_get_max_version(const SSL_CIPHER *cipher);
// SSL_CIPHER_standard_name returns the standard IETF name for |cipher|. For
// example, "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256".
OPENSSL_EXPORT const char *SSL_CIPHER_standard_name(const SSL_CIPHER *cipher);
// SSL_CIPHER_get_name returns the OpenSSL name of |cipher|. For example,
// "ECDHE-RSA-AES128-GCM-SHA256".
OPENSSL_EXPORT const char *SSL_CIPHER_get_name(const SSL_CIPHER *cipher);
// SSL_CIPHER_get_kx_name returns a string that describes the key-exchange
// method used by |cipher|. For example, "ECDHE_ECDSA". TLS 1.3 AEAD-only
// ciphers return the string "GENERIC".
OPENSSL_EXPORT const char *SSL_CIPHER_get_kx_name(const SSL_CIPHER *cipher);
// SSL_CIPHER_get_bits returns the strength, in bits, of |cipher|. If
// |out_alg_bits| is not NULL, it writes the number of bits consumed by the
// symmetric algorithm to |*out_alg_bits|.
OPENSSL_EXPORT int SSL_CIPHER_get_bits(const SSL_CIPHER *cipher,
int *out_alg_bits);
// Cipher suite configuration.
//
// OpenSSL uses a mini-language to configure cipher suites. The language
// maintains an ordered list of enabled ciphers, along with an ordered list of
// disabled but available ciphers. Initially, all ciphers are disabled with a
// default ordering. The cipher string is then interpreted as a sequence of
// directives, separated by colons, each of which modifies this state.
//
// Most directives consist of a one character or empty opcode followed by a
// selector which matches a subset of available ciphers.
//
// Available opcodes are:
//
// The empty opcode enables and appends all matching disabled ciphers to the
// end of the enabled list. The newly appended ciphers are ordered relative to
// each other matching their order in the disabled list.
//
// |-| disables all matching enabled ciphers and prepends them to the disabled
// list, with relative order from the enabled list preserved. This means the
// most recently disabled ciphers get highest preference relative to other
// disabled ciphers if re-enabled.
//
// |+| moves all matching enabled ciphers to the end of the enabled list, with
// relative order preserved.
//
// |!| deletes all matching ciphers, enabled or not, from either list. Deleted
// ciphers will not matched by future operations.
//
// A selector may be a specific cipher (using either the standard or OpenSSL
// name for the cipher) or one or more rules separated by |+|. The final
// selector matches the intersection of each rule. For instance, |AESGCM+aECDSA|
// matches ECDSA-authenticated AES-GCM ciphers.
//
// Available cipher rules are:
//
// |ALL| matches all ciphers.
//
// |kRSA|, |kDHE|, |kECDHE|, and |kPSK| match ciphers using plain RSA, DHE,
// ECDHE, and plain PSK key exchanges, respectively. Note that ECDHE_PSK is
// matched by |kECDHE| and not |kPSK|.
//
// |aRSA|, |aECDSA|, and |aPSK| match ciphers authenticated by RSA, ECDSA, and
// a pre-shared key, respectively.
//
// |RSA|, |DHE|, |ECDHE|, |PSK|, |ECDSA|, and |PSK| are aliases for the
// corresponding |k*| or |a*| cipher rule. |RSA| is an alias for |kRSA|, not
// |aRSA|.
//
// |3DES|, |AES128|, |AES256|, |AES|, |AESGCM|, |CHACHA20| match ciphers
// whose bulk cipher use the corresponding encryption scheme. Note that
// |AES|, |AES128|, and |AES256| match both CBC and GCM ciphers.
//
// |SHA1|, |SHA256|, and |SHA384| match legacy cipher suites using the
// corresponding hash function in their MAC. AEADs are matched by none of
// these.
//
// |SHA| is an alias for |SHA1|.
//
// Although implemented, authentication-only ciphers match no rules and must be
// explicitly selected by name.
//
// Deprecated cipher rules:
//
// |kEDH|, |EDH|, |kEECDH|, and |EECDH| are legacy aliases for |kDHE|, |DHE|,
// |kECDHE|, and |ECDHE|, respectively.
//
// |HIGH| is an alias for |ALL|.
//
// |FIPS| is an alias for |HIGH|.
//
// |SSLv3| and |TLSv1| match ciphers available in TLS 1.1 or earlier.
// |TLSv1_2| matches ciphers new in TLS 1.2. This is confusing and should not
// be used.
//
// Unknown rules are silently ignored by legacy APIs, and rejected by APIs with
// "strict" in the name, which should be preferred. Cipher lists can be long
// and it's easy to commit typos. Strict functions will also reject the use of
// spaces, semi-colons and commas as alternative separators.
//
// The special |@STRENGTH| directive will sort all enabled ciphers by strength.
//
// The |DEFAULT| directive, when appearing at the front of the string, expands
// to the default ordering of available ciphers.
//
// If configuring a server, one may also configure equal-preference groups to
// partially respect the client's preferences when
// |SSL_OP_CIPHER_SERVER_PREFERENCE| is enabled. Ciphers in an equal-preference
// group have equal priority and use the client order. This may be used to
// enforce that AEADs are preferred but select AES-GCM vs. ChaCha20-Poly1305
// based on client preferences. An equal-preference is specified with square
// brackets, combining multiple selectors separated by |. For example:
//
// [ECDHE-ECDSA-CHACHA20-POLY1305|ECDHE-ECDSA-AES128-GCM-SHA256]
//
// Once an equal-preference group is used, future directives must be
// opcode-less. Inside an equal-preference group, spaces are not allowed.
//
// TLS 1.3 ciphers do not participate in this mechanism and instead have a
// built-in preference order. Functions to set cipher lists do not affect TLS
// 1.3, and functions to query the cipher list do not include TLS 1.3
// ciphers.
// SSL_DEFAULT_CIPHER_LIST is the default cipher suite configuration. It is
// substituted when a cipher string starts with 'DEFAULT'.
#define SSL_DEFAULT_CIPHER_LIST "ALL"
// SSL_CTX_set_strict_cipher_list configures the cipher list for |ctx|,
// evaluating |str| as a cipher string and returning error if |str| contains
// anything meaningless. It returns one on success and zero on failure.
OPENSSL_EXPORT int SSL_CTX_set_strict_cipher_list(SSL_CTX *ctx,
const char *str);
// SSL_CTX_set_cipher_list configures the cipher list for |ctx|, evaluating
// |str| as a cipher string. It returns one on success and zero on failure.
//
// Prefer to use |SSL_CTX_set_strict_cipher_list|. This function tolerates
// garbage inputs, unless an empty cipher list results.
OPENSSL_EXPORT int SSL_CTX_set_cipher_list(SSL_CTX *ctx, const char *str);
// SSL_set_strict_cipher_list configures the cipher list for |ssl|, evaluating
// |str| as a cipher string and returning error if |str| contains anything
// meaningless. It returns one on success and zero on failure.
OPENSSL_EXPORT int SSL_set_strict_cipher_list(SSL *ssl, const char *str);
// SSL_set_cipher_list configures the cipher list for |ssl|, evaluating |str| as
// a cipher string. It returns one on success and zero on failure.
//
// Prefer to use |SSL_set_strict_cipher_list|. This function tolerates garbage
// inputs, unless an empty cipher list results.
OPENSSL_EXPORT int SSL_set_cipher_list(SSL *ssl, const char *str);
// SSL_CTX_get_ciphers returns the cipher list for |ctx|, in order of
// preference.
OPENSSL_EXPORT STACK_OF(SSL_CIPHER) *SSL_CTX_get_ciphers(const SSL_CTX *ctx);
// SSL_CTX_cipher_in_group returns one if the |i|th cipher (see
// |SSL_CTX_get_ciphers|) is in the same equipreference group as the one
// following it and zero otherwise.
OPENSSL_EXPORT int SSL_CTX_cipher_in_group(const SSL_CTX *ctx, size_t i);
// SSL_get_ciphers returns the cipher list for |ssl|, in order of preference.
OPENSSL_EXPORT STACK_OF(SSL_CIPHER) *SSL_get_ciphers(const SSL *ssl);
// Connection information.
// SSL_is_init_finished returns one if |ssl| has completed its initial handshake
// and has no pending handshake. It returns zero otherwise.
OPENSSL_EXPORT int SSL_is_init_finished(const SSL *ssl);
// SSL_in_init returns one if |ssl| has a pending handshake and zero
// otherwise.
OPENSSL_EXPORT int SSL_in_init(const SSL *ssl);
// SSL_in_false_start returns one if |ssl| has a pending handshake that is in
// False Start. |SSL_write| may be called at this point without waiting for the
// peer, but |SSL_read| will complete the handshake before accepting application
// data.
//
// See also |SSL_MODE_ENABLE_FALSE_START|.
OPENSSL_EXPORT int SSL_in_false_start(const SSL *ssl);
// SSL_get_peer_certificate returns the peer's leaf certificate or NULL if the
// peer did not use certificates. The caller must call |X509_free| on the
// result to release it.
OPENSSL_EXPORT X509 *SSL_get_peer_certificate(const SSL *ssl);
// SSL_get_peer_cert_chain returns the peer's certificate chain or NULL if
// unavailable or the peer did not use certificates. This is the unverified list
// of certificates as sent by the peer, not the final chain built during
// verification. The caller does not take ownership of the result.
//
// WARNING: This function behaves differently between client and server. If
// |ssl| is a server, the returned chain does not include the leaf certificate.
// If a client, it does.
OPENSSL_EXPORT STACK_OF(X509) *SSL_get_peer_cert_chain(const SSL *ssl);
// SSL_get_peer_full_cert_chain returns the peer's certificate chain, or NULL if
// unavailable or the peer did not use certificates. This is the unverified list
// of certificates as sent by the peer, not the final chain built during
// verification. The caller does not take ownership of the result.
//
// This is the same as |SSL_get_peer_cert_chain| except that this function
// always returns the full chain, i.e. the first element of the return value
// (if any) will be the leaf certificate. In constrast,
// |SSL_get_peer_cert_chain| returns only the intermediate certificates if the
// |ssl| is a server.
OPENSSL_EXPORT STACK_OF(X509) *SSL_get_peer_full_cert_chain(const SSL *ssl);
// SSL_get0_peer_certificates returns the peer's certificate chain, or NULL if
// unavailable or the peer did not use certificates. This is the unverified list
// of certificates as sent by the peer, not the final chain built during
// verification. The caller does not take ownership of the result.
//
// This is the |CRYPTO_BUFFER| variant of |SSL_get_peer_full_cert_chain|.
OPENSSL_EXPORT STACK_OF(CRYPTO_BUFFER) *
SSL_get0_peer_certificates(const SSL *ssl);
// SSL_get0_signed_cert_timestamp_list sets |*out| and |*out_len| to point to
// |*out_len| bytes of SCT information from the server. This is only valid if
// |ssl| is a client. The SCT information is a SignedCertificateTimestampList
// (including the two leading length bytes).
// See https://tools.ietf.org/html/rfc6962#section-3.3
// If no SCT was received then |*out_len| will be zero on return.
//
// WARNING: the returned data is not guaranteed to be well formed.
OPENSSL_EXPORT void SSL_get0_signed_cert_timestamp_list(const SSL *ssl,
const uint8_t **out,
size_t *out_len);
// SSL_get0_ocsp_response sets |*out| and |*out_len| to point to |*out_len|
// bytes of an OCSP response from the server. This is the DER encoding of an
// OCSPResponse type as defined in RFC 2560.
//
// WARNING: the returned data is not guaranteed to be well formed.
OPENSSL_EXPORT void SSL_get0_ocsp_response(const SSL *ssl, const uint8_t **out,
size_t *out_len);
// SSL_get_tls_unique writes at most |max_out| bytes of the tls-unique value
// for |ssl| to |out| and sets |*out_len| to the number of bytes written. It
// returns one on success or zero on error. In general |max_out| should be at
// least 12.
//
// This function will always fail if the initial handshake has not completed.
// The tls-unique value will change after a renegotiation but, since
// renegotiations can be initiated by the server at any point, the higher-level
// protocol must either leave them disabled or define states in which the
// tls-unique value can be read.
//
// The tls-unique value is defined by
// https://tools.ietf.org/html/rfc5929#section-3.1. Due to a weakness in the
// TLS protocol, tls-unique is broken for resumed connections unless the
// Extended Master Secret extension is negotiated. Thus this function will
// return zero if |ssl| performed session resumption unless EMS was used when
// negotiating the original session.
OPENSSL_EXPORT int SSL_get_tls_unique(const SSL *ssl, uint8_t *out,
size_t *out_len, size_t max_out);
// SSL_get_extms_support returns one if the Extended Master Secret extension or
// TLS 1.3 was negotiated. Otherwise, it returns zero.
OPENSSL_EXPORT int SSL_get_extms_support(const SSL *ssl);
// SSL_get_current_cipher returns the cipher used in the current outgoing
// connection state, or NULL if the null cipher is active.
OPENSSL_EXPORT const SSL_CIPHER *SSL_get_current_cipher(const SSL *ssl);
// SSL_session_reused returns one if |ssl| performed an abbreviated handshake
// and zero otherwise.
//
// TODO(davidben): Hammer down the semantics of this API while a handshake,
// initial or renego, is in progress.
OPENSSL_EXPORT int SSL_session_reused(const SSL *ssl);
// SSL_get_secure_renegotiation_support returns one if the peer supports secure
// renegotiation (RFC 5746) or TLS 1.3. Otherwise, it returns zero.
OPENSSL_EXPORT int SSL_get_secure_renegotiation_support(const SSL *ssl);
// SSL_export_keying_material exports a value derived from the master secret, as
// specified in RFC 5705. It writes |out_len| bytes to |out| given a label and
// optional context. (Since a zero length context is allowed, the |use_context|
// flag controls whether a context is included.)
//
// It returns one on success and zero otherwise.
OPENSSL_EXPORT int SSL_export_keying_material(
SSL *ssl, uint8_t *out, size_t out_len, const char *label, size_t label_len,
const uint8_t *context, size_t context_len, int use_context);
// Custom extensions.
//
// The custom extension functions allow TLS extensions to be added to
// ClientHello and ServerHello messages.
// SSL_custom_ext_add_cb is a callback function that is called when the
// ClientHello (for clients) or ServerHello (for servers) is constructed. In
// the case of a server, this callback will only be called for a given
// extension if the ClientHello contained that extension – it's not possible to
// inject extensions into a ServerHello that the client didn't request.
//
// When called, |extension_value| will contain the extension number that is
// being considered for addition (so that a single callback can handle multiple
// extensions). If the callback wishes to include the extension, it must set
// |*out| to point to |*out_len| bytes of extension contents and return one. In
// this case, the corresponding |SSL_custom_ext_free_cb| callback will later be
// called with the value of |*out| once that data has been copied.
//
// If the callback does not wish to add an extension it must return zero.
//
// Alternatively, the callback can abort the connection by setting
// |*out_alert_value| to a TLS alert number and returning -1.
typedef int (*SSL_custom_ext_add_cb)(SSL *ssl, unsigned extension_value,
const uint8_t **out, size_t *out_len,
int *out_alert_value, void *add_arg);
// SSL_custom_ext_free_cb is a callback function that is called by OpenSSL iff
// an |SSL_custom_ext_add_cb| callback previously returned one. In that case,
// this callback is called and passed the |out| pointer that was returned by
// the add callback. This is to free any dynamically allocated data created by
// the add callback.
typedef void (*SSL_custom_ext_free_cb)(SSL *ssl, unsigned extension_value,
const uint8_t *out, void *add_arg);
// SSL_custom_ext_parse_cb is a callback function that is called by OpenSSL to
// parse an extension from the peer: that is from the ServerHello for a client
// and from the ClientHello for a server.
//
// When called, |extension_value| will contain the extension number and the
// contents of the extension are |contents_len| bytes at |contents|.
//
// The callback must return one to continue the handshake. Otherwise, if it
// returns zero, a fatal alert with value |*out_alert_value| is sent and the
// handshake is aborted.
typedef int (*SSL_custom_ext_parse_cb)(SSL *ssl, unsigned extension_value,
const uint8_t *contents,
size_t contents_len,
int *out_alert_value, void *parse_arg);
// SSL_extension_supported returns one iff OpenSSL internally handles
// extensions of type |extension_value|. This can be used to avoid registering
// custom extension handlers for extensions that a future version of OpenSSL
// may handle internally.
OPENSSL_EXPORT int SSL_extension_supported(unsigned extension_value);
// SSL_CTX_add_client_custom_ext registers callback functions for handling
// custom TLS extensions for client connections.
//
// If |add_cb| is NULL then an empty extension will be added in each
// ClientHello. Otherwise, see the comment for |SSL_custom_ext_add_cb| about
// this callback.
//
// The |free_cb| may be NULL if |add_cb| doesn't dynamically allocate data that
// needs to be freed.
//
// It returns one on success or zero on error. It's always an error to register
// callbacks for the same extension twice, or to register callbacks for an
// extension that OpenSSL handles internally. See |SSL_extension_supported| to
// discover, at runtime, which extensions OpenSSL handles internally.
OPENSSL_EXPORT int SSL_CTX_add_client_custom_ext(
SSL_CTX *ctx, unsigned extension_value, SSL_custom_ext_add_cb add_cb,
SSL_custom_ext_free_cb free_cb, void *add_arg,
SSL_custom_ext_parse_cb parse_cb, void *parse_arg);
// SSL_CTX_add_server_custom_ext is the same as
// |SSL_CTX_add_client_custom_ext|, but for server connections.
//
// Unlike on the client side, if |add_cb| is NULL no extension will be added.
// The |add_cb|, if any, will only be called if the ClientHello contained a
// matching extension.
OPENSSL_EXPORT int SSL_CTX_add_server_custom_ext(
SSL_CTX *ctx, unsigned extension_value, SSL_custom_ext_add_cb add_cb,
SSL_custom_ext_free_cb free_cb, void *add_arg,
SSL_custom_ext_parse_cb parse_cb, void *parse_arg);
// Sessions.
//
// An |SSL_SESSION| represents an SSL session that may be resumed in an
// abbreviated handshake. It is reference-counted and immutable. Once
// established, an |SSL_SESSION| may be shared by multiple |SSL| objects on
// different threads and must not be modified.
DECLARE_PEM_rw(SSL_SESSION, SSL_SESSION)
// SSL_SESSION_new returns a newly-allocated blank |SSL_SESSION| or NULL on
// error. This may be useful when writing tests but should otherwise not be
// used.
OPENSSL_EXPORT SSL_SESSION *SSL_SESSION_new(const SSL_CTX *ctx);
// SSL_SESSION_up_ref increments the reference count of |session| and returns
// one.
OPENSSL_EXPORT int SSL_SESSION_up_ref(SSL_SESSION *session);
// SSL_SESSION_free decrements the reference count of |session|. If it reaches
// zero, all data referenced by |session| and |session| itself are released.
OPENSSL_EXPORT void SSL_SESSION_free(SSL_SESSION *session);
// SSL_SESSION_to_bytes serializes |in| into a newly allocated buffer and sets
// |*out_data| to that buffer and |*out_len| to its length. The caller takes
// ownership of the buffer and must call |OPENSSL_free| when done. It returns
// one on success and zero on error.
OPENSSL_EXPORT int SSL_SESSION_to_bytes(const SSL_SESSION *in,
uint8_t **out_data, size_t *out_len);
// SSL_SESSION_to_bytes_for_ticket serializes |in|, but excludes the session
// identification information, namely the session ID and ticket.
OPENSSL_EXPORT int SSL_SESSION_to_bytes_for_ticket(const SSL_SESSION *in,
uint8_t **out_data,
size_t *out_len);
// SSL_SESSION_from_bytes parses |in_len| bytes from |in| as an SSL_SESSION. It
// returns a newly-allocated |SSL_SESSION| on success or NULL on error.
OPENSSL_EXPORT SSL_SESSION *SSL_SESSION_from_bytes(
const uint8_t *in, size_t in_len, const SSL_CTX *ctx);
// SSL_SESSION_get_version returns a string describing the TLS or DTLS version
// |session| was established at. For example, "TLSv1.2" or "SSLv3".
OPENSSL_EXPORT const char *SSL_SESSION_get_version(const SSL_SESSION *session);
// SSL_SESSION_get_protocol_version returns the TLS or DTLS version |session|
// was established at.
OPENSSL_EXPORT uint16_t
SSL_SESSION_get_protocol_version(const SSL_SESSION *session);
// SSL_SESSION_set_protocol_version sets |session|'s TLS or DTLS version to
// |version|. This may be useful when writing tests but should otherwise not be
// used. It returns one on success and zero on error.
OPENSSL_EXPORT int SSL_SESSION_set_protocol_version(SSL_SESSION *session,
uint16_t version);
// SSL_SESSION_get_id returns a pointer to a buffer containing |session|'s
// session ID and sets |*out_len| to its length.
OPENSSL_EXPORT const uint8_t *SSL_SESSION_get_id(const SSL_SESSION *session,
unsigned *out_len);
// SSL_SESSION_get_time returns the time at which |session| was established in
// seconds since the UNIX epoch.
OPENSSL_EXPORT uint64_t SSL_SESSION_get_time(const SSL_SESSION *session);
// SSL_SESSION_get_timeout returns the lifetime of |session| in seconds.
OPENSSL_EXPORT uint32_t SSL_SESSION_get_timeout(const SSL_SESSION *session);
// SSL_SESSION_get0_peer returns the peer leaf certificate stored in
// |session|.
//
// TODO(davidben): This should return a const X509 *.
OPENSSL_EXPORT X509 *SSL_SESSION_get0_peer(const SSL_SESSION *session);
// SSL_SESSION_get_master_key writes up to |max_out| bytes of |session|'s master
// secret to |out| and returns the number of bytes written. If |max_out| is
// zero, it returns the size of the master secret.
OPENSSL_EXPORT size_t SSL_SESSION_get_master_key(const SSL_SESSION *session,
uint8_t *out, size_t max_out);
// SSL_SESSION_set_time sets |session|'s creation time to |time| and returns
// |time|. This function may be useful in writing tests but otherwise should not
// be used.
OPENSSL_EXPORT uint64_t SSL_SESSION_set_time(SSL_SESSION *session,
uint64_t time);
// SSL_SESSION_set_timeout sets |session|'s timeout to |timeout| and returns
// one. This function may be useful in writing tests but otherwise should not
// be used.
OPENSSL_EXPORT uint32_t SSL_SESSION_set_timeout(SSL_SESSION *session,
uint32_t timeout);
// SSL_SESSION_set1_id_context sets |session|'s session ID context (see
// |SSL_CTX_set_session_id_context|) to |sid_ctx|. It returns one on success and
// zero on error. This function may be useful in writing tests but otherwise
// should not be used.
OPENSSL_EXPORT int SSL_SESSION_set1_id_context(SSL_SESSION *session,
const uint8_t *sid_ctx,
size_t sid_ctx_len);
// SSL_SESSION_should_be_single_use returns one if |session| should be
// single-use (TLS 1.3 and later) and zero otherwise.
//
// If this function returns one, clients retain multiple sessions and use each
// only once. This prevents passive observers from correlating connections with
// tickets. See draft-ietf-tls-tls13-18, appendix B.5. If it returns zero,
// |session| cannot be used without leaking a correlator.
OPENSSL_EXPORT int SSL_SESSION_should_be_single_use(const SSL_SESSION *session);
// SSL_SESSION_is_resumable returns one if |session| is resumable and zero
// otherwise.
OPENSSL_EXPORT int SSL_SESSION_is_resumable(const SSL_SESSION *session);
// SSL_SESSION_has_ticket returns one if |session| has a ticket and zero
// otherwise.
OPENSSL_EXPORT int SSL_SESSION_has_ticket(const SSL_SESSION *session);
// SSL_SESSION_get0_ticket sets |*out_ticket| and |*out_len| to |session|'s
// ticket, or NULL and zero if it does not have one. |out_ticket| may be NULL
// if only the ticket length is needed.
OPENSSL_EXPORT void SSL_SESSION_get0_ticket(const SSL_SESSION *session,
const uint8_t **out_ticket,
size_t *out_len);
// SSL_SESSION_get_ticket_lifetime_hint returns ticket lifetime hint of
// |session| in seconds or zero if none was set.
OPENSSL_EXPORT uint32_t
SSL_SESSION_get_ticket_lifetime_hint(const SSL_SESSION *session);
// Session caching.
//
// Session caching allows connections to be established more efficiently based
// on saved parameters from a previous connection, called a session (see
// |SSL_SESSION|). The client offers a saved session, using an opaque identifier
// from a previous connection. The server may accept the session, if it has the
// parameters available. Otherwise, it will decline and continue with a full
// handshake.
//
// This requires both the client and the server to retain session state. A
// client does so with a stateful session cache. A server may do the same or, if
// supported by both sides, statelessly using session tickets. For more
// information on the latter, see the next section.
//
// For a server, the library implements a built-in internal session cache as an
// in-memory hash table. Servers may also use |SSL_CTX_sess_set_get_cb| and
// |SSL_CTX_sess_set_new_cb| to implement a custom external session cache. In
// particular, this may be used to share a session cache between multiple
// servers in a large deployment. An external cache may be used in addition to
// or instead of the internal one. Use |SSL_CTX_set_session_cache_mode| to
// toggle the internal cache.
//
// For a client, the only option is an external session cache. Clients may use
// |SSL_CTX_sess_set_new_cb| to register a callback for when new sessions are
// available. These may be cached and, in subsequent compatible connections,
// configured with |SSL_set_session|.
//
// Note that offering or accepting a session short-circuits certificate
// verification and most parameter negotiation. Resuming sessions across
// different contexts may result in security failures and surprising
// behavior. For a typical client, this means sessions for different hosts must
// be cached under different keys. A client that connects to the same host with,
// e.g., different cipher suite settings or client certificates should also use
// separate session caches between those contexts. Servers should also partition
// session caches between SNI hosts with |SSL_CTX_set_session_id_context|.
//
// Note also, in TLS 1.2 and earlier, offering sessions allows passive observers
// to correlate different client connections. TLS 1.3 and later fix this,
// provided clients use sessions at most once. Session caches are managed by the
// caller in BoringSSL, so this must be implemented externally. See
// |SSL_SESSION_should_be_single_use| for details.
// SSL_SESS_CACHE_OFF disables all session caching.
#define SSL_SESS_CACHE_OFF 0x0000
// SSL_SESS_CACHE_CLIENT enables session caching for a client. The internal
// cache is never used on a client, so this only enables the callbacks.
#define SSL_SESS_CACHE_CLIENT 0x0001
// SSL_SESS_CACHE_SERVER enables session caching for a server.
#define SSL_SESS_CACHE_SERVER 0x0002
// SSL_SESS_CACHE_BOTH enables session caching for both client and server.
#define SSL_SESS_CACHE_BOTH (SSL_SESS_CACHE_CLIENT | SSL_SESS_CACHE_SERVER)
// SSL_SESS_CACHE_NO_AUTO_CLEAR disables automatically calling
// |SSL_CTX_flush_sessions| every 255 connections.
#define SSL_SESS_CACHE_NO_AUTO_CLEAR 0x0080
// SSL_SESS_CACHE_NO_INTERNAL_LOOKUP, on a server, disables looking up a session
// from the internal session cache.
#define SSL_SESS_CACHE_NO_INTERNAL_LOOKUP 0x0100
// SSL_SESS_CACHE_NO_INTERNAL_STORE, on a server, disables storing sessions in
// the internal session cache.
#define SSL_SESS_CACHE_NO_INTERNAL_STORE 0x0200
// SSL_SESS_CACHE_NO_INTERNAL, on a server, disables the internal session
// cache.
#define SSL_SESS_CACHE_NO_INTERNAL \
(SSL_SESS_CACHE_NO_INTERNAL_LOOKUP | SSL_SESS_CACHE_NO_INTERNAL_STORE)
// SSL_CTX_set_session_cache_mode sets the session cache mode bits for |ctx| to
// |mode|. It returns the previous value.
OPENSSL_EXPORT int SSL_CTX_set_session_cache_mode(SSL_CTX *ctx, int mode);
// SSL_CTX_get_session_cache_mode returns the session cache mode bits for
// |ctx|
OPENSSL_EXPORT int SSL_CTX_get_session_cache_mode(const SSL_CTX *ctx);
// SSL_set_session, for a client, configures |ssl| to offer to resume |session|
// in the initial handshake and returns one. The caller retains ownership of
// |session|.
//
// It is an error to call this function after the handshake has begun.
OPENSSL_EXPORT int SSL_set_session(SSL *ssl, SSL_SESSION *session);
// SSL_DEFAULT_SESSION_TIMEOUT is the default lifetime, in seconds, of a
// session in TLS 1.2 or earlier. This is how long we are willing to use the
// secret to encrypt traffic without fresh key material.
#define SSL_DEFAULT_SESSION_TIMEOUT (2 * 60 * 60)
// SSL_DEFAULT_SESSION_PSK_DHE_TIMEOUT is the default lifetime, in seconds, of a
// session for TLS 1.3 psk_dhe_ke. This is how long we are willing to use the
// secret as an authenticator.
#define SSL_DEFAULT_SESSION_PSK_DHE_TIMEOUT (2 * 24 * 60 * 60)
// SSL_DEFAULT_SESSION_AUTH_TIMEOUT is the default non-renewable lifetime, in
// seconds, of a TLS 1.3 session. This is how long we are willing to trust the
// signature in the initial handshake.
#define SSL_DEFAULT_SESSION_AUTH_TIMEOUT (7 * 24 * 60 * 60)
// SSL_CTX_set_timeout sets the lifetime, in seconds, of TLS 1.2 (or earlier)
// sessions created in |ctx| to |timeout|.
OPENSSL_EXPORT uint32_t SSL_CTX_set_timeout(SSL_CTX *ctx, uint32_t timeout);
// SSL_CTX_set_session_psk_dhe_timeout sets the lifetime, in seconds, of TLS 1.3
// sessions created in |ctx| to |timeout|.
OPENSSL_EXPORT void SSL_CTX_set_session_psk_dhe_timeout(SSL_CTX *ctx,
uint32_t timeout);
// SSL_CTX_get_timeout returns the lifetime, in seconds, of TLS 1.2 (or earlier)
// sessions created in |ctx|.
OPENSSL_EXPORT uint32_t SSL_CTX_get_timeout(const SSL_CTX *ctx);
// SSL_CTX_set_session_id_context sets |ctx|'s session ID context to |sid_ctx|.
// It returns one on success and zero on error. The session ID context is an
// application-defined opaque byte string. A session will not be used in a
// connection without a matching session ID context.
//
// For a server, if |SSL_VERIFY_PEER| is enabled, it is an error to not set a
// session ID context.
OPENSSL_EXPORT int SSL_CTX_set_session_id_context(SSL_CTX *ctx,
const uint8_t *sid_ctx,
size_t sid_ctx_len);
// SSL_set_session_id_context sets |ssl|'s session ID context to |sid_ctx|. It
// returns one on success and zero on error. See also
// |SSL_CTX_set_session_id_context|.
OPENSSL_EXPORT int SSL_set_session_id_context(SSL *ssl, const uint8_t *sid_ctx,
size_t sid_ctx_len);
// SSL_get0_session_id_context returns a pointer to |ssl|'s session ID context
// and sets |*out_len| to its length.
OPENSSL_EXPORT const uint8_t *SSL_get0_session_id_context(const SSL *ssl,
size_t *out_len);
// SSL_SESSION_CACHE_MAX_SIZE_DEFAULT is the default maximum size of a session
// cache.
#define SSL_SESSION_CACHE_MAX_SIZE_DEFAULT (1024 * 20)
// SSL_CTX_sess_set_cache_size sets the maximum size of |ctx|'s internal session
// cache to |size|. It returns the previous value.
OPENSSL_EXPORT unsigned long SSL_CTX_sess_set_cache_size(SSL_CTX *ctx,
unsigned long size);
// SSL_CTX_sess_get_cache_size returns the maximum size of |ctx|'s internal
// session cache.
OPENSSL_EXPORT unsigned long SSL_CTX_sess_get_cache_size(const SSL_CTX *ctx);
// SSL_CTX_sess_number returns the number of sessions in |ctx|'s internal
// session cache.
OPENSSL_EXPORT size_t SSL_CTX_sess_number(const SSL_CTX *ctx);
// SSL_CTX_add_session inserts |session| into |ctx|'s internal session cache. It
// returns one on success and zero on error or if |session| is already in the
// cache. The caller retains its reference to |session|.
OPENSSL_EXPORT int SSL_CTX_add_session(SSL_CTX *ctx, SSL_SESSION *session);
// SSL_CTX_remove_session removes |session| from |ctx|'s internal session cache.
// It returns one on success and zero if |session| was not in the cache.
OPENSSL_EXPORT int SSL_CTX_remove_session(SSL_CTX *ctx, SSL_SESSION *session);
// SSL_CTX_flush_sessions removes all sessions from |ctx| which have expired as
// of time |time|. If |time| is zero, all sessions are removed.
OPENSSL_EXPORT void SSL_CTX_flush_sessions(SSL_CTX *ctx, uint64_t time);
// SSL_CTX_sess_set_new_cb sets the callback to be called when a new session is
// established and ready to be cached. If the session cache is disabled (the
// appropriate one of |SSL_SESS_CACHE_CLIENT| or |SSL_SESS_CACHE_SERVER| is
// unset), the callback is not called.
//
// The callback is passed a reference to |session|. It returns one if it takes
// ownership (and then calls |SSL_SESSION_free| when done) and zero otherwise. A
// consumer which places |session| into an in-memory cache will likely return
// one, with the cache calling |SSL_SESSION_free|. A consumer which serializes
// |session| with |SSL_SESSION_to_bytes| may not need to retain |session| and
// will likely return zero. Returning one is equivalent to calling
// |SSL_SESSION_up_ref| and then returning zero.
//
// Note: For a client, the callback may be called on abbreviated handshakes if a
// ticket is renewed. Further, it may not be called until some time after
// |SSL_do_handshake| or |SSL_connect| completes if False Start is enabled. Thus
// it's recommended to use this callback over calling |SSL_get_session| on
// handshake completion.
OPENSSL_EXPORT void SSL_CTX_sess_set_new_cb(
SSL_CTX *ctx, int (*new_session_cb)(SSL *ssl, SSL_SESSION *session));
// SSL_CTX_sess_get_new_cb returns the callback set by
// |SSL_CTX_sess_set_new_cb|.
OPENSSL_EXPORT int (*SSL_CTX_sess_get_new_cb(SSL_CTX *ctx))(
SSL *ssl, SSL_SESSION *session);
// SSL_CTX_sess_set_remove_cb sets a callback which is called when a session is
// removed from the internal session cache.
//
// TODO(davidben): What is the point of this callback? It seems useless since it
// only fires on sessions in the internal cache.
OPENSSL_EXPORT void SSL_CTX_sess_set_remove_cb(
SSL_CTX *ctx,
void (*remove_session_cb)(SSL_CTX *ctx, SSL_SESSION *session));
// SSL_CTX_sess_get_remove_cb returns the callback set by
// |SSL_CTX_sess_set_remove_cb|.
OPENSSL_EXPORT void (*SSL_CTX_sess_get_remove_cb(SSL_CTX *ctx))(
SSL_CTX *ctx, SSL_SESSION *session);
// SSL_CTX_sess_set_get_cb sets a callback to look up a session by ID for a
// server. The callback is passed the session ID and should return a matching
// |SSL_SESSION| or NULL if not found. It should set |*out_copy| to zero and
// return a new reference to the session. This callback is not used for a
// client.
//
// For historical reasons, if |*out_copy| is set to one (default), the SSL
// library will take a new reference to the returned |SSL_SESSION|, expecting
// the callback to return a non-owning pointer. This is not recommended. If
// |ctx| and thus the callback is used on multiple threads, the session may be
// removed and invalidated before the SSL library calls |SSL_SESSION_up_ref|,
// whereas the callback may synchronize internally.
//
// To look up a session asynchronously, the callback may return
// |SSL_magic_pending_session_ptr|. See the documentation for that function and
// |SSL_ERROR_PENDING_SESSION|.
//
// If the internal session cache is enabled, the callback is only consulted if
// the internal cache does not return a match.
OPENSSL_EXPORT void SSL_CTX_sess_set_get_cb(
SSL_CTX *ctx, SSL_SESSION *(*get_session_cb)(SSL *ssl, const uint8_t *id,
int id_len, int *out_copy));
// SSL_CTX_sess_get_get_cb returns the callback set by
// |SSL_CTX_sess_set_get_cb|.
OPENSSL_EXPORT SSL_SESSION *(*SSL_CTX_sess_get_get_cb(SSL_CTX *ctx))(
SSL *ssl, const uint8_t *id, int id_len, int *out_copy);
// SSL_magic_pending_session_ptr returns a magic |SSL_SESSION|* which indicates
// that the session isn't currently unavailable. |SSL_get_error| will then
// return |SSL_ERROR_PENDING_SESSION| and the handshake can be retried later
// when the lookup has completed.
OPENSSL_EXPORT SSL_SESSION *SSL_magic_pending_session_ptr(void);
// Session tickets.
//
// Session tickets, from RFC 5077, allow session resumption without server-side
// state. The server maintains a secret ticket key and sends the client opaque
// encrypted session parameters, called a ticket. When offering the session, the
// client sends the ticket which the server decrypts to recover session state.
// Session tickets are enabled by default but may be disabled with
// |SSL_OP_NO_TICKET|.
//
// On the client, ticket-based sessions use the same APIs as ID-based tickets.
// Callers do not need to handle them differently.
//
// On the server, tickets are encrypted and authenticated with a secret key. By
// default, an |SSL_CTX| generates a key on creation and uses it for the
// lifetime of the |SSL_CTX|. Tickets are minted and processed
// transparently. The following functions may be used to configure a persistent
// key or implement more custom behavior, including key rotation and sharing
// keys between multiple servers in a large deployment. There are three levels
// of customisation possible:
//
// 1) One can simply set the keys with |SSL_CTX_set_tlsext_ticket_keys|.
// 2) One can configure an |EVP_CIPHER_CTX| and |HMAC_CTX| directly for
// encryption and authentication.
// 3) One can configure an |SSL_TICKET_AEAD_METHOD| to have more control
// and the option of asynchronous decryption.
//
// An attacker that compromises a server's session ticket key can impersonate
// the server and, prior to TLS 1.3, retroactively decrypt all application
// traffic from sessions using that ticket key. Thus ticket keys must be
// regularly rotated for forward secrecy. Note the default key is rotated
// automatically once every 48 hours but manually configured keys are not.
// SSL_DEFAULT_TICKET_KEY_ROTATION_INTERVAL is the interval with which the
// default session ticket encryption key is rotated, if in use. If any
// non-default ticket encryption mechanism is configured, automatic rotation is
// disabled.
#define SSL_DEFAULT_TICKET_KEY_ROTATION_INTERVAL (2 * 24 * 60 * 60)
// SSL_CTX_get_tlsext_ticket_keys writes |ctx|'s session ticket key material to
// |len| bytes of |out|. It returns one on success and zero if |len| is not
// 48. If |out| is NULL, it returns 48 instead.
OPENSSL_EXPORT int SSL_CTX_get_tlsext_ticket_keys(SSL_CTX *ctx, void *out,
size_t len);
// SSL_CTX_set_tlsext_ticket_keys sets |ctx|'s session ticket key material to
// |len| bytes of |in|. It returns one on success and zero if |len| is not
// 48. If |in| is NULL, it returns 48 instead.
OPENSSL_EXPORT int SSL_CTX_set_tlsext_ticket_keys(SSL_CTX *ctx, const void *in,
size_t len);
// SSL_TICKET_KEY_NAME_LEN is the length of the key name prefix of a session
// ticket.
#define SSL_TICKET_KEY_NAME_LEN 16
// SSL_CTX_set_tlsext_ticket_key_cb sets the ticket callback to |callback| and
// returns one. |callback| will be called when encrypting a new ticket and when
// decrypting a ticket from the client.
//
// In both modes, |ctx| and |hmac_ctx| will already have been initialized with
// |EVP_CIPHER_CTX_init| and |HMAC_CTX_init|, respectively. |callback|
// configures |hmac_ctx| with an HMAC digest and key, and configures |ctx|
// for encryption or decryption, based on the mode.
//
// When encrypting a new ticket, |encrypt| will be one. It writes a public
// 16-byte key name to |key_name| and a fresh IV to |iv|. The output IV length
// must match |EVP_CIPHER_CTX_iv_length| of the cipher selected. In this mode,
// |callback| returns 1 on success and -1 on error.
//
// When decrypting a ticket, |encrypt| will be zero. |key_name| will point to a
// 16-byte key name and |iv| points to an IV. The length of the IV consumed must
// match |EVP_CIPHER_CTX_iv_length| of the cipher selected. In this mode,
// |callback| returns -1 to abort the handshake, 0 if decrypting the ticket
// failed, and 1 or 2 on success. If it returns 2, the ticket will be renewed.
// This may be used to re-key the ticket.
//
// WARNING: |callback| wildly breaks the usual return value convention and is
// called in two different modes.
OPENSSL_EXPORT int SSL_CTX_set_tlsext_ticket_key_cb(
SSL_CTX *ctx, int (*callback)(SSL *ssl, uint8_t *key_name, uint8_t *iv,
EVP_CIPHER_CTX *ctx, HMAC_CTX *hmac_ctx,
int encrypt));
// ssl_ticket_aead_result_t enumerates the possible results from decrypting a
// ticket with an |SSL_TICKET_AEAD_METHOD|.
enum ssl_ticket_aead_result_t {
// ssl_ticket_aead_success indicates that the ticket was successfully
// decrypted.
ssl_ticket_aead_success,
// ssl_ticket_aead_retry indicates that the operation could not be
// immediately completed and must be reattempted, via |open|, at a later
// point.
ssl_ticket_aead_retry,
// ssl_ticket_aead_ignore_ticket indicates that the ticket should be ignored
// (i.e. is corrupt or otherwise undecryptable).
ssl_ticket_aead_ignore_ticket,
// ssl_ticket_aead_error indicates that a fatal error occured and the
// handshake should be terminated.
ssl_ticket_aead_error,
};
// ssl_ticket_aead_method_st (aka |SSL_TICKET_AEAD_METHOD|) contains methods
// for encrypting and decrypting session tickets.
struct ssl_ticket_aead_method_st {
// max_overhead returns the maximum number of bytes of overhead that |seal|
// may add.
size_t (*max_overhead)(SSL *ssl);
// seal encrypts and authenticates |in_len| bytes from |in|, writes, at most,
// |max_out_len| bytes to |out|, and puts the number of bytes written in
// |*out_len|. The |in| and |out| buffers may be equal but will not otherwise
// alias. It returns one on success or zero on error.
int (*seal)(SSL *ssl, uint8_t *out, size_t *out_len, size_t max_out_len,
const uint8_t *in, size_t in_len);
// open authenticates and decrypts |in_len| bytes from |in|, writes, at most,
// |max_out_len| bytes of plaintext to |out|, and puts the number of bytes
// written in |*out_len|. The |in| and |out| buffers may be equal but will
// not otherwise alias. See |ssl_ticket_aead_result_t| for details of the
// return values. In the case that a retry is indicated, the caller should
// arrange for the high-level operation on |ssl| to be retried when the
// operation is completed, which will result in another call to |open|.
enum ssl_ticket_aead_result_t (*open)(SSL *ssl, uint8_t *out, size_t *out_len,
size_t max_out_len, const uint8_t *in,
size_t in_len);
};
// SSL_CTX_set_ticket_aead_method configures a custom ticket AEAD method table
// on |ctx|. |aead_method| must remain valid for the lifetime of |ctx|.
OPENSSL_EXPORT void SSL_CTX_set_ticket_aead_method(
SSL_CTX *ctx, const SSL_TICKET_AEAD_METHOD *aead_method);
// Elliptic curve Diffie-Hellman.
//
// Cipher suites using an ECDHE key exchange perform Diffie-Hellman over an
// elliptic curve negotiated by both endpoints. See RFC 4492. Only named curves
// are supported. ECDHE is always enabled, but the curve preferences may be
// configured with these functions.
//
// Note that TLS 1.3 renames these from curves to groups. For consistency, we
// currently use the TLS 1.2 name in the API.
// SSL_CTX_set1_curves sets the preferred curves for |ctx| to be |curves|. Each
// element of |curves| should be a curve nid. It returns one on success and
// zero on failure.
//
// Note that this API uses nid values from nid.h and not the |SSL_CURVE_*|
// values defined below.
OPENSSL_EXPORT int SSL_CTX_set1_curves(SSL_CTX *ctx, const int *curves,
size_t curves_len);
// SSL_set1_curves sets the preferred curves for |ssl| to be |curves|. Each
// element of |curves| should be a curve nid. It returns one on success and
// zero on failure.
//
// Note that this API uses nid values from nid.h and not the |SSL_CURVE_*|
// values defined below.
OPENSSL_EXPORT int SSL_set1_curves(SSL *ssl, const int *curves,
size_t curves_len);
// SSL_CTX_set1_curves_list sets the preferred curves for |ctx| to be the
// colon-separated list |curves|. Each element of |curves| should be a curve
// name (e.g. P-256, X25519, ...). It returns one on success and zero on
// failure.
OPENSSL_EXPORT int SSL_CTX_set1_curves_list(SSL_CTX *ctx, const char *curves);
// SSL_set1_curves_list sets the preferred curves for |ssl| to be the
// colon-separated list |curves|. Each element of |curves| should be a curve
// name (e.g. P-256, X25519, ...). It returns one on success and zero on
// failure.
OPENSSL_EXPORT int SSL_set1_curves_list(SSL *ssl, const char *curves);
// SSL_CURVE_* define TLS curve IDs.
#define SSL_CURVE_SECP224R1 21
#define SSL_CURVE_SECP256R1 23
#define SSL_CURVE_SECP384R1 24
#define SSL_CURVE_SECP521R1 25
#define SSL_CURVE_X25519 29
// SSL_get_curve_id returns the ID of the curve used by |ssl|'s most recently
// completed handshake or 0 if not applicable.
//
// TODO(davidben): This API currently does not work correctly if there is a
// renegotiation in progress. Fix this.
OPENSSL_EXPORT uint16_t SSL_get_curve_id(const SSL *ssl);
// SSL_get_curve_name returns a human-readable name for the curve specified by
// the given TLS curve id, or NULL if the curve is unknown.
OPENSSL_EXPORT const char *SSL_get_curve_name(uint16_t curve_id);
// Certificate verification.
//
// SSL may authenticate either endpoint with an X.509 certificate. Typically
// this is used to authenticate the server to the client. These functions
// configure certificate verification.
//
// WARNING: By default, certificate verification errors on a client are not
// fatal. See |SSL_VERIFY_NONE| This may be configured with
// |SSL_CTX_set_verify|.
//
// By default clients are anonymous but a server may request a certificate from
// the client by setting |SSL_VERIFY_PEER|.
//
// Many of these functions use OpenSSL's legacy X.509 stack which is
// underdocumented and deprecated, but the replacement isn't ready yet. For
// now, consumers may use the existing stack or bypass it by performing
// certificate verification externally. This may be done with
// |SSL_CTX_set_cert_verify_callback| or by extracting the chain with
// |SSL_get_peer_cert_chain| after the handshake. In the future, functions will
// be added to use the SSL stack without dependency on any part of the legacy
// X.509 and ASN.1 stack.
//
// To augment certificate verification, a client may also enable OCSP stapling
// (RFC 6066) and Certificate Transparency (RFC 6962) extensions.
// SSL_VERIFY_NONE, on a client, verifies the server certificate but does not
// make errors fatal. The result may be checked with |SSL_get_verify_result|. On
// a server it does not request a client certificate. This is the default.
#define SSL_VERIFY_NONE 0x00
// SSL_VERIFY_PEER, on a client, makes server certificate errors fatal. On a
// server it requests a client certificate and makes errors fatal. However,
// anonymous clients are still allowed. See
// |SSL_VERIFY_FAIL_IF_NO_PEER_CERT|.
#define SSL_VERIFY_PEER 0x01
// SSL_VERIFY_FAIL_IF_NO_PEER_CERT configures a server to reject connections if
// the client declines to send a certificate. This flag must be used together
// with |SSL_VERIFY_PEER|, otherwise it won't work.
#define SSL_VERIFY_FAIL_IF_NO_PEER_CERT 0x02
// SSL_VERIFY_PEER_IF_NO_OBC configures a server to request a client certificate
// if and only if Channel ID is not negotiated.
#define SSL_VERIFY_PEER_IF_NO_OBC 0x04
// SSL_CTX_set_verify configures certificate verification behavior. |mode| is
// one of the |SSL_VERIFY_*| values defined above. |callback|, if not NULL, is
// used to customize certificate verification. See the behavior of
// |X509_STORE_CTX_set_verify_cb|.
//
// The callback may use |SSL_get_ex_data_X509_STORE_CTX_idx| with
// |X509_STORE_CTX_get_ex_data| to look up the |SSL| from |store_ctx|.
OPENSSL_EXPORT void SSL_CTX_set_verify(
SSL_CTX *ctx, int mode, int (*callback)(int ok, X509_STORE_CTX *store_ctx));
// SSL_set_verify configures certificate verification behavior. |mode| is one of
// the |SSL_VERIFY_*| values defined above. |callback|, if not NULL, is used to
// customize certificate verification. See the behavior of
// |X509_STORE_CTX_set_verify_cb|.
//
// The callback may use |SSL_get_ex_data_X509_STORE_CTX_idx| with
// |X509_STORE_CTX_get_ex_data| to look up the |SSL| from |store_ctx|.
OPENSSL_EXPORT void SSL_set_verify(SSL *ssl, int mode,
int (*callback)(int ok,
X509_STORE_CTX *store_ctx));
enum ssl_verify_result_t {
ssl_verify_ok,
ssl_verify_invalid,
ssl_verify_retry,
};
// SSL_CTX_set_custom_verify configures certificate verification. |mode| is one
// of the |SSL_VERIFY_*| values defined above. |callback| performs the
// certificate verification.
//
// The callback may call |SSL_get0_peer_certificates| for the certificate chain
// to validate. The callback should return |ssl_verify_ok| if the certificate is
// valid. If the certificate is invalid, the callback should return
// |ssl_verify_invalid| and optionally set |*out_alert| to an alert to send to
// the peer. Some useful alerts include |SSL_AD_CERTIFICATE_EXPIRED|,
// |SSL_AD_CERTIFICATE_REVOKED|, |SSL_AD_UNKNOWN_CA|, |SSL_AD_BAD_CERTIFICATE|,
// |SSL_AD_CERTIFICATE_UNKNOWN|, and |SSL_AD_INTERNAL_ERROR|. See RFC 5246
// section 7.2.2 for their precise meanings. If unspecified,
// |SSL_AD_CERTIFICATE_UNKNOWN| will be sent by default.
//
// To verify a certificate asynchronously, the callback may return
// |ssl_verify_retry|. The handshake will then pause with |SSL_get_error|
// returning |SSL_ERROR_WANT_CERTIFICATE_VERIFY|.
OPENSSL_EXPORT void SSL_CTX_set_custom_verify(
SSL_CTX *ctx, int mode,
enum ssl_verify_result_t (*callback)(SSL *ssl, uint8_t *out_alert));
// SSL_set_custom_verify behaves like |SSL_CTX_set_custom_verify| but configures
// an individual |SSL|.
OPENSSL_EXPORT void SSL_set_custom_verify(
SSL *ssl, int mode,
enum ssl_verify_result_t (*callback)(SSL *ssl, uint8_t *out_alert));
// SSL_CTX_get_verify_mode returns |ctx|'s verify mode, set by
// |SSL_CTX_set_verify|.
OPENSSL_EXPORT int SSL_CTX_get_verify_mode(const SSL_CTX *ctx);
// SSL_get_verify_mode returns |ssl|'s verify mode, set by |SSL_CTX_set_verify|
// or |SSL_set_verify|.
OPENSSL_EXPORT int SSL_get_verify_mode(const SSL *ssl);
// SSL_CTX_get_verify_callback returns the callback set by
// |SSL_CTX_set_verify|.
OPENSSL_EXPORT int (*SSL_CTX_get_verify_callback(const SSL_CTX *ctx))(
int ok, X509_STORE_CTX *store_ctx);
// SSL_get_verify_callback returns the callback set by |SSL_CTX_set_verify| or
// |SSL_set_verify|.
OPENSSL_EXPORT int (*SSL_get_verify_callback(const SSL *ssl))(
int ok, X509_STORE_CTX *store_ctx);
// SSL_CTX_set_verify_depth sets the maximum depth of a certificate chain
// accepted in verification. This number does not include the leaf, so a depth
// of 1 allows the leaf and one CA certificate.
OPENSSL_EXPORT void SSL_CTX_set_verify_depth(SSL_CTX *ctx, int depth);
// SSL_set_verify_depth sets the maximum depth of a certificate chain accepted
// in verification. This number does not include the leaf, so a depth of 1
// allows the leaf and one CA certificate.
OPENSSL_EXPORT void SSL_set_verify_depth(SSL *ssl, int depth);
// SSL_CTX_get_verify_depth returns the maximum depth of a certificate accepted
// in verification.
OPENSSL_EXPORT int SSL_CTX_get_verify_depth(const SSL_CTX *ctx);
// SSL_get_verify_depth returns the maximum depth of a certificate accepted in
// verification.
OPENSSL_EXPORT int SSL_get_verify_depth(const SSL *ssl);
// SSL_CTX_set1_param sets verification parameters from |param|. It returns one
// on success and zero on failure. The caller retains ownership of |param|.
OPENSSL_EXPORT int SSL_CTX_set1_param(SSL_CTX *ctx,
const X509_VERIFY_PARAM *param);
// SSL_set1_param sets verification parameters from |param|. It returns one on
// success and zero on failure. The caller retains ownership of |param|.
OPENSSL_EXPORT int SSL_set1_param(SSL *ssl,
const X509_VERIFY_PARAM *param);
// SSL_CTX_get0_param returns |ctx|'s |X509_VERIFY_PARAM| for certificate
// verification. The caller must not release the returned pointer but may call
// functions on it to configure it.
OPENSSL_EXPORT X509_VERIFY_PARAM *SSL_CTX_get0_param(SSL_CTX *ctx);
// SSL_get0_param returns |ssl|'s |X509_VERIFY_PARAM| for certificate
// verification. The caller must not release the returned pointer but may call
// functions on it to configure it.
OPENSSL_EXPORT X509_VERIFY_PARAM *SSL_get0_param(SSL *ssl);
// SSL_CTX_set_purpose sets |ctx|'s |X509_VERIFY_PARAM|'s 'purpose' parameter to
// |purpose|. It returns one on success and zero on error.
OPENSSL_EXPORT int SSL_CTX_set_purpose(SSL_CTX *ctx, int purpose);
// SSL_set_purpose sets |ssl|'s |X509_VERIFY_PARAM|'s 'purpose' parameter to
// |purpose|. It returns one on success and zero on error.
OPENSSL_EXPORT int SSL_set_purpose(SSL *ssl, int purpose);
// SSL_CTX_set_trust sets |ctx|'s |X509_VERIFY_PARAM|'s 'trust' parameter to
// |trust|. It returns one on success and zero on error.
OPENSSL_EXPORT int SSL_CTX_set_trust(SSL_CTX *ctx, int trust);
// SSL_set_trust sets |ssl|'s |X509_VERIFY_PARAM|'s 'trust' parameter to
// |trust|. It returns one on success and zero on error.
OPENSSL_EXPORT int SSL_set_trust(SSL *ssl, int trust);
// SSL_CTX_set_cert_store sets |ctx|'s certificate store to |store|. It takes
// ownership of |store|. The store is used for certificate verification.
//
// The store is also used for the auto-chaining feature, but this is deprecated.
// See also |SSL_MODE_NO_AUTO_CHAIN|.
OPENSSL_EXPORT void SSL_CTX_set_cert_store(SSL_CTX *ctx, X509_STORE *store);
// SSL_CTX_get_cert_store returns |ctx|'s certificate store.
OPENSSL_EXPORT X509_STORE *SSL_CTX_get_cert_store(const SSL_CTX *ctx);
// SSL_CTX_set_default_verify_paths loads the OpenSSL system-default trust
// anchors into |ctx|'s store. It returns one on success and zero on failure.
OPENSSL_EXPORT int SSL_CTX_set_default_verify_paths(SSL_CTX *ctx);
// SSL_CTX_load_verify_locations loads trust anchors into |ctx|'s store from
// |ca_file| and |ca_dir|, either of which may be NULL. If |ca_file| is passed,
// it is opened and PEM-encoded CA certificates are read. If |ca_dir| is passed,
// it is treated as a directory in OpenSSL's hashed directory format. It returns
// one on success and zero on failure.
//
// See
// https://www.openssl.org/docs/manmaster/ssl/SSL_CTX_load_verify_locations.html
// for documentation on the directory format.
OPENSSL_EXPORT int SSL_CTX_load_verify_locations(SSL_CTX *ctx,
const char *ca_file,
const char *ca_dir);
// SSL_get_verify_result returns the result of certificate verification. It is
// either |X509_V_OK| or a |X509_V_ERR_*| value.
OPENSSL_EXPORT long SSL_get_verify_result(const SSL *ssl);
// SSL_get_ex_data_X509_STORE_CTX_idx returns the ex_data index used to look up
// the |SSL| associated with an |X509_STORE_CTX| in the verify callback.
OPENSSL_EXPORT int SSL_get_ex_data_X509_STORE_CTX_idx(void);
// SSL_CTX_set_cert_verify_callback sets a custom callback to be called on
// certificate verification rather than |X509_verify_cert|. |store_ctx| contains
// the verification parameters. The callback should return one on success and
// zero on fatal error. It may use |X509_STORE_CTX_set_error| to set a
// verification result.
//
// The callback may use |SSL_get_ex_data_X509_STORE_CTX_idx| to recover the
// |SSL| object from |store_ctx|.
OPENSSL_EXPORT void SSL_CTX_set_cert_verify_callback(
SSL_CTX *ctx, int (*callback)(X509_STORE_CTX *store_ctx, void *arg),
void *arg);
// SSL_enable_signed_cert_timestamps causes |ssl| (which must be the client end
// of a connection) to request SCTs from the server. See
// https://tools.ietf.org/html/rfc6962.
//
// Call |SSL_get0_signed_cert_timestamp_list| to recover the SCT after the
// handshake.
OPENSSL_EXPORT void SSL_enable_signed_cert_timestamps(SSL *ssl);
// SSL_CTX_enable_signed_cert_timestamps enables SCT requests on all client SSL
// objects created from |ctx|.
//
// Call |SSL_get0_signed_cert_timestamp_list| to recover the SCT after the
// handshake.
OPENSSL_EXPORT void SSL_CTX_enable_signed_cert_timestamps(SSL_CTX *ctx);
// SSL_enable_ocsp_stapling causes |ssl| (which must be the client end of a
// connection) to request a stapled OCSP response from the server.
//
// Call |SSL_get0_ocsp_response| to recover the OCSP response after the
// handshake.
OPENSSL_EXPORT void SSL_enable_ocsp_stapling(SSL *ssl);
// SSL_CTX_enable_ocsp_stapling enables OCSP stapling on all client SSL objects
// created from |ctx|.
//
// Call |SSL_get0_ocsp_response| to recover the OCSP response after the
// handshake.
OPENSSL_EXPORT void SSL_CTX_enable_ocsp_stapling(SSL_CTX *ctx);
// SSL_CTX_set0_verify_cert_store sets an |X509_STORE| that will be used
// exclusively for certificate verification and returns one. Ownership of
// |store| is transferred to the |SSL_CTX|.
OPENSSL_EXPORT int SSL_CTX_set0_verify_cert_store(SSL_CTX *ctx,
X509_STORE *store);
// SSL_CTX_set1_verify_cert_store sets an |X509_STORE| that will be used
// exclusively for certificate verification and returns one. An additional
// reference to |store| will be taken.
OPENSSL_EXPORT int SSL_CTX_set1_verify_cert_store(SSL_CTX *ctx,
X509_STORE *store);
// SSL_set0_verify_cert_store sets an |X509_STORE| that will be used
// exclusively for certificate verification and returns one. Ownership of
// |store| is transferred to the |SSL|.
OPENSSL_EXPORT int SSL_set0_verify_cert_store(SSL *ssl, X509_STORE *store);
// SSL_set1_verify_cert_store sets an |X509_STORE| that will be used
// exclusively for certificate verification and returns one. An additional
// reference to |store| will be taken.
OPENSSL_EXPORT int SSL_set1_verify_cert_store(SSL *ssl, X509_STORE *store);
// SSL_CTX_set_ed25519_enabled configures whether |ctx| advertises support for
// the Ed25519 signature algorithm when using the default preference list.
OPENSSL_EXPORT void SSL_CTX_set_ed25519_enabled(SSL_CTX *ctx, int enabled);
// SSL_CTX_set_verify_algorithm_prefs confingures |ctx| to use |prefs| as the
// preference list when verifying signature's from the peer's long-term key. It
// returns one on zero on error. |prefs| should not include the internal-only
// value |SSL_SIGN_RSA_PKCS1_MD5_SHA1|.
OPENSSL_EXPORT int SSL_CTX_set_verify_algorithm_prefs(SSL_CTX *ctx,
const uint16_t *prefs,
size_t num_prefs);
// Client certificate CA list.
//
// When requesting a client certificate, a server may advertise a list of
// certificate authorities which are accepted. These functions may be used to
// configure this list.
// SSL_set_client_CA_list sets |ssl|'s client certificate CA list to
// |name_list|. It takes ownership of |name_list|.
OPENSSL_EXPORT void SSL_set_client_CA_list(SSL *ssl,
STACK_OF(X509_NAME) *name_list);
// SSL_CTX_set_client_CA_list sets |ctx|'s client certificate CA list to
// |name_list|. It takes ownership of |name_list|.
OPENSSL_EXPORT void SSL_CTX_set_client_CA_list(SSL_CTX *ctx,
STACK_OF(X509_NAME) *name_list);
// SSL_set0_client_CAs sets |ssl|'s client certificate CA list to |name_list|,
// which should contain DER-encoded distinguished names (RFC 5280). It takes
// ownership of |name_list|.
OPENSSL_EXPORT void SSL_set0_client_CAs(SSL *ssl,
STACK_OF(CRYPTO_BUFFER) *name_list);
// SSL_CTX_set0_client_CAs sets |ctx|'s client certificate CA list to
// |name_list|, which should contain DER-encoded distinguished names (RFC 5280).
// It takes ownership of |name_list|.
OPENSSL_EXPORT void SSL_CTX_set0_client_CAs(SSL_CTX *ctx,
STACK_OF(CRYPTO_BUFFER) *name_list);
// SSL_get_client_CA_list returns |ssl|'s client certificate CA list. If |ssl|
// has not been configured as a client, this is the list configured by
// |SSL_CTX_set_client_CA_list|.
//
// If configured as a client, it returns the client certificate CA list sent by
// the server. In this mode, the behavior is undefined except during the
// callbacks set by |SSL_CTX_set_cert_cb| and |SSL_CTX_set_client_cert_cb| or
// when the handshake is paused because of them.
OPENSSL_EXPORT STACK_OF(X509_NAME) *SSL_get_client_CA_list(const SSL *ssl);
// SSL_get0_server_requested_CAs returns the CAs sent by a server to guide a
// client in certificate selection. They are a series of DER-encoded X.509
// names. This function may only be called during a callback set by
// |SSL_CTX_set_cert_cb| or when the handshake is paused because of it.
//
// The returned stack is owned by |ssl|, as are its contents. It should not be
// used past the point where the handshake is restarted after the callback.
OPENSSL_EXPORT STACK_OF(CRYPTO_BUFFER) *SSL_get0_server_requested_CAs(
const SSL *ssl);
// SSL_CTX_get_client_CA_list returns |ctx|'s client certificate CA list.
OPENSSL_EXPORT STACK_OF(X509_NAME) *
SSL_CTX_get_client_CA_list(const SSL_CTX *ctx);
// SSL_add_client_CA appends |x509|'s subject to the client certificate CA list.
// It returns one on success or zero on error. The caller retains ownership of
// |x509|.
OPENSSL_EXPORT int SSL_add_client_CA(SSL *ssl, X509 *x509);
// SSL_CTX_add_client_CA appends |x509|'s subject to the client certificate CA
// list. It returns one on success or zero on error. The caller retains
// ownership of |x509|.
OPENSSL_EXPORT int SSL_CTX_add_client_CA(SSL_CTX *ctx, X509 *x509);
// SSL_load_client_CA_file opens |file| and reads PEM-encoded certificates from
// it. It returns a newly-allocated stack of the certificate subjects or NULL
// on error.
OPENSSL_EXPORT STACK_OF(X509_NAME) *SSL_load_client_CA_file(const char *file);
// SSL_dup_CA_list makes a deep copy of |list|. It returns the new list on
// success or NULL on allocation error.
OPENSSL_EXPORT STACK_OF(X509_NAME) *SSL_dup_CA_list(STACK_OF(X509_NAME) *list);
// SSL_add_file_cert_subjects_to_stack behaves like |SSL_load_client_CA_file|
// but appends the result to |out|. It returns one on success or zero on
// error.
OPENSSL_EXPORT int SSL_add_file_cert_subjects_to_stack(STACK_OF(X509_NAME) *out,
const char *file);
// Server name indication.
//
// The server_name extension (RFC 3546) allows the client to advertise the name
// of the server it is connecting to. This is used in virtual hosting
// deployments to select one of a several certificates on a single IP. Only the
// host_name name type is supported.
#define TLSEXT_NAMETYPE_host_name 0
// SSL_set_tlsext_host_name, for a client, configures |ssl| to advertise |name|
// in the server_name extension. It returns one on success and zero on error.
OPENSSL_EXPORT int SSL_set_tlsext_host_name(SSL *ssl, const char *name);
// SSL_get_servername, for a server, returns the hostname supplied by the
// client or NULL if there was none. The |type| argument must be
// |TLSEXT_NAMETYPE_host_name|.
OPENSSL_EXPORT const char *SSL_get_servername(const SSL *ssl, const int type);
// SSL_get_servername_type, for a server, returns |TLSEXT_NAMETYPE_host_name|
// if the client sent a hostname and -1 otherwise.
OPENSSL_EXPORT int SSL_get_servername_type(const SSL *ssl);
// SSL_CTX_set_tlsext_servername_callback configures |callback| to be called on
// the server after ClientHello extensions have been parsed and returns one.
// The callback may use |SSL_get_servername| to examine the server_name
// extension and returns a |SSL_TLSEXT_ERR_*| value. The value of |arg| may be
// set by calling |SSL_CTX_set_tlsext_servername_arg|.
//
// If the callback returns |SSL_TLSEXT_ERR_NOACK|, the server_name extension is
// not acknowledged in the ServerHello. If the return value is
// |SSL_TLSEXT_ERR_ALERT_FATAL|, then |*out_alert| is the alert to send,
// defaulting to |SSL_AD_UNRECOGNIZED_NAME|. |SSL_TLSEXT_ERR_ALERT_WARNING| is
// ignored and treated as |SSL_TLSEXT_ERR_OK|.
OPENSSL_EXPORT int SSL_CTX_set_tlsext_servername_callback(
SSL_CTX *ctx, int (*callback)(SSL *ssl, int *out_alert, void *arg));
// SSL_CTX_set_tlsext_servername_arg sets the argument to the servername
// callback and returns one. See |SSL_CTX_set_tlsext_servername_callback|.
OPENSSL_EXPORT int SSL_CTX_set_tlsext_servername_arg(SSL_CTX *ctx, void *arg);
// SSL_TLSEXT_ERR_* are values returned by some extension-related callbacks.
#define SSL_TLSEXT_ERR_OK 0
#define SSL_TLSEXT_ERR_ALERT_WARNING 1
#define SSL_TLSEXT_ERR_ALERT_FATAL 2
#define SSL_TLSEXT_ERR_NOACK 3
// SSL_set_SSL_CTX changes |ssl|'s |SSL_CTX|. |ssl| will use the
// certificate-related settings from |ctx|, and |SSL_get_SSL_CTX| will report
// |ctx|. This function may be used during the callbacks registered by
// |SSL_CTX_set_select_certificate_cb|,
// |SSL_CTX_set_tlsext_servername_callback|, and |SSL_CTX_set_cert_cb| or when
// the handshake is paused from them. It is typically used to switch
// certificates based on SNI.
//
// Note the session cache and related settings will continue to use the initial
// |SSL_CTX|. Callers should use |SSL_CTX_set_session_id_context| to partition
// the session cache between different domains.
//
// TODO(davidben): Should other settings change after this call?
OPENSSL_EXPORT SSL_CTX *SSL_set_SSL_CTX(SSL *ssl, SSL_CTX *ctx);
// Application-layer protocol negotiation.
//
// The ALPN extension (RFC 7301) allows negotiating different application-layer
// protocols over a single port. This is used, for example, to negotiate
// HTTP/2.
// SSL_CTX_set_alpn_protos sets the client ALPN protocol list on |ctx| to
// |protos|. |protos| must be in wire-format (i.e. a series of non-empty, 8-bit
// length-prefixed strings). It returns zero on success and one on failure.
// Configuring this list enables ALPN on a client.
//
// WARNING: this function is dangerous because it breaks the usual return value
// convention.
OPENSSL_EXPORT int SSL_CTX_set_alpn_protos(SSL_CTX *ctx, const uint8_t *protos,
unsigned protos_len);
// SSL_set_alpn_protos sets the client ALPN protocol list on |ssl| to |protos|.
// |protos| must be in wire-format (i.e. a series of non-empty, 8-bit
// length-prefixed strings). It returns zero on success and one on failure.
// Configuring this list enables ALPN on a client.
//
// WARNING: this function is dangerous because it breaks the usual return value
// convention.
OPENSSL_EXPORT int SSL_set_alpn_protos(SSL *ssl, const uint8_t *protos,
unsigned protos_len);
// SSL_CTX_set_alpn_select_cb sets a callback function on |ctx| that is called
// during ClientHello processing in order to select an ALPN protocol from the
// client's list of offered protocols. Configuring this callback enables ALPN on
// a server.
//
// The callback is passed a wire-format (i.e. a series of non-empty, 8-bit
// length-prefixed strings) ALPN protocol list in |in|. It should set |*out| and
// |*out_len| to the selected protocol and return |SSL_TLSEXT_ERR_OK| on
// success. It does not pass ownership of the buffer. Otherwise, it should
// return |SSL_TLSEXT_ERR_NOACK|. Other |SSL_TLSEXT_ERR_*| values are
// unimplemented and will be treated as |SSL_TLSEXT_ERR_NOACK|.
//
// The cipher suite is selected before negotiating ALPN. The callback may use
// |SSL_get_pending_cipher| to query the cipher suite.
OPENSSL_EXPORT void SSL_CTX_set_alpn_select_cb(
SSL_CTX *ctx, int (*cb)(SSL *ssl, const uint8_t **out, uint8_t *out_len,
const uint8_t *in, unsigned in_len, void *arg),
void *arg);
// SSL_get0_alpn_selected gets the selected ALPN protocol (if any) from |ssl|.
// On return it sets |*out_data| to point to |*out_len| bytes of protocol name
// (not including the leading length-prefix byte). If the server didn't respond
// with a negotiated protocol then |*out_len| will be zero.
OPENSSL_EXPORT void SSL_get0_alpn_selected(const SSL *ssl,
const uint8_t **out_data,
unsigned *out_len);
// SSL_CTX_set_allow_unknown_alpn_protos configures client connections on |ctx|
// to allow unknown ALPN protocols from the server. Otherwise, by default, the
// client will require that the protocol be advertised in
// |SSL_CTX_set_alpn_protos|.
OPENSSL_EXPORT void SSL_CTX_set_allow_unknown_alpn_protos(SSL_CTX *ctx,
int enabled);
// Next protocol negotiation.
//
// The NPN extension (draft-agl-tls-nextprotoneg-03) is the predecessor to ALPN
// and deprecated in favor of it.
// SSL_CTX_set_next_protos_advertised_cb sets a callback that is called when a
// TLS server needs a list of supported protocols for Next Protocol
// Negotiation. The returned list must be in wire format. The list is returned
// by setting |*out| to point to it and |*out_len| to its length. This memory
// will not be modified, but one should assume that |ssl| keeps a reference to
// it.
//
// The callback should return |SSL_TLSEXT_ERR_OK| if it wishes to advertise.
// Otherwise, no such extension will be included in the ServerHello.
OPENSSL_EXPORT void SSL_CTX_set_next_protos_advertised_cb(
SSL_CTX *ctx,
int (*cb)(SSL *ssl, const uint8_t **out, unsigned *out_len, void *arg),
void *arg);
// SSL_CTX_set_next_proto_select_cb sets a callback that is called when a client
// needs to select a protocol from the server's provided list. |*out| must be
// set to point to the selected protocol (which may be within |in|). The length
// of the protocol name must be written into |*out_len|. The server's advertised
// protocols are provided in |in| and |in_len|. The callback can assume that
// |in| is syntactically valid.
//
// The client must select a protocol. It is fatal to the connection if this
// callback returns a value other than |SSL_TLSEXT_ERR_OK|.
//
// Configuring this callback enables NPN on a client.
OPENSSL_EXPORT void SSL_CTX_set_next_proto_select_cb(
SSL_CTX *ctx, int (*cb)(SSL *ssl, uint8_t **out, uint8_t *out_len,
const uint8_t *in, unsigned in_len, void *arg),
void *arg);
// SSL_get0_next_proto_negotiated sets |*out_data| and |*out_len| to point to
// the client's requested protocol for this connection. If the client didn't
// request any protocol, then |*out_data| is set to NULL.
//
// Note that the client can request any protocol it chooses. The value returned
// from this function need not be a member of the list of supported protocols
// provided by the server.
OPENSSL_EXPORT void SSL_get0_next_proto_negotiated(const SSL *ssl,
const uint8_t **out_data,
unsigned *out_len);
// SSL_select_next_proto implements the standard protocol selection. It is
// expected that this function is called from the callback set by
// |SSL_CTX_set_next_proto_select_cb|.
//
// |peer| and |supported| must be vectors of 8-bit, length-prefixed byte strings
// containing the peer and locally-configured protocols, respectively. The
// length byte itself is not included in the length. A byte string of length 0
// is invalid. No byte string may be truncated. |supported| is assumed to be
// non-empty.
//
// This function finds the first protocol in |peer| which is also in
// |supported|. If one was found, it sets |*out| and |*out_len| to point to it
// and returns |OPENSSL_NPN_NEGOTIATED|. Otherwise, it returns
// |OPENSSL_NPN_NO_OVERLAP| and sets |*out| and |*out_len| to the first
// supported protocol.
OPENSSL_EXPORT int SSL_select_next_proto(uint8_t **out, uint8_t *out_len,
const uint8_t *peer, unsigned peer_len,
const uint8_t *supported,
unsigned supported_len);
#define OPENSSL_NPN_UNSUPPORTED 0
#define OPENSSL_NPN_NEGOTIATED 1
#define OPENSSL_NPN_NO_OVERLAP 2
// Channel ID.
//
// See draft-balfanz-tls-channelid-01.
// SSL_CTX_set_tls_channel_id_enabled configures whether connections associated
// with |ctx| should enable Channel ID.
OPENSSL_EXPORT void SSL_CTX_set_tls_channel_id_enabled(SSL_CTX *ctx,
int enabled);
// SSL_set_tls_channel_id_enabled configures whether |ssl| should enable Channel
// ID.
OPENSSL_EXPORT void SSL_set_tls_channel_id_enabled(SSL *ssl, int enabled);
// SSL_CTX_set1_tls_channel_id configures a TLS client to send a TLS Channel ID
// to compatible servers. |private_key| must be a P-256 EC key. It returns one
// on success and zero on error.
OPENSSL_EXPORT int SSL_CTX_set1_tls_channel_id(SSL_CTX *ctx,
EVP_PKEY *private_key);
// SSL_set1_tls_channel_id configures a TLS client to send a TLS Channel ID to
// compatible servers. |private_key| must be a P-256 EC key. It returns one on
// success and zero on error.
OPENSSL_EXPORT int SSL_set1_tls_channel_id(SSL *ssl, EVP_PKEY *private_key);
// SSL_get_tls_channel_id gets the client's TLS Channel ID from a server |SSL*|
// and copies up to the first |max_out| bytes into |out|. The Channel ID
// consists of the client's P-256 public key as an (x,y) pair where each is a
// 32-byte, big-endian field element. It returns 0 if the client didn't offer a
// Channel ID and the length of the complete Channel ID otherwise.
OPENSSL_EXPORT size_t SSL_get_tls_channel_id(SSL *ssl, uint8_t *out,
size_t max_out);
// SSL_CTX_set_channel_id_cb sets a callback to be called when a TLS Channel ID
// is requested. The callback may set |*out_pkey| to a key, passing a reference
// to the caller. If none is returned, the handshake will pause and
// |SSL_get_error| will return |SSL_ERROR_WANT_CHANNEL_ID_LOOKUP|.
//
// See also |SSL_ERROR_WANT_CHANNEL_ID_LOOKUP|.
OPENSSL_EXPORT void SSL_CTX_set_channel_id_cb(
SSL_CTX *ctx, void (*channel_id_cb)(SSL *ssl, EVP_PKEY **out_pkey));
// SSL_CTX_get_channel_id_cb returns the callback set by
// |SSL_CTX_set_channel_id_cb|.
OPENSSL_EXPORT void (*SSL_CTX_get_channel_id_cb(SSL_CTX *ctx))(
SSL *ssl, EVP_PKEY **out_pkey);
// DTLS-SRTP.
//
// See RFC 5764.
// srtp_protection_profile_st (aka |SRTP_PROTECTION_PROFILE|) is an SRTP
// profile for use with the use_srtp extension.
struct srtp_protection_profile_st {
const char *name;
unsigned long id;
} /* SRTP_PROTECTION_PROFILE */;
DEFINE_CONST_STACK_OF(SRTP_PROTECTION_PROFILE)
// SRTP_* define constants for SRTP profiles.
#define SRTP_AES128_CM_SHA1_80 0x0001
#define SRTP_AES128_CM_SHA1_32 0x0002
#define SRTP_AES128_F8_SHA1_80 0x0003
#define SRTP_AES128_F8_SHA1_32 0x0004
#define SRTP_NULL_SHA1_80 0x0005
#define SRTP_NULL_SHA1_32 0x0006
#define SRTP_AEAD_AES_128_GCM 0x0007
#define SRTP_AEAD_AES_256_GCM 0x0008
// SSL_CTX_set_srtp_profiles enables SRTP for all SSL objects created from
// |ctx|. |profile| contains a colon-separated list of profile names. It returns
// one on success and zero on failure.
OPENSSL_EXPORT int SSL_CTX_set_srtp_profiles(SSL_CTX *ctx,
const char *profiles);
// SSL_set_srtp_profiles enables SRTP for |ssl|. |profile| contains a
// colon-separated list of profile names. It returns one on success and zero on
// failure.
OPENSSL_EXPORT int SSL_set_srtp_profiles(SSL *ssl, const char *profiles);
// SSL_get_srtp_profiles returns the SRTP profiles supported by |ssl|.
OPENSSL_EXPORT STACK_OF(SRTP_PROTECTION_PROFILE) *SSL_get_srtp_profiles(
SSL *ssl);
// SSL_get_selected_srtp_profile returns the selected SRTP profile, or NULL if
// SRTP was not negotiated.
OPENSSL_EXPORT const SRTP_PROTECTION_PROFILE *SSL_get_selected_srtp_profile(
SSL *ssl);
// Pre-shared keys.
//
// Connections may be configured with PSK (Pre-Shared Key) cipher suites. These
// authenticate using out-of-band pre-shared keys rather than certificates. See
// RFC 4279.
//
// This implementation uses NUL-terminated C strings for identities and identity
// hints, so values with a NUL character are not supported. (RFC 4279 does not
// specify the format of an identity.)
// PSK_MAX_IDENTITY_LEN is the maximum supported length of a PSK identity,
// excluding the NUL terminator.
#define PSK_MAX_IDENTITY_LEN 128
// PSK_MAX_PSK_LEN is the maximum supported length of a pre-shared key.
#define PSK_MAX_PSK_LEN 256
// SSL_CTX_set_psk_client_callback sets the callback to be called when PSK is
// negotiated on the client. This callback must be set to enable PSK cipher
// suites on the client.
//
// The callback is passed the identity hint in |hint| or NULL if none was
// provided. It should select a PSK identity and write the identity and the
// corresponding PSK to |identity| and |psk|, respectively. The identity is
// written as a NUL-terminated C string of length (excluding the NUL terminator)
// at most |max_identity_len|. The PSK's length must be at most |max_psk_len|.
// The callback returns the length of the PSK or 0 if no suitable identity was
// found.
OPENSSL_EXPORT void SSL_CTX_set_psk_client_callback(
SSL_CTX *ctx, unsigned (*cb)(SSL *ssl, const char *hint, char *identity,
unsigned max_identity_len, uint8_t *psk,
unsigned max_psk_len));
// SSL_set_psk_client_callback sets the callback to be called when PSK is
// negotiated on the client. This callback must be set to enable PSK cipher
// suites on the client. See also |SSL_CTX_set_psk_client_callback|.
OPENSSL_EXPORT void SSL_set_psk_client_callback(
SSL *ssl, unsigned (*cb)(SSL *ssl, const char *hint, char *identity,
unsigned max_identity_len, uint8_t *psk,
unsigned max_psk_len));
// SSL_CTX_set_psk_server_callback sets the callback to be called when PSK is
// negotiated on the server. This callback must be set to enable PSK cipher
// suites on the server.
//
// The callback is passed the identity in |identity|. It should write a PSK of
// length at most |max_psk_len| to |psk| and return the number of bytes written
// or zero if the PSK identity is unknown.
OPENSSL_EXPORT void SSL_CTX_set_psk_server_callback(
SSL_CTX *ctx, unsigned (*cb)(SSL *ssl, const char *identity, uint8_t *psk,
unsigned max_psk_len));
// SSL_set_psk_server_callback sets the callback to be called when PSK is
// negotiated on the server. This callback must be set to enable PSK cipher
// suites on the server. See also |SSL_CTX_set_psk_server_callback|.
OPENSSL_EXPORT void SSL_set_psk_server_callback(
SSL *ssl, unsigned (*cb)(SSL *ssl, const char *identity, uint8_t *psk,
unsigned max_psk_len));
// SSL_CTX_use_psk_identity_hint configures server connections to advertise an
// identity hint of |identity_hint|. It returns one on success and zero on
// error.
OPENSSL_EXPORT int SSL_CTX_use_psk_identity_hint(SSL_CTX *ctx,
const char *identity_hint);
// SSL_use_psk_identity_hint configures server connections to advertise an
// identity hint of |identity_hint|. It returns one on success and zero on
// error.
OPENSSL_EXPORT int SSL_use_psk_identity_hint(SSL *ssl,
const char *identity_hint);
// SSL_get_psk_identity_hint returns the PSK identity hint advertised for |ssl|
// or NULL if there is none.
OPENSSL_EXPORT const char *SSL_get_psk_identity_hint(const SSL *ssl);
// SSL_get_psk_identity, after the handshake completes, returns the PSK identity
// that was negotiated by |ssl| or NULL if PSK was not used.
OPENSSL_EXPORT const char *SSL_get_psk_identity(const SSL *ssl);
// Early data.
//
// WARNING: 0-RTT support in BoringSSL is currently experimental and not fully
// implemented. It may cause interoperability or security failures when used.
//
// Early data, or 0-RTT, is a feature in TLS 1.3 which allows clients to send
// data on the first flight during a resumption handshake. This can save a
// round-trip in some application protocols.
//
// WARNING: A 0-RTT handshake has different security properties from normal
// handshake, so it is off by default unless opted in. In particular, early data
// is replayable by a network attacker. Callers must account for this when
// sending or processing data before the handshake is confirmed. See
// draft-ietf-tls-tls13-18 for more information.
//
// As a server, if early data is accepted, |SSL_do_handshake| will complete as
// soon as the ClientHello is processed and server flight sent. |SSL_write| may
// be used to send half-RTT data. |SSL_read| will consume early data and
// transition to 1-RTT data as appropriate. Prior to the transition,
// |SSL_in_init| will report the handshake is still in progress. Callers may use
// it or |SSL_in_early_data| to defer or reject requests as needed.
//
// Early data as a client is more complex. If the offered session (see
// |SSL_set_session|) is 0-RTT-capable, the handshake will return after sending
// the ClientHello. The predicted peer certificates and ALPN protocol will be
// available via the usual APIs. |SSL_write| will write early data, up to the
// session's limit. Writes past this limit and |SSL_read| will complete the
// handshake before continuing. Callers may also call |SSL_do_handshake| again
// to complete the handshake sooner.
//
// If the server accepts early data, the handshake will succeed. |SSL_read| and
// |SSL_write| will then act as in a 1-RTT handshake. The peer certificates and
// ALPN protocol will be as predicted and need not be re-queried.
//
// If the server rejects early data, |SSL_do_handshake| (and thus |SSL_read| and
// |SSL_write|) will then fail with |SSL_get_error| returning
// |SSL_ERROR_EARLY_DATA_REJECTED|. The caller should treat this as a connection
// error and most likely perform a high-level retry. Note the server may still
// have processed the early data due to attacker replays.
//
// To then continue the handshake on the original connection, use
// |SSL_reset_early_data_reject|. The connection will then behave as one which
// had not yet completed the handshake. This allows a faster retry than making a
// fresh connection. |SSL_do_handshake| will complete the full handshake,
// possibly resulting in different peer certificates, ALPN protocol, and other
// properties. The caller must disregard any values from before the reset and
// query again.
//
// Finally, to implement the fallback described in draft-ietf-tls-tls13-18
// appendix C.3, retry on a fresh connection without 0-RTT if the handshake
// fails with |SSL_R_WRONG_VERSION_ON_EARLY_DATA|.
// SSL_CTX_set_early_data_enabled sets whether early data is allowed to be used
// with resumptions using |ctx|.
OPENSSL_EXPORT void SSL_CTX_set_early_data_enabled(SSL_CTX *ctx, int enabled);
// SSL_set_early_data_enabled sets whether early data is allowed to be used
// with resumptions using |ssl|. See |SSL_CTX_set_early_data_enabled| for more
// information.
OPENSSL_EXPORT void SSL_set_early_data_enabled(SSL *ssl, int enabled);
// SSL_in_early_data returns one if |ssl| has a pending handshake that has
// progressed enough to send or receive early data. Clients may call |SSL_write|
// to send early data, but |SSL_read| will complete the handshake before
// accepting application data. Servers may call |SSL_read| to read early data
// and |SSL_write| to send half-RTT data.
OPENSSL_EXPORT int SSL_in_early_data(const SSL *ssl);
// SSL_early_data_accepted returns whether early data was accepted on the
// handshake performed by |ssl|.
OPENSSL_EXPORT int SSL_early_data_accepted(const SSL *ssl);
// SSL_reset_early_data_reject resets |ssl| after an early data reject. All
// 0-RTT state is discarded, including any pending |SSL_write| calls. The caller
// should treat |ssl| as a logically fresh connection, usually by driving the
// handshake to completion using |SSL_do_handshake|.
//
// It is an error to call this function on an |SSL| object that is not signaling
// |SSL_ERROR_EARLY_DATA_REJECTED|.
OPENSSL_EXPORT void SSL_reset_early_data_reject(SSL *ssl);
// Alerts.
//
// TLS and SSL 3.0 use alerts to signal error conditions. Alerts have a type
// (warning or fatal) and description. OpenSSL internally handles fatal alerts
// with dedicated error codes (see |SSL_AD_REASON_OFFSET|). Except for
// close_notify, warning alerts are silently ignored and may only be surfaced
// with |SSL_CTX_set_info_callback|.
// SSL_AD_REASON_OFFSET is the offset between error reasons and |SSL_AD_*|
// values. Any error code under |ERR_LIB_SSL| with an error reason above this
// value corresponds to an alert description. Consumers may add or subtract
// |SSL_AD_REASON_OFFSET| to convert between them.
//
// make_errors.go reserves error codes above 1000 for manually-assigned errors.
// This value must be kept in sync with reservedReasonCode in make_errors.h
#define SSL_AD_REASON_OFFSET 1000
// SSL_AD_* are alert descriptions for SSL 3.0 and TLS.
#define SSL_AD_CLOSE_NOTIFY SSL3_AD_CLOSE_NOTIFY
#define SSL_AD_UNEXPECTED_MESSAGE SSL3_AD_UNEXPECTED_MESSAGE
#define SSL_AD_BAD_RECORD_MAC SSL3_AD_BAD_RECORD_MAC
#define SSL_AD_DECRYPTION_FAILED TLS1_AD_DECRYPTION_FAILED
#define SSL_AD_RECORD_OVERFLOW TLS1_AD_RECORD_OVERFLOW
#define SSL_AD_DECOMPRESSION_FAILURE SSL3_AD_DECOMPRESSION_FAILURE
#define SSL_AD_HANDSHAKE_FAILURE SSL3_AD_HANDSHAKE_FAILURE
#define SSL_AD_NO_CERTIFICATE SSL3_AD_NO_CERTIFICATE // Not used in TLS
#define SSL_AD_BAD_CERTIFICATE SSL3_AD_BAD_CERTIFICATE
#define SSL_AD_UNSUPPORTED_CERTIFICATE SSL3_AD_UNSUPPORTED_CERTIFICATE
#define SSL_AD_CERTIFICATE_REVOKED SSL3_AD_CERTIFICATE_REVOKED
#define SSL_AD_CERTIFICATE_EXPIRED SSL3_AD_CERTIFICATE_EXPIRED
#define SSL_AD_CERTIFICATE_UNKNOWN SSL3_AD_CERTIFICATE_UNKNOWN
#define SSL_AD_ILLEGAL_PARAMETER SSL3_AD_ILLEGAL_PARAMETER
#define SSL_AD_UNKNOWN_CA TLS1_AD_UNKNOWN_CA
#define SSL_AD_ACCESS_DENIED TLS1_AD_ACCESS_DENIED
#define SSL_AD_DECODE_ERROR TLS1_AD_DECODE_ERROR
#define SSL_AD_DECRYPT_ERROR TLS1_AD_DECRYPT_ERROR
#define SSL_AD_EXPORT_RESTRICTION TLS1_AD_EXPORT_RESTRICTION
#define SSL_AD_PROTOCOL_VERSION TLS1_AD_PROTOCOL_VERSION
#define SSL_AD_INSUFFICIENT_SECURITY TLS1_AD_INSUFFICIENT_SECURITY
#define SSL_AD_INTERNAL_ERROR TLS1_AD_INTERNAL_ERROR
#define SSL_AD_INAPPROPRIATE_FALLBACK SSL3_AD_INAPPROPRIATE_FALLBACK
#define SSL_AD_USER_CANCELLED TLS1_AD_USER_CANCELLED
#define SSL_AD_NO_RENEGOTIATION TLS1_AD_NO_RENEGOTIATION
#define SSL_AD_MISSING_EXTENSION TLS1_AD_MISSING_EXTENSION
#define SSL_AD_UNSUPPORTED_EXTENSION TLS1_AD_UNSUPPORTED_EXTENSION
#define SSL_AD_CERTIFICATE_UNOBTAINABLE TLS1_AD_CERTIFICATE_UNOBTAINABLE
#define SSL_AD_UNRECOGNIZED_NAME TLS1_AD_UNRECOGNIZED_NAME
#define SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE \
TLS1_AD_BAD_CERTIFICATE_STATUS_RESPONSE
#define SSL_AD_BAD_CERTIFICATE_HASH_VALUE TLS1_AD_BAD_CERTIFICATE_HASH_VALUE
#define SSL_AD_UNKNOWN_PSK_IDENTITY TLS1_AD_UNKNOWN_PSK_IDENTITY
#define SSL_AD_CERTIFICATE_REQUIRED TLS1_AD_CERTIFICATE_REQUIRED
// SSL_alert_type_string_long returns a string description of |value| as an
// alert type (warning or fatal).
OPENSSL_EXPORT const char *SSL_alert_type_string_long(int value);
// SSL_alert_desc_string_long returns a string description of |value| as an
// alert description or "unknown" if unknown.
OPENSSL_EXPORT const char *SSL_alert_desc_string_long(int value);
// SSL_send_fatal_alert sends a fatal alert over |ssl| of the specified type,
// which should be one of the |SSL_AD_*| constants. It returns one on success
// and <= 0 on error. The caller should pass the return value into
// |SSL_get_error| to determine how to proceed. Once this function has been
// called, future calls to |SSL_write| will fail.
//
// If retrying a failed operation due to |SSL_ERROR_WANT_WRITE|, subsequent
// calls must use the same |alert| parameter.
OPENSSL_EXPORT int SSL_send_fatal_alert(SSL *ssl, uint8_t alert);
// ex_data functions.
//
// See |ex_data.h| for details.
OPENSSL_EXPORT int SSL_set_ex_data(SSL *ssl, int idx, void *data);
OPENSSL_EXPORT void *SSL_get_ex_data(const SSL *ssl, int idx);
OPENSSL_EXPORT int SSL_get_ex_new_index(long argl, void *argp,
CRYPTO_EX_unused *unused,
CRYPTO_EX_dup *dup_unused,
CRYPTO_EX_free *free_func);
OPENSSL_EXPORT int SSL_SESSION_set_ex_data(SSL_SESSION *session, int idx,
void *data);
OPENSSL_EXPORT void *SSL_SESSION_get_ex_data(const SSL_SESSION *session,
int idx);
OPENSSL_EXPORT int SSL_SESSION_get_ex_new_index(long argl, void *argp,
CRYPTO_EX_unused *unused,