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boringssl/ssl/handshake_client.cc
Steven Valdez 4d71a9a2ca Migrate TLS 1.2 and below state machines to the new style. 
Bug: 128
Change-Id: Ief3779b1c43dd34a154a0f1d2f94d0da756bc07a
Reviewed-on: https://boringssl-review.googlesource.com/19144
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2017-08-29 19:23:22 +00:00

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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.
*
* Portions of the attached software ("Contribution") are developed by
* SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project.
*
* The Contribution is licensed pursuant to the OpenSSL open source
* license provided above.
*
* ECC cipher suite support in OpenSSL originally written by
* Vipul Gupta and Sumit Gupta of Sun Microsystems Laboratories.
*
*/
/* ====================================================================
* 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.
*/
#include <openssl/ssl.h>
#include <assert.h>
#include <limits.h>
#include <string.h>
#include <utility>
#include <openssl/aead.h>
#include <openssl/bn.h>
#include <openssl/buf.h>
#include <openssl/bytestring.h>
#include <openssl/ec_key.h>
#include <openssl/ecdsa.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/md5.h>
#include <openssl/mem.h>
#include <openssl/rand.h>
#include "../crypto/internal.h"
#include "internal.h"
namespace bssl {
enum ssl_client_hs_state_t {
state_start_connect = 0,
state_send_client_hello,
state_enter_early_data,
state_read_hello_verify_request,
state_read_server_hello,
state_tls13,
state_read_server_certificate,
state_read_certificate_status,
state_verify_server_certificate,
state_read_server_key_exchange,
state_read_certificate_request,
state_read_server_hello_done,
state_send_client_certificate,
state_send_client_key_exchange,
state_send_client_certificate_verify,
state_send_second_client_flight,
state_send_channel_id,
state_send_client_finished,
state_finish_flight,
state_read_session_ticket,
state_process_change_cipher_spec,
state_read_server_finished,
state_finish_client_handshake,
state_done,
};
/* ssl_get_client_disabled sets |*out_mask_a| and |*out_mask_k| to masks of
* disabled algorithms. */
static void ssl_get_client_disabled(SSL *ssl, uint32_t *out_mask_a,
uint32_t *out_mask_k) {
*out_mask_a = 0;
*out_mask_k = 0;
/* PSK requires a client callback. */
if (ssl->psk_client_callback == NULL) {
*out_mask_a |= SSL_aPSK;
*out_mask_k |= SSL_kPSK;
}
}
static int ssl_write_client_cipher_list(SSL_HANDSHAKE *hs, CBB *out) {
SSL *const ssl = hs->ssl;
uint32_t mask_a, mask_k;
ssl_get_client_disabled(ssl, &mask_a, &mask_k);
CBB child;
if (!CBB_add_u16_length_prefixed(out, &child)) {
return 0;
}
/* Add a fake cipher suite. See draft-davidben-tls-grease-01. */
if (ssl->ctx->grease_enabled &&
!CBB_add_u16(&child, ssl_get_grease_value(ssl, ssl_grease_cipher))) {
return 0;
}
/* Add TLS 1.3 ciphers. Order ChaCha20-Poly1305 relative to AES-GCM based on
* hardware support. */
if (hs->max_version >= TLS1_3_VERSION) {
if (!EVP_has_aes_hardware() &&
!CBB_add_u16(&child, TLS1_CK_CHACHA20_POLY1305_SHA256 & 0xffff)) {
return 0;
}
if (!CBB_add_u16(&child, TLS1_CK_AES_128_GCM_SHA256 & 0xffff) ||
!CBB_add_u16(&child, TLS1_CK_AES_256_GCM_SHA384 & 0xffff)) {
return 0;
}
if (EVP_has_aes_hardware() &&
!CBB_add_u16(&child, TLS1_CK_CHACHA20_POLY1305_SHA256 & 0xffff)) {
return 0;
}
}
if (hs->min_version < TLS1_3_VERSION) {
int any_enabled = 0;
for (const SSL_CIPHER *cipher : SSL_get_ciphers(ssl)) {
/* Skip disabled ciphers */
if ((cipher->algorithm_mkey & mask_k) ||
(cipher->algorithm_auth & mask_a)) {
continue;
}
if (SSL_CIPHER_get_min_version(cipher) > hs->max_version ||
SSL_CIPHER_get_max_version(cipher) < hs->min_version) {
continue;
}
any_enabled = 1;
if (!CBB_add_u16(&child, ssl_cipher_get_value(cipher))) {
return 0;
}
}
/* If all ciphers were disabled, return the error to the caller. */
if (!any_enabled && hs->max_version < TLS1_3_VERSION) {
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_CIPHERS_AVAILABLE);
return 0;
}
}
/* For SSLv3, the SCSV is added. Otherwise the renegotiation extension is
* added. */
if (hs->max_version == SSL3_VERSION &&
!ssl->s3->initial_handshake_complete) {
if (!CBB_add_u16(&child, SSL3_CK_SCSV & 0xffff)) {
return 0;
}
}
if (ssl->mode & SSL_MODE_SEND_FALLBACK_SCSV) {
if (!CBB_add_u16(&child, SSL3_CK_FALLBACK_SCSV & 0xffff)) {
return 0;
}
}
return CBB_flush(out);
}
int ssl_write_client_hello(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
ScopedCBB cbb;
CBB body;
if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_CLIENT_HELLO)) {
return 0;
}
/* Renegotiations do not participate in session resumption. */
int has_session_id = ssl->session != NULL &&
!ssl->s3->initial_handshake_complete &&
ssl->session->session_id_length > 0;
CBB child;
if (!CBB_add_u16(&body, hs->client_version) ||
!CBB_add_bytes(&body, ssl->s3->client_random, SSL3_RANDOM_SIZE) ||
!CBB_add_u8_length_prefixed(&body, &child)) {
return 0;
}
if (has_session_id) {
if (!CBB_add_bytes(&child, ssl->session->session_id,
ssl->session->session_id_length)) {
return 0;
}
} else {
/* In TLS 1.3 experimental encodings, send a fake placeholder session ID
* when we do not otherwise have one to send. */
if (hs->max_version >= TLS1_3_VERSION &&
ssl->tls13_variant == tls13_experiment &&
!CBB_add_bytes(&child, hs->session_id, hs->session_id_len)) {
return 0;
}
}
if (SSL_is_dtls(ssl)) {
if (!CBB_add_u8_length_prefixed(&body, &child) ||
!CBB_add_bytes(&child, ssl->d1->cookie, ssl->d1->cookie_len)) {
return 0;
}
}
size_t header_len =
SSL_is_dtls(ssl) ? DTLS1_HM_HEADER_LENGTH : SSL3_HM_HEADER_LENGTH;
if (!ssl_write_client_cipher_list(hs, &body) ||
!CBB_add_u8(&body, 1 /* one compression method */) ||
!CBB_add_u8(&body, 0 /* null compression */) ||
!ssl_add_clienthello_tlsext(hs, &body, header_len + CBB_len(&body))) {
return 0;
}
uint8_t *msg = NULL;
size_t len;
if (!ssl->method->finish_message(ssl, cbb.get(), &msg, &len)) {
return 0;
}
/* Now that the length prefixes have been computed, fill in the placeholder
* PSK binder. */
if (hs->needs_psk_binder &&
!tls13_write_psk_binder(hs, msg, len)) {
OPENSSL_free(msg);
return 0;
}
return ssl->method->add_message(ssl, msg, len);
}
static int parse_server_version(SSL_HANDSHAKE *hs, uint16_t *out,
const SSLMessage &msg) {
SSL *const ssl = hs->ssl;
if (msg.type != SSL3_MT_SERVER_HELLO &&
msg.type != SSL3_MT_HELLO_RETRY_REQUEST) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE);
return 0;
}
CBS server_hello = msg.body;
if (!CBS_get_u16(&server_hello, out)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return 0;
}
/* The server version may also be in the supported_versions extension if
* applicable. */
if (msg.type != SSL3_MT_SERVER_HELLO || *out != TLS1_2_VERSION) {
return 1;
}
uint8_t sid_length;
if (!CBS_skip(&server_hello, SSL3_RANDOM_SIZE) ||
!CBS_get_u8(&server_hello, &sid_length) ||
!CBS_skip(&server_hello, sid_length + 2 /* cipher_suite */ +
1 /* compression_method */)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return 0;
}
/* The extensions block may not be present. */
if (CBS_len(&server_hello) == 0) {
return 1;
}
CBS extensions;
if (!CBS_get_u16_length_prefixed(&server_hello, &extensions) ||
CBS_len(&server_hello) != 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return 0;
}
int have_supported_versions;
CBS supported_versions;
const SSL_EXTENSION_TYPE ext_types[] = {
{TLSEXT_TYPE_supported_versions, &have_supported_versions,
&supported_versions},
};
uint8_t alert = SSL_AD_DECODE_ERROR;
if (!ssl_parse_extensions(&extensions, &alert, ext_types,
OPENSSL_ARRAY_SIZE(ext_types),
1 /* ignore unknown */)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
return 0;
}
if (have_supported_versions &&
(!CBS_get_u16(&supported_versions, out) ||
CBS_len(&supported_versions) != 0)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return 0;
}
return 1;
}
static enum ssl_hs_wait_t do_start_connect(SSL_HANDSHAKE *hs) {
ssl_do_info_callback(hs->ssl, SSL_CB_HANDSHAKE_START, 1);
hs->state = state_send_client_hello;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_send_client_hello(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
/* The handshake buffer is reset on every ClientHello. Notably, in DTLS, we
* may send multiple ClientHellos if we receive HelloVerifyRequest. */
if (!hs->transcript.Init()) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return ssl_hs_error;
}
/* Freeze the version range. */
if (!ssl_get_version_range(ssl, &hs->min_version, &hs->max_version)) {
return ssl_hs_error;
}
/* Always advertise the ClientHello version from the original maximum version,
* even on renegotiation. The static RSA key exchange uses this field, and
* some servers fail when it changes across handshakes. */
if (SSL_is_dtls(hs->ssl)) {
hs->client_version =
hs->max_version >= TLS1_2_VERSION ? DTLS1_2_VERSION : DTLS1_VERSION;
} else {
hs->client_version =
hs->max_version >= TLS1_2_VERSION ? TLS1_2_VERSION : hs->max_version;
}
/* If the configured session has expired or was created at a disabled
* version, drop it. */
if (ssl->session != NULL) {
if (ssl->session->is_server ||
!ssl_supports_version(hs, ssl->session->ssl_version) ||
(ssl->session->session_id_length == 0 &&
ssl->session->tlsext_ticklen == 0) ||
ssl->session->not_resumable ||
!ssl_session_is_time_valid(ssl, ssl->session)) {
ssl_set_session(ssl, NULL);
}
}
/* If resending the ClientHello in DTLS after a HelloVerifyRequest, don't
* renegerate the client_random. The random must be reused. */
if ((!SSL_is_dtls(ssl) || !ssl->d1->send_cookie) &&
!RAND_bytes(ssl->s3->client_random, sizeof(ssl->s3->client_random))) {
return ssl_hs_error;
}
/* Initialize a random session ID for the experimental TLS 1.3 variant
* requiring a session id. */
if (ssl->tls13_variant == tls13_experiment) {
hs->session_id_len = sizeof(hs->session_id);
if (!RAND_bytes(hs->session_id, hs->session_id_len)) {
return ssl_hs_error;
}
}
if (!ssl_write_client_hello(hs)) {
return ssl_hs_error;
}
hs->state = state_enter_early_data;
return ssl_hs_flush;
}
static enum ssl_hs_wait_t do_enter_early_data(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
if (SSL_is_dtls(ssl) && !ssl->d1->send_cookie) {
hs->state = state_read_hello_verify_request;
return ssl_hs_ok;
}
if (!hs->early_data_offered) {
hs->state = state_read_server_hello;
return ssl_hs_ok;
}
if (!tls13_init_early_key_schedule(hs) ||
!tls13_advance_key_schedule(hs, ssl->session->master_key,
ssl->session->master_key_length) ||
!tls13_derive_early_secrets(hs) ||
!tls13_set_traffic_key(ssl, evp_aead_seal, hs->early_traffic_secret,
hs->hash_len)) {
return ssl_hs_error;
}
/* Stash the early data session, so connection properties may be queried out
* of it. */
hs->in_early_data = 1;
SSL_SESSION_up_ref(ssl->session);
hs->early_session.reset(ssl->session);
hs->can_early_write = 1;
hs->state = state_read_server_hello;
return ssl_hs_early_return;
}
static enum ssl_hs_wait_t do_read_hello_verify_request(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
assert(SSL_is_dtls(ssl));
SSLMessage msg;
if (!ssl->method->get_message(ssl, &msg)) {
return ssl_hs_read_message;
}
if (msg.type != DTLS1_MT_HELLO_VERIFY_REQUEST) {
ssl->d1->send_cookie = false;
hs->state = state_read_server_hello;
return ssl_hs_ok;
}
CBS hello_verify_request = msg.body, cookie;
uint16_t server_version;
if (!CBS_get_u16(&hello_verify_request, &server_version) ||
!CBS_get_u8_length_prefixed(&hello_verify_request, &cookie) ||
CBS_len(&cookie) > sizeof(ssl->d1->cookie) ||
CBS_len(&hello_verify_request) != 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
OPENSSL_memcpy(ssl->d1->cookie, CBS_data(&cookie), CBS_len(&cookie));
ssl->d1->cookie_len = CBS_len(&cookie);
ssl->d1->send_cookie = true;
ssl->method->next_message(ssl);
hs->state = state_send_client_hello;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_read_server_hello(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
SSLMessage msg;
if (!ssl->method->get_message(ssl, &msg)) {
return ssl_hs_read_server_hello;
}
uint16_t server_version;
if (!parse_server_version(hs, &server_version, msg)) {
return ssl_hs_error;
}
if (!ssl_supports_version(hs, server_version)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNSUPPORTED_PROTOCOL);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_PROTOCOL_VERSION);
return ssl_hs_error;
}
assert(ssl->s3->have_version == ssl->s3->initial_handshake_complete);
if (!ssl->s3->have_version) {
ssl->version = server_version;
/* At this point, the connection's version is known and ssl->version is
* fixed. Begin enforcing the record-layer version. */
ssl->s3->have_version = 1;
} else if (server_version != ssl->version) {
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_SSL_VERSION);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_PROTOCOL_VERSION);
return ssl_hs_error;
}
if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
hs->state = state_tls13;
return ssl_hs_ok;
}
if (hs->early_data_offered) {
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_VERSION_ON_EARLY_DATA);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_PROTOCOL_VERSION);
return ssl_hs_error;
}
ssl_clear_tls13_state(hs);
if (!ssl_check_message_type(ssl, msg, SSL3_MT_SERVER_HELLO)) {
return ssl_hs_error;
}
CBS server_hello = msg.body, server_random, session_id;
uint16_t cipher_suite;
uint8_t compression_method;
if (!CBS_skip(&server_hello, 2 /* version */) ||
!CBS_get_bytes(&server_hello, &server_random, SSL3_RANDOM_SIZE) ||
!CBS_get_u8_length_prefixed(&server_hello, &session_id) ||
CBS_len(&session_id) > SSL3_SESSION_ID_SIZE ||
!CBS_get_u16(&server_hello, &cipher_suite) ||
!CBS_get_u8(&server_hello, &compression_method)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
/* Copy over the server random. */
OPENSSL_memcpy(ssl->s3->server_random, CBS_data(&server_random),
SSL3_RANDOM_SIZE);
/* TODO(davidben): Implement the TLS 1.1 and 1.2 downgrade sentinels once TLS
* 1.3 is finalized and we are not implementing a draft version. */
if (!ssl->s3->initial_handshake_complete && ssl->session != NULL &&
ssl->session->session_id_length != 0 &&
CBS_mem_equal(&session_id, ssl->session->session_id,
ssl->session->session_id_length)) {
ssl->s3->session_reused = 1;
} else {
/* The session wasn't resumed. Create a fresh SSL_SESSION to
* fill out. */
ssl_set_session(ssl, NULL);
if (!ssl_get_new_session(hs, 0 /* client */)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
/* Note: session_id could be empty. */
hs->new_session->session_id_length = CBS_len(&session_id);
OPENSSL_memcpy(hs->new_session->session_id, CBS_data(&session_id),
CBS_len(&session_id));
}
const SSL_CIPHER *cipher = SSL_get_cipher_by_value(cipher_suite);
if (cipher == NULL) {
/* unknown cipher */
OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_CIPHER_RETURNED);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
/* The cipher must be allowed in the selected version and enabled. */
uint32_t mask_a, mask_k;
ssl_get_client_disabled(ssl, &mask_a, &mask_k);
if ((cipher->algorithm_mkey & mask_k) || (cipher->algorithm_auth & mask_a) ||
SSL_CIPHER_get_min_version(cipher) > ssl3_protocol_version(ssl) ||
SSL_CIPHER_get_max_version(cipher) < ssl3_protocol_version(ssl) ||
!sk_SSL_CIPHER_find(SSL_get_ciphers(ssl), NULL, cipher)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_CIPHER_RETURNED);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
if (ssl->session != NULL) {
if (ssl->session->ssl_version != ssl->version) {
OPENSSL_PUT_ERROR(SSL, SSL_R_OLD_SESSION_VERSION_NOT_RETURNED);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
if (ssl->session->cipher != cipher) {
OPENSSL_PUT_ERROR(SSL, SSL_R_OLD_SESSION_CIPHER_NOT_RETURNED);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
if (!ssl_session_is_context_valid(ssl, ssl->session)) {
/* This is actually a client application bug. */
OPENSSL_PUT_ERROR(SSL,
SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
} else {
hs->new_session->cipher = cipher;
}
hs->new_cipher = cipher;
/* Now that the cipher is known, initialize the handshake hash and hash the
* ServerHello. */
if (!hs->transcript.InitHash(ssl3_protocol_version(ssl), hs->new_cipher) ||
!ssl_hash_message(hs, msg)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
/* If doing a full handshake, the server may request a client certificate
* which requires hashing the handshake transcript. Otherwise, the handshake
* buffer may be released. */
if (ssl->session != NULL ||
!ssl_cipher_uses_certificate_auth(hs->new_cipher)) {
hs->transcript.FreeBuffer();
}
/* Only the NULL compression algorithm is supported. */
if (compression_method != 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNSUPPORTED_COMPRESSION_ALGORITHM);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
/* TLS extensions */
if (!ssl_parse_serverhello_tlsext(hs, &server_hello)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_PARSE_TLSEXT);
return ssl_hs_error;
}
/* There should be nothing left over in the record. */
if (CBS_len(&server_hello) != 0) {
/* wrong packet length */
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
if (ssl->session != NULL &&
hs->extended_master_secret != ssl->session->extended_master_secret) {
if (ssl->session->extended_master_secret) {
OPENSSL_PUT_ERROR(SSL, SSL_R_RESUMED_EMS_SESSION_WITHOUT_EMS_EXTENSION);
} else {
OPENSSL_PUT_ERROR(SSL, SSL_R_RESUMED_NON_EMS_SESSION_WITH_EMS_EXTENSION);
}
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
return ssl_hs_error;
}
ssl->method->next_message(ssl);
if (ssl->session != NULL) {
hs->state = state_read_session_ticket;
return ssl_hs_ok;
}
hs->state = state_read_server_certificate;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_tls13(SSL_HANDSHAKE *hs) {
enum ssl_hs_wait_t wait = tls13_client_handshake(hs);
if (wait == ssl_hs_ok) {
hs->state = state_finish_client_handshake;
return ssl_hs_ok;
}
return wait;
}
static enum ssl_hs_wait_t do_read_server_certificate(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
if (!ssl_cipher_uses_certificate_auth(hs->new_cipher)) {
hs->state = state_read_certificate_status;
return ssl_hs_ok;
}
SSLMessage msg;
if (!ssl->method->get_message(ssl, &msg)) {
return ssl_hs_read_message;
}
if (!ssl_check_message_type(ssl, msg, SSL3_MT_CERTIFICATE) ||
!ssl_hash_message(hs, msg)) {
return ssl_hs_error;
}
CBS body = msg.body;
uint8_t alert = SSL_AD_DECODE_ERROR;
UniquePtr<STACK_OF(CRYPTO_BUFFER)> chain;
if (!ssl_parse_cert_chain(&alert, &chain, &hs->peer_pubkey, NULL, &body,
ssl->ctx->pool)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
return ssl_hs_error;
}
sk_CRYPTO_BUFFER_pop_free(hs->new_session->certs, CRYPTO_BUFFER_free);
hs->new_session->certs = chain.release();
if (sk_CRYPTO_BUFFER_num(hs->new_session->certs) == 0 ||
CBS_len(&body) != 0 ||
!ssl->ctx->x509_method->session_cache_objects(hs->new_session.get())) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
if (!ssl_check_leaf_certificate(
hs, hs->peer_pubkey.get(),
sk_CRYPTO_BUFFER_value(hs->new_session->certs, 0))) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
ssl->method->next_message(ssl);
hs->state = state_read_certificate_status;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_read_certificate_status(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
if (!hs->certificate_status_expected) {
hs->state = state_verify_server_certificate;
return ssl_hs_ok;
}
SSLMessage msg;
if (!ssl->method->get_message(ssl, &msg)) {
return ssl_hs_read_message;
}
if (msg.type != SSL3_MT_CERTIFICATE_STATUS) {
/* A server may send status_request in ServerHello and then change
* its mind about sending CertificateStatus. */
hs->state = state_verify_server_certificate;
return ssl_hs_ok;
}
if (!ssl_hash_message(hs, msg)) {
return ssl_hs_error;
}
CBS certificate_status = msg.body, ocsp_response;
uint8_t status_type;
if (!CBS_get_u8(&certificate_status, &status_type) ||
status_type != TLSEXT_STATUSTYPE_ocsp ||
!CBS_get_u24_length_prefixed(&certificate_status, &ocsp_response) ||
CBS_len(&ocsp_response) == 0 ||
CBS_len(&certificate_status) != 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
CRYPTO_BUFFER_free(hs->new_session->ocsp_response);
hs->new_session->ocsp_response =
CRYPTO_BUFFER_new_from_CBS(&ocsp_response, ssl->ctx->pool);
if (hs->new_session->ocsp_response == nullptr) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
ssl->method->next_message(ssl);
hs->state = state_verify_server_certificate;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_verify_server_certificate(SSL_HANDSHAKE *hs) {
if (!ssl_cipher_uses_certificate_auth(hs->new_cipher)) {
hs->state = state_read_server_key_exchange;
return ssl_hs_ok;
}
switch (ssl_verify_peer_cert(hs)) {
case ssl_verify_ok:
break;
case ssl_verify_invalid:
return ssl_hs_error;
case ssl_verify_retry:
hs->state = state_verify_server_certificate;
return ssl_hs_certificate_verify;
}
hs->state = state_read_server_key_exchange;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_read_server_key_exchange(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
SSLMessage msg;
if (!ssl->method->get_message(ssl, &msg)) {
return ssl_hs_read_message;
}
if (msg.type != SSL3_MT_SERVER_KEY_EXCHANGE) {
/* Some ciphers (pure PSK) have an optional ServerKeyExchange message. */
if (ssl_cipher_requires_server_key_exchange(hs->new_cipher)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
return ssl_hs_error;
}
hs->state = state_read_certificate_request;
return ssl_hs_ok;
}
if (!ssl_hash_message(hs, msg)) {
return ssl_hs_error;
}
uint32_t alg_k = hs->new_cipher->algorithm_mkey;
uint32_t alg_a = hs->new_cipher->algorithm_auth;
CBS server_key_exchange = msg.body;
if (alg_a & SSL_aPSK) {
CBS psk_identity_hint;
/* Each of the PSK key exchanges begins with a psk_identity_hint. */
if (!CBS_get_u16_length_prefixed(&server_key_exchange,
&psk_identity_hint)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
/* Store PSK identity hint for later use, hint is used in
* ssl3_send_client_key_exchange. Assume that the maximum length of a PSK
* identity hint can be as long as the maximum length of a PSK identity.
* Also do not allow NULL characters; identities are saved as C strings.
*
* TODO(davidben): Should invalid hints be ignored? It's a hint rather than
* a specific identity. */
if (CBS_len(&psk_identity_hint) > PSK_MAX_IDENTITY_LEN ||
CBS_contains_zero_byte(&psk_identity_hint)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DATA_LENGTH_TOO_LONG);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
return ssl_hs_error;
}
/* Save non-empty identity hints as a C string. Empty identity hints we
* treat as missing. Plain PSK makes it possible to send either no hint
* (omit ServerKeyExchange) or an empty hint, while ECDHE_PSK can only spell
* empty hint. Having different capabilities is odd, so we interpret empty
* and missing as identical. */
char *raw = nullptr;
if (CBS_len(&psk_identity_hint) != 0 &&
!CBS_strdup(&psk_identity_hint, &raw)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
hs->peer_psk_identity_hint.reset(raw);
}
if (alg_k & SSL_kECDHE) {
/* Parse the server parameters. */
uint8_t group_type;
uint16_t group_id;
CBS point;
if (!CBS_get_u8(&server_key_exchange, &group_type) ||
group_type != NAMED_CURVE_TYPE ||
!CBS_get_u16(&server_key_exchange, &group_id) ||
!CBS_get_u8_length_prefixed(&server_key_exchange, &point)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
hs->new_session->group_id = group_id;
/* Ensure the group is consistent with preferences. */
if (!tls1_check_group_id(ssl, group_id)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_CURVE);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER);
return ssl_hs_error;
}
/* Initialize ECDH and save the peer public key for later. */
hs->key_share = SSLKeyShare::Create(group_id);
if (!hs->key_share ||
!CBS_stow(&point, &hs->peer_key, &hs->peer_key_len)) {
return ssl_hs_error;
}
} else if (!(alg_k & SSL_kPSK)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
return ssl_hs_error;
}
/* At this point, |server_key_exchange| contains the signature, if any, while
* |msg.body| contains the entire message. From that, derive a CBS containing
* just the parameter. */
CBS parameter;
CBS_init(&parameter, CBS_data(&msg.body),
CBS_len(&msg.body) - CBS_len(&server_key_exchange));
/* ServerKeyExchange should be signed by the server's public key. */
if (ssl_cipher_uses_certificate_auth(hs->new_cipher)) {
uint16_t signature_algorithm = 0;
if (ssl3_protocol_version(ssl) >= TLS1_2_VERSION) {
if (!CBS_get_u16(&server_key_exchange, &signature_algorithm)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
uint8_t alert = SSL_AD_DECODE_ERROR;
if (!tls12_check_peer_sigalg(ssl, &alert, signature_algorithm)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
return ssl_hs_error;
}
hs->new_session->peer_signature_algorithm = signature_algorithm;
} else if (!tls1_get_legacy_signature_algorithm(&signature_algorithm,
hs->peer_pubkey.get())) {
OPENSSL_PUT_ERROR(SSL, SSL_R_PEER_ERROR_UNSUPPORTED_CERTIFICATE_TYPE);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNSUPPORTED_CERTIFICATE);
return ssl_hs_error;
}
/* The last field in |server_key_exchange| is the signature. */
CBS signature;
if (!CBS_get_u16_length_prefixed(&server_key_exchange, &signature) ||
CBS_len(&server_key_exchange) != 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
ScopedCBB transcript;
uint8_t *transcript_data;
size_t transcript_len;
if (!CBB_init(transcript.get(),
2 * SSL3_RANDOM_SIZE + CBS_len(&parameter)) ||
!CBB_add_bytes(transcript.get(), ssl->s3->client_random,
SSL3_RANDOM_SIZE) ||
!CBB_add_bytes(transcript.get(), ssl->s3->server_random,
SSL3_RANDOM_SIZE) ||
!CBB_add_bytes(transcript.get(), CBS_data(&parameter),
CBS_len(&parameter)) ||
!CBB_finish(transcript.get(), &transcript_data, &transcript_len)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
int sig_ok = ssl_public_key_verify(
ssl, CBS_data(&signature), CBS_len(&signature), signature_algorithm,
hs->peer_pubkey.get(), transcript_data, transcript_len);
OPENSSL_free(transcript_data);
#if defined(BORINGSSL_UNSAFE_FUZZER_MODE)
sig_ok = 1;
ERR_clear_error();
#endif
if (!sig_ok) {
/* bad signature */
OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SIGNATURE);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECRYPT_ERROR);
return ssl_hs_error;
}
} else {
/* PSK ciphers are the only supported certificate-less ciphers. */
assert(alg_a == SSL_aPSK);
if (CBS_len(&server_key_exchange) > 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_EXTRA_DATA_IN_MESSAGE);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
return ssl_hs_error;
}
}
ssl->method->next_message(ssl);
hs->state = state_read_certificate_request;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_read_certificate_request(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
if (!ssl_cipher_uses_certificate_auth(hs->new_cipher)) {
hs->state = state_read_server_hello_done;
return ssl_hs_ok;
}
SSLMessage msg;
if (!ssl->method->get_message(ssl, &msg)) {
return ssl_hs_read_message;
}
if (msg.type == SSL3_MT_SERVER_HELLO_DONE) {
/* If we get here we don't need the handshake buffer as we won't be doing
* client auth. */
hs->transcript.FreeBuffer();
hs->state = state_read_server_hello_done;
return ssl_hs_ok;
}
if (!ssl_check_message_type(ssl, msg, SSL3_MT_CERTIFICATE_REQUEST) ||
!ssl_hash_message(hs, msg)) {
return ssl_hs_error;
}
/* Get the certificate types. */
CBS body = msg.body, certificate_types;
if (!CBS_get_u8_length_prefixed(&body, &certificate_types)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
return ssl_hs_error;
}
if (!CBS_stow(&certificate_types, &hs->certificate_types,
&hs->num_certificate_types)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
return ssl_hs_error;
}
if (ssl3_protocol_version(ssl) >= TLS1_2_VERSION) {
CBS supported_signature_algorithms;
if (!CBS_get_u16_length_prefixed(&body, &supported_signature_algorithms) ||
!tls1_parse_peer_sigalgs(hs, &supported_signature_algorithms)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
return ssl_hs_error;
}
}
uint8_t alert = SSL_AD_DECODE_ERROR;
UniquePtr<STACK_OF(CRYPTO_BUFFER)> ca_names =
ssl_parse_client_CA_list(ssl, &alert, &body);
if (!ca_names) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
return ssl_hs_error;
}
if (CBS_len(&body) != 0) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
return ssl_hs_error;
}
hs->cert_request = 1;
hs->ca_names = std::move(ca_names);
ssl->ctx->x509_method->hs_flush_cached_ca_names(hs);
ssl->method->next_message(ssl);
hs->state = state_read_server_hello_done;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_read_server_hello_done(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
SSLMessage msg;
if (!ssl->method->get_message(ssl, &msg)) {
return ssl_hs_read_message;
}
if (!ssl_check_message_type(ssl, msg, SSL3_MT_SERVER_HELLO_DONE) ||
!ssl_hash_message(hs, msg)) {
return ssl_hs_error;
}
/* ServerHelloDone is empty. */
if (CBS_len(&msg.body) != 0) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
return ssl_hs_error;
}
ssl->method->next_message(ssl);
hs->state = state_send_client_certificate;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_send_client_certificate(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
/* The peer didn't request a certificate. */
if (!hs->cert_request) {
hs->state = state_send_client_key_exchange;
return ssl_hs_ok;
}
/* Call cert_cb to update the certificate. */
if (ssl->cert->cert_cb != NULL) {
int rv = ssl->cert->cert_cb(ssl, ssl->cert->cert_cb_arg);
if (rv == 0) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
OPENSSL_PUT_ERROR(SSL, SSL_R_CERT_CB_ERROR);
return ssl_hs_error;
}
if (rv < 0) {
hs->state = state_send_client_certificate;
return ssl_hs_x509_lookup;
}
}
if (!ssl_has_certificate(ssl)) {
/* Without a client certificate, the handshake buffer may be released. */
hs->transcript.FreeBuffer();
/* In SSL 3.0, the Certificate message is replaced with a warning alert. */
if (ssl->version == SSL3_VERSION) {
if (!ssl->method->add_alert(ssl, SSL3_AL_WARNING,
SSL_AD_NO_CERTIFICATE)) {
return ssl_hs_error;
}
hs->state = state_send_client_key_exchange;
return ssl_hs_ok;
}
}
if (!ssl_on_certificate_selected(hs) ||
!ssl3_output_cert_chain(ssl)) {
return ssl_hs_error;
}
hs->state = state_send_client_key_exchange;
return ssl_hs_ok;
}
static_assert(sizeof(size_t) >= sizeof(unsigned),
"size_t is smaller than unsigned");
static enum ssl_hs_wait_t do_send_client_key_exchange(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
ScopedCBB cbb;
CBB body;
if (!ssl->method->init_message(ssl, cbb.get(), &body,
SSL3_MT_CLIENT_KEY_EXCHANGE)) {
return ssl_hs_error;
}
uint8_t *pms = NULL;
size_t pms_len = 0;
uint32_t alg_k = hs->new_cipher->algorithm_mkey;
uint32_t alg_a = hs->new_cipher->algorithm_auth;
/* If using a PSK key exchange, prepare the pre-shared key. */
unsigned psk_len = 0;
uint8_t psk[PSK_MAX_PSK_LEN];
if (alg_a & SSL_aPSK) {
if (ssl->psk_client_callback == NULL) {
OPENSSL_PUT_ERROR(SSL, SSL_R_PSK_NO_CLIENT_CB);
goto err;
}
char identity[PSK_MAX_IDENTITY_LEN + 1];
OPENSSL_memset(identity, 0, sizeof(identity));
psk_len =
ssl->psk_client_callback(ssl, hs->peer_psk_identity_hint.get(),
identity, sizeof(identity), psk, sizeof(psk));
if (psk_len == 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_PSK_IDENTITY_NOT_FOUND);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
goto err;
}
assert(psk_len <= PSK_MAX_PSK_LEN);
OPENSSL_free(hs->new_session->psk_identity);
hs->new_session->psk_identity = BUF_strdup(identity);
if (hs->new_session->psk_identity == NULL) {
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
goto err;
}
/* Write out psk_identity. */
CBB child;
if (!CBB_add_u16_length_prefixed(&body, &child) ||
!CBB_add_bytes(&child, (const uint8_t *)identity,
OPENSSL_strnlen(identity, sizeof(identity))) ||
!CBB_flush(&body)) {
goto err;
}
}
/* Depending on the key exchange method, compute |pms| and |pms_len|. */
if (alg_k & SSL_kRSA) {
pms_len = SSL_MAX_MASTER_KEY_LENGTH;
pms = (uint8_t *)OPENSSL_malloc(pms_len);
if (pms == NULL) {
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
goto err;
}
RSA *rsa = EVP_PKEY_get0_RSA(hs->peer_pubkey.get());
if (rsa == NULL) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
goto err;
}
pms[0] = hs->client_version >> 8;
pms[1] = hs->client_version & 0xff;
if (!RAND_bytes(&pms[2], SSL_MAX_MASTER_KEY_LENGTH - 2)) {
goto err;
}
CBB child, *enc_pms = &body;
size_t enc_pms_len;
/* In TLS, there is a length prefix. */
if (ssl->version > SSL3_VERSION) {
if (!CBB_add_u16_length_prefixed(&body, &child)) {
goto err;
}
enc_pms = &child;
}
uint8_t *ptr;
if (!CBB_reserve(enc_pms, &ptr, RSA_size(rsa)) ||
!RSA_encrypt(rsa, &enc_pms_len, ptr, RSA_size(rsa), pms, pms_len,
RSA_PKCS1_PADDING) ||
!CBB_did_write(enc_pms, enc_pms_len) ||
!CBB_flush(&body)) {
goto err;
}
} else if (alg_k & SSL_kECDHE) {
/* Generate a keypair and serialize the public half. */
CBB child;
if (!CBB_add_u8_length_prefixed(&body, &child)) {
goto err;
}
/* Compute the premaster. */
uint8_t alert = SSL_AD_DECODE_ERROR;
if (!hs->key_share->Accept(&child, &pms, &pms_len, &alert, hs->peer_key,
hs->peer_key_len)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
goto err;
}
if (!CBB_flush(&body)) {
goto err;
}
/* The key exchange state may now be discarded. */
hs->key_share.reset();
OPENSSL_free(hs->peer_key);
hs->peer_key = NULL;
hs->peer_key_len = 0;
} else if (alg_k & SSL_kPSK) {
/* For plain PSK, other_secret is a block of 0s with the same length as
* the pre-shared key. */
pms_len = psk_len;
pms = (uint8_t *)OPENSSL_malloc(pms_len);
if (pms == NULL) {
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
goto err;
}
OPENSSL_memset(pms, 0, pms_len);
} else {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
goto err;
}
/* For a PSK cipher suite, other_secret is combined with the pre-shared
* key. */
if (alg_a & SSL_aPSK) {
ScopedCBB pms_cbb;
CBB child;
uint8_t *new_pms;
size_t new_pms_len;
if (!CBB_init(pms_cbb.get(), 2 + psk_len + 2 + pms_len) ||
!CBB_add_u16_length_prefixed(pms_cbb.get(), &child) ||
!CBB_add_bytes(&child, pms, pms_len) ||
!CBB_add_u16_length_prefixed(pms_cbb.get(), &child) ||
!CBB_add_bytes(&child, psk, psk_len) ||
!CBB_finish(pms_cbb.get(), &new_pms, &new_pms_len)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
goto err;
}
OPENSSL_cleanse(pms, pms_len);
OPENSSL_free(pms);
pms = new_pms;
pms_len = new_pms_len;
}
/* The message must be added to the finished hash before calculating the
* master secret. */
if (!ssl_add_message_cbb(ssl, cbb.get())) {
goto err;
}
hs->new_session->master_key_length = tls1_generate_master_secret(
hs, hs->new_session->master_key, pms, pms_len);
if (hs->new_session->master_key_length == 0) {
goto err;
}
hs->new_session->extended_master_secret = hs->extended_master_secret;
OPENSSL_cleanse(pms, pms_len);
OPENSSL_free(pms);
hs->state = state_send_client_certificate_verify;
return ssl_hs_ok;
err:
if (pms != NULL) {
OPENSSL_cleanse(pms, pms_len);
OPENSSL_free(pms);
}
return ssl_hs_error;
}
static enum ssl_hs_wait_t do_send_client_certificate_verify(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
if (!hs->cert_request || !ssl_has_certificate(ssl)) {
hs->state = state_send_second_client_flight;
return ssl_hs_ok;
}
assert(ssl_has_private_key(ssl));
ScopedCBB cbb;
CBB body, child;
if (!ssl->method->init_message(ssl, cbb.get(), &body,
SSL3_MT_CERTIFICATE_VERIFY)) {
return ssl_hs_error;
}
uint16_t signature_algorithm;
if (!tls1_choose_signature_algorithm(hs, &signature_algorithm)) {
return ssl_hs_error;
}
if (ssl3_protocol_version(ssl) >= TLS1_2_VERSION) {
/* Write out the digest type in TLS 1.2. */
if (!CBB_add_u16(&body, signature_algorithm)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return ssl_hs_error;
}
}
/* Set aside space for the signature. */
const size_t max_sig_len = EVP_PKEY_size(hs->local_pubkey.get());
uint8_t *ptr;
if (!CBB_add_u16_length_prefixed(&body, &child) ||
!CBB_reserve(&child, &ptr, max_sig_len)) {
return ssl_hs_error;
}
size_t sig_len = max_sig_len;
/* The SSL3 construction for CertificateVerify does not decompose into a
* single final digest and signature, and must be special-cased. */
if (ssl3_protocol_version(ssl) == SSL3_VERSION) {
if (ssl->cert->key_method != NULL) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNSUPPORTED_PROTOCOL_FOR_CUSTOM_KEY);
return ssl_hs_error;
}
uint8_t digest[EVP_MAX_MD_SIZE];
size_t digest_len;
if (!hs->transcript.GetSSL3CertVerifyHash(
digest, &digest_len, hs->new_session.get(), signature_algorithm)) {
return ssl_hs_error;
}
UniquePtr<EVP_PKEY_CTX> pctx(EVP_PKEY_CTX_new(ssl->cert->privatekey, NULL));
if (!pctx ||
!EVP_PKEY_sign_init(pctx.get()) ||
!EVP_PKEY_sign(pctx.get(), ptr, &sig_len, digest, digest_len)) {
return ssl_hs_error;
}
} else {
switch (ssl_private_key_sign(
hs, ptr, &sig_len, max_sig_len, signature_algorithm,
hs->transcript.buffer_data(), hs->transcript.buffer_len())) {
case ssl_private_key_success:
break;
case ssl_private_key_failure:
return ssl_hs_error;
case ssl_private_key_retry:
hs->state = state_send_client_certificate_verify;
return ssl_hs_private_key_operation;
}
}
if (!CBB_did_write(&child, sig_len) ||
!ssl_add_message_cbb(ssl, cbb.get())) {
return ssl_hs_error;
}
/* The handshake buffer is no longer necessary. */
hs->transcript.FreeBuffer();
hs->state = state_send_second_client_flight;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_send_second_client_flight(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
if (!ssl->method->add_change_cipher_spec(ssl) ||
!tls1_change_cipher_state(hs, SSL3_CHANGE_CIPHER_CLIENT_WRITE)) {
return ssl_hs_error;
}
if (hs->next_proto_neg_seen) {
static const uint8_t kZero[32] = {0};
size_t padding_len = 32 - ((ssl->s3->next_proto_negotiated_len + 2) % 32);
ScopedCBB cbb;
CBB body, child;
if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_NEXT_PROTO) ||
!CBB_add_u8_length_prefixed(&body, &child) ||
!CBB_add_bytes(&child, ssl->s3->next_proto_negotiated,
ssl->s3->next_proto_negotiated_len) ||
!CBB_add_u8_length_prefixed(&body, &child) ||
!CBB_add_bytes(&child, kZero, padding_len) ||
!ssl_add_message_cbb(ssl, cbb.get())) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return ssl_hs_error;
}
}
hs->state = state_send_channel_id;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_send_channel_id(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
if (!ssl->s3->tlsext_channel_id_valid) {
hs->state = state_send_client_finished;
return ssl_hs_ok;
}
if (!ssl_do_channel_id_callback(ssl)) {
return ssl_hs_error;
}
if (ssl->tlsext_channel_id_private == NULL) {
hs->state = state_send_channel_id;
return ssl_hs_channel_id_lookup;
}
ScopedCBB cbb;
CBB body;
if (!ssl->method->init_message(ssl, cbb.get(), &body, SSL3_MT_CHANNEL_ID) ||
!tls1_write_channel_id(hs, &body) ||
!ssl_add_message_cbb(ssl, cbb.get())) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return ssl_hs_error;
}
hs->state = state_send_client_finished;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_send_client_finished(SSL_HANDSHAKE *hs) {
if (!ssl3_send_finished(hs)) {
return ssl_hs_error;
}
hs->state = state_finish_flight;
return ssl_hs_flush;
}
static enum ssl_hs_wait_t do_finish_flight(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
if (ssl->session != NULL) {
hs->state = state_finish_client_handshake;
return ssl_hs_ok;
}
/* This is a full handshake. If it involves ChannelID, then record the
* handshake hashes at this point in the session so that any resumption of
* this session with ChannelID can sign those hashes. */
if (!tls1_record_handshake_hashes_for_channel_id(hs)) {
return ssl_hs_error;
}
hs->state = state_read_session_ticket;
if ((SSL_get_mode(ssl) & SSL_MODE_ENABLE_FALSE_START) &&
ssl3_can_false_start(ssl) &&
/* No False Start on renegotiation (would complicate the state
* machine). */
!ssl->s3->initial_handshake_complete) {
hs->in_false_start = 1;
hs->can_early_write = 1;
return ssl_hs_early_return;
}
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_read_session_ticket(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
if (!hs->ticket_expected) {
hs->state = state_process_change_cipher_spec;
return ssl_hs_read_change_cipher_spec;
}
SSLMessage msg;
if (!ssl->method->get_message(ssl, &msg)) {
return ssl_hs_read_message;
}
if (!ssl_check_message_type(ssl, msg, SSL3_MT_NEW_SESSION_TICKET) ||
!ssl_hash_message(hs, msg)) {
return ssl_hs_error;
}
CBS new_session_ticket = msg.body, ticket;
uint32_t tlsext_tick_lifetime_hint;
if (!CBS_get_u32(&new_session_ticket, &tlsext_tick_lifetime_hint) ||
!CBS_get_u16_length_prefixed(&new_session_ticket, &ticket) ||
CBS_len(&new_session_ticket) != 0) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
return ssl_hs_error;
}
if (CBS_len(&ticket) == 0) {
/* RFC 5077 allows a server to change its mind and send no ticket after
* negotiating the extension. The value of |ticket_expected| is checked in
* |ssl_update_cache| so is cleared here to avoid an unnecessary update. */
hs->ticket_expected = 0;
ssl->method->next_message(ssl);
hs->state = state_process_change_cipher_spec;
return ssl_hs_read_change_cipher_spec;
}
SSL_SESSION *session = hs->new_session.get();
UniquePtr<SSL_SESSION> renewed_session;
if (ssl->session != NULL) {
/* The server is sending a new ticket for an existing session. Sessions are
* immutable once established, so duplicate all but the ticket of the
* existing session. */
renewed_session =
SSL_SESSION_dup(ssl->session, SSL_SESSION_INCLUDE_NONAUTH);
if (!renewed_session) {
/* This should never happen. */
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return ssl_hs_error;
}
session = renewed_session.get();
}
/* |tlsext_tick_lifetime_hint| is measured from when the ticket was issued. */
ssl_session_rebase_time(ssl, session);
if (!CBS_stow(&ticket, &session->tlsext_tick, &session->tlsext_ticklen)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
return ssl_hs_error;
}
session->tlsext_tick_lifetime_hint = tlsext_tick_lifetime_hint;
/* Generate a session ID for this session based on the session ticket. We use
* the session ID mechanism for detecting ticket resumption. This also fits in
* with assumptions elsewhere in OpenSSL.*/
if (!EVP_Digest(CBS_data(&ticket), CBS_len(&ticket),
session->session_id, &session->session_id_length,
EVP_sha256(), NULL)) {
return ssl_hs_error;
}
if (renewed_session) {
session->not_resumable = 0;
SSL_SESSION_free(ssl->session);
ssl->session = renewed_session.release();
}
ssl->method->next_message(ssl);
hs->state = state_process_change_cipher_spec;
return ssl_hs_read_change_cipher_spec;
}
static enum ssl_hs_wait_t do_process_change_cipher_spec(SSL_HANDSHAKE *hs) {
if (!tls1_change_cipher_state(hs, SSL3_CHANGE_CIPHER_CLIENT_READ)) {
return ssl_hs_error;
}
hs->state = state_read_server_finished;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_read_server_finished(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
enum ssl_hs_wait_t wait = ssl_get_finished(hs);
if (wait != ssl_hs_ok) {
return wait;
}
if (ssl->session != NULL) {
hs->state = state_send_second_client_flight;
return ssl_hs_ok;
}
hs->state = state_finish_client_handshake;
return ssl_hs_ok;
}
static enum ssl_hs_wait_t do_finish_client_handshake(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
ssl->method->on_handshake_complete(ssl);
SSL_SESSION_free(ssl->s3->established_session);
if (ssl->session != NULL) {
SSL_SESSION_up_ref(ssl->session);
ssl->s3->established_session = ssl->session;
} else {
/* We make a copy of the session in order to maintain the immutability
* of the new established_session due to False Start. The caller may
* have taken a reference to the temporary session. */
ssl->s3->established_session =
SSL_SESSION_dup(hs->new_session.get(), SSL_SESSION_DUP_ALL)
.release();
if (ssl->s3->established_session == NULL) {
return ssl_hs_error;
}
/* Renegotiations do not participate in session resumption. */
if (!ssl->s3->initial_handshake_complete) {
ssl->s3->established_session->not_resumable = 0;
}
hs->new_session.reset();
}
ssl->s3->initial_handshake_complete = 1;
ssl_update_cache(hs, SSL_SESS_CACHE_CLIENT);
hs->state = state_done;
return ssl_hs_ok;
}
enum ssl_hs_wait_t ssl_client_handshake(SSL_HANDSHAKE *hs) {
while (hs->state != state_done) {
enum ssl_hs_wait_t ret = ssl_hs_error;
enum ssl_client_hs_state_t state =
static_cast<enum ssl_client_hs_state_t>(hs->state);
switch (state) {
case state_start_connect:
ret = do_start_connect(hs);
break;
case state_send_client_hello:
ret = do_send_client_hello(hs);
break;
case state_enter_early_data:
ret = do_enter_early_data(hs);
break;
case state_read_hello_verify_request:
ret = do_read_hello_verify_request(hs);
break;
case state_read_server_hello:
ret = do_read_server_hello(hs);
break;
case state_tls13:
ret = do_tls13(hs);
break;
case state_read_server_certificate:
ret = do_read_server_certificate(hs);
break;
case state_read_certificate_status:
ret = do_read_certificate_status(hs);
break;
case state_verify_server_certificate:
ret = do_verify_server_certificate(hs);
break;
case state_read_server_key_exchange:
ret = do_read_server_key_exchange(hs);
break;
case state_read_certificate_request:
ret = do_read_certificate_request(hs);
break;
case state_read_server_hello_done:
ret = do_read_server_hello_done(hs);
break;
case state_send_client_certificate:
ret = do_send_client_certificate(hs);
break;
case state_send_client_key_exchange:
ret = do_send_client_key_exchange(hs);
break;
case state_send_client_certificate_verify:
ret = do_send_client_certificate_verify(hs);
break;
case state_send_second_client_flight:
ret = do_send_second_client_flight(hs);
break;
case state_send_channel_id:
ret = do_send_channel_id(hs);
break;
case state_send_client_finished:
ret = do_send_client_finished(hs);
break;
case state_finish_flight:
ret = do_finish_flight(hs);
break;
case state_read_session_ticket:
ret = do_read_session_ticket(hs);
break;
case state_process_change_cipher_spec:
ret = do_process_change_cipher_spec(hs);
break;
case state_read_server_finished:
ret = do_read_server_finished(hs);
break;
case state_finish_client_handshake:
ret = do_finish_client_handshake(hs);
break;
case state_done:
ret = ssl_hs_ok;
break;
}
if (hs->state != state) {
ssl_do_info_callback(hs->ssl, SSL_CB_CONNECT_LOOP, 1);
}
if (ret != ssl_hs_ok) {
return ret;
}
}
ssl_do_info_callback(hs->ssl, SSL_CB_HANDSHAKE_DONE, 1);
return ssl_hs_ok;
}
const char *ssl_client_handshake_state(SSL_HANDSHAKE *hs) {
enum ssl_client_hs_state_t state =
static_cast<enum ssl_client_hs_state_t>(hs->state);
switch (state) {
case state_start_connect:
return "TLS client start_connect";
case state_send_client_hello:
return "TLS client send_client_hello";
case state_enter_early_data:
return "TLS client enter_early_data";
case state_read_hello_verify_request:
return "TLS client read_hello_verify_request";
case state_read_server_hello:
return "TLS client read_server_hello";
case state_tls13:
return tls13_client_handshake_state(hs);
case state_read_server_certificate:
return "TLS client read_server_certificate";
case state_read_certificate_status:
return "TLS client read_certificate_status";
case state_verify_server_certificate:
return "TLS client verify_server_certificate";
case state_read_server_key_exchange:
return "TLS client read_server_key_exchange";
case state_read_certificate_request:
return "TLS client read_certificate_request";
case state_read_server_hello_done:
return "TLS client read_server_hello_done";
case state_send_client_certificate:
return "TLS client send_client_certificate";
case state_send_client_key_exchange:
return "TLS client send_client_key_exchange";
case state_send_client_certificate_verify:
return "TLS client send_client_certificate_verify";
case state_send_second_client_flight:
return "TLS client send_second_client_flight";
case state_send_channel_id:
return "TLS client send_channel_id";
case state_send_client_finished:
return "TLS client send_client_finished";
case state_finish_flight:
return "TLS client finish_flight";
case state_read_session_ticket:
return "TLS client read_session_ticket";
case state_process_change_cipher_spec:
return "TLS client process_change_cipher_spec";
case state_read_server_finished:
return "TLS client read_server_finished";
case state_finish_client_handshake:
return "TLS client finish_client_handshake";
case state_done:
return "TLS client done";
}
return "TLS client unknown";
}
}
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