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cfec7c60b9
boringssl/ssl/handshake_server.c
David Benjamin cfec7c60b9 Rename s3_{clnt,srvr}.c 
Give them much more reasonable names.

Change-Id: Id14d983ab3231da21a4f987e662c2e01af7a2cd6
Reviewed-on: https://boringssl-review.googlesource.com/8185
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
2016-06-08 19:25:31 +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 <string.h>
#include <openssl/bn.h>
#include <openssl/buf.h>
#include <openssl/bytestring.h>
#include <openssl/cipher.h>
#include <openssl/dh.h>
#include <openssl/ec.h>
#include <openssl/ecdsa.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <openssl/md5.h>
#include <openssl/mem.h>
#include <openssl/nid.h>
#include <openssl/rand.h>
#include <openssl/sha.h>
#include <openssl/x509.h>
#include "internal.h"
#include "../crypto/internal.h"
#include "../crypto/dh/internal.h"
static int ssl3_get_initial_bytes(SSL *ssl);
static int ssl3_get_v2_client_hello(SSL *ssl);
static int ssl3_get_client_hello(SSL *ssl);
static int ssl3_send_server_hello(SSL *ssl);
static int ssl3_send_server_certificate(SSL *ssl);
static int ssl3_send_certificate_status(SSL *ssl);
static int ssl3_send_server_key_exchange(SSL *ssl);
static int ssl3_send_certificate_request(SSL *ssl);
static int ssl3_send_server_done(SSL *ssl);
static int ssl3_get_client_certificate(SSL *ssl);
static int ssl3_get_client_key_exchange(SSL *ssl);
static int ssl3_get_cert_verify(SSL *ssl);
static int ssl3_get_next_proto(SSL *ssl);
static int ssl3_get_channel_id(SSL *ssl);
static int ssl3_send_new_session_ticket(SSL *ssl);
int ssl3_accept(SSL *ssl) {
BUF_MEM *buf = NULL;
uint32_t alg_a;
int ret = -1;
int state, skip = 0;
assert(ssl->handshake_func == ssl3_accept);
assert(ssl->server);
for (;;) {
state = ssl->state;
switch (ssl->state) {
case SSL_ST_ACCEPT:
ssl_do_info_callback(ssl, SSL_CB_HANDSHAKE_START, 1);
if (ssl->init_buf == NULL) {
buf = BUF_MEM_new();
if (!buf || !BUF_MEM_reserve(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
ret = -1;
goto end;
}
ssl->init_buf = buf;
buf = NULL;
}
ssl->init_num = 0;
/* Enable a write buffer. This groups handshake messages within a flight
* into a single write. */
if (!ssl_init_wbio_buffer(ssl)) {
ret = -1;
goto end;
}
if (!ssl3_init_handshake_buffer(ssl)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
ret = -1;
goto end;
}
if (!ssl->s3->have_version && !SSL_IS_DTLS(ssl)) {
ssl->state = SSL3_ST_SR_INITIAL_BYTES;
} else {
ssl->state = SSL3_ST_SR_CLNT_HELLO_A;
}
break;
case SSL3_ST_SR_INITIAL_BYTES:
assert(!SSL_IS_DTLS(ssl));
ret = ssl3_get_initial_bytes(ssl);
if (ret <= 0) {
goto end;
}
/* ssl3_get_initial_bytes sets ssl->state to one of
* SSL3_ST_SR_V2_CLIENT_HELLO or SSL3_ST_SR_CLNT_HELLO_A on success. */
break;
case SSL3_ST_SR_V2_CLIENT_HELLO:
assert(!SSL_IS_DTLS(ssl));
ret = ssl3_get_v2_client_hello(ssl);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_SR_CLNT_HELLO_A;
break;
case SSL3_ST_SR_CLNT_HELLO_A:
case SSL3_ST_SR_CLNT_HELLO_B:
case SSL3_ST_SR_CLNT_HELLO_C:
ret = ssl3_get_client_hello(ssl);
if (ret <= 0) {
goto end;
}
ssl->method->received_flight(ssl);
ssl->state = SSL3_ST_SW_SRVR_HELLO_A;
break;
case SSL3_ST_SW_SRVR_HELLO_A:
case SSL3_ST_SW_SRVR_HELLO_B:
ret = ssl3_send_server_hello(ssl);
if (ret <= 0) {
goto end;
}
if (ssl->hit) {
if (ssl->tlsext_ticket_expected) {
ssl->state = SSL3_ST_SW_SESSION_TICKET_A;
} else {
ssl->state = SSL3_ST_SW_CHANGE_A;
}
} else {
ssl->state = SSL3_ST_SW_CERT_A;
}
break;
case SSL3_ST_SW_CERT_A:
case SSL3_ST_SW_CERT_B:
if (ssl_cipher_uses_certificate_auth(ssl->s3->tmp.new_cipher)) {
ret = ssl3_send_server_certificate(ssl);
if (ret <= 0) {
goto end;
}
if (ssl->s3->tmp.certificate_status_expected) {
ssl->state = SSL3_ST_SW_CERT_STATUS_A;
} else {
ssl->state = SSL3_ST_SW_KEY_EXCH_A;
}
} else {
skip = 1;
ssl->state = SSL3_ST_SW_KEY_EXCH_A;
}
break;
case SSL3_ST_SW_CERT_STATUS_A:
case SSL3_ST_SW_CERT_STATUS_B:
ret = ssl3_send_certificate_status(ssl);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_SW_KEY_EXCH_A;
break;
case SSL3_ST_SW_KEY_EXCH_A:
case SSL3_ST_SW_KEY_EXCH_B:
case SSL3_ST_SW_KEY_EXCH_C:
alg_a = ssl->s3->tmp.new_cipher->algorithm_auth;
/* PSK ciphers send ServerKeyExchange if there is an identity hint. */
if (ssl_cipher_requires_server_key_exchange(ssl->s3->tmp.new_cipher) ||
((alg_a & SSL_aPSK) && ssl->psk_identity_hint)) {
ret = ssl3_send_server_key_exchange(ssl);
if (ret <= 0) {
goto end;
}
} else {
skip = 1;
}
ssl->state = SSL3_ST_SW_CERT_REQ_A;
break;
case SSL3_ST_SW_CERT_REQ_A:
case SSL3_ST_SW_CERT_REQ_B:
if (ssl->s3->tmp.cert_request) {
ret = ssl3_send_certificate_request(ssl);
if (ret <= 0) {
goto end;
}
} else {
skip = 1;
}
ssl->state = SSL3_ST_SW_SRVR_DONE_A;
break;
case SSL3_ST_SW_SRVR_DONE_A:
case SSL3_ST_SW_SRVR_DONE_B:
ret = ssl3_send_server_done(ssl);
if (ret <= 0) {
goto end;
}
ssl->s3->tmp.next_state = SSL3_ST_SR_CERT_A;
ssl->state = SSL3_ST_SW_FLUSH;
break;
case SSL3_ST_SR_CERT_A:
if (ssl->s3->tmp.cert_request) {
ret = ssl3_get_client_certificate(ssl);
if (ret <= 0) {
goto end;
}
}
ssl->state = SSL3_ST_SR_KEY_EXCH_A;
break;
case SSL3_ST_SR_KEY_EXCH_A:
case SSL3_ST_SR_KEY_EXCH_B:
ret = ssl3_get_client_key_exchange(ssl);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_SR_CERT_VRFY_A;
break;
case SSL3_ST_SR_CERT_VRFY_A:
ret = ssl3_get_cert_verify(ssl);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_SR_CHANGE;
break;
case SSL3_ST_SR_CHANGE:
ret = ssl->method->ssl_read_change_cipher_spec(ssl);
if (ret <= 0) {
goto end;
}
if (!tls1_change_cipher_state(ssl, SSL3_CHANGE_CIPHER_SERVER_READ)) {
ret = -1;
goto end;
}
if (ssl->s3->next_proto_neg_seen) {
ssl->state = SSL3_ST_SR_NEXT_PROTO_A;
} else if (ssl->s3->tlsext_channel_id_valid) {
ssl->state = SSL3_ST_SR_CHANNEL_ID_A;
} else {
ssl->state = SSL3_ST_SR_FINISHED_A;
}
break;
case SSL3_ST_SR_NEXT_PROTO_A:
ret = ssl3_get_next_proto(ssl);
if (ret <= 0) {
goto end;
}
if (ssl->s3->tlsext_channel_id_valid) {
ssl->state = SSL3_ST_SR_CHANNEL_ID_A;
} else {
ssl->state = SSL3_ST_SR_FINISHED_A;
}
break;
case SSL3_ST_SR_CHANNEL_ID_A:
ret = ssl3_get_channel_id(ssl);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_SR_FINISHED_A;
break;
case SSL3_ST_SR_FINISHED_A:
ret = ssl3_get_finished(ssl);
if (ret <= 0) {
goto end;
}
ssl->method->received_flight(ssl);
if (ssl->hit) {
ssl->state = SSL_ST_OK;
} else if (ssl->tlsext_ticket_expected) {
ssl->state = SSL3_ST_SW_SESSION_TICKET_A;
} else {
ssl->state = SSL3_ST_SW_CHANGE_A;
}
/* If this is a full handshake with ChannelID then record the hashshake
* hashes in |ssl->session| in case we need them to verify a ChannelID
* signature on a resumption of this session in the future. */
if (!ssl->hit && ssl->s3->tlsext_channel_id_valid) {
ret = tls1_record_handshake_hashes_for_channel_id(ssl);
if (ret <= 0) {
goto end;
}
}
break;
case SSL3_ST_SW_SESSION_TICKET_A:
case SSL3_ST_SW_SESSION_TICKET_B:
ret = ssl3_send_new_session_ticket(ssl);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_SW_CHANGE_A;
break;
case SSL3_ST_SW_CHANGE_A:
case SSL3_ST_SW_CHANGE_B:
ret = ssl->method->send_change_cipher_spec(ssl, SSL3_ST_SW_CHANGE_A,
SSL3_ST_SW_CHANGE_B);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_SW_FINISHED_A;
if (!tls1_change_cipher_state(ssl, SSL3_CHANGE_CIPHER_SERVER_WRITE)) {
ret = -1;
goto end;
}
break;
case SSL3_ST_SW_FINISHED_A:
case SSL3_ST_SW_FINISHED_B:
ret = ssl3_send_finished(ssl, SSL3_ST_SW_FINISHED_A,
SSL3_ST_SW_FINISHED_B);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_SW_FLUSH;
if (ssl->hit) {
ssl->s3->tmp.next_state = SSL3_ST_SR_CHANGE;
} else {
ssl->s3->tmp.next_state = SSL_ST_OK;
}
break;
case SSL3_ST_SW_FLUSH:
if (BIO_flush(ssl->wbio) <= 0) {
ssl->rwstate = SSL_WRITING;
ret = -1;
goto end;
}
ssl->state = ssl->s3->tmp.next_state;
if (ssl->state != SSL_ST_OK) {
ssl->method->expect_flight(ssl);
}
break;
case SSL_ST_OK:
/* clean a few things up */
ssl3_cleanup_key_block(ssl);
/* In DTLS, |init_buf| cannot be released because post-handshake
* retransmit relies on that buffer being available as scratch space.
*
* TODO(davidben): Fix this. */
if (!SSL_IS_DTLS(ssl)) {
BUF_MEM_free(ssl->init_buf);
ssl->init_buf = NULL;
ssl->init_num = 0;
}
/* remove buffering on output */
ssl_free_wbio_buffer(ssl);
/* If we aren't retaining peer certificates then we can discard it
* now. */
if (ssl->ctx->retain_only_sha256_of_client_certs) {
X509_free(ssl->session->peer);
ssl->session->peer = NULL;
sk_X509_pop_free(ssl->session->cert_chain, X509_free);
ssl->session->cert_chain = NULL;
}
if (SSL_IS_DTLS(ssl)) {
ssl->d1->handshake_read_seq = 0;
ssl->d1->handshake_write_seq = 0;
ssl->d1->next_handshake_write_seq = 0;
}
ssl->s3->initial_handshake_complete = 1;
ssl_update_cache(ssl, SSL_SESS_CACHE_SERVER);
ssl_do_info_callback(ssl, SSL_CB_HANDSHAKE_DONE, 1);
ret = 1;
goto end;
default:
OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_STATE);
ret = -1;
goto end;
}
if (!ssl->s3->tmp.reuse_message && !skip && ssl->state != state) {
int new_state = ssl->state;
ssl->state = state;
ssl_do_info_callback(ssl, SSL_CB_ACCEPT_LOOP, 1);
ssl->state = new_state;
}
skip = 0;
}
end:
BUF_MEM_free(buf);
ssl_do_info_callback(ssl, SSL_CB_ACCEPT_EXIT, ret);
return ret;
}
static int ssl3_get_initial_bytes(SSL *ssl) {
/* Read the first 5 bytes, the size of the TLS record header. This is
* sufficient to detect a V2ClientHello and ensures that we never read beyond
* the first record. */
int ret = ssl_read_buffer_extend_to(ssl, SSL3_RT_HEADER_LENGTH);
if (ret <= 0) {
return ret;
}
assert(ssl_read_buffer_len(ssl) == SSL3_RT_HEADER_LENGTH);
const uint8_t *p = ssl_read_buffer(ssl);
/* Some dedicated error codes for protocol mixups should the application wish
* to interpret them differently. (These do not overlap with ClientHello or
* V2ClientHello.) */
if (strncmp("GET ", (const char *)p, 4) == 0 ||
strncmp("POST ", (const char *)p, 5) == 0 ||
strncmp("HEAD ", (const char *)p, 5) == 0 ||
strncmp("PUT ", (const char *)p, 4) == 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_HTTP_REQUEST);
return -1;
}
if (strncmp("CONNE", (const char *)p, 5) == 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_HTTPS_PROXY_REQUEST);
return -1;
}
/* Determine if this is a V2ClientHello. */
if ((p[0] & 0x80) && p[2] == SSL2_MT_CLIENT_HELLO &&
p[3] >= SSL3_VERSION_MAJOR) {
/* This is a V2ClientHello. */
ssl->state = SSL3_ST_SR_V2_CLIENT_HELLO;
return 1;
}
/* Fall through to the standard logic. */
ssl->state = SSL3_ST_SR_CLNT_HELLO_A;
return 1;
}
static int ssl3_get_v2_client_hello(SSL *ssl) {
const uint8_t *p;
int ret;
CBS v2_client_hello, cipher_specs, session_id, challenge;
size_t msg_length, rand_len;
uint8_t msg_type;
uint16_t version, cipher_spec_length, session_id_length, challenge_length;
CBB client_hello, hello_body, cipher_suites;
uint8_t random[SSL3_RANDOM_SIZE];
/* Determine the length of the V2ClientHello. */
assert(ssl_read_buffer_len(ssl) >= SSL3_RT_HEADER_LENGTH);
p = ssl_read_buffer(ssl);
msg_length = ((p[0] & 0x7f) << 8) | p[1];
if (msg_length > (1024 * 4)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_RECORD_TOO_LARGE);
return -1;
}
if (msg_length < SSL3_RT_HEADER_LENGTH - 2) {
/* Reject lengths that are too short early. We have already read
* |SSL3_RT_HEADER_LENGTH| bytes, so we should not attempt to process an
* (invalid) V2ClientHello which would be shorter than that. */
OPENSSL_PUT_ERROR(SSL, SSL_R_RECORD_LENGTH_MISMATCH);
return -1;
}
/* Read the remainder of the V2ClientHello. */
ret = ssl_read_buffer_extend_to(ssl, 2 + msg_length);
if (ret <= 0) {
return ret;
}
assert(ssl_read_buffer_len(ssl) == msg_length + 2);
CBS_init(&v2_client_hello, ssl_read_buffer(ssl) + 2, msg_length);
/* The V2ClientHello without the length is incorporated into the handshake
* hash. */
if (!ssl3_update_handshake_hash(ssl, CBS_data(&v2_client_hello),
CBS_len(&v2_client_hello))) {
return -1;
}
ssl_do_msg_callback(ssl, 0 /* read */, SSL2_VERSION, 0,
CBS_data(&v2_client_hello), CBS_len(&v2_client_hello));
if (!CBS_get_u8(&v2_client_hello, &msg_type) ||
!CBS_get_u16(&v2_client_hello, &version) ||
!CBS_get_u16(&v2_client_hello, &cipher_spec_length) ||
!CBS_get_u16(&v2_client_hello, &session_id_length) ||
!CBS_get_u16(&v2_client_hello, &challenge_length) ||
!CBS_get_bytes(&v2_client_hello, &cipher_specs, cipher_spec_length) ||
!CBS_get_bytes(&v2_client_hello, &session_id, session_id_length) ||
!CBS_get_bytes(&v2_client_hello, &challenge, challenge_length) ||
CBS_len(&v2_client_hello) != 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
return -1;
}
/* msg_type has already been checked. */
assert(msg_type == SSL2_MT_CLIENT_HELLO);
/* The client_random is the V2ClientHello challenge. Truncate or
* left-pad with zeros as needed. */
memset(random, 0, SSL3_RANDOM_SIZE);
rand_len = CBS_len(&challenge);
if (rand_len > SSL3_RANDOM_SIZE) {
rand_len = SSL3_RANDOM_SIZE;
}
memcpy(random + (SSL3_RANDOM_SIZE - rand_len), CBS_data(&challenge),
rand_len);
/* Write out an equivalent SSLv3 ClientHello. */
CBB_zero(&client_hello);
if (!CBB_init_fixed(&client_hello, (uint8_t *)ssl->init_buf->data,
ssl->init_buf->max) ||
!CBB_add_u8(&client_hello, SSL3_MT_CLIENT_HELLO) ||
!CBB_add_u24_length_prefixed(&client_hello, &hello_body) ||
!CBB_add_u16(&hello_body, version) ||
!CBB_add_bytes(&hello_body, random, SSL3_RANDOM_SIZE) ||
/* No session id. */
!CBB_add_u8(&hello_body, 0) ||
!CBB_add_u16_length_prefixed(&hello_body, &cipher_suites)) {
CBB_cleanup(&client_hello);
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
return -1;
}
/* Copy the cipher suites. */
while (CBS_len(&cipher_specs) > 0) {
uint32_t cipher_spec;
if (!CBS_get_u24(&cipher_specs, &cipher_spec)) {
CBB_cleanup(&client_hello);
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
return -1;
}
/* Skip SSLv2 ciphers. */
if ((cipher_spec & 0xff0000) != 0) {
continue;
}
if (!CBB_add_u16(&cipher_suites, cipher_spec)) {
CBB_cleanup(&client_hello);
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return -1;
}
}
/* Add the null compression scheme and finish. */
if (!CBB_add_u8(&hello_body, 1) || !CBB_add_u8(&hello_body, 0) ||
!CBB_finish(&client_hello, NULL, &ssl->init_buf->length)) {
CBB_cleanup(&client_hello);
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return -1;
}
/* Mark the message for "re"-use by the version-specific method. */
ssl->s3->tmp.reuse_message = 1;
ssl->s3->tmp.message_type = SSL3_MT_CLIENT_HELLO;
ssl->s3->tmp.message_complete = 1;
/* Consume and discard the V2ClientHello. */
ssl_read_buffer_consume(ssl, 2 + msg_length);
ssl_read_buffer_discard(ssl);
return 1;
}
static int ssl3_get_client_hello(SSL *ssl) {
int ok, al = SSL_AD_INTERNAL_ERROR, ret = -1;
long n;
const SSL_CIPHER *c;
STACK_OF(SSL_CIPHER) *ciphers = NULL;
struct ssl_early_callback_ctx early_ctx;
CBS client_hello;
uint16_t client_version;
CBS client_random, session_id, cipher_suites, compression_methods;
SSL_SESSION *session = NULL;
/* We do this so that we will respond with our native type. If we are TLSv1
* and we get SSLv3, we will respond with TLSv1, This down switching should
* be handled by a different method. If we are SSLv3, we will respond with
* SSLv3, even if prompted with TLSv1. */
switch (ssl->state) {
case SSL3_ST_SR_CLNT_HELLO_A:
n = ssl->method->ssl_get_message(ssl, SSL3_MT_CLIENT_HELLO,
ssl_hash_message, &ok);
if (!ok) {
return n;
}
ssl->state = SSL3_ST_SR_CLNT_HELLO_B;
/* fallthrough */
case SSL3_ST_SR_CLNT_HELLO_B:
case SSL3_ST_SR_CLNT_HELLO_C:
/* We have previously parsed the ClientHello message, and can't call
* ssl_get_message again without hashing the message into the Finished
* digest again. */
n = ssl->init_num;
memset(&early_ctx, 0, sizeof(early_ctx));
early_ctx.ssl = ssl;
early_ctx.client_hello = ssl->init_msg;
early_ctx.client_hello_len = n;
if (!ssl_early_callback_init(&early_ctx)) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_CLIENTHELLO_PARSE_FAILED);
goto f_err;
}
if (ssl->state == SSL3_ST_SR_CLNT_HELLO_B &&
ssl->ctx->select_certificate_cb != NULL) {
ssl->state = SSL3_ST_SR_CLNT_HELLO_C;
switch (ssl->ctx->select_certificate_cb(&early_ctx)) {
case 0:
ssl->rwstate = SSL_CERTIFICATE_SELECTION_PENDING;
goto err;
case -1:
/* Connection rejected. */
al = SSL_AD_ACCESS_DENIED;
OPENSSL_PUT_ERROR(SSL, SSL_R_CONNECTION_REJECTED);
goto f_err;
default:
/* fallthrough */;
}
}
ssl->state = SSL3_ST_SR_CLNT_HELLO_C;
break;
default:
OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_STATE);
return -1;
}
CBS_init(&client_hello, ssl->init_msg, n);
if (!CBS_get_u16(&client_hello, &client_version) ||
!CBS_get_bytes(&client_hello, &client_random, SSL3_RANDOM_SIZE) ||
!CBS_get_u8_length_prefixed(&client_hello, &session_id) ||
CBS_len(&session_id) > SSL_MAX_SSL_SESSION_ID_LENGTH) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
goto f_err;
}
/* use version from inside client hello, not from record header (may differ:
* see RFC 2246, Appendix E, second paragraph) */
ssl->client_version = client_version;
/* Load the client random. */
memcpy(ssl->s3->client_random, CBS_data(&client_random), SSL3_RANDOM_SIZE);
if (SSL_IS_DTLS(ssl)) {
CBS cookie;
if (!CBS_get_u8_length_prefixed(&client_hello, &cookie) ||
CBS_len(&cookie) > DTLS1_COOKIE_LENGTH) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
goto f_err;
}
}
/* Note: This codepath may run twice if |ssl_get_prev_session| completes
* asynchronously.
*
* TODO(davidben): Clean up the order of events around ClientHello
* processing. */
if (!ssl->s3->have_version) {
/* Select version to use */
uint16_t version = ssl3_get_mutual_version(ssl, client_version);
if (version == 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNSUPPORTED_PROTOCOL);
ssl->version = ssl->client_version;
al = SSL_AD_PROTOCOL_VERSION;
goto f_err;
}
ssl->version = version;
ssl->s3->enc_method = ssl3_get_enc_method(version);
assert(ssl->s3->enc_method != NULL);
/* 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 (SSL_IS_DTLS(ssl) ? (ssl->client_version > ssl->version)
: (ssl->client_version < ssl->version)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_VERSION_NUMBER);
al = SSL_AD_PROTOCOL_VERSION;
goto f_err;
}
ssl->hit = 0;
int send_new_ticket = 0;
switch (ssl_get_prev_session(ssl, &session, &send_new_ticket, &early_ctx)) {
case ssl_session_success:
break;
case ssl_session_error:
goto err;
case ssl_session_retry:
ssl->rwstate = SSL_PENDING_SESSION;
goto err;
}
ssl->tlsext_ticket_expected = send_new_ticket;
/* The EMS state is needed when making the resumption decision, but
* extensions are not normally parsed until later. This detects the EMS
* extension for the resumption decision and it's checked against the result
* of the normal parse later in this function. */
const uint8_t *ems_data;
size_t ems_len;
int have_extended_master_secret =
ssl->version != SSL3_VERSION &&
SSL_early_callback_ctx_extension_get(&early_ctx,
TLSEXT_TYPE_extended_master_secret,
&ems_data, &ems_len) &&
ems_len == 0;
if (session != NULL) {
if (session->extended_master_secret &&
!have_extended_master_secret) {
/* A ClientHello without EMS that attempts to resume a session with EMS
* is fatal to the connection. */
al = SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, SSL_R_RESUMED_EMS_SESSION_WITHOUT_EMS_EXTENSION);
goto f_err;
}
ssl->hit =
/* Only resume if the session's version matches the negotiated version:
* most clients do not accept a mismatch. */
ssl->version == session->ssl_version &&
/* If the client offers the EMS extension, but the previous session
* didn't use it, then negotiate a new session. */
have_extended_master_secret == session->extended_master_secret;
}
if (ssl->hit) {
/* Use the new session. */
SSL_SESSION_free(ssl->session);
ssl->session = session;
session = NULL;
ssl->verify_result = ssl->session->verify_result;
} else {
if (!ssl_get_new_session(ssl, 1 /* server */)) {
goto err;
}
/* Clear the session ID if we want the session to be single-use. */
if (!(ssl->ctx->session_cache_mode & SSL_SESS_CACHE_SERVER)) {
ssl->session->session_id_length = 0;
}
}
if (ssl->ctx->dos_protection_cb != NULL &&
ssl->ctx->dos_protection_cb(&early_ctx) == 0) {
/* Connection rejected for DOS reasons. */
al = SSL_AD_ACCESS_DENIED;
OPENSSL_PUT_ERROR(SSL, SSL_R_CONNECTION_REJECTED);
goto f_err;
}
if (!CBS_get_u16_length_prefixed(&client_hello, &cipher_suites) ||
CBS_len(&cipher_suites) == 0 ||
CBS_len(&cipher_suites) % 2 != 0 ||
!CBS_get_u8_length_prefixed(&client_hello, &compression_methods) ||
CBS_len(&compression_methods) == 0) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
goto f_err;
}
ciphers = ssl_bytes_to_cipher_list(ssl, &cipher_suites);
if (ciphers == NULL) {
goto err;
}
/* If it is a hit, check that the cipher is in the list. */
if (ssl->hit) {
size_t j;
int found_cipher = 0;
uint32_t id = ssl->session->cipher->id;
for (j = 0; j < sk_SSL_CIPHER_num(ciphers); j++) {
c = sk_SSL_CIPHER_value(ciphers, j);
if (c->id == id) {
found_cipher = 1;
break;
}
}
if (!found_cipher) {
/* we need to have the cipher in the cipher list if we are asked to reuse
* it */
al = SSL_AD_ILLEGAL_PARAMETER;
OPENSSL_PUT_ERROR(SSL, SSL_R_REQUIRED_CIPHER_MISSING);
goto f_err;
}
}
/* Only null compression is supported. */
if (memchr(CBS_data(&compression_methods), 0,
CBS_len(&compression_methods)) == NULL) {
al = SSL_AD_ILLEGAL_PARAMETER;
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_COMPRESSION_SPECIFIED);
goto f_err;
}
/* TLS extensions. */
if (ssl->version >= SSL3_VERSION &&
!ssl_parse_clienthello_tlsext(ssl, &client_hello)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_PARSE_TLSEXT);
goto err;
}
/* There should be nothing left over in the record. */
if (CBS_len(&client_hello) != 0) {
/* wrong packet length */
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_PACKET_LENGTH);
goto f_err;
}
if (have_extended_master_secret != ssl->s3->tmp.extended_master_secret) {
al = SSL_AD_INTERNAL_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_EMS_STATE_INCONSISTENT);
goto f_err;
}
/* Given ciphers and SSL_get_ciphers, we must pick a cipher */
if (!ssl->hit) {
if (ciphers == NULL) {
al = SSL_AD_ILLEGAL_PARAMETER;
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_CIPHERS_PASSED);
goto f_err;
}
/* Let cert callback update server certificates if required */
if (ssl->cert->cert_cb) {
int rv = ssl->cert->cert_cb(ssl, ssl->cert->cert_cb_arg);
if (rv == 0) {
al = SSL_AD_INTERNAL_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_CERT_CB_ERROR);
goto f_err;
}
if (rv < 0) {
ssl->rwstate = SSL_X509_LOOKUP;
goto err;
}
}
c = ssl3_choose_cipher(ssl, ciphers, ssl_get_cipher_preferences(ssl));
if (c == NULL) {
al = SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_SHARED_CIPHER);
goto f_err;
}
ssl->session->cipher = c;
ssl->s3->tmp.new_cipher = c;
/* Determine whether to request a client certificate. */
ssl->s3->tmp.cert_request = !!(ssl->verify_mode & SSL_VERIFY_PEER);
/* Only request a certificate if Channel ID isn't negotiated. */
if ((ssl->verify_mode & SSL_VERIFY_PEER_IF_NO_OBC) &&
ssl->s3->tlsext_channel_id_valid) {
ssl->s3->tmp.cert_request = 0;
}
/* CertificateRequest may only be sent in certificate-based ciphers. */
if (!ssl_cipher_uses_certificate_auth(ssl->s3->tmp.new_cipher)) {
ssl->s3->tmp.cert_request = 0;
}
} else {
/* Session-id reuse */
ssl->s3->tmp.new_cipher = ssl->session->cipher;
ssl->s3->tmp.cert_request = 0;
}
/* Now that the cipher is known, initialize the handshake hash. */
if (!ssl3_init_handshake_hash(ssl)) {
goto f_err;
}
/* In TLS 1.2, client authentication requires hashing the handshake transcript
* under a different hash. Otherwise, release the handshake buffer. */
if (!ssl->s3->tmp.cert_request ||
ssl3_protocol_version(ssl) < TLS1_2_VERSION) {
ssl3_free_handshake_buffer(ssl);
}
/* we now have the following setup;
* client_random
* cipher_list - our prefered list of ciphers
* ciphers - the clients prefered list of ciphers
* compression - basically ignored right now
* ssl version is set - sslv3
* ssl->session - The ssl session has been setup.
* ssl->hit - session reuse flag
* ssl->tmp.new_cipher - the new cipher to use. */
ret = 1;
if (0) {
f_err:
ssl3_send_alert(ssl, SSL3_AL_FATAL, al);
}
err:
sk_SSL_CIPHER_free(ciphers);
SSL_SESSION_free(session);
return ret;
}
static int ssl3_send_server_hello(SSL *ssl) {
if (ssl->state == SSL3_ST_SW_SRVR_HELLO_B) {
return ssl_do_write(ssl);
}
assert(ssl->state == SSL3_ST_SW_SRVR_HELLO_A);
/* We only accept ChannelIDs on connections with ECDHE in order to avoid a
* known attack while we fix ChannelID itself. */
if (ssl->s3->tlsext_channel_id_valid &&
(ssl->s3->tmp.new_cipher->algorithm_mkey & SSL_kECDHE) == 0) {
ssl->s3->tlsext_channel_id_valid = 0;
}
/* If this is a resumption and the original handshake didn't support
* ChannelID then we didn't record the original handshake hashes in the
* session and so cannot resume with ChannelIDs. */
if (ssl->hit && ssl->session->original_handshake_hash_len == 0) {
ssl->s3->tlsext_channel_id_valid = 0;
}
if (!ssl_fill_hello_random(ssl->s3->server_random, SSL3_RANDOM_SIZE,
1 /* server */)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return -1;
}
CBB cbb, session_id;
size_t length;
CBB_zero(&cbb);
if (!CBB_init_fixed(&cbb, ssl_handshake_start(ssl),
ssl->init_buf->max - SSL_HM_HEADER_LENGTH(ssl)) ||
!CBB_add_u16(&cbb, ssl->version) ||
!CBB_add_bytes(&cbb, ssl->s3->server_random, SSL3_RANDOM_SIZE) ||
!CBB_add_u8_length_prefixed(&cbb, &session_id) ||
!CBB_add_bytes(&session_id, ssl->session->session_id,
ssl->session->session_id_length) ||
!CBB_add_u16(&cbb, ssl_cipher_get_value(ssl->s3->tmp.new_cipher)) ||
!CBB_add_u8(&cbb, 0 /* no compression */) ||
!ssl_add_serverhello_tlsext(ssl, &cbb) ||
!CBB_finish(&cbb, NULL, &length) ||
!ssl_set_handshake_header(ssl, SSL3_MT_SERVER_HELLO, length)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
CBB_cleanup(&cbb);
return -1;
}
ssl->state = SSL3_ST_SW_SRVR_HELLO_B;
return ssl_do_write(ssl);
}
static int ssl3_send_server_certificate(SSL *ssl) {
if (ssl->state == SSL3_ST_SW_CERT_A) {
if (!ssl3_output_cert_chain(ssl)) {
return 0;
}
ssl->state = SSL3_ST_SW_CERT_B;
}
/* SSL3_ST_SW_CERT_B */
return ssl_do_write(ssl);
}
static int ssl3_send_certificate_status(SSL *ssl) {
if (ssl->state == SSL3_ST_SW_CERT_STATUS_A) {
CBB out, ocsp_response;
size_t length;
CBB_zero(&out);
if (!CBB_init_fixed(&out, ssl_handshake_start(ssl),
ssl->init_buf->max - SSL_HM_HEADER_LENGTH(ssl)) ||
!CBB_add_u8(&out, TLSEXT_STATUSTYPE_ocsp) ||
!CBB_add_u24_length_prefixed(&out, &ocsp_response) ||
!CBB_add_bytes(&ocsp_response, ssl->ctx->ocsp_response,
ssl->ctx->ocsp_response_length) ||
!CBB_finish(&out, NULL, &length) ||
!ssl_set_handshake_header(ssl, SSL3_MT_CERTIFICATE_STATUS, length)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
CBB_cleanup(&out);
return -1;
}
ssl->state = SSL3_ST_SW_CERT_STATUS_B;
}
/* SSL3_ST_SW_CERT_STATUS_B */
return ssl_do_write(ssl);
}
static int ssl3_send_server_key_exchange(SSL *ssl) {
if (ssl->state == SSL3_ST_SW_KEY_EXCH_C) {
return ssl_do_write(ssl);
}
CBB cbb, child;
if (!CBB_init_fixed(&cbb, ssl_handshake_start(ssl),
ssl->init_buf->max - SSL_HM_HEADER_LENGTH(ssl))) {
goto err;
}
if (ssl->state == SSL3_ST_SW_KEY_EXCH_A) {
/* This is the first iteration, so write parameters. */
uint32_t alg_k = ssl->s3->tmp.new_cipher->algorithm_mkey;
uint32_t alg_a = ssl->s3->tmp.new_cipher->algorithm_auth;
/* PSK ciphers begin with an identity hint. */
if (alg_a & SSL_aPSK) {
size_t len =
(ssl->psk_identity_hint == NULL) ? 0 : strlen(ssl->psk_identity_hint);
if (!CBB_add_u16_length_prefixed(&cbb, &child) ||
!CBB_add_bytes(&child, (const uint8_t *)ssl->psk_identity_hint,
len)) {
goto err;
}
}
if (alg_k & SSL_kDHE) {
/* Determine the group to use. */
DH *params = ssl->cert->dh_tmp;
if (params == NULL && ssl->cert->dh_tmp_cb != NULL) {
params = ssl->cert->dh_tmp_cb(ssl, 0, 1024);
}
if (params == NULL) {
OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_TMP_DH_KEY);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
goto err;
}
ssl->session->key_exchange_info = DH_num_bits(params);
/* Set up DH, generate a key, and emit the public half. */
DH *dh = DHparams_dup(params);
if (dh == NULL) {
goto err;
}
SSL_ECDH_CTX_init_for_dhe(&ssl->s3->tmp.ecdh_ctx, dh);
if (!CBB_add_u16_length_prefixed(&cbb, &child) ||
!BN_bn2cbb_padded(&child, BN_num_bytes(params->p), params->p) ||
!CBB_add_u16_length_prefixed(&cbb, &child) ||
!BN_bn2cbb_padded(&child, BN_num_bytes(params->g), params->g) ||
!CBB_add_u16_length_prefixed(&cbb, &child) ||
!SSL_ECDH_CTX_offer(&ssl->s3->tmp.ecdh_ctx, &child)) {
goto err;
}
} else if (alg_k & SSL_kECDHE) {
/* Determine the group to use. */
uint16_t group_id;
if (!tls1_get_shared_group(ssl, &group_id)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_TMP_ECDH_KEY);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
goto err;
}
ssl->session->key_exchange_info = group_id;
/* Set up ECDH, generate a key, and emit the public half. */
if (!SSL_ECDH_CTX_init(&ssl->s3->tmp.ecdh_ctx, group_id) ||
!CBB_add_u8(&cbb, NAMED_CURVE_TYPE) ||
!CBB_add_u16(&cbb, group_id) ||
!CBB_add_u8_length_prefixed(&cbb, &child) ||
!SSL_ECDH_CTX_offer(&ssl->s3->tmp.ecdh_ctx, &child)) {
goto err;
}
} else if (alg_k & SSL_kCECPQ1) {
if (!SSL_ECDH_CTX_init(&ssl->s3->tmp.ecdh_ctx, SSL_GROUP_CECPQ1) ||
!CBB_add_u16_length_prefixed(&cbb, &child) ||
!SSL_ECDH_CTX_offer(&ssl->s3->tmp.ecdh_ctx, &child)) {
goto err;
}
} else {
assert(alg_k & SSL_kPSK);
}
/* Otherwise, restore |cbb| from the previous iteration.
* TODO(davidben): When |ssl->init_buf| is gone, come up with a simpler
* pattern. Probably keep the |CBB| around in the handshake state. */
} else if (!CBB_did_write(&cbb, ssl->init_num - SSL_HM_HEADER_LENGTH(ssl))) {
goto err;
}
/* Add a signature. */
if (ssl_cipher_uses_certificate_auth(ssl->s3->tmp.new_cipher)) {
if (!ssl_has_private_key(ssl)) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
goto err;
}
const size_t max_sig_len = ssl_private_key_max_signature_len(ssl);
size_t sig_len;
enum ssl_private_key_result_t sign_result;
if (ssl->state == SSL3_ST_SW_KEY_EXCH_A) {
/* This is the first iteration, so set up the signature. Sample the
* parameter length before adding a signature algorithm. */
if (!CBB_flush(&cbb)) {
goto err;
}
size_t params_len = CBB_len(&cbb);
/* Determine signature algorithm. */
const EVP_MD *md;
if (ssl3_protocol_version(ssl) >= TLS1_2_VERSION) {
md = tls1_choose_signing_digest(ssl);
if (!tls12_add_sigandhash(ssl, &cbb, md)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
goto err;
}
} else if (ssl_private_key_type(ssl) == EVP_PKEY_RSA) {
md = EVP_md5_sha1();
} else {
md = EVP_sha1();
}
/* Compute the digest and sign it. */
uint8_t digest[EVP_MAX_MD_SIZE];
unsigned digest_len = 0;
EVP_MD_CTX md_ctx;
EVP_MD_CTX_init(&md_ctx);
int digest_ret =
EVP_DigestInit_ex(&md_ctx, md, NULL) &&
EVP_DigestUpdate(&md_ctx, ssl->s3->client_random, SSL3_RANDOM_SIZE) &&
EVP_DigestUpdate(&md_ctx, ssl->s3->server_random, SSL3_RANDOM_SIZE) &&
EVP_DigestUpdate(&md_ctx, CBB_data(&cbb), params_len) &&
EVP_DigestFinal_ex(&md_ctx, digest, &digest_len);
EVP_MD_CTX_cleanup(&md_ctx);
uint8_t *ptr;
if (!digest_ret ||
!CBB_add_u16_length_prefixed(&cbb, &child) ||
!CBB_reserve(&child, &ptr, max_sig_len)) {
goto err;
}
sign_result = ssl_private_key_sign(ssl, ptr, &sig_len, max_sig_len, md,
digest, digest_len);
} else {
assert(ssl->state == SSL3_ST_SW_KEY_EXCH_B);
/* Retry the signature. */
uint8_t *ptr;
if (!CBB_add_u16_length_prefixed(&cbb, &child) ||
!CBB_reserve(&child, &ptr, max_sig_len)) {
goto err;
}
sign_result =
ssl_private_key_sign_complete(ssl, ptr, &sig_len, max_sig_len);
}
switch (sign_result) {
case ssl_private_key_success:
if (!CBB_did_write(&child, sig_len)) {
goto err;
}
break;
case ssl_private_key_failure:
goto err;
case ssl_private_key_retry:
/* Discard the unfinished signature and save the state of |cbb| for the
* next iteration. */
CBB_discard_child(&cbb);
ssl->init_num = SSL_HM_HEADER_LENGTH(ssl) + CBB_len(&cbb);
ssl->rwstate = SSL_PRIVATE_KEY_OPERATION;
ssl->state = SSL3_ST_SW_KEY_EXCH_B;
goto err;
}
}
size_t length;
if (!CBB_finish(&cbb, NULL, &length) ||
!ssl_set_handshake_header(ssl, SSL3_MT_SERVER_KEY_EXCHANGE, length)) {
goto err;
}
ssl->state = SSL3_ST_SW_KEY_EXCH_C;
return ssl_do_write(ssl);
err:
CBB_cleanup(&cbb);
return -1;
}
static int ssl3_send_certificate_request(SSL *ssl) {
uint8_t *p, *d;
size_t i;
int j, nl, off, n;
STACK_OF(X509_NAME) *sk = NULL;
X509_NAME *name;
BUF_MEM *buf;
if (ssl->state == SSL3_ST_SW_CERT_REQ_A) {
buf = ssl->init_buf;
d = p = ssl_handshake_start(ssl);
/* get the list of acceptable cert types */
p++;
n = ssl3_get_req_cert_type(ssl, p);
d[0] = n;
p += n;
n++;
if (ssl3_protocol_version(ssl) >= TLS1_2_VERSION) {
const uint8_t *psigs;
nl = tls12_get_psigalgs(ssl, &psigs);
s2n(nl, p);
memcpy(p, psigs, nl);
p += nl;
n += nl + 2;
}
off = n;
p += 2;
n += 2;
sk = SSL_get_client_CA_list(ssl);
nl = 0;
if (sk != NULL) {
for (i = 0; i < sk_X509_NAME_num(sk); i++) {
name = sk_X509_NAME_value(sk, i);
j = i2d_X509_NAME(name, NULL);
if (!BUF_MEM_grow_clean(buf, SSL_HM_HEADER_LENGTH(ssl) + n + j + 2)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_BUF_LIB);
goto err;
}
p = ssl_handshake_start(ssl) + n;
s2n(j, p);
i2d_X509_NAME(name, &p);
n += 2 + j;
nl += 2 + j;
}
}
/* else no CA names */
p = ssl_handshake_start(ssl) + off;
s2n(nl, p);
if (!ssl_set_handshake_header(ssl, SSL3_MT_CERTIFICATE_REQUEST, n)) {
goto err;
}
ssl->state = SSL3_ST_SW_CERT_REQ_B;
}
/* SSL3_ST_SW_CERT_REQ_B */
return ssl_do_write(ssl);
err:
return -1;
}
static int ssl3_send_server_done(SSL *ssl) {
if (ssl->state == SSL3_ST_SW_SRVR_DONE_A) {
if (!ssl_set_handshake_header(ssl, SSL3_MT_SERVER_DONE, 0)) {
return -1;
}
ssl->state = SSL3_ST_SW_SRVR_DONE_B;
}
/* SSL3_ST_SW_SRVR_DONE_B */
return ssl_do_write(ssl);
}
static int ssl3_get_client_certificate(SSL *ssl) {
int ok, al, ret = -1;
X509 *x = NULL;
unsigned long n;
STACK_OF(X509) *sk = NULL;
SHA256_CTX sha256;
CBS certificate_msg, certificate_list;
int is_first_certificate = 1;
assert(ssl->s3->tmp.cert_request);
n = ssl->method->ssl_get_message(ssl, -1, ssl_hash_message, &ok);
if (!ok) {
return n;
}
if (ssl->s3->tmp.message_type != SSL3_MT_CERTIFICATE) {
if (ssl->version == SSL3_VERSION &&
ssl->s3->tmp.message_type == SSL3_MT_CLIENT_KEY_EXCHANGE) {
/* In SSL 3.0, the Certificate message is omitted to signal no certificate. */
if ((ssl->verify_mode & SSL_VERIFY_PEER) &&
(ssl->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE);
al = SSL_AD_HANDSHAKE_FAILURE;
goto f_err;
}
ssl->s3->tmp.reuse_message = 1;
return 1;
}
al = SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE);
goto f_err;
}
CBS_init(&certificate_msg, ssl->init_msg, n);
sk = sk_X509_new_null();
if (sk == NULL) {
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
goto err;
}
if (!CBS_get_u24_length_prefixed(&certificate_msg, &certificate_list) ||
CBS_len(&certificate_msg) != 0) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
goto f_err;
}
while (CBS_len(&certificate_list) > 0) {
CBS certificate;
const uint8_t *data;
if (!CBS_get_u24_length_prefixed(&certificate_list, &certificate)) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
goto f_err;
}
if (is_first_certificate && ssl->ctx->retain_only_sha256_of_client_certs) {
/* If this is the first certificate, and we don't want to keep peer
* certificates in memory, then we hash it right away. */
SHA256_Init(&sha256);
SHA256_Update(&sha256, CBS_data(&certificate), CBS_len(&certificate));
SHA256_Final(ssl->session->peer_sha256, &sha256);
ssl->session->peer_sha256_valid = 1;
}
is_first_certificate = 0;
/* A u24 length cannot overflow a long. */
data = CBS_data(&certificate);
x = d2i_X509(NULL, &data, (long)CBS_len(&certificate));
if (x == NULL) {
al = SSL_AD_BAD_CERTIFICATE;
OPENSSL_PUT_ERROR(SSL, ERR_R_ASN1_LIB);
goto f_err;
}
if (data != CBS_data(&certificate) + CBS_len(&certificate)) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_CERT_LENGTH_MISMATCH);
goto f_err;
}
if (!sk_X509_push(sk, x)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
goto err;
}
x = NULL;
}
if (sk_X509_num(sk) <= 0) {
/* No client certificate so the handshake buffer may be discarded. */
ssl3_free_handshake_buffer(ssl);
/* TLS does not mind 0 certs returned */
if (ssl->version == SSL3_VERSION) {
al = SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_CERTIFICATES_RETURNED);
goto f_err;
} else if ((ssl->verify_mode & SSL_VERIFY_PEER) &&
(ssl->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) {
/* Fail for TLS only if we required a certificate */
OPENSSL_PUT_ERROR(SSL, SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE);
al = SSL_AD_HANDSHAKE_FAILURE;
goto f_err;
}
} else {
if (ssl_verify_cert_chain(ssl, sk) <= 0) {
al = ssl_verify_alarm_type(ssl->verify_result);
OPENSSL_PUT_ERROR(SSL, SSL_R_CERTIFICATE_VERIFY_FAILED);
goto f_err;
}
}
X509_free(ssl->session->peer);
ssl->session->peer = sk_X509_shift(sk);
ssl->session->verify_result = ssl->verify_result;
sk_X509_pop_free(ssl->session->cert_chain, X509_free);
ssl->session->cert_chain = sk;
/* Inconsistency alert: cert_chain does *not* include the peer's own
* certificate, while we do include it in s3_clnt.c */
sk = NULL;
ret = 1;
if (0) {
f_err:
ssl3_send_alert(ssl, SSL3_AL_FATAL, al);
}
err:
X509_free(x);
sk_X509_pop_free(sk, X509_free);
return ret;
}
static int ssl3_get_client_key_exchange(SSL *ssl) {
int al;
CBS client_key_exchange;
uint32_t alg_k;
uint32_t alg_a;
uint8_t *premaster_secret = NULL;
size_t premaster_secret_len = 0;
uint8_t *decrypt_buf = NULL;
unsigned psk_len = 0;
uint8_t psk[PSK_MAX_PSK_LEN];
if (ssl->state == SSL3_ST_SR_KEY_EXCH_A) {
int ok;
const long n = ssl->method->ssl_get_message(
ssl, SSL3_MT_CLIENT_KEY_EXCHANGE, ssl_hash_message, &ok);
if (!ok) {
return n;
}
}
CBS_init(&client_key_exchange, ssl->init_msg, ssl->init_num);
alg_k = ssl->s3->tmp.new_cipher->algorithm_mkey;
alg_a = ssl->s3->tmp.new_cipher->algorithm_auth;
/* If using a PSK key exchange, prepare the pre-shared key. */
if (alg_a & SSL_aPSK) {
CBS psk_identity;
/* If using PSK, the ClientKeyExchange contains a psk_identity. If PSK,
* then this is the only field in the message. */
if (!CBS_get_u16_length_prefixed(&client_key_exchange, &psk_identity) ||
((alg_k & SSL_kPSK) && CBS_len(&client_key_exchange) != 0)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
al = SSL_AD_DECODE_ERROR;
goto f_err;
}
if (ssl->psk_server_callback == NULL) {
OPENSSL_PUT_ERROR(SSL, SSL_R_PSK_NO_SERVER_CB);
al = SSL_AD_INTERNAL_ERROR;
goto f_err;
}
if (CBS_len(&psk_identity) > PSK_MAX_IDENTITY_LEN ||
CBS_contains_zero_byte(&psk_identity)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DATA_LENGTH_TOO_LONG);
al = SSL_AD_ILLEGAL_PARAMETER;
goto f_err;
}
if (!CBS_strdup(&psk_identity, &ssl->session->psk_identity)) {
al = SSL_AD_INTERNAL_ERROR;
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
goto f_err;
}
/* Look up the key for the identity. */
psk_len = ssl->psk_server_callback(ssl, ssl->session->psk_identity, psk,
sizeof(psk));
if (psk_len > PSK_MAX_PSK_LEN) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
al = SSL_AD_INTERNAL_ERROR;
goto f_err;
} else if (psk_len == 0) {
/* PSK related to the given identity not found */
OPENSSL_PUT_ERROR(SSL, SSL_R_PSK_IDENTITY_NOT_FOUND);
al = SSL_AD_UNKNOWN_PSK_IDENTITY;
goto f_err;
}
}
/* Depending on the key exchange method, compute |premaster_secret| and
* |premaster_secret_len|. */
if (alg_k & SSL_kRSA) {
/* Allocate a buffer large enough for an RSA decryption. */
const size_t rsa_size = ssl_private_key_max_signature_len(ssl);
decrypt_buf = OPENSSL_malloc(rsa_size);
if (decrypt_buf == NULL) {
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
goto err;
}
enum ssl_private_key_result_t decrypt_result;
size_t decrypt_len;
if (ssl->state == SSL3_ST_SR_KEY_EXCH_A) {
if (!ssl_has_private_key(ssl) ||
ssl_private_key_type(ssl) != EVP_PKEY_RSA) {
al = SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_RSA_CERTIFICATE);
goto f_err;
}
CBS encrypted_premaster_secret;
if (ssl->version > SSL3_VERSION) {
if (!CBS_get_u16_length_prefixed(&client_key_exchange,
&encrypted_premaster_secret) ||
CBS_len(&client_key_exchange) != 0) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL,
SSL_R_TLS_RSA_ENCRYPTED_VALUE_LENGTH_IS_WRONG);
goto f_err;
}
} else {
encrypted_premaster_secret = client_key_exchange;
}
/* Decrypt with no padding. PKCS#1 padding will be removed as part of the
* timing-sensitive code below. */
decrypt_result = ssl_private_key_decrypt(
ssl, decrypt_buf, &decrypt_len, rsa_size,
CBS_data(&encrypted_premaster_secret),
CBS_len(&encrypted_premaster_secret));
} else {
assert(ssl->state == SSL3_ST_SR_KEY_EXCH_B);
/* Complete async decrypt. */
decrypt_result = ssl_private_key_decrypt_complete(
ssl, decrypt_buf, &decrypt_len, rsa_size);
}
switch (decrypt_result) {
case ssl_private_key_success:
break;
case ssl_private_key_failure:
goto err;
case ssl_private_key_retry:
ssl->rwstate = SSL_PRIVATE_KEY_OPERATION;
ssl->state = SSL3_ST_SR_KEY_EXCH_B;
goto err;
}
if (decrypt_len != rsa_size) {
al = SSL_AD_DECRYPT_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_DECRYPTION_FAILED);
goto f_err;
}
/* Prepare a random premaster, to be used on invalid padding. See RFC 5246,
* section 7.4.7.1. */
premaster_secret_len = SSL_MAX_MASTER_KEY_LENGTH;
premaster_secret = OPENSSL_malloc(premaster_secret_len);
if (premaster_secret == NULL) {
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
goto err;
}
if (!RAND_bytes(premaster_secret, premaster_secret_len)) {
goto err;
}
/* The smallest padded premaster is 11 bytes of overhead. Small keys are
* publicly invalid. */
if (decrypt_len < 11 + premaster_secret_len) {
al = SSL_AD_DECRYPT_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_DECRYPTION_FAILED);
goto f_err;
}
/* Check the padding. See RFC 3447, section 7.2.2. */
size_t padding_len = decrypt_len - premaster_secret_len;
uint8_t good = constant_time_eq_int_8(decrypt_buf[0], 0) &
constant_time_eq_int_8(decrypt_buf[1], 2);
size_t i;
for (i = 2; i < padding_len - 1; i++) {
good &= ~constant_time_is_zero_8(decrypt_buf[i]);
}
good &= constant_time_is_zero_8(decrypt_buf[padding_len - 1]);
/* The premaster secret must begin with |client_version|. This too must be
* checked in constant time (http://eprint.iacr.org/2003/052/). */
good &= constant_time_eq_8(decrypt_buf[padding_len],
(unsigned)(ssl->client_version >> 8));
good &= constant_time_eq_8(decrypt_buf[padding_len + 1],
(unsigned)(ssl->client_version & 0xff));
/* Select, in constant time, either the decrypted premaster or the random
* premaster based on |good|. */
for (i = 0; i < premaster_secret_len; i++) {
premaster_secret[i] = constant_time_select_8(
good, decrypt_buf[padding_len + i], premaster_secret[i]);
}
OPENSSL_free(decrypt_buf);
decrypt_buf = NULL;
} else if (alg_k & (SSL_kECDHE|SSL_kDHE|SSL_kCECPQ1)) {
/* Parse the ClientKeyExchange. */
CBS peer_key;
if (!SSL_ECDH_CTX_get_key(&ssl->s3->tmp.ecdh_ctx, &client_key_exchange,
&peer_key) ||
CBS_len(&client_key_exchange) != 0) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
goto f_err;
}
/* Compute the premaster. */
uint8_t alert;
if (!SSL_ECDH_CTX_finish(&ssl->s3->tmp.ecdh_ctx, &premaster_secret,
&premaster_secret_len, &alert, CBS_data(&peer_key),
CBS_len(&peer_key))) {
al = alert;
goto f_err;
}
/* The key exchange state may now be discarded. */
SSL_ECDH_CTX_cleanup(&ssl->s3->tmp.ecdh_ctx);
} 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. */
premaster_secret_len = psk_len;
premaster_secret = OPENSSL_malloc(premaster_secret_len);
if (premaster_secret == NULL) {
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
goto err;
}
memset(premaster_secret, 0, premaster_secret_len);
} else {
al = SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_CIPHER_TYPE);
goto f_err;
}
/* For a PSK cipher suite, the actual pre-master secret is combined with the
* pre-shared key. */
if (alg_a & SSL_aPSK) {
CBB new_premaster, child;
uint8_t *new_data;
size_t new_len;
CBB_zero(&new_premaster);
if (!CBB_init(&new_premaster, 2 + psk_len + 2 + premaster_secret_len) ||
!CBB_add_u16_length_prefixed(&new_premaster, &child) ||
!CBB_add_bytes(&child, premaster_secret, premaster_secret_len) ||
!CBB_add_u16_length_prefixed(&new_premaster, &child) ||
!CBB_add_bytes(&child, psk, psk_len) ||
!CBB_finish(&new_premaster, &new_data, &new_len)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
CBB_cleanup(&new_premaster);
goto err;
}
OPENSSL_cleanse(premaster_secret, premaster_secret_len);
OPENSSL_free(premaster_secret);
premaster_secret = new_data;
premaster_secret_len = new_len;
}
/* Compute the master secret */
ssl->session->master_key_length = tls1_generate_master_secret(
ssl, ssl->session->master_key, premaster_secret, premaster_secret_len);
if (ssl->session->master_key_length == 0) {
goto err;
}
ssl->session->extended_master_secret = ssl->s3->tmp.extended_master_secret;
OPENSSL_cleanse(premaster_secret, premaster_secret_len);
OPENSSL_free(premaster_secret);
return 1;
f_err:
ssl3_send_alert(ssl, SSL3_AL_FATAL, al);
err:
if (premaster_secret != NULL) {
OPENSSL_cleanse(premaster_secret, premaster_secret_len);
OPENSSL_free(premaster_secret);
}
OPENSSL_free(decrypt_buf);
return -1;
}
static int ssl3_get_cert_verify(SSL *ssl) {
int al, ok, ret = 0;
long n;
CBS certificate_verify, signature;
X509 *peer = ssl->session->peer;
EVP_PKEY *pkey = NULL;
const EVP_MD *md = NULL;
uint8_t digest[EVP_MAX_MD_SIZE];
size_t digest_length;
EVP_PKEY_CTX *pctx = NULL;
/* Only RSA and ECDSA client certificates are supported, so a
* CertificateVerify is required if and only if there's a client certificate.
* */
if (peer == NULL) {
ssl3_free_handshake_buffer(ssl);
return 1;
}
n = ssl->method->ssl_get_message(ssl, SSL3_MT_CERTIFICATE_VERIFY,
ssl_dont_hash_message, &ok);
if (!ok) {
return n;
}
/* Filter out unsupported certificate types. */
pkey = X509_get_pubkey(peer);
if (pkey == NULL) {
goto err;
}
if (!(X509_certificate_type(peer, pkey) & EVP_PKT_SIGN) ||
(pkey->type != EVP_PKEY_RSA && pkey->type != EVP_PKEY_EC)) {
al = SSL_AD_UNSUPPORTED_CERTIFICATE;
OPENSSL_PUT_ERROR(SSL, SSL_R_PEER_ERROR_UNSUPPORTED_CERTIFICATE_TYPE);
goto f_err;
}
CBS_init(&certificate_verify, ssl->init_msg, n);
/* Determine the digest type if needbe. */
if (ssl3_protocol_version(ssl) >= TLS1_2_VERSION) {
uint8_t hash, signature_type;
if (!CBS_get_u8(&certificate_verify, &hash) ||
!CBS_get_u8(&certificate_verify, &signature_type)) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
goto f_err;
}
if (!tls12_check_peer_sigalg(ssl, &md, &al, hash, signature_type, pkey)) {
goto f_err;
}
}
/* Compute the digest. */
if (!ssl3_cert_verify_hash(ssl, digest, &digest_length, &md, pkey->type)) {
goto err;
}
/* The handshake buffer is no longer necessary, and we may hash the current
* message.*/
ssl3_free_handshake_buffer(ssl);
if (!ssl3_hash_current_message(ssl)) {
goto err;
}
/* Parse and verify the signature. */
if (!CBS_get_u16_length_prefixed(&certificate_verify, &signature) ||
CBS_len(&certificate_verify) != 0) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
goto f_err;
}
pctx = EVP_PKEY_CTX_new(pkey, NULL);
if (pctx == NULL) {
goto err;
}
int sig_ok = EVP_PKEY_verify_init(pctx) &&
EVP_PKEY_CTX_set_signature_md(pctx, md) &&
EVP_PKEY_verify(pctx, CBS_data(&signature), CBS_len(&signature),
digest, digest_length);
#if defined(BORINGSSL_UNSAFE_FUZZER_MODE)
sig_ok = 1;
ERR_clear_error();
#endif
if (!sig_ok) {
al = SSL_AD_DECRYPT_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_SIGNATURE);
goto f_err;
}
ret = 1;
if (0) {
f_err:
ssl3_send_alert(ssl, SSL3_AL_FATAL, al);
}
err:
EVP_PKEY_CTX_free(pctx);
EVP_PKEY_free(pkey);
return ret;
}
/* ssl3_get_next_proto reads a Next Protocol Negotiation handshake message. It
* sets the next_proto member in s if found */
static int ssl3_get_next_proto(SSL *ssl) {
int ok;
long n;
CBS next_protocol, selected_protocol, padding;
/* Clients cannot send a NextProtocol message if we didn't see the extension
* in their ClientHello */
if (!ssl->s3->next_proto_neg_seen) {
OPENSSL_PUT_ERROR(SSL, SSL_R_GOT_NEXT_PROTO_WITHOUT_EXTENSION);
return -1;
}
n = ssl->method->ssl_get_message(ssl, SSL3_MT_NEXT_PROTO, ssl_hash_message,
&ok);
if (!ok) {
return n;
}
CBS_init(&next_protocol, ssl->init_msg, n);
/* The payload looks like:
* uint8 proto_len;
* uint8 proto[proto_len];
* uint8 padding_len;
* uint8 padding[padding_len]; */
if (!CBS_get_u8_length_prefixed(&next_protocol, &selected_protocol) ||
!CBS_get_u8_length_prefixed(&next_protocol, &padding) ||
CBS_len(&next_protocol) != 0 ||
!CBS_stow(&selected_protocol, &ssl->s3->next_proto_negotiated,
&ssl->s3->next_proto_negotiated_len)) {
return 0;
}
return 1;
}
/* ssl3_get_channel_id reads and verifies a ClientID handshake message. */
static int ssl3_get_channel_id(SSL *ssl) {
int ret = -1, ok;
long n;
uint8_t channel_id_hash[EVP_MAX_MD_SIZE];
size_t channel_id_hash_len;
const uint8_t *p;
uint16_t extension_type;
EC_GROUP *p256 = NULL;
EC_KEY *key = NULL;
EC_POINT *point = NULL;
ECDSA_SIG sig;
BIGNUM x, y;
CBS encrypted_extensions, extension;
n = ssl->method->ssl_get_message(ssl, SSL3_MT_CHANNEL_ID_ENCRYPTED_EXTENSIONS,
ssl_dont_hash_message, &ok);
if (!ok) {
return n;
}
/* Before incorporating the EncryptedExtensions message to the handshake
* hash, compute the hash that should have been signed. */
if (!tls1_channel_id_hash(ssl, channel_id_hash, &channel_id_hash_len)) {
return -1;
}
assert(channel_id_hash_len == SHA256_DIGEST_LENGTH);
if (!ssl3_hash_current_message(ssl)) {
return -1;
}
CBS_init(&encrypted_extensions, ssl->init_msg, n);
/* EncryptedExtensions could include multiple extensions, but the only
* extension that could be negotiated is ChannelID, so there can only be one
* entry.
*
* The payload looks like:
* uint16 extension_type
* uint16 extension_len;
* uint8 x[32];
* uint8 y[32];
* uint8 r[32];
* uint8 s[32]; */
if (!CBS_get_u16(&encrypted_extensions, &extension_type) ||
!CBS_get_u16_length_prefixed(&encrypted_extensions, &extension) ||
CBS_len(&encrypted_extensions) != 0 ||
extension_type != TLSEXT_TYPE_channel_id ||
CBS_len(&extension) != TLSEXT_CHANNEL_ID_SIZE) {
OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_MESSAGE);
return -1;
}
p256 = EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1);
if (!p256) {
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_P256_SUPPORT);
return -1;
}
BN_init(&x);
BN_init(&y);
sig.r = BN_new();
sig.s = BN_new();
if (sig.r == NULL || sig.s == NULL) {
goto err;
}
p = CBS_data(&extension);
if (BN_bin2bn(p + 0, 32, &x) == NULL ||
BN_bin2bn(p + 32, 32, &y) == NULL ||
BN_bin2bn(p + 64, 32, sig.r) == NULL ||
BN_bin2bn(p + 96, 32, sig.s) == NULL) {
goto err;
}
point = EC_POINT_new(p256);
if (!point ||
!EC_POINT_set_affine_coordinates_GFp(p256, point, &x, &y, NULL)) {
goto err;
}
key = EC_KEY_new();
if (!key || !EC_KEY_set_group(key, p256) ||
!EC_KEY_set_public_key(key, point)) {
goto err;
}
/* We stored the handshake hash in |tlsext_channel_id| the first time that we
* were called. */
if (!ECDSA_do_verify(channel_id_hash, channel_id_hash_len, &sig, key)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_CHANNEL_ID_SIGNATURE_INVALID);
ssl->s3->tlsext_channel_id_valid = 0;
goto err;
}
memcpy(ssl->s3->tlsext_channel_id, p, 64);
ret = 1;
err:
BN_free(&x);
BN_free(&y);
BN_free(sig.r);
BN_free(sig.s);
EC_KEY_free(key);
EC_POINT_free(point);
EC_GROUP_free(p256);
return ret;
}
/* send a new session ticket (not necessarily for a new session) */
static int ssl3_send_new_session_ticket(SSL *ssl) {
int ret = -1;
uint8_t *session = NULL;
size_t session_len;
EVP_CIPHER_CTX ctx;
HMAC_CTX hctx;
EVP_CIPHER_CTX_init(&ctx);
HMAC_CTX_init(&hctx);
if (ssl->state == SSL3_ST_SW_SESSION_TICKET_A) {
uint8_t *p, *macstart;
int len;
unsigned int hlen;
SSL_CTX *tctx = ssl->initial_ctx;
uint8_t iv[EVP_MAX_IV_LENGTH];
uint8_t key_name[16];
/* The maximum overhead of encrypting the session is 16 (key name) + IV +
* one block of encryption overhead + HMAC. */
const size_t max_ticket_overhead =
16 + EVP_MAX_IV_LENGTH + EVP_MAX_BLOCK_LENGTH + EVP_MAX_MD_SIZE;
/* Serialize the SSL_SESSION to be encoded into the ticket. */
if (!SSL_SESSION_to_bytes_for_ticket(ssl->session, &session,
&session_len)) {
goto err;
}
/* If the session is too long, emit a dummy value rather than abort the
* connection. */
if (session_len > 0xFFFF - max_ticket_overhead) {
static const char kTicketPlaceholder[] = "TICKET TOO LARGE";
const size_t placeholder_len = strlen(kTicketPlaceholder);
OPENSSL_free(session);
session = NULL;
p = ssl_handshake_start(ssl);
/* Emit ticket_lifetime_hint. */
l2n(0, p);
/* Emit ticket. */
s2n(placeholder_len, p);
memcpy(p, kTicketPlaceholder, placeholder_len);
p += placeholder_len;
len = p - ssl_handshake_start(ssl);
if (!ssl_set_handshake_header(ssl, SSL3_MT_NEW_SESSION_TICKET, len)) {
goto err;
}
ssl->state = SSL3_ST_SW_SESSION_TICKET_B;
return ssl_do_write(ssl);
}
/* Grow buffer if need be: the length calculation is as follows:
* handshake_header_length + 4 (ticket lifetime hint) + 2 (ticket length) +
* max_ticket_overhead + * session_length */
if (!BUF_MEM_grow(ssl->init_buf, SSL_HM_HEADER_LENGTH(ssl) + 6 +
max_ticket_overhead + session_len)) {
goto err;
}
p = ssl_handshake_start(ssl);
/* Initialize HMAC and cipher contexts. If callback present it does all the
* work otherwise use generated values from parent ctx. */
if (tctx->tlsext_ticket_key_cb) {
if (tctx->tlsext_ticket_key_cb(ssl, key_name, iv, &ctx, &hctx,
1 /* encrypt */) < 0) {
goto err;
}
} else {
if (!RAND_bytes(iv, 16) ||
!EVP_EncryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
tctx->tlsext_tick_aes_key, iv) ||
!HMAC_Init_ex(&hctx, tctx->tlsext_tick_hmac_key, 16, tlsext_tick_md(),
NULL)) {
goto err;
}
memcpy(key_name, tctx->tlsext_tick_key_name, 16);
}
/* Ticket lifetime hint (advisory only): We leave this unspecified for
* resumed session (for simplicity), and guess that tickets for new
* sessions will live as long as their sessions. */
l2n(ssl->hit ? 0 : ssl->session->timeout, p);
/* Skip ticket length for now */
p += 2;
/* Output key name */
macstart = p;
memcpy(p, key_name, 16);
p += 16;
/* output IV */
memcpy(p, iv, EVP_CIPHER_CTX_iv_length(&ctx));
p += EVP_CIPHER_CTX_iv_length(&ctx);
/* Encrypt session data */
if (!EVP_EncryptUpdate(&ctx, p, &len, session, session_len)) {
goto err;
}
p += len;
if (!EVP_EncryptFinal_ex(&ctx, p, &len)) {
goto err;
}
p += len;
if (!HMAC_Update(&hctx, macstart, p - macstart) ||
!HMAC_Final(&hctx, p, &hlen)) {
goto err;
}
p += hlen;
/* Now write out lengths: p points to end of data written */
/* Total length */
len = p - ssl_handshake_start(ssl);
/* Skip ticket lifetime hint */
p = ssl_handshake_start(ssl) + 4;
s2n(len - 6, p);
if (!ssl_set_handshake_header(ssl, SSL3_MT_NEW_SESSION_TICKET, len)) {
goto err;
}
ssl->state = SSL3_ST_SW_SESSION_TICKET_B;
}
/* SSL3_ST_SW_SESSION_TICKET_B */
ret = ssl_do_write(ssl);
err:
OPENSSL_free(session);
EVP_CIPHER_CTX_cleanup(&ctx);
HMAC_CTX_cleanup(&hctx);
return ret;
}
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