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boringssl/ssl/handshake_server.c
David Benjamin 25fe85b38c Insert a state before cert_cb. 
If cert_cb runs asynchronously, we end up repeating a large part of very
stateful ClientHello processing. This seems to be mostly fine and there
are few users of server-side cert_cb (it's a new API in 1.0.2), but it's
a little scary.

This is also visible to external consumers because some callbacks get
called multiple times. We especially should try to avoid that as there
is no guarantee that these callbacks are idempotent and give the same
answer each time.

Change-Id: I212b2325eae2cfca0fb423dace101e466c5e5d4e
Reviewed-on: https://boringssl-review.googlesource.com/10224
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2016-08-11 15:45:00 +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/x509.h>
#include "internal.h"
#include "../crypto/internal.h"
#include "../crypto/dh/internal.h"
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_hello_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) {
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);
ssl->s3->hs = ssl_handshake_new(tls13_server_handshake);
if (ssl->s3->hs == NULL) {
ret = -1;
goto end;
}
/* 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;
}
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:
case SSL3_ST_SR_CLNT_HELLO_D:
ret = ssl3_get_client_hello(ssl);
if (ssl->state == SSL_ST_TLS13) {
break;
}
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->session != NULL) {
ssl->state = SSL3_ST_SW_SESSION_TICKET_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;
}
} else {
skip = 1;
}
ssl->state = SSL3_ST_SW_CERT_STATUS_A;
break;
case SSL3_ST_SW_CERT_STATUS_A:
case SSL3_ST_SW_CERT_STATUS_B:
if (ssl->s3->tmp.certificate_status_expected) {
ret = ssl3_send_certificate_status(ssl);
if (ret <= 0) {
goto end;
}
} else {
skip = 1;
}
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_hello_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->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;
}
ssl->state = SSL3_ST_SR_NEXT_PROTO_A;
break;
case SSL3_ST_SR_NEXT_PROTO_A:
if (ssl->s3->next_proto_neg_seen) {
ret = ssl3_get_next_proto(ssl);
if (ret <= 0) {
goto end;
}
} else {
skip = 1;
}
ssl->state = SSL3_ST_SR_CHANNEL_ID_A;
break;
case SSL3_ST_SR_CHANNEL_ID_A:
if (ssl->s3->tlsext_channel_id_valid) {
ret = ssl3_get_channel_id(ssl);
if (ret <= 0) {
goto end;
}
} else {
skip = 1;
}
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->session != NULL) {
ssl->state = SSL_ST_OK;
} else {
ssl->state = SSL3_ST_SW_SESSION_TICKET_A;
}
/* If this is a full handshake with ChannelID then record the handshake
* hashes in |ssl->s3->new_session| in case we need them to verify a
* ChannelID signature on a resumption of this session in the future. */
if (ssl->session == NULL && 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:
if (ssl->tlsext_ticket_expected) {
ret = ssl3_send_new_session_ticket(ssl);
if (ret <= 0) {
goto end;
}
} else {
skip = 1;
}
ssl->state = SSL3_ST_SW_CHANGE;
break;
case SSL3_ST_SW_CHANGE:
ret = ssl->method->send_change_cipher_spec(ssl);
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->session != NULL) {
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_TLS13:
ret = tls13_handshake(ssl);
if (ret <= 0) {
goto end;
}
ssl->state = SSL_ST_OK;
break;
case SSL_ST_OK:
/* Clean a few things up. */
ssl3_cleanup_key_block(ssl);
ssl->method->release_current_message(ssl, 1 /* free_buffer */);
/* If we aren't retaining peer certificates then we can discard it
* now. */
if (ssl->s3->new_session != NULL &&
ssl->ctx->retain_only_sha256_of_client_certs) {
X509_free(ssl->s3->new_session->peer);
ssl->s3->new_session->peer = NULL;
sk_X509_pop_free(ssl->s3->new_session->cert_chain, X509_free);
ssl->s3->new_session->cert_chain = NULL;
}
SSL_SESSION_free(ssl->s3->established_session);
if (ssl->session != NULL) {
SSL_SESSION_up_ref(ssl->session);
ssl->s3->established_session = ssl->session;
} else {
ssl->s3->established_session = ssl->s3->new_session;
ssl->s3->established_session->not_resumable = 0;
ssl->s3->new_session = NULL;
}
/* remove buffering on output */
ssl_free_wbio_buffer(ssl);
ssl_handshake_free(ssl->s3->hs);
ssl->s3->hs = NULL;
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:
ssl_do_info_callback(ssl, SSL_CB_ACCEPT_EXIT, ret);
return ret;
}
int ssl_client_cipher_list_contains_cipher(
const struct ssl_early_callback_ctx *client_hello, uint16_t id) {
CBS cipher_suites;
CBS_init(&cipher_suites, client_hello->cipher_suites,
client_hello->cipher_suites_len);
while (CBS_len(&cipher_suites) > 0) {
uint16_t got_id;
if (!CBS_get_u16(&cipher_suites, &got_id)) {
return 0;
}
if (got_id == id) {
return 1;
}
}
return 0;
}
static int negotiate_version(
SSL *ssl, int *out_alert,
const struct ssl_early_callback_ctx *client_hello) {
uint16_t min_version, max_version;
if (!ssl_get_version_range(ssl, &min_version, &max_version)) {
*out_alert = SSL_AD_PROTOCOL_VERSION;
return 0;
}
uint16_t client_version =
ssl->method->version_from_wire(client_hello->version);
ssl->client_version = client_hello->version;
/* Select the version to use. */
uint16_t version = client_version;
if (version > max_version) {
version = max_version;
}
if (version < min_version) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNSUPPORTED_PROTOCOL);
*out_alert = SSL_AD_PROTOCOL_VERSION;
return 0;
}
/* Handle FALLBACK_SCSV. */
if (ssl_client_cipher_list_contains_cipher(client_hello,
SSL3_CK_FALLBACK_SCSV & 0xffff) &&
version < max_version) {
OPENSSL_PUT_ERROR(SSL, SSL_R_INAPPROPRIATE_FALLBACK);
*out_alert = SSL3_AD_INAPPROPRIATE_FALLBACK;
return 0;
}
ssl->version = ssl->method->version_to_wire(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;
return 1;
}
static int ssl3_get_client_hello(SSL *ssl) {
int al = SSL_AD_INTERNAL_ERROR, ret = -1;
SSL_SESSION *session = NULL;
if (ssl->state == SSL3_ST_SR_CLNT_HELLO_A) {
/* The first time around, read the ClientHello. */
int msg_ret = ssl->method->ssl_get_message(ssl, SSL3_MT_CLIENT_HELLO,
ssl_hash_message);
if (msg_ret <= 0) {
return msg_ret;
}
ssl->state = SSL3_ST_SR_CLNT_HELLO_B;
}
struct ssl_early_callback_ctx client_hello;
if (!ssl_early_callback_init(ssl, &client_hello, ssl->init_msg,
ssl->init_num)) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
goto f_err;
}
if (ssl->state == SSL3_ST_SR_CLNT_HELLO_B) {
/* Unlike other callbacks, the early callback is not run a second time if
* paused. */
ssl->state = SSL3_ST_SR_CLNT_HELLO_C;
/* Run the early callback. */
if (ssl->ctx->select_certificate_cb != NULL) {
switch (ssl->ctx->select_certificate_cb(&client_hello)) {
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 */;
}
}
}
/* Negotiate the protocol version if we have not done so yet. */
if (!ssl->s3->have_version) {
if (!negotiate_version(ssl, &al, &client_hello)) {
goto f_err;
}
if (ssl3_protocol_version(ssl) >= TLS1_3_VERSION) {
ssl->state = SSL_ST_TLS13;
return 1;
}
}
if (ssl->state == SSL3_ST_SR_CLNT_HELLO_C) {
/* Load the client random. */
if (client_hello.random_len != SSL3_RANDOM_SIZE) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return -1;
}
memcpy(ssl->s3->client_random, client_hello.random,
client_hello.random_len);
/* Determine whether we are doing session resumption. */
int send_new_ticket = 0;
switch (
ssl_get_prev_session(ssl, &session, &send_new_ticket, &client_hello)) {
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. */
CBS ems;
int have_extended_master_secret =
ssl->version != SSL3_VERSION &&
ssl_early_callback_get_extension(&client_hello, &ems,
TLSEXT_TYPE_extended_master_secret) &&
CBS_len(&ems) == 0;
int has_session = 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;
}
has_session =
/* 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 (has_session) {
/* Use the old session. */
ssl->session = session;
session = NULL;
ssl->verify_result = ssl->session->verify_result;
} else {
SSL_set_session(ssl, NULL);
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->s3->new_session->session_id_length = 0;
}
}
if (ssl->ctx->dos_protection_cb != NULL &&
ssl->ctx->dos_protection_cb(&client_hello) == 0) {
/* Connection rejected for DOS reasons. */
al = SSL_AD_ACCESS_DENIED;
OPENSSL_PUT_ERROR(SSL, SSL_R_CONNECTION_REJECTED);
goto f_err;
}
/* Only null compression is supported. */
if (memchr(client_hello.compression_methods, 0,
client_hello.compression_methods_len) == NULL) {
al = SSL_AD_ILLEGAL_PARAMETER;
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_COMPRESSION_SPECIFIED);
goto f_err;
}
/* TLS extensions. */
if (!ssl_parse_clienthello_tlsext(ssl, &client_hello)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_PARSE_TLSEXT);
goto 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;
}
ssl->state = SSL3_ST_SR_CLNT_HELLO_D;
}
/* Determine the remaining connection parameters. This is a separate state so
* |cert_cb| does not cause earlier logic to run multiple times. */
assert(ssl->state == SSL3_ST_SR_CLNT_HELLO_D);
if (ssl->session != NULL) {
/* Check that the cipher is in the list. */
if (!ssl_client_cipher_list_contains_cipher(
&client_hello, (uint16_t)ssl->session->cipher->id)) {
al = SSL_AD_ILLEGAL_PARAMETER;
OPENSSL_PUT_ERROR(SSL, SSL_R_REQUIRED_CIPHER_MISSING);
goto f_err;
}
ssl->s3->tmp.new_cipher = ssl->session->cipher;
ssl->s3->tmp.cert_request = 0;
} else {
/* Call |cert_cb| to update server certificates if required. */
if (ssl->cert->cert_cb != NULL) {
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;
}
}
const SSL_CIPHER *c =
ssl3_choose_cipher(ssl, &client_hello, 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->s3->new_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;
}
}
/* Now that the cipher is known, initialize the handshake hash. */
if (!ssl3_init_handshake_hash(ssl)) {
goto f_err;
}
/* Release the handshake buffer if client authentication isn't required. */
if (!ssl->s3->tmp.cert_request) {
ssl3_free_handshake_buffer(ssl);
}
ret = 1;
if (0) {
f_err:
ssl3_send_alert(ssl, SSL3_AL_FATAL, al);
}
err:
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->method->write_message(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->session != NULL &&
ssl->session->original_handshake_hash_len == 0) {
ssl->s3->tlsext_channel_id_valid = 0;
}
struct timeval now;
ssl_get_current_time(ssl, &now);
ssl->s3->server_random[0] = now.tv_sec >> 24;
ssl->s3->server_random[1] = now.tv_sec >> 16;
ssl->s3->server_random[2] = now.tv_sec >> 8;
ssl->s3->server_random[3] = now.tv_sec;
if (!RAND_bytes(ssl->s3->server_random + 4, SSL3_RANDOM_SIZE - 4)) {
return -1;
}
/* Fill in the TLS 1.2 downgrade signal. See draft-ietf-tls-tls13-14.
*
* TODO(davidben): Also implement the TLS 1.1 sentinel when things have
* settled down. */
uint16_t min_version, max_version;
if (!ssl_get_version_range(ssl, &min_version, &max_version)) {
return -1;
}
if (max_version >= TLS1_3_VERSION &&
ssl3_protocol_version(ssl) <= TLS1_2_VERSION) {
static const uint8_t kDowngradeTLS12[8] = {0x44, 0x4f, 0x57, 0x4e,
0x47, 0x52, 0x44, 0x01};
memcpy(ssl->s3->server_random + SSL3_RANDOM_SIZE - 8, kDowngradeTLS12, 8);
}
const SSL_SESSION *session = ssl->s3->new_session;
if (ssl->session != NULL) {
session = ssl->session;
}
CBB cbb, body, session_id;
if (!ssl->method->init_message(ssl, &cbb, &body, SSL3_MT_SERVER_HELLO) ||
!CBB_add_u16(&body, ssl->version) ||
!CBB_add_bytes(&body, ssl->s3->server_random, SSL3_RANDOM_SIZE) ||
!CBB_add_u8_length_prefixed(&body, &session_id) ||
!CBB_add_bytes(&session_id, session->session_id,
session->session_id_length) ||
!CBB_add_u16(&body, ssl_cipher_get_value(ssl->s3->tmp.new_cipher)) ||
!CBB_add_u8(&body, 0 /* no compression */) ||
!ssl_add_serverhello_tlsext(ssl, &body) ||
!ssl->method->finish_message(ssl, &cbb)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
CBB_cleanup(&cbb);
return -1;
}
ssl->state = SSL3_ST_SW_SRVR_HELLO_B;
return ssl->method->write_message(ssl);
}
static int ssl3_send_server_certificate(SSL *ssl) {
if (ssl->state == SSL3_ST_SW_CERT_B) {
return ssl->method->write_message(ssl);
}
if (!ssl_has_certificate(ssl)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_CERTIFICATE_SET);
return 0;
}
if (!ssl3_output_cert_chain(ssl)) {
return 0;
}
ssl->state = SSL3_ST_SW_CERT_B;
return ssl->method->write_message(ssl);
}
static int ssl3_send_certificate_status(SSL *ssl) {
if (ssl->state == SSL3_ST_SW_CERT_STATUS_B) {
return ssl->method->write_message(ssl);
}
CBB cbb, body, ocsp_response;
if (!ssl->method->init_message(ssl, &cbb, &body,
SSL3_MT_CERTIFICATE_STATUS) ||
!CBB_add_u8(&body, TLSEXT_STATUSTYPE_ocsp) ||
!CBB_add_u24_length_prefixed(&body, &ocsp_response) ||
!CBB_add_bytes(&ocsp_response, ssl->ctx->ocsp_response,
ssl->ctx->ocsp_response_length) ||
!ssl->method->finish_message(ssl, &cbb)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
CBB_cleanup(&cbb);
return -1;
}
ssl->state = SSL3_ST_SW_CERT_STATUS_B;
return ssl->method->write_message(ssl);
}
static int ssl3_send_server_key_exchange(SSL *ssl) {
if (ssl->state == SSL3_ST_SW_KEY_EXCH_C) {
return ssl->method->write_message(ssl);
}
CBB cbb, child;
CBB_zero(&cbb);
/* Put together the parameters. */
if (ssl->state == SSL3_ST_SW_KEY_EXCH_A) {
uint32_t alg_k = ssl->s3->tmp.new_cipher->algorithm_mkey;
uint32_t alg_a = ssl->s3->tmp.new_cipher->algorithm_auth;
/* Pre-allocate enough room to comfortably fit an ECDHE public key. */
if (!CBB_init(&cbb, 128)) {
goto err;
}
/* 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->s3->new_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->s3->new_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) {
SSL_ECDH_CTX_init_for_cecpq1(&ssl->s3->tmp.ecdh_ctx);
if (!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);
}
size_t len;
if (!CBB_finish(&cbb, &ssl->s3->tmp.server_params, &len) ||
len > 0xffffffffu) {
OPENSSL_free(ssl->s3->tmp.server_params);
ssl->s3->tmp.server_params = NULL;
goto err;
}
ssl->s3->tmp.server_params_len = (uint32_t)len;
}
/* Assemble the message. */
CBB body;
if (!ssl->method->init_message(ssl, &cbb, &body,
SSL3_MT_SERVER_KEY_EXCHANGE) ||
!CBB_add_bytes(&body, ssl->s3->tmp.server_params,
ssl->s3->tmp.server_params_len)) {
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;
}
/* Determine the signature algorithm. */
uint16_t signature_algorithm;
if (!tls1_choose_signature_algorithm(ssl, &signature_algorithm)) {
goto err;
}
if (ssl3_protocol_version(ssl) >= TLS1_2_VERSION) {
if (!CBB_add_u16(&body, signature_algorithm)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
goto err;
}
}
/* Add space for the signature. */
const size_t max_sig_len = ssl_private_key_max_signature_len(ssl);
uint8_t *ptr;
if (!CBB_add_u16_length_prefixed(&body, &child) ||
!CBB_reserve(&child, &ptr, max_sig_len)) {
goto err;
}
size_t sig_len;
enum ssl_private_key_result_t sign_result;
if (ssl->state == SSL3_ST_SW_KEY_EXCH_A) {
CBB transcript;
uint8_t *transcript_data;
size_t transcript_len;
if (!CBB_init(&transcript,
2*SSL3_RANDOM_SIZE + ssl->s3->tmp.server_params_len) ||
!CBB_add_bytes(&transcript, ssl->s3->client_random, SSL3_RANDOM_SIZE) ||
!CBB_add_bytes(&transcript, ssl->s3->server_random, SSL3_RANDOM_SIZE) ||
!CBB_add_bytes(&transcript, ssl->s3->tmp.server_params,
ssl->s3->tmp.server_params_len) ||
!CBB_finish(&transcript, &transcript_data, &transcript_len)) {
CBB_cleanup(&transcript);
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
goto err;
}
sign_result = ssl_private_key_sign(ssl, ptr, &sig_len, max_sig_len,
signature_algorithm, transcript_data,
transcript_len);
OPENSSL_free(transcript_data);
} else {
assert(ssl->state == SSL3_ST_SW_KEY_EXCH_B);
sign_result = ssl_private_key_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:
ssl->rwstate = SSL_PRIVATE_KEY_OPERATION;
ssl->state = SSL3_ST_SW_KEY_EXCH_B;
goto err;
}
}
if (!ssl->method->finish_message(ssl, &cbb)) {
goto err;
}
OPENSSL_free(ssl->s3->tmp.server_params);
ssl->s3->tmp.server_params = NULL;
ssl->s3->tmp.server_params_len = 0;
ssl->state = SSL3_ST_SW_KEY_EXCH_C;
return ssl->method->write_message(ssl);
err:
CBB_cleanup(&cbb);
return -1;
}
static int add_cert_types(SSL *ssl, CBB *cbb) {
/* Get configured signature algorithms. */
int have_rsa_sign = 0;
int have_ecdsa_sign = 0;
const uint16_t *sig_algs;
size_t sig_algs_len = tls12_get_psigalgs(ssl, &sig_algs);
size_t i;
for (i = 0; i < sig_algs_len; i++) {
switch (sig_algs[i]) {
case SSL_SIGN_RSA_PKCS1_SHA512:
case SSL_SIGN_RSA_PKCS1_SHA384:
case SSL_SIGN_RSA_PKCS1_SHA256:
case SSL_SIGN_RSA_PKCS1_SHA1:
have_rsa_sign = 1;
break;
case SSL_SIGN_ECDSA_SECP521R1_SHA512:
case SSL_SIGN_ECDSA_SECP384R1_SHA384:
case SSL_SIGN_ECDSA_SECP256R1_SHA256:
case SSL_SIGN_ECDSA_SHA1:
have_ecdsa_sign = 1;
break;
}
}
if (have_rsa_sign && !CBB_add_u8(cbb, SSL3_CT_RSA_SIGN)) {
return 0;
}
/* ECDSA certs can be used with RSA cipher suites as well so we don't need to
* check for SSL_kECDH or SSL_kECDHE. */
if (ssl->version >= TLS1_VERSION && have_ecdsa_sign &&
!CBB_add_u8(cbb, TLS_CT_ECDSA_SIGN)) {
return 0;
}
return 1;
}
static int ssl3_send_certificate_request(SSL *ssl) {
if (ssl->state == SSL3_ST_SW_CERT_REQ_B) {
return ssl->method->write_message(ssl);
}
CBB cbb, body, cert_types, sigalgs_cbb;
if (!ssl->method->init_message(ssl, &cbb, &body,
SSL3_MT_CERTIFICATE_REQUEST) ||
!CBB_add_u8_length_prefixed(&body, &cert_types) ||
!add_cert_types(ssl, &cert_types)) {
goto err;
}
if (ssl3_protocol_version(ssl) >= TLS1_2_VERSION) {
const uint16_t *sigalgs;
size_t sigalgs_len = tls12_get_psigalgs(ssl, &sigalgs);
if (!CBB_add_u16_length_prefixed(&body, &sigalgs_cbb)) {
goto err;
}
size_t i;
for (i = 0; i < sigalgs_len; i++) {
if (!CBB_add_u16(&sigalgs_cbb, sigalgs[i])) {
goto err;
}
}
}
if (!ssl_add_client_CA_list(ssl, &body) ||
!ssl->method->finish_message(ssl, &cbb)) {
goto err;
}
ssl->state = SSL3_ST_SW_CERT_REQ_B;
return ssl->method->write_message(ssl);
err:
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
CBB_cleanup(&cbb);
return -1;
}
static int ssl3_send_server_hello_done(SSL *ssl) {
if (ssl->state == SSL3_ST_SW_SRVR_DONE_B) {
return ssl->method->write_message(ssl);
}
CBB cbb, body;
if (!ssl->method->init_message(ssl, &cbb, &body, SSL3_MT_SERVER_HELLO_DONE) ||
!ssl->method->finish_message(ssl, &cbb)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
CBB_cleanup(&cbb);
return -1;
}
ssl->state = SSL3_ST_SW_SRVR_DONE_B;
return ssl->method->write_message(ssl);
}
static int ssl3_get_client_certificate(SSL *ssl) {
assert(ssl->s3->tmp.cert_request);
int msg_ret = ssl->method->ssl_get_message(ssl, -1, ssl_hash_message);
if (msg_ret <= 0) {
return msg_ret;
}
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_FAIL_IF_NO_PEER_CERT) {
OPENSSL_PUT_ERROR(SSL, SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
return -1;
}
ssl->s3->tmp.reuse_message = 1;
return 1;
}
OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_MESSAGE);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
return -1;
}
CBS certificate_msg;
CBS_init(&certificate_msg, ssl->init_msg, ssl->init_num);
uint8_t alert;
STACK_OF(X509) *chain = ssl_parse_cert_chain(
ssl, &alert, ssl->ctx->retain_only_sha256_of_client_certs
? ssl->s3->new_session->peer_sha256
: NULL,
&certificate_msg);
if (chain == NULL) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, alert);
goto err;
}
if (CBS_len(&certificate_msg) != 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
goto err;
}
if (sk_X509_num(chain) == 0) {
/* No client certificate so the handshake buffer may be discarded. */
ssl3_free_handshake_buffer(ssl);
/* In SSL 3.0, sending no certificate is signaled by omitting the
* Certificate message. */
if (ssl->version == SSL3_VERSION) {
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_CERTIFICATES_RETURNED);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
goto err;
}
if (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);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
goto err;
}
} else {
/* The hash would have been filled in. */
if (ssl->ctx->retain_only_sha256_of_client_certs) {
ssl->s3->new_session->peer_sha256_valid = 1;
}
if (!ssl_verify_cert_chain(ssl, chain)) {
goto err;
}
}
X509_free(ssl->s3->new_session->peer);
ssl->s3->new_session->peer = sk_X509_shift(chain);
ssl->s3->new_session->verify_result = ssl->verify_result;
sk_X509_pop_free(ssl->s3->new_session->cert_chain, X509_free);
ssl->s3->new_session->cert_chain = chain;
/* Inconsistency alert: cert_chain does *not* include the peer's own
* certificate, while we do include it in s3_clnt.c */
return 1;
err:
sk_X509_pop_free(chain, X509_free);
return -1;
}
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 ret = ssl->method->ssl_get_message(ssl, SSL3_MT_CLIENT_KEY_EXCHANGE,
ssl_hash_message);
if (ret <= 0) {
return ret;
}
}
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->s3->new_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->s3->new_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) != NID_rsaEncryption) {
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_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->s3->new_session->master_key_length = tls1_generate_master_secret(
ssl, ssl->s3->new_session->master_key, premaster_secret,
premaster_secret_len);
if (ssl->s3->new_session->master_key_length == 0) {
goto err;
}
ssl->s3->new_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, ret = 0;
CBS certificate_verify, signature;
X509 *peer = ssl->s3->new_session->peer;
EVP_PKEY *pkey = 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;
}
int msg_ret = ssl->method->ssl_get_message(ssl, SSL3_MT_CERTIFICATE_VERIFY,
ssl_dont_hash_message);
if (msg_ret <= 0) {
return msg_ret;
}
/* Filter out unsupported certificate types. */
pkey = X509_get_pubkey(peer);
if (pkey == NULL) {
goto err;
}
CBS_init(&certificate_verify, ssl->init_msg, ssl->init_num);
/* Determine the digest type if needbe. */
uint16_t signature_algorithm = 0;
if (ssl3_protocol_version(ssl) >= TLS1_2_VERSION) {
if (!CBS_get_u16(&certificate_verify, &signature_algorithm)) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
goto f_err;
}
if (!tls12_check_peer_sigalg(ssl, &al, signature_algorithm)) {
goto f_err;
}
ssl->s3->tmp.peer_signature_algorithm = signature_algorithm;
} else if (pkey->type == EVP_PKEY_RSA) {
signature_algorithm = SSL_SIGN_RSA_PKCS1_MD5_SHA1;
} else if (pkey->type == EVP_PKEY_EC) {
signature_algorithm = SSL_SIGN_ECDSA_SHA1;
} else {
al = SSL_AD_UNSUPPORTED_CERTIFICATE;
OPENSSL_PUT_ERROR(SSL, SSL_R_PEER_ERROR_UNSUPPORTED_CERTIFICATE_TYPE);
goto f_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;
}
int sig_ok;
/* 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) {
const EVP_MD *md;
uint8_t digest[EVP_MAX_MD_SIZE];
size_t digest_len;
if (!ssl3_cert_verify_hash(ssl, &md, digest, &digest_len,
signature_algorithm)) {
goto err;
}
EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new(pkey, NULL);
sig_ok = pctx != NULL &&
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_len);
EVP_PKEY_CTX_free(pctx);
} else {
sig_ok = ssl_public_key_verify(
ssl, CBS_data(&signature), CBS_len(&signature), signature_algorithm,
pkey, (const uint8_t *)ssl->s3->handshake_buffer->data,
ssl->s3->handshake_buffer->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;
}
/* The handshake buffer is no longer necessary, and we may hash the current
* message.*/
ssl3_free_handshake_buffer(ssl);
if (!ssl->method->hash_current_message(ssl)) {
goto err;
}
ret = 1;
if (0) {
f_err:
ssl3_send_alert(ssl, SSL3_AL_FATAL, al);
}
err:
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 ret =
ssl->method->ssl_get_message(ssl, SSL3_MT_NEXT_PROTO, ssl_hash_message);
if (ret <= 0) {
return ret;
}
CBS next_protocol, selected_protocol, padding;
CBS_init(&next_protocol, ssl->init_msg, ssl->init_num);
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;
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;
int msg_ret = ssl->method->ssl_get_message(ssl, SSL3_MT_CHANNEL_ID,
ssl_dont_hash_message);
if (msg_ret <= 0) {
return msg_ret;
}
/* 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 (!ssl->method->hash_current_message(ssl)) {
return -1;
}
CBS_init(&encrypted_extensions, ssl->init_msg, ssl->init_num);
/* EncryptedExtensions could include multiple extensions, but the only
* extension that could be negotiated is Channel ID, so there can only be one
* entry. */
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;
}
static int ssl3_send_new_session_ticket(SSL *ssl) {
if (ssl->state == SSL3_ST_SW_SESSION_TICKET_B) {
return ssl->method->write_message(ssl);
}
CBB cbb, body, ticket;
if (!ssl->method->init_message(ssl, &cbb, &body,
SSL3_MT_NEW_SESSION_TICKET) ||
/* 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. */
!CBB_add_u32(&body,
ssl->session != NULL ? 0 : ssl->s3->new_session->timeout) ||
!CBB_add_u16_length_prefixed(&body, &ticket) ||
!ssl_encrypt_ticket(ssl, &ticket, ssl->session != NULL
? ssl->session
: ssl->s3->new_session) ||
!ssl->method->finish_message(ssl, &cbb)) {
return 0;
}
ssl->state = SSL3_ST_SW_SESSION_TICKET_B;
return ssl->method->write_message(ssl);
}
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