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boringssl/ssl/s3_srvr.c
David Benjamin bdf5e72f50 Don't resume sessions if the negotiated version doesn't match. 
All of NSS, upstream OpenSSL, SChannel, and Secure Transport require, on the
client, that the ServerHello version match the session's version on resumption.
OpenSSL's current behavior is incompatible with all of these. Fall back to a
full handshake on the server instead of mismatch.

Add a comment on the client for why we are, as of
30ddb434bf, not currently enforcing the same in
the client.

Change-Id: I60aec972d81368c4ec30e2fd515dabd69401d175
Reviewed-on: https://boringssl-review.googlesource.com/2244
Reviewed-by: Adam Langley <agl@google.com>
2014-11-13 22:05:12 +00:00

2873 lines
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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. */
#define NETSCAPE_HANG_BUG
#include <assert.h>
#include <stdio.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/evp.h>
#include <openssl/hmac.h>
#include <openssl/md5.h>
#include <openssl/mem.h>
#include <openssl/obj.h>
#include <openssl/rand.h>
#include <openssl/sha.h>
#include <openssl/x509.h>
#include "ssl_locl.h"
#include "../crypto/internal.h"
#include "../crypto/dh/internal.h"
static const SSL_METHOD *ssl3_get_server_method(int ver)
{
switch (ver)
{
case TLS1_2_VERSION:
return TLSv1_2_server_method();
case TLS1_1_VERSION:
return TLSv1_1_server_method();
case TLS1_VERSION:
return TLSv1_server_method();
case SSL3_VERSION:
return SSLv3_server_method();
default:
return NULL;
}
}
IMPLEMENT_tls_meth_func(TLS1_2_VERSION, TLSv1_2_server_method,
ssl3_accept,
ssl_undefined_function,
ssl3_get_server_method,
TLSv1_2_enc_data)
IMPLEMENT_tls_meth_func(TLS1_1_VERSION, TLSv1_1_server_method,
ssl3_accept,
ssl_undefined_function,
ssl3_get_server_method,
TLSv1_1_enc_data)
IMPLEMENT_tls_meth_func(TLS1_VERSION, TLSv1_server_method,
ssl3_accept,
ssl_undefined_function,
ssl3_get_server_method,
TLSv1_enc_data)
IMPLEMENT_tls_meth_func(SSL3_VERSION, SSLv3_server_method,
ssl3_accept,
ssl_undefined_function,
ssl3_get_server_method,
SSLv3_enc_data)
int ssl3_accept(SSL *s)
{
BUF_MEM *buf;
unsigned long alg_a;
void (*cb)(const SSL *ssl,int type,int val)=NULL;
int ret= -1;
int new_state,state,skip=0;
ERR_clear_error();
ERR_clear_system_error();
if (s->info_callback != NULL)
cb=s->info_callback;
else if (s->ctx->info_callback != NULL)
cb=s->ctx->info_callback;
/* init things to blank */
s->in_handshake++;
if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s);
if (s->cert == NULL)
{
OPENSSL_PUT_ERROR(SSL, ssl3_accept, SSL_R_NO_CERTIFICATE_SET);
return(-1);
}
for (;;)
{
state=s->state;
switch (s->state)
{
case SSL_ST_RENEGOTIATE:
s->renegotiate=1;
/* s->state=SSL_ST_ACCEPT; */
case SSL_ST_BEFORE:
case SSL_ST_ACCEPT:
case SSL_ST_BEFORE|SSL_ST_ACCEPT:
case SSL_ST_OK|SSL_ST_ACCEPT:
s->server=1;
if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);
if ((s->version>>8) != 3)
{
OPENSSL_PUT_ERROR(SSL, ssl3_accept, ERR_R_INTERNAL_ERROR);
return -1;
}
s->type=SSL_ST_ACCEPT;
if (s->init_buf == NULL)
{
if ((buf=BUF_MEM_new()) == NULL)
{
ret= -1;
goto end;
}
if (!BUF_MEM_grow(buf,SSL3_RT_MAX_PLAIN_LENGTH))
{
ret= -1;
goto end;
}
s->init_buf=buf;
}
if (!ssl3_setup_buffers(s))
{
ret= -1;
goto end;
}
s->init_num=0;
if (s->state != SSL_ST_RENEGOTIATE)
{
/* Ok, we now need to push on a buffering BIO so that
* the output is sent in a way that TCP likes :-)
*/
if (!ssl_init_wbio_buffer(s,1)) { ret= -1; goto end; }
ssl3_init_finished_mac(s);
s->state=SSL3_ST_SR_CLNT_HELLO_A;
s->ctx->stats.sess_accept++;
}
else if (!s->s3->send_connection_binding &&
!(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
{
/* Server attempting to renegotiate with
* client that doesn't support secure
* renegotiation.
*/
OPENSSL_PUT_ERROR(SSL, ssl3_accept, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_HANDSHAKE_FAILURE);
ret = -1;
goto end;
}
else
{
/* s->state == SSL_ST_RENEGOTIATE,
* we will just send a HelloRequest */
s->ctx->stats.sess_accept_renegotiate++;
s->state=SSL3_ST_SW_HELLO_REQ_A;
}
break;
case SSL3_ST_SW_HELLO_REQ_A:
case SSL3_ST_SW_HELLO_REQ_B:
s->shutdown=0;
ret=ssl3_send_hello_request(s);
if (ret <= 0) goto end;
s->s3->tmp.next_state=SSL3_ST_SW_HELLO_REQ_C;
s->state=SSL3_ST_SW_FLUSH;
s->init_num=0;
ssl3_init_finished_mac(s);
break;
case SSL3_ST_SW_HELLO_REQ_C:
s->state=SSL_ST_OK;
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:
s->shutdown=0;
ret=ssl3_get_client_hello(s);
if (ret == PENDING_SESSION) {
s->rwstate = SSL_PENDING_SESSION;
goto end;
}
if (ret == CERTIFICATE_SELECTION_PENDING)
{
s->rwstate = SSL_CERTIFICATE_SELECTION_PENDING;
goto end;
}
if (ret <= 0) goto end;
s->renegotiate = 2;
s->state=SSL3_ST_SW_SRVR_HELLO_A;
s->init_num=0;
break;
case SSL3_ST_SW_SRVR_HELLO_A:
case SSL3_ST_SW_SRVR_HELLO_B:
ret=ssl3_send_server_hello(s);
if (ret <= 0) goto end;
if (s->hit)
{
if (s->tlsext_ticket_expected)
s->state=SSL3_ST_SW_SESSION_TICKET_A;
else
s->state=SSL3_ST_SW_CHANGE_A;
}
else
s->state = SSL3_ST_SW_CERT_A;
s->init_num = 0;
break;
case SSL3_ST_SW_CERT_A:
case SSL3_ST_SW_CERT_B:
if (ssl_cipher_has_server_public_key(s->s3->tmp.new_cipher))
{
ret=ssl3_send_server_certificate(s);
if (ret <= 0) goto end;
if (s->s3->tmp.certificate_status_expected)
s->state=SSL3_ST_SW_CERT_STATUS_A;
else
s->state=SSL3_ST_SW_KEY_EXCH_A;
}
else
{
skip = 1;
s->state=SSL3_ST_SW_KEY_EXCH_A;
}
s->init_num=0;
break;
case SSL3_ST_SW_KEY_EXCH_A:
case SSL3_ST_SW_KEY_EXCH_B:
alg_a = s->s3->tmp.new_cipher->algorithm_auth;
/* Send a ServerKeyExchange message if:
* - The key exchange is ephemeral or anonymous
* Diffie-Hellman.
* - There is a PSK identity hint.
*
* TODO(davidben): This logic is currently duplicated
* in d1_srvr.c. Fix this. In the meantime, keep them
* in sync.
*/
if (ssl_cipher_requires_server_key_exchange(s->s3->tmp.new_cipher) ||
((alg_a & SSL_aPSK) && s->psk_identity_hint))
{
ret=ssl3_send_server_key_exchange(s);
if (ret <= 0) goto end;
}
else
skip=1;
s->state=SSL3_ST_SW_CERT_REQ_A;
s->init_num=0;
break;
case SSL3_ST_SW_CERT_REQ_A:
case SSL3_ST_SW_CERT_REQ_B:
if (/* don't request cert unless asked for it: */
!(s->verify_mode & SSL_VERIFY_PEER) ||
/* Don't request a certificate if an obc was presented */
((s->verify_mode & SSL_VERIFY_PEER_IF_NO_OBC) &&
s->s3->tlsext_channel_id_valid) ||
/* if SSL_VERIFY_CLIENT_ONCE is set,
* don't request cert during re-negotiation: */
((s->session->peer != NULL) &&
(s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) ||
/* never request cert in anonymous ciphersuites
* (see section "Certificate request" in SSL 3 drafts
* and in RFC 2246): */
((s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) &&
/* ... except when the application insists on verification
* (against the specs, but s3_clnt.c accepts this for SSL 3) */
!(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) ||
/* With normal PSK Certificates and
* Certificate Requests are omitted */
(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK))
{
/* no cert request */
skip=1;
s->s3->tmp.cert_request=0;
s->state=SSL3_ST_SW_SRVR_DONE_A;
if (s->s3->handshake_buffer)
if (!ssl3_digest_cached_records(s, free_handshake_buffer))
return -1;
}
else
{
s->s3->tmp.cert_request=1;
ret=ssl3_send_certificate_request(s);
if (ret <= 0) goto end;
#ifndef NETSCAPE_HANG_BUG
s->state=SSL3_ST_SW_SRVR_DONE_A;
#else
s->state=SSL3_ST_SW_FLUSH;
s->s3->tmp.next_state=SSL3_ST_SR_CERT_A;
#endif
s->init_num=0;
}
break;
case SSL3_ST_SW_SRVR_DONE_A:
case SSL3_ST_SW_SRVR_DONE_B:
ret=ssl3_send_server_done(s);
if (ret <= 0) goto end;
s->s3->tmp.next_state=SSL3_ST_SR_CERT_A;
s->state=SSL3_ST_SW_FLUSH;
s->init_num=0;
break;
case SSL3_ST_SW_FLUSH:
/* This code originally checked to see if
* any data was pending using BIO_CTRL_INFO
* and then flushed. This caused problems
* as documented in PR#1939. The proposed
* fix doesn't completely resolve this issue
* as buggy implementations of BIO_CTRL_PENDING
* still exist. So instead we just flush
* unconditionally.
*/
s->rwstate=SSL_WRITING;
if (BIO_flush(s->wbio) <= 0)
{
ret= -1;
goto end;
}
s->rwstate=SSL_NOTHING;
s->state=s->s3->tmp.next_state;
break;
case SSL3_ST_SR_CERT_A:
case SSL3_ST_SR_CERT_B:
if (s->s3->tmp.cert_request)
{
ret=ssl3_get_client_certificate(s);
if (ret <= 0) goto end;
}
s->init_num=0;
s->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(s);
if (ret <= 0)
goto end;
s->state=SSL3_ST_SR_CERT_VRFY_A;
s->init_num=0;
break;
case SSL3_ST_SR_CERT_VRFY_A:
case SSL3_ST_SR_CERT_VRFY_B:
ret=ssl3_get_cert_verify(s);
if (ret <= 0) goto end;
s->state = SSL3_ST_SR_CHANGE;
s->init_num=0;
break;
case SSL3_ST_SR_CHANGE: {
char next_proto_neg = 0;
char channel_id = 0;
next_proto_neg = s->s3->next_proto_neg_seen;
channel_id = s->s3->tlsext_channel_id_valid;
/* At this point, the next message must be entirely
* behind a ChangeCipherSpec. */
if (!ssl3_expect_change_cipher_spec(s))
{
ret = -1;
goto end;
}
if (next_proto_neg)
s->state = SSL3_ST_SR_NEXT_PROTO_A;
else if (channel_id)
s->state = SSL3_ST_SR_CHANNEL_ID_A;
else
s->state = SSL3_ST_SR_FINISHED_A;
break;
}
case SSL3_ST_SR_NEXT_PROTO_A:
case SSL3_ST_SR_NEXT_PROTO_B:
ret=ssl3_get_next_proto(s);
if (ret <= 0) goto end;
s->init_num = 0;
if (s->s3->tlsext_channel_id_valid)
s->state=SSL3_ST_SR_CHANNEL_ID_A;
else
s->state=SSL3_ST_SR_FINISHED_A;
break;
case SSL3_ST_SR_CHANNEL_ID_A:
case SSL3_ST_SR_CHANNEL_ID_B:
ret=ssl3_get_channel_id(s);
if (ret <= 0) goto end;
s->init_num = 0;
s->state=SSL3_ST_SR_FINISHED_A;
break;
case SSL3_ST_SR_FINISHED_A:
case SSL3_ST_SR_FINISHED_B:
ret=ssl3_get_finished(s,SSL3_ST_SR_FINISHED_A,
SSL3_ST_SR_FINISHED_B);
if (ret <= 0) goto end;
if (s->hit)
s->state=SSL_ST_OK;
else if (s->tlsext_ticket_expected)
s->state=SSL3_ST_SW_SESSION_TICKET_A;
else
s->state=SSL3_ST_SW_CHANGE_A;
/* If this is a full handshake with ChannelID then
* record the hashshake hashes in |s->session| in case
* we need them to verify a ChannelID signature on a
* resumption of this session in the future. */
if (!s->hit && s->s3->tlsext_channel_id_new)
{
ret = tls1_record_handshake_hashes_for_channel_id(s);
if (ret <= 0) goto end;
}
s->init_num=0;
break;
case SSL3_ST_SW_SESSION_TICKET_A:
case SSL3_ST_SW_SESSION_TICKET_B:
ret=ssl3_send_new_session_ticket(s);
if (ret <= 0) goto end;
s->state=SSL3_ST_SW_CHANGE_A;
s->init_num=0;
break;
#if 0
// TODO(davidben): Implement OCSP stapling on the server.
case SSL3_ST_SW_CERT_STATUS_A:
case SSL3_ST_SW_CERT_STATUS_B:
ret=ssl3_send_cert_status(s);
if (ret <= 0) goto end;
s->state=SSL3_ST_SW_KEY_EXCH_A;
s->init_num=0;
break;
#endif
case SSL3_ST_SW_CHANGE_A:
case SSL3_ST_SW_CHANGE_B:
s->session->cipher=s->s3->tmp.new_cipher;
if (!s->method->ssl3_enc->setup_key_block(s))
{ ret= -1; goto end; }
ret=ssl3_send_change_cipher_spec(s,
SSL3_ST_SW_CHANGE_A,SSL3_ST_SW_CHANGE_B);
if (ret <= 0) goto end;
s->state=SSL3_ST_SW_FINISHED_A;
s->init_num=0;
if (!s->method->ssl3_enc->change_cipher_state(s,
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(s,
SSL3_ST_SW_FINISHED_A,SSL3_ST_SW_FINISHED_B,
s->method->ssl3_enc->server_finished_label,
s->method->ssl3_enc->server_finished_label_len);
if (ret <= 0) goto end;
s->state = SSL3_ST_SW_FLUSH;
if (s->hit)
s->s3->tmp.next_state = SSL3_ST_SR_CHANGE;
else
s->s3->tmp.next_state = SSL_ST_OK;
s->init_num=0;
break;
case SSL_ST_OK:
/* clean a few things up */
ssl3_cleanup_key_block(s);
BUF_MEM_free(s->init_buf);
s->init_buf=NULL;
/* remove buffering on output */
ssl_free_wbio_buffer(s);
s->init_num=0;
/* If we aren't retaining peer certificates then we can
* discard it now. */
if (s->session->peer && s->ctx->retain_only_sha256_of_client_certs)
{
X509_free(s->session->peer);
s->session->peer = NULL;
}
if (s->renegotiate == 2) /* skipped if we just sent a HelloRequest */
{
s->renegotiate=0;
s->new_session=0;
ssl_update_cache(s,SSL_SESS_CACHE_SERVER);
s->ctx->stats.sess_accept_good++;
/* s->server=1; */
s->handshake_func=ssl3_accept;
if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_DONE,1);
}
ret = 1;
goto end;
/* break; */
default:
OPENSSL_PUT_ERROR(SSL, ssl3_accept, SSL_R_UNKNOWN_STATE);
ret= -1;
goto end;
/* break; */
}
if (!s->s3->tmp.reuse_message && !skip)
{
if (s->debug)
{
if ((ret=BIO_flush(s->wbio)) <= 0)
goto end;
}
if ((cb != NULL) && (s->state != state))
{
new_state=s->state;
s->state=state;
cb(s,SSL_CB_ACCEPT_LOOP,1);
s->state=new_state;
}
}
skip=0;
}
end:
/* BIO_flush(s->wbio); */
s->in_handshake--;
if (cb != NULL)
cb(s,SSL_CB_ACCEPT_EXIT,ret);
return(ret);
}
int ssl3_send_hello_request(SSL *s)
{
if (s->state == SSL3_ST_SW_HELLO_REQ_A)
{
ssl_set_handshake_header(s, SSL3_MT_HELLO_REQUEST, 0);
s->state=SSL3_ST_SW_HELLO_REQ_B;
}
/* SSL3_ST_SW_HELLO_REQ_B */
return ssl_do_write(s);
}
int ssl3_get_client_hello(SSL *s)
{
int i,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;
/* 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 (s->state) {
case SSL3_ST_SR_CLNT_HELLO_A:
case SSL3_ST_SR_CLNT_HELLO_B:
s->first_packet=1;
n=s->method->ssl_get_message(s,
SSL3_ST_SR_CLNT_HELLO_A,
SSL3_ST_SR_CLNT_HELLO_B,
SSL3_MT_CLIENT_HELLO,
SSL3_RT_MAX_PLAIN_LENGTH,
SSL_GET_MESSAGE_HASH_MESSAGE,
&ok);
if (!ok) return((int)n);
s->first_packet=0;
/* If we require cookies and this ClientHello doesn't
* contain one, just return since we do not want to
* allocate any memory yet. So check cookie length...
*/
if (SSL_IS_DTLS(s) && (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE))
{
CBS session_id;
uint8_t cookie_length;
CBS_init(&client_hello, s->init_msg, n);
if (!CBS_skip(&client_hello, 2 + SSL3_RANDOM_SIZE) ||
!CBS_get_u8_length_prefixed(&client_hello, &session_id) ||
!CBS_get_u8(&client_hello, &cookie_length))
{
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_hello, SSL_R_DECODE_ERROR);
goto f_err;
}
if (cookie_length == 0)
return 1;
}
s->state = SSL3_ST_SR_CLNT_HELLO_C;
/* fallthrough */
case SSL3_ST_SR_CLNT_HELLO_C:
case SSL3_ST_SR_CLNT_HELLO_D:
/* 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 = s->init_num;
memset(&early_ctx, 0, sizeof(early_ctx));
early_ctx.ssl = s;
early_ctx.client_hello = s->init_msg;
early_ctx.client_hello_len = n;
if (!ssl_early_callback_init(&early_ctx))
{
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_hello, SSL_R_CLIENTHELLO_PARSE_FAILED);
goto f_err;
}
if (s->state == SSL3_ST_SR_CLNT_HELLO_C &&
s->ctx->select_certificate_cb != NULL)
{
int ret;
s->state = SSL3_ST_SR_CLNT_HELLO_D;
ret = s->ctx->select_certificate_cb(&early_ctx);
if (ret == 0)
return CERTIFICATE_SELECTION_PENDING;
else if (ret == -1)
{
/* Connection rejected. */
al = SSL_AD_ACCESS_DENIED;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_hello, SSL_R_CONNECTION_REJECTED);
goto f_err;
}
}
s->state = SSL3_ST_SR_CLNT_HELLO_D;
break;
default:
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_hello, SSL_R_UNKNOWN_STATE);
return -1;
}
CBS_init(&client_hello, s->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, ssl3_get_client_hello, 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) */
s->client_version = client_version;
if (SSL_IS_DTLS(s) ? (s->client_version > s->version &&
s->method->version != DTLS_ANY_VERSION)
: (s->client_version < s->version))
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_hello, SSL_R_WRONG_VERSION_NUMBER);
if ((s->client_version>>8) == SSL3_VERSION_MAJOR &&
!s->enc_write_ctx && !s->write_hash)
{
/* similar to ssl3_get_record, send alert using remote version number */
s->version = s->client_version;
}
al = SSL_AD_PROTOCOL_VERSION;
goto f_err;
}
/* Load the client random. */
memcpy(s->s3->client_random, CBS_data(&client_random), SSL3_RANDOM_SIZE);
s->hit=0;
/* Versions before 0.9.7 always allow clients to resume sessions in renegotiation.
* 0.9.7 and later allow this by default, but optionally ignore resumption requests
* with flag SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION (it's a new flag rather
* than a change to default behavior so that applications relying on this for security
* won't even compile against older library versions).
*
* 1.0.1 and later also have a function SSL_renegotiate_abbreviated() to request
* renegotiation but not a new session (s->new_session remains unset): for servers,
* this essentially just means that the SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
* setting will be ignored.
*/
if ((s->new_session && (s->options & SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION)))
{
if (!ssl_get_new_session(s,1))
goto err;
}
else
{
i = ssl_get_prev_session(s, &early_ctx);
if (i == PENDING_SESSION)
{
ret = PENDING_SESSION;
goto err;
}
else if (i == -1)
{
goto err;
}
/* Only resume if the session's version matches the negotiated
* version: most clients do not accept a mismatch. */
if (i == 1 && s->version == s->session->ssl_version)
{
s->hit = 1;
}
else
{
/* No session was found or it was unacceptable. */
if (!ssl_get_new_session(s, 1))
goto err;
}
}
if (SSL_IS_DTLS(s))
{
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, ssl3_get_client_hello, SSL_R_DECODE_ERROR);
goto f_err;
}
/* Verify the cookie if appropriate option is set. */
if ((SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE) &&
CBS_len(&cookie) > 0)
{
if (s->ctx->app_verify_cookie_cb != NULL)
{
if (s->ctx->app_verify_cookie_cb(s,
CBS_data(&cookie), CBS_len(&cookie)) == 0)
{
al=SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_hello, SSL_R_COOKIE_MISMATCH);
goto f_err;
}
/* else cookie verification succeeded */
}
else if (!CBS_mem_equal(&cookie, s->d1->cookie, s->d1->cookie_len))
{
/* default verification */
al=SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_hello, SSL_R_COOKIE_MISMATCH);
goto f_err;
}
/* Set to -2 so if successful we return 2 and
* don't send HelloVerifyRequest. */
ret = -2;
}
if (s->method->version == DTLS_ANY_VERSION)
{
/* Select version to use */
if (s->client_version <= DTLS1_2_VERSION &&
!(s->options & SSL_OP_NO_DTLSv1_2))
{
s->version = DTLS1_2_VERSION;
s->method = DTLSv1_2_server_method();
}
else if (s->client_version <= DTLS1_VERSION &&
!(s->options & SSL_OP_NO_DTLSv1))
{
s->version = DTLS1_VERSION;
s->method = DTLSv1_server_method();
}
else
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_hello, SSL_R_WRONG_VERSION_NUMBER);
s->version = s->client_version;
al = SSL_AD_PROTOCOL_VERSION;
goto f_err;
}
s->session->ssl_version = s->version;
}
}
if (!CBS_get_u16_length_prefixed(&client_hello, &cipher_suites) ||
!CBS_get_u8_length_prefixed(&client_hello, &compression_methods) ||
CBS_len(&compression_methods) == 0)
{
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_hello, SSL_R_DECODE_ERROR);
goto f_err;
}
/* TODO(davidben): Per spec, cipher_suites can never be empty
* (specified at the ClientHello structure level). This logic
* allows it to be empty if resuming a session. Can we always
* require non-empty? If a client sends empty cipher_suites
* because it's resuming a session, it could always fail to
* resume a session, so it's unlikely to actually work. */
if (CBS_len(&cipher_suites) == 0 && CBS_len(&session_id) != 0)
{
/* We need a cipher if we are not resuming a session. */
al = SSL_AD_ILLEGAL_PARAMETER;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_hello, SSL_R_NO_CIPHERS_SPECIFIED);
goto f_err;
}
ciphers = ssl_bytes_to_cipher_list(s, &cipher_suites);
if (ciphers == NULL)
{
goto err;
}
/* If it is a hit, check that the cipher is in the list */
if (s->hit && CBS_len(&cipher_suites) > 0)
{
size_t j;
int found_cipher = 0;
unsigned long id = s->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, ssl3_get_client_hello, 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, ssl3_get_client_hello, SSL_R_NO_COMPRESSION_SPECIFIED);
goto f_err;
}
/* TLS extensions*/
if (s->version >= SSL3_VERSION)
{
if (!ssl_parse_clienthello_tlsext(s, &client_hello))
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_hello, 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, ssl3_get_client_hello, SSL_R_BAD_PACKET_LENGTH);
goto f_err;
}
/* Check if we want to use external pre-shared secret for this
* handshake for not reused session only. We need to generate
* server_random before calling tls_session_secret_cb in order to allow
* SessionTicket processing to use it in key derivation. */
{
unsigned char *pos;
pos=s->s3->server_random;
if (ssl_fill_hello_random(s, 1, pos, SSL3_RANDOM_SIZE) <= 0)
{
goto f_err;
}
}
if (!s->hit && s->version >= TLS1_VERSION && s->tls_session_secret_cb)
{
const SSL_CIPHER *pref_cipher=NULL;
s->session->master_key_length=sizeof(s->session->master_key);
if(s->tls_session_secret_cb(s, s->session->master_key, &s->session->master_key_length,
ciphers, &pref_cipher, s->tls_session_secret_cb_arg))
{
s->hit=1;
s->session->verify_result=X509_V_OK;
/* check if some cipher was preferred by call back */
pref_cipher=pref_cipher ? pref_cipher : ssl3_choose_cipher(s, ciphers, ssl_get_cipher_preferences(s));
if (pref_cipher == NULL)
{
al=SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_hello, SSL_R_NO_SHARED_CIPHER);
goto f_err;
}
s->session->cipher=pref_cipher;
if (s->cipher_list)
ssl_cipher_preference_list_free(s->cipher_list);
if (s->cipher_list_by_id)
sk_SSL_CIPHER_free(s->cipher_list_by_id);
s->cipher_list = ssl_cipher_preference_list_from_ciphers(ciphers);
s->cipher_list_by_id = sk_SSL_CIPHER_dup(ciphers);
}
}
/* Given ciphers and SSL_get_ciphers, we must pick a cipher */
if (!s->hit)
{
if (ciphers == NULL)
{
al=SSL_AD_ILLEGAL_PARAMETER;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_hello, SSL_R_NO_CIPHERS_PASSED);
goto f_err;
}
/* Let cert callback update server certificates if required */
if (s->cert->cert_cb)
{
int rv = s->cert->cert_cb(s, s->cert->cert_cb_arg);
if (rv == 0)
{
al=SSL_AD_INTERNAL_ERROR;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_hello, SSL_R_CERT_CB_ERROR);
goto f_err;
}
if (rv < 0)
{
s->rwstate=SSL_X509_LOOKUP;
goto err;
}
s->rwstate = SSL_NOTHING;
}
c=ssl3_choose_cipher(s, ciphers, ssl_get_cipher_preferences(s));
if (c == NULL)
{
al=SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_hello, SSL_R_NO_SHARED_CIPHER);
goto f_err;
}
s->s3->tmp.new_cipher=c;
}
else
{
/* Session-id reuse */
s->s3->tmp.new_cipher=s->session->cipher;
}
if (!SSL_USE_SIGALGS(s) || !(s->verify_mode & SSL_VERIFY_PEER))
{
if (!ssl3_digest_cached_records(s, free_handshake_buffer))
goto f_err;
}
/* 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
* s->session - The ssl session has been setup.
* s->hit - session reuse flag
* s->tmp.new_cipher - the new cipher to use.
*/
if (ret < 0) ret=-ret;
if (0)
{
f_err:
ssl3_send_alert(s,SSL3_AL_FATAL,al);
}
err:
if (ciphers != NULL) sk_SSL_CIPHER_free(ciphers);
return ret;
}
int ssl3_send_server_hello(SSL *s)
{
unsigned char *buf;
unsigned char *p,*d;
int sl;
unsigned long l;
if (s->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 (s->s3->tlsext_channel_id_valid &&
(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kEECDH) == 0)
s->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 (s->hit &&
s->s3->tlsext_channel_id_new &&
s->session->original_handshake_hash_len == 0)
s->s3->tlsext_channel_id_valid = 0;
buf=(unsigned char *)s->init_buf->data;
/* Do the message type and length last */
d=p= ssl_handshake_start(s);
*(p++)=s->version>>8;
*(p++)=s->version&0xff;
/* Random stuff */
memcpy(p,s->s3->server_random,SSL3_RANDOM_SIZE);
p+=SSL3_RANDOM_SIZE;
/* There are several cases for the session ID to send
* back in the server hello:
* - For session reuse from the session cache,
* we send back the old session ID.
* - If stateless session reuse (using a session ticket)
* is successful, we send back the client's "session ID"
* (which doesn't actually identify the session).
* - If it is a new session, we send back the new
* session ID.
* - However, if we want the new session to be single-use,
* we send back a 0-length session ID.
* s->hit is non-zero in either case of session reuse,
* so the following won't overwrite an ID that we're supposed
* to send back.
*/
if (!(s->ctx->session_cache_mode & SSL_SESS_CACHE_SERVER)
&& !s->hit)
s->session->session_id_length=0;
sl=s->session->session_id_length;
if (sl > (int)sizeof(s->session->session_id))
{
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_hello, ERR_R_INTERNAL_ERROR);
return -1;
}
*(p++)=sl;
memcpy(p,s->session->session_id,sl);
p+=sl;
/* put the cipher */
s2n(ssl3_get_cipher_value(s->s3->tmp.new_cipher), p);
/* put the compression method */
*(p++)=0;
if (ssl_prepare_serverhello_tlsext(s) <= 0)
{
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_hello, SSL_R_SERVERHELLO_TLSEXT);
return -1;
}
if ((p = ssl_add_serverhello_tlsext(s, p, buf+SSL3_RT_MAX_PLAIN_LENGTH)) == NULL)
{
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_hello, ERR_R_INTERNAL_ERROR);
return -1;
}
/* do the header */
l=(p-d);
ssl_set_handshake_header(s, SSL3_MT_SERVER_HELLO, l);
s->state=SSL3_ST_SW_SRVR_HELLO_B;
}
/* SSL3_ST_SW_SRVR_HELLO_B */
return ssl_do_write(s);
}
int ssl3_send_server_done(SSL *s)
{
if (s->state == SSL3_ST_SW_SRVR_DONE_A)
{
ssl_set_handshake_header(s, SSL3_MT_SERVER_DONE, 0);
s->state = SSL3_ST_SW_SRVR_DONE_B;
}
/* SSL3_ST_SW_SRVR_DONE_B */
return ssl_do_write(s);
}
int ssl3_send_server_key_exchange(SSL *s)
{
unsigned char *q;
int j,num;
unsigned char md_buf[MD5_DIGEST_LENGTH+SHA_DIGEST_LENGTH];
unsigned int u;
DH *dh=NULL,*dhp;
EC_KEY *ecdh=NULL, *ecdhp;
unsigned char *encodedPoint = NULL;
int encodedlen = 0;
int curve_id = 0;
BN_CTX *bn_ctx = NULL;
const char* psk_identity_hint = NULL;
size_t psk_identity_hint_len = 0;
EVP_PKEY *pkey;
const EVP_MD *md = NULL;
unsigned char *p,*d;
int al,i;
unsigned long alg_k;
unsigned long alg_a;
int n;
CERT *cert;
BIGNUM *r[4];
int nr[4],kn;
BUF_MEM *buf;
EVP_MD_CTX md_ctx;
EVP_MD_CTX_init(&md_ctx);
if (s->state == SSL3_ST_SW_KEY_EXCH_A)
{
alg_k=s->s3->tmp.new_cipher->algorithm_mkey;
alg_a=s->s3->tmp.new_cipher->algorithm_auth;
cert=s->cert;
buf=s->init_buf;
r[0]=r[1]=r[2]=r[3]=NULL;
n=0;
if (alg_a & SSL_aPSK)
{
/* size for PSK identity hint */
psk_identity_hint = s->psk_identity_hint;
if (psk_identity_hint)
psk_identity_hint_len = strlen(psk_identity_hint);
else
psk_identity_hint_len = 0;
n+=2+psk_identity_hint_len;
}
if (alg_k & SSL_kEDH)
{
dhp=cert->dh_tmp;
if ((dhp == NULL) && (s->cert->dh_tmp_cb != NULL))
dhp=s->cert->dh_tmp_cb(s, 0, 1024);
if (dhp == NULL)
{
al=SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_key_exchange, SSL_R_MISSING_TMP_DH_KEY);
goto f_err;
}
if (s->s3->tmp.dh != NULL)
{
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_key_exchange, ERR_R_INTERNAL_ERROR);
goto err;
}
if ((dh=DHparams_dup(dhp)) == NULL)
{
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_key_exchange, ERR_R_DH_LIB);
goto err;
}
s->s3->tmp.dh=dh;
if ((dhp->pub_key == NULL ||
dhp->priv_key == NULL ||
(s->options & SSL_OP_SINGLE_DH_USE)))
{
if(!DH_generate_key(dh))
{
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_key_exchange, ERR_R_DH_LIB);
goto err;
}
}
else
{
dh->pub_key=BN_dup(dhp->pub_key);
dh->priv_key=BN_dup(dhp->priv_key);
if ((dh->pub_key == NULL) ||
(dh->priv_key == NULL))
{
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_key_exchange, ERR_R_DH_LIB);
goto err;
}
}
r[0]=dh->p;
r[1]=dh->g;
r[2]=dh->pub_key;
}
else
if (alg_k & SSL_kEECDH)
{
const EC_GROUP *group;
ecdhp=cert->ecdh_tmp;
if (s->cert->ecdh_tmp_auto)
{
/* Get NID of appropriate shared curve */
int nid = tls1_get_shared_curve(s);
if (nid != NID_undef)
ecdhp = EC_KEY_new_by_curve_name(nid);
}
else if ((ecdhp == NULL) && s->cert->ecdh_tmp_cb)
{
ecdhp = s->cert->ecdh_tmp_cb(s, 0, 1024);
}
if (ecdhp == NULL)
{
al=SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_key_exchange, SSL_R_MISSING_TMP_ECDH_KEY);
goto f_err;
}
if (s->s3->tmp.ecdh != NULL)
{
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_key_exchange, ERR_R_INTERNAL_ERROR);
goto err;
}
/* Duplicate the ECDH structure. */
if (ecdhp == NULL)
{
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_key_exchange, ERR_R_ECDH_LIB);
goto err;
}
if (s->cert->ecdh_tmp_auto)
ecdh = ecdhp;
else if ((ecdh = EC_KEY_dup(ecdhp)) == NULL)
{
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_key_exchange, ERR_R_ECDH_LIB);
goto err;
}
s->s3->tmp.ecdh=ecdh;
if ((EC_KEY_get0_public_key(ecdh) == NULL) ||
(EC_KEY_get0_private_key(ecdh) == NULL) ||
(s->options & SSL_OP_SINGLE_ECDH_USE))
{
if(!EC_KEY_generate_key(ecdh))
{
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_key_exchange, ERR_R_ECDH_LIB);
goto err;
}
}
if (((group = EC_KEY_get0_group(ecdh)) == NULL) ||
(EC_KEY_get0_public_key(ecdh) == NULL) ||
(EC_KEY_get0_private_key(ecdh) == NULL))
{
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_key_exchange, ERR_R_ECDH_LIB);
goto err;
}
/* XXX: For now, we only support ephemeral ECDH
* keys over named (not generic) curves. For
* supported named curves, curve_id is non-zero.
*/
if ((curve_id =
tls1_ec_nid2curve_id(EC_GROUP_get_curve_name(group)))
== 0)
{
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_key_exchange, SSL_R_UNSUPPORTED_ELLIPTIC_CURVE);
goto err;
}
/* Encode the public key.
* First check the size of encoding and
* allocate memory accordingly.
*/
encodedlen = EC_POINT_point2oct(group,
EC_KEY_get0_public_key(ecdh),
POINT_CONVERSION_UNCOMPRESSED,
NULL, 0, NULL);
encodedPoint = (unsigned char *)
OPENSSL_malloc(encodedlen*sizeof(unsigned char));
bn_ctx = BN_CTX_new();
if ((encodedPoint == NULL) || (bn_ctx == NULL))
{
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_key_exchange, ERR_R_MALLOC_FAILURE);
goto err;
}
encodedlen = EC_POINT_point2oct(group,
EC_KEY_get0_public_key(ecdh),
POINT_CONVERSION_UNCOMPRESSED,
encodedPoint, encodedlen, bn_ctx);
if (encodedlen == 0)
{
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_key_exchange, ERR_R_ECDH_LIB);
goto err;
}
BN_CTX_free(bn_ctx); bn_ctx=NULL;
/* XXX: For now, we only support named (not
* generic) curves in ECDH ephemeral key exchanges.
* In this situation, we need four additional bytes
* to encode the entire ServerECDHParams
* structure.
*/
n += 4 + encodedlen;
/* We'll generate the serverKeyExchange message
* explicitly so we can set these to NULLs
*/
r[0]=NULL;
r[1]=NULL;
r[2]=NULL;
r[3]=NULL;
}
else
if (!(alg_k & SSL_kPSK))
{
al=SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_key_exchange, SSL_R_UNKNOWN_KEY_EXCHANGE_TYPE);
goto f_err;
}
for (i=0; i < 4 && r[i] != NULL; i++)
{
nr[i]=BN_num_bytes(r[i]);
n+=2+nr[i];
}
if (ssl_cipher_has_server_public_key(s->s3->tmp.new_cipher))
{
if ((pkey=ssl_get_sign_pkey(s,s->s3->tmp.new_cipher,&md))
== NULL)
{
al=SSL_AD_DECODE_ERROR;
goto f_err;
}
kn=EVP_PKEY_size(pkey);
}
else
{
pkey=NULL;
kn=0;
}
if (!BUF_MEM_grow_clean(buf,n+SSL_HM_HEADER_LENGTH(s)+kn))
{
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_key_exchange, ERR_LIB_BUF);
goto err;
}
d = p = ssl_handshake_start(s);
for (i=0; i < 4 && r[i] != NULL; i++)
{
s2n(nr[i],p);
BN_bn2bin(r[i],p);
p+=nr[i];
}
/* Note: ECDHE PSK ciphersuites use SSL_kEECDH and SSL_aPSK.
* When one of them is used, the server key exchange record needs to have both
* the psk_identity_hint and the ServerECDHParams. */
if (alg_a & SSL_aPSK)
{
/* copy PSK identity hint (if provided) */
s2n(psk_identity_hint_len, p);
if (psk_identity_hint_len > 0)
{
memcpy(p, psk_identity_hint, psk_identity_hint_len);
p+=psk_identity_hint_len;
}
}
if (alg_k & SSL_kEECDH)
{
/* XXX: For now, we only support named (not generic) curves.
* In this situation, the serverKeyExchange message has:
* [1 byte CurveType], [2 byte CurveName]
* [1 byte length of encoded point], followed by
* the actual encoded point itself
*/
*p = NAMED_CURVE_TYPE;
p += 1;
*p = 0;
p += 1;
*p = curve_id;
p += 1;
*p = encodedlen;
p += 1;
memcpy((unsigned char*)p,
(unsigned char *)encodedPoint,
encodedlen);
OPENSSL_free(encodedPoint);
encodedPoint = NULL;
p += encodedlen;
}
/* not anonymous */
if (pkey != NULL)
{
/* n is the length of the params, they start at &(d[4])
* and p points to the space at the end. */
if (pkey->type == EVP_PKEY_RSA && !SSL_USE_SIGALGS(s))
{
q=md_buf;
j=0;
for (num=2; num > 0; num--)
{
EVP_DigestInit_ex(&md_ctx,
(num == 2) ? EVP_md5() : EVP_sha1(), NULL);
EVP_DigestUpdate(&md_ctx,&(s->s3->client_random[0]),SSL3_RANDOM_SIZE);
EVP_DigestUpdate(&md_ctx,&(s->s3->server_random[0]),SSL3_RANDOM_SIZE);
EVP_DigestUpdate(&md_ctx,d,n);
EVP_DigestFinal_ex(&md_ctx,q,
(unsigned int *)&i);
q+=i;
j+=i;
}
if (RSA_sign(NID_md5_sha1, md_buf, j,
&(p[2]), &u, pkey->pkey.rsa) <= 0)
{
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_key_exchange, ERR_LIB_RSA);
goto err;
}
s2n(u,p);
n+=u+2;
}
else
if (md)
{
size_t sig_len = EVP_PKEY_size(pkey);
/* send signature algorithm */
if (SSL_USE_SIGALGS(s))
{
if (!tls12_get_sigandhash(p, pkey, md))
{
/* Should never happen */
al=SSL_AD_INTERNAL_ERROR;
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_key_exchange, ERR_R_INTERNAL_ERROR);
goto f_err;
}
p+=2;
}
if (!EVP_DigestSignInit(&md_ctx, NULL, md, NULL, pkey) ||
!EVP_DigestSignUpdate(&md_ctx, s->s3->client_random, SSL3_RANDOM_SIZE) ||
!EVP_DigestSignUpdate(&md_ctx, s->s3->server_random, SSL3_RANDOM_SIZE) ||
!EVP_DigestSignUpdate(&md_ctx, d, n) ||
!EVP_DigestSignFinal(&md_ctx, &p[2], &sig_len))
{
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_key_exchange, ERR_LIB_EVP);
goto err;
}
s2n(sig_len, p);
n += sig_len + 2;
if (SSL_USE_SIGALGS(s))
n += 2;
}
else
{
/* Is this error check actually needed? */
al=SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_key_exchange, SSL_R_UNKNOWN_PKEY_TYPE);
goto f_err;
}
}
ssl_set_handshake_header(s, SSL3_MT_SERVER_KEY_EXCHANGE, n);
}
s->state = SSL3_ST_SW_KEY_EXCH_B;
EVP_MD_CTX_cleanup(&md_ctx);
return ssl_do_write(s);
f_err:
ssl3_send_alert(s,SSL3_AL_FATAL,al);
err:
if (encodedPoint != NULL) OPENSSL_free(encodedPoint);
BN_CTX_free(bn_ctx);
EVP_MD_CTX_cleanup(&md_ctx);
return(-1);
}
int ssl3_send_certificate_request(SSL *s)
{
unsigned char *p,*d;
size_t i;
int j,nl,off,n;
STACK_OF(X509_NAME) *sk=NULL;
X509_NAME *name;
BUF_MEM *buf;
if (s->state == SSL3_ST_SW_CERT_REQ_A)
{
buf=s->init_buf;
d=p=ssl_handshake_start(s);
/* get the list of acceptable cert types */
p++;
n=ssl3_get_req_cert_type(s,p);
d[0]=n;
p+=n;
n++;
if (SSL_USE_SIGALGS(s))
{
const unsigned char *psigs;
nl = tls12_get_psigalgs(s, &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(s);
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(s)+n+j+2))
{
OPENSSL_PUT_ERROR(SSL, ssl3_send_certificate_request, ERR_R_BUF_LIB);
goto err;
}
p = ssl_handshake_start(s) + n;
s2n(j,p);
i2d_X509_NAME(name,&p);
n+=2+j;
nl+=2+j;
}
}
/* else no CA names */
p = ssl_handshake_start(s) + off;
s2n(nl,p);
ssl_set_handshake_header(s, SSL3_MT_CERTIFICATE_REQUEST, n);
#ifdef NETSCAPE_HANG_BUG
if (!SSL_IS_DTLS(s))
{
if (!BUF_MEM_grow_clean(buf, s->init_num + 4))
{
OPENSSL_PUT_ERROR(SSL, ssl3_send_certificate_request, ERR_R_BUF_LIB);
goto err;
}
p=(unsigned char *)s->init_buf->data + s->init_num;
/* do the header */
*(p++)=SSL3_MT_SERVER_DONE;
*(p++)=0;
*(p++)=0;
*(p++)=0;
s->init_num += 4;
}
#endif
s->state = SSL3_ST_SW_CERT_REQ_B;
}
/* SSL3_ST_SW_CERT_REQ_B */
return ssl_do_write(s);
err:
return(-1);
}
int ssl3_get_client_key_exchange(SSL *s)
{
int al,ok;
long n;
CBS client_key_exchange;
unsigned long alg_k;
unsigned long alg_a;
uint8_t *premaster_secret = NULL;
size_t premaster_secret_len = 0;
RSA *rsa=NULL;
uint8_t *decrypt_buf = NULL;
EVP_PKEY *pkey=NULL;
BIGNUM *pub=NULL;
DH *dh_srvr;
EC_KEY *srvr_ecdh = NULL;
EVP_PKEY *clnt_pub_pkey = NULL;
EC_POINT *clnt_ecpoint = NULL;
BN_CTX *bn_ctx = NULL;
unsigned int psk_len = 0;
unsigned char psk[PSK_MAX_PSK_LEN];
n=s->method->ssl_get_message(s,
SSL3_ST_SR_KEY_EXCH_A,
SSL3_ST_SR_KEY_EXCH_B,
SSL3_MT_CLIENT_KEY_EXCHANGE,
2048, /* ??? */
SSL_GET_MESSAGE_HASH_MESSAGE,
&ok);
if (!ok) return((int)n);
CBS_init(&client_key_exchange, s->init_msg, n);
alg_k=s->s3->tmp.new_cipher->algorithm_mkey;
alg_a=s->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, ssl3_get_client_key_exchange, SSL_R_DECODE_ERROR);
al = SSL_AD_DECODE_ERROR;
goto f_err;
}
if (s->psk_server_callback == NULL)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, 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, ssl3_get_client_key_exchange, SSL_R_DATA_LENGTH_TOO_LONG);
al = SSL_AD_ILLEGAL_PARAMETER;
goto f_err;
}
if (!CBS_strdup(&psk_identity, &s->session->psk_identity))
{
al = SSL_AD_INTERNAL_ERROR;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, ERR_R_MALLOC_FAILURE);
goto f_err;
}
/* Look up the key for the identity. */
psk_len = s->psk_server_callback(s, s->session->psk_identity, psk, sizeof(psk));
if (psk_len > PSK_MAX_PSK_LEN)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, 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, ssl3_get_client_key_exchange, 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)
{
CBS encrypted_premaster_secret;
uint8_t rand_premaster_secret[SSL_MAX_MASTER_KEY_LENGTH];
uint8_t good;
size_t rsa_size, decrypt_len, premaster_index, j;
pkey=s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey;
if ( (pkey == NULL) ||
(pkey->type != EVP_PKEY_RSA) ||
(pkey->pkey.rsa == NULL))
{
al=SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, SSL_R_MISSING_RSA_CERTIFICATE);
goto f_err;
}
rsa=pkey->pkey.rsa;
/* TLS and [incidentally] DTLS{0xFEFF} */
if (s->version > SSL3_VERSION)
{
CBS copy = client_key_exchange;
if (!CBS_get_u16_length_prefixed(&client_key_exchange,
&encrypted_premaster_secret) ||
CBS_len(&client_key_exchange) != 0)
{
if (!(s->options & SSL_OP_TLS_D5_BUG))
{
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, SSL_R_TLS_RSA_ENCRYPTED_VALUE_LENGTH_IS_WRONG);
goto f_err;
}
else
encrypted_premaster_secret = copy;
}
}
else
encrypted_premaster_secret = client_key_exchange;
/* Reject overly short RSA keys because we want to be sure that
* the buffer size makes it safe to iterate over the entire size
* of a premaster secret (SSL_MAX_MASTER_KEY_LENGTH). The actual
* expected size is larger due to RSA padding, but the bound is
* sufficient to be safe. */
rsa_size = RSA_size(rsa);
if (rsa_size < SSL_MAX_MASTER_KEY_LENGTH)
{
al = SSL_AD_DECRYPT_ERROR;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, SSL_R_DECRYPTION_FAILED);
goto f_err;
}
/* We must not leak whether a decryption failure occurs because
* of Bleichenbacher's attack on PKCS #1 v1.5 RSA padding (see
* RFC 2246, section 7.4.7.1). The code follows that advice of
* the TLS RFC and generates a random premaster secret for the
* case that the decrypt fails. See
* https://tools.ietf.org/html/rfc5246#section-7.4.7.1 */
if (RAND_pseudo_bytes(rand_premaster_secret,
sizeof(rand_premaster_secret)) <= 0)
goto err;
/* Allocate a buffer large enough for an RSA decryption. */
decrypt_buf = OPENSSL_malloc(rsa_size);
if (decrypt_buf == NULL)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, ERR_R_MALLOC_FAILURE);
goto err;
}
/* Decrypt with no padding. PKCS#1 padding will be removed as
* part of the timing-sensitive code below. */
if (!RSA_decrypt(rsa, &decrypt_len, decrypt_buf, rsa_size,
CBS_data(&encrypted_premaster_secret),
CBS_len(&encrypted_premaster_secret),
RSA_NO_PADDING))
{
goto err;
}
if (decrypt_len != rsa_size)
{
/* This should never happen, but do a check so we do not
* read uninitialized memory. */
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, ERR_R_INTERNAL_ERROR);
goto err;
}
/* Remove the PKCS#1 padding and adjust |decrypt_len| as
* appropriate. |good| will be 0xff if the premaster is
* acceptable and zero otherwise. */
good = constant_time_eq_int_8(
RSA_message_index_PKCS1_type_2(decrypt_buf, decrypt_len, &premaster_index), 1);
decrypt_len = decrypt_len - premaster_index;
/* decrypt_len should be SSL_MAX_MASTER_KEY_LENGTH. */
good &= constant_time_eq_8(decrypt_len, SSL_MAX_MASTER_KEY_LENGTH);
/* Copy over the unpadded premaster. Whatever the value of
* |decrypt_good_mask|, copy as if the premaster were the right
* length. It is important the memory access pattern be
* constant. */
premaster_secret = BUF_memdup(
decrypt_buf + (rsa_size - SSL_MAX_MASTER_KEY_LENGTH),
SSL_MAX_MASTER_KEY_LENGTH);
if (premaster_secret == NULL)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, ERR_R_MALLOC_FAILURE);
goto err;
}
OPENSSL_free(decrypt_buf);
decrypt_buf = NULL;
/* If the version in the decrypted pre-master secret is correct
* then version_good will be 0xff, otherwise it'll be zero. The
* Klima-Pokorny-Rosa extension of Bleichenbacher's attack
* (http://eprint.iacr.org/2003/052/) exploits the version
* number check as a "bad version oracle". Thus version checks
* are done in constant time and are treated like any other
* decryption error. */
good &= constant_time_eq_8(premaster_secret[0], (unsigned)(s->client_version>>8));
good &= constant_time_eq_8(premaster_secret[1], (unsigned)(s->client_version&0xff));
/* Now copy rand_premaster_secret over premaster_secret using
* decrypt_good_mask. */
for (j = 0; j < sizeof(rand_premaster_secret); j++)
{
premaster_secret[j] = constant_time_select_8(good, premaster_secret[j], rand_premaster_secret[j]);
}
premaster_secret_len = sizeof(rand_premaster_secret);
}
else if (alg_k & SSL_kEDH)
{
CBS dh_Yc;
int dh_len;
if (!CBS_get_u16_length_prefixed(&client_key_exchange, &dh_Yc) ||
CBS_len(&dh_Yc) == 0 ||
CBS_len(&client_key_exchange) != 0)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, SSL_R_DH_PUBLIC_VALUE_LENGTH_IS_WRONG);
al = SSL_R_DECODE_ERROR;
goto f_err;
}
if (s->s3->tmp.dh == NULL)
{
al=SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, SSL_R_MISSING_TMP_DH_KEY);
goto f_err;
}
dh_srvr=s->s3->tmp.dh;
pub = BN_bin2bn(CBS_data(&dh_Yc), CBS_len(&dh_Yc), NULL);
if (pub == NULL)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, SSL_R_BN_LIB);
goto err;
}
/* Allocate a buffer for the premaster secret. */
premaster_secret = OPENSSL_malloc(DH_size(dh_srvr));
if (premaster_secret == NULL)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, ERR_R_MALLOC_FAILURE);
goto err;
}
dh_len = DH_compute_key(premaster_secret, pub, dh_srvr);
if (dh_len <= 0)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, ERR_R_DH_LIB);
BN_clear_free(pub);
goto err;
}
DH_free(s->s3->tmp.dh);
s->s3->tmp.dh=NULL;
BN_clear_free(pub);
pub=NULL;
premaster_secret_len = dh_len;
}
else if (alg_k & SSL_kEECDH)
{
int field_size = 0, ecdh_len;
const EC_KEY *tkey;
const EC_GROUP *group;
const BIGNUM *priv_key;
CBS ecdh_Yc;
/* initialize structures for server's ECDH key pair */
if ((srvr_ecdh = EC_KEY_new()) == NULL)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, ERR_R_MALLOC_FAILURE);
goto err;
}
/* Use the ephermeral values we saved when generating the
* ServerKeyExchange msg. */
tkey = s->s3->tmp.ecdh;
group = EC_KEY_get0_group(tkey);
priv_key = EC_KEY_get0_private_key(tkey);
if (!EC_KEY_set_group(srvr_ecdh, group) ||
!EC_KEY_set_private_key(srvr_ecdh, priv_key))
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, ERR_R_EC_LIB);
goto err;
}
/* Let's get client's public key */
if ((clnt_ecpoint = EC_POINT_new(group)) == NULL)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, ERR_R_MALLOC_FAILURE);
goto err;
}
/* Get client's public key from encoded point
* in the ClientKeyExchange message.
*/
if (!CBS_get_u8_length_prefixed(&client_key_exchange, &ecdh_Yc) ||
CBS_len(&client_key_exchange) != 0)
{
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, SSL_R_DECODE_ERROR);
goto f_err;
}
if ((bn_ctx = BN_CTX_new()) == NULL)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, ERR_R_MALLOC_FAILURE);
goto err;
}
if (!EC_POINT_oct2point(group, clnt_ecpoint,
CBS_data(&ecdh_Yc), CBS_len(&ecdh_Yc), bn_ctx))
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, ERR_R_EC_LIB);
goto err;
}
/* Allocate a buffer for both the secret and the PSK. */
field_size = EC_GROUP_get_degree(group);
if (field_size <= 0)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, ERR_R_ECDH_LIB);
goto err;
}
ecdh_len = (field_size + 7) / 8;
premaster_secret = OPENSSL_malloc(ecdh_len);
if (premaster_secret == NULL)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, ERR_R_MALLOC_FAILURE);
goto err;
}
/* Compute the shared pre-master secret */
ecdh_len = ECDH_compute_key(premaster_secret,
ecdh_len, clnt_ecpoint, srvr_ecdh, NULL);
if (ecdh_len <= 0)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, ERR_R_ECDH_LIB);
goto err;
}
EVP_PKEY_free(clnt_pub_pkey);
clnt_pub_pkey = NULL;
EC_POINT_free(clnt_ecpoint);
clnt_ecpoint = NULL;
EC_KEY_free(srvr_ecdh);
srvr_ecdh = NULL;
BN_CTX_free(bn_ctx);
bn_ctx = NULL;
EC_KEY_free(s->s3->tmp.ecdh);
s->s3->tmp.ecdh = NULL;
premaster_secret_len = ecdh_len;
}
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, ssl3_get_client_key_exchange, ERR_R_MALLOC_FAILURE);
goto err;
}
memset(premaster_secret, 0, premaster_secret_len);
}
else
{
al=SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, 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;
if (!CBB_init(&new_premaster, 2 + psk_len + 2 + premaster_secret_len))
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_key_exchange, ERR_R_MALLOC_FAILURE);
goto err;
}
if (!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, ssl3_get_client_key_exchange, ERR_R_INTERNAL_ERROR);
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 */
s->session->master_key_length = s->method->ssl3_enc
->generate_master_secret(s,
s->session->master_key, premaster_secret, premaster_secret_len);
if (s->session->master_key_length == 0)
goto err;
s->session->extended_master_secret = s->s3->tmp.extended_master_secret;
OPENSSL_cleanse(premaster_secret, premaster_secret_len);
OPENSSL_free(premaster_secret);
return 1;
f_err:
ssl3_send_alert(s,SSL3_AL_FATAL,al);
err:
if (premaster_secret)
{
if (premaster_secret_len)
OPENSSL_cleanse(premaster_secret, premaster_secret_len);
OPENSSL_free(premaster_secret);
}
if (decrypt_buf)
OPENSSL_free(decrypt_buf);
EVP_PKEY_free(clnt_pub_pkey);
EC_POINT_free(clnt_ecpoint);
if (srvr_ecdh != NULL)
EC_KEY_free(srvr_ecdh);
BN_CTX_free(bn_ctx);
return(-1);
}
int ssl3_get_cert_verify(SSL *s)
{
int al,ok,ret=0;
long n;
CBS certificate_verify, signature;
X509 *peer = s->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)
{
if (s->s3->handshake_buffer && !ssl3_digest_cached_records(s, free_handshake_buffer))
return -1;
return 1;
}
n=s->method->ssl_get_message(s,
SSL3_ST_SR_CERT_VRFY_A,
SSL3_ST_SR_CERT_VRFY_B,
SSL3_MT_CERTIFICATE_VERIFY,
SSL3_RT_MAX_PLAIN_LENGTH,
SSL_GET_MESSAGE_DONT_HASH_MESSAGE,
&ok);
if (!ok)
return (int)n;
/* Filter out unsupported certificate types. */
pkey = X509_get_pubkey(peer);
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, ssl3_get_cert_verify, SSL_R_PEER_ERROR_UNSUPPORTED_CERTIFICATE_TYPE);
goto f_err;
}
CBS_init(&certificate_verify, s->init_msg, n);
/* Determine the digest type if needbe. */
if (SSL_USE_SIGALGS(s))
{
if (!tls12_check_peer_sigalg(&md, &al, s, &certificate_verify, pkey))
goto f_err;
}
/* Compute the digest. */
if (!ssl3_cert_verify_hash(s, digest, &digest_length, &md, pkey))
goto err;
/* The handshake buffer is no longer necessary, and we may hash the
* current message.*/
if (s->s3->handshake_buffer && !ssl3_digest_cached_records(s, free_handshake_buffer))
goto err;
ssl3_hash_current_message(s);
/* 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, ssl3_get_cert_verify, SSL_R_DECODE_ERROR);
goto f_err;
}
pctx = EVP_PKEY_CTX_new(pkey, NULL);
if (pctx == NULL)
goto err;
if (!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))
{
al = SSL_AD_DECRYPT_ERROR;
OPENSSL_PUT_ERROR(SSL, ssl3_get_cert_verify, SSL_R_BAD_SIGNATURE);
goto f_err;
}
ret = 1;
if (0)
{
f_err:
ssl3_send_alert(s,SSL3_AL_FATAL,al);
}
err:
EVP_PKEY_CTX_free(pctx);
EVP_PKEY_free(pkey);
return(ret);
}
int ssl3_get_client_certificate(SSL *s)
{
int i,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;
n=s->method->ssl_get_message(s,
SSL3_ST_SR_CERT_A,
SSL3_ST_SR_CERT_B,
-1,
s->max_cert_list,
SSL_GET_MESSAGE_HASH_MESSAGE,
&ok);
if (!ok) return((int)n);
if (s->s3->tmp.message_type == SSL3_MT_CLIENT_KEY_EXCHANGE)
{
if ( (s->verify_mode & SSL_VERIFY_PEER) &&
(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT))
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_certificate, SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE);
al=SSL_AD_HANDSHAKE_FAILURE;
goto f_err;
}
/* If tls asked for a client cert, the client must return a 0 list */
if ((s->version > SSL3_VERSION) && s->s3->tmp.cert_request)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_certificate, SSL_R_TLS_PEER_DID_NOT_RESPOND_WITH_CERTIFICATE_LIST);
al=SSL_AD_UNEXPECTED_MESSAGE;
goto f_err;
}
s->s3->tmp.reuse_message=1;
return(1);
}
if (s->s3->tmp.message_type != SSL3_MT_CERTIFICATE)
{
al=SSL_AD_UNEXPECTED_MESSAGE;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_certificate, SSL_R_WRONG_MESSAGE_TYPE);
goto f_err;
}
CBS_init(&certificate_msg, s->init_msg, n);
if ((sk=sk_X509_new_null()) == NULL)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_certificate, 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, ssl3_get_client_certificate, 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, ssl3_get_client_certificate, SSL_R_DECODE_ERROR);
goto f_err;
}
if (is_first_certificate && s->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(s->session->peer_sha256, &sha256);
s->session->peer_sha256_valid = 1;
}
is_first_certificate = 0;
data = CBS_data(&certificate);
x = d2i_X509(NULL, &data, CBS_len(&certificate));
if (x == NULL)
{
al = SSL_AD_BAD_CERTIFICATE;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_certificate, ERR_R_ASN1_LIB);
goto f_err;
}
if (!CBS_skip(&certificate, data - CBS_data(&certificate)))
{
al = SSL_AD_INTERNAL_ERROR;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_certificate, ERR_R_INTERNAL_ERROR);
goto f_err;
}
if (CBS_len(&certificate) != 0)
{
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_certificate, SSL_R_CERT_LENGTH_MISMATCH);
goto f_err;
}
if (!sk_X509_push(sk,x))
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_certificate, ERR_R_MALLOC_FAILURE);
goto err;
}
x = NULL;
}
if (sk_X509_num(sk) <= 0)
{
/* TLS does not mind 0 certs returned */
if (s->version == SSL3_VERSION)
{
al=SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_certificate, SSL_R_NO_CERTIFICATES_RETURNED);
goto f_err;
}
/* Fail for TLS only if we required a certificate */
else if ((s->verify_mode & SSL_VERIFY_PEER) &&
(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT))
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_certificate, SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE);
al=SSL_AD_HANDSHAKE_FAILURE;
goto f_err;
}
/* No client certificate so digest cached records */
if (s->s3->handshake_buffer && !ssl3_digest_cached_records(s, free_handshake_buffer))
{
al=SSL_AD_INTERNAL_ERROR;
goto f_err;
}
}
else
{
i=ssl_verify_cert_chain(s,sk);
if (i <= 0)
{
al=ssl_verify_alarm_type(s->verify_result);
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_certificate, SSL_R_CERTIFICATE_VERIFY_FAILED);
goto f_err;
}
}
if (s->session->peer != NULL) /* This should not be needed */
X509_free(s->session->peer);
s->session->peer=sk_X509_shift(sk);
s->session->verify_result = s->verify_result;
/* With the current implementation, sess_cert will always be NULL
* when we arrive here. */
if (s->session->sess_cert == NULL)
{
s->session->sess_cert = ssl_sess_cert_new();
if (s->session->sess_cert == NULL)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_client_certificate, ERR_R_MALLOC_FAILURE);
goto err;
}
}
if (s->session->sess_cert->cert_chain != NULL)
sk_X509_pop_free(s->session->sess_cert->cert_chain, X509_free);
s->session->sess_cert->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(s,SSL3_AL_FATAL,al);
}
err:
if (x != NULL) X509_free(x);
if (sk != NULL) sk_X509_pop_free(sk,X509_free);
return(ret);
}
int ssl3_send_server_certificate(SSL *s)
{
CERT_PKEY *cpk;
if (s->state == SSL3_ST_SW_CERT_A)
{
cpk=ssl_get_server_send_pkey(s);
if (cpk == NULL)
{
OPENSSL_PUT_ERROR(SSL, ssl3_send_server_certificate, ERR_R_INTERNAL_ERROR);
return(0);
}
ssl3_output_cert_chain(s,cpk);
s->state=SSL3_ST_SW_CERT_B;
}
/* SSL3_ST_SW_CERT_B */
return ssl_do_write(s);
}
/* send a new session ticket (not necessarily for a new session) */
int ssl3_send_new_session_ticket(SSL *s)
{
if (s->state == SSL3_ST_SW_SESSION_TICKET_A)
{
uint8_t *session;
size_t session_len;
uint8_t *p, *macstart;
int len;
unsigned int hlen;
EVP_CIPHER_CTX ctx;
HMAC_CTX hctx;
SSL_CTX *tctx = s->initial_ctx;
unsigned char iv[EVP_MAX_IV_LENGTH];
unsigned char 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(s->session, &session,
&session_len))
{
return -1;
}
/* If the session is too long, emit a dummy value rather than
* abort the connection. */
if (session_len > 0xFFFF - max_ticket_overhead)
{
const char kTicketPlaceholder[] = "TICKET TOO LARGE";
size_t placeholder_len = strlen(kTicketPlaceholder);
OPENSSL_free(session);
p = ssl_handshake_start(s);
/* 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(s);
ssl_set_handshake_header(s, SSL3_MT_NEWSESSION_TICKET, len);
s->state = SSL3_ST_SW_SESSION_TICKET_B;
return ssl_do_write(s);
}
/* 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(s->init_buf,
SSL_HM_HEADER_LENGTH(s) + 6 +
max_ticket_overhead + session_len))
{
OPENSSL_free(session);
return -1;
}
p = ssl_handshake_start(s);
EVP_CIPHER_CTX_init(&ctx);
HMAC_CTX_init(&hctx);
/* 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(s, key_name, iv, &ctx,
&hctx, 1) < 0)
{
OPENSSL_free(session);
return -1;
}
}
else
{
RAND_pseudo_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);
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(s->hit ? 0 : s->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 */
EVP_EncryptUpdate(&ctx, p, &len, session, session_len);
p += len;
EVP_EncryptFinal_ex(&ctx, p, &len);
p += len;
EVP_CIPHER_CTX_cleanup(&ctx);
HMAC_Update(&hctx, macstart, p - macstart);
HMAC_Final(&hctx, p, &hlen);
HMAC_CTX_cleanup(&hctx);
p += hlen;
/* Now write out lengths: p points to end of data written */
/* Total length */
len = p - ssl_handshake_start(s);
ssl_set_handshake_header(s, SSL3_MT_NEWSESSION_TICKET, len);
/* Skip ticket lifetime hint */
p = ssl_handshake_start(s) + 4;
s2n(len - 6, p);
s->state=SSL3_ST_SW_SESSION_TICKET_B;
OPENSSL_free(session);
}
/* SSL3_ST_SW_SESSION_TICKET_B */
return ssl_do_write(s);
}
#if 0
int ssl3_send_cert_status(SSL *s)
{
if (s->state == SSL3_ST_SW_CERT_STATUS_A)
{
unsigned char *p;
/* Grow buffer if need be: the length calculation is as
* follows 1 (message type) + 3 (message length) +
* 1 (ocsp response type) + 3 (ocsp response length)
* + (ocsp response)
*/
if (!BUF_MEM_grow(s->init_buf, 8 + s->tlsext_ocsp_resplen))
return -1;
p=(unsigned char *)s->init_buf->data;
/* do the header */
*(p++)=SSL3_MT_CERTIFICATE_STATUS;
/* message length */
l2n3(s->tlsext_ocsp_resplen + 4, p);
/* status type */
*(p++)= s->tlsext_status_type;
/* length of OCSP response */
l2n3(s->tlsext_ocsp_resplen, p);
/* actual response */
memcpy(p, s->tlsext_ocsp_resp, s->tlsext_ocsp_resplen);
/* number of bytes to write */
s->init_num = 8 + s->tlsext_ocsp_resplen;
s->state=SSL3_ST_SW_CERT_STATUS_B;
s->init_off = 0;
}
/* SSL3_ST_SW_CERT_STATUS_B */
return(ssl3_do_write(s,SSL3_RT_HANDSHAKE));
}
#endif
/* ssl3_get_next_proto reads a Next Protocol Negotiation handshake message. It
* sets the next_proto member in s if found */
int ssl3_get_next_proto(SSL *s)
{
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 (!s->s3->next_proto_neg_seen)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_next_proto, SSL_R_GOT_NEXT_PROTO_WITHOUT_EXTENSION);
return -1;
}
n=s->method->ssl_get_message(s,
SSL3_ST_SR_NEXT_PROTO_A,
SSL3_ST_SR_NEXT_PROTO_B,
SSL3_MT_NEXT_PROTO,
514, /* See the payload format below */
SSL_GET_MESSAGE_HASH_MESSAGE,
&ok);
if (!ok)
return((int)n);
/* s->state doesn't reflect whether ChangeCipherSpec has been received
* in this handshake, but s->s3->change_cipher_spec does (will be reset
* by ssl3_get_finished).
* TODO(davidben): Is this check now redundant with
* SSL3_FLAGS_EXPECT_CCS? */
if (!s->s3->change_cipher_spec)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_next_proto, SSL_R_GOT_NEXT_PROTO_BEFORE_A_CCS);
return -1;
}
CBS_init(&next_protocol, s->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)
return 0;
if (!CBS_stow(&selected_protocol,
&s->next_proto_negotiated,
&s->next_proto_negotiated_len))
return 0;
return 1;
}
/* ssl3_get_channel_id reads and verifies a ClientID handshake message. */
int ssl3_get_channel_id(SSL *s)
{
int ret = -1, ok;
long n;
EVP_MD_CTX md_ctx;
uint8_t channel_id_hash[SHA256_DIGEST_LENGTH];
unsigned int channel_id_hash_len;
const uint8_t *p;
uint16_t extension_type, expected_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 = s->method->ssl_get_message(s,
SSL3_ST_SR_CHANNEL_ID_A,
SSL3_ST_SR_CHANNEL_ID_B,
SSL3_MT_ENCRYPTED_EXTENSIONS,
2 + 2 + TLSEXT_CHANNEL_ID_SIZE,
SSL_GET_MESSAGE_DONT_HASH_MESSAGE,
&ok);
if (!ok)
return((int)n);
/* Before incorporating the EncryptedExtensions message to the
* handshake hash, compute the hash that should have been signed. */
channel_id_hash_len = sizeof(channel_id_hash);
EVP_MD_CTX_init(&md_ctx);
if (!EVP_DigestInit_ex(&md_ctx, EVP_sha256(), NULL) ||
!tls1_channel_id_hash(&md_ctx, s) ||
!EVP_DigestFinal(&md_ctx, channel_id_hash, &channel_id_hash_len))
{
EVP_MD_CTX_cleanup(&md_ctx);
return -1;
}
EVP_MD_CTX_cleanup(&md_ctx);
assert(channel_id_hash_len == SHA256_DIGEST_LENGTH);
ssl3_hash_current_message(s);
/* s->state doesn't reflect whether ChangeCipherSpec has been received
* in this handshake, but s->s3->change_cipher_spec does (will be reset
* by ssl3_get_finished).
* TODO(davidben): Is this check now redundant with
* SSL3_FLAGS_EXPECT_CCS? */
if (!s->s3->change_cipher_spec)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_channel_id, SSL_R_GOT_CHANNEL_ID_BEFORE_A_CCS);
return -1;
}
CBS_init(&encrypted_extensions, s->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];
*/
expected_extension_type = TLSEXT_TYPE_channel_id;
if (s->s3->tlsext_channel_id_new)
expected_extension_type = TLSEXT_TYPE_channel_id_new;
if (!CBS_get_u16(&encrypted_extensions, &extension_type) ||
!CBS_get_u16_length_prefixed(&encrypted_extensions, &extension) ||
CBS_len(&encrypted_extensions) != 0 ||
extension_type != expected_extension_type ||
CBS_len(&extension) != TLSEXT_CHANNEL_ID_SIZE)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_channel_id, SSL_R_INVALID_MESSAGE);
return -1;
}
p256 = EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1);
if (!p256)
{
OPENSSL_PUT_ERROR(SSL, ssl3_get_channel_id, SSL_R_NO_P256_SUPPORT);
return -1;
}
BN_init(&x);
BN_init(&y);
sig.r = BN_new();
sig.s = BN_new();
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, ssl3_get_channel_id, SSL_R_CHANNEL_ID_SIGNATURE_INVALID);
s->s3->tlsext_channel_id_valid = 0;
goto err;
}
memcpy(s->s3->tlsext_channel_id, p, 64);
ret = 1;
err:
BN_free(&x);
BN_free(&y);
BN_free(sig.r);
BN_free(sig.s);
if (key)
EC_KEY_free(key);
if (point)
EC_POINT_free(point);
if (p256)
EC_GROUP_free(p256);
return ret;
}
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