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boringssl/ssl/s3_srvr.c
David Benjamin 894f48c6b3 Only read 5 bytes (record header length) in sniffing for V2ClientHello. 
This guarantees that we never read beyond the first record, even if the
first record is empty. Between removing SSL_set_read_ahead and DTLS
enforcing record boundaries, this means the buffer need never memmove
data.

The memmove isn't really much of a burden and we can probably just put
SSL_set_read_ahead back after the cleanup if desired. But while the
non-existant read_ahead is off, we should avoid reading more than needed.

(Also the current memmove logic is completely wrong for TLS. Checking
align != 0 doesn't make sense. The real reason to memmove is that the
next record may still be full size. So now line 209 of s3_pkt.c should
*actually* be unreachable.)

SSL_R_HTTPS_PROXY_REQUEST detection is now slightly less accurate, but
OpenSSL was already not parsing HTTP completely. We could asynchronously
read the extra 3 bytes once the first 5 match, but that seems
unnecessary. (Shall we just get rid of all these HTTP detectors? The
only consumer of those error codes is some diagnostics logic.)

BUG=468889

Change-Id: Ie3bf148ae7274795e1d048d78282d1d8063278ea
Reviewed-on: https://boringssl-review.googlesource.com/5714
Reviewed-by: Adam Langley <agl@google.com>
2015-08-17 20:58:09 +00:00

2551 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. */
#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/err.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 "internal.h"
#include "../crypto/internal.h"
#include "../crypto/dh/internal.h"
int ssl3_accept(SSL *s) {
BUF_MEM *buf = NULL;
uint32_t alg_a;
void (*cb)(const SSL *ssl, int type, int val) = NULL;
int ret = -1;
int new_state, state, skip = 0;
assert(s->handshake_func == ssl3_accept);
assert(s->server);
assert(!SSL_IS_DTLS(s));
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;
}
s->in_handshake++;
if (s->cert == NULL) {
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_CERTIFICATE_SET);
return -1;
}
for (;;) {
state = s->state;
switch (s->state) {
case SSL_ST_ACCEPT:
if (cb != NULL) {
cb(s, SSL_CB_HANDSHAKE_START, 1);
}
if (s->init_buf == NULL) {
buf = BUF_MEM_new();
if (!buf || !BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
ret = -1;
goto end;
}
s->init_buf = buf;
buf = NULL;
}
s->init_num = 0;
/* Enable a write buffer. This groups handshake messages within a flight
* into a single write. */
if (!ssl_init_wbio_buffer(s, 1)) {
ret = -1;
goto end;
}
if (!ssl3_init_handshake_buffer(s)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
ret = -1;
goto end;
}
if (!s->s3->have_version) {
s->state = SSL3_ST_SR_INITIAL_BYTES;
} else {
s->state = SSL3_ST_SR_CLNT_HELLO_A;
}
break;
case SSL3_ST_SR_INITIAL_BYTES:
ret = ssl3_get_initial_bytes(s);
if (ret <= 0) {
goto end;
}
/* ssl3_get_initial_bytes sets s->state to one of
* SSL3_ST_SR_V2_CLIENT_HELLO or SSL3_ST_SR_CLNT_HELLO_A on success. */
break;
case SSL3_ST_SR_V2_CLIENT_HELLO:
ret = ssl3_get_v2_client_hello(s);
if (ret <= 0) {
goto end;
}
s->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:
s->shutdown = 0;
ret = ssl3_get_client_hello(s);
if (ret <= 0) {
goto end;
}
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:
case SSL3_ST_SW_KEY_EXCH_C:
case SSL3_ST_SW_KEY_EXCH_D:
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 (s->s3->tmp.cert_request) {
ret = ssl3_send_certificate_request(s);
if (ret <= 0) {
goto end;
}
} else {
skip = 1;
}
s->state = SSL3_ST_SW_SRVR_DONE_A;
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) {
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;
case SSL3_ST_SW_CHANGE_A:
case SSL3_ST_SW_CHANGE_B:
s->session->cipher = s->s3->tmp.new_cipher;
if (!s->enc_method->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->enc_method->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->enc_method->server_finished_label,
s->enc_method->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->ctx->retain_only_sha256_of_client_certs) {
X509_free(s->session->peer);
s->session->peer = NULL;
}
s->s3->initial_handshake_complete = 1;
ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
if (cb != NULL) {
cb(s, SSL_CB_HANDSHAKE_DONE, 1);
}
ret = 1;
goto end;
default:
OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_STATE);
ret = -1;
goto end;
}
if (!s->s3->tmp.reuse_message && !skip && 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:
s->in_handshake--;
BUF_MEM_free(buf);
if (cb != NULL) {
cb(s, SSL_CB_ACCEPT_EXIT, ret);
}
return ret;
}
int ssl3_get_initial_bytes(SSL *s) {
/* Read the first 5 bytes, the size of the TLS record header. This is
* sufficient to detect a V2ClientHello and ensures that we never read beyond
* the first record. */
int ret = ssl3_read_n(s, SSL3_RT_HEADER_LENGTH, 0 /* new packet */);
if (ret <= 0) {
return ret;
}
assert(s->packet_length == SSL3_RT_HEADER_LENGTH);
const uint8_t *p = s->packet;
/* Some dedicated error codes for protocol mixups should the application wish
* to interpret them differently. (These do not overlap with ClientHello or
* V2ClientHello.) */
if (strncmp("GET ", (const char *)p, 4) == 0 ||
strncmp("POST ", (const char *)p, 5) == 0 ||
strncmp("HEAD ", (const char *)p, 5) == 0 ||
strncmp("PUT ", (const char *)p, 4) == 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_HTTP_REQUEST);
return -1;
}
if (strncmp("CONNE", (const char *)p, 5) == 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_HTTPS_PROXY_REQUEST);
return -1;
}
/* Determine if this is a V2ClientHello. */
if ((p[0] & 0x80) && p[2] == SSL2_MT_CLIENT_HELLO &&
p[3] >= SSL3_VERSION_MAJOR) {
/* This is a V2ClientHello. */
s->state = SSL3_ST_SR_V2_CLIENT_HELLO;
return 1;
}
/* Fall through to the standard logic. Unread what's been read to re-process
* it. */
assert(s->rstate == SSL_ST_READ_HEADER);
assert(s->s3->rbuf.offset >= SSL3_RT_HEADER_LENGTH);
s->s3->rbuf.offset -= SSL3_RT_HEADER_LENGTH;
s->s3->rbuf.left += SSL3_RT_HEADER_LENGTH;
s->packet = NULL;
s->packet_length = 0;
s->state = SSL3_ST_SR_CLNT_HELLO_A;
return 1;
}
int ssl3_get_v2_client_hello(SSL *s) {
const uint8_t *p;
int ret;
CBS v2_client_hello, cipher_specs, session_id, challenge;
size_t msg_length, rand_len, len;
uint8_t msg_type;
uint16_t version, cipher_spec_length, session_id_length, challenge_length;
CBB client_hello, hello_body, cipher_suites;
uint8_t random[SSL3_RANDOM_SIZE];
/* Determine the length of the V2ClientHello. */
assert(s->packet_length >= SSL3_RT_HEADER_LENGTH);
p = (const uint8_t *)s->packet;
msg_length = ((p[0] & 0x7f) << 8) | p[1];
if (msg_length > (1024 * 4)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_RECORD_TOO_LARGE);
return -1;
}
if (msg_length < SSL3_RT_HEADER_LENGTH - 2) {
/* Reject lengths that are too short early. We have already read
* |SSL3_RT_HEADER_LENGTH| bytes, so we should not attempt to process an
* (invalid) V2ClientHello which would be shorter than that. */
OPENSSL_PUT_ERROR(SSL, SSL_R_RECORD_LENGTH_MISMATCH);
return -1;
}
/* Read the remainder of the V2ClientHello. We have previously read
* |SSL3_RT_HEADER_LENGTH| bytes in ssl3_get_initial_bytes. */
ret = ssl3_read_n(s, msg_length - (SSL3_RT_HEADER_LENGTH - 2),
1 /* extend */);
if (ret <= 0) {
return ret;
}
assert(s->packet_length == msg_length + 2);
CBS_init(&v2_client_hello, (const uint8_t *)s->packet + 2,
msg_length);
/* The V2ClientHello without the length is incorporated into the handshake
* hash. */
if (!ssl3_update_handshake_hash(s, CBS_data(&v2_client_hello),
CBS_len(&v2_client_hello))) {
return -1;
}
if (s->msg_callback) {
s->msg_callback(0, SSL2_VERSION, 0, CBS_data(&v2_client_hello),
CBS_len(&v2_client_hello), s, s->msg_callback_arg);
}
if (!CBS_get_u8(&v2_client_hello, &msg_type) ||
!CBS_get_u16(&v2_client_hello, &version) ||
!CBS_get_u16(&v2_client_hello, &cipher_spec_length) ||
!CBS_get_u16(&v2_client_hello, &session_id_length) ||
!CBS_get_u16(&v2_client_hello, &challenge_length) ||
!CBS_get_bytes(&v2_client_hello, &cipher_specs, cipher_spec_length) ||
!CBS_get_bytes(&v2_client_hello, &session_id, session_id_length) ||
!CBS_get_bytes(&v2_client_hello, &challenge, challenge_length) ||
CBS_len(&v2_client_hello) != 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
return -1;
}
/* msg_type has already been checked. */
assert(msg_type == SSL2_MT_CLIENT_HELLO);
/* The client_random is the V2ClientHello challenge. Truncate or
* left-pad with zeros as needed. */
memset(random, 0, SSL3_RANDOM_SIZE);
rand_len = CBS_len(&challenge);
if (rand_len > SSL3_RANDOM_SIZE) {
rand_len = SSL3_RANDOM_SIZE;
}
memcpy(random + (SSL3_RANDOM_SIZE - rand_len), CBS_data(&challenge),
rand_len);
/* Write out an equivalent SSLv3 ClientHello. */
CBB_zero(&client_hello);
if (!CBB_init_fixed(&client_hello, (uint8_t *)s->init_buf->data,
s->init_buf->max) ||
!CBB_add_u8(&client_hello, SSL3_MT_CLIENT_HELLO) ||
!CBB_add_u24_length_prefixed(&client_hello, &hello_body) ||
!CBB_add_u16(&hello_body, version) ||
!CBB_add_bytes(&hello_body, random, SSL3_RANDOM_SIZE) ||
/* No session id. */
!CBB_add_u8(&hello_body, 0) ||
!CBB_add_u16_length_prefixed(&hello_body, &cipher_suites)) {
CBB_cleanup(&client_hello);
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
return -1;
}
/* Copy the cipher suites. */
while (CBS_len(&cipher_specs) > 0) {
uint32_t cipher_spec;
if (!CBS_get_u24(&cipher_specs, &cipher_spec)) {
CBB_cleanup(&client_hello);
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
return -1;
}
/* Skip SSLv2 ciphers. */
if ((cipher_spec & 0xff0000) != 0) {
continue;
}
if (!CBB_add_u16(&cipher_suites, cipher_spec)) {
CBB_cleanup(&client_hello);
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return -1;
}
}
/* Add the null compression scheme and finish. */
if (!CBB_add_u8(&hello_body, 1) || !CBB_add_u8(&hello_body, 0) ||
!CBB_finish(&client_hello, NULL, &len)) {
CBB_cleanup(&client_hello);
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return -1;
}
/* Mark the message for "re"-use by the version-specific method. */
s->s3->tmp.reuse_message = 1;
s->s3->tmp.message_type = SSL3_MT_CLIENT_HELLO;
/* The handshake message header is 4 bytes. */
s->s3->tmp.message_size = len - 4;
/* The V2ClientHello was processed, so it may be released now. */
if (s->s3->rbuf.left == 0) {
ssl3_release_read_buffer(s);
}
return 1;
}
int ssl3_get_client_hello(SSL *s) {
int ok, al = SSL_AD_INTERNAL_ERROR, ret = -1;
long n;
const SSL_CIPHER *c;
STACK_OF(SSL_CIPHER) *ciphers = NULL;
struct ssl_early_callback_ctx early_ctx;
CBS client_hello;
uint16_t client_version;
CBS client_random, session_id, cipher_suites, compression_methods;
SSL_SESSION *session = NULL;
/* We do this so that we will respond with our native type. If we are TLSv1
* and we get SSLv3, we will respond with TLSv1, This down switching should
* be handled by a different method. If we are SSLv3, we will respond with
* SSLv3, even if prompted with TLSv1. */
switch (s->state) {
case SSL3_ST_SR_CLNT_HELLO_A:
case SSL3_ST_SR_CLNT_HELLO_B:
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_hash_message, &ok);
if (!ok) {
return n;
}
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, SSL_R_CLIENTHELLO_PARSE_FAILED);
goto f_err;
}
if (s->state == SSL3_ST_SR_CLNT_HELLO_C &&
s->ctx->select_certificate_cb != NULL) {
s->state = SSL3_ST_SR_CLNT_HELLO_D;
switch (s->ctx->select_certificate_cb(&early_ctx)) {
case 0:
s->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 */;
}
}
s->state = SSL3_ST_SR_CLNT_HELLO_D;
break;
default:
OPENSSL_PUT_ERROR(SSL, 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, 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;
/* Load the client random. */
memcpy(s->s3->client_random, CBS_data(&client_random), SSL3_RANDOM_SIZE);
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, SSL_R_DECODE_ERROR);
goto f_err;
}
}
/* Note: This codepath may run twice if |ssl_get_prev_session| completes
* asynchronously.
*
* TODO(davidben): Clean up the order of events around ClientHello
* processing. */
if (!s->s3->have_version) {
/* Select version to use */
uint16_t version = ssl3_get_mutual_version(s, client_version);
if (version == 0) {
OPENSSL_PUT_ERROR(SSL, SSL_R_UNSUPPORTED_PROTOCOL);
s->version = s->client_version;
al = SSL_AD_PROTOCOL_VERSION;
goto f_err;
}
s->version = version;
s->enc_method = ssl3_get_enc_method(version);
assert(s->enc_method != NULL);
/* At this point, the connection's version is known and |s->version| is
* fixed. Begin enforcing the record-layer version. */
s->s3->have_version = 1;
} else if (SSL_IS_DTLS(s) ? (s->client_version > s->version)
: (s->client_version < s->version)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_WRONG_VERSION_NUMBER);
al = SSL_AD_PROTOCOL_VERSION;
goto f_err;
}
s->hit = 0;
int send_new_ticket = 0;
switch (ssl_get_prev_session(s, &session, &send_new_ticket, &early_ctx)) {
case ssl_session_success:
break;
case ssl_session_error:
goto err;
case ssl_session_retry:
s->rwstate = SSL_PENDING_SESSION;
goto err;
}
s->tlsext_ticket_expected = send_new_ticket;
/* The EMS state is needed when making the resumption decision, but
* extensions are not normally parsed until later. This detects the EMS
* extension for the resumption decision and it's checked against the result
* of the normal parse later in this function. */
const uint8_t *ems_data;
size_t ems_len;
int have_extended_master_secret =
s->version != SSL3_VERSION &&
SSL_early_callback_ctx_extension_get(&early_ctx,
TLSEXT_TYPE_extended_master_secret,
&ems_data, &ems_len) &&
ems_len == 0;
if (session != NULL) {
if (session->extended_master_secret &&
!have_extended_master_secret) {
/* A ClientHello without EMS that attempts to resume a session with EMS
* is fatal to the connection. */
al = SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, SSL_R_RESUMED_EMS_SESSION_WITHOUT_EMS_EXTENSION);
goto f_err;
}
s->hit =
/* Only resume if the session's version matches the negotiated version:
* most clients do not accept a mismatch. */
s->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 (s->hit) {
/* Use the new session. */
SSL_SESSION_free(s->session);
s->session = session;
session = NULL;
s->verify_result = s->session->verify_result;
} else if (!ssl_get_new_session(s, 1)) {
goto err;
}
if (s->ctx->dos_protection_cb != NULL && s->ctx->dos_protection_cb(&early_ctx) == 0) {
/* Connection rejected for DOS reasons. */
al = SSL_AD_ACCESS_DENIED;
OPENSSL_PUT_ERROR(SSL, SSL_R_CONNECTION_REJECTED);
goto f_err;
}
if (!CBS_get_u16_length_prefixed(&client_hello, &cipher_suites) ||
CBS_len(&cipher_suites) == 0 ||
CBS_len(&cipher_suites) % 2 != 0 ||
!CBS_get_u8_length_prefixed(&client_hello, &compression_methods) ||
CBS_len(&compression_methods) == 0) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
goto f_err;
}
ciphers = ssl_bytes_to_cipher_list(s, &cipher_suites);
if (ciphers == NULL) {
goto err;
}
/* If it is a hit, check that the cipher is in the list. */
if (s->hit) {
size_t j;
int found_cipher = 0;
uint32_t 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, SSL_R_REQUIRED_CIPHER_MISSING);
goto f_err;
}
}
/* Only null compression is supported. */
if (memchr(CBS_data(&compression_methods), 0,
CBS_len(&compression_methods)) == NULL) {
al = SSL_AD_ILLEGAL_PARAMETER;
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_COMPRESSION_SPECIFIED);
goto f_err;
}
/* TLS extensions. */
if (s->version >= SSL3_VERSION &&
!ssl_parse_clienthello_tlsext(s, &client_hello)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_PARSE_TLSEXT);
goto err;
}
/* There should be nothing left over in the record. */
if (CBS_len(&client_hello) != 0) {
/* wrong packet length */
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_BAD_PACKET_LENGTH);
goto f_err;
}
if (have_extended_master_secret != s->s3->tmp.extended_master_secret) {
al = SSL_AD_INTERNAL_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_EMS_STATE_INCONSISTENT);
goto f_err;
}
/* Given ciphers and SSL_get_ciphers, we must pick a cipher */
if (!s->hit) {
if (ciphers == NULL) {
al = SSL_AD_ILLEGAL_PARAMETER;
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_CIPHERS_PASSED);
goto f_err;
}
/* Let cert callback update server certificates if required */
if (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, 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, SSL_R_NO_SHARED_CIPHER);
goto f_err;
}
s->s3->tmp.new_cipher = c;
/* Determine whether to request a client certificate. */
s->s3->tmp.cert_request = !!(s->verify_mode & SSL_VERIFY_PEER);
/* Only request a certificate if Channel ID isn't negotiated. */
if ((s->verify_mode & SSL_VERIFY_PEER_IF_NO_OBC) &&
s->s3->tlsext_channel_id_valid) {
s->s3->tmp.cert_request = 0;
}
/* Plain PSK forbids Certificate and CertificateRequest. */
if (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK) {
s->s3->tmp.cert_request = 0;
}
} else {
/* Session-id reuse */
s->s3->tmp.new_cipher = s->session->cipher;
s->s3->tmp.cert_request = 0;
}
/* Now that the cipher is known, initialize the handshake hash. */
if (!ssl3_init_handshake_hash(s)) {
goto f_err;
}
/* In TLS 1.2, client authentication requires hashing the handshake transcript
* under a different hash. Otherwise, release the handshake buffer. */
if (!SSL_USE_SIGALGS(s) || !s->s3->tmp.cert_request) {
ssl3_free_handshake_buffer(s);
}
/* 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:
sk_SSL_CIPHER_free(ciphers);
SSL_SESSION_free(session);
return ret;
}
int ssl3_send_server_hello(SSL *s) {
uint8_t *buf;
uint8_t *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_kECDHE) == 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->session->original_handshake_hash_len == 0) {
s->s3->tlsext_channel_id_valid = 0;
}
buf = (uint8_t *)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 */
if (!ssl_fill_hello_random(s->s3->server_random, SSL3_RANDOM_SIZE,
1 /* server */)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return -1;
}
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, ERR_R_INTERNAL_ERROR);
return -1;
}
*(p++) = sl;
memcpy(p, s->session->session_id, sl);
p += sl;
/* put the cipher */
s2n(ssl_cipher_get_value(s->s3->tmp.new_cipher), p);
/* put the compression method */
*(p++) = 0;
p = ssl_add_serverhello_tlsext(s, p, buf + SSL3_RT_MAX_PLAIN_LENGTH);
if (p == NULL) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return -1;
}
/* do the header */
l = (p - d);
if (!ssl_set_handshake_header(s, SSL3_MT_SERVER_HELLO, l)) {
return -1;
}
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) {
if (!ssl_set_handshake_header(s, SSL3_MT_SERVER_DONE, 0)) {
return -1;
}
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) {
DH *dh = NULL, *dhp;
EC_KEY *ecdh = NULL;
uint8_t *encodedPoint = NULL;
int encodedlen = 0;
uint16_t curve_id = 0;
BN_CTX *bn_ctx = NULL;
const char *psk_identity_hint = NULL;
size_t psk_identity_hint_len = 0;
size_t sig_len;
size_t max_sig_len;
uint8_t *p, *d;
int al, i;
uint32_t alg_k;
uint32_t alg_a;
int n;
CERT *cert;
BIGNUM *r[4];
int nr[4];
BUF_MEM *buf;
EVP_MD_CTX md_ctx;
if (ssl_cipher_has_server_public_key(s->s3->tmp.new_cipher)) {
if (!ssl_has_private_key(s)) {
al = SSL_AD_INTERNAL_ERROR;
goto f_err;
}
max_sig_len = ssl_private_key_max_signature_len(s);
} else {
max_sig_len = 0;
}
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_kDHE) {
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, SSL_R_MISSING_TMP_DH_KEY);
goto f_err;
}
if (s->s3->tmp.dh != NULL) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
goto err;
}
dh = DHparams_dup(dhp);
if (dh == NULL) {
OPENSSL_PUT_ERROR(SSL, ERR_R_DH_LIB);
goto err;
}
s->s3->tmp.dh = dh;
if (!DH_generate_key(dh)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_DH_LIB);
goto err;
}
r[0] = dh->p;
r[1] = dh->g;
r[2] = dh->pub_key;
} else if (alg_k & SSL_kECDHE) {
/* Determine the curve to use. */
int nid = NID_undef;
if (cert->ecdh_nid != NID_undef) {
nid = cert->ecdh_nid;
} else if (cert->ecdh_tmp_cb != NULL) {
/* Note: |ecdh_tmp_cb| does NOT pass ownership of the result
* to the caller. */
EC_KEY *template = s->cert->ecdh_tmp_cb(s, 0, 1024);
if (template != NULL && EC_KEY_get0_group(template) != NULL) {
nid = EC_GROUP_get_curve_name(EC_KEY_get0_group(template));
}
} else {
nid = tls1_get_shared_curve(s);
}
if (nid == NID_undef) {
al = SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, SSL_R_MISSING_TMP_ECDH_KEY);
goto f_err;
}
if (s->s3->tmp.ecdh != NULL) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
goto err;
}
ecdh = EC_KEY_new_by_curve_name(nid);
if (ecdh == NULL) {
goto err;
}
s->s3->tmp.ecdh = ecdh;
if (!EC_KEY_generate_key(ecdh)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_ECDH_LIB);
goto err;
}
/* We only support ephemeral ECDH keys over named (not generic) curves. */
const EC_GROUP *group = EC_KEY_get0_group(ecdh);
if (!tls1_ec_nid2curve_id(&curve_id, EC_GROUP_get_curve_name(group))) {
OPENSSL_PUT_ERROR(SSL, 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 = (uint8_t *)OPENSSL_malloc(encodedlen * sizeof(uint8_t));
bn_ctx = BN_CTX_new();
if (encodedPoint == NULL || bn_ctx == NULL) {
OPENSSL_PUT_ERROR(SSL, 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, ERR_R_ECDH_LIB);
goto err;
}
BN_CTX_free(bn_ctx);
bn_ctx = NULL;
/* 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, 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 (!BUF_MEM_grow_clean(buf, n + SSL_HM_HEADER_LENGTH(s) + max_sig_len)) {
OPENSSL_PUT_ERROR(SSL, 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_kECDHE 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_kECDHE) {
/* 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++) = (uint8_t)(curve_id >> 8);
*(p++) = (uint8_t)(curve_id & 0xff);
*(p++) = encodedlen;
memcpy(p, encodedPoint, encodedlen);
p += encodedlen;
OPENSSL_free(encodedPoint);
encodedPoint = NULL;
}
/* not anonymous */
if (ssl_cipher_has_server_public_key(s->s3->tmp.new_cipher)) {
/* n is the length of the params, they start at d and p points to
* the space at the end. */
const EVP_MD *md;
uint8_t digest[EVP_MAX_MD_SIZE];
unsigned int digest_length;
const int pkey_type = ssl_private_key_type(s);
/* Determine signature algorithm. */
if (SSL_USE_SIGALGS(s)) {
md = tls1_choose_signing_digest(s);
if (!tls12_get_sigandhash(s, p, md)) {
/* Should never happen */
al = SSL_AD_INTERNAL_ERROR;
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
goto f_err;
}
p += 2;
} else if (pkey_type == EVP_PKEY_RSA) {
md = EVP_md5_sha1();
} else {
md = EVP_sha1();
}
if (!EVP_DigestInit_ex(&md_ctx, md, NULL) ||
!EVP_DigestUpdate(&md_ctx, s->s3->client_random, SSL3_RANDOM_SIZE) ||
!EVP_DigestUpdate(&md_ctx, s->s3->server_random, SSL3_RANDOM_SIZE) ||
!EVP_DigestUpdate(&md_ctx, d, n) ||
!EVP_DigestFinal_ex(&md_ctx, digest, &digest_length)) {
OPENSSL_PUT_ERROR(SSL, ERR_LIB_EVP);
goto err;
}
const enum ssl_private_key_result_t sign_result = ssl_private_key_sign(
s, &p[2], &sig_len, max_sig_len, EVP_MD_CTX_md(&md_ctx),
digest, digest_length);
if (sign_result == ssl_private_key_retry) {
s->rwstate = SSL_PRIVATE_KEY_OPERATION;
/* Stash away |p|. */
s->init_num = p - ssl_handshake_start(s) + SSL_HM_HEADER_LENGTH(s);
s->state = SSL3_ST_SW_KEY_EXCH_B;
goto err;
} else if (sign_result != ssl_private_key_success) {
goto err;
}
}
s->state = SSL3_ST_SW_KEY_EXCH_C;
} else if (s->state == SSL3_ST_SW_KEY_EXCH_B) {
/* Complete async sign. */
/* Restore |p|. */
p = ssl_handshake_start(s) + s->init_num - SSL_HM_HEADER_LENGTH(s);
const enum ssl_private_key_result_t sign_result =
ssl_private_key_sign_complete(s, &p[2], &sig_len, max_sig_len);
if (sign_result == ssl_private_key_retry) {
s->rwstate = SSL_PRIVATE_KEY_OPERATION;
goto err;
} else if (sign_result != ssl_private_key_success) {
goto err;
}
s->rwstate = SSL_NOTHING;
s->state = SSL3_ST_SW_KEY_EXCH_C;
}
if (s->state == SSL3_ST_SW_KEY_EXCH_C) {
if (ssl_cipher_has_server_public_key(s->s3->tmp.new_cipher)) {
s2n(sig_len, p);
p += sig_len;
}
if (!ssl_set_handshake_header(s, SSL3_MT_SERVER_KEY_EXCHANGE,
p - ssl_handshake_start(s))) {
goto err;
}
s->state = SSL3_ST_SW_KEY_EXCH_D;
}
/* state SSL3_ST_SW_KEY_EXCH_D */
EVP_MD_CTX_cleanup(&md_ctx);
return ssl_do_write(s);
f_err:
ssl3_send_alert(s, SSL3_AL_FATAL, al);
err:
OPENSSL_free(encodedPoint);
BN_CTX_free(bn_ctx);
EVP_MD_CTX_cleanup(&md_ctx);
return -1;
}
int ssl3_send_certificate_request(SSL *s) {
uint8_t *p, *d;
size_t i;
int j, nl, off, n;
STACK_OF(X509_NAME) *sk = NULL;
X509_NAME *name;
BUF_MEM *buf;
if (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 uint8_t *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, 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);
if (!ssl_set_handshake_header(s, SSL3_MT_CERTIFICATE_REQUEST, n)) {
goto err;
}
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;
uint32_t alg_k;
uint32_t 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;
uint8_t 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_hash_message, &ok);
if (!ok) {
return 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, SSL_R_DECODE_ERROR);
al = SSL_AD_DECODE_ERROR;
goto f_err;
}
if (s->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, &s->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 =
s->psk_server_callback(s, s->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) {
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->privatekey;
if (pkey == NULL || pkey->type != EVP_PKEY_RSA || pkey->pkey.rsa == NULL) {
al = SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, 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, 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, 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_bytes(rand_premaster_secret, sizeof(rand_premaster_secret))) {
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, 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, 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, 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_kDHE) {
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, 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, 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, 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, ERR_R_MALLOC_FAILURE);
BN_clear_free(pub);
goto err;
}
dh_len = DH_compute_key(premaster_secret, pub, dh_srvr);
if (dh_len <= 0) {
OPENSSL_PUT_ERROR(SSL, 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_kECDHE) {
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 */
srvr_ecdh = EC_KEY_new();
if (srvr_ecdh == NULL) {
OPENSSL_PUT_ERROR(SSL, 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, ERR_R_EC_LIB);
goto err;
}
/* Let's get client's public key */
clnt_ecpoint = EC_POINT_new(group);
if (clnt_ecpoint == NULL) {
OPENSSL_PUT_ERROR(SSL, 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, SSL_R_DECODE_ERROR);
goto f_err;
}
bn_ctx = BN_CTX_new();
if (bn_ctx == NULL) {
OPENSSL_PUT_ERROR(SSL, 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, 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, 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, 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, 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, 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 */
s->session->master_key_length = s->enc_method->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);
}
OPENSSL_free(decrypt_buf);
EVP_PKEY_free(clnt_pub_pkey);
EC_POINT_free(clnt_ecpoint);
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) {
ssl3_free_handshake_buffer(s);
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_dont_hash_message, &ok);
if (!ok) {
return n;
}
/* Filter out unsupported certificate types. */
pkey = X509_get_pubkey(peer);
if (pkey == NULL) {
goto err;
}
if (!(X509_certificate_type(peer, pkey) & EVP_PKT_SIGN) ||
(pkey->type != EVP_PKEY_RSA && pkey->type != EVP_PKEY_EC)) {
al = SSL_AD_UNSUPPORTED_CERTIFICATE;
OPENSSL_PUT_ERROR(SSL, SSL_R_PEER_ERROR_UNSUPPORTED_CERTIFICATE_TYPE);
goto f_err;
}
CBS_init(&certificate_verify, s->init_msg, n);
/* Determine the digest type if needbe. */
if (SSL_USE_SIGALGS(s) &&
!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->type)) {
goto err;
}
/* The handshake buffer is no longer necessary, and we may hash the current
* message.*/
ssl3_free_handshake_buffer(s);
if (!ssl3_hash_current_message(s)) {
goto err;
}
/* Parse and verify the signature. */
if (!CBS_get_u16_length_prefixed(&certificate_verify, &signature) ||
CBS_len(&certificate_verify) != 0) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
goto f_err;
}
pctx = EVP_PKEY_CTX_new(pkey, NULL);
if (pctx == NULL) {
goto err;
}
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, 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,
(long)s->max_cert_list, ssl_hash_message, &ok);
if (!ok) {
return 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, 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,
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, SSL_R_WRONG_MESSAGE_TYPE);
goto f_err;
}
CBS_init(&certificate_msg, s->init_msg, n);
sk = sk_X509_new_null();
if (sk == NULL) {
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
goto err;
}
if (!CBS_get_u24_length_prefixed(&certificate_msg, &certificate_list) ||
CBS_len(&certificate_msg) != 0) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
goto f_err;
}
while (CBS_len(&certificate_list) > 0) {
CBS certificate;
const uint8_t *data;
if (!CBS_get_u24_length_prefixed(&certificate_list, &certificate)) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
goto f_err;
}
if (is_first_certificate && 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, ERR_R_ASN1_LIB);
goto f_err;
}
if (data != CBS_data(&certificate) + CBS_len(&certificate)) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_CERT_LENGTH_MISMATCH);
goto f_err;
}
if (!sk_X509_push(sk, x)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
goto err;
}
x = NULL;
}
if (sk_X509_num(sk) <= 0) {
/* No client certificate so the handshake buffer may be discarded. */
ssl3_free_handshake_buffer(s);
/* TLS does not mind 0 certs returned */
if (s->version == SSL3_VERSION) {
al = SSL_AD_HANDSHAKE_FAILURE;
OPENSSL_PUT_ERROR(SSL, SSL_R_NO_CERTIFICATES_RETURNED);
goto f_err;
} else if ((s->verify_mode & SSL_VERIFY_PEER) &&
(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) {
/* Fail for TLS only if we required a certificate */
OPENSSL_PUT_ERROR(SSL, SSL_R_PEER_DID_NOT_RETURN_A_CERTIFICATE);
al = SSL_AD_HANDSHAKE_FAILURE;
goto f_err;
}
} else {
i = ssl_verify_cert_chain(s, sk);
if (i <= 0) {
al = ssl_verify_alarm_type(s->verify_result);
OPENSSL_PUT_ERROR(SSL, SSL_R_CERTIFICATE_VERIFY_FAILED);
goto f_err;
}
}
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, ERR_R_MALLOC_FAILURE);
goto err;
}
}
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:
X509_free(x);
sk_X509_pop_free(sk, X509_free);
return ret;
}
int ssl3_send_server_certificate(SSL *s) {
if (s->state == SSL3_ST_SW_CERT_A) {
if (!ssl3_output_cert_chain(s)) {
return 0;
}
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) {
int ret = -1;
uint8_t *session = NULL;
size_t session_len;
EVP_CIPHER_CTX ctx;
HMAC_CTX hctx;
EVP_CIPHER_CTX_init(&ctx);
HMAC_CTX_init(&hctx);
if (s->state == SSL3_ST_SW_SESSION_TICKET_A) {
uint8_t *p, *macstart;
int len;
unsigned int hlen;
SSL_CTX *tctx = s->initial_ctx;
uint8_t iv[EVP_MAX_IV_LENGTH];
uint8_t key_name[16];
/* The maximum overhead of encrypting the session is 16 (key name) + IV +
* one block of encryption overhead + HMAC. */
const size_t max_ticket_overhead =
16 + EVP_MAX_IV_LENGTH + EVP_MAX_BLOCK_LENGTH + EVP_MAX_MD_SIZE;
/* Serialize the SSL_SESSION to be encoded into the ticket. */
if (!SSL_SESSION_to_bytes_for_ticket(s->session, &session, &session_len)) {
goto err;
}
/* If the session is too long, emit a dummy value rather than abort the
* connection. */
if (session_len > 0xFFFF - max_ticket_overhead) {
static const char kTicketPlaceholder[] = "TICKET TOO LARGE";
const size_t placeholder_len = strlen(kTicketPlaceholder);
OPENSSL_free(session);
session = NULL;
p = ssl_handshake_start(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);
if (!ssl_set_handshake_header(s, SSL3_MT_NEWSESSION_TICKET, len)) {
goto err;
}
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)) {
goto err;
}
p = ssl_handshake_start(s);
/* 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 /* encrypt */) < 0) {
goto err;
}
} else {
if (!RAND_bytes(iv, 16) ||
!EVP_EncryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL,
tctx->tlsext_tick_aes_key, iv) ||
!HMAC_Init_ex(&hctx, tctx->tlsext_tick_hmac_key, 16, tlsext_tick_md(),
NULL)) {
goto err;
}
memcpy(key_name, tctx->tlsext_tick_key_name, 16);
}
/* Ticket lifetime hint (advisory only): We leave this unspecified for
* resumed session (for simplicity), and guess that tickets for new
* sessions will live as long as their sessions. */
l2n(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 */
if (!EVP_EncryptUpdate(&ctx, p, &len, session, session_len)) {
goto err;
}
p += len;
if (!EVP_EncryptFinal_ex(&ctx, p, &len)) {
goto err;
}
p += len;
if (!HMAC_Update(&hctx, macstart, p - macstart) ||
!HMAC_Final(&hctx, p, &hlen)) {
goto err;
}
p += hlen;
/* Now write out lengths: p points to end of data written */
/* Total length */
len = p - ssl_handshake_start(s);
/* Skip ticket lifetime hint */
p = ssl_handshake_start(s) + 4;
s2n(len - 6, p);
if (!ssl_set_handshake_header(s, SSL3_MT_NEWSESSION_TICKET, len)) {
goto err;
}
s->state = SSL3_ST_SW_SESSION_TICKET_B;
}
/* SSL3_ST_SW_SESSION_TICKET_B */
ret = ssl_do_write(s);
err:
OPENSSL_free(session);
EVP_CIPHER_CTX_cleanup(&ctx);
HMAC_CTX_cleanup(&hctx);
return ret;
}
/* 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, 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_hash_message, &ok);
if (!ok) {
return 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, 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 ||
!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;
uint8_t channel_id_hash[EVP_MAX_MD_SIZE];
size_t channel_id_hash_len;
const uint8_t *p;
uint16_t extension_type;
EC_GROUP *p256 = NULL;
EC_KEY *key = NULL;
EC_POINT *point = NULL;
ECDSA_SIG sig;
BIGNUM x, y;
CBS encrypted_extensions, extension;
n = 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_dont_hash_message, &ok);
if (!ok) {
return n;
}
/* Before incorporating the EncryptedExtensions message to the handshake
* hash, compute the hash that should have been signed. */
if (!tls1_channel_id_hash(s, channel_id_hash, &channel_id_hash_len)) {
return -1;
}
assert(channel_id_hash_len == SHA256_DIGEST_LENGTH);
if (!ssl3_hash_current_message(s)) {
return -1;
}
/* 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, 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]; */
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);
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);
EC_KEY_free(key);
EC_POINT_free(point);
EC_GROUP_free(p256);
return ret;
}
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