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boringssl/ssl/s3_srvr.c
David Benjamin b8d28cf532 Factor out the buffering and low-level record code. 
This begins decoupling the transport from the SSL state machine. The buffering
logic is hidden behind an opaque API. Fields like ssl->packet and
ssl->packet_length are gone.

ssl3_get_record and dtls1_get_record now call low-level tls_open_record and
dtls_open_record functions that unpack a single record independent of who owns
the buffer. Both may be called in-place. This removes ssl->rstate which was
redundant with the buffer length.

Future work will push the buffer up the stack until it is above the handshake.
Then we can expose SSL_open and SSL_seal APIs which act like *_open_record but
return a slightly larger enum due to other events being possible. Likewise the
handshake state machine will be detached from its buffer. The existing
SSL_read, SSL_write, etc., APIs will be implemented on top of SSL_open, etc.,
combined with ssl_read_buffer_* and ssl_write_buffer_*. (Which is why
ssl_read_buffer_extend still tries to abstract between TLS's and DTLS's fairly
different needs.)

The new buffering logic does not support read-ahead (removed previously) since
it lacks a memmove on ssl_read_buffer_discard for TLS, but this could be added
if desired. The old buffering logic wasn't quite right anyway; it tried to
avoid the memmove in some cases and could get stuck too far into the buffer and
not accept records. (The only time the memmove is optional is in DTLS or if
enough of the record header is available to know that the entire next record
would fit in the buffer.)

The new logic also now actually decrypts the ciphertext in-place again, rather
than almost in-place when there's an explicit nonce/IV. (That accidentally
switched in https://boringssl-review.googlesource.com/#/c/4792/; see
3d59e04bce96474099ba76786a2337e99ae14505.)

BUG=468889

Change-Id: I403c1626253c46897f47c7ae93aeab1064b767b2
Reviewed-on: https://boringssl-review.googlesource.com/5715
Reviewed-by: Adam Langley <agl@google.com>
2015-08-28 22:01:02 +00:00

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/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
/* ====================================================================
* Copyright (c) 1998-2007 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* openssl-core@openssl.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com).
*
*/
/* ====================================================================
* Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
*
* Portions of the attached software ("Contribution") are developed by
* SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project.
*
* The Contribution is licensed pursuant to the OpenSSL open source
* license provided above.
*
* ECC cipher suite support in OpenSSL originally written by
* Vipul Gupta and Sumit Gupta of Sun Microsystems Laboratories.
*
*/
/* ====================================================================
* Copyright 2005 Nokia. All rights reserved.
*
* The portions of the attached software ("Contribution") is developed by
* Nokia Corporation and is licensed pursuant to the OpenSSL open source
* license.
*
* The Contribution, originally written by Mika Kousa and Pasi Eronen of
* Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites
* support (see RFC 4279) to OpenSSL.
*
* No patent licenses or other rights except those expressly stated in
* the OpenSSL open source license shall be deemed granted or received
* expressly, by implication, estoppel, or otherwise.
*
* No assurances are provided by Nokia that the Contribution does not
* infringe the patent or other intellectual property rights of any third
* party or that the license provides you with all the necessary rights
* to make use of the Contribution.
*
* THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN
* ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA
* SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY
* OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR
* OTHERWISE. */
#include <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_CERT_STATUS_A:
case SSL3_ST_SW_CERT_STATUS_B:
ret = ssl3_send_certificate_status(s);
if (ret <= 0) {
goto end;
}
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 = ssl_read_buffer_extend_to(s, SSL3_RT_HEADER_LENGTH);
if (ret <= 0) {
return ret;
}
assert(ssl_read_buffer_len(s) == SSL3_RT_HEADER_LENGTH);
const uint8_t *p = ssl_read_buffer(s);
/* 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. */
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(ssl_read_buffer_len(s) >= SSL3_RT_HEADER_LENGTH);
p = ssl_read_buffer(s);
msg_length = ((p[0] & 0x7f) << 8) | p[1];
if (msg_length > (1024 * 4)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_RECORD_TOO_LARGE);
return -1;
}
if (msg_length < SSL3_RT_HEADER_LENGTH - 2) {
/* Reject lengths that are too short early. We have already read
* |SSL3_RT_HEADER_LENGTH| bytes, so we should not attempt to process an
* (invalid) V2ClientHello which would be shorter than that. */
OPENSSL_PUT_ERROR(SSL, SSL_R_RECORD_LENGTH_MISMATCH);
return -1;
}
/* Read the remainder of the V2ClientHello. */
ret = ssl_read_buffer_extend_to(s, 2 + msg_length);
if (ret <= 0) {
return ret;
}
assert(ssl_read_buffer_len(s) == msg_length + 2);
CBS_init(&v2_client_hello, ssl_read_buffer(s) + 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;
/* Consume and discard the V2ClientHello. */
ssl_read_buffer_consume(s, 2 + msg_length);
ssl_read_buffer_discard(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_certificate_status(SSL *ssl) {
if (ssl->state == SSL3_ST_SW_CERT_STATUS_A) {
CBB out, ocsp_response;
size_t length;
CBB_zero(&out);
if (!CBB_init_fixed(&out, ssl_handshake_start(ssl),
ssl->init_buf->max - SSL_HM_HEADER_LENGTH(ssl)) ||
!CBB_add_u8(&out, TLSEXT_STATUSTYPE_ocsp) ||
!CBB_add_u24_length_prefixed(&out, &ocsp_response) ||
!CBB_add_bytes(&ocsp_response, ssl->ctx->ocsp_response,
ssl->ctx->ocsp_response_length) ||
!CBB_finish(&out, NULL, &length) ||
!ssl_set_handshake_header(ssl, SSL3_MT_CERTIFICATE_STATUS, length)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
CBB_cleanup(&out);
return -1;
}
ssl->state = SSL3_ST_SW_CERT_STATUS_B;
}
/* SSL3_ST_SW_CERT_STATUS_B */
return ssl_do_write(ssl);
}
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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