boringssl/ssl/tls_method.c
David Benjamin 61672818ef Check for buffered handshake messages on cipher change in DTLS.
This is the equivalent of FragmentAcrossChangeCipherSuite for DTLS. It
is possible for us to, while receiving pre-CCS handshake messages, to
buffer up a message with sequence number meant for a post-CCS Finished.
When we then get to the new epoch and attempt to read the Finished, we
will process the buffered Finished although it was sent with the wrong
encryption.

Move ssl_set_{read,write}_state to SSL_PROTOCOL_METHOD hooks as this is
a property of the transport. Notably, read_state may fail. In DTLS
check the handshake buffer size. We could place this check in
read_change_cipher_spec, but TLS 1.3 has no ChangeCipherSpec message, so
we will need to implement this at the cipher change point anyway. (For
now, there is only an assert on the TLS side. This will be replaced with
a proper check in TLS 1.3.)

Change-Id: Ia52b0b81e7db53e9ed2d4f6d334a1cce13e93297
Reviewed-on: https://boringssl-review.googlesource.com/8790
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2016-07-16 08:25:02 +00:00

230 lines
6.7 KiB
C

/* 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.] */
#include <openssl/ssl.h>
#include <assert.h>
#include <string.h>
#include <openssl/buf.h>
#include "internal.h"
static uint16_t ssl3_version_from_wire(uint16_t wire_version) {
return wire_version;
}
static uint16_t ssl3_version_to_wire(uint16_t version) { return version; }
static int ssl3_begin_handshake(SSL *ssl) {
if (ssl->init_buf != NULL) {
return 1;
}
BUF_MEM *buf = BUF_MEM_new();
if (buf == NULL || !BUF_MEM_reserve(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
BUF_MEM_free(buf);
return 0;
}
ssl->init_buf = buf;
ssl->init_num = 0;
return 1;
}
static void ssl3_finish_handshake(SSL *ssl) {
BUF_MEM_free(ssl->init_buf);
ssl->init_buf = NULL;
ssl->init_num = 0;
}
static int ssl3_set_read_state(SSL *ssl, SSL_AEAD_CTX *aead_ctx) {
/* TODO(davidben): In TLS 1.3, cipher changes are not always preceeded by a
* ChangeCipherSpec, so this must become a runtime check. */
assert(ssl->s3->rrec.length == 0);
memset(ssl->s3->read_sequence, 0, sizeof(ssl->s3->read_sequence));
SSL_AEAD_CTX_free(ssl->s3->aead_read_ctx);
ssl->s3->aead_read_ctx = aead_ctx;
return 1;
}
static int ssl3_set_write_state(SSL *ssl, SSL_AEAD_CTX *aead_ctx) {
memset(ssl->s3->write_sequence, 0, sizeof(ssl->s3->write_sequence));
SSL_AEAD_CTX_free(ssl->s3->aead_write_ctx);
ssl->s3->aead_write_ctx = aead_ctx;
return 1;
}
static const SSL_PROTOCOL_METHOD kTLSProtocolMethod = {
0 /* is_dtls */,
SSL3_VERSION,
TLS1_3_VERSION,
ssl3_version_from_wire,
ssl3_version_to_wire,
ssl3_new,
ssl3_free,
ssl3_begin_handshake,
ssl3_finish_handshake,
ssl3_get_message,
ssl3_hash_current_message,
ssl3_read_app_data,
ssl3_read_change_cipher_spec,
ssl3_read_close_notify,
ssl3_write_app_data,
ssl3_dispatch_alert,
ssl3_supports_cipher,
ssl3_init_message,
ssl3_finish_message,
ssl3_write_message,
ssl3_send_change_cipher_spec,
ssl3_expect_flight,
ssl3_received_flight,
ssl3_set_read_state,
ssl3_set_write_state,
};
const SSL_METHOD *TLS_method(void) {
static const SSL_METHOD kMethod = {
0,
&kTLSProtocolMethod,
};
return &kMethod;
}
const SSL_METHOD *SSLv23_method(void) {
return TLS_method();
}
/* Legacy version-locked methods. */
const SSL_METHOD *TLSv1_2_method(void) {
static const SSL_METHOD kMethod = {
TLS1_2_VERSION,
&kTLSProtocolMethod,
};
return &kMethod;
}
const SSL_METHOD *TLSv1_1_method(void) {
static const SSL_METHOD kMethod = {
TLS1_1_VERSION,
&kTLSProtocolMethod,
};
return &kMethod;
}
const SSL_METHOD *TLSv1_method(void) {
static const SSL_METHOD kMethod = {
TLS1_VERSION,
&kTLSProtocolMethod,
};
return &kMethod;
}
const SSL_METHOD *SSLv3_method(void) {
static const SSL_METHOD kMethod = {
SSL3_VERSION,
&kTLSProtocolMethod,
};
return &kMethod;
}
/* Legacy side-specific methods. */
const SSL_METHOD *TLSv1_2_server_method(void) {
return TLSv1_2_method();
}
const SSL_METHOD *TLSv1_1_server_method(void) {
return TLSv1_1_method();
}
const SSL_METHOD *TLSv1_server_method(void) {
return TLSv1_method();
}
const SSL_METHOD *SSLv3_server_method(void) {
return SSLv3_method();
}
const SSL_METHOD *TLSv1_2_client_method(void) {
return TLSv1_2_method();
}
const SSL_METHOD *TLSv1_1_client_method(void) {
return TLSv1_1_method();
}
const SSL_METHOD *TLSv1_client_method(void) {
return TLSv1_method();
}
const SSL_METHOD *SSLv3_client_method(void) {
return SSLv3_method();
}
const SSL_METHOD *SSLv23_server_method(void) {
return SSLv23_method();
}
const SSL_METHOD *SSLv23_client_method(void) {
return SSLv23_method();
}