boringssl/ssl/tls_method.c
Steven Valdez 8f36c51f98 Revise version negotiation logic on the C side.
This is in preparation for upcoming experiments which will require
supporting multiple experimental versions of TLS 1.3 with, on the
server, the ability to enable multiple variants at once. This means the
version <-> wire bijection no longer exists, even when limiting to a
single SSL*.  Thus version_to_wire is removed and instead we treat the
wire version as the canonical version value.

There is a mapping from valid wire versions to protocol versions which
describe the high-level handshake protocol in use. This mapping is not
injective, so uses of version_from_wire are rewritten differently.

All the version-munging logic is moved to ssl_versions.c with a master
preference list of all TLS and DTLS versions. The legacy version
negotiation is converted to the new scheme. The version lists and
negotiation are driven by the preference lists and a
ssl_supports_version API.

To simplify the mess around SSL_SESSION and versions, version_from_wire
is now DTLS/TLS-agnostic, with any filtering being done by
ssl_supports_version. This is screwy but allows parsing SSL_SESSIONs to
sanity-check it and reject all bogus versions in SSL_SESSION. This
reduces a mess of error cases.

As part of this, the weird logic where ssl->version is set early when
sending the ClientHello is removed. The one place where we were relying
on this behavior is tweaked to query hs->max_version instead.

Change-Id: Ic91b348481ceba94d9ae06d6781187c11adc15b0
Reviewed-on: https://boringssl-review.googlesource.com/17524
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
2017-07-05 19:13:17 +00:00

292 lines
9.0 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 "../crypto/internal.h"
#include "internal.h"
static int ssl3_supports_cipher(const SSL_CIPHER *cipher) { return 1; }
static void ssl3_expect_flight(SSL *ssl) {}
static void ssl3_received_flight(SSL *ssl) {}
static int ssl3_set_read_state(SSL *ssl, SSL_AEAD_CTX *aead_ctx) {
if (ssl->s3->rrec.length != 0) {
/* There may not be unprocessed record data at a cipher change. */
OPENSSL_PUT_ERROR(SSL, SSL_R_BUFFERED_MESSAGES_ON_CIPHER_CHANGE);
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
SSL_AEAD_CTX_free(aead_ctx);
return 0;
}
OPENSSL_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) {
OPENSSL_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_new,
ssl3_free,
ssl3_get_message,
ssl3_get_current_message,
ssl3_release_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_add_message,
ssl3_add_change_cipher_spec,
ssl3_add_alert,
ssl3_flush_flight,
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,
&ssl_crypto_x509_method,
};
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,
&ssl_crypto_x509_method,
};
return &kMethod;
}
const SSL_METHOD *TLSv1_1_method(void) {
static const SSL_METHOD kMethod = {
TLS1_1_VERSION,
&kTLSProtocolMethod,
&ssl_crypto_x509_method,
};
return &kMethod;
}
const SSL_METHOD *TLSv1_method(void) {
static const SSL_METHOD kMethod = {
TLS1_VERSION,
&kTLSProtocolMethod,
&ssl_crypto_x509_method,
};
return &kMethod;
}
const SSL_METHOD *SSLv3_method(void) {
static const SSL_METHOD kMethod = {
SSL3_VERSION,
&kTLSProtocolMethod,
&ssl_crypto_x509_method,
};
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();
}
const SSL_METHOD *TLS_server_method(void) {
return TLS_method();
}
const SSL_METHOD *TLS_client_method(void) {
return TLS_method();
}
static int ssl_noop_x509_check_client_CA_names(
STACK_OF(CRYPTO_BUFFER) *names) {
return 1;
}
static void ssl_noop_x509_clear(CERT *cert) {}
static void ssl_noop_x509_free(CERT *cert) {}
static void ssl_noop_x509_dup(CERT *new_cert, const CERT *cert) {}
static void ssl_noop_x509_flush_cached_leaf(CERT *cert) {}
static void ssl_noop_x509_flush_cached_chain(CERT *cert) {}
static int ssl_noop_x509_session_cache_objects(SSL_SESSION *sess) {
return 1;
}
static int ssl_noop_x509_session_dup(SSL_SESSION *new_session,
const SSL_SESSION *session) {
return 1;
}
static void ssl_noop_x509_session_clear(SSL_SESSION *session) {}
static int ssl_noop_x509_session_verify_cert_chain(SSL_SESSION *session,
SSL *ssl) {
if (!ssl->ctx->i_promise_to_verify_certs_after_the_handshake) {
ssl3_send_alert(ssl, SSL3_AL_FATAL, SSL_AD_UNKNOWN_CA);
OPENSSL_PUT_ERROR(SSL, SSL_R_CERTIFICATE_VERIFY_FAILED);
return 0;
}
session->verify_result = X509_V_OK;
return 1;
}
static void ssl_noop_x509_hs_flush_cached_ca_names(SSL_HANDSHAKE *hs) {}
static int ssl_noop_x509_ssl_new(SSL *ctx) { return 1; }
static void ssl_noop_x509_ssl_free(SSL *ctx) { }
static void ssl_noop_x509_ssl_flush_cached_client_CA(SSL *ssl) {}
static int ssl_noop_x509_ssl_auto_chain_if_needed(SSL *ssl) { return 1; }
static int ssl_noop_x509_ssl_ctx_new(SSL_CTX *ctx) { return 1; }
static void ssl_noop_x509_ssl_ctx_free(SSL_CTX *ctx) { }
static void ssl_noop_x509_ssl_ctx_flush_cached_client_CA(SSL_CTX *ctx) {}
static const SSL_X509_METHOD ssl_noop_x509_method = {
ssl_noop_x509_check_client_CA_names,
ssl_noop_x509_clear,
ssl_noop_x509_free,
ssl_noop_x509_dup,
ssl_noop_x509_flush_cached_chain,
ssl_noop_x509_flush_cached_leaf,
ssl_noop_x509_session_cache_objects,
ssl_noop_x509_session_dup,
ssl_noop_x509_session_clear,
ssl_noop_x509_session_verify_cert_chain,
ssl_noop_x509_hs_flush_cached_ca_names,
ssl_noop_x509_ssl_new,
ssl_noop_x509_ssl_free,
ssl_noop_x509_ssl_flush_cached_client_CA,
ssl_noop_x509_ssl_auto_chain_if_needed,
ssl_noop_x509_ssl_ctx_new,
ssl_noop_x509_ssl_ctx_free,
ssl_noop_x509_ssl_ctx_flush_cached_client_CA,
};
const SSL_METHOD *TLS_with_buffers_method(void) {
static const SSL_METHOD kMethod = {
0,
&kTLSProtocolMethod,
&ssl_noop_x509_method,
};
return &kMethod;
}