boringssl/ssl/d1_lib.cc
David Benjamin 86e95b852e Move libssl's internals into the bssl namespace.
This is horrible, but everything else I tried was worse. The goal with
this CL is to take the extern "C" out of ssl/internal.h and move most
symbols to namespace bssl, so we can start using C++ helpers and
destructors without worry.

Complications:

- Public API functions must be extern "C" and match their declaration in
  ssl.h, which is unnamespaced. C++ really does not want you to
  interleave namespaced and unnamespaced things. One can actually write
  a namespaced extern "C" function, but this means, from C++'s
  perspective, the function is namespaced. Trying to namespace the
  public header would worked but ended up too deep a rabbithole.

- Our STACK_OF macros do not work right in namespaces.

- The typedefs for our exposed but opaque types are visible in the
  header files and copied into consuming projects as forward
  declarations. We ultimately want to give SSL a destructor, but
  clobbering an unnamespaced ssl_st::~ssl_st seems bad manners.

- MSVC complains about ambiguous names if one typedefs SSL to bssl::SSL.

This CL opts for:

- ssl/*.cc must begin with #define BORINGSSL_INTERNAL_CXX_TYPES. This
  informs the public headers to create forward declarations which are
  compatible with our namespaces.

- For now, C++-defined type FOO ends up at bssl::FOO with a typedef
  outside. Later I imagine we'll rename many of them.

- Internal functions get namespace bssl, so we stop worrying about
  stomping the tls1_prf symbol. Exported C functions are stuck as they
  are. Rather than try anything weird, bite the bullet and reorder files
  which have a mix of public and private functions. I expect that over
  time, the public functions will become fairly small as we move logic
  to more idiomatic C++.

  Files without any public C functions can just be written normally.

- To avoid MSVC troubles, some bssl types are renamed to CPlusPlusStyle
  in advance of them being made idiomatic C++.

Bug: 132
Change-Id: Ic931895e117c38b14ff8d6e5a273e868796c7581
Reviewed-on: https://boringssl-review.googlesource.com/18124
Reviewed-by: David Benjamin <davidben@google.com>
2017-07-19 19:10:59 +00:00

272 lines
8.1 KiB
C++

/*
* DTLS implementation written by Nagendra Modadugu
* (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
*/
/* ====================================================================
* Copyright (c) 1999-2005 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). */
#define BORINGSSL_INTERNAL_CXX_TYPES
#include <openssl/ssl.h>
#include <assert.h>
#include <limits.h>
#include <string.h>
#include <openssl/err.h>
#include <openssl/mem.h>
#include <openssl/nid.h>
#include "../crypto/internal.h"
#include "internal.h"
namespace bssl {
/* DTLS1_MTU_TIMEOUTS is the maximum number of timeouts to expire
* before starting to decrease the MTU. */
#define DTLS1_MTU_TIMEOUTS 2
/* DTLS1_MAX_TIMEOUTS is the maximum number of timeouts to expire
* before failing the DTLS handshake. */
#define DTLS1_MAX_TIMEOUTS 12
int dtls1_new(SSL *ssl) {
if (!ssl3_new(ssl)) {
return 0;
}
DTLS1_STATE *d1 = (DTLS1_STATE *)OPENSSL_malloc(sizeof *d1);
if (d1 == NULL) {
ssl3_free(ssl);
return 0;
}
OPENSSL_memset(d1, 0, sizeof *d1);
ssl->d1 = d1;
/* Set the version to the highest supported version.
*
* TODO(davidben): Move this field into |s3|, have it store the normalized
* protocol version, and implement this pre-negotiation quirk in |SSL_version|
* at the API boundary rather than in internal state. */
ssl->version = DTLS1_2_VERSION;
return 1;
}
void dtls1_free(SSL *ssl) {
ssl3_free(ssl);
if (ssl == NULL || ssl->d1 == NULL) {
return;
}
dtls_clear_incoming_messages(ssl);
dtls_clear_outgoing_messages(ssl);
OPENSSL_free(ssl->d1);
ssl->d1 = NULL;
}
void dtls1_start_timer(SSL *ssl) {
/* If timer is not set, initialize duration (by default, 1 second) */
if (ssl->d1->next_timeout.tv_sec == 0 && ssl->d1->next_timeout.tv_usec == 0) {
ssl->d1->timeout_duration_ms = ssl->initial_timeout_duration_ms;
}
/* Set timeout to current time */
ssl_get_current_time(ssl, &ssl->d1->next_timeout);
/* Add duration to current time */
ssl->d1->next_timeout.tv_sec += ssl->d1->timeout_duration_ms / 1000;
ssl->d1->next_timeout.tv_usec += (ssl->d1->timeout_duration_ms % 1000) * 1000;
if (ssl->d1->next_timeout.tv_usec >= 1000000) {
ssl->d1->next_timeout.tv_sec++;
ssl->d1->next_timeout.tv_usec -= 1000000;
}
}
int dtls1_is_timer_expired(SSL *ssl) {
struct timeval timeleft;
/* Get time left until timeout, return false if no timer running */
if (!DTLSv1_get_timeout(ssl, &timeleft)) {
return 0;
}
/* Return false if timer is not expired yet */
if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) {
return 0;
}
/* Timer expired, so return true */
return 1;
}
void dtls1_double_timeout(SSL *ssl) {
ssl->d1->timeout_duration_ms *= 2;
if (ssl->d1->timeout_duration_ms > 60000) {
ssl->d1->timeout_duration_ms = 60000;
}
dtls1_start_timer(ssl);
}
void dtls1_stop_timer(SSL *ssl) {
/* Reset everything */
ssl->d1->num_timeouts = 0;
OPENSSL_memset(&ssl->d1->next_timeout, 0, sizeof(ssl->d1->next_timeout));
ssl->d1->timeout_duration_ms = ssl->initial_timeout_duration_ms;
/* Clear retransmission buffer */
dtls_clear_outgoing_messages(ssl);
}
int dtls1_check_timeout_num(SSL *ssl) {
ssl->d1->num_timeouts++;
/* Reduce MTU after 2 unsuccessful retransmissions */
if (ssl->d1->num_timeouts > DTLS1_MTU_TIMEOUTS &&
!(SSL_get_options(ssl) & SSL_OP_NO_QUERY_MTU)) {
long mtu = BIO_ctrl(ssl->wbio, BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
if (mtu >= 0 && mtu <= (1 << 30) && (unsigned)mtu >= dtls1_min_mtu()) {
ssl->d1->mtu = (unsigned)mtu;
}
}
if (ssl->d1->num_timeouts > DTLS1_MAX_TIMEOUTS) {
/* fail the connection, enough alerts have been sent */
OPENSSL_PUT_ERROR(SSL, SSL_R_READ_TIMEOUT_EXPIRED);
return -1;
}
return 0;
}
} // namespace bssl
using namespace bssl;
void DTLSv1_set_initial_timeout_duration(SSL *ssl, unsigned int duration_ms) {
ssl->initial_timeout_duration_ms = duration_ms;
}
int DTLSv1_get_timeout(const SSL *ssl, struct timeval *out) {
if (!SSL_is_dtls(ssl)) {
return 0;
}
/* If no timeout is set, just return NULL */
if (ssl->d1->next_timeout.tv_sec == 0 && ssl->d1->next_timeout.tv_usec == 0) {
return 0;
}
struct OPENSSL_timeval timenow;
ssl_get_current_time(ssl, &timenow);
/* If timer already expired, set remaining time to 0 */
if (ssl->d1->next_timeout.tv_sec < timenow.tv_sec ||
(ssl->d1->next_timeout.tv_sec == timenow.tv_sec &&
ssl->d1->next_timeout.tv_usec <= timenow.tv_usec)) {
OPENSSL_memset(out, 0, sizeof(*out));
return 1;
}
/* Calculate time left until timer expires */
struct OPENSSL_timeval ret;
OPENSSL_memcpy(&ret, &ssl->d1->next_timeout, sizeof(ret));
ret.tv_sec -= timenow.tv_sec;
if (ret.tv_usec >= timenow.tv_usec) {
ret.tv_usec -= timenow.tv_usec;
} else {
ret.tv_usec = 1000000 + ret.tv_usec - timenow.tv_usec;
ret.tv_sec--;
}
/* If remaining time is less than 15 ms, set it to 0 to prevent issues
* because of small divergences with socket timeouts. */
if (ret.tv_sec == 0 && ret.tv_usec < 15000) {
OPENSSL_memset(&ret, 0, sizeof(ret));
}
/* Clamp the result in case of overflow. */
if (ret.tv_sec > INT_MAX) {
assert(0);
out->tv_sec = INT_MAX;
} else {
out->tv_sec = ret.tv_sec;
}
out->tv_usec = ret.tv_usec;
return 1;
}
int DTLSv1_handle_timeout(SSL *ssl) {
ssl_reset_error_state(ssl);
if (!SSL_is_dtls(ssl)) {
return -1;
}
/* if no timer is expired, don't do anything */
if (!dtls1_is_timer_expired(ssl)) {
return 0;
}
dtls1_double_timeout(ssl);
if (dtls1_check_timeout_num(ssl) < 0) {
return -1;
}
dtls1_start_timer(ssl);
return dtls1_retransmit_outgoing_messages(ssl);
}