d1_lib.c

Branch :
Show log
Commit
Author : jsing
Date : 2026-05-16 08:20:41
Hash : a9b4b4b8
Message : Introduce and use dtls12_handshake_msg. Add struct dtls12_handshake_msg and various related functions, which allow for the construction of DTLS handshake messages and associated fragments. Use this on the DTLS write path for sending handshake message fragments. This means that we no longer modify the init buffer, which also fixes a bug where the message callback is called with a corrupted handshake message when multiple fragments have been sent. We also now correctly track fragment offsets when sending a handshake message that results in multiple calls to dtls1_do_write_handshake_message(). This is the first step towards further untangling of the write path in the legacy TLS stack. ok kenjiro@ tb@
lib/libssl/d1_lib.c
/* $OpenBSD: d1_lib.c,v 1.66 2026/05/16 08:20:41 jsing Exp $ */
/*
 * 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).
 *
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>

#include <netinet/in.h>

#include <stdio.h>

#include <openssl/objects.h>

#include "dtls_local.h"
#include "pqueue.h"
#include "ssl_local.h"

void dtls1_hm_fragment_free(hm_fragment *frag);

static int dtls1_listen(SSL *s, struct sockaddr *client);

int
dtls1_new(SSL *s)
{
	if (!ssl3_new(s))
		goto err;

	if ((s->d1 = calloc(1, sizeof(*s->d1))) == NULL)
		goto err;

	if ((s->d1->unprocessed_rcds.q = pqueue_new()) == NULL)
		goto err;
	if ((s->d1->buffered_messages = pqueue_new()) == NULL)
		goto err;
	if ((s->d1->sent_messages = pqueue_new()) == NULL)
		goto err;
	if ((s->d1->buffered_app_data.q = pqueue_new()) == NULL)
		goto err;

	if (s->server)
		s->d1->cookie_len = sizeof(s->d1->cookie);

	s->method->ssl_clear(s);
	return (1);

 err:
	dtls1_free(s);
	return (0);
}

static void
dtls1_drain_rcontents(pqueue queue)
{
	DTLS1_RCONTENT_DATA_INTERNAL *rdata;
	pitem *item;

	if (queue == NULL)
		return;

	while ((item = pqueue_pop(queue)) != NULL) {
		rdata = (DTLS1_RCONTENT_DATA_INTERNAL *)item->data;
		tls_content_free(rdata->rcontent);
		free(item->data);
		pitem_free(item);
	}
}

static void
dtls1_drain_records(pqueue queue)
{
	pitem *item;
	DTLS1_RECORD_DATA_INTERNAL *rdata;

	if (queue == NULL)
		return;

	while ((item = pqueue_pop(queue)) != NULL) {
		rdata = (DTLS1_RECORD_DATA_INTERNAL *)item->data;
		ssl3_release_buffer(&rdata->rbuf);
		free(item->data);
		pitem_free(item);
	}
}

static void
dtls1_drain_fragments(pqueue queue)
{
	pitem *item;

	if (queue == NULL)
		return;

	while ((item = pqueue_pop(queue)) != NULL) {
		dtls1_hm_fragment_free(item->data);
		pitem_free(item);
	}
}

static void
dtls1_clear_queues(SSL *s)
{
	dtls1_drain_records(s->d1->unprocessed_rcds.q);
	dtls1_drain_fragments(s->d1->buffered_messages);
	dtls1_drain_fragments(s->d1->sent_messages);
	dtls1_drain_rcontents(s->d1->buffered_app_data.q);
}

void
dtls1_free(SSL *s)
{
	if (s == NULL)
		return;

	ssl3_free(s);

	if (s->d1 == NULL)
		return;

	dtls1_clear_queues(s);

	pqueue_free(s->d1->unprocessed_rcds.q);
	pqueue_free(s->d1->buffered_messages);
	pqueue_free(s->d1->sent_messages);
	pqueue_free(s->d1->buffered_app_data.q);

	dtls12_handshake_msg_free(s->d1->hs_msg);

	freezero(s->d1, sizeof(*s->d1));
	s->d1 = NULL;
}

void
dtls1_clear(SSL *s)
{
	pqueue unprocessed_rcds;
	pqueue buffered_messages;
	pqueue sent_messages;
	pqueue buffered_app_data;
	unsigned int mtu;

	if (s->d1) {
		unprocessed_rcds = s->d1->unprocessed_rcds.q;
		buffered_messages = s->d1->buffered_messages;
		sent_messages = s->d1->sent_messages;
		buffered_app_data = s->d1->buffered_app_data.q;
		mtu = s->d1->mtu;

		dtls12_handshake_msg_free(s->d1->hs_msg);
		s->d1->hs_msg = NULL;

		dtls1_clear_queues(s);

		memset(s->d1, 0, sizeof(*s->d1));

		s->d1->unprocessed_rcds.epoch =
		    tls12_record_layer_read_epoch(s->rl) + 1;

		if (s->server) {
			s->d1->cookie_len = sizeof(s->d1->cookie);
		}

		if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU) {
			s->d1->mtu = mtu;
		}

		s->d1->unprocessed_rcds.q = unprocessed_rcds;
		s->d1->buffered_messages = buffered_messages;
		s->d1->sent_messages = sent_messages;
		s->d1->buffered_app_data.q = buffered_app_data;
	}

	ssl3_clear(s);

	s->version = DTLS1_VERSION;
}

long
dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
{
	int ret = 0;

	switch (cmd) {
	case DTLS_CTRL_GET_TIMEOUT:
		if (dtls1_get_timeout(s, (struct timeval*) parg) != NULL) {
			ret = 1;
		}
		break;
	case DTLS_CTRL_HANDLE_TIMEOUT:
		ret = dtls1_handle_timeout(s);
		break;
	case DTLS_CTRL_LISTEN:
		ret = dtls1_listen(s, parg);
		break;

	default:
		ret = ssl3_ctrl(s, cmd, larg, parg);
		break;
	}
	return (ret);
}

void
dtls1_start_timer(SSL *s)
{

	/* If timer is not set, initialize duration with 1 second */
	if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
		s->d1->timeout_duration = 1;
	}

	/* Set timeout to current time */
	gettimeofday(&(s->d1->next_timeout), NULL);

	/* Add duration to current time */
	s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
	BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
	    &s->d1->next_timeout);
}

struct timeval*
dtls1_get_timeout(SSL *s, struct timeval* timeleft)
{
	struct timeval timenow;

	/* If no timeout is set, just return NULL */
	if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
		return NULL;
	}

	/* Get current time */
	gettimeofday(&timenow, NULL);

	/* If timer already expired, set remaining time to 0 */
	if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
	    (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
	     s->d1->next_timeout.tv_usec <= timenow.tv_usec)) {
		memset(timeleft, 0, sizeof(struct timeval));
		return timeleft;
	}

	/* Calculate time left until timer expires */
	memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
	timeleft->tv_sec -= timenow.tv_sec;
	timeleft->tv_usec -= timenow.tv_usec;
	if (timeleft->tv_usec < 0) {
		timeleft->tv_sec--;
		timeleft->tv_usec += 1000000;
	}

	/* If remaining time is less than 15 ms, set it to 0
	 * to prevent issues because of small devergences with
	 * socket timeouts.
	 */
	if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) {
		memset(timeleft, 0, sizeof(struct timeval));
	}


	return timeleft;
}

int
dtls1_is_timer_expired(SSL *s)
{
	struct timeval timeleft;

	/* Get time left until timeout, return false if no timer running */
	if (dtls1_get_timeout(s, &timeleft) == NULL) {
		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 *s)
{
	s->d1->timeout_duration *= 2;
	if (s->d1->timeout_duration > 60)
		s->d1->timeout_duration = 60;
	dtls1_start_timer(s);
}

void
dtls1_stop_timer(SSL *s)
{
	/* Reset everything */
	memset(&(s->d1->timeout), 0, sizeof(struct dtls1_timeout_st));
	memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
	s->d1->timeout_duration = 1;
	BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
	    &(s->d1->next_timeout));
	/* Clear retransmission buffer */
	dtls1_clear_record_buffer(s);
}

int
dtls1_check_timeout_num(SSL *s)
{
	s->d1->timeout.num_alerts++;

	/* Reduce MTU after 2 unsuccessful retransmissions */
	if (s->d1->timeout.num_alerts > 2) {
		s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
		    BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);

	}

	if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) {
		/* fail the connection, enough alerts have been sent */
		SSLerror(s, SSL_R_READ_TIMEOUT_EXPIRED);
		return -1;
	}

	return 0;
}

int
dtls1_handle_timeout(SSL *s)
{
	/* if no timer is expired, don't do anything */
	if (!dtls1_is_timer_expired(s)) {
		return 0;
	}

	dtls1_double_timeout(s);

	if (dtls1_check_timeout_num(s) < 0)
		return -1;

	s->d1->timeout.read_timeouts++;
	if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) {
		s->d1->timeout.read_timeouts = 1;
	}

	dtls1_start_timer(s);
	return dtls1_retransmit_buffered_messages(s);
}

int
dtls1_listen(SSL *s, struct sockaddr *client)
{
	int ret;

	/* Ensure there is no state left over from a previous invocation */
	SSL_clear(s);

	SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
	s->d1->listen = 1;

	ret = SSL_accept(s);
	if (ret <= 0)
		return ret;

	(void)BIO_dgram_get_peer(SSL_get_rbio(s), client);
	return 1;
}
IABSD.fr/src/lib/libssl/d1_lib.c

Commit

IABSD.fr/src /lib/libssl/d1_lib.c
