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/* ssl/d1_lib.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).
*
*/
#include <stdio.h>
#define USE_SOCKETS
#include <openssl/objects.h>
#include "ssl_locl.h"
#if defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VMS)
#include <sys/timeb.h>
#endif
static void get_current_time(struct timeval *t);
const char dtls1_version_str[]="DTLSv1" OPENSSL_VERSION_PTEXT;
int dtls1_listen(SSL *s, struct sockaddr *client);
SSL3_ENC_METHOD DTLSv1_enc_data={
dtls1_enc,
tls1_mac,
tls1_setup_key_block,
tls1_generate_master_secret,
tls1_change_cipher_state,
tls1_final_finish_mac,
TLS1_FINISH_MAC_LENGTH,
tls1_cert_verify_mac,
TLS_MD_CLIENT_FINISH_CONST,TLS_MD_CLIENT_FINISH_CONST_SIZE,
TLS_MD_SERVER_FINISH_CONST,TLS_MD_SERVER_FINISH_CONST_SIZE,
tls1_alert_code,
tls1_export_keying_material,
};
long dtls1_default_timeout(void)
{
/* 2 hours, the 24 hours mentioned in the DTLSv1 spec
* is way too long for http, the cache would over fill */
return(60*60*2);
}
int dtls1_new(SSL *s)
{
DTLS1_STATE *d1;
if (!ssl3_new(s)) return(0);
if ((d1=OPENSSL_malloc(sizeof *d1)) == NULL) return (0);
memset(d1,0, sizeof *d1);
/* d1->handshake_epoch=0; */
d1->unprocessed_rcds.q=pqueue_new();
d1->processed_rcds.q=pqueue_new();
d1->buffered_messages = pqueue_new();
d1->sent_messages=pqueue_new();
d1->buffered_app_data.q=pqueue_new();
if ( s->server)
{
d1->cookie_len = sizeof(s->d1->cookie);
}
d1->link_mtu = 0;
d1->mtu = 0;
if( ! d1->unprocessed_rcds.q || ! d1->processed_rcds.q
|| ! d1->buffered_messages || ! d1->sent_messages || ! d1->buffered_app_data.q)
{
if ( d1->unprocessed_rcds.q) pqueue_free(d1->unprocessed_rcds.q);
if ( d1->processed_rcds.q) pqueue_free(d1->processed_rcds.q);
if ( d1->buffered_messages) pqueue_free(d1->buffered_messages);
if ( d1->sent_messages) pqueue_free(d1->sent_messages);
if ( d1->buffered_app_data.q) pqueue_free(d1->buffered_app_data.q);
OPENSSL_free(d1);
return (0);
}
s->d1=d1;
s->method->ssl_clear(s);
return(1);
}
static void dtls1_clear_queues(SSL *s)
{
pitem *item = NULL;
hm_fragment *frag = NULL;
DTLS1_RECORD_DATA *rdata;
while( (item = pqueue_pop(s->d1->unprocessed_rcds.q)) != NULL)
{
rdata = (DTLS1_RECORD_DATA *) item->data;
if (rdata->rbuf.buf)
{
OPENSSL_free(rdata->rbuf.buf);
}
OPENSSL_free(item->data);
pitem_free(item);
}
while( (item = pqueue_pop(s->d1->processed_rcds.q)) != NULL)
{
rdata = (DTLS1_RECORD_DATA *) item->data;
if (rdata->rbuf.buf)
{
OPENSSL_free(rdata->rbuf.buf);
}
OPENSSL_free(item->data);
pitem_free(item);
}
while( (item = pqueue_pop(s->d1->buffered_messages)) != NULL)
{
frag = (hm_fragment *)item->data;
dtls1_hm_fragment_free(frag);
pitem_free(item);
}
while ( (item = pqueue_pop(s->d1->sent_messages)) != NULL)
{
frag = (hm_fragment *)item->data;
dtls1_hm_fragment_free(frag);
pitem_free(item);
}
while ( (item = pqueue_pop(s->d1->buffered_app_data.q)) != NULL)
{
rdata = (DTLS1_RECORD_DATA *) item->data;
if (rdata->rbuf.buf)
{
OPENSSL_free(rdata->rbuf.buf);
}
OPENSSL_free(item->data);
pitem_free(item);
}
}
void dtls1_free(SSL *s)
{
ssl3_free(s);
dtls1_clear_queues(s);
pqueue_free(s->d1->unprocessed_rcds.q);
pqueue_free(s->d1->processed_rcds.q);
pqueue_free(s->d1->buffered_messages);
pqueue_free(s->d1->sent_messages);
pqueue_free(s->d1->buffered_app_data.q);
OPENSSL_free(s->d1);
s->d1 = NULL;
}
void dtls1_clear(SSL *s)
{
pqueue unprocessed_rcds;
pqueue processed_rcds;
pqueue buffered_messages;
pqueue sent_messages;
pqueue buffered_app_data;
unsigned int mtu;
unsigned int link_mtu;
if (s->d1)
{
unprocessed_rcds = s->d1->unprocessed_rcds.q;
processed_rcds = s->d1->processed_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;
link_mtu = s->d1->link_mtu;
dtls1_clear_queues(s);
memset(s->d1, 0, sizeof(*(s->d1)));
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->link_mtu = link_mtu;
}
s->d1->unprocessed_rcds.q = unprocessed_rcds;
s->d1->processed_rcds.q = processed_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);
if (s->options & SSL_OP_CISCO_ANYCONNECT)
s->version=DTLS1_BAD_VER;
else
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;
case SSL_CTRL_CHECK_PROTO_VERSION:
/* For library-internal use; checks that the current protocol
* is the highest enabled version (according to s->ctx->method,
* as version negotiation may have changed s->method). */
#if DTLS_MAX_VERSION != DTLS1_VERSION
# error Code needs update for DTLS_method() support beyond DTLS1_VERSION.
#endif
/* Just one protocol version is supported so far;
* fail closed if the version is not as expected. */
return s->version == DTLS_MAX_VERSION;
case DTLS_CTRL_SET_LINK_MTU:
if (larg < (long)dtls1_link_min_mtu())
return 0;
s->d1->link_mtu = larg;
return 1;
case DTLS_CTRL_GET_LINK_MIN_MTU:
return (long)dtls1_link_min_mtu();
case SSL_CTRL_SET_MTU:
/*
* We may not have a BIO set yet so can't call dtls1_min_mtu()
* We'll have to make do with dtls1_link_min_mtu() and max overhead
*/
if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
return 0;
s->d1->mtu = larg;
return larg;
default:
ret = ssl3_ctrl(s, cmd, larg, parg);
break;
}
return(ret);
}
/*
* As it's impossible to use stream ciphers in "datagram" mode, this
* simple filter is designed to disengage them in DTLS. Unfortunately
* there is no universal way to identify stream SSL_CIPHER, so we have
* to explicitly list their SSL_* codes. Currently RC4 is the only one
* available, but if new ones emerge, they will have to be added...
*/
const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
{
const SSL_CIPHER *ciph = ssl3_get_cipher(u);
if (ciph != NULL)
{
if (ciph->algorithm_enc == SSL_RC4)
return NULL;
}
return ciph;
}
void dtls1_start_timer(SSL *s)
{
#ifndef OPENSSL_NO_SCTP
/* Disable timer for SCTP */
if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
{
memset(&(s->d1->next_timeout), 0, sizeof(struct timeval));
return;
}
#endif
/* 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 */
get_current_time(&(s->d1->next_timeout));
/* 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 */
get_current_time(&timenow);
/* 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)
{
unsigned int mtu;
s->d1->timeout.num_alerts++;
/* Reduce MTU after 2 unsuccessful retransmissions */
if (s->d1->timeout.num_alerts > 2
&& !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
{
mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
if(mtu < s->d1->mtu)
s->d1->mtu = mtu;
}
if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
{
/* fail the connection, enough alerts have been sent */
SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM,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;
}
#ifndef OPENSSL_NO_HEARTBEATS
if (s->tlsext_hb_pending)
{
s->tlsext_hb_pending = 0;
return dtls1_heartbeat(s);
}
#endif
dtls1_start_timer(s);
return dtls1_retransmit_buffered_messages(s);
}
static void get_current_time(struct timeval *t)
{
#ifdef OPENSSL_SYS_WIN32
struct _timeb tb;
_ftime(&tb);
t->tv_sec = (long)tb.time;
t->tv_usec = (long)tb.millitm * 1000;
#elif defined(OPENSSL_SYS_VMS)
struct timeb tb;
ftime(&tb);
t->tv_sec = (long)tb.time;
t->tv_usec = (long)tb.millitm * 1000;
#else
gettimeofday(t, NULL);
#endif
}
int dtls1_listen(SSL *s, struct sockaddr *client)
{
int ret;
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;
}