ssl/d1_lib.c - third_party/openssl - Git at Google

 /* 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_VMS)
 # include <sys/timeb.h>
 #elif defined(OPENSSL_SYS_NETWARE) && !defined(_WINSOCK2API_)
 # include <sys/timeval.h>
 #elif defined(OPENSSL_SYS_VXWORKS)
 # include <sys/times.h>
 #elif !defined(OPENSSL_SYS_WIN32)
 # include <sys/time.h>
 #endif

 static void get_current_time(struct timeval *t);
 static int dtls1_set_handshake_header(SSL *s, int type, unsigned long len);
 static int dtls1_handshake_write(SSL *s);
 const char dtls1_version_str[] = "DTLSv1" OPENSSL_VERSION_PTEXT;
 int dtls1_listen(SSL *s, struct sockaddr *client);

 const SSL3_ENC_METHOD DTLSv1_enc_data = {
     tls1_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,
     SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_EXPLICIT_IV,
     DTLS1_HM_HEADER_LENGTH,
     dtls1_set_handshake_header,
     dtls1_handshake_write
 };

 const SSL3_ENC_METHOD DTLSv1_2_enc_data = {
     tls1_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,
     SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_EXPLICIT_IV | SSL_ENC_FLAG_SIGALGS
         | SSL_ENC_FLAG_SHA256_PRF | SSL_ENC_FLAG_TLS1_2_CIPHERS,
     DTLS1_HM_HEADER_LENGTH,
     dtls1_set_handshake_header,
     dtls1_handshake_write
 };

 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 (!DTLS_RECORD_LAYER_new(&s->rlayer)) {
         return 0;
     }

     if (!ssl3_new(s))
         return (0);
     if ((d1 = OPENSSL_malloc(sizeof(*d1))) == NULL) {
         ssl3_free(s);
         return (0);
     }
     memset(d1, 0, sizeof(*d1));

     d1->buffered_messages = pqueue_new();
     d1->sent_messages = pqueue_new();

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

     d1->link_mtu = 0;
     d1->mtu = 0;

     if (!d1->buffered_messages || !d1->sent_messages) {
         pqueue_free(d1->buffered_messages);
         pqueue_free(d1->sent_messages);
         OPENSSL_free(d1);
         ssl3_free(s);
         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;

     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);
     }
 }

 void dtls1_free(SSL *s)
 {
     DTLS_RECORD_LAYER_free(&s->rlayer);

     ssl3_free(s);

     dtls1_clear_queues(s);

     pqueue_free(s->d1->buffered_messages);
     pqueue_free(s->d1->sent_messages);

     OPENSSL_free(s->d1);
     s->d1 = NULL;
 }

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

     DTLS_RECORD_LAYER_clear(&s->rlayer);

     if (s->d1) {
         buffered_messages = s->d1->buffered_messages;
         sent_messages = s->d1->sent_messages;
         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->buffered_messages = buffered_messages;
         s->d1->sent_messages = sent_messages;
     }

     ssl3_clear(s);
     if (s->options & SSL_OP_CISCO_ANYCONNECT)
         s->client_version = s->version = DTLS1_BAD_VER;
     else if (s->method->version == DTLS_ANY_VERSION)
         s->version = DTLS1_2_VERSION;
     else
         s->version = s->method->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 (s->version == s->ctx->method->version)
             return 1;
         /*
          * Apparently we're using a version-flexible SSL_METHOD (not at its
          * highest protocol version).
          */
         if (s->ctx->method->version == DTLS_method()->version) {
 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
 # error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
 #endif
             if (!(s->options & SSL_OP_NO_DTLSv1_2))
                 return s->version == DTLS1_2_VERSION;
             if (!(s->options & SSL_OP_NO_DTLSv1))
                 return s->version == DTLS1_VERSION;
         }
         return 0;               /* Unexpected state; fail closed. */
     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(s->d1->next_timeout));
         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(*timeleft));
         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(*timeleft));
     }

     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(s->d1->timeout));
     memset(&s->d1->next_timeout, 0, sizeof(s->d1->next_timeout));
     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)
 {
 #if defined(_WIN32)
     SYSTEMTIME st;
     union {
         unsigned __int64 ul;
         FILETIME ft;
     } now;

     GetSystemTime(&st);
     SystemTimeToFileTime(&st, &now.ft);
 # ifdef  __MINGW32__
     now.ul -= 116444736000000000ULL;
 # else
     now.ul -= 116444736000000000UI64; /* re-bias to 1/1/1970 */
 # endif
     t->tv_sec = (long)(now.ul / 10000000);
     t->tv_usec = ((int)(now.ul % 10000000)) / 10;
 #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;

     /* Ensure there is no state left over from a previous invocation */
     if (!SSL_clear(s))
         return -1;

     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;
 }

 static int dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
 {
     unsigned char *p = (unsigned char *)s->init_buf->data;
     dtls1_set_message_header(s, p, htype, len, 0, len);
     s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
     s->init_off = 0;
     /* Buffer the message to handle re-xmits */

     if (!dtls1_buffer_message(s, 0))
         return 0;

     return 1;
 }

 static int dtls1_handshake_write(SSL *s)
 {
     return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
 }
	/* 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_VMS)
	# include <sys/timeb.h>
	#elif defined(OPENSSL_SYS_NETWARE) && !defined(_WINSOCK2API_)
	# include <sys/timeval.h>
	#elif defined(OPENSSL_SYS_VXWORKS)
	# include <sys/times.h>
	#elif !defined(OPENSSL_SYS_WIN32)
	# include <sys/time.h>
	#endif

	static void get_current_time(struct timeval *t);
	static int dtls1_set_handshake_header(SSL *s, int type, unsigned long len);
	static int dtls1_handshake_write(SSL *s);
	const char dtls1_version_str[] = "DTLSv1" OPENSSL_VERSION_PTEXT;
	int dtls1_listen(SSL s, struct sockaddr client);

	const SSL3_ENC_METHOD DTLSv1_enc_data = {
	tls1_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,
	SSL_ENC_FLAG_DTLS \| SSL_ENC_FLAG_EXPLICIT_IV,
	DTLS1_HM_HEADER_LENGTH,
	dtls1_set_handshake_header,
	dtls1_handshake_write
	};

	const SSL3_ENC_METHOD DTLSv1_2_enc_data = {
	tls1_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,
	SSL_ENC_FLAG_DTLS \| SSL_ENC_FLAG_EXPLICIT_IV \| SSL_ENC_FLAG_SIGALGS
	\| SSL_ENC_FLAG_SHA256_PRF \| SSL_ENC_FLAG_TLS1_2_CIPHERS,
	DTLS1_HM_HEADER_LENGTH,
	dtls1_set_handshake_header,
	dtls1_handshake_write
	};

	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 (!DTLS_RECORD_LAYER_new(&s->rlayer)) {
	return 0;
	}

	if (!ssl3_new(s))
	return (0);
	if ((d1 = OPENSSL_malloc(sizeof(*d1))) == NULL) {
	ssl3_free(s);
	return (0);
	}
	memset(d1, 0, sizeof(*d1));

	d1->buffered_messages = pqueue_new();
	d1->sent_messages = pqueue_new();

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

	d1->link_mtu = 0;
	d1->mtu = 0;

	if (!d1->buffered_messages \|\| !d1->sent_messages) {
	pqueue_free(d1->buffered_messages);
	pqueue_free(d1->sent_messages);
	OPENSSL_free(d1);
	ssl3_free(s);
	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;

	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);
	}
	}

	void dtls1_free(SSL *s)
	{
	DTLS_RECORD_LAYER_free(&s->rlayer);

	ssl3_free(s);

	dtls1_clear_queues(s);

	pqueue_free(s->d1->buffered_messages);
	pqueue_free(s->d1->sent_messages);

	OPENSSL_free(s->d1);
	s->d1 = NULL;
	}

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

	DTLS_RECORD_LAYER_clear(&s->rlayer);

	if (s->d1) {
	buffered_messages = s->d1->buffered_messages;
	sent_messages = s->d1->sent_messages;
	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->buffered_messages = buffered_messages;
	s->d1->sent_messages = sent_messages;
	}

	ssl3_clear(s);
	if (s->options & SSL_OP_CISCO_ANYCONNECT)
	s->client_version = s->version = DTLS1_BAD_VER;
	else if (s->method->version == DTLS_ANY_VERSION)
	s->version = DTLS1_2_VERSION;
	else
	s->version = s->method->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 (s->version == s->ctx->method->version)
	return 1;
	/*
	* Apparently we're using a version-flexible SSL_METHOD (not at its
	* highest protocol version).
	*/
	if (s->ctx->method->version == DTLS_method()->version) {
	#if DTLS_MAX_VERSION != DTLS1_2_VERSION
	# error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
	#endif
	if (!(s->options & SSL_OP_NO_DTLSv1_2))
	return s->version == DTLS1_2_VERSION;
	if (!(s->options & SSL_OP_NO_DTLSv1))
	return s->version == DTLS1_VERSION;
	}
	return 0; /* Unexpected state; fail closed. */
	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(s->d1->next_timeout));
	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(*timeleft));
	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(*timeleft));
	}

	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(s->d1->timeout));
	memset(&s->d1->next_timeout, 0, sizeof(s->d1->next_timeout));
	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)
	{
	#if defined(_WIN32)
	SYSTEMTIME st;
	union {
	unsigned __int64 ul;
	FILETIME ft;
	} now;

	GetSystemTime(&st);
	SystemTimeToFileTime(&st, &now.ft);
	# ifdef __MINGW32__
	now.ul -= 116444736000000000ULL;
	# else
	now.ul -= 116444736000000000UI64; /* re-bias to 1/1/1970 */
	# endif
	t->tv_sec = (long)(now.ul / 10000000);
	t->tv_usec = ((int)(now.ul % 10000000)) / 10;
	#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;

	/* Ensure there is no state left over from a previous invocation */
	if (!SSL_clear(s))
	return -1;

	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;
	}

	static int dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
	{
	unsigned char p = (unsigned char )s->init_buf->data;
	dtls1_set_message_header(s, p, htype, len, 0, len);
	s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
	s->init_off = 0;
	/* Buffer the message to handle re-xmits */

	if (!dtls1_buffer_message(s, 0))
	return 0;

	return 1;
	}

	static int dtls1_handshake_write(SSL *s)
	{
	return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
	}