PR: 2535

Submitted by: Robin Seggelmann <seggelmann@fh-muenster.de>
Reviewed by: steve

Add SCTP support for DTLS (RFC 6083).

8 files changed, 474 insertions, 31 deletions

diff --git a/ssl/d1_both.c b/ssl/d1_both.c
index 9f898d6997..89338e9430 100644
--- a/ssl/d1_both.c
+++ b/ssl/d1_both.c
@@ -1417,3 +1417,24 @@ dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
 
 	ccs_hdr->type = *(data++);
 	}
+
+int dtls1_shutdown(SSL *s)
+	{
+	int ret;
+#ifndef OPENSSL_NO_SCTP
+	if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
+	    !(s->shutdown & SSL_SENT_SHUTDOWN))
+		{
+		ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
+		if (ret < 0) return -1;
+
+		if (ret == 0)
+			BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL);
+		}
+#endif
+	ret = ssl3_shutdown(s);
+#ifndef OPENSSL_NO_SCTP
+	BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
+#endif
+	return ret;
+	}
diff --git a/ssl/d1_clnt.c b/ssl/d1_clnt.c
index aacfacf4b5..8a0d6fc07c 100644
--- a/ssl/d1_clnt.c
+++ b/ssl/d1_clnt.c
@@ -150,7 +150,11 @@ int dtls1_connect(SSL *s)
 	unsigned long Time=(unsigned long)time(NULL);
 	void (*cb)(const SSL *ssl,int type,int val)=NULL;
 	int ret= -1;
-	int new_state,state,skip=0;;
+	int new_state,state,skip=0;
+#ifndef OPENSSL_NO_SCTP
+	unsigned char sctpauthkey[64];
+	char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];
+#endif
 
 	RAND_add(&Time,sizeof(Time),0);
 	ERR_clear_error();
@@ -164,6 +168,14 @@ int dtls1_connect(SSL *s)
 	s->in_handshake++;
 	if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s); 
 
+#ifndef OPENSSL_NO_SCTP
+	/* Notify SCTP BIO socket to enter handshake
+	 * mode and prevent stream identifier other
+	 * than 0. Will be ignored if no SCTP is used.
+	 */
+	BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE, s->in_handshake, NULL);
+#endif
+
 	for (;;)
 		{
 		state=s->state;
@@ -226,6 +238,42 @@ int dtls1_connect(SSL *s)
 			s->hit = 0;
 			break;
 
+#ifndef OPENSSL_NO_SCTP
+		case DTLS1_SCTP_ST_CR_READ_SOCK:
+
+			if (BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
+			{
+				s->s3->in_read_app_data=2;
+				s->rwstate=SSL_READING;
+				BIO_clear_retry_flags(SSL_get_rbio(s));
+				BIO_set_retry_read(SSL_get_rbio(s));
+				ret = -1;
+				goto end;
+			}
+
+			s->state=s->s3->tmp.next_state;
+			break;
+
+		case DTLS1_SCTP_ST_CW_WRITE_SOCK:
+			/* read app data until dry event */
+
+			ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
+			if (ret < 0) goto end;
+
+			if (ret == 0)
+			{
+				s->s3->in_read_app_data=2;
+				s->rwstate=SSL_READING;
+				BIO_clear_retry_flags(SSL_get_rbio(s));
+				BIO_set_retry_read(SSL_get_rbio(s));
+				ret = -1;
+				goto end;
+			}
+
+			s->state=s->d1->next_state;
+			break;
+#endif
+
 		case SSL3_ST_CW_CLNT_HELLO_A:
 		case SSL3_ST_CW_CLNT_HELLO_B:
 
@@ -248,9 +296,17 @@ int dtls1_connect(SSL *s)
 
 			s->init_num=0;
 
-			/* turn on buffering for the next lot of output */
-			if (s->bbio != s->wbio)
-				s->wbio=BIO_push(s->bbio,s->wbio);
+#ifndef OPENSSL_NO_SCTP
+			/* Disable buffering for SCTP */
+			if (!BIO_dgram_is_sctp(SSL_get_wbio(s)))
+				{
+#endif
+				/* turn on buffering for the next lot of output */
+				if (s->bbio != s->wbio)
+					s->wbio=BIO_push(s->bbio,s->wbio);
+#ifndef OPENSSL_NO_SCTP
+				}
+#endif
 
 			break;
 
@@ -262,7 +318,24 @@ int dtls1_connect(SSL *s)
 				{
 				dtls1_stop_timer(s);
 				if (s->hit)
+					{
+#ifndef OPENSSL_NO_SCTP
+					/* Add new shared key for SCTP-Auth,
+					 * will be ignored if no SCTP used.
+					 */
+					snprintf((char*) labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
+					         DTLS1_SCTP_AUTH_LABEL);
+
+					SSL_export_keying_material(s, sctpauthkey,
+					                           sizeof(sctpauthkey), labelbuffer,
+					                           sizeof(labelbuffer), NULL, 0, 0);
+
+					BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
+							 sizeof(sctpauthkey), sctpauthkey);
+#endif
+
 					s->state=SSL3_ST_CR_FINISHED_A;
+					}
 				else
 					s->state=DTLS1_ST_CR_HELLO_VERIFY_REQUEST_A;
 				}
@@ -355,11 +428,18 @@ int dtls1_connect(SSL *s)
 			ret=ssl3_get_server_done(s);
 			if (ret <= 0) goto end;
 			if (s->s3->tmp.cert_req)
-				s->state=SSL3_ST_CW_CERT_A;
+				s->s3->tmp.next_state=SSL3_ST_CW_CERT_A;
 			else
-				s->state=SSL3_ST_CW_KEY_EXCH_A;
+				s->s3->tmp.next_state=SSL3_ST_CW_KEY_EXCH_A;
 			s->init_num=0;
 
+#ifndef OPENSSL_NO_SCTP			
+			if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
+			    state == SSL_ST_RENEGOTIATE)
+				s->state=DTLS1_SCTP_ST_CR_READ_SOCK;
+			else
+#endif			
+			s->state=s->s3->tmp.next_state;
 			break;
 
 		case SSL3_ST_CW_CERT_A:
@@ -378,6 +458,22 @@ int dtls1_connect(SSL *s)
 			dtls1_start_timer(s);
 			ret=dtls1_send_client_key_exchange(s);
 			if (ret <= 0) goto end;
+
+#ifndef OPENSSL_NO_SCTP
+			/* Add new shared key for SCTP-Auth,
+			 * will be ignored if no SCTP used.
+			 */
+			snprintf((char*) labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
+			         DTLS1_SCTP_AUTH_LABEL);
+
+			SSL_export_keying_material(s, sctpauthkey,
+			                           sizeof(sctpauthkey), labelbuffer,
+			                           sizeof(labelbuffer), NULL, 0, 0);
+
+			BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
+					 sizeof(sctpauthkey), sctpauthkey);
+#endif
+
 			/* EAY EAY EAY need to check for DH fix cert
 			 * sent back */
 			/* For TLS, cert_req is set to 2, so a cert chain
@@ -388,7 +484,15 @@ int dtls1_connect(SSL *s)
 				}
 			else
 				{
-				s->state=SSL3_ST_CW_CHANGE_A;
+#ifndef OPENSSL_NO_SCTP
+				if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
+					{
+					s->d1->next_state=SSL3_ST_CW_CHANGE_A;
+					s->state=DTLS1_SCTP_ST_CW_WRITE_SOCK;
+					}
+				else
+#endif
+					s->state=SSL3_ST_CW_CHANGE_A;
 				s->s3->change_cipher_spec=0;
 				}
 
@@ -400,7 +504,15 @@ int dtls1_connect(SSL *s)
 			dtls1_start_timer(s);
 			ret=dtls1_send_client_verify(s);
 			if (ret <= 0) goto end;
-			s->state=SSL3_ST_CW_CHANGE_A;
+#ifndef OPENSSL_NO_SCTP
+			if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
+			{
+				s->d1->next_state=SSL3_ST_CW_CHANGE_A;
+				s->state=DTLS1_SCTP_ST_CW_WRITE_SOCK;
+			}
+			else
+#endif
+				s->state=SSL3_ST_CW_CHANGE_A;
 			s->init_num=0;
 			s->s3->change_cipher_spec=0;
 			break;
@@ -412,6 +524,14 @@ int dtls1_connect(SSL *s)
 			ret=dtls1_send_change_cipher_spec(s,
 				SSL3_ST_CW_CHANGE_A,SSL3_ST_CW_CHANGE_B);
 			if (ret <= 0) goto end;
+
+#ifndef OPENSSL_NO_SCTP
+			/* Change to new shared key of SCTP-Auth,
+			 * will be ignored if no SCTP used.
+			 */
+			BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY, 0, NULL);
+#endif
+
 			s->state=SSL3_ST_CW_FINISHED_A;
 			s->init_num=0;
 
@@ -457,9 +577,23 @@ int dtls1_connect(SSL *s)
 			if (s->hit)
 				{
 				s->s3->tmp.next_state=SSL_ST_OK;
+#ifndef OPENSSL_NO_SCTP
+				if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
+					{
+						s->d1->next_state = s->s3->tmp.next_state;
+						s->s3->tmp.next_state=DTLS1_SCTP_ST_CW_WRITE_SOCK;
+					}
+#endif
 				if (s->s3->flags & SSL3_FLAGS_DELAY_CLIENT_FINISHED)
 					{
 					s->state=SSL_ST_OK;
+#ifndef OPENSSL_NO_SCTP
+					if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
+						{
+							s->d1->next_state = SSL_ST_OK;
+							s->state=DTLS1_SCTP_ST_CW_WRITE_SOCK;
+						}
+#endif
 					s->s3->flags|=SSL3_FLAGS_POP_BUFFER;
 					s->s3->delay_buf_pop_ret=0;
 					}
@@ -508,6 +642,16 @@ int dtls1_connect(SSL *s)
 				s->state=SSL3_ST_CW_CHANGE_A;
 			else
 				s->state=SSL_ST_OK;
+
+#ifndef OPENSSL_NO_SCTP
+			if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
+				state == SSL_ST_RENEGOTIATE)
+				{
+				s->d1->next_state=s->state;
+				s->state=DTLS1_SCTP_ST_CW_WRITE_SOCK;
+				}
+#endif
+
 			s->init_num=0;
 			break;
 
@@ -515,6 +659,13 @@ int dtls1_connect(SSL *s)
 			s->rwstate=SSL_WRITING;
 			if (BIO_flush(s->wbio) <= 0)
 				{
+				/* If the write error was fatal, stop trying */
+				if (!BIO_should_retry(s->wbio))
+					{
+					s->rwstate=SSL_NOTHING;
+					s->state=s->s3->tmp.next_state;
+					}
+				
 				ret= -1;
 				goto end;
 				}
@@ -588,6 +739,15 @@ int dtls1_connect(SSL *s)
 		}
 end:
 	s->in_handshake--;
+	
+#ifndef OPENSSL_NO_SCTP
+	/* Notify SCTP BIO socket to leave handshake
+	 * mode and allow stream identifier other
+	 * than 0. Will be ignored if no SCTP is used.
+	 */
+	BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE, s->in_handshake, NULL);
+#endif
+
 	if (buf != NULL)
 		BUF_MEM_free(buf);
 	if (cb != NULL)
diff --git a/ssl/d1_lib.c b/ssl/d1_lib.c
index a94290a834..4999f0151b 100644
--- a/ssl/d1_lib.c
+++ b/ssl/d1_lib.c
@@ -292,6 +292,15 @@ const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
 
 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)
 		{
diff --git a/ssl/d1_pkt.c b/ssl/d1_pkt.c
index 77da0c975a..5fe1321fca 100644
--- a/ssl/d1_pkt.c
+++ b/ssl/d1_pkt.c
@@ -232,6 +232,14 @@ dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
 
 	item->data = rdata;
 
+#ifndef OPENSSL_NO_SCTP
+	/* Store bio_dgram_sctp_rcvinfo struct */
+	if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
+	    (s->state == SSL3_ST_SR_FINISHED_A || s->state == SSL3_ST_CR_FINISHED_A)) {
+		BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
+	}
+#endif
+
 	/* insert should not fail, since duplicates are dropped */
 	if (pqueue_insert(queue->q, item) == NULL)
 		{
@@ -638,20 +646,28 @@ again:
 		goto again;   /* get another record */
 		}
 
-	/* Check whether this is a repeat, or aged record.
-	 * Don't check if we're listening and this message is
-	 * a ClientHello. They can look as if they're replayed,
-	 * since they arrive from different connections and
-	 * would be dropped unnecessarily.
-	 */
-	if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
-		*p == SSL3_MT_CLIENT_HELLO) &&
-		!dtls1_record_replay_check(s, bitmap))
-		{
-		rr->length = 0;
-		s->packet_length=0; /* dump this record */
-		goto again;     /* get another record */
-		}
+#ifndef OPENSSL_NO_SCTP
+	/* Only do replay check if no SCTP bio */
+	if (!BIO_dgram_is_sctp(SSL_get_rbio(s)))
+  		{
+#endif
+		/* Check whether this is a repeat, or aged record.
+		 * Don't check if we're listening and this message is
+		 * a ClientHello. They can look as if they're replayed,
+		 * since they arrive from different connections and
+		 * would be dropped unnecessarily.
+		 */
+		if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
+		    *p == SSL3_MT_CLIENT_HELLO) &&
+		    !dtls1_record_replay_check(s, bitmap))
+			{
+			rr->length = 0;
+			s->packet_length=0; /* dump this record */
+			goto again;     /* get another record */
+			}
+#ifndef OPENSSL_NO_SCTP
+  		}
+#endif
 
 	/* just read a 0 length packet */
 	if (rr->length == 0) goto again;
@@ -737,7 +753,17 @@ int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 
 	/* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 
+#ifndef OPENSSL_NO_SCTP
+	/* Continue handshake if it had to be interrupted to read
+	 * app data with SCTP.
+	 */
+	if ((!s->in_handshake && SSL_in_init(s)) ||
+	    (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
+	     (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK) &&
+	     s->s3->in_read_app_data != 2))
+#else
 	if (!s->in_handshake && SSL_in_init(s))
+#endif
 		{
 		/* type == SSL3_RT_APPLICATION_DATA */
 		i=s->handshake_func(s);
@@ -768,6 +794,15 @@ start:
 		item = pqueue_pop(s->d1->buffered_app_data.q);
 		if (item)
 			{
+#ifndef OPENSSL_NO_SCTP
+			/* Restore bio_dgram_sctp_rcvinfo struct */
+			if (BIO_dgram_is_sctp(SSL_get_rbio(s)))
+				{
+				DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *) item->data;
+				BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
+				}
+#endif
+
 			dtls1_copy_record(s, item);
 
 			OPENSSL_free(item->data);
@@ -850,6 +885,31 @@ start:
 				rr->off=0;
 				}
 			}
+
+#ifndef OPENSSL_NO_SCTP
+			/* We were about to renegotiate but had to read
+			 * belated application data first, so retry.
+			 */
+			if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
+			    rr->type == SSL3_RT_APPLICATION_DATA &&
+			    (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK))
+				{
+				s->rwstate=SSL_READING;
+				BIO_clear_retry_flags(SSL_get_rbio(s));
+				BIO_set_retry_read(SSL_get_rbio(s));
+				}
+
+			/* We might had to delay a close_notify alert because
+			 * of reordered app data. If there was an alert and there
+			 * is no message to read anymore, finally set shutdown.
+			 */
+			if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
+			    s->d1->shutdown_received && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
+				{
+				s->shutdown |= SSL_RECEIVED_SHUTDOWN;
+				return(0);
+				}
+#endif			
 		return(n);
 		}
 
@@ -1022,6 +1082,21 @@ start:
 			s->s3->warn_alert = alert_descr;
 			if (alert_descr == SSL_AD_CLOSE_NOTIFY)
 				{
+#ifndef OPENSSL_NO_SCTP
+				/* With SCTP and streams the socket may deliver app data
+				 * after a close_notify alert. We have to check this
+				 * first so that nothing gets discarded.
+				 */
+				if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
+					BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
+					{
+					s->d1->shutdown_received = 1;
+					s->rwstate=SSL_READING;
+					BIO_clear_retry_flags(SSL_get_rbio(s));
+					BIO_set_retry_read(SSL_get_rbio(s));
+					return -1;
+					}
+#endif
 				s->shutdown |= SSL_RECEIVED_SHUTDOWN;
 				return(0);
 				}
@@ -1128,6 +1203,15 @@ start:
 		if (s->version == DTLS1_BAD_VER)
 			s->d1->handshake_read_seq++;
 
+#ifndef OPENSSL_NO_SCTP
+		/* Remember that a CCS has been received,
+		 * so that an old key of SCTP-Auth can be
+		 * deleted when a CCS is sent. Will be ignored
+		 * if no SCTP is used
+		 */
+		BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
+#endif
+
 		goto start;
 		}
 
@@ -1264,7 +1348,16 @@ dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
 	{
 	int i;
 
-	if (SSL_in_init(s) && !s->in_handshake)
+#ifndef OPENSSL_NO_SCTP
+		/* Check if we have to continue an interrupted handshake
+		 * for reading belated app data with SCTP.
+		 */
+		if ((SSL_in_init(s) && !s->in_handshake) ||
+		    (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
+		     (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)))
+#else
+		if (SSL_in_init(s) && !s->in_handshake)
+#endif
 		{
 		i=s->handshake_func(s);
 		if (i < 0) return(i);
diff --git a/ssl/d1_srvr.c b/ssl/d1_srvr.c
index 360f873463..24e0553086 100644
--- a/ssl/d1_srvr.c
+++ b/ssl/d1_srvr.c
@@ -151,6 +151,10 @@ int dtls1_accept(SSL *s)
 	int ret= -1;
 	int new_state,state,skip=0;
 	int listen;
+#ifndef OPENSSL_NO_SCTP
+	unsigned char sctpauthkey[64];
+	char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];
+#endif
 
 	RAND_add(&Time,sizeof(Time),0);
 	ERR_clear_error();
@@ -168,6 +172,13 @@ int dtls1_accept(SSL *s)
 	if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s);
 
 	s->d1->listen = listen;
+#ifndef OPENSSL_NO_SCTP
+	/* Notify SCTP BIO socket to enter handshake
+	 * mode and prevent stream identifier other
+	 * than 0. Will be ignored if no SCTP is used.
+	 */
+	BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE, s->in_handshake, NULL);
+#endif
 
 	if (s->cert == NULL)
 		{
@@ -227,8 +238,12 @@ int dtls1_accept(SSL *s)
 				{
 				/* Ok, we now need to push on a buffering BIO so that
 				 * the output is sent in a way that TCP likes :-)
+				 * ...but not with SCTP :-)
 				 */
-				if (!ssl_init_wbio_buffer(s,1)) { ret= -1; goto end; }
+#ifndef OPENSSL_NO_SCTP
+				if (!BIO_dgram_is_sctp(SSL_get_wbio(s)))
+#endif
+					if (!ssl_init_wbio_buffer(s,1)) { ret= -1; goto end; }
 
 				ssl3_init_finished_mac(s);
 				s->state=SSL3_ST_SR_CLNT_HELLO_A;
@@ -313,6 +328,43 @@ int dtls1_accept(SSL *s)
 				ssl3_init_finished_mac(s);
 			break;
 			
+#ifndef OPENSSL_NO_SCTP
+		case DTLS1_SCTP_ST_SR_READ_SOCK:
+			
+			if (BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))		
+				{
+				s->s3->in_read_app_data=2;
+				s->rwstate=SSL_READING;
+				BIO_clear_retry_flags(SSL_get_rbio(s));
+				BIO_set_retry_read(SSL_get_rbio(s));
+				ret = -1;
+				goto end;
+				}
+			
+			s->state=SSL3_ST_SR_FINISHED_A;
+			break;
+			
+		case DTLS1_SCTP_ST_SW_WRITE_SOCK:
+			ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
+			if (ret < 0) goto end;
+			
+			if (ret == 0)
+				{
+				if (s->d1->next_state != SSL_ST_OK)
+					{
+					s->s3->in_read_app_data=2;
+					s->rwstate=SSL_READING;
+					BIO_clear_retry_flags(SSL_get_rbio(s));
+					BIO_set_retry_read(SSL_get_rbio(s));
+					ret = -1;
+					goto end;
+					}
+				}
+
+			s->state=s->d1->next_state;
+			break;
+#endif
+
 		case SSL3_ST_SW_SRVR_HELLO_A:
 		case SSL3_ST_SW_SRVR_HELLO_B:
 			s->renegotiate = 2;
@@ -320,18 +372,31 @@ int dtls1_accept(SSL *s)
 			ret=dtls1_send_server_hello(s);
 			if (ret <= 0) goto end;
 
-#ifndef OPENSSL_NO_TLSEXT
 			if (s->hit)
 				{
+#ifndef OPENSSL_NO_SCTP
+				/* Add new shared key for SCTP-Auth,
+				 * will be ignored if no SCTP used.
+				 */
+				snprintf((char*) labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
+				         DTLS1_SCTP_AUTH_LABEL);
+
+				SSL_export_keying_material(s, sctpauthkey,
+				                           sizeof(sctpauthkey), labelbuffer,
+				                           sizeof(labelbuffer), NULL, 0, 0);
+				
+				BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
+                         sizeof(sctpauthkey), sctpauthkey);
+#endif
+#ifndef OPENSSL_NO_TLSEXT
 				if (s->tlsext_ticket_expected)
 					s->state=SSL3_ST_SW_SESSION_TICKET_A;
 				else
 					s->state=SSL3_ST_SW_CHANGE_A;
-				}
 #else
-			if (s->hit)
-					s->state=SSL3_ST_SW_CHANGE_A;
+				s->state=SSL3_ST_SW_CHANGE_A;
 #endif
+				}
 			else
 				s->state=SSL3_ST_SW_CERT_A;
 			s->init_num=0;
@@ -441,6 +506,13 @@ int dtls1_accept(SSL *s)
 				skip=1;
 				s->s3->tmp.cert_request=0;
 				s->state=SSL3_ST_SW_SRVR_DONE_A;
+#ifndef OPENSSL_NO_SCTP
+				if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
+					{
+					s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
+					s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
+					}
+#endif
 				}
 			else
 				{
@@ -450,9 +522,23 @@ int dtls1_accept(SSL *s)
 				if (ret <= 0) goto end;
 #ifndef NETSCAPE_HANG_BUG
 				s->state=SSL3_ST_SW_SRVR_DONE_A;
+#ifndef OPENSSL_NO_SCTP
+				if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
+					{
+					s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
+					s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
+					}
+#endif
 #else
 				s->state=SSL3_ST_SW_FLUSH;
 				s->s3->tmp.next_state=SSL3_ST_SR_CERT_A;
+#ifndef OPENSSL_NO_SCTP
+				if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
+					{
+					s->d1->next_state = s->s3->tmp.next_state;
+					s->s3->tmp.next_state=DTLS1_SCTP_ST_SW_WRITE_SOCK;
+					}
+#endif
 #endif
 				s->init_num=0;
 				}
@@ -472,6 +558,13 @@ int dtls1_accept(SSL *s)
 			s->rwstate=SSL_WRITING;
 			if (BIO_flush(s->wbio) <= 0)
 				{
+				/* If the write error was fatal, stop trying */
+				if (!BIO_should_retry(s->wbio))
+					{
+					s->rwstate=SSL_NOTHING;
+					s->state=s->s3->tmp.next_state;
+					}
+				
 				ret= -1;
 				goto end;
 				}
@@ -504,6 +597,21 @@ int dtls1_accept(SSL *s)
 			ret=ssl3_get_client_key_exchange(s);
 			if (ret <= 0) goto end;
 			dtls1_stop_timer(s);
+#ifndef OPENSSL_NO_SCTP
+			/* Add new shared key for SCTP-Auth,
+			 * will be ignored if no SCTP used.
+			 */
+			snprintf((char *) labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
+			         DTLS1_SCTP_AUTH_LABEL);
+
+			SSL_export_keying_material(s, sctpauthkey,
+			                           sizeof(sctpauthkey), labelbuffer,
+			                           sizeof(labelbuffer), NULL, 0, 0);
+
+			BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
+			         sizeof(sctpauthkey), sctpauthkey);
+#endif
+
 			s->state=SSL3_ST_SR_CERT_VRFY_A;
 			s->init_num=0;
 
@@ -541,8 +649,13 @@ int dtls1_accept(SSL *s)
 			ret=ssl3_get_cert_verify(s);
 			if (ret <= 0) goto end;
 			dtls1_stop_timer(s);
-
-			s->state=SSL3_ST_SR_FINISHED_A;
+#ifndef OPENSSL_NO_SCTP
+			if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
+			    state == SSL_ST_RENEGOTIATE)
+				s->state=DTLS1_SCTP_ST_SR_READ_SOCK;
+			else
+#endif			
+				s->state=SSL3_ST_SR_FINISHED_A;
 			s->init_num=0;
 			break;
 
@@ -594,6 +707,14 @@ int dtls1_accept(SSL *s)
 				SSL3_ST_SW_CHANGE_A,SSL3_ST_SW_CHANGE_B);
 
 			if (ret <= 0) goto end;
+
+#ifndef OPENSSL_NO_SCTP
+			/* Change to new shared key of SCTP-Auth,
+			 * will be ignored if no SCTP used.
+			 */
+			BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY, 0, NULL);
+#endif
+
 			s->state=SSL3_ST_SW_FINISHED_A;
 			s->init_num=0;
 
@@ -618,7 +739,16 @@ int dtls1_accept(SSL *s)
 			if (s->hit)
 				s->s3->tmp.next_state=SSL3_ST_SR_FINISHED_A;
 			else
+				{
 				s->s3->tmp.next_state=SSL_ST_OK;
+#ifndef OPENSSL_NO_SCTP
+				if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
+					{
+					s->d1->next_state = s->s3->tmp.next_state;
+					s->s3->tmp.next_state=DTLS1_SCTP_ST_SW_WRITE_SOCK;
+					}
+#endif
+				}
 			s->init_num=0;
 			break;
 
@@ -690,6 +820,14 @@ end:
 	/* BIO_flush(s->wbio); */
 
 	s->in_handshake--;
+#ifndef OPENSSL_NO_SCTP
+		/* Notify SCTP BIO socket to leave handshake
+		 * mode and prevent stream identifier other
+		 * than 0. Will be ignored if no SCTP is used.
+		 */
+		BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE, s->in_handshake, NULL);
+#endif
+
 	if (cb != NULL)
 		cb(s,SSL_CB_ACCEPT_EXIT,ret);
 	return(ret);
diff --git a/ssl/dtls1.h b/ssl/dtls1.h
index e9e4e5f226..f68a10f196 100644
--- a/ssl/dtls1.h
+++ b/ssl/dtls1.h
@@ -107,6 +107,9 @@ extern "C" {
 
 #ifndef OPENSSL_NO_SSL_INTERN
 
+#ifndef OPENSSL_NO_SCTP
+#define DTLS1_SCTP_AUTH_LABEL	"EXPORTER_DTLS_OVER_SCTP"
+#endif
 
 typedef struct dtls1_bitmap_st
 	{
@@ -245,6 +248,13 @@ typedef struct dtls1_state_st
 	unsigned int retransmitting;
 	unsigned int change_cipher_spec_ok;
 
+#ifndef OPENSSL_NO_SCTP
+	/* used when SSL_ST_XX_FLUSH is entered */
+	int next_state;
+
+	int shutdown_received;
+#endif
+
 	} DTLS1_STATE;
 
 typedef struct dtls1_record_data_st
@@ -253,6 +263,9 @@ typedef struct dtls1_record_data_st
 	unsigned int   packet_length;
 	SSL3_BUFFER    rbuf;
 	SSL3_RECORD    rrec;
+#ifndef OPENSSL_NO_SCTP
+	struct bio_dgram_sctp_rcvinfo recordinfo;
+#endif
 	} DTLS1_RECORD_DATA;
 
 #endif
diff --git a/ssl/ssl3.h b/ssl/ssl3.h
index 43aadbd013..1aa2f02d64 100644
--- a/ssl/ssl3.h
+++ b/ssl/ssl3.h
@@ -532,6 +532,10 @@ typedef struct ssl3_state_st
 /*client */
 /* extra state */
 #define SSL3_ST_CW_FLUSH		(0x100|SSL_ST_CONNECT)
+#ifndef OPENSSL_NO_SCTP
+#define DTLS1_SCTP_ST_CW_WRITE_SOCK			(0x310|SSL_ST_CONNECT)
+#define DTLS1_SCTP_ST_CR_READ_SOCK			(0x320|SSL_ST_CONNECT)
+#endif	
 /* write to server */
 #define SSL3_ST_CW_CLNT_HELLO_A		(0x110|SSL_ST_CONNECT)
 #define SSL3_ST_CW_CLNT_HELLO_B		(0x111|SSL_ST_CONNECT)
@@ -576,6 +580,10 @@ typedef struct ssl3_state_st
 /* server */
 /* extra state */
 #define SSL3_ST_SW_FLUSH		(0x100|SSL_ST_ACCEPT)
+#ifndef OPENSSL_NO_SCTP
+#define DTLS1_SCTP_ST_SW_WRITE_SOCK			(0x310|SSL_ST_ACCEPT)
+#define DTLS1_SCTP_ST_SR_READ_SOCK			(0x320|SSL_ST_ACCEPT)
+#endif	
 /* read from client */
 /* Do not change the number values, they do matter */
 #define SSL3_ST_SR_CLNT_HELLO_A		(0x110|SSL_ST_ACCEPT)
diff --git a/ssl/ssl_locl.h b/ssl/ssl_locl.h
index 80a0749d26..d03aa8d422 100644
--- a/ssl/ssl_locl.h
+++ b/ssl/ssl_locl.h
@@ -774,7 +774,7 @@ const SSL_METHOD *func_name(void)  \
 		ssl3_read, \
 		ssl3_peek, \
 		ssl3_write, \
-		ssl3_shutdown, \
+		dtls1_shutdown, \
 		ssl3_renegotiate, \
 		ssl3_renegotiate_check, \
 		dtls1_get_message, \
@@ -1041,6 +1041,7 @@ int	dtls1_connect(SSL *s);
 void dtls1_free(SSL *s);
 void dtls1_clear(SSL *s);
 long dtls1_ctrl(SSL *s,int cmd, long larg, void *parg);
+int dtls1_shutdown(SSL *s);
 
 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok);
 int dtls1_get_record(SSL *s);