From: Dr. Stephen Henson <steve@openssl.org>
Date: Fri, 5 Jun 2009 14:46:49 +0000 (+0000)
Subject: PR: 1950
X-Git-Tag: OpenSSL_1_0_0-beta3~59
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=4e63da06698fd217d89a5ec39fd0c7b26dc8d0c0;p=oweals%2Fopenssl.git

PR: 1950
Submitted by: Robin Seggelmann <seggelmann@fh-muenster.de>
Reviewed by: steve@openssl.org

DTLS fragment retransmission bug.
---

diff --git a/crypto/bio/bss_dgram.c b/crypto/bio/bss_dgram.c
index 2e1a6fac33..027cdf943b 100644
--- a/crypto/bio/bss_dgram.c
+++ b/crypto/bio/bss_dgram.c
@@ -217,12 +217,19 @@ static void dgram_adjust_rcv_timeout(BIO *b)
 			timeleft.tv_usec += 1000000;
 			}
 
+		if (timeleft.tv_sec < 0)
+			{
+			timeleft.tv_sec = 0;
+			timeleft.tv_usec = 1;
+			}
+
 		/* Adjust socket timeout if next handhake message timer
 		 * will expire earlier.
 		 */
-		if (data->socket_timeout.tv_sec < timeleft.tv_sec ||
+		if ((data->socket_timeout.tv_sec == 0 && data->socket_timeout.tv_usec == 0) ||
+			(data->socket_timeout.tv_sec > timeleft.tv_sec) ||
 			(data->socket_timeout.tv_sec == timeleft.tv_sec &&
-			 data->socket_timeout.tv_usec <= timeleft.tv_usec))
+			 data->socket_timeout.tv_usec >= timeleft.tv_usec))
 			{
 #ifdef OPENSSL_SYS_WINDOWS
 			timeout = timeleft.tv_sec * 1000 + timeleft.tv_usec / 1000;
diff --git a/ssl/d1_both.c b/ssl/d1_both.c
index ebc03482f0..7039d05f0e 100644
--- a/ssl/d1_both.c
+++ b/ssl/d1_both.c
@@ -569,9 +569,13 @@ dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
 	item = pqueue_find(s->d1->buffered_messages, seq64be);
 	
 	/* Discard the message if sequence number was already there, is
-	 * too far in the future or the fragment is already in the queue */
+	 * too far in the future, already in the queue or if we received
+	 * a FINISHED before the SERVER_HELLO, which then must be a stale
+	 * retransmit.
+	 */
 	if (msg_hdr->seq <= s->d1->handshake_read_seq ||
-		msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL)
+		msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
+		s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)
 		{
 		unsigned char devnull [256];
 
diff --git a/ssl/d1_clnt.c b/ssl/d1_clnt.c
index 2364ad2f8d..a4a438ac79 100644
--- a/ssl/d1_clnt.c
+++ b/ssl/d1_clnt.c
@@ -442,7 +442,7 @@ int dtls1_connect(SSL *s)
 
 		case SSL3_ST_CR_FINISHED_A:
 		case SSL3_ST_CR_FINISHED_B:
-
+			s->d1->change_cipher_spec_ok = 1;
 			ret=ssl3_get_finished(s,SSL3_ST_CR_FINISHED_A,
 				SSL3_ST_CR_FINISHED_B);
 			if (ret <= 0) goto end;
diff --git a/ssl/d1_pkt.c b/ssl/d1_pkt.c
index a89edbc7a7..394daf6258 100644
--- a/ssl/d1_pkt.c
+++ b/ssl/d1_pkt.c
@@ -1102,6 +1102,16 @@ start:
 			s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 
 				rr->data, 1, s, s->msg_callback_arg);
 
+		/* We can't process a CCS now, because previous handshake
+		 * messages are still missing, so just drop it.
+		 */
+		if (!s->d1->change_cipher_spec_ok)
+			{
+			goto start;
+			}
+
+		s->d1->change_cipher_spec_ok = 0;
+
 		s->s3->change_cipher_spec=1;
 		if (!ssl3_do_change_cipher_spec(s))
 			goto err;
diff --git a/ssl/d1_srvr.c b/ssl/d1_srvr.c
index 6d6363f04f..ac09b45ef1 100644
--- a/ssl/d1_srvr.c
+++ b/ssl/d1_srvr.c
@@ -497,6 +497,7 @@ int dtls1_accept(SSL *s)
 		case SSL3_ST_SR_CERT_VRFY_A:
 		case SSL3_ST_SR_CERT_VRFY_B:
 
+			s->d1->change_cipher_spec_ok = 1;
 			/* we should decide if we expected this one */
 			ret=ssl3_get_cert_verify(s);
 			if (ret <= 0) goto end;
@@ -508,6 +509,7 @@ int dtls1_accept(SSL *s)
 
 		case SSL3_ST_SR_FINISHED_A:
 		case SSL3_ST_SR_FINISHED_B:
+			s->d1->change_cipher_spec_ok = 1;
 			ret=ssl3_get_finished(s,SSL3_ST_SR_FINISHED_A,
 				SSL3_ST_SR_FINISHED_B);
 			if (ret <= 0) goto end;
diff --git a/ssl/dtls1.h b/ssl/dtls1.h
index 2fe0405011..73af56d45c 100644
--- a/ssl/dtls1.h
+++ b/ssl/dtls1.h
@@ -231,6 +231,7 @@ typedef struct dtls1_state_st
 	unsigned int handshake_fragment_len;
 
 	unsigned int retransmitting;
+	unsigned int change_cipher_spec_ok;
 
 	} DTLS1_STATE;