X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=ssl%2Fd1_both.c;h=a2a39baa60cdcaadbe5f85ecd3ca44641c6e8728;hp=808d4d14eb4aaa10902ed445e3de1694b9f214f8;hb=4ca0e95b92811f7dac9fff213350c248619a135c;hpb=1872083ca1171d40b9b519a9aefa3da7d47c5cea

diff --git a/ssl/d1_both.c b/ssl/d1_both.c
index 808d4d14eb..a2a39baa60 100644
--- a/ssl/d1_both.c
+++ b/ssl/d1_both.c
@@ -259,33 +259,12 @@ static int dtls1_query_mtu(SSL *s)
 int dtls1_do_write(SSL *s, int type)
 	{
 	int ret;
-	int curr_mtu;
-	unsigned int len, frag_off, mac_size, blocksize;
+	unsigned int curr_mtu;
+	int retry = 1;
+	unsigned int len, frag_off, mac_size, blocksize, used_len;
 
 	if(!dtls1_query_mtu(s))
 		return -1;
-#if 0 
-	mtu = s->d1->mtu;
-
-	fprintf(stderr, "using MTU = %d\n", mtu);
-
-	mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
-
-	curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
-
-	if ( curr_mtu > 0)
-		mtu = curr_mtu;
-	else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
-		return ret;
-
-	if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
-		{
-		ret = BIO_flush(SSL_get_wbio(s));
-		if ( ret <= 0)
-			return ret;
-		mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
-		}
-#endif
 
 	OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu(s));  /* should have something reasonable now */
 
@@ -310,10 +289,15 @@ int dtls1_do_write(SSL *s, int type)
 		blocksize = 0;
 
 	frag_off = 0;
-	while( s->init_num)
+	/* s->init_num shouldn't ever be < 0...but just in case */
+	while(s->init_num > 0)
 		{
-		curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) - 
-			DTLS1_RT_HEADER_LENGTH - mac_size - blocksize;
+		used_len = BIO_wpending(SSL_get_wbio(s)) +  DTLS1_RT_HEADER_LENGTH
+			+ mac_size + blocksize;
+		if(s->d1->mtu > used_len)
+			curr_mtu = s->d1->mtu - used_len;
+		else
+			curr_mtu = 0;
 
 		if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
 			{
@@ -321,15 +305,27 @@ int dtls1_do_write(SSL *s, int type)
 			ret = BIO_flush(SSL_get_wbio(s));
 			if ( ret <= 0)
 				return ret;
-			curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH -
-				mac_size - blocksize;
+			used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize;
+			if(s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH)
+				{
+				curr_mtu = s->d1->mtu - used_len;
+				}
+			else
+				{
+				/* Shouldn't happen */
+				return -1;
+				}
 			}
 
-		if ( s->init_num > curr_mtu)
+		/* We just checked that s->init_num > 0 so this cast should be safe */
+		if (((unsigned int)s->init_num) > curr_mtu)
 			len = curr_mtu;
 		else
 			len = s->init_num;
 
+		/* Shouldn't ever happen */
+		if(len > INT_MAX)
+			len = INT_MAX;
 
 		/* XDTLS: this function is too long.  split out the CCS part */
 		if ( type == SSL3_RT_HANDSHAKE)
@@ -340,12 +336,17 @@ int dtls1_do_write(SSL *s, int type)
 				s->init_off -= DTLS1_HM_HEADER_LENGTH;
 				s->init_num += DTLS1_HM_HEADER_LENGTH;
 
-				if ( s->init_num > curr_mtu)
+				/* We just checked that s->init_num > 0 so this cast should be safe */
+				if (((unsigned int)s->init_num) > curr_mtu)
 					len = curr_mtu;
 				else
 					len = s->init_num;
 				}
 
+			/* Shouldn't ever happen */
+			if(len > INT_MAX)
+				len = INT_MAX;
+
 			if ( len < DTLS1_HM_HEADER_LENGTH )
 				{
 				/*
@@ -370,13 +371,15 @@ int dtls1_do_write(SSL *s, int type)
 			 * is fine and wait for an alert to handle the
 			 * retransmit 
 			 */
-			if ( BIO_ctrl(SSL_get_wbio(s),
+			if ( retry && BIO_ctrl(SSL_get_wbio(s),
 				BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
 				{
 				if(!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 					{
 					if(!dtls1_query_mtu(s))
 						return -1;
+					/* Have one more go */
+					retry = 0;
 					}
 				else
 					return -1;