X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=ssl%2Fd1_pkt.c;h=d367524536a27b3c6fa802c8b0515be00c0b32bf;hp=bc75b537fbd948ce6ba7505948440a89cec98103;hb=b3a959a337b8083bc855623f24cebaf43a477350;hpb=b29b576957c53ca1eef1525f82dbad8d9a14fca2

diff --git a/ssl/d1_pkt.c b/ssl/d1_pkt.c
index bc75b537fb..d367524536 100644
--- a/ssl/d1_pkt.c
+++ b/ssl/d1_pkt.c
@@ -134,12 +134,11 @@ static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
 	unsigned short *priority, unsigned long *offset);
 #endif
 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
-	PQ_64BIT priority);
+	PQ_64BIT *priority);
 static int dtls1_process_record(SSL *s);
 #if PQ_64BIT_IS_INTEGER
 static PQ_64BIT bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num);
 #endif
-static void dtls1_clear_timeouts(SSL *s);
 
 /* copy buffered record into SSL structure */
 static int
@@ -156,13 +155,16 @@ dtls1_copy_record(SSL *s, pitem *item)
     s->packet_length = rdata->packet_length;
     memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
     memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
+	
+	/* Set proper sequence number for mac calculation */
+	memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
     
     return(1);
     }
 
 
 static int
-dtls1_buffer_record(SSL *s, record_pqueue *queue, PQ_64BIT priority)
+dtls1_buffer_record(SSL *s, record_pqueue *queue, PQ_64BIT *priority)
 {
     DTLS1_RECORD_DATA *rdata;
 	pitem *item;
@@ -172,7 +174,7 @@ dtls1_buffer_record(SSL *s, record_pqueue *queue, PQ_64BIT priority)
 		return 0;
 		
 	rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
-	item = pitem_new(priority, rdata);
+	item = pitem_new(*priority, rdata);
 	if (rdata == NULL || item == NULL)
 		{
 		if (rdata != NULL) OPENSSL_free(rdata);
@@ -253,9 +255,6 @@ dtls1_process_buffered_records(SSL *s)
     item = pqueue_peek(s->d1->unprocessed_rcds.q);
     if (item)
         {
-        DTLS1_RECORD_DATA *rdata;
-        rdata = (DTLS1_RECORD_DATA *)item->data;
-        
         /* Check if epoch is current. */
         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
             return(1);  /* Nothing to do. */
@@ -267,7 +266,7 @@ dtls1_process_buffered_records(SSL *s)
             if ( ! dtls1_process_record(s))
                 return(0);
             dtls1_buffer_record(s, &(s->d1->processed_rcds), 
-                s->s3->rrec.seq_num);
+                &s->s3->rrec.seq_num);
             }
         }
 
@@ -328,13 +327,16 @@ dtls1_get_buffered_record(SSL *s)
 static int
 dtls1_process_record(SSL *s)
 {
-    int i,al;
+    int al;
 	int clear=0;
     int enc_err;
 	SSL_SESSION *sess;
     SSL3_RECORD *rr;
 	unsigned int mac_size;
 	unsigned char md[EVP_MAX_MD_SIZE];
+	int decryption_failed_or_bad_record_mac = 0;
+	unsigned char *mac = NULL;
+	int i;
 
 
 	rr= &(s->s3->rrec);
@@ -365,16 +367,15 @@ dtls1_process_record(SSL *s)
 
 	/* decrypt in place in 'rr->input' */
 	rr->data=rr->input;
+	rr->orig_len=rr->length;
 
 	enc_err = s->method->ssl3_enc->enc(s,0);
 	if (enc_err <= 0)
 		{
-		if (enc_err == 0)
-			/* SSLerr() and ssl3_send_alert() have been called */
-			goto err;
-
-		/* otherwise enc_err == -1 */
-		goto decryption_failed_or_bad_record_mac;
+		/* To minimize information leaked via timing, we will always
+		 * perform all computations before discarding the message.
+		 */
+		decryption_failed_or_bad_record_mac = 1;
 		}
 
 #ifdef TLS_DEBUG
@@ -400,28 +401,32 @@ if (	(sess == NULL) ||
 			SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
 			goto f_err;
 #else
-			goto decryption_failed_or_bad_record_mac;
+			decryption_failed_or_bad_record_mac = 1;
 #endif			
 			}
 		/* check the MAC for rr->input (it's in mac_size bytes at the tail) */
-		if (rr->length < mac_size)
+		if (rr->length >= mac_size)
 			{
-#if 0 /* OK only for stream ciphers */
-			al=SSL_AD_DECODE_ERROR;
-			SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
-			goto f_err;
-#else
-			goto decryption_failed_or_bad_record_mac;
-#endif
+			rr->length -= mac_size;
+			mac = &rr->data[rr->length];
 			}
-		rr->length-=mac_size;
+		else
+			rr->length = 0;
 		i=s->method->ssl3_enc->mac(s,md,0);
-		if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
+		if (i < 0 || mac == NULL || CRYPTO_memcmp(md,mac,mac_size) != 0)
 			{
-			goto decryption_failed_or_bad_record_mac;
+			decryption_failed_or_bad_record_mac = 1;
 			}
 		}
 
+	if (decryption_failed_or_bad_record_mac)
+		{
+		/* decryption failed, silently discard message */
+		rr->length = 0;
+		s->packet_length = 0;
+		goto err;
+		}
+
 	/* r->length is now just compressed */
 	if (s->expand != NULL)
 		{
@@ -460,14 +465,6 @@ if (	(sess == NULL) ||
     dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
     return(1);
 
-decryption_failed_or_bad_record_mac:
-	/* Separate 'decryption_failed' alert was introduced with TLS 1.0,
-	 * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
-	 * failure is directly visible from the ciphertext anyway,
-	 * we should not reveal which kind of error occured -- this
-	 * might become visible to an attacker (e.g. via logfile) */
-	al=SSL_AD_BAD_RECORD_MAC;
-	SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
 f_err:
 	ssl3_send_alert(s,SSL3_AL_FATAL,al);
 err:
@@ -486,22 +483,19 @@ err:
 /* used only by dtls1_read_bytes */
 int dtls1_get_record(SSL *s)
 	{
-	int ssl_major,ssl_minor,al;
+	int ssl_major,ssl_minor;
 	int i,n;
 	SSL3_RECORD *rr;
-	SSL_SESSION *sess;
-	unsigned char *p;
+	unsigned char *p = NULL;
 	unsigned short version;
 	DTLS1_BITMAP *bitmap;
 	unsigned int is_next_epoch;
 
 	rr= &(s->s3->rrec);
-	sess=s->session;
 
     /* The epoch may have changed.  If so, process all the
      * pending records.  This is a non-blocking operation. */
-    if ( ! dtls1_process_buffered_records(s))
-        return 0;
+    dtls1_process_buffered_records(s);
 
 	/* if we're renegotiating, then there may be buffered records */
 	if (dtls1_get_processed_record(s))
@@ -517,7 +511,12 @@ again:
 		/* read timeout is handled by dtls1_read_bytes */
 		if (n <= 0) return(n); /* error or non-blocking */
 
-		OPENSSL_assert(s->packet_length == DTLS1_RT_HEADER_LENGTH);
+		/* this packet contained a partial record, dump it */
+		if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
+			{
+			s->packet_length = 0;
+			goto again;
+			}
 
 		s->rstate=SSL_ST_READ_BODY;
 
@@ -542,27 +541,28 @@ again:
 			{
 			if (version != s->version && version != DTLS1_BAD_VER)
 				{
-				SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
-				/* Send back error using their
-				 * version number :-) */
-				s->version=version;
-				al=SSL_AD_PROTOCOL_VERSION;
-				goto f_err;
+				/* unexpected version, silently discard */
+				rr->length = 0;
+				s->packet_length = 0;
+				goto again;
 				}
 			}
 
 		if ((version & 0xff00) != (DTLS1_VERSION & 0xff00) &&
 		    (version & 0xff00) != (DTLS1_BAD_VER & 0xff00))
 			{
-			SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
-			goto err;
+			/* wrong version, silently discard record */
+			rr->length = 0;
+			s->packet_length = 0;
+			goto again;
 			}
 
 		if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 			{
-			al=SSL_AD_RECORD_OVERFLOW;
-			SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
-			goto f_err;
+			/* record too long, silently discard it */
+			rr->length = 0;
+			s->packet_length = 0;
+			goto again;
 			}
 
 		s->client_version = version;
@@ -600,8 +600,15 @@ again:
         goto again;   /* get another record */
 		}
 
-	/* check whether this is a repeat, or aged record */
-	if ( ! dtls1_record_replay_check(s, bitmap, &(rr->seq_num)))
+ 	/* 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->seq_num)))
 		{
 		rr->length = 0;
 		s->packet_length=0; /* dump this record */
@@ -611,29 +618,31 @@ again:
 	/* just read a 0 length packet */
 	if (rr->length == 0) goto again;
 
-    /* If this record is from the next epoch (either HM or ALERT), buffer it
-     * since it cannot be processed at this time.
-     * Records from the next epoch are marked as received even though they are 
-     * not processed, so as to prevent any potential resource DoS attack */
-    if (is_next_epoch)
-        {
-        dtls1_record_bitmap_update(s, bitmap);
-        dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
-	rr->length = 0;
+	/* If this record is from the next epoch (either HM or ALERT),
+	 * and a handshake is currently in progress, buffer it since it
+	 * cannot be processed at this time. However, do not buffer
+	 * anything while listening.
+	 */
+	if (is_next_epoch)
+		{
+		if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
+			{
+			dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), &rr->seq_num);
+			}
+		rr->length = 0;
         s->packet_length = 0;
         goto again;
         }
 
-    if ( ! dtls1_process_record(s))
-        return(0);
+    if (!dtls1_process_record(s))
+		{
+		rr->length = 0;
+		s->packet_length=0; /* dump this record */
+		goto again;     /* get another record */
+		}
 
-	dtls1_clear_timeouts(s);  /* done waiting */
 	return(1);
 
-f_err:
-	ssl3_send_alert(s,SSL3_AL_FATAL,al);
-err:
-	return(0);
 	}
 
 /* Return up to 'len' payload bytes received in 'type' records.
@@ -728,11 +737,8 @@ start:
 		}
 
 	/* Check for timeout */
-	if (dtls1_is_timer_expired(s))
-		{
-		if (dtls1_read_failed(s, -1) > 0);
-			goto start;
-		}
+	if (dtls1_handle_timeout(s) > 0)
+		goto start;
 
 	/* get new packet if necessary */
 	if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
@@ -760,7 +766,7 @@ start:
 		 * buffer the application data for later processing rather
 		 * than dropping the connection.
 		 */
-		dtls1_buffer_record(s, &(s->d1->buffered_app_data), 0);
+		dtls1_buffer_record(s, &(s->d1->buffered_app_data), &rr->seq_num);
 		rr->length = 0;
 		goto start;
 		}
@@ -1103,6 +1109,9 @@ start:
 		 */
 		if (msg_hdr.type == SSL3_MT_FINISHED)
 			{
+			if (dtls1_check_timeout_num(s) < 0)
+				return -1;
+
 			dtls1_retransmit_buffered_messages(s);
 			rr->length = 0;
 			goto start;
@@ -1214,7 +1223,6 @@ err:
 int
 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
 	{
-	unsigned int n,tot;
 	int i;
 
 	if (SSL_in_init(s) && !s->in_handshake)
@@ -1228,31 +1236,14 @@ dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
 			}
 		}
 
-	tot = s->s3->wnum;
-	n = len - tot;
-
-	while( n)
+	if (len > SSL3_RT_MAX_PLAIN_LENGTH)
 		{
-		/* dtls1_write_bytes sends one record at a time, sized according to 
-		 * the currently known MTU */
-		i = dtls1_write_bytes(s, type, buf_, len);
-		if (i <= 0) return i;
-		
-		if ((i == (int)n) ||
-			(type == SSL3_RT_APPLICATION_DATA &&
-				(s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
-			{
-			/* next chunk of data should get another prepended empty fragment
-			 * in ciphersuites with known-IV weakness: */
-			s->s3->empty_fragment_done = 0;
-			return tot+i;
-			}
-
-		tot += i;
-		n-=i;
+			SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
+			return -1;
 		}
 
-	return tot;
+	i = dtls1_write_bytes(s, type, buf_, len);
+	return i;
 	}
 
 
@@ -1293,46 +1284,13 @@ have_handshake_fragment(SSL *s, int type, unsigned char *buf,
 /* Call this to write data in records of type 'type'
  * It will return <= 0 if not all data has been sent or non-blocking IO.
  */
-int dtls1_write_bytes(SSL *s, int type, const void *buf_, int len)
+int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
 	{
-	const unsigned char *buf=buf_;
-	unsigned int tot,n,nw;
 	int i;
-	unsigned int mtu;
 
+	OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
 	s->rwstate=SSL_NOTHING;
-	tot=s->s3->wnum;
-
-	n=(len-tot);
-
-	/* handshake layer figures out MTU for itself, but data records
-	 * are also sent through this interface, so need to figure out MTU */
-#if 0
-	mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_MTU, 0, NULL);
-	mtu += DTLS1_HM_HEADER_LENGTH;  /* HM already inserted */
-#endif
-	mtu = s->d1->mtu;
-
-	if (mtu > SSL3_RT_MAX_PLAIN_LENGTH)
-		mtu = SSL3_RT_MAX_PLAIN_LENGTH;
-
-	if (n > mtu)
-		nw=mtu;
-	else
-		nw=n;
-	
-	i=do_dtls1_write(s, type, &(buf[tot]), nw, 0);
-	if (i <= 0)
-		{
-		s->s3->wnum=tot;
-		return i;
-		}
-
-	if ( (int)s->s3->wnum + i == len)
-		s->s3->wnum = 0;
-	else 
-		s->s3->wnum += i;
-
+	i=do_dtls1_write(s, type, buf, len, 0);
 	return i;
 	}
 
@@ -1857,10 +1815,3 @@ bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num)
        return _num;
        }
 #endif
-
-
-static void
-dtls1_clear_timeouts(SSL *s)
-	{
-	memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
-	}