X-Git-Url: https://git.openssl.org/gitweb/?a=blobdiff_plain;f=ssl%2Fd1_pkt.c;h=20d24b6fd8da186f911a8bec9b7b94f740ef78ed;hb=f6d13ac8cf4cacf4f0150290b4aee67062bfacc7;hp=daf1fee88189c40b31c04fffcca3c381912f747b;hpb=fe1c7fecf172f57834df2fca9ba32fec12dccf9f;p=openssl.git

diff --git a/ssl/d1_pkt.c b/ssl/d1_pkt.c
index daf1fee881..20d24b6fd8 100644
--- a/ssl/d1_pkt.c
+++ b/ssl/d1_pkt.c
@@ -207,6 +207,10 @@ dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
 	DTLS1_RECORD_DATA *rdata;
 	pitem *item;
 
+	/* Limit the size of the queue to prevent DOS attacks */
+	if (pqueue_size(queue->q) >= 100)
+		return 0;
+		
 	rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
 	item = pitem_new(priority, rdata);
 	if (rdata == NULL || item == NULL)
@@ -428,7 +432,10 @@ printf("\n");
 	if (!clear)
 		{
 		/* !clear => s->read_hash != NULL => mac_size != -1 */
-		mac_size=EVP_MD_CTX_size(s->read_hash);
+		int t;
+		t=EVP_MD_CTX_size(s->read_hash);
+		OPENSSL_assert(t >= 0);
+		mac_size=t;
 
 		if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
 			{
@@ -453,7 +460,7 @@ printf("\n");
 			}
 		rr->length-=mac_size;
 		i=s->method->ssl3_enc->mac(s,md,0);
-		if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
+		if (i < 0 || memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
 			{
 			goto decryption_failed_or_bad_record_mac;
 			}
@@ -523,11 +530,11 @@ 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;
@@ -554,7 +561,12 @@ 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;
 
@@ -579,26 +591,27 @@ again:
 			{
 			if (version != s->version)
 				{
-				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))
+		if ((version & 0xff00) != (s->version & 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;
 			}
 
 		/* now s->rstate == SSL_ST_READ_BODY */
@@ -616,6 +629,7 @@ again:
 		/* this packet contained a partial record, dump it */
 		if ( n != i)
 			{
+			rr->length = 0;
 			s->packet_length = 0;
 			goto again;
 			}
@@ -629,12 +643,20 @@ again:
 	bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 	if ( bitmap == NULL)
 		{
+		rr->length = 0;
 		s->packet_length = 0;  /* dump this record */
 		goto again;   /* get another record */
 		}
 
-	/* check whether this is a repeat, or aged record */
-	if ( ! dtls1_record_replay_check(s, bitmap))
+	/* 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 */
@@ -645,14 +667,15 @@ again:
 	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 */
+	 * and a handshake is currently in progress, buffer it since it
+	 * cannot be processed at this time. */
 	if (is_next_epoch)
 		{
-		dtls1_record_bitmap_update(s, bitmap);
-		dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
+		if (SSL_in_init(s) || s->in_handshake)
+			{
+			dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
+			}
+		rr->length = 0;
 		s->packet_length = 0;
 		goto again;
 		}
@@ -663,10 +686,6 @@ again:
 	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.
@@ -743,6 +762,27 @@ start:
 	 * s->s3->rrec.length,  - number of bytes. */
 	rr = &(s->s3->rrec);
 
+	/* We are not handshaking and have no data yet,
+	 * so process data buffered during the last handshake
+	 * in advance, if any.
+	 */
+	if (s->state == SSL_ST_OK && rr->length == 0)
+		{
+		pitem *item;
+		item = pqueue_pop(s->d1->buffered_app_data.q);
+		if (item)
+			{
+			dtls1_copy_record(s, item);
+
+			OPENSSL_free(item->data);
+			pitem_free(item);
+			}
+		}
+
+	/* Check for timeout */
+	if (dtls1_handle_timeout(s) > 0)
+		goto start;
+
 	/* get new packet if necessary */
 	if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 		{
@@ -764,9 +804,14 @@ start:
 	                               * reset by ssl3_get_finished */
 		&& (rr->type != SSL3_RT_HANDSHAKE))
 		{
-		al=SSL_AD_UNEXPECTED_MESSAGE;
-		SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
-		goto err;
+		/* We now have application data between CCS and Finished.
+		 * Most likely the packets were reordered on their way, so
+		 * buffer the application data for later processing rather
+		 * than dropping the connection.
+		 */
+		dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num);
+		rr->length = 0;
+		goto start;
 		}
 
 	/* If the other end has shut down, throw anything we read away
@@ -836,15 +881,28 @@ start:
 			dest = s->d1->alert_fragment;
 			dest_len = &s->d1->alert_fragment_len;
 			}
-                /* else it's a CCS message, or it's wrong */
-                else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
-                        {
-                          /* Not certain if this is the right error handling */
-                          al=SSL_AD_UNEXPECTED_MESSAGE;
-                          SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
-                          goto f_err;
-                        }
+		/* else it's a CCS message, or application data or wrong */
+		else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
+			{
+			/* Application data while renegotiating
+			 * is allowed. Try again reading.
+			 */
+			if (rr->type == SSL3_RT_APPLICATION_DATA)
+				{
+				BIO *bio;
+				s->s3->in_read_app_data=2;
+				bio=SSL_get_rbio(s);
+				s->rwstate=SSL_READING;
+				BIO_clear_retry_flags(bio);
+				BIO_set_retry_read(bio);
+				return(-1);
+				}
 
+			/* Not certain if this is the right error handling */
+			al=SSL_AD_UNEXPECTED_MESSAGE;
+			SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
+			goto f_err;
+			}
 
 		if (dest_maxlen > 0)
 			{
@@ -982,7 +1040,9 @@ start:
 				n2s(p, seq);
 				n2l3(p, frag_off);
 
-				dtls1_retransmit_message(s, seq, frag_off, &found);
+				dtls1_retransmit_message(s,
+										 dtls1_get_queue_priority(frag->msg_header.seq, 0),
+										 frag_off, &found);
 				if ( ! found  && SSL_in_init(s))
 					{
 					/* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
@@ -1027,13 +1087,17 @@ start:
 	if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
 		{
 		struct ccs_header_st ccs_hdr;
+		unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
 
 		dtls1_get_ccs_header(rr->data, &ccs_hdr);
 
+		if (s->version == DTLS1_BAD_VER)
+			ccs_hdr_len = 3;
+
 		/* 'Change Cipher Spec' is just a single byte, so we know
 		 * exactly what the record payload has to look like */
 		/* XDTLS: check that epoch is consistent */
-		if (	(rr->length != DTLS1_CCS_HEADER_LENGTH) || 
+		if (	(rr->length != ccs_hdr_len) || 
 			(rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
 			{
 			i=SSL_AD_ILLEGAL_PARAMETER;
@@ -1047,6 +1111,16 @@ 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;
@@ -1054,6 +1128,9 @@ start:
 		/* do this whenever CCS is processed */
 		dtls1_reset_seq_numbers(s, SSL3_CC_READ);
 
+		if (s->version == DTLS1_BAD_VER)
+			s->d1->handshake_read_seq++;
+
 		goto start;
 		}
 
@@ -1071,6 +1148,16 @@ start:
 			goto start;
 			}
 
+		/* If we are server, we may have a repeated FINISHED of the
+		 * client here, then retransmit our CCS and FINISHED.
+		 */
+		if (msg_hdr.type == SSL3_MT_FINISHED)
+			{
+			dtls1_retransmit_buffered_messages(s);
+			rr->length = 0;
+			goto start;
+			}
+
 		if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
 			!(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
 			{
@@ -1177,7 +1264,6 @@ 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)
@@ -1191,31 +1277,14 @@ 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;
 	}
 
 
@@ -1256,46 +1325,13 @@ 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;
 	}
 
@@ -1341,13 +1377,17 @@ int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len,
 	if (clear)
 		mac_size=0;
 	else
+		{
 		mac_size=EVP_MD_CTX_size(s->write_hash);
+		if (mac_size < 0)
+			goto err;
+		}
 
 	/* DTLS implements explicit IV, so no need for empty fragments */
 #if 0
 	/* 'create_empty_fragment' is true only when this function calls itself */
 	if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
-		&& SSL_version(s) != DTLS1_VERSION)
+	    && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
 		{
 		/* countermeasure against known-IV weakness in CBC ciphersuites
 		 * (see http://www.openssl.org/~bodo/tls-cbc.txt) 
@@ -1374,7 +1414,6 @@ int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len,
 		s->s3->empty_fragment_done = 1;
 		}
 #endif
-
 	p = wb->buf + prefix_len;
 
 	/* write the header */
@@ -1428,7 +1467,8 @@ int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len,
 
 	if (mac_size != 0)
 		{
-		s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1);
+		if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
+			goto err;
 		wr->length+=mac_size;
 		}
 
@@ -1720,6 +1760,7 @@ dtls1_reset_seq_numbers(SSL *s, int rw)
 	else
 		{
 		seq = s->s3->write_sequence;
+		memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
 		s->d1->w_epoch++;
 		}