X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fsptps.c;h=7bd271b936ba2591d39a926762d8a5b8d6870977;hp=e5946ed6fd8cc8cb9211141063f159188e0c6e8f;hb=706d855e507980de3845556989d7de7a3b9c76e8;hpb=d237efd325cd7bdd73f5eb111c769470238dce6e

diff --git a/src/sptps.c b/src/sptps.c
index e5946ed6..7bd271b9 100644
--- a/src/sptps.c
+++ b/src/sptps.c
@@ -1,6 +1,6 @@
 /*
     sptps.c -- Simple Peer-to-Peer Security
-    Copyright (C) 2011-2014 Guus Sliepen <guus@tinc-vpn.org>,
+    Copyright (C) 2011-2015 Guus Sliepen <guus@tinc-vpn.org>,
                   2010      Brandon L. Black <blblack@gmail.com>
 
     This program is free software; you can redistribute it and/or modify
@@ -384,10 +384,11 @@ static bool sptps_check_seqno(sptps_t *s, uint32_t seqno, bool update_state) {
 				if (update_state)
 					s->farfuture++;
 				if(farfuture)
-					return error(s, EIO, "Packet is %d seqs in the future, dropped (%u)\n", seqno - s->inseqno, s->farfuture);
+					return update_state ? error(s, EIO, "Packet is %d seqs in the future, dropped (%u)\n", seqno - s->inseqno, s->farfuture) : false;
 
 				// Unless we have seen lots of them, in which case we consider the others lost.
-				warning(s, "Lost %d packets\n", seqno - s->inseqno);
+				if(update_state)
+					warning(s, "Lost %d packets\n", seqno - s->inseqno);
 				if (update_state) {
 					// Mark all packets in the replay window as being late.
 					memset(s->late, 255, s->replaywin);
@@ -395,7 +396,7 @@ static bool sptps_check_seqno(sptps_t *s, uint32_t seqno, bool update_state) {
 			} else if (seqno < s->inseqno) {
 				// If the sequence number is farther in the past than the bitmap goes, or if the packet was already received, drop it.
 				if((s->inseqno >= s->replaywin * 8 && seqno < s->inseqno - s->replaywin * 8) || !(s->late[(seqno / 8) % s->replaywin] & (1 << seqno % 8)))
-					return error(s, EIO, "Received late or replayed packet, seqno %d, last received %d\n", seqno, s->inseqno);
+					return update_state ? error(s, EIO, "Received late or replayed packet, seqno %d, last received %d\n", seqno, s->inseqno) : false;
 			} else if (update_state) {
 				// We missed some packets. Mark them in the bitmap as being late.
 				for(int i = s->inseqno; i < seqno; i++)
@@ -447,6 +448,7 @@ static bool sptps_receive_data_datagram(sptps_t *s, const char *data, size_t len
 	uint32_t seqno;
 	memcpy(&seqno, data, 4);
 	seqno = ntohl(seqno);
+	data += 4; len -= 4;
 
 	if(!s->instate) {
 		if(seqno != s->inseqno)
@@ -454,38 +456,39 @@ static bool sptps_receive_data_datagram(sptps_t *s, const char *data, size_t len
 
 		s->inseqno = seqno + 1;
 
-		uint8_t type = data[4];
+		uint8_t type = *(data++); len--;
 
 		if(type != SPTPS_HANDSHAKE)
 			return error(s, EIO, "Application record received before handshake finished");
 
-		return receive_handshake(s, data + 5, len - 5);
+		return receive_handshake(s, data, len);
 	}
 
 	// Decrypt
 
 	char buffer[len];
-
 	size_t outlen;
-
-	if(!chacha_poly1305_decrypt(s->incipher, seqno, data + 4, len - 4, buffer, &outlen))
+	if(!chacha_poly1305_decrypt(s->incipher, seqno, data, len, buffer, &outlen))
 		return error(s, EIO, "Failed to decrypt and verify packet");
 
 	if(!sptps_check_seqno(s, seqno, true))
 		return false;
 
 	// Append a NULL byte for safety.
-	buffer[len - 20] = 0;
+	buffer[outlen] = 0;
+
+	data = buffer;
+	len = outlen;
 
-	uint8_t type = buffer[0];
+	uint8_t type = *(data++); len--;
 
 	if(type < SPTPS_HANDSHAKE) {
 		if(!s->instate)
 			return error(s, EIO, "Application record received before handshake finished");
-		if(!s->receive_record(s->handle, type, buffer + 1, len - 21))
+		if(!s->receive_record(s->handle, type, data, len))
 			return false;
 	} else if(type == SPTPS_HANDSHAKE) {
-		if(!receive_handshake(s, buffer + 1, len - 21))
+		if(!receive_handshake(s, data, len))
 			return false;
 	} else {
 		return error(s, EIO, "Invalid record type %d", type);