X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Fsptps.c;h=2e9ac6fe63331917c320805fdac592fea91753f7;hb=fe1a9111456a73a6e690927e90d8bfa1e1d0ad22;hp=e03b18a8b12e498182ee16b04deb37f337d90be1;hpb=2cfd1205dc9c6e9d42cc569f415afe13f52357ec;p=meshlink

diff --git a/src/sptps.c b/src/sptps.c
index e03b18a8..2e9ac6fe 100644
--- a/src/sptps.c
+++ b/src/sptps.c
@@ -371,12 +371,20 @@ static bool receive_handshake(sptps_t *s, const char *data, uint16_t len) {
 
 // Check datagram for valid HMAC
 bool sptps_verify_datagram(sptps_t *s, const void *data, size_t len) {
-	if(!s->instate || len < 21)
-		return error(s, EIO, "Received short packet");
+	if (!s->instate)
+		return error(s, EIO, "SPTPS state not ready to verify this datagram");
 
-	// TODO: just decrypt without updating the replay window
+	if(len < 21)
+		return error(s, EIO, "Received short packet in sptps_verify_datagram");
 
-	return true;
+	uint32_t seqno;
+	memcpy(&seqno, data, 4);
+	seqno = ntohl(seqno);
+	// TODO: check whether seqno makes sense, to avoid CPU intensive decrypt
+
+	char buffer[len];
+	size_t outlen;
+	return chacha_poly1305_decrypt(s->incipher, seqno, data + 4, len - 4, buffer, &outlen);
 }
 
 // Receive incoming data, datagram version.
@@ -384,7 +392,7 @@ static bool sptps_receive_data_datagram(sptps_t *s, const void *vdata, size_t le
 	const char *data = vdata;
 
 	if(len < (s->instate ? 21 : 5))
-		return error(s, EIO, "Received short packet");
+		return error(s, EIO, "Received short packet in sptps_receive_data_datagram");
 
 	uint32_t seqno;
 	memcpy(&seqno, data, 4);
@@ -557,6 +565,9 @@ bool sptps_receive_data(sptps_t *s, const void *data, size_t len) {
 
 // Start a SPTPS session.
 bool sptps_start(sptps_t *s, void *handle, bool initiator, bool datagram, ecdsa_t *mykey, ecdsa_t *hiskey, const char *label, size_t labellen, send_data_t send_data, receive_record_t receive_record) {
+	if(!s || !mykey || !hiskey || !label || !labellen || !send_data || !receive_record)
+		return error(s, EINVAL, "Invalid argument to sptps_start()");
+
 	// Initialise struct sptps
 	memset(s, 0, sizeof *s);