X-Git-Url: https://www.tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fsptps.c;h=9fe93cc7e7f0107d1251fee513244eab6668dbb3;hb=cfc9fee931c70554353ce6c4acc3407baac08745;hp=93a7ad3ff1e9037d9846ecbd56dfae66813589e5;hpb=f6e87ab476a0faf8b124ecaaa27f967d825e6457;p=tinc

diff --git a/src/sptps.c b/src/sptps.c
index 93a7ad3f..9fe93cc7 100644
--- a/src/sptps.c
+++ b/src/sptps.c
@@ -51,9 +51,16 @@ unsigned int sptps_replaywin = 16;
 */
 
 void sptps_log_quiet(sptps_t *s, int s_errno, const char *format, va_list ap) {
+	(void)s;
+	(void)s_errno;
+	(void)format;
+	(void)ap;
 }
 
 void sptps_log_stderr(sptps_t *s, int s_errno, const char *format, va_list ap) {
+	(void)s;
+	(void)s_errno;
+
 	vfprintf(stderr, format, ap);
 	fputc('\n', stderr);
 }
@@ -62,6 +69,9 @@ void (*sptps_log)(sptps_t *s, int s_errno, const char *format, va_list ap) = spt
 
 // Log an error message.
 static bool error(sptps_t *s, int s_errno, const char *format, ...) {
+	(void)s;
+	(void)s_errno;
+
 	if(format) {
 		va_list ap;
 		va_start(ap, format);
@@ -82,7 +92,7 @@ static void warning(sptps_t *s, const char *format, ...) {
 
 // Send a record (datagram version, accepts all record types, handles encryption and authentication).
 static bool send_record_priv_datagram(sptps_t *s, uint8_t type, const void *data, uint16_t len) {
-	char buffer[len + 21UL];
+	uint8_t *buffer = alloca(len + 21UL);
 
 	// Create header with sequence number, length and record type
 	uint32_t seqno = s->outseqno++;
@@ -107,7 +117,7 @@ static bool send_record_priv(sptps_t *s, uint8_t type, const void *data, uint16_
 		return send_record_priv_datagram(s, type, data, len);
 	}
 
-	char buffer[len + 19UL];
+	uint8_t *buffer = alloca(len + 19UL);
 
 	// Create header with sequence number, length and record type
 	uint32_t seqno = s->outseqno++;
@@ -177,8 +187,9 @@ static bool send_sig(sptps_t *s) {
 	size_t siglen = ecdsa_size(s->mykey);
 
 	// Concatenate both KEX messages, plus tag indicating if it is from the connection originator, plus label
-	char msg[(1 + 32 + keylen) * 2 + 1 + s->labellen];
-	char sig[siglen];
+	const size_t msglen = (1 + 32 + keylen) * 2 + 1 + s->labellen;
+	uint8_t *msg = alloca(msglen);
+	uint8_t *sig = alloca(siglen);
 
 	msg[0] = s->initiator;
 	memcpy(msg + 1, s->mykex, 1 + 32 + keylen);
@@ -186,16 +197,16 @@ static bool send_sig(sptps_t *s) {
 	memcpy(msg + 1 + 2 * (33 + keylen), s->label, s->labellen);
 
 	// Sign the result.
-	if(!ecdsa_sign(s->mykey, msg, sizeof(msg), sig)) {
+	if(!ecdsa_sign(s->mykey, msg, msglen, sig)) {
 		return error(s, EINVAL, "Failed to sign SIG record");
 	}
 
 	// Send the SIG exchange record.
-	return send_record_priv(s, SPTPS_HANDSHAKE, sig, sizeof(sig));
+	return send_record_priv(s, SPTPS_HANDSHAKE, sig, siglen);
 }
 
 // Generate key material from the shared secret created from the ECDHE key exchange.
-static bool generate_key_material(sptps_t *s, const char *shared, size_t len) {
+static bool generate_key_material(sptps_t *s, const uint8_t *shared, size_t len) {
 	// Initialise cipher and digest structures if necessary
 	if(!s->outstate) {
 		s->incipher = chacha_poly1305_init();
@@ -216,7 +227,7 @@ static bool generate_key_material(sptps_t *s, const char *shared, size_t len) {
 	}
 
 	// Create the HMAC seed, which is "key expansion" + session label + server nonce + client nonce
-	char seed[s->labellen + 64 + 13];
+	uint8_t *seed = alloca(s->labellen + 64 + 13);
 	memcpy(seed, "key expansion", 13);
 
 	if(s->initiator) {
@@ -243,7 +254,9 @@ static bool send_ack(sptps_t *s) {
 }
 
 // Receive an ACKnowledgement record.
-static bool receive_ack(sptps_t *s, const char *data, uint16_t len) {
+static bool receive_ack(sptps_t *s, const uint8_t *data, uint16_t len) {
+	(void)data;
+
 	if(len) {
 		return error(s, EIO, "Invalid ACK record length");
 	}
@@ -266,7 +279,7 @@ static bool receive_ack(sptps_t *s, const char *data, uint16_t len) {
 }
 
 // Receive a Key EXchange record, respond by sending a SIG record.
-static bool receive_kex(sptps_t *s, const char *data, uint16_t len) {
+static bool receive_kex(sptps_t *s, const uint8_t *data, uint16_t len) {
 	// Verify length of the HELLO record
 	if(len != 1 + 32 + ECDH_SIZE) {
 		return error(s, EIO, "Invalid KEX record length");
@@ -287,11 +300,15 @@ static bool receive_kex(sptps_t *s, const char *data, uint16_t len) {
 
 	memcpy(s->hiskex, data, len);
 
-	return send_sig(s);
+	if(s->initiator) {
+		return send_sig(s);
+	} else {
+		return true;
+	}
 }
 
 // Receive a SIGnature record, verify it, if it passed, compute the shared secret and calculate the session keys.
-static bool receive_sig(sptps_t *s, const char *data, uint16_t len) {
+static bool receive_sig(sptps_t *s, const uint8_t *data, uint16_t len) {
 	size_t keylen = ECDH_SIZE;
 	size_t siglen = ecdsa_size(s->hiskey);
 
@@ -301,7 +318,8 @@ static bool receive_sig(sptps_t *s, const char *data, uint16_t len) {
 	}
 
 	// Concatenate both KEX messages, plus tag indicating if it is from the connection originator
-	char msg[(1 + 32 + keylen) * 2 + 1 + s->labellen];
+	const size_t msglen = (1 + 32 + keylen) * 2 + 1 + s->labellen;
+	uint8_t *msg = alloca(msglen);
 
 	msg[0] = !s->initiator;
 	memcpy(msg + 1, s->hiskex, 1 + 32 + keylen);
@@ -309,12 +327,12 @@ static bool receive_sig(sptps_t *s, const char *data, uint16_t len) {
 	memcpy(msg + 1 + 2 * (33 + keylen), s->label, s->labellen);
 
 	// Verify signature.
-	if(!ecdsa_verify(s->hiskey, msg, sizeof(msg), data)) {
+	if(!ecdsa_verify(s->hiskey, msg, msglen, data)) {
 		return error(s, EIO, "Failed to verify SIG record");
 	}
 
 	// Compute shared secret.
-	char shared[ECDH_SHARED_SIZE];
+	uint8_t shared[ECDH_SHARED_SIZE];
 
 	if(!ecdh_compute_shared(s->ecdh, s->hiskex + 1 + 32, shared)) {
 		return error(s, EINVAL, "Failed to compute ECDH shared secret");
@@ -327,6 +345,10 @@ static bool receive_sig(sptps_t *s, const char *data, uint16_t len) {
 		return false;
 	}
 
+	if(!s->initiator && !send_sig(s)) {
+		return false;
+	}
+
 	free(s->mykex);
 	free(s->hiskex);
 
@@ -363,7 +385,7 @@ bool sptps_force_kex(sptps_t *s) {
 }
 
 // Receive a handshake record.
-static bool receive_handshake(sptps_t *s, const char *data, uint16_t len) {
+static bool receive_handshake(sptps_t *s, const uint8_t *data, uint16_t len) {
 	// Only a few states to deal with handshaking.
 	switch(s->state) {
 	case SPTPS_SECONDARY_KEX:
@@ -373,6 +395,7 @@ static bool receive_handshake(sptps_t *s, const char *data, uint16_t len) {
 			return false;
 		}
 
+	// Fall through
 	case SPTPS_KEX:
 
 		// We have sent our KEX request, we expect our peer to sent one as well.
@@ -458,7 +481,7 @@ static bool sptps_check_seqno(sptps_t *s, uint32_t seqno, bool update_state) {
 				}
 			} else if(update_state) {
 				// We missed some packets. Mark them in the bitmap as being late.
-				for(int i = s->inseqno; i < seqno; i++) {
+				for(uint32_t i = s->inseqno; i < seqno; i++) {
 					s->late[(i / 8) % s->replaywin] |= 1 << i % 8;
 				}
 			}
@@ -487,11 +510,12 @@ static bool sptps_check_seqno(sptps_t *s, uint32_t seqno, bool update_state) {
 }
 
 // Check datagram for valid HMAC
-bool sptps_verify_datagram(sptps_t *s, const void *data, size_t len) {
+bool sptps_verify_datagram(sptps_t *s, const void *vdata, size_t len) {
 	if(!s->instate || len < 21) {
 		return error(s, EIO, "Received short packet");
 	}
 
+	const uint8_t *data = vdata;
 	uint32_t seqno;
 	memcpy(&seqno, data, 4);
 	seqno = ntohl(seqno);
@@ -500,13 +524,13 @@ bool sptps_verify_datagram(sptps_t *s, const void *data, size_t len) {
 		return false;
 	}
 
-	char buffer[len];
+	uint8_t *buffer = alloca(len);
 	size_t outlen;
 	return chacha_poly1305_decrypt(s->incipher, seqno, data + 4, len - 4, buffer, &outlen);
 }
 
 // Receive incoming data, datagram version.
-static bool sptps_receive_data_datagram(sptps_t *s, const char *data, size_t len) {
+static bool sptps_receive_data_datagram(sptps_t *s, const uint8_t *data, size_t len) {
 	if(len < (s->instate ? 21 : 5)) {
 		return error(s, EIO, "Received short packet");
 	}
@@ -536,7 +560,7 @@ static bool sptps_receive_data_datagram(sptps_t *s, const char *data, size_t len
 
 	// Decrypt
 
-	char buffer[len];
+	uint8_t *buffer = alloca(len);
 	size_t outlen;
 
 	if(!chacha_poly1305_decrypt(s->incipher, seqno, data, len, buffer, &outlen)) {
@@ -576,7 +600,8 @@ static bool sptps_receive_data_datagram(sptps_t *s, const char *data, size_t len
 }
 
 // Receive incoming data. Check if it contains a complete record, if so, handle it.
-size_t sptps_receive_data(sptps_t *s, const void *data, size_t len) {
+size_t sptps_receive_data(sptps_t *s, const void *vdata, size_t len) {
+	const uint8_t *data = vdata;
 	size_t total_read = 0;
 
 	if(!s->state) {