X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fsptps.c;h=d22390e836a53ee630c42851492a0552c8914f76;hb=3fba80174dbe29bcfe0d121a2a1d2e61be5ee57b;hp=dc602e3e2154ec09e4ace56842aa93ed51531d4b;hpb=30013511504e925729ebc67772205a74c4b8aeea;p=tinc

diff --git a/src/sptps.c b/src/sptps.c
index dc602e3e..d22390e8 100644
--- a/src/sptps.c
+++ b/src/sptps.c
@@ -45,7 +45,7 @@ char *logfilename;
 
    Maybe do add some alert messages to give helpful error messages? Not more than TLS sends.
 
-   Use counter mode instead of OFB.
+   Use counter mode instead of OFB. (done)
 
    Make sure ECC operations are fixed time (aka prevent side-channel attacks).
 */
@@ -78,7 +78,7 @@ static bool send_record_priv(sptps_t *s, uint8_t type, const char *data, uint16_
 		if(!digest_create(&s->outdigest, plaintext, len + 7, plaintext + 7 + len))
 			return false;
 
-		if(!cipher_encrypt(&s->outcipher, plaintext + 4, sizeof ciphertext, ciphertext, NULL, false))
+		if(!cipher_counter_xor(&s->outcipher, plaintext + 4, sizeof ciphertext, ciphertext))
 			return false;
 
 		return s->send_data(s->handle, ciphertext, len + 19);
@@ -149,8 +149,8 @@ static bool generate_key_material(sptps_t *s, const char *shared, size_t len) {
 	// Initialise cipher and digest structures if necessary
 	if(!s->outstate) {
 		bool result
-			=  cipher_open_by_name(&s->incipher, "aes-256-ofb")
-			&& cipher_open_by_name(&s->outcipher, "aes-256-ofb")
+			=  cipher_open_by_name(&s->incipher, "aes-256-ecb")
+			&& cipher_open_by_name(&s->outcipher, "aes-256-ecb")
 			&& digest_open_by_name(&s->indigest, "sha256", 16)
 			&& digest_open_by_name(&s->outdigest, "sha256", 16);
 		if(!result)
@@ -191,10 +191,27 @@ static bool send_ack(sptps_t *s) {
 // Receive an ACKnowledgement record.
 static bool receive_ack(sptps_t *s, const char *data, uint16_t len) {
 	if(len)
-		return false;
+		return error(s, EIO, "Invalid ACK record length");
+
+	if(s->initiator) {
+		bool result
+			= cipher_set_counter_key(&s->incipher, s->key)
+			&& digest_set_key(&s->indigest, s->key + cipher_keylength(&s->incipher), digest_keylength(&s->indigest));
+		if(!result)
+			return false;
+	} else {
+		bool result
+			= cipher_set_counter_key(&s->incipher, s->key + cipher_keylength(&s->outcipher) + digest_keylength(&s->outdigest))
+			&& digest_set_key(&s->indigest, s->key + cipher_keylength(&s->outcipher) + digest_keylength(&s->outdigest) + cipher_keylength(&s->incipher), digest_keylength(&s->indigest));
+		if(!result)
+			return false;
+	}
 
-	// TODO: set cipher/digest keys
-	return error(s, ENOSYS, "receive_ack() not completely implemented yet");
+	free(s->key);
+	s->key = NULL;
+	s->instate = true;
+
+	return true;
 }
 
 // Receive a Key EXchange record, respond by sending a SIG record.
@@ -244,31 +261,32 @@ static bool receive_sig(sptps_t *s, const char *data, uint16_t len) {
 	if(!generate_key_material(s, shared, sizeof shared))
 		return false;
 
-	// Send cipher change record if necessary
-	//if(s->outstate && !send_ack(s))
-	//	return false;
+	free(s->mykex);
+	free(s->hiskex);
+
+	s->mykex = NULL;
+	s->hiskex = NULL;
+
+	// Send cipher change record
+	if(!send_ack(s))
+		return false;
 
 	// TODO: only set new keys after ACK has been set/received
 	if(s->initiator) {
 		bool result
-			=  cipher_set_key(&s->incipher, s->key, false)
-			&& digest_set_key(&s->indigest, s->key + cipher_keylength(&s->incipher), digest_keylength(&s->indigest))
-			&& cipher_set_key(&s->outcipher, s->key + cipher_keylength(&s->incipher) + digest_keylength(&s->indigest), true)
+			= cipher_set_counter_key(&s->outcipher, s->key + cipher_keylength(&s->incipher) + digest_keylength(&s->indigest))
 			&& digest_set_key(&s->outdigest, s->key + cipher_keylength(&s->incipher) + digest_keylength(&s->indigest) + cipher_keylength(&s->outcipher), digest_keylength(&s->outdigest));
 		if(!result)
 			return false;
 	} else {
 		bool result
-			=  cipher_set_key(&s->outcipher, s->key, true)
-			&& digest_set_key(&s->outdigest, s->key + cipher_keylength(&s->outcipher), digest_keylength(&s->outdigest))
-			&& cipher_set_key(&s->incipher, s->key + cipher_keylength(&s->outcipher) + digest_keylength(&s->outdigest), false)
-			&& digest_set_key(&s->indigest, s->key + cipher_keylength(&s->outcipher) + digest_keylength(&s->outdigest) + cipher_keylength(&s->incipher), digest_keylength(&s->indigest));
+			=  cipher_set_counter_key(&s->outcipher, s->key)
+			&& digest_set_key(&s->outdigest, s->key + cipher_keylength(&s->outcipher), digest_keylength(&s->outdigest));
 		if(!result)
 			return false;
 	}
 
 	s->outstate = true;
-	s->instate = true;
 
 	return true;
 }
@@ -302,7 +320,7 @@ static bool receive_handshake(sptps_t *s, const char *data, uint16_t len) {
 			if(!receive_sig(s, data, len))
 				return false;
 			// s->state = SPTPS_ACK;
-			s->state = SPTPS_SECONDARY_KEX;
+			s->state = SPTPS_ACK;
 			return true;
 		case SPTPS_ACK:
 			// We expect a handshake message to indicate transition to the new keys.
@@ -326,7 +344,7 @@ bool receive_data(sptps_t *s, const char *data, size_t len) {
 				toread = len;
 
 			if(s->instate) {
-				if(!cipher_decrypt(&s->incipher, data, toread, s->inbuf + s->buflen, NULL, false))
+				if(!cipher_counter_xor(&s->incipher, data, toread, s->inbuf + s->buflen))
 					return false;
 			} else {
 				memcpy(s->inbuf + s->buflen, data, toread);
@@ -366,7 +384,7 @@ bool receive_data(sptps_t *s, const char *data, size_t len) {
 			toread = len;
 
 		if(s->instate) {
-			if(!cipher_decrypt(&s->incipher, data, toread, s->inbuf + s->buflen, NULL, false))
+			if(!cipher_counter_xor(&s->incipher, data, toread, s->inbuf + s->buflen))
 				return false;
 		} else {
 			memcpy(s->inbuf + s->buflen, data, toread);
@@ -389,6 +407,8 @@ bool receive_data(sptps_t *s, const char *data, size_t len) {
 
 		// Handle record.
 		if(type < SPTPS_HANDSHAKE) {
+			if(!s->instate)
+				return error(s, EIO, "Application record received before handshake finished");
 			if(!s->receive_record(s->handle, type, s->inbuf + 7, reclen))
 				return false;
 		} else if(type == SPTPS_HANDSHAKE) {