Make use of the improved hex and base64 functions.

Also, use base64 for all EC related data, it is shorter and easy to
distinguish from the legacy protocol.

src/control.c

@@ -134,7 +134,6 @@ bool control_h(connection_t *c, char *request) {
 bool init_control(void) {
 	randomize(controlcookie, sizeof controlcookie / 2);
 	bin2hex(controlcookie, controlcookie, sizeof controlcookie / 2);
-	controlcookie[sizeof controlcookie - 1] = 0;
 
 	FILE *f = fopen(pidfilename, "w");
 	if(!f) {

src/protocol_auth.c

@@ -143,24 +143,19 @@ bool send_metakey_ec(connection_t *c) {
 
 	size_t siglen = ecdsa_size(&myself->connection->ecdsa);
 
-	char key[ECDH_SIZE];
+	char key[(ECDH_SIZE + siglen) * 2 + 1];
-	char sig[siglen];
 
 	// TODO: include nonce? Use relevant parts of SSH or TLS protocol
 
 	if(!ecdh_generate_public(&c->ecdh, key))
 		return false;
 
-	if(!ecdsa_sign(&myself->connection->ecdsa, key, ECDH_SIZE, sig))
+	if(!ecdsa_sign(&myself->connection->ecdsa, key, ECDH_SIZE, key + ECDH_SIZE))
 		return false;
 
-	char out[MAX_STRING_SIZE];
+	b64encode(key, key, ECDH_SIZE + siglen);
-
-	bin2hex(key, out, ECDH_SIZE);
-	bin2hex(sig, out + ECDH_SIZE * 2, siglen);
-	out[(ECDH_SIZE + siglen) * 2] = 0;
 	
-	bool result = send_request(c, "%d %s", METAKEY, out);
+	bool result = send_request(c, "%d %s", METAKEY, key);
 }
 
 bool send_metakey(connection_t *c) {
@@ -198,7 +193,6 @@ bool send_metakey(connection_t *c) {
 
 	ifdebug(SCARY_THINGS) {
 		bin2hex(key, hexkey, len);
-		hexkey[len * 2] = '\0';
 		logger(LOG_DEBUG, "Generated random meta key (unencrypted): %s", hexkey);
 	}
 
@@ -217,7 +211,6 @@ bool send_metakey(connection_t *c) {
 	/* Convert the encrypted random data to a hexadecimal formatted string */
 
 	bin2hex(enckey, hexkey, len);
-	hexkey[len * 2] = '\0';
 
 	/* Send the meta key */
 
@@ -232,31 +225,29 @@ bool send_metakey(connection_t *c) {
 
 static bool metakey_ec_h(connection_t *c, const char *request) {
 	size_t siglen = ecdsa_size(&c->ecdsa);
-	char in[MAX_STRING_SIZE];
 	char key[MAX_STRING_SIZE];
 	char sig[siglen];
 
 	logger(LOG_DEBUG, "Got ECDH metakey from %s", c->name);
 
-	if(sscanf(request, "%*d " MAX_STRING, in) != 1) {
+	if(sscanf(request, "%*d " MAX_STRING, key) != 1) {
 		logger(LOG_ERR, "Got bad %s from %s (%s)", "METAKEY", c->name, c->hostname);
 		return false;
 	}
 
-	if(strlen(in) != (ECDH_SIZE + siglen) * 2) {
+	int inlen = b64decode(key, key, sizeof key);
-		logger(LOG_ERR, "Possible intruder %s (%s): %s %d != %d", c->name, c->hostname, "wrong keylength", strlen(in) / 2, (ECDH_SIZE + siglen));
+
+	if(inlen != (ECDH_SIZE + siglen)) {
+		logger(LOG_ERR, "Possible intruder %s (%s): %s", c->name, c->hostname, "wrong keylength");
 		return false;
 	}
 
-	hex2bin(in, key, ECDH_SIZE);
+	if(!ecdsa_verify(&c->ecdsa, key, ECDH_SIZE, key + ECDH_SIZE)) {
-	hex2bin(in + ECDH_SIZE * 2, sig, siglen);
-
-	if(!ecdsa_verify(&c->ecdsa, key, ECDH_SIZE, sig)) {
 		logger(LOG_ERR, "Possible intruder %s (%s): %s", c->name, c->hostname, "invalid ECDSA signature");
 		return false;
 	}
 
-	char shared[ECDH_SHARED_SIZE * 2 + 1];
+	char shared[ECDH_SHARED_SIZE];
 
 	if(!ecdh_compute_shared(&c->ecdh, key, shared))
 		return false;
@@ -294,10 +285,6 @@ static bool metakey_ec_h(connection_t *c, const char *request) {
 
 	free(seed);
 
-	bin2hex(shared, shared, ECDH_SHARED_SIZE);
-	shared[ECDH_SHARED_SIZE * 2] = 0;
-	logger(LOG_DEBUG, "Shared secret is %s", shared);
-
 	cipher_set_key(&c->incipher, mykey, true);
 	digest_set_key(&c->indigest, mykey + mykeylen, mykeylen);
 
@@ -326,17 +313,17 @@ bool metakey_h(connection_t *c, char *request) {
 		return false;
 	}
 
+	/* Convert the challenge from hexadecimal back to binary */
+
+	int inlen = hex2bin(hexkey, enckey, sizeof enckey);
+
 	/* Check if the length of the meta key is all right */
 
-	if(strlen(hexkey) != len * 2) {
+	if(inlen != len) {
 		logger(LOG_ERR, "Possible intruder %s (%s): %s", c->name, c->hostname, "wrong keylength");
 		return false;
 	}
 
-	/* Convert the challenge from hexadecimal back to binary */
-
-	hex2bin(hexkey, enckey, len);
-
 	/* Decrypt the meta key */
 
 	if(!rsa_private_decrypt(&myself->connection->rsa, enckey, len, key)) {
@@ -346,7 +333,6 @@ bool metakey_h(connection_t *c, char *request) {
 
 	ifdebug(SCARY_THINGS) {
 		bin2hex(key, hexkey, len);
-		hexkey[len * 2] = '\0';
 		logger(LOG_DEBUG, "Received random meta key (unencrypted): %s", hexkey);
 	}
 
@@ -383,7 +369,6 @@ bool send_challenge(connection_t *c) {
 	/* Convert to hex */
 
 	bin2hex(c->hischallenge, buffer, len);
-	buffer[len * 2] = '\0';
 
 	/* Send the challenge */
 
@@ -401,17 +386,17 @@ bool challenge_h(connection_t *c, char *request) {
 		return false;
 	}
 
+	/* Convert the challenge from hexadecimal back to binary */
+
+	int inlen = hex2bin(buffer, buffer, sizeof buffer);
+
 	/* Check if the length of the challenge is all right */
 
-	if(strlen(buffer) != len * 2) {
+	if(inlen != len) {
 		logger(LOG_ERR, "Possible intruder %s (%s): %s", c->name, c->hostname, "wrong challenge length");
 		return false;
 	}
 
-	/* Convert the challenge from hexadecimal back to binary */
-
-	hex2bin(buffer, buffer, len);
-
 	c->allow_request = CHAL_REPLY;
 
 	/* Calculate the hash from the challenge we received */
@@ -421,7 +406,6 @@ bool challenge_h(connection_t *c, char *request) {
 	/* Convert the hash to a hexadecimal formatted string */
 
 	bin2hex(digest, buffer, digestlen);
-	buffer[digestlen * 2] = '\0';
 
 	/* Send the reply */
 
@@ -437,16 +421,17 @@ bool chal_reply_h(connection_t *c, char *request) {
 		return false;
 	}
 
+	/* Convert the hash to binary format */
+
+	int inlen = hex2bin(hishash, hishash, sizeof hishash);
+
 	/* Check if the length of the hash is all right */
 
-	if(strlen(hishash) != digest_length(&c->outdigest) * 2) {
+	if(inlen != digest_length(&c->outdigest)) {
 		logger(LOG_ERR, "Possible intruder %s (%s): %s", c->name, c->hostname, "wrong challenge reply length");
 		return false;
 	}
 
-	/* Convert the hash to binary format */
-
-	hex2bin(hishash, hishash, digest_length(&c->outdigest));
 
 	/* Verify the hash */
 

src/protocol_key.c

@@ -149,8 +149,7 @@ bool send_ans_key_ecdh(node_t *to) {
 
 	ecdh_generate_public(&to->ecdh, key);
 
-	bin2hex(key, key, ECDH_SIZE);
+	b64encode(key, key, ECDH_SIZE);
-	key[ECDH_SIZE * 2] = '\0';
 
 	return send_request(to->nexthop->connection, "%d %s %s ECDH:%s %d %d %zu %d", ANS_KEY,
 						myself->name, to->name, key,
@@ -176,7 +175,6 @@ bool send_ans_key(node_t *to) {
 	digest_set_key(&to->indigest, key, keylen);
 
 	bin2hex(key, key, keylen);
-	key[keylen * 2] = '\0';
 
 	// Reset sequence number and late packet window
 	mykeyused = true;
@@ -281,7 +279,7 @@ bool ans_key_h(connection_t *c, char *request) {
 	/* ECDH or old-style key exchange? */
 	
 	if(experimental && !strncmp(key, "ECDH:", 5)) {
-		keylen = (strlen(key) - 5) / 2;
+		int keylen = b64decode(key + 5, key + 5, sizeof key - 5);
 
 		if(keylen != ECDH_SIZE) {
 			logger(LOG_ERR, "Node %s (%s) uses wrong keylength!", from->name, from->hostname);
@@ -300,8 +298,6 @@ bool ans_key_h(connection_t *c, char *request) {
 		}
 
 		char shared[ECDH_SHARED_SIZE * 2 + 1];
-		char hex[ECDH_SHARED_SIZE * 2 + 1];
-		hex2bin(key + 5, key + 5, keylen);
 
 		if(!ecdh_compute_shared(&from->ecdh, key + 5, shared))
 			return false;
@@ -349,8 +345,7 @@ bool ans_key_h(connection_t *c, char *request) {
 		if(strcmp(myself->name, from->name) < 0)
 			memmove(key, key + mykeylen * 2, hiskeylen * 2);
 	} else {
-		keylen = strlen(key) / 2;
+		keylen = hex2bin(key, key, sizeof key);
-		hex2bin(key, key, keylen);
 
 		if(keylen != cipher_keylength(&from->outcipher)) {
 			logger(LOG_ERR, "Node %s (%s) uses wrong keylength!", from->name, from->hostname);