Merge branch 'master' of git://tinc-vpn.org/tinc into 1.1

[tinc] / src / protocol_key.c

diff --git a/src/protocol_key.c b/src/protocol_key.c
index 313681b..c392a46 100644 (file)
--- a/src/protocol_key.c
+++ b/src/protocol_key.c
@@ -40,7 +40,7 @@ void send_key_changed(void) {
        splay_node_t *node;
        connection_t *c;
 
-       send_request(broadcast, "%d %x %s", KEY_CHANGED, rand(), myself->name);
+       send_request(everyone, "%d %x %s", KEY_CHANGED, rand(), myself->name);
 
        /* Immediately send new keys to directly connected nodes to keep UDP mappings alive */
 
@@ -145,18 +145,31 @@ bool req_key_h(connection_t *c, char *request) {
 }
 
 bool send_ans_key_ecdh(node_t *to) {
-       char key[ECDH_SIZE * 2 + 1];
+       int siglen = ecdsa_size(&myself->connection->ecdsa);
+       char key[(ECDH_SIZE + siglen) * 2 + 1];
 
-       ecdh_generate_public(&to->ecdh, key);
+       if(!ecdh_generate_public(&to->ecdh, key))
+               return false;
 
-       b64encode(key, key, ECDH_SIZE);
+       if(!ecdsa_sign(&myself->connection->ecdsa, key, ECDH_SIZE, key + ECDH_SIZE))
+               return false;
 
-       return send_request(to->nexthop->connection, "%d %s %s ECDH:%s %d %d %zu %d", ANS_KEY,
-                                               myself->name, to->name, key,
+       b64encode(key, key, ECDH_SIZE + siglen);
+
+       char *pubkey = ecdsa_get_base64_public_key(&myself->connection->ecdsa);
+
+       if(!pubkey)
+               return false;
+
+       int result = send_request(to->nexthop->connection, "%d %s %s ECDH:%s:%s %d %d %zu %d", ANS_KEY,
+                                               myself->name, to->name, key, pubkey,
                                                cipher_get_nid(&myself->incipher),
                                                digest_get_nid(&myself->indigest),
                                                digest_length(&myself->indigest),
                                                myself->incompression);
+
+       free(pubkey);
+       return result;
 }
 
 bool send_ans_key(node_t *to) {
@@ -279,28 +292,53 @@ bool ans_key_h(connection_t *c, char *request) {
        /* ECDH or old-style key exchange? */
        
        if(experimental && !strncmp(key, "ECDH:", 5)) {
+               char *pubkey = strchr(key + 5, ':');
+               if(pubkey)
+                       *pubkey++ = 0;
+                       
+               /* Check if we already have an ECDSA public key for this node.
+                * If not, use the one from the key exchange, and store it. */
+
+               if(!node_read_ecdsa_public_key(from)) {
+                       if(!pubkey) {
+                               logger(LOG_ERR, "No ECDSA public key known for %s (%s), cannot verify ECDH key exchange!", from->name, from->hostname);
+                               return true;
+                       }
+
+                       if(!ecdsa_set_base64_public_key(&from->ecdsa, pubkey))
+                               return true;
+
+                       append_config_file(from->name, "ECDSAPublicKey", pubkey);
+               }
+
+               int siglen = ecdsa_size(&from->ecdsa);
                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);
-                       return false;
+               if(keylen != ECDH_SIZE + siglen) {
+                       logger(LOG_ERR, "Node %s (%s) uses wrong keylength! %d != %d", from->name, from->hostname, keylen, ECDH_SIZE + siglen);
+                       return true;
                }
 
                if(ECDH_SHARED_SIZE < cipher_keylength(&from->outcipher)) {
                        logger(LOG_ERR, "ECDH key too short for cipher of %s!", from->name);
-                       return false;
+                       return true;
+               }
+
+               if(!ecdsa_verify(&from->ecdsa, key + 5, ECDH_SIZE, key + 5 + ECDH_SIZE)) {
+                       logger(LOG_ERR, "Possible intruder %s (%s): %s", from->name, from->hostname, "invalid ECDSA signature");
+                       return true;
                }
 
                if(!from->ecdh) {
                        from->status.ecdh = true;
                        if(!send_ans_key(from))
-                               return false;
+                               return true;
                }
 
                char shared[ECDH_SHARED_SIZE * 2 + 1];
 
                if(!ecdh_compute_shared(&from->ecdh, key + 5, shared))
-                       return false;
+                       return true;
 
                /* Update our crypto end */
 
@@ -322,7 +360,7 @@ bool ans_key_h(connection_t *c, char *request) {
                }
 
                if(!prf(shared, ECDH_SHARED_SIZE, seed, strlen(seed), key, hiskeylen * 2 + mykeylen * 2))
-                       return false;
+                       return true;
 
                free(seed);
 
@@ -349,7 +387,7 @@ bool ans_key_h(connection_t *c, char *request) {
 
                if(keylen != cipher_keylength(&from->outcipher)) {
                        logger(LOG_ERR, "Node %s (%s) uses wrong keylength!", from->name, from->hostname);
-                       return false;
+                       return true;
                }
 
                /* Update our copy of the origin's packet key */