Use minor protocol version to determine whether to use ECDH key exchange between...

diff --git a/src/info.c b/src/info.c
index df5d11d..eb0d395 100644 (file)
--- a/src/info.c
+++ b/src/info.c
@@ -104,8 +104,6 @@ static int info_node(int fd, const char *item) {
                printf(" reachable");
        if(status.indirect)
                printf(" indirect");
-       if(status.ecdh)
-               printf(" ecdh");
        printf("\n");
        printf("Options:     ");
        if(options & OPTION_INDIRECT)

diff --git a/src/node.h b/src/node.h
index 62ed3ac..b338815 100644 (file)
--- a/src/node.h
+++ b/src/node.h
@@ -35,8 +35,7 @@ typedef struct node_status_t {
        unsigned int visited:1;                 /* 1 if this node has been visited by one of the graph algorithms */
        unsigned int reachable:1;               /* 1 if this node is reachable in the graph */
        unsigned int indirect:1;                /* 1 if this node is not directly reachable by us */
-       unsigned int ecdh:1;                    /* 1 if this node supports ECDH key exchange */
-       unsigned int unused:25;
+       unsigned int unused:26;
 } node_status_t;
 
 typedef struct node_t {

diff --git a/src/protocol.h b/src/protocol.h
index ee6f1f0..a561539 100644 (file)
--- a/src/protocol.h
+++ b/src/protocol.h
@@ -43,7 +43,9 @@ typedef enum request_t {
        ADD_EDGE, DEL_EDGE,
        KEY_CHANGED, REQ_KEY, ANS_KEY,
        PACKET,
+       /* Tinc 1.1 requests */
        CONTROL,
+       REQ_PUBKEY, ANS_PUBKEY,
        LAST                                            /* Guardian for the highest request number */
 } request_t;
 

diff --git a/src/protocol_auth.c b/src/protocol_auth.c
index 3fd80c4..f6192d7 100644 (file)
--- a/src/protocol_auth.c
+++ b/src/protocol_auth.c
@@ -626,9 +626,6 @@ bool ack_h(connection_t *c, const char *request) {
                        c->options &= ~OPTION_CLAMP_MSS;
        }
 
-       if(c->protocol_minor > 0)
-               c->node->status.ecdh = true;
-
        /* Activate this connection */
 
        c->allow_request = ALL;

diff --git a/src/protocol_key.c b/src/protocol_key.c
index 12dab09..0e02c6e 100644 (file)
--- a/src/protocol_key.c
+++ b/src/protocol_key.c
@@ -84,16 +84,54 @@ bool key_changed_h(connection_t *c, const char *request) {
 }
 
 bool send_req_key(node_t *to) {
-       return send_request(to->nexthop->connection, "%d %s %s %d", REQ_KEY, myself->name, to->name, experimental ? 1 : 0);
+       if(experimental && OPTION_VERSION(to->options) >= 2) {
+               if(!node_read_ecdsa_public_key(to))
+                       send_request(to->nexthop->connection, "%d %s %s %d", REQ_KEY, myself->name, to->name, REQ_PUBKEY);
+       }
+       return send_request(to->nexthop->connection, "%d %s %s", REQ_KEY, myself->name, to->name);
+}
+
+/* REQ_KEY is overloaded to allow arbitrary requests to be routed between two nodes. */
+
+static bool req_key_ext_h(connection_t *c, const char *request, node_t *from, int reqno) {
+       switch(reqno) {
+               case REQ_PUBKEY: {
+                       char *pubkey = ecdsa_get_base64_public_key(&myself->connection->ecdsa);
+                       send_request(from->nexthop->connection, "%d %s %s %d %s", REQ_KEY, myself->name, from->name, ANS_PUBKEY, pubkey);
+                       free(pubkey);
+                       return true;
+               }
+
+               case ANS_PUBKEY: {
+                       if(node_read_ecdsa_public_key(from)) {
+                               logger(DEBUG_ALWAYS, LOG_WARNING, "Got ANS_PUBKEY from %s (%s) even though we already have his pubkey", from->name, from->hostname);
+                               return true;
+                       }
+
+                       char pubkey[4096];
+                       if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, pubkey) != 1 || !ecdsa_set_base64_public_key(&from->ecdsa, pubkey)) {
+                               logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "ANS_PUBKEY", from->name, from->hostname, "invalid pubkey");
+                               return true;
+                       }
+
+                       logger(DEBUG_ALWAYS, LOG_INFO, "Learned ECDSA public key from %s (%s)", from->name, from->hostname);
+                       append_config_file(from->name, "ECDSAPublicKey", pubkey);
+                       return true;
+               }
+
+               default:
+                       logger(DEBUG_ALWAYS, LOG_ERR, "Unknown extended REQ_KEY request from %s (%s): %s", from->name, from->hostname, request);
+                       return true;
+       }
 }
 
 bool req_key_h(connection_t *c, const char *request) {
        char from_name[MAX_STRING_SIZE];
        char to_name[MAX_STRING_SIZE];
        node_t *from, *to;
-       int kx_version = 0;
+       int reqno = 0;
 
-       if(sscanf(request, "%*d " MAX_STRING " " MAX_STRING " %d", from_name, to_name, &kx_version) < 2) {
+       if(sscanf(request, "%*d " MAX_STRING " " MAX_STRING " %d", from_name, to_name, &reqno) < 2) {
                logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "REQ_KEY", c->name,
                           c->hostname);
                return false;
@@ -123,10 +161,9 @@ bool req_key_h(connection_t *c, const char *request) {
        /* Check if this key request is for us */
 
        if(to == myself) {                      /* Yes, send our own key back */
-               if(experimental && kx_version >= 1) {
-                       logger(DEBUG_ALWAYS, LOG_DEBUG, "Got ECDH key request from %s", from->name);
-                       from->status.ecdh = true;
-               }
+               if(experimental && reqno)
+                       return req_key_ext_h(c, request, from, reqno);
+
                send_ans_key(from);
        } else {
                if(tunnelserver)
@@ -156,24 +193,18 @@ bool send_ans_key_ecdh(node_t *to) {
 
        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,
+       int result = send_request(to->nexthop->connection, "%d %s %s %s %d %d %zu %d", ANS_KEY,
+                                               myself->name, to->name, key,
                                                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) {
-       if(experimental && to->status.ecdh)
+       if(experimental && OPTION_VERSION(to->options) >= 2)
                return send_ans_key_ecdh(to);
 
        size_t keylen = cipher_keylength(&myself->incipher);
@@ -291,28 +322,16 @@ bool ans_key_h(connection_t *c, const 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(experimental && OPTION_VERSION(from->options) >= 2) {
+               /* Check if we already have an ECDSA public key for this node. */
 
                if(!node_read_ecdsa_public_key(from)) {
-                       if(!pubkey) {
-                               logger(DEBUG_ALWAYS, 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);
+                       logger(DEBUG_ALWAYS, LOG_ERR, "No ECDSA public key known for %s (%s), cannot verify ECDH key exchange!", from->name, from->hostname);
+                       return true;
                }
 
                int siglen = ecdsa_size(&from->ecdsa);
-               int keylen = b64decode(key + 5, key + 5, sizeof key - 5);
+               int keylen = b64decode(key, key, sizeof key);
 
                if(keylen != ECDH_SIZE + siglen) {
                        logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses wrong keylength! %d != %d", from->name, from->hostname, keylen, ECDH_SIZE + siglen);
@@ -324,20 +343,19 @@ bool ans_key_h(connection_t *c, const char *request) {
                        return true;
                }
 
-               if(!ecdsa_verify(&from->ecdsa, key + 5, ECDH_SIZE, key + 5 + ECDH_SIZE)) {
+               if(!ecdsa_verify(&from->ecdsa, key, ECDH_SIZE, key + ECDH_SIZE)) {
                        logger(DEBUG_ALWAYS, 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))
+                       if(!send_ans_key_ecdh(from))
                                return true;
                }
 
                char shared[ECDH_SHARED_SIZE * 2 + 1];
 
-               if(!ecdh_compute_shared(&from->ecdh, key + 5, shared))
+               if(!ecdh_compute_shared(&from->ecdh, key, shared))
                        return true;
 
                /* Update our crypto end */