* src/keyexchange.c (do_handle_kexinit): Disconnect if there is no

common host key algorithm. Pass on "extra" to KEYEXCHANGE_INIT().

* src/keyexchange.h: Added argument "extra" to init-method.
(make_kexinit_handler): Added "extra" argument.

Rev: src/keyexchange.c:1.58
Rev: src/keyexchange.h:1.40

src/keyexchange.c

@@ -51,6 +51,9 @@
        (type simple int)
        (init object make_kexinit)
 
+       ; Extra rgument for the KEYEXCHANGE_INIT call.
+       (extra object lsh_object)
+       
        ; Maps names to algorithms. It's dangerous to lookup random atoms
        ; in this table, as not all objects have the same type. This
        ; mapping is used only on atoms that have appeared in *both* the
@@ -269,6 +272,12 @@ do_handle_kexinit(struct packet_handler *c,
     = select_algorithm(connection->kexinits[0]->server_hostkey_algorithms,
 		       connection->kexinits[1]->server_hostkey_algorithms);
 
+  if (!hostkey_algorithm_atom)
+    {
+      disconnect_kex_failed(connection, "No common hostkey algorithm.\r\n");
+      return;
+    }
+  
 #if 0
 #if DATAFELLOWS_WORKAROUNDS
   if ( (hostkey_algorithm_atom == ATOM_SSH_DSS)
@@ -300,20 +309,25 @@ do_handle_kexinit(struct packet_handler *c,
   {
     CAST_SUBTYPE(keyexchange_algorithm, kex_algorithm,
 		 ALIST_GET(closure->algorithms, kex_algorithm_atom));
+
+#if 0
     CAST_SUBTYPE(signature_algorithm, hostkey_algorithm,
 		 ALIST_GET(closure->algorithms,
 			   hostkey_algorithm_atom));
+#endif
     KEYEXCHANGE_INIT( kex_algorithm,
 		      connection,
 		      hostkey_algorithm_atom,
-		      hostkey_algorithm,
+		      closure->extra, /* hostkey_algorithm, */
 		      algorithms);
   }
 }
 
-struct packet_handler *make_kexinit_handler(int type,
-					    struct make_kexinit *init,
-					    struct alist *algorithms)
+struct packet_handler *
+make_kexinit_handler(int type,
+		     struct make_kexinit *init,
+		     struct lsh_object *extra,
+		     struct alist *algorithms)
 {
   NEW(kexinit_handler, self);
 
@@ -321,6 +335,7 @@ struct packet_handler *make_kexinit_handler(int type,
 
   self->type = type;
   self->init = init;
+  self->extra = extra;
   self->algorithms = algorithms;
   
   return &self->super;

src/keyexchange.h

@@ -74,13 +74,16 @@
 	     "struct ssh_connection *connection"
 	     ;; "struct ssh_service *finished"
 	     "int hostkey_algorithm_atom"
-	     ;; FIXME: The algorithm object seems unnecessary.
-	     "struct signature_algorithm *hostkey_algorithm"
+	     ;; "struct signature_algorithm *hostkey_algorithm"
+
+	     "struct lsh_object *extra"
+	     ; Secret key (if applicable and available).
+	     ;;"struct keypair *key"
 	     "struct object_list *algorithms")))
 */
 
-#define KEYEXCHANGE_INIT(kex, connection, ha, h, a) \
-((kex)->init((kex), (connection), (ha), (h), (a)))
+#define KEYEXCHANGE_INIT(kex, connection, ha, e, a) \
+((kex)->init((kex), (connection), (ha), (e), (a)))
 
 /* GABA:
    (class
@@ -178,9 +181,11 @@ struct make_kexinit *make_test_kexinit(struct randomness *r);
 void initiate_keyexchange(struct ssh_connection *connection,
 			 int type);
 
-struct packet_handler *make_kexinit_handler(int type,
-					    struct make_kexinit *init,
-					    struct alist *algorithms);
+struct packet_handler *
+make_kexinit_handler(int type,
+		     struct make_kexinit *init,
+		     struct lsh_object *extra,
+		     struct alist *algorithms);
 
 struct packet_handler *
 make_newkeys_handler(struct crypto_instance *crypto,