New silcconfig library and server parser. Merged silc-newconfig-final.patch.
[silc.git] / apps / silcd / protocol.c
index 53b31d9727f476cbbc81a7b41ad62131db3d6c2e..a7a1b707d7d1a39000626dbf555ac8f20a52cd2d 100644 (file)
@@ -56,6 +56,13 @@ silc_verify_public_key_internal(SilcServer server, SilcSocketConnection sock,
     return TRUE;
   }
 
+  /* XXX For now, accept server keys without verification too. We are
+     currently always doing mutual authentication so the proof of posession
+     of the private key is verified, and if server is authenticated in
+     conn auth protocol with public key we MUST have the key already. */
+  return TRUE;
+  /* Rest is unreachable code! */
+  
   memset(filename, 0, sizeof(filename));
   memset(file, 0, sizeof(file));
   snprintf(file, sizeof(file) - 1, "serverkey_%s_%d.pub", sock->hostname, 
@@ -124,12 +131,11 @@ silc_verify_public_key_internal(SilcServer server, SilcSocketConnection sock,
 
       /* Save the key for future checking */
       unlink(filename);
-      silc_pkcs_save_public_key_data(filename, pk, pk_len,
-                                    SILC_PKCS_FILE_PEM);
+      silc_pkcs_save_public_key_data(filename, pk, pk_len, SILC_PKCS_FILE_PEM);
       return TRUE;
     }
 
-    if (memcmp(encpk, pk, encpk_len)) {
+    if (memcmp(pk, encpk, encpk_len)) {
       SILC_LOG_WARNING(("%s (%s) port %d server public key does not match "
                        "with local copy", sock->hostname, sock->ip, 
                        sock->port));
@@ -199,7 +205,8 @@ static void silc_server_protocol_ke_send_packet(SilcSKE ske,
 
 /* Sets the negotiated key material into use for particular connection. */
 
-int silc_server_protocol_ke_set_keys(SilcSKE ske,
+int silc_server_protocol_ke_set_keys(SilcServer server,
+                                    SilcSKE ske,
                                     SilcSocketConnection sock,
                                     SilcSKEKeyMaterial *keymat,
                                     SilcCipher cipher,
@@ -227,6 +234,23 @@ int silc_server_protocol_ke_set_keys(SilcSKE ske,
     return FALSE;
   }
   
+  if (!silc_hmac_alloc((char *)silc_hmac_get_name(hmac), NULL, 
+                      &idata->hmac_send)) {
+    silc_cipher_free(idata->send_key);
+    silc_cipher_free(idata->receive_key);
+    silc_free(conn_data);
+    return FALSE;
+  }
+
+  if (!silc_hmac_alloc((char *)silc_hmac_get_name(hmac), NULL, 
+                      &idata->hmac_receive)) {
+    silc_cipher_free(idata->send_key);
+    silc_cipher_free(idata->receive_key);
+    silc_hmac_free(idata->hmac_send);
+    silc_free(conn_data);
+    return FALSE;
+  }
+
   if (is_responder == TRUE) {
     silc_cipher_set_key(idata->send_key, keymat->receive_enc_key, 
                        keymat->enc_key_len);
@@ -234,6 +258,10 @@ int silc_server_protocol_ke_set_keys(SilcSKE ske,
     silc_cipher_set_key(idata->receive_key, keymat->send_enc_key, 
                        keymat->enc_key_len);
     silc_cipher_set_iv(idata->receive_key, keymat->send_iv);
+    silc_hmac_set_key(idata->hmac_send, keymat->receive_hmac_key, 
+                     keymat->hmac_key_len);
+    silc_hmac_set_key(idata->hmac_receive, keymat->send_hmac_key, 
+                     keymat->hmac_key_len);
   } else {
     silc_cipher_set_key(idata->send_key, keymat->send_enc_key, 
                        keymat->enc_key_len);
@@ -241,6 +269,10 @@ int silc_server_protocol_ke_set_keys(SilcSKE ske,
     silc_cipher_set_key(idata->receive_key, keymat->receive_enc_key, 
                        keymat->enc_key_len);
     silc_cipher_set_iv(idata->receive_key, keymat->receive_iv);
+    silc_hmac_set_key(idata->hmac_send, keymat->send_hmac_key, 
+                     keymat->hmac_key_len);
+    silc_hmac_set_key(idata->hmac_receive, keymat->receive_hmac_key, 
+                     keymat->hmac_key_len);
   }
 
   idata->rekey = silc_calloc(1, sizeof(*idata->rekey));
@@ -255,31 +287,31 @@ int silc_server_protocol_ke_set_keys(SilcSKE ske,
     idata->rekey->pfs = TRUE;
   idata->rekey->ske_group = silc_ske_group_get_number(group);
 
-  /* Save the remote host's public key */
-  silc_pkcs_public_key_decode(ske->ke1_payload->pk_data, 
-                             ske->ke1_payload->pk_len, &idata->public_key);
-
   /* Save the hash */
   if (!silc_hash_alloc(hash->hash->name, &idata->hash)) {
     silc_cipher_free(idata->send_key);
     silc_cipher_free(idata->receive_key);
+    silc_hmac_free(idata->hmac_send);
+    silc_hmac_free(idata->hmac_receive);
     silc_free(conn_data);
     return FALSE;
   }
 
-  /* Save HMAC key to be used in the communication. */
-  if (!silc_hmac_alloc(hmac->hmac->name, NULL, &idata->hmac_send)) {
-    silc_cipher_free(idata->send_key);
-    silc_cipher_free(idata->receive_key);
-    silc_hash_free(idata->hash);
-    silc_free(conn_data);
-    return FALSE;
-  }
-  silc_hmac_set_key(idata->hmac_send, keymat->hmac_key, keymat->hmac_key_len);
-  idata->hmac_receive = idata->hmac_send;
+  /* Save the remote host's public key */
+  silc_pkcs_public_key_decode(ske->ke1_payload->pk_data, 
+                             ske->ke1_payload->pk_len, &idata->public_key);
+  if (ske->prop->flags & SILC_SKE_SP_FLAG_MUTUAL)
+    silc_hash_make(server->sha1hash, ske->ke1_payload->pk_data,
+                  ske->ke1_payload->pk_len, idata->fingerprint);
 
   sock->user_data = (void *)conn_data;
 
+  SILC_LOG_INFO(("%s (%s) security properties: %s %s %s", 
+                sock->hostname, sock->ip,
+                idata->send_key->cipher->name,
+                (char *)silc_hmac_get_name(idata->hmac_send),
+                idata->hash->hash->name));
+
   return TRUE;
 }
 
@@ -335,8 +367,18 @@ SilcSKEStatus silc_ske_check_version(SilcSKE ske, unsigned char *version,
 
   if (maj != maj2)
     status = SILC_SKE_STATUS_BAD_VERSION;
+#if 0
   if (min > min2)
     status = SILC_SKE_STATUS_BAD_VERSION;
+#endif
+
+  /* XXX < 0.6 is not allowed */
+  if (maj == 0 && min < 5)
+    status = SILC_SKE_STATUS_BAD_VERSION;
+
+  /* XXX backward support for 0.6.1 */
+  if (maj == 0 && min == 6 && build < 2)
+    ske->backward_version = 1;
 
   return status;
 }
@@ -359,10 +401,10 @@ static void silc_server_protocol_ke_continue(SilcSKE ske, void *context)
   SILC_LOG_DEBUG(("Start"));
 
   if (ske->status != SILC_SKE_STATUS_OK) {
-    SILC_LOG_WARNING(("Error (type %d) during Key Exchange protocol",
-                     ske->status));
-    SILC_LOG_DEBUG(("Error (type %d) during Key Exchange protocol",
-                   ske->status));
+    SILC_LOG_WARNING(("Error (%s) during Key Exchange protocol",
+                     silc_ske_map_status(ske->status)));
+    SILC_LOG_DEBUG(("Error (%s) during Key Exchange protocol",
+                   silc_ske_map_status(ske->status)));
     
     protocol->state = SILC_PROTOCOL_STATE_ERROR;
     silc_protocol_execute(protocol, server->schedule, 0, 300000);
@@ -429,12 +471,12 @@ SILC_TASK_CALLBACK(silc_server_protocol_key_exchange)
           properties packet from initiator. */
        status = silc_ske_responder_start(ske, ctx->rng, ctx->sock,
                                          silc_version_string,
-                                         ctx->packet->buffer, FALSE);
+                                         ctx->packet->buffer, TRUE);
       } else {
        SilcSKEStartPayload *start_payload;
 
        /* Assemble security properties. */
-       silc_ske_assemble_security_properties(ske, SILC_SKE_SP_FLAG_NONE
+       silc_ske_assemble_security_properties(ske, SILC_SKE_SP_FLAG_MUTUAL
                                              silc_version_string,
                                              &start_payload);
 
@@ -449,10 +491,10 @@ SILC_TASK_CALLBACK(silc_server_protocol_key_exchange)
        return;
 
       if (status != SILC_SKE_STATUS_OK) {
-       SILC_LOG_WARNING(("Error (type %d) during Key Exchange protocol",
-                         status));
-       SILC_LOG_DEBUG(("Error (type %d) during Key Exchange protocol",
-                       status));
+       SILC_LOG_WARNING(("Error (%s) during Key Exchange protocol",
+                         silc_ske_map_status(status)));
+       SILC_LOG_DEBUG(("Error (%s) during Key Exchange protocol",
+                       silc_ske_map_status(status)));
 
        protocol->state = SILC_PROTOCOL_STATE_ERROR;
        silc_protocol_execute(protocol, server->schedule, 0, 300000);
@@ -487,10 +529,10 @@ SILC_TASK_CALLBACK(silc_server_protocol_key_exchange)
        return;
 
       if (status != SILC_SKE_STATUS_OK) {
-       SILC_LOG_WARNING(("Error (type %d) during Key Exchange protocol",
-                         status));
-       SILC_LOG_DEBUG(("Error (type %d) during Key Exchange protocol",
-                       status));
+       SILC_LOG_WARNING(("Error (%s) during Key Exchange protocol",
+                         silc_ske_map_status(status)));
+       SILC_LOG_DEBUG(("Error (%s) during Key Exchange protocol",
+                       silc_ske_map_status(status)));
 
        protocol->state = SILC_PROTOCOL_STATE_ERROR;
        silc_protocol_execute(protocol, server->schedule, 0, 300000);
@@ -529,10 +571,10 @@ SILC_TASK_CALLBACK(silc_server_protocol_key_exchange)
        return;
 
       if (status != SILC_SKE_STATUS_OK) {
-       SILC_LOG_WARNING(("Error (type %d) during Key Exchange protocol",
-                         status));
-       SILC_LOG_DEBUG(("Error (type %d) during Key Exchange protocol",
-                       status));
+       SILC_LOG_WARNING(("Error (%s) during Key Exchange protocol",
+                         silc_ske_map_status(status)));
+       SILC_LOG_DEBUG(("Error (%s) during Key Exchange protocol",
+                       silc_ske_map_status(status)));
 
        protocol->state = SILC_PROTOCOL_STATE_ERROR;
        silc_protocol_execute(protocol, server->schedule, 0, 300000);
@@ -567,10 +609,10 @@ SILC_TASK_CALLBACK(silc_server_protocol_key_exchange)
        return;
 
       if (status != SILC_SKE_STATUS_OK) {
-       SILC_LOG_WARNING(("Error (type %d) during Key Exchange protocol",
-                         status));
-       SILC_LOG_DEBUG(("Error (type %d) during Key Exchange protocol",
-                       status));
+       SILC_LOG_WARNING(("Error (%s) during Key Exchange protocol",
+                         silc_ske_map_status(status)));
+       SILC_LOG_DEBUG(("Error (%s) during Key Exchange protocol",
+                       silc_ske_map_status(status)));
 
        protocol->state = SILC_PROTOCOL_STATE_ERROR;
        silc_protocol_execute(protocol, server->schedule, 0, 300000);
@@ -611,6 +653,11 @@ SILC_TASK_CALLBACK(silc_server_protocol_key_exchange)
       if (ctx->timeout_task)
        silc_schedule_task_del(server->schedule, ctx->timeout_task);
 
+      /* Assure that after calling final callback there cannot be pending
+        executions for this protocol anymore. This just unregisters any 
+        timeout callbacks for this protocol. */
+      silc_protocol_cancel(protocol, server->schedule);
+
       /* Call the final callback */
       if (protocol->final_callback)
        silc_protocol_execute_final(protocol, server->schedule);
@@ -633,6 +680,11 @@ SILC_TASK_CALLBACK(silc_server_protocol_key_exchange)
     if (ctx->timeout_task)
       silc_schedule_task_del(server->schedule, ctx->timeout_task);
 
+    /* Assure that after calling final callback there cannot be pending
+       executions for this protocol anymore. This just unregisters any 
+       timeout callbacks for this protocol. */
+    silc_protocol_cancel(protocol, server->schedule);
+
     /* On error the final callback is always called. */
     if (protocol->final_callback)
       silc_protocol_execute_final(protocol, server->schedule);
@@ -651,6 +703,11 @@ SILC_TASK_CALLBACK(silc_server_protocol_key_exchange)
     if (ctx->timeout_task)
       silc_schedule_task_del(server->schedule, ctx->timeout_task);
 
+    /* Assure that after calling final callback there cannot be pending
+       executions for this protocol anymore. This just unregisters any 
+       timeout callbacks for this protocol. */
+    silc_protocol_cancel(protocol, server->schedule);
+    
     /* On error the final callback is always called. */
     if (protocol->final_callback)
       silc_protocol_execute_final(protocol, server->schedule);
@@ -668,13 +725,13 @@ SILC_TASK_CALLBACK(silc_server_protocol_key_exchange)
  */
 
 static int 
-silc_server_password_authentication(SilcServer server, char *auth1
-                                   char *auth2)
+silc_server_password_authentication(SilcServer server, char *remote_auth
+                                   char *local_auth)
 {
-  if (!auth1 || !auth2)
+  if (!remote_auth || !local_auth)
     return FALSE;
 
-  if (!memcmp(auth1, auth2, strlen(auth1)))
+  if (!memcmp(remote_auth, local_auth, strlen(local_auth)))
     return TRUE;
 
   return FALSE;
@@ -849,7 +906,7 @@ SILC_TASK_CALLBACK(silc_server_protocol_connection_auth)
 
        /* Remote end is client */
        if (conn_type == SILC_SOCKET_TYPE_CLIENT) {
-         SilcServerConfigSectionClientConnection *client = ctx->cconfig;
+         SilcServerConfigSectionClient *client = ctx->cconfig;
          
          if (client) {
            switch(client->auth_meth) {
@@ -898,8 +955,8 @@ SILC_TASK_CALLBACK(silc_server_protocol_connection_auth)
              return;
            }
          } else {
-           SILC_LOG_DEBUG(("No configuration for remote connection"));
-           SILC_LOG_ERROR(("Remote connection not configured"));
+           SILC_LOG_DEBUG(("No configuration for remote client connection"));
+           SILC_LOG_ERROR(("Remote client connection not configured"));
            SILC_LOG_ERROR(("Authentication failed"));
            silc_free(auth_data);
            protocol->state = SILC_PROTOCOL_STATE_ERROR;
@@ -911,7 +968,7 @@ SILC_TASK_CALLBACK(silc_server_protocol_connection_auth)
        
        /* Remote end is server */
        if (conn_type == SILC_SOCKET_TYPE_SERVER) {
-         SilcServerConfigSectionServerConnection *serv = ctx->sconfig;
+         SilcServerConfigSectionServer *serv = ctx->sconfig;
          
          if (serv) {
            switch(serv->auth_meth) {
@@ -960,8 +1017,8 @@ SILC_TASK_CALLBACK(silc_server_protocol_connection_auth)
              return;
            }
          } else {
-           SILC_LOG_DEBUG(("No configuration for remote connection"));
-           SILC_LOG_ERROR(("Remote connection not configured"));
+           SILC_LOG_DEBUG(("No configuration for remote server connection"));
+           SILC_LOG_ERROR(("Remote server connection not configured"));
            SILC_LOG_ERROR(("Authentication failed"));
            protocol->state = SILC_PROTOCOL_STATE_ERROR;
            silc_protocol_execute(protocol, server->schedule, 
@@ -973,7 +1030,7 @@ SILC_TASK_CALLBACK(silc_server_protocol_connection_auth)
        
        /* Remote end is router */
        if (conn_type == SILC_SOCKET_TYPE_ROUTER) {
-         SilcServerConfigSectionServerConnection *serv = ctx->rconfig;
+         SilcServerConfigSectionRouter *serv = ctx->rconfig;
 
          if (serv) {
            switch(serv->auth_meth) {
@@ -1022,8 +1079,8 @@ SILC_TASK_CALLBACK(silc_server_protocol_connection_auth)
              return;
            }
          } else {
-           SILC_LOG_DEBUG(("No configuration for remote connection"));
-           SILC_LOG_ERROR(("Remote connection not configured"));
+           SILC_LOG_DEBUG(("No configuration for remote router connection"));
+           SILC_LOG_ERROR(("Remote router connection not configured"));
            SILC_LOG_ERROR(("Authentication failed"));
            silc_free(auth_data);
            protocol->state = SILC_PROTOCOL_STATE_ERROR;
@@ -1129,6 +1186,11 @@ SILC_TASK_CALLBACK(silc_server_protocol_connection_auth)
       if (ctx->timeout_task)
        silc_schedule_task_del(server->schedule, ctx->timeout_task);
 
+      /* Assure that after calling final callback there cannot be pending
+        executions for this protocol anymore. This just unregisters any 
+        timeout callbacks for this protocol. */
+      silc_protocol_cancel(protocol, server->schedule);
+    
       /* Protocol has ended, call the final callback */
       if (protocol->final_callback)
        silc_protocol_execute_final(protocol, server->schedule);
@@ -1155,6 +1217,11 @@ SILC_TASK_CALLBACK(silc_server_protocol_connection_auth)
       if (ctx->timeout_task)
        silc_schedule_task_del(server->schedule, ctx->timeout_task);
 
+      /* Assure that after calling final callback there cannot be pending
+        executions for this protocol anymore. This just unregisters any 
+        timeout callbacks for this protocol. */
+      silc_protocol_cancel(protocol, server->schedule);
+    
       /* On error the final callback is always called. */
       if (protocol->final_callback)
        silc_protocol_execute_final(protocol, server->schedule);
@@ -1174,6 +1241,11 @@ SILC_TASK_CALLBACK(silc_server_protocol_connection_auth)
     if (ctx->timeout_task)
       silc_schedule_task_del(server->schedule, ctx->timeout_task);
 
+    /* Assure that after calling final callback there cannot be pending
+       executions for this protocol anymore. This just unregisters any 
+       timeout callbacks for this protocol. */
+    silc_protocol_cancel(protocol, server->schedule);
+    
     /* On error the final callback is always called. */
     if (protocol->final_callback)
       silc_protocol_execute_final(protocol, server->schedule);
@@ -1204,32 +1276,31 @@ silc_server_protocol_rekey_validate(SilcServer server,
       silc_cipher_set_key(idata->send_key, keymat->receive_enc_key, 
                          keymat->enc_key_len);
       silc_cipher_set_iv(idata->send_key, keymat->receive_iv);
+      silc_hmac_set_key(idata->hmac_send, keymat->receive_hmac_key, 
+                       keymat->hmac_key_len);
     } else {
       silc_cipher_set_key(idata->receive_key, keymat->send_enc_key, 
                          keymat->enc_key_len);
       silc_cipher_set_iv(idata->receive_key, keymat->send_iv);
+      silc_hmac_set_key(idata->hmac_receive, keymat->send_hmac_key, 
+                       keymat->hmac_key_len);
     }
   } else {
     if (send) {
       silc_cipher_set_key(idata->send_key, keymat->send_enc_key, 
                          keymat->enc_key_len);
       silc_cipher_set_iv(idata->send_key, keymat->send_iv);
+      silc_hmac_set_key(idata->hmac_send, keymat->send_hmac_key, 
+                       keymat->hmac_key_len);
     } else {
       silc_cipher_set_key(idata->receive_key, keymat->receive_enc_key, 
                          keymat->enc_key_len);
       silc_cipher_set_iv(idata->receive_key, keymat->receive_iv);
+      silc_hmac_set_key(idata->hmac_receive, keymat->receive_hmac_key, 
+                       keymat->hmac_key_len);
     }
   }
 
-  if (send) {
-    silc_hmac_alloc(idata->hmac_send->hmac->name, NULL, &idata->hmac_send);
-    silc_hmac_set_key(idata->hmac_send, keymat->hmac_key, 
-                     keymat->hmac_key_len);
-  } else {
-    silc_hmac_free(idata->hmac_receive);
-    idata->hmac_receive = idata->hmac_send;
-  }
-
   /* Save the current sending encryption key */
   if (!send) {
     memset(idata->rekey->send_enc_key, 0, idata->rekey->enc_key_len);
@@ -1370,7 +1441,7 @@ SILC_TASK_CALLBACK(silc_server_protocol_rekey)
          ctx->ske = silc_ske_alloc();
          ctx->ske->rng = server->rng;
          ctx->ske->prop = silc_calloc(1, sizeof(*ctx->ske->prop));
-         silc_ske_get_group_by_number(idata->rekey->ske_group,
+         silc_ske_group_get_by_number(idata->rekey->ske_group,
                                       &ctx->ske->prop->group);
 
          silc_ske_set_callbacks(ctx->ske, 
@@ -1380,8 +1451,8 @@ SILC_TASK_CALLBACK(silc_server_protocol_rekey)
       
          status = silc_ske_responder_phase_2(ctx->ske, ctx->packet->buffer);
          if (status != SILC_SKE_STATUS_OK) {
-           SILC_LOG_WARNING(("Error (type %d) during Re-key (PFS)",
-                             status));
+           SILC_LOG_WARNING(("Error (%s) during Re-key (PFS)",
+                             silc_ske_map_status(status)));
            
            protocol->state = SILC_PROTOCOL_STATE_ERROR;
            silc_protocol_execute(protocol, server->schedule, 0, 300000);
@@ -1426,7 +1497,7 @@ SILC_TASK_CALLBACK(silc_server_protocol_rekey)
          ctx->ske = silc_ske_alloc();
          ctx->ske->rng = server->rng;
          ctx->ske->prop = silc_calloc(1, sizeof(*ctx->ske->prop));
-         silc_ske_get_group_by_number(idata->rekey->ske_group,
+         silc_ske_group_get_by_number(idata->rekey->ske_group,
                                       &ctx->ske->prop->group);
 
          silc_ske_set_callbacks(ctx->ske, 
@@ -1436,8 +1507,8 @@ SILC_TASK_CALLBACK(silc_server_protocol_rekey)
       
          status = silc_ske_initiator_phase_2(ctx->ske, NULL, NULL);
          if (status != SILC_SKE_STATUS_OK) {
-           SILC_LOG_WARNING(("Error (type %d) during Re-key (PFS)",
-                             status));
+           SILC_LOG_WARNING(("Error (%s) during Re-key (PFS)",
+                             silc_ske_map_status(status)));
            
            protocol->state = SILC_PROTOCOL_STATE_ERROR;
            silc_protocol_execute(protocol, server->schedule, 0, 300000);
@@ -1481,8 +1552,8 @@ SILC_TASK_CALLBACK(silc_server_protocol_rekey)
        status = silc_ske_responder_finish(ctx->ske, NULL, NULL, 
                                           SILC_SKE_PK_TYPE_SILC);
        if (status != SILC_SKE_STATUS_OK) {
-         SILC_LOG_WARNING(("Error (type %d) during Re-key (PFS)",
-                           status));
+         SILC_LOG_WARNING(("Error (%s) during Re-key (PFS)",
+                           silc_ske_map_status(status)));
          
          protocol->state = SILC_PROTOCOL_STATE_ERROR;
          silc_protocol_execute(protocol, server->schedule, 0, 300000);
@@ -1504,8 +1575,8 @@ SILC_TASK_CALLBACK(silc_server_protocol_rekey)
        
        status = silc_ske_initiator_finish(ctx->ske, ctx->packet->buffer);
        if (status != SILC_SKE_STATUS_OK) {
-         SILC_LOG_WARNING(("Error (type %d) during Re-key (PFS)",
-                           status));
+         SILC_LOG_WARNING(("Error (%s) during Re-key (PFS)",
+                           silc_ske_map_status(status)));
          
          protocol->state = SILC_PROTOCOL_STATE_ERROR;
          silc_protocol_execute(protocol, server->schedule, 0, 300000);
@@ -1544,6 +1615,11 @@ SILC_TASK_CALLBACK(silc_server_protocol_rekey)
        encrypted with the new key so set the decryption key to the new key */
     silc_server_protocol_rekey_generate(server, ctx, FALSE);
 
+    /* Assure that after calling final callback there cannot be pending
+       executions for this protocol anymore. This just unregisters any 
+       timeout callbacks for this protocol. */
+    silc_protocol_cancel(protocol, server->schedule);
+    
     /* Protocol has ended, call the final callback */
     if (protocol->final_callback)
       silc_protocol_execute_final(protocol, server->schedule);
@@ -1561,6 +1637,11 @@ SILC_TASK_CALLBACK(silc_server_protocol_rekey)
       silc_ske_abort(ctx->ske, ctx->ske->status);
     }
 
+    /* Assure that after calling final callback there cannot be pending
+       executions for this protocol anymore. This just unregisters any 
+       timeout callbacks for this protocol. */
+    silc_protocol_cancel(protocol, server->schedule);
+    
     /* On error the final callback is always called. */
     if (protocol->final_callback)
       silc_protocol_execute_final(protocol, server->schedule);
@@ -1573,6 +1654,11 @@ SILC_TASK_CALLBACK(silc_server_protocol_rekey)
      * We have received failure from remote
      */
 
+    /* Assure that after calling final callback there cannot be pending
+       executions for this protocol anymore. This just unregisters any 
+       timeout callbacks for this protocol. */
+    silc_protocol_cancel(protocol, server->schedule);
+    
     /* On error the final callback is always called. */
     if (protocol->final_callback)
       silc_protocol_execute_final(protocol, server->schedule);
@@ -1596,6 +1682,8 @@ void silc_server_protocols_register(void)
                         silc_server_protocol_key_exchange);
   silc_protocol_register(SILC_PROTOCOL_SERVER_REKEY,
                         silc_server_protocol_rekey);
+  silc_protocol_register(SILC_PROTOCOL_SERVER_BACKUP,
+                        silc_server_protocol_backup);
 }
 
 /* Unregisters protocols */
@@ -1608,4 +1696,6 @@ void silc_server_protocols_unregister(void)
                           silc_server_protocol_key_exchange);
   silc_protocol_unregister(SILC_PROTOCOL_SERVER_REKEY,
                           silc_server_protocol_rekey);
+  silc_protocol_unregister(SILC_PROTOCOL_SERVER_BACKUP,
+                          silc_server_protocol_backup);
 }