updates.
[silc.git] / apps / silcd / protocol.c
index aef7267c13ba45be4f11d6c045138c3676dc0880..794a20880279462c6b473c8896443a1c971969e2 100644 (file)
@@ -2,7 +2,7 @@
 
   protocol.c
 
-  Author: Pekka Riikonen <priikone@poseidon.pspt.fi>
+  Author: Pekka Riikonen <priikone@silcnet.org>
 
   Copyright (C) 1997 - 2001 Pekka Riikonen
 
@@ -35,6 +35,156 @@ extern char *silc_version_string;
  * Key Exhange protocol functions
  */
 
+static bool 
+silc_verify_public_key_internal(SilcServer server, SilcSocketConnection sock,
+                               SilcSocketType conn_type,
+                               unsigned char *pk, uint32 pk_len, 
+                               SilcSKEPKType pk_type)
+{
+  char file[256], filename[256], *fingerprint;
+  struct stat st;
+
+  if (pk_type != SILC_SKE_PK_TYPE_SILC) {
+    SILC_LOG_WARNING(("We don't support %s (%s) port %d public key type %d", 
+                     sock->hostname, sock->ip, sock->port, pk_type));
+    return FALSE;
+  }
+
+  /* Accept client keys without verification */
+  if (conn_type == SILC_SOCKET_TYPE_CLIENT) {
+    SILC_LOG_DEBUG(("Accepting client public key without verification"));
+    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, 
+          sock->port);
+  snprintf(filename, sizeof(filename) - 1, SILC_ETCDIR "/serverkeys/%s", 
+          file);
+
+  /* Create serverkeys directory if it doesn't exist. */
+  if (stat(SILC_ETCDIR "/serverkeys", &st) < 0) {
+    /* If dir doesn't exist */
+    if (errno == ENOENT) {  
+      if (mkdir(SILC_ETCDIR "/serverkeys", 0755) < 0) {
+       SILC_LOG_ERROR(("Couldn't create `%s' directory\n", 
+                       SILC_ETCDIR "/serverkeys"));
+       return TRUE;
+      }
+    } else {
+      SILC_LOG_ERROR(("%s\n", strerror(errno)));
+      return TRUE;
+    }
+  }
+
+  /* Take fingerprint of the public key */
+  fingerprint = silc_hash_fingerprint(NULL, pk, pk_len);
+  SILC_LOG_DEBUG(("Received server %s (%s) port %d public key (%s)", 
+                 sock->hostname, sock->ip, sock->port, fingerprint));
+  silc_free(fingerprint);
+
+  /* Check whether this key already exists */
+  if (stat(filename, &st) < 0) {
+    /* We don't have it, then cache it. */
+    SILC_LOG_DEBUG(("New public key from server"));
+
+    silc_pkcs_save_public_key_data(filename, pk, pk_len, 
+                                  SILC_PKCS_FILE_PEM);
+    return TRUE;
+  } else {
+    /* The key already exists, verify it. */
+    SilcPublicKey public_key;
+    unsigned char *encpk;
+    uint32 encpk_len;
+
+    SILC_LOG_DEBUG(("We have the public key saved locally"));
+
+    /* Load the key file */
+    if (!silc_pkcs_load_public_key(filename, &public_key, 
+                                  SILC_PKCS_FILE_PEM))
+      if (!silc_pkcs_load_public_key(filename, &public_key, 
+                                    SILC_PKCS_FILE_BIN)) {
+       SILC_LOG_WARNING(("Could not load local copy of the %s (%s) port %d "
+                         "server public key", sock->hostname, sock->ip, 
+                         sock->port));
+
+       /* Save the key for future checking */
+       unlink(filename);
+       silc_pkcs_save_public_key_data(filename, pk, pk_len,
+                                      SILC_PKCS_FILE_PEM);
+       return TRUE;
+      }
+  
+    /* Encode the key data */
+    encpk = silc_pkcs_public_key_encode(public_key, &encpk_len);
+    if (!encpk) {
+      SILC_LOG_WARNING(("Local copy of the server %s (%s) port %d public key "
+                       "is malformed", sock->hostname, sock->ip, sock->port));
+
+      /* Save the key for future checking */
+      unlink(filename);
+      silc_pkcs_save_public_key_data(filename, pk, pk_len, SILC_PKCS_FILE_PEM);
+      return TRUE;
+    }
+
+    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));
+      SILC_LOG_WARNING(("It is possible that the key has expired or changed"));
+      SILC_LOG_WARNING(("It is also possible that some one is performing "
+                       "man-in-the-middle attack"));
+      SILC_LOG_WARNING(("Will not accept the server %s (%s) port %d public "
+                       "key",
+                       sock->hostname, sock->ip, sock->port));
+      return FALSE;
+    }
+
+    /* Local copy matched */
+    return TRUE;
+  }
+}
+
+/* Callback that is called when we have received KE2 payload from
+   responder. We try to verify the public key now. */
+
+static void 
+silc_server_protocol_ke_verify_key(SilcSKE ske,
+                                  unsigned char *pk_data,
+                                  uint32 pk_len,
+                                  SilcSKEPKType pk_type,
+                                  void *context,
+                                  SilcSKEVerifyCbCompletion completion,
+                                  void *completion_context)
+{
+  SilcProtocol protocol = (SilcProtocol)context;
+  SilcServerKEInternalContext *ctx = 
+    (SilcServerKEInternalContext *)protocol->context;
+  SilcServer server = (SilcServer)ctx->server;
+
+  SILC_LOG_DEBUG(("Start"));
+
+  if (silc_verify_public_key_internal(server, ctx->sock, 
+                                     (ctx->responder == FALSE ?
+                                      SILC_SOCKET_TYPE_ROUTER:
+                                      ctx->sconfig ? SILC_SOCKET_TYPE_SERVER :
+                                      ctx->rconfig ? SILC_SOCKET_TYPE_ROUTER :
+                                      SILC_SOCKET_TYPE_CLIENT),
+                                     pk_data, pk_len, pk_type))
+    completion(ske, SILC_SKE_STATUS_OK, completion_context);
+  else
+    completion(ske, SILC_SKE_STATUS_UNSUPPORTED_PUBLIC_KEY, 
+              completion_context);
+}
+
 /* Packet sending callback. This function is provided as packet sending
    routine to the Key Exchange functions. */
 
@@ -55,7 +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,
@@ -83,6 +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);
@@ -90,6 +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);
@@ -97,53 +269,57 @@ 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));
-  idata->rekey->send_enc_key = 
-    silc_calloc(keymat->enc_key_len / 8,
-               sizeof(*idata->rekey->send_enc_key));
-  memcpy(idata->rekey->send_enc_key, 
-        keymat->send_enc_key, keymat->enc_key_len / 8);
+  idata->rekey->send_enc_key = silc_memdup(keymat->send_enc_key,
+                                          keymat->enc_key_len / 8);
   idata->rekey->enc_key_len = keymat->enc_key_len / 8;
 
-  if (ske->start_payload->flags & SILC_SKE_SP_FLAG_PFS)
+  if (ske->prop->flags & SILC_SKE_SP_FLAG_PFS)
     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)) {
-    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, keymat->hmac_key, keymat->hmac_key_len);
+  /* 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;
 }
 
 /* Check remote host version string */
 
 SilcSKEStatus silc_ske_check_version(SilcSKE ske, unsigned char *version,
-                                    uint32 len)
+                                    uint32 len, void *context)
 {
   SilcSKEStatus status = SILC_SKE_STATUS_OK;
+  char *cp;
+  int maj = 0, min = 0, build = 0, maj2 = 0, min2 = 0, build2 = 0;
 
   SILC_LOG_INFO(("%s (%s) is version %s", ske->sock->hostname,
                 ske->sock->ip, version));
@@ -154,15 +330,102 @@ SilcSKEStatus silc_ske_check_version(SilcSKE ske, unsigned char *version,
 
   /* Check software version */
 
-  if (len < strlen(silc_version_string))
+  cp = version + 9;
+  if (!cp)
     status = SILC_SKE_STATUS_BAD_VERSION;
 
-  /* XXX for now there is no other tests due to the abnormal version
-     string that is used */
+  maj = atoi(cp);
+  cp = strchr(cp, '.');
+  if (cp) {
+    min = atoi(cp + 1);
+    cp++;
+  }
+  if (cp) {
+    cp = strchr(cp, '.');
+    if (cp)
+      build = atoi(cp + 1);
+  }
+
+  cp = silc_version_string + 9;
+  if (!cp)
+    status = SILC_SKE_STATUS_BAD_VERSION;
+
+  maj2 = atoi(cp);
+  cp = strchr(cp, '.');
+  if (cp) {
+    min2 = atoi(cp + 1);
+    cp++;
+  }
+  if (cp) {
+    cp = strchr(cp, '.');
+    if (cp)
+      build2 = atoi(cp + 1);
+  }
+
+  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;
 }
 
+/* Callback that is called by the SKE to indicate that it is safe to
+   continue the execution of the protocol. This is used only if we are
+   initiator.  Is given as argument to the silc_ske_initiator_finish or
+   silc_ske_responder_phase_2 functions. This is called due to the fact
+   that the public key verification process is asynchronous and we must
+   not continue the protocl until the public key has been verified and
+   this callback is called. */
+
+static void silc_server_protocol_ke_continue(SilcSKE ske, void *context)
+{
+  SilcProtocol protocol = (SilcProtocol)context;
+  SilcServerKEInternalContext *ctx = 
+    (SilcServerKEInternalContext *)protocol->context;
+  SilcServer server = (SilcServer)ctx->server;
+
+  SILC_LOG_DEBUG(("Start"));
+
+  if (ske->status != SILC_SKE_STATUS_OK) {
+    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);
+    return;
+  }
+
+  /* Send Ok to the other end. We will end the protocol as responder
+     sends Ok to us when we will take the new keys into use. */
+  if (ctx->responder == FALSE) {
+    silc_ske_end(ctx->ske);
+
+    /* End the protocol on the next round */
+    protocol->state = SILC_PROTOCOL_STATE_END;
+  }
+
+  /* Advance protocol state and call the next state if we are responder. 
+     This happens when this callback was sent to silc_ske_responder_phase_2
+     function. */
+  if (ctx->responder == TRUE) {
+    protocol->state++;
+    silc_protocol_execute(protocol, server->schedule, 0, 100000);
+  }
+}
+
 /* Performs key exchange protocol. This is used for both initiator
    and responder key exchange. This is performed always when accepting
    new connection to the server. This may be called recursively. */
@@ -173,7 +436,7 @@ SILC_TASK_CALLBACK(silc_server_protocol_key_exchange)
   SilcServerKEInternalContext *ctx = 
     (SilcServerKEInternalContext *)protocol->context;
   SilcServer server = (SilcServer)ctx->server;
-  SilcSKEStatus status = 0;
+  SilcSKEStatus status = SILC_SKE_STATUS_OK;
 
   SILC_LOG_DEBUG(("Start"));
 
@@ -191,48 +454,52 @@ SILC_TASK_CALLBACK(silc_server_protocol_key_exchange)
       SilcSKE ske;
 
       /* Allocate Key Exchange object */
-      ske = silc_ske_alloc();
-      ctx->ske = ske;
-      ske->rng = server->rng;
+      ctx->ske = ske = silc_ske_alloc(server->rng, server);
+      
+      silc_ske_set_callbacks(ske, silc_server_protocol_ke_send_packet, NULL,
+                            silc_server_protocol_ke_verify_key,
+                            silc_server_protocol_ke_continue,
+                            silc_ske_check_version, context);
       
       if (ctx->responder == TRUE) {
        /* Start the key exchange by processing the received security
           properties packet from initiator. */
        status = silc_ske_responder_start(ske, ctx->rng, ctx->sock,
                                          silc_version_string,
-                                         ctx->packet->buffer, FALSE,
-                                         NULL, NULL);
+                                         ctx->packet->buffer, ctx->flags);
       } else {
        SilcSKEStartPayload *start_payload;
 
        /* Assemble security properties. */
-       silc_ske_assemble_security_properties(ske, SILC_SKE_SP_FLAG_NONE
+       silc_ske_assemble_security_properties(ske, ctx->flags
                                              silc_version_string,
                                              &start_payload);
 
        /* Start the key exchange by sending our security properties
           to the remote end. */
        status = silc_ske_initiator_start(ske, ctx->rng, ctx->sock,
-                                         start_payload,
-                                         silc_server_protocol_ke_send_packet,
-                                         context);
+                                         start_payload);
       }
 
+      /* Return now if the procedure is pending. */
+      if (status == SILC_SKE_STATUS_PENDING)
+       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;
-       protocol->execute(server->timeout_queue, 0, protocol, fd, 0, 300000);
+       silc_protocol_execute(protocol, server->schedule, 0, 300000);
        return;
       }
 
       /* Advance protocol state and call the next state if we are responder */
       protocol->state++;
       if (ctx->responder == TRUE)
-       protocol->execute(server->timeout_queue, 0, protocol, fd, 0, 100000);
+       silc_protocol_execute(protocol, server->schedule, 0, 100000);
     }
     break;
   case 2:
@@ -242,35 +509,34 @@ SILC_TASK_CALLBACK(silc_server_protocol_key_exchange)
        */
       if (ctx->responder == TRUE) {
        /* Sends the selected security properties to the initiator. */
-       status = 
-         silc_ske_responder_phase_1(ctx->ske, 
-                                    ctx->ske->start_payload,
-                                    silc_server_protocol_ke_send_packet,
-                                    context);
+       status = silc_ske_responder_phase_1(ctx->ske);
       } else {
        /* Call Phase-1 function. This processes the Key Exchange Start
           paylaod reply we just got from the responder. The callback
           function will receive the processed payload where we will
           save it. */
-       status = silc_ske_initiator_phase_1(ctx->ske, ctx->packet->buffer,
-                                           NULL, NULL);
+       status = silc_ske_initiator_phase_1(ctx->ske, ctx->packet->buffer);
       }
 
+      /* Return now if the procedure is pending. */
+      if (status == SILC_SKE_STATUS_PENDING)
+       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;
-       protocol->execute(server->timeout_queue, 0, protocol, fd, 0, 300000);
+       silc_protocol_execute(protocol, server->schedule, 0, 300000);
        return;
       }
 
       /* Advance protocol state and call next state if we are initiator */
       protocol->state++;
       if (ctx->responder == FALSE)
-       protocol->execute(server->timeout_queue, 0, protocol, fd, 0, 100000);
+       silc_protocol_execute(protocol, server->schedule, 0, 100000);
     }
     break;
   case 3:
@@ -281,36 +547,34 @@ SILC_TASK_CALLBACK(silc_server_protocol_key_exchange)
       if (ctx->responder == TRUE) {
        /* Process the received Key Exchange 1 Payload packet from
           the initiator. This also creates our parts of the Diffie
-          Hellman algorithm. */
-       status = silc_ske_responder_phase_2(ctx->ske, ctx->packet->buffer, 
-                                           NULL, NULL, NULL, NULL);
+          Hellman algorithm. The silc_server_protocol_ke_continue
+          will be called after the public key has been verified. */
+       status = silc_ske_responder_phase_2(ctx->ske, ctx->packet->buffer);
       } else {
        /* Call the Phase-2 function. This creates Diffie Hellman
           key exchange parameters and sends our public part inside
           Key Exhange 1 Payload to the responder. */
-       status = 
-         silc_ske_initiator_phase_2(ctx->ske,
-                                    server->public_key,
-                                    server->private_key,
-                                    silc_server_protocol_ke_send_packet,
-                                    context);
+       status = silc_ske_initiator_phase_2(ctx->ske,
+                                           server->public_key,
+                                           server->private_key,
+                                           SILC_SKE_PK_TYPE_SILC);
+       protocol->state++;
       }
 
+      /* Return now if the procedure is pending. */
+      if (status == SILC_SKE_STATUS_PENDING)
+       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;
-       protocol->execute(server->timeout_queue, 0, protocol, fd, 0, 300000);
+       silc_protocol_execute(protocol, server->schedule, 0, 300000);
        return;
       }
-
-      /* Advance protocol state and call the next state if we are responder */
-      protocol->state++;
-      if (ctx->responder == TRUE)
-       protocol->execute(server->timeout_queue, 0, protocol, fd, 0, 100000);
     }
     break;
   case 4:
@@ -321,37 +585,34 @@ SILC_TASK_CALLBACK(silc_server_protocol_key_exchange)
       if (ctx->responder == TRUE) {
        /* This creates the key exchange material and sends our
           public parts to the initiator inside Key Exchange 2 Payload. */
-       status = 
-         silc_ske_responder_finish(ctx->ske, 
-                                   server->public_key, server->private_key,
-                                   SILC_SKE_PK_TYPE_SILC,
-                                   silc_server_protocol_ke_send_packet,
-                                   context);
+       status = silc_ske_responder_finish(ctx->ske, 
+                                          server->public_key, 
+                                          server->private_key,
+                                          SILC_SKE_PK_TYPE_SILC);
+
+       /* End the protocol on the next round */
+       protocol->state = SILC_PROTOCOL_STATE_END;
       } else {
        /* Finish the protocol. This verifies the Key Exchange 2 payload
-          sent by responder. */
-       status = silc_ske_initiator_finish(ctx->ske, ctx->packet->buffer, 
-                                          NULL, NULL, NULL, NULL);
+          sent by responder. The silc_server_protocol_ke_continue will
+          be called after the public key has been verified. */
+       status = silc_ske_initiator_finish(ctx->ske, ctx->packet->buffer);
       }
 
+      /* Return now if the procedure is pending. */
+      if (status == SILC_SKE_STATUS_PENDING)
+       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;
-       protocol->execute(server->timeout_queue, 0, protocol, fd, 0, 300000);
+       silc_protocol_execute(protocol, server->schedule, 0, 300000);
        return;
       }
-
-      /* Send Ok to the other end. We will end the protocol as responder
-        sends Ok to us when we will take the new keys into use. */
-      if (ctx->responder == FALSE)
-       silc_ske_end(ctx->ske, silc_server_protocol_ke_send_packet, context);
-
-      /* End the protocol on the next round */
-      protocol->state = SILC_PROTOCOL_STATE_END;
     }
     break;
 
@@ -370,7 +631,7 @@ SILC_TASK_CALLBACK(silc_server_protocol_key_exchange)
                                             keymat);
       if (status != SILC_SKE_STATUS_OK) {
        protocol->state = SILC_PROTOCOL_STATE_ERROR;
-       protocol->execute(server->timeout_queue, 0, protocol, fd, 0, 300000);
+       silc_protocol_execute(protocol, server->schedule, 0, 300000);
        silc_ske_free_key_material(keymat);
        return;
       }
@@ -379,17 +640,22 @@ SILC_TASK_CALLBACK(silc_server_protocol_key_exchange)
       /* Send Ok to the other end if we are responder. If we are initiator
         we have sent this already. */
       if (ctx->responder == TRUE)
-       silc_ske_end(ctx->ske, silc_server_protocol_ke_send_packet, context);
+       silc_ske_end(ctx->ske);
 
       /* Unregister the timeout task since the protocol has ended. 
         This was the timeout task to be executed if the protocol is
         not completed fast enough. */
       if (ctx->timeout_task)
-       silc_task_unregister(server->timeout_queue, 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)
-       protocol->execute_final(server->timeout_queue, 0, protocol, fd);
+       silc_protocol_execute_final(protocol, server->schedule);
       else
        silc_protocol_free(protocol);
     }
@@ -401,19 +667,22 @@ SILC_TASK_CALLBACK(silc_server_protocol_key_exchange)
      */
 
     /* Send abort notification */
-    silc_ske_abort(ctx->ske, ctx->ske->status, 
-                  silc_server_protocol_ke_send_packet,
-                  context);
+    silc_ske_abort(ctx->ske, ctx->ske->status);
 
     /* Unregister the timeout task since the protocol has ended. 
        This was the timeout task to be executed if the protocol is
        not completed fast enough. */
     if (ctx->timeout_task)
-      silc_task_unregister(server->timeout_queue, 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)
-      protocol->execute_final(server->timeout_queue, 0, protocol, fd);
+      silc_protocol_execute_final(protocol, server->schedule);
     else
       silc_protocol_free(protocol);
     break;
@@ -427,11 +696,16 @@ SILC_TASK_CALLBACK(silc_server_protocol_key_exchange)
        This was the timeout task to be executed if the protocol is
        not completed fast enough. */
     if (ctx->timeout_task)
-      silc_task_unregister(server->timeout_queue, 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)
-      protocol->execute_final(server->timeout_queue, 0, protocol, fd);
+      silc_protocol_execute_final(protocol, server->schedule);
     else
       silc_protocol_free(protocol);
     break;
@@ -446,13 +720,13 @@ 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;
@@ -490,7 +764,8 @@ silc_server_public_key_authentication(SilcServer server,
                     SILC_STR_END);
 
   /* Verify signature */
-  if (silc_pkcs_verify(pkcs, sign, sign_len, auth->data, auth->len)) {
+  if (silc_pkcs_verify_with_hash(pkcs, ske->prop->hash, sign, sign_len, 
+                                auth->data, auth->len)) {
     silc_pkcs_free(pkcs);
     silc_buffer_free(auth);
     return TRUE;
@@ -503,8 +778,7 @@ silc_server_public_key_authentication(SilcServer server,
 
 static int
 silc_server_get_public_key_auth(SilcServer server,
-                               SilcPublicKey pub_key,
-                               unsigned char *auth_data,
+                               unsigned char **auth_data,
                                uint32 *auth_data_len,
                                SilcSKE ske)
 {
@@ -512,14 +786,7 @@ silc_server_get_public_key_auth(SilcServer server,
   SilcPKCS pkcs;
   SilcBuffer auth;
 
-  if (!pub_key)
-    return FALSE;
-
-  silc_pkcs_alloc(pub_key->name, &pkcs);
-  if (!silc_pkcs_public_key_set(pkcs, pub_key)) {
-    silc_pkcs_free(pkcs);
-    return FALSE;
-  }
+  pkcs = server->pkcs;
 
   /* Make the authentication data. Protocol says it is HASH plus
      KE Start Payload. */
@@ -532,17 +799,63 @@ silc_server_get_public_key_auth(SilcServer server,
                                          ske->start_payload_copy->len),
                     SILC_STR_END);
 
-  if (silc_pkcs_sign(pkcs, auth->data, auth->len, auth_data, auth_data_len)) {
-    silc_pkcs_free(pkcs);
+  *auth_data = silc_calloc(silc_pkcs_get_key_len(pkcs), sizeof(**auth_data));
+  if (silc_pkcs_sign_with_hash(pkcs, ske->prop->hash, auth->data, 
+                              auth->len, *auth_data, auth_data_len)) {
     silc_buffer_free(auth);
     return TRUE;
   }
 
-  silc_pkcs_free(pkcs);
+  silc_free(*auth_data);
   silc_buffer_free(auth);
   return FALSE;
 }
 
+/* Function that actually performs the authentication to the remote. This
+   supports both passphrase and public key authentication. */
+
+static bool 
+silc_server_get_authentication(SilcServerConnAuthInternalContext *ctx,
+                              char *local_passphrase,
+                              void *local_publickey,
+                              unsigned char *remote_auth,
+                              uint32 remote_auth_len)
+{
+  SilcServer server = (SilcServer)ctx->server;
+  SilcSKE ske = ctx->ske;
+  bool result = FALSE;
+
+  /* If we don't have authentication data set at all we do not require
+     authentication at all */
+  if (!local_passphrase && !local_publickey) {
+    SILC_LOG_DEBUG(("No authentication required"));
+    return TRUE;
+  }
+
+  /* If both passphrase and public key is provided then we'll try both of
+     them and see which one of them authenticates.  If only one of them is
+     set, then try only that. */
+
+  /* Try first passphrase (as it is faster to check) */
+  if (local_passphrase) {
+    SILC_LOG_DEBUG(("Password authentication"));
+    result = silc_server_password_authentication(server, local_passphrase,
+                                                remote_auth);
+  }
+
+  /* Try public key authenetication */
+  if (!result && local_publickey) {
+    SILC_LOG_DEBUG(("Public key authentication"));
+    result = silc_server_public_key_authentication(server, 
+                                                  local_publickey,
+                                                  remote_auth,
+                                                  remote_auth_len, 
+                                                  ske);
+  }
+
+  return result;
+}
+
 /* Performs connection authentication protocol. If responder, we 
    authenticate the remote data received. If initiator, we will send
    authentication data to the remote end. */
@@ -589,14 +902,14 @@ SILC_TASK_CALLBACK(silc_server_protocol_connection_auth)
        if (ret == -1) {
          SILC_LOG_DEBUG(("Bad payload in authentication packet"));
          protocol->state = SILC_PROTOCOL_STATE_ERROR;
-         protocol->execute(server->timeout_queue, 0, protocol, fd, 0, 300000);
+         silc_protocol_execute(protocol, server->schedule, 0, 300000);
          return;
        }
        
        if (payload_len != ctx->packet->buffer->len) {
          SILC_LOG_DEBUG(("Bad payload in authentication packet"));
          protocol->state = SILC_PROTOCOL_STATE_ERROR;
-         protocol->execute(server->timeout_queue, 0, protocol, fd, 0, 300000);
+         silc_protocol_execute(protocol, server->schedule, 0, 300000);
          return;
        }
        
@@ -606,7 +919,7 @@ SILC_TASK_CALLBACK(silc_server_protocol_connection_auth)
            conn_type > SILC_SOCKET_TYPE_ROUTER) {
          SILC_LOG_ERROR(("Bad connection type %d", conn_type));
          protocol->state = SILC_PROTOCOL_STATE_ERROR;
-         protocol->execute(server->timeout_queue, 0, protocol, fd, 0, 300000);
+         silc_protocol_execute(protocol, server->schedule, 0, 300000);
          return;
        }
        
@@ -620,8 +933,7 @@ SILC_TASK_CALLBACK(silc_server_protocol_connection_auth)
          if (ret == -1) {
            SILC_LOG_DEBUG(("Bad payload in authentication packet"));
            protocol->state = SILC_PROTOCOL_STATE_ERROR;
-           protocol->execute(server->timeout_queue, 0, 
-                             protocol, fd, 0, 300000);
+           silc_protocol_execute(protocol, server->schedule, 0, 300000);
            return;
          }
        }
@@ -636,137 +948,57 @@ SILC_TASK_CALLBACK(silc_server_protocol_connection_auth)
 
        /* Remote end is client */
        if (conn_type == SILC_SOCKET_TYPE_CLIENT) {
-         SilcServerConfigSectionClientConnection *client = NULL;
-         client = silc_server_config_find_client_conn(server->config,
-                                                      ctx->sock->ip,
-                                                      ctx->sock->port);
-         if (!client)
-           client = silc_server_config_find_client_conn(server->config,
-                                                        ctx->sock->hostname,
-                                                        ctx->sock->port);
+         SilcServerConfigClient *client = ctx->cconfig;
          
          if (client) {
-           switch(client->auth_meth) {
-           case SILC_AUTH_NONE:
-             /* No authentication required */
-             SILC_LOG_DEBUG(("No authentication required"));
-             break;
-             
-           case SILC_AUTH_PASSWORD:
-             /* Password authentication */
-             SILC_LOG_DEBUG(("Password authentication"));
-             ret = silc_server_password_authentication(server, auth_data,
-                                                       client->auth_data);
-
-             if (ret)
-               break;
-
+           ret = silc_server_get_authentication(ctx, client->passphrase,
+                                                client->publickey,
+                                                auth_data, payload_len);
+           if (!ret) {
              /* Authentication failed */
              SILC_LOG_ERROR(("Authentication failed"));
              SILC_LOG_DEBUG(("Authentication failed"));
              silc_free(auth_data);
              protocol->state = SILC_PROTOCOL_STATE_ERROR;
-             protocol->execute(server->timeout_queue, 0, 
-                               protocol, fd, 0, 300000);
-             return;
-             break;
-             
-           case SILC_AUTH_PUBLIC_KEY:
-             /* Public key authentication */
-             SILC_LOG_DEBUG(("Public key authentication"));
-             ret = silc_server_public_key_authentication(server, 
-                                                         client->auth_data,
-                                                         auth_data,
-                                                         payload_len, 
-                                                         ctx->ske);
-
-             if (ret)
-               break;
-
-             SILC_LOG_ERROR(("Authentication failed"));
-             SILC_LOG_DEBUG(("Authentication failed"));
-             silc_free(auth_data);
-             protocol->state = SILC_PROTOCOL_STATE_ERROR;
-             protocol->execute(server->timeout_queue, 0, 
-                               protocol, fd, 0, 300000);
+             silc_protocol_execute(protocol, server->schedule, 0, 300000);
              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;
-           protocol->execute(server->timeout_queue, 0
-                             protocol, fd, 0, 300000);
+           silc_protocol_execute(protocol, server->schedule
+                                 0, 300000);
            return;
          }
        }
        
        /* Remote end is server */
        if (conn_type == SILC_SOCKET_TYPE_SERVER) {
-         SilcServerConfigSectionServerConnection *serv = NULL;
-         serv = silc_server_config_find_server_conn(server->config,
-                                                    ctx->sock->ip,
-                                                    ctx->sock->port);
-         if (!serv)
-           serv = silc_server_config_find_server_conn(server->config,
-                                                      ctx->sock->hostname,
-                                                      ctx->sock->port);
-
+         SilcServerConfigServer *serv = ctx->sconfig;
+         
          if (serv) {
-           switch(serv->auth_meth) {
-           case SILC_AUTH_NONE:
-             /* No authentication required */
-             SILC_LOG_DEBUG(("No authentication required"));
-             break;
-             
-           case SILC_AUTH_PASSWORD:
-             /* Password authentication */
-             SILC_LOG_DEBUG(("Password authentication"));
-             ret = silc_server_password_authentication(server, auth_data,
-                                                       serv->auth_data);
-
-             if (ret)
-               break;
-             
+           ret = silc_server_get_authentication(ctx, serv->passphrase,
+                                                serv->publickey,
+                                                auth_data, payload_len);
+           if (!ret) {
              /* Authentication failed */
              SILC_LOG_ERROR(("Authentication failed"));
              SILC_LOG_DEBUG(("Authentication failed"));
              silc_free(auth_data);
              protocol->state = SILC_PROTOCOL_STATE_ERROR;
-             protocol->execute(server->timeout_queue, 0, 
-                               protocol, fd, 0, 300000);
-             return;
-             break;
-
-           case SILC_AUTH_PUBLIC_KEY:
-             /* Public key authentication */
-             SILC_LOG_DEBUG(("Public key authentication"));
-             ret = silc_server_public_key_authentication(server, 
-                                                         serv->auth_data,
-                                                         auth_data,
-                                                         payload_len, 
-                                                         ctx->ske);
-                                                         
-             if (ret)
-               break;
-
-             SILC_LOG_ERROR(("Authentication failed"));
-             SILC_LOG_DEBUG(("Authentication failed"));
-             silc_free(auth_data);
-             protocol->state = SILC_PROTOCOL_STATE_ERROR;
-             protocol->execute(server->timeout_queue, 0, 
-                               protocol, fd, 0, 300000);
+             silc_protocol_execute(protocol, server->schedule, 0, 300000);
              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;
-           protocol->execute(server->timeout_queue, 0
-                             protocol, fd, 0, 300000);
+           silc_protocol_execute(protocol, server->schedule
+                                 0, 300000);
            silc_free(auth_data);
            return;
          }
@@ -774,69 +1006,29 @@ SILC_TASK_CALLBACK(silc_server_protocol_connection_auth)
        
        /* Remote end is router */
        if (conn_type == SILC_SOCKET_TYPE_ROUTER) {
-         SilcServerConfigSectionServerConnection *serv = NULL;
-         serv = silc_server_config_find_router_conn(server->config,
-                                                    ctx->sock->ip,
-                                                    ctx->sock->port);
-         if (!serv)
-           serv = silc_server_config_find_router_conn(server->config,
-                                                      ctx->sock->hostname,
-                                                      ctx->sock->port);
-         
+         SilcServerConfigRouter *serv = ctx->rconfig;
+
          if (serv) {
-           switch(serv->auth_meth) {
-           case SILC_AUTH_NONE:
-             /* No authentication required */
-             SILC_LOG_DEBUG(("No authentication required"));
-             break;
-             
-           case SILC_AUTH_PASSWORD:
-             /* Password authentication */
-             SILC_LOG_DEBUG(("Password authentication"));
-             ret = silc_server_password_authentication(server, auth_data,
-                                                       serv->auth_data);
-
-             if (ret)
-               break;
-             
+           ret = silc_server_get_authentication(ctx, serv->passphrase,
+                                                serv->publickey,
+                                                auth_data, payload_len);
+           if (!ret) {
              /* Authentication failed */
              SILC_LOG_ERROR(("Authentication failed"));
              SILC_LOG_DEBUG(("Authentication failed"));
              silc_free(auth_data);
              protocol->state = SILC_PROTOCOL_STATE_ERROR;
-             protocol->execute(server->timeout_queue, 0, 
-                               protocol, fd, 0, 300000);
-             return;
-             break;
-             
-           case SILC_AUTH_PUBLIC_KEY:
-             /* Public key authentication */
-             SILC_LOG_DEBUG(("Public key authentication"));
-             ret = silc_server_public_key_authentication(server, 
-                                                         serv->auth_data,
-                                                         auth_data,
-                                                         payload_len, 
-                                                         ctx->ske);
-                                                         
-             if (ret)
-               break;
-             
-             SILC_LOG_ERROR(("Authentication failed"));
-             SILC_LOG_DEBUG(("Authentication failed"));
-             silc_free(auth_data);
-             protocol->state = SILC_PROTOCOL_STATE_ERROR;
-             protocol->execute(server->timeout_queue, 0, 
-                               protocol, fd, 0, 300000);
+             silc_protocol_execute(protocol, server->schedule, 0, 300000);
              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;
-           protocol->execute(server->timeout_queue, 0
-                             protocol, fd, 0, 300000);
+           silc_protocol_execute(protocol, server->schedule
+                                 0, 300000);
            return;
          }
        }
@@ -849,7 +1041,7 @@ SILC_TASK_CALLBACK(silc_server_protocol_connection_auth)
          
        /* Advance protocol state. */
        protocol->state = SILC_PROTOCOL_STATE_END;
-       protocol->execute(server->timeout_queue, 0, protocol, fd, 0, 0);
+       silc_protocol_execute(protocol, server->schedule, 0, 0);
 
       } else {
        /* 
@@ -878,14 +1070,9 @@ SILC_TASK_CALLBACK(silc_server_protocol_connection_auth)
          
        case SILC_AUTH_PUBLIC_KEY:
          {
-           unsigned char sign[1024];
-
            /* Public key authentication */
-           silc_server_get_public_key_auth(server, ctx->auth_data,
-                                           sign, &auth_data_len,
+           silc_server_get_public_key_auth(server, &auth_data, &auth_data_len,
                                            ctx->ske);
-           auth_data = silc_calloc(auth_data_len, sizeof(*auth_data));
-           memcpy(auth_data, sign, auth_data_len);
            break;
          }
        }
@@ -936,11 +1123,16 @@ SILC_TASK_CALLBACK(silc_server_protocol_connection_auth)
         This was the timeout task to be executed if the protocol is
         not completed fast enough. */
       if (ctx->timeout_task)
-       silc_task_unregister(server->timeout_queue, 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)
-       protocol->execute_final(server->timeout_queue, 0, protocol, fd);
+       silc_protocol_execute_final(protocol, server->schedule);
       else
        silc_protocol_free(protocol);
     }
@@ -962,11 +1154,16 @@ SILC_TASK_CALLBACK(silc_server_protocol_connection_auth)
         This was the timeout task to be executed if the protocol is
         not completed fast enough. */
       if (ctx->timeout_task)
-       silc_task_unregister(server->timeout_queue, 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)
-       protocol->execute_final(server->timeout_queue, 0, protocol, fd);
+       silc_protocol_execute_final(protocol, server->schedule);
       else
        silc_protocol_free(protocol);
     }
@@ -981,11 +1178,16 @@ SILC_TASK_CALLBACK(silc_server_protocol_connection_auth)
        This was the timeout task to be executed if the protocol is
        not completed fast enough. */
     if (ctx->timeout_task)
-      silc_task_unregister(server->timeout_queue, 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)
-      protocol->execute_final(server->timeout_queue, 0, protocol, fd);
+      silc_protocol_execute_final(protocol, server->schedule);
     else
       silc_protocol_free(protocol);
     break;
@@ -1005,49 +1207,63 @@ static void
 silc_server_protocol_rekey_validate(SilcServer server,
                                    SilcServerRekeyInternalContext *ctx,
                                    SilcIDListData idata,
-                                   SilcSKEKeyMaterial *keymat)
+                                   SilcSKEKeyMaterial *keymat,
+                                   bool send)
 {
   if (ctx->responder == TRUE) {
-    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_cipher_set_key(idata->receive_key, keymat->send_enc_key, 
-                       keymat->enc_key_len);
-    silc_cipher_set_iv(idata->receive_key, keymat->send_iv);
+    if (send) {
+      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 {
-    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_cipher_set_key(idata->receive_key, keymat->receive_enc_key, 
-                       keymat->enc_key_len);
-    silc_cipher_set_iv(idata->receive_key, keymat->receive_iv);
+    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);
+    }
   }
 
-  silc_hmac_set_key(idata->hmac, keymat->hmac_key, keymat->hmac_key_len);
-
   /* Save the current sending encryption key */
-  memset(idata->rekey->send_enc_key, 0, idata->rekey->enc_key_len);
-  silc_free(idata->rekey->send_enc_key);
-  idata->rekey->send_enc_key = 
-    silc_calloc(keymat->enc_key_len / 8,
-               sizeof(*idata->rekey->send_enc_key));
-  memcpy(idata->rekey->send_enc_key, keymat->send_enc_key, 
-        keymat->enc_key_len / 8);
-  idata->rekey->enc_key_len = keymat->enc_key_len / 8;
+  if (!send) {
+    memset(idata->rekey->send_enc_key, 0, idata->rekey->enc_key_len);
+    silc_free(idata->rekey->send_enc_key);
+    idata->rekey->send_enc_key = silc_memdup(keymat->send_enc_key,
+                                            keymat->enc_key_len / 8);
+    idata->rekey->enc_key_len = keymat->enc_key_len / 8;
+  }
 }
 
 /* This function actually re-generates (when not using PFS) the keys and
    takes them into use. */
 
 void silc_server_protocol_rekey_generate(SilcServer server,
-                                        SilcServerRekeyInternalContext *ctx)
+                                        SilcServerRekeyInternalContext *ctx,
+                                        bool send)
 {
   SilcIDListData idata = (SilcIDListData)ctx->sock->user_data;
   SilcSKEKeyMaterial *keymat;
   uint32 key_len = silc_cipher_get_key_len(idata->send_key);
   uint32 hash_len = idata->hash->hash->hash_len;
 
-  SILC_LOG_DEBUG(("Generating new session keys (no PFS)"));
+  SILC_LOG_DEBUG(("Generating new %s session keys (no PFS)",
+                 send ? "sending" : "receiving"));
 
   /* Generate the new key */
   keymat = silc_calloc(1, sizeof(*keymat));
@@ -1057,7 +1273,7 @@ void silc_server_protocol_rekey_generate(SilcServer server,
                                     idata->hash, keymat);
 
   /* Set the keys into use */
-  silc_server_protocol_rekey_validate(server, ctx, idata, keymat);
+  silc_server_protocol_rekey_validate(server, ctx, idata, keymat, send);
 
   silc_ske_free_key_material(keymat);
 }
@@ -1067,7 +1283,8 @@ void silc_server_protocol_rekey_generate(SilcServer server,
 
 void 
 silc_server_protocol_rekey_generate_pfs(SilcServer server,
-                                       SilcServerRekeyInternalContext *ctx)
+                                       SilcServerRekeyInternalContext *ctx,
+                                       bool send)
 {
   SilcIDListData idata = (SilcIDListData)ctx->sock->user_data;
   SilcSKEKeyMaterial *keymat;
@@ -1076,7 +1293,8 @@ silc_server_protocol_rekey_generate_pfs(SilcServer server,
   unsigned char *tmpbuf;
   uint32 klen;
 
-  SILC_LOG_DEBUG(("Generating new session keys (with PFS)"));
+  SILC_LOG_DEBUG(("Generating new %s session keys (with PFS)",
+                 send ? "sending" : "receiving"));
 
   /* Encode KEY to binary data */
   tmpbuf = silc_mp_mp2bin(ctx->ske->KEY, 0, &klen);
@@ -1087,7 +1305,7 @@ silc_server_protocol_rekey_generate_pfs(SilcServer server,
                                     idata->hash, keymat);
 
   /* Set the keys into use */
-  silc_server_protocol_rekey_validate(server, ctx, idata, keymat);
+  silc_server_protocol_rekey_validate(server, ctx, idata, keymat, send);
 
   memset(tmpbuf, 0, klen);
   silc_free(tmpbuf);
@@ -1152,31 +1370,33 @@ SILC_TASK_CALLBACK(silc_server_protocol_rekey)
          if (ctx->packet->type != SILC_PACKET_KEY_EXCHANGE_1) {
            /* Error in protocol */
            protocol->state = SILC_PROTOCOL_STATE_ERROR;
-           protocol->execute(server->timeout_queue, 0, protocol, fd, 
-                             0, 300000);
+           silc_protocol_execute(protocol, server->schedule, 0, 300000);
+           return;
          }
 
-         ctx->ske = silc_ske_alloc();
-         ctx->ske->rng = server->rng;
+         ctx->ske = silc_ske_alloc(server->rng, server);
          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);
 
-         status = silc_ske_responder_phase_2(ctx->ske, ctx->packet->buffer,
-                                             NULL, NULL, NULL, NULL);
+         silc_ske_set_callbacks(ctx->ske, 
+                                silc_server_protocol_rekey_send_packet, 
+                                NULL, NULL, NULL, silc_ske_check_version,
+                                context);
+      
+         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;
-           protocol->execute(server->timeout_queue, 0, 
-                             protocol, fd, 0, 300000);
+           silc_protocol_execute(protocol, server->schedule, 0, 300000);
            return;
          }
 
          /* Advance the protocol state */
          protocol->state++;
-         protocol->execute(server->timeout_queue, 0, protocol, fd, 0, 0);
+         silc_protocol_execute(protocol, server->schedule, 0, 0);
        } else {
          /*
           * Do normal and simple re-key.
@@ -1186,6 +1406,11 @@ SILC_TASK_CALLBACK(silc_server_protocol_rekey)
          silc_server_packet_send(server, ctx->sock, SILC_PACKET_REKEY_DONE,
                                  0, NULL, 0, FALSE);
 
+         /* After we send REKEY_DONE we must set the sending encryption
+            key to the new key since all packets after this packet must
+            encrypted with the new key. */
+         silc_server_protocol_rekey_generate(server, ctx, TRUE);
+
          /* The protocol ends in next stage. */
          protocol->state = SILC_PROTOCOL_STATE_END;
        }
@@ -1204,24 +1429,23 @@ SILC_TASK_CALLBACK(silc_server_protocol_rekey)
           * Use Perfect Forward Secrecy, ie. negotiate the key material
           * using the SKE protocol.
           */
-         ctx->ske = silc_ske_alloc();
-         ctx->ske->rng = server->rng;
+         ctx->ske = silc_ske_alloc(server->rng, server);
          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);
 
-         status = 
-           silc_ske_initiator_phase_2(ctx->ske, NULL, NULL,
-                                      silc_server_protocol_rekey_send_packet,
-                                      context);
-
+         silc_ske_set_callbacks(ctx->ske, 
+                                silc_server_protocol_rekey_send_packet, 
+                                NULL, NULL, NULL, silc_ske_check_version,
+                                context);
+      
+         status = silc_ske_initiator_phase_2(ctx->ske, NULL, NULL, 0);
          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;
-           protocol->execute(server->timeout_queue, 0, 
-                             protocol, fd, 0, 300000);
+           silc_protocol_execute(protocol, server->schedule, 0, 300000);
            return;
          }
 
@@ -1237,6 +1461,11 @@ SILC_TASK_CALLBACK(silc_server_protocol_rekey)
          silc_server_packet_send(server, ctx->sock, SILC_PACKET_REKEY_DONE,
                                  0, NULL, 0, FALSE);
 
+         /* After we send REKEY_DONE we must set the sending encryption
+            key to the new key since all packets after this packet must
+            encrypted with the new key. */
+         silc_server_protocol_rekey_generate(server, ctx, TRUE);
+
          /* The protocol ends in next stage. */
          protocol->state = SILC_PROTOCOL_STATE_END;
        }
@@ -1254,21 +1483,16 @@ SILC_TASK_CALLBACK(silc_server_protocol_rekey)
         * Send our KE packe to the initiator now that we've processed
         * the initiator's KE packet.
         */
-       status = 
-         silc_ske_responder_finish(ctx->ske, NULL, NULL, 
-                                   SILC_SKE_PK_TYPE_SILC,
-                                   silc_server_protocol_rekey_send_packet,
-                                   context);
-
-         if (status != SILC_SKE_STATUS_OK) {
-           SILC_LOG_WARNING(("Error (type %d) during Re-key (PFS)",
-                             status));
-           
-           protocol->state = SILC_PROTOCOL_STATE_ERROR;
-           protocol->execute(server->timeout_queue, 0, 
-                             protocol, fd, 0, 300000);
-           return;
-         }
+       status = silc_ske_responder_finish(ctx->ske, NULL, NULL, 
+                                          SILC_SKE_PK_TYPE_SILC);
+       if (status != SILC_SKE_STATUS_OK) {
+         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);
+         return;
+       }
       }
 
     } else {
@@ -1279,18 +1503,17 @@ SILC_TASK_CALLBACK(silc_server_protocol_rekey)
        if (ctx->packet->type != SILC_PACKET_KEY_EXCHANGE_2) {
          /* Error in protocol */
          protocol->state = SILC_PROTOCOL_STATE_ERROR;
-         protocol->execute(server->timeout_queue, 0, protocol, fd, 0, 300000);
+         silc_protocol_execute(protocol, server->schedule, 0, 300000);
+         return;
        }
        
-       status = silc_ske_initiator_finish(ctx->ske, ctx->packet->buffer,
-                                          NULL, NULL, NULL, NULL);
+       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;
-         protocol->execute(server->timeout_queue, 0, 
-                           protocol, fd, 0, 300000);
+         silc_protocol_execute(protocol, server->schedule, 0, 300000);
          return;
        }
       }
@@ -1301,6 +1524,11 @@ SILC_TASK_CALLBACK(silc_server_protocol_rekey)
     silc_server_packet_send(server, ctx->sock, SILC_PACKET_REKEY_DONE,
                            0, NULL, 0, FALSE);
     
+    /* After we send REKEY_DONE we must set the sending encryption
+       key to the new key since all packets after this packet must
+       encrypted with the new key. */
+    silc_server_protocol_rekey_generate_pfs(server, ctx, TRUE);
+
     /* The protocol ends in next stage. */
     protocol->state = SILC_PROTOCOL_STATE_END;
     break;
@@ -1313,12 +1541,22 @@ SILC_TASK_CALLBACK(silc_server_protocol_rekey)
     if (ctx->packet->type != SILC_PACKET_REKEY_DONE) {
       /* Error in protocol */
       protocol->state = SILC_PROTOCOL_STATE_ERROR;
-      protocol->execute(server->timeout_queue, 0, protocol, fd, 0, 0);
+      silc_protocol_execute(protocol, server->schedule, 0, 300000);
+      return;
     }
 
+    /* We received the REKEY_DONE packet and all packets after this is
+       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)
-      protocol->execute_final(server->timeout_queue, 0, protocol, fd);
+      silc_protocol_execute_final(protocol, server->schedule);
     else
       silc_protocol_free(protocol);
     break;
@@ -1330,14 +1568,17 @@ SILC_TASK_CALLBACK(silc_server_protocol_rekey)
 
     if (ctx->pfs == TRUE) {
       /* Send abort notification */
-      silc_ske_abort(ctx->ske, ctx->ske->status, 
-                    silc_server_protocol_ke_send_packet,
-                    context);
+      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)
-      protocol->execute_final(server->timeout_queue, 0, protocol, fd);
+      silc_protocol_execute_final(protocol, server->schedule);
     else
       silc_protocol_free(protocol);
     break;
@@ -1347,9 +1588,14 @@ 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)
-      protocol->execute_final(server->timeout_queue, 0, protocol, fd);
+      silc_protocol_execute_final(protocol, server->schedule);
     else
       silc_protocol_free(protocol);
     break;
@@ -1370,6 +1616,8 @@ 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 */
@@ -1382,4 +1630,6 @@ 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);
 }