SKE: support for simplified key exchange
[silc.git] / lib / silcske / silcske.c
index d49d9ccb040a412e82d7abbdc6b96198bf6ae791..129c178e6896ec67261dca6984d5287e14567b79 100644 (file)
@@ -4,7 +4,7 @@
 
   Author: Pekka Riikonen <priikone@silcnet.org>
 
-  Copyright (C) 2000 - 2006 Pekka Riikonen
+  Copyright (C) 2000 - 2014 Pekka Riikonen
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -55,6 +55,11 @@ SILC_FSM_STATE(silc_ske_st_responder_error);
 SILC_FSM_STATE(silc_ske_st_rekey_initiator_start);
 SILC_FSM_STATE(silc_ske_st_rekey_initiator_done);
 SILC_FSM_STATE(silc_ske_st_rekey_initiator_end);
+SILC_FSM_STATE(silc_ske_st_rekey_responder_wait);
+SILC_FSM_STATE(silc_ske_st_rekey_responder_start);
+SILC_FSM_STATE(silc_ske_st_rekey_responder_done);
+SILC_FSM_STATE(silc_ske_st_rekey_responder_end);
+SILC_TASK_CALLBACK(silc_ske_packet_send_retry);
 
 SilcSKEKeyMaterial
 silc_ske_process_key_material(SilcSKE ske,
@@ -68,6 +73,41 @@ static SilcBool silc_ske_packet_send(SilcSKE ske,
                                     const unsigned char *data,
                                     SilcUInt32 data_len);
 
+/*
+ * Notify the owner of the ske that we failed.  Ensures that we don't make the
+ * same callout twice, as the notification callback routines are not designed
+ * to handle that case.
+ */
+static void silc_ske_notify_failure(SilcSKE ske)
+{
+  SILC_LOG_DEBUG(("Notifying SKE %p owner of failure (failure_notified = %d)",
+                 ske, ske->failure_notified));
+
+  /*
+   * First, check if we have already made a failure callout.  If so, then we
+   * will stop here.
+   */
+  if (ske->failure_notified)
+    return;
+
+  /*
+   * Mark ourselves as having already sent the failure notification here and
+   * now.
+   */
+  ske->failure_notified = TRUE;
+
+  SILC_LOG_DEBUG(("Deliver failure notification for SKE %p (%s)",
+                 ske, ske->responder ? "responder" : "initiator"));
+
+  /*
+   * Finally, make the call to the owner's registered failure callback.
+   */
+  if (ske->responder)
+    silc_fsm_next(&ske->fsm, silc_ske_st_responder_failure);
+  else
+    silc_fsm_next(&ske->fsm, silc_ske_st_initiator_failure);
+}
+
 /* Packet callback */
 
 static SilcBool silc_ske_packet_receive(SilcPacketEngine engine,
@@ -81,7 +121,8 @@ static SilcBool silc_ske_packet_receive(SilcPacketEngine engine,
   /* Clear retransmission */
   ske->retry_timer = SILC_SKE_RETRY_MIN;
   ske->retry_count = 0;
-  silc_schedule_task_del_by_context(ske->schedule, ske);
+  silc_schedule_task_del_by_callback(ske->schedule,
+                                    silc_ske_packet_send_retry);
 
   /* Signal for new packet */
   ske->packet = packet;
@@ -101,15 +142,13 @@ static SilcBool silc_ske_packet_receive(SilcPacketEngine engine,
   }
 
   /* See if received failure from remote */
-  if (packet->type == SILC_PACKET_FAILURE) {
-    if (ske->responder)
-      silc_fsm_next(&ske->fsm, silc_ske_st_responder_failure);
-    else
-      silc_fsm_next(&ske->fsm, silc_ske_st_initiator_failure);
-  }
+  if (packet->type == SILC_PACKET_FAILURE)
+    silc_ske_notify_failure(ske);
 
-  /* Handle rekey synchronously */
-  if (ske->rekeying)
+  /* Handle rekey and SUCCESS packets synchronously.  After SUCCESS packets
+     they keys are taken into use immediately, hence the synchronous
+     processing to get the keys in use as soon as possible. */
+  if (ske->rekeying || packet->type == SILC_PACKET_SUCCESS)
     silc_fsm_continue_sync(&ske->fsm);
   else
     silc_fsm_continue(&ske->fsm);
@@ -174,36 +213,13 @@ static void silc_ske_skr_callback(SilcSKR repository,
 
 static SilcSKEStatus silc_ske_check_version(SilcSKE ske)
 {
-  SilcUInt32 l_protocol_version = 0, r_protocol_version = 0;
-  SilcUInt32 r_software_version = 0;
-
   if (!ske->remote_version || !ske->version)
     return SILC_SKE_STATUS_BAD_VERSION;
 
-  if (!silc_parse_version_string(ske->remote_version, &r_protocol_version,
-                                NULL, &r_software_version, NULL, NULL))
+  if (!silc_parse_version_string(ske->remote_version, NULL, NULL,
+                                NULL, NULL, NULL))
     return SILC_SKE_STATUS_BAD_VERSION;
 
-  if (!silc_parse_version_string(ske->version, &l_protocol_version,
-                                NULL, NULL, NULL, NULL))
-    return SILC_SKE_STATUS_BAD_VERSION;
-
-  /* If remote is too new, don't connect */
-  if (l_protocol_version < r_protocol_version)
-    return SILC_SKE_STATUS_BAD_VERSION;
-
-  /* Backwards compatibility checks */
-
-  /* Old server versions requires "valid" looking Source ID in the SILC
-     packets during initial key exchange.  All version before 1.1.0. */
-  if (r_software_version < 110) {
-    SilcClientID id;
-    memset(&id, 0, sizeof(id));
-    id.ip.data_len = 4;
-    SILC_LOG_DEBUG(("Remote is old version, add dummy Source ID to packets"));
-    silc_packet_set_ids(ske->stream, SILC_ID_CLIENT, &id, 0, NULL);
-  }
-
   return SILC_SKE_STATUS_OK;
 }
 
@@ -224,6 +240,8 @@ silc_ske_select_security_properties(SilcSKE ske,
   SILC_LOG_DEBUG(("Parsing KE Start Payload"));
 
   rp = remote_payload;
+  if (!rp)
+    return SILC_SKE_STATUS_BAD_VERSION;
 
   /* Check for mandatory fields */
   if (!rp->ke_grp_len) {
@@ -682,19 +700,29 @@ static SilcSKEStatus silc_ske_make_hash(SilcSKE ske,
 {
   SilcSKEStatus status = SILC_SKE_STATUS_OK;
   SilcBuffer buf;
-  unsigned char *e, *f, *KEY;
-  SilcUInt32 e_len, f_len, KEY_len;
+  unsigned char *e, *f, *KEY, *s_data;
+  SilcUInt32 e_len, f_len, KEY_len, s_len;
   int ret;
 
   SILC_LOG_DEBUG(("Start"));
 
   if (initiator == FALSE) {
+    s_data = (ske->start_payload_copy ?
+            silc_buffer_data(ske->start_payload_copy) : NULL);
+    s_len = (ske->start_payload_copy ?
+            silc_buffer_len(ske->start_payload_copy) : 0);
     e = silc_mp_mp2bin(&ske->ke1_payload->x, 0, &e_len);
+    if (!e)
+      return SILC_SKE_STATUS_OUT_OF_MEMORY;
     f = silc_mp_mp2bin(&ske->ke2_payload->x, 0, &f_len);
+    if (!f)
+      return SILC_SKE_STATUS_OUT_OF_MEMORY;
     KEY = silc_mp_mp2bin(ske->KEY, 0, &KEY_len);
+    if (!KEY)
+      return SILC_SKE_STATUS_OUT_OF_MEMORY;
 
     /* Format the buffer used to compute the hash value */
-    buf = silc_buffer_alloc_size(silc_buffer_len(ske->start_payload_copy) +
+    buf = silc_buffer_alloc_size(s_len +
                                 ske->ke2_payload->pk_len +
                                 ske->ke1_payload->pk_len +
                                 e_len + f_len + KEY_len);
@@ -705,28 +733,24 @@ static SilcSKEStatus silc_ske_make_hash(SilcSKE ske,
     if (!ske->ke1_payload->pk_data) {
       ret =
        silc_buffer_format(buf,
-                          SILC_STR_UI_XNSTRING(
-                                  ske->start_payload_copy->data,
-                                  silc_buffer_len(ske->start_payload_copy)),
-                          SILC_STR_UI_XNSTRING(ske->ke2_payload->pk_data,
-                                               ske->ke2_payload->pk_len),
-                          SILC_STR_UI_XNSTRING(e, e_len),
-                          SILC_STR_UI_XNSTRING(f, f_len),
-                          SILC_STR_UI_XNSTRING(KEY, KEY_len),
+                          SILC_STR_DATA(s_data, s_len),
+                          SILC_STR_DATA(ske->ke2_payload->pk_data,
+                                        ske->ke2_payload->pk_len),
+                          SILC_STR_DATA(e, e_len),
+                          SILC_STR_DATA(f, f_len),
+                          SILC_STR_DATA(KEY, KEY_len),
                           SILC_STR_END);
     } else {
       ret =
        silc_buffer_format(buf,
-                          SILC_STR_UI_XNSTRING(
-                                  ske->start_payload_copy->data,
-                                  silc_buffer_len(ske->start_payload_copy)),
-                          SILC_STR_UI_XNSTRING(ske->ke2_payload->pk_data,
-                                               ske->ke2_payload->pk_len),
-                          SILC_STR_UI_XNSTRING(ske->ke1_payload->pk_data,
-                                               ske->ke1_payload->pk_len),
-                          SILC_STR_UI_XNSTRING(e, e_len),
-                          SILC_STR_UI_XNSTRING(f, f_len),
-                          SILC_STR_UI_XNSTRING(KEY, KEY_len),
+                          SILC_STR_DATA(s_data, s_len),
+                          SILC_STR_DATA(ske->ke2_payload->pk_data,
+                                        ske->ke2_payload->pk_len),
+                          SILC_STR_DATA(ske->ke1_payload->pk_data,
+                                        ske->ke1_payload->pk_len),
+                          SILC_STR_DATA(e, e_len),
+                          SILC_STR_DATA(f, f_len),
+                          SILC_STR_DATA(KEY, KEY_len),
                           SILC_STR_END);
     }
     if (ret == -1) {
@@ -747,21 +771,25 @@ static SilcSKEStatus silc_ske_make_hash(SilcSKE ske,
     silc_free(f);
     silc_free(KEY);
   } else {
+    s_data = (ske->start_payload_copy ?
+            silc_buffer_data(ske->start_payload_copy) : NULL);
+    s_len = (ske->start_payload_copy ?
+            silc_buffer_len(ske->start_payload_copy) : 0);
     e = silc_mp_mp2bin(&ske->ke1_payload->x, 0, &e_len);
+    if (!e)
+      return SILC_SKE_STATUS_OUT_OF_MEMORY;
 
-    buf = silc_buffer_alloc_size(silc_buffer_len(ske->start_payload_copy) +
-                                ske->ke1_payload->pk_len + e_len);
+    buf = silc_buffer_alloc_size(s_len + ske->ke1_payload->pk_len + e_len);
     if (!buf)
       return SILC_SKE_STATUS_OUT_OF_MEMORY;
 
     /* Format the buffer used to compute the hash value */
     ret =
       silc_buffer_format(buf,
-                        SILC_STR_UI_XNSTRING(ske->start_payload_copy->data,
-                                    silc_buffer_len(ske->start_payload_copy)),
-                        SILC_STR_UI_XNSTRING(ske->ke1_payload->pk_data,
-                                             ske->ke1_payload->pk_len),
-                        SILC_STR_UI_XNSTRING(e, e_len),
+                        SILC_STR_DATA(s_data, s_len),
+                        SILC_STR_DATA(ske->ke1_payload->pk_data,
+                                      ske->ke1_payload->pk_len),
+                        SILC_STR_DATA(e, e_len),
                         SILC_STR_END);
     if (ret == -1) {
       silc_buffer_free(buf);
@@ -800,6 +828,9 @@ silc_ske_make_rekey_material(SilcSKE ske, SilcSKEKeyMaterial keymat)
   SilcSKERekeyMaterial rekey;
   const char *hash;
 
+  if (!keymat)
+    return NULL;
+
   /* Create rekey material */
   rekey = silc_calloc(1, sizeof(*rekey));
   if (!rekey)
@@ -833,7 +864,8 @@ silc_ske_make_rekey_material(SilcSKE ske, SilcSKEKeyMaterial keymat)
 static SilcSKEStartPayload
 silc_ske_assemble_security_properties(SilcSKE ske,
                                      SilcSKESecurityPropertyFlag flags,
-                                     const char *version)
+                                     const char *version,
+                                     SilcBool small_proposal)
 {
   SilcSKEStartPayload rp;
   int i;
@@ -841,12 +873,18 @@ silc_ske_assemble_security_properties(SilcSKE ske,
   SILC_LOG_DEBUG(("Assembling KE Start Payload"));
 
   rp = silc_calloc(1, sizeof(*rp));
+  if (!rp)
+    return NULL;
 
   /* Set flags */
   rp->flags = (unsigned char)flags;
 
   /* Set random cookie */
   rp->cookie = silc_calloc(SILC_SKE_COOKIE_LEN, sizeof(*rp->cookie));
+  if (!rp->cookie) {
+    silc_free(rp);
+    return NULL;
+  }
   for (i = 0; i < SILC_SKE_COOKIE_LEN; i++)
     rp->cookie[i] = silc_rng_get_byte_fast(ske->rng);
   rp->cookie_len = SILC_SKE_COOKIE_LEN;
@@ -858,32 +896,52 @@ silc_ske_assemble_security_properties(SilcSKE ske,
 
   /* Put version */
   rp->version = strdup(version);
-  rp->version_len = strlen(version);
+  if (rp->version)
+    rp->version_len = strlen(version);
 
   /* Get supported Key Exhange groups */
-  rp->ke_grp_list = silc_ske_get_supported_groups();
-  rp->ke_grp_len = strlen(rp->ke_grp_list);
+  rp->ke_grp_list = silc_ske_get_supported_groups(small_proposal);
+  if (rp->ke_grp_list)
+    rp->ke_grp_len = strlen(rp->ke_grp_list);
 
   /* Get supported PKCS algorithms */
-  rp->pkcs_alg_list = silc_pkcs_get_supported();
-  rp->pkcs_alg_len = strlen(rp->pkcs_alg_list);
+  if (small_proposal)
+    rp->pkcs_alg_list = strdup(silc_default_pkcs_alg[0].name);
+  else
+    rp->pkcs_alg_list = silc_pkcs_get_supported();
+  if (rp->pkcs_alg_list)
+    rp->pkcs_alg_len = strlen(rp->pkcs_alg_list);
 
   /* Get supported encryption algorithms */
-  rp->enc_alg_list = silc_cipher_get_supported();
-  rp->enc_alg_len = strlen(rp->enc_alg_list);
+  if (small_proposal)
+    rp->enc_alg_list = strdup(silc_default_ciphers[0].name);
+  else
+    rp->enc_alg_list = silc_cipher_get_supported();
+  if (rp->enc_alg_list)
+    rp->enc_alg_len = strlen(rp->enc_alg_list);
 
   /* Get supported hash algorithms */
-  rp->hash_alg_list = silc_hash_get_supported();
-  rp->hash_alg_len = strlen(rp->hash_alg_list);
+  if (small_proposal)
+    rp->hash_alg_list = strdup(silc_default_hash[0].name);
+  else
+    rp->hash_alg_list = silc_hash_get_supported();
+  if (rp->hash_alg_list)
+    rp->hash_alg_len = strlen(rp->hash_alg_list);
 
   /* Get supported HMACs */
-  rp->hmac_alg_list = silc_hmac_get_supported();
-  rp->hmac_alg_len = strlen(rp->hmac_alg_list);
+  if (small_proposal)
+    rp->hmac_alg_list = strdup(silc_default_hmacs[0].name);
+  else
+    rp->hmac_alg_list = silc_hmac_get_supported();
+  if (rp->hmac_alg_list)
+    rp->hmac_alg_len = strlen(rp->hmac_alg_list);
 
-  /* XXX */
-  /* Get supported compression algorithms */
-  rp->comp_alg_list = strdup("none");
-  rp->comp_alg_len = strlen("none");
+  if (!small_proposal) {
+    /* XXX */
+    /* Get supported compression algorithms */
+    rp->comp_alg_list = strdup("none");
+    rp->comp_alg_len = strlen("none");
+  }
 
   rp->len = 1 + 1 + 2 + SILC_SKE_COOKIE_LEN +
     2 + rp->version_len +
@@ -908,10 +966,7 @@ SILC_TASK_CALLBACK(silc_ske_packet_send_retry)
     silc_free(ske->retrans.data);
     ske->retrans.data = NULL;
     ske->status = SILC_SKE_STATUS_TIMEOUT;
-    if (ske->responder)
-      silc_fsm_next(&ske->fsm, silc_ske_st_responder_failure);
-    else
-      silc_fsm_next(&ske->fsm, silc_ske_st_initiator_failure);
+    silc_ske_notify_failure(ske);
     silc_fsm_continue_sync(&ske->fsm);
     return;
   }
@@ -957,24 +1012,22 @@ static SilcBool silc_ske_packet_send(SilcSKE ske,
     ske->retrans.type = type;
     ske->retrans.flags = flags;
     ske->retrans.data = silc_memdup(data, data_len);
-    ske->retrans.data_len = data_len;
-    silc_ske_install_retransmission(ske);
+    if (ske->retrans.data) {
+      ske->retrans.data_len = data_len;
+      silc_ske_install_retransmission(ske);
+    }
   }
 
   return ret;
 }
 
-/* SKE FSM destructor.  We call completion callback here.  All SKE
-   machines go here and call the completion.  Completion must not be called
-   from any other place. */
+/* Calls completion callback.  Completion is called always in this function
+   and must not be called anywhere else. */
 
-static void silc_ske_finished(SilcFSM fsm, void *fsm_context,
-                             void *destructor_context)
+static void silc_ske_completion(SilcSKE ske)
 {
-  SilcSKE ske = fsm_context;
-
   /* Call the completion callback */
-  if (!ske->freed && !ske->aborted && ske->callbacks->completed) {
+  if (!ske->aborted && ske->callbacks->completed) {
     if (ske->status != SILC_SKE_STATUS_OK)
       ske->callbacks->completed(ske, ske->status, NULL, NULL, NULL,
                                ske->callbacks->context);
@@ -982,10 +1035,45 @@ static void silc_ske_finished(SilcFSM fsm, void *fsm_context,
       ske->callbacks->completed(ske, ske->status, ske->prop, ske->keymat,
                                ske->rekey, ske->callbacks->context);
   }
+}
+
+/* SKE FSM destructor. */
+
+static void silc_ske_finished(SilcFSM fsm, void *fsm_context,
+                             void *destructor_context)
+{
+  SilcSKE ske = fsm_context;
+  silc_ske_free(ske);
+}
+
+/* Key exchange timeout task callback */
+
+SILC_TASK_CALLBACK(silc_ske_timeout)
+{
+  SilcSKE ske = context;
+
+  SILC_LOG_DEBUG(("Timeout"));
 
-  ske->running = FALSE;
-  if (ske->freed)
-    silc_ske_free(ske);
+  ske->packet = NULL;
+  ske->status = SILC_SKE_STATUS_TIMEOUT;
+  silc_ske_notify_failure(ske);
+
+  silc_fsm_continue_sync(&ske->fsm);
+}
+
+/* Key exchange timeout task callback */
+
+SILC_TASK_CALLBACK(silc_ske_probe_timeout)
+{
+  SilcSKE ske = context;
+
+  SILC_LOG_DEBUG(("Probe timeout"));
+
+  ske->packet = NULL;
+  ske->status = SILC_SKE_STATUS_PROBE_TIMEOUT;
+  silc_ske_notify_failure(ske);
+
+  silc_fsm_continue_sync(&ske->fsm);
 }
 
 /******************************* Protocol API *******************************/
@@ -1019,6 +1107,7 @@ SilcSKE silc_ske_alloc(SilcRng rng, SilcSchedule schedule,
   ske->public_key = public_key;
   ske->private_key = private_key;
   ske->retry_timer = SILC_SKE_RETRY_MIN;
+  ske->refcnt = 1;
 
   return ske;
 }
@@ -1027,16 +1116,36 @@ SilcSKE silc_ske_alloc(SilcRng rng, SilcSchedule schedule,
 
 void silc_ske_free(SilcSKE ske)
 {
-  SILC_LOG_DEBUG(("Freeing Key Exchange object"));
-
   if (!ske)
     return;
 
-  if (ske->running) {
-    ske->freed = TRUE;
-    return;
+  SILC_LOG_DEBUG(("Freeing Key Exchange object %p: aborted=%u refcount=%hu",
+                 ske, ske->aborted, ske->refcnt));
+
+  if (ske->aborted) {
+    /*
+     * If already aborted, destroy the session immediately.  Only do the
+     * notification work if we have not already though, as doing so twice
+     * results in memory corruption.  We may have silc_ske_free called
+     * twice, once when the abort is requested, and then again when the
+     * FSM finish routine is called.  We have to be prepared to handle
+     * that case.
+     */
+    ske->packet = NULL;
+    ske->status = SILC_SKE_STATUS_ERROR;
+
+    silc_ske_notify_failure(ske);
+
+    if (silc_fsm_is_started(&ske->fsm))
+      silc_fsm_continue_sync(&ske->fsm);
+    else
+      SILC_LOG_DEBUG(("Not continuing FSM as it's finished for SKE %p", ske));
   }
 
+  ske->refcnt--;
+  if (ske->refcnt > 0)
+    return;
+
   /* Free start payload */
   if (ske->start_payload)
     silc_ske_payload_start_free(ske->start_payload);
@@ -1058,6 +1167,8 @@ void silc_ske_free(SilcSKE ske)
       silc_hash_free(ske->prop->hash);
     if (ske->prop->hmac)
       silc_hmac_free(ske->prop->hmac);
+    if (ske->prop->public_key)
+      silc_pkcs_public_key_free(ske->prop->public_key);
     silc_free(ske->prop);
   }
   if (ske->keymat)
@@ -1076,7 +1187,7 @@ void silc_ske_free(SilcSKE ske)
   silc_free(ske->hash);
   silc_free(ske->callbacks);
 
-  memset(ske, 'F', sizeof(*ske));
+  memset(ske, 0xdd, sizeof(*ske));
   silc_free(ske);
 }
 
@@ -1120,7 +1231,7 @@ SILC_FSM_STATE(silc_ske_st_initiator_start)
   if (ske->aborted) {
     /** Aborted */
     silc_fsm_next(fsm, silc_ske_st_initiator_aborted);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   /* Encode the payload */
@@ -1130,7 +1241,7 @@ SILC_FSM_STATE(silc_ske_st_initiator_start)
     /** Error encoding Start Payload */
     ske->status = status;
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   /* Save the the payload buffer for future use. It is later used to
@@ -1145,15 +1256,13 @@ SILC_FSM_STATE(silc_ske_st_initiator_start)
     SILC_LOG_DEBUG(("Error sending packet"));
     ske->status = SILC_SKE_STATUS_ERROR;
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
-  /* XXX timeout */
-
   /** Wait for responder proposal */
-  SILC_LOG_DEBUG(("Waiting for reponder proposal"));
+  SILC_LOG_DEBUG(("Waiting for responder proposal"));
   silc_fsm_next(fsm, silc_ske_st_initiator_phase1);
-  SILC_FSM_WAIT;
+  return SILC_FSM_WAIT;
 }
 
 /* Phase-1.  Receives responder's proposal */
@@ -1177,9 +1286,11 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase1)
     silc_ske_install_retransmission(ske);
     silc_packet_free(ske->packet);
     ske->packet = NULL;
-    SILC_FSM_WAIT;
+    return SILC_FSM_WAIT;
   }
 
+  silc_schedule_task_del_by_all(ske->schedule, 0, silc_ske_probe_timeout, ske);
+
   /* Decode the payload */
   status = silc_ske_payload_start_decode(ske, packet_buf, &payload);
   if (status != SILC_SKE_STATUS_OK) {
@@ -1188,11 +1299,13 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase1)
     ske->packet = NULL;
     ske->status = status;
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   /* Get remote ID and set it to stream */
-  if (ske->packet->src_id_len) {
+  if (ske->packet->src_id_len &&
+      (ske->packet->src_id_type == SILC_ID_SERVER ||
+       ske->packet->src_id_type == SILC_ID_CLIENT)) {
     silc_id_str2id(ske->packet->src_id, ske->packet->src_id_len,
                   ske->packet->src_id_type,
                   (ske->packet->src_id_type == SILC_ID_SERVER ?
@@ -1221,7 +1334,7 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase1)
     SILC_LOG_ERROR(("Invalid cookie, modified or unsupported feature"));
     ske->status = SILC_SKE_STATUS_INVALID_COOKIE;
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   /* Check version string */
@@ -1231,7 +1344,7 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase1)
     /** Version mismatch */
     ske->status = status;
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   /* Free our KE Start Payload context, we don't need it anymore. */
@@ -1274,20 +1387,22 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase1)
 
   /** Send KE Payload */
   silc_fsm_next(fsm, silc_ske_st_initiator_phase2);
-  SILC_FSM_CONTINUE;
+  return SILC_FSM_CONTINUE;
 
  err:
   if (payload)
     silc_ske_payload_start_free(payload);
   if (group)
     silc_ske_group_free(group);
-  if (prop->cipher)
-    silc_cipher_free(prop->cipher);
-  if (prop->hash)
-    silc_hash_free(prop->hash);
-  if (prop->hmac)
-    silc_hmac_free(prop->hmac);
-  silc_free(prop);
+  if (prop) {
+    if (prop->cipher)
+      silc_cipher_free(prop->cipher);
+    if (prop->hash)
+      silc_hash_free(prop->hash);
+    if (prop->hmac)
+      silc_hmac_free(prop->hmac);
+    silc_free(prop);
+  }
   ske->prop = NULL;
 
   if (status == SILC_SKE_STATUS_OK)
@@ -1296,7 +1411,7 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase1)
   /** Error */
   ske->status = status;
   silc_fsm_next(fsm, silc_ske_st_initiator_error);
-  SILC_FSM_CONTINUE;
+  return SILC_FSM_CONTINUE;
 }
 
 /* Phase-2.  Send KE payload */
@@ -1314,11 +1429,11 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase2)
 
   /* Create the random number x, 1 < x < q. */
   x = silc_calloc(1, sizeof(*x));
-  if (!x){
+  if (!x) {
     /** Out of memory */
     ske->status = SILC_SKE_STATUS_OUT_OF_MEMORY;
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
   silc_mp_init(x);
   status =
@@ -1331,7 +1446,7 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase2)
     silc_free(x);
     ske->status = status;
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   /* Encode the result to Key Exchange Payload. */
@@ -1343,7 +1458,7 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase2)
     silc_free(x);
     ske->status = SILC_SKE_STATUS_OUT_OF_MEMORY;
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
   ske->ke1_payload = payload;
 
@@ -1365,14 +1480,14 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase2)
     ske->ke1_payload = NULL;
     ske->status = SILC_SKE_STATUS_ERROR;
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
   payload->pk_len = pk_len;
   payload->pk_type = silc_pkcs_get_type(ske->public_key);
 
   /* Compute signature data if we are doing mutual authentication */
   if (ske->private_key && ske->prop->flags & SILC_SKE_SP_FLAG_MUTUAL) {
-    unsigned char hash[SILC_HASH_MAXLEN], sign[2048 + 1];
+    unsigned char hash[SILC_HASH_MAXLEN], sign[65536 + 1];
     SilcUInt32 hash_len, sign_len;
 
     SILC_LOG_DEBUG(("We are doing mutual authentication"));
@@ -1380,13 +1495,25 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase2)
 
     /* Compute the hash value */
     memset(hash, 0, sizeof(hash));
-    silc_ske_make_hash(ske, hash, &hash_len, TRUE);
+    if (silc_ske_make_hash(ske, hash, &hash_len, TRUE) != SILC_SKE_STATUS_OK)
+      {
+       /** Error computing hash */
+       silc_mp_uninit(x);
+       silc_free(x);
+       silc_mp_uninit(&payload->x);
+       silc_free(payload->pk_data);
+       silc_free(payload);
+       ske->ke1_payload = NULL;
+       ske->status = SILC_SKE_STATUS_SIGNATURE_ERROR;
+       silc_fsm_next(fsm, silc_ske_st_initiator_error);
+       return SILC_FSM_CONTINUE;
+      }
 
     SILC_LOG_DEBUG(("Signing HASH_i value"));
 
     /* Sign the hash value */
     if (!silc_pkcs_sign(ske->private_key, hash, hash_len, sign,
-                       sizeof(sign) - 1, &sign_len, NULL)) {
+                       sizeof(sign) - 1, &sign_len, FALSE, ske->prop->hash)) {
       /** Error computing signature */
       silc_mp_uninit(x);
       silc_free(x);
@@ -1396,7 +1523,7 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase2)
       ske->ke1_payload = NULL;
       ske->status = SILC_SKE_STATUS_SIGNATURE_ERROR;
       silc_fsm_next(fsm, silc_ske_st_initiator_error);
-      SILC_FSM_CONTINUE;
+      return SILC_FSM_CONTINUE;
     }
     payload->sign_data = silc_memdup(sign, sign_len);
     if (payload->sign_data)
@@ -1416,7 +1543,7 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase2)
     ske->ke1_payload = NULL;
     ske->status = status;
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   ske->x = x;
@@ -1431,14 +1558,14 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase2)
     SILC_LOG_DEBUG(("Error sending packet"));
     ske->status = SILC_SKE_STATUS_ERROR;
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   silc_buffer_free(payload_buf);
 
   /** Waiting responder's KE payload */
   silc_fsm_next(fsm, silc_ske_st_initiator_phase3);
-  SILC_FSM_WAIT;
+  return SILC_FSM_WAIT;
 }
 
 /* Phase-3.  Process responder's KE payload */
@@ -1458,7 +1585,7 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase3)
     silc_ske_install_retransmission(ske);
     silc_packet_free(ske->packet);
     ske->packet = NULL;
-    SILC_FSM_WAIT;
+    return SILC_FSM_WAIT;
   }
 
   /* Decode the payload */
@@ -1469,7 +1596,7 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase3)
     ske->packet = NULL;
     ske->status = status;
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
   silc_packet_free(ske->packet);
   ske->packet = NULL;
@@ -1486,6 +1613,10 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase3)
 
   /* Compute the shared secret key */
   KEY = silc_calloc(1, sizeof(*KEY));
+  if (!KEY) {
+    ske->status = SILC_SKE_STATUS_OUT_OF_MEMORY;
+    goto err;
+  }
   silc_mp_init(KEY);
   silc_mp_pow_mod(KEY, &payload->x, ske->x, &ske->prop->group->group);
   ske->KEY = KEY;
@@ -1522,8 +1653,8 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase3)
       silc_skr_find_set_usage(find, SILC_SKR_USAGE_KEY_AGREEMENT);
 
       /* Find key from repository */
-      SILC_FSM_CALL(silc_skr_find(ske->repository, find,
-                                 silc_ske_skr_callback, ske));
+      SILC_FSM_CALL(silc_skr_find(ske->repository, silc_fsm_get_schedule(fsm),
+                                 find, silc_ske_skr_callback, ske));
     } else {
       /* Verify from application */
       SILC_FSM_CALL(ske->callbacks->verify_key(ske, ske->prop->public_key,
@@ -1535,7 +1666,7 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase3)
 
   /** Process key material */
   silc_fsm_next(fsm, silc_ske_st_initiator_phase4);
-  SILC_FSM_CONTINUE;
+  return SILC_FSM_CONTINUE;
 
  err:
   silc_ske_payload_ke_free(payload);
@@ -1551,7 +1682,7 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase3)
   /** Error */
   ske->status = status;
   silc_fsm_next(fsm, silc_ske_st_initiator_error);
-  SILC_FSM_CONTINUE;
+  return SILC_FSM_CONTINUE;
 }
 
 /* Process key material */
@@ -1568,7 +1699,7 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase4)
   if (ske->aborted) {
     /** Aborted */
     silc_fsm_next(fsm, silc_ske_st_initiator_aborted);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   /* Check result of public key verification */
@@ -1576,19 +1707,25 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase4)
     /** Public key not verified */
     SILC_LOG_DEBUG(("Public key verification failed"));
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   payload = ske->ke2_payload;
 
+  /* Compute the HASH value */
+  SILC_LOG_DEBUG(("Computing HASH value"));
+  status = silc_ske_make_hash(ske, hash, &hash_len, FALSE);
+  if (status != SILC_SKE_STATUS_OK)
+    goto err;
+  ske->hash = silc_memdup(hash, hash_len);
+  if (!ske->hash) {
+    status = SILC_SKE_STATUS_OUT_OF_MEMORY;
+    goto err;
+  }
+  ske->hash_len = hash_len;
+
   if (ske->prop->public_key) {
     SILC_LOG_DEBUG(("Public key is authentic"));
-
-    /* Compute the hash value */
-    status = silc_ske_make_hash(ske, hash, &hash_len, FALSE);
-    if (status != SILC_SKE_STATUS_OK)
-      goto err;
-
     SILC_LOG_DEBUG(("Verifying signature (HASH)"));
 
     /* Verify signature */
@@ -1600,9 +1737,6 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase4)
     }
 
     SILC_LOG_DEBUG(("Signature is Ok"));
-
-    ske->hash = silc_memdup(hash, hash_len);
-    ske->hash_len = hash_len;
     memset(hash, 'F', hash_len);
   }
 
@@ -1612,7 +1746,7 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase4)
   if (ske->rekey) {
     /** Finish rekey */
     silc_fsm_next(fsm, silc_ske_st_rekey_initiator_done);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   /* Process key material */
@@ -1628,19 +1762,25 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase4)
     goto err;
   }
 
-  /* Send SUCCESS packet */
-  SILC_PUT32_MSB((SilcUInt32)SILC_SKE_STATUS_OK, hash);
-  if (!silc_ske_packet_send(ske, SILC_PACKET_SUCCESS, 0, hash, 4)) {
-    /** Error sending packet */
-    SILC_LOG_DEBUG(("Error sending packet"));
-    ske->status = SILC_SKE_STATUS_ERROR;
-    silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
-  }
+  if (!ske->no_acks) {
+    /* Send SUCCESS packet */
+    SILC_PUT32_MSB((SilcUInt32)SILC_SKE_STATUS_OK, hash);
+    if (!silc_ske_packet_send(ske, SILC_PACKET_SUCCESS, 0, hash, 4)) {
+      /** Error sending packet */
+      SILC_LOG_DEBUG(("Error sending packet"));
+      ske->status = SILC_SKE_STATUS_ERROR;
+      silc_fsm_next(fsm, silc_ske_st_initiator_error);
+      return SILC_FSM_CONTINUE;
+    }
 
-  /** Waiting completion */
-  silc_fsm_next(fsm, silc_ske_st_initiator_end);
-  SILC_FSM_WAIT;
+    /** Waiting completion */
+    silc_fsm_next(fsm, silc_ske_st_initiator_end);
+    return SILC_FSM_WAIT;
+  } else {
+    /** Complete protocol */
+    silc_fsm_next(fsm, silc_ske_st_initiator_end);
+    return SILC_FSM_CONTINUE;
+  }
 
  err:
   memset(hash, 'F', sizeof(hash));
@@ -1663,7 +1803,7 @@ SILC_FSM_STATE(silc_ske_st_initiator_phase4)
   /** Error */
   ske->status = status;
   silc_fsm_next(fsm, silc_ske_st_initiator_error);
-  SILC_FSM_CONTINUE;
+  return SILC_FSM_CONTINUE;
 }
 
 /* Protocol completed */
@@ -1674,22 +1814,26 @@ SILC_FSM_STATE(silc_ske_st_initiator_end)
 
   SILC_LOG_DEBUG(("Start"));
 
-  if (ske->packet->type != SILC_PACKET_SUCCESS) {
+  if (!ske->no_acks && ske->packet->type != SILC_PACKET_SUCCESS) {
     SILC_LOG_DEBUG(("Remote retransmitted an old packet"));
     silc_ske_install_retransmission(ske);
     silc_packet_free(ske->packet);
     ske->packet = NULL;
-    SILC_FSM_WAIT;
+    return SILC_FSM_WAIT;
   }
 
   SILC_LOG_DEBUG(("Key exchange completed successfully"));
 
-  silc_packet_free(ske->packet);
+  if (ske->packet)
+    silc_packet_free(ske->packet);
   ske->packet = NULL;
   silc_packet_stream_unlink(ske->stream, &silc_ske_stream_cbs, ske);
   silc_schedule_task_del_by_context(ske->schedule, ske);
 
-  SILC_FSM_FINISH;
+  /* Call completion */
+  silc_ske_completion(ske);
+
+  return SILC_FSM_FINISH;
 }
 
 /* Aborted by application */
@@ -1708,7 +1852,10 @@ SILC_FSM_STATE(silc_ske_st_initiator_aborted)
   silc_packet_stream_unlink(ske->stream, &silc_ske_stream_cbs, ske);
   silc_schedule_task_del_by_context(ske->schedule, ske);
 
-  SILC_FSM_FINISH;
+  /* Call completion */
+  silc_ske_completion(ske);
+
+  return SILC_FSM_FINISH;
 }
 
 /* Error occurred.  Send error to remote host */
@@ -1716,7 +1863,7 @@ SILC_FSM_STATE(silc_ske_st_initiator_aborted)
 SILC_FSM_STATE(silc_ske_st_initiator_error)
 {
   SilcSKE ske = fsm_context;
-  SilcSKEStatus status;
+  SilcUInt32 status;
   unsigned char data[4];
 
   SILC_LOG_DEBUG(("Error %s (%d) occurred during key exchange",
@@ -1727,13 +1874,16 @@ SILC_FSM_STATE(silc_ske_st_initiator_error)
     status = SILC_SKE_STATUS_ERROR;
 
   /* Send FAILURE packet */
-  SILC_PUT32_MSB((SilcUInt32)status, data);
+  SILC_PUT32_MSB(status, data);
   silc_ske_packet_send(ske, SILC_PACKET_FAILURE, 0, data, 4);
 
   silc_packet_stream_unlink(ske->stream, &silc_ske_stream_cbs, ske);
   silc_schedule_task_del_by_context(ske->schedule, ske);
 
-  SILC_FSM_FINISH;
+  /* Call completion */
+  silc_ske_completion(ske);
+
+  return SILC_FSM_FINISH;
 }
 
 /* Failure received from remote */
@@ -1741,33 +1891,38 @@ SILC_FSM_STATE(silc_ske_st_initiator_error)
 SILC_FSM_STATE(silc_ske_st_initiator_failure)
 {
   SilcSKE ske = fsm_context;
-  SilcUInt32 error = SILC_SKE_STATUS_ERROR;
-
-  SILC_LOG_DEBUG(("Error %s (%d) received during key exchange",
-                 silc_ske_map_status(ske->status), ske->status));
+  SilcUInt32 error = ske->status;
 
   if (ske->packet && silc_buffer_len(&ske->packet->buffer) == 4) {
     SILC_GET32_MSB(error, ske->packet->buffer.data);
-    ske->status = error;
     silc_packet_free(ske->packet);
     ske->packet = NULL;
   }
+  if (error == SILC_SKE_STATUS_OK)
+    error = SILC_SKE_STATUS_ERROR;
+  ske->status = error;
+
+  SILC_LOG_DEBUG(("Error %s (%d) received during key exchange",
+                 silc_ske_map_status(ske->status), ske->status));
 
   silc_packet_stream_unlink(ske->stream, &silc_ske_stream_cbs, ske);
   silc_schedule_task_del_by_context(ske->schedule, ske);
 
-  SILC_FSM_FINISH;
+  /* Call completion */
+  silc_ske_completion(ske);
+
+  return SILC_FSM_FINISH;
 }
 
 /* Starts the protocol as initiator */
 
-SilcAsyncOperation
-silc_ske_initiator(SilcSKE ske,
-                  SilcPacketStream stream,
-                  SilcSKEParams params,
-                  SilcSKEStartPayload start_payload)
+SilcAsyncOperation silc_ske_initiator(SilcSKE ske,
+                                     SilcPacketStream stream,
+                                     SilcSKEParams params,
+                                     SilcSKEStartPayload start_payload)
 {
-  SILC_LOG_DEBUG(("Start SKE as initiator"));
+  SILC_LOG_DEBUG(("Start SKE %p as initiator; stream=%p; params=%p; "
+                 "start_payload=%p", ske, stream, params, start_payload));
 
   if (!ske || !stream || !params || !params->version)
     return NULL;
@@ -1782,17 +1937,23 @@ silc_ske_initiator(SilcSKE ske,
     ske->session_port = params->session_port;
 
   /* Generate security properties if not provided */
-  if (!start_payload) {
-    start_payload = silc_ske_assemble_security_properties(ske,
-                                                         params->flags,
-                                                         params->version);
+  if (!start_payload && !params->prop) {
+    start_payload =
+      silc_ske_assemble_security_properties(ske, params->flags,
+                                           params->version,
+                                           params->small_proposal);
     if (!start_payload)
       return NULL;
   }
 
+  ske->timeout = params->timeout_secs ? params->timeout_secs : 30;
+  ske->probe_timeout = (params->probe_timeout_secs ?
+                       params->probe_timeout_secs : 30);
   ske->start_payload = start_payload;
+  ske->prop = params->prop;
   ske->version = params->version;
-  ske->running = TRUE;
+  ske->no_acks = params->no_acks;
+  ++ske->refcnt;
 
   /* Link to packet stream to get key exchange packets */
   ske->stream = stream;
@@ -1802,8 +1963,18 @@ silc_ske_initiator(SilcSKE ske,
                          SILC_PACKET_SUCCESS,
                          SILC_PACKET_FAILURE, -1);
 
+  /* Add key exchange timeout */
+  silc_schedule_task_add_timeout(ske->schedule, silc_ske_timeout,
+                                ske, ske->timeout, 0);
+  if (ske->timeout != ske->probe_timeout)
+    silc_schedule_task_add_timeout(ske->schedule, silc_ske_probe_timeout,
+                                  ske, ske->probe_timeout, 0);
+
   /* Start SKE as initiator */
-  silc_fsm_start(&ske->fsm, silc_ske_st_initiator_start);
+  if (!ske->prop)
+    silc_fsm_start(&ske->fsm, silc_ske_st_initiator_start);
+  else
+    silc_fsm_start(&ske->fsm, silc_ske_st_initiator_phase2);
 
   return &ske->op;
 }
@@ -1821,15 +1992,15 @@ SILC_FSM_STATE(silc_ske_st_responder_start)
   if (ske->aborted) {
     /** Aborted */
     silc_fsm_next(fsm, silc_ske_st_responder_aborted);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
-  /* Start timeout */
-  /* XXX */
-
   /** Wait for initiator */
-  silc_fsm_next(fsm, silc_ske_st_responder_phase1);
-  SILC_FSM_WAIT;
+  if (!ske->prop)
+    silc_fsm_next(fsm, silc_ske_st_responder_phase1);
+  else
+    silc_fsm_next(fsm, silc_ske_st_responder_phase2);
+  return SILC_FSM_WAIT;
 }
 
 /* Decode initiator's start payload.  Select the security properties from
@@ -1841,6 +2012,7 @@ SILC_FSM_STATE(silc_ske_st_responder_phase1)
   SilcSKEStatus status;
   SilcSKEStartPayload remote_payload = NULL;
   SilcBuffer packet_buf = &ske->packet->buffer;
+  SilcID id;
 
   SILC_LOG_DEBUG(("Start"));
 
@@ -1852,12 +2024,34 @@ SILC_FSM_STATE(silc_ske_st_responder_phase1)
     ske->packet = NULL;
     ske->status = status;
     silc_fsm_next(fsm, silc_ske_st_responder_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
+  }
+
+  /* Get remote ID and set it to stream */
+  if (ske->packet->src_id_len &&
+      (ske->packet->src_id_type == SILC_ID_SERVER ||
+       ske->packet->src_id_type == SILC_ID_CLIENT)) {
+    silc_id_str2id(ske->packet->src_id, ske->packet->src_id_len,
+                  ske->packet->src_id_type,
+                  (ske->packet->src_id_type == SILC_ID_SERVER ?
+                   (void *)&id.u.server_id : (void *)&id.u.client_id),
+                  (ske->packet->src_id_type == SILC_ID_SERVER ?
+                   sizeof(id.u.server_id) : sizeof(id.u.client_id)));
+    silc_packet_set_ids(ske->stream, 0, NULL, ske->packet->src_id_type,
+                       (ske->packet->src_id_type == SILC_ID_SERVER ?
+                        (void *)&id.u.server_id : (void *)&id.u.client_id));
   }
 
   /* Take a copy of the payload buffer for future use. It is used to
      compute the HASH value. */
   ske->start_payload_copy = silc_buffer_copy(packet_buf);
+  if (!ske->start_payload_copy) {
+    silc_packet_free(ske->packet);
+    ske->packet = NULL;
+    ske->status = status;
+    silc_fsm_next(fsm, silc_ske_st_responder_error);
+    return SILC_FSM_CONTINUE;
+  }
 
   silc_packet_free(ske->packet);
   ske->packet = NULL;
@@ -1889,7 +2083,7 @@ SILC_FSM_STATE(silc_ske_st_responder_phase1)
     silc_ske_payload_start_free(remote_payload);
     ske->status = status;
     silc_fsm_next(fsm, silc_ske_st_responder_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   silc_ske_payload_start_free(remote_payload);
@@ -1910,7 +2104,7 @@ SILC_FSM_STATE(silc_ske_st_responder_phase1)
 
   /** Waiting initiator's KE payload */
   silc_fsm_next(fsm, silc_ske_st_responder_phase2);
-  SILC_FSM_WAIT;
+  return SILC_FSM_WAIT;
 
  err:
   if (ske->prop->group)
@@ -1930,7 +2124,7 @@ SILC_FSM_STATE(silc_ske_st_responder_phase1)
   /** Error */
   ske->status = status;
   silc_fsm_next(fsm, silc_ske_st_responder_error);
-  SILC_FSM_CONTINUE;
+  return SILC_FSM_CONTINUE;
 }
 
 /* Phase-2.  Decode initiator's KE payload */
@@ -1949,7 +2143,7 @@ SILC_FSM_STATE(silc_ske_st_responder_phase2)
     silc_ske_install_retransmission(ske);
     silc_packet_free(ske->packet);
     ske->packet = NULL;
-    SILC_FSM_WAIT;
+    return SILC_FSM_WAIT;
   }
 
   /* Decode Key Exchange Payload */
@@ -1960,7 +2154,7 @@ SILC_FSM_STATE(silc_ske_st_responder_phase2)
     ske->packet = NULL;
     ske->status = status;
     silc_fsm_next(fsm, silc_ske_st_responder_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   ske->ke1_payload = recv_payload;
@@ -1968,26 +2162,19 @@ SILC_FSM_STATE(silc_ske_st_responder_phase2)
   silc_packet_free(ske->packet);
   ske->packet = NULL;
 
-  /* Verify the received public key and verify the signature if we are
-     doing mutual authentication. */
-  if (ske->start_payload &&
-      ske->start_payload->flags & SILC_SKE_SP_FLAG_MUTUAL) {
-
-    SILC_LOG_DEBUG(("We are doing mutual authentication"));
-
-    if (!recv_payload->pk_data && (ske->callbacks->verify_key ||
-                                  ske->repository)) {
+  /* Verify public key, except in rekey, when it is not sent */
+  if (!ske->rekey) {
+    if (!recv_payload->pk_data) {
       /** Public key not provided */
       SILC_LOG_ERROR(("Remote end did not send its public key (or "
                      "certificate), even though we require it"));
       ske->status = SILC_SKE_STATUS_PUBLIC_KEY_NOT_PROVIDED;
       silc_fsm_next(fsm, silc_ske_st_responder_error);
-      SILC_FSM_CONTINUE;
+      return SILC_FSM_CONTINUE;
     }
 
     /* Decode the remote's public key */
-    if (recv_payload->pk_data &&
-       !silc_pkcs_public_key_alloc(recv_payload->pk_type,
+    if (!silc_pkcs_public_key_alloc(recv_payload->pk_type,
                                    recv_payload->pk_data,
                                    recv_payload->pk_len,
                                    &ske->prop->public_key)) {
@@ -1995,47 +2182,45 @@ SILC_FSM_STATE(silc_ske_st_responder_phase2)
       SILC_LOG_ERROR(("Unsupported/malformed public key received"));
       ske->status = SILC_SKE_STATUS_UNSUPPORTED_PUBLIC_KEY;
       silc_fsm_next(fsm, silc_ske_st_responder_error);
-      SILC_FSM_CONTINUE;
+      return SILC_FSM_CONTINUE;
     }
 
-    if (ske->prop->public_key && (ske->callbacks->verify_key ||
-                                 ske->repository)) {
-      SILC_LOG_DEBUG(("Verifying public key"));
+    SILC_LOG_DEBUG(("Verifying public key"));
 
-      /** Waiting public key verification */
-      silc_fsm_next(fsm, silc_ske_st_responder_phase4);
+    /** Waiting public key verification */
+    silc_fsm_next(fsm, silc_ske_st_responder_phase4);
 
-      /* If repository is provided, verify the key from there. */
-      if (ske->repository) {
-       SilcSKRFind find;
+    /* If repository is provided, verify the key from there. */
+    if (ske->repository) {
+      SilcSKRFind find;
 
-       find = silc_skr_find_alloc();
-       if (!find) {
-         ske->status = SILC_SKE_STATUS_OUT_OF_MEMORY;
-         silc_fsm_next(fsm, silc_ske_st_responder_error);
-         SILC_FSM_CONTINUE;
-       }
-       silc_skr_find_set_pkcs_type(find,
-                                   silc_pkcs_get_type(ske->prop->public_key));
-       silc_skr_find_set_public_key(find, ske->prop->public_key);
-       silc_skr_find_set_usage(find, SILC_SKR_USAGE_KEY_AGREEMENT);
-
-       /* Find key from repository */
-       SILC_FSM_CALL(silc_skr_find(ske->repository, find,
-                                   silc_ske_skr_callback, ske));
-      } else {
-       /* Verify from application */
+      find = silc_skr_find_alloc();
+      if (!find) {
+       ske->status = SILC_SKE_STATUS_OUT_OF_MEMORY;
+       silc_fsm_next(fsm, silc_ske_st_responder_error);
+       return SILC_FSM_CONTINUE;
+      }
+      silc_skr_find_set_pkcs_type(find,
+                                 silc_pkcs_get_type(ske->prop->public_key));
+      silc_skr_find_set_public_key(find, ske->prop->public_key);
+      silc_skr_find_set_usage(find, SILC_SKR_USAGE_KEY_AGREEMENT);
+
+      /* Find key from repository */
+      SILC_FSM_CALL(silc_skr_find(ske->repository,
+                                 silc_fsm_get_schedule(fsm), find,
+                                 silc_ske_skr_callback, ske));
+    } else {
+      /* Verify from application */
+      if (ske->callbacks->verify_key)
        SILC_FSM_CALL(ske->callbacks->verify_key(ske, ske->prop->public_key,
                                                 ske->callbacks->context,
                                                 silc_ske_pk_verified, NULL));
-      }
-      /* NOT REACHED */
     }
   }
 
   /** Generate KE2 payload */
   silc_fsm_next(fsm, silc_ske_st_responder_phase4);
-  SILC_FSM_CONTINUE;
+  return SILC_FSM_CONTINUE;
 }
 
 /* Phase-4. Generate KE2 payload */
@@ -2044,41 +2229,41 @@ SILC_FSM_STATE(silc_ske_st_responder_phase4)
 {
   SilcSKE ske = fsm_context;
   SilcSKEStatus status;
-  SilcSKEKEPayload recv_payload, send_payload;
-  SilcMPInt *x, *KEY;
+  SilcSKEKEPayload recv_payload, send_payload = NULL;
+  SilcMPInt *x = NULL, *KEY;
 
   if (ske->aborted) {
     /** Aborted */
     silc_fsm_next(fsm, silc_ske_st_responder_aborted);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   /* Check result of public key verification */
   if (ske->status != SILC_SKE_STATUS_OK) {
     /** Public key not verified */
     SILC_LOG_DEBUG(("Public key verification failed"));
-    silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    goto err;
   }
 
   recv_payload = ske->ke1_payload;
 
   /* The public key verification was performed only if the Mutual
      Authentication flag is set. */
-  if (ske->start_payload &&
-      ske->start_payload->flags & SILC_SKE_SP_FLAG_MUTUAL) {
+  if ((ske->start_payload &&
+       ske->start_payload->flags & SILC_SKE_SP_FLAG_MUTUAL) ||
+      ske->prop->flags & SILC_SKE_SP_FLAG_MUTUAL) {
     unsigned char hash[SILC_HASH_MAXLEN];
     SilcUInt32 hash_len;
 
-    SILC_LOG_DEBUG(("Public key is authentic"));
+    SILC_LOG_DEBUG(("We are doing mutual authentication"));
 
     /* Compute the hash value */
     status = silc_ske_make_hash(ske, hash, &hash_len, TRUE);
     if (status != SILC_SKE_STATUS_OK) {
       /** Error computing hash */
+      SILC_LOG_DEBUG(("Error computing hash"));
       ske->status = status;
-      silc_fsm_next(fsm, silc_ske_st_responder_error);
-      SILC_FSM_CONTINUE;
+      goto err;
     }
 
     SILC_LOG_DEBUG(("Verifying signature (HASH_i)"));
@@ -2089,8 +2274,7 @@ SILC_FSM_STATE(silc_ske_st_responder_phase4)
       /** Incorrect signature */
       SILC_LOG_ERROR(("Signature verification failed, incorrect signature"));
       ske->status = SILC_SKE_STATUS_INCORRECT_SIGNATURE;
-      silc_fsm_next(fsm, silc_ske_st_responder_error);
-      SILC_FSM_CONTINUE;
+      goto err;
     }
 
     SILC_LOG_DEBUG(("Signature is Ok"));
@@ -2100,6 +2284,10 @@ SILC_FSM_STATE(silc_ske_st_responder_phase4)
 
   /* Create the random number x, 1 < x < q. */
   x = silc_calloc(1, sizeof(*x));
+  if (!x) {
+    ske->status = SILC_SKE_STATUS_OUT_OF_MEMORY;
+    goto err;
+  }
   silc_mp_init(x);
   status =
     silc_ske_create_rnd(ske, &ske->prop->group->group_order,
@@ -2107,15 +2295,16 @@ SILC_FSM_STATE(silc_ske_st_responder_phase4)
                        x);
   if (status != SILC_SKE_STATUS_OK) {
     /** Error generating random number */
-    silc_mp_uninit(x);
-    silc_free(x);
     ske->status = status;
-    silc_fsm_next(fsm, silc_ske_st_responder_error);
-    SILC_FSM_CONTINUE;
+    goto err;
   }
 
   /* Save the results for later processing */
   send_payload = silc_calloc(1, sizeof(*send_payload));
+  if (!send_payload) {
+    ske->status = SILC_SKE_STATUS_OUT_OF_MEMORY;
+    goto err;
+  }
   ske->x = x;
   ske->ke2_payload = send_payload;
 
@@ -2130,6 +2319,10 @@ SILC_FSM_STATE(silc_ske_st_responder_phase4)
 
   /* Compute the shared secret key */
   KEY = silc_calloc(1, sizeof(*KEY));
+  if (!KEY) {
+    ske->status = SILC_SKE_STATUS_OUT_OF_MEMORY;
+    goto err;
+  }
   silc_mp_init(KEY);
   silc_mp_pow_mod(KEY, &ske->ke1_payload->x, ske->x,
                  &ske->prop->group->group);
@@ -2137,7 +2330,17 @@ SILC_FSM_STATE(silc_ske_st_responder_phase4)
 
   /** Send KE2 payload */
   silc_fsm_next(fsm, silc_ske_st_responder_phase5);
-  SILC_FSM_CONTINUE;
+  return SILC_FSM_CONTINUE;
+
+ err:
+  silc_mp_uninit(x);
+  silc_free(x);
+  ske->x = NULL;
+  silc_free(send_payload);
+  ske->ke2_payload = NULL;
+
+  silc_fsm_next(fsm, silc_ske_st_responder_error);
+  return SILC_FSM_CONTINUE;
 }
 
 /* Phase-5.  Send KE2 payload */
@@ -2147,7 +2350,7 @@ SILC_FSM_STATE(silc_ske_st_responder_phase5)
   SilcSKE ske = fsm_context;
   SilcSKEStatus status;
   SilcBuffer payload_buf;
-  unsigned char hash[SILC_HASH_MAXLEN], sign[2048 + 1], *pk;
+  unsigned char hash[SILC_HASH_MAXLEN], sign[65536 + 1], *pk;
   SilcUInt32 hash_len, sign_len, pk_len;
 
   SILC_LOG_DEBUG(("Start"));
@@ -2159,39 +2362,52 @@ SILC_FSM_STATE(silc_ske_st_responder_phase5)
     pk = silc_pkcs_public_key_encode(ske->public_key, &pk_len);
     if (!pk) {
       /** Error encoding public key */
-      status = SILC_SKE_STATUS_OUT_OF_MEMORY;
+      ske->status = SILC_SKE_STATUS_OUT_OF_MEMORY;
       silc_fsm_next(fsm, silc_ske_st_responder_error);
-      SILC_FSM_CONTINUE;
+      return SILC_FSM_CONTINUE;
     }
     ske->ke2_payload->pk_data = pk;
     ske->ke2_payload->pk_len = pk_len;
+  }
 
-    SILC_LOG_DEBUG(("Computing HASH value"));
+  SILC_LOG_DEBUG(("Computing HASH value"));
 
-    /* Compute the hash value */
-    memset(hash, 0, sizeof(hash));
-    status = silc_ske_make_hash(ske, hash, &hash_len, FALSE);
-    if (status != SILC_SKE_STATUS_OK) {
-      /** Error computing hash */
-      ske->status = status;
-      silc_fsm_next(fsm, silc_ske_st_responder_error);
-      SILC_FSM_CONTINUE;
-    }
-
-    ske->hash = silc_memdup(hash, hash_len);
-    ske->hash_len = hash_len;
+  /* Compute the hash value */
+  memset(hash, 0, sizeof(hash));
+  status = silc_ske_make_hash(ske, hash, &hash_len, FALSE);
+  if (status != SILC_SKE_STATUS_OK) {
+    /** Error computing hash */
+    ske->status = status;
+    silc_fsm_next(fsm, silc_ske_st_responder_error);
+    return SILC_FSM_CONTINUE;
+  }
+  ske->hash = silc_memdup(hash, hash_len);
+  if (!ske->hash) {
+    /** Error computing hash */
+    ske->status = SILC_SKE_STATUS_OUT_OF_MEMORY;
+    silc_fsm_next(fsm, silc_ske_st_responder_error);
+    return SILC_FSM_CONTINUE;
+  }
+  ske->hash_len = hash_len;
 
+  if (ske->public_key && ske->private_key) {
     SILC_LOG_DEBUG(("Signing HASH value"));
 
     /* Sign the hash value */
     if (!silc_pkcs_sign(ske->private_key, hash, hash_len, sign,
-                       sizeof(sign) - 1, &sign_len, NULL)) {
+                       sizeof(sign) - 1, &sign_len, FALSE, ske->prop->hash)) {
       /** Error computing signature */
-      status = SILC_SKE_STATUS_SIGNATURE_ERROR;
+      ske->status = SILC_SKE_STATUS_SIGNATURE_ERROR;
       silc_fsm_next(fsm, silc_ske_st_responder_error);
-      SILC_FSM_CONTINUE;
+      return SILC_FSM_CONTINUE;
     }
     ske->ke2_payload->sign_data = silc_memdup(sign, sign_len);
+    if (!ske->ke2_payload->sign_data) {
+      /** Error computing hash */
+      ske->status = SILC_SKE_STATUS_OUT_OF_MEMORY;
+      silc_fsm_next(fsm, silc_ske_st_responder_error);
+      return SILC_FSM_CONTINUE;
+    }
     ske->ke2_payload->sign_len = sign_len;
     memset(sign, 0, sizeof(sign));
   }
@@ -2204,7 +2420,7 @@ SILC_FSM_STATE(silc_ske_st_responder_phase5)
     /** Error encoding KE payload */
     ske->status = status;
     silc_fsm_next(fsm, silc_ske_st_responder_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   /* Send the packet. */
@@ -2213,14 +2429,27 @@ SILC_FSM_STATE(silc_ske_st_responder_phase5)
     SILC_LOG_DEBUG(("Error sending packet"));
     ske->status = SILC_SKE_STATUS_ERROR;
     silc_fsm_next(fsm, silc_ske_st_responder_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   silc_buffer_free(payload_buf);
 
-  /** Waiting completion */
-  silc_fsm_next(fsm, silc_ske_st_responder_end);
-  SILC_FSM_WAIT;
+  /* In case we are doing rekey move to finish it. */
+  if (ske->rekey) {
+    /** Finish rekey */
+    silc_fsm_next(fsm, silc_ske_st_rekey_responder_done);
+    return SILC_FSM_CONTINUE;
+  }
+
+  if (!ske->no_acks) {
+    /** Waiting completion */
+    silc_fsm_next(fsm, silc_ske_st_responder_end);
+    return SILC_FSM_WAIT;
+  } else {
+    /** Complete protocol */
+    silc_fsm_next(fsm, silc_ske_st_responder_end);
+    return SILC_FSM_CONTINUE;
+  }
 }
 
 /* Protocol completed */
@@ -2231,14 +2460,15 @@ SILC_FSM_STATE(silc_ske_st_responder_end)
   unsigned char tmp[4];
   SilcUInt32 hash_len, key_len, block_len;
 
-  if (ske->packet->type != SILC_PACKET_SUCCESS) {
+  if (!ske->no_acks && ske->packet->type != SILC_PACKET_SUCCESS) {
     SILC_LOG_DEBUG(("Remote retransmitted an old packet"));
     silc_ske_install_retransmission(ske);
     silc_packet_free(ske->packet);
     ske->packet = NULL;
-    SILC_FSM_WAIT;
+    return SILC_FSM_WAIT;
   }
-  silc_packet_free(ske->packet);
+  if (ske->packet)
+    silc_packet_free(ske->packet);
   ske->packet = NULL;
 
   /* Process key material */
@@ -2252,17 +2482,22 @@ SILC_FSM_STATE(silc_ske_st_responder_end)
     /** Error processing key material */
     ske->status = SILC_SKE_STATUS_ERROR;
     silc_fsm_next(fsm, silc_ske_st_responder_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
-  /* Send SUCCESS packet */
-  SILC_PUT32_MSB(SILC_SKE_STATUS_OK, tmp);
-  silc_ske_packet_send(ske, SILC_PACKET_SUCCESS, 0, tmp, 4);
+  if (!ske->no_acks) {
+    /* Send SUCCESS packet */
+    SILC_PUT32_MSB(SILC_SKE_STATUS_OK, tmp);
+    silc_ske_packet_send(ske, SILC_PACKET_SUCCESS, 0, tmp, 4);
+  }
 
   silc_packet_stream_unlink(ske->stream, &silc_ske_stream_cbs, ske);
   silc_schedule_task_del_by_context(ske->schedule, ske);
 
-  SILC_FSM_FINISH;
+  /* Call completion */
+  silc_ske_completion(ske);
+
+  return SILC_FSM_FINISH;
 }
 
 /* Aborted by application */
@@ -2281,7 +2516,10 @@ SILC_FSM_STATE(silc_ske_st_responder_aborted)
   silc_packet_stream_unlink(ske->stream, &silc_ske_stream_cbs, ske);
   silc_schedule_task_del_by_context(ske->schedule, ske);
 
-  SILC_FSM_FINISH;
+  /* Call completion */
+  silc_ske_completion(ske);
+
+  return SILC_FSM_FINISH;
 }
 
 /* Failure received from remote */
@@ -2289,21 +2527,26 @@ SILC_FSM_STATE(silc_ske_st_responder_aborted)
 SILC_FSM_STATE(silc_ske_st_responder_failure)
 {
   SilcSKE ske = fsm_context;
-  SilcUInt32 error = SILC_SKE_STATUS_ERROR;
+  SilcUInt32 error = ske->status;
 
   SILC_LOG_DEBUG(("Key exchange protocol failed"));
 
   if (ske->packet && silc_buffer_len(&ske->packet->buffer) == 4) {
     SILC_GET32_MSB(error, ske->packet->buffer.data);
-    ske->status = error;
     silc_packet_free(ske->packet);
     ske->packet = NULL;
   }
+  if (error == SILC_SKE_STATUS_OK)
+    error = SILC_SKE_STATUS_ERROR;
+  ske->status = error;
 
   silc_packet_stream_unlink(ske->stream, &silc_ske_stream_cbs, ske);
   silc_schedule_task_del_by_context(ske->schedule, ske);
 
-  SILC_FSM_FINISH;
+  /* Call completion */
+  silc_ske_completion(ske);
+
+  return SILC_FSM_FINISH;
 }
 
 /* Error occurred */
@@ -2312,28 +2555,32 @@ SILC_FSM_STATE(silc_ske_st_responder_error)
 {
   SilcSKE ske = fsm_context;
   unsigned char tmp[4];
+  SilcUInt32 status;
 
   SILC_LOG_DEBUG(("Error %d (%s) during key exchange protocol",
                  ske->status, silc_ske_map_status(ske->status)));
 
   /* Send FAILURE packet */
-  if (ske->status > SILC_SKE_STATUS_INVALID_COOKIE)
-    ske->status = SILC_SKE_STATUS_BAD_PAYLOAD;
-  SILC_PUT32_MSB(ske->status, tmp);
+  status = ske->status;
+  if (status > SILC_SKE_STATUS_INVALID_COOKIE)
+    status = SILC_SKE_STATUS_ERROR;
+  SILC_PUT32_MSB(status, tmp);
   silc_ske_packet_send(ske, SILC_PACKET_FAILURE, 0, tmp, 4);
 
   silc_packet_stream_unlink(ske->stream, &silc_ske_stream_cbs, ske);
   silc_schedule_task_del_by_context(ske->schedule, ske);
 
-  SILC_FSM_FINISH;
+  /* Call completion */
+  silc_ske_completion(ske);
+
+  return SILC_FSM_FINISH;
 }
 
 /* Starts the protocol as responder. */
 
-SilcAsyncOperation
-silc_ske_responder(SilcSKE ske,
-                  SilcPacketStream stream,
-                  SilcSKEParams params)
+SilcAsyncOperation silc_ske_responder(SilcSKE ske,
+                                     SilcPacketStream stream,
+                                     SilcSKEParams params)
 {
   SILC_LOG_DEBUG(("Start SKE as responder"));
 
@@ -2348,12 +2595,15 @@ silc_ske_responder(SilcSKE ske,
 
   ske->responder = TRUE;
   ske->flags = params->flags;
+  ske->timeout = params->timeout_secs ? params->timeout_secs : 30;
   if (ske->flags & SILC_SKE_SP_FLAG_IV_INCLUDED)
     ske->session_port = params->session_port;
-  ske->version = strdup(params->version);
+  ske->version = params->version;
+  ske->no_acks = params->no_acks;
+  ske->prop = params->prop;
   if (!ske->version)
     return NULL;
-  ske->running = TRUE;
+  ++ske->refcnt;
 
   /* Link to packet stream to get key exchange packets */
   ske->stream = stream;
@@ -2363,6 +2613,10 @@ silc_ske_responder(SilcSKE ske,
                          SILC_PACKET_SUCCESS,
                          SILC_PACKET_FAILURE, -1);
 
+  /* Add key exchange timeout */
+  silc_schedule_task_add_timeout(ske->schedule, silc_ske_timeout,
+                                ske, ske->timeout, 0);
+
   /* Start SKE as responder */
   silc_fsm_start(&ske->fsm, silc_ske_st_responder_start);
 
@@ -2383,17 +2637,26 @@ SILC_FSM_STATE(silc_ske_st_rekey_initiator_start)
   if (ske->aborted) {
     /** Aborted */
     silc_fsm_next(fsm, silc_ske_st_initiator_aborted);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
-  /* XXX timeout */
+  /* Add rekey exchange timeout */
+  silc_schedule_task_add_timeout(ske->schedule, silc_ske_timeout,
+                                ske, 30, 0);
 
   ske->prop = silc_calloc(1, sizeof(*ske->prop));
   if (!ske->prop) {
     /** No memory */
     ske->status = SILC_SKE_STATUS_OUT_OF_MEMORY;
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
+  }
+
+  if (!silc_hash_alloc(ske->rekey->hash, &ske->prop->hash)) {
+    /** Cannot allocate hash */
+    ske->status = SILC_SKE_STATUS_OUT_OF_MEMORY;
+    silc_fsm_next(fsm, silc_ske_st_initiator_error);
+    return SILC_FSM_CONTINUE;
   }
 
   /* Send REKEY packet to start rekey protocol */
@@ -2402,14 +2665,14 @@ SILC_FSM_STATE(silc_ske_st_rekey_initiator_start)
     SILC_LOG_DEBUG(("Error sending packet"));
     ske->status = SILC_SKE_STATUS_ERROR;
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   /* If doing rekey without PFS, move directly to the end of the protocol. */
   if (!ske->rekey->pfs) {
     /** Rekey without PFS */
     silc_fsm_next(fsm, silc_ske_st_rekey_initiator_done);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   status = silc_ske_group_get_by_number(ske->rekey->ske_group,
@@ -2417,12 +2680,12 @@ SILC_FSM_STATE(silc_ske_st_rekey_initiator_start)
   if (status != SILC_SKE_STATUS_OK) {
     /** Unknown group */
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   /** Rekey with PFS */
   silc_fsm_next(fsm, silc_ske_st_initiator_phase2);
-  SILC_FSM_CONTINUE;
+  return SILC_FSM_CONTINUE;
 }
 
 /* Sends REKEY_DONE packet to finish the protocol. */
@@ -2441,26 +2704,23 @@ SILC_FSM_STATE(silc_ske_st_rekey_initiator_done)
   silc_packet_get_keys(ske->stream, &send_key, NULL, &hmac_send, NULL);
   key_len = silc_cipher_get_key_len(send_key);
   block_len = silc_cipher_get_block_len(send_key);
-
-  if (!silc_hash_alloc(ske->rekey->hash, &hash)) {
-    /** Cannot allocate hash */
-    ske->status = SILC_SKE_STATUS_OUT_OF_MEMORY;
-    silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
-  }
+  hash = ske->prop->hash;
   hash_len = silc_hash_len(hash);
 
   /* Process key material */
   if (ske->rekey->pfs) {
     /* PFS */
     pfsbuf = silc_mp_mp2bin(ske->KEY, 0, &x_len);
-    if (pfsbuf) {
-      ske->keymat = silc_ske_process_key_material_data(pfsbuf, x_len,
-                                                      block_len, key_len,
-                                                      hash_len, hash);
-      memset(pfsbuf, 0, x_len);
-      silc_free(pfsbuf);
+    if (!pfsbuf) {
+      SILC_LOG_ERROR(("Error processing key material"));
+      silc_fsm_next(fsm, silc_ske_st_initiator_error);
+      return SILC_FSM_CONTINUE;
     }
+    ske->keymat = silc_ske_process_key_material_data(pfsbuf, x_len,
+                                                    block_len, key_len,
+                                                    hash_len, hash);
+    memset(pfsbuf, 0, x_len);
+    silc_free(pfsbuf);
   } else {
     /* No PFS */
     ske->keymat =
@@ -2473,22 +2733,26 @@ SILC_FSM_STATE(silc_ske_st_rekey_initiator_done)
   if (!ske->keymat) {
     SILC_LOG_ERROR(("Error processing key material"));
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   ske->prop->cipher = send_key;
   ske->prop->hmac = hmac_send;
-  ske->prop->hash = hash;
 
   /* Get sending keys */
   if (!silc_ske_set_keys(ske, ske->keymat, ske->prop, &send_key, NULL,
                         &hmac_send, NULL, NULL)) {
     /** Cannot get keys */
     ske->status = SILC_SKE_STATUS_ERROR;
+    ske->prop->cipher = NULL;
+    ske->prop->hmac = NULL;
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
+  ske->prop->cipher = NULL;
+  ske->prop->hmac = NULL;
+
   /* Set the new keys into use.  This will also send REKEY_DONE packet.  Any
      packet sent after this call will be protected with the new keys. */
   if (!silc_packet_set_keys(ske->stream, send_key, NULL, hmac_send, NULL,
@@ -2496,13 +2760,15 @@ SILC_FSM_STATE(silc_ske_st_rekey_initiator_done)
     /** Cannot set keys */
     SILC_LOG_DEBUG(("Cannot set new keys, error sending REKEY_DONE"));
     ske->status = SILC_SKE_STATUS_ERROR;
+    silc_cipher_free(send_key);
+    silc_hmac_free(hmac_send);
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   /** Wait for REKEY_DONE */
   silc_fsm_next(fsm, silc_ske_st_rekey_initiator_end);
-  SILC_FSM_WAIT;
+  return SILC_FSM_WAIT;
 }
 
 /* Rekey protocol end */
@@ -2520,7 +2786,7 @@ SILC_FSM_STATE(silc_ske_st_rekey_initiator_end)
     SILC_LOG_DEBUG(("Remote retransmitted an old packet"));
     silc_packet_free(ske->packet);
     ske->packet = NULL;
-    SILC_FSM_WAIT;
+    return SILC_FSM_WAIT;
   }
 
   silc_packet_get_keys(ske->stream, NULL, &receive_key, NULL, &hmac_receive);
@@ -2532,8 +2798,10 @@ SILC_FSM_STATE(silc_ske_st_rekey_initiator_end)
                         NULL, &hmac_receive, NULL)) {
     /** Cannot get keys */
     ske->status = SILC_SKE_STATUS_ERROR;
+    ske->prop->cipher = NULL;
+    ske->prop->hmac = NULL;
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   /* Set new receiving keys into use.  All packets received after this will
@@ -2543,8 +2811,10 @@ SILC_FSM_STATE(silc_ske_st_rekey_initiator_end)
     /** Cannot set keys */
     SILC_LOG_DEBUG(("Cannot set new keys"));
     ske->status = SILC_SKE_STATUS_ERROR;
+    silc_cipher_free(receive_key);
+    silc_hmac_free(hmac_receive);
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
 
   SILC_LOG_DEBUG(("Rekey completed successfully"));
@@ -2554,8 +2824,10 @@ SILC_FSM_STATE(silc_ske_st_rekey_initiator_end)
   if (!rekey) {
     /** No memory */
     ske->status = SILC_SKE_STATUS_OUT_OF_MEMORY;
+    ske->prop->cipher = NULL;
+    ske->prop->hmac = NULL;
     silc_fsm_next(fsm, silc_ske_st_initiator_error);
-    SILC_FSM_CONTINUE;
+    return SILC_FSM_CONTINUE;
   }
   rekey->pfs = ske->rekey->pfs;
   ske->rekey = rekey;
@@ -2567,7 +2839,10 @@ SILC_FSM_STATE(silc_ske_st_rekey_initiator_end)
   silc_packet_stream_unlink(ske->stream, &silc_ske_stream_cbs, ske);
   silc_schedule_task_del_by_context(ske->schedule, ske);
 
-  SILC_FSM_FINISH;
+  /* Call completion */
+  silc_ske_completion(ske);
+
+  return SILC_FSM_FINISH;
 }
 
 /* Starts rekey protocol as initiator */
@@ -2579,8 +2854,11 @@ silc_ske_rekey_initiator(SilcSKE ske,
 {
   SILC_LOG_DEBUG(("Start SKE rekey as initator"));
 
-  if (!ske || !stream || !rekey)
+  if (!ske || !stream || !rekey) {
+    SILC_LOG_ERROR(("Missing arguments to silc_ske_rekey_initiator"));
+    SILC_ASSERT(rekey);
     return NULL;
+  }
 
   if (!silc_async_init(&ske->op, silc_ske_abort, NULL, ske))
     return NULL;
@@ -2590,8 +2868,8 @@ silc_ske_rekey_initiator(SilcSKE ske,
 
   ske->rekey = rekey;
   ske->responder = FALSE;
-  ske->running = TRUE;
   ske->rekeying = TRUE;
+  ++ske->refcnt;
 
   /* Link to packet stream to get key exchange packets */
   ske->stream = stream;
@@ -2610,11 +2888,243 @@ silc_ske_rekey_initiator(SilcSKE ske,
 
 /***************************** Responder Rekey ******************************/
 
-SILC_FSM_STATE(silc_ske_st_rekey_responder_start);
+/* Wait for initiator's packet */
+
+SILC_FSM_STATE(silc_ske_st_rekey_responder_wait)
+{
+  SilcSKE ske = fsm_context;
+
+  SILC_LOG_DEBUG(("Start rekey (%s)", ske->rekey->pfs ? "PFS" : "No PFS"));
+
+  if (ske->aborted) {
+    /** Aborted */
+    silc_fsm_next(fsm, silc_ske_st_responder_aborted);
+    return SILC_FSM_CONTINUE;
+  }
+
+  /* Add rekey exchange timeout */
+  silc_schedule_task_add_timeout(ske->schedule, silc_ske_timeout,
+                                ske, 30, 0);
+
+  silc_fsm_next(fsm, silc_ske_st_rekey_responder_start);
+
+  /* If REKEY packet already received process it directly */
+  if (ske->packet && ske->packet->type == SILC_PACKET_REKEY)
+    return SILC_FSM_CONTINUE;
+
+  /* Wait for REKEY */
+  return SILC_FSM_WAIT;
+}
+
+/* Process initiator's REKEY packet */
 
 SILC_FSM_STATE(silc_ske_st_rekey_responder_start)
 {
-  SILC_FSM_FINISH;
+  SilcSKE ske = fsm_context;
+  SilcSKEStatus status;
+
+  SILC_LOG_DEBUG(("Start"));
+
+  if (ske->packet->type != SILC_PACKET_REKEY) {
+    ske->status = SILC_SKE_STATUS_ERROR;
+    silc_packet_free(ske->packet);
+    ske->packet = NULL;
+    silc_fsm_next(fsm, silc_ske_st_responder_error);
+    return SILC_FSM_CONTINUE;
+  }
+
+  ske->prop = silc_calloc(1, sizeof(*ske->prop));
+  if (!ske->prop) {
+    /** No memory */
+    ske->status = SILC_SKE_STATUS_OUT_OF_MEMORY;
+    silc_fsm_next(fsm, silc_ske_st_responder_error);
+    return SILC_FSM_CONTINUE;
+  }
+
+  if (!silc_hash_alloc(ske->rekey->hash, &ske->prop->hash)) {
+    /** Cannot allocate hash */
+    ske->status = SILC_SKE_STATUS_OUT_OF_MEMORY;
+    silc_fsm_next(fsm, silc_ske_st_responder_error);
+    return SILC_FSM_CONTINUE;
+  }
+
+  /* If doing rekey without PFS, move directly to the end of the protocol. */
+  if (!ske->rekey->pfs) {
+    /** Rekey without PFS */
+    silc_fsm_next(fsm, silc_ske_st_rekey_responder_done);
+    return SILC_FSM_CONTINUE;
+  }
+
+  status = silc_ske_group_get_by_number(ske->rekey->ske_group,
+                                       &ske->prop->group);
+  if (status != SILC_SKE_STATUS_OK) {
+    /** Unknown group */
+    silc_fsm_next(fsm, silc_ske_st_responder_error);
+    return SILC_FSM_CONTINUE;
+  }
+
+  /** Rekey with PFS */
+  silc_fsm_next(fsm, silc_ske_st_responder_phase2);
+  return SILC_FSM_WAIT;
+}
+
+/* Sends REKEY_DONE packet to finish the protocol. */
+
+SILC_FSM_STATE(silc_ske_st_rekey_responder_done)
+{
+  SilcSKE ske = fsm_context;
+  SilcCipher send_key;
+  SilcHmac hmac_send;
+  SilcHash hash;
+  SilcUInt32 key_len, block_len, hash_len, x_len;
+  unsigned char *pfsbuf;
+
+  SILC_LOG_DEBUG(("Start"));
+
+  silc_packet_get_keys(ske->stream, &send_key, NULL, &hmac_send, NULL);
+  key_len = silc_cipher_get_key_len(send_key);
+  block_len = silc_cipher_get_block_len(send_key);
+  hash = ske->prop->hash;
+  hash_len = silc_hash_len(hash);
+
+  /* Process key material */
+  if (ske->rekey->pfs) {
+    /* PFS */
+    pfsbuf = silc_mp_mp2bin(ske->KEY, 0, &x_len);
+    if (!pfsbuf) {
+      SILC_LOG_ERROR(("Error processing key material"));
+      silc_fsm_next(fsm, silc_ske_st_responder_error);
+      return SILC_FSM_CONTINUE;
+    }
+    ske->keymat = silc_ske_process_key_material_data(pfsbuf, x_len,
+                                                    block_len, key_len,
+                                                    hash_len, hash);
+    memset(pfsbuf, 0, x_len);
+    silc_free(pfsbuf);
+  } else {
+    /* No PFS */
+    ske->keymat =
+      silc_ske_process_key_material_data(ske->rekey->send_enc_key,
+                                        ske->rekey->enc_key_len / 8,
+                                        block_len, key_len,
+                                        hash_len, hash);
+  }
+
+  if (!ske->keymat) {
+    SILC_LOG_ERROR(("Error processing key material"));
+    silc_fsm_next(fsm, silc_ske_st_responder_error);
+    return SILC_FSM_CONTINUE;
+  }
+
+  ske->prop->cipher = send_key;
+  ske->prop->hmac = hmac_send;
+
+  /* Get sending keys */
+  if (!silc_ske_set_keys(ske, ske->keymat, ske->prop, &send_key, NULL,
+                        &hmac_send, NULL, NULL)) {
+    /** Cannot get keys */
+    ske->status = SILC_SKE_STATUS_ERROR;
+    ske->prop->cipher = NULL;
+    ske->prop->hmac = NULL;
+    silc_fsm_next(fsm, silc_ske_st_responder_error);
+    return SILC_FSM_CONTINUE;
+  }
+
+  ske->prop->cipher = NULL;
+  ske->prop->hmac = NULL;
+
+  /* Set the new keys into use.  This will also send REKEY_DONE packet.  Any
+     packet sent after this call will be protected with the new keys. */
+  if (!silc_packet_set_keys(ske->stream, send_key, NULL, hmac_send, NULL,
+                           TRUE)) {
+    /** Cannot set keys */
+    SILC_LOG_DEBUG(("Cannot set new keys, error sending REKEY_DONE"));
+    ske->status = SILC_SKE_STATUS_ERROR;
+    silc_cipher_free(send_key);
+    silc_hmac_free(hmac_send);
+    silc_fsm_next(fsm, silc_ske_st_responder_error);
+    return SILC_FSM_CONTINUE;
+  }
+
+  /** Wait for REKEY_DONE */
+  silc_fsm_next(fsm, silc_ske_st_rekey_responder_end);
+  return SILC_FSM_WAIT;
+}
+
+/* Rekey protocol end */
+
+SILC_FSM_STATE(silc_ske_st_rekey_responder_end)
+{
+  SilcSKE ske = fsm_context;
+  SilcCipher receive_key;
+  SilcHmac hmac_receive;
+  SilcSKERekeyMaterial rekey;
+
+  SILC_LOG_DEBUG(("Start"));
+
+  if (ske->packet->type != SILC_PACKET_REKEY_DONE) {
+    SILC_LOG_DEBUG(("Remote retransmitted an old packet"));
+    silc_packet_free(ske->packet);
+    ske->packet = NULL;
+    return SILC_FSM_WAIT;
+  }
+
+  silc_packet_get_keys(ske->stream, NULL, &receive_key, NULL, &hmac_receive);
+  ske->prop->cipher = receive_key;
+  ske->prop->hmac = hmac_receive;
+
+  /* Get receiving keys */
+  if (!silc_ske_set_keys(ske, ske->keymat, ske->prop, NULL, &receive_key,
+                        NULL, &hmac_receive, NULL)) {
+    /** Cannot get keys */
+    ske->status = SILC_SKE_STATUS_ERROR;
+    ske->prop->cipher = NULL;
+    ske->prop->hmac = NULL;
+    silc_fsm_next(fsm, silc_ske_st_responder_error);
+    return SILC_FSM_CONTINUE;
+  }
+
+  /* Set new receiving keys into use.  All packets received after this will
+     be decrypted with the new keys. */
+  if (!silc_packet_set_keys(ske->stream, NULL, receive_key, NULL,
+                           hmac_receive, FALSE)) {
+    /** Cannot set keys */
+    SILC_LOG_DEBUG(("Cannot set new keys"));
+    ske->status = SILC_SKE_STATUS_ERROR;
+    ske->prop->cipher = NULL;
+    ske->prop->hmac = NULL;
+    silc_cipher_free(receive_key);
+    silc_hmac_free(hmac_receive);
+    silc_fsm_next(fsm, silc_ske_st_responder_error);
+    return SILC_FSM_CONTINUE;
+  }
+
+  SILC_LOG_DEBUG(("Rekey completed successfully"));
+
+  /* Generate new rekey material */
+  rekey = silc_ske_make_rekey_material(ske, ske->keymat);
+  if (!rekey) {
+    /** No memory */
+    ske->status = SILC_SKE_STATUS_OUT_OF_MEMORY;
+    ske->prop->cipher = NULL;
+    ske->prop->hmac = NULL;
+    silc_fsm_next(fsm, silc_ske_st_responder_error);
+    return SILC_FSM_CONTINUE;
+  }
+  rekey->pfs = ske->rekey->pfs;
+  ske->rekey = rekey;
+
+  ske->prop->cipher = NULL;
+  ske->prop->hmac = NULL;
+  silc_packet_free(ske->packet);
+  ske->packet = NULL;
+  silc_packet_stream_unlink(ske->stream, &silc_ske_stream_cbs, ske);
+  silc_schedule_task_del_by_context(ske->schedule, ske);
+
+  /* Call completion */
+  silc_ske_completion(ske);
+
+  return SILC_FSM_FINISH;
 }
 
 /* Starts rekey protocol as responder */
@@ -2622,7 +3132,8 @@ SILC_FSM_STATE(silc_ske_st_rekey_responder_start)
 SilcAsyncOperation
 silc_ske_rekey_responder(SilcSKE ske,
                         SilcPacketStream stream,
-                        SilcSKERekeyMaterial rekey)
+                        SilcSKERekeyMaterial rekey,
+                        SilcPacket packet)
 {
   SILC_LOG_DEBUG(("Start SKE rekey as responder"));
 
@@ -2637,8 +3148,9 @@ silc_ske_rekey_responder(SilcSKE ske,
 
   ske->rekey = rekey;
   ske->responder = TRUE;
-  ske->running = TRUE;
   ske->rekeying = TRUE;
+  ske->packet = packet;
+  ++ske->refcnt;
 
   /* Link to packet stream to get key exchange packets */
   ske->stream = stream;
@@ -2650,7 +3162,7 @@ silc_ske_rekey_responder(SilcSKE ske,
                          SILC_PACKET_FAILURE, -1);
 
   /* Start SKE rekey as responder */
-  silc_fsm_start(&ske->fsm, silc_ske_st_rekey_responder_start);
+  silc_fsm_start_sync(&ske->fsm, silc_ske_st_rekey_responder_wait);
 
   return &ske->op;
 }
@@ -2686,7 +3198,7 @@ silc_ske_process_key_material_data(unsigned char *data,
     return NULL;
   silc_buffer_format(buf,
                     SILC_STR_UI_CHAR(0),
-                    SILC_STR_UI_XNSTRING(data, data_len),
+                    SILC_STR_DATA(data, data_len),
                     SILC_STR_END);
 
   /* Take IVs */
@@ -2694,11 +3206,23 @@ silc_ske_process_key_material_data(unsigned char *data,
   buf->data[0] = 0;
   silc_hash_make(hash, buf->data, silc_buffer_len(buf), hashd);
   key->send_iv = silc_calloc(req_iv_len, sizeof(unsigned char));
+  if (!key->send_iv) {
+    silc_buffer_clear(buf);
+    silc_buffer_free(buf);
+    silc_free(key);
+    return NULL;
+  }
   memcpy(key->send_iv, hashd, req_iv_len);
   memset(hashd, 0, sizeof(hashd));
   buf->data[0] = 1;
   silc_hash_make(hash, buf->data, silc_buffer_len(buf), hashd);
   key->receive_iv = silc_calloc(req_iv_len, sizeof(unsigned char));
+  if (!key->receive_iv) {
+    silc_buffer_clear(buf);
+    silc_buffer_free(buf);
+    silc_free(key);
+    return NULL;
+  }
   memcpy(key->receive_iv, hashd, req_iv_len);
   key->iv_len = req_iv_len;
 
@@ -2725,8 +3249,8 @@ silc_ske_process_key_material_data(unsigned char *data,
     if (!dist)
       return NULL;
     silc_buffer_format(dist,
-                      SILC_STR_UI_XNSTRING(data, data_len),
-                      SILC_STR_UI_XNSTRING(k1, hash_len),
+                      SILC_STR_DATA(data, data_len),
+                      SILC_STR_DATA(k1, hash_len),
                       SILC_STR_END);
     memset(k2, 0, sizeof(k2));
     silc_hash_make(hash, dist->data, silc_buffer_len(dist), k2);
@@ -2736,7 +3260,7 @@ silc_ske_process_key_material_data(unsigned char *data,
     silc_buffer_pull_tail(dist, hash_len);
     silc_buffer_pull(dist, data_len + hash_len);
     silc_buffer_format(dist,
-                      SILC_STR_UI_XNSTRING(k2, hash_len),
+                      SILC_STR_DATA(k2, hash_len),
                       SILC_STR_END);
     silc_buffer_push(dist, data_len + hash_len);
     memset(k3, 0, sizeof(k3));
@@ -2744,11 +3268,24 @@ silc_ske_process_key_material_data(unsigned char *data,
 
     /* Then, save the keys */
     dtmp = silc_calloc((3 * hash_len), sizeof(unsigned char));
+    if (!dtmp) {
+      silc_buffer_clear(buf);
+      silc_buffer_free(buf);
+      silc_free(key);
+      return NULL;
+    }
     memcpy(dtmp, k1, hash_len);
     memcpy(dtmp + hash_len, k2, hash_len);
     memcpy(dtmp + hash_len + hash_len, k3, hash_len);
 
     key->send_enc_key = silc_calloc(enc_key_len, sizeof(unsigned char));
+    if (!key->send_enc_key) {
+      silc_buffer_clear(buf);
+      silc_buffer_free(buf);
+      silc_free(key);
+      silc_free(dtmp);
+      return NULL;
+    }
     memcpy(key->send_enc_key, dtmp, enc_key_len);
     key->enc_key_len = req_enc_key_len;
 
@@ -2764,6 +3301,12 @@ silc_ske_process_key_material_data(unsigned char *data,
     memset(hashd, 0, sizeof(hashd));
     silc_hash_make(hash, buf->data, silc_buffer_len(buf), hashd);
     key->send_enc_key = silc_calloc(enc_key_len, sizeof(unsigned char));
+    if (!key->send_enc_key) {
+      silc_buffer_clear(buf);
+      silc_buffer_free(buf);
+      silc_free(key);
+      return NULL;
+    }
     memcpy(key->send_enc_key, hashd, enc_key_len);
     key->enc_key_len = req_enc_key_len;
   }
@@ -2788,8 +3331,8 @@ silc_ske_process_key_material_data(unsigned char *data,
     if (!dist)
       return NULL;
     silc_buffer_format(dist,
-                      SILC_STR_UI_XNSTRING(data, data_len),
-                      SILC_STR_UI_XNSTRING(k1, hash_len),
+                      SILC_STR_DATA(data, data_len),
+                      SILC_STR_DATA(k1, hash_len),
                       SILC_STR_END);
     memset(k2, 0, sizeof(k2));
     silc_hash_make(hash, dist->data, silc_buffer_len(dist), k2);
@@ -2799,7 +3342,7 @@ silc_ske_process_key_material_data(unsigned char *data,
     silc_buffer_pull_tail(dist, hash_len);
     silc_buffer_pull(dist, data_len + hash_len);
     silc_buffer_format(dist,
-                      SILC_STR_UI_XNSTRING(k2, hash_len),
+                      SILC_STR_DATA(k2, hash_len),
                       SILC_STR_END);
     silc_buffer_push(dist, data_len + hash_len);
     memset(k3, 0, sizeof(k3));
@@ -2807,11 +3350,24 @@ silc_ske_process_key_material_data(unsigned char *data,
 
     /* Then, save the keys */
     dtmp = silc_calloc((3 * hash_len), sizeof(unsigned char));
+    if (!dtmp) {
+      silc_buffer_clear(buf);
+      silc_buffer_free(buf);
+      silc_free(key);
+      return NULL;
+    }
     memcpy(dtmp, k1, hash_len);
     memcpy(dtmp + hash_len, k2, hash_len);
     memcpy(dtmp + hash_len + hash_len, k3, hash_len);
 
     key->receive_enc_key = silc_calloc(enc_key_len, sizeof(unsigned char));
+    if (!key->receive_enc_key) {
+      silc_buffer_clear(buf);
+      silc_buffer_free(buf);
+      silc_free(key);
+      silc_free(dtmp);
+      return NULL;
+    }
     memcpy(key->receive_enc_key, dtmp, enc_key_len);
     key->enc_key_len = req_enc_key_len;
 
@@ -2827,6 +3383,12 @@ silc_ske_process_key_material_data(unsigned char *data,
     memset(hashd, 0, sizeof(hashd));
     silc_hash_make(hash, buf->data, silc_buffer_len(buf), hashd);
     key->receive_enc_key = silc_calloc(enc_key_len, sizeof(unsigned char));
+    if (!key->receive_enc_key) {
+      silc_buffer_clear(buf);
+      silc_buffer_free(buf);
+      silc_free(key);
+      return NULL;
+    }
     memcpy(key->receive_enc_key, hashd, enc_key_len);
     key->enc_key_len = req_enc_key_len;
   }
@@ -2836,11 +3398,23 @@ silc_ske_process_key_material_data(unsigned char *data,
   buf->data[0] = 4;
   silc_hash_make(hash, buf->data, silc_buffer_len(buf), hashd);
   key->send_hmac_key = silc_calloc(req_hmac_key_len, sizeof(unsigned char));
+  if (!key->send_hmac_key) {
+    silc_buffer_clear(buf);
+    silc_buffer_free(buf);
+    silc_free(key);
+    return NULL;
+  }
   memcpy(key->send_hmac_key, hashd, req_hmac_key_len);
   memset(hashd, 0, sizeof(hashd));
   buf->data[0] = 5;
   silc_hash_make(hash, buf->data, silc_buffer_len(buf), hashd);
   key->receive_hmac_key = silc_calloc(req_hmac_key_len, sizeof(unsigned char));
+  if (!key->receive_hmac_key) {
+    silc_buffer_clear(buf);
+    silc_buffer_free(buf);
+    silc_free(key);
+    return NULL;
+  }
   memcpy(key->receive_hmac_key, hashd, req_hmac_key_len);
   key->hmac_key_len = req_hmac_key_len;
   memset(hashd, 0, sizeof(hashd));
@@ -2875,8 +3449,8 @@ silc_ske_process_key_material(SilcSKE ske,
   if (!buf)
     return NULL;
   silc_buffer_format(buf,
-                    SILC_STR_UI_XNSTRING(tmpbuf, klen),
-                    SILC_STR_UI_XNSTRING(ske->hash, ske->hash_len),
+                    SILC_STR_DATA(tmpbuf, klen),
+                    SILC_STR_DATA(ske->hash, ske->hash_len),
                     SILC_STR_END);
 
   /* Process the key material */
@@ -2954,7 +3528,8 @@ SilcBool silc_ske_set_keys(SilcSKE ske,
                           SilcHmac *ret_hmac_receive,
                           SilcHash *ret_hash)
 {
-  unsigned char iv[32];
+  unsigned char iv[SILC_HASH_MAXLEN];
+  SilcBool iv_included = (prop->flags & SILC_SKE_SP_FLAG_IV_INCLUDED);
 
   /* Allocate ciphers to be used in the communication */
   if (ret_send_key) {
@@ -2980,6 +3555,12 @@ SilcBool silc_ske_set_keys(SilcSKE ske,
       return FALSE;
   }
 
+  /* Allocate hash */
+  if (ret_hash) {
+    if (!silc_hash_alloc(silc_hash_get_name(prop->hash), ret_hash))
+      return FALSE;
+  }
+
   /* Set key material */
   memset(iv, 0, sizeof(iv));
   if (ske->responder) {
@@ -2988,10 +3569,24 @@ SilcBool silc_ske_set_keys(SilcSKE ske,
                          keymat->enc_key_len, TRUE);
 
       if (silc_cipher_get_mode(*ret_send_key) == SILC_CIPHER_MODE_CTR) {
-        memcpy(iv, ske->hash, 4);
-        memcpy(iv + 4, keymat->receive_iv, 4);
+       /* Counter mode */
+       if (!ske->rekeying) {
+         /* Set IV. */
+         memcpy(iv, ske->hash, 4);
+         if (!iv_included)
+           memcpy(iv + 4, keymat->receive_iv, 8);
+       } else {
+         /* Rekey, recompute the truncated hash value. */
+         silc_hash_make(prop->hash, keymat->receive_iv, 8, iv);
+         if (!iv_included)
+           memcpy(iv + 4, keymat->receive_iv, 8);
+         else
+           memset(iv + 4, 0, 12);
+       }
+
         silc_cipher_set_iv(*ret_send_key, iv);
       } else {
+       /* Other modes */
        silc_cipher_set_iv(*ret_send_key, keymat->receive_iv);
       }
     }
@@ -3000,10 +3595,24 @@ SilcBool silc_ske_set_keys(SilcSKE ske,
                          keymat->enc_key_len, FALSE);
 
       if (silc_cipher_get_mode(*ret_receive_key) == SILC_CIPHER_MODE_CTR) {
-        memcpy(iv, ske->hash, 4);
-        memcpy(iv + 4, keymat->send_iv, 4);
+       /* Counter mode */
+       if (!ske->rekeying) {
+         /* Set IV. */
+         memcpy(iv, ske->hash, 4);
+         if (!iv_included)
+           memcpy(iv + 4, keymat->send_iv, 8);
+       } else {
+         /* Rekey, recompute the truncated hash value. */
+         silc_hash_make(prop->hash, keymat->send_iv, 8, iv);
+         if (!iv_included)
+           memcpy(iv + 4, keymat->send_iv, 8);
+         else
+           memset(iv + 4, 0, 12);
+       }
+
         silc_cipher_set_iv(*ret_receive_key, iv);
       } else {
+       /* Other modes */
        silc_cipher_set_iv(*ret_receive_key, keymat->send_iv);
       }
     }
@@ -3019,10 +3628,24 @@ SilcBool silc_ske_set_keys(SilcSKE ske,
                          keymat->enc_key_len, TRUE);
 
       if (silc_cipher_get_mode(*ret_send_key) == SILC_CIPHER_MODE_CTR) {
-        memcpy(iv, ske->hash, 4);
-        memcpy(iv + 4, keymat->send_iv, 4);
+       /* Counter mode */
+       if (!ske->rekeying) {
+         /* Set IV. */
+         memcpy(iv, ske->hash, 4);
+         if (!iv_included)
+           memcpy(iv + 4, keymat->send_iv, 8);
+       } else {
+         /* Rekey, recompute the truncated hash value. */
+         silc_hash_make(prop->hash, keymat->send_iv, 8, iv);
+         if (!iv_included)
+           memcpy(iv + 4, keymat->send_iv, 8);
+         else
+           memset(iv + 4, 0, 12);
+       }
+
        silc_cipher_set_iv(*ret_send_key, iv);
       } else {
+       /* Other modes */
        silc_cipher_set_iv(*ret_send_key, keymat->send_iv);
       }
     }
@@ -3031,10 +3654,25 @@ SilcBool silc_ske_set_keys(SilcSKE ske,
                          keymat->enc_key_len, FALSE);
 
       if (silc_cipher_get_mode(*ret_receive_key) == SILC_CIPHER_MODE_CTR) {
-        memcpy(iv, ske->hash, 4);
-        memcpy(iv + 4, keymat->receive_iv, 4);
+       /* Counter mode */
+       if (!ske->rekeying) {
+         /* Set IV.  If IV Included flag was negotiated we only set the
+            truncated hash value. */
+         memcpy(iv, ske->hash, 4);
+         if (!iv_included)
+           memcpy(iv + 4, keymat->receive_iv, 8);
+       } else {
+         /* Rekey, recompute the truncated hash value. */
+         silc_hash_make(prop->hash, keymat->receive_iv, 8, iv);
+         if (!iv_included)
+           memcpy(iv + 4, keymat->receive_iv, 8);
+         else
+           memset(iv + 4, 0, 12);
+       }
+
        silc_cipher_set_iv(*ret_receive_key, iv);
       } else {
+       /* Other modes */
        silc_cipher_set_iv(*ret_receive_key, keymat->receive_iv);
       }
     }
@@ -3046,12 +3684,6 @@ SilcBool silc_ske_set_keys(SilcSKE ske,
                        keymat->hmac_key_len);
   }
 
-  /* Allocate hash */
-  if (ret_hash) {
-    if (!silc_hash_alloc(silc_hash_get_name(prop->hash), ret_hash))
-      return FALSE;
-  }
-
   return TRUE;
 }
 
@@ -3059,14 +3691,14 @@ const char *silc_ske_status_string[] =
 {
   /* Official */
   "Ok",
-  "Unkown error occurred",
+  "Unexpected error occurred",
   "Bad payload in packet",
   "Unsupported group",
   "Unsupported cipher",
   "Unsupported PKCS",
   "Unsupported hash function",
   "Unsupported HMAC",
-  "Unsupported public key (or certificate)",
+  "Public key not accepted",
   "Incorrect signature",
   "Bad or unsupported version",
   "Invalid cookie",
@@ -3077,6 +3709,8 @@ const char *silc_ske_status_string[] =
   "Bad payload length in packet",
   "Error computing signature",
   "System out of memory",
+  "Key exchange timeout",
+  "Key exchange timeout",
 
   NULL
 };