Merged from silc_1_0_branch.
[silc.git] / lib / silcske / silcske.c
index 612abd81dea4f09920e12746caf2d11b85e7f47e..2fd4e0107ea646bea7f2fe87dabc7d29830a80a6 100644 (file)
@@ -1,16 +1,15 @@
 /*
 
-  silcske.c
+  silcske.c 
 
   Author: Pekka Riikonen <priikone@silcnet.org>
 
-  Copyright (C) 2000 - 2001 Pekka Riikonen
+  Copyright (C) 2000 - 2002 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
-  the Free Software Foundation; either version 2 of the License, or
-  (at your option) any later version.
-  
+  the Free Software Foundation; version 2 of the License.
+
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 #include "silcske.h"
 #include "groups_internal.h"
 
+/* Static functions */
+static SilcSKEStatus silc_ske_create_rnd(SilcSKE ske, SilcMPInt *n, 
+                                        SilcUInt32 len, 
+                                        SilcMPInt *rnd);
+static SilcSKEStatus silc_ske_make_hash(SilcSKE ske, 
+                                       unsigned char *return_hash,
+                                       SilcUInt32 *return_hash_len,
+                                       int initiator);
+
 /* Structure to hold all SKE callbacks. */
 struct SilcSKECallbacksStruct {
   SilcSKESendPacketCb send_packet;
@@ -35,14 +43,18 @@ struct SilcSKECallbacksStruct {
 
 /* Allocates new SKE object. */
 
-SilcSKE silc_ske_alloc()
+SilcSKE silc_ske_alloc(SilcRng rng, void *context)
 {
   SilcSKE ske;
 
   SILC_LOG_DEBUG(("Allocating new Key Exchange object"));
 
   ske = silc_calloc(1, sizeof(*ske));
+  if (!ske)
+    return NULL;
   ske->status = SILC_SKE_STATUS_OK;
+  ske->rng = rng;
+  ske->user_data = context;
   ske->users = 1;
 
   return ske;
@@ -69,10 +81,14 @@ void silc_ske_free(SilcSKE ske)
     /* Free KE payload */
     if (ske->ke1_payload)
       silc_ske_payload_ke_free(ske->ke1_payload);
+    if (ske->ke2_payload)
+      silc_ske_payload_ke_free(ske->ke2_payload);
+    silc_free(ske->remote_version);
 
     /* Free rest */
     if (ske->prop) {
-      silc_free(ske->prop->group);
+      if (ske->prop->group)
+       silc_ske_group_free(ske->prop->group);
       if (ske->prop->pkcs)
        silc_pkcs_free(ske->prop->pkcs);
       if (ske->prop->cipher)
@@ -95,6 +111,8 @@ void silc_ske_free(SilcSKE ske)
     }
     silc_free(ske->hash);
     silc_free(ske->callbacks);
+
+    memset(ske, 'F', sizeof(*ske));
     silc_free(ske);
   }
 }
@@ -143,6 +161,8 @@ void silc_ske_set_callbacks(SilcSKE ske,
   if (ske->callbacks)
     silc_free(ske->callbacks);
   ske->callbacks = silc_calloc(1, sizeof(*ske->callbacks));
+  if (!ske->callbacks)
+    return;
   ske->callbacks->send_packet = send_packet;
   ske->callbacks->payload_receive = payload_receive;
   ske->callbacks->verify_key = verify_key;
@@ -222,7 +242,7 @@ SilcSKEStatus silc_ske_initiator_phase_1(SilcSKE ske,
   /* Check that the cookie is returned unmodified */
   if (memcmp(ske->start_payload->cookie, payload->cookie,
             ske->start_payload->cookie_len)) {
-    SILC_LOG_DEBUG(("Responder modified our cookie and it must not do it"));
+    SILC_LOG_ERROR(("Responder modified our cookie and it must not do it"));
     ske->status = SILC_SKE_STATUS_INVALID_COOKIE;
     silc_ske_payload_start_free(ske->start_payload);
     return status;
@@ -248,8 +268,10 @@ SilcSKEStatus silc_ske_initiator_phase_1(SilcSKE ske,
      exchange. The same data is returned to upper levels by calling
      the callback function. */
   ske->prop = prop = silc_calloc(1, sizeof(*prop));
+  if (!ske->prop)
+    goto err;
   prop->flags = payload->flags;
-  status = silc_ske_get_group_by_name(payload->ke_grp_list, &group);
+  status = silc_ske_group_get_by_name(payload->ke_grp_list, &group);
   if (status != SILC_SKE_STATUS_OK)
     goto err;
 
@@ -288,7 +310,7 @@ SilcSKEStatus silc_ske_initiator_phase_1(SilcSKE ske,
   if (payload)
     silc_ske_payload_start_free(payload);
 
-  silc_free(group);
+  silc_ske_group_free(group);
 
   if (prop->pkcs)
     silc_pkcs_free(prop->pkcs);
@@ -314,18 +336,23 @@ SilcSKEStatus silc_ske_initiator_phase_1(SilcSKE ske,
 
 SilcSKEStatus silc_ske_initiator_phase_2(SilcSKE ske,
                                         SilcPublicKey public_key,
-                                        SilcPrivateKey private_key)
+                                        SilcPrivateKey private_key,
+                                        SilcSKEPKType pk_type)
 {
   SilcSKEStatus status = SILC_SKE_STATUS_OK;
   SilcBuffer payload_buf;
   SilcMPInt *x;
   SilcSKEKEPayload *payload;
-  uint32 pk_len;
+  SilcUInt32 pk_len;
 
   SILC_LOG_DEBUG(("Start"));
 
   /* Create the random number x, 1 < x < q. */
   x = silc_calloc(1, sizeof(*x));
+  if (!x){
+    ske->status = SILC_SKE_STATUS_OUT_OF_MEMORY;
+    return ske->status;
+  }
   silc_mp_init(x);
   status = 
     silc_ske_create_rnd(ske, &ske->prop->group->group_order,
@@ -341,6 +368,12 @@ SilcSKEStatus silc_ske_initiator_phase_2(SilcSKE ske,
   /* Encode the result to Key Exchange Payload. */
 
   payload = silc_calloc(1, sizeof(*payload));
+  if (!payload) {
+    silc_mp_uninit(x);
+    silc_free(x);
+    ske->status = SILC_SKE_STATUS_OUT_OF_MEMORY;
+    return ske->status;
+  }
   ske->ke1_payload = payload;
 
   SILC_LOG_DEBUG(("Computing e = g ^ x mod p"));
@@ -358,17 +391,18 @@ SilcSKEStatus silc_ske_initiator_phase_2(SilcSKE ske,
       silc_free(x);
       silc_mp_uninit(&payload->x);
       silc_free(payload);
+      ske->ke1_payload = NULL;
       ske->status = SILC_SKE_STATUS_OK;
       return ske->status;
     }
     payload->pk_len = pk_len;
   }
-  payload->pk_type = SILC_SKE_PK_TYPE_SILC;
+  payload->pk_type = pk_type;
 
   /* Compute signature data if we are doing mutual authentication */
   if (private_key && ske->start_payload->flags & SILC_SKE_SP_FLAG_MUTUAL) {
-    unsigned char hash[32], sign[1024];
-    uint32 hash_len, sign_len;
+    unsigned char hash[32], sign[2048 + 1];
+    SilcUInt32 hash_len, sign_len;
 
     SILC_LOG_DEBUG(("We are doing mutual authentication"));
     SILC_LOG_DEBUG(("Computing HASH_i value"));
@@ -382,7 +416,17 @@ SilcSKEStatus silc_ske_initiator_phase_2(SilcSKE ske,
     /* Sign the hash value */
     silc_pkcs_private_key_data_set(ske->prop->pkcs, private_key->prv, 
                                   private_key->prv_len);
-    silc_pkcs_sign(ske->prop->pkcs, hash, hash_len, sign, &sign_len);
+    if (silc_pkcs_get_key_len(ske->prop->pkcs) / 8 > sizeof(sign) - 1 ||
+       !silc_pkcs_sign(ske->prop->pkcs, hash, hash_len, sign, &sign_len)) {
+      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;
+      return ske->status;
+    }
     payload->sign_data = silc_calloc(sign_len, sizeof(unsigned char));
     memcpy(payload->sign_data, sign, sign_len);
     memset(sign, 0, sizeof(sign));
@@ -395,7 +439,9 @@ SilcSKEStatus silc_ske_initiator_phase_2(SilcSKE ske,
     silc_free(x);
     silc_mp_uninit(&payload->x);
     silc_free(payload->pk_data);
+    silc_free(payload->sign_data);
     silc_free(payload);
+    ske->ke1_payload = NULL;
     ske->status = status;
     return status;
   }
@@ -422,7 +468,7 @@ static void silc_ske_initiator_finish_final(SilcSKE ske,
 {
   SilcSKEKEPayload *payload;
   unsigned char hash[32];
-  uint32 hash_len;
+  SilcUInt32 hash_len;
   SilcPublicKey public_key = NULL;
 
   /* If the SKE was freed during the async call then free it really now,
@@ -455,6 +501,7 @@ static void silc_ske_initiator_finish_final(SilcSKE ske,
     if (!silc_pkcs_public_key_decode(payload->pk_data, payload->pk_len, 
                                     &public_key)) {
       status = SILC_SKE_STATUS_UNSUPPORTED_PUBLIC_KEY;
+      SILC_LOG_ERROR(("Unsupported/malformed public key received"));
       if (ske->callbacks->proto_continue)
        ske->callbacks->proto_continue(ske, ske->callbacks->context);
       return;
@@ -477,9 +524,7 @@ static void silc_ske_initiator_finish_final(SilcSKE ske,
     silc_pkcs_public_key_set(ske->prop->pkcs, public_key);
     if (silc_pkcs_verify(ske->prop->pkcs, payload->sign_data, 
                         payload->sign_len, hash, hash_len) == FALSE) {
-      
-      SILC_LOG_DEBUG(("Signature don't match"));
-      
+      SILC_LOG_ERROR(("Signature verification failed, incorrect signature"));
       status = SILC_SKE_STATUS_INCORRECT_SIGNATURE;
       goto err;
     }
@@ -530,7 +575,7 @@ static void silc_ske_initiator_finish_final(SilcSKE ske,
    public key, f, and signature. This function verifies the public key,
    computes the secret shared key and verifies the signature. 
 
-   The `callback' will be called to indicate that the caller may
+   The `proto_continue' will be called to indicate that the caller may
    continue with the SKE protocol.  The caller must not continue
    before the SKE libary has called that callback.  If this function
    returns an error the callback will not be called.  It is called
@@ -619,9 +664,9 @@ SilcSKEStatus silc_ske_initiator_finish(SilcSKE ske,
 
 SilcSKEStatus silc_ske_responder_start(SilcSKE ske, SilcRng rng,
                                       SilcSocketConnection sock,
-                                      char *version,
+                                      const char *version,
                                       SilcBuffer start_payload,
-                                      bool mutual_auth)
+                                      SilcSKESecurityPropertyFlag flags)
 {
   SilcSKEStatus status = SILC_SKE_STATUS_OK;
   SilcSKEStartPayload *remote_payload = NULL, *payload = NULL;
@@ -643,11 +688,24 @@ SilcSKEStatus silc_ske_responder_start(SilcSKE ske, SilcRng rng,
   ske->start_payload_copy = silc_buffer_copy(start_payload);
 
   /* Force the mutual authentication flag if we want to do it. */
-  if (mutual_auth) {
+  if (flags & SILC_SKE_SP_FLAG_MUTUAL) {
     SILC_LOG_DEBUG(("Force mutual authentication"));
     remote_payload->flags |= SILC_SKE_SP_FLAG_MUTUAL;
   }
 
+  /* Force PFS flag if we require it */
+  if (flags & SILC_SKE_SP_FLAG_PFS) {
+    SILC_LOG_DEBUG(("Force PFS"));
+    remote_payload->flags |= SILC_SKE_SP_FLAG_PFS;
+  }
+
+  /* Disable IV Included flag if requested */
+  if (remote_payload->flags & SILC_SKE_SP_FLAG_IV_INCLUDED &&
+      !(flags & SILC_SKE_SP_FLAG_IV_INCLUDED)) {
+    SILC_LOG_DEBUG(("We do not support IV Included flag"));
+    remote_payload->flags &= ~SILC_SKE_SP_FLAG_IV_INCLUDED;
+  }
+
   /* Parse and select the security properties from the payload */
   payload = silc_calloc(1, sizeof(*payload));
   status = silc_ske_select_security_properties(ske, version,
@@ -681,8 +739,7 @@ SilcSKEStatus silc_ske_responder_start(SilcSKE ske, SilcRng rng,
 /* The selected security properties from the initiator payload is now 
    encoded into Key Exchange Start Payload and sent to the initiator. */
 
-SilcSKEStatus silc_ske_responder_phase_1(SilcSKE ske, 
-                                        SilcSKEStartPayload *start_payload)
+SilcSKEStatus silc_ske_responder_phase_1(SilcSKE ske)
 {
   SilcSKEStatus status = SILC_SKE_STATUS_OK;
   SilcBuffer payload_buf;
@@ -694,39 +751,40 @@ SilcSKEStatus silc_ske_responder_phase_1(SilcSKE ske,
   /* Allocate security properties from the payload. These are allocated
      only for this negotiation and will be free'd after KE is over. */
   ske->prop = prop = silc_calloc(1, sizeof(*prop));
-  prop->flags = start_payload->flags;
-  status = silc_ske_get_group_by_name(start_payload->ke_grp_list, &group);
+  prop->flags = ske->start_payload->flags;
+  status = silc_ske_group_get_by_name(ske->start_payload->ke_grp_list, &group);
   if (status != SILC_SKE_STATUS_OK)
     goto err;
 
   prop->group = group;
 
-  if (silc_pkcs_alloc(start_payload->pkcs_alg_list, 
+  if (silc_pkcs_alloc(ske->start_payload->pkcs_alg_list, 
                      &prop->pkcs) == FALSE) {
     status = SILC_SKE_STATUS_UNKNOWN_PKCS;
     goto err;
   }
 
-  if (silc_cipher_alloc(start_payload->enc_alg_list, 
+  if (silc_cipher_alloc(ske->start_payload->enc_alg_list, 
                        &prop->cipher) == FALSE) {
     status = SILC_SKE_STATUS_UNKNOWN_CIPHER;
     goto err;
   }
 
-  if (silc_hash_alloc(start_payload->hash_alg_list,
+  if (silc_hash_alloc(ske->start_payload->hash_alg_list,
                      &prop->hash) == FALSE) {
     status = SILC_SKE_STATUS_UNKNOWN_HASH_FUNCTION;
     goto err;
   }
 
-  if (silc_hmac_alloc(start_payload->hmac_alg_list, NULL,
+  if (silc_hmac_alloc(ske->start_payload->hmac_alg_list, NULL,
                      &prop->hmac) == FALSE) {
     status = SILC_SKE_STATUS_UNKNOWN_HMAC;
     goto err;
   }
 
   /* Encode the payload */
-  status = silc_ske_payload_start_encode(ske, start_payload, &payload_buf);
+  status = silc_ske_payload_start_encode(ske, ske->start_payload, 
+                                        &payload_buf);
   if (status != SILC_SKE_STATUS_OK)
     goto err;
 
@@ -741,7 +799,7 @@ SilcSKEStatus silc_ske_responder_phase_1(SilcSKE ske,
 
  err:
   if (group)
-    silc_free(group);
+    silc_ske_group_free(group);
 
   if (prop->pkcs)
     silc_pkcs_free(prop->pkcs);
@@ -802,13 +860,14 @@ static void silc_ske_responder_phase2_final(SilcSKE ske,
       ske->start_payload->flags & SILC_SKE_SP_FLAG_MUTUAL) {
     SilcPublicKey public_key = NULL;
     unsigned char hash[32];
-    uint32 hash_len;
+    SilcUInt32 hash_len;
 
     /* Decode the public key */
     if (!silc_pkcs_public_key_decode(recv_payload->pk_data, 
                                     recv_payload->pk_len, 
                                     &public_key)) {
       ske->status = SILC_SKE_STATUS_UNSUPPORTED_PUBLIC_KEY;
+      SILC_LOG_ERROR(("Unsupported/malformed public key received"));
       if (ske->callbacks->proto_continue)
        ske->callbacks->proto_continue(ske, ske->callbacks->context);
       return;
@@ -831,9 +890,7 @@ static void silc_ske_responder_phase2_final(SilcSKE ske,
     silc_pkcs_public_key_set(ske->prop->pkcs, public_key);
     if (silc_pkcs_verify(ske->prop->pkcs, recv_payload->sign_data, 
                         recv_payload->sign_len, hash, hash_len) == FALSE) {
-      
-      SILC_LOG_DEBUG(("Signature don't match"));
-      
+      SILC_LOG_ERROR(("Signature verification failed, incorrect signature"));
       ske->status = SILC_SKE_STATUS_INCORRECT_SIGNATURE;
       if (ske->callbacks->proto_continue)
        ske->callbacks->proto_continue(ske, ske->callbacks->context);
@@ -886,7 +943,7 @@ static void silc_ske_responder_phase2_final(SilcSKE ske,
    and computes f = g ^ x mod p. This then puts the result f to a Key
    Exchange Payload. 
 
-   The `callback' will be called to indicate that the caller may
+   The `proto_continue' will be called to indicate that the caller may
    continue with the SKE protocol.  The caller must not continue
    before the SKE libary has called that callback.  If this function
    returns an error the callback will not be called.  It is called
@@ -924,7 +981,7 @@ SilcSKEStatus silc_ske_responder_phase_2(SilcSKE ske,
     SILC_LOG_DEBUG(("We are doing mutual authentication"));
     
     if (!recv_payload->pk_data && ske->callbacks->verify_key) {
-      SILC_LOG_DEBUG(("Remote end did not send its public key (or "
+      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;
       return status;
@@ -965,8 +1022,8 @@ SilcSKEStatus silc_ske_responder_finish(SilcSKE ske,
   SilcSKEStatus status = SILC_SKE_STATUS_OK;
   SilcBuffer payload_buf;
   SilcMPInt *KEY;
-  unsigned char hash[32], sign[1024], *pk;
-  uint32 hash_len, sign_len, pk_len;
+  unsigned char hash[32], sign[2048 + 1], *pk;
+  SilcUInt32 hash_len, sign_len, pk_len;
 
   SILC_LOG_DEBUG(("Start"));
 
@@ -985,7 +1042,7 @@ SilcSKEStatus silc_ske_responder_finish(SilcSKE ske,
     /* Get the public key */
     pk = silc_pkcs_public_key_encode(public_key, &pk_len);
     if (!pk) {
-      status = SILC_SKE_STATUS_ERROR;
+      status = SILC_SKE_STATUS_OUT_OF_MEMORY;
       goto err;
     }
     ske->ke2_payload->pk_data = pk;
@@ -1008,7 +1065,11 @@ SilcSKEStatus silc_ske_responder_finish(SilcSKE ske,
     /* Sign the hash value */
     silc_pkcs_private_key_data_set(ske->prop->pkcs, private_key->prv, 
                                   private_key->prv_len);
-    silc_pkcs_sign(ske->prop->pkcs, hash, hash_len, sign, &sign_len);
+    if (silc_pkcs_get_key_len(ske->prop->pkcs) / 8 > sizeof(sign) - 1 ||
+       !silc_pkcs_sign(ske->prop->pkcs, hash, hash_len, sign, &sign_len)) {
+      status = SILC_SKE_STATUS_SIGNATURE_ERROR;
+      goto err;
+    }
     ske->ke2_payload->sign_data = silc_calloc(sign_len, sizeof(unsigned char));
     memcpy(ske->ke2_payload->sign_data, sign, sign_len);
     memset(sign, 0, sizeof(sign));
@@ -1055,10 +1116,11 @@ SilcSKEStatus silc_ske_end(SilcSKE ske)
 
   SILC_LOG_DEBUG(("Start"));
 
-  packet = silc_buffer_alloc(4);
-  silc_buffer_pull_tail(packet, SILC_BUFFER_END(packet));
+  packet = silc_buffer_alloc_size(4);
+  if (!packet)
+    return SILC_SKE_STATUS_OUT_OF_MEMORY;
   silc_buffer_format(packet,
-                    SILC_STR_UI_INT((uint32)SILC_SKE_STATUS_OK),
+                    SILC_STR_UI_INT((SilcUInt32)SILC_SKE_STATUS_OK),
                     SILC_STR_END);
 
   if (ske->callbacks->send_packet)
@@ -1080,10 +1142,14 @@ SilcSKEStatus silc_ske_abort(SilcSKE ske, SilcSKEStatus status)
 
   SILC_LOG_DEBUG(("Start"));
 
-  packet = silc_buffer_alloc(4);
-  silc_buffer_pull_tail(packet, SILC_BUFFER_END(packet));
+  if (status > SILC_SKE_STATUS_INVALID_COOKIE)
+    status = SILC_SKE_STATUS_BAD_PAYLOAD;
+
+  packet = silc_buffer_alloc_size(4);
+  if (!packet)
+    return SILC_SKE_STATUS_OUT_OF_MEMORY;
   silc_buffer_format(packet,
-                    SILC_STR_UI_INT((uint32)status),
+                    SILC_STR_UI_INT((SilcUInt32)status),
                     SILC_STR_END);
 
   if (ske->callbacks->send_packet)
@@ -1104,8 +1170,8 @@ SilcSKEStatus silc_ske_abort(SilcSKE ske, SilcSKEStatus status)
 
 SilcSKEStatus 
 silc_ske_assemble_security_properties(SilcSKE ske,
-                                     unsigned char flags,
-                                     char *version,
+                                     SilcSKESecurityPropertyFlag flags,
+                                     const char *version,
                                      SilcSKEStartPayload **return_payload)
 {
   SilcSKEStartPayload *rp;
@@ -1116,12 +1182,12 @@ silc_ske_assemble_security_properties(SilcSKE ske,
   rp = silc_calloc(1, sizeof(*rp));
 
   /* Set flags */
-  rp->flags = flags;
+  rp->flags = (unsigned char)flags;
 
   /* Set random cookie */
   rp->cookie = silc_calloc(SILC_SKE_COOKIE_LEN, sizeof(*rp->cookie));
   for (i = 0; i < SILC_SKE_COOKIE_LEN; i++)
-    rp->cookie[i] = silc_rng_get_byte(ske->rng);
+    rp->cookie[i] = silc_rng_get_byte_fast(ske->rng);
   rp->cookie_len = SILC_SKE_COOKIE_LEN;
 
   /* Put version */
@@ -1150,8 +1216,8 @@ silc_ske_assemble_security_properties(SilcSKE ske,
 
   /* XXX */
   /* Get supported compression algorithms */
-  rp->comp_alg_list = strdup("");
-  rp->comp_alg_len = 0;
+  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 +
@@ -1169,7 +1235,7 @@ silc_ske_assemble_security_properties(SilcSKE ske,
 
 SilcSKEStatus 
 silc_ske_select_security_properties(SilcSKE ske,
-                                   char *version,
+                                   const char *version,
                                    SilcSKEStartPayload *payload,
                                    SilcSKEStartPayload *remote_payload)
 {
@@ -1193,6 +1259,8 @@ silc_ske_select_security_properties(SilcSKE ske,
     }
   }
 
+  ske->remote_version = silc_memdup(rp->version, rp->version_len);
+
   /* Flags are returned unchanged. */
   payload->flags = rp->flags;
 
@@ -1217,7 +1285,7 @@ silc_ske_select_security_properties(SilcSKE ske,
 
       SILC_LOG_DEBUG(("Proposed KE group `%s'", item));
 
-      if (silc_ske_get_group_by_name(item, NULL) == SILC_SKE_STATUS_OK) {
+      if (silc_ske_group_get_by_name(item, NULL) == SILC_SKE_STATUS_OK) {
        SILC_LOG_DEBUG(("Found KE group `%s'", item));
 
        payload->ke_grp_len = len;
@@ -1475,9 +1543,8 @@ silc_ske_select_security_properties(SilcSKE ske,
     payload->hmac_alg_list = strdup(rp->hmac_alg_list);
   }
 
-#if 0
   /* Get supported compression algorithms */
-  cp = rp->hash_alg_list;
+  cp = rp->comp_alg_list;
   if (cp && strchr(cp, ',')) {
     while(cp) {
       char *item;
@@ -1486,15 +1553,23 @@ silc_ske_select_security_properties(SilcSKE ske,
       item = silc_calloc(len + 1, sizeof(char));
       memcpy(item, cp, len);
 
-      SILC_LOG_DEBUG(("Proposed hash alg `%s'", item));
-
-      if (silc_hash_is_supported(item) == TRUE) {
-       SILC_LOG_DEBUG(("Found hash alg `%s'", item));
+      SILC_LOG_DEBUG(("Proposed Compression `%s'", item));
 
-       payload->hash_alg_len = len;
-       payload->hash_alg_list = item;
+#if 1
+      if (!strcmp(item, "none")) {
+       SILC_LOG_DEBUG(("Found Compression `%s'", item));
+       payload->comp_alg_len = len;
+       payload->comp_alg_list = item;
+       break;
+      }
+#else
+      if (silc_hmac_is_supported(item) == TRUE) {
+       SILC_LOG_DEBUG(("Found Compression `%s'", item));
+       payload->comp_alg_len = len;
+       payload->comp_alg_list = item;
        break;
       }
+#endif
 
       cp += len;
       if (strlen(cp) == 0)
@@ -1505,20 +1580,7 @@ silc_ske_select_security_properties(SilcSKE ske,
       if (item)
        silc_free(item);
     }
-
-    if (!payload->hash_alg_len && !payload->hash_alg_list) {
-      SILC_LOG_DEBUG(("Could not find supported hash alg"));
-      silc_ske_abort(ske, SILC_SKE_STATUS_UNKNOWN_HASH_FUNCTION);
-      silc_free(payload->ke_grp_list);
-      silc_free(payload->pkcs_alg_list);
-      silc_free(payload->enc_alg_list);
-      silc_free(payload);
-      return;
-    }
-  } else {
-
   }
-#endif
 
   payload->len = 1 + 1 + 2 + SILC_SKE_COOKIE_LEN + 
     2 + payload->version_len + 
@@ -1532,32 +1594,37 @@ silc_ske_select_security_properties(SilcSKE ske,
 /* Creates random number such that 1 < rnd < n and at most length
    of len bits. The rnd sent as argument must be initialized. */
 
-SilcSKEStatus silc_ske_create_rnd(SilcSKE ske, SilcMPInt *n, 
-                                 uint32 len, 
-                                 SilcMPInt *rnd)
+static SilcSKEStatus silc_ske_create_rnd(SilcSKE ske, SilcMPInt *n, 
+                                        SilcUInt32 len, 
+                                        SilcMPInt *rnd)
 {
   SilcSKEStatus status = SILC_SKE_STATUS_OK;
   unsigned char *string;
+  SilcUInt32 l;
+
+  if (!len)
+    return SILC_SKE_STATUS_ERROR;
 
   SILC_LOG_DEBUG(("Creating random number"));
 
+  l = ((len - 1) / 8);
+
   /* Get the random number as string */
-  string = silc_rng_get_rn_data(ske->rng, (len / 8));
+  string = silc_rng_get_rn_data(ske->rng, l);
   if (!string)
-    return SILC_SKE_STATUS_ERROR;
+    return SILC_SKE_STATUS_OUT_OF_MEMORY;
 
   /* Decode the string into a MP integer */
-  silc_mp_bin2mp(string, (len / 8), rnd);
+  silc_mp_bin2mp(string, l, rnd);
   silc_mp_mod_2exp(rnd, rnd, len);
 
   /* Checks */
   if (silc_mp_cmp_ui(rnd, 1) < 0)
     status = SILC_SKE_STATUS_ERROR;
-
   if (silc_mp_cmp(rnd, n) >= 0)
     status = SILC_SKE_STATUS_ERROR;
 
-  memset(string, 'F', (len / 8));
+  memset(string, 'F', l);
   silc_free(string);
 
   return status;
@@ -1568,15 +1635,15 @@ SilcSKEStatus silc_ske_create_rnd(SilcSKE ske, SilcMPInt *n,
    hash value defined in the protocol. If it is FALSE then this is used
    to create the HASH value defined by the protocol. */
 
-SilcSKEStatus silc_ske_make_hash(SilcSKE ske, 
-                                unsigned char *return_hash,
-                                uint32 *return_hash_len,
-                                int initiator)
+static SilcSKEStatus silc_ske_make_hash(SilcSKE ske, 
+                                       unsigned char *return_hash,
+                                       SilcUInt32 *return_hash_len,
+                                       int initiator)
 {
   SilcSKEStatus status = SILC_SKE_STATUS_OK;
   SilcBuffer buf;
   unsigned char *e, *f, *KEY;
-  uint32 e_len, f_len, KEY_len;
+  SilcUInt32 e_len, f_len, KEY_len;
   int ret;
 
   SILC_LOG_DEBUG(("Start"));
@@ -1587,18 +1654,21 @@ SilcSKEStatus silc_ske_make_hash(SilcSKE ske,
     KEY = silc_mp_mp2bin(ske->KEY, 0, &KEY_len);
     
     /* Format the buffer used to compute the hash value */
-    /* XXX Backward support for 0.6.1 */
-    if (ske->backward_version == 1) {
-      SILC_LOG_DEBUG(("*********** Using old KE payload"));
-      buf = silc_buffer_alloc(ske->start_payload_copy->len + 
-                             ske->ke2_payload->pk_len + e_len + 
-                             f_len + KEY_len);
-      silc_buffer_pull_tail(buf, SILC_BUFFER_END(buf));
-
+    buf = silc_buffer_alloc_size(ske->start_payload_copy->len + 
+                                ske->ke2_payload->pk_len + 
+                                ske->ke1_payload->pk_len + 
+                                e_len + f_len + KEY_len);
+    if (!buf)
+      return SILC_SKE_STATUS_OUT_OF_MEMORY;
+
+    /* Initiator is not required to send its public key */
+    if (!ske->ke1_payload->pk_data) {
       ret = 
        silc_buffer_format(buf,
-                          SILC_STR_UI_XNSTRING(ske->start_payload_copy->data,
-                                               ske->start_payload_copy->len),
+                          SILC_STR_UI_XNSTRING(ske->start_payload_copy->
+                                               data,
+                                               ske->start_payload_copy->
+                                               len),
                           SILC_STR_UI_XNSTRING(ske->ke2_payload->pk_data, 
                                                ske->ke2_payload->pk_len),
                           SILC_STR_UI_XNSTRING(e, e_len),
@@ -1606,43 +1676,20 @@ SilcSKEStatus silc_ske_make_hash(SilcSKE ske,
                           SILC_STR_UI_XNSTRING(KEY, KEY_len),
                           SILC_STR_END);
     } else {
-      /* Initiator is not required to send its public key */
-      SILC_LOG_DEBUG(("*********** Using new KE payload"));
-      buf = silc_buffer_alloc(ske->start_payload_copy->len + 
-                             ske->ke2_payload->pk_len + 
-                             ske->ke1_payload->pk_len + 
-                             e_len + f_len + KEY_len);
-      silc_buffer_pull_tail(buf, SILC_BUFFER_END(buf));
-
-      if (!ske->ke1_payload->pk_data) {
-       ret = 
-         silc_buffer_format(buf,
-                            SILC_STR_UI_XNSTRING(ske->start_payload_copy->
-                                                 data,
-                                                 ske->start_payload_copy->
-                                                 len),
-                            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_END);
-      } else {
-       ret = 
-         silc_buffer_format(buf,
-                            SILC_STR_UI_XNSTRING(ske->start_payload_copy->
-                                                 data,
-                                                 ske->start_payload_copy->
-                                                 len),
-                            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_END);
-      }
+      ret = 
+       silc_buffer_format(buf,
+                          SILC_STR_UI_XNSTRING(ske->start_payload_copy->
+                                               data,
+                                               ske->start_payload_copy->
+                                               len),
+                          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_END);
     }
     if (ret == -1) {
       silc_buffer_free(buf);
@@ -1664,9 +1711,10 @@ SilcSKEStatus silc_ske_make_hash(SilcSKE ske,
   } else {
     e = silc_mp_mp2bin(&ske->ke1_payload->x, 0, &e_len);
 
-    buf = silc_buffer_alloc(ske->start_payload_copy->len + 
-                           ske->ke1_payload->pk_len + e_len);
-    silc_buffer_pull_tail(buf, SILC_BUFFER_END(buf));
+    buf = silc_buffer_alloc_size(ske->start_payload_copy->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 = 
@@ -1690,7 +1738,7 @@ SilcSKEStatus silc_ske_make_hash(SilcSKE ske,
 
   /* Make the hash */
   silc_hash_make(ske->prop->hash, buf->data, buf->len, return_hash);
-  *return_hash_len = ske->prop->hash->hash->hash_len;
+  *return_hash_len = silc_hash_len(ske->prop->hash);
 
   if (initiator == FALSE) {
     SILC_LOG_HEXDUMP(("HASH"), return_hash, *return_hash_len);
@@ -1708,25 +1756,26 @@ SilcSKEStatus silc_ske_make_hash(SilcSKE ske,
 
 SilcSKEStatus 
 silc_ske_process_key_material_data(unsigned char *data,
-                                  uint32 data_len,
-                                  uint32 req_iv_len,
-                                  uint32 req_enc_key_len,
-                                  uint32 req_hmac_key_len,
+                                  SilcUInt32 data_len,
+                                  SilcUInt32 req_iv_len,
+                                  SilcUInt32 req_enc_key_len,
+                                  SilcUInt32 req_hmac_key_len,
                                   SilcHash hash,
                                   SilcSKEKeyMaterial *key)
 {
   SilcBuffer buf;
   unsigned char hashd[32];
-  uint32 hash_len = req_hmac_key_len;
-  uint32 enc_key_len = req_enc_key_len / 8;
+  SilcUInt32 hash_len = req_hmac_key_len;
+  SilcUInt32 enc_key_len = req_enc_key_len / 8;
 
   SILC_LOG_DEBUG(("Start"));
 
   if (!req_iv_len || !req_enc_key_len || !req_hmac_key_len)
     return SILC_SKE_STATUS_ERROR;
 
-  buf = silc_buffer_alloc(1 + data_len);
-  silc_buffer_pull_tail(buf, SILC_BUFFER_END(buf));
+  buf = silc_buffer_alloc_size(1 + data_len);
+  if (!buf)
+    return SILC_SKE_STATUS_OUT_OF_MEMORY;
   silc_buffer_format(buf,
                     SILC_STR_UI_CHAR(0),
                     SILC_STR_UI_XNSTRING(data, data_len),
@@ -1763,8 +1812,9 @@ silc_ske_process_key_material_data(unsigned char *data,
     silc_hash_make(hash, buf->data, buf->len, k1);
     
     /* Take second round */
-    dist = silc_buffer_alloc(data_len + hash_len);
-    silc_buffer_pull_tail(dist, SILC_BUFFER_END(dist));
+    dist = silc_buffer_alloc_size(data_len + hash_len);
+    if (!dist)
+      return SILC_SKE_STATUS_OUT_OF_MEMORY;
     silc_buffer_format(dist,
                       SILC_STR_UI_XNSTRING(data, data_len),
                       SILC_STR_UI_XNSTRING(k1, hash_len),
@@ -1798,6 +1848,7 @@ silc_ske_process_key_material_data(unsigned char *data,
     memset(k2, 0, sizeof(k2));
     memset(k3, 0, sizeof(k3));
     silc_free(dtmp);
+    silc_buffer_clear(dist);
     silc_buffer_free(dist);
   } else {
     /* Take normal hash as key */
@@ -1823,8 +1874,9 @@ silc_ske_process_key_material_data(unsigned char *data,
     silc_hash_make(hash, buf->data, buf->len, k1);
     
     /* Take second round */
-    dist = silc_buffer_alloc(data_len + hash_len);
-    silc_buffer_pull_tail(dist, SILC_BUFFER_END(dist));
+    dist = silc_buffer_alloc_size(data_len + hash_len);
+    if (!dist)
+      return SILC_SKE_STATUS_OUT_OF_MEMORY;
     silc_buffer_format(dist,
                       SILC_STR_UI_XNSTRING(data, data_len),
                       SILC_STR_UI_XNSTRING(k1, hash_len),
@@ -1858,6 +1910,7 @@ silc_ske_process_key_material_data(unsigned char *data,
     memset(k2, 0, sizeof(k2));
     memset(k3, 0, sizeof(k3));
     silc_free(dtmp);
+    silc_buffer_clear(dist);
     silc_buffer_free(dist);
   } else {
     /* Take normal hash as key */
@@ -1882,6 +1935,7 @@ silc_ske_process_key_material_data(unsigned char *data,
   key->hmac_key_len = req_hmac_key_len;
   memset(hashd, 0, sizeof(hashd));
 
+  silc_buffer_clear(buf);
   silc_buffer_free(buf);
 
   return SILC_SKE_STATUS_OK;
@@ -1891,21 +1945,22 @@ silc_ske_process_key_material_data(unsigned char *data,
    the actual keys to be used in the SILC. */
 
 SilcSKEStatus silc_ske_process_key_material(SilcSKE ske, 
-                                           uint32 req_iv_len,
-                                           uint32 req_enc_key_len,
-                                           uint32 req_hmac_key_len,
+                                           SilcUInt32 req_iv_len,
+                                           SilcUInt32 req_enc_key_len,
+                                           SilcUInt32 req_hmac_key_len,
                                            SilcSKEKeyMaterial *key)
 {
   SilcSKEStatus status;
   SilcBuffer buf;
   unsigned char *tmpbuf;
-  uint32 klen;
+  SilcUInt32 klen;
 
   /* Encode KEY to binary data */
   tmpbuf = silc_mp_mp2bin(ske->KEY, 0, &klen);
 
-  buf = silc_buffer_alloc(klen + ske->hash_len);
-  silc_buffer_pull_tail(buf, SILC_BUFFER_END(buf));
+  buf = silc_buffer_alloc_size(klen + ske->hash_len);
+  if (!buf)
+    return SILC_SKE_STATUS_OUT_OF_MEMORY;
   silc_buffer_format(buf,
                     SILC_STR_UI_XNSTRING(tmpbuf, klen),
                     SILC_STR_UI_XNSTRING(ske->hash, ske->hash_len),
@@ -1919,6 +1974,7 @@ SilcSKEStatus silc_ske_process_key_material(SilcSKE ske,
 
   memset(tmpbuf, 0, klen);
   silc_free(tmpbuf);
+  silc_buffer_clear(buf);
   silc_buffer_free(buf);
 
   return status;
@@ -1976,7 +2032,8 @@ const char *silc_ske_status_string[] =
   "Key exchange protocol is not active",
   "Bad reserved field in packet",
   "Bad payload length in packet",
-  "Incorrect hash",
+  "Error computing signature",
+  "System out of memory",
 
   NULL
 };
@@ -1994,3 +2051,20 @@ const char *silc_ske_map_status(SilcSKEStatus status)
 
   return "";
 }
+
+/* Parses remote host's version string. */
+
+bool silc_ske_parse_version(SilcSKE ske, 
+                           SilcUInt32 *protocol_version,
+                           char **protocol_version_string,
+                           SilcUInt32 *software_version, 
+                           char **software_version_string,
+                           char **vendor_version)
+{
+  return silc_parse_version_string(ske->remote_version,
+                                  protocol_version, 
+                                  protocol_version_string, 
+                                  software_version,
+                                  software_version_string,
+                                  vendor_version);
+}