updates.
[silc.git] / lib / silcclient / protocol.c
index a408802684560e4685614280028bee2eafd8bbee..a21ea9c45975a53b436e88bbe7174bfe854521fa 100644 (file)
@@ -27,6 +27,7 @@
 
 SILC_TASK_CALLBACK(silc_client_protocol_connection_auth);
 SILC_TASK_CALLBACK(silc_client_protocol_key_exchange);
+SILC_TASK_CALLBACK(silc_client_protocol_rekey);
 
 extern char *silc_version_string;
 
@@ -49,18 +50,16 @@ void silc_client_protocol_ke_send_packet(SilcSKE ske,
   /* Send the packet immediately */
   silc_client_packet_send(client, ske->sock, type, NULL, 0, NULL, NULL,
                          packet->data, packet->len, TRUE);
-
 }
 
 /* Callback that is called when we have received KE2 payload from
    responder. We try to verify the public key now. */
 
-static SilcSKEStatus 
-silc_client_protocol_ke_verify_key(SilcSKE ske,
-                                  unsigned char *pk_data,
-                                  unsigned int pk_len,
-                                  SilcSKEPKType pk_type,
-                                  void *context)
+SilcSKEStatus silc_client_protocol_ke_verify_key(SilcSKE ske,
+                                                unsigned char *pk_data,
+                                                uint32 pk_len,
+                                                SilcSKEPKType pk_type,
+                                                void *context)
 {
   SilcProtocol protocol = (SilcProtocol)context;
   SilcClientKEInternalContext *ctx = 
@@ -69,8 +68,9 @@ silc_client_protocol_ke_verify_key(SilcSKE ske,
 
   SILC_LOG_DEBUG(("Start"));
 
-  /* Verify server key from user. */
-  if (!client->ops->verify_server_key(client, ctx->sock->user_data, 
+  /* Verify public key from user. */
+  if (!client->ops->verify_public_key(client, ctx->sock->user_data, 
+                                     ctx->sock->type,
                                      pk_data, pk_len, pk_type))
     return SILC_SKE_STATUS_UNSUPPORTED_PUBLIC_KEY;
 
@@ -85,7 +85,8 @@ void silc_client_protocol_ke_set_keys(SilcSKE ske,
                                      SilcCipher cipher,
                                      SilcPKCS pkcs,
                                      SilcHash hash,
-                                     SilcHmac hmac)
+                                     SilcHmac hmac,
+                                     SilcSKEDiffieHellmanGroup group)
 {
   SilcClientConnection conn = (SilcClientConnection)sock->user_data;
 
@@ -114,15 +115,30 @@ void silc_client_protocol_ke_set_keys(SilcSKE ske,
                           ske->ke2_payload->pk_len);
 #endif
 
+  conn->rekey = silc_calloc(1, sizeof(*conn->rekey));
+  conn->rekey->send_enc_key = 
+    silc_calloc(keymat->enc_key_len / 8,
+               sizeof(*conn->rekey->send_enc_key));
+  memcpy(conn->rekey->send_enc_key, 
+        keymat->send_enc_key, keymat->enc_key_len / 8);
+  conn->rekey->enc_key_len = keymat->enc_key_len / 8;
+
+  if (ske->start_payload->flags & SILC_SKE_SP_FLAG_PFS)
+    conn->rekey->pfs = TRUE;
+  conn->rekey->ske_group = silc_ske_group_get_number(group);
+
   /* Save HMAC key to be used in the communication. */
   silc_hmac_alloc(hmac->hmac->name, NULL, &conn->hmac);
   silc_hmac_set_key(conn->hmac, keymat->hmac_key, keymat->hmac_key_len);
+
+  /* Save the HASH function */
+  silc_hash_alloc(hash->hash->name, &conn->hash);
 }
 
 /* Checks the version string of the server. */
 
 SilcSKEStatus silc_ske_check_version(SilcSKE ske, unsigned char *version,
-                                    unsigned int len)
+                                    uint32 len)
 {
   SilcClientConnection conn = (SilcClientConnection)ske->sock->user_data;
   SilcClient client = (SilcClient)ske->user_data;
@@ -183,7 +199,8 @@ SILC_TASK_CALLBACK(silc_client_protocol_key_exchange)
           properties packet from initiator. */
        status = silc_ske_responder_start(ske, ctx->rng, ctx->sock,
                                          silc_version_string,
-                                         ctx->packet->buffer, NULL, NULL);
+                                         ctx->packet->buffer, TRUE,
+                                         NULL, NULL);
       } else {
        SilcSKEStartPayload *start_payload;
 
@@ -265,16 +282,16 @@ SILC_TASK_CALLBACK(silc_client_protocol_key_exchange)
           the initiator. This also creates our parts of the Diffie
           Hellman algorithm. */
        status = silc_ske_responder_phase_2(ctx->ske, ctx->packet->buffer, 
-                                           NULL, NULL);
+                                           ctx->verify, context, NULL, NULL);
       } else {
        /* Call the Phase-2 function. This creates Diffie Hellman
           key exchange parameters and sends our public part inside
           Key Exhange 1 Payload to the responder. */
-       status = 
-         silc_ske_initiator_phase_2(ctx->ske,
-                                    client->public_key,
-                                    ctx->send_packet,
-                                    context);
+       status = silc_ske_initiator_phase_2(ctx->ske,
+                                           client->public_key,
+                                           client->private_key,
+                                           ctx->send_packet,
+                                           context);
       }
 
       if (status != SILC_SKE_STATUS_OK) {
@@ -313,8 +330,7 @@ SILC_TASK_CALLBACK(silc_client_protocol_key_exchange)
        /* Finish the protocol. This verifies the Key Exchange 2 payload
           sent by responder. */
        status = silc_ske_initiator_finish(ctx->ske, ctx->packet->buffer,
-                                          silc_client_protocol_ke_verify_key,
-                                          context, NULL, NULL);
+                                          ctx->verify, context, NULL, NULL);
       }
 
       if (status != SILC_SKE_STATUS_OK) {
@@ -425,6 +441,53 @@ SILC_TASK_CALLBACK(silc_client_protocol_key_exchange)
  * Connection Authentication protocol functions
  */
 
+static int
+silc_client_get_public_key_auth(SilcClient client,
+                               char *filepath,
+                               unsigned char *auth_data,
+                               uint32 *auth_data_len,
+                               SilcSKE ske)
+{
+  int len;
+  SilcPKCS pkcs;
+  SilcBuffer auth;
+  SilcPublicKey pub_key;
+
+  if (!silc_pkcs_load_public_key(filepath,&pub_key, SILC_PKCS_FILE_PEM))
+    if (!silc_pkcs_load_public_key(filepath, &pub_key, SILC_PKCS_FILE_BIN))
+      return FALSE;
+
+  silc_pkcs_alloc(pub_key->name, &pkcs);
+  if (!silc_pkcs_public_key_set(pkcs, pub_key)) {
+    silc_pkcs_free(pkcs);
+    silc_pkcs_public_key_free(pub_key);
+    return FALSE;
+  }
+
+  /* Make the authentication data. Protocol says it is HASH plus
+     KE Start Payload. */
+  len = ske->hash_len + ske->start_payload_copy->len;
+  auth = silc_buffer_alloc(len);
+  silc_buffer_pull_tail(auth, len);
+  silc_buffer_format(auth,
+                    SILC_STR_UI_XNSTRING(ske->hash, ske->hash_len),
+                    SILC_STR_UI_XNSTRING(ske->start_payload_copy->data,
+                                         ske->start_payload_copy->len),
+                    SILC_STR_END);
+
+  if (silc_pkcs_sign(pkcs, auth->data, auth->len, auth_data, auth_data_len)) {
+    silc_pkcs_free(pkcs);
+    silc_buffer_free(auth);
+    silc_pkcs_public_key_free(pub_key);
+    return TRUE;
+  }
+
+  silc_pkcs_free(pkcs);
+  silc_buffer_free(auth);
+  silc_pkcs_public_key_free(pub_key);
+  return FALSE;
+}
+
 SILC_TASK_CALLBACK(silc_client_protocol_connection_auth)
 {
   SilcProtocol protocol = (SilcProtocol)context;
@@ -448,7 +511,7 @@ SILC_TASK_CALLBACK(silc_client_protocol_connection_auth)
       SilcBuffer packet;
       int payload_len = 0;
       unsigned char *auth_data = NULL;
-      unsigned int auth_data_len = 0;
+      uint32 auth_data_len = 0;
 
       switch(ctx->auth_meth) {
       case SILC_AUTH_NONE:
@@ -471,8 +534,17 @@ SILC_TASK_CALLBACK(silc_client_protocol_connection_auth)
        break;
 
       case SILC_AUTH_PUBLIC_KEY:
-       /* XXX */
-       break;
+       {
+         unsigned char sign[1024];
+
+         /* Public key authentication */
+         silc_client_get_public_key_auth(client, ctx->auth_data,
+                                         sign, &auth_data_len, 
+                                         ctx->ske);
+         auth_data = silc_calloc(auth_data_len, sizeof(*auth_data));
+         memcpy(auth_data, sign, auth_data_len);
+         break;
+       }
       }
 
       payload_len = 4 + auth_data_len;
@@ -553,6 +625,381 @@ SILC_TASK_CALLBACK(silc_client_protocol_connection_auth)
   }
 }
 
+/*
+ * Re-key protocol routines
+ */
+
+/* Actually takes the new keys into use. */
+
+static void 
+silc_client_protocol_rekey_validate(SilcClient client,
+                                   SilcClientRekeyInternalContext *ctx,
+                                   SilcSocketConnection sock,
+                                   SilcSKEKeyMaterial *keymat)
+{
+  SilcClientConnection conn = (SilcClientConnection)sock->user_data;
+
+  if (ctx->responder == TRUE) {
+    silc_cipher_set_key(conn->send_key, keymat->receive_enc_key, 
+                       keymat->enc_key_len);
+    silc_cipher_set_iv(conn->send_key, keymat->receive_iv);
+    silc_cipher_set_key(conn->receive_key, keymat->send_enc_key, 
+                       keymat->enc_key_len);
+    silc_cipher_set_iv(conn->receive_key, keymat->send_iv);
+  } else {
+    silc_cipher_set_key(conn->send_key, keymat->send_enc_key, 
+                       keymat->enc_key_len);
+    silc_cipher_set_iv(conn->send_key, keymat->send_iv);
+    silc_cipher_set_key(conn->receive_key, keymat->receive_enc_key, 
+                       keymat->enc_key_len);
+    silc_cipher_set_iv(conn->receive_key, keymat->receive_iv);
+  }
+
+  silc_hmac_set_key(conn->hmac, keymat->hmac_key, keymat->hmac_key_len);
+
+  /* Save the current sending encryption key */
+  memset(conn->rekey->send_enc_key, 0, conn->rekey->enc_key_len);
+  silc_free(conn->rekey->send_enc_key);
+  conn->rekey->send_enc_key = 
+    silc_calloc(keymat->enc_key_len / 8,
+               sizeof(*conn->rekey->send_enc_key));
+  memcpy(conn->rekey->send_enc_key, keymat->send_enc_key, 
+        keymat->enc_key_len / 8);
+  conn->rekey->enc_key_len = keymat->enc_key_len / 8;
+}
+
+/* This function actually re-generates (when not using PFS) the keys and
+   takes them into use. */
+
+void silc_client_protocol_rekey_generate(SilcClient client,
+                                        SilcClientRekeyInternalContext *ctx)
+{
+  SilcClientConnection conn = (SilcClientConnection)ctx->sock->user_data;
+  SilcSKEKeyMaterial *keymat;
+  uint32 key_len = silc_cipher_get_key_len(conn->send_key);
+  uint32 hash_len = conn->hash->hash->hash_len;
+
+  SILC_LOG_DEBUG(("Generating new session keys (no PFS)"));
+
+  /* Generate the new key */
+  keymat = silc_calloc(1, sizeof(*keymat));
+  silc_ske_process_key_material_data(conn->rekey->send_enc_key,
+                                    conn->rekey->enc_key_len,
+                                    16, key_len, hash_len, 
+                                    conn->hash, keymat);
+
+  /* Set the keys into use */
+  silc_client_protocol_rekey_validate(client, ctx, ctx->sock, keymat);
+
+  silc_ske_free_key_material(keymat);
+}
+
+/* This function actually re-generates (with PFS) the keys and
+   takes them into use. */
+
+void 
+silc_client_protocol_rekey_generate_pfs(SilcClient client,
+                                       SilcClientRekeyInternalContext *ctx)
+{
+  SilcClientConnection conn = (SilcClientConnection)ctx->sock->user_data;
+  SilcSKEKeyMaterial *keymat;
+  uint32 key_len = silc_cipher_get_key_len(conn->send_key);
+  uint32 hash_len = conn->hash->hash->hash_len;
+  unsigned char *tmpbuf;
+  uint32 klen;
+
+  SILC_LOG_DEBUG(("Generating new session keys (with PFS)"));
+
+  /* Encode KEY to binary data */
+  tmpbuf = silc_mp_mp2bin(ctx->ske->KEY, 0, &klen);
+
+  /* Generate the new key */
+  keymat = silc_calloc(1, sizeof(*keymat));
+  silc_ske_process_key_material_data(tmpbuf, klen, 16, key_len, hash_len, 
+                                    conn->hash, keymat);
+
+  /* Set the keys into use */
+  silc_client_protocol_rekey_validate(client, ctx, ctx->sock, keymat);
+
+  memset(tmpbuf, 0, klen);
+  silc_free(tmpbuf);
+  silc_ske_free_key_material(keymat);
+}
+
+/* Packet sending callback. This function is provided as packet sending
+   routine to the Key Exchange functions. */
+
+static void 
+silc_client_protocol_rekey_send_packet(SilcSKE ske,
+                                      SilcBuffer packet,
+                                      SilcPacketType type,
+                                      void *context)
+{
+  SilcProtocol protocol = (SilcProtocol)context;
+  SilcClientRekeyInternalContext *ctx = 
+    (SilcClientRekeyInternalContext *)protocol->context;
+  SilcClient client = (SilcClient)ctx->client;
+
+  /* Send the packet immediately */
+  silc_client_packet_send(client, ctx->sock, type, NULL, 0, NULL, NULL,
+                         packet->data, packet->len, TRUE);
+}
+
+/* Performs re-key as defined in the SILC protocol specification. */
+
+SILC_TASK_CALLBACK(silc_client_protocol_rekey)
+{
+  SilcProtocol protocol = (SilcProtocol)context;
+  SilcClientRekeyInternalContext *ctx = 
+    (SilcClientRekeyInternalContext *)protocol->context;
+  SilcClient client = (SilcClient)ctx->client;
+  SilcClientConnection conn = (SilcClientConnection)ctx->sock->user_data;
+  SilcSKEStatus status;
+
+  SILC_LOG_DEBUG(("Start"));
+
+  if (protocol->state == SILC_PROTOCOL_STATE_UNKNOWN)
+    protocol->state = SILC_PROTOCOL_STATE_START;
+
+  SILC_LOG_DEBUG(("State=%d", protocol->state));
+
+  switch(protocol->state) {
+  case SILC_PROTOCOL_STATE_START:
+    {
+      /* 
+       * Start protocol.
+       */
+
+      if (ctx->responder == TRUE) {
+       /*
+        * We are receiving party
+        */
+
+       if (ctx->pfs == TRUE) {
+         /* 
+          * Use Perfect Forward Secrecy, ie. negotiate the key material
+          * using the SKE protocol.
+          */
+
+         if (ctx->packet->type != SILC_PACKET_KEY_EXCHANGE_1) {
+           /* Error in protocol */
+           protocol->state = SILC_PROTOCOL_STATE_ERROR;
+           protocol->execute(client->timeout_queue, 0, protocol, fd, 
+                             0, 300000);
+         }
+
+         ctx->ske = silc_ske_alloc();
+         ctx->ske->rng = client->rng;
+         ctx->ske->prop = silc_calloc(1, sizeof(*ctx->ske->prop));
+         silc_ske_get_group_by_number(conn->rekey->ske_group,
+                                      &ctx->ske->prop->group);
+
+         status = silc_ske_responder_phase_2(ctx->ske, ctx->packet->buffer,
+                                             NULL, NULL, NULL, NULL);
+         if (status != SILC_SKE_STATUS_OK) {
+           SILC_LOG_WARNING(("Error (type %d) during Re-key (PFS)",
+                             status));
+           
+           protocol->state = SILC_PROTOCOL_STATE_ERROR;
+           protocol->execute(client->timeout_queue, 0, 
+                             protocol, fd, 0, 300000);
+           return;
+         }
+
+         /* Advance the protocol state */
+         protocol->state++;
+         protocol->execute(client->timeout_queue, 0, protocol, fd, 0, 0);
+       } else {
+         /*
+          * Do normal and simple re-key.
+          */
+
+         /* Send the REKEY_DONE to indicate we will take new keys into use */
+         silc_client_packet_send(client, ctx->sock, 
+                                 SILC_PACKET_REKEY_DONE, 
+                                 NULL, 0, NULL, NULL, NULL, 0, TRUE);
+
+         /* The protocol ends in next stage. */
+         protocol->state = SILC_PROTOCOL_STATE_END;
+       }
+      
+      } else {
+       /*
+        * We are the initiator of this protocol
+        */
+
+       /* Start the re-key by sending the REKEY packet */
+       silc_client_packet_send(client, ctx->sock, SILC_PACKET_REKEY, 
+                               NULL, 0, NULL, NULL, NULL, 0, TRUE);
+
+       if (ctx->pfs == TRUE) {
+         /* 
+          * Use Perfect Forward Secrecy, ie. negotiate the key material
+          * using the SKE protocol.
+          */
+         ctx->ske = silc_ske_alloc();
+         ctx->ske->rng = client->rng;
+         ctx->ske->prop = silc_calloc(1, sizeof(*ctx->ske->prop));
+         silc_ske_get_group_by_number(conn->rekey->ske_group,
+                                      &ctx->ske->prop->group);
+
+         status = 
+           silc_ske_initiator_phase_2(ctx->ske, NULL, NULL,
+                                      silc_client_protocol_rekey_send_packet,
+                                      context);
+
+         if (status != SILC_SKE_STATUS_OK) {
+           SILC_LOG_WARNING(("Error (type %d) during Re-key (PFS)",
+                             status));
+           
+           protocol->state = SILC_PROTOCOL_STATE_ERROR;
+           protocol->execute(client->timeout_queue, 0, 
+                             protocol, fd, 0, 300000);
+           return;
+         }
+
+         /* Advance the protocol state */
+         protocol->state++;
+       } else {
+         /*
+          * Do normal and simple re-key.
+          */
+
+         /* The protocol ends in next stage. We have sent the REKEY packet
+            and now we just wait that the responder send REKEY_DONE and
+            the we'll generate the new key, simple. */
+         protocol->state = SILC_PROTOCOL_STATE_END;
+       }
+      }
+    }
+    break;
+
+  case 2:
+    /*
+     * Second state, used only when oding re-key with PFS.
+     */
+    if (ctx->responder == TRUE) {
+      if (ctx->pfs == TRUE) {
+       /*
+        * Send our KE packe to the initiator now that we've processed
+        * the initiator's KE packet.
+        */
+       status = 
+         silc_ske_responder_finish(ctx->ske, NULL, NULL, 
+                                   SILC_SKE_PK_TYPE_SILC,
+                                   silc_client_protocol_rekey_send_packet,
+                                   context);
+
+         if (status != SILC_SKE_STATUS_OK) {
+           SILC_LOG_WARNING(("Error (type %d) during Re-key (PFS)",
+                             status));
+           
+           protocol->state = SILC_PROTOCOL_STATE_ERROR;
+           protocol->execute(client->timeout_queue, 0, 
+                             protocol, fd, 0, 300000);
+           return;
+         }
+      }
+
+    } else {
+      if (ctx->pfs == TRUE) {
+       /*
+        * The packet type must be KE packet
+        */
+       if (ctx->packet->type != SILC_PACKET_KEY_EXCHANGE_2) {
+         /* Error in protocol */
+         protocol->state = SILC_PROTOCOL_STATE_ERROR;
+         protocol->execute(client->timeout_queue, 0, protocol, fd, 0, 300000);
+       }
+       
+       status = silc_ske_initiator_finish(ctx->ske, ctx->packet->buffer,
+                                          NULL, NULL, NULL, NULL);
+       if (status != SILC_SKE_STATUS_OK) {
+         SILC_LOG_WARNING(("Error (type %d) during Re-key (PFS)",
+                           status));
+         
+         protocol->state = SILC_PROTOCOL_STATE_ERROR;
+         protocol->execute(client->timeout_queue, 0, 
+                           protocol, fd, 0, 300000);
+         return;
+       }
+      }
+    }
+
+    /* Send the REKEY_DONE to indicate we will take new keys into use 
+       now. */ 
+    silc_client_packet_send(client, ctx->sock, SILC_PACKET_REKEY_DONE, 
+                           NULL, 0, NULL, NULL, NULL, 0, TRUE);
+    
+    /* The protocol ends in next stage. */
+    protocol->state = SILC_PROTOCOL_STATE_END;
+    break;
+
+  case SILC_PROTOCOL_STATE_END:
+    /* 
+     * End protocol
+     */
+
+    if (ctx->packet->type != SILC_PACKET_REKEY_DONE) {
+      /* Error in protocol */
+      protocol->state = SILC_PROTOCOL_STATE_ERROR;
+      protocol->execute(client->timeout_queue, 0, protocol, fd, 0, 0);
+    }
+
+    if (ctx->responder == FALSE) {
+      if (ctx->pfs == FALSE) {
+       /* Send the REKEY_DONE to indicate we will take new keys into use 
+          now. */ 
+       silc_client_packet_send(client, ctx->sock, 
+                               SILC_PACKET_REKEY_DONE, 
+                               NULL, 0, NULL, NULL, NULL, 0, TRUE);
+      }
+    }
+
+    /* Protocol has ended, call the final callback */
+    if (protocol->final_callback)
+      protocol->execute_final(client->timeout_queue, 0, protocol, fd);
+    else
+      silc_protocol_free(protocol);
+    break;
+
+  case SILC_PROTOCOL_STATE_ERROR:
+    /*
+     * Error occured
+     */
+
+    if (ctx->pfs == TRUE) {
+      /* Send abort notification */
+      silc_ske_abort(ctx->ske, ctx->ske->status, 
+                    silc_client_protocol_ke_send_packet,
+                    context);
+    }
+
+    /* On error the final callback is always called. */
+    if (protocol->final_callback)
+      protocol->execute_final(client->timeout_queue, 0, protocol, fd);
+    else
+      silc_protocol_free(protocol);
+    break;
+
+  case SILC_PROTOCOL_STATE_FAILURE:
+    /*
+     * We have received failure from remote
+     */
+
+    /* On error the final callback is always called. */
+    if (protocol->final_callback)
+      protocol->execute_final(client->timeout_queue, 0, protocol, fd);
+    else
+      silc_protocol_free(protocol);
+    break;
+
+  case SILC_PROTOCOL_STATE_UNKNOWN:
+    break;
+  }
+
+}
+
 /* Registers protocols used in client */
 
 void silc_client_protocols_register(void)
@@ -561,6 +1008,8 @@ void silc_client_protocols_register(void)
                         silc_client_protocol_connection_auth);
   silc_protocol_register(SILC_PROTOCOL_CLIENT_KEY_EXCHANGE,
                         silc_client_protocol_key_exchange);
+  silc_protocol_register(SILC_PROTOCOL_CLIENT_REKEY,
+                        silc_client_protocol_rekey);
 }
 
 /* Unregisters protocols */
@@ -571,4 +1020,6 @@ void silc_client_protocols_unregister(void)
                           silc_client_protocol_connection_auth);
   silc_protocol_unregister(SILC_PROTOCOL_CLIENT_KEY_EXCHANGE,
                           silc_client_protocol_key_exchange);
+  silc_protocol_unregister(SILC_PROTOCOL_CLIENT_REKEY,
+                          silc_client_protocol_rekey);
 }