+++ /dev/null
-/*
-
- client_keyagr.c
-
- Author: Pekka Riikonen <priikone@silcnet.org>
-
- Copyright (C) 2001 - 2007 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; 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
- GNU General Public License for more details.
-
-*/
-
-#include "silc.h"
-#include "silcclient.h"
-#include "client_internal.h"
-
-/************************** Types and definitions ***************************/
-
-/* Key agreement context, used by responder */
-struct SilcClientKeyAgreementStruct {
- SilcClient client; /* Client */
- SilcClientConnection conn; /* Server connection */
- SilcClientListener listener; /* Listener */
- SilcKeyAgreementCallback completion; /* Key agreement completion */
- void *context; /* User context */
- SilcAsyncOperation op; /* Async operation, initiator */
-};
-
-/************************ Static utility functions **************************/
-
-/* Destroyes key agreement session */
-
-static void silc_client_keyagr_free(SilcClient client,
- SilcClientConnection conn,
- SilcClientEntry client_entry)
-{
- SilcClientKeyAgreement ke = client_entry->internal.ke;
-
- silc_client_listener_free(ke->listener);
- silc_schedule_task_del_by_context(conn->internal->schedule, client_entry);
- if (ke->op)
- silc_async_abort(ke->op, NULL, NULL);
- client_entry->internal.ke = NULL;
- client_entry->internal.prv_resp = FALSE;
- silc_client_unref_client(client, conn, client_entry);
- silc_free(ke);
-}
-
-/* Key agreement timeout callback */
-
-SILC_TASK_CALLBACK(silc_client_keyagr_timeout)
-{
- SilcClientEntry client_entry = context;
- SilcClientKeyAgreement ke = client_entry->internal.ke;
-
- if (!ke)
- return;
-
- SILC_LOG_DEBUG(("Key agreement %p timeout", ke));
-
- ke->completion(ke->client, ke->conn, client_entry,
- SILC_KEY_AGREEMENT_TIMEOUT, NULL, ke->context);
-
- silc_client_keyagr_free(ke->client, ke->conn, client_entry);
-}
-
-/* Client resolving callback. Continues with the key agreement processing */
-
-static void silc_client_keyagr_resolved(SilcClient client,
- SilcClientConnection conn,
- SilcStatus status,
- SilcDList clients,
- void *context)
-{
- /* If no client found, ignore the packet, a silent error */
- if (!clients)
- silc_fsm_next(context, silc_client_key_agreement_error);
-
- /* Continue processing the packet */
- SILC_FSM_CALL_CONTINUE(context);
-}
-
-/* Key exchange completion callback. Called after connected to remote host
- and performed key exchange, when we are initiator. As responder, this is
- called after the remote has connected to us and have performed the key
- exchange. */
-
-static void silc_client_keyagr_completion(SilcClient client,
- SilcClientConnection conn,
- SilcClientConnectionStatus status,
- SilcStatus error,
- const char *message,
- void *context)
-{
- SilcClientEntry client_entry = context;
- SilcClientKeyAgreement ke = client_entry->internal.ke;
- SilcSKEKeyMaterial keymat;
-
- ke->op = NULL;
-
- switch (status) {
- case SILC_CLIENT_CONN_SUCCESS:
- SILC_LOG_DEBUG(("Key agreement %p successful", ke));
-
- keymat = silc_ske_get_key_material(conn->internal->ske);
- ke->completion(ke->client, ke->conn, client_entry, SILC_KEY_AGREEMENT_OK,
- keymat, ke->context);
- break;
-
- case SILC_CLIENT_CONN_ERROR_TIMEOUT:
- SILC_LOG_DEBUG(("Key agreement %p timeout", ke));
- ke->completion(ke->client, ke->conn, client_entry,
- SILC_KEY_AGREEMENT_TIMEOUT, NULL, ke->context);
- break;
-
- default:
- SILC_LOG_DEBUG(("Key agreement %p error %d", ke, status));
- ke->completion(ke->client, ke->conn, client_entry,
- SILC_KEY_AGREEMENT_FAILURE, NULL, ke->context);
- break;
- }
-
- /* Close the connection */
- if (conn)
- silc_client_close_connection(ke->client, conn);
-
- silc_client_keyagr_free(ke->client, ke->conn, client_entry);
-}
-
-/*************************** Key Agreement API ******************************/
-
-/* Sends key agreement packet to remote client. If IP addresses are provided
- creates also listener for íncoming key agreement connection. Supports
- both TCP and UDP transports. */
-
-void silc_client_send_key_agreement(SilcClient client,
- SilcClientConnection conn,
- SilcClientEntry client_entry,
- SilcClientConnectionParams *params,
- SilcPublicKey public_key,
- SilcPrivateKey private_key,
- SilcKeyAgreementCallback completion,
- void *context)
-{
- SilcClientKeyAgreement ke = NULL;
- SilcBuffer buffer;
- SilcUInt16 port = 0, protocol = 0;
- char *local_ip = NULL;
-
- SILC_LOG_DEBUG(("Sending key agreement"));
-
- if (!client_entry)
- return;
- if (conn->internal->disconnected)
- return;
-
- if (client_entry->internal.ke) {
- completion(client, conn, client_entry, SILC_KEY_AGREEMENT_ALREADY_STARTED,
- NULL, context);
- return;
- }
-
- if (client_entry == conn->local_entry) {
- completion(client, conn, client_entry, SILC_KEY_AGREEMENT_SELF_DENIED,
- NULL, context);
- return;
- }
-
- /* If local IP is provided, create listener. If this is not provided,
- we'll just send empty key agreement payload */
- if (params && (params->local_ip || params->bind_ip)) {
- ke = silc_calloc(1, sizeof(*ke));
- if (!ke) {
- completion(client, conn, client_entry, SILC_KEY_AGREEMENT_NO_MEMORY,
- NULL, context);
- return;
- }
-
- /* Create listener */
- ke->listener = silc_client_listener_add(client, conn->internal->schedule,
- params, public_key, private_key,
- silc_client_keyagr_completion,
- client_entry);
- if (!ke->listener) {
- completion(client, conn, client_entry, SILC_KEY_AGREEMENT_NO_MEMORY,
- NULL, context);
- return;
- }
-
- local_ip = params->local_ip;
- protocol = params->udp;
-
- ke->client = client;
- ke->conn = conn;
- ke->completion = completion;
- ke->context = context;
- silc_client_ref_client(client, conn, client_entry);
- client_entry->internal.ke = ke;
- client_entry->internal.prv_resp = TRUE;
- }
-
- /* Encode the key agreement payload */
- buffer = silc_key_agreement_payload_encode(local_ip, protocol, port);
- if (!buffer) {
- completion(client, conn, client_entry, SILC_KEY_AGREEMENT_NO_MEMORY,
- NULL, context);
- silc_client_keyagr_free(client, conn, client_entry);
- return;
- }
-
- /* Send the key agreement packet to the client */
- if (!silc_packet_send_ext(conn->stream, SILC_PACKET_KEY_AGREEMENT, 0,
- 0, NULL, SILC_ID_CLIENT, &client_entry->id,
- silc_buffer_datalen(buffer), NULL, NULL)) {
- completion(client, conn, client_entry, SILC_KEY_AGREEMENT_ERROR,
- NULL, context);
- silc_client_keyagr_free(client, conn, client_entry);
- silc_buffer_free(buffer);
- return;
- }
-
- /* Add key agreement timeout task */
- if (params && params->timeout_secs)
- silc_schedule_task_add_timeout(conn->internal->schedule,
- silc_client_keyagr_timeout,
- client_entry, params->timeout_secs, 0);
-
- silc_buffer_free(buffer);
-}
-
-/* Perform key agreement protocol as initiator. Conneects to remote host. */
-
-void silc_client_perform_key_agreement(SilcClient client,
- SilcClientConnection conn,
- SilcClientEntry client_entry,
- SilcClientConnectionParams *params,
- SilcPublicKey public_key,
- SilcPrivateKey private_key,
- char *hostname, int port,
- SilcKeyAgreementCallback completion,
- void *context)
-{
- SilcClientKeyAgreement ke;
-
- SILC_LOG_DEBUG(("Performing key agreement"));
-
- if (!client_entry || !hostname || !port) {
- completion(client, conn, client_entry, SILC_KEY_AGREEMENT_ERROR,
- NULL, context);
- return;
- }
-
- if (client_entry == conn->local_entry) {
- completion(client, conn, client_entry, SILC_KEY_AGREEMENT_SELF_DENIED,
- NULL, context);
- return;
- }
-
- ke = silc_calloc(1, sizeof(*ke));
- if (!ke) {
- completion(client, conn, client_entry, SILC_KEY_AGREEMENT_NO_MEMORY,
- NULL, context);
- return;
- }
- ke->client = client;
- ke->conn = conn;
- ke->completion = completion;
- ke->context = context;
- silc_client_ref_client(client, conn, client_entry);
- client_entry->internal.ke = ke;
-
- if (params)
- params->no_authentication = TRUE;
-
- /* Connect to the remote client. Performs key exchange automatically. */
- ke->op = silc_client_connect_to_client(client, params, public_key,
- private_key, hostname, port,
- silc_client_keyagr_completion,
- client_entry);
- if (!ke->op) {
- completion(client, conn, client_entry, SILC_KEY_AGREEMENT_ERROR,
- NULL, context);
- silc_client_keyagr_free(client, conn, client_entry);
- return;
- }
-}
-
-/* Same as above but caller has created connection. */
-
-void
-silc_client_perform_key_agreement_stream(SilcClient client,
- SilcClientConnection conn,
- SilcClientEntry client_entry,
- SilcClientConnectionParams *params,
- SilcPublicKey public_key,
- SilcPrivateKey private_key,
- SilcStream stream,
- SilcKeyAgreementCallback completion,
- void *context)
-{
- SilcClientKeyAgreement ke;
-
- SILC_LOG_DEBUG(("Performing key agreement"));
-
- if (!client_entry || !stream) {
- completion(client, conn, client_entry, SILC_KEY_AGREEMENT_ERROR,
- NULL, context);
- return;
- }
-
- if (client_entry == conn->local_entry) {
- completion(client, conn, client_entry, SILC_KEY_AGREEMENT_SELF_DENIED,
- NULL, context);
- return;
- }
-
- ke = silc_calloc(1, sizeof(*ke));
- if (!ke) {
- completion(client, conn, client_entry, SILC_KEY_AGREEMENT_NO_MEMORY,
- NULL, context);
- return;
- }
- ke->client = client;
- ke->conn = conn;
- ke->completion = completion;
- ke->context = context;
- silc_client_ref_client(client, conn, client_entry);
- client_entry->internal.ke = ke;
-
- if (params)
- params->no_authentication = TRUE;
-
- /* Perform key exchange protocol */
- ke->op = silc_client_key_exchange(client, params, public_key,
- private_key, stream, SILC_CONN_CLIENT,
- silc_client_keyagr_completion,
- client_entry);
- if (!ke->op) {
- completion(client, conn, client_entry, SILC_KEY_AGREEMENT_ERROR,
- NULL, context);
- silc_client_keyagr_free(client, conn, client_entry);
- return;
- }
-}
-
-/* This function can be called to unbind the hostname and the port for
- the key agreement protocol. However, this function has effect only
- before the key agreement protocol has been performed. After it has
- been performed the library will automatically unbind the port. The
- `client_entry' is the client to which we sent the key agreement
- request. */
-
-void silc_client_abort_key_agreement(SilcClient client,
- SilcClientConnection conn,
- SilcClientEntry client_entry)
-{
- SilcClientKeyAgreement ke;
-
- if (!client_entry || !client_entry->internal.ke)
- return;
-
- ke = client_entry->internal.ke;
-
- SILC_LOG_DEBUG(("Abort key agreement %p"));
-
- ke->completion(client, conn, client_entry,
- SILC_KEY_AGREEMENT_ABORTED, NULL, ke->context);
-
- silc_client_keyagr_free(client, conn, client_entry);
-}
-
-/* Key agreement packet received */
-
-SILC_FSM_STATE(silc_client_key_agreement)
-{
- SilcClientConnection conn = fsm_context;
- SilcClient client = conn->client;
- SilcPacket packet = state_context;
- SilcClientID remote_id;
- SilcClientEntry remote_client;
- SilcKeyAgreementPayload payload;
-
- if (packet->src_id_type != SILC_ID_CLIENT) {
- /** Invalid packet */
- silc_fsm_next(fsm, silc_client_key_agreement_error);
- return SILC_FSM_CONTINUE;
- }
-
- if (!silc_id_str2id(packet->src_id, packet->src_id_len, SILC_ID_CLIENT,
- &remote_id, sizeof(remote_id))) {
- /** Invalid source ID */
- silc_fsm_next(fsm, silc_client_key_agreement_error);
- return SILC_FSM_CONTINUE;
- }
-
- /* Check whether we know this client already */
- remote_client = silc_client_get_client_by_id(client, conn, &remote_id);
- if (!remote_client || !remote_client->internal.valid) {
- /** Resolve client info */
- silc_client_unref_client(client, conn, remote_client);
- SILC_FSM_CALL(silc_client_get_client_by_id_resolve(
- client, conn, &remote_id, NULL,
- silc_client_keyagr_resolved, fsm));
- /* NOT REACHED */
- }
-
- /* Parse the key agreement payload */
- payload = silc_key_agreement_payload_parse(silc_buffer_data(&packet->buffer),
- silc_buffer_len(&packet->buffer));
- if (!payload) {
- /** Malformed Payload */
- SILC_LOG_DEBUG(("Malformed key agreement payload"));
- silc_fsm_next(fsm, silc_client_key_agreement_error);
- return SILC_FSM_CONTINUE;
- }
-
- /* If remote did not provide connection endpoint, we will assume that we
- will provide it and will be responder. */
- if (!silc_key_agreement_get_hostname(payload))
- remote_client->internal.prv_resp = TRUE;
- else
- remote_client->internal.prv_resp = FALSE;
-
- /* Notify application for key agreement request */
- client->internal->ops->key_agreement(
- client, conn, remote_client,
- silc_key_agreement_get_hostname(payload),
- silc_key_agreement_get_protocol(payload),
- silc_key_agreement_get_port(payload));
-
- silc_key_agreement_payload_free(payload);
-
- silc_packet_free(packet);
- return SILC_FSM_FINISH;
-}
-
-/* Key agreement packet processing error */
-
-SILC_FSM_STATE(silc_client_key_agreement_error)
-{
- SilcPacket packet = state_context;
- silc_packet_free(packet);
- return SILC_FSM_FINISH;
-}
projects / crypto.git / blobdiff