+++ /dev/null
-/*
-
- protocol.c
-
- Author: Pekka Riikonen <priikone@silcnet.org>
-
- Copyright (C) 1997 - 2004, 2006 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.
-
-*/
-/* $Id$ */
-
-#include "silc.h"
-#include "silcclient.h"
-#include "client_internal.h"
-
-SILC_TASK_CALLBACK(silc_client_protocol_connection_auth);
-SILC_TASK_CALLBACK(silc_client_protocol_key_exchange);
-SILC_TASK_CALLBACK(silc_client_protocol_rekey);
-
-/*
- * Key Exhange protocol functions
- */
-
-/* Function that is called when SKE protocol sends packets to network. */
-
-void silc_client_protocol_ke_send_packet(SilcSKE ske,
- SilcBuffer packet,
- SilcPacketType type,
- void *context)
-{
- SilcProtocol protocol = (SilcProtocol)context;
- SilcClientKEInternalContext *ctx =
- (SilcClientKEInternalContext *)protocol->context;
- SilcClient client = (SilcClient)ctx->client;
-
- /* Send the packet immediately */
- silc_client_packet_send(client, ske->sock, type, NULL, 0, NULL, NULL,
- packet->data, packet->len, TRUE);
-}
-
-/* Public key verification callback. Called by the application. */
-
-typedef struct {
- SilcSKE ske;
- SilcSKEVerifyCbCompletion completion;
- void *completion_context;
-} *VerifyKeyContext;
-
-static void silc_client_verify_key_cb(SilcBool success, void *context)
-{
- VerifyKeyContext verify = (VerifyKeyContext)context;
-
- SILC_LOG_DEBUG(("Start"));
-
- /* Call the completion callback back to the SKE */
- verify->completion(verify->ske, success ? SILC_SKE_STATUS_OK :
- SILC_SKE_STATUS_UNSUPPORTED_PUBLIC_KEY,
- verify->completion_context);
-
- silc_free(verify);
-}
-
-/* Callback that is called when we have received KE payload from
- responder. We try to verify the public key now. */
-
-void silc_client_protocol_ke_verify_key(SilcSKE ske,
- unsigned char *pk_data,
- SilcUInt32 pk_len,
- SilcSKEPKType pk_type,
- void *context,
- SilcSKEVerifyCbCompletion completion,
- void *completion_context)
-{
- SilcProtocol protocol = (SilcProtocol)context;
- SilcClientKEInternalContext *ctx =
- (SilcClientKEInternalContext *)protocol->context;
- SilcClient client = (SilcClient)ctx->client;
- VerifyKeyContext verify;
-
- SILC_LOG_DEBUG(("Start"));
-
- verify = silc_calloc(1, sizeof(*verify));
- verify->ske = ske;
- verify->completion = completion;
- verify->completion_context = completion_context;
-
- /* Verify public key from user. */
- client->internal->ops->verify_public_key(client, ctx->sock->user_data,
- ctx->sock->type,
- pk_data, pk_len, pk_type,
- silc_client_verify_key_cb, verify);
-}
-
-/* Sets the negotiated key material into use for particular connection. */
-
-void silc_client_protocol_ke_set_keys(SilcSKE ske,
- SilcSocketConnection sock,
- SilcSKEKeyMaterial *keymat,
- SilcCipher cipher,
- SilcPKCS pkcs,
- SilcHash hash,
- SilcHmac hmac,
- SilcSKEDiffieHellmanGroup group,
- SilcBool is_responder)
-{
- SilcClientConnection conn = (SilcClientConnection)sock->user_data;
- const char *cname = silc_cipher_get_name(cipher);
-
- SILC_LOG_DEBUG(("Setting new keys into use"));
-
- /* Allocate cipher to be used in the communication */
- silc_cipher_alloc((char *)cname, &conn->internal->send_key);
- silc_cipher_alloc((char *)cname, &conn->internal->receive_key);
- silc_hmac_alloc((char *)silc_hmac_get_name(hmac), NULL,
- &conn->internal->hmac_send);
- silc_hmac_alloc((char *)silc_hmac_get_name(hmac), NULL,
- &conn->internal->hmac_receive);
-
- if (is_responder == TRUE) {
- silc_cipher_set_key(conn->internal->send_key, keymat->receive_enc_key,
- keymat->enc_key_len);
- silc_cipher_set_iv(conn->internal->send_key, keymat->receive_iv);
- silc_cipher_set_key(conn->internal->receive_key, keymat->send_enc_key,
- keymat->enc_key_len);
- silc_cipher_set_iv(conn->internal->receive_key, keymat->send_iv);
- silc_hmac_set_key(conn->internal->hmac_send, keymat->receive_hmac_key,
- keymat->hmac_key_len);
- silc_hmac_set_key(conn->internal->hmac_receive, keymat->send_hmac_key,
- keymat->hmac_key_len);
- } else {
- silc_cipher_set_key(conn->internal->send_key, keymat->send_enc_key,
- keymat->enc_key_len);
- silc_cipher_set_iv(conn->internal->send_key, keymat->send_iv);
- silc_cipher_set_key(conn->internal->receive_key, keymat->receive_enc_key,
- keymat->enc_key_len);
- silc_cipher_set_iv(conn->internal->receive_key, keymat->receive_iv);
- silc_hmac_set_key(conn->internal->hmac_send, keymat->send_hmac_key,
- keymat->hmac_key_len);
- silc_hmac_set_key(conn->internal->hmac_receive, keymat->receive_hmac_key,
- keymat->hmac_key_len);
- }
-
- /* Rekey stuff */
- conn->internal->rekey = silc_calloc(1, sizeof(*conn->internal->rekey));
- conn->internal->rekey->send_enc_key = silc_memdup(keymat->send_enc_key,
- keymat->enc_key_len / 8);
- conn->internal->rekey->enc_key_len = keymat->enc_key_len / 8;
-
- if (ske->start_payload->flags & SILC_SKE_SP_FLAG_PFS)
- conn->internal->rekey->pfs = TRUE;
- conn->internal->rekey->ske_group = silc_ske_group_get_number(group);
-
- /* Save the HASH function */
- silc_hash_alloc(silc_hash_get_name(hash), &conn->internal->hash);
-}
-
-/* Checks the version string of the server. */
-
-SilcSKEStatus silc_ske_check_version(SilcSKE ske, unsigned char *version,
- SilcUInt32 len, void *context)
-{
- SilcClientConnection conn = (SilcClientConnection)ske->sock->user_data;
- SilcClient client = (SilcClient)ske->user_data;
- SilcUInt32 l_protocol_version = 0, r_protocol_version = 0;
-
- if (!silc_parse_version_string(version, &r_protocol_version, NULL, NULL,
- NULL, NULL)) {
- client->internal->ops->say(client, conn, SILC_CLIENT_MESSAGE_AUDIT,
- "We don't support server version `%s'",
- version);
- return SILC_SKE_STATUS_BAD_VERSION;
- }
-
- if (!silc_parse_version_string(client->internal->silc_client_version,
- &l_protocol_version, NULL, NULL,
- NULL, NULL)) {
- client->internal->ops->say(client, conn, SILC_CLIENT_MESSAGE_AUDIT,
- "We don't support server version `%s'",
- version);
- return SILC_SKE_STATUS_BAD_VERSION;
- }
-
- /* If remote is too new, don't connect */
- if (l_protocol_version < r_protocol_version) {
- client->internal->ops->say(client, conn, SILC_CLIENT_MESSAGE_AUDIT,
- "We don't support server version `%s'",
- version);
- return SILC_SKE_STATUS_BAD_VERSION;
- }
-
- ske->sock->version = r_protocol_version;
-
- return SILC_SKE_STATUS_OK;
-}
-
-/* Callback that is called by the SKE to indicate that it is safe to
- continue the execution of the protocol. Is given as argument to the
- silc_ske_initiator_finish or silc_ske_responder_phase_2 functions.
- This is called due to the fact that the public key verification
- process is asynchronous and we must not continue the protocl until
- the public key has been verified and this callback is called. */
-
-static void silc_client_protocol_ke_continue(SilcSKE ske,
- void *context)
-{
- SilcProtocol protocol = (SilcProtocol)context;
- SilcClientKEInternalContext *ctx =
- (SilcClientKEInternalContext *)protocol->context;
- SilcClient client = (SilcClient)ctx->client;
- SilcClientConnection conn = ctx->sock->user_data;
-
- SILC_LOG_DEBUG(("Start"));
-
- if (ske->status != SILC_SKE_STATUS_OK) {
- /* Call failure client operation */
- client->internal->ops->failure(client, conn, protocol,
- (void *)ske->status);
- protocol->state = SILC_PROTOCOL_STATE_ERROR;
- silc_protocol_execute(protocol, client->schedule, 0, 0);
- return;
- }
-
- /* Send Ok to the other end. We will end the protocol as server
- sends Ok to us when we will take the new keys into use. Do this
- if we are initiator. This is happens when this callback was sent
- to silc_ske_initiator_finish function. */
- if (ctx->responder == FALSE) {
- silc_ske_end(ctx->ske);
-
- /* End the protocol on the next round */
- protocol->state = SILC_PROTOCOL_STATE_END;
- }
-
- /* Advance protocol state and call the next state if we are responder.
- This happens when this callback was sent to silc_ske_responder_phase_2
- function. */
- if (ctx->responder == TRUE) {
- protocol->state++;
- silc_protocol_execute(protocol, client->schedule, 0, 1);
- }
-}
-
-/* Performs key exchange protocol. This is used for both initiator
- and responder key exchange. This may be called recursively. */
-
-SILC_TASK_CALLBACK(silc_client_protocol_key_exchange)
-{
- SilcProtocol protocol = (SilcProtocol)context;
- SilcClientKEInternalContext *ctx =
- (SilcClientKEInternalContext *)protocol->context;
- SilcClient client = (SilcClient)ctx->client;
- SilcClientConnection conn = ctx->sock->user_data;
- SilcSKEStatus status = SILC_SKE_STATUS_OK;
-
- SILC_LOG_DEBUG(("Start"));
-
- if (protocol->state == SILC_PROTOCOL_STATE_UNKNOWN)
- protocol->state = SILC_PROTOCOL_STATE_START;
-
- switch(protocol->state) {
- case SILC_PROTOCOL_STATE_START:
- {
- /*
- * Start Protocol
- */
- SilcSKE ske;
-
- /* Allocate Key Exchange object */
- ctx->ske = ske = silc_ske_alloc(client->rng, client);
-
- silc_ske_set_callbacks(ske, ctx->send_packet, NULL,
- ctx->verify,
- silc_client_protocol_ke_continue,
- silc_ske_check_version,
- context);
-
- if (ctx->responder == TRUE) {
- if (!ctx->packet) {
- SILC_LOG_WARNING(("Error (type %d) during Key Exchange protocol",
- status));
- protocol->state = SILC_PROTOCOL_STATE_ERROR;
- silc_protocol_execute(protocol, client->schedule, 0, 0);
- return;
- }
-
- /* Start the key exchange by processing the received security
- properties packet from initiator. */
- status =
- silc_ske_responder_start(ske, ctx->rng, ctx->sock,
- client->internal->silc_client_version,
- ctx->packet->buffer, TRUE);
- } else {
- SilcSKEStartPayload *start_payload;
-
- /* Assemble security properties. */
- silc_ske_assemble_security_properties(
- ske, SILC_SKE_SP_FLAG_MUTUAL,
- client->internal->silc_client_version,
- &start_payload);
-
- /* Start the key exchange by sending our security properties
- to the remote end. */
- status = silc_ske_initiator_start(ske, ctx->rng, ctx->sock,
- start_payload);
- }
-
- /* Return now if the procedure is pending */
- if (status == SILC_SKE_STATUS_PENDING)
- return;
-
- if (status != SILC_SKE_STATUS_OK) {
- SILC_LOG_WARNING(("Error (type %d) during Key Exchange protocol",
- status));
- SILC_LOG_DEBUG(("Error (type %d) during Key Exchange protocol",
- status));
-
- protocol->state = SILC_PROTOCOL_STATE_ERROR;
- silc_protocol_execute(protocol, client->schedule, 0, 0);
- return;
- }
-
- /* Advance protocol state and call the next state if we are responder */
- protocol->state++;
- if (ctx->responder == TRUE)
- silc_protocol_execute(protocol, client->schedule, 0, 1);
- }
- break;
- case 2:
- {
- /*
- * Phase 1
- */
- if (ctx->responder == TRUE) {
- /* Sends the selected security properties to the initiator. */
- status = silc_ske_responder_phase_1(ctx->ske);
- } else {
- if (!ctx->packet) {
- SILC_LOG_WARNING(("Error (type %d) during Key Exchange protocol",
- status));
- protocol->state = SILC_PROTOCOL_STATE_ERROR;
- silc_protocol_execute(protocol, client->schedule, 0, 0);
- return;
- }
-
- /* Call Phase-1 function. This processes the Key Exchange Start
- paylaod reply we just got from the responder. The callback
- function will receive the processed payload where we will
- save it. */
- status = silc_ske_initiator_phase_1(ctx->ske, ctx->packet->buffer);
- }
-
- if (status != SILC_SKE_STATUS_OK) {
- SILC_LOG_WARNING(("Error (type %d) during Key Exchange protocol",
- status));
- SILC_LOG_DEBUG(("Error (type %d) during Key Exchange protocol",
- status));
-
- protocol->state = SILC_PROTOCOL_STATE_ERROR;
- silc_protocol_execute(protocol, client->schedule, 0, 0);
- return;
- }
-
- /* Advance protocol state and call next state if we are initiator */
- protocol->state++;
- if (ctx->responder == FALSE)
- silc_protocol_execute(protocol, client->schedule, 0, 1);
- }
- break;
- case 3:
- {
- /*
- * Phase 2
- */
- if (ctx->responder == TRUE) {
- if (!ctx->packet) {
- SILC_LOG_WARNING(("Error (type %d) during Key Exchange protocol",
- status));
- protocol->state = SILC_PROTOCOL_STATE_ERROR;
- silc_protocol_execute(protocol, client->schedule, 0, 0);
- return;
- }
-
- /* Process the received Key Exchange 1 Payload packet from
- the initiator. This also creates our parts of the Diffie
- Hellman algorithm. The silc_client_protocol_ke_continue will
- be called after the public key has been verified. */
- status = silc_ske_responder_phase_2(ctx->ske, ctx->packet->buffer);
- } else {
- /* Call the Phase-2 function. This creates Diffie Hellman
- key exchange parameters and sends our public part inside
- Key Exhange 1 Payload to the responder. */
- status = silc_ske_initiator_phase_2(ctx->ske,
- client->public_key,
- client->private_key,
- SILC_SKE_PK_TYPE_SILC);
- protocol->state++;
- }
-
- /* Return now if the procedure is pending */
- if (status == SILC_SKE_STATUS_PENDING)
- return;
-
- if (status != SILC_SKE_STATUS_OK) {
- SILC_LOG_WARNING(("Error (type %d) during Key Exchange protocol",
- status));
- SILC_LOG_DEBUG(("Error (type %d) during Key Exchange protocol",
- status));
-
- protocol->state = SILC_PROTOCOL_STATE_ERROR;
- silc_protocol_execute(protocol, client->schedule, 0, 0);
- return;
- }
- }
- break;
- case 4:
- {
- /*
- * Finish protocol
- */
- if (ctx->responder == TRUE) {
- /* This creates the key exchange material and sends our
- public parts to the initiator inside Key Exchange 2 Payload. */
- status =
- silc_ske_responder_finish(ctx->ske,
- client->public_key, client->private_key,
- SILC_SKE_PK_TYPE_SILC);
-
- /* End the protocol on the next round */
- protocol->state = SILC_PROTOCOL_STATE_END;
- } else {
- if (!ctx->packet) {
- SILC_LOG_WARNING(("Error (type %d) during Key Exchange protocol",
- status));
- protocol->state = SILC_PROTOCOL_STATE_ERROR;
- silc_protocol_execute(protocol, client->schedule, 0, 0);
- return;
- }
-
- /* Finish the protocol. This verifies the Key Exchange 2 payload
- sent by responder. The silc_client_protocol_ke_continue will
- be called after the public key has been verified. */
- status = silc_ske_initiator_finish(ctx->ske, ctx->packet->buffer);
- }
-
- /* Return now if the procedure is pending */
- if (status == SILC_SKE_STATUS_PENDING)
- return;
-
- if (status != SILC_SKE_STATUS_OK) {
- if (status == SILC_SKE_STATUS_UNSUPPORTED_PUBLIC_KEY) {
- client->internal->ops->say(
- client, conn, SILC_CLIENT_MESSAGE_AUDIT,
- "Received unsupported server %s public key",
- ctx->sock->hostname);
- } else {
- client->internal->ops->say(
- client, conn, SILC_CLIENT_MESSAGE_AUDIT,
- "Error during key exchange protocol with server %s",
- ctx->sock->hostname);
- }
- protocol->state = SILC_PROTOCOL_STATE_ERROR;
- silc_protocol_execute(protocol, client->schedule, 0, 0);
- return;
- }
- }
- break;
-
- case SILC_PROTOCOL_STATE_END:
- {
- /*
- * End protocol
- */
- SilcSKEKeyMaterial *keymat;
- int key_len = silc_cipher_get_key_len(ctx->ske->prop->cipher);
- int hash_len = silc_hash_len(ctx->ske->prop->hash);
-
- /* Process the key material */
- keymat = silc_calloc(1, sizeof(*keymat));
- status = silc_ske_process_key_material(ctx->ske, 16, key_len, hash_len,
- keymat);
- if (status != SILC_SKE_STATUS_OK) {
- protocol->state = SILC_PROTOCOL_STATE_ERROR;
- silc_protocol_execute(protocol, client->schedule, 0, 300000);
- silc_ske_free_key_material(keymat);
- return;
- }
- ctx->keymat = keymat;
-
- /* Send Ok to the other end if we are responder. If we are initiator
- we have sent this already. */
- if (ctx->responder == TRUE)
- silc_ske_end(ctx->ske);
-
- /* Unregister the timeout task since the protocol has ended.
- This was the timeout task to be executed if the protocol is
- not completed fast enough. */
- if (ctx->timeout_task)
- silc_schedule_task_del(client->schedule, ctx->timeout_task);
-
- /* Protocol has ended, call the final callback */
- if (protocol->final_callback)
- silc_protocol_execute_final(protocol, client->schedule);
- else
- silc_protocol_free(protocol);
- }
- break;
-
- case SILC_PROTOCOL_STATE_ERROR:
- /*
- * Error during protocol
- */
-
- /* Send abort notification */
- silc_ske_abort(ctx->ske, ctx->ske->status);
-
- /* On error the final callback is always called. */
- if (protocol->final_callback)
- silc_protocol_execute_final(protocol, client->schedule);
- else
- silc_protocol_free(protocol);
- break;
-
- case SILC_PROTOCOL_STATE_FAILURE:
- /*
- * Received failure from remote.
- */
-
- /* Unregister the timeout task since the protocol has ended.
- This was the timeout task to be executed if the protocol is
- not completed fast enough. */
- if (ctx->timeout_task)
- silc_schedule_task_del(client->schedule, ctx->timeout_task);
-
- /* On error the final callback is always called. */
- if (protocol->final_callback)
- silc_protocol_execute_final(protocol, client->schedule);
- else
- silc_protocol_free(protocol);
- break;
- case SILC_PROTOCOL_STATE_UNKNOWN:
- break;
- }
-}
-
-/*
- * Connection Authentication protocol functions
- */
-
-static int
-silc_client_get_public_key_auth(SilcClient client,
- SilcClientConnection conn,
- unsigned char *auth_data,
- SilcUInt32 *auth_data_len,
- SilcSKE ske)
-{
- int len;
- SilcPKCS pkcs;
- SilcBuffer auth;
-
- /* Use our default key */
- pkcs = client->pkcs;
-
- /* 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_with_hash(pkcs, ske->prop->hash, auth->data,
- auth->len, auth_data, auth_data_len)) {
- silc_buffer_free(auth);
- return TRUE;
- }
-
- silc_buffer_free(auth);
- return FALSE;
-}
-
-/* Continues the connection authentication protocol. This funtion may
- be called directly or used as SilcAskPassphrase callback. */
-
-static void
-silc_client_conn_auth_continue(unsigned char *auth_data,
- SilcUInt32 auth_data_len, void *context)
-{
- SilcProtocol protocol = (SilcProtocol)context;
- SilcClientConnAuthInternalContext *ctx =
- (SilcClientConnAuthInternalContext *)protocol->context;
- SilcClient client = (SilcClient)ctx->client;
- SilcBuffer packet;
- int payload_len = 0;
- unsigned char *autf8 = NULL;
-
- SILC_LOG_DEBUG(("Sending authentication to server"));
-
- /* Passphrase must be UTF-8 encoded, if it isn't encode it */
- if (ctx->auth_meth == SILC_AUTH_PASSWORD &&
- !silc_utf8_valid(auth_data, auth_data_len)) {
- payload_len = silc_utf8_encoded_len(auth_data, auth_data_len,
- SILC_STRING_ASCII);
- autf8 = silc_calloc(payload_len, sizeof(*autf8));
- auth_data_len = silc_utf8_encode(auth_data, auth_data_len,
- SILC_STRING_ASCII, autf8, payload_len);
- auth_data = autf8;
- }
-
- payload_len = 4 + auth_data_len;
- packet = silc_buffer_alloc(payload_len);
- silc_buffer_pull_tail(packet, SILC_BUFFER_END(packet));
- silc_buffer_format(packet,
- SILC_STR_UI_SHORT(payload_len),
- SILC_STR_UI_SHORT(SILC_SOCKET_TYPE_CLIENT),
- SILC_STR_UI_XNSTRING(auth_data, auth_data_len),
- SILC_STR_END);
-
- /* Send the packet to server */
- silc_client_packet_send(client, ctx->sock,
- SILC_PACKET_CONNECTION_AUTH,
- NULL, 0, NULL, NULL,
- packet->data, packet->len, TRUE);
- silc_buffer_free(packet);
- silc_free(autf8);
-
- /* Next state is end of protocol */
- protocol->state = SILC_PROTOCOL_STATE_END;
-}
-
-SILC_TASK_CALLBACK(silc_client_protocol_connection_auth)
-{
- SilcProtocol protocol = (SilcProtocol)context;
- SilcClientConnAuthInternalContext *ctx =
- (SilcClientConnAuthInternalContext *)protocol->context;
- SilcClient client = (SilcClient)ctx->client;
- SilcClientConnection conn = ctx->sock->user_data;
-
- SILC_LOG_DEBUG(("Start"));
-
- if (protocol->state == SILC_PROTOCOL_STATE_UNKNOWN)
- protocol->state = SILC_PROTOCOL_STATE_START;
-
- switch(protocol->state) {
- case SILC_PROTOCOL_STATE_START:
- {
- /*
- * Start protocol. We send authentication data to the server
- * to be authenticated.
- */
- unsigned char *auth_data = NULL;
- SilcUInt32 auth_data_len = 0;
- unsigned char sign[2048 + 1];
-
- switch(ctx->auth_meth) {
- case SILC_AUTH_NONE:
- /* No authentication required */
- break;
-
- case SILC_AUTH_PASSWORD:
- /* Password authentication */
- if (ctx->auth_data && ctx->auth_data_len) {
- auth_data = ctx->auth_data;
- auth_data_len = ctx->auth_data_len;
- break;
- }
-
- client->internal->ops->say(
- client, conn, SILC_CLIENT_MESSAGE_INFO,
- "Password authentication required by server %s",
- ctx->sock->hostname);
- client->internal->ops->ask_passphrase(client, conn,
- silc_client_conn_auth_continue,
- protocol);
- return;
- break;
-
- case SILC_AUTH_PUBLIC_KEY:
- if (!ctx->auth_data) {
- /* Public key authentication */
- silc_client_get_public_key_auth(client, conn, sign, &auth_data_len,
- ctx->ske);
- auth_data = sign;
- } else {
- auth_data = ctx->auth_data;
- auth_data_len = ctx->auth_data_len;
- }
-
- break;
- }
-
- silc_client_conn_auth_continue(auth_data,
- auth_data_len, protocol);
- }
- break;
-
- case SILC_PROTOCOL_STATE_END:
- {
- /*
- * End protocol. Nothing special to be done here.
- */
-
- /* Protocol has ended, call the final callback */
- if (protocol->final_callback)
- silc_protocol_execute_final(protocol, client->schedule);
- else
- silc_protocol_free(protocol);
- }
- break;
-
- case SILC_PROTOCOL_STATE_ERROR:
- {
- /*
- * Error. Send notify to remote.
- */
- unsigned char error[4];
-
- SILC_PUT32_MSB(SILC_AUTH_FAILED, error);
-
- /* Error in protocol. Send FAILURE packet. Although I don't think
- this could ever happen on client side. */
- silc_client_packet_send(client, ctx->sock, SILC_PACKET_FAILURE,
- NULL, 0, NULL, NULL, error, 4, TRUE);
-
- /* On error the final callback is always called. */
- if (protocol->final_callback)
- silc_protocol_execute_final(protocol, client->schedule);
- else
- silc_protocol_free(protocol);
- }
-
- case SILC_PROTOCOL_STATE_FAILURE:
- /*
- * Received failure from remote.
- */
-
- /* On error the final callback is always called. */
- if (protocol->final_callback)
- silc_protocol_execute_final(protocol, client->schedule);
- else
- silc_protocol_free(protocol);
- break;
-
- case SILC_PROTOCOL_STATE_UNKNOWN:
- break;
- }
-}
-
-/*
- * 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,
- SilcBool send)
-{
- SilcClientConnection conn = (SilcClientConnection)sock->user_data;
-
- if (ctx->responder == TRUE) {
- if (send) {
- silc_cipher_set_key(conn->internal->send_key, keymat->receive_enc_key,
- keymat->enc_key_len);
- silc_cipher_set_iv(conn->internal->send_key, keymat->receive_iv);
- silc_hmac_set_key(conn->internal->hmac_send, keymat->receive_hmac_key,
- keymat->hmac_key_len);
- } else {
- silc_cipher_set_key(conn->internal->receive_key, keymat->send_enc_key,
- keymat->enc_key_len);
- silc_cipher_set_iv(conn->internal->receive_key, keymat->send_iv);
- silc_hmac_set_key(conn->internal->hmac_receive, keymat->send_hmac_key,
- keymat->hmac_key_len);
- }
- } else {
- if (send) {
- silc_cipher_set_key(conn->internal->send_key, keymat->send_enc_key,
- keymat->enc_key_len);
- silc_cipher_set_iv(conn->internal->send_key, keymat->send_iv);
- silc_hmac_set_key(conn->internal->hmac_send, keymat->send_hmac_key,
- keymat->hmac_key_len);
- } else {
- silc_cipher_set_key(conn->internal->receive_key,
- keymat->receive_enc_key, keymat->enc_key_len);
- silc_cipher_set_iv(conn->internal->receive_key, keymat->receive_iv);
- silc_hmac_set_key(conn->internal->hmac_receive,
- keymat->receive_hmac_key, keymat->hmac_key_len);
- }
- }
-
- /* Save the current sending encryption key */
- if (!send) {
- memset(conn->internal->rekey->send_enc_key, 0,
- conn->internal->rekey->enc_key_len);
- silc_free(conn->internal->rekey->send_enc_key);
- conn->internal->rekey->send_enc_key = silc_memdup(keymat->send_enc_key,
- keymat->enc_key_len / 8);
- conn->internal->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. */
-
-static void
-silc_client_protocol_rekey_generate(SilcClient client,
- SilcClientRekeyInternalContext *ctx,
- SilcBool send)
-{
- SilcClientConnection conn = (SilcClientConnection)ctx->sock->user_data;
- SilcSKEKeyMaterial *keymat;
- SilcUInt32 key_len = silc_cipher_get_key_len(conn->internal->send_key);
- SilcUInt32 hash_len = silc_hash_len(conn->internal->hash);
-
- SILC_LOG_DEBUG(("Generating new %s session keys (no PFS)",
- send ? "sending" : "receiving"));
-
- /* Generate the new key */
- keymat = silc_calloc(1, sizeof(*keymat));
- silc_ske_process_key_material_data(conn->internal->rekey->send_enc_key,
- conn->internal->rekey->enc_key_len,
- 16, key_len, hash_len,
- conn->internal->hash, keymat);
-
- /* Set the keys into use */
- silc_client_protocol_rekey_validate(client, ctx, ctx->sock, keymat, send);
-
- silc_ske_free_key_material(keymat);
-}
-
-/* This function actually re-generates (with PFS) the keys and
- takes them into use. */
-
-static void
-silc_client_protocol_rekey_generate_pfs(SilcClient client,
- SilcClientRekeyInternalContext *ctx,
- SilcBool send)
-{
- SilcClientConnection conn = (SilcClientConnection)ctx->sock->user_data;
- SilcSKEKeyMaterial *keymat;
- SilcUInt32 key_len = silc_cipher_get_key_len(conn->internal->send_key);
- SilcUInt32 hash_len = silc_hash_len(conn->internal->hash);
- unsigned char *tmpbuf;
- SilcUInt32 klen;
-
- SILC_LOG_DEBUG(("Generating new %s session keys (with PFS)",
- send ? "sending" : "receiving"));
-
- /* Encode KEY to binary data */
- tmpbuf = silc_mp_mp2bin(ctx->ske->KEY, 0, &klen);
-
- /* Generate the new key */
- keymat = silc_calloc(1, sizeof(*keymat));
- silc_ske_process_key_material_data(tmpbuf, klen, 16, key_len, hash_len,
- conn->internal->hash, keymat);
-
- /* Set the keys into use */
- silc_client_protocol_rekey_validate(client, ctx, ctx->sock, keymat, send);
-
- 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, FALSE);
-}
-
-/* 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) {
- SILC_LOG_WARNING(("Error during Re-key"));
- protocol->state = SILC_PROTOCOL_STATE_ERROR;
- silc_protocol_execute(protocol, client->schedule, 0, 300000);
- return;
- }
-
- if (ctx->packet->type != SILC_PACKET_KEY_EXCHANGE_1) {
- /* Error in protocol */
- protocol->state = SILC_PROTOCOL_STATE_ERROR;
- silc_protocol_execute(protocol, client->schedule, 0, 300000);
- }
-
- ctx->ske = silc_ske_alloc(client->rng, client);
- ctx->ske->prop = silc_calloc(1, sizeof(*ctx->ske->prop));
- silc_ske_group_get_by_number(conn->internal->rekey->ske_group,
- &ctx->ske->prop->group);
-
- silc_ske_set_callbacks(ctx->ske,
- silc_client_protocol_rekey_send_packet,
- NULL, NULL, NULL, silc_ske_check_version,
- context);
-
- status = silc_ske_responder_phase_2(ctx->ske, ctx->packet->buffer);
- if (status != SILC_SKE_STATUS_OK) {
- SILC_LOG_WARNING(("Error (type %d) during Re-key (PFS)",
- status));
-
- protocol->state = SILC_PROTOCOL_STATE_ERROR;
- silc_protocol_execute(protocol, client->schedule, 0, 300000);
- return;
- }
-
- /* Advance the protocol state */
- protocol->state++;
- silc_protocol_execute(protocol, client->schedule, 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_queue_purge(client, ctx->sock);
- silc_client_packet_send(client, ctx->sock,
- SILC_PACKET_REKEY_DONE,
- NULL, 0, NULL, NULL, NULL, 0, FALSE);
-
- /* After we send REKEY_DONE we must set the sending encryption
- key to the new key since all packets after this packet must
- encrypted with the new key. */
- silc_client_protocol_rekey_generate(client, ctx, TRUE);
- silc_client_packet_queue_purge(client, ctx->sock);
-
- /* 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, FALSE);
-
- if (ctx->pfs == TRUE) {
- /*
- * Use Perfect Forward Secrecy, ie. negotiate the key material
- * using the SKE protocol.
- */
- ctx->ske = silc_ske_alloc(client->rng, client);
- ctx->ske->prop = silc_calloc(1, sizeof(*ctx->ske->prop));
- silc_ske_group_get_by_number(conn->internal->rekey->ske_group,
- &ctx->ske->prop->group);
-
- silc_ske_set_callbacks(ctx->ske,
- silc_client_protocol_rekey_send_packet,
- NULL, NULL, NULL, silc_ske_check_version,
- context);
-
- status = silc_ske_initiator_phase_2(ctx->ske, NULL, NULL, 0);
- if (status != SILC_SKE_STATUS_OK) {
- SILC_LOG_WARNING(("Error (type %d) during Re-key (PFS)",
- status));
-
- protocol->state = SILC_PROTOCOL_STATE_ERROR;
- silc_protocol_execute(protocol, client->schedule, 0, 300000);
- return;
- }
-
- /* Advance the protocol state */
- protocol->state++;
- } else {
- /*
- * Do normal and simple re-key.
- */
-
- /* Send the REKEY_DONE to indicate we will take new keys into use
- now. */
- silc_client_packet_queue_purge(client, ctx->sock);
- silc_client_packet_send(client, ctx->sock,
- SILC_PACKET_REKEY_DONE,
- NULL, 0, NULL, NULL, NULL, 0, FALSE);
-
- /* After we send REKEY_DONE we must set the sending encryption
- key to the new key since all packets after this packet must
- encrypted with the new key. */
- silc_client_protocol_rekey_generate(client, ctx, TRUE);
- silc_client_packet_queue_purge(client, ctx->sock);
-
- /* The protocol ends in next stage. */
- 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);
-
- if (status != SILC_SKE_STATUS_OK) {
- SILC_LOG_WARNING(("Error (type %d) during Re-key (PFS)",
- status));
-
- protocol->state = SILC_PROTOCOL_STATE_ERROR;
- silc_protocol_execute(protocol, client->schedule, 0, 300000);
- return;
- }
- }
-
- } else {
- if (ctx->pfs == TRUE) {
- /*
- * The packet type must be KE packet
- */
- if (!ctx->packet) {
- SILC_LOG_WARNING(("Error during Re-key"));
- protocol->state = SILC_PROTOCOL_STATE_ERROR;
- silc_protocol_execute(protocol, client->schedule, 0, 300000);
- return;
- }
-
- if (ctx->packet->type != SILC_PACKET_KEY_EXCHANGE_2) {
- /* Error in protocol */
- protocol->state = SILC_PROTOCOL_STATE_ERROR;
- silc_protocol_execute(protocol, client->schedule, 0, 300000);
- }
-
- status = silc_ske_initiator_finish(ctx->ske, ctx->packet->buffer);
- if (status != SILC_SKE_STATUS_OK) {
- SILC_LOG_WARNING(("Error (type %d) during Re-key (PFS)",
- status));
-
- protocol->state = SILC_PROTOCOL_STATE_ERROR;
- silc_protocol_execute(protocol, client->schedule, 0, 300000);
- return;
- }
- }
- }
-
- /* Send the REKEY_DONE to indicate we will take new keys into use
- now. */
- silc_client_packet_queue_purge(client, ctx->sock);
- silc_client_packet_send(client, ctx->sock, SILC_PACKET_REKEY_DONE,
- NULL, 0, NULL, NULL, NULL, 0, FALSE);
-
- /* After we send REKEY_DONE we must set the sending encryption
- key to the new key since all packets after this packet must
- encrypted with the new key. */
- silc_client_protocol_rekey_generate_pfs(client, ctx, TRUE);
- silc_client_packet_queue_purge(client, ctx->sock);
-
- /* The protocol ends in next stage. */
- protocol->state = SILC_PROTOCOL_STATE_END;
- break;
-
- case SILC_PROTOCOL_STATE_END:
- /*
- * End protocol
- */
-
- if (!ctx->packet) {
- SILC_LOG_WARNING(("Error during Re-key"));
- protocol->state = SILC_PROTOCOL_STATE_ERROR;
- silc_protocol_execute(protocol, client->schedule, 0, 300000);
- return;
- }
-
- if (ctx->packet->type != SILC_PACKET_REKEY_DONE) {
- /* Error in protocol */
- protocol->state = SILC_PROTOCOL_STATE_ERROR;
- silc_protocol_execute(protocol, client->schedule, 0, 0);
- }
-
- /* We received the REKEY_DONE packet and all packets after this is
- encrypted with the new key so set the decryption key to the new key */
- if (ctx->pfs == TRUE)
- silc_client_protocol_rekey_generate_pfs(client, ctx, FALSE);
- else
- silc_client_protocol_rekey_generate(client, ctx, FALSE);
- silc_client_packet_queue_purge(client, ctx->sock);
-
- /* Protocol has ended, call the final callback */
- if (protocol->final_callback)
- silc_protocol_execute_final(protocol, client->schedule);
- 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);
- }
-
- /* On error the final callback is always called. */
- if (protocol->final_callback)
- silc_protocol_execute_final(protocol, client->schedule);
- 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)
- silc_protocol_execute_final(protocol, client->schedule);
- else
- silc_protocol_free(protocol);
- break;
-
- case SILC_PROTOCOL_STATE_UNKNOWN:
- break;
- }
-
-}
projects / silc.git / blobdiff