27e762d06f
The FreeRDP library is intended to be threadsafe, but is not reliably so with respect to legacy RDP encryption and outbound messages. When outbound messages are sent by multiple threads, the encryption key used for legacy RDP encryption may not be updated correctly, resulting in a fatal connection error like: "ERRINFO_DECRYPT_FAILED (0x00001192):(a) Decryption using Standard RDP Security mechanisms (section 5.3.6) failed. (b) Session key creation using Standard RDP Security mechanisms (section 5.3.5) failed."
105 lines
3.9 KiB
C
105 lines
3.9 KiB
C
/*
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* Licensed to the Apache Software Foundation (ASF) under one
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* or more contributor license agreements. See the NOTICE file
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* distributed with this work for additional information
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* regarding copyright ownership. The ASF licenses this file
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* to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance
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* with the License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing,
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* software distributed under the License is distributed on an
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* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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* KIND, either express or implied. See the License for the
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* specific language governing permissions and limitations
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* under the License.
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*/
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#include "channels/common-svc.h"
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#include "plugins/channels.h"
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#include "rdp.h"
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#include <freerdp/settings.h>
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#include <guacamole/client.h>
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#include <guacamole/string.h>
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#include <winpr/stream.h>
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#include <winpr/wtsapi.h>
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#include <winpr/wtypes.h>
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#include <stdlib.h>
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int guac_rdp_common_svc_load_plugin(rdpContext* context,
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char* name, ULONG channel_options,
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guac_rdp_common_svc_connect_handler* connect_handler,
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guac_rdp_common_svc_receive_handler* receive_handler,
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guac_rdp_common_svc_terminate_handler* terminate_handler) {
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guac_client* client = ((rdp_freerdp_context*) context)->client;
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guac_rdp_common_svc* svc = calloc(1, sizeof(guac_rdp_common_svc));
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svc->client = client;
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svc->name = svc->_channel_def.name;
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svc->_connect_handler = connect_handler;
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svc->_receive_handler = receive_handler;
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svc->_terminate_handler = terminate_handler;
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/* Init FreeRDP channel definition */
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int name_length = guac_strlcpy(svc->_channel_def.name, name, GUAC_RDP_SVC_MAX_LENGTH);
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svc->_channel_def.options =
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CHANNEL_OPTION_INITIALIZED
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| CHANNEL_OPTION_ENCRYPT_RDP
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| channel_options;
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/* Warn about name length */
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if (name_length >= GUAC_RDP_SVC_MAX_LENGTH)
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guac_client_log(client, GUAC_LOG_WARNING,
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"Static channel name \"%s\" exceeds maximum length of %i "
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"characters and will be truncated to \"%s\".",
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name, GUAC_RDP_SVC_MAX_LENGTH - 1, svc->name);
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/* Attempt to load the common SVC plugin for new static channel */
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int result = guac_freerdp_channels_load_plugin(context, "guac-common-svc", svc);
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if (result) {
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guac_client_log(client, GUAC_LOG_WARNING, "Cannot create static "
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"channel \"%s\": failed to load \"guac-common-svc\" plugin "
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"for FreeRDP.", svc->name);
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free(svc);
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}
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/* Store and log on success (SVC structure will be freed on channel termination) */
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else
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guac_client_log(client, GUAC_LOG_DEBUG, "Support for static channel "
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"\"%s\" loaded.", svc->name);
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return result;
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}
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void guac_rdp_common_svc_write(guac_rdp_common_svc* svc,
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wStream* output_stream) {
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/* Do not write if plugin not associated */
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if (!svc->_open_handle) {
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guac_client_log(svc->client, GUAC_LOG_WARNING, "%i bytes of data "
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"written to SVC \"%s\" are being dropped because the remote "
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"desktop side of that SVC is not yet connected.",
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Stream_Length(output_stream), svc->name);
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return;
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}
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guac_rdp_client* rdp_client = (guac_rdp_client*) svc->client->data;
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/* NOTE: The wStream sent via pVirtualChannelWriteEx will automatically be
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* freed later with a call to Stream_Free() when handling the
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* corresponding write cancel/completion event. */
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pthread_mutex_lock(&(rdp_client->message_lock));
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svc->_entry_points.pVirtualChannelWriteEx(svc->_init_handle,
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svc->_open_handle, Stream_Buffer(output_stream),
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Stream_GetPosition(output_stream), output_stream);
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pthread_mutex_unlock(&(rdp_client->message_lock));
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}
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