text: /**
   * FreeRDP: A Remote Desktop Protocol Implementation
   * Multiparty Virtual Channel
   *
   * Copyright 2014 Marc-Andre Moreau <marcandre.moreau@gmail.com>
   * Copyright 2015 Thincast Technologies GmbH
   * Copyright 2015 DI (FH) Martin Haimberger <martin.haimberger@thincast.com>
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #ifdef HAVE_CONFIG_H
  #include "config.h"
  #endif
  
  #include <winpr/crt.h>
  #include <winpr/print.h>
  
  #include <freerdp/channels/log.h>
  #include <freerdp/client/encomsp.h>
  
  #include "encomsp_main.h"
  
  /**
   * Function description
   *
   * @return 0 on success, otherwise a Win32 error code
   */
  static UINT encomsp_read_header(wStream* s, ENCOMSP_ORDER_HEADER* header)
  {
  	if (Stream_GetRemainingLength(s) < ENCOMSP_ORDER_HEADER_SIZE)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	Stream_Read_UINT16(s, header->Type); /* Type (2 bytes) */
  	Stream_Read_UINT16(s, header->Length); /* Length (2 bytes) */
  	return CHANNEL_RC_OK;
  }
  
  /**
   * Function description
   *
   * @return 0 on success, otherwise a Win32 error code
   */
  static UINT encomsp_write_header(wStream* s, ENCOMSP_ORDER_HEADER* header)
  {
  	Stream_Write_UINT16(s, header->Type); /* Type (2 bytes) */
  	Stream_Write_UINT16(s, header->Length); /* Length (2 bytes) */
  	return CHANNEL_RC_OK;
  }
  
  /**
   * Function description
   *
   * @return 0 on success, otherwise a Win32 error code
   */
  static UINT encomsp_read_unicode_string(wStream* s, ENCOMSP_UNICODE_STRING* str)
  {
  	ZeroMemory(str, sizeof(ENCOMSP_UNICODE_STRING));
  
  	if (Stream_GetRemainingLength(s) < 2)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	Stream_Read_UINT16(s, str->cchString); /* cchString (2 bytes) */
  
  	if (str->cchString > 1024)
  	{
  		WLog_ERR(TAG, "cchString was %"PRIu16" but has to be < 1025!", str->cchString);
  		return ERROR_INVALID_DATA;
  	}
  
  	if (Stream_GetRemainingLength(s) < (size_t)(str->cchString * 2))
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	Stream_Read(s, &(str->wString), (str->cchString * 2)); /* String (variable) */
  	return CHANNEL_RC_OK;
  }
  
  static EncomspClientContext* encomsp_get_client_interface(
      encomspPlugin* encomsp)
  {
  	EncomspClientContext* pInterface;
  	pInterface = (EncomspClientContext*) encomsp->channelEntryPoints.pInterface;
  	return pInterface;
  }
  
  /**
   * Function description
   *
   * @return 0 on success, otherwise a Win32 error code
   */
  static UINT encomsp_virtual_channel_write(encomspPlugin* encomsp, wStream* s)
  {
  	UINT status;
  
  	if (!encomsp)
  		return ERROR_INVALID_HANDLE;
  
  #if 0
  	WLog_INFO(TAG, "EncomspWrite (%"PRIuz")", Stream_Length(s));
  	winpr_HexDump(Stream_Buffer(s), Stream_Length(s));
  #endif
  	status = encomsp->channelEntryPoints.pVirtualChannelWriteEx(encomsp->InitHandle,
  	         encomsp->OpenHandle,
  	         Stream_Buffer(s), (UINT32) Stream_Length(s), s);
  
  	if (status != CHANNEL_RC_OK)
  		WLog_ERR(TAG,  "VirtualChannelWriteEx failed with %s [%08"PRIX32"]",
  		         WTSErrorToString(status), status);
  
  	return status;
  }
  
  /**
   * Function description
   *
   * @return 0 on success, otherwise a Win32 error code
   */
  static UINT encomsp_recv_filter_updated_pdu(encomspPlugin* encomsp, wStream* s,
          ENCOMSP_ORDER_HEADER* header)
  {
  	int beg, end;
  	EncomspClientContext* context;
  	ENCOMSP_FILTER_UPDATED_PDU pdu;
  	UINT error = CHANNEL_RC_OK;
  	context = encomsp_get_client_interface(encomsp);
  
  	if (!context)
  		return ERROR_INVALID_HANDLE;
  
  	beg = ((int) Stream_GetPosition(s)) - ENCOMSP_ORDER_HEADER_SIZE;
  	CopyMemory(&pdu, header, sizeof(ENCOMSP_ORDER_HEADER));
  
  	if (Stream_GetRemainingLength(s) < 1)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	Stream_Read_UINT8(s, pdu.Flags); /* Flags (1 byte) */
  	end = (int) Stream_GetPosition(s);
  
  	if ((beg + header->Length) < end)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	if ((beg + header->Length) > end)
  	{
  		if (Stream_GetRemainingLength(s) < (size_t)((beg + header->Length) - end))
  		{
  			WLog_ERR(TAG, "Not enough data!");
  			return ERROR_INVALID_DATA;
  		}
  
  		Stream_SetPosition(s, (beg + header->Length));
  	}
  
  	IFCALLRET(context->FilterUpdated, error, context, &pdu);
  
  	if (error)
  		WLog_ERR(TAG, "context->FilterUpdated failed with error %"PRIu32"", error);
  
  	return error;
  }
  
  /**
   * Function description
   *
   * @return 0 on success, otherwise a Win32 error code
   */
  static UINT encomsp_recv_application_created_pdu(encomspPlugin* encomsp,
          wStream* s, ENCOMSP_ORDER_HEADER* header)
  {
  	int beg, end;
  	EncomspClientContext* context;
  	ENCOMSP_APPLICATION_CREATED_PDU pdu;
  	UINT error;
  	context = encomsp_get_client_interface(encomsp);
  
  	if (!context)
  		return ERROR_INVALID_HANDLE;
  
  	beg = ((int) Stream_GetPosition(s)) - ENCOMSP_ORDER_HEADER_SIZE;
  	CopyMemory(&pdu, header, sizeof(ENCOMSP_ORDER_HEADER));
  
  	if (Stream_GetRemainingLength(s) < 6)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	Stream_Read_UINT16(s, pdu.Flags); /* Flags (2 bytes) */
  	Stream_Read_UINT32(s, pdu.AppId); /* AppId (4 bytes) */
  
  	if ((error = encomsp_read_unicode_string(s, &(pdu.Name))))
  	{
  		WLog_ERR(TAG, "encomsp_read_unicode_string failed with error %"PRIu32"", error);
  		return error;
  	}
  
  	end = (int) Stream_GetPosition(s);
  
  	if ((beg + header->Length) < end)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	if ((beg + header->Length) > end)
  	{
  		if (Stream_GetRemainingLength(s) < (size_t)((beg + header->Length) - end))
  		{
  			WLog_ERR(TAG, "Not enough data!");
  			return ERROR_INVALID_DATA;
  		}
  
  		Stream_SetPosition(s, (beg + header->Length));
  	}
  
  	IFCALLRET(context->ApplicationCreated, error, context, &pdu);
  
  	if (error)
  		WLog_ERR(TAG, "context->ApplicationCreated failed with error %"PRIu32"", error);
  
  	return error;
  }
  
  /**
   * Function description
   *
   * @return 0 on success, otherwise a Win32 error code
   */
  static UINT encomsp_recv_application_removed_pdu(encomspPlugin* encomsp,
          wStream* s, ENCOMSP_ORDER_HEADER* header)
  {
  	int beg, end;
  	EncomspClientContext* context;
  	ENCOMSP_APPLICATION_REMOVED_PDU pdu;
  	UINT error = CHANNEL_RC_OK;
  	context = encomsp_get_client_interface(encomsp);
  
  	if (!context)
  		return ERROR_INVALID_HANDLE;
  
  	beg = ((int) Stream_GetPosition(s)) - ENCOMSP_ORDER_HEADER_SIZE;
  	CopyMemory(&pdu, header, sizeof(ENCOMSP_ORDER_HEADER));
  
  	if (Stream_GetRemainingLength(s) < 4)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	Stream_Read_UINT32(s, pdu.AppId); /* AppId (4 bytes) */
  	end = (int) Stream_GetPosition(s);
  
  	if ((beg + header->Length) < end)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	if ((beg + header->Length) > end)
  	{
  		if (Stream_GetRemainingLength(s) < (size_t)((beg + header->Length) - end))
  		{
  			WLog_ERR(TAG, "Not enough data!");
  			return ERROR_INVALID_DATA;
  		}
  
  		Stream_SetPosition(s, (beg + header->Length));
  	}
  
  	IFCALLRET(context->ApplicationRemoved, error, context, &pdu);
  
  	if (error)
  		WLog_ERR(TAG, "context->ApplicationRemoved failed with error %"PRIu32"", error);
  
  	return error;
  }
  
  /**
   * Function description
   *
   * @return 0 on success, otherwise a Win32 error code
   */
  static UINT encomsp_recv_window_created_pdu(encomspPlugin* encomsp, wStream* s,
          ENCOMSP_ORDER_HEADER* header)
  {
  	int beg, end;
  	EncomspClientContext* context;
  	ENCOMSP_WINDOW_CREATED_PDU pdu;
  	UINT error;
  	context = encomsp_get_client_interface(encomsp);
  
  	if (!context)
  		return ERROR_INVALID_HANDLE;
  
  	beg = ((int) Stream_GetPosition(s)) - ENCOMSP_ORDER_HEADER_SIZE;
  	CopyMemory(&pdu, header, sizeof(ENCOMSP_ORDER_HEADER));
  
  	if (Stream_GetRemainingLength(s) < 10)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	Stream_Read_UINT16(s, pdu.Flags); /* Flags (2 bytes) */
  	Stream_Read_UINT32(s, pdu.AppId); /* AppId (4 bytes) */
  	Stream_Read_UINT32(s, pdu.WndId); /* WndId (4 bytes) */
  
  	if ((error = encomsp_read_unicode_string(s, &(pdu.Name))))
  	{
  		WLog_ERR(TAG, "encomsp_read_unicode_string failed with error %"PRIu32"", error);
  		return error;
  	}
  
  	end = (int) Stream_GetPosition(s);
  
  	if ((beg + header->Length) < end)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	if ((beg + header->Length) > end)
  	{
  		if (Stream_GetRemainingLength(s) < (size_t)((beg + header->Length) - end))
  		{
  			WLog_ERR(TAG, "Not enough data!");
  			return ERROR_INVALID_DATA;
  		}
  
  		Stream_SetPosition(s, (beg + header->Length));
  	}
  
  	IFCALLRET(context->WindowCreated, error, context, &pdu);
  
  	if (error)
  		WLog_ERR(TAG, "context->WindowCreated failed with error %"PRIu32"", error);
  
  	return error;
  }
  
  /**
   * Function description
   *
   * @return 0 on success, otherwise a Win32 error code
   */
  static UINT encomsp_recv_window_removed_pdu(encomspPlugin* encomsp, wStream* s,
          ENCOMSP_ORDER_HEADER* header)
  {
  	int beg, end;
  	EncomspClientContext* context;
  	ENCOMSP_WINDOW_REMOVED_PDU pdu;
  	UINT error = CHANNEL_RC_OK;
  	context = encomsp_get_client_interface(encomsp);
  
  	if (!context)
  		return ERROR_INVALID_HANDLE;
  
  	beg = ((int) Stream_GetPosition(s)) - ENCOMSP_ORDER_HEADER_SIZE;
  	CopyMemory(&pdu, header, sizeof(ENCOMSP_ORDER_HEADER));
  
  	if (Stream_GetRemainingLength(s) < 4)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	Stream_Read_UINT32(s, pdu.WndId); /* WndId (4 bytes) */
  	end = (int) Stream_GetPosition(s);
  
  	if ((beg + header->Length) < end)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	if ((beg + header->Length) > end)
  	{
  		if (Stream_GetRemainingLength(s) < (size_t)((beg + header->Length) - end))
  		{
  			WLog_ERR(TAG, "Not enough data!");
  			return ERROR_INVALID_DATA;
  		}
  
  		Stream_SetPosition(s, (beg + header->Length));
  	}
  
  	IFCALLRET(context->WindowRemoved, error, context, &pdu);
  
  	if (error)
  		WLog_ERR(TAG, "context->WindowRemoved failed with error %"PRIu32"", error);
  
  	return error;
  }
  
  /**
   * Function description
   *
   * @return 0 on success, otherwise a Win32 error code
   */
  static UINT encomsp_recv_show_window_pdu(encomspPlugin* encomsp, wStream* s,
          ENCOMSP_ORDER_HEADER* header)
  {
  	int beg, end;
  	EncomspClientContext* context;
  	ENCOMSP_SHOW_WINDOW_PDU pdu;
  	UINT error = CHANNEL_RC_OK;
  	context = encomsp_get_client_interface(encomsp);
  
  	if (!context)
  		return ERROR_INVALID_HANDLE;
  
  	beg = ((int) Stream_GetPosition(s)) - ENCOMSP_ORDER_HEADER_SIZE;
  	CopyMemory(&pdu, header, sizeof(ENCOMSP_ORDER_HEADER));
  
  	if (Stream_GetRemainingLength(s) < 4)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	Stream_Read_UINT32(s, pdu.WndId); /* WndId (4 bytes) */
  	end = (int) Stream_GetPosition(s);
  
  	if ((beg + header->Length) < end)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	if ((beg + header->Length) > end)
  	{
  		if (Stream_GetRemainingLength(s) < (size_t)((beg + header->Length) - end))
  		{
  			WLog_ERR(TAG, "Not enough data!");
  			return ERROR_INVALID_DATA;
  		}
  
  		Stream_SetPosition(s, (beg + header->Length));
  	}
  
  	IFCALLRET(context->ShowWindow, error, context, &pdu);
  
  	if (error)
  		WLog_ERR(TAG, "context->ShowWindow failed with error %"PRIu32"", error);
  
  	return error;
  }
  
  /**
   * Function description
   *
   * @return 0 on success, otherwise a Win32 error code
   */
  static UINT encomsp_recv_participant_created_pdu(encomspPlugin* encomsp,
          wStream* s, ENCOMSP_ORDER_HEADER* header)
  {
  	int beg, end;
  	EncomspClientContext* context;
  	ENCOMSP_PARTICIPANT_CREATED_PDU pdu;
  	UINT error;
  	context = encomsp_get_client_interface(encomsp);
  
  	if (!context)
  		return ERROR_INVALID_HANDLE;
  
  	beg = ((int) Stream_GetPosition(s)) - ENCOMSP_ORDER_HEADER_SIZE;
  	CopyMemory(&pdu, header, sizeof(ENCOMSP_ORDER_HEADER));
  
  	if (Stream_GetRemainingLength(s) < 10)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	Stream_Read_UINT32(s, pdu.ParticipantId); /* ParticipantId (4 bytes) */
  	Stream_Read_UINT32(s, pdu.GroupId); /* GroupId (4 bytes) */
  	Stream_Read_UINT16(s, pdu.Flags); /* Flags (2 bytes) */
  
  	if ((error = encomsp_read_unicode_string(s, &(pdu.FriendlyName))))
  	{
  		WLog_ERR(TAG, "encomsp_read_unicode_string failed with error %"PRIu32"", error);
  		return error;
  	}
  
  	end = (int) Stream_GetPosition(s);
  
  	if ((beg + header->Length) < end)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	if ((beg + header->Length) > end)
  	{
  		if (Stream_GetRemainingLength(s) < (size_t)((beg + header->Length) - end))
  		{
  			WLog_ERR(TAG, "Not enough data!");
  			return ERROR_INVALID_DATA;
  		}
  
  		Stream_SetPosition(s, (beg + header->Length));
  	}
  
  	IFCALLRET(context->ParticipantCreated, error, context, &pdu);
  
  	if (error)
  		WLog_ERR(TAG, "context->ParticipantCreated failed with error %"PRIu32"", error);
  
  	return error;
  }
  
  /**
   * Function description
   *
   * @return 0 on success, otherwise a Win32 error code
   */
  static UINT encomsp_recv_participant_removed_pdu(encomspPlugin* encomsp,
          wStream* s, ENCOMSP_ORDER_HEADER* header)
  {
  	int beg, end;
  	EncomspClientContext* context;
  	ENCOMSP_PARTICIPANT_REMOVED_PDU pdu;
  	UINT error = CHANNEL_RC_OK;
  	context = encomsp_get_client_interface(encomsp);
  
  	if (!context)
  		return ERROR_INVALID_HANDLE;
  
  	beg = ((int) Stream_GetPosition(s)) - ENCOMSP_ORDER_HEADER_SIZE;
  	CopyMemory(&pdu, header, sizeof(ENCOMSP_ORDER_HEADER));
  
  	if (Stream_GetRemainingLength(s) < 12)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	Stream_Read_UINT32(s, pdu.ParticipantId); /* ParticipantId (4 bytes) */
  	Stream_Read_UINT32(s, pdu.DiscType); /* DiscType (4 bytes) */
  	Stream_Read_UINT32(s, pdu.DiscCode); /* DiscCode (4 bytes) */
  	end = (int) Stream_GetPosition(s);
  
  	if ((beg + header->Length) < end)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	if ((beg + header->Length) > end)
  	{
  		if (Stream_GetRemainingLength(s) < (size_t)((beg + header->Length) - end))
  		{
  			WLog_ERR(TAG, "Not enough data!");
  			return ERROR_INVALID_DATA;
  		}
  
  		Stream_SetPosition(s, (beg + header->Length));
  	}
  
  	IFCALLRET(context->ParticipantRemoved, error, context, &pdu);
  
  	if (error)
  		WLog_ERR(TAG, "context->ParticipantRemoved failed with error %"PRIu32"", error);
  
  	return error;
  }
  
  /**
   * Function description
   *
   * @return 0 on success, otherwise a Win32 error code
   */
  static UINT encomsp_recv_change_participant_control_level_pdu(
      encomspPlugin* encomsp, wStream* s, ENCOMSP_ORDER_HEADER* header)
  {
  	int beg, end;
  	EncomspClientContext* context;
  	ENCOMSP_CHANGE_PARTICIPANT_CONTROL_LEVEL_PDU pdu;
  	UINT error = CHANNEL_RC_OK;
  	context = encomsp_get_client_interface(encomsp);
  
  	if (!context)
  		return ERROR_INVALID_HANDLE;
  
  	beg = ((int) Stream_GetPosition(s)) - ENCOMSP_ORDER_HEADER_SIZE;
  	CopyMemory(&pdu, header, sizeof(ENCOMSP_ORDER_HEADER));
  
  	if (Stream_GetRemainingLength(s) < 6)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	Stream_Read_UINT16(s, pdu.Flags); /* Flags (2 bytes) */
  	Stream_Read_UINT32(s, pdu.ParticipantId); /* ParticipantId (4 bytes) */
  	end = (int) Stream_GetPosition(s);
  
  	if ((beg + header->Length) < end)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	if ((beg + header->Length) > end)
  	{
  		if (Stream_GetRemainingLength(s) < (size_t)((beg + header->Length) - end))
  		{
  			WLog_ERR(TAG, "Not enough data!");
  			return ERROR_INVALID_DATA;
  		}
  
  		Stream_SetPosition(s, (beg + header->Length));
  	}
  
  	IFCALLRET(context->ChangeParticipantControlLevel, error, context, &pdu);
  
  	if (error)
  		WLog_ERR(TAG, "context->ChangeParticipantControlLevel failed with error %"PRIu32"",
  		         error);
  
  	return error;
  }
  
  /**
   * Function description
   *
   * @return 0 on success, otherwise a Win32 error code
   */
  static UINT encomsp_send_change_participant_control_level_pdu(
      EncomspClientContext* context,
      ENCOMSP_CHANGE_PARTICIPANT_CONTROL_LEVEL_PDU* pdu)
  {
  	wStream* s;
  	encomspPlugin* encomsp;
  	UINT error;
  	encomsp = (encomspPlugin*) context->handle;
  	pdu->Type = ODTYPE_PARTICIPANT_CTRL_CHANGED;
  	pdu->Length = ENCOMSP_ORDER_HEADER_SIZE + 6;
  	s = Stream_New(NULL, pdu->Length);
  
  	if (!s)
  	{
  		WLog_ERR(TAG, "Stream_New failed!");
  		return CHANNEL_RC_NO_MEMORY;
  	}
  
  	if ((error = encomsp_write_header(s, (ENCOMSP_ORDER_HEADER*) pdu)))
  	{
  		WLog_ERR(TAG, "encomsp_write_header failed with error %"PRIu32"!", error);
  		return error;
  	}
  
  	Stream_Write_UINT16(s, pdu->Flags); /* Flags (2 bytes) */
  	Stream_Write_UINT32(s, pdu->ParticipantId); /* ParticipantId (4 bytes) */
  	Stream_SealLength(s);
  	return encomsp_virtual_channel_write(encomsp, s);
  }
  
  /**
   * Function description
   *
   * @return 0 on success, otherwise a Win32 error code
   */
  static UINT encomsp_recv_graphics_stream_paused_pdu(encomspPlugin* encomsp,
          wStream* s, ENCOMSP_ORDER_HEADER* header)
  {
  	int beg, end;
  	EncomspClientContext* context;
  	ENCOMSP_GRAPHICS_STREAM_PAUSED_PDU pdu;
  	UINT error = CHANNEL_RC_OK;
  	context = encomsp_get_client_interface(encomsp);
  
  	if (!context)
  		return ERROR_INVALID_HANDLE;
  
  	beg = ((int) Stream_GetPosition(s)) - ENCOMSP_ORDER_HEADER_SIZE;
  	CopyMemory(&pdu, header, sizeof(ENCOMSP_ORDER_HEADER));
  	end = (int) Stream_GetPosition(s);
  
  	if ((beg + header->Length) < end)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	if ((beg + header->Length) > end)
  	{
  		if (Stream_GetRemainingLength(s) < (size_t)((beg + header->Length) - end))
  		{
  			WLog_ERR(TAG, "Not enough data!");
  			return ERROR_INVALID_DATA;
  		}
  
  		Stream_SetPosition(s, (beg + header->Length));
  	}
  
  	IFCALLRET(context->GraphicsStreamPaused, error, context, &pdu);
  
  	if (error)
  		WLog_ERR(TAG, "context->GraphicsStreamPaused failed with error %"PRIu32"", error);
  
  	return error;
  }
  
  /**
   * Function description
   *
   * @return 0 on success, otherwise a Win32 error code
   */
  static UINT encomsp_recv_graphics_stream_resumed_pdu(encomspPlugin* encomsp,
          wStream* s, ENCOMSP_ORDER_HEADER* header)
  {
  	int beg, end;
  	EncomspClientContext* context;
  	ENCOMSP_GRAPHICS_STREAM_RESUMED_PDU pdu;
  	UINT error = CHANNEL_RC_OK;
  	context = encomsp_get_client_interface(encomsp);
  
  	if (!context)
  		return ERROR_INVALID_HANDLE;
  
  	beg = ((int) Stream_GetPosition(s)) - ENCOMSP_ORDER_HEADER_SIZE;
  	CopyMemory(&pdu, header, sizeof(ENCOMSP_ORDER_HEADER));
  	end = (int) Stream_GetPosition(s);
  
  	if ((beg + header->Length) < end)
  	{
  		WLog_ERR(TAG, "Not enough data!");
  		return ERROR_INVALID_DATA;
  	}
  
  	if ((beg + header->Length) > end)
  	{
  		if (Stream_GetRemainingLength(s) < (size_t)((beg + header->Length) - end))
  		{
  			WLog_ERR(TAG, "Not enough data!");
  			return ERROR_INVALID_DATA;
  		}
  
  		Stream_SetPosition(s, (beg + header->Length));
  	}
  
  	IFCALLRET(context->GraphicsStreamResumed, error, context, &pdu);
  
  	if (error)
  		WLog_ERR(TAG, "context->GraphicsStreamResumed failed with error %"PRIu32"", error);
  
  	return error;
  }
  
  /**
   * Function description
   *
   * @return 0 on success, otherwise a Win32 error code
   */
  static UINT encomsp_process_receive(encomspPlugin* encomsp, wStream* s)
  {
  	UINT error = CHANNEL_RC_OK;
  	ENCOMSP_ORDER_HEADER header;
  
  	while (Stream_GetRemainingLength(s) > 0)
  	{
  		if ((error = encomsp_read_header(s, &header)))
  		{
  			WLog_ERR(TAG, "encomsp_read_header failed with error %"PRIu32"!", error);
  			return error;
  		}
  
  		//WLog_DBG(TAG, "EncomspReceive: Type: %"PRIu16" Length: %"PRIu16"", header.Type, header.Length);
  
  		switch (header.Type)
  		{
  			case ODTYPE_FILTER_STATE_UPDATED:
  				if ((error = encomsp_recv_filter_updated_pdu(encomsp, s, &header)))
  				{
  					WLog_ERR(TAG, "encomsp_recv_filter_updated_pdu failed with error %"PRIu32"!", error);
  					return error;
  				}
  
  				break;
  
  			case ODTYPE_APP_REMOVED:
  				if ((error = encomsp_recv_application_removed_pdu(encomsp, s, &header)))
  				{
  					WLog_ERR(TAG, "encomsp_recv_application_removed_pdu failed with error %"PRIu32"!",
  					         error);
  					return error;
  				}
  
  				break;
  
  			case ODTYPE_APP_CREATED:
  				if ((error = encomsp_recv_application_created_pdu(encomsp, s, &header)))
  				{
  					WLog_ERR(TAG, "encomsp_recv_application_removed_pdu failed with error %"PRIu32"!",
  					         error);
  					return error;
  				}
  
  				break;
  
  			case ODTYPE_WND_REMOVED:
  				if ((error = encomsp_recv_window_removed_pdu(encomsp, s, &header)))
  				{
  					WLog_ERR(TAG, "encomsp_recv_window_removed_pdu failed with error %"PRIu32"!", error);
  					return error;
  				}
  
  				break;
  
  			case ODTYPE_WND_CREATED:
  				if ((error = encomsp_recv_window_created_pdu(encomsp, s, &header)))
  				{
  					WLog_ERR(TAG, "encomsp_recv_window_created_pdu failed with error %"PRIu32"!", error);
  					return error;
  				}
  
  				break;
  
  			case ODTYPE_WND_SHOW:
  				if ((error = encomsp_recv_show_window_pdu(encomsp, s, &header)))
  				{
  					WLog_ERR(TAG, "encomsp_recv_show_window_pdu failed with error %"PRIu32"!", error);
  					return error;
  				}
  
  				break;
  
  			case ODTYPE_PARTICIPANT_REMOVED:
  				if ((error = encomsp_recv_participant_removed_pdu(encomsp, s, &header)))
  				{
  					WLog_ERR(TAG, "encomsp_recv_participant_removed_pdu failed with error %"PRIu32"!",
  					         error);
  					return error;
  				}
  
  				break;
  
  			case ODTYPE_PARTICIPANT_CREATED:
  				if ((error = encomsp_recv_participant_created_pdu(encomsp, s, &header)))
  				{
  					WLog_ERR(TAG, "encomsp_recv_participant_created_pdu failed with error %"PRIu32"!",
  					         error);
  					return error;
  				}
  
  				break;
  
  			case ODTYPE_PARTICIPANT_CTRL_CHANGED:
  				if ((error = encomsp_recv_change_participant_control_level_pdu(encomsp, s,
  				             &header)))
  				{
  					WLog_ERR(TAG,
  					         "encomsp_recv_change_participant_control_level_pdu failed with error %"PRIu32"!",
  					         error);
  					return error;
  				}
  
  				break;
  
  			case ODTYPE_GRAPHICS_STREAM_PAUSED:
  				if ((error = encomsp_recv_graphics_stream_paused_pdu(encomsp, s, &header)))
  				{
  					WLog_ERR(TAG, "encomsp_recv_graphics_stream_paused_pdu failed with error %"PRIu32"!",
  					         error);
  					return error;
  				}
  
  				break;
  
  			case ODTYPE_GRAPHICS_STREAM_RESUMED:
  				if ((error = encomsp_recv_graphics_stream_resumed_pdu(encomsp, s, &header)))
  				{
  					WLog_ERR(TAG, "encomsp_recv_graphics_stream_resumed_pdu failed with error %"PRIu32"!",
  					         error);
  					return error;
  				}
  
  				break;
  
  			default:
  				WLog_ERR(TAG, "header.Type %"PRIu16" not found", header.Type);
  				return ERROR_INVALID_DATA;
  				break;
  		}
  	}
  
  	return error;
  }
  
  static void encomsp_process_connect(encomspPlugin* encomsp)
  {
  }
  
  /**
   * Function description
   *
   * @return 0 on success, otherwise a Win32 error code
   */
  static UINT encomsp_virtual_channel_event_data_received(encomspPlugin* encomsp,
          void* pData, UINT32 dataLength, UINT32 totalLength, UINT32 dataFlags)
  {
  	wStream* data_in;
  
  	if ((dataFlags & CHANNEL_FLAG_SUSPEND) || (dataFlags & CHANNEL_FLAG_RESUME))
  		return CHANNEL_RC_OK;
  
  	if (dataFlags & CHANNEL_FLAG_FIRST)
  	{
  		if (encomsp->data_in)
  			Stream_Free(encomsp->data_in, TRUE);
  
  		encomsp->data_in = Stream_New(NULL, totalLength);
  
  		if (!encomsp->data_in)
  		{
  			WLog_ERR(TAG, "Stream_New failed!");
  			return CHANNEL_RC_NO_MEMORY;
  		}
  	}
  
  	data_in = encomsp->data_in;
  
  	if (!Stream_EnsureRemainingCapacity(data_in, (int) dataLength))
  	{
  		WLog_ERR(TAG, "Stream_EnsureRemainingCapacity failed!");
  		return ERROR_INTERNAL_ERROR;
  	}
  
  	Stream_Write(data_in, pData, dataLength);
  
  	if (dataFlags & CHANNEL_FLAG_LAST)
  	{
  		if (Stream_Capacity(data_in) != Stream_GetPosition(data_in))
  		{
  			WLog_ERR(TAG,  "encomsp_plugin_process_received: read error");
  			return ERROR_INVALID_DATA;
  		}
  
  		encomsp->data_in = NULL;
  		Stream_SealLength(data_in);
  		Stream_SetPosition(data_in, 0);
  
  		if (!MessageQueue_Post(encomsp->queue, NULL, 0, (void*) data_in, NULL))
  		{
  			WLog_ERR(TAG, "MessageQueue_Post failed!");
  			return ERROR_INTERNAL_ERROR;
  		}
  	}
  
  	return CHANNEL_RC_OK;
  }
  
  static VOID VCAPITYPE encomsp_virtual_channel_open_event_ex(LPVOID lpUserParam, DWORD openHandle,
          UINT event,
          LPVOID pData, UINT32 dataLength, UINT32 totalLength, UINT32 dataFlags)
  {
  	UINT error = CHANNEL_RC_OK;
  	encomspPlugin* encomsp = (encomspPlugin*) lpUserParam;
  
  	if (!encomsp || (encomsp->OpenHandle != openHandle))
  	{
  		WLog_ERR(TAG,  "error no match");
  		return;
  	}
  
  	switch (event)
  	{
  		case CHANNEL_EVENT_DATA_RECEIVED:
  			if ((error = encomsp_virtual_channel_event_data_received(encomsp, pData,
  			             dataLength, totalLength, dataFlags)))
  				WLog_ERR(TAG, "encomsp_virtual_channel_event_data_received failed with error %"PRIu32"", error);
  
  			break;
  
  		case CHANNEL_EVENT_WRITE_COMPLETE:
  			Stream_Free((wStream*) pData, TRUE);
  			break;
  
  		case CHANNEL_EVENT_USER:
  			break;
  	}
  
  	if (error && encomsp->rdpcontext)
  		setChannelError(encomsp->rdpcontext, error, "encomsp_virtual_channel_open_event reported an error");
  
  	return;
  }
  
  static DWORD WINAPI encomsp_virtual_channel_client_thread(LPVOID arg)
  {
  	wStream* data;
  	wMessage message;
  	encomspPlugin* encomsp = (encomspPlugin*) arg;
  	UINT error = CHANNEL_RC_OK;
  	encomsp_process_connect(encomsp);
  
  	while (1)
  	{
  		if (!MessageQueue_Wait(encomsp->queue))
  		{
  			WLog_ERR(TAG, "MessageQueue_Wait failed!");
  			error = ERROR_INTERNAL_ERROR;
  			break;
  		}
  
  		if (!MessageQueue_Peek(encomsp->queue, &message, TRUE))
  		{
  			WLog_ERR(TAG, "MessageQueue_Peek failed!");
  			error = ERROR_INTERNAL_ERROR;
  			break;
  		}
  
  		if (message.id == WMQ_QUIT)
  			break;
  
  		if (message.id == 0)
  		{
  			data = (wStream*) message.wParam;
  
  			if ((error = encomsp_process_receive(encomsp, data)))
  			{
  				WLog_ERR(TAG, "encomsp_process_receive failed with error %"PRIu32"!", error);
  				break;
  			}
  		}
  	}
  
  	if (error && encomsp->rdpcontext)
  		setChannelError(encomsp->rdpcontext, error,
  		                "encomsp_virtual_channel_client_thread reported an error");
  
  	ExitThread(error);
  	return error;
  }
  
  /**
   * Function description
   *
   * @return 0 on success, otherwise a Win32 error code
   */
  static UINT encomsp_virtual_channel_event_connected(encomspPlugin* encomsp,
          LPVOID pData, UINT32 dataLength)
  {
  	UINT32 status;
  	status = encomsp->channelEntryPoints.pVirtualChannelOpenEx(encomsp->InitHandle,
  	         &encomsp->OpenHandle, encomsp->channelDef.name,
  	         encomsp_virtual_channel_open_event_ex);
  
  	if (status != CHANNEL_RC_OK)
  	{
  		WLog_ERR(TAG, "pVirtualChannelOpen failed with %s [%08"PRIX32"]",
  		         WTSErrorToString(status), status);
  		return status;
  	}
  
  	encomsp->queue = MessageQueue_New(NULL);
  
  	if (!encomsp->queue)
  	{
  		WLog_ERR(TAG, "MessageQueue_New failed!");
  		return CHANNEL_RC_NO_MEMORY;
  	}
  
  	if (!(encomsp->thread = CreateThread(NULL, 0,
  										 encomsp_virtual_channel_client_thread, (void*) encomsp,
  	                                     0, NULL)))
  	{
  		WLog_ERR(TAG, "CreateThread failed!");
  		MessageQueue_Free(encomsp->queue);
  		return ERROR_INTERNAL_ERROR;
  	}
  
  	return CHANNEL_RC_OK;
  }
  
  /**
   * Function description
   *
   * @return 0 on success, otherwise a Win32 error code
   */
  static UINT encomsp_virtual_channel_event_disconnected(encomspPlugin* encomsp)
  {
  	UINT rc;
  
  	if (MessageQueue_PostQuit(encomsp->queue, 0)
  	    && (WaitForSingleObject(encomsp->thread, INFINITE) == WAIT_FAILED))
  	{
  		rc = GetLastError();
  		WLog_ERR(TAG, "WaitForSingleObject failed with error %"PRIu32"", rc);
  		return rc;
  	}
  
  	MessageQueue_Free(encomsp->queue);
  	CloseHandle(encomsp->thread);
  	encomsp->queue = NULL;
  	encomsp->thread = NULL;
  	rc = encomsp->channelEntryPoints.pVirtualChannelCloseEx(encomsp->InitHandle, encomsp->OpenHandle);
  
  	if (CHANNEL_RC_OK != rc)
  	{
  		WLog_ERR(TAG, "pVirtualChannelClose failed with %s [%08"PRIX32"]",
  		         WTSErrorToString(rc), rc);
  		return rc;
  	}
  
  	encomsp->OpenHandle = 0;
  
  	if (encomsp->data_in)
  	{
  		Stream_Free(encomsp->data_in, TRUE);
  		encomsp->data_in = NULL;
  	}
  
  	return CHANNEL_RC_OK;
  }
  
  
  /**
   * Function description
   *
   * @return 0 on success, otherwise a Win32 error code
   */
  static UINT encomsp_virtual_channel_event_terminated(encomspPlugin* encomsp)
  {
  	encomsp->InitHandle = 0;
  	free(encomsp->context);
  	free(encomsp);
  	return CHANNEL_RC_OK;
  }
  
  static VOID VCAPITYPE encomsp_virtual_channel_init_event_ex(LPVOID lpUserParam, LPVOID pInitHandle,
          UINT event, LPVOID pData, UINT dataLength)
  {
  	UINT error = CHANNEL_RC_OK;
  	encomspPlugin* encomsp = (encomspPlugin*) lpUserParam;
  
  	if (!encomsp || (encomsp->InitHandle != pInitHandle))
  	{
  		WLog_ERR(TAG,  "error no match");
  		return;
  	}
  
  	switch (event)
  	{
  		case CHANNEL_EVENT_CONNECTED:
  			if ((error = encomsp_virtual_channel_event_connected(encomsp, pData,
  			             dataLength)))
  				WLog_ERR(TAG, "encomsp_virtual_channel_event_connected failed with error %"PRIu32"",
  				         error);
  
  			break;
  
  		case CHANNEL_EVENT_DISCONNECTED:
  			if ((error = encomsp_virtual_channel_event_disconnected(encomsp)))
  				WLog_ERR(TAG,
  				         "encomsp_virtual_channel_event_disconnected failed with error %"PRIu32"", error);
  
  			break;
  
  		case CHANNEL_EVENT_TERMINATED:
  			encomsp_virtual_channel_event_terminated(encomsp);
  			break;
  
  		default:
  			WLog_ERR(TAG, "Unhandled event type %"PRIu32"", event);
  	}
  
  	if (error && encomsp->rdpcontext)
  		setChannelError(encomsp->rdpcontext, error, "encomsp_virtual_channel_init_event reported an error");
  }
  
  /* encomsp is always built-in */
  #define VirtualChannelEntryEx	encomsp_VirtualChannelEntryEx
  
  BOOL VCAPITYPE VirtualChannelEntryEx(PCHANNEL_ENTRY_POINTS_EX pEntryPoints, PVOID pInitHandle)
  {
  	UINT rc;
  	encomspPlugin* encomsp;
  	EncomspClientContext* context = NULL;
  	CHANNEL_ENTRY_POINTS_FREERDP_EX* pEntryPointsEx;
  	BOOL isFreerdp = FALSE;
  	encomsp = (encomspPlugin*) calloc(1, sizeof(encomspPlugin));
  
  	if (!encomsp)
  	{
  		WLog_ERR(TAG, "calloc failed!");
  		return FALSE;
  	}
  
  	encomsp->channelDef.options =
  	    CHANNEL_OPTION_INITIALIZED |
  	    CHANNEL_OPTION_ENCRYPT_RDP |
  	    CHANNEL_OPTION_COMPRESS_RDP |
  	    CHANNEL_OPTION_SHOW_PROTOCOL;
  	strcpy(encomsp->channelDef.name, "encomsp");
  	pEntryPointsEx = (CHANNEL_ENTRY_POINTS_FREERDP_EX*) pEntryPoints;
  
  	if ((pEntryPointsEx->cbSize >= sizeof(CHANNEL_ENTRY_POINTS_FREERDP_EX)) &&
  	    (pEntryPointsEx->MagicNumber == FREERDP_CHANNEL_MAGIC_NUMBER))
  	{
  		context = (EncomspClientContext*) calloc(1, sizeof(EncomspClientContext));
  
  		if (!context)
  		{
  			WLog_ERR(TAG, "calloc failed!");
  			goto error_out;
  		}
  
  		context->handle = (void*) encomsp;
  		context->FilterUpdated = NULL;
  		context->ApplicationCreated = NULL;
  		context->ApplicationRemoved = NULL;
  		context->WindowCreated = NULL;
  		context->WindowRemoved = NULL;
  		context->ShowWindow = NULL;
  		context->ParticipantCreated = NULL;
  		context->ParticipantRemoved = NULL;
  		context->ChangeParticipantControlLevel =
  		    encomsp_send_change_participant_control_level_pdu;
  		context->GraphicsStreamPaused = NULL;
  		context->GraphicsStreamResumed = NULL;
  		encomsp->context = context;
  		encomsp->rdpcontext = pEntryPointsEx->context;
  		isFreerdp = TRUE;
  	}
  
  	CopyMemory(&(encomsp->channelEntryPoints), pEntryPoints,
  	           sizeof(CHANNEL_ENTRY_POINTS_FREERDP_EX));
  	encomsp->InitHandle = pInitHandle;
  	rc = encomsp->channelEntryPoints.pVirtualChannelInitEx(encomsp, context, pInitHandle,
  	        &encomsp->channelDef, 1, VIRTUAL_CHANNEL_VERSION_WIN2000,
  	        encomsp_virtual_channel_init_event_ex);
  
  	if (CHANNEL_RC_OK != rc)
  	{
  		WLog_ERR(TAG, "failed with %s [%08"PRIX32"]",
  		         WTSErrorToString(rc), rc);
  		goto error_out;
  	}
  
  	encomsp->channelEntryPoints.pInterface = context;
  	return TRUE;
  error_out:
  
  	if (isFreerdp)
  		free(encomsp->context);
  
  	free(encomsp);
  	return FALSE;
  }
  