/// <summary>
/// Reassemble chunk data by the member field channelManager.
/// This method is called when processing Virtual Channel PDU.
/// </summary>
/// <param name="pdu">The channel pdu includes header and data. This argument can be null.</param>
/// <returns>If the reassemble is complete, then return the Virtual_Channel_Complete_Pdu.
/// Else return null.</returns>
internal Virtual_Channel_Complete_Pdu ReassembleChunkData(Virtual_Channel_RAW_Pdu pdu)
{
lock (contextLock)
{
return channelManager.ReassembleChunkData(pdu);
}
}
/// <summary>
/// Decode Virtual Channel PDU
/// </summary>
/// <param name="data">data to be parsed</param>
/// <param name="decryptedUserData">decrypted user data</param>
/// <param name="type">security header type</param>
/// <returns>decoded Virtual Channel PDU</returns>
public StackPacket DecodeVirtualChannelPDU(
byte[] data,
byte[] decryptedUserData,
SecurityHeaderType type)
{
Virtual_Channel_RAW_Pdu pdu = new Virtual_Channel_RAW_Pdu();
// data index
int dataIndex = 0;
// Virtual_Channel_RAW_Pdu: commonHeader
pdu.commonHeader = ParseMcsCommonHeader(data, ref dataIndex, type);
// user data index
int userDataIndex = 0;
// Virtual_Channel_RAW_PDU: channelPduHeader
pdu.channelPduHeader = ParseChannelPduHeader(decryptedUserData, ref userDataIndex);
// Virtual_Channel_RAW_PDU: virtualChannelData
int remainLength = decryptedUserData.Length - Marshal.SizeOf(pdu.channelPduHeader);
pdu.virtualChannelData = GetBytes(decryptedUserData, ref userDataIndex, remainLength);
/*
// ETW Provider Dump Message
if (pdu.commonHeader.securityHeader != null)
{
// RDP Standard Security
string messageName = "RDPBCGR:" + pdu.GetType().Name;
ExtendedLogger.DumpMessage(messageName, RdpbcgrUtility.DumpLevel_Layer3, pdu.GetType().Name, decryptedUserData);
}
* */
// Check if data length exceeded expectation
VerifyDataLength(decryptedUserData.Length, userDataIndex, ConstValue.ERROR_MESSAGE_DATA_LENGTH_EXCEEDED);
return pdu;
}
/// <summary>
/// Decompress the virtual channel data into decompressedBuffer buffer.
/// After decompressing the last pdu, the member decompressedBuffer contains
/// the complete virtual data.
/// </summary>
/// <param name="pdu">The virtual channel pdu includes header and data.</param>
/// <returns>If the reassemble is complete, then return the completePdu. Else return null.</returns>
internal Virtual_Channel_Complete_Pdu ReassembleChunkData(Virtual_Channel_RAW_Pdu pdu)
{
if (pdu == null || pdu.virtualChannelData == null)
{
return null;
}
// the first chunk
if ((pdu.channelPduHeader.flags & CHANNEL_PDU_HEADER_flags_Values.CHANNEL_FLAG_FIRST)
== CHANNEL_PDU_HEADER_flags_Values.CHANNEL_FLAG_FIRST)
{
completePdu = new Virtual_Channel_Complete_Pdu();
completePdu.rawPdus = new System.Collections.ObjectModel.Collection<Virtual_Channel_RAW_Pdu>();
completePdu.channelId = channelId;
decompressedBuffer.Clear();
}
byte[] decompressedData = pdu.virtualChannelData;
if (mppcDecompressor != null) // has compression
{
CompressMode flag = CompressMode.None;
if ((pdu.channelPduHeader.flags & CHANNEL_PDU_HEADER_flags_Values.CHANNEL_PACKET_AT_FRONT)
== CHANNEL_PDU_HEADER_flags_Values.CHANNEL_PACKET_AT_FRONT)
{
flag |= CompressMode.SetToFront;
}
if ((pdu.channelPduHeader.flags & CHANNEL_PDU_HEADER_flags_Values.CHANNEL_PACKET_COMPRESSED)
== CHANNEL_PDU_HEADER_flags_Values.CHANNEL_PACKET_COMPRESSED)
{
flag |= CompressMode.Compressed;
}
if ((pdu.channelPduHeader.flags & CHANNEL_PDU_HEADER_flags_Values.CHANNEL_PACKET_FLUSHED)
== CHANNEL_PDU_HEADER_flags_Values.CHANNEL_PACKET_FLUSHED)
{
flag |= CompressMode.Flush;
}
if (flag != CompressMode.None)
{
decompressedData = mppcDecompressor.Decompress(pdu.virtualChannelData, flag);
}
}
if (completePdu != null)
{
completePdu.rawPdus.Add(pdu);
decompressedBuffer.AddRange(decompressedData);
}
else
{
// not need to reassemble
Virtual_Channel_Complete_Pdu returnPDU = new Virtual_Channel_Complete_Pdu();
returnPDU.rawPdus = new System.Collections.ObjectModel.Collection<Virtual_Channel_RAW_Pdu>();
returnPDU.channelId = channelId;
returnPDU.rawPdus.Add(pdu);
returnPDU.virtualChannelData = decompressedData;
return returnPDU;
}
// the last chunk
if ((pdu.channelPduHeader.flags & CHANNEL_PDU_HEADER_flags_Values.CHANNEL_FLAG_LAST)
== CHANNEL_PDU_HEADER_flags_Values.CHANNEL_FLAG_LAST)
{
if (decompressedBuffer != null)
{
completePdu.virtualChannelData = decompressedBuffer.ToArray();
}
Virtual_Channel_Complete_Pdu returnPDU = completePdu;
completePdu = null;
return returnPDU;
}
return null;
}
/// <summary>
/// Reasemble Chunk Data
/// </summary>
/// <param name="pdu"></param>
/// <returns></returns>
internal Virtual_Channel_Complete_Pdu ReassembleChunkData(Virtual_Channel_RAW_Pdu pdu)
{
if (!channelDicById.ContainsKey(pdu.commonHeader.channelId))
{
// drop the pdu if the channel id does not exist
//return null;
throw new ArgumentException("The channel id of the pdu does not exist!");
}
ServerStaticVirtualChannel channel = (ServerStaticVirtualChannel)channelDicById[pdu.commonHeader.channelId];
return channel.ReassembleChunkData(pdu);
}
/// <summary>
/// Split the virtualChannelData to several chunk data to send.
/// </summary>
public void SplitToChunks()
{
ChannelChunk[] chunks = context.SplitToChunks(channelId, virtualChannelData);
if (chunks != null && chunks.Length > 0)
{
rawPdus = new Collection<Virtual_Channel_RAW_Pdu>();
for (int i = 0; i < chunks.Length; ++i)
{
Virtual_Channel_RAW_Pdu rawPdu = new Virtual_Channel_RAW_Pdu(context);
rawPdu.channelPduHeader = chunks[i].channelPduHeader;
rawPdu.virtualChannelData = chunks[i].chunkData;
rawPdus.Add(rawPdu);
RdpbcgrUtility.FillCommonHeader(ref rawPdus[i].commonHeader,
TS_SECURITY_HEADER_flags_Values.SEC_IGNORE_SEQNO
| TS_SECURITY_HEADER_flags_Values.SEC_RESET_SEQNO,
context,
channelId);
}
}
}