//
// Summary:
// Writes encoded bytes to the underlying stream from the specified byte
// array.
//
// Parameters:
// array:
// The array used to store encoded bytes.
//
// offset:
// The location in the array to begin reading.
//
// count:
// The number of bytes encoded.
//
// Exceptions:
// System.ArgumentNullException:
// array is null.
//
// System.InvalidOperationException:
// The Q3Cypher.CypherMode value was Decode when the object
// was created. - or - The underlying stream does not support writing.
//
// System.ArgumentOutOfRangeException:
// offset or count is less than zero. -or- array length minus the index starting
// point is less than count.
//
// System.ObjectDisposedException:
// The stream is closed.
public override void Write(byte [] array, int offset, int count)
{
#region Exception checks
if (array == null)
{
throw new ArgumentNullException("array");
}
if (baseStream == null)
{
throw new ObjectDisposedException("baseStream");
}
if (mode == CypherMode.Decode)
{
throw new InvalidOperationException("Stream cannot be written while its mode set to Q3Cypher.CypherMode.Decode");
}
if (!baseStream.CanWrite)
{
throw new InvalidOperationException("Underlying stream cannot be written");
}
if (offset < 0)
{
throw new ArgumentOutOfRangeException("offset");
}
if (count < 0)
{
throw new ArgumentOutOfRangeException("count");
}
if (array.Length < offset)
{
throw new ArgumentOutOfRangeException("offset");
}
if (array.Length < offset + count)
{
throw new ArgumentOutOfRangeException("count");
}
#endregion Exception checks
(baseStream as Q3DatagramStream).BeginWritePacket(PacketKind.ConnectionOriented);
Q3HuffmanStream huff = connection.Q3HuffDStream;
int bloc = 0;
int serverId = huff.DecompressBufferToInt32(array, 0, ref bloc);
int messageAcknowledge = huff.DecompressBufferToInt32(array, 0, ref bloc);
int reliableAcknowledge = huff.DecompressBufferToInt32(array, 0, ref bloc);
byte [] buffer = new byte [count];
Array.Copy(array, buffer, CL_ENCODE_START < count ? CL_ENCODE_START : count);
string pattern = connection.IncomingReliableCommands [reliableAcknowledge & (Q3Connection.MAX_RELIABLE_COMMANDS - 1)];
int index = 0;
byte key = ( byte )(connection.Challenge ^ serverId ^ messageAcknowledge);
for (int i = CL_ENCODE_START; i < count; i++)
{
// modify the key with the last received now acknowledged server command
if (pattern == null || index >= pattern.Length)
{
index = 0;
}
if (pattern != null && (pattern [index] > 127 || pattern [index] == '%'))
{
key ^= ( byte )('.' << (i & 1));
}
else
{
key ^= ( byte )((pattern != null ? pattern [index] : 0) << (i & 1));
}
index++;
// encode the data with this key
buffer [i] = ( byte )(array [i + offset] ^ key);
}
baseStream.Write(buffer, 0, count);
}
//
// Summary:
// Reads a number of decoded bytes into the specified byte array.
//
// Parameters:
// array:
// The array used to store decoded bytes.
//
// offset:
// The byte offset in array at which to begin writing data read from the stream.
//
// count:
// The number of bytes to decode.
//
// Returns:
// The number of bytes that were decoded into the byte array. If the end
// of the stream has been reached, zero or the number of bytes read is returned.
//
// Exceptions:
// System.ArgumentNullException:
// array is null.
//
// System.InvalidOperationException:
// The Q3Cypher.CypherMode value was Encode when the object
// was created. - or - The underlying stream does not support reading.
//
// System.ArgumentOutOfRangeException:
// offset or count is less than zero. -or- array length minus the index starting
// point is less than count.
//
// System.ObjectDisposedException:
// The stream is closed.
public override int Read(byte [] array, int offset, int count)
{
#region Exception checks
if (array == null)
{
throw new ArgumentNullException("array");
}
if (baseStream == null)
{
throw new ObjectDisposedException("baseStream");
}
if (mode == CypherMode.Encode)
{
throw new InvalidOperationException("Stream cannot be read while its mode set to CypherMode.Encode");
}
if (!baseStream.CanRead)
{
throw new InvalidOperationException("Underlying stream cannot be read");
}
if (offset < 0)
{
throw new ArgumentOutOfRangeException("offset");
}
if (count < 0)
{
throw new ArgumentOutOfRangeException("count");
}
if (array.Length < offset)
{
throw new ArgumentOutOfRangeException("offset");
}
if (array.Length < offset + count)
{
throw new ArgumentOutOfRangeException("count");
}
#endregion Exception checks
if (this.readPosition == 0)
{
(( Q3DatagramStream )baseStream).BeginReadPacket();
}
int bytesRead = baseStream.Read(array, offset, count);
int encStart = 0,
encEnd = 0;
if (this.readPosition < CL_DECODE_START)
{
Array.Copy(array, offset,
this.readBuffer, this.readPosition,
bytesRead + this.readPosition > CL_DECODE_START ?
CL_DECODE_START - this.readPosition : bytesRead);
if (this.readPosition + bytesRead >= CL_DECODE_START)
{
Q3HuffmanStream huff = connection.Q3HuffDStream;
int bloc = 0;
this.readReliableAcknowledge = huff.DecompressBufferToInt32(this.readBuffer, 0, ref bloc);
encStart = CL_DECODE_START - this.readPosition + offset;
encEnd = bytesRead + offset;
this.readPattern = connection.OutgoingReliableCommands [this.readReliableAcknowledge & (Q3Connection.MAX_RELIABLE_COMMANDS - 1)];
this.readKey = ( byte )(connection.Challenge ^ connection.IncomingSequence);
this.readPatternIndex = 0;
}
}
else
{
encStart = offset;
encEnd = bytesRead;
}
for (int i = encStart; i < encEnd; i++)
{
// modify the key with the last received now acknowledged server command
if (this.readPattern == null || this.readPatternIndex >= this.readPattern.Length)
{
this.readPatternIndex = 0;
}
if (this.readPattern != null && (this.readPattern [this.readPatternIndex] > 127 || this.readPattern [this.readPatternIndex] == '%'))
{
this.readKey ^= ( byte )('.' << (i & 1));
}
else
{
this.readKey ^= ( byte )((this.readPattern != null ? this.readPattern [this.readPatternIndex] : 0) << (i & 1));
}
this.readPatternIndex++;
array [i] = ( byte )(array [i] ^ this.readKey);
}
this.readPosition += bytesRead;
//string dump = BufferInfo.DumpBuffer ( "Decrypted buffer", array, offset, bytesRead, true, true, true );
//Console.Write ( dump );
return(bytesRead);
}
