public static bool ReadAndDecryptPacket(BinaryReader srcStreamReader, MemoryStream destStream, SymmetricAlgorithm alg)
{
destStream.SetLength(0);
//int tmout = srcStreamReader.BaseStream.ReadTimeout;
if (srcStreamReader.ReadChar() != 'P')
{
return(false);
}
int len = srcStreamReader.ReadInt32();
if (len > MaxInPacketLength)
{
return(false);
}
int iv = srcStreamReader.ReadInt32() - 200;
byte[] buf = srcStreamReader.ReadBytes(len - 8);
uint crc = srcStreamReader.ReadUInt32() - 200;
if (CRCGenerator.CRC32(buf, 0, buf.Length, CRCSeed) != crc)
{
return(false);
}
alg.IV = Encoding.ASCII.GetBytes(iv.ToString("X8"));
MemoryStream tmpStream = new MemoryStream(buf);
Crypto.Decrypt(tmpStream, destStream, alg, 64);
destStream.Position = 0;
return(true);
}
public static bool EncryptAndWritePacket(BinaryWriter destStreamWriter, MemoryStream srcStream, SymmetricAlgorithm alg)
{
if (srcStream.Length == 0)
{
return(true);
}
int iv = GetRandom();
alg.IV = Encoding.ASCII.GetBytes(iv.ToString("X8"));
MemoryStream tmpStream = new MemoryStream();
CryptoStream encStream = new CryptoStream(tmpStream, alg.CreateEncryptor(), CryptoStreamMode.Write);
encStream.Write(srcStream.GetBuffer(), 0, (int)srcStream.Length);
encStream.FlushFinalBlock();
destStreamWriter.Write('P');
destStreamWriter.Write((Int32)(tmpStream.Length + 8));
destStreamWriter.Write(iv + 200);
int offset = 0;
while (offset < tmpStream.Length)
{
int l = (int)tmpStream.Length - offset;
if (l > 4096)
{
l = 4096;
}
destStreamWriter.Write(tmpStream.GetBuffer(), offset, l);
destStreamWriter.BaseStream.Flush();
offset += l;
}
destStreamWriter.Write(CRCGenerator.CRC32(tmpStream.GetBuffer(), 0, (int)tmpStream.Length, CRCSeed) + 200);
encStream.Close();
return(true);
}
