private static bool Decrypt(Stream input, Stream output)
{
var size = (int)input.Length;
ThCrypt.Decrypt(input, output, size, 0x3A, 0xCD, 0x0100, 0x0C00);
var data = new byte[size];
output.Seek(0, SeekOrigin.Begin);
output.Read(data, 0, size);
uint checksum = 0;
byte temp = 0;
for (var index = 2; index < size; index++)
{
temp += data[index - 1];
temp = (byte)((temp >> 5) | (temp << 3));
data[index] ^= temp;
if (index > 3)
{
checksum += data[index];
}
}
output.Seek(0, SeekOrigin.Begin);
output.Write(data, 0, size);
return((ushort)checksum == BitConverter.ToUInt16(data, 2));
}
private static bool Decrypt(Stream input, Stream output)
{
var reader = new BinaryReader(input);
var writer = new BinaryWriter(output);
var header = new Header();
header.ReadFrom(reader);
if (!header.IsValid)
{
return(false);
}
if (header.EncodedAllSize != reader.BaseStream.Length)
{
return(false);
}
header.WriteTo(writer);
ThCrypt.Decrypt(input, output, header.EncodedBodySize, 0xAC, 0x35, 0x10, header.EncodedBodySize);
return(true);
}