/**
* Encrypts the given signature
*
* @param input input data
* @param msSinceStart time since start
* @return encrypted signature
*/
public static byte[] Encrypt(byte[] uncryptedSignature, uint msSinceStart)
{
try
{
Rand rand = new Rand(msSinceStart);
object[] key = TwoFish.MakeKey(KEY);
var xor_byte = new byte[TwoFish.BLOCK_SIZE];
for (int i = 0; i < TwoFish.BLOCK_SIZE; ++i)
{
xor_byte[i] = (byte)rand.Next();
}
int block_count = (uncryptedSignature.Length + 256) / 256;
int output_size = 4 + (block_count * 256) + 1;
var output = new byte[output_size];
output[0] = (byte)(msSinceStart >> 24);
output[1] = (byte)(msSinceStart >> 16);
output[2] = (byte)(msSinceStart >> 8);
output[3] = (byte)msSinceStart;
Array.Copy(uncryptedSignature, 0, output, 4, uncryptedSignature.Length);
output[output_size - 2] = (byte)(256 - uncryptedSignature.Length % 256);
for (int offset = 0; offset < block_count * 256; offset += TwoFish.BLOCK_SIZE)
{
for (int i = 0; i < TwoFish.BLOCK_SIZE; i++)
{
output[4 + offset + i] ^= xor_byte[i];
}
byte[] block = TwoFish.blockEncrypt(output, offset + 4, key);
Array.Copy(block, 0, output, offset + 4, block.Length);
Array.Copy(output, 4 + offset, xor_byte, 0, TwoFish.BLOCK_SIZE);
}
output[output_size - 1] = 0x23;
Encrypt_cipher(output, output_size);
return(output);
}
catch (Exception)
{
return(null);
}
}
/**
* Encrypts the given signature
*
* @param input input data
* @param msSinceStart time since start
* @return encrypted signature
*/
public static byte[] Encrypt(byte[] input, uint msSinceStart)
{
try
{
object[] key = TwoFish.MakeKey(KEY);
Rand rand = new Rand(msSinceStart);
byte[] iv = MakeIv(rand);
int blockCount = (input.Length + 256) / 256;
int outputSize = (blockCount * 256) + 5;
byte[] output = new byte[outputSize];
output[0] = (byte)(msSinceStart >> 24);
output[1] = (byte)(msSinceStart >> 16);
output[2] = (byte)(msSinceStart >> 8);
output[3] = (byte)msSinceStart;
Array.Copy(input, 0, output, 4, input.Length);
output[outputSize - 2] = (byte)(256 - input.Length % 256);
for (int offset = 0; offset < blockCount * 256; offset += TwoFish.BLOCK_SIZE)
{
for (int i = 0; i < TwoFish.BLOCK_SIZE; i++)
{
output[4 + offset + i] ^= iv[i];
}
byte[] block = TwoFish.blockEncrypt(output, offset + 4, key);
Array.Copy(block, 0, output, offset + 4, block.Length);
Array.Copy(output, 4 + offset, iv, 0, TwoFish.BLOCK_SIZE);
}
output[outputSize - 1] = MakeIntegrityByte(rand);
return(output);
}
catch (Exception)
{
return(null);
}
}
