public void GenerateConfiguration()
{
ThreefishCipher cipher = ThreefishCipher.CreateCipher(m_StateSize);
UBITweak tweak = new UBITweak();
ulong[] initial_state = new ulong[m_ConfigValue.Length];
// Initialize the tweak value
tweak.StartNewType(UBIType.Config);
tweak.SetFinalFlag(true);
tweak.IncrementCount(32);
cipher.SetKey(initial_state);
cipher.SetTweak(tweak.Tweak);
cipher.Encrypt(m_ConfigString, m_ConfigValue);
m_ConfigValue[0] ^= m_ConfigString[0];
m_ConfigValue[1] ^= m_ConfigString[1];
}
public Skein(int state_size, int output_size)
{
// Make sure the output bit size > 0
if (output_size <= 0)
throw new CryptographicException("Output bit size must be greater than zero.");
m_CipherStateBits = state_size;
m_CipherStateBytes = state_size / 8;
m_CipherStateWords = state_size / 64;
base.HashSizeValue = output_size;
m_OutputBytes = (output_size + 7) / 8;
// Figure out which cipher we need based on
// the state size
m_Cipher = ThreefishCipher.CreateCipher(state_size);
if (m_Cipher == null) throw new CryptographicException("Unsupported state size.");
// Allocate buffers
m_InputBuffer = new byte[m_CipherStateBytes];
m_CipherInput = new ulong[m_CipherStateWords];
m_State = new ulong[m_CipherStateWords];
// Allocate tweak
m_Tweak = new UBITweak();
// Set default payload type (regular straight hashing)
m_PayloadType = UBIType.Message;
// Generate the configuration string
m_Configuration = new SkeinConfig(this);
m_Configuration.SetSchema("SHA3");
m_Configuration.SetVersion(1);
m_Configuration.GenerateConfiguration();
// Initialize hash
Initialize();
}