public int DoOutput(byte[] output, int outOff, int outLen)
{
if (firstOutput)
{
if (!initialised)
{
throw new InvalidOperationException("KMAC not initialized");
}
byte[] encOut = XofUtilities.RightEncode(0);
cshake.BlockUpdate(encOut, 0, encOut.Length);
firstOutput = false;
}
return(cshake.DoOutput(output, outOff, outLen));
}
public int DoFinal(byte[] output, int outOff, int outLen)
{
if (firstOutput)
{
if (!initialised)
{
throw new InvalidOperationException("KMAC not initialized");
}
byte[] encOut = XofUtilities.RightEncode(outLen * 8);
cshake.BlockUpdate(encOut, 0, encOut.Length);
}
int rv = cshake.DoFinal(output, outOff, outLen);
Reset();
return(rv);
}
private void bytePad(byte[] X, int w)
{
byte[] bytes = XofUtilities.LeftEncode(w);
BlockUpdate(bytes, 0, bytes.Length);
byte[] encX = encode(X);
BlockUpdate(encX, 0, encX.Length);
int required = w - ((bytes.Length + encX.Length) % w);
if (required > 0 && required != w)
{
while (required > padding.Length)
{
BlockUpdate(padding, 0, padding.Length);
required -= padding.Length;
}
BlockUpdate(padding, 0, required);
}
}
private static byte[] encode(byte[] X)
{
return(Arrays.Concatenate(XofUtilities.LeftEncode(X.Length * 8), X));
}