public static BitString FormatMessage(BitString message, int capacity, string functionNameString, BitString customization)
{
var functionName = Sha3DerivedHelpers.StringToHex(functionNameString);
BitString bytepad;
if (capacity == 256)
{
bytepad = Sha3DerivedHelpers.Bytepad(BitString.ConcatenateBits(Sha3DerivedHelpers.EncodeString(functionName), Sha3DerivedHelpers.EncodeString(customization)), new BitString("A8")); // "A8" is 168 (the rate)
}
else // capacity == 512
{
bytepad = Sha3DerivedHelpers.Bytepad(BitString.ConcatenateBits(Sha3DerivedHelpers.EncodeString(functionName), Sha3DerivedHelpers.EncodeString(customization)), new BitString("88")); // "88" is 136 (the rate)
}
message = BitString.ConcatenateBits(bytepad, message);
message = Sha3DerivedHelpers.SafeConcatenation(message, BitString.Zeroes(2));
return(message);
}
/// <summary>
/// Call this method to format correctly for cSHAKE
/// </summary>
/// <param name="message">BitString representation of message</param>
/// <param name="capacity">Capacity</param>
/// <param name="functionNameString">Character string representation of functionName</param>
/// <param name="customizationString">Character string for customization</param>
/// <returns>Formatted message before calling Keccak</returns>
public static BitString FormatMessage(BitString message, int capacity, string functionNameString, string customizationString)
{
var customization = Sha3DerivedHelpers.StringToHex(customizationString);
return(FormatMessage(message, capacity, functionNameString, customization));
}