public IKdfParameter CreateParameter(OneStepNoCounterConfiguration kdfConfiguration)
{
var fiPieces = kdfConfiguration.FixedInfoPattern.Split("||", StringSplitOptions.RemoveEmptyEntries).ToList();
var fiPiecesRemovedDelimiter = fiPieces.Select(fiPiece => fiPiece.Replace("||", "")).ToList();
var param = new KdfParameterOneStepNoCounter()
{
L = kdfConfiguration.L,
AuxFunction = kdfConfiguration.AuxFunction,
FixedInfoPattern = kdfConfiguration.FixedInfoPattern,
FixedInputEncoding = kdfConfiguration.FixedInfoEncoding,
// If the fixedInfoPattern contains these optional context specific fields, make up a value for them
Context = kdfConfiguration.FixedInfoPattern.Contains(nameof(KdfParameterOneStep.Context), StringComparison.OrdinalIgnoreCase) ?
_entropyProvider.GetEntropy(BitsOfEntropy) : null,
AlgorithmId = kdfConfiguration.FixedInfoPattern.Contains(nameof(KdfParameterOneStep.AlgorithmId), StringComparison.OrdinalIgnoreCase) ?
_entropyProvider.GetEntropy(BitsOfEntropy) : null,
Label = kdfConfiguration.FixedInfoPattern.Contains(nameof(KdfParameterOneStep.Label), StringComparison.OrdinalIgnoreCase) ?
_entropyProvider.GetEntropy(BitsOfEntropy) : null,
T = GetNullOrT(kdfConfiguration.FixedInfoPattern),
EntropyBits = GetEntropyBitsOrNull(kdfConfiguration.FixedInfoPattern),
};
if (kdfConfiguration.SaltLen > 0)
{
param.Salt = kdfConfiguration.SaltMethod == MacSaltMethod.Default
? new BitString(kdfConfiguration.SaltLen)
: _entropyProvider.GetEntropy(kdfConfiguration.SaltLen);
}
return(param);
}
public KdfResult Kdf(KdfParameterOneStepNoCounter param, BitString fixedInfo)
{
var result = _kdfVisitor.Kdf(param, fixedInfo);
var dkmBytesLen = result.DerivedKey.BitLength.CeilingDivide(BitString.BITSINBYTE);
// Modify a random byte within DKM
result.DerivedKey[_random.GetRandomInt(0, dkmBytesLen)] += 2;
return(result);
}
public KdfResult Kdf(KdfParameterOneStepNoCounter param, BitString fixedInfo)
{
var zBytesLen = param.Z.BitLength.CeilingDivide(BitString.BITSINBYTE);
var modifiedParam = new KdfParameterOneStepNoCounter()
{
L = param.L,
Salt = param.Salt,
Z = param.Z.GetDeepCopy(),
AuxFunction = param.AuxFunction,
FixedInfoPattern = param.FixedInfoPattern,
FixedInputEncoding = param.FixedInputEncoding
};
// Modify a random byte within Z
modifiedParam.Z[_random.GetRandomInt(0, zBytesLen)] += 2;
return(_kdfVisitor.Kdf(modifiedParam, fixedInfo));
}
public KdfResult Kdf(KdfParameterOneStepNoCounter param, BitString fixedInfo)
{
var kdf = _kdfOneStepFactory.GetInstance(param.AuxFunction, false);
return(kdf.DeriveKey(param.Z, param.L, fixedInfo, param.Salt));
}
