public void ShouldMultiExpandSameResult()
{
var fixedInfo = new BitString(128);
var salt = new BitString(128);
var z = new BitString(128);
var hmacAlg = HashFunctions.Sha2_d256;
var l = 256;
var hkdfParam = new KdfParameterHkdf()
{
L = l,
Salt = salt,
Z = z,
HmacAlg = hmacAlg
};
var multiExpandHkdfParam = new KdfMultiExpansionParameterHkdf()
{
Salt = salt,
Z = z,
HmacAlg = hmacAlg,
IterationParameters = new List <KdfMultiExpansionIterationParameter>()
{
new KdfMultiExpansionIterationParameter(l, fixedInfo),
new KdfMultiExpansionIterationParameter(l, fixedInfo),
}
};
var hkdfResult = _kdfVisitor.Kdf(hkdfParam, fixedInfo);
var multiExpandHkdfResult = _kdfMultiExpansionVisitor.Kdf(multiExpandHkdfParam);
Assert.True(multiExpandHkdfResult.Results.Count == 2);
Assert.AreEqual(hkdfResult.DerivedKey, multiExpandHkdfResult.Results[0].DerivedKey);
Assert.AreEqual(hkdfResult.DerivedKey, multiExpandHkdfResult.Results[1].DerivedKey);
}
public KdfResult Kdf(KdfParameterHkdf 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(KdfParameterHkdf param, BitString fixedInfo)
{
var kdf = _hkdfFactory.GetKdf(ShaAttributes.GetHashFunctionFromEnum(param.HmacAlg));
var result = kdf.DeriveKey(param.Salt, param.Z, fixedInfo, param.L / BitString.BITSINBYTE);
if (result.Success)
{
return(new KdfResult(result.DerivedKey));
}
return(new KdfResult(result.ErrorMessage));
}
public KdfResult Kdf(KdfParameterHkdf param, BitString fixedInfo)
{
var zBytesLen = param.Z.BitLength.CeilingDivide(BitString.BITSINBYTE);
var modifiedParam = new KdfParameterIkeV1()
{
L = param.L,
Z = param.Z.GetDeepCopy(),
HashFunction = param.HmacAlg
};
// Modify a random byte within Z
modifiedParam.Z[_random.GetRandomInt(0, zBytesLen)] += 2;
return(_kdfVisitor.Kdf(modifiedParam, fixedInfo));
}
