public KdfResult Kdf(KdfParameterTwoStep param, BitString fixedInfo)
{
IMac randomnessExtractionMac = null;
MacModes keyExpansionMacMode = param.MacMode;
switch (param.MacMode)
{
case MacModes.CMAC_AES128:
randomnessExtractionMac = _cmacFactory.GetCmacInstance(CmacTypes.AES128);
break;
case MacModes.CMAC_AES192:
randomnessExtractionMac = _cmacFactory.GetCmacInstance(CmacTypes.AES192);
keyExpansionMacMode = MacModes.CMAC_AES128;
break;
case MacModes.CMAC_AES256:
randomnessExtractionMac = _cmacFactory.GetCmacInstance(CmacTypes.AES256);
keyExpansionMacMode = MacModes.CMAC_AES128;
break;
case MacModes.HMAC_SHA1:
randomnessExtractionMac =
_hmacFactory.GetHmacInstance(new HashFunction(ModeValues.SHA1, DigestSizes.d160));
break;
case MacModes.HMAC_SHA224:
randomnessExtractionMac =
_hmacFactory.GetHmacInstance(new HashFunction(ModeValues.SHA2, DigestSizes.d224));
break;
case MacModes.HMAC_SHA256:
randomnessExtractionMac =
_hmacFactory.GetHmacInstance(new HashFunction(ModeValues.SHA2, DigestSizes.d256));
break;
case MacModes.HMAC_SHA384:
randomnessExtractionMac =
_hmacFactory.GetHmacInstance(new HashFunction(ModeValues.SHA2, DigestSizes.d384));
break;
case MacModes.HMAC_SHA512:
randomnessExtractionMac =
_hmacFactory.GetHmacInstance(new HashFunction(ModeValues.SHA2, DigestSizes.d512));
break;
case MacModes.HMAC_SHA_d512t224:
randomnessExtractionMac =
_hmacFactory.GetHmacInstance(new HashFunction(ModeValues.SHA2, DigestSizes.d512t224));
break;
case MacModes.HMAC_SHA_d512t256:
randomnessExtractionMac =
_hmacFactory.GetHmacInstance(new HashFunction(ModeValues.SHA2, DigestSizes.d512t256));
break;
case MacModes.HMAC_SHA3_224:
randomnessExtractionMac =
_hmacFactory.GetHmacInstance(new HashFunction(ModeValues.SHA3, DigestSizes.d224));
break;
case MacModes.HMAC_SHA3_256:
randomnessExtractionMac =
_hmacFactory.GetHmacInstance(new HashFunction(ModeValues.SHA3, DigestSizes.d256));
break;
case MacModes.HMAC_SHA3_384:
randomnessExtractionMac =
_hmacFactory.GetHmacInstance(new HashFunction(ModeValues.SHA3, DigestSizes.d384));
break;
case MacModes.HMAC_SHA3_512:
randomnessExtractionMac =
_hmacFactory.GetHmacInstance(new HashFunction(ModeValues.SHA3, DigestSizes.d512));
break;
default:
throw new ArgumentException($"Invalid {nameof(MacModes)} provided to KdfVisitor.");
}
// Randomness extraction (step one)
var randomnessExtraction = randomnessExtractionMac.Generate(param.Salt, param.Z);
// Key Expansion (step two)
var kdf = _kdfTwoStepFactory.GetKdfInstance(
param.KdfMode,
keyExpansionMacMode,
param.CounterLocation,
param.CounterLen);
return(new KdfResult(kdf.DeriveKey(randomnessExtraction.Mac, fixedInfo, param.L, param.Iv, 0).DerivedKey));
}
protected BitString PseudoRandomFunction(BitString key, BitString data)
{
return(Mac.Generate(key, data).Mac);
}