public void Init(
IDerivationParameters param)
{
DHKdfParameters parameters = (DHKdfParameters)param;
this.algorithm = parameters.Algorithm;
this.keySize = parameters.KeySize;
this.z = parameters.GetZ(); // TODO Clone?
}
public override BigInteger CalculateAgreement(
ICipherParameters pubKey)
{
// Note that the ec.KeyAgreement class in JCE only uses kdf in one
// of the engineGenerateSecret methods.
BigInteger result = base.CalculateAgreement(pubKey);
int keySize = GeneratorUtilities.GetDefaultKeySize(algorithm);
DHKdfParameters dhKdfParams = new DHKdfParameters(
new DerObjectIdentifier(algorithm),
keySize,
bigIntToBytes(result));
kdf.Init(dhKdfParams);
byte[] keyBytes = new byte[keySize / 8];
kdf.GenerateBytes(keyBytes, 0, keyBytes.Length);
return new BigInteger(1, keyBytes);
}