/**
* initialise the ElGamal engine.
*
* @param forEncryption true if we are encrypting, false otherwise.
* @param param the necessary ElGamal key parameters.
*/
public void Init(
bool forEncryption,
ICipherParameters parameters)
{
if (parameters is ParametersWithRandom)
{
ParametersWithRandom p = (ParametersWithRandom) parameters;
this.key = (ElGamalKeyParameters) p.Parameters;
this.random = p.Random;
}
else
{
this.key = (ElGamalKeyParameters) parameters;
this.random = new SecureRandom();
}
this.forEncryption = forEncryption;
this.bitSize = key.Parameters.P.BitLength;
if (forEncryption)
{
if (!(key is ElGamalPublicKeyParameters))
{
throw new ArgumentException("ElGamalPublicKeyParameters are required for encryption.");
}
}
else
{
if (!(key is ElGamalPrivateKeyParameters))
{
throw new ArgumentException("ElGamalPrivateKeyParameters are required for decryption.");
}
}
}
protected bool Equals(
ElGamalKeyParameters other)
{
return Platform.Equals(parameters, other.parameters)
&& base.Equals(other);
}
