X931SecureRandomBuilder
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Crypto.Utilities;
using Org.BouncyCastle.Security;
using Org.BouncyCastle.Utilities.Date;
using System;
namespace Org.BouncyCastle.Crypto.Prng
{
public class X931SecureRandomBuilder
{
private readonly SecureRandom mRandom;
private IEntropySourceProvider mEntropySourceProvider;
private byte[] mDateTimeVector;
public X931SecureRandomBuilder()
: this(CryptoServicesRegistrar.GetSecureRandom(), false)
{
}
public X931SecureRandomBuilder(SecureRandom entropySource, bool predictionResistant)
{
if (entropySource == null)
throw new ArgumentNullException("entropySource");
mRandom = entropySource;
mEntropySourceProvider = new BasicEntropySourceProvider(mRandom, predictionResistant);
}
public X931SecureRandomBuilder(IEntropySourceProvider entropySourceProvider)
{
mRandom = null;
mEntropySourceProvider = entropySourceProvider;
}
public X931SecureRandomBuilder SetDateTimeVector(byte[] dateTimeVector)
{
mDateTimeVector = dateTimeVector;
return this;
}
public X931SecureRandom Build(IBlockCipher engine, KeyParameter key, bool predictionResistant)
{
if (mDateTimeVector == null) {
mDateTimeVector = new byte[engine.GetBlockSize()];
Pack.UInt64_To_BE((ulong)DateTimeUtilities.CurrentUnixMs(), mDateTimeVector, 0);
}
engine.Init(true, key);
return new X931SecureRandom(mRandom, new X931Rng(engine, mDateTimeVector, mEntropySourceProvider.Get(engine.GetBlockSize() * 8)), predictionResistant);
}
}
}