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