46 lines
1.0 KiB
C#
46 lines
1.0 KiB
C#
using System;
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using Org.BouncyCastle.Crypto.Utilities;
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namespace Org.BouncyCastle.Crypto.Engines;
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public class ChaCha7539Engine : Salsa20Engine
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{
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public override string AlgorithmName => "ChaCha7539" + rounds;
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protected override int NonceSize => 12;
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protected override void AdvanceCounter()
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{
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uint[] array;
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if (((array = engineState)[12] = array[12] + 1) == 0)
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{
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throw new InvalidOperationException("attempt to increase counter past 2^32.");
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}
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}
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protected override void ResetCounter()
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{
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engineState[12] = 0u;
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}
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protected override void SetKey(byte[] keyBytes, byte[] ivBytes)
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{
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if (keyBytes != null)
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{
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if (keyBytes.Length != 32)
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{
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throw new ArgumentException(AlgorithmName + " requires 256 bit key");
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}
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PackTauOrSigma(keyBytes.Length, engineState, 0);
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Pack.LE_To_UInt32(keyBytes, 0, engineState, 4, 8);
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}
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Pack.LE_To_UInt32(ivBytes, 0, engineState, 13, 3);
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}
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protected override void GenerateKeyStream(byte[] output)
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{
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ChaChaEngine.ChachaCore(rounds, engineState, x);
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Pack.UInt32_To_LE(x, output, 0);
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}
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}
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