70 lines
1.8 KiB
C#
70 lines
1.8 KiB
C#
#if !BESTHTTP_DISABLE_ALTERNATE_SSL && (!UNITY_WEBGL || UNITY_EDITOR)
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#pragma warning disable
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using System;
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using BestHTTP.SecureProtocol.Org.BouncyCastle.Crypto.Utilities;
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namespace BestHTTP.SecureProtocol.Org.BouncyCastle.Crypto.Engines
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{
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/// <summary>
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/// Implementation of Daniel J. Bernstein's ChaCha stream cipher.
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/// </summary>
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public class ChaCha7539Engine
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: Salsa20Engine
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{
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/// <summary>
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/// Creates a 20 rounds ChaCha engine.
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/// </summary>
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public ChaCha7539Engine()
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{
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}
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public override string AlgorithmName
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{
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get { return "ChaCha7539" + rounds; }
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}
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protected override int NonceSize
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{
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get { return 12; }
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}
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protected override void AdvanceCounter()
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{
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if (++engineState[12] == 0)
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throw new InvalidOperationException("attempt to increase counter past 2^32.");
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}
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protected override void ResetCounter()
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{
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engineState[12] = 0;
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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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throw new ArgumentException(AlgorithmName + " requires 256 bit key");
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PackTauOrSigma(keyBytes.Length, engineState, 0);
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// Key
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Pack.LE_To_UInt32(keyBytes, 0, engineState, 4, 8);
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}
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// IV
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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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}
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#pragma warning restore
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#endif
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