init commit

output/Libraries/BouncyCastle.Crypto/Org/BouncyCastle/Crypto/Engines/RC564Engine.cs

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+using System;
+using Org.BouncyCastle.Crypto.Parameters;
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Crypto.Engines;
+
+public class RC564Engine : IBlockCipher
+{
+	private static readonly int wordSize = 64;
+
+	private static readonly int bytesPerWord = wordSize / 8;
+
+	private int _noRounds;
+
+	private long[] _S;
+
+	private static readonly long P64 = -5196783011329398165L;
+
+	private static readonly long Q64 = -7046029254386353131L;
+
+	private bool forEncryption;
+
+	public virtual string AlgorithmName => "RC5-64";
+
+	public virtual bool IsPartialBlockOkay => false;
+
+	public RC564Engine()
+	{
+		_noRounds = 12;
+	}
+
+	public virtual int GetBlockSize()
+	{
+		return 2 * bytesPerWord;
+	}
+
+	public virtual void Init(bool forEncryption, ICipherParameters parameters)
+	{
+		if (!typeof(RC5Parameters).IsInstanceOfType(parameters))
+		{
+			throw new ArgumentException("invalid parameter passed to RC564 init - " + Platform.GetTypeName(parameters));
+		}
+		RC5Parameters rC5Parameters = (RC5Parameters)parameters;
+		this.forEncryption = forEncryption;
+		_noRounds = rC5Parameters.Rounds;
+		SetKey(rC5Parameters.GetKey());
+	}
+
+	public virtual int ProcessBlock(byte[] input, int inOff, byte[] output, int outOff)
+	{
+		if (!forEncryption)
+		{
+			return DecryptBlock(input, inOff, output, outOff);
+		}
+		return EncryptBlock(input, inOff, output, outOff);
+	}
+
+	public virtual void Reset()
+	{
+	}
+
+	private void SetKey(byte[] key)
+	{
+		long[] array = new long[(key.Length + (bytesPerWord - 1)) / bytesPerWord];
+		for (int i = 0; i != key.Length; i++)
+		{
+			long[] array3;
+			long[] array2 = (array3 = array);
+			int num = i / bytesPerWord;
+			nint num2 = num;
+			array2[num] = array3[num2] + ((long)(key[i] & 0xFF) << 8 * (i % bytesPerWord));
+		}
+		_S = new long[2 * (_noRounds + 1)];
+		_S[0] = P64;
+		for (int j = 1; j < _S.Length; j++)
+		{
+			_S[j] = _S[j - 1] + Q64;
+		}
+		int num3 = ((array.Length <= _S.Length) ? (3 * _S.Length) : (3 * array.Length));
+		long num4 = 0L;
+		long num5 = 0L;
+		int num6 = 0;
+		int num7 = 0;
+		for (int k = 0; k < num3; k++)
+		{
+			num4 = (_S[num6] = RotateLeft(_S[num6] + num4 + num5, 3L));
+			num5 = (array[num7] = RotateLeft(array[num7] + num4 + num5, num4 + num5));
+			num6 = (num6 + 1) % _S.Length;
+			num7 = (num7 + 1) % array.Length;
+		}
+	}
+
+	private int EncryptBlock(byte[] input, int inOff, byte[] outBytes, int outOff)
+	{
+		long num = BytesToWord(input, inOff) + _S[0];
+		long num2 = BytesToWord(input, inOff + bytesPerWord) + _S[1];
+		for (int i = 1; i <= _noRounds; i++)
+		{
+			num = RotateLeft(num ^ num2, num2) + _S[2 * i];
+			num2 = RotateLeft(num2 ^ num, num) + _S[2 * i + 1];
+		}
+		WordToBytes(num, outBytes, outOff);
+		WordToBytes(num2, outBytes, outOff + bytesPerWord);
+		return 2 * bytesPerWord;
+	}
+
+	private int DecryptBlock(byte[] input, int inOff, byte[] outBytes, int outOff)
+	{
+		long num = BytesToWord(input, inOff);
+		long num2 = BytesToWord(input, inOff + bytesPerWord);
+		for (int num3 = _noRounds; num3 >= 1; num3--)
+		{
+			num2 = RotateRight(num2 - _S[2 * num3 + 1], num) ^ num;
+			num = RotateRight(num - _S[2 * num3], num2) ^ num2;
+		}
+		WordToBytes(num - _S[0], outBytes, outOff);
+		WordToBytes(num2 - _S[1], outBytes, outOff + bytesPerWord);
+		return 2 * bytesPerWord;
+	}
+
+	private long RotateLeft(long x, long y)
+	{
+		return (x << (int)(y & (wordSize - 1))) | (x >>> (int)(wordSize - (y & (wordSize - 1))));
+	}
+
+	private long RotateRight(long x, long y)
+	{
+		return (x >>> (int)(y & (wordSize - 1))) | (x << (int)(wordSize - (y & (wordSize - 1))));
+	}
+
+	private long BytesToWord(byte[] src, int srcOff)
+	{
+		long num = 0L;
+		for (int num2 = bytesPerWord - 1; num2 >= 0; num2--)
+		{
+			num = (num << 8) + (src[num2 + srcOff] & 0xFF);
+		}
+		return num;
+	}
+
+	private void WordToBytes(long word, byte[] dst, int dstOff)
+	{
+		for (int i = 0; i < bytesPerWord; i++)
+		{
+			dst[i + dstOff] = (byte)word;
+			word >>>= 8;
+		}
+	}
+}