init commit

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

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+using System;
+using Org.BouncyCastle.Crypto.Parameters;
+using Org.BouncyCastle.Crypto.Utilities;
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Crypto.Engines;
+
+public class TeaEngine : IBlockCipher
+{
+	private const int rounds = 32;
+
+	private const int block_size = 8;
+
+	private const uint delta = 2654435769u;
+
+	private const uint d_sum = 3337565984u;
+
+	private uint _a;
+
+	private uint _b;
+
+	private uint _c;
+
+	private uint _d;
+
+	private bool _initialised;
+
+	private bool _forEncryption;
+
+	public virtual string AlgorithmName => "TEA";
+
+	public virtual bool IsPartialBlockOkay => false;
+
+	public TeaEngine()
+	{
+		_initialised = false;
+	}
+
+	public virtual int GetBlockSize()
+	{
+		return 8;
+	}
+
+	public virtual void Init(bool forEncryption, ICipherParameters parameters)
+	{
+		if (!(parameters is KeyParameter))
+		{
+			throw new ArgumentException("invalid parameter passed to TEA init - " + Platform.GetTypeName(parameters));
+		}
+		_forEncryption = forEncryption;
+		_initialised = true;
+		KeyParameter keyParameter = (KeyParameter)parameters;
+		setKey(keyParameter.GetKey());
+	}
+
+	public virtual int ProcessBlock(byte[] inBytes, int inOff, byte[] outBytes, int outOff)
+	{
+		if (!_initialised)
+		{
+			throw new InvalidOperationException(AlgorithmName + " not initialised");
+		}
+		Check.DataLength(inBytes, inOff, 8, "input buffer too short");
+		Check.OutputLength(outBytes, outOff, 8, "output buffer too short");
+		if (!_forEncryption)
+		{
+			return decryptBlock(inBytes, inOff, outBytes, outOff);
+		}
+		return encryptBlock(inBytes, inOff, outBytes, outOff);
+	}
+
+	public virtual void Reset()
+	{
+	}
+
+	private void setKey(byte[] key)
+	{
+		_a = Pack.BE_To_UInt32(key, 0);
+		_b = Pack.BE_To_UInt32(key, 4);
+		_c = Pack.BE_To_UInt32(key, 8);
+		_d = Pack.BE_To_UInt32(key, 12);
+	}
+
+	private int encryptBlock(byte[] inBytes, int inOff, byte[] outBytes, int outOff)
+	{
+		uint num = Pack.BE_To_UInt32(inBytes, inOff);
+		uint num2 = Pack.BE_To_UInt32(inBytes, inOff + 4);
+		uint num3 = 0u;
+		for (int i = 0; i != 32; i++)
+		{
+			num3 += 2654435769u;
+			num += ((num2 << 4) + _a) ^ (num2 + num3) ^ ((num2 >> 5) + _b);
+			num2 += ((num << 4) + _c) ^ (num + num3) ^ ((num >> 5) + _d);
+		}
+		Pack.UInt32_To_BE(num, outBytes, outOff);
+		Pack.UInt32_To_BE(num2, outBytes, outOff + 4);
+		return 8;
+	}
+
+	private int decryptBlock(byte[] inBytes, int inOff, byte[] outBytes, int outOff)
+	{
+		uint num = Pack.BE_To_UInt32(inBytes, inOff);
+		uint num2 = Pack.BE_To_UInt32(inBytes, inOff + 4);
+		uint num3 = 3337565984u;
+		for (int i = 0; i != 32; i++)
+		{
+			num2 -= ((num << 4) + _c) ^ (num + num3) ^ ((num >> 5) + _d);
+			num -= ((num2 << 4) + _a) ^ (num2 + num3) ^ ((num2 >> 5) + _b);
+			num3 -= 2654435769u;
+		}
+		Pack.UInt32_To_BE(num, outBytes, outOff);
+		Pack.UInt32_To_BE(num2, outBytes, outOff + 4);
+		return 8;
+	}
+}