init commit

output/Libraries/BouncyCastle.Crypto/Org/BouncyCastle/Crypto/Modes/SicBlockCipher.cs

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+using System;
+using Org.BouncyCastle.Crypto.Parameters;
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Crypto.Modes;
+
+public class SicBlockCipher : IBlockCipher
+{
+	private readonly IBlockCipher cipher;
+
+	private readonly int blockSize;
+
+	private readonly byte[] counter;
+
+	private readonly byte[] counterOut;
+
+	private byte[] IV;
+
+	public virtual string AlgorithmName => cipher.AlgorithmName + "/SIC";
+
+	public virtual bool IsPartialBlockOkay => true;
+
+	public SicBlockCipher(IBlockCipher cipher)
+	{
+		this.cipher = cipher;
+		blockSize = cipher.GetBlockSize();
+		counter = new byte[blockSize];
+		counterOut = new byte[blockSize];
+		IV = new byte[blockSize];
+	}
+
+	public virtual IBlockCipher GetUnderlyingCipher()
+	{
+		return cipher;
+	}
+
+	public virtual void Init(bool forEncryption, ICipherParameters parameters)
+	{
+		if (!(parameters is ParametersWithIV parametersWithIV))
+		{
+			throw new ArgumentException("CTR/SIC mode requires ParametersWithIV", "parameters");
+		}
+		IV = Arrays.Clone(parametersWithIV.GetIV());
+		if (blockSize < IV.Length)
+		{
+			throw new ArgumentException("CTR/SIC mode requires IV no greater than: " + blockSize + " bytes.");
+		}
+		int num = System.Math.Min(8, blockSize / 2);
+		if (blockSize - IV.Length > num)
+		{
+			throw new ArgumentException("CTR/SIC mode requires IV of at least: " + (blockSize - num) + " bytes.");
+		}
+		if (parametersWithIV.Parameters != null)
+		{
+			cipher.Init(forEncryption: true, parametersWithIV.Parameters);
+		}
+		Reset();
+	}
+
+	public virtual int GetBlockSize()
+	{
+		return cipher.GetBlockSize();
+	}
+
+	public virtual int ProcessBlock(byte[] input, int inOff, byte[] output, int outOff)
+	{
+		cipher.ProcessBlock(counter, 0, counterOut, 0);
+		for (int i = 0; i < counterOut.Length; i++)
+		{
+			output[outOff + i] = (byte)(counterOut[i] ^ input[inOff + i]);
+		}
+		int num = counter.Length;
+		while (--num >= 0)
+		{
+			byte[] array2;
+			byte[] array = (array2 = counter);
+			int num2 = num;
+			nint num3 = num2;
+			if ((array[num2] = (byte)(array2[num3] + 1)) != 0)
+			{
+				break;
+			}
+		}
+		return counter.Length;
+	}
+
+	public virtual void Reset()
+	{
+		Arrays.Fill(counter, 0);
+		Array.Copy(IV, 0, counter, 0, IV.Length);
+		cipher.Reset();
+	}
+}