BufferedCipherBase.cs :  » PDF » iTextSharp » Org » BouncyCastle » Crypto » C# / CSharp Open Source

using System;

namespace Org.BouncyCastle.Crypto{
  public abstract class BufferedCipherBase
    : IBufferedCipher
  {
    protected static readonly byte[] EmptyBuffer = new byte[0];

    public abstract string AlgorithmName { get; }

    public abstract void Init(bool forEncryption, ICipherParameters parameters);

    public abstract int GetBlockSize();

    public abstract int GetOutputSize(int inputLen);
    public abstract int GetUpdateOutputSize(int inputLen);

    public abstract byte[] ProcessByte(byte input);

    public virtual int ProcessByte(
      byte  input,
      byte[]  output,
      int    outOff)
    {
      byte[] outBytes = ProcessByte(input);
      if (outBytes == null)
        return 0;
      if (outOff + outBytes.Length > output.Length)
        throw new DataLengthException("output buffer too short");
      outBytes.CopyTo(output, outOff);
      return outBytes.Length;
    }

    public virtual byte[] ProcessBytes(
      byte[] input)
    {
      return ProcessBytes(input, 0, input.Length);
    }

    public abstract byte[] ProcessBytes(byte[] input, int inOff, int length);

    public virtual int ProcessBytes(
      byte[]  input,
      byte[]  output,
      int    outOff)
    {
      return ProcessBytes(input, 0, input.Length, output, outOff);
    }

    public virtual int ProcessBytes(
      byte[]  input,
      int    inOff,
      int    length,
      byte[]  output,
      int    outOff)
    {
      byte[] outBytes = ProcessBytes(input, inOff, length);
      if (outBytes == null)
        return 0;
      if (outOff + outBytes.Length > output.Length)
        throw new DataLengthException("output buffer too short");
      outBytes.CopyTo(output, outOff);
      return outBytes.Length;
    }

    public abstract byte[] DoFinal();

    public virtual byte[] DoFinal(
      byte[] input)
    {
      return DoFinal(input, 0, input.Length);
    }

    public abstract byte[] DoFinal(
      byte[]  input,
      int    inOff,
      int    length);

    public virtual int DoFinal(
      byte[]  output,
      int    outOff)
    {
      byte[] outBytes = DoFinal();
      if (outOff + outBytes.Length > output.Length)
        throw new DataLengthException("output buffer too short");
      outBytes.CopyTo(output, outOff);
      return outBytes.Length;
    }

    public virtual int DoFinal(
      byte[]  input,
      byte[]  output,
      int    outOff)
    {
      return DoFinal(input, 0, input.Length, output, outOff);
    }

    public virtual int DoFinal(
      byte[]  input,
      int    inOff,
      int    length,
      byte[]  output,
      int    outOff)
    {
      int len = ProcessBytes(input, inOff, length, output, outOff);
      len += DoFinal(output, outOff + len);
      return len;
    }

    public abstract void Reset();
  }
}