VMPCKSA3Engine.cs :  » PDF » iTextSharp » Org » BouncyCastle » Crypto » Engines » C# / CSharp Open Source

using System;

namespace Org.BouncyCastle.Crypto.Engines{
  public class VmpcKsa3Engine
    : VmpcEngine
  {
    public override string AlgorithmName
    {
      get { return "VMPC-KSA3"; }
    }

    protected override void InitKey(
      byte[]  keyBytes,
      byte[]  ivBytes)
    {
      s = 0;
      P = new byte[256];
      for (int i = 0; i < 256; i++)
      {
        P[i] = (byte) i;
      }

      for (int m = 0; m < 768; m++)
      {
        s = P[(s + P[m & 0xff] + keyBytes[m % keyBytes.Length]) & 0xff];
        byte temp = P[m & 0xff];
        P[m & 0xff] = P[s & 0xff];
        P[s & 0xff] = temp;
      }

      for (int m = 0; m < 768; m++)
      {
        s = P[(s + P[m & 0xff] + ivBytes[m % ivBytes.Length]) & 0xff];
        byte temp = P[m & 0xff];
        P[m & 0xff] = P[s & 0xff];
        P[s & 0xff] = temp;
      }

      for (int m = 0; m < 768; m++)
      {
        s = P[(s + P[m & 0xff] + keyBytes[m % keyBytes.Length]) & 0xff];
        byte temp = P[m & 0xff];
        P[m & 0xff] = P[s & 0xff];
        P[s & 0xff] = temp;
      }

      n = 0;
    }
  }
}