path: root/gnu/javax/crypto/cipher/Rijndael.java

/* Rijndael.java -- 
   Copyright (C) 2001, 2002, 2003, 2006 Free Software Foundation, Inc.

This file is a part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at
your option) any later version.

GNU Classpath is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Classpath; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
USA

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
module.  An independent module is a module which is not derived from
or based on this library.  If you modify this library, you may extend
this exception to your version of the library, but you are not
obligated to do so.  If you do not wish to do so, delete this
exception statement from your version.  */


package gnu.javax.crypto.cipher;

import gnu.java.security.Registry;
import gnu.java.security.util.Util;

//import java.io.PrintWriter;
import java.security.InvalidKeyException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;

/**
 * <p>Rijndael --pronounced Reindaal-- is the AES. It is a variable block-size
 * (128-, 192- and 256-bit), variable key-size (128-, 192- and 256-bit)
 * symmetric key block cipher.</p>
 *
 * <p>References:</p>
 *
 * <ol>
 *    <li><a href="http://www.esat.kuleuven.ac.be/~rijmen/rijndael/">The
 *    Rijndael Block Cipher - AES Proposal</a>.<br>
 *    <a href="mailto:vincent.rijmen@esat.kuleuven.ac.be">Vincent Rijmen</a> and
 *    <a href="mailto:daemen.j@protonworld.com">Joan Daemen</a>.</li>
 * </ol>
 */
public final class Rijndael extends BaseCipher
{

  // Debugging methods and variables
  // -------------------------------------------------------------------------

  //   private static final String NAME = "rijndael";
  private static final boolean DEBUG = false;

  private static final int debuglevel = 9;

  //   private static final PrintWriter err = new PrintWriter(System.out, true);
  //   private static void debug(String s) {
  //      err.println(">>> "+NAME+": "+s);
  //   }

  // Constants and variables
  // -------------------------------------------------------------------------

  private static final int DEFAULT_BLOCK_SIZE = 16; // in bytes

  private static final int DEFAULT_KEY_SIZE = 16; // in bytes

  private static final String SS = "\u637C\u777B\uF26B\u6FC5\u3001\u672B\uFED7\uAB76"
                                   + "\uCA82\uC97D\uFA59\u47F0\uADD4\uA2AF\u9CA4\u72C0"
                                   + "\uB7FD\u9326\u363F\uF7CC\u34A5\uE5F1\u71D8\u3115"
                                   + "\u04C7\u23C3\u1896\u059A\u0712\u80E2\uEB27\uB275"
                                   + "\u0983\u2C1A\u1B6E\u5AA0\u523B\uD6B3\u29E3\u2F84"
                                   + "\u53D1\u00ED\u20FC\uB15B\u6ACB\uBE39\u4A4C\u58CF"
                                   + "\uD0EF\uAAFB\u434D\u3385\u45F9\u027F\u503C\u9FA8"
                                   + "\u51A3\u408F\u929D\u38F5\uBCB6\uDA21\u10FF\uF3D2"
                                   + "\uCD0C\u13EC\u5F97\u4417\uC4A7\u7E3D\u645D\u1973"
                                   + "\u6081\u4FDC\u222A\u9088\u46EE\uB814\uDE5E\u0BDB"
                                   + "\uE032\u3A0A\u4906\u245C\uC2D3\uAC62\u9195\uE479"
                                   + "\uE7C8\u376D\u8DD5\u4EA9\u6C56\uF4EA\u657A\uAE08"
                                   + "\uBA78\u252E\u1CA6\uB4C6\uE8DD\u741F\u4BBD\u8B8A"
                                   + "\u703E\uB566\u4803\uF60E\u6135\u57B9\u86C1\u1D9E"
                                   + "\uE1F8\u9811\u69D9\u8E94\u9B1E\u87E9\uCE55\u28DF"
                                   + "\u8CA1\u890D\uBFE6\u4268\u4199\u2D0F\uB054\uBB16";

  private static final byte[] S = new byte[256];

  private static final byte[] Si = new byte[256];

  private static final int[] T1 = new int[256];

  private static final int[] T2 = new int[256];

  private static final int[] T3 = new int[256];

  private static final int[] T4 = new int[256];

  private static final int[] T5 = new int[256];

  private static final int[] T6 = new int[256];

  private static final int[] T7 = new int[256];

  private static final int[] T8 = new int[256];

  private static final int[] U1 = new int[256];

  private static final int[] U2 = new int[256];

  private static final int[] U3 = new int[256];

  private static final int[] U4 = new int[256];

  private static final byte[] rcon = new byte[30];

  private static final int[][][] shifts = new int[][][] {
                                                         { { 0, 0 }, { 1, 3 },
                                                          { 2, 2 }, { 3, 1 } },
                                                         { { 0, 0 }, { 1, 5 },
                                                          { 2, 4 }, { 3, 3 } },
                                                         { { 0, 0 }, { 1, 7 },
                                                          { 3, 5 }, { 4, 4 } } };

  /**
   * KAT vector (from ecb_vk):
   * I=96
   * KEY=0000000000000000000000010000000000000000000000000000000000000000
   * CT=E44429474D6FC3084EB2A6B8B46AF754
   */
  private static final byte[] KAT_KEY = Util.toBytesFromString("0000000000000000000000010000000000000000000000000000000000000000");

  private static final byte[] KAT_CT = Util.toBytesFromString("E44429474D6FC3084EB2A6B8B46AF754");

  /** caches the result of the correctness test, once executed. */
  private static Boolean valid;

  // Static code - to intialise lookup tables --------------------------------

  static
    {
      long time = System.currentTimeMillis();

      int ROOT = 0x11B;
      int i, j = 0;

      // S-box, inverse S-box, T-boxes, U-boxes
      int s, s2, s3, i2, i4, i8, i9, ib, id, ie, t;
      char c;
      for (i = 0; i < 256; i++)
        {
          c = SS.charAt(i >>> 1);
          S[i] = (byte) (((i & 1) == 0) ? c >>> 8 : c & 0xFF);
          s = S[i] & 0xFF;
          Si[s] = (byte) i;
          s2 = s << 1;
          if (s2 >= 0x100)
            {
              s2 ^= ROOT;
            }
          s3 = s2 ^ s;
          i2 = i << 1;
          if (i2 >= 0x100)
            {
              i2 ^= ROOT;
            }
          i4 = i2 << 1;
          if (i4 >= 0x100)
            {
              i4 ^= ROOT;
            }
          i8 = i4 << 1;
          if (i8 >= 0x100)
            {
              i8 ^= ROOT;
            }
          i9 = i8 ^ i;
          ib = i9 ^ i2;
          id = i9 ^ i4;
          ie = i8 ^ i4 ^ i2;

          T1[i] = t = (s2 << 24) | (s << 16) | (s << 8) | s3;
          T2[i] = (t >>> 8) | (t << 24);
          T3[i] = (t >>> 16) | (t << 16);
          T4[i] = (t >>> 24) | (t << 8);

          T5[s] = U1[i] = t = (ie << 24) | (i9 << 16) | (id << 8) | ib;
          T6[s] = U2[i] = (t >>> 8) | (t << 24);
          T7[s] = U3[i] = (t >>> 16) | (t << 16);
          T8[s] = U4[i] = (t >>> 24) | (t << 8);
        }
      //
      // round constants
      //
      int r = 1;
      rcon[0] = 1;
      for (i = 1; i < 30; i++)
        {
          r <<= 1;
          if (r >= 0x100)
            {
              r ^= ROOT;
            }
          rcon[i] = (byte) r;
        }

      time = System.currentTimeMillis() - time;

      if (DEBUG && debuglevel > 8)
        {
          System.out.println("==========");
          System.out.println();
          System.out.println("Static Data");
          System.out.println();
          System.out.println("S[]:");
          for (i = 0; i < 16; i++)
            {
              for (j = 0; j < 16; j++)
                {
                  System.out.print("0x" + Util.toString(S[i * 16 + j]) + ", ");
                }
              System.out.println();
            }
          System.out.println();
          System.out.println("Si[]:");
          for (i = 0; i < 16; i++)
            {
              for (j = 0; j < 16; j++)
                {
                  System.out.print("0x" + Util.toString(Si[i * 16 + j]) + ", ");
                }
              System.out.println();
            }

          System.out.println();
          System.out.println("T1[]:");
          for (i = 0; i < 64; i++)
            {
              for (j = 0; j < 4; j++)
                {
                  System.out.print("0x" + Util.toString(T1[i * 4 + j]) + ", ");
                }
              System.out.println();
            }
          System.out.println();
          System.out.println("T2[]:");
          for (i = 0; i < 64; i++)
            {
              for (j = 0; j < 4; j++)
                {
                  System.out.print("0x" + Util.toString(T2[i * 4 + j]) + ", ");
                }
              System.out.println();
            }
          System.out.println();
          System.out.println("T3[]:");
          for (i = 0; i < 64; i++)
            {
              for (j = 0; j < 4; j++)
                {
                  System.out.print("0x" + Util.toString(T3[i * 4 + j]) + ", ");
                }
              System.out.println();
            }
          System.out.println();
          System.out.println("T4[]:");
          for (i = 0; i < 64; i++)
            {
              for (j = 0; j < 4; j++)
                {
                  System.out.print("0x" + Util.toString(T4[i * 4 + j]) + ", ");
                }
              System.out.println();
            }
          System.out.println();
          System.out.println("T5[]:");
          for (i = 0; i < 64; i++)
            {
              for (j = 0; j < 4; j++)
                {
                  System.out.print("0x" + Util.toString(T5[i * 4 + j]) + ", ");
                }
              System.out.println();
            }
          System.out.println();
          System.out.println("T6[]:");
          for (i = 0; i < 64; i++)
            {
              for (j = 0; j < 4; j++)
                {
                  System.out.print("0x" + Util.toString(T6[i * 4 + j]) + ", ");
                }
              System.out.println();
            }
          System.out.println();
          System.out.println("T7[]:");
          for (i = 0; i < 64; i++)
            {
              for (j = 0; j < 4; j++)
                {
                  System.out.print("0x" + Util.toString(T7[i * 4 + j]) + ", ");
                }
              System.out.println();
            }
          System.out.println();
          System.out.println("T8[]:");
          for (i = 0; i < 64; i++)
            {
              for (j = 0; j < 4; j++)
                {
                  System.out.print("0x" + Util.toString(T8[i * 4 + j]) + ", ");
                }
              System.out.println();
            }

          System.out.println();
          System.out.println("U1[]:");
          for (i = 0; i < 64; i++)
            {
              for (j = 0; j < 4; j++)
                {
                  System.out.print("0x" + Util.toString(U1[i * 4 + j]) + ", ");
                }
              System.out.println();
            }
          System.out.println();
          System.out.println("U2[]:");
          for (i = 0; i < 64; i++)
            {
              for (j = 0; j < 4; j++)
                {
                  System.out.print("0x" + Util.toString(U2[i * 4 + j]) + ", ");
                }
              System.out.println();
            }
          System.out.println();
          System.out.println("U3[]:");
          for (i = 0; i < 64; i++)
            {
              for (j = 0; j < 4; j++)
                {
                  System.out.print("0x" + Util.toString(U3[i * 4 + j]) + ", ");
                }
              System.out.println();
            }
          System.out.println();
          System.out.println("U4[]:");
          for (i = 0; i < 64; i++)
            {
              for (j = 0; j < 4; j++)
                {
                  System.out.println("0x" + Util.toString(U4[i * 4 + j]) + ", ");
                }
              System.out.println();
            }

          System.out.println();
          System.out.println("rcon[]:");
          for (i = 0; i < 5; i++)
            {
              for (j = 0; j < 6; j++)
                {
                  System.out.print("0x" + Util.toString(rcon[i * 6 + j]) + ", ");
                }
              System.out.println();
            }

          System.out.println();
          System.out.println("Total initialization time: " + time + " ms.");
          System.out.println();
        }
    }

  // Constructor(s)
  // -------------------------------------------------------------------------

  /** Trivial 0-arguments constructor. */
  public Rijndael()
  {
    super(Registry.RIJNDAEL_CIPHER, DEFAULT_BLOCK_SIZE, DEFAULT_KEY_SIZE);
  }

  // Class methods
  // -------------------------------------------------------------------------

  /**
   * <p>Returns the number of rounds for a given Rijndael's key and block
   * sizes.</p>
   *
   * @param ks the size of the user key material in bytes.
   * @param bs the desired block size in bytes.
   * @return the number of rounds for a given Rijndael's key and block sizes.
   */
  public static int getRounds(int ks, int bs)
  {
    switch (ks)
      {
      case 16:
        return bs == 16 ? 10 : (bs == 24 ? 12 : 14);
      case 24:
        return bs != 32 ? 12 : 14;
      default: // 32 bytes = 256 bits
        return 14;
      }
  }

  private static void rijndaelEncrypt(byte[] in, int inOffset, byte[] out,
                                      int outOffset, Object sessionKey, int bs)
  {
    Object[] sKey = (Object[]) sessionKey; // extract encryption round keys
    int[][] Ke = (int[][]) sKey[0];

    int BC = bs / 4;
    int ROUNDS = Ke.length - 1;
    int SC = BC == 4 ? 0 : (BC == 6 ? 1 : 2);
    int s1 = shifts[SC][1][0];
    int s2 = shifts[SC][2][0];
    int s3 = shifts[SC][3][0];
    int[] a = new int[BC];
    int[] t = new int[BC]; // temporary work array
    int i, tt;

    for (i = 0; i < BC; i++)
      { // plaintext to ints + key
        t[i] = (in[inOffset++] << 24 | (in[inOffset++] & 0xFF) << 16
                | (in[inOffset++] & 0xFF) << 8 | (in[inOffset++] & 0xFF))
               ^ Ke[0][i];
      }

    for (int r = 1; r < ROUNDS; r++)
      { // apply round transforms
        for (i = 0; i < BC; i++)
          {
            a[i] = (T1[(t[i] >>> 24)] ^ T2[(t[(i + s1) % BC] >>> 16) & 0xFF]
                    ^ T3[(t[(i + s2) % BC] >>> 8) & 0xFF] ^ T4[t[(i + s3) % BC] & 0xFF])
                   ^ Ke[r][i];
          }

        System.arraycopy(a, 0, t, 0, BC);

        if (DEBUG && debuglevel > 6)
          {
            System.out.println("CT" + r + "=" + Util.toString(t));
          }
      }

    for (i = 0; i < BC; i++)
      { // last round is special
        tt = Ke[ROUNDS][i];
        out[outOffset++] = (byte) (S[(t[i] >>> 24)] ^ (tt >>> 24));
        out[outOffset++] = (byte) (S[(t[(i + s1) % BC] >>> 16) & 0xFF] ^ (tt >>> 16));
        out[outOffset++] = (byte) (S[(t[(i + s2) % BC] >>> 8) & 0xFF] ^ (tt >>> 8));
        out[outOffset++] = (byte) (S[t[(i + s3) % BC] & 0xFF] ^ tt);
      }

    if (DEBUG && debuglevel > 6)
      {
        System.out.println("CT=" + Util.toString(out, outOffset - bs + 1, bs));
        System.out.println();
      }
  }

  private static void rijndaelDecrypt(byte[] in, int inOffset, byte[] out,
                                      int outOffset, Object sessionKey, int bs)
  {
    Object[] sKey = (Object[]) sessionKey; // extract decryption round keys
    int[][] Kd = (int[][]) sKey[1];

    int BC = bs / 4;
    int ROUNDS = Kd.length - 1;
    int SC = BC == 4 ? 0 : (BC == 6 ? 1 : 2);
    int s1 = shifts[SC][1][1];
    int s2 = shifts[SC][2][1];
    int s3 = shifts[SC][3][1];
    int[] a = new int[BC];
    int[] t = new int[BC]; // temporary work array
    int i, tt;

    for (i = 0; i < BC; i++)
      { // ciphertext to ints + key
        t[i] = (in[inOffset++] << 24 | (in[inOffset++] & 0xFF) << 16
                | (in[inOffset++] & 0xFF) << 8 | (in[inOffset++] & 0xFF))
               ^ Kd[0][i];
      }

    for (int r = 1; r < ROUNDS; r++)
      { // apply round transforms
        for (i = 0; i < BC; i++)
          {
            a[i] = (T5[(t[i] >>> 24)] ^ T6[(t[(i + s1) % BC] >>> 16) & 0xFF]
                    ^ T7[(t[(i + s2) % BC] >>> 8) & 0xFF] ^ T8[t[(i + s3) % BC] & 0xFF])
                   ^ Kd[r][i];
          }

        System.arraycopy(a, 0, t, 0, BC);

        if (DEBUG && debuglevel > 6)
          {
            System.out.println("PT" + r + "=" + Util.toString(t));
          }
      }

    for (i = 0; i < BC; i++)
      { // last round is special
        tt = Kd[ROUNDS][i];
        out[outOffset++] = (byte) (Si[(t[i] >>> 24)] ^ (tt >>> 24));
        out[outOffset++] = (byte) (Si[(t[(i + s1) % BC] >>> 16) & 0xFF] ^ (tt >>> 16));
        out[outOffset++] = (byte) (Si[(t[(i + s2) % BC] >>> 8) & 0xFF] ^ (tt >>> 8));
        out[outOffset++] = (byte) (Si[t[(i + s3) % BC] & 0xFF] ^ tt);
      }

    if (DEBUG && debuglevel > 6)
      {
        System.out.println("PT=" + Util.toString(out, outOffset - bs + 1, bs));
        System.out.println();
      }
  }

  private static void aesEncrypt(byte[] in, int i, byte[] out, int j, Object key)
  {
    int[][] Ke = (int[][]) ((Object[]) key)[0]; // extract encryption round keys
    int ROUNDS = Ke.length - 1;
    int[] Ker = Ke[0];

    // plaintext to ints + key
    int t0 = (in[i++] << 24 | (in[i++] & 0xFF) << 16 | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF))
             ^ Ker[0];
    int t1 = (in[i++] << 24 | (in[i++] & 0xFF) << 16 | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF))
             ^ Ker[1];
    int t2 = (in[i++] << 24 | (in[i++] & 0xFF) << 16 | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF))
             ^ Ker[2];
    int t3 = (in[i++] << 24 | (in[i++] & 0xFF) << 16 | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF))
             ^ Ker[3];

    int a0, a1, a2, a3;
    for (int r = 1; r < ROUNDS; r++)
      { // apply round transforms
        Ker = Ke[r];
        a0 = (T1[(t0 >>> 24)] ^ T2[(t1 >>> 16) & 0xFF] ^ T3[(t2 >>> 8) & 0xFF] ^ T4[t3 & 0xFF])
             ^ Ker[0];
        a1 = (T1[(t1 >>> 24)] ^ T2[(t2 >>> 16) & 0xFF] ^ T3[(t3 >>> 8) & 0xFF] ^ T4[t0 & 0xFF])
             ^ Ker[1];
        a2 = (T1[(t2 >>> 24)] ^ T2[(t3 >>> 16) & 0xFF] ^ T3[(t0 >>> 8) & 0xFF] ^ T4[t1 & 0xFF])
             ^ Ker[2];
        a3 = (T1[(t3 >>> 24)] ^ T2[(t0 >>> 16) & 0xFF] ^ T3[(t1 >>> 8) & 0xFF] ^ T4[t2 & 0xFF])
             ^ Ker[3];
        t0 = a0;
        t1 = a1;
        t2 = a2;
        t3 = a3;

        if (DEBUG && debuglevel > 6)
          {
            System.out.println("CT" + r + "=" + Util.toString(t0)
                               + Util.toString(t1) + Util.toString(t2)
                               + Util.toString(t3));
          }
      }

    // last round is special
    Ker = Ke[ROUNDS];
    int tt = Ker[0];
    out[j++] = (byte) (S[(t0 >>> 24)] ^ (tt >>> 24));
    out[j++] = (byte) (S[(t1 >>> 16) & 0xFF] ^ (tt >>> 16));
    out[j++] = (byte) (S[(t2 >>> 8) & 0xFF] ^ (tt >>> 8));
    out[j++] = (byte) (S[t3 & 0xFF] ^ tt);
    tt = Ker[1];
    out[j++] = (byte) (S[(t1 >>> 24)] ^ (tt >>> 24));
    out[j++] = (byte) (S[(t2 >>> 16) & 0xFF] ^ (tt >>> 16));
    out[j++] = (byte) (S[(t3 >>> 8) & 0xFF] ^ (tt >>> 8));
    out[j++] = (byte) (S[t0 & 0xFF] ^ tt);
    tt = Ker[2];
    out[j++] = (byte) (S[(t2 >>> 24)] ^ (tt >>> 24));
    out[j++] = (byte) (S[(t3 >>> 16) & 0xFF] ^ (tt >>> 16));
    out[j++] = (byte) (S[(t0 >>> 8) & 0xFF] ^ (tt >>> 8));
    out[j++] = (byte) (S[t1 & 0xFF] ^ tt);
    tt = Ker[3];
    out[j++] = (byte) (S[(t3 >>> 24)] ^ (tt >>> 24));
    out[j++] = (byte) (S[(t0 >>> 16) & 0xFF] ^ (tt >>> 16));
    out[j++] = (byte) (S[(t1 >>> 8) & 0xFF] ^ (tt >>> 8));
    out[j++] = (byte) (S[t2 & 0xFF] ^ tt);

    if (DEBUG && debuglevel > 6)
      {
        System.out.println("CT=" + Util.toString(out, j - 15, 16));
        System.out.println();
      }
  }

  private static void aesDecrypt(byte[] in, int i, byte[] out, int j, Object key)
  {
    int[][] Kd = (int[][]) ((Object[]) key)[1]; // extract decryption round keys
    int ROUNDS = Kd.length - 1;
    int[] Kdr = Kd[0];

    // ciphertext to ints + key
    int t0 = (in[i++] << 24 | (in[i++] & 0xFF) << 16 | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF))
             ^ Kdr[0];
    int t1 = (in[i++] << 24 | (in[i++] & 0xFF) << 16 | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF))
             ^ Kdr[1];
    int t2 = (in[i++] << 24 | (in[i++] & 0xFF) << 16 | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF))
             ^ Kdr[2];
    int t3 = (in[i++] << 24 | (in[i++] & 0xFF) << 16 | (in[i++] & 0xFF) << 8 | (in[i++] & 0xFF))
             ^ Kdr[3];

    int a0, a1, a2, a3;
    for (int r = 1; r < ROUNDS; r++)
      { // apply round transforms
        Kdr = Kd[r];
        a0 = (T5[(t0 >>> 24)] ^ T6[(t3 >>> 16) & 0xFF] ^ T7[(t2 >>> 8) & 0xFF] ^ T8[t1 & 0xFF])
             ^ Kdr[0];
        a1 = (T5[(t1 >>> 24)] ^ T6[(t0 >>> 16) & 0xFF] ^ T7[(t3 >>> 8) & 0xFF] ^ T8[t2 & 0xFF])
             ^ Kdr[1];
        a2 = (T5[(t2 >>> 24)] ^ T6[(t1 >>> 16) & 0xFF] ^ T7[(t0 >>> 8) & 0xFF] ^ T8[t3 & 0xFF])
             ^ Kdr[2];
        a3 = (T5[(t3 >>> 24)] ^ T6[(t2 >>> 16) & 0xFF] ^ T7[(t1 >>> 8) & 0xFF] ^ T8[t0 & 0xFF])
             ^ Kdr[3];
        t0 = a0;
        t1 = a1;
        t2 = a2;
        t3 = a3;

        if (DEBUG && debuglevel > 6)
          {
            System.out.println("PT" + r + "=" + Util.toString(t0)
                               + Util.toString(t1) + Util.toString(t2)
                               + Util.toString(t3));
          }
      }

    // last round is special
    Kdr = Kd[ROUNDS];
    int tt = Kdr[0];
    out[j++] = (byte) (Si[(t0 >>> 24)] ^ (tt >>> 24));
    out[j++] = (byte) (Si[(t3 >>> 16) & 0xFF] ^ (tt >>> 16));
    out[j++] = (byte) (Si[(t2 >>> 8) & 0xFF] ^ (tt >>> 8));
    out[j++] = (byte) (Si[t1 & 0xFF] ^ tt);
    tt = Kdr[1];
    out[j++] = (byte) (Si[(t1 >>> 24)] ^ (tt >>> 24));
    out[j++] = (byte) (Si[(t0 >>> 16) & 0xFF] ^ (tt >>> 16));
    out[j++] = (byte) (Si[(t3 >>> 8) & 0xFF] ^ (tt >>> 8));
    out[j++] = (byte) (Si[t2 & 0xFF] ^ tt);
    tt = Kdr[2];
    out[j++] = (byte) (Si[(t2 >>> 24)] ^ (tt >>> 24));
    out[j++] = (byte) (Si[(t1 >>> 16) & 0xFF] ^ (tt >>> 16));
    out[j++] = (byte) (Si[(t0 >>> 8) & 0xFF] ^ (tt >>> 8));
    out[j++] = (byte) (Si[t3 & 0xFF] ^ tt);
    tt = Kdr[3];
    out[j++] = (byte) (Si[(t3 >>> 24)] ^ (tt >>> 24));
    out[j++] = (byte) (Si[(t2 >>> 16) & 0xFF] ^ (tt >>> 16));
    out[j++] = (byte) (Si[(t1 >>> 8) & 0xFF] ^ (tt >>> 8));
    out[j++] = (byte) (Si[t0 & 0xFF] ^ tt);

    if (DEBUG && debuglevel > 6)
      {
        System.out.println("PT=" + Util.toString(out, j - 15, 16));
        System.out.println();
      }
  }

  // Instance methods
  // -------------------------------------------------------------------------

  // java.lang.Cloneable interface implementation ----------------------------

  public Object clone()
  {
    Rijndael result = new Rijndael();
    result.currentBlockSize = this.currentBlockSize;

    return result;
  }

  // IBlockCipherSpi interface implementation --------------------------------

  public Iterator blockSizes()
  {
    ArrayList al = new ArrayList();
    al.add(new Integer(128 / 8));
    al.add(new Integer(192 / 8));
    al.add(new Integer(256 / 8));

    return Collections.unmodifiableList(al).iterator();
  }

  public Iterator keySizes()
  {
    ArrayList al = new ArrayList();
    al.add(new Integer(128 / 8));
    al.add(new Integer(192 / 8));
    al.add(new Integer(256 / 8));

    return Collections.unmodifiableList(al).iterator();
  }

  /**
   * Expands a user-supplied key material into a session key for a designated
   * <i>block size</i>.
   *
   * @param k the 128/192/256-bit user-key to use.
   * @param bs the block size in bytes of this Rijndael.
   * @return an Object encapsulating the session key.
   * @exception IllegalArgumentException if the block size is not 16, 24 or 32.
   * @exception InvalidKeyException if the key data is invalid.
   */
  public Object makeKey(byte[] k, int bs) throws InvalidKeyException
  {
    if (k == null)
      {
        throw new InvalidKeyException("Empty key");
      }
    if (!(k.length == 16 || k.length == 24 || k.length == 32))
      {
        throw new InvalidKeyException("Incorrect key length");
      }
    if (!(bs == 16 || bs == 24 || bs == 32))
      {
        throw new IllegalArgumentException();
      }

    int ROUNDS = getRounds(k.length, bs);
    int BC = bs / 4;
    int[][] Ke = new int[ROUNDS + 1][BC]; // encryption round keys
    int[][] Kd = new int[ROUNDS + 1][BC]; // decryption round keys
    int ROUND_KEY_COUNT = (ROUNDS + 1) * BC;
    int KC = k.length / 4;
    int[] tk = new int[KC];
    int i, j;

    // copy user material bytes into temporary ints
    for (i = 0, j = 0; i < KC;)
      {
        tk[i++] = k[j++] << 24 | (k[j++] & 0xFF) << 16 | (k[j++] & 0xFF) << 8
                  | (k[j++] & 0xFF);
      }
    // copy values into round key arrays
    int t = 0;
    for (j = 0; (j < KC) && (t < ROUND_KEY_COUNT); j++, t++)
      {
        Ke[t / BC][t % BC] = tk[j];
        Kd[ROUNDS - (t / BC)][t % BC] = tk[j];
      }
    int tt, rconpointer = 0;
    while (t < ROUND_KEY_COUNT)
      {
        // extrapolate using phi (the round key evolution function)
        tt = tk[KC - 1];
        tk[0] ^= (S[(tt >>> 16) & 0xFF] & 0xFF) << 24
                 ^ (S[(tt >>> 8) & 0xFF] & 0xFF) << 16
                 ^ (S[tt & 0xFF] & 0xFF) << 8 ^ (S[(tt >>> 24)] & 0xFF)
                 ^ rcon[rconpointer++] << 24;
        if (KC != 8)
          {
            for (i = 1, j = 0; i < KC;)
              {
                tk[i++] ^= tk[j++];
              }
          }
        else
          {
            for (i = 1, j = 0; i < KC / 2;)
              {
                tk[i++] ^= tk[j++];
              }
            tt = tk[KC / 2 - 1];
            tk[KC / 2] ^= (S[tt & 0xFF] & 0xFF)
                          ^ (S[(tt >>> 8) & 0xFF] & 0xFF) << 8
                          ^ (S[(tt >>> 16) & 0xFF] & 0xFF) << 16
                          ^ S[(tt >>> 24) & 0xFF] << 24;
            for (j = KC / 2, i = j + 1; i < KC;)
              {
                tk[i++] ^= tk[j++];
              }
          }
        // copy values into round key arrays
        for (j = 0; (j < KC) && (t < ROUND_KEY_COUNT); j++, t++)
          {
            Ke[t / BC][t % BC] = tk[j];
            Kd[ROUNDS - (t / BC)][t % BC] = tk[j];
          }
      }
    for (int r = 1; r < ROUNDS; r++)
      { // inverse MixColumn where needed
        for (j = 0; j < BC; j++)
          {
            tt = Kd[r][j];
            Kd[r][j] = U1[(tt >>> 24)] ^ U2[(tt >>> 16) & 0xFF]
                       ^ U3[(tt >>> 8) & 0xFF] ^ U4[tt & 0xFF];
          }
      }

    return new Object[] { Ke, Kd };
  }

  public void encrypt(byte[] in, int i, byte[] out, int j, Object k, int bs)
  {
    if (!(bs == 16 || bs == 24 || bs == 32))
      {
        throw new IllegalArgumentException();
      }

    if (bs == DEFAULT_BLOCK_SIZE)
      {
        aesEncrypt(in, i, out, j, k);
      }
    else
      {
        rijndaelEncrypt(in, i, out, j, k, bs);
      }
  }

  public void decrypt(byte[] in, int i, byte[] out, int j, Object k, int bs)
  {
    if (!(bs == 16 || bs == 24 || bs == 32))
      {
        throw new IllegalArgumentException();
      }

    if (bs == DEFAULT_BLOCK_SIZE)
      {
        aesDecrypt(in, i, out, j, k);
      }
    else
      {
        rijndaelDecrypt(in, i, out, j, k, bs);
      }
  }

  public boolean selfTest()
  {
    if (valid == null)
      {
        boolean result = super.selfTest(); // do symmetry tests
        if (result)
          {
            result = testKat(KAT_KEY, KAT_CT);
          }
        valid = new Boolean(result);
      }
    return valid.booleanValue();
  }
}