twofishengine.java~

KeePass for J2ME is a J2ME port of KeePass Password Safe, a free, open source, light-weight and easy

package org.bouncycastle.crypto.engines;

import org.bouncycastle.crypto.BlockCipher;
import org.bouncycastle.crypto.CipherParameters;
import org.bouncycastle.crypto.DataLengthException;
import org.bouncycastle.crypto.params.KeyParameter;

/**
 * A class that provides Twofish encryption operations.
 *
 * This Java implementation is based on the Java reference
 * implementation provided by Bruce Schneier and developed
 * by Raif S. Naffah.
 */
public final class TwofishEngine
    implements BlockCipher
{
    private static final byte[][] P =  {
    {  // p0
        (byte) 0xA9, (byte) 0x67, (byte) 0xB3, (byte) 0xE8,
        (byte) 0x04, (byte) 0xFD, (byte) 0xA3, (byte) 0x76,
        (byte) 0x9A, (byte) 0x92, (byte) 0x80, (byte) 0x78,
        (byte) 0xE4, (byte) 0xDD, (byte) 0xD1, (byte) 0x38,
        (byte) 0x0D, (byte) 0xC6, (byte) 0x35, (byte) 0x98,
        (byte) 0x18, (byte) 0xF7, (byte) 0xEC, (byte) 0x6C,
        (byte) 0x43, (byte) 0x75, (byte) 0x37, (byte) 0x26,
        (byte) 0xFA, (byte) 0x13, (byte) 0x94, (byte) 0x48,
        (byte) 0xF2, (byte) 0xD0, (byte) 0x8B, (byte) 0x30,
        (byte) 0x84, (byte) 0x54, (byte) 0xDF, (byte) 0x23,
        (byte) 0x19, (byte) 0x5B, (byte) 0x3D, (byte) 0x59,
        (byte) 0xF3, (byte) 0xAE, (byte) 0xA2, (byte) 0x82,
        (byte) 0x63, (byte) 0x01, (byte) 0x83, (byte) 0x2E,
        (byte) 0xD9, (byte) 0x51, (byte) 0x9B, (byte) 0x7C,
        (byte) 0xA6, (byte) 0xEB, (byte) 0xA5, (byte) 0xBE,
        (byte) 0x16, (byte) 0x0C, (byte) 0xE3, (byte) 0x61,
        (byte) 0xC0, (byte) 0x8C, (byte) 0x3A, (byte) 0xF5,
        (byte) 0x73, (byte) 0x2C, (byte) 0x25, (byte) 0x0B,
        (byte) 0xBB, (byte) 0x4E, (byte) 0x89, (byte) 0x6B,
        (byte) 0x53, (byte) 0x6A, (byte) 0xB4, (byte) 0xF1,
        (byte) 0xE1, (byte) 0xE6, (byte) 0xBD, (byte) 0x45,
        (byte) 0xE2, (byte) 0xF4, (byte) 0xB6, (byte) 0x66,
        (byte) 0xCC, (byte) 0x95, (byte) 0x03, (byte) 0x56,
        (byte) 0xD4, (byte) 0x1C, (byte) 0x1E, (byte) 0xD7,
        (byte) 0xFB, (byte) 0xC3, (byte) 0x8E, (byte) 0xB5,
        (byte) 0xE9, (byte) 0xCF, (byte) 0xBF, (byte) 0xBA,
        (byte) 0xEA, (byte) 0x77, (byte) 0x39, (byte) 0xAF,
        (byte) 0x33, (byte) 0xC9, (byte) 0x62, (byte) 0x71,
        (byte) 0x81, (byte) 0x79, (byte) 0x09, (byte) 0xAD,
        (byte) 0x24, (byte) 0xCD, (byte) 0xF9, (byte) 0xD8,
        (byte) 0xE5, (byte) 0xC5, (byte) 0xB9, (byte) 0x4D,
        (byte) 0x44, (byte) 0x08, (byte) 0x86, (byte) 0xE7,
        (byte) 0xA1, (byte) 0x1D, (byte) 0xAA, (byte) 0xED,
        (byte) 0x06, (byte) 0x70, (byte) 0xB2, (byte) 0xD2,
        (byte) 0x41, (byte) 0x7B, (byte) 0xA0, (byte) 0x11,
        (byte) 0x31, (byte) 0xC2, (byte) 0x27, (byte) 0x90,
        (byte) 0x20, (byte) 0xF6, (byte) 0x60, (byte) 0xFF,
        (byte) 0x96, (byte) 0x5C, (byte) 0xB1, (byte) 0xAB,
        (byte) 0x9E, (byte) 0x9C, (byte) 0x52, (byte) 0x1B,
        (byte) 0x5F, (byte) 0x93, (byte) 0x0A, (byte) 0xEF,
        (byte) 0x91, (byte) 0x85, (byte) 0x49, (byte) 0xEE,
        (byte) 0x2D, (byte) 0x4F, (byte) 0x8F, (byte) 0x3B,
        (byte) 0x47, (byte) 0x87, (byte) 0x6D, (byte) 0x46,
        (byte) 0xD6, (byte) 0x3E, (byte) 0x69, (byte) 0x64,
        (byte) 0x2A, (byte) 0xCE, (byte) 0xCB, (byte) 0x2F,
        (byte) 0xFC, (byte) 0x97, (byte) 0x05, (byte) 0x7A,
        (byte) 0xAC, (byte) 0x7F, (byte) 0xD5, (byte) 0x1A,
        (byte) 0x4B, (byte) 0x0E, (byte) 0xA7, (byte) 0x5A,
        (byte) 0x28, (byte) 0x14, (byte) 0x3F, (byte) 0x29,
        (byte) 0x88, (byte) 0x3C, (byte) 0x4C, (byte) 0x02,
        (byte) 0xB8, (byte) 0xDA, (byte) 0xB0, (byte) 0x17,
        (byte) 0x55, (byte) 0x1F, (byte) 0x8A, (byte) 0x7D,
        (byte) 0x57, (byte) 0xC7, (byte) 0x8D, (byte) 0x74,
        (byte) 0xB7, (byte) 0xC4, (byte) 0x9F, (byte) 0x72,
        (byte) 0x7E, (byte) 0x15, (byte) 0x22, (byte) 0x12,
        (byte) 0x58, (byte) 0x07, (byte) 0x99, (byte) 0x34,
        (byte) 0x6E, (byte) 0x50, (byte) 0xDE, (byte) 0x68,
        (byte) 0x65, (byte) 0xBC, (byte) 0xDB, (byte) 0xF8,
        (byte) 0xC8, (byte) 0xA8, (byte) 0x2B, (byte) 0x40,
        (byte) 0xDC, (byte) 0xFE, (byte) 0x32, (byte) 0xA4,
        (byte) 0xCA, (byte) 0x10, (byte) 0x21, (byte) 0xF0,
        (byte) 0xD3, (byte) 0x5D, (byte) 0x0F, (byte) 0x00,
        (byte) 0x6F, (byte) 0x9D, (byte) 0x36, (byte) 0x42,
        (byte) 0x4A, (byte) 0x5E, (byte) 0xC1, (byte) 0xE0 },
    {  // p1
        (byte) 0x75, (byte) 0xF3, (byte) 0xC6, (byte) 0xF4,
        (byte) 0xDB, (byte) 0x7B, (byte) 0xFB, (byte) 0xC8,
        (byte) 0x4A, (byte) 0xD3, (byte) 0xE6, (byte) 0x6B,
        (byte) 0x45, (byte) 0x7D, (byte) 0xE8, (byte) 0x4B,
        (byte) 0xD6, (byte) 0x32, (byte) 0xD8, (byte) 0xFD,
        (byte) 0x37, (byte) 0x71, (byte) 0xF1, (byte) 0xE1,
        (byte) 0x30, (byte) 0x0F, (byte) 0xF8, (byte) 0x1B,
        (byte) 0x87, (byte) 0xFA, (byte) 0x06, (byte) 0x3F,
        (byte) 0x5E, (byte) 0xBA, (byte) 0xAE, (byte) 0x5B,
        (byte) 0x8A, (byte) 0x00, (byte) 0xBC, (byte) 0x9D,
        (byte) 0x6D, (byte) 0xC1, (byte) 0xB1, (byte) 0x0E,
        (byte) 0x80, (byte) 0x5D, (byte) 0xD2, (byte) 0xD5,
        (byte) 0xA0, (byte) 0x84, (byte) 0x07, (byte) 0x14,
        (byte) 0xB5, (byte) 0x90, (byte) 0x2C, (byte) 0xA3,
        (byte) 0xB2, (byte) 0x73, (byte) 0x4C, (byte) 0x54,
        (byte) 0x92, (byte) 0x74, (byte) 0x36, (byte) 0x51,
        (byte) 0x38, (byte) 0xB0, (byte) 0xBD, (byte) 0x5A,
        (byte) 0xFC, (byte) 0x60, (byte) 0x62, (byte) 0x96,
        (byte) 0x6C, (byte) 0x42, (byte) 0xF7, (byte) 0x10,
        (byte) 0x7C, (byte) 0x28, (byte) 0x27, (byte) 0x8C,
        (byte) 0x13, (byte) 0x95, (byte) 0x9C, (byte) 0xC7,
        (byte) 0x24, (byte) 0x46, (byte) 0x3B, (byte) 0x70,
        (byte) 0xCA, (byte) 0xE3, (byte) 0x85, (byte) 0xCB,
        (byte) 0x11, (byte) 0xD0, (byte) 0x93, (byte) 0xB8,
        (byte) 0xA6, (byte) 0x83, (byte) 0x20, (byte) 0xFF,
        (byte) 0x9F, (byte) 0x77, (byte) 0xC3, (byte) 0xCC,
        (byte) 0x03, (byte) 0x6F, (byte) 0x08, (byte) 0xBF,
        (byte) 0x40, (byte) 0xE7, (byte) 0x2B, (byte) 0xE2,
        (byte) 0x79, (byte) 0x0C, (byte) 0xAA, (byte) 0x82,
        (byte) 0x41, (byte) 0x3A, (byte) 0xEA, (byte) 0xB9,
        (byte) 0xE4, (byte) 0x9A, (byte) 0xA4, (byte) 0x97,
        (byte) 0x7E, (byte) 0xDA, (byte) 0x7A, (byte) 0x17,
        (byte) 0x66, (byte) 0x94, (byte) 0xA1, (byte) 0x1D,
        (byte) 0x3D, (byte) 0xF0, (byte) 0xDE, (byte) 0xB3,
        (byte) 0x0B, (byte) 0x72, (byte) 0xA7, (byte) 0x1C,
        (byte) 0xEF, (byte) 0xD1, (byte) 0x53, (byte) 0x3E,
        (byte) 0x8F, (byte) 0x33, (byte) 0x26, (byte) 0x5F,
        (byte) 0xEC, (byte) 0x76, (byte) 0x2A, (byte) 0x49,
        (byte) 0x81, (byte) 0x88, (byte) 0xEE, (byte) 0x21,
        (byte) 0xC4, (byte) 0x1A, (byte) 0xEB, (byte) 0xD9,
        (byte) 0xC5, (byte) 0x39, (byte) 0x99, (byte) 0xCD,
        (byte) 0xAD, (byte) 0x31, (byte) 0x8B, (byte) 0x01,
        (byte) 0x18, (byte) 0x23, (byte) 0xDD, (byte) 0x1F,
        (byte) 0x4E, (byte) 0x2D, (byte) 0xF9, (byte) 0x48,
        (byte) 0x4F, (byte) 0xF2, (byte) 0x65, (byte) 0x8E,
        (byte) 0x78, (byte) 0x5C, (byte) 0x58, (byte) 0x19,
        (byte) 0x8D, (byte) 0xE5, (byte) 0x98, (byte) 0x57,
        (byte) 0x67, (byte) 0x7F, (byte) 0x05, (byte) 0x64,
        (byte) 0xAF, (byte) 0x63, (byte) 0xB6, (byte) 0xFE,
        (byte) 0xF5, (byte) 0xB7, (byte) 0x3C, (byte) 0xA5,
        (byte) 0xCE, (byte) 0xE9, (byte) 0x68, (byte) 0x44,
        (byte) 0xE0, (byte) 0x4D, (byte) 0x43, (byte) 0x69,
        (byte) 0x29, (byte) 0x2E, (byte) 0xAC, (byte) 0x15,
        (byte) 0x59, (byte) 0xA8, (byte) 0x0A, (byte) 0x9E,
        (byte) 0x6E, (byte) 0x47, (byte) 0xDF, (byte) 0x34,
        (byte) 0x35, (byte) 0x6A, (byte) 0xCF, (byte) 0xDC,
        (byte) 0x22, (byte) 0xC9, (byte) 0xC0, (byte) 0x9B,
        (byte) 0x89, (byte) 0xD4, (byte) 0xED, (byte) 0xAB,
        (byte) 0x12, (byte) 0xA2, (byte) 0x0D, (byte) 0x52,
        (byte) 0xBB, (byte) 0x02, (byte) 0x2F, (byte) 0xA9,
        (byte) 0xD7, (byte) 0x61, (byte) 0x1E, (byte) 0xB4,
        (byte) 0x50, (byte) 0x04, (byte) 0xF6, (byte) 0xC2,
        (byte) 0x16, (byte) 0x25, (byte) 0x86, (byte) 0x56,
        (byte) 0x55, (byte) 0x09, (byte) 0xBE, (byte) 0x91  }
    };

    /**
    * Define the fixed p0/p1 permutations used in keyed S-box lookup.
    * By changing the following constant definitions, the S-boxes will
    * automatically get changed in the Twofish engine.
    */
    private static final int P_00 = 1;
    private static final int P_01 = 0;
    private static final int P_02 = 0;
    private static final int P_03 = P_01 ^ 1;
    private static final int P_04 = 1;

    private static final int P_10 = 0;
    private static final int P_11 = 0;
    private static final int P_12 = 1;
    private static final int P_13 = P_11 ^ 1;
    private static final int P_14 = 0;

    private static final int P_20 = 1;
    private static final int P_21 = 1;
    private static final int P_22 = 0;
    private static final int P_23 = P_21 ^ 1;
    private static final int P_24 = 0;

    private static final int P_30 = 0;
    private static final int P_31 = 1;
    private static final int P_32 = 1;
    private static final int P_33 = P_31 ^ 1;
    private static final int P_34 = 1;

    /* Primitive polynomial for GF(256) */
    private static final int GF256_FDBK =   0x169;
    private static final int GF256_FDBK_2 = GF256_FDBK / 2;
    private static final int GF256_FDBK_4 = GF256_FDBK / 4;

    private static final int RS_GF_FDBK = 0x14D; // field generator

    //====================================
    // Useful constants
    //====================================

    private static final int    ROUNDS = 16;
    private static final int    MAX_ROUNDS = 16;  // bytes = 128 bits
    private static final int    BLOCK_SIZE = 16;  // bytes = 128 bits
    private static final int    MAX_KEY_BITS = 256;

    private static final int    INPUT_WHITEN=0;
    private static final int    OUTPUT_WHITEN=INPUT_WHITEN+BLOCK_SIZE/4; // 4
    private static final int    ROUND_SUBKEYS=OUTPUT_WHITEN+BLOCK_SIZE/4;// 8

    private static final int    TOTAL_SUBKEYS=ROUND_SUBKEYS+2*MAX_ROUNDS;// 40

    private static final int    SK_STEP = 0x02020202;
    private static final int    SK_BUMP = 0x01010101;
    private static final int    SK_ROTL = 9;

    private boolean encrypting = false;

    private int[] gMDS0 = new int[MAX_KEY_BITS];
    private int[] gMDS1 = new int[MAX_KEY_BITS];
    private int[] gMDS2 = new int[MAX_KEY_BITS];
    private int[] gMDS3 = new int[MAX_KEY_BITS];

    /**
     * gSubKeys[] and gSBox[] are eventually used in the 
     * encryption and decryption methods.
     */
    private int[] gSubKeys;
    private int[] gSBox;

    private int k64Cnt = 0;

    private byte[] workingKey = null;

    public TwofishEngine()
    {
        // calculate the MDS matrix
        int[] m1 = new int[2];
        int[] mX = new int[2];
        int[] mY = new int[2];
        int j;

        for (int i=0; i< MAX_KEY_BITS ; i++)
        {
            j = P[0][i] & 0xff;
            m1[0] = j;
            mX[0] = Mx_X(j) & 0xff;
            mY[0] = Mx_Y(j) & 0xff;

            j = P[1][i] & 0xff;
            m1[1] = j;
            mX[1] = Mx_X(j) & 0xff;
            mY[1] = Mx_Y(j) & 0xff;

            gMDS0[i] = m1[P_00]       | mX[P_00] <<  8 |
                         mY[P_00] << 16 | mY[P_00] << 24;

            gMDS1[i] = mY[P_10]       | mY[P_10] <<  8 |
                         mX[P_10] << 16 | m1[P_10] << 24;

            gMDS2[i] = mX[P_20]       | mY[P_20] <<  8 |
                         m1[P_20] << 16 | mY[P_20] << 24;

            gMDS3[i] = mX[P_30]       | m1[P_30] <<  8 |
                         mY[P_30] << 16 | mX[P_30] << 24;
        }
    }

    /**
     * initialise a Twofish cipher.
     *
     * @param encrypting whether or not we are for encryption.
     * @param params the parameters required to set up the cipher.
     * @exception IllegalArgumentException if the params argument is
     * inappropriate.
     */
    public void init(
        boolean             encrypting,
        CipherParameters    params)
    {
        if (params instanceof KeyParameter)
        {
            this.encrypting = encrypting;
            this.workingKey = ((KeyParameter)params).getKey();
            this.k64Cnt = (this.workingKey.length / 8); // pre-padded ?
            setKey(this.workingKey);

            return;
        }

        throw new IllegalArgumentException("invalid parameter passed to Twofish init - " + params.getClass().getName());
    }

    public String getAlgorithmName()
    {
        return "Twofish";
    }

    public final int processBlock(
        byte[] in,
        int inOff,
        byte[] out,
        int outOff)
    {
        if (workingKey == null)
        {
            throw new IllegalStateException("Twofish not initialised");
        }

        if ((inOff + BLOCK_SIZE) > in.length)
        {
            throw new DataLengthException("input buffer too short");
        }

        if ((outOff + BLOCK_SIZE) > out.length)
        {
            throw new DataLengthException("output buffer too short");
        }

        if (encrypting)
        {
            encryptBlock(in, inOff, out, outOff);
        }
        else
        {    
            decryptBlock(in, inOff, out, outOff);
        }

        return BLOCK_SIZE;
    }

    public void reset()
    {
        if (this.workingKey != null)
        {
            setKey(this.workingKey);
        }
    }

    public int getBlockSize()
    {
        return BLOCK_SIZE;
    }

    //==================================
    // Private Implementation
    //==================================

    private void setKey(byte[] key)
    {