| 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 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) |
| { |
| int[] k32e = new int[MAX_KEY_BITS/64]; // 4 |
| int[] k32o = new int[MAX_KEY_BITS/64]; // 4 |
| |
| int[] sBoxKeys = new int[MAX_KEY_BITS/64]; // 4 |
| gSubKeys = new int[TOTAL_SUBKEYS]; |
| |
| if (k64Cnt < 1) |
| { |
| throw new IllegalArgumentException("Key size less than 64 bits"); |
| } |
| |
| if (k64Cnt > 4) |
| { |
| throw new IllegalArgumentException("Key size larger than 256 bits"); |
| } |
| |
| /* |
| * k64Cnt is the number of 8 byte blocks (64 chunks) |
| * that are in the input key. The input key is a |
| * maximum of 32 bytes (256 bits), so the range |
| * for k64Cnt is 1..4 |
| */ |
| for (int i=0; i<k64Cnt ; i++) |
| { |
| int p = i* 8; |
| |
| k32e[i] = BytesTo32Bits(key, p); |
| k32o[i] = BytesTo32Bits(key, p+4); |
| |
| sBoxKeys[k64Cnt-1-i] = RS_MDS_Encode(k32e[i], k32o[i]); |
| } |
| |
| int q,A,B; |
| for (int i=0; i < TOTAL_SUBKEYS / 2 ; i++) |
| { |
| q = i*SK_STEP; |
| A = F32(q, k32e); |
| B = F32(q+SK_BUMP, k32o); |
| B = B << 8 | B >>> 24; |
| A += B; |
| gSubKeys[i*2] = A; |
| A += B; |
| gSubKeys[i*2 + 1] = A << SK_ROTL | A >>> (32-SK_ROTL); |
| } |
| |
| /* |
| * fully expand the table for speed |
| */ |
| int k0 = sBoxKeys[0]; |
| int k1 = sBoxKeys[1]; |
| int k2 = sBoxKeys[2]; |
| int k3 = sBoxKeys[3]; |
| int b0, b1, b2, b3; |
| gSBox = new int[4*MAX_KEY_BITS]; |
| for (int i=0; i<MAX_KEY_BITS; i++) |
| { |
| b0 = b1 = b2 = b3 = i; |
| switch (k64Cnt & 3) |
| { |
| case 1: |
| gSBox[i*2] = gMDS0[(P[P_01][b0] & 0xff) ^ b0(k0)]; |
| gSBox[i*2+1] = gMDS1[(P[P_11][b1] & 0xff) ^ b1(k0)]; |
| gSBox[i*2+0x200] = gMDS2[(P[P_21][b2] & 0xff) ^ b2(k0)]; |
| gSBox[i*2+0x201] = gMDS3[(P[P_31][b3] & 0xff) ^ b3(k0)]; |
| break; |
| case 0: // 256 bits of key |
| b0 = (P[P_04][b0] & 0xff) ^ b0(k3); |
| b1 = (P[P_14][b1] & 0xff) ^ b1(k3); |
| b2 = (P[P_24][b2] & 0xff) ^ b2(k3); |
| b3 = (P[P_34][b3] & 0xff) ^ b3(k3); |
| // fall through, having pre-processed b[0]..b[3] with k32[3] |
| case 3: // 192 bits of key |
| b0 = (P[P_03][b0] & 0xff) ^ b0(k2); |
| b1 = (P[P_13][b1] & 0xff) ^ b1(k2); |
| b2 = (P[P_23][b2] & 0xff) ^ b2(k2); |
| b3 = (P[P_33][b3] & 0xff) ^ b3(k2); |
| // fall through, having pre-processed b[0]..b[3] with k32[2] |
| case 2: // 128 bits of key |
| gSBox[i*2] = gMDS0[(P[P_01] |
| [(P[P_02][b0] & 0xff) ^ b0(k1)] & 0xff) ^ b0(k0)]; |
| gSBox[i*2+1] = gMDS1[(P[P_11] |
| [(P[P_12][b1] & 0xff) ^ b1(k1)] & 0xff) ^ b1(k0)]; |
| gSBox[i*2+0x200] = gMDS2[(P[P_21] |
| [(P[P_22][b2] & 0xff) ^ b2(k1)] & 0xff) ^ b2(k0)]; |
| gSBox[i*2+0x201] = gMDS3[(P[P_31] |
| [(P[P_32][b3] & 0xff) ^ b3(k1)] & 0xff) ^ b3(k0)]; |
| break; |
| } |
| } |
| |
| /* |
| * the function exits having setup the gSBox with the |
| * input key material. |
| */ |
| } |
| |
| /** |
| * Encrypt the given input starting at the given offset and place |
| * the result in the provided buffer starting at the given offset. |
| * The input will be an exact multiple of our blocksize. |
| * |
| * encryptBlock uses the pre-calculated gSBox[] and subKey[] |
| * arrays. |
| */ |
| private void encryptBlock( |
| byte[] src, |
| int srcIndex, |
| byte[] dst, |
| int dstIndex) |
| { |
| int x0 = BytesTo32Bits(src, srcIndex) ^ gSubKeys[INPUT_WHITEN]; |
| int x1 = BytesTo32Bits(src, srcIndex + 4) ^ gSubKeys[INPUT_WHITEN + 1]; |
| int x2 = BytesTo32Bits(src, srcIndex + 8) ^ gSubKeys[INPUT_WHITEN + 2]; |
| int x3 = BytesTo32Bits(src, srcIndex + 12) ^ gSubKeys[INPUT_WHITEN + 3]; |
| |
| int k = ROUND_SUBKEYS; |
| int t0, t1; |
| for (int r = 0; r < ROUNDS; r +=2) |
| { |
| t0 = Fe32_0(x0); |
| t1 = Fe32_3(x1); |
| x2 ^= t0 + t1 + gSubKeys[k++]; |
| x2 = x2 >>>1 | x2 << 31; |
| x3 = (x3 << 1 | x3 >>> 31) ^ (t0 + 2*t1 + gSubKeys[k++]); |
| |
| t0 = Fe32_0(x2); |
| t1 = Fe32_3(x3); |
| x0 ^= t0 + t1 + gSubKeys[k++]; |
| x0 = x0 >>>1 | x0 << 31; |
| x1 = (x1 << 1 | x1 >>> 31) ^ (t0 + 2*t1 + gSubKeys[k++]); |
| } |
| |
| Bits32ToBytes(x2 ^ gSubKeys[OUTPUT_WHITEN], dst, dstIndex); |
| Bits32ToBytes(x3 ^ gSubKeys[OUTPUT_WHITEN + 1], dst, dstIndex + 4); |
| Bits32ToBytes(x0 ^ gSubKeys[OUTPUT_WHITEN + 2], dst, dstIndex + 8); |
| Bits32ToBytes(x1 ^ gSubKeys[OUTPUT_WHITEN + 3], dst, dstIndex + 12); |
| } |
| |
| /** |
| * Decrypt the given input starting at the given offset and place |
| * the result in the provided buffer starting at the given offset. |
| * The input will be an exact multiple of our blocksize. |
| */ |
| private void decryptBlock( |
| byte[] src, |
| int srcIndex, |
| byte[] dst, |
| int dstIndex) |
| { |
| int x2 = BytesTo32Bits(src, srcIndex) ^ gSubKeys[OUTPUT_WHITEN]; |
| int x3 = BytesTo32Bits(src, srcIndex+4) ^ gSubKeys[OUTPUT_WHITEN + 1]; |
| int x0 = BytesTo32Bits(src, srcIndex+8) ^ gSubKeys[OUTPUT_WHITEN + 2]; |
| int x1 = BytesTo32Bits(src, srcIndex+12) ^ gSubKeys[OUTPUT_WHITEN + 3]; |
| |
| int k = ROUND_SUBKEYS + 2 * ROUNDS -1 ; |
| int t0, t1; |
| for (int r = 0; r< ROUNDS ; r +=2) |
| { |
| t0 = Fe32_0(x2); |
| t1 = Fe32_3(x3); |
| x1 ^= t0 + 2*t1 + gSubKeys[k--]; |
| x0 = (x0 << 1 | x0 >>> 31) ^ (t0 + t1 + gSubKeys[k--]); |
| x1 = x1 >>>1 | x1 << 31; |
| |
| t0 = Fe32_0(x0); |
| t1 = Fe32_3(x1); |
| x3 ^= t0 + 2*t1 + gSubKeys[k--]; |
| x2 = (x2 << 1 | x2 >>> 31) ^ (t0 + t1 + gSubKeys[k--]); |
| x3 = x3 >>>1 | x3 << 31; |
| } |
| |
| Bits32ToBytes(x0 ^ gSubKeys[INPUT_WHITEN], dst, dstIndex); |
| Bits32ToBytes(x1 ^ gSubKeys[INPUT_WHITEN + 1], dst, dstIndex + 4); |
| Bits32ToBytes(x2 ^ gSubKeys[INPUT_WHITEN + 2], dst, dstIndex + 8); |
| Bits32ToBytes(x3 ^ gSubKeys[INPUT_WHITEN + 3], dst, dstIndex + 12); |
| } |
| |
| /* |
| * TODO: This can be optimised and made cleaner by combining |
| * the functionality in this function and applying it appropriately |
| * to the creation of the subkeys during key setup. |
| */ |
| private int F32(int x, int[] k32) |
| { |
| int b0 = b0(x); |
| int b1 = b1(x); |
| int b2 = b2(x); |
| int b3 = b3(x); |
| int k0 = k32[0]; |
| int k1 = k32[1]; |
| int k2 = k32[2]; |
| int k3 = k32[3]; |
| |
| int result = 0; |
| switch (k64Cnt & 3) |
| { |
| case 1: |
| result = gMDS0[(P[P_01][b0] & 0xff) ^ b0(k0)] ^ |
| gMDS1[(P[P_11][b1] & 0xff) ^ b1(k0)] ^ |
| gMDS2[(P[P_21][b2] & 0xff) ^ b2(k0)] ^ |
| gMDS3[(P[P_31][b3] & 0xff) ^ b3(k0)]; |
| break; |
| case 0: /* 256 bits of key */ |
| b0 = (P[P_04][b0] & 0xff) ^ b0(k3); |
| b1 = (P[P_14][b1] & 0xff) ^ b1(k3); |
| b2 = (P[P_24][b2] & 0xff) ^ b2(k3); |
| b3 = (P[P_34][b3] & 0xff) ^ b3(k3); |
| case 3: |
| b0 = (P[P_03][b0] & 0xff) ^ b0(k2); |
| b1 = (P[P_13][b1] & 0xff) ^ b1(k2); |
| b2 = (P[P_23][b2] & 0xff) ^ b2(k2); |
| b3 = (P[P_33][b3] & 0xff) ^ b3(k2); |
| case 2: |
| result = |
| gMDS0[(P[P_01][(P[P_02][b0]&0xff)^b0(k1)]&0xff)^b0(k0)] ^ |
| gMDS1[(P[P_11][(P[P_12][b1]&0xff)^b1(k1)]&0xff)^b1(k0)] ^ |
| gMDS2[(P[P_21][(P[P_22][b2]&0xff)^b2(k1)]&0xff)^b2(k0)] ^ |
| gMDS3[(P[P_31][(P[P_32][b3]&0xff)^b3(k1)]&0xff)^b3(k0)]; |
| break; |
| } |
| return result; |
| } |
| |
| /** |
| * Use (12, 8) Reed-Solomon code over GF(256) to produce |
| * a key S-box 32-bit entity from 2 key material 32-bit |
| * entities. |
| * |
| * @param k0 first 32-bit entity |
| * @param k1 second 32-bit entity |
| * @return Remainder polynomial generated using RS code |
| */ |
| private int RS_MDS_Encode(int k0, int k1) |
| { |
| int r = k1; |
| for (int i = 0 ; i < 4 ; i++) // shift 1 byte at a time |
| { |
| r = RS_rem(r); |
| } |
| r ^= k0; |
| for (int i=0 ; i < 4 ; i++) |
| { |
| r = RS_rem(r); |
| } |
| |
| return r; |
| } |
| |
| /** |
| * Reed-Solomon code parameters: (12,8) reversible code:<p> |
| * <pre> |
| * g(x) = x^4 + (a+1/a)x^3 + ax^2 + (a+1/a)x + 1 |
| * </pre> |
| * where a = primitive root of field generator 0x14D |
| */ |
| private int RS_rem(int x) |
| { |
| int b = (x >>> 24) & 0xff; |
| int g2 = ((b << 1) ^ |
| ((b & 0x80) != 0 ? RS_GF_FDBK : 0)) & 0xff; |
| int g3 = ((b >>> 1) ^ |
| ((b & 0x01) != 0 ? (RS_GF_FDBK >>> 1) : 0)) ^ g2 ; |
| return ((x << 8) ^ (g3 << 24) ^ (g2 << 16) ^ (g3 << 8) ^ b); |
| } |
| |
| private int LFSR1(int x) |
| { |
| return (x >> 1) ^ |
| (((x & 0x01) != 0) ? GF256_FDBK_2 : 0); |
| } |
| |
| private int LFSR2(int x) |
| { |
| return (x >> 2) ^ |
| (((x & 0x02) != 0) ? GF256_FDBK_2 : 0) ^ |
| (((x & 0x01) != 0) ? GF256_FDBK_4 : 0); |
| } |
| |
| private int Mx_X(int x) |
| { |
| return x ^ LFSR2(x); |
| } // 5B |
| |
| private int Mx_Y(int x) |
| { |
| return x ^ LFSR1(x) ^ LFSR2(x); |
| } // EF |
| |
| private int b0(int x) |
| { |
| return x & 0xff; |
| } |
| |
| private int b1(int x) |
| { |
| return (x >>> 8) & 0xff; |
| } |
| |
| private int b2(int x) |
| { |
| return (x >>> 16) & 0xff; |
| } |
| |
| private int b3(int x) |
| { |
| return (x >>> 24) & 0xff; |
| } |
| |
| private int Fe32_0(int x) |
| { |
| return gSBox[ 0x000 + 2*(x & 0xff) ] ^ |
| gSBox[ 0x001 + 2*((x >>> 8) & 0xff) ] ^ |
| gSBox[ 0x200 + 2*((x >>> 16) & 0xff) ] ^ |
| gSBox[ 0x201 + 2*((x >>> 24) & 0xff) ]; |
| } |
| |
| private int Fe32_3(int x) |
| { |
| return gSBox[ 0x000 + 2*((x >>> 24) & 0xff) ] ^ |
| gSBox[ 0x001 + 2*(x & 0xff) ] ^ |
| gSBox[ 0x200 + 2*((x >>> 8) & 0xff) ] ^ |
| gSBox[ 0x201 + 2*((x >>> 16) & 0xff) ]; |
| } |
| |
| private int BytesTo32Bits(byte[] b, int p) |
| { |
| return ((b[p] & 0xff)) | |
| ((b[p+1] & 0xff) << 8) | |
| ((b[p+2] & 0xff) << 16) | |
| ((b[p+3] & 0xff) << 24); |
| } |
| |
| private void Bits32ToBytes(int in, byte[] b, int offset) |
| { |
| b[offset] = (byte)in; |
| b[offset + 1] = (byte)(in >> 8); |
| b[offset + 2] = (byte)(in >> 16); |
| b[offset + 3] = (byte)(in >> 24); |
| } |
| } |
