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Diffstat (limited to 'core/src/main/java/org/bouncycastle/crypto/engines/TwofishEngine.java')
| -rw-r--r-- | core/src/main/java/org/bouncycastle/crypto/engines/TwofishEngine.java | 680 |
1 files changed, 0 insertions, 680 deletions
diff --git a/core/src/main/java/org/bouncycastle/crypto/engines/TwofishEngine.java b/core/src/main/java/org/bouncycastle/crypto/engines/TwofishEngine.java deleted file mode 100644 index 31ac0878..00000000 --- a/core/src/main/java/org/bouncycastle/crypto/engines/TwofishEngine.java +++ /dev/null @@ -1,680 +0,0 @@ -package org.bouncycastle.crypto.engines; - -import org.bouncycastle.crypto.BlockCipher; -import org.bouncycastle.crypto.CipherParameters; -import org.bouncycastle.crypto.DataLengthException; -import org.bouncycastle.crypto.OutputLengthException; -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 OutputLengthException("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); - } -} |