#if !BESTHTTP_DISABLE_ALTERNATE_SSL && (!UNITY_WEBGL || UNITY_EDITOR) using System; using Org.BouncyCastle.Crypto.Parameters; using Org.BouncyCastle.Utilities; namespace Org.BouncyCastle.Crypto.Engines { /** * 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 sealed class TwofishEngine : IBlockCipher { private static readonly 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 const int P_00 = 1; private const int P_01 = 0; private const int P_02 = 0; private const int P_03 = P_01 ^ 1; private const int P_04 = 1; private const int P_10 = 0; private const int P_11 = 0; private const int P_12 = 1; private const int P_13 = P_11 ^ 1; private const int P_14 = 0; private const int P_20 = 1; private const int P_21 = 1; private const int P_22 = 0; private const int P_23 = P_21 ^ 1; private const int P_24 = 0; private const int P_30 = 0; private const int P_31 = 1; private const int P_32 = 1; private const int P_33 = P_31 ^ 1; private const int P_34 = 1; /* Primitive polynomial for GF(256) */ private const int GF256_FDBK = 0x169; private const int GF256_FDBK_2 = GF256_FDBK / 2; private const int GF256_FDBK_4 = GF256_FDBK / 4; private const int RS_GF_FDBK = 0x14D; // field generator //==================================== // Useful constants //==================================== private const int ROUNDS = 16; private const int MAX_ROUNDS = 16; // bytes = 128 bits private const int BLOCK_SIZE = 16; // bytes = 128 bits private const int MAX_KEY_BITS = 256; private const int INPUT_WHITEN=0; private const int OUTPUT_WHITEN=INPUT_WHITEN+BLOCK_SIZE/4; // 4 private const int ROUND_SUBKEYS=OUTPUT_WHITEN+BLOCK_SIZE/4;// 8 private const int TOTAL_SUBKEYS=ROUND_SUBKEYS+2*MAX_ROUNDS;// 40 private const int SK_STEP = 0x02020202; private const int SK_BUMP = 0x01010101; private const int SK_ROTL = 9; private bool encrypting; 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; private byte[] workingKey; 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 forEncryption whether or not we are for encryption. * @param parameters the parameters required to set up the cipher. * @exception ArgumentException if the parameters argument is * inappropriate. */ public void Init( bool forEncryption, ICipherParameters parameters) { if (!(parameters is KeyParameter)) throw new ArgumentException("invalid parameter passed to Twofish init - " + Org.BouncyCastle.Utilities.Platform.GetTypeName(parameters)); this.encrypting = forEncryption; this.workingKey = ((KeyParameter)parameters).GetKey(); this.k64Cnt = (this.workingKey.Length / 8); // pre-padded ? SetKey(this.workingKey); } public string AlgorithmName { get { return "Twofish"; } } public bool IsPartialBlockOkay { get { return false; } } public int ProcessBlock( byte[] input, int inOff, byte[] output, int outOff) { if (workingKey == null) throw new InvalidOperationException("Twofish not initialised"); Check.DataLength(input, inOff, BLOCK_SIZE, "input buffer too short"); Check.OutputLength(output, outOff, BLOCK_SIZE, "output buffer too short"); if (encrypting) { EncryptBlock(input, inOff, output, outOff); } else { DecryptBlock(input, inOff, output, 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 ArgumentException("Key size less than 64 bits"); } if (k64Cnt > 4) { throw new ArgumentException("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,p=0; i> 24); A += B; gSubKeys[i*2] = A; A += B; gSubKeys[i*2 + 1] = A << SK_ROTL | (int)((uint)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>1) | x2 << 31; x3 = (x3 << 1 | (int) ((uint)x3 >> 31)) ^ (t0 + 2*t1 + gSubKeys[k++]); t0 = Fe32_0(x2); t1 = Fe32_3(x3); x0 ^= t0 + t1 + gSubKeys[k++]; x0 = (int) ((uint)x0 >>1) | x0 << 31; x1 = (x1 << 1 | (int)((uint)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 | (int)((uint) x0 >> 31)) ^ (t0 + t1 + gSubKeys[k--]); x1 = (int) ((uint)x1 >>1) | x1 << 31; t0 = Fe32_0(x0); t1 = Fe32_3(x1); x3 ^= t0 + 2*t1 + gSubKeys[k--]; x2 = (x2 << 1 | (int)((uint)x2 >> 31)) ^ (t0 + t1 + gSubKeys[k--]); x3 = (int)((uint)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 = M_b0(x); int b1 = M_b1(x); int b2 = M_b2(x); int b3 = M_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) ^ M_b0(k0)] ^ gMDS1[(P[P_11,b1] & 0xff) ^ M_b1(k0)] ^ gMDS2[(P[P_21,b2] & 0xff) ^ M_b2(k0)] ^ gMDS3[(P[P_31,b3] & 0xff) ^ M_b3(k0)]; break; case 0: /* 256 bits of key */ b0 = (P[P_04,b0] & 0xff) ^ M_b0(k3); b1 = (P[P_14,b1] & 0xff) ^ M_b1(k3); b2 = (P[P_24,b2] & 0xff) ^ M_b2(k3); b3 = (P[P_34,b3] & 0xff) ^ M_b3(k3); goto case 3; case 3: b0 = (P[P_03,b0] & 0xff) ^ M_b0(k2); b1 = (P[P_13,b1] & 0xff) ^ M_b1(k2); b2 = (P[P_23,b2] & 0xff) ^ M_b2(k2); b3 = (P[P_33,b3] & 0xff) ^ M_b3(k2); goto case 2; case 2: result = gMDS0[(P[P_01,(P[P_02,b0]&0xff)^M_b0(k1)]&0xff)^M_b0(k0)] ^ gMDS1[(P[P_11,(P[P_12,b1]&0xff)^M_b1(k1)]&0xff)^M_b1(k0)] ^ gMDS2[(P[P_21,(P[P_22,b2]&0xff)^M_b2(k1)]&0xff)^M_b2(k0)] ^ gMDS3[(P[P_31,(P[P_32,b3]&0xff)^M_b3(k1)]&0xff)^M_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: *

* 

        * G(x) = x^4 + (a+1/a)x^3 + ax^2 + (a+1/a)x + 1
        *
* where a = primitive root of field generator 0x14D *

*/ private int RS_rem(int x) { int b = (int) (((uint)x >> 24) & 0xff); int g2 = ((b << 1) ^ ((b & 0x80) != 0 ? RS_GF_FDBK : 0)) & 0xff; int g3 = ( (int)((uint)b >> 1) ^ ((b & 0x01) != 0 ? (int)((uint)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 M_b0(int x) { return x & 0xff; } private int M_b1(int x) { return (int)((uint)x >> 8) & 0xff; } private int M_b2(int x) { return (int)((uint)x >> 16) & 0xff; } private int M_b3(int x) { return (int)((uint)x >> 24) & 0xff; } private int Fe32_0(int x) { return gSBox[ 0x000 + 2*(x & 0xff) ] ^ gSBox[ 0x001 + 2*((int)((uint)x >> 8) & 0xff) ] ^ gSBox[ 0x200 + 2*((int)((uint)x >> 16) & 0xff) ] ^ gSBox[ 0x201 + 2*((int)((uint)x >> 24) & 0xff) ]; } private int Fe32_3(int x) { return gSBox[ 0x000 + 2*((int)((uint)x >> 24) & 0xff) ] ^ gSBox[ 0x001 + 2*(x & 0xff) ] ^ gSBox[ 0x200 + 2*((int)((uint)x >> 8) & 0xff) ] ^ gSBox[ 0x201 + 2*((int)((uint)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 inData, byte[] b, int offset) { b[offset] = (byte)inData; b[offset + 1] = (byte)(inData >> 8); b[offset + 2] = (byte)(inData >> 16); b[offset + 3] = (byte)(inData >> 24); } } } #endif