/* * Copyright (C) 1999 Derek Fawcus * * This code may be used under the terms of Version 2 of the GPL, * read the file COPYING for details. * */ /* * These routines do some reordering of the supplied data before * calling engine() to do the main work. * * The reordering seems similar to that done by the initial stages of * the DES algorithm, in that it looks like it's just been done to * try and make software decoding slower. I'm not sure that it * actually adds anything to the security. * * The nature of the shuffling is that the bits of the supplied * parameter 'varient' are reorganised (and some inverted), and * the bytes of the parameter 'challenge' are reorganised. * * The reorganisation in each routine is different, and the first * (CryptKey1) does not bother of play with the 'varient' parameter. * * Since this code is only run once per disk change, I've made the * code table driven in order to improve readability. * * Since these routines are so similar to each other, one could even * abstract them all to one routine supplied a parameter determining * the nature of the reordering it has to do. */ #include "css-auth.h" typedef unsigned long u32; static void engine(int varient, byte const *input, struct block *output); void CryptKey1(int varient, byte const *challenge, struct block *key) { static byte perm_challenge[] = {1,3,0,7,5, 2,9,6,4,8}; byte scratch[10]; int i; for (i = 9; i >= 0; --i) scratch[i] = challenge[perm_challenge[i]]; engine(varient, scratch, key); } /* This shuffles the bits in varient to make perm_varient such that * 4 -> !3 * 3 -> 4 * varient bits: 2 -> 0 perm_varient bits * 1 -> 2 * 0 -> !1 */ void CryptKey2(int varient, byte const *challenge, struct block *key) { static byte perm_challenge[] = {6,1,9,3,8, 5,7,4,0,2}; static byte perm_varient[] = { 0x0a, 0x08, 0x0e, 0x0c, 0x0b, 0x09, 0x0f, 0x0d, 0x1a, 0x18, 0x1e, 0x1c, 0x1b, 0x19, 0x1f, 0x1d, 0x02, 0x00, 0x06, 0x04, 0x03, 0x01, 0x07, 0x05, 0x12, 0x10, 0x16, 0x14, 0x13, 0x11, 0x17, 0x15}; byte scratch[10]; int i; for (i = 9; i >= 0; --i) scratch[i] = challenge[perm_challenge[i]]; engine(perm_varient[varient], scratch, key); } /* This shuffles the bits in varient to make perm_varient such that * 4 -> 0 * 3 -> !1 * varient bits: 2 -> !4 perm_varient bits * 1 -> 2 * 0 -> 3 */ void CryptBusKey(int varient, byte const *challenge, struct block *key) { static byte perm_challenge[] = {4,0,3,5,7, 2,8,6,1,9}; static byte perm_varient[] = { 0x12, 0x1a, 0x16, 0x1e, 0x02, 0x0a, 0x06, 0x0e, 0x10, 0x18, 0x14, 0x1c, 0x00, 0x08, 0x04, 0x0c, 0x13, 0x1b, 0x17, 0x1f, 0x03, 0x0b, 0x07, 0x0f, 0x11, 0x19, 0x15, 0x1d, 0x01, 0x09, 0x05, 0x0d}; byte scratch[10]; int i; for (i = 9; i >= 0; --i) scratch[i] = challenge[perm_challenge[i]]; engine(perm_varient[varient], scratch, key); } /* * We use two LFSR's (seeded from some of the input data bytes) to * generate two streams of pseudo-random bits. These two bit streams * are then combined by simply adding with carry to generate a final * sequence of pseudo-random bits which is stored in the buffer that * 'output' points to the end of - len is the size of this buffer. * * The first LFSR is of degree 25, and has a polynomial of: * x^13 + x^5 + x^4 + x^1 + 1 * * The second LSFR is of degree 17, and has a (primitive) polynomial of: * x^15 + x^1 + 1 * * I don't know if these polynomials are primitive modulo 2, and thus * represent maximal-period LFSR's. * * * Note that we take the output of each LFSR from the new shifted in * bit, not the old shifted out bit. Thus for ease of use the LFSR's * are implemented in bit reversed order. * */ static void generate_bits(byte *output, int len, struct block const *s) { u32 lfsr0, lfsr1; byte carry; /* In order to ensure that the LFSR works we need to ensure that the * initial values are non-zero. Thus when we initialise them from * the seed, we ensure that a bit is set. */ lfsr0 = (s->b[0] << 17) | (s->b[1] << 9) | ((s->b[2] & ~7) << 1) | 8 | (s->b[2] & 7); lfsr1 = (s->b[3] << 9) | 0x100 | s->b[4]; ++output; carry = 0; do { int bit; byte val; for (bit = 0, val = 0; bit < 8; ++bit) { byte o_lfsr0, o_lfsr1; /* Actually only 1 bit each */ byte combined; o_lfsr0 = ((lfsr0 >> 24) ^ (lfsr0 >> 21) ^ (lfsr0 >> 20) ^ (lfsr0 >> 12)) & 1; lfsr0 = (lfsr0 << 1) | o_lfsr0; o_lfsr1 = ((lfsr1 >> 16) ^ (lfsr1 >> 2)) & 1; lfsr1 = (lfsr1 << 1) | o_lfsr1; #define BIT0(x) ((x) & 1) #define BIT1(x) (((x) >> 1) & 1) combined = !o_lfsr1 + carry + !o_lfsr0; carry = BIT1(combined); val |= BIT0(combined) << bit; } *--output = val; } while (--len > 0); } static byte Secret[]; static byte Varients[]; static byte Table0[]; static byte Table1[]; static byte Table2[]; static byte Table3[]; /* * This encryption engine implements one of 32 variations * one the same theme depending upon the choice in the * varient parameter (0 - 31). * * The algorithm itself manipulates a 40 bit input into * a 40 bit output. * The parameter 'input' is 80 bits. It consists of * the 40 bit input value that is to be encrypted followed * by a 40 bit seed value for the pseudo random number * generators. */ static void engine(int varient, byte const *input, struct block *output) { byte cse, term, index; struct block temp1; struct block temp2; byte bits[30]; int i; /* Feed the secret into the input values such that * we alter the seed to the LFSR's used above, then * generate the bits to play with. */ for (i = 5; --i >= 0; ) temp1.b[i] = input[5 + i] ^ Secret[i] ^ Table2[i]; generate_bits(&bits[29], sizeof bits, &temp1); /* This term is used throughout the following to * select one of 32 different variations on the * algorithm. */ cse = Varients[varient] ^ Table2[varient]; /* Now the actual blocks doing the encryption. Each * of these works on 40 bits at a time and are quite * similar. */ for (i = 5, term = 0; --i >= 0; term = input[i]) { index = bits[25 + i] ^ input[i]; index = Table1[index] ^ ~Table2[index] ^ cse; temp1.b[i] = Table2[index] ^ Table3[index] ^ term; } temp1.b[4] ^= temp1.b[0]; for (i = 5, term = 0; --i >= 0; term = temp1.b[i]) { index = bits[20 + i] ^ temp1.b[i]; index = Table1[index] ^ ~Table2[index] ^ cse; temp2.b[i] = Table2[index] ^ Table3[index] ^ term; } temp2.b[4] ^= temp2.b[0]; for (i = 5, term = 0; --i >= 0; term = temp2.b[i]) { index = bits[15 + i] ^ temp2.b[i]; index = Table1[index] ^ ~Table2[index] ^ cse; index = Table2[index] ^ Table3[index] ^ term; temp1.b[i] = Table0[index] ^ Table2[index]; } temp1.b[4] ^= temp1.b[0]; for (i = 5, term = 0; --i >= 0; term = temp1.b[i]) { index = bits[10 + i] ^ temp1.b[i]; index = Table1[index] ^ ~Table2[index] ^ cse; index = Table2[index] ^ Table3[index] ^ term; temp2.b[i] = Table0[index] ^ Table2[index]; } temp2.b[4] ^= temp2.b[0]; for (i = 5, term = 0; --i >= 0; term = temp2.b[i]) { index = bits[5 + i] ^ temp2.b[i]; index = Table1[index] ^ ~Table2[index] ^ cse; temp1.b[i] = Table2[index] ^ Table3[index] ^ term; } temp1.b[4] ^= temp1.b[0]; for (i = 5, term = 0; --i >= 0; term = temp1.b[i]) { index = bits[i] ^ temp1.b[i]; index = Table1[index] ^ ~Table2[index] ^ cse; output->b[i] = Table2[index] ^ Table3[index] ^ term; } } static byte Varients[] = { 0xB7, 0x74, 0x85, 0xD0, 0xCC, 0xDB, 0xCA, 0x73, 0x03, 0xFE, 0x31, 0x03, 0x52, 0xE0, 0xB7, 0x42, 0x63, 0x16, 0xF2, 0x2A, 0x79, 0x52, 0xFF, 0x1B, 0x7A, 0x11, 0xCA, 0x1A, 0x9B, 0x40, 0xAD, 0x01}; static byte Secret[] = {0x55, 0xD6, 0xC4, 0xC5, 0x28}; static byte Table0[] = { 0xB7, 0xF4, 0x82, 0x57, 0xDA, 0x4D, 0xDB, 0xE2, 0x2F, 0x52, 0x1A, 0xA8, 0x68, 0x5A, 0x8A, 0xFF, 0xFB, 0x0E, 0x6D, 0x35, 0xF7, 0x5C, 0x76, 0x12, 0xCE, 0x25, 0x79, 0x29, 0x39, 0x62, 0x08, 0x24, 0xA5, 0x85, 0x7B, 0x56, 0x01, 0x23, 0x68, 0xCF, 0x0A, 0xE2, 0x5A, 0xED, 0x3D, 0x59, 0xB0, 0xA9, 0xB0, 0x2C, 0xF2, 0xB8, 0xEF, 0x32, 0xA9, 0x40, 0x80, 0x71, 0xAF, 0x1E, 0xDE, 0x8F, 0x58, 0x88, 0xB8, 0x3A, 0xD0, 0xFC, 0xC4, 0x1E, 0xB5, 0xA0, 0xBB, 0x3B, 0x0F, 0x01, 0x7E, 0x1F, 0x9F, 0xD9, 0xAA, 0xB8, 0x3D, 0x9D, 0x74, 0x1E, 0x25, 0xDB, 0x37, 0x56, 0x8F, 0x16, 0xBA, 0x49, 0x2B, 0xAC, 0xD0, 0xBD, 0x95, 0x20, 0xBE, 0x7A, 0x28, 0xD0, 0x51, 0x64, 0x63, 0x1C, 0x7F, 0x66, 0x10, 0xBB, 0xC4, 0x56, 0x1A, 0x04, 0x6E, 0x0A, 0xEC, 0x9C, 0xD6, 0xE8, 0x9A, 0x7A, 0xCF, 0x8C, 0xDB, 0xB1, 0xEF, 0x71, 0xDE, 0x31, 0xFF, 0x54, 0x3E, 0x5E, 0x07, 0x69, 0x96, 0xB0, 0xCF, 0xDD, 0x9E, 0x47, 0xC7, 0x96, 0x8F, 0xE4, 0x2B, 0x59, 0xC6, 0xEE, 0xB9, 0x86, 0x9A, 0x64, 0x84, 0x72, 0xE2, 0x5B, 0xA2, 0x96, 0x58, 0x99, 0x50, 0x03, 0xF5, 0x38, 0x4D, 0x02, 0x7D, 0xE7, 0x7D, 0x75, 0xA7, 0xB8, 0x67, 0x87, 0x84, 0x3F, 0x1D, 0x11, 0xE5, 0xFC, 0x1E, 0xD3, 0x83, 0x16, 0xA5, 0x29, 0xF6, 0xC7, 0x15, 0x61, 0x29, 0x1A, 0x43, 0x4F, 0x9B, 0xAF, 0xC5, 0x87, 0x34, 0x6C, 0x0F, 0x3B, 0xA8, 0x1D, 0x45, 0x58, 0x25, 0xDC, 0xA8, 0xA3, 0x3B, 0xD1, 0x79, 0x1B, 0x48, 0xF2, 0xE9, 0x93, 0x1F, 0xFC, 0xDB, 0x2A, 0x90, 0xA9, 0x8A, 0x3D, 0x39, 0x18, 0xA3, 0x8E, 0x58, 0x6C, 0xE0, 0x12, 0xBB, 0x25, 0xCD, 0x71, 0x22, 0xA2, 0x64, 0xC6, 0xE7, 0xFB, 0xAD, 0x94, 0x77, 0x04, 0x9A, 0x39, 0xCF, 0x7C}; static byte Table1[] = { 0x8C, 0x47, 0xB0, 0xE1, 0xEB, 0xFC, 0xEB, 0x56, 0x10, 0xE5, 0x2C, 0x1A, 0x5D, 0xEF, 0xBE, 0x4F, 0x08, 0x75, 0x97, 0x4B, 0x0E, 0x25, 0x8E, 0x6E, 0x39, 0x5A, 0x87, 0x53, 0xC4, 0x1F, 0xF4, 0x5C, 0x4E, 0xE6, 0x99, 0x30, 0xE0, 0x42, 0x88, 0xAB, 0xE5, 0x85, 0xBC, 0x8F, 0xD8, 0x3C, 0x54, 0xC9, 0x53, 0x47, 0x18, 0xD6, 0x06, 0x5B, 0x41, 0x2C, 0x67, 0x1E, 0x41, 0x74, 0x33, 0xE2, 0xB4, 0xE0, 0x23, 0x29, 0x42, 0xEA, 0x55, 0x0F, 0x25, 0xB4, 0x24, 0x2C, 0x99, 0x13, 0xEB, 0x0A, 0x0B, 0xC9, 0xF9, 0x63, 0x67, 0x43, 0x2D, 0xC7, 0x7D, 0x07, 0x60, 0x89, 0xD1, 0xCC, 0xE7, 0x94, 0x77, 0x74, 0x9B, 0x7E, 0xD7, 0xE6, 0xFF, 0xBB, 0x68, 0x14, 0x1E, 0xA3, 0x25, 0xDE, 0x3A, 0xA3, 0x54, 0x7B, 0x87, 0x9D, 0x50, 0xCA, 0x27, 0xC3, 0xA4, 0x50, 0x91, 0x27, 0xD4, 0xB0, 0x82, 0x41, 0x97, 0x79, 0x94, 0x82, 0xAC, 0xC7, 0x8E, 0xA5, 0x4E, 0xAA, 0x78, 0x9E, 0xE0, 0x42, 0xBA, 0x28, 0xEA, 0xB7, 0x74, 0xAD, 0x35, 0xDA, 0x92, 0x60, 0x7E, 0xD2, 0x0E, 0xB9, 0x24, 0x5E, 0x39, 0x4F, 0x5E, 0x63, 0x09, 0xB5, 0xFA, 0xBF, 0xF1, 0x22, 0x55, 0x1C, 0xE2, 0x25, 0xDB, 0xC5, 0xD8, 0x50, 0x03, 0x98, 0xC4, 0xAC, 0x2E, 0x11, 0xB4, 0x38, 0x4D, 0xD0, 0xB9, 0xFC, 0x2D, 0x3C, 0x08, 0x04, 0x5A, 0xEF, 0xCE, 0x32, 0xFB, 0x4C, 0x92, 0x1E, 0x4B, 0xFB, 0x1A, 0xD0, 0xE2, 0x3E, 0xDA, 0x6E, 0x7C, 0x4D, 0x56, 0xC3, 0x3F, 0x42, 0xB1, 0x3A, 0x23, 0x4D, 0x6E, 0x84, 0x56, 0x68, 0xF4, 0x0E, 0x03, 0x64, 0xD0, 0xA9, 0x92, 0x2F, 0x8B, 0xBC, 0x39, 0x9C, 0xAC, 0x09, 0x5E, 0xEE, 0xE5, 0x97, 0xBF, 0xA5, 0xCE, 0xFA, 0x28, 0x2C, 0x6D, 0x4F, 0xEF, 0x77, 0xAA, 0x1B, 0x79, 0x8E, 0x97, 0xB4, 0xC3, 0xF4}; static byte Table2[] = { 0xB7, 0x75, 0x81, 0xD5, 0xDC, 0xCA, 0xDE, 0x66, 0x23, 0xDF, 0x15, 0x26, 0x62, 0xD1, 0x83, 0x77, 0xE3, 0x97, 0x76, 0xAF, 0xE9, 0xC3, 0x6B, 0x8E, 0xDA, 0xB0, 0x6E, 0xBF, 0x2B, 0xF1, 0x19, 0xB4, 0x95, 0x34, 0x48, 0xE4, 0x37, 0x94, 0x5D, 0x7B, 0x36, 0x5F, 0x65, 0x53, 0x07, 0xE2, 0x89, 0x11, 0x98, 0x85, 0xD9, 0x12, 0xC1, 0x9D, 0x84, 0xEC, 0xA4, 0xD4, 0x88, 0xB8, 0xFC, 0x2C, 0x79, 0x28, 0xD8, 0xDB, 0xB3, 0x1E, 0xA2, 0xF9, 0xD0, 0x44, 0xD7, 0xD6, 0x60, 0xEF, 0x14, 0xF4, 0xF6, 0x31, 0xD2, 0x41, 0x46, 0x67, 0x0A, 0xE1, 0x58, 0x27, 0x43, 0xA3, 0xF8, 0xE0, 0xC8, 0xBA, 0x5A, 0x5C, 0x80, 0x6C, 0xC6, 0xF2, 0xE8, 0xAD, 0x7D, 0x04, 0x0D, 0xB9, 0x3C, 0xC2, 0x25, 0xBD, 0x49, 0x63, 0x8C, 0x9F, 0x51, 0xCE, 0x20, 0xC5, 0xA1, 0x50, 0x92, 0x2D, 0xDD, 0xBC, 0x8D, 0x4F, 0x9A, 0x71, 0x2F, 0x30, 0x1D, 0x73, 0x39, 0x13, 0xFB, 0x1A, 0xCB, 0x24, 0x59, 0xFE, 0x05, 0x96, 0x57, 0x0F, 0x1F, 0xCF, 0x54, 0xBE, 0xF5, 0x06, 0x1B, 0xB2, 0x6D, 0xD3, 0x4D, 0x32, 0x56, 0x21, 0x33, 0x0B, 0x52, 0xE7, 0xAB, 0xEB, 0xA6, 0x74, 0x00, 0x4C, 0xB1, 0x7F, 0x82, 0x99, 0x87, 0x0E, 0x5E, 0xC0, 0x8F, 0xEE, 0x6F, 0x55, 0xF3, 0x7E, 0x08, 0x90, 0xFA, 0xB6, 0x64, 0x70, 0x47, 0x4A, 0x17, 0xA7, 0xB5, 0x40, 0x8A, 0x38, 0xE5, 0x68, 0x3E, 0x8B, 0x69, 0xAA, 0x9B, 0x42, 0xA5, 0x10, 0x01, 0x35, 0xFD, 0x61, 0x9E, 0xE6, 0x16, 0x9C, 0x86, 0xED, 0xCD, 0x2E, 0xFF, 0xC4, 0x5B, 0xA0, 0xAE, 0xCC, 0x4B, 0x3B, 0x03, 0xBB, 0x1C, 0x2A, 0xAC, 0x0C, 0x3F, 0x93, 0xC7, 0x72, 0x7A, 0x09, 0x22, 0x3D, 0x45, 0x78, 0xA9, 0xA8, 0xEA, 0xC9, 0x6A, 0xF7, 0x29, 0x91, 0xF0, 0x02, 0x18, 0x3A, 0x4E, 0x7C}; static byte Table3[] = { 0x73, 0x51, 0x95, 0xE1, 0x12, 0xE4, 0xC0, 0x58, 0xEE, 0xF2, 0x08, 0x1B, 0xA9, 0xFA, 0x98, 0x4C, 0xA7, 0x33, 0xE2, 0x1B, 0xA7, 0x6D, 0xF5, 0x30, 0x97, 0x1D, 0xF3, 0x02, 0x60, 0x5A, 0x82, 0x0F, 0x91, 0xD0, 0x9C, 0x10, 0x39, 0x7A, 0x83, 0x85, 0x3B, 0xB2, 0xB8, 0xAE, 0x0C, 0x09, 0x52, 0xEA, 0x1C, 0xE1, 0x8D, 0x66, 0x4F, 0xF3, 0xDA, 0x92, 0x29, 0xB9, 0xD5, 0xC5, 0x77, 0x47, 0x22, 0x53, 0x14, 0xF7, 0xAF, 0x22, 0x64, 0xDF, 0xC6, 0x72, 0x12, 0xF3, 0x75, 0xDA, 0xD7, 0xD7, 0xE5, 0x02, 0x9E, 0xED, 0xDA, 0xDB, 0x4C, 0x47, 0xCE, 0x91, 0x06, 0x06, 0x6D, 0x55, 0x8B, 0x19, 0xC9, 0xEF, 0x8C, 0x80, 0x1A, 0x0E, 0xEE, 0x4B, 0xAB, 0xF2, 0x08, 0x5C, 0xE9, 0x37, 0x26, 0x5E, 0x9A, 0x90, 0x00, 0xF3, 0x0D, 0xB2, 0xA6, 0xA3, 0xF7, 0x26, 0x17, 0x48, 0x88, 0xC9, 0x0E, 0x2C, 0xC9, 0x02, 0xE7, 0x18, 0x05, 0x4B, 0xF3, 0x39, 0xE1, 0x20, 0x02, 0x0D, 0x40, 0xC7, 0xCA, 0xB9, 0x48, 0x30, 0x57, 0x67, 0xCC, 0x06, 0xBF, 0xAC, 0x81, 0x08, 0x24, 0x7A, 0xD4, 0x8B, 0x19, 0x8E, 0xAC, 0xB4, 0x5A, 0x0F, 0x73, 0x13, 0xAC, 0x9E, 0xDA, 0xB6, 0xB8, 0x96, 0x5B, 0x60, 0x88, 0xE1, 0x81, 0x3F, 0x07, 0x86, 0x37, 0x2D, 0x79, 0x14, 0x52, 0xEA, 0x73, 0xDF, 0x3D, 0x09, 0xC8, 0x25, 0x48, 0xD8, 0x75, 0x60, 0x9A, 0x08, 0x27, 0x4A, 0x2C, 0xB9, 0xA8, 0x8B, 0x8A, 0x73, 0x62, 0x37, 0x16, 0x02, 0xBD, 0xC1, 0x0E, 0x56, 0x54, 0x3E, 0x14, 0x5F, 0x8C, 0x8F, 0x6E, 0x75, 0x1C, 0x07, 0x39, 0x7B, 0x4B, 0xDB, 0xD3, 0x4B, 0x1E, 0xC8, 0x7E, 0xFE, 0x3E, 0x72, 0x16, 0x83, 0x7D, 0xEE, 0xF5, 0xCA, 0xC5, 0x18, 0xF9, 0xD8, 0x68, 0xAB, 0x38, 0x85, 0xA8, 0xF0, 0xA1, 0x73, 0x9F, 0x5D, 0x19, 0x0B, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x33, 0x72, 0x39, 0x25, 0x67, 0x26, 0x6D, 0x71, 0x36, 0x77, 0x3C, 0x20, 0x62, 0x23, 0x68, 0x74, 0xC3, 0x82, 0xC9, 0x15, 0x57, 0x16, 0x5D, 0x81};