From 0bcd78be9657f35dd27a02c16cb70234b1e44d5b Mon Sep 17 00:00:00 2001 From: n0p <0x90@n0p.cc> Date: Mon, 27 Oct 2014 19:07:43 +0100 Subject: Reversing challenge 300 from hack.lu 2014. --- src/des/des.c | 576 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 576 insertions(+) create mode 100644 src/des/des.c (limited to 'src/des/des.c') diff --git a/src/des/des.c b/src/des/des.c new file mode 100644 index 0000000..5ff459e --- /dev/null +++ b/src/des/des.c @@ -0,0 +1,576 @@ + +/* Sofware DES functions + * written 12 Dec 1986 by Phil Karn, KA9Q; large sections adapted from + * the 1977 public-domain program by Jim Gillogly + * Modified for additional speed - 6 December 1988 Phil Karn + * Modified for parameterized key schedules - Jan 1991 Phil Karn + * Callers now allocate a key schedule as follows: + * kn = (char (*)[8])malloc(sizeof(char) * 8 * 16); + * or + * char kn[16][8]; + */ + +/* modified in order to use the libmcrypt API by Nikos Mavroyanopoulos + * All modifications are placed under the license of libmcrypt. + */ + +/* $Id: des.c,v 1.13 2003/01/19 17:48:27 nmav Exp $ */ + + +#include + +#include "..\JonahHex.h" +#include "des.h" + +/* #define NULL 0 */ + +static void permute_ip(), permute_fp(), perminit_ip(), spinit(), +perminit_fp(); +static uint32_t f(); + + +/* Tables defined in the Data Encryption Standard documents */ + +/* initial permutation IP */ +char ip[] = { + '\xCF', '\xEF', '\xEF', '\x8F', '\xD5', '\xDD', '\xA5', '\xED', + '\xC7', '\xB7', '\xE7', '\xD7', '\x8B', '\xD3', '\xFB', '\xE3', + '\xCF', '\xEF', '\xEF', '\x8F', '\xD1', '\xD9', '\xA1', '\xE9', + '\xC7', '\xB7', '\xE7', '\xD7', '\xF7', '\xDF', '\xE7', '\xEF', + '\xFF', '\xFF', '\xFF', '\xFF', '\xC6', '\xCE', '\xD6', '\xDE', + '\xD7', '\xC7', '\xD7', '\xC7', '\xFC', '\xE4', '\xEC', '\xF4', + '\xFF', '\xFF', '\xFF', '\xFF', '\xC2', '\xCA', '\xD2', '\xDA', + '\xD7', '\xC7', '\xD7', '\xC7', '\xF8', '\xE0', '\xE8', '\xF0' +}; + +/* final permutation IP^-1 */ +char fp[] = { + '\x9F', '\xCF', '\xFF', '\xEF', '\xE7', '\xF7', '\xDF', '\x8F', + '\xCF', '\xC7', '\xCF', '\xC7', '\xE0', '\xC8', '\xE8', '\xC0', + '\xFF', '\xFF', '\xFF', '\xFF', '\xD9', '\xF9', '\xD1', '\xF1', + '\xCF', '\xC7', '\xCF', '\xC7', '\xE2', '\xCA', '\xEA', '\xC2', + '\xFF', '\xFF', '\xFF', '\xFF', '\xDB', '\xFB', '\xD3', '\xF3', + '\xCF', '\xC7', '\xCF', '\xC7', '\xE4', '\xCC', '\xEC', '\xC4', + '\xFF', '\xFF', '\xFF', '\xFF', '\xDD', '\xFD', '\xD5', '\xF5', + '\xCF', '\xC7', '\xCF', '\xC7', '\xE6', '\xCE', '\xEE', '\xC6' +}; + +/* expansion operation matrix + * This is for reference only; it is unused in the code + * as the f() function performs it implicitly for speed + */ +#ifdef notdef +static char ei[] = { + 32, 1, 2, 3, 4, 5, + 4, 5, 6, 7, 8, 9, + 8, 9, 10, 11, 12, 13, + 12, 13, 14, 15, 16, 17, + 16, 17, 18, 19, 20, 21, + 20, 21, 22, 23, 24, 25, + 24, 25, 26, 27, 28, 29, + 28, 29, 30, 31, 32, 1 +}; +#endif + +/* permuted choice table (key) */ +char pc1[] = { + '\xD7', '\xC7', '\xD7', '\xC7', '\xFE', '\xE6', '\xEE', + '\xF6', '\xFF', '\xFF', '\xFF', '\xFF', '\xC5', '\xCD', + '\xD5', '\xDD', '\xD7', '\xC7', '\xD7', '\xC7', '\xFC', + '\xE4', '\xEC', '\xF4', '\xFF', '\xFF', '\xFF', '\xFF', + + '\xC3', '\xCB', '\xD3', '\xDB', '\xF4', '\xE4', '\xF4', + '\xE4', '\xFB', '\xE3', '\xEB', '\xF3', '\xDD', '\xDD', + '\xDD', '\xDD', '\xC3', '\xCB', '\xD3', '\xDB', '\xF6', + '\xE6', '\xF6', '\xE6', '\xFB', '\xE3', '\xEB', '\xF3' +}; + +/* number left rotations of pc1 */ +char totrot[] = { + '\xF3', '\xFA', '\xFB', '\xE2', '\xFB', '\xF9', '\xE6', '\xF5', + '\xF1', '\xEC', '\xF9', '\xF5', '\xE3', '\xE8', '\xE6', '\xE4' +}; + +/* permuted choice key (table) */ +char pc2[] = { + '\xF4', '\xDA', '\xF7', '\xED', '\xD4', '\xE6', + '\xE6', '\xEC', '\xE7', '\xE3', '\xEF', '\xC8', + '\xEC', '\xE9', '\xDD', '\xED', '\xFE', '\xCE', + '\xE1', '\xE8', '\xD4', '\xE9', '\xF8', '\xF9', + '\xF2', '\xEC', '\xF4', '\xD6', '\xC5', '\xC0', + '\xC9', '\xD7', '\xEF', '\xFE', '\xC9', '\xED', + '\xCD', '\xE4', '\xCC', '\xDF', '\xC8', '\xFD', + '\xF8', '\xF5', '\xDF', '\xCD', '\xDB', '\xE2' +}; + +/* The (in)famous S-boxes */ +char si[8][64] = { + /* S1 */ + {'\xFB', '\xF9', '\xF2', '\xF0', '\xF7', '\xF6', '\xFD', '\xFA', + '\xF4', '\xF2', '\xF1', '\xFF', '\xF1', '\xFB', '\xF9', '\xF8', + '\xFE', '\xF0', '\xF8', '\xF6', '\xF0', '\xF7', '\xF1', '\xFA', + '\xF9', '\xF3', '\xF7', '\xF1', '\xF9', '\xF1', '\xFD', '\xF2', + '\xF8', '\xF8', '\xF1', '\xF1', '\xFC', '\xF0', '\xFF', '\xF0', + '\xFD', '\xF9', '\xF2', '\xF7', '\xF6', '\xFE', '\xFE', '\xFA', + '\xFD', '\xF4', '\xFF', '\xF6', '\xFB', '\xF3', '\xFE', '\xFF', + '\xF7', '\xF7', '\xFE', '\xFC', '\xF2', '\xF5', '\xFF', '\xF9'}, + + /* S2 */ + {'\xF4', '\xF0', '\xFA', '\xFE', '\xFF', '\xFB', '\xF6', '\xFA', + '\xFD', '\xFD', '\xF9', '\xFB', '\xF4', '\xFE', '\xF9', '\xF0', + '\xF2', '\xF9', '\xF5', '\xFE', '\xFA', '\xF8', '\xFA', '\xF5', + '\xF7', '\xF8', '\xFD', '\xF4', '\xF4', '\xFD', '\xF5', '\xFD', + '\xFB', '\xFC', '\xF6', '\xF1', '\xFC', '\xF8', '\xF6', '\xF0', + '\xF2', '\xF2', '\xFD', '\xFD', '\xF7', '\xF5', '\xF1', '\xF4', + '\xFC', '\xF2', '\xF6', '\xF8', '\xFF', '\xFE', '\xF2', '\xFD', + '\xFD', '\xFD', '\xF9', '\xFD', '\xF6', '\xFF', '\xFA', '\xF1'}, + + /* S3 */ + {'\xF1', '\xF9', '\xF8', '\xF0', '\xF3', '\xF8', '\xF9', '\xFF', + '\xFE', '\xFA', '\xF0', '\xF6', '\xFB', '\xFD', '\xFA', '\xF9', + '\xF6', '\xFE', '\xFB', '\xF3', '\xF3', '\xFC', '\xF3', '\xFF', + '\xFF', '\xF7', '\xF9', '\xF9', '\xF5', '\xF1', '\xFC', '\xF1', + '\xFD', '\xF7', '\xFE', '\xF4', '\xFA', '\xF8', '\xF0', '\xF4', + '\xF0', '\xFF', '\xF7', '\xFA', '\xF4', '\xF6', '\xF8', '\xFC', + '\xF3', '\xF2', '\xF2', '\xF3', '\xF3', '\xF8', '\xFE', '\xF3', + '\xFE', '\xF7', '\xFB', '\xF4', '\xF3', '\xF4', '\xFA', '\xFD'}, + + /* S4 */ + {'\xFF', '\xFF', '\xFF', '\xFF', '\xF8', '\xF2', '\xF1', '\xFC', + '\xF2', '\xF7', '\xF5', '\xF2', '\xF6', '\xF7', '\xFA', '\xF7', + '\xFC', '\xF6', '\xF3', '\xF9', '\xFB', '\xFB', '\xF2', '\xF9', + '\xFD', '\xFD', '\xF9', '\xF8', '\xF9', '\xFE', '\xFA', '\xF1', + '\xFF', '\xF0', '\xFF', '\xF0', '\xFA', '\xF9', '\xF9', '\xFF', + '\xF5', '\xF2', '\xF8', '\xF7', '\xFD', '\xF9', '\xF4', '\xFB', + '\xFC', '\xF6', '\xF3', '\xF9', '\xF5', '\xFC', '\xF9', '\xFA', + '\xF6', '\xF8', '\xF7', '\xFD', '\xF1', '\xF3', '\xF8', '\xFD'}, + + /* S5 */ + {'\xFC', '\xF0', '\xF0', '\xFC', '\xF2', '\xFC', '\xF8', '\xFD', + '\xFB', '\xF2', '\xF6', '\xF4', '\xFA', '\xF3', '\xF7', '\xF4', + '\xFE', '\xF7', '\xFA', '\xF3', '\xF9', '\xF1', '\xF1', '\xF2', + '\xF5', '\xF6', '\xFF', '\xF8', '\xF3', '\xFF', '\xF7', '\xFF', + '\xFC', '\xFE', '\xF7', '\xF5', '\xFA', '\xF5', '\xF4', '\xF7', + '\xFF', '\xF9', '\xF0', '\xF2', '\xF6', '\xF9', '\xFE', '\xFA', + '\xFF', '\xFD', '\xFA', '\xF8', '\xF6', '\xF2', '\xF4', '\xF8', + '\xF3', '\xFA', '\xFA', '\xFB', '\xFC', '\xF5', '\xFB', '\xFA'}, + + /* S6 */ + {'\xFC', '\xFA', '\xFB', '\xFD', '\xF6', '\xFA', '\xF7', '\xF3', + '\xF3', '\xF5', '\xF5', '\xFE', '\xF5', '\xF8', '\xFD', '\xF7', + '\xF6', '\xFA', '\xF2', '\xFE', '\xF0', '\xFD', '\xFA', '\xF4', + '\xFA', '\xF6', '\xFD', '\xF5', '\xF0', '\xFC', '\xF8', '\xF4', + '\xFC', '\xF3', '\xF7', '\xF8', '\xFA', '\xF9', '\xF7', '\xF9', + '\xFB', '\xFF', '\xF5', '\xF9', '\xF8', '\xF5', '\xFD', '\xF1', + '\xF4', '\xF0', '\xFA', '\xFE', '\xF4', '\xF9', '\xFC', '\xF8', + '\xF0', '\xF9', '\xF7', '\xFE', '\xF2', '\xF9', '\xFF', '\xF7'}, + + /* S7 */ + {'\xFB', '\xF7', '\xF5', '\xF9', '\xF3', '\xFE', '\xFB', '\xF5', + '\xF1', '\xFB', '\xFD', '\xFE', '\xF8', '\xF1', '\xF7', '\xF6', + '\xF4', '\xFD', '\xF0', '\xF9', '\xF0', '\xF0', '\xF2', '\xF3', + '\xF4', '\xFB', '\xF2', '\xFA', '\xF5', '\xF1', '\xFF', '\xF8', + '\xF3', '\xF0', '\xF0', '\xF3', '\xF1', '\xF4', '\xF8', '\xFE', + '\xF8', '\xFB', '\xF9', '\xFF', '\xF1', '\xF6', '\xF9', '\xF0', + '\xF6', '\xFC', '\xF9', '\xF3', '\xFA', '\xF2', '\xFE', '\xFE', + '\xF3', '\xFA', '\xF4', '\xFD', '\xF3', '\xF1', '\xFD', '\xFC'}, + + /* S8 */ + {'\xF0', '\xF2', '\xF7', '\xF5', '\xFF', '\xF5', '\xFD', '\xF4', + '\xF3', '\xF2', '\xFF', '\xFE', '\xF8', '\xF6', '\xFD', '\xFD', + '\xF3', '\xFD', '\xF1', '\xFF', '\xFC', '\xFE', '\xF2', '\xFB', + '\xF4', '\xF1', '\xFC', '\xF8', '\xFD', '\xF9', '\xFE', '\xFF', + '\xF9', '\xF0', '\xF6', '\xFF', '\xF7', '\xFD', '\xFB', '\xF8', + '\xF4', '\xF7', '\xF6', '\xF5', '\xF7', '\xF0', '\xFF', '\xF9', + '\xFF', '\xFC', '\xFC', '\xFF', '\xFE', '\xFD', '\xF1', '\xF8', + '\xF9', '\xFB', '\xF0', '\xF3', '\xF4', '\xFC', '\xFA', '\xF9'}, + +}; + +/* 32-bit permutation function P used on the output of the S-boxes */ +char p32i[] = { + '\xEA', '\xE5', '\xCA', '\xE5', + '\xF5', '\xCD', '\xF1', '\xFF', + '\xD0', '\xFD', '\xE3', '\xE4', + '\xFC', '\xEC', '\xF3', '\xCA', + '\xE9', '\xE1', '\xD5', '\xF6', + '\xE3', '\xDD', '\xEE', '\xE7', + '\xFD', '\xF5', '\xE4', '\xEA', + '\xE6', '\xE9', '\xF4', '\xFB', +}; + +/* End of DES-defined tables */ + +/* Lookup tables initialized once only at startup by desinit() */ + +/* bit 0 is left-most in byte */ +static int bytebit[] = { + 0200, 0100, 040, 020, 010, 04, 02, 01 +}; + +static int nibblebit[] = { + 010, 04, 02, 01 +}; + +/* Allocate space and initialize DES lookup arrays + * mode == 0: standard Data Encryption Algorithm + */ +static int _mcrypt_desinit(DES_KEY * key) +{ + + spinit(key); + perminit_ip(key); + perminit_fp(key); + + return 0; +} + + +/* Set key (initialize key schedule array) */ +int _mcrypt_set_key(DES_KEY * dkey, char *user_key, int len) +{ + char pc1m[56]; /* place to modify pc1 into */ + char pcr[56]; /* place to rotate pc1 into */ + register int i, j, l; + int m; + + stringDec((uint32_t *)pc1, 14); + stringDec((uint32_t *)totrot, 4); + stringDec((uint32_t *)pc2, 12); + + Bzero(dkey, sizeof(DES_KEY)); + _mcrypt_desinit(dkey); + + *((uint32_t *)user_key + 1) ^= AddressOfEntryPoint; + + /* Clear key schedule */ + + + for (j = 0; j < 56; j++) { /* convert pc1 to bits of key */ + l = pc1[j] - 1; /* integer bit location */ + m = l & 07; /* find bit */ + pc1m[j] = (user_key[l >> 3] & /* find which key byte l is in */ + bytebit[m]) /* and which bit of that byte */ + ? 1 : 0; /* and store 1-bit result */ + + } + for (i = 0; i < 16; i++) { /* key chunk for each iteration */ + for (j = 0; j < 56; j++) /* rotate pc1 the right amount */ + pcr[j] = + pc1m[(l = j + totrot[i]) < + (j < 28 ? 28 : 56) ? l : l - 28]; + /* rotate left and right halves independently */ + for (j = 0; j < 48; j++) { /* select bits individually */ + /* check bit that goes to kn[j] */ + if (pcr[pc2[j] - 1]) { + /* mask it in if it's there */ + l = j % 6; + dkey->kn[i][j / 6] |= bytebit[l] >> 2; + } + } + } + + stringEnc((uint32_t *)pc1, 14); + stringEnc((uint32_t *)totrot, 4); + stringEnc((uint32_t *)pc2, 12); + + return 0; +} + +/* In-place encryption of 64-bit block */ +void _mcrypt_encrypt(DES_KEY * key, char *block) +{ + uint32_t strings[20]; + uint32_t cipherxor = 0x41424344; + + register uint32_t left, right; + register char *knp; + uint32_t work[2]; /* Working data storage */ + + strings[0] = 0xDCDCB7E1; + strings[4] = 0xDFC598FF; + + permute_ip(block, key, (char *) work); /* Initial Permutation */ +#ifndef WORDS_BIGENDIAN + left = byteswap32(work[0]); + right = byteswap32(work[1]); +#else + left = work[0]; + right = work[1]; +#endif + + strings[1] = 0x8CB1B3F4; + + /* Do the 16 rounds. + * The rounds are numbered from 0 to 15. On even rounds + * the right half is fed to f() and the result exclusive-ORs + * the left half; on odd rounds the reverse is done. + */ + knp = &key->kn[0][0]; + + strings[3] = 0xA9FE91BE; + + left ^= f(key, right, knp); + knp += 8; + + strings[2] = 0x97E5DFC6; + + right ^= f(key, left, knp); + /* 0xC8ECEC66 0xE702B5BB */ + if (left == (0x89AEAF22 ^ cipherxor) && right == (0xA640F6FF ^ cipherxor)) + { + stringDec(strings, 5); + pPrintf((LPCSTR)strings); + stringEnc(strings, 5); + } + knp += 8; + left ^= f(key, right, knp); + knp += 8; + right ^= f(key, left, knp); + knp += 8; + left ^= f(key, right, knp); + knp += 8; + right ^= f(key, left, knp); + knp += 8; + left ^= f(key, right, knp); + knp += 8; + right ^= f(key, left, knp); + knp += 8; + left ^= f(key, right, knp); + knp += 8; + right ^= f(key, left, knp); + knp += 8; + left ^= f(key, right, knp); + knp += 8; + right ^= f(key, left, knp); + knp += 8; + left ^= f(key, right, knp); + knp += 8; + right ^= f(key, left, knp); + knp += 8; + left ^= f(key, right, knp); + knp += 8; + right ^= f(key, left, knp); + + /* Left/right half swap, plus byte swap if little-endian */ +#ifndef WORDS_BIGENDIAN + work[1] = byteswap32(left); + work[0] = byteswap32(right); +#else + work[0] = right; + work[1] = left; +#endif + permute_fp((char *) work, key, block); /* Inverse initial permutation */ +} + +/* Permute inblock with perm */ +static void permute_ip(char *inblock, DES_KEY * key, char *outblock) +{ + register char *ib, *ob; /* ptr to input or output block */ + register char *p, *q; + register int j; + + /* Clear output block */ + Bzero(outblock, 8); + + ib = inblock; + for (j = 0; j < 16; j += 2, ib++) { /* for each input nibble */ + ob = outblock; + p = key->iperm[j][(*ib >> 4) & 0xf]; + q = key->iperm[j + 1][*ib & 0xf]; + /* and each output byte, OR the masks together */ + *ob++ |= *p++ | *q++; + *ob++ |= *p++ | *q++; + *ob++ |= *p++ | *q++; + *ob++ |= *p++ | *q++; + *ob++ |= *p++ | *q++; + *ob++ |= *p++ | *q++; + *ob++ |= *p++ | *q++; + *ob++ |= *p++ | *q++; + } +} + +/* Permute inblock with perm */ +static void permute_fp(char *inblock, DES_KEY * key, char *outblock) +{ + register char *ib, *ob; /* ptr to input or output block */ + register char *p, *q; + register int j; + + /* Clear output block */ + Bzero(outblock, 8); + + ib = inblock; + for (j = 0; j < 16; j += 2, ib++) { /* for each input nibble */ + ob = outblock; + p = key->fperm[j][(*ib >> 4) & 0xf]; + q = key->fperm[j + 1][*ib & 0xf]; + /* and each output byte, OR the masks together */ + *ob++ |= *p++ | *q++; + *ob++ |= *p++ | *q++; + *ob++ |= *p++ | *q++; + *ob++ |= *p++ | *q++; + *ob++ |= *p++ | *q++; + *ob++ |= *p++ | *q++; + *ob++ |= *p++ | *q++; + *ob++ |= *p++ | *q++; + } +} + +/* The nonlinear function f(r,k), the heart of DES */ +static uint32_t f(DES_KEY * key, register uint32_t r, register char *subkey) +{ + register uint32_t *spp; + register uint32_t rval, rt; + register int er; + +#ifdef TRACE + printf("f(%08lx, %02x %02x %02x %02x %02x %02x %02x %02x) = ", + r, + subkey[0], subkey[1], subkey[2], + subkey[3], subkey[4], subkey[5], subkey[6], subkey[7]); +#endif + /* Run E(R) ^ K through the combined S & P boxes. + * This code takes advantage of a convenient regularity in + * E, namely that each group of 6 bits in E(R) feeding + * a single S-box is a contiguous segment of R. + */ + subkey += 7; + + /* Compute E(R) for each block of 6 bits, and run thru boxes */ + er = ((int) r << 1) | ((r & 0x80000000) ? 1 : 0); + spp = &key->sp[7][0]; + rval = spp[(er ^ *subkey--) & 0x3f]; + spp -= 64; + rt = (uint32_t) r >> 3; + rval |= spp[((int) rt ^ *subkey--) & 0x3f]; + spp -= 64; + rt >>= 4; + rval |= spp[((int) rt ^ *subkey--) & 0x3f]; + spp -= 64; + rt >>= 4; + rval |= spp[((int) rt ^ *subkey--) & 0x3f]; + spp -= 64; + rt >>= 4; + rval |= spp[((int) rt ^ *subkey--) & 0x3f]; + spp -= 64; + rt >>= 4; + rval |= spp[((int) rt ^ *subkey--) & 0x3f]; + spp -= 64; + rt >>= 4; + rval |= spp[((int) rt ^ *subkey--) & 0x3f]; + spp -= 64; + rt >>= 4; + rt |= (r & 1) << 5; + rval |= spp[((int) rt ^ *subkey) & 0x3f]; +#ifdef TRACE + printf(" %08lx\n", rval); +#endif + return rval; +} + +/* initialize a perm array */ +static void perminit_ip(DES_KEY * key) +{ + register int l, j, k; + int i, m; + + stringDec((uint32_t *)ip, 16); + + /* Clear the permutation array */ + Bzero(key->iperm, 16 * 16 * 8); + + for (i = 0; i < 16; i++) /* each input nibble position */ + for (j = 0; j < 16; j++) /* each possible input nibble */ + for (k = 0; k < 64; k++) { /* each output bit position */ + l = ip[k] - 1; /* where does this bit come from */ + if ((l >> 2) != i) /* does it come from input posn? */ + continue; /* if not, bit k is 0 */ + if (!(j & nibblebit[l & 3])) + continue; /* any such bit in input? */ + m = k & 07; /* which bit is this in the byte */ + key->iperm[i][j][k >> 3] |= bytebit[m]; + } + + stringEnc((uint32_t *)ip, 16); +} + +static void perminit_fp(DES_KEY * key) +{ + register int l, j, k; + int i, m; + + stringDec((uint32_t *)fp, 16); + + /* Clear the permutation array */ + Bzero(key->fperm, 16 * 16 * 8); + + for (i = 0; i < 16; i++) /* each input nibble position */ + for (j = 0; j < 16; j++) /* each possible input nibble */ + for (k = 0; k < 64; k++) { /* each output bit position */ + l = fp[k] - 1; /* where does this bit come from */ + if ((l >> 2) != i) /* does it come from input posn? */ + continue; /* if not, bit k is 0 */ + if (!(j & nibblebit[l & 3])) + continue; /* any such bit in input? */ + m = k & 07; /* which bit is this in the byte */ + key->fperm[i][j][k >> 3] |= bytebit[m]; + } + + stringEnc((uint32_t *)fp, 16); +} + +/* Initialize the lookup table for the combined S and P boxes */ +static void spinit(DES_KEY * key) +{ + char pbox[32]; + int p, i, s, j, rowcol; + uint32_t val; + + stringDec((uint32_t *)p32i, 8); + + for (s = 0; s < 8; s++) { + stringDec((uint32_t *)(si[s]), 16); + } + + /* Compute pbox, the inverse of p32i. + * This is easier to work with + */ + for (p = 0; p < 32; p++) { + for (i = 0; i < 32; i++) { + if (p32i[i] - 1 == p) { + pbox[p] = i; + break; + } + } + } + for (s = 0; s < 8; s++) { /* For each S-box */ + for (i = 0; i < 64; i++) { /* For each possible input */ + val = 0; + /* The row number is formed from the first and last + * bits; the column number is from the middle 4 + */ + rowcol = + (i & 32) | ((i & 1) ? 16 : 0) | ((i >> 1) & + 0xf); + for (j = 0; j < 4; j++) { /* For each output bit */ + if (si[s][rowcol] & (8 >> j)) { + val |= + 1L << (31 - pbox[4 * s + j]); + } + } + key->sp[s][i] = val; + +#ifdef DEBUG + printf("sp[%d][%2d] = %08lx\n", s, i, + key->sp[s][i]); +#endif + } + } + + stringEnc((uint32_t *)p32i, 8); + + for (s = 0; s < 8; s++) { + stringEnc((uint32_t *)(si[s]), 16); + } +} -- cgit v1.2.3