Annotation of early-roguelike/urogue/xcrypt.c, Revision 1.1
1.1 ! rubenllo 1: /*
! 2: * FreeSec: libcrypt
! 3: *
! 4: * Copyright (C) 1994 David Burren
! 5: * All rights reserved.
! 6: *
! 7: * Redistribution and use in source and binary forms, with or without
! 8: * modification, are permitted provided that the following conditions
! 9: * are met:
! 10: * 1. Redistributions of source code must retain the above copyright
! 11: * notice, this list of conditions and the following disclaimer.
! 12: * 2. Redistributions in binary form must reproduce the above copyright
! 13: * notice, this list of conditions and the following disclaimer in the
! 14: * documentation and/or other materials provided with the distribution.
! 15: * 3. Neither the name(s) of the author(s) nor the names of other contributors
! 16: * may be used to endorse or promote products derived from this software
! 17: * without specific prior written permission.
! 18: *
! 19: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) AND CONTRIBUTORS ``AS IS'' AND
! 20: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 21: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 22: * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR(S) OR CONTRIBUTORS BE LIABLE
! 23: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 24: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 25: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 26: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 27: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 28: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 29: * SUCH DAMAGE.
! 30: *
! 31: *
! 32: * This is an original implementation of the DES and the crypt(3) interfaces
! 33: * by David Burren <davidb@werj.com.au>.
! 34: *
! 35: * An excellent reference on the underlying algorithm (and related
! 36: * algorithms) is:
! 37: *
! 38: * B. Schneier, Applied Cryptography: protocols, algorithms,
! 39: * and source code in C, John Wiley & Sons, 1994.
! 40: *
! 41: * Note that in that book's description of DES the lookups for the initial,
! 42: * pbox, and final permutations are inverted (this has been brought to the
! 43: * attention of the author). A list of errata for this book has been
! 44: * posted to the sci.crypt newsgroup by the author and is available for FTP.
! 45: *
! 46: * NOTE:
! 47: * This file has a static version of des_setkey() so that crypt.o exports
! 48: * only the crypt() interface. This is required to make binaries linked
! 49: * against crypt.o exportable or re-exportable from the USA.
! 50: */
! 51:
! 52: #include <sys/types.h>
! 53: #include <string.h>
! 54:
! 55: extern unsigned long int md_ntohl(unsigned long int x);
! 56: extern unsigned long int md_htonl(unsigned long int x);
! 57:
! 58: #define _PASSWORD_EFMT1 '_'
! 59:
! 60: static unsigned char IP[64] = {
! 61: 58, 50, 42, 34, 26, 18, 10, 2, 60, 52, 44, 36, 28, 20, 12, 4,
! 62: 62, 54, 46, 38, 30, 22, 14, 6, 64, 56, 48, 40, 32, 24, 16, 8,
! 63: 57, 49, 41, 33, 25, 17, 9, 1, 59, 51, 43, 35, 27, 19, 11, 3,
! 64: 61, 53, 45, 37, 29, 21, 13, 5, 63, 55, 47, 39, 31, 23, 15, 7
! 65: };
! 66:
! 67: static unsigned char inv_key_perm[64];
! 68: static unsigned char key_perm[56] = {
! 69: 57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 34, 26, 18,
! 70: 10, 2, 59, 51, 43, 35, 27, 19, 11, 3, 60, 52, 44, 36,
! 71: 63, 55, 47, 39, 31, 23, 15, 7, 62, 54, 46, 38, 30, 22,
! 72: 14, 6, 61, 53, 45, 37, 29, 21, 13, 5, 28, 20, 12, 4
! 73: };
! 74:
! 75: static unsigned char key_shifts[16] = {
! 76: 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1
! 77: };
! 78:
! 79: static unsigned char inv_comp_perm[56];
! 80: static unsigned char comp_perm[48] = {
! 81: 14, 17, 11, 24, 1, 5, 3, 28, 15, 6, 21, 10,
! 82: 23, 19, 12, 4, 26, 8, 16, 7, 27, 20, 13, 2,
! 83: 41, 52, 31, 37, 47, 55, 30, 40, 51, 45, 33, 48,
! 84: 44, 49, 39, 56, 34, 53, 46, 42, 50, 36, 29, 32
! 85: };
! 86:
! 87: /*
! 88: * No E box is used, as it's replaced by some ANDs, shifts, and ORs.
! 89: */
! 90:
! 91: static unsigned char u_sbox[8][64];
! 92: static unsigned char sbox[8][64] = {
! 93: {
! 94: 14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,
! 95: 0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,
! 96: 4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,
! 97: 15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13
! 98: },
! 99: {
! 100: 15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,
! 101: 3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,
! 102: 0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,
! 103: 13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9
! 104: },
! 105: {
! 106: 10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,
! 107: 13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,
! 108: 13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,
! 109: 1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12
! 110: },
! 111: {
! 112: 7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,
! 113: 13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,
! 114: 10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,
! 115: 3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14
! 116: },
! 117: {
! 118: 2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,
! 119: 14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,
! 120: 4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,
! 121: 11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3
! 122: },
! 123: {
! 124: 12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,
! 125: 10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,
! 126: 9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,
! 127: 4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13
! 128: },
! 129: {
! 130: 4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,
! 131: 13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,
! 132: 1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,
! 133: 6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12
! 134: },
! 135: {
! 136: 13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7,
! 137: 1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,
! 138: 7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,
! 139: 2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11
! 140: }
! 141: };
! 142:
! 143: static unsigned char un_pbox[32];
! 144: static unsigned char pbox[32] = {
! 145: 16, 7, 20, 21, 29, 12, 28, 17, 1, 15, 23, 26, 5, 18, 31, 10,
! 146: 2, 8, 24, 14, 32, 27, 3, 9, 19, 13, 30, 6, 22, 11, 4, 25
! 147: };
! 148:
! 149: static unsigned int bits32[32] =
! 150: {
! 151: 0x80000000, 0x40000000, 0x20000000, 0x10000000,
! 152: 0x08000000, 0x04000000, 0x02000000, 0x01000000,
! 153: 0x00800000, 0x00400000, 0x00200000, 0x00100000,
! 154: 0x00080000, 0x00040000, 0x00020000, 0x00010000,
! 155: 0x00008000, 0x00004000, 0x00002000, 0x00001000,
! 156: 0x00000800, 0x00000400, 0x00000200, 0x00000100,
! 157: 0x00000080, 0x00000040, 0x00000020, 0x00000010,
! 158: 0x00000008, 0x00000004, 0x00000002, 0x00000001
! 159: };
! 160:
! 161: static unsigned char bits8[8] = { 0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, 0x01 };
! 162:
! 163: static unsigned int saltbits;
! 164: static int old_salt;
! 165: static unsigned int *bits28, *bits24;
! 166: static unsigned char init_perm[64], final_perm[64];
! 167: static unsigned int en_keysl[16], en_keysr[16];
! 168: static unsigned int de_keysl[16], de_keysr[16];
! 169: static int des_initialised = 0;
! 170: static unsigned char m_sbox[4][4096];
! 171: static unsigned int psbox[4][256];
! 172: static unsigned int ip_maskl[8][256], ip_maskr[8][256];
! 173: static unsigned int fp_maskl[8][256], fp_maskr[8][256];
! 174: static unsigned int key_perm_maskl[8][128], key_perm_maskr[8][128];
! 175: static unsigned int comp_maskl[8][128], comp_maskr[8][128];
! 176: static unsigned int old_rawkey0, old_rawkey1;
! 177:
! 178: static unsigned char ascii64[] =
! 179: "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
! 180: /* 0000000000111111111122222222223333333333444444444455555555556666 */
! 181: /* 0123456789012345678901234567890123456789012345678901234567890123 */
! 182:
! 183: static __inline int
! 184: ascii_to_bin(char ch)
! 185: {
! 186: if (ch > 'z')
! 187: return(0);
! 188: if (ch >= 'a')
! 189: return(ch - 'a' + 38);
! 190: if (ch > 'Z')
! 191: return(0);
! 192: if (ch >= 'A')
! 193: return(ch - 'A' + 12);
! 194: if (ch > '9')
! 195: return(0);
! 196: if (ch >= '.')
! 197: return(ch - '.');
! 198: return(0);
! 199: }
! 200:
! 201: static void
! 202: des_init()
! 203: {
! 204: int j, b, k, inbit, obit;
! 205: unsigned int *p, *il, *ir, *fl, *fr;
! 206: unsigned char i;
! 207:
! 208: old_rawkey0 = old_rawkey1 = 0;
! 209: saltbits = 0;
! 210: old_salt = 0;
! 211: bits24 = (bits28 = bits32 + 4) + 4;
! 212:
! 213: /*
! 214: * Invert the S-boxes, reordering the input bits.
! 215: */
! 216: for (i = 0; i < 8; i++)
! 217: for (j = 0; j < 64; j++) {
! 218: b = (j & 0x20) | ((j & 1) << 4) | ((j >> 1) & 0xf);
! 219: u_sbox[i][j] = sbox[i][b];
! 220: }
! 221:
! 222: /*
! 223: * Convert the inverted S-boxes into 4 arrays of 8 bits.
! 224: * Each will handle 12 bits of the S-box input.
! 225: */
! 226: for (b = 0; b < 4; b++)
! 227: for (i = 0; i < 64; i++)
! 228: for (j = 0; j < 64; j++)
! 229: m_sbox[b][(i << 6) | j] =
! 230: (u_sbox[(b << 1)][i] << 4) |
! 231: u_sbox[(b << 1) + 1][j];
! 232:
! 233: /*
! 234: * Set up the initial & final permutations into a useful form, and
! 235: * initialise the inverted key permutation.
! 236: */
! 237: for (i = 0; i < 64; i++) {
! 238: init_perm[final_perm[i] = IP[i] - 1] = i;
! 239: inv_key_perm[i] = 255;
! 240: }
! 241:
! 242: /*
! 243: * Invert the key permutation and initialise the inverted key
! 244: * compression permutation.
! 245: */
! 246: for (i = 0; i < 56; i++) {
! 247: inv_key_perm[key_perm[i] - 1] = i;
! 248: inv_comp_perm[i] = 255;
! 249: }
! 250:
! 251: /*
! 252: * Invert the key compression permutation.
! 253: */
! 254: for (i = 0; i < 48; i++) {
! 255: inv_comp_perm[comp_perm[i] - 1] = i;
! 256: }
! 257:
! 258: /*
! 259: * Set up the OR-mask arrays for the initial and final permutations,
! 260: * and for the key initial and compression permutations.
! 261: */
! 262: for (k = 0; k < 8; k++) {
! 263: for (i = 0; i < 256; i++) {
! 264: *(il = &ip_maskl[k][i]) = 0;
! 265: *(ir = &ip_maskr[k][i]) = 0;
! 266: *(fl = &fp_maskl[k][i]) = 0;
! 267: *(fr = &fp_maskr[k][i]) = 0;
! 268: for (j = 0; j < 8; j++) {
! 269: inbit = 8 * k + j;
! 270: if (i & bits8[j]) {
! 271: if ((obit = init_perm[inbit]) < 32)
! 272: *il |= bits32[obit];
! 273: else
! 274: *ir |= bits32[obit-32];
! 275: if ((obit = final_perm[inbit]) < 32)
! 276: *fl |= bits32[obit];
! 277: else
! 278: *fr |= bits32[obit - 32];
! 279: }
! 280: }
! 281: }
! 282: for (i = 0; i < 128; i++) {
! 283: *(il = &key_perm_maskl[k][i]) = 0;
! 284: *(ir = &key_perm_maskr[k][i]) = 0;
! 285: for (j = 0; j < 7; j++) {
! 286: inbit = 8 * k + j;
! 287: if (i & bits8[j + 1]) {
! 288: if ((obit = inv_key_perm[inbit]) == 255)
! 289: continue;
! 290: if (obit < 28)
! 291: *il |= bits28[obit];
! 292: else
! 293: *ir |= bits28[obit - 28];
! 294: }
! 295: }
! 296: *(il = &comp_maskl[k][i]) = 0;
! 297: *(ir = &comp_maskr[k][i]) = 0;
! 298: for (j = 0; j < 7; j++) {
! 299: inbit = 7 * k + j;
! 300: if (i & bits8[j + 1]) {
! 301: if ((obit=inv_comp_perm[inbit]) == 255)
! 302: continue;
! 303: if (obit < 24)
! 304: *il |= bits24[obit];
! 305: else
! 306: *ir |= bits24[obit - 24];
! 307: }
! 308: }
! 309: }
! 310: }
! 311:
! 312: /*
! 313: * Invert the P-box permutation, and convert into OR-masks for
! 314: * handling the output of the S-box arrays setup above.
! 315: */
! 316: for (i = 0; i < 32; i++)
! 317: un_pbox[pbox[i] - 1] = i;
! 318:
! 319: for (b = 0; b < 4; b++)
! 320: for (i = 0; i < 256; i++) {
! 321: *(p = &psbox[b][i]) = 0;
! 322: for (j = 0; j < 8; j++) {
! 323: if (i & bits8[j])
! 324: *p |= bits32[un_pbox[8 * b + j]];
! 325: }
! 326: }
! 327:
! 328: des_initialised = 1;
! 329: }
! 330:
! 331: static void
! 332: setup_salt(int salt)
! 333: {
! 334: unsigned int obit, saltbit;
! 335: int i;
! 336:
! 337: if (salt == old_salt)
! 338: return;
! 339: old_salt = salt;
! 340:
! 341: saltbits = 0;
! 342: saltbit = 1;
! 343: obit = 0x800000;
! 344: for (i = 0; i < 24; i++) {
! 345: if (salt & saltbit)
! 346: saltbits |= obit;
! 347: saltbit <<= 1;
! 348: obit >>= 1;
! 349: }
! 350: }
! 351:
! 352: static int
! 353: des_setkey(const unsigned char *key)
! 354: {
! 355: unsigned int k0, k1, rawkey0, rawkey1;
! 356: int shifts, round;
! 357:
! 358: if (!des_initialised)
! 359: des_init();
! 360:
! 361: rawkey0 = md_ntohl(*(unsigned int *) key);
! 362: rawkey1 = md_ntohl(*(unsigned int *) (key + 4));
! 363:
! 364: if ((rawkey0 | rawkey1)
! 365: && rawkey0 == old_rawkey0
! 366: && rawkey1 == old_rawkey1) {
! 367: /*
! 368: * Already setup for this key.
! 369: * This optimisation fails on a zero key (which is weak and
! 370: * has bad parity anyway) in order to simplify the starting
! 371: * conditions.
! 372: */
! 373: return(0);
! 374: }
! 375: old_rawkey0 = rawkey0;
! 376: old_rawkey1 = rawkey1;
! 377:
! 378: /*
! 379: * Do key permutation and split into two 28-bit subkeys.
! 380: */
! 381: k0 = key_perm_maskl[0][rawkey0 >> 25]
! 382: | key_perm_maskl[1][(rawkey0 >> 17) & 0x7f]
! 383: | key_perm_maskl[2][(rawkey0 >> 9) & 0x7f]
! 384: | key_perm_maskl[3][(rawkey0 >> 1) & 0x7f]
! 385: | key_perm_maskl[4][rawkey1 >> 25]
! 386: | key_perm_maskl[5][(rawkey1 >> 17) & 0x7f]
! 387: | key_perm_maskl[6][(rawkey1 >> 9) & 0x7f]
! 388: | key_perm_maskl[7][(rawkey1 >> 1) & 0x7f];
! 389: k1 = key_perm_maskr[0][rawkey0 >> 25]
! 390: | key_perm_maskr[1][(rawkey0 >> 17) & 0x7f]
! 391: | key_perm_maskr[2][(rawkey0 >> 9) & 0x7f]
! 392: | key_perm_maskr[3][(rawkey0 >> 1) & 0x7f]
! 393: | key_perm_maskr[4][rawkey1 >> 25]
! 394: | key_perm_maskr[5][(rawkey1 >> 17) & 0x7f]
! 395: | key_perm_maskr[6][(rawkey1 >> 9) & 0x7f]
! 396: | key_perm_maskr[7][(rawkey1 >> 1) & 0x7f];
! 397: /*
! 398: * Rotate subkeys and do compression permutation.
! 399: */
! 400: shifts = 0;
! 401: for (round = 0; round < 16; round++) {
! 402: unsigned int t0, t1;
! 403:
! 404: shifts += key_shifts[round];
! 405:
! 406: t0 = (k0 << shifts) | (k0 >> (28 - shifts));
! 407: t1 = (k1 << shifts) | (k1 >> (28 - shifts));
! 408:
! 409: de_keysl[15 - round] =
! 410: en_keysl[round] = comp_maskl[0][(t0 >> 21) & 0x7f]
! 411: | comp_maskl[1][(t0 >> 14) & 0x7f]
! 412: | comp_maskl[2][(t0 >> 7) & 0x7f]
! 413: | comp_maskl[3][t0 & 0x7f]
! 414: | comp_maskl[4][(t1 >> 21) & 0x7f]
! 415: | comp_maskl[5][(t1 >> 14) & 0x7f]
! 416: | comp_maskl[6][(t1 >> 7) & 0x7f]
! 417: | comp_maskl[7][t1 & 0x7f];
! 418:
! 419: de_keysr[15 - round] =
! 420: en_keysr[round] = comp_maskr[0][(t0 >> 21) & 0x7f]
! 421: | comp_maskr[1][(t0 >> 14) & 0x7f]
! 422: | comp_maskr[2][(t0 >> 7) & 0x7f]
! 423: | comp_maskr[3][t0 & 0x7f]
! 424: | comp_maskr[4][(t1 >> 21) & 0x7f]
! 425: | comp_maskr[5][(t1 >> 14) & 0x7f]
! 426: | comp_maskr[6][(t1 >> 7) & 0x7f]
! 427: | comp_maskr[7][t1 & 0x7f];
! 428: }
! 429: return(0);
! 430: }
! 431:
! 432: static int
! 433: do_des(unsigned int l_in, unsigned int r_in, unsigned int *l_out,
! 434: unsigned int *r_out, int count)
! 435: {
! 436: /*
! 437: * l_in, r_in, l_out, and r_out are in pseudo-"big-endian" format.
! 438: */
! 439: unsigned int l, r, *kl, *kr, *kl1, *kr1;
! 440: unsigned int f = 0, r48l, r48r;
! 441: int round;
! 442:
! 443: if (count == 0) {
! 444: return(1);
! 445: } else if (count > 0) {
! 446: /*
! 447: * Encrypting
! 448: */
! 449: kl1 = en_keysl;
! 450: kr1 = en_keysr;
! 451: } else {
! 452: /*
! 453: * Decrypting
! 454: */
! 455: count = -count;
! 456: kl1 = de_keysl;
! 457: kr1 = de_keysr;
! 458: }
! 459:
! 460: /*
! 461: * Do initial permutation (IP).
! 462: */
! 463: l = ip_maskl[0][l_in >> 24]
! 464: | ip_maskl[1][(l_in >> 16) & 0xff]
! 465: | ip_maskl[2][(l_in >> 8) & 0xff]
! 466: | ip_maskl[3][l_in & 0xff]
! 467: | ip_maskl[4][r_in >> 24]
! 468: | ip_maskl[5][(r_in >> 16) & 0xff]
! 469: | ip_maskl[6][(r_in >> 8) & 0xff]
! 470: | ip_maskl[7][r_in & 0xff];
! 471: r = ip_maskr[0][l_in >> 24]
! 472: | ip_maskr[1][(l_in >> 16) & 0xff]
! 473: | ip_maskr[2][(l_in >> 8) & 0xff]
! 474: | ip_maskr[3][l_in & 0xff]
! 475: | ip_maskr[4][r_in >> 24]
! 476: | ip_maskr[5][(r_in >> 16) & 0xff]
! 477: | ip_maskr[6][(r_in >> 8) & 0xff]
! 478: | ip_maskr[7][r_in & 0xff];
! 479:
! 480: while (count--) {
! 481: /*
! 482: * Do each round.
! 483: */
! 484: kl = kl1;
! 485: kr = kr1;
! 486: round = 16;
! 487: while (round--) {
! 488: /*
! 489: * Expand R to 48 bits (simulate the E-box).
! 490: */
! 491: r48l = ((r & 0x00000001) << 23)
! 492: | ((r & 0xf8000000) >> 9)
! 493: | ((r & 0x1f800000) >> 11)
! 494: | ((r & 0x01f80000) >> 13)
! 495: | ((r & 0x001f8000) >> 15);
! 496:
! 497: r48r = ((r & 0x0001f800) << 7)
! 498: | ((r & 0x00001f80) << 5)
! 499: | ((r & 0x000001f8) << 3)
! 500: | ((r & 0x0000001f) << 1)
! 501: | ((r & 0x80000000) >> 31);
! 502: /*
! 503: * Do salting for crypt() and friends, and
! 504: * XOR with the permuted key.
! 505: */
! 506: f = (r48l ^ r48r) & saltbits;
! 507: r48l ^= f ^ *kl++;
! 508: r48r ^= f ^ *kr++;
! 509: /*
! 510: * Do sbox lookups (which shrink it back to 32 bits)
! 511: * and do the pbox permutation at the same time.
! 512: */
! 513: f = psbox[0][m_sbox[0][r48l >> 12]]
! 514: | psbox[1][m_sbox[1][r48l & 0xfff]]
! 515: | psbox[2][m_sbox[2][r48r >> 12]]
! 516: | psbox[3][m_sbox[3][r48r & 0xfff]];
! 517: /*
! 518: * Now that we've permuted things, complete f().
! 519: */
! 520: f ^= l;
! 521: l = r;
! 522: r = f;
! 523: }
! 524: r = l;
! 525: l = f;
! 526: }
! 527: /*
! 528: * Do final permutation (inverse of IP).
! 529: */
! 530: *l_out = fp_maskl[0][l >> 24]
! 531: | fp_maskl[1][(l >> 16) & 0xff]
! 532: | fp_maskl[2][(l >> 8) & 0xff]
! 533: | fp_maskl[3][l & 0xff]
! 534: | fp_maskl[4][r >> 24]
! 535: | fp_maskl[5][(r >> 16) & 0xff]
! 536: | fp_maskl[6][(r >> 8) & 0xff]
! 537: | fp_maskl[7][r & 0xff];
! 538: *r_out = fp_maskr[0][l >> 24]
! 539: | fp_maskr[1][(l >> 16) & 0xff]
! 540: | fp_maskr[2][(l >> 8) & 0xff]
! 541: | fp_maskr[3][l & 0xff]
! 542: | fp_maskr[4][r >> 24]
! 543: | fp_maskr[5][(r >> 16) & 0xff]
! 544: | fp_maskr[6][(r >> 8) & 0xff]
! 545: | fp_maskr[7][r & 0xff];
! 546: return(0);
! 547: }
! 548:
! 549: static int
! 550: des_cipher(const unsigned char *in, unsigned char *out, int salt, int count)
! 551: {
! 552: unsigned int l_out, r_out, rawl, rawr;
! 553: unsigned int x[2];
! 554: int retval;
! 555:
! 556: if (!des_initialised)
! 557: des_init();
! 558:
! 559: setup_salt(salt);
! 560:
! 561: memcpy(x, in, sizeof x);
! 562: rawl = md_ntohl(x[0]);
! 563: rawr = md_ntohl(x[1]);
! 564: retval = do_des(rawl, rawr, &l_out, &r_out, count);
! 565:
! 566: x[0] = md_htonl(l_out);
! 567: x[1] = md_htonl(r_out);
! 568: memcpy(out, x, sizeof x);
! 569: return(retval);
! 570: }
! 571:
! 572: char *
! 573: xcrypt(const char *key, const char *setting)
! 574: {
! 575: int i;
! 576: unsigned int count, salt, l, r0, r1, keybuf[2];
! 577: unsigned char *p, *q;
! 578: static unsigned char output[21];
! 579:
! 580: if (!des_initialised)
! 581: des_init();
! 582:
! 583: /*
! 584: * Copy the key, shifting each character up by one bit
! 585: * and padding with zeros.
! 586: */
! 587: q = (unsigned char *) keybuf;
! 588: while ((q - (unsigned char *) keybuf) < sizeof(keybuf)) {
! 589: if ((*q++ = *key << 1))
! 590: key++;
! 591: }
! 592: if (des_setkey((unsigned char *) keybuf))
! 593: return(NULL);
! 594:
! 595: if (*setting == _PASSWORD_EFMT1) {
! 596: /*
! 597: * "new"-style:
! 598: * setting - underscore, 4 bytes of count, 4 bytes of salt
! 599: * key - unlimited characters
! 600: */
! 601: for (i = 1, count = 0; i < 5; i++)
! 602: count |= ascii_to_bin(setting[i]) << (i - 1) * 6;
! 603:
! 604: for (i = 5, salt = 0; i < 9; i++)
! 605: salt |= ascii_to_bin(setting[i]) << (i - 5) * 6;
! 606:
! 607: while (*key) {
! 608: /*
! 609: * Encrypt the key with itself.
! 610: */
! 611: if (des_cipher((unsigned char*)keybuf, (unsigned char*)keybuf, 0, 1))
! 612: return(NULL);
! 613: /*
! 614: * And XOR with the next 8 characters of the key.
! 615: */
! 616: q = (unsigned char *) keybuf;
! 617: while (((q - (unsigned char *) keybuf) < sizeof(keybuf)) &&
! 618: *key)
! 619: *q++ ^= *key++ << 1;
! 620:
! 621: if (des_setkey((unsigned char *) keybuf))
! 622: return(NULL);
! 623: }
! 624: strncpy((char *)output, setting, 9);
! 625:
! 626: /*
! 627: * Double check that we weren't given a short setting.
! 628: * If we were, the above code will probably have created
! 629: * wierd values for count and salt, but we don't really care.
! 630: * Just make sure the output string doesn't have an extra
! 631: * NUL in it.
! 632: */
! 633: output[9] = '\0';
! 634: p = output + strlen((const char *)output);
! 635: } else {
! 636: /*
! 637: * "old"-style:
! 638: * setting - 2 bytes of salt
! 639: * key - up to 8 characters
! 640: */
! 641: count = 25;
! 642:
! 643: salt = (ascii_to_bin(setting[1]) << 6)
! 644: | ascii_to_bin(setting[0]);
! 645:
! 646: output[0] = setting[0];
! 647: /*
! 648: * If the encrypted password that the salt was extracted from
! 649: * is only 1 character long, the salt will be corrupted. We
! 650: * need to ensure that the output string doesn't have an extra
! 651: * NUL in it!
! 652: */
! 653: output[1] = setting[1] ? setting[1] : output[0];
! 654:
! 655: p = output + 2;
! 656: }
! 657: setup_salt(salt);
! 658: /*
! 659: * Do it.
! 660: */
! 661: if (do_des(0, 0, &r0, &r1, count))
! 662: return(NULL);
! 663: /*
! 664: * Now encode the result...
! 665: */
! 666: l = (r0 >> 8);
! 667: *p++ = ascii64[(l >> 18) & 0x3f];
! 668: *p++ = ascii64[(l >> 12) & 0x3f];
! 669: *p++ = ascii64[(l >> 6) & 0x3f];
! 670: *p++ = ascii64[l & 0x3f];
! 671:
! 672: l = (r0 << 16) | ((r1 >> 16) & 0xffff);
! 673: *p++ = ascii64[(l >> 18) & 0x3f];
! 674: *p++ = ascii64[(l >> 12) & 0x3f];
! 675: *p++ = ascii64[(l >> 6) & 0x3f];
! 676: *p++ = ascii64[l & 0x3f];
! 677:
! 678: l = r1 << 2;
! 679: *p++ = ascii64[(l >> 12) & 0x3f];
! 680: *p++ = ascii64[(l >> 6) & 0x3f];
! 681: *p++ = ascii64[l & 0x3f];
! 682: *p = 0;
! 683:
! 684: return((char *)output);
! 685: }
CVSweb
![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to xcrypt.c CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [contributed] / early-roguelike / urogue