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Import UltraRogue from the Roguelike Restoration Project (r1490)
author John "Elwin" Edwards
date Tue, 31 Jan 2017 19:56:04 -0500
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children e52a8a7ad4c5
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253:d9badb9c0179 256:c495a4f288c6
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 }