1 /*
2 * FreeSec: libcrypt for NetBSD
3 *
4 * Copyright (c) 1994 David Burren
5 * All rights reserved.
6 *
7 * Adapted for FreeBSD-2.0 by Geoffrey M. Rehmet
8 * this file should now *only* export crypt(), in order to make
9 * binaries of libcrypt exportable from the USA
10 *
11 * Adapted for FreeBSD-4.0 by Mark R V Murray
12 * this file should now *only* export crypt_des(), in order to make
13 * a module that can be optionally included in libcrypt.
14 *
15 * Redistribution and use in source and binary forms, with or without
16 * modification, are permitted provided that the following conditions
17 * are met:
18 * 1. Redistributions of source code must retain the above copyright
19 * notice, this list of conditions and the following disclaimer.
20 * 2. Redistributions in binary form must reproduce the above copyright
21 * notice, this list of conditions and the following disclaimer in the
22 * documentation and/or other materials provided with the distribution.
23 * 3. Neither the name of the author nor the names of other contributors
24 * may be used to endorse or promote products derived from this software
25 * without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 *
39 * This is an original implementation of the DES and the crypt(3) interfaces
40 * by David Burren <davidb@werj.com.au>.
41 *
42 * An excellent reference on the underlying algorithm (and related
43 * algorithms) is:
44 *
45 * B. Schneier, Applied Cryptography: protocols, algorithms,
46 * and source code in C, John Wiley & Sons, 1994.
47 *
48 * Note that in that book's description of DES the lookups for the initial,
49 * pbox, and final permutations are inverted (this has been brought to the
50 * attention of the author). A list of errata for this book has been
51 * posted to the sci.crypt newsgroup by the author and is available for FTP.
52 *
53 * ARCHITECTURE ASSUMPTIONS:
54 * It is assumed that the 8-byte arrays passed by reference can be
55 * addressed as arrays of u_int32_t's (ie. the CPU is not picky about
56 * alignment).
57 */
58
59 #include <sys/cdefs.h>
60 #include <sys/types.h>
61 #include <sys/param.h>
62 #include <netinet/in.h>
63 #include <pwd.h>
64 #include <string.h>
65 #include <crypt.h>
66 #include "libcrypt.h"
67 #include "des_tables.c"
68
69 /* Re-entrantify me -- all this junk needs to be in
70 * struct crypt_data to make this really reentrant... */
71 static u_int32_t en_keysl[16], en_keysr[16];
72 static u_int32_t de_keysl[16], de_keysr[16];
73 static u_int32_t saltbits;
74 static u_int32_t old_salt;
75 static u_int32_t old_rawkey0, old_rawkey1;
76
77 /* A pile of data */
78 static const u_char ascii64[] = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
79
80 static const u_char key_shifts[16] = {
81 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1
82 };
83
84 static const u_int32_t bits32[32] =
85 {
86 0x80000000, 0x40000000, 0x20000000, 0x10000000,
87 0x08000000, 0x04000000, 0x02000000, 0x01000000,
88 0x00800000, 0x00400000, 0x00200000, 0x00100000,
89 0x00080000, 0x00040000, 0x00020000, 0x00010000,
90 0x00008000, 0x00004000, 0x00002000, 0x00001000,
91 0x00000800, 0x00000400, 0x00000200, 0x00000100,
92 0x00000080, 0x00000040, 0x00000020, 0x00000010,
93 0x00000008, 0x00000004, 0x00000002, 0x00000001
94 };
95
96 static const u_char bits8[8] = { 0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, 0x01 };
97
98
99 static int
ascii_to_bin(char ch)100 ascii_to_bin(char ch)
101 {
102 if (ch > 'z')
103 return(0);
104 if (ch >= 'a')
105 return(ch - 'a' + 38);
106 if (ch > 'Z')
107 return(0);
108 if (ch >= 'A')
109 return(ch - 'A' + 12);
110 if (ch > '9')
111 return(0);
112 if (ch >= '.')
113 return(ch - '.');
114 return(0);
115 }
116
117 static void
des_init(void)118 des_init(void)
119 {
120 static int des_initialised = 0;
121
122 if (des_initialised==1)
123 return;
124
125 old_rawkey0 = old_rawkey1 = 0L;
126 saltbits = 0L;
127 old_salt = 0L;
128
129 des_initialised = 1;
130 }
131
132 static void
setup_salt(u_int32_t salt)133 setup_salt(u_int32_t salt)
134 {
135 u_int32_t obit, saltbit;
136 int i;
137
138 if (salt == old_salt)
139 return;
140 old_salt = salt;
141
142 saltbits = 0L;
143 saltbit = 1;
144 obit = 0x800000;
145 for (i = 0; i < 24; i++) {
146 if (salt & saltbit)
147 saltbits |= obit;
148 saltbit <<= 1;
149 obit >>= 1;
150 }
151 }
152
153
154 static void
des_setkey(const char * key)155 des_setkey(const char *key)
156 {
157 u_int32_t k0, k1, rawkey0, rawkey1;
158 int shifts, round;
159
160 des_init();
161
162 rawkey0 = ntohl(*(const u_int32_t *) key);
163 rawkey1 = ntohl(*(const u_int32_t *) (key + 4));
164
165 if ((rawkey0 | rawkey1)
166 && rawkey0 == old_rawkey0
167 && rawkey1 == old_rawkey1) {
168 /*
169 * Already setup for this key.
170 * This optimisation fails on a zero key (which is weak and
171 * has bad parity anyway) in order to simplify the starting
172 * conditions.
173 */
174 return;
175 }
176 old_rawkey0 = rawkey0;
177 old_rawkey1 = rawkey1;
178
179 /*
180 * Do key permutation and split into two 28-bit subkeys.
181 */
182 k0 = key_perm_maskl[0][rawkey0 >> 25]
183 | key_perm_maskl[1][(rawkey0 >> 17) & 0x7f]
184 | key_perm_maskl[2][(rawkey0 >> 9) & 0x7f]
185 | key_perm_maskl[3][(rawkey0 >> 1) & 0x7f]
186 | key_perm_maskl[4][rawkey1 >> 25]
187 | key_perm_maskl[5][(rawkey1 >> 17) & 0x7f]
188 | key_perm_maskl[6][(rawkey1 >> 9) & 0x7f]
189 | key_perm_maskl[7][(rawkey1 >> 1) & 0x7f];
190 k1 = key_perm_maskr[0][rawkey0 >> 25]
191 | key_perm_maskr[1][(rawkey0 >> 17) & 0x7f]
192 | key_perm_maskr[2][(rawkey0 >> 9) & 0x7f]
193 | key_perm_maskr[3][(rawkey0 >> 1) & 0x7f]
194 | key_perm_maskr[4][rawkey1 >> 25]
195 | key_perm_maskr[5][(rawkey1 >> 17) & 0x7f]
196 | key_perm_maskr[6][(rawkey1 >> 9) & 0x7f]
197 | key_perm_maskr[7][(rawkey1 >> 1) & 0x7f];
198 /*
199 * Rotate subkeys and do compression permutation.
200 */
201 shifts = 0;
202 for (round = 0; round < 16; round++) {
203 u_int32_t t0, t1;
204
205 shifts += key_shifts[round];
206
207 t0 = (k0 << shifts) | (k0 >> (28 - shifts));
208 t1 = (k1 << shifts) | (k1 >> (28 - shifts));
209
210 de_keysl[15 - round] =
211 en_keysl[round] = comp_maskl[0][(t0 >> 21) & 0x7f]
212 | comp_maskl[1][(t0 >> 14) & 0x7f]
213 | comp_maskl[2][(t0 >> 7) & 0x7f]
214 | comp_maskl[3][t0 & 0x7f]
215 | comp_maskl[4][(t1 >> 21) & 0x7f]
216 | comp_maskl[5][(t1 >> 14) & 0x7f]
217 | comp_maskl[6][(t1 >> 7) & 0x7f]
218 | comp_maskl[7][t1 & 0x7f];
219
220 de_keysr[15 - round] =
221 en_keysr[round] = comp_maskr[0][(t0 >> 21) & 0x7f]
222 | comp_maskr[1][(t0 >> 14) & 0x7f]
223 | comp_maskr[2][(t0 >> 7) & 0x7f]
224 | comp_maskr[3][t0 & 0x7f]
225 | comp_maskr[4][(t1 >> 21) & 0x7f]
226 | comp_maskr[5][(t1 >> 14) & 0x7f]
227 | comp_maskr[6][(t1 >> 7) & 0x7f]
228 | comp_maskr[7][t1 & 0x7f];
229 }
230 }
231
232
233 static int
do_des(u_int32_t l_in,u_int32_t r_in,u_int32_t * l_out,u_int32_t * r_out,int count)234 do_des( u_int32_t l_in, u_int32_t r_in, u_int32_t *l_out, u_int32_t *r_out, int count)
235 {
236 /* l_in, r_in, l_out, and r_out are in pseudo-"big-endian" format. */
237 u_int32_t l, r, *kl, *kr, *kl1, *kr1;
238 u_int32_t f, r48l, r48r;
239 int round;
240
241 if (count == 0) {
242 return 1;
243 }
244 if (count > 0) {
245 /* Encrypting */
246 kl1 = en_keysl;
247 kr1 = en_keysr;
248 } else {
249 /* Decrypting */
250 count = -count;
251 kl1 = de_keysl;
252 kr1 = de_keysr;
253 }
254
255 /* Do initial permutation (IP). */
256 l = ip_maskl[0][l_in >> 24]
257 | ip_maskl[1][(l_in >> 16) & 0xff]
258 | ip_maskl[2][(l_in >> 8) & 0xff]
259 | ip_maskl[3][l_in & 0xff]
260 | ip_maskl[4][r_in >> 24]
261 | ip_maskl[5][(r_in >> 16) & 0xff]
262 | ip_maskl[6][(r_in >> 8) & 0xff]
263 | ip_maskl[7][r_in & 0xff];
264 r = ip_maskr[0][l_in >> 24]
265 | ip_maskr[1][(l_in >> 16) & 0xff]
266 | ip_maskr[2][(l_in >> 8) & 0xff]
267 | ip_maskr[3][l_in & 0xff]
268 | ip_maskr[4][r_in >> 24]
269 | ip_maskr[5][(r_in >> 16) & 0xff]
270 | ip_maskr[6][(r_in >> 8) & 0xff]
271 | ip_maskr[7][r_in & 0xff];
272
273 while (count--) {
274 /* Do each round. */
275 kl = kl1;
276 kr = kr1;
277 round = 16;
278 do {
279 /* Expand R to 48 bits (simulate the E-box). */
280 r48l = ((r & 0x00000001) << 23)
281 | ((r & 0xf8000000) >> 9)
282 | ((r & 0x1f800000) >> 11)
283 | ((r & 0x01f80000) >> 13)
284 | ((r & 0x001f8000) >> 15);
285 r48r = ((r & 0x0001f800) << 7)
286 | ((r & 0x00001f80) << 5)
287 | ((r & 0x000001f8) << 3)
288 | ((r & 0x0000001f) << 1)
289 | ((r & 0x80000000) >> 31);
290 /*
291 * Do salting for crypt() and friends, and
292 * XOR with the permuted key.
293 */
294 f = (r48l ^ r48r) & saltbits;
295 r48l ^= f ^ *kl++;
296 r48r ^= f ^ *kr++;
297 /*
298 * Do sbox lookups (which shrink it back to 32 bits)
299 * and do the pbox permutation at the same time.
300 */
301 f = psbox[0][m_sbox[0][r48l >> 12]]
302 | psbox[1][m_sbox[1][r48l & 0xfff]]
303 | psbox[2][m_sbox[2][r48r >> 12]]
304 | psbox[3][m_sbox[3][r48r & 0xfff]];
305 /* Now that we've permuted things, complete f(). */
306 f ^= l;
307 l = r;
308 r = f;
309 } while (--round);
310 r = l;
311 l = f;
312 }
313 /* Do final permutation (inverse of IP). */
314 *l_out = fp_maskl[0][l >> 24]
315 | fp_maskl[1][(l >> 16) & 0xff]
316 | fp_maskl[2][(l >> 8) & 0xff]
317 | fp_maskl[3][l & 0xff]
318 | fp_maskl[4][r >> 24]
319 | fp_maskl[5][(r >> 16) & 0xff]
320 | fp_maskl[6][(r >> 8) & 0xff]
321 | fp_maskl[7][r & 0xff];
322 *r_out = fp_maskr[0][l >> 24]
323 | fp_maskr[1][(l >> 16) & 0xff]
324 | fp_maskr[2][(l >> 8) & 0xff]
325 | fp_maskr[3][l & 0xff]
326 | fp_maskr[4][r >> 24]
327 | fp_maskr[5][(r >> 16) & 0xff]
328 | fp_maskr[6][(r >> 8) & 0xff]
329 | fp_maskr[7][r & 0xff];
330 return(0);
331 }
332
333
334 #if 0
335 static int
336 des_cipher(const char *in, char *out, u_int32_t salt, int count)
337 {
338 u_int32_t l_out, r_out, rawl, rawr;
339 int retval;
340 union {
341 u_int32_t *ui32;
342 const char *c;
343 } trans;
344
345 des_init();
346
347 setup_salt(salt);
348
349 trans.c = in;
350 rawl = ntohl(*trans.ui32++);
351 rawr = ntohl(*trans.ui32);
352
353 retval = do_des(rawl, rawr, &l_out, &r_out, count);
354
355 trans.c = out;
356 *trans.ui32++ = htonl(l_out);
357 *trans.ui32 = htonl(r_out);
358 return(retval);
359 }
360 #endif
361
362
363 void
setkey(const char * key)364 setkey(const char *key)
365 {
366 int i, j;
367 u_int32_t packed_keys[2];
368 u_char *p;
369
370 p = (u_char *) packed_keys;
371
372 for (i = 0; i < 8; i++) {
373 p[i] = 0;
374 for (j = 0; j < 8; j++)
375 if (*key++ & 1)
376 p[i] |= bits8[j];
377 }
378 des_setkey((char *)p);
379 }
380
381
382 void
encrypt(char * block,int flag)383 encrypt(char *block, int flag)
384 {
385 u_int32_t io[2];
386 u_char *p;
387 int i, j;
388
389 des_init();
390
391 setup_salt(0L);
392 p = (u_char*)block;
393 for (i = 0; i < 2; i++) {
394 io[i] = 0L;
395 for (j = 0; j < 32; j++)
396 if (*p++ & 1)
397 io[i] |= bits32[j];
398 }
399 do_des(io[0], io[1], io, io + 1, flag ? -1 : 1);
400 for (i = 0; i < 2; i++)
401 for (j = 0; j < 32; j++)
402 block[(i << 5) | j] = (io[i] & bits32[j]) ? 1 : 0;
403 }
404
__des_crypt(const unsigned char * key,const unsigned char * setting)405 char *__des_crypt(const unsigned char *key, const unsigned char *setting)
406 {
407 u_int32_t count, salt, l, r0, r1, keybuf[2];
408 u_char *p, *q;
409 static char output[21];
410
411 des_init();
412
413 /*
414 * Copy the key, shifting each character up by one bit
415 * and padding with zeros.
416 */
417 q = (u_char *)keybuf;
418 while (q - (u_char *)keybuf - 8) {
419 *q++ = *key << 1;
420 if (*(q - 1))
421 key++;
422 }
423 des_setkey((char *)keybuf);
424
425 #if 0
426 if (*setting == _PASSWORD_EFMT1) {
427 int i;
428 /*
429 * "new"-style:
430 * setting - underscore, 4 bytes of count, 4 bytes of salt
431 * key - unlimited characters
432 */
433 for (i = 1, count = 0L; i < 5; i++)
434 count |= ascii_to_bin(setting[i]) << ((i - 1) * 6);
435
436 for (i = 5, salt = 0L; i < 9; i++)
437 salt |= ascii_to_bin(setting[i]) << ((i - 5) * 6);
438
439 while (*key) {
440 /*
441 * Encrypt the key with itself.
442 */
443 if (des_cipher((char *)keybuf, (char *)keybuf, 0L, 1))
444 return(NULL);
445 /*
446 * And XOR with the next 8 characters of the key.
447 */
448 q = (u_char *)keybuf;
449 while (q - (u_char *)keybuf - 8 && *key)
450 *q++ ^= *key++ << 1;
451
452 des_setkey((char *)keybuf);
453 }
454 strncpy(output, setting, 9);
455
456 /*
457 * Double check that we weren't given a short setting.
458 * If we were, the above code will probably have created
459 * wierd values for count and salt, but we don't really care.
460 * Just make sure the output string doesn't have an extra
461 * NUL in it.
462 */
463 output[9] = '\0';
464 p = (u_char *)output + strlen(output);
465 } else
466 #endif
467 {
468 /*
469 * "old"-style:
470 * setting - 2 bytes of salt
471 * key - up to 8 characters
472 */
473 count = 25;
474
475 salt = (ascii_to_bin(setting[1]) << 6)
476 | ascii_to_bin(setting[0]);
477
478 output[0] = setting[0];
479 /*
480 * If the encrypted password that the salt was extracted from
481 * is only 1 character long, the salt will be corrupted. We
482 * need to ensure that the output string doesn't have an extra
483 * NUL in it!
484 */
485 output[1] = setting[1] ? setting[1] : output[0];
486
487 p = (u_char *)output + 2;
488 }
489 setup_salt(salt);
490 /*
491 * Do it.
492 */
493 if (do_des(0L, 0L, &r0, &r1, (int)count))
494 return(NULL);
495 /*
496 * Now encode the result...
497 */
498 l = (r0 >> 8);
499 *p++ = ascii64[(l >> 18) & 0x3f];
500 *p++ = ascii64[(l >> 12) & 0x3f];
501 *p++ = ascii64[(l >> 6) & 0x3f];
502 *p++ = ascii64[l & 0x3f];
503
504 l = (r0 << 16) | ((r1 >> 16) & 0xffff);
505 *p++ = ascii64[(l >> 18) & 0x3f];
506 *p++ = ascii64[(l >> 12) & 0x3f];
507 *p++ = ascii64[(l >> 6) & 0x3f];
508 *p++ = ascii64[l & 0x3f];
509
510 l = r1 << 2;
511 *p++ = ascii64[(l >> 12) & 0x3f];
512 *p++ = ascii64[(l >> 6) & 0x3f];
513 *p++ = ascii64[l & 0x3f];
514 *p = 0;
515
516 return(output);
517 }
518
519