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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: static unsigned int md_endian = 0x01020304;
56:
57: unsigned int
58: xntohl(unsigned int x)
59: {
60: if ( *((char *)&md_endian) == 0x01 )
61: return(x);
62: else
63: return( ((x & 0x000000ffU) << 24) |
64: ((x & 0x0000ff00U) << 8) |
65: ((x & 0x00ff0000U) >> 8) |
66: ((x & 0xff000000U) >> 24) );
67: }
68:
69: unsigned int
70: xhtonl(unsigned int x)
71: {
72: if ( *((char *)&md_endian) == 0x01 )
73: return(x);
74: else
75: return( ((x & 0x000000ffU) << 24) |
76: ((x & 0x0000ff00U) << 8) |
77: ((x & 0x00ff0000U) >> 8) |
78: ((x & 0xff000000U) >> 24) );
79: }
80:
81: #define _PASSWORD_EFMT1 '_'
82:
83: static unsigned char IP[64] = {
84: 58, 50, 42, 34, 26, 18, 10, 2, 60, 52, 44, 36, 28, 20, 12, 4,
85: 62, 54, 46, 38, 30, 22, 14, 6, 64, 56, 48, 40, 32, 24, 16, 8,
86: 57, 49, 41, 33, 25, 17, 9, 1, 59, 51, 43, 35, 27, 19, 11, 3,
87: 61, 53, 45, 37, 29, 21, 13, 5, 63, 55, 47, 39, 31, 23, 15, 7
88: };
89:
90: static unsigned char inv_key_perm[64];
91: static unsigned char key_perm[56] = {
92: 57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 34, 26, 18,
93: 10, 2, 59, 51, 43, 35, 27, 19, 11, 3, 60, 52, 44, 36,
94: 63, 55, 47, 39, 31, 23, 15, 7, 62, 54, 46, 38, 30, 22,
95: 14, 6, 61, 53, 45, 37, 29, 21, 13, 5, 28, 20, 12, 4
96: };
97:
98: static unsigned char key_shifts[16] = {
99: 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1
100: };
101:
102: static unsigned char inv_comp_perm[56];
103: static unsigned char comp_perm[48] = {
104: 14, 17, 11, 24, 1, 5, 3, 28, 15, 6, 21, 10,
105: 23, 19, 12, 4, 26, 8, 16, 7, 27, 20, 13, 2,
106: 41, 52, 31, 37, 47, 55, 30, 40, 51, 45, 33, 48,
107: 44, 49, 39, 56, 34, 53, 46, 42, 50, 36, 29, 32
108: };
109:
110: /*
111: * No E box is used, as it's replaced by some ANDs, shifts, and ORs.
112: */
113:
114: static unsigned char u_sbox[8][64];
115: static unsigned char sbox[8][64] = {
116: {
117: 14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,
118: 0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,
119: 4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,
120: 15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13
121: },
122: {
123: 15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,
124: 3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,
125: 0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,
126: 13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9
127: },
128: {
129: 10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,
130: 13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,
131: 13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,
132: 1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12
133: },
134: {
135: 7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,
136: 13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,
137: 10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,
138: 3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14
139: },
140: {
141: 2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,
142: 14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,
143: 4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,
144: 11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3
145: },
146: {
147: 12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,
148: 10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,
149: 9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,
150: 4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13
151: },
152: {
153: 4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,
154: 13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,
155: 1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,
156: 6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12
157: },
158: {
159: 13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7,
160: 1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,
161: 7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,
162: 2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11
163: }
164: };
165:
166: static unsigned char un_pbox[32];
167: static unsigned char pbox[32] = {
168: 16, 7, 20, 21, 29, 12, 28, 17, 1, 15, 23, 26, 5, 18, 31, 10,
169: 2, 8, 24, 14, 32, 27, 3, 9, 19, 13, 30, 6, 22, 11, 4, 25
170: };
171:
172: static unsigned int bits32[32] =
173: {
174: 0x80000000, 0x40000000, 0x20000000, 0x10000000,
175: 0x08000000, 0x04000000, 0x02000000, 0x01000000,
176: 0x00800000, 0x00400000, 0x00200000, 0x00100000,
177: 0x00080000, 0x00040000, 0x00020000, 0x00010000,
178: 0x00008000, 0x00004000, 0x00002000, 0x00001000,
179: 0x00000800, 0x00000400, 0x00000200, 0x00000100,
180: 0x00000080, 0x00000040, 0x00000020, 0x00000010,
181: 0x00000008, 0x00000004, 0x00000002, 0x00000001
182: };
183:
184: static unsigned char bits8[8] = { 0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, 0x01 };
185:
186: static unsigned int saltbits;
187: static int old_salt;
188: static unsigned int *bits28, *bits24;
189: static unsigned char init_perm[64], final_perm[64];
190: static unsigned int en_keysl[16], en_keysr[16];
191: static unsigned int de_keysl[16], de_keysr[16];
192: static int des_initialised = 0;
193: static unsigned char m_sbox[4][4096];
194: static unsigned int psbox[4][256];
195: static unsigned int ip_maskl[8][256], ip_maskr[8][256];
196: static unsigned int fp_maskl[8][256], fp_maskr[8][256];
197: static unsigned int key_perm_maskl[8][128], key_perm_maskr[8][128];
198: static unsigned int comp_maskl[8][128], comp_maskr[8][128];
199: static unsigned int old_rawkey0, old_rawkey1;
200:
201: static unsigned char ascii64[] =
202: "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
203: /* 0000000000111111111122222222223333333333444444444455555555556666 */
204: /* 0123456789012345678901234567890123456789012345678901234567890123 */
205:
206: static __inline int
207: ascii_to_bin(int ch)
208: {
209: if (ch > 'z')
210: return(0);
211: if (ch >= 'a')
212: return(ch - 'a' + 38);
213: if (ch > 'Z')
214: return(0);
215: if (ch >= 'A')
216: return(ch - 'A' + 12);
217: if (ch > '9')
218: return(0);
219: if (ch >= '.')
220: return(ch - '.');
221: return(0);
222: }
223:
224: static void
225: des_init(void)
226: {
227: int i, j, b, k, inbit, obit;
228: unsigned int *p, *il, *ir, *fl, *fr;
229:
230: old_rawkey0 = old_rawkey1 = 0;
231: saltbits = 0;
232: old_salt = 0;
233: bits24 = (bits28 = bits32 + 4) + 4;
234:
235: /*
236: * Invert the S-boxes, reordering the input bits.
237: */
238: for (i = 0; i < 8; i++)
239: for (j = 0; j < 64; j++) {
240: b = (j & 0x20) | ((j & 1) << 4) | ((j >> 1) & 0xf);
241: u_sbox[i][j] = sbox[i][b];
242: }
243:
244: /*
245: * Convert the inverted S-boxes into 4 arrays of 8 bits.
246: * Each will handle 12 bits of the S-box input.
247: */
248: for (b = 0; b < 4; b++)
249: for (i = 0; i < 64; i++)
250: for (j = 0; j < 64; j++)
251: m_sbox[b][(i << 6) | j] =
252: (u_sbox[(b << 1)][i] << 4) |
253: u_sbox[(b << 1) + 1][j];
254:
255: /*
256: * Set up the initial & final permutations into a useful form, and
257: * initialise the inverted key permutation.
258: */
259: for (i = 0; i < 64; i++) {
260: init_perm[final_perm[i] = IP[i] - 1] = (unsigned char) i;
261: inv_key_perm[i] = 255;
262: }
263:
264: /*
265: * Invert the key permutation and initialise the inverted key
266: * compression permutation.
267: */
268: for (i = 0; i < 56; i++) {
269: inv_key_perm[key_perm[i] - 1] = (unsigned char) i;
270: inv_comp_perm[i] = 255;
271: }
272:
273: /*
274: * Invert the key compression permutation.
275: */
276: for (i = 0; i < 48; i++) {
277: inv_comp_perm[comp_perm[i] - 1] = (unsigned char) i;
278: }
279:
280: /*
281: * Set up the OR-mask arrays for the initial and final permutations,
282: * and for the key initial and compression permutations.
283: */
284: for (k = 0; k < 8; k++) {
285: for (i = 0; i < 256; i++) {
286: *(il = &ip_maskl[k][i]) = 0;
287: *(ir = &ip_maskr[k][i]) = 0;
288: *(fl = &fp_maskl[k][i]) = 0;
289: *(fr = &fp_maskr[k][i]) = 0;
290: for (j = 0; j < 8; j++) {
291: inbit = 8 * k + j;
292: if (i & bits8[j]) {
293: if ((obit = init_perm[inbit]) < 32)
294: *il |= bits32[obit];
295: else
296: *ir |= bits32[obit-32];
297: if ((obit = final_perm[inbit]) < 32)
298: *fl |= bits32[obit];
299: else
300: *fr |= bits32[obit - 32];
301: }
302: }
303: }
304: for (i = 0; i < 128; i++) {
305: *(il = &key_perm_maskl[k][i]) = 0;
306: *(ir = &key_perm_maskr[k][i]) = 0;
307: for (j = 0; j < 7; j++) {
308: inbit = 8 * k + j;
309: if (i & bits8[j + 1]) {
310: if ((obit = inv_key_perm[inbit]) == 255)
311: continue;
312: if (obit < 28)
313: *il |= bits28[obit];
314: else
315: *ir |= bits28[obit - 28];
316: }
317: }
318: *(il = &comp_maskl[k][i]) = 0;
319: *(ir = &comp_maskr[k][i]) = 0;
320: for (j = 0; j < 7; j++) {
321: inbit = 7 * k + j;
322: if (i & bits8[j + 1]) {
323: if ((obit=inv_comp_perm[inbit]) == 255)
324: continue;
325: if (obit < 24)
326: *il |= bits24[obit];
327: else
328: *ir |= bits24[obit - 24];
329: }
330: }
331: }
332: }
333:
334: /*
335: * Invert the P-box permutation, and convert into OR-masks for
336: * handling the output of the S-box arrays setup above.
337: */
338: for (i = 0; i < 32; i++)
339: un_pbox[pbox[i] - 1] = (unsigned char) i;
340:
341: for (b = 0; b < 4; b++)
342: for (i = 0; i < 256; i++) {
343: *(p = &psbox[b][i]) = 0;
344: for (j = 0; j < 8; j++) {
345: if (i & bits8[j])
346: *p |= bits32[un_pbox[8 * b + j]];
347: }
348: }
349:
350: des_initialised = 1;
351: }
352:
353: static void
354: setup_salt(int salt)
355: {
356: unsigned int obit, saltbit;
357: int i;
358:
359: if (salt == old_salt)
360: return;
361: old_salt = salt;
362:
363: saltbits = 0;
364: saltbit = 1;
365: obit = 0x800000;
366: for (i = 0; i < 24; i++) {
367: if (salt & saltbit)
368: saltbits |= obit;
369: saltbit <<= 1;
370: obit >>= 1;
371: }
372: }
373:
374: static int
375: des_setkey(const char *key)
376: {
377: unsigned int k0, k1, rawkey0, rawkey1;
378: int shifts, round;
379:
380: if (!des_initialised)
381: des_init();
382:
383: rawkey0 = xntohl(*(unsigned int *) key);
384: rawkey1 = xntohl(*(unsigned int *) (key + 4));
385:
386: if ((rawkey0 | rawkey1)
387: && rawkey0 == old_rawkey0
388: && rawkey1 == old_rawkey1) {
389: /*
390: * Already setup for this key.
391: * This optimisation fails on a zero key (which is weak and
392: * has bad parity anyway) in order to simplify the starting
393: * conditions.
394: */
395: return(0);
396: }
397: old_rawkey0 = rawkey0;
398: old_rawkey1 = rawkey1;
399:
400: /*
401: * Do key permutation and split into two 28-bit subkeys.
402: */
403: k0 = key_perm_maskl[0][rawkey0 >> 25]
404: | key_perm_maskl[1][(rawkey0 >> 17) & 0x7f]
405: | key_perm_maskl[2][(rawkey0 >> 9) & 0x7f]
406: | key_perm_maskl[3][(rawkey0 >> 1) & 0x7f]
407: | key_perm_maskl[4][rawkey1 >> 25]
408: | key_perm_maskl[5][(rawkey1 >> 17) & 0x7f]
409: | key_perm_maskl[6][(rawkey1 >> 9) & 0x7f]
410: | key_perm_maskl[7][(rawkey1 >> 1) & 0x7f];
411: k1 = key_perm_maskr[0][rawkey0 >> 25]
412: | key_perm_maskr[1][(rawkey0 >> 17) & 0x7f]
413: | key_perm_maskr[2][(rawkey0 >> 9) & 0x7f]
414: | key_perm_maskr[3][(rawkey0 >> 1) & 0x7f]
415: | key_perm_maskr[4][rawkey1 >> 25]
416: | key_perm_maskr[5][(rawkey1 >> 17) & 0x7f]
417: | key_perm_maskr[6][(rawkey1 >> 9) & 0x7f]
418: | key_perm_maskr[7][(rawkey1 >> 1) & 0x7f];
419: /*
420: * Rotate subkeys and do compression permutation.
421: */
422: shifts = 0;
423: for (round = 0; round < 16; round++) {
424: unsigned int t0, t1;
425:
426: shifts += key_shifts[round];
427:
428: t0 = (k0 << shifts) | (k0 >> (28 - shifts));
429: t1 = (k1 << shifts) | (k1 >> (28 - shifts));
430:
431: de_keysl[15 - round] =
432: en_keysl[round] = comp_maskl[0][(t0 >> 21) & 0x7f]
433: | comp_maskl[1][(t0 >> 14) & 0x7f]
434: | comp_maskl[2][(t0 >> 7) & 0x7f]
435: | comp_maskl[3][t0 & 0x7f]
436: | comp_maskl[4][(t1 >> 21) & 0x7f]
437: | comp_maskl[5][(t1 >> 14) & 0x7f]
438: | comp_maskl[6][(t1 >> 7) & 0x7f]
439: | comp_maskl[7][t1 & 0x7f];
440:
441: de_keysr[15 - round] =
442: en_keysr[round] = comp_maskr[0][(t0 >> 21) & 0x7f]
443: | comp_maskr[1][(t0 >> 14) & 0x7f]
444: | comp_maskr[2][(t0 >> 7) & 0x7f]
445: | comp_maskr[3][t0 & 0x7f]
446: | comp_maskr[4][(t1 >> 21) & 0x7f]
447: | comp_maskr[5][(t1 >> 14) & 0x7f]
448: | comp_maskr[6][(t1 >> 7) & 0x7f]
449: | comp_maskr[7][t1 & 0x7f];
450: }
451: return(0);
452: }
453:
454: static int
455: do_des(unsigned int l_in, unsigned int r_in, unsigned int *l_out,
456: unsigned int *r_out, int count)
457: {
458: /*
459: * l_in, r_in, l_out, and r_out are in pseudo-"big-endian" format.
460: */
461: unsigned int l, r, *kl, *kr, *kl1, *kr1;
462: unsigned int f = 0, r48l, r48r;
463: int round;
464:
465: if (count == 0) {
466: return(1);
467: } else if (count > 0) {
468: /*
469: * Encrypting
470: */
471: kl1 = en_keysl;
472: kr1 = en_keysr;
473: } else {
474: /*
475: * Decrypting
476: */
477: count = -count;
478: kl1 = de_keysl;
479: kr1 = de_keysr;
480: }
481:
482: /*
483: * Do initial permutation (IP).
484: */
485: l = ip_maskl[0][l_in >> 24]
486: | ip_maskl[1][(l_in >> 16) & 0xff]
487: | ip_maskl[2][(l_in >> 8) & 0xff]
488: | ip_maskl[3][l_in & 0xff]
489: | ip_maskl[4][r_in >> 24]
490: | ip_maskl[5][(r_in >> 16) & 0xff]
491: | ip_maskl[6][(r_in >> 8) & 0xff]
492: | ip_maskl[7][r_in & 0xff];
493: r = ip_maskr[0][l_in >> 24]
494: | ip_maskr[1][(l_in >> 16) & 0xff]
495: | ip_maskr[2][(l_in >> 8) & 0xff]
496: | ip_maskr[3][l_in & 0xff]
497: | ip_maskr[4][r_in >> 24]
498: | ip_maskr[5][(r_in >> 16) & 0xff]
499: | ip_maskr[6][(r_in >> 8) & 0xff]
500: | ip_maskr[7][r_in & 0xff];
501:
502: while (count--) {
503: /*
504: * Do each round.
505: */
506: kl = kl1;
507: kr = kr1;
508: round = 16;
509: while (round--) {
510: /*
511: * Expand R to 48 bits (simulate the E-box).
512: */
513: r48l = ((r & 0x00000001) << 23)
514: | ((r & 0xf8000000) >> 9)
515: | ((r & 0x1f800000) >> 11)
516: | ((r & 0x01f80000) >> 13)
517: | ((r & 0x001f8000) >> 15);
518:
519: r48r = ((r & 0x0001f800) << 7)
520: | ((r & 0x00001f80) << 5)
521: | ((r & 0x000001f8) << 3)
522: | ((r & 0x0000001f) << 1)
523: | ((r & 0x80000000) >> 31);
524: /*
525: * Do salting for crypt() and friends, and
526: * XOR with the permuted key.
527: */
528: f = (r48l ^ r48r) & saltbits;
529: r48l ^= f ^ *kl++;
530: r48r ^= f ^ *kr++;
531: /*
532: * Do sbox lookups (which shrink it back to 32 bits)
533: * and do the pbox permutation at the same time.
534: */
535: f = psbox[0][m_sbox[0][r48l >> 12]]
536: | psbox[1][m_sbox[1][r48l & 0xfff]]
537: | psbox[2][m_sbox[2][r48r >> 12]]
538: | psbox[3][m_sbox[3][r48r & 0xfff]];
539: /*
540: * Now that we've permuted things, complete f().
541: */
542: f ^= l;
543: l = r;
544: r = f;
545: }
546: r = l;
547: l = f;
548: }
549: /*
550: * Do final permutation (inverse of IP).
551: */
552: *l_out = fp_maskl[0][l >> 24]
553: | fp_maskl[1][(l >> 16) & 0xff]
554: | fp_maskl[2][(l >> 8) & 0xff]
555: | fp_maskl[3][l & 0xff]
556: | fp_maskl[4][r >> 24]
557: | fp_maskl[5][(r >> 16) & 0xff]
558: | fp_maskl[6][(r >> 8) & 0xff]
559: | fp_maskl[7][r & 0xff];
560: *r_out = fp_maskr[0][l >> 24]
561: | fp_maskr[1][(l >> 16) & 0xff]
562: | fp_maskr[2][(l >> 8) & 0xff]
563: | fp_maskr[3][l & 0xff]
564: | fp_maskr[4][r >> 24]
565: | fp_maskr[5][(r >> 16) & 0xff]
566: | fp_maskr[6][(r >> 8) & 0xff]
567: | fp_maskr[7][r & 0xff];
568: return(0);
569: }
570:
571: static int
572: des_cipher(const char *in, char *out, int salt, int count)
573: {
574: unsigned int l_out, r_out, rawl, rawr;
575: unsigned int x[2];
576: int retval;
577:
578: if (!des_initialised)
579: des_init();
580:
581: setup_salt(salt);
582:
583: memcpy(x, in, sizeof x);
584: rawl = xntohl(x[0]);
585: rawr = xntohl(x[1]);
586: retval = do_des(rawl, rawr, &l_out, &r_out, count);
587:
588: x[0] = xhtonl(l_out);
589: x[1] = xhtonl(r_out);
590: memcpy(out, x, sizeof x);
591: return(retval);
592: }
593:
594: char *
595: xcrypt(const char *key, const char *setting)
596: {
597: int i;
598: unsigned int count, salt, l, r0, r1, keybuf[2];
599: unsigned char *p, *q;
600: static unsigned char output[21];
601:
602: if (!des_initialised)
603: des_init();
604:
605: /*
606: * Copy the key, shifting each character up by one bit
607: * and padding with zeros.
608: */
609: q = (unsigned char *) keybuf;
610: while ((q - (unsigned char *) keybuf) < sizeof(keybuf)) {
611: if ((*q++ = *key << 1))
612: key++;
613: }
614: if (des_setkey((const char *) keybuf))
615: return(NULL);
616:
617: if (*setting == _PASSWORD_EFMT1) {
618: /*
619: * "new"-style:
620: * setting - underscore, 4 bytes of count, 4 bytes of salt
621: * key - unlimited characters
622: */
623: for (i = 1, count = 0; i < 5; i++)
624: count |= ascii_to_bin(setting[i]) << (i - 1) * 6;
625:
626: for (i = 5, salt = 0; i < 9; i++)
627: salt |= ascii_to_bin(setting[i]) << (i - 5) * 6;
628:
629: while (*key) {
630: /*
631: * Encrypt the key with itself.
632: */
633: if (des_cipher((const char*)keybuf, (char*)keybuf, 0, 1))
634: return(NULL);
635: /*
636: * And XOR with the next 8 characters of the key.
637: */
638: q = (unsigned char *) keybuf;
639: while (((q - (unsigned char *) keybuf) < sizeof(keybuf)) &&
640: *key)
641: *q++ ^= *key++ << 1;
642:
643: if (des_setkey((const char *) keybuf))
644: return(NULL);
645: }
646: strncpy((char *)output, setting, 9);
647:
648: /*
649: * Double check that we weren't given a short setting.
650: * If we were, the above code will probably have created
651: * wierd values for count and salt, but we don't really care.
652: * Just make sure the output string doesn't have an extra
653: * NUL in it.
654: */
655: output[9] = '\0';
656: p = output + strlen((const char *)output);
657: } else {
658: /*
659: * "old"-style:
660: * setting - 2 bytes of salt
661: * key - up to 8 characters
662: */
663: count = 25;
664:
665: salt = (ascii_to_bin(setting[1]) << 6)
666: | ascii_to_bin(setting[0]);
667:
668: output[0] = setting[0];
669: /*
670: * If the encrypted password that the salt was extracted from
671: * is only 1 character long, the salt will be corrupted. We
672: * need to ensure that the output string doesn't have an extra
673: * NUL in it!
674: */
675: output[1] = setting[1] ? setting[1] : output[0];
676:
677: p = output + 2;
678: }
679: setup_salt(salt);
680: /*
681: * Do it.
682: */
683: if (do_des(0, 0, &r0, &r1, count))
684: return(NULL);
685: /*
686: * Now encode the result...
687: */
688: l = (r0 >> 8);
689: *p++ = ascii64[(l >> 18) & 0x3f];
690: *p++ = ascii64[(l >> 12) & 0x3f];
691: *p++ = ascii64[(l >> 6) & 0x3f];
692: *p++ = ascii64[l & 0x3f];
693:
694: l = (r0 << 16) | ((r1 >> 16) & 0xffff);
695: *p++ = ascii64[(l >> 18) & 0x3f];
696: *p++ = ascii64[(l >> 12) & 0x3f];
697: *p++ = ascii64[(l >> 6) & 0x3f];
698: *p++ = ascii64[l & 0x3f];
699:
700: l = r1 << 2;
701: *p++ = ascii64[(l >> 12) & 0x3f];
702: *p++ = ascii64[(l >> 6) & 0x3f];
703: *p++ = ascii64[l & 0x3f];
704: *p = 0;
705:
706: return((char *)output);
707: }