Annotation of early-roguelike/arogue5/xcrypt.c, Revision 1.1.1.1
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: unsigned long int md_htonl(unsigned long int x);
56: unsigned long int md_ntohl(unsigned long int x);
57:
58: #ifdef DEBUG
59: # include <stdio.h>
60: #endif
61: #define _PASSWORD_EFMT1 '_'
62:
63: static unsigned char IP[64] = {
64: 58, 50, 42, 34, 26, 18, 10, 2, 60, 52, 44, 36, 28, 20, 12, 4,
65: 62, 54, 46, 38, 30, 22, 14, 6, 64, 56, 48, 40, 32, 24, 16, 8,
66: 57, 49, 41, 33, 25, 17, 9, 1, 59, 51, 43, 35, 27, 19, 11, 3,
67: 61, 53, 45, 37, 29, 21, 13, 5, 63, 55, 47, 39, 31, 23, 15, 7
68: };
69:
70: static unsigned char inv_key_perm[64];
71: static unsigned char key_perm[56] = {
72: 57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 34, 26, 18,
73: 10, 2, 59, 51, 43, 35, 27, 19, 11, 3, 60, 52, 44, 36,
74: 63, 55, 47, 39, 31, 23, 15, 7, 62, 54, 46, 38, 30, 22,
75: 14, 6, 61, 53, 45, 37, 29, 21, 13, 5, 28, 20, 12, 4
76: };
77:
78: static unsigned char key_shifts[16] = {
79: 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1
80: };
81:
82: static unsigned char inv_comp_perm[56];
83: static unsigned char comp_perm[48] = {
84: 14, 17, 11, 24, 1, 5, 3, 28, 15, 6, 21, 10,
85: 23, 19, 12, 4, 26, 8, 16, 7, 27, 20, 13, 2,
86: 41, 52, 31, 37, 47, 55, 30, 40, 51, 45, 33, 48,
87: 44, 49, 39, 56, 34, 53, 46, 42, 50, 36, 29, 32
88: };
89:
90: /*
91: * No E box is used, as it's replaced by some ANDs, shifts, and ORs.
92: */
93:
94: static unsigned char u_sbox[8][64];
95: static unsigned char sbox[8][64] = {
96: {
97: 14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,
98: 0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,
99: 4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,
100: 15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13
101: },
102: {
103: 15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,
104: 3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,
105: 0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,
106: 13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9
107: },
108: {
109: 10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,
110: 13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,
111: 13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,
112: 1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12
113: },
114: {
115: 7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,
116: 13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,
117: 10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,
118: 3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14
119: },
120: {
121: 2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,
122: 14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,
123: 4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,
124: 11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3
125: },
126: {
127: 12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,
128: 10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,
129: 9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,
130: 4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13
131: },
132: {
133: 4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,
134: 13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,
135: 1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,
136: 6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12
137: },
138: {
139: 13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7,
140: 1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,
141: 7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,
142: 2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11
143: }
144: };
145:
146: static unsigned char un_pbox[32];
147: static unsigned char pbox[32] = {
148: 16, 7, 20, 21, 29, 12, 28, 17, 1, 15, 23, 26, 5, 18, 31, 10,
149: 2, 8, 24, 14, 32, 27, 3, 9, 19, 13, 30, 6, 22, 11, 4, 25
150: };
151:
152: static unsigned int bits32[32] =
153: {
154: 0x80000000, 0x40000000, 0x20000000, 0x10000000,
155: 0x08000000, 0x04000000, 0x02000000, 0x01000000,
156: 0x00800000, 0x00400000, 0x00200000, 0x00100000,
157: 0x00080000, 0x00040000, 0x00020000, 0x00010000,
158: 0x00008000, 0x00004000, 0x00002000, 0x00001000,
159: 0x00000800, 0x00000400, 0x00000200, 0x00000100,
160: 0x00000080, 0x00000040, 0x00000020, 0x00000010,
161: 0x00000008, 0x00000004, 0x00000002, 0x00000001
162: };
163:
164: static unsigned char bits8[8] = { 0x80, 0x40, 0x20, 0x10, 0x08, 0x04, 0x02, 0x01 };
165:
166: static unsigned int saltbits;
167: static int old_salt;
168: static unsigned int *bits28, *bits24;
169: static unsigned char init_perm[64], final_perm[64];
170: static unsigned int en_keysl[16], en_keysr[16];
171: static unsigned int de_keysl[16], de_keysr[16];
172: static int des_initialised = 0;
173: static unsigned char m_sbox[4][4096];
174: static unsigned int psbox[4][256];
175: static unsigned int ip_maskl[8][256], ip_maskr[8][256];
176: static unsigned int fp_maskl[8][256], fp_maskr[8][256];
177: static unsigned int key_perm_maskl[8][128], key_perm_maskr[8][128];
178: static unsigned int comp_maskl[8][128], comp_maskr[8][128];
179: static unsigned int old_rawkey0, old_rawkey1;
180:
181: static unsigned char ascii64[] =
182: "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
183: /* 0000000000111111111122222222223333333333444444444455555555556666 */
184: /* 0123456789012345678901234567890123456789012345678901234567890123 */
185:
186: static __inline int
187: ascii_to_bin(ch)
188: char ch;
189: {
190: if (ch > 'z')
191: return(0);
192: if (ch >= 'a')
193: return(ch - 'a' + 38);
194: if (ch > 'Z')
195: return(0);
196: if (ch >= 'A')
197: return(ch - 'A' + 12);
198: if (ch > '9')
199: return(0);
200: if (ch >= '.')
201: return(ch - '.');
202: return(0);
203: }
204:
205: static void
206: des_init()
207: {
208: int i, j, b, k, inbit, obit;
209: unsigned int *p, *il, *ir, *fl, *fr;
210:
211: old_rawkey0 = old_rawkey1 = 0;
212: saltbits = 0;
213: old_salt = 0;
214: bits24 = (bits28 = bits32 + 4) + 4;
215:
216: /*
217: * Invert the S-boxes, reordering the input bits.
218: */
219: for (i = 0; i < 8; i++)
220: for (j = 0; j < 64; j++) {
221: b = (j & 0x20) | ((j & 1) << 4) | ((j >> 1) & 0xf);
222: u_sbox[i][j] = sbox[i][b];
223: }
224:
225: /*
226: * Convert the inverted S-boxes into 4 arrays of 8 bits.
227: * Each will handle 12 bits of the S-box input.
228: */
229: for (b = 0; b < 4; b++)
230: for (i = 0; i < 64; i++)
231: for (j = 0; j < 64; j++)
232: m_sbox[b][(i << 6) | j] =
233: (u_sbox[(b << 1)][i] << 4) |
234: u_sbox[(b << 1) + 1][j];
235:
236: /*
237: * Set up the initial & final permutations into a useful form, and
238: * initialise the inverted key permutation.
239: */
240: for (i = 0; i < 64; i++) {
241: init_perm[final_perm[i] = IP[i] - 1] = i;
242: inv_key_perm[i] = 255;
243: }
244:
245: /*
246: * Invert the key permutation and initialise the inverted key
247: * compression permutation.
248: */
249: for (i = 0; i < 56; i++) {
250: inv_key_perm[key_perm[i] - 1] = i;
251: inv_comp_perm[i] = 255;
252: }
253:
254: /*
255: * Invert the key compression permutation.
256: */
257: for (i = 0; i < 48; i++) {
258: inv_comp_perm[comp_perm[i] - 1] = i;
259: }
260:
261: /*
262: * Set up the OR-mask arrays for the initial and final permutations,
263: * and for the key initial and compression permutations.
264: */
265: for (k = 0; k < 8; k++) {
266: for (i = 0; i < 256; i++) {
267: *(il = &ip_maskl[k][i]) = 0;
268: *(ir = &ip_maskr[k][i]) = 0;
269: *(fl = &fp_maskl[k][i]) = 0;
270: *(fr = &fp_maskr[k][i]) = 0;
271: for (j = 0; j < 8; j++) {
272: inbit = 8 * k + j;
273: if (i & bits8[j]) {
274: if ((obit = init_perm[inbit]) < 32)
275: *il |= bits32[obit];
276: else
277: *ir |= bits32[obit-32];
278: if ((obit = final_perm[inbit]) < 32)
279: *fl |= bits32[obit];
280: else
281: *fr |= bits32[obit - 32];
282: }
283: }
284: }
285: for (i = 0; i < 128; i++) {
286: *(il = &key_perm_maskl[k][i]) = 0;
287: *(ir = &key_perm_maskr[k][i]) = 0;
288: for (j = 0; j < 7; j++) {
289: inbit = 8 * k + j;
290: if (i & bits8[j + 1]) {
291: if ((obit = inv_key_perm[inbit]) == 255)
292: continue;
293: if (obit < 28)
294: *il |= bits28[obit];
295: else
296: *ir |= bits28[obit - 28];
297: }
298: }
299: *(il = &comp_maskl[k][i]) = 0;
300: *(ir = &comp_maskr[k][i]) = 0;
301: for (j = 0; j < 7; j++) {
302: inbit = 7 * k + j;
303: if (i & bits8[j + 1]) {
304: if ((obit=inv_comp_perm[inbit]) == 255)
305: continue;
306: if (obit < 24)
307: *il |= bits24[obit];
308: else
309: *ir |= bits24[obit - 24];
310: }
311: }
312: }
313: }
314:
315: /*
316: * Invert the P-box permutation, and convert into OR-masks for
317: * handling the output of the S-box arrays setup above.
318: */
319: for (i = 0; i < 32; i++)
320: un_pbox[pbox[i] - 1] = i;
321:
322: for (b = 0; b < 4; b++)
323: for (i = 0; i < 256; i++) {
324: *(p = &psbox[b][i]) = 0;
325: for (j = 0; j < 8; j++) {
326: if (i & bits8[j])
327: *p |= bits32[un_pbox[8 * b + j]];
328: }
329: }
330:
331: des_initialised = 1;
332: }
333:
334: static void
335: setup_salt(salt)
336: int salt;
337: {
338: unsigned int obit, saltbit;
339: int i;
340:
341: if (salt == old_salt)
342: return;
343: old_salt = salt;
344:
345: saltbits = 0;
346: saltbit = 1;
347: obit = 0x800000;
348: for (i = 0; i < 24; i++) {
349: if (salt & saltbit)
350: saltbits |= obit;
351: saltbit <<= 1;
352: obit >>= 1;
353: }
354: }
355:
356: static int
357: des_setkey(key)
358: const char *key;
359: {
360: unsigned int k0, k1, rawkey0, rawkey1;
361: int shifts, round;
362:
363: if (!des_initialised)
364: des_init();
365:
366: rawkey0 = md_ntohl(*(unsigned int *) key);
367: rawkey1 = md_ntohl(*(unsigned int *) (key + 4));
368:
369: if ((rawkey0 | rawkey1)
370: && rawkey0 == old_rawkey0
371: && rawkey1 == old_rawkey1) {
372: /*
373: * Already setup for this key.
374: * This optimisation fails on a zero key (which is weak and
375: * has bad parity anyway) in order to simplify the starting
376: * conditions.
377: */
378: return(0);
379: }
380: old_rawkey0 = rawkey0;
381: old_rawkey1 = rawkey1;
382:
383: /*
384: * Do key permutation and split into two 28-bit subkeys.
385: */
386: k0 = key_perm_maskl[0][rawkey0 >> 25]
387: | key_perm_maskl[1][(rawkey0 >> 17) & 0x7f]
388: | key_perm_maskl[2][(rawkey0 >> 9) & 0x7f]
389: | key_perm_maskl[3][(rawkey0 >> 1) & 0x7f]
390: | key_perm_maskl[4][rawkey1 >> 25]
391: | key_perm_maskl[5][(rawkey1 >> 17) & 0x7f]
392: | key_perm_maskl[6][(rawkey1 >> 9) & 0x7f]
393: | key_perm_maskl[7][(rawkey1 >> 1) & 0x7f];
394: k1 = key_perm_maskr[0][rawkey0 >> 25]
395: | key_perm_maskr[1][(rawkey0 >> 17) & 0x7f]
396: | key_perm_maskr[2][(rawkey0 >> 9) & 0x7f]
397: | key_perm_maskr[3][(rawkey0 >> 1) & 0x7f]
398: | key_perm_maskr[4][rawkey1 >> 25]
399: | key_perm_maskr[5][(rawkey1 >> 17) & 0x7f]
400: | key_perm_maskr[6][(rawkey1 >> 9) & 0x7f]
401: | key_perm_maskr[7][(rawkey1 >> 1) & 0x7f];
402: /*
403: * Rotate subkeys and do compression permutation.
404: */
405: shifts = 0;
406: for (round = 0; round < 16; round++) {
407: unsigned int t0, t1;
408:
409: shifts += key_shifts[round];
410:
411: t0 = (k0 << shifts) | (k0 >> (28 - shifts));
412: t1 = (k1 << shifts) | (k1 >> (28 - shifts));
413:
414: de_keysl[15 - round] =
415: en_keysl[round] = comp_maskl[0][(t0 >> 21) & 0x7f]
416: | comp_maskl[1][(t0 >> 14) & 0x7f]
417: | comp_maskl[2][(t0 >> 7) & 0x7f]
418: | comp_maskl[3][t0 & 0x7f]
419: | comp_maskl[4][(t1 >> 21) & 0x7f]
420: | comp_maskl[5][(t1 >> 14) & 0x7f]
421: | comp_maskl[6][(t1 >> 7) & 0x7f]
422: | comp_maskl[7][t1 & 0x7f];
423:
424: de_keysr[15 - round] =
425: en_keysr[round] = comp_maskr[0][(t0 >> 21) & 0x7f]
426: | comp_maskr[1][(t0 >> 14) & 0x7f]
427: | comp_maskr[2][(t0 >> 7) & 0x7f]
428: | comp_maskr[3][t0 & 0x7f]
429: | comp_maskr[4][(t1 >> 21) & 0x7f]
430: | comp_maskr[5][(t1 >> 14) & 0x7f]
431: | comp_maskr[6][(t1 >> 7) & 0x7f]
432: | comp_maskr[7][t1 & 0x7f];
433: }
434: return(0);
435: }
436:
437: static int
438: do_des(l_in, r_in, l_out, r_out, count)
439: unsigned int l_in, r_in, *l_out, *r_out;
440: int count;
441: {
442: /*
443: * l_in, r_in, l_out, and r_out are in pseudo-"big-endian" format.
444: */
445: unsigned int l, r, *kl, *kr, *kl1, *kr1;
446: unsigned int f = 0, r48l, r48r;
447: int round;
448:
449: if (count == 0) {
450: return(1);
451: } else if (count > 0) {
452: /*
453: * Encrypting
454: */
455: kl1 = en_keysl;
456: kr1 = en_keysr;
457: } else {
458: /*
459: * Decrypting
460: */
461: count = -count;
462: kl1 = de_keysl;
463: kr1 = de_keysr;
464: }
465:
466: /*
467: * Do initial permutation (IP).
468: */
469: l = ip_maskl[0][l_in >> 24]
470: | ip_maskl[1][(l_in >> 16) & 0xff]
471: | ip_maskl[2][(l_in >> 8) & 0xff]
472: | ip_maskl[3][l_in & 0xff]
473: | ip_maskl[4][r_in >> 24]
474: | ip_maskl[5][(r_in >> 16) & 0xff]
475: | ip_maskl[6][(r_in >> 8) & 0xff]
476: | ip_maskl[7][r_in & 0xff];
477: r = ip_maskr[0][l_in >> 24]
478: | ip_maskr[1][(l_in >> 16) & 0xff]
479: | ip_maskr[2][(l_in >> 8) & 0xff]
480: | ip_maskr[3][l_in & 0xff]
481: | ip_maskr[4][r_in >> 24]
482: | ip_maskr[5][(r_in >> 16) & 0xff]
483: | ip_maskr[6][(r_in >> 8) & 0xff]
484: | ip_maskr[7][r_in & 0xff];
485:
486: while (count--) {
487: /*
488: * Do each round.
489: */
490: kl = kl1;
491: kr = kr1;
492: round = 16;
493: while (round--) {
494: /*
495: * Expand R to 48 bits (simulate the E-box).
496: */
497: r48l = ((r & 0x00000001) << 23)
498: | ((r & 0xf8000000) >> 9)
499: | ((r & 0x1f800000) >> 11)
500: | ((r & 0x01f80000) >> 13)
501: | ((r & 0x001f8000) >> 15);
502:
503: r48r = ((r & 0x0001f800) << 7)
504: | ((r & 0x00001f80) << 5)
505: | ((r & 0x000001f8) << 3)
506: | ((r & 0x0000001f) << 1)
507: | ((r & 0x80000000) >> 31);
508: /*
509: * Do salting for crypt() and friends, and
510: * XOR with the permuted key.
511: */
512: f = (r48l ^ r48r) & saltbits;
513: r48l ^= f ^ *kl++;
514: r48r ^= f ^ *kr++;
515: /*
516: * Do sbox lookups (which shrink it back to 32 bits)
517: * and do the pbox permutation at the same time.
518: */
519: f = psbox[0][m_sbox[0][r48l >> 12]]
520: | psbox[1][m_sbox[1][r48l & 0xfff]]
521: | psbox[2][m_sbox[2][r48r >> 12]]
522: | psbox[3][m_sbox[3][r48r & 0xfff]];
523: /*
524: * Now that we've permuted things, complete f().
525: */
526: f ^= l;
527: l = r;
528: r = f;
529: }
530: r = l;
531: l = f;
532: }
533: /*
534: * Do final permutation (inverse of IP).
535: */
536: *l_out = fp_maskl[0][l >> 24]
537: | fp_maskl[1][(l >> 16) & 0xff]
538: | fp_maskl[2][(l >> 8) & 0xff]
539: | fp_maskl[3][l & 0xff]
540: | fp_maskl[4][r >> 24]
541: | fp_maskl[5][(r >> 16) & 0xff]
542: | fp_maskl[6][(r >> 8) & 0xff]
543: | fp_maskl[7][r & 0xff];
544: *r_out = fp_maskr[0][l >> 24]
545: | fp_maskr[1][(l >> 16) & 0xff]
546: | fp_maskr[2][(l >> 8) & 0xff]
547: | fp_maskr[3][l & 0xff]
548: | fp_maskr[4][r >> 24]
549: | fp_maskr[5][(r >> 16) & 0xff]
550: | fp_maskr[6][(r >> 8) & 0xff]
551: | fp_maskr[7][r & 0xff];
552: return(0);
553: }
554:
555: static int
556: des_cipher(in, out, salt, count)
557: const char *in;
558: char *out;
559: int salt;
560: int count;
561: {
562: unsigned int l_out, r_out, rawl, rawr;
563: unsigned int x[2];
564: int retval;
565:
566: if (!des_initialised)
567: des_init();
568:
569: setup_salt(salt);
570:
571: memcpy(x, in, sizeof x);
572: rawl = md_ntohl(x[0]);
573: rawr = md_ntohl(x[1]);
574: retval = do_des(rawl, rawr, &l_out, &r_out, count);
575:
576: x[0] = md_htonl(l_out);
577: x[1] = md_htonl(r_out);
578: memcpy(out, x, sizeof x);
579: return(retval);
580: }
581:
582: char *
583: xcrypt(key, setting)
584: const char *key;
585: const char *setting;
586: {
587: int i;
588: unsigned int count, salt, l, r0, r1, keybuf[2];
589: unsigned char *p, *q;
590: static unsigned char output[21];
591:
592: if (!des_initialised)
593: des_init();
594:
595: /*
596: * Copy the key, shifting each character up by one bit
597: * and padding with zeros.
598: */
599: q = (unsigned char *) keybuf;
600: while ((q - (unsigned char *) keybuf) < sizeof(keybuf)) {
601: if ((*q++ = *key << 1))
602: key++;
603: }
604: if (des_setkey((unsigned char *) keybuf))
605: return(NULL);
606:
607: if (*setting == _PASSWORD_EFMT1) {
608: /*
609: * "new"-style:
610: * setting - underscore, 4 bytes of count, 4 bytes of salt
611: * key - unlimited characters
612: */
613: for (i = 1, count = 0; i < 5; i++)
614: count |= ascii_to_bin(setting[i]) << (i - 1) * 6;
615:
616: for (i = 5, salt = 0; i < 9; i++)
617: salt |= ascii_to_bin(setting[i]) << (i - 5) * 6;
618:
619: while (*key) {
620: /*
621: * Encrypt the key with itself.
622: */
623: if (des_cipher((unsigned char*)keybuf, (unsigned char*)keybuf, 0, 1))
624: return(NULL);
625: /*
626: * And XOR with the next 8 characters of the key.
627: */
628: q = (unsigned char *) keybuf;
629: while (((q - (unsigned char *) keybuf) < sizeof(keybuf)) &&
630: *key)
631: *q++ ^= *key++ << 1;
632:
633: if (des_setkey((unsigned char *) keybuf))
634: return(NULL);
635: }
636: strncpy((char *)output, setting, 9);
637:
638: /*
639: * Double check that we weren't given a short setting.
640: * If we were, the above code will probably have created
641: * wierd values for count and salt, but we don't really care.
642: * Just make sure the output string doesn't have an extra
643: * NUL in it.
644: */
645: output[9] = '\0';
646: p = output + strlen((const char *)output);
647: } else {
648: /*
649: * "old"-style:
650: * setting - 2 bytes of salt
651: * key - up to 8 characters
652: */
653: count = 25;
654:
655: salt = (ascii_to_bin(setting[1]) << 6)
656: | ascii_to_bin(setting[0]);
657:
658: output[0] = setting[0];
659: /*
660: * If the encrypted password that the salt was extracted from
661: * is only 1 character long, the salt will be corrupted. We
662: * need to ensure that the output string doesn't have an extra
663: * NUL in it!
664: */
665: output[1] = setting[1] ? setting[1] : output[0];
666:
667: p = output + 2;
668: }
669: setup_salt(salt);
670: /*
671: * Do it.
672: */
673: if (do_des(0, 0, &r0, &r1, count))
674: return(NULL);
675: /*
676: * Now encode the result...
677: */
678: l = (r0 >> 8);
679: *p++ = ascii64[(l >> 18) & 0x3f];
680: *p++ = ascii64[(l >> 12) & 0x3f];
681: *p++ = ascii64[(l >> 6) & 0x3f];
682: *p++ = ascii64[l & 0x3f];
683:
684: l = (r0 << 16) | ((r1 >> 16) & 0xffff);
685: *p++ = ascii64[(l >> 18) & 0x3f];
686: *p++ = ascii64[(l >> 12) & 0x3f];
687: *p++ = ascii64[(l >> 6) & 0x3f];
688: *p++ = ascii64[l & 0x3f];
689:
690: l = r1 << 2;
691: *p++ = ascii64[(l >> 12) & 0x3f];
692: *p++ = ascii64[(l >> 6) & 0x3f];
693: *p++ = ascii64[l & 0x3f];
694: *p = 0;
695:
696: return((char *)output);
697: }
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