Annotation of early-roguelike/xrogue/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: #define _PASSWORD_EFMT1 '_'
56:
57: unsigned long int md_htonl(unsigned long int x);
58: unsigned long int md_ntohl(unsigned long int x);
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(ch)
185: char ch;
186: {
187: if (ch > 'z')
188: return(0);
189: if (ch >= 'a')
190: return(ch - 'a' + 38);
191: if (ch > 'Z')
192: return(0);
193: if (ch >= 'A')
194: return(ch - 'A' + 12);
195: if (ch > '9')
196: return(0);
197: if (ch >= '.')
198: return(ch - '.');
199: return(0);
200: }
201:
202: static void
203: des_init()
204: {
205: int i, j, b, k, inbit, obit;
206: unsigned int *p, *il, *ir, *fl, *fr;
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(salt)
333: int salt;
334: {
335: unsigned int obit, saltbit;
336: int i;
337:
338: if (salt == old_salt)
339: return;
340: old_salt = salt;
341:
342: saltbits = 0;
343: saltbit = 1;
344: obit = 0x800000;
345: for (i = 0; i < 24; i++) {
346: if (salt & saltbit)
347: saltbits |= obit;
348: saltbit <<= 1;
349: obit >>= 1;
350: }
351: }
352:
353: static int
354: des_setkey(key)
355: const char *key;
356: {
357: unsigned int k0, k1, rawkey0, rawkey1;
358: int shifts, round;
359:
360: if (!des_initialised)
361: des_init();
362:
363: rawkey0 = md_ntohl(*(unsigned int *) key);
364: rawkey1 = md_ntohl(*(unsigned int *) (key + 4));
365:
366: if ((rawkey0 | rawkey1)
367: && rawkey0 == old_rawkey0
368: && rawkey1 == old_rawkey1) {
369: /*
370: * Already setup for this key.
371: * This optimisation fails on a zero key (which is weak and
372: * has bad parity anyway) in order to simplify the starting
373: * conditions.
374: */
375: return(0);
376: }
377: old_rawkey0 = rawkey0;
378: old_rawkey1 = rawkey1;
379:
380: /*
381: * Do key permutation and split into two 28-bit subkeys.
382: */
383: k0 = key_perm_maskl[0][rawkey0 >> 25]
384: | key_perm_maskl[1][(rawkey0 >> 17) & 0x7f]
385: | key_perm_maskl[2][(rawkey0 >> 9) & 0x7f]
386: | key_perm_maskl[3][(rawkey0 >> 1) & 0x7f]
387: | key_perm_maskl[4][rawkey1 >> 25]
388: | key_perm_maskl[5][(rawkey1 >> 17) & 0x7f]
389: | key_perm_maskl[6][(rawkey1 >> 9) & 0x7f]
390: | key_perm_maskl[7][(rawkey1 >> 1) & 0x7f];
391: k1 = key_perm_maskr[0][rawkey0 >> 25]
392: | key_perm_maskr[1][(rawkey0 >> 17) & 0x7f]
393: | key_perm_maskr[2][(rawkey0 >> 9) & 0x7f]
394: | key_perm_maskr[3][(rawkey0 >> 1) & 0x7f]
395: | key_perm_maskr[4][rawkey1 >> 25]
396: | key_perm_maskr[5][(rawkey1 >> 17) & 0x7f]
397: | key_perm_maskr[6][(rawkey1 >> 9) & 0x7f]
398: | key_perm_maskr[7][(rawkey1 >> 1) & 0x7f];
399: /*
400: * Rotate subkeys and do compression permutation.
401: */
402: shifts = 0;
403: for (round = 0; round < 16; round++) {
404: unsigned int t0, t1;
405:
406: shifts += key_shifts[round];
407:
408: t0 = (k0 << shifts) | (k0 >> (28 - shifts));
409: t1 = (k1 << shifts) | (k1 >> (28 - shifts));
410:
411: de_keysl[15 - round] =
412: en_keysl[round] = comp_maskl[0][(t0 >> 21) & 0x7f]
413: | comp_maskl[1][(t0 >> 14) & 0x7f]
414: | comp_maskl[2][(t0 >> 7) & 0x7f]
415: | comp_maskl[3][t0 & 0x7f]
416: | comp_maskl[4][(t1 >> 21) & 0x7f]
417: | comp_maskl[5][(t1 >> 14) & 0x7f]
418: | comp_maskl[6][(t1 >> 7) & 0x7f]
419: | comp_maskl[7][t1 & 0x7f];
420:
421: de_keysr[15 - round] =
422: en_keysr[round] = comp_maskr[0][(t0 >> 21) & 0x7f]
423: | comp_maskr[1][(t0 >> 14) & 0x7f]
424: | comp_maskr[2][(t0 >> 7) & 0x7f]
425: | comp_maskr[3][t0 & 0x7f]
426: | comp_maskr[4][(t1 >> 21) & 0x7f]
427: | comp_maskr[5][(t1 >> 14) & 0x7f]
428: | comp_maskr[6][(t1 >> 7) & 0x7f]
429: | comp_maskr[7][t1 & 0x7f];
430: }
431: return(0);
432: }
433:
434: static int
435: do_des(l_in, r_in, l_out, r_out, count)
436: unsigned int l_in, r_in, *l_out, *r_out;
437: int count;
438: {
439: /*
440: * l_in, r_in, l_out, and r_out are in pseudo-"big-endian" format.
441: */
442: unsigned int l, r, *kl, *kr, *kl1, *kr1;
443: unsigned int f = 0, r48l, r48r;
444: int round;
445:
446: if (count == 0) {
447: return(1);
448: } else if (count > 0) {
449: /*
450: * Encrypting
451: */
452: kl1 = en_keysl;
453: kr1 = en_keysr;
454: } else {
455: /*
456: * Decrypting
457: */
458: count = -count;
459: kl1 = de_keysl;
460: kr1 = de_keysr;
461: }
462:
463: /*
464: * Do initial permutation (IP).
465: */
466: l = ip_maskl[0][l_in >> 24]
467: | ip_maskl[1][(l_in >> 16) & 0xff]
468: | ip_maskl[2][(l_in >> 8) & 0xff]
469: | ip_maskl[3][l_in & 0xff]
470: | ip_maskl[4][r_in >> 24]
471: | ip_maskl[5][(r_in >> 16) & 0xff]
472: | ip_maskl[6][(r_in >> 8) & 0xff]
473: | ip_maskl[7][r_in & 0xff];
474: r = ip_maskr[0][l_in >> 24]
475: | ip_maskr[1][(l_in >> 16) & 0xff]
476: | ip_maskr[2][(l_in >> 8) & 0xff]
477: | ip_maskr[3][l_in & 0xff]
478: | ip_maskr[4][r_in >> 24]
479: | ip_maskr[5][(r_in >> 16) & 0xff]
480: | ip_maskr[6][(r_in >> 8) & 0xff]
481: | ip_maskr[7][r_in & 0xff];
482:
483: while (count--) {
484: /*
485: * Do each round.
486: */
487: kl = kl1;
488: kr = kr1;
489: round = 16;
490: while (round--) {
491: /*
492: * Expand R to 48 bits (simulate the E-box).
493: */
494: r48l = ((r & 0x00000001) << 23)
495: | ((r & 0xf8000000) >> 9)
496: | ((r & 0x1f800000) >> 11)
497: | ((r & 0x01f80000) >> 13)
498: | ((r & 0x001f8000) >> 15);
499:
500: r48r = ((r & 0x0001f800) << 7)
501: | ((r & 0x00001f80) << 5)
502: | ((r & 0x000001f8) << 3)
503: | ((r & 0x0000001f) << 1)
504: | ((r & 0x80000000) >> 31);
505: /*
506: * Do salting for crypt() and friends, and
507: * XOR with the permuted key.
508: */
509: f = (r48l ^ r48r) & saltbits;
510: r48l ^= f ^ *kl++;
511: r48r ^= f ^ *kr++;
512: /*
513: * Do sbox lookups (which shrink it back to 32 bits)
514: * and do the pbox permutation at the same time.
515: */
516: f = psbox[0][m_sbox[0][r48l >> 12]]
517: | psbox[1][m_sbox[1][r48l & 0xfff]]
518: | psbox[2][m_sbox[2][r48r >> 12]]
519: | psbox[3][m_sbox[3][r48r & 0xfff]];
520: /*
521: * Now that we've permuted things, complete f().
522: */
523: f ^= l;
524: l = r;
525: r = f;
526: }
527: r = l;
528: l = f;
529: }
530: /*
531: * Do final permutation (inverse of IP).
532: */
533: *l_out = fp_maskl[0][l >> 24]
534: | fp_maskl[1][(l >> 16) & 0xff]
535: | fp_maskl[2][(l >> 8) & 0xff]
536: | fp_maskl[3][l & 0xff]
537: | fp_maskl[4][r >> 24]
538: | fp_maskl[5][(r >> 16) & 0xff]
539: | fp_maskl[6][(r >> 8) & 0xff]
540: | fp_maskl[7][r & 0xff];
541: *r_out = fp_maskr[0][l >> 24]
542: | fp_maskr[1][(l >> 16) & 0xff]
543: | fp_maskr[2][(l >> 8) & 0xff]
544: | fp_maskr[3][l & 0xff]
545: | fp_maskr[4][r >> 24]
546: | fp_maskr[5][(r >> 16) & 0xff]
547: | fp_maskr[6][(r >> 8) & 0xff]
548: | fp_maskr[7][r & 0xff];
549: return(0);
550: }
551:
552: static int
553: des_cipher(in, out, salt, count)
554: const char *in;
555: char *out;
556: int salt;
557: int count;
558: {
559: unsigned int l_out, r_out, rawl, rawr;
560: unsigned int x[2];
561: int retval;
562:
563: if (!des_initialised)
564: des_init();
565:
566: setup_salt(salt);
567:
568: memcpy(x, in, sizeof x);
569: rawl = md_ntohl(x[0]);
570: rawr = md_ntohl(x[1]);
571: retval = do_des(rawl, rawr, &l_out, &r_out, count);
572:
573: x[0] = md_htonl(l_out);
574: x[1] = md_htonl(r_out);
575: memcpy(out, x, sizeof x);
576: return(retval);
577: }
578:
579: char *
580: xcrypt(key, setting)
581: const char *key;
582: const char *setting;
583: {
584: int i;
585: unsigned int count, salt, l, r0, r1, keybuf[2];
586: unsigned char *p, *q;
587: static unsigned char output[21];
588:
589: if (!des_initialised)
590: des_init();
591:
592: /*
593: * Copy the key, shifting each character up by one bit
594: * and padding with zeros.
595: */
596: q = (unsigned char *) keybuf;
597: while ((q - (unsigned char *) keybuf) < sizeof(keybuf)) {
598: if ((*q++ = *key << 1))
599: key++;
600: }
601: if (des_setkey((unsigned char *) keybuf))
602: return(NULL);
603:
604: if (*setting == _PASSWORD_EFMT1) {
605: /*
606: * "new"-style:
607: * setting - underscore, 4 bytes of count, 4 bytes of salt
608: * key - unlimited characters
609: */
610: for (i = 1, count = 0; i < 5; i++)
611: count |= ascii_to_bin(setting[i]) << (i - 1) * 6;
612:
613: for (i = 5, salt = 0; i < 9; i++)
614: salt |= ascii_to_bin(setting[i]) << (i - 5) * 6;
615:
616: while (*key) {
617: /*
618: * Encrypt the key with itself.
619: */
620: if (des_cipher((unsigned char*)keybuf, (unsigned char*)keybuf, 0, 1))
621: return(NULL);
622: /*
623: * And XOR with the next 8 characters of the key.
624: */
625: q = (unsigned char *) keybuf;
626: while (((q - (unsigned char *) keybuf) < sizeof(keybuf)) &&
627: *key)
628: *q++ ^= *key++ << 1;
629:
630: if (des_setkey((unsigned char *) keybuf))
631: return(NULL);
632: }
633: strncpy((char *)output, setting, 9);
634:
635: /*
636: * Double check that we weren't given a short setting.
637: * If we were, the above code will probably have created
638: * wierd values for count and salt, but we don't really care.
639: * Just make sure the output string doesn't have an extra
640: * NUL in it.
641: */
642: output[9] = '\0';
643: p = output + strlen((const char *)output);
644: } else {
645: /*
646: * "old"-style:
647: * setting - 2 bytes of salt
648: * key - up to 8 characters
649: */
650: count = 25;
651:
652: salt = (ascii_to_bin(setting[1]) << 6)
653: | ascii_to_bin(setting[0]);
654:
655: output[0] = setting[0];
656: /*
657: * If the encrypted password that the salt was extracted from
658: * is only 1 character long, the salt will be corrupted. We
659: * need to ensure that the output string doesn't have an extra
660: * NUL in it!
661: */
662: output[1] = setting[1] ? setting[1] : output[0];
663:
664: p = output + 2;
665: }
666: setup_salt(salt);
667: /*
668: * Do it.
669: */
670: if (do_des(0, 0, &r0, &r1, count))
671: return(NULL);
672: /*
673: * Now encode the result...
674: */
675: l = (r0 >> 8);
676: *p++ = ascii64[(l >> 18) & 0x3f];
677: *p++ = ascii64[(l >> 12) & 0x3f];
678: *p++ = ascii64[(l >> 6) & 0x3f];
679: *p++ = ascii64[l & 0x3f];
680:
681: l = (r0 << 16) | ((r1 >> 16) & 0xffff);
682: *p++ = ascii64[(l >> 18) & 0x3f];
683: *p++ = ascii64[(l >> 12) & 0x3f];
684: *p++ = ascii64[(l >> 6) & 0x3f];
685: *p++ = ascii64[l & 0x3f];
686:
687: l = r1 << 2;
688: *p++ = ascii64[(l >> 12) & 0x3f];
689: *p++ = ascii64[(l >> 6) & 0x3f];
690: *p++ = ascii64[l & 0x3f];
691: *p = 0;
692:
693: return((char *)output);
694: }
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