crypt.c 6.5 KB

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  1. /* $Id$ */
  2. /* From Andy Tanenbaum's book "Computer Networks",
  3. rewritten in C
  4. */
  5. struct block {
  6. unsigned char b_data[64];
  7. };
  8. struct ordering {
  9. unsigned char o_data[64];
  10. };
  11. static struct block key;
  12. static struct ordering InitialTr = {
  13. 58,50,42,34,26,18,10, 2,60,52,44,36,28,20,12, 4,
  14. 62,54,46,38,30,22,14, 6,64,56,48,40,32,24,16, 8,
  15. 57,49,41,33,25,17, 9, 1,59,51,43,35,27,19,11, 3,
  16. 61,53,45,37,29,21,13, 5,63,55,47,39,31,23,15, 7,
  17. };
  18. static struct ordering FinalTr = {
  19. 40, 8,48,16,56,24,64,32,39, 7,47,15,55,23,63,31,
  20. 38, 6,46,14,54,22,62,30,37, 5,45,13,53,21,61,29,
  21. 36, 4,44,12,52,20,60,28,35, 3,43,11,51,19,59,27,
  22. 34, 2,42,10,50,18,58,26,33, 1,41, 9,49,17,57,25,
  23. };
  24. static struct ordering swap = {
  25. 33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,
  26. 49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,
  27. 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15,16,
  28. 17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,
  29. };
  30. static struct ordering KeyTr1 = {
  31. 57,49,41,33,25,17, 9, 1,58,50,42,34,26,18,
  32. 10, 2,59,51,43,35,27,19,11, 3,60,52,44,36,
  33. 63,55,47,39,31,23,15, 7,62,54,46,38,30,22,
  34. 14, 6,61,53,45,37,29,21,13, 5,28,20,12, 4,
  35. };
  36. static struct ordering KeyTr2 = {
  37. 14,17,11,24, 1, 5, 3,28,15, 6,21,10,
  38. 23,19,12, 4,26, 8,16, 7,27,20,13, 2,
  39. 41,52,31,37,47,55,30,40,51,45,33,48,
  40. 44,49,39,56,34,53,46,42,50,36,29,32,
  41. };
  42. static struct ordering etr = {
  43. 32, 1, 2, 3, 4, 5, 4, 5, 6, 7, 8, 9,
  44. 8, 9,10,11,12,13,12,13,14,15,16,17,
  45. 16,17,18,19,20,21,20,21,22,23,24,25,
  46. 24,25,26,27,28,29,28,29,30,31,32, 1,
  47. };
  48. static struct ordering ptr = {
  49. 16, 7,20,21,29,12,28,17, 1,15,23,26, 5,18,31,10,
  50. 2, 8,24,14,32,27, 3, 9,19,13,30, 6,22,11, 4,25,
  51. };
  52. static unsigned char s_boxes[8][64] = {
  53. { 14, 4,13, 1, 2,15,11, 8, 3,10, 6,12, 5, 9, 0, 7,
  54. 0,15, 7, 4,14, 2,13, 1,10, 6,12,11, 9, 5, 3, 8,
  55. 4, 1,14, 8,13, 6, 2,11,15,12, 9, 7, 3,10, 5, 0,
  56. 15,12, 8, 2, 4, 9, 1, 7, 5,11, 3,14,10, 0, 6,13,
  57. },
  58. { 15, 1, 8,14, 6,11, 3, 4, 9, 7, 2,13,12, 0, 5,10,
  59. 3,13, 4, 7,15, 2, 8,14,12, 0, 1,10, 6, 9,11, 5,
  60. 0,14, 7,11,10, 4,13, 1, 5, 8,12, 6, 9, 3, 2,15,
  61. 13, 8,10, 1, 3,15, 4, 2,11, 6, 7,12, 0, 5,14, 9,
  62. },
  63. { 10, 0, 9,14, 6, 3,15, 5, 1,13,12, 7,11, 4, 2, 8,
  64. 13, 7, 0, 9, 3, 4, 6,10, 2, 8, 5,14,12,11,15, 1,
  65. 13, 6, 4, 9, 8,15, 3, 0,11, 1, 2,12, 5,10,14, 7,
  66. 1,10,13, 0, 6, 9, 8, 7, 4,15,14, 3,11, 5, 2,12,
  67. },
  68. { 7,13,14, 3, 0, 6, 9,10, 1, 2, 8, 5,11,12, 4,15,
  69. 13, 8,11, 5, 6,15, 0, 3, 4, 7, 2,12, 1,10,14, 9,
  70. 10, 6, 9, 0,12,11, 7,13,15, 1, 3,14, 5, 2, 8, 4,
  71. 3,15, 0, 6,10, 1,13, 8, 9, 4, 5,11,12, 7, 2,14,
  72. },
  73. { 2,12, 4, 1, 7,10,11, 6, 8, 5, 3,15,13, 0,14, 9,
  74. 14,11, 2,12, 4, 7,13, 1, 5, 0,15,10, 3, 9, 8, 6,
  75. 4, 2, 1,11,10,13, 7, 8,15, 9,12, 5, 6, 3, 0,14,
  76. 11, 8,12, 7, 1,14, 2,13, 6,15, 0, 9,10, 4, 5, 3,
  77. },
  78. { 12, 1,10,15, 9, 2, 6, 8, 0,13, 3, 4,14, 7, 5,11,
  79. 10,15, 4, 2, 7,12, 9, 5, 6, 1,13,14, 0,11, 3, 8,
  80. 9,14,15, 5, 2, 8,12, 3, 7, 0, 4,10, 1,13,11, 6,
  81. 4, 3, 2,12, 9, 5,15,10,11,14, 1, 7, 6, 0, 8,13,
  82. },
  83. { 4,11, 2,14,15, 0, 8,13, 3,12, 9, 7, 5,10, 6, 1,
  84. 13, 0,11, 7, 4, 9, 1,10,14, 3, 5,12, 2,15, 8, 6,
  85. 1, 4,11,13,12, 3, 7,14,10,15, 6, 8, 0, 5, 9, 2,
  86. 6,11,13, 8, 1, 4,10, 7, 9, 5, 0,15,14, 2, 3,12,
  87. },
  88. { 13, 2, 8, 4, 6,15,11, 1,10, 9, 3,14, 5, 0,12, 7,
  89. 1,15,13, 8,10, 3, 7, 4,12, 5, 6,11, 0,14, 9, 2,
  90. 7,11, 4, 1, 9,12,14, 2, 0, 6,10,13,15, 3, 5, 8,
  91. 2, 1,14, 7, 4,10, 8,13,15,12, 9, 0, 3, 5, 6,11,
  92. },
  93. };
  94. static int rots[] = {
  95. 1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1,
  96. };
  97. static
  98. transpose(data, t, n)
  99. register struct block *data;
  100. register struct ordering *t;
  101. register int n;
  102. {
  103. struct block x;
  104. x = *data;
  105. while (n-- > 0) {
  106. data->b_data[n] = x.b_data[t->o_data[n] - 1];
  107. }
  108. }
  109. static
  110. rotate(key)
  111. register struct block *key;
  112. {
  113. register unsigned char *p = key->b_data;
  114. register unsigned char *ep = &(key->b_data[55]);
  115. int data0 = key->b_data[0], data28 = key->b_data[28];
  116. while (p++ < ep) *(p-1) = *p;
  117. key->b_data[27] = data0;
  118. key->b_data[55] = data28;
  119. }
  120. static struct ordering *EP = &etr;
  121. static
  122. f(i, key, a, x)
  123. struct block *key, *a;
  124. register struct block *x;
  125. {
  126. struct block e, ikey, y;
  127. int k;
  128. register unsigned char *p, *q, *r;
  129. e = *a;
  130. transpose(&e, EP, 48);
  131. for (k = rots[i]; k; k--) rotate(key);
  132. ikey = *key;
  133. transpose(&ikey, &KeyTr2, 48);
  134. p = &(y.b_data[48]);
  135. q = &(e.b_data[48]);
  136. r = &(ikey.b_data[48]);
  137. while (p > y.b_data) {
  138. *--p = *--q ^ *--r;
  139. }
  140. q = x->b_data;
  141. for (k = 0; k < 8; k++) {
  142. register int xb, r;
  143. r = *p++ << 5;
  144. r += *p++ << 3;
  145. r += *p++ << 2;
  146. r += *p++ << 1;
  147. r += *p++;
  148. r += *p++ << 4;
  149. xb = s_boxes[k][r];
  150. *q++ = (xb >> 3) & 1;
  151. *q++ = (xb>>2) & 1;
  152. *q++ = (xb>>1) & 1;
  153. *q++ = (xb & 1);
  154. }
  155. transpose(x, &ptr, 32);
  156. }
  157. setkey(k)
  158. register char *k;
  159. {
  160. key = *((struct block *) k);
  161. transpose(&key, &KeyTr1, 56);
  162. }
  163. encrypt(blck, edflag)
  164. char *blck;
  165. {
  166. register struct block *p = (struct block *) blck;
  167. register int i;
  168. transpose(p, &InitialTr, 64);
  169. for (i = 15; i>= 0; i--) {
  170. int j = edflag ? i : 15 - i;
  171. register int k;
  172. struct block b, x;
  173. b = *p;
  174. for (k = 31; k >= 0; k--) {
  175. p->b_data[k] = b.b_data[k + 32];
  176. }
  177. f(j, &key, p, &x);
  178. for (k = 31; k >= 0; k--) {
  179. p->b_data[k+32] = b.b_data[k] ^ x.b_data[k];
  180. }
  181. }
  182. transpose(p, &swap, 64);
  183. transpose(p, &FinalTr, 64);
  184. }
  185. char *
  186. crypt(pw,salt)
  187. register char *pw;
  188. char *salt;
  189. {
  190. /* Unfortunately, I had to look at the sources of V7 crypt.
  191. There was no other way to find out what this routine
  192. actually does.
  193. */
  194. char pwb[66];
  195. static char result[16];
  196. register char *p = pwb;
  197. struct ordering new_etr;
  198. register int i;
  199. while (*pw && p < &pwb[64]) {
  200. register int j = 7;
  201. while (j--) {
  202. *p++ = (*pw >> j) & 01;
  203. }
  204. pw++;
  205. *p++ = 0;
  206. }
  207. while (p < &pwb[64]) *p++ = 0;
  208. setkey(p = pwb);
  209. while (p < &pwb[66]) *p++ = 0;
  210. new_etr = etr;
  211. EP = &new_etr;
  212. for (i = 0; i < 2; i++) {
  213. register char c = *salt++;
  214. register int j;
  215. result[i] = c;
  216. if ( c > 'Z') c -= 6 + 7 + '.'; /* c was a lower case letter */
  217. else if ( c > '9') c -= 7 + '.';/* c was upper case letter */
  218. else c -= '.'; /* c was digit, '.' or '/'. */
  219. /* now, 0 <= c <= 63 */
  220. for (j = 0; j < 6; j++) {
  221. if ((c >> j) & 01) {
  222. int t = 6*i + j;
  223. int temp = new_etr.o_data[t];
  224. new_etr.o_data[t] = new_etr.o_data[t+24];
  225. new_etr.o_data[t+24] = temp;
  226. }
  227. }
  228. }
  229. if (result[1] == 0) result[1] = result[0];
  230. for (i = 0; i < 25; i++) encrypt(pwb,0);
  231. EP = &etr;
  232. p = pwb;
  233. pw = result+2;
  234. while (p < &pwb[66]) {
  235. register int c = 0;
  236. register int j = 6;
  237. while (j--) {
  238. c <<= 1;
  239. c |= *p++;
  240. }
  241. c += '.'; /* becomes >= '.' */
  242. if (c > '9') c += 7; /* not in [./0-9], becomes upper */
  243. if (c > 'Z') c += 6; /* not in [A-Z], becomes lower */
  244. *pw++ = c;
  245. }
  246. *pw = 0;
  247. return result;
  248. }