1 /*- 2 * "enigma.c" is in file cbw.tar from 3 * anonymous FTP host watmsg.waterloo.edu: pub/crypt/cbw.tar.Z 4 * 5 * A one-rotor machine designed along the lines of Enigma 6 * but considerably trivialized. 7 * 8 * A public-domain replacement for the UNIX "crypt" command. 9 * 10 * Upgraded to function properly on 64-bit machines. 11 */ 12 13 #include <sys/cdefs.h> 14 __FBSDID("$FreeBSD$"); 15 16 #include <sys/types.h> 17 18 #include <stdio.h> 19 #include <stdlib.h> 20 #include <string.h> 21 #include <unistd.h> 22 23 #define MINUSKVAR "CrYpTkEy" 24 25 #define ROTORSZ 256 26 #define MASK 0377 27 static char t1[ROTORSZ]; 28 static char t2[ROTORSZ]; 29 static char t3[ROTORSZ]; 30 static char deck[ROTORSZ]; 31 static char buf[13]; 32 33 static void shuffle(char *); 34 static void setup(char *); 35 36 static void 37 setup(char *pw) 38 { 39 int ic, i, k, temp; 40 char salt[3]; 41 unsigned rnd; 42 int32_t seed; 43 char *cryptpw; 44 45 if (crypt_set_format("des") == 0) { 46 fprintf(stderr, "crypt_set_format(\"des\") failed.\n"); 47 exit(1); 48 } 49 50 strlcpy(salt, pw, sizeof(salt)); 51 cryptpw = crypt(pw, salt); 52 if (cryptpw == NULL) { 53 fprintf(stderr, "crypt(3) failure\n"); 54 exit(1); 55 } 56 memcpy(buf, cryptpw, sizeof(buf)); 57 seed = 123; 58 for (i=0; i<13; i++) 59 seed = seed*buf[i] + i; 60 for(i=0;i<ROTORSZ;i++) { 61 t1[i] = i; 62 deck[i] = i; 63 } 64 for(i=0;i<ROTORSZ;i++) { 65 seed = 5*seed + buf[i%13]; 66 rnd = seed % 65521; 67 k = ROTORSZ-1 - i; 68 ic = (rnd&MASK)%(k+1); 69 rnd >>= 8; 70 temp = t1[k]; 71 t1[k] = t1[ic]; 72 t1[ic] = temp; 73 if(t3[k]!=0) continue; 74 ic = (rnd&MASK) % k; 75 while(t3[ic]!=0) ic = (ic+1) % k; 76 t3[k] = ic; 77 t3[ic] = k; 78 } 79 for(i=0;i<ROTORSZ;i++) 80 t2[t1[i]&MASK] = i; 81 } 82 83 int 84 main(int argc, char *argv[]) 85 { 86 int i, n1, n2, nr1, nr2; 87 int secureflg = 0, kflag = 0; 88 char *cp; 89 90 if (argc > 1 && argv[1][0] == '-') { 91 if (argv[1][1] == 's') { 92 argc--; 93 argv++; 94 secureflg = 1; 95 } else if (argv[1][1] == 'k') { 96 argc--; 97 argv++; 98 kflag = 1; 99 } 100 } 101 if (kflag) { 102 if ((cp = getenv(MINUSKVAR)) == NULL) { 103 fprintf(stderr, "%s not set\n", MINUSKVAR); 104 exit(1); 105 } 106 setup(cp); 107 } else if (argc != 2) { 108 setup(getpass("Enter key:")); 109 } 110 else 111 setup(argv[1]); 112 n1 = 0; 113 n2 = 0; 114 nr2 = 0; 115 116 while((i=getchar()) != -1) { 117 if (secureflg) { 118 nr1 = deck[n1]&MASK; 119 nr2 = deck[nr1]&MASK; 120 } else { 121 nr1 = n1; 122 } 123 i = t2[(t3[(t1[(i+nr1)&MASK]+nr2)&MASK]-nr2)&MASK]-nr1; 124 putchar(i); 125 n1++; 126 if(n1==ROTORSZ) { 127 n1 = 0; 128 n2++; 129 if(n2==ROTORSZ) n2 = 0; 130 if (secureflg) { 131 shuffle(deck); 132 } else { 133 nr2 = n2; 134 } 135 } 136 } 137 138 return 0; 139 } 140 141 static void 142 shuffle(char deckary[]) 143 { 144 int i, ic, k, temp; 145 unsigned rnd; 146 static int32_t seed = 123; 147 148 for(i=0;i<ROTORSZ;i++) { 149 seed = 5*seed + buf[i%13]; 150 rnd = seed % 65521; 151 k = ROTORSZ-1 - i; 152 ic = (rnd&MASK)%(k+1); 153 temp = deckary[k]; 154 deckary[k] = deckary[ic]; 155 deckary[ic] = temp; 156 } 157 } 158