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 ECHO 010 26 #define ROTORSZ 256 27 #define MASK 0377 28 static char t1[ROTORSZ]; 29 static char t2[ROTORSZ]; 30 static char t3[ROTORSZ]; 31 static char deck[ROTORSZ]; 32 static char buf[13]; 33 34 static void shuffle(char *); 35 static void setup(char *); 36 37 static void 38 setup(char *pw) 39 { 40 int ic, i, k, temp; 41 char salt[3]; 42 unsigned rnd; 43 int32_t seed; 44 char *cryptpw; 45 46 if (crypt_set_format("des") == 0) { 47 fprintf(stderr, "crypt_set_format(\"des\") failed.\n"); 48 exit(1); 49 } 50 51 strlcpy(salt, pw, sizeof(salt)); 52 cryptpw = crypt(pw, salt); 53 if (cryptpw == NULL) { 54 fprintf(stderr, "crypt(3) failure\n"); 55 exit(1); 56 } 57 memcpy(buf, cryptpw, sizeof(buf)); 58 seed = 123; 59 for (i=0; i<13; i++) 60 seed = seed*buf[i] + i; 61 for(i=0;i<ROTORSZ;i++) { 62 t1[i] = i; 63 deck[i] = i; 64 } 65 for(i=0;i<ROTORSZ;i++) { 66 seed = 5*seed + buf[i%13]; 67 rnd = seed % 65521; 68 k = ROTORSZ-1 - i; 69 ic = (rnd&MASK)%(k+1); 70 rnd >>= 8; 71 temp = t1[k]; 72 t1[k] = t1[ic]; 73 t1[ic] = temp; 74 if(t3[k]!=0) continue; 75 ic = (rnd&MASK) % k; 76 while(t3[ic]!=0) ic = (ic+1) % k; 77 t3[k] = ic; 78 t3[ic] = k; 79 } 80 for(i=0;i<ROTORSZ;i++) 81 t2[t1[i]&MASK] = i; 82 } 83 84 int 85 main(int argc, char *argv[]) 86 { 87 int i, n1, n2, nr1, nr2; 88 int secureflg = 0, kflag = 0; 89 char *cp; 90 91 if (argc > 1 && argv[1][0] == '-') { 92 if (argv[1][1] == 's') { 93 argc--; 94 argv++; 95 secureflg = 1; 96 } else if (argv[1][1] == 'k') { 97 argc--; 98 argv++; 99 kflag = 1; 100 } 101 } 102 if (kflag) { 103 if ((cp = getenv(MINUSKVAR)) == NULL) { 104 fprintf(stderr, "%s not set\n", MINUSKVAR); 105 exit(1); 106 } 107 setup(cp); 108 } else if (argc != 2) { 109 setup(getpass("Enter key:")); 110 } 111 else 112 setup(argv[1]); 113 n1 = 0; 114 n2 = 0; 115 nr2 = 0; 116 117 while((i=getchar()) != -1) { 118 if (secureflg) { 119 nr1 = deck[n1]&MASK; 120 nr2 = deck[nr1]&MASK; 121 } else { 122 nr1 = n1; 123 } 124 i = t2[(t3[(t1[(i+nr1)&MASK]+nr2)&MASK]-nr2)&MASK]-nr1; 125 putchar(i); 126 n1++; 127 if(n1==ROTORSZ) { 128 n1 = 0; 129 n2++; 130 if(n2==ROTORSZ) n2 = 0; 131 if (secureflg) { 132 shuffle(deck); 133 } else { 134 nr2 = n2; 135 } 136 } 137 } 138 139 return 0; 140 } 141 142 static void 143 shuffle(char deckary[]) 144 { 145 int i, ic, k, temp; 146 unsigned rnd; 147 static int32_t seed = 123; 148 149 for(i=0;i<ROTORSZ;i++) { 150 seed = 5*seed + buf[i%13]; 151 rnd = seed % 65521; 152 k = ROTORSZ-1 - i; 153 ic = (rnd&MASK)%(k+1); 154 temp = deckary[k]; 155 deckary[k] = deckary[ic]; 156 deckary[ic] = temp; 157 } 158 } 159