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