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
setup(char * pw)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
main(int argc,char * argv[])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
shuffle(char deckary[])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