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