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#ifndef lint
14static const char rcsid[] =
15 "$FreeBSD: head/usr.bin/enigma/enigma.c 79452 2001-07-09 09:24:06Z brian $";
16#endif /* not lint */
17
18#include <sys/types.h>
19#include <sys/wait.h>
20
21#include <stdio.h>
22#include <stdlib.h>
23#include <string.h>
24#include <unistd.h>
25
26#define MINUSKVAR "CrYpTkEy"
27
28#define ECHO 010
29#define ROTORSZ 256
30#define MASK 0377
31char t1[ROTORSZ];
32char t2[ROTORSZ];
33char t3[ROTORSZ];
34char deck[ROTORSZ];
35char buf[13];
36
37void shuffle(char *);
38void setup(char *);
39
40void
41setup(pw)
42 char *pw;
43{
44 int ic, i, k, temp, pf[2], pid;
45 unsigned rnd;
46 long seed;
47
48 strncpy(buf, pw, 8);
49 while (*pw)
50 *pw++ = '\0';
51 buf[8] = buf[0];
52 buf[9] = buf[1];
53 pipe(pf);
54 if ((pid=fork())==0) {
55 close(0);
56 close(1);
57 dup(pf[0]);
58 dup(pf[1]);
59 execlp("makekey", "-", (char *)0);
60 execl("/usr/libexec/makekey", "-", (char *)0); /* BSDI */
61 execl("/usr/lib/makekey", "-", (char *)0);
62 execl("/usr/bin/makekey", "-", (char *)0); /* IBM */
63 execl("/lib/makekey", "-", (char *)0);
64 perror("makekey");
65 fprintf(stderr, "enigma: cannot execute 'makekey', aborting\n");
66 exit(1);
67 }
68 write(pf[1], buf, 10);
69 close(pf[1]);
70 i=wait((int *)NULL);
71 if (i<0) perror("enigma: wait");
72 if (i!=pid) {
73 fprintf(stderr, "enigma: expected pid %d, got pid %d\n", pid, i);
74 exit(1);
75 }
76 if ((i=read(pf[0], buf, 13)) != 13) {
77 fprintf(stderr, "enigma: cannot generate key, read %d\n",i);
78 exit(1);
79 }
80 seed = 123;
81 for (i=0; i<13; i++)
82 seed = seed*buf[i] + i;
83 for(i=0;i<ROTORSZ;i++) {
84 t1[i] = i;
85 deck[i] = i;
86 }
87 for(i=0;i<ROTORSZ;i++) {
88 seed = 5*seed + buf[i%13];
89 if( sizeof(long) > 4 ) {
90 /* Force seed to stay in 32-bit signed math */
91 if( seed & 0x80000000 )
92 seed = seed | (-1L & ~0xFFFFFFFFL);
93 else
94 seed &= 0x7FFFFFFF;
95 }
96 rnd = seed % 65521;
97 k = ROTORSZ-1 - i;
98 ic = (rnd&MASK)%(k+1);
99 rnd >>= 8;
100 temp = t1[k];
101 t1[k] = t1[ic];
102 t1[ic] = temp;
103 if(t3[k]!=0) continue;
104 ic = (rnd&MASK) % k;
105 while(t3[ic]!=0) ic = (ic+1) % k;
106 t3[k] = ic;
107 t3[ic] = k;
108 }
109 for(i=0;i<ROTORSZ;i++)
110 t2[t1[i]&MASK] = i;
111}
112
113int
114main(argc, argv)
115 int argc;
116 char *argv[];
117{
118 register int i, n1, n2, nr1, nr2;
119 int secureflg = 0, kflag = 0;
120 char *cp;
121
122 if (argc > 1 && argv[1][0] == '-') {
123 if (argv[1][1] == 's') {
124 argc--;
125 argv++;
126 secureflg = 1;
127 } else if (argv[1][1] == 'k') {
128 argc--;
129 argv++;
130 kflag = 1;
131 }
132 }
133 if (kflag) {
134 if ((cp = getenv(MINUSKVAR)) == NULL) {
135 fprintf(stderr, "%s not set\n", MINUSKVAR);
136 exit(1);
137 }
138 setup(cp);
139 } else if (argc != 2) {
140 setup(getpass("Enter key:"));
141 }
142 else
143 setup(argv[1]);
144 n1 = 0;
145 n2 = 0;
146 nr2 = 0;
147
148 while((i=getchar()) != -1) {
149 if (secureflg) {
150 nr1 = deck[n1]&MASK;
151 nr2 = deck[nr1]&MASK;
152 } else {
153 nr1 = n1;
154 }
155 i = t2[(t3[(t1[(i+nr1)&MASK]+nr2)&MASK]-nr2)&MASK]-nr1;
156 putchar(i);
157 n1++;
158 if(n1==ROTORSZ) {
159 n1 = 0;
160 n2++;
161 if(n2==ROTORSZ) n2 = 0;
162 if (secureflg) {
163 shuffle(deck);
164 } else {
165 nr2 = n2;
166 }
167 }
168 }
169
170 return 0;
171}
172
173void
174shuffle(deckary)
175 char deckary[];
176{
177 int i, ic, k, temp;
178 unsigned rnd;
179 static long seed = 123;
180
181 for(i=0;i<ROTORSZ;i++) {
182 seed = 5*seed + buf[i%13];
183 rnd = seed % 65521;
184 k = ROTORSZ-1 - i;
185 ic = (rnd&MASK)%(k+1);
186 temp = deckary[k];
187 deckary[k] = deckary[ic];
188 deckary[ic] = temp;
189 }
190}