xref: /illumos-gate/usr/src/cmd/crypt/crypt.c (revision 32991bed)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
23 /*	  All Rights Reserved  	*/
24 
25 
26 /*
27  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
28  * Use is subject to license terms.
29  */
30 
31 /*
32  *	A one-rotor machine designed along the lines of Enigma
33  *	but considerably trivialized.
34  */
35 
36 #define	ECHO 010
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <unistd.h>
40 #include <string.h>
41 #include <crypt.h>
42 #include <errno.h>
43 
44 #define	ROTORSZ 256
45 #define	MASK 0377
46 char	t1[ROTORSZ];
47 char	t2[ROTORSZ];
48 char	t3[ROTORSZ];
49 
50 static void
51 setup(pw)
52 char *pw;
53 {
54 	int ic, i, k, temp;
55 	unsigned random;
56 	char buf[13];
57 	long seed;
58 	char *ret;
59 	int err;
60 
61 	(void) strncpy(buf, pw, 8);
62 	buf[8] = buf[0];
63 	buf[9] = buf[1];
64 	errno = 0;
65 	ret = des_crypt(buf, &buf[8]);
66 	if (ret == NULL) {
67 		err = errno;
68 		(void) fprintf(stderr, "crypt: setup failed, unable to"
69 		    " initialize rotors: %s\n", strerror(err));
70 		exit(1);
71 	}
72 	(void) strncpy(buf, ret, 13);
73 	seed = 123;
74 	for (i = 0; i < 13; i++)
75 		seed = seed*buf[i] + i;
76 	for (i = 0; i < ROTORSZ; i++) {
77 		t1[i] = i;
78 		t3[i] = 0;
79 	}
80 	for (i = 0; i < ROTORSZ; i++) {
81 		seed = 5*seed + buf[i%13];
82 		random = seed % 65521;
83 		k = ROTORSZ-1 - i;
84 		ic = (random&MASK)%(k+1);
85 		random >>= 8;
86 		temp = t1[k];
87 		t1[k] = t1[ic];
88 		t1[ic] = temp;
89 		if (t3[k] != 0) continue;
90 		ic = (random&MASK) % k;
91 		while (t3[ic] != 0) ic = (ic+1) % k;
92 		t3[k] = ic;
93 		t3[ic] = k;
94 	}
95 	for (i = 0; i < ROTORSZ; i++)
96 		t2[t1[i]&MASK] = i;
97 }
98 
99 int
100 main(int argc, char **argv)
101 {
102 	extern int optind;
103 	char *p1;
104 	int i, n1, n2, nchar;
105 	int c;
106 	struct {
107 		long offset;
108 		unsigned int count;
109 	} header;
110 	int pflag = 0;
111 	int kflag = 0;
112 	char *buf;
113 	char key[8];
114 	char keyvar[] = "CrYpTkEy=XXXXXXXX";
115 	char *s;
116 
117 	if (argc < 2) {
118 		if ((buf = (char *)getpass("Enter key:")) == NULL) {
119 			(void) fprintf(stderr, "Cannot open /dev/tty\n");
120 			exit(1);
121 		}
122 		setup(buf);
123 	} else {
124 		while ((c = getopt(argc, argv, "pk")) != EOF)
125 			switch (c) {
126 			case 'p':
127 			/* notify editor that exec has succeeded */
128 				if (write(1, "y", 1) != 1)
129 					exit(1);
130 				if (read(0, key, 8) != 8)
131 					exit(1);
132 				setup(key);
133 				pflag = 1;
134 				break;
135 			case 'k':
136 				if ((s = getenv("CrYpTkEy")) == (char *)NULL) {
137 					(void) fprintf(stderr,
138 					    "CrYpTkEy not set.\n");
139 					exit(1);
140 				}
141 				(void) strncpy(key, s, 8);
142 				setup(key);
143 				kflag = 1;
144 				break;
145 			case '?':
146 				(void) fprintf(stderr,
147 				    "usage: crypt [ -k ] [ key]\n");
148 				exit(2);
149 			}
150 		if (pflag == 0 && kflag == 0) {
151 			(void) strncpy(keyvar+9, argv[optind], 8);
152 			(void) putenv(keyvar);
153 			(void) execlp("crypt", "crypt", "-k", 0);
154 		}
155 	}
156 	if (pflag)
157 		for (;;) {
158 			if ((nchar = read(0, (char *)&header, sizeof (header)))
159 			    != sizeof (header))
160 				exit(nchar);
161 			n1 = (int)(header.offset&MASK);
162 			n2 = (int)((header.offset >> 8) &MASK);
163 			nchar = header.count;
164 			buf = (char *)malloc(nchar);
165 			p1 = buf;
166 			if (read(0, buf, nchar) != nchar)
167 				exit(1);
168 			while (nchar--) {
169 				*p1 = t2[(t3[(t1[(*p1 + n1)&MASK]+
170 				    n2)&MASK] - n2)&MASK] - n1;
171 				n1++;
172 				if (n1 == ROTORSZ) {
173 					n1 = 0;
174 					n2++;
175 					if (n2 == ROTORSZ) n2 = 0;
176 				}
177 				p1++;
178 			}
179 			nchar = header.count;
180 			if (write(1, buf, nchar) != nchar)
181 				exit(1);
182 			free(buf);
183 		}
184 
185 	n1 = 0;
186 	n2 = 0;
187 
188 	while ((i = getchar()) >= 0) {
189 		i = t2[(t3[(t1[(i+n1)&MASK]+n2)&MASK]-n2)&MASK]-n1;
190 		(void) putchar(i);
191 		n1++;
192 		if (n1 == ROTORSZ) {
193 			n1 = 0;
194 			n2++;
195 			if (n2 == ROTORSZ) n2 = 0;
196 		}
197 	}
198 	return (0);
199 }
200