xref: /illumos-gate/usr/src/cmd/crypt/crypt.c (revision 7c478bd9)
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 #pragma ident	"%Z%%M%	%I%	%E% SMI"
32 /*
33  *	A one-rotor machine designed along the lines of Enigma
34  *	but considerably trivialized.
35  */
36 
37 /* EXPORT DELETE START */
38 #define	ECHO 010
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <unistd.h>
42 #include <string.h>
43 #include <crypt.h>
44 #include <errno.h>
45 
46 #define	ROTORSZ 256
47 #define	MASK 0377
48 char	t1[ROTORSZ];
49 char	t2[ROTORSZ];
50 char	t3[ROTORSZ];
51 
52 static void
53 setup(pw)
54 char *pw;
55 {
56 	int ic, i, k, temp;
57 	unsigned random;
58 	char buf[13];
59 	long seed;
60 	char *ret;
61 	int err;
62 
63 	(void) strncpy(buf, pw, 8);
64 	buf[8] = buf[0];
65 	buf[9] = buf[1];
66 	errno = 0;
67 	ret = des_crypt(buf, &buf[8]);
68 	if (ret == NULL) {
69 		err = errno;
70 		(void) fprintf(stderr, "crypt: setup failed, unable to"
71 		    " initialize rotors: %s\n", strerror(err));
72 		exit(1);
73 	}
74 	(void) strncpy(buf, ret, 13);
75 	seed = 123;
76 	for (i = 0; i < 13; i++)
77 		seed = seed*buf[i] + i;
78 	for (i = 0; i < ROTORSZ; i++) {
79 		t1[i] = i;
80 		t3[i] = 0;
81 	}
82 	for (i = 0; i < ROTORSZ; i++) {
83 		seed = 5*seed + buf[i%13];
84 		random = seed % 65521;
85 		k = ROTORSZ-1 - i;
86 		ic = (random&MASK)%(k+1);
87 		random >>= 8;
88 		temp = t1[k];
89 		t1[k] = t1[ic];
90 		t1[ic] = temp;
91 		if (t3[k] != 0) continue;
92 		ic = (random&MASK) % k;
93 		while (t3[ic] != 0) ic = (ic+1) % k;
94 		t3[k] = ic;
95 		t3[ic] = k;
96 	}
97 	for (i = 0; i < ROTORSZ; i++)
98 		t2[t1[i]&MASK] = i;
99 }
100 /* EXPORT DELETE END */
101 
102 int
103 main(int argc, char **argv)
104 {
105 /* EXPORT DELETE START */
106 	extern int optind;
107 	char *p1;
108 	int i, n1, n2, nchar;
109 	int c;
110 	struct {
111 		long offset;
112 		unsigned int count;
113 	} header;
114 	int pflag = 0;
115 	int kflag = 0;
116 	char *buf;
117 	char key[8];
118 	char *keyvar = "CrYpTkEy=XXXXXXXX";
119 	char *s;
120 
121 	if (argc < 2) {
122 		if ((buf = (char *)getpass("Enter key:")) == NULL) {
123 			(void) fprintf(stderr, "Cannot open /dev/tty\n");
124 			exit(1);
125 		}
126 		setup(buf);
127 	} else {
128 		while ((c = getopt(argc, argv, "pk")) != EOF)
129 			switch (c) {
130 			case 'p':
131 			/* notify editor that exec has succeeded */
132 				if (write(1, "y", 1) != 1)
133 					exit(1);
134 				if (read(0, key, 8) != 8)
135 					exit(1);
136 				setup(key);
137 				pflag = 1;
138 				break;
139 			case 'k':
140 				if ((s = getenv("CrYpTkEy")) == (char *)NULL) {
141 					(void) fprintf(stderr,
142 					    "CrYpTkEy not set.\n");
143 					exit(1);
144 				}
145 				(void) strncpy(key, s, 8);
146 				setup(key);
147 				kflag = 1;
148 				break;
149 			case '?':
150 				(void) fprintf(stderr,
151 				    "usage: crypt [ -k ] [ key]\n");
152 				exit(2);
153 			}
154 		if (pflag == 0 && kflag == 0) {
155 			(void) strncpy(keyvar+9, argv[optind], 8);
156 			(void) putenv(keyvar);
157 			(void) execlp("crypt", "crypt", "-k", 0);
158 		}
159 	}
160 	if (pflag)
161 		for (;;) {
162 			if ((nchar = read(0, (char *)&header, sizeof (header)))
163 			    != sizeof (header))
164 				exit(nchar);
165 			n1 = (int)(header.offset&MASK);
166 			n2 = (int)((header.offset >> 8) &MASK);
167 			nchar = header.count;
168 			buf = (char *)malloc(nchar);
169 			p1 = buf;
170 			if (read(0, buf, nchar) != nchar)
171 				exit(1);
172 			while (nchar--) {
173 				*p1 = t2[(t3[(t1[(*p1 + n1)&MASK]+
174 				    n2)&MASK] - n2)&MASK] - n1;
175 				n1++;
176 				if (n1 == ROTORSZ) {
177 					n1 = 0;
178 					n2++;
179 					if (n2 == ROTORSZ) n2 = 0;
180 				}
181 				p1++;
182 			}
183 			nchar = header.count;
184 			if (write(1, buf, nchar) != nchar)
185 				exit(1);
186 			free(buf);
187 		}
188 
189 	n1 = 0;
190 	n2 = 0;
191 
192 	while ((i = getchar()) >= 0) {
193 		i = t2[(t3[(t1[(i+n1)&MASK]+n2)&MASK]-n2)&MASK]-n1;
194 		(void) putchar(i);
195 		n1++;
196 		if (n1 == ROTORSZ) {
197 			n1 = 0;
198 			n2++;
199 			if (n2 == ROTORSZ) n2 = 0;
200 		}
201 	}
202 	return (0);
203 /* EXPORT DELETE END */
204 }
205