uudecode.c revision 1.13 
1/*	$OpenBSD: uudecode.c,v 1.13 2003/12/09 01:31:42 mickey Exp $	*/
2/*	$NetBSD: uudecode.c,v 1.6 1994/11/17 07:40:43 jtc Exp $	*/
3
4/*-
5 * Copyright (c) 1983, 1993
6 *	The Regents of the University of California.  All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33char copyright[] =
34"@(#) Copyright (c) 1983, 1993\n\
35	The Regents of the University of California.  All rights reserved.\n";
36
37#ifndef lint
38#if 0
39static char sccsid[] = "@(#)uudecode.c	8.2 (Berkeley) 4/2/94";
40#endif
41static char rcsid[] = "$OpenBSD: uudecode.c,v 1.13 2003/12/09 01:31:42 mickey Exp $";
42#endif /* not lint */
43
44/*
45 * uudecode [-p] [file ...]
46 *
47 * create the specified file, decoding as you go.
48 * used with uuencode.
49 *
50 * Write to stdout if '-p' is specified.  Use this option if you care about
51 * security at all.
52 */
53#include <stdio.h>
54#include <stdlib.h>
55#include <string.h>
56#include <locale.h>
57#include <errno.h>
58#include <sys/param.h>
59#include <sys/stat.h>
60
61#include <pwd.h>
62#include <unistd.h>
63#include <err.h>
64
65static int decode(int);
66static void usage(void);
67char *filename;
68
69int
70main(int argc, char *argv[])
71{
72	int rval;
73	int ch;
74	int tostdout = 0;
75
76	setlocale(LC_ALL, "");
77
78	while ((ch = getopt(argc, argv, "p")) != -1)
79		switch((char)ch) {
80		case 'p':
81			tostdout++;
82			break;
83		case '?':
84		default:
85			usage();
86		}
87	argc -= optind;
88	argv += optind;
89
90	if (*argv) {
91		rval = 0;
92		do {
93			if (!freopen(filename = *argv, "r", stdin)) {
94				warn("%s", *argv);
95				rval = 1;
96				continue;
97			}
98			rval |= decode(tostdout);
99		} while (*++argv);
100	} else {
101		filename = "stdin";
102		rval = decode(tostdout);
103	}
104	exit(rval);
105}
106
107static int
108decode(int tostdout)
109{
110	struct passwd *pw;
111	int n;
112	char ch, *p;
113	int mode, n1;
114	char buf[MAXPATHLEN];
115
116	/* search for header line */
117	do {
118		if (!fgets(buf, sizeof(buf), stdin)) {
119			warnx("%s: no \"begin\" line", filename);
120			return(1);
121		}
122	} while (strncmp(buf, "begin ", 6));
123	(void)sscanf(buf, "begin %o %1023[^\n\r]", &mode, buf);
124
125	/* handle ~user/file format */
126	if (buf[0] == '~') {
127		if (!(p = strchr(buf, '/'))) {
128			warnx("%s: illegal ~user", filename);
129			return(1);
130		}
131		*p++ = NULL;
132		if (!(pw = getpwnam(buf + 1))) {
133			warnx("%s: no user %s", filename, buf);
134			return(1);
135		}
136		n = strlen(pw->pw_dir);
137		n1 = strlen(p);
138		if (n + n1 + 2 > MAXPATHLEN) {
139			warnx("%s: path too long", filename);
140			return(1);
141		}
142		bcopy(p, buf + n + 1, n1 + 1);
143		bcopy(pw->pw_dir, buf, n);
144		buf[n] = '/';
145	}
146
147	if (!tostdout) {
148		/* create output file, set mode */
149		if (!freopen(buf, "w", stdout) ||
150		    fchmod(fileno(stdout), mode&0666)) {
151			warn("%s: %s", buf, filename);
152			return(1);
153		}
154	}
155
156	/* for each input line */
157	for (;;) {
158		if (!fgets(p = buf, sizeof(buf), stdin)) {
159			warnx("%s: short file", filename);
160			return(1);
161		}
162#define	DEC(c)	(((c) - ' ') & 077)		/* single character decode */
163		/*
164		 * `n' is used to avoid writing out all the characters
165		 * at the end of the file.
166		 */
167		if ((n = DEC(*p)) <= 0)
168			break;
169		for (++p; n > 0; p += 4, n -= 3)
170			if (n >= 3) {
171				ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
172				putchar(ch);
173				ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
174				putchar(ch);
175				ch = DEC(p[2]) << 6 | DEC(p[3]);
176				putchar(ch);
177			}
178			else {
179				if (n >= 1) {
180					ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
181					putchar(ch);
182				}
183				if (n >= 2) {
184					ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
185					putchar(ch);
186				}
187				if (n >= 3) {
188					ch = DEC(p[2]) << 6 | DEC(p[3]);
189					putchar(ch);
190				}
191			}
192	}
193	if (!fgets(buf, sizeof(buf), stdin) || strcmp(buf, "end\n")) {
194		warnx("%s: no \"end\" line", filename);
195		return(1);
196	}
197	return(0);
198}
199
200static void
201usage(void)
202{
203	(void)fprintf(stderr, "usage: uudecode [-p] [file ...]\n");
204	exit(1);
205}
206