xref: /netbsd-src/usr.bin/uudecode/uudecode.c (revision a536ee5124e62c9a0051a252f7833dc8f50f44c9)
1 /*	$NetBSD: uudecode.c,v 1.26 2011/09/06 18:44:26 joerg Exp $	*/
2 
3 /*-
4  * Copyright (c) 1983, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #if HAVE_NBTOOL_CONFIG_H
33 #include "nbtool_config.h"
34 #endif
35 
36 #include <sys/cdefs.h>
37 #if !defined(lint)
38 __COPYRIGHT("@(#) Copyright (c) 1983, 1993\
39  The Regents of the University of California.  All rights reserved.");
40 #if 0
41 static char sccsid[] = "@(#)uudecode.c	8.2 (Berkeley) 4/2/94";
42 #endif
43 __RCSID("$NetBSD: uudecode.c,v 1.26 2011/09/06 18:44:26 joerg Exp $");
44 #endif /* not lint */
45 
46 /*
47  * uudecode [file ...]
48  *
49  * create the specified file, decoding as you go.
50  * used with uuencode.
51  */
52 #include <sys/param.h>
53 #include <sys/stat.h>
54 #include <ctype.h>
55 #include <err.h>
56 #include <errno.h>
57 #include <limits.h>
58 #include <locale.h>
59 #include <pwd.h>
60 #include <stdio.h>
61 #include <stdlib.h>
62 #include <string.h>
63 #include <unistd.h>
64 
65 #ifndef NO_BASE64
66 #include <netinet/in.h>
67 #include <resolv.h>
68 #endif
69 
70 static int decode(void);
71 __dead static void usage(void);
72 static int checkend(const char *, const char *, const char *);
73 static int base64_decode(void);
74 
75 static int base64, pflag;
76 static const char *filename;
77 
78 int
79 main(int argc, char *argv[])
80 {
81 	int ch, rval;
82 
83 	setlocale(LC_ALL, "");
84 	setprogname(argv[0]);
85 
86 	pflag = 0;
87 	while ((ch = getopt(argc, argv, "mp")) != -1)
88 		switch (ch) {
89 		case 'm':
90 			base64 = 1;
91 			break;
92 		case 'p':
93 			pflag = 1;
94 			break;
95 		default:
96 			usage();
97 		}
98 	argc -= optind;
99 	argv += optind;
100 
101 	if (*argv) {
102 		rval = 0;
103 		do {
104 			if (!freopen(filename = *argv, "r", stdin)) {
105 				warn("%s", *argv);
106 				rval = 1;
107 				continue;
108 			}
109 			rval |= decode();
110 		} while (*++argv);
111 	} else {
112 		filename = "stdin";
113 		rval = decode();
114 	}
115 	exit(rval);
116 }
117 
118 static int
119 decode(void)
120 {
121 	struct passwd *pw;
122 	int n;
123 	char ch, *p;
124 	int n1;
125 	long mode;
126 	char *fn;
127 	char buf[MAXPATHLEN];
128 
129 	/* search for header line */
130 	for (;;) {
131 		if (!fgets(buf, sizeof(buf), stdin)) {
132 			warnx("%s: no \"%s\" line", filename, base64 ?
133 					"begin-base64" : "begin");
134 			return(1);
135 		}
136 		p = buf;
137 		if (strncmp(p, "begin-base64", 12) == 0) {
138 			base64 = 1;
139 			p += 13;
140 			break;
141 		} else if (strncmp(p, "begin", 5) == 0)  {
142 			p += 6;
143 			break;
144 		} else
145 			continue;
146 	}
147 
148         /* must be followed by an octal mode and a space */
149 	mode = strtol(p, &fn, 8);
150 	if (fn == (p) || !isspace((unsigned char)*fn) || mode==LONG_MIN || mode==LONG_MAX)
151 	{
152 	        warnx("%s: invalid mode on \"%s\" line", filename,
153 			base64 ? "begin-base64" : "begin");
154 		return(1);
155 	}
156 	/* skip whitespace for file name */
157 	while (*fn && isspace((unsigned char)*fn)) fn++;
158 	if (*fn == 0) {
159                 warnx("%s: no filename on \"%s\" line", filename,
160 			base64 ? "begin-base64" : "begin");
161 		return(1);
162 	}
163 	/* zap newline */
164 	for (p = fn; *p && *p != '\n'; p++)
165 	        ;
166 	if (*p) *p = 0;
167 
168 	/* handle ~user/file format */
169 	if (*fn == '~') {
170 		if (!(p = strchr(fn, '/'))) {
171 			warnx("%s: illegal ~user.", filename);
172 			return(1);
173 		}
174 		*p++ = '\0';
175 		if (!(pw = getpwnam(fn + 1))) {
176 			warnx("%s: no user %s.", filename, buf);
177 			return(1);
178 		}
179 		n = strlen(pw->pw_dir);
180 		n1 = strlen(p);
181 		if (n + n1 + 2 > MAXPATHLEN) {
182 			warnx("%s: path too long.", filename);
183 			return(1);
184 		}
185 		/* make space at beginning of buf by moving end of pathname */
186 		memmove(buf + n + 1, p, n1 + 1);
187 		memmove(buf, pw->pw_dir, n);
188 		buf[n] = '/';
189 		fn = buf;
190 	}
191 
192 	/* create output file, set mode */
193 	if (!pflag && (!freopen(fn, "w", stdout) ||
194 	    fchmod(fileno(stdout), mode & 0666))) {
195 		warn("%s: %s", fn, filename);
196 		return(1);
197 	}
198 
199 	if (base64)
200 		return base64_decode();
201 	else {
202 		/* for each input line */
203 		for (;;) {
204 			if (!fgets(p = buf, sizeof(buf), stdin)) {
205 				warnx("%s: short file.", filename);
206 				return(1);
207 			}
208 #define	DEC(c)	(((c) - ' ') & 077)		/* single character decode */
209 			/*
210 		 	* `n' is used to avoid writing out all the characters
211 		 	* at the end of the file.
212 		 	*/
213 			if ((n = DEC(*p)) <= 0)
214 				break;
215 			for (++p; n > 0; p += 4, n -= 3)
216 				if (n >= 3) {
217 					ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
218 					putchar(ch);
219 					ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
220 					putchar(ch);
221 					ch = DEC(p[2]) << 6 | DEC(p[3]);
222 					putchar(ch);
223 				}
224 				else {
225 					if (n >= 1) {
226 						ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
227 						putchar(ch);
228 					}
229 					if (n >= 2) {
230 						ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
231 						putchar(ch);
232 					}
233 					if (n >= 3) {
234 						ch = DEC(p[2]) << 6 | DEC(p[3]);
235 						putchar(ch);
236 					}
237 				}
238 		}
239 		if (!fgets(buf, sizeof(buf), stdin) || strcmp(buf, "end\n")) {
240 			warnx("%s: no \"end\" line.", filename);
241 			return(1);
242 		}
243 		return(0);
244 	}
245 }
246 
247 static int
248 checkend(const char *ptr, const char *end, const char *msg)
249 {
250 	size_t n;
251 
252 	n = strlen(end);
253 	if (strncmp(ptr, end, n) != 0 ||
254 	    strspn(ptr + n, "\t\r\n") != strlen(ptr + n)) {
255 		warnx("%s", msg);
256 		return (1);
257 	}
258 	return (0);
259 }
260 
261 static int
262 base64_decode(void)
263 {
264 	int n;
265 	char inbuf[MAXPATHLEN];
266 	unsigned char outbuf[MAXPATHLEN * 4];
267 
268 	for (;;) {
269 		if (!fgets(inbuf, sizeof(inbuf), stdin)) {
270 			warnx("%s: short file.", filename);
271 			return (1);
272 		}
273 #ifdef NO_BASE64
274 		warnx("%s: base64 decoding is not supported", filename);
275 		return (1);
276 #else
277 		n = b64_pton(inbuf, outbuf, sizeof(outbuf));
278 #endif
279 		if (n < 0)
280 			break;
281 		fwrite(outbuf, 1, n, stdout);
282 	}
283 	return (checkend(inbuf, "====",
284 			"error decoding base64 input stream"));
285 }
286 
287 static void
288 usage(void)
289 {
290 	(void)fprintf(stderr, "usage: %s [-m | -p] [encoded-file ...]\n",
291 		      getprogname());
292 	exit(1);
293 }
294