xref: /minix/usr.bin/uudecode/uudecode.c (revision 83133719)
1 /*	$NetBSD: uudecode.c,v 1.28 2013/01/28 19:50:30 apb 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 1.28 2013/01/28 19:50:30 apb 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(char *);
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;
76 static const char *inputname;
77 
78 int
79 main(int argc, char *argv[])
80 {
81 	int ch, rval;
82 	char *outputname = NULL;
83 
84 	setlocale(LC_ALL, "");
85 	setprogname(argv[0]);
86 
87 	while ((ch = getopt(argc, argv, "mo:p")) != -1)
88 		switch (ch) {
89 		case 'm':
90 			base64 = 1;
91 			break;
92 		case 'o':
93 			outputname = optarg;
94 			break;
95 		case 'p':
96 			outputname = __UNCONST("/dev/stdout");
97 			break;
98 		default:
99 			usage();
100 		}
101 	argc -= optind;
102 	argv += optind;
103 
104 	if (*argv) {
105 		rval = 0;
106 		do {
107 			if (!freopen(inputname = *argv, "r", stdin)) {
108 				warn("%s", *argv);
109 				rval = 1;
110 				continue;
111 			}
112 			rval |= decode(outputname);
113 		} while (*++argv);
114 	} else {
115 		inputname = "stdin";
116 		rval = decode(outputname);
117 	}
118 	exit(rval);
119 }
120 
121 /*
122  * Decode one file from stdin.  If outputname is not NULL
123  * then it overrides the file name embedded in the input data.
124  */
125 static int
126 decode(char *outputname)
127 {
128 	struct passwd *pw;
129 	int n;
130 	char ch, *p;
131 	int n1;
132 	long mode;
133 	char *fn;
134 	char buf[MAXPATHLEN];
135 
136 	/* search for header line */
137 	for (;;) {
138 		if (!fgets(buf, sizeof(buf), stdin)) {
139 			warnx("%s: no \"%s\" line", inputname, base64 ?
140 					"begin-base64" : "begin");
141 			return(1);
142 		}
143 		p = buf;
144 		if (strncmp(p, "begin-base64", 12) == 0) {
145 			base64 = 1;
146 			p += 13;
147 			break;
148 		} else if (strncmp(p, "begin", 5) == 0)  {
149 			p += 6;
150 			break;
151 		} else
152 			continue;
153 	}
154 
155         /* must be followed by an octal mode and a space */
156 	mode = strtol(p, &fn, 8);
157 	if (fn == (p) || !isspace((unsigned char)*fn) || mode==LONG_MIN || mode==LONG_MAX)
158 	{
159 	        warnx("%s: invalid mode on \"%s\" line", inputname,
160 			base64 ? "begin-base64" : "begin");
161 		return(1);
162 	}
163 	/* skip whitespace for file name */
164 	while (*fn && isspace((unsigned char)*fn)) fn++;
165 	if (*fn == 0) {
166                 warnx("%s: no filename on \"%s\" line", inputname,
167 			base64 ? "begin-base64" : "begin");
168 		return(1);
169 	}
170 	/* zap newline */
171 	for (p = fn; *p && *p != '\n'; p++)
172 	        ;
173 	if (*p) *p = 0;
174 
175 	/* outputname overrides fn */
176 	if (outputname)
177 		fn = outputname;
178 
179 	/* handle ~user/file format */
180 	if (*fn == '~') {
181 		if (!(p = strchr(fn, '/'))) {
182 			warnx("%s: illegal ~user.", inputname);
183 			return(1);
184 		}
185 		*p++ = '\0';
186 		if (!(pw = getpwnam(fn + 1))) {
187 			warnx("%s: no user %s.", inputname, buf);
188 			return(1);
189 		}
190 		n = strlen(pw->pw_dir);
191 		n1 = strlen(p);
192 		if (n + n1 + 2 > MAXPATHLEN) {
193 			warnx("%s: path too long.", inputname);
194 			return(1);
195 		}
196 		/* make space at beginning of buf by moving end of pathname */
197 		memmove(buf + n + 1, p, n1 + 1);
198 		memmove(buf, pw->pw_dir, n);
199 		buf[n] = '/';
200 		fn = buf;
201 	}
202 
203 	if (strcmp(fn, "/dev/stdout") == 0 || strcmp(fn, "-") == 0) {
204 		/*
205 		 * POSIX.1-2008 says that both "-" and "/dev/stdout"
206 		 * refer to standard output when they appear in the file
207 		 * header, but only "/dev/stdout" refers to standard
208 		 * output when it appears as the argument to the "-o"
209 		 * command line option.
210 		 *
211 		 * We handle both special names, regardless of whether
212 		 * they came from the "-o" option or from the header of
213 		 * the input stream.
214 		 */
215 	} else {
216 		/*
217 		 * Create output file, and set its mode.  POSIX.1-2008
218 		 * requires the mode to be used exactly, ignoring the
219 		 * umask and anything else, but we mask it with 0666.
220 		 */
221 		if (freopen(fn, "w", stdout) == NULL ||
222 		    fchmod(fileno(stdout), mode & 0666) != 0) {
223 			warn("%s: %s", fn, inputname);
224 			return(1);
225 		}
226 	}
227 
228 	if (base64)
229 		return base64_decode();
230 	else {
231 		/* for each input line */
232 		for (;;) {
233 			if (!fgets(p = buf, sizeof(buf), stdin)) {
234 				warnx("%s: short file.", inputname);
235 				return(1);
236 			}
237 #define	DEC(c)	(((c) - ' ') & 077)		/* single character decode */
238 			/*
239 		 	* `n' is used to avoid writing out all the characters
240 		 	* at the end of the file.
241 		 	*/
242 			if ((n = DEC(*p)) <= 0)
243 				break;
244 			for (++p; n > 0; p += 4, n -= 3)
245 				if (n >= 3) {
246 					ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
247 					putchar(ch);
248 					ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
249 					putchar(ch);
250 					ch = DEC(p[2]) << 6 | DEC(p[3]);
251 					putchar(ch);
252 				}
253 				else {
254 					if (n >= 1) {
255 						ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
256 						putchar(ch);
257 					}
258 					if (n >= 2) {
259 						ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
260 						putchar(ch);
261 					}
262 					if (n >= 3) {
263 						ch = DEC(p[2]) << 6 | DEC(p[3]);
264 						putchar(ch);
265 					}
266 				}
267 		}
268 		if (!fgets(buf, sizeof(buf), stdin) || strcmp(buf, "end\n")) {
269 			warnx("%s: no \"end\" line.", inputname);
270 			return(1);
271 		}
272 		return(0);
273 	}
274 }
275 
276 static int
277 checkend(const char *ptr, const char *end, const char *msg)
278 {
279 	size_t n;
280 
281 	n = strlen(end);
282 	if (strncmp(ptr, end, n) != 0 ||
283 	    strspn(ptr + n, "\t\r\n") != strlen(ptr + n)) {
284 		warnx("%s", msg);
285 		return (1);
286 	}
287 	return (0);
288 }
289 
290 static int
291 base64_decode(void)
292 {
293 	int n;
294 	char inbuf[MAXPATHLEN];
295 	unsigned char outbuf[MAXPATHLEN * 4];
296 
297 	for (;;) {
298 		if (!fgets(inbuf, sizeof(inbuf), stdin)) {
299 			warnx("%s: short file.", inputname);
300 			return (1);
301 		}
302 #ifdef NO_BASE64
303 		warnx("%s: base64 decoding is not supported", inputname);
304 		return (1);
305 #else
306 		n = b64_pton(inbuf, outbuf, sizeof(outbuf));
307 #endif
308 		if (n < 0)
309 			break;
310 		fwrite(outbuf, 1, n, stdout);
311 	}
312 	return (checkend(inbuf, "====",
313 			"error decoding base64 input stream"));
314 }
315 
316 static void
317 usage(void)
318 {
319 	(void)fprintf(stderr,
320 		      "usage: %s [-m] [-p | -o outfile] [encoded-file ...]\n",
321 		      getprogname());
322 	exit(1);
323 }
324