uudecode.c revision 103198 
1/*-
2 * Copyright (c) 1983, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#ifndef lint
35static const char copyright[] =
36"@(#) Copyright (c) 1983, 1993\n\
37	The Regents of the University of California.  All rights reserved.\n";
38#endif /* not lint */
39
40#if 0
41#ifndef lint
42static char sccsid[] = "@(#)uudecode.c	8.2 (Berkeley) 4/2/94";
43#endif /* not lint */
44#endif
45
46#include <sys/cdefs.h>
47__FBSDID("$FreeBSD: head/usr.bin/uudecode/uudecode.c 103198 2002-09-10 19:23:44Z fanf $");
48
49/*
50 * uudecode [file ...]
51 *
52 * create the specified file, decoding as you go.
53 * used with uuencode.
54 */
55#include <sys/param.h>
56#include <sys/socket.h>
57#include <sys/stat.h>
58
59#include <netinet/in.h>
60
61#include <err.h>
62#include <pwd.h>
63#include <resolv.h>
64#include <stdio.h>
65#include <stdlib.h>
66#include <string.h>
67#include <unistd.h>
68
69const char *filename;
70char *outfile;
71int cflag, iflag, oflag, pflag, sflag;
72
73static void usage(void);
74int	decode(void);
75int	decode2(int);
76void	base64_decode(const char *);
77
78int
79main(int argc, char *argv[])
80{
81	int rval, ch;
82
83	while ((ch = getopt(argc, argv, "cio:ps")) != -1) {
84		switch(ch) {
85		case 'c':
86			if (oflag)
87				usage();
88			cflag = 1; /* multiple uudecode'd files */
89			break;
90		case 'i':
91			iflag = 1; /* ask before override files */
92			break;
93		case 'o':
94			if (cflag || pflag || sflag)
95				usage();
96			oflag = 1; /* output to the specified file */
97			sflag = 1; /* do not strip pathnames for output */
98			outfile = optarg; /* set the output filename */
99			break;
100		case 'p':
101			if (oflag)
102				usage();
103			pflag = 1; /* print output to stdout */
104			break;
105		case 's':
106			if (oflag)
107				usage();
108			sflag = 1; /* do not strip pathnames for output */
109			break;
110		default:
111			usage();
112		}
113	}
114        argc -= optind;
115        argv += optind;
116
117	if (*argv) {
118		rval = 0;
119		do {
120			if (!freopen(filename = *argv, "r", stdin)) {
121				warn("%s", *argv);
122				rval = 1;
123				continue;
124			}
125			rval |= decode();
126		} while (*++argv);
127	} else {
128		filename = "stdin";
129		rval = decode();
130	}
131	exit(rval);
132}
133
134int
135decode(void)
136{
137	int flag;
138
139	/* decode only one file per input stream */
140	if (!cflag)
141		return (decode2(0));
142
143	/* multiple uudecode'd files */
144	for (flag = 0; ; flag++)
145		if (decode2(flag))
146			return (1);
147		else if (feof(stdin))
148			break;
149
150	return (0);
151}
152
153int
154decode2(int flag)
155{
156	struct passwd *pw;
157	int n;
158	char ch, *p;
159	int base64, n1;
160	char buf[MAXPATHLEN+1];
161	char buffn[MAXPATHLEN+1]; /* file name buffer */
162	char *mode, *s;
163	void *mode_handle;
164	struct stat st;
165
166	base64 = 0;
167	/* search for header line */
168	do {
169		if (!fgets(buf, sizeof(buf), stdin)) {
170			if (flag) /* no error */
171				return (0);
172
173			warnx("%s: no \"begin\" line", filename);
174			return (1);
175		}
176	} while (strncmp(buf, "begin", 5) != 0);
177
178	if (strncmp(buf, "begin-base64", 12) == 0)
179		base64 = 1;
180
181	/* Parse the header: begin{,-base64} mode outfile. */
182	s = strtok(buf, " ");
183	if (s == NULL)
184		errx(1, "no mode or filename in input file");
185	s = strtok(NULL, " ");
186	if (s == NULL)
187		errx(1, "no mode in input file");
188	else {
189		mode = strdup(s);
190		if (mode == NULL)
191			err(1, "strdup()");
192	}
193	if (!oflag) {
194		outfile = strtok(NULL, "\r\n");
195		if (outfile == NULL)
196			errx(1, "no filename in input file");
197	}
198
199	if (strlcpy(buf, outfile, sizeof(buf)) >= sizeof(buf))
200		errx(1, "%s: filename too long", outfile);
201	if (!sflag && !pflag) {
202		strlcpy(buffn, buf, sizeof(buffn));
203		if (strrchr(buffn, '/') != NULL)
204			strncpy(buf, strrchr(buffn, '/') + 1, sizeof(buf));
205		if (buf[0] == '\0') {
206			warnx("%s: illegal filename", buffn);
207			return (1);
208		}
209
210		/* handle ~user/file format */
211		if (buf[0] == '~') {
212			if (!(p = index(buf, '/'))) {
213				warnx("%s: illegal ~user", filename);
214				return (1);
215			}
216			*p++ = '\0';
217			if (!(pw = getpwnam(buf + 1))) {
218				warnx("%s: no user %s", filename, buf);
219				return (1);
220			}
221			n = strlen(pw->pw_dir);
222			n1 = strlen(p);
223			if (n + n1 + 2 > MAXPATHLEN) {
224				warnx("%s: path too long", filename);
225				return (1);
226			}
227			bcopy(p, buf + n + 1, n1 + 1);
228			bcopy(pw->pw_dir, buf, n);
229			buf[n] = '/';
230		}
231	}
232
233	/* create output file, set mode */
234	if (pflag)
235		; /* print to stdout */
236
237	else {
238		mode_handle = setmode(mode);
239		if (mode_handle == NULL)
240			err(1, "setmode()");
241		if (iflag && !access(buf, F_OK)) {
242			warnx("not overwritten: %s", buf);
243			return (0);
244		} else if (freopen(buf, "w", stdout) == NULL ||
245		    stat(buf, &st) < 0 || (S_ISREG(st.st_mode) &&
246		    fchmod(fileno(stdout), getmode(mode_handle, 0) & 0666))) {
247			warn("%s: %s", buf, filename);
248			return (1);
249		}
250		free(mode_handle);
251		free(mode);
252	}
253	strcpy(buffn, buf); /* store file name from header line */
254
255	/* for each input line */
256next:
257	for (;;) {
258		if (!fgets(p = buf, sizeof(buf), stdin)) {
259			warnx("%s: short file", filename);
260			return (1);
261		}
262		if (base64) {
263			if (strncmp(buf, "====", 4) == 0)
264				return (0);
265			base64_decode(buf);
266			goto next;
267		}
268#define	DEC(c)	(((c) - ' ') & 077)		/* single character decode */
269#define IS_DEC(c) ( (((c) - ' ') >= 0) &&  (((c) - ' ') <= 077 + 1) )
270/* #define IS_DEC(c) (1) */
271
272#define OUT_OF_RANGE \
273{	\
274    warnx( \
275"\n\tinput file: %s\n\tencoded file: %s\n\tcharacter out of range: [%d-%d]", \
276 	filename, buffn, 1 + ' ', 077 + ' ' + 1); \
277        return (1); \
278}
279
280		/*
281		 * `n' is used to avoid writing out all the characters
282		 * at the end of the file.
283		 */
284		if ((n = DEC(*p)) <= 0)
285			break;
286		for (++p; n > 0; p += 4, n -= 3)
287			if (n >= 3) {
288				if (!(IS_DEC(*p) && IS_DEC(*(p + 1)) &&
289				     IS_DEC(*(p + 2)) && IS_DEC(*(p + 3))))
290                                	OUT_OF_RANGE
291
292				ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
293				putchar(ch);
294				ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
295				putchar(ch);
296				ch = DEC(p[2]) << 6 | DEC(p[3]);
297				putchar(ch);
298			}
299			else {
300				if (n >= 1) {
301					if (!(IS_DEC(*p) && IS_DEC(*(p + 1))))
302	                                	OUT_OF_RANGE
303					ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
304					putchar(ch);
305				}
306				if (n >= 2) {
307					if (!(IS_DEC(*(p + 1)) &&
308						IS_DEC(*(p + 2))))
309		                                OUT_OF_RANGE
310
311					ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
312					putchar(ch);
313				}
314				if (n >= 3) {
315					if (!(IS_DEC(*(p + 2)) &&
316						IS_DEC(*(p + 3))))
317		                                OUT_OF_RANGE
318					ch = DEC(p[2]) << 6 | DEC(p[3]);
319					putchar(ch);
320				}
321			}
322	}
323	if (fgets(buf, sizeof(buf), stdin) == NULL ||
324	    (strcmp(buf, "end") && strcmp(buf, "end\n") &&
325	     strcmp(buf, "end\r\n"))) {
326		warnx("%s: no \"end\" line", filename);
327		return (1);
328	}
329	return (0);
330}
331
332void
333base64_decode(const char *stream)
334{
335	unsigned char out[MAXPATHLEN * 4];
336	int rv;
337
338	if (index(stream, '\r') != NULL)
339		*index(stream, '\r') = '\0';
340	if (index(stream, '\n') != NULL)
341		*index(stream, '\n') = '\0';
342	rv = b64_pton(stream, out, (sizeof(out) / sizeof(out[0])));
343	if (rv == -1)
344		errx(1, "b64_pton: error decoding base64 input stream");
345	fwrite(out, 1, rv, stdout);
346}
347
348static void
349usage(void)
350{
351	(void)fprintf(stderr,
352"usage: uudecode [-cips] [file ...]\n"
353"       uudecode [-i] -o output_file [file]\n"
354"       b64decode [-cips] [file ...]\n"
355"       b64decode [-i] -o output_file [file]\n");
356	exit(1);
357}
358