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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 #if 0
35 #ifndef lint
36 static const char copyright[] =
37 "@(#) Copyright (c) 1983, 1993\n\
38 The Regents of the University of California. All rights reserved.\n";
39 #endif /* not lint */
40
41 #ifndef lint
42 static char sccsid[] = "@(#)uudecode.c 8.2 (Berkeley) 4/2/94";
43 #endif /* not lint */
44 #endif
45 #include <sys/cdefs.h>
46 __FBSDID("$FreeBSD: head/usr.bin/uudecode/uudecode.c 214010 2010-10-18 05:44:11Z edwin $");
47
48 /*
49 * uudecode [file ...]
50 *
51 * create the specified file, decoding as you go.
52 * used with uuencode.
53 */
54 #include <sys/param.h>
55 #include <sys/socket.h>
56 #include <sys/stat.h>
57
58 #include <netinet/in.h>
59
60 #include <ctype.h>
61 #include <err.h>
62 #include <errno.h>
63 #include <fcntl.h>
64 #include <libgen.h>
65 #include <pwd.h>
66 #include <resolv.h>
67 #include <stdio.h>
68 #include <stdlib.h>
69 #include <string.h>
70 #include <unistd.h>
71
72 static const char *infile, *outfile;
73 static FILE *infp, *outfp;
74 static int base64, cflag, iflag, oflag, pflag, rflag, sflag;
75
76 static void usage(void);
77 static int decode(void);
78 static int decode2(void);
79 static int uu_decode(void);
80 static int base64_decode(void);
81
82 int
83 main(int argc, char *argv[])
84 {
85 int rval, ch;
86
87 if (strcmp(basename(argv[0]), "b64decode") == 0)
88 base64 = 1;
89
90 while ((ch = getopt(argc, argv, "cimo:prs")) != -1) {
91 switch (ch) {
92 case 'c':
93 if (oflag || rflag)
94 usage();
95 cflag = 1; /* multiple uudecode'd files */
96 break;
97 case 'i':
98 iflag = 1; /* ask before override files */
99 break;
100 case 'm':
101 base64 = 1;
102 break;
103 case 'o':
104 if (cflag || pflag || rflag || sflag)
105 usage();
106 oflag = 1; /* output to the specified file */
107 sflag = 1; /* do not strip pathnames for output */
108 outfile = optarg; /* set the output filename */
109 break;
110 case 'p':
111 if (oflag)
112 usage();
113 pflag = 1; /* print output to stdout */
114 break;
115 case 'r':
116 if (cflag || oflag)
117 usage();
118 rflag = 1; /* decode raw data */
119 break;
120 case 's':
121 if (oflag)
122 usage();
123 sflag = 1; /* do not strip pathnames for output */
124 break;
125 default:
126 usage();
127 }
128 }
129 // argc -= optind;
130 argv += optind;
131
132 if (*argv != NULL) {
133 rval = 0;
134 do {
135 infp = fopen(infile = *argv, "r");
136 if (infp == NULL) {
137 warn("%s", *argv);
138 rval = 1;
139 continue;
140 }
141 rval |= decode();
142 fclose(infp);
143 } while (*++argv);
144 } else {
145 infile = "stdin";
146 infp = stdin;
147 rval = decode();
148 }
149 exit(rval);
150 }
151
152 static int
153 decode(void)
154 {
155 int r, v;
156
157 if (rflag) {
158 /* relaxed alternative to decode2() */
159 outfile = "/dev/stdout";
160 outfp = stdout;
161 if (base64)
162 return (base64_decode());
163 else
164 return (uu_decode());
165 }
166 v = decode2();
167 if (v == EOF) {
168 warnx("%s: missing or bad \"begin\" line", infile);
169 return (1);
170 }
171 for (r = v; cflag; r |= v) {
172 v = decode2();
173 if (v == EOF)
174 break;
175 }
176 return (r);
177 }
178
179 static int
180 decode2(void)
181 {
182 int flags, fd, mode;
183 size_t n, m;
184 char *p, *q = NULL, *orig_outfile = NULL;
185 void *handle;
186 struct passwd *pw;
187 struct stat st;
188 char buf[MAXPATHLEN + 1];
189
190 base64 = 0;
191 /* search for header line */
192 for (;;) {
193 if (fgets(buf, sizeof(buf), infp) == NULL)
194 return (EOF);
195 p = buf;
196 if (strncmp(p, "begin-base64 ", 13) == 0) {
197 base64 = 1;
198 p += 13;
199 } else if (strncmp(p, "begin ", 6) == 0)
200 p += 6;
201 else
202 continue;
203 /* p points to mode */
204 q = strchr(p, ' ');
205 if (q == NULL)
206 continue;
207 *q++ = '\0';
208 /* q points to filename */
209 n = strlen(q);
210 while (n > 0 && (q[n-1] == '\n' || q[n-1] == '\r'))
211 q[--n] = '\0';
212 /* found valid header? */
213 if (n > 0)
214 break;
215 }
216 orig_outfile = q;
217 handle = setmode(p);
218 if (handle == NULL) {
219 warnx("%s: unable to parse file mode", infile);
220 return (1);
221 }
222 mode = getmode(handle, 0);
223 free(handle);
224
225 if (sflag) {
226 /* don't strip, so try ~user/file expansion */
227 p = NULL;
228 pw = NULL;
229 if (*q == '~')
230 p = strchr(q, '/');
231 if (p != NULL) {
232 *p = '\0';
233 pw = getpwnam(q + 1);
234 *p = '/';
235 }
236 if (pw != NULL) {
237 n = strlen(pw->pw_dir);
238 if (buf + n > p) {
239 /* make room */
240 m = strlen(p);
241 if (sizeof(buf) < n + m) {
242 warnx("%s: bad output filename",
243 infile);
244 return (1);
245 }
246 p = memmove(buf + n, p, m);
247 }
248 q = memcpy(p - n, pw->pw_dir, n);
249 }
250 } else {
251 /* strip down to leaf name */
252 p = strrchr(q, '/');
253 if (p != NULL)
254 q = p + 1;
255 }
256 if (!oflag) {
257 outfile = q ? strdup(q) : q;
258 }
259
260 /* POSIX says "/dev/stdout" is a 'magic cookie' not a special file. */
261 if (pflag || (strcmp(oflag ? outfile : orig_outfile, "/dev/stdout") == 0)) {
262 outfp = stdout;
263 } else {
264 char pwd[MAXPATHLEN] = "";
265 char targetpath[MAXPATHLEN];
266 flags = O_WRONLY | O_CREAT | O_EXCL;
267 if (lstat(outfile, &st) == 0) {
268 if (iflag && !S_ISFIFO(st.st_mode)) {
269 warnc(EEXIST, "%s: %s", infile, outfile);
270 return (0);
271 }
272
273 flags = O_RDWR;
274 switch (st.st_mode & S_IFMT) {
275 case S_IFREG:
276 flags |= O_NOFOLLOW | O_TRUNC;
277 break;
278 case S_IFLNK:
279 if (NULL == realpath(".", pwd)) {
280 warn("Unable to get realpath for .");
281 return (1);
282 }
283 flags |= O_CREAT; // for dangling symlinks
284 break;
285 case S_IFDIR:
286 warnc(EISDIR, "%s: %s", infile, outfile);
287 return (1);
288 case S_IFIFO:
289 flags &= ~O_EXCL;
290 break;
291 default:
292 if (oflag) {
293 /* trust command-line names */
294 flags &= ~O_EXCL;
295 break;
296 }
297 warnc(EEXIST, "%s: %s", infile, outfile);
298 return (1);
299 }
300 } else if (errno != ENOENT) {
301 warn("%s: %s", infile, outfile);
302 return (1);
303 }
304 fd = open(outfile, flags, mode);
305 if (fd < 0) {
306 warn("%s: %s", infile, outfile);
307 return (1);
308 }
309 if (pwd[0]) {
310 if (-1 != fcntl(fd, F_GETPATH, targetpath)) {
311 if (strstr(targetpath, pwd) != targetpath) {
312 warnx("Target path %s is not based at %s", targetpath, pwd);
313 close(fd);
314 return (1);
315 }
316 ftruncate(fd, 0);
317 } else {
318 close(fd);
319 warn("Unable to get path for target: %s", outfile);
320 return (1);
321 }
322 }
323 if ((outfp = fdopen(fd, "w")) == NULL) {
324 warn("%s: %s", infile, outfile);
325 close(fd);
326 return (1);
327 }
328 if (fchmod(fileno(outfp), mode) && (EPERM != errno)) {
329 warn("%s: %s", infile, outfile);
330 close(fd);
331 return 1;
332 }
333 }
334 if (base64)
335 return (base64_decode());
336 else
337 return (uu_decode());
338 }
339
340 static int
341 uugetline(char *buf, size_t size)
342 {
343
344 if (fgets(buf, size, infp) != NULL)
345 return (2);
346 if (rflag)
347 return (0);
348 warnx("%s: %s: short file", infile, outfile);
349 return (1);
350 }
351
352 static int
353 checkend(const char *ptr, const char *end, const char *msg)
354 {
355 size_t n;
356
357 n = strlen(end);
358 if (strncmp(ptr, end, n) != 0 ||
359 strspn(ptr + n, " \t\r\n") != strlen(ptr + n)) {
360 warnx("%s: %s: %s", infile, outfile, msg);
361 return (1);
362 }
363 if (fclose(outfp) != 0) {
364 warn("%s: %s", infile, outfile);
365 return (1);
366 }
367 return (0);
368 }
369
370 static int
371 uu_decode(void)
372 {
373 int i, ch;
374 char *p;
375 char buf[MAXPATHLEN+1];
376
377 /* for each input line */
378 for (;;) {
379 switch (uugetline(buf, sizeof(buf))) {
380 case 0:
381 return (0);
382 case 1:
383 return (1);
384 }
385
386 #define DEC(c) (((c) - ' ') & 077) /* single character decode */
387 #define IS_DEC(c) ( (((c) - ' ') >= 0) && (((c) - ' ') <= 077 + 1) )
388
389 #define OUT_OF_RANGE do { \
390 warnx("%s: %s: character out of range: [%d-%d]", \
391 infile, outfile, 1 + ' ', 077 + ' ' + 1); \
392 return (1); \
393 } while (0)
394
395 /*
396 * `i' is used to avoid writing out all the characters
397 * at the end of the file.
398 */
399 p = buf;
400 if ((i = DEC(*p)) <= 0)
401 break;
402 for (++p; i > 0; p += 4, i -= 3)
403 if (i >= 3) {
404 if (!(IS_DEC(*p) && IS_DEC(*(p + 1)) &&
405 IS_DEC(*(p + 2)) && IS_DEC(*(p + 3))))
406 OUT_OF_RANGE;
407
408 ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
409 putc(ch, outfp);
410 ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
411 putc(ch, outfp);
412 ch = DEC(p[2]) << 6 | DEC(p[3]);
413 putc(ch, outfp);
414 } else {
415 if (i >= 1) {
416 if (!(IS_DEC(*p) && IS_DEC(*(p + 1))))
417 OUT_OF_RANGE;
418 ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
419 putc(ch, outfp);
420 }
421 if (i >= 2) {
422 if (!(IS_DEC(*(p + 1)) &&
423 IS_DEC(*(p + 2))))
424 OUT_OF_RANGE;
425
426 ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
427 putc(ch, outfp);
428 }
429 if (i >= 3) {
430 if (!(IS_DEC(*(p + 2)) &&
431 IS_DEC(*(p + 3))))
432 OUT_OF_RANGE;
433 ch = DEC(p[2]) << 6 | DEC(p[3]);
434 putc(ch, outfp);
435 }
436 }
437 }
438 switch (uugetline(buf, sizeof(buf))) {
439 case 0:
440 return (0);
441 case 1:
442 return (1);
443 default:
444 return (checkend(buf, "end", "no \"end\" line"));
445 }
446 }
447
448 static int
449 base64_decode(void)
450 {
451 int n, count, count4;
452 char inbuf[MAXPATHLEN + 1], *p;
453 unsigned char outbuf[MAXPATHLEN * 4];
454 char leftover[MAXPATHLEN + 1];
455
456 leftover[0] = '\0';
457 for (;;) {
458 strcpy(inbuf, leftover);
459 switch (uugetline(inbuf + strlen(inbuf),
460 sizeof(inbuf) - strlen(inbuf))) {
461 case 0:
462 return (0);
463 case 1:
464 return (1);
465 }
466
467 count = 0;
468 count4 = -1;
469 p = inbuf;
470 while (*p != '\0') {
471 /*
472 * Base64 encoded strings have the following
473 * characters in them: A-Z, a-z, 0-9 and +, / and =
474 */
475 if (isalnum(*p) || *p == '+' || *p == '/' || *p == '=')
476 count++;
477 if (count % 4 == 0)
478 count4 = p - inbuf;
479 p++;
480 }
481
482 strcpy(leftover, inbuf + count4 + 1);
483 inbuf[count4 + 1] = 0;
484
485 n = b64_pton(inbuf, outbuf, sizeof(outbuf));
486
487 if (n < 0)
488 break;
489 fwrite(outbuf, 1, n, outfp);
490 }
491 return (checkend(inbuf, "====", "error decoding base64 input stream"));
492 }
493
494 static void
495 usage(void)
496 {
497
498 (void)fprintf(stderr,
499 "usage: uudecode [-cimprs] [file ...]\n"
500 " uudecode [-i] -o output_file [file]\n"
501 " b64decode [-cimprs] [file ...]\n"
502 " b64decode [-i] -o output_file [file]\n");
503 exit(1);
504 }