1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
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 0
33 #ifndef lint
34 static const char copyright[] =
35 "@(#) Copyright (c) 1983, 1993\n\
36 The Regents of the University of California. All rights reserved.\n";
37 #endif /* not lint */
38
39 #ifndef lint
40 static char sccsid[] = "@(#)uudecode.c 8.2 (Berkeley) 4/2/94";
41 #endif /* not lint */
42 #endif
43 #include <sys/cdefs.h>
44 /*
45 * uudecode [file ...]
46 *
47 * create the specified file, decoding as you go.
48 * used with uuencode.
49 */
50 #include <sys/param.h>
51 #include <sys/socket.h>
52 #include <sys/stat.h>
53
54 #include <netinet/in.h>
55
56 #include <ctype.h>
57 #include <err.h>
58 #include <errno.h>
59 #include <fcntl.h>
60 #include <libgen.h>
61 #include <pwd.h>
62 #include <resolv.h>
63 #include <stdbool.h>
64 #include <stdio.h>
65 #include <stdlib.h>
66 #include <string.h>
67 #include <unistd.h>
68
69 extern int main_decode(int, char *[]);
70 extern int main_base64_decode(const char *);
71
72 static const char *infile, *outfile;
73 static FILE *infp, *outfp;
74 static bool 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
main_base64_decode(const char * in)83 main_base64_decode(const char *in)
84 {
85 base64 = 1;
86 rflag = 1;
87 if (in != NULL) {
88 infile = in;
89 infp = fopen(infile, "r");
90 if (infp == NULL)
91 err(1, "%s", in);
92 } else {
93 infile = "stdin";
94 infp = stdin;
95 }
96 exit(decode());
97 }
98
99 int
main_decode(int argc,char * argv[])100 main_decode(int argc, char *argv[])
101 {
102 int rval, ch;
103
104 if (strcmp(basename(argv[0]), "b64decode") == 0)
105 base64 = true;
106
107 while ((ch = getopt(argc, argv, "cimo:prs")) != -1) {
108 switch (ch) {
109 case 'c':
110 if (oflag || rflag)
111 usage();
112 cflag = true; /* multiple uudecode'd files */
113 break;
114 case 'i':
115 iflag = true; /* ask before override files */
116 break;
117 case 'm':
118 base64 = true;
119 break;
120 case 'o':
121 if (cflag || pflag || rflag || sflag)
122 usage();
123 oflag = true; /* output to the specified file */
124 sflag = true; /* do not strip pathnames for output */
125 outfile = optarg; /* set the output filename */
126 break;
127 case 'p':
128 if (oflag)
129 usage();
130 pflag = true; /* print output to stdout */
131 break;
132 case 'r':
133 if (cflag || oflag)
134 usage();
135 rflag = true; /* decode raw data */
136 break;
137 case 's':
138 if (oflag)
139 usage();
140 sflag = true; /* do not strip pathnames for output */
141 break;
142 default:
143 usage();
144 }
145 }
146 argc -= optind;
147 argv += optind;
148
149 if (*argv != NULL) {
150 rval = 0;
151 do {
152 infp = fopen(infile = *argv, "r");
153 if (infp == NULL) {
154 warn("%s", *argv);
155 rval = 1;
156 continue;
157 }
158 rval |= decode();
159 fclose(infp);
160 } while (*++argv);
161 } else {
162 infile = "stdin";
163 infp = stdin;
164 rval = decode();
165 }
166 exit(rval);
167 }
168
169 static int
decode(void)170 decode(void)
171 {
172 int r, v;
173
174 if (rflag) {
175 /* relaxed alternative to decode2() */
176 outfile = "/dev/stdout";
177 outfp = stdout;
178 if (base64)
179 return (base64_decode());
180 else
181 return (uu_decode());
182 }
183 v = decode2();
184 if (v == EOF) {
185 warnx("%s: missing or bad \"begin\" line", infile);
186 return (1);
187 }
188 for (r = v; cflag; r |= v) {
189 v = decode2();
190 if (v == EOF)
191 break;
192 }
193 return (r);
194 }
195
196 static int
decode2(void)197 decode2(void)
198 {
199 int flags, fd, mode;
200 size_t n, m;
201 char *p, *q;
202 void *handle;
203 struct passwd *pw;
204 struct stat st;
205 char buf[MAXPATHLEN + 1];
206
207 base64 = false;
208 /* search for header line */
209 for (;;) {
210 if (fgets(buf, sizeof(buf), infp) == NULL)
211 return (EOF);
212 p = buf;
213 if (strncmp(p, "begin-base64 ", 13) == 0) {
214 base64 = true;
215 p += 13;
216 } else if (strncmp(p, "begin ", 6) == 0)
217 p += 6;
218 else
219 continue;
220 /* p points to mode */
221 q = strchr(p, ' ');
222 if (q == NULL)
223 continue;
224 *q++ = '\0';
225 /* q points to filename */
226 n = strlen(q);
227 while (n > 0 && (q[n-1] == '\n' || q[n-1] == '\r'))
228 q[--n] = '\0';
229 /* found valid header? */
230 if (n > 0)
231 break;
232 }
233
234 handle = setmode(p);
235 if (handle == NULL) {
236 warnx("%s: unable to parse file mode", infile);
237 return (1);
238 }
239 mode = getmode(handle, 0) & 0666;
240 free(handle);
241
242 if (sflag) {
243 /* don't strip, so try ~user/file expansion */
244 p = NULL;
245 pw = NULL;
246 if (*q == '~')
247 p = strchr(q, '/');
248 if (p != NULL) {
249 *p = '\0';
250 pw = getpwnam(q + 1);
251 *p = '/';
252 }
253 if (pw != NULL) {
254 n = strlen(pw->pw_dir);
255 if (buf + n > p) {
256 /* make room */
257 m = strlen(p);
258 if (sizeof(buf) < n + m) {
259 warnx("%s: bad output filename",
260 infile);
261 return (1);
262 }
263 p = memmove(buf + n, p, m);
264 }
265 q = memcpy(p - n, pw->pw_dir, n);
266 }
267 } else {
268 /* strip down to leaf name */
269 p = strrchr(q, '/');
270 if (p != NULL)
271 q = p + 1;
272 }
273 if (!oflag)
274 outfile = q;
275
276 /* POSIX says "/dev/stdout" is a 'magic cookie' not a special file. */
277 if (pflag || strcmp(outfile, "/dev/stdout") == 0)
278 outfp = stdout;
279 else {
280 flags = O_WRONLY | O_CREAT | O_EXCL;
281 if (lstat(outfile, &st) == 0) {
282 if (iflag) {
283 warnc(EEXIST, "%s: %s", infile, outfile);
284 return (0);
285 }
286 switch (st.st_mode & S_IFMT) {
287 case S_IFREG:
288 case S_IFLNK:
289 /* avoid symlink attacks */
290 if (unlink(outfile) == 0 || errno == ENOENT)
291 break;
292 warn("%s: unlink %s", infile, outfile);
293 return (1);
294 case S_IFDIR:
295 warnc(EISDIR, "%s: %s", infile, outfile);
296 return (1);
297 default:
298 if (oflag) {
299 /* trust command-line names */
300 flags &= ~O_EXCL;
301 break;
302 }
303 warnc(EEXIST, "%s: %s", infile, outfile);
304 return (1);
305 }
306 } else if (errno != ENOENT) {
307 warn("%s: %s", infile, outfile);
308 return (1);
309 }
310 if ((fd = open(outfile, flags, mode)) < 0 ||
311 (outfp = fdopen(fd, "w")) == NULL) {
312 warn("%s: %s", infile, outfile);
313 return (1);
314 }
315 }
316
317 if (base64)
318 return (base64_decode());
319 else
320 return (uu_decode());
321 }
322
323 static int
get_line(char * buf,size_t size)324 get_line(char *buf, size_t size)
325 {
326
327 if (fgets(buf, size, infp) != NULL)
328 return (2);
329 if (rflag)
330 return (0);
331 warnx("%s: %s: short file", infile, outfile);
332 return (1);
333 }
334
335 static int
checkend(const char * ptr,const char * end,const char * msg)336 checkend(const char *ptr, const char *end, const char *msg)
337 {
338 size_t n;
339
340 n = strlen(end);
341 if (strncmp(ptr, end, n) != 0 ||
342 strspn(ptr + n, " \t\r\n") != strlen(ptr + n)) {
343 warnx("%s: %s: %s", infile, outfile, msg);
344 return (1);
345 }
346 return (0);
347 }
348
349 static int
checkout(int rval)350 checkout(int rval)
351 {
352 if (fflush(outfp) != 0) {
353 warn("%s: %s", infile, outfile);
354 rval = 1;
355 }
356 if (outfp != stdout) {
357 (void)fclose(outfp);
358 outfp = stdout;
359 }
360 outfile = "/dev/stdout";
361 return (rval);
362 }
363
364 static int
uu_decode(void)365 uu_decode(void)
366 {
367 int i, ch;
368 char *p;
369 char buf[MAXPATHLEN+1];
370
371 /* for each input line */
372 for (;;) {
373 switch (get_line(buf, sizeof(buf))) {
374 case 0:
375 return (checkout(0));
376 case 1:
377 return (checkout(1));
378 }
379
380 #define DEC(c) (((c) - ' ') & 077) /* single character decode */
381 #define IS_DEC(c) ( (((c) - ' ') >= 0) && (((c) - ' ') <= 077 + 1) )
382
383 #define OUT_OF_RANGE do { \
384 warnx("%s: %s: character out of range: [%d-%d]", \
385 infile, outfile, ' ', 077 + ' ' + 1); \
386 return (1); \
387 } while (0)
388
389 /*
390 * `i' is used to avoid writing out all the characters
391 * at the end of the file.
392 */
393 p = buf;
394 if ((i = DEC(*p)) <= 0)
395 break;
396 for (++p; i > 0; p += 4, i -= 3)
397 if (i >= 3) {
398 if (!(IS_DEC(*p) && IS_DEC(*(p + 1)) &&
399 IS_DEC(*(p + 2)) && IS_DEC(*(p + 3))))
400 OUT_OF_RANGE;
401
402 ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
403 putc(ch, outfp);
404 ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
405 putc(ch, outfp);
406 ch = DEC(p[2]) << 6 | DEC(p[3]);
407 putc(ch, outfp);
408 } else {
409 if (i >= 1) {
410 if (!(IS_DEC(*p) && IS_DEC(*(p + 1))))
411 OUT_OF_RANGE;
412 ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
413 putc(ch, outfp);
414 }
415 if (i >= 2) {
416 if (!(IS_DEC(*(p + 1)) &&
417 IS_DEC(*(p + 2))))
418 OUT_OF_RANGE;
419
420 ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
421 putc(ch, outfp);
422 }
423 if (i >= 3) {
424 if (!(IS_DEC(*(p + 2)) &&
425 IS_DEC(*(p + 3))))
426 OUT_OF_RANGE;
427 ch = DEC(p[2]) << 6 | DEC(p[3]);
428 putc(ch, outfp);
429 }
430 }
431 }
432 switch (get_line(buf, sizeof(buf))) {
433 case 0:
434 return (checkout(0));
435 case 1:
436 return (checkout(1));
437 default:
438 return (checkout(checkend(buf, "end", "no \"end\" line")));
439 }
440 }
441
442 static int
base64_decode(void)443 base64_decode(void)
444 {
445 int n, count, count4;
446 char inbuf[MAXPATHLEN + 1], *p;
447 unsigned char outbuf[MAXPATHLEN * 4];
448 char leftover[MAXPATHLEN + 1];
449
450 leftover[0] = '\0';
451 for (;;) {
452 strcpy(inbuf, leftover);
453 switch (get_line(inbuf + strlen(inbuf),
454 sizeof(inbuf) - strlen(inbuf))) {
455 case 0:
456 return (checkout(0));
457 case 1:
458 return (checkout(1));
459 }
460
461 count = 0;
462 count4 = -1;
463 p = inbuf;
464 while (*p != '\0') {
465 /*
466 * Base64 encoded strings have the following
467 * characters in them: A-Z, a-z, 0-9 and +, / and =
468 */
469 if (isalnum(*p) || *p == '+' || *p == '/' || *p == '=')
470 count++;
471 if (count % 4 == 0)
472 count4 = p - inbuf;
473 p++;
474 }
475
476 strcpy(leftover, inbuf + count4 + 1);
477 inbuf[count4 + 1] = 0;
478
479 n = b64_pton(inbuf, outbuf, sizeof(outbuf));
480
481 if (n < 0)
482 break;
483 fwrite(outbuf, 1, n, outfp);
484 }
485 return (checkout(checkend(inbuf, "====", "error decoding base64 input stream")));
486 }
487
488 static void
usage(void)489 usage(void)
490 {
491
492 (void)fprintf(stderr,
493 "usage: uudecode [-cimprs] [file ...]\n"
494 " uudecode [-i] -o output_file [file]\n"
495 " b64decode [-cimprs] [file ...]\n"
496 " b64decode [-i] -o output_file [file]\n");
497 exit(1);
498 }
499