1 /* $OpenBSD: uudecode.c,v 1.14 2004/04/09 22:54:02 millert Exp $ */ 2 /* $FreeBSD: uudecode.c,v 1.49 2003/05/03 19:44:46 obrien Exp $ */ 3 4 /*- 5 * Copyright (c) 1983, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 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 #if 0 41 static const char sccsid[] = "@(#)uudecode.c 8.2 (Berkeley) 4/2/94"; 42 #endif 43 static const char rcsid[] = "$OpenBSD: uudecode.c,v 1.14 2004/04/09 22:54:02 millert Exp $"; 44 #endif /* not lint */ 45 46 /* 47 * Create the specified file, decoding as you go. 48 * Used with uuencode. 49 */ 50 51 #include <sys/param.h> 52 #include <sys/socket.h> 53 #include <sys/stat.h> 54 55 #include <netinet/in.h> 56 57 #include <err.h> 58 #include <errno.h> 59 #include <fcntl.h> 60 #include <locale.h> 61 #include <pwd.h> 62 #include <resolv.h> 63 #include <stdio.h> 64 #include <stdlib.h> 65 #include <string.h> 66 #include <unistd.h> 67 68 static const char *infile, *outfile; 69 static FILE *infp, *outfp; 70 static int base64, cflag, iflag, oflag, pflag, rflag, sflag; 71 72 static void usage(void); 73 static int decode(void); 74 static int decode2(void); 75 static int uu_decode(void); 76 static int base64_decode(void); 77 78 int 79 main(int argc, char *argv[]) 80 { 81 int rval, ch; 82 extern char *__progname; 83 84 if (strcmp(__progname, "b64decode") == 0) 85 base64 = 1; 86 87 setlocale(LC_ALL, ""); 88 while ((ch = getopt(argc, argv, "cimo:prs")) != -1) { 89 switch(ch) { 90 case 'c': 91 if (oflag || rflag) 92 usage(); 93 cflag = 1; /* multiple uudecode'd files */ 94 break; 95 case 'i': 96 iflag = 1; /* ask before override files */ 97 break; 98 case 'm': 99 base64 = 1; 100 break; 101 case 'o': 102 if (cflag || pflag || rflag || sflag) 103 usage(); 104 oflag = 1; /* output to the specified file */ 105 sflag = 1; /* do not strip pathnames for output */ 106 outfile = optarg; /* set the output filename */ 107 break; 108 case 'p': 109 if (oflag) 110 usage(); 111 pflag = 1; /* print output to stdout */ 112 break; 113 case 'r': 114 if (cflag || oflag) 115 usage(); 116 rflag = 1; /* decode raw data */ 117 break; 118 case 's': 119 if (oflag) 120 usage(); 121 sflag = 1; /* do not strip pathnames for output */ 122 break; 123 default: 124 usage(); 125 } 126 } 127 argc -= optind; 128 argv += optind; 129 130 if (*argv) { 131 rval = 0; 132 do { 133 infp = fopen(infile = *argv, "r"); 134 if (infp == NULL) { 135 warn("%s", *argv); 136 rval = 1; 137 continue; 138 } 139 rval |= decode(); 140 fclose(infp); 141 } while (*++argv); 142 } else { 143 infile = "stdin"; 144 infp = stdin; 145 rval = decode(); 146 } 147 exit(rval); 148 } 149 150 static int 151 decode(void) 152 { 153 int r, v; 154 155 if (rflag) { 156 /* relaxed alternative to decode2() */ 157 outfile = "/dev/stdout"; 158 outfp = stdout; 159 if (base64) 160 return (base64_decode()); 161 else 162 return (uu_decode()); 163 } 164 v = decode2(); 165 if (v == EOF) { 166 warnx("%s: missing or bad \"begin\" line", infile); 167 return (1); 168 } 169 for (r = v; cflag; r |= v) { 170 v = decode2(); 171 if (v == EOF) 172 break; 173 } 174 return (r); 175 } 176 177 static int 178 decode2(void) 179 { 180 int flags, fd, mode; 181 size_t n, m; 182 char *p, *q; 183 void *handle; 184 struct passwd *pw; 185 struct stat st; 186 char buf[MAXPATHLEN]; 187 188 base64 = 0; 189 /* search for header line */ 190 for (;;) { 191 if (fgets(buf, sizeof(buf), infp) == NULL) 192 return (EOF); 193 p = buf; 194 if (strncmp(p, "begin-base64 ", 13) == 0) { 195 base64 = 1; 196 p += 13; 197 } else if (strncmp(p, "begin ", 6) == 0) 198 p += 6; 199 else 200 continue; 201 /* p points to mode */ 202 q = strchr(p, ' '); 203 if (q == NULL) 204 continue; 205 *q++ = '\0'; 206 /* q points to filename */ 207 n = strlen(q); 208 while (n > 0 && (q[n-1] == '\n' || q[n-1] == '\r')) 209 q[--n] = '\0'; 210 /* found valid header? */ 211 if (n > 0) 212 break; 213 } 214 215 handle = setmode(p); 216 if (handle == NULL) { 217 warnx("%s: unable to parse file mode", infile); 218 return (1); 219 } 220 mode = getmode(handle, 0) & 0666; 221 free(handle); 222 223 if (sflag) { 224 /* don't strip, so try ~user/file expansion */ 225 p = NULL; 226 pw = NULL; 227 if (*q == '~') 228 p = strchr(q, '/'); 229 if (p != NULL) { 230 *p = '\0'; 231 pw = getpwnam(q + 1); 232 *p = '/'; 233 } 234 if (pw != NULL) { 235 n = strlen(pw->pw_dir); 236 if (buf + n > p) { 237 /* make room */ 238 m = strlen(p); 239 if (sizeof(buf) < n + m) { 240 warnx("%s: bad output filename", 241 infile); 242 return (1); 243 } 244 p = memmove(buf + n, p, m); 245 } 246 q = memcpy(p - n, pw->pw_dir, n); 247 } 248 } else { 249 /* strip down to leaf name */ 250 p = strrchr(q, '/'); 251 if (p != NULL) 252 q = p + 1; 253 } 254 if (!oflag) 255 outfile = q; 256 257 /* POSIX says "/dev/stdout" is a 'magic cookie' not a special file. */ 258 if (pflag || strcmp(outfile, "/dev/stdout") == 0) 259 outfp = stdout; 260 else { 261 flags = O_WRONLY|O_CREAT|O_EXCL|O_NOFOLLOW; 262 if (lstat(outfile, &st) == 0) { 263 if (iflag) { 264 errno = EEXIST; 265 warn("%s: %s", infile, outfile); 266 return (0); 267 } 268 switch (st.st_mode & S_IFMT) { 269 case S_IFREG: 270 case S_IFLNK: 271 /* avoid symlink attacks */ 272 if (unlink(outfile) == 0 || errno == ENOENT) 273 break; 274 warn("%s: unlink %s", infile, outfile); 275 return (1); 276 case S_IFDIR: 277 errno = EISDIR; 278 warn("%s: %s", infile, outfile); 279 return (1); 280 default: 281 if (oflag) { 282 /* trust command-line names */ 283 flags &= ~(O_EXCL|O_NOFOLLOW); 284 break; 285 } 286 errno = EEXIST; 287 warn("%s: %s", infile, outfile); 288 return (1); 289 } 290 } else if (errno != ENOENT) { 291 warn("%s: %s", infile, outfile); 292 return (1); 293 } 294 if ((fd = open(outfile, flags, mode)) < 0 || 295 (outfp = fdopen(fd, "w")) == NULL) { 296 warn("%s: %s", infile, outfile); 297 return (1); 298 } 299 } 300 301 if (base64) 302 return (base64_decode()); 303 else 304 return (uu_decode()); 305 } 306 307 static int 308 getline(char *buf, size_t size) 309 { 310 if (fgets(buf, size, infp) != NULL) 311 return (2); 312 if (rflag) 313 return (0); 314 warnx("%s: %s: short file", infile, outfile); 315 return (1); 316 } 317 318 static int 319 checkend(const char *ptr, const char *end, const char *msg) 320 { 321 size_t n; 322 323 n = strlen(end); 324 if (strncmp(ptr, end, n) != 0 || 325 strspn(ptr + n, " \t\r\n") != strlen(ptr + n)) { 326 warnx("%s: %s: %s", infile, outfile, msg); 327 return (1); 328 } 329 if (fclose(outfp) != 0) { 330 warn("%s: %s", infile, outfile); 331 return (1); 332 } 333 return (0); 334 } 335 336 static int 337 uu_decode(void) 338 { 339 int i, ch; 340 char *p; 341 char buf[MAXPATHLEN]; 342 343 /* for each input line */ 344 for (;;) { 345 switch (getline(buf, sizeof(buf))) { 346 case 0: 347 return (0); 348 case 1: 349 return (1); 350 } 351 352 #define DEC(c) (((c) - ' ') & 077) /* single character decode */ 353 #define IS_DEC(c) ( (((c) - ' ') >= 0) && (((c) - ' ') <= 077 + 1) ) 354 355 #define OUT_OF_RANGE do { \ 356 warnx("%s: %s: character out of range: [%d-%d]", \ 357 infile, outfile, 1 + ' ', 077 + ' ' + 1); \ 358 return (1); \ 359 } while (0) 360 361 /* 362 * `i' is used to avoid writing out all the characters 363 * at the end of the file. 364 */ 365 p = buf; 366 if ((i = DEC(*p)) <= 0) 367 break; 368 for (++p; i > 0; p += 4, i -= 3) 369 if (i >= 3) { 370 if (!(IS_DEC(*p) && IS_DEC(*(p + 1)) && 371 IS_DEC(*(p + 2)) && IS_DEC(*(p + 3)))) 372 OUT_OF_RANGE; 373 374 ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4; 375 putc(ch, outfp); 376 ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2; 377 putc(ch, outfp); 378 ch = DEC(p[2]) << 6 | DEC(p[3]); 379 putc(ch, outfp); 380 } 381 else { 382 if (i >= 1) { 383 if (!(IS_DEC(*p) && IS_DEC(*(p + 1)))) 384 OUT_OF_RANGE; 385 ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4; 386 putc(ch, outfp); 387 } 388 if (i >= 2) { 389 if (!(IS_DEC(*(p + 1)) && 390 IS_DEC(*(p + 2)))) 391 OUT_OF_RANGE; 392 393 ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2; 394 putc(ch, outfp); 395 } 396 if (i >= 3) { 397 if (!(IS_DEC(*(p + 2)) && 398 IS_DEC(*(p + 3)))) 399 OUT_OF_RANGE; 400 ch = DEC(p[2]) << 6 | DEC(p[3]); 401 putc(ch, outfp); 402 } 403 } 404 } 405 switch (getline(buf, sizeof(buf))) { 406 case 0: 407 return (0); 408 case 1: 409 return (1); 410 default: 411 return (checkend(buf, "end", "no \"end\" line")); 412 } 413 } 414 415 static int 416 base64_decode(void) 417 { 418 int n; 419 char inbuf[MAXPATHLEN]; 420 unsigned char outbuf[MAXPATHLEN * 4]; 421 422 for (;;) { 423 switch (getline(inbuf, sizeof(inbuf))) { 424 case 0: 425 return (0); 426 case 1: 427 return (1); 428 } 429 n = b64_pton(inbuf, outbuf, sizeof(outbuf)); 430 if (n < 0) 431 break; 432 fwrite(outbuf, 1, n, outfp); 433 } 434 return (checkend(inbuf, "====", 435 "error decoding base64 input stream")); 436 } 437 438 static void 439 usage(void) 440 { 441 (void)fprintf(stderr, 442 "usage: uudecode [-cimprs] [file ...]\n" 443 " uudecode [-i] -o output_file [file]\n" 444 " b64decode [-cimprs] [file ...]\n" 445 " b64decode [-i] -o output_file [file]\n"); 446 exit(1); 447 } 448