uudecode.c revision 111588
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 111588 2003-02-27 03:28:29Z 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 <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 72static const char *infile, *outfile; 73static FILE *infp, *outfp; 74static int base64, cflag, iflag, oflag, pflag, rflag, sflag; 75 76static void usage(void); 77static int decode(void); 78static int decode2(void); 79static int uu_decode(void); 80static int base64_decode(void); 81 82int 83main(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) { 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 152static int 153decode(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 179static int 180decode2(void) 181{ 182 int flags, fd, mode; 183 size_t n, m; 184 char *p, *q; 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 } 216 217 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) & 0666; 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 if (strcmp(q, "/dev/stdout") != 0) { 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; 258 259 /* POSIX says "/dev/stdout" is a 'magic cookie' not a special file. */ 260 if (pflag || strcmp(outfile, "/dev/stdout") == 0) 261 outfp = stdout; 262 else { 263 flags = O_WRONLY|O_CREAT|O_EXCL; 264 if (lstat(outfile, &st) == 0) { 265 if (iflag) { 266 warnc(EEXIST, "%s: %s", infile, outfile); 267 return (0); 268 } 269 switch (st.st_mode & S_IFMT) { 270 case S_IFREG: 271 case S_IFLNK: 272 /* avoid symlink attacks */ 273 if (unlink(outfile) == 0 || errno == ENOENT) 274 break; 275 warn("%s: unlink %s", infile, outfile); 276 return (1); 277 case S_IFDIR: 278 warnc(EISDIR, "%s: %s", infile, outfile); 279 return (1); 280 default: 281 if (oflag) { 282 /* trust command-line names */ 283 flags &= ~O_EXCL; 284 break; 285 } 286 warnc(EEXIST, "%s: %s", infile, outfile); 287 return (1); 288 } 289 } else if (errno != ENOENT) { 290 warn("%s: %s", infile, outfile); 291 return (1); 292 } 293 if ((fd = open(outfile, flags, mode)) < 0 || 294 (outfp = fdopen(fd, "w")) == NULL) { 295 warn("%s: %s", infile, outfile); 296 return (1); 297 } 298 } 299 300 if (base64) 301 return (base64_decode()); 302 else 303 return (uu_decode()); 304} 305 306static int 307uu_decode(void) 308{ 309 int i, ch; 310 char *p; 311 char buf[MAXPATHLEN+1]; 312 313 /* for each input line */ 314 for (;;) { 315 if (fgets(p = buf, sizeof(buf), infp) == NULL) { 316 if (rflag) 317 return (0); 318 warnx("%s: %s: short file", infile, outfile); 319 return (1); 320 } 321 322#define DEC(c) (((c) - ' ') & 077) /* single character decode */ 323#define IS_DEC(c) ( (((c) - ' ') >= 0) && (((c) - ' ') <= 077 + 1) ) 324 325#define OUT_OF_RANGE do { \ 326 warnx("%s: %s: character out of range: [%d-%d]", \ 327 infile, outfile, 1 + ' ', 077 + ' ' + 1); \ 328 return (1); \ 329} while (0) 330 331 /* 332 * `i' is used to avoid writing out all the characters 333 * at the end of the file. 334 */ 335 if ((i = DEC(*p)) <= 0) 336 break; 337 for (++p; i > 0; p += 4, i -= 3) 338 if (i >= 3) { 339 if (!(IS_DEC(*p) && IS_DEC(*(p + 1)) && 340 IS_DEC(*(p + 2)) && IS_DEC(*(p + 3)))) 341 OUT_OF_RANGE; 342 343 ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4; 344 putc(ch, outfp); 345 ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2; 346 putc(ch, outfp); 347 ch = DEC(p[2]) << 6 | DEC(p[3]); 348 putc(ch, outfp); 349 } 350 else { 351 if (i >= 1) { 352 if (!(IS_DEC(*p) && IS_DEC(*(p + 1)))) 353 OUT_OF_RANGE; 354 ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4; 355 putc(ch, outfp); 356 } 357 if (i >= 2) { 358 if (!(IS_DEC(*(p + 1)) && 359 IS_DEC(*(p + 2)))) 360 OUT_OF_RANGE; 361 362 ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2; 363 putc(ch, outfp); 364 } 365 if (i >= 3) { 366 if (!(IS_DEC(*(p + 2)) && 367 IS_DEC(*(p + 3)))) 368 OUT_OF_RANGE; 369 ch = DEC(p[2]) << 6 | DEC(p[3]); 370 putc(ch, outfp); 371 } 372 } 373 } 374 if (fgets(buf, sizeof(buf), infp) == NULL || 375 (strcmp(buf, "end") && strcmp(buf, "end\n") && 376 strcmp(buf, "end\r\n"))) { 377 warnx("%s: no \"end\" line", infile); 378 return (1); 379 } 380 if (fclose(outfp) != 0) { 381 warn("%s: %s", infile, outfile); 382 return (1); 383 } 384 return (0); 385} 386 387static int 388base64_decode(void) 389{ 390 int n; 391 char inbuf[MAXPATHLEN+1]; 392 unsigned char outbuf[MAXPATHLEN * 4]; 393 394 for (;;) { 395 if (fgets(inbuf, sizeof(inbuf), infp) == NULL) { 396 if (rflag) 397 return (0); 398 warnx("%s: %s: short file", infile, outfile); 399 return (1); 400 } 401 if (strcmp(inbuf, "====") == 0 || 402 strcmp(inbuf, "====\n") == 0 || 403 strcmp(inbuf, "====\r\n") == 0) { 404 if (fclose(outfp) != 0) { 405 warn("%s: %s", infile, outfile); 406 return (1); 407 } 408 return (0); 409 } 410 n = strlen(inbuf); 411 while (n > 0 && (inbuf[n-1] == '\n' || inbuf[n-1] == '\r')) 412 inbuf[--n] = '\0'; 413 n = b64_pton(inbuf, outbuf, sizeof(outbuf)); 414 if (n < 0) { 415 warnx("%s: %s: error decoding base64 input stream", infile, outfile); 416 return (1); 417 } 418 fwrite(outbuf, 1, n, outfp); 419 } 420} 421 422static void 423usage(void) 424{ 425 (void)fprintf(stderr, 426"usage: uudecode [-cimprs] [file ...]\n" 427" uudecode [-i] -o output_file [file]\n" 428" b64decode [-cimprs] [file ...]\n" 429" b64decode [-i] -o output_file [file]\n"); 430 exit(1); 431} 432