uudecode.c revision 112377
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 112377 2003-03-18 14:19:26Z 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 { 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 307getline(char *buf, size_t size) 308{ 309 if (fgets(buf, size, infp) != NULL) 310 return (2); 311 if (rflag) 312 return (0); 313 warnx("%s: %s: short file", infile, outfile); 314 return (1); 315} 316 317static int 318checkend(const char *ptr, const char *end, const char *msg) 319{ 320 size_t n; 321 322 n = strlen(end); 323 if (strncmp(ptr, end, n) != 0 || 324 strspn(ptr + n, " \t\r\n") != strlen(ptr + n)) { 325 warnx("%s: %s: %s", infile, outfile, msg); 326 return (1); 327 } 328 if (fclose(outfp) != 0) { 329 warn("%s: %s", infile, outfile); 330 return (1); 331 } 332 return (0); 333} 334 335static int 336uu_decode(void) 337{ 338 int i, ch; 339 char *p; 340 char buf[MAXPATHLEN+1]; 341 342 /* for each input line */ 343 for (;;) { 344 switch (getline(buf, sizeof(buf))) { 345 case 0: return (0); 346 case 1: return (1); 347 } 348 349#define DEC(c) (((c) - ' ') & 077) /* single character decode */ 350#define IS_DEC(c) ( (((c) - ' ') >= 0) && (((c) - ' ') <= 077 + 1) ) 351 352#define OUT_OF_RANGE do { \ 353 warnx("%s: %s: character out of range: [%d-%d]", \ 354 infile, outfile, 1 + ' ', 077 + ' ' + 1); \ 355 return (1); \ 356} while (0) 357 358 /* 359 * `i' is used to avoid writing out all the characters 360 * at the end of the file. 361 */ 362 p = buf; 363 if ((i = DEC(*p)) <= 0) 364 break; 365 for (++p; i > 0; p += 4, i -= 3) 366 if (i >= 3) { 367 if (!(IS_DEC(*p) && IS_DEC(*(p + 1)) && 368 IS_DEC(*(p + 2)) && IS_DEC(*(p + 3)))) 369 OUT_OF_RANGE; 370 371 ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4; 372 putc(ch, outfp); 373 ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2; 374 putc(ch, outfp); 375 ch = DEC(p[2]) << 6 | DEC(p[3]); 376 putc(ch, outfp); 377 } 378 else { 379 if (i >= 1) { 380 if (!(IS_DEC(*p) && IS_DEC(*(p + 1)))) 381 OUT_OF_RANGE; 382 ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4; 383 putc(ch, outfp); 384 } 385 if (i >= 2) { 386 if (!(IS_DEC(*(p + 1)) && 387 IS_DEC(*(p + 2)))) 388 OUT_OF_RANGE; 389 390 ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2; 391 putc(ch, outfp); 392 } 393 if (i >= 3) { 394 if (!(IS_DEC(*(p + 2)) && 395 IS_DEC(*(p + 3)))) 396 OUT_OF_RANGE; 397 ch = DEC(p[2]) << 6 | DEC(p[3]); 398 putc(ch, outfp); 399 } 400 } 401 } 402 switch (getline(buf, sizeof(buf))) { 403 case 0: return (0); 404 case 1: return (1); 405 default: return (checkend(buf, "end", "no \"end\" line")); 406 } 407} 408 409static int 410base64_decode(void) 411{ 412 int n; 413 char inbuf[MAXPATHLEN+1]; 414 unsigned char outbuf[MAXPATHLEN * 4]; 415 416 for (;;) { 417 switch (getline(inbuf, sizeof(inbuf))) { 418 case 0: return (0); 419 case 1: return (1); 420 } 421 n = b64_pton(inbuf, outbuf, sizeof(outbuf)); 422 if (n < 0) 423 break; 424 fwrite(outbuf, 1, n, outfp); 425 } 426 return (checkend(inbuf, "====", 427 "error decoding base64 input stream")); 428} 429 430static void 431usage(void) 432{ 433 (void)fprintf(stderr, 434"usage: uudecode [-cimprs] [file ...]\n" 435" uudecode [-i] -o output_file [file]\n" 436" b64decode [-cimprs] [file ...]\n" 437" b64decode [-i] -o output_file [file]\n"); 438 exit(1); 439} 440