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. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#) Copyright (c) 1983, 1993 The Regents of the University of California. All rights reserved. 30 * @(#)uudecode.c 8.2 (Berkeley) 4/2/94 31 * $FreeBSD: src/usr.bin/uudecode/uudecode.c,v 1.13.2.6 2003/04/07 20:10:33 fanf Exp $ 32 */ 33 34 /* 35 * uudecode [file ...] 36 * 37 * create the specified file, decoding as you go. 38 * used with uuencode. 39 */ 40 #include <sys/param.h> 41 #include <sys/socket.h> 42 #include <sys/stat.h> 43 44 #include <netinet/in.h> 45 46 #include <err.h> 47 #include <errno.h> 48 #include <fcntl.h> 49 #include <libgen.h> 50 #include <pwd.h> 51 #include <resolv.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <string.h> 55 #include <unistd.h> 56 57 static const char *infile, *outfile; 58 static FILE *infp, *outfp; 59 static int base64, cflag, iflag, oflag, pflag, rflag, sflag; 60 61 static void usage(void); 62 static int decode(void); 63 static int decode2(void); 64 static int uu_decode(void); 65 static int base64_decode(void); 66 67 int 68 main(int argc, char *argv[]) 69 { 70 int rval, ch; 71 72 if (strcmp(basename(argv[0]), "b64decode") == 0) 73 base64 = 1; 74 75 while ((ch = getopt(argc, argv, "cimo:prs")) != -1) { 76 switch (ch) { 77 case 'c': 78 if (oflag || rflag) 79 usage(); 80 cflag = 1; /* multiple uudecode'd files */ 81 break; 82 case 'i': 83 iflag = 1; /* ask before override files */ 84 break; 85 case 'm': 86 base64 = 1; 87 break; 88 case 'o': 89 if (cflag || pflag || rflag || sflag) 90 usage(); 91 oflag = 1; /* output to the specified file */ 92 sflag = 1; /* do not strip pathnames for output */ 93 outfile = optarg; /* set the output filename */ 94 break; 95 case 'p': 96 if (oflag) 97 usage(); 98 pflag = 1; /* print output to stdout */ 99 break; 100 case 'r': 101 if (cflag || oflag) 102 usage(); 103 rflag = 1; /* decode raw data */ 104 break; 105 case 's': 106 if (oflag) 107 usage(); 108 sflag = 1; /* do not strip pathnames for output */ 109 break; 110 default: 111 usage(); 112 } 113 } 114 argc -= optind; 115 argv += optind; 116 117 if (*argv != NULL) { 118 rval = 0; 119 do { 120 infp = fopen(infile = *argv, "r"); 121 if (infp == NULL) { 122 warn("%s", *argv); 123 rval = 1; 124 continue; 125 } 126 rval |= decode(); 127 fclose(infp); 128 } while (*++argv); 129 } else { 130 infile = "stdin"; 131 infp = stdin; 132 rval = decode(); 133 } 134 exit(rval); 135 } 136 137 static int 138 decode(void) 139 { 140 int r, v; 141 142 if (rflag) { 143 /* relaxed alternative to decode2() */ 144 outfile = "/dev/stdout"; 145 outfp = stdout; 146 if (base64) 147 return (base64_decode()); 148 else 149 return (uu_decode()); 150 } 151 v = decode2(); 152 if (v == EOF) { 153 warnx("%s: missing or bad \"begin\" line", infile); 154 return (1); 155 } 156 for (r = v; cflag; r |= v) { 157 v = decode2(); 158 if (v == EOF) 159 break; 160 } 161 return (r); 162 } 163 164 static int 165 decode2(void) 166 { 167 int flags, fd; 168 size_t n, m; 169 char *p, *q; 170 void *handle; 171 mode_t mode; 172 struct passwd *pw; 173 struct stat st; 174 char buf[MAXPATHLEN + 1]; 175 176 base64 = 0; 177 /* search for header line */ 178 for (;;) { 179 if (fgets(buf, sizeof(buf), infp) == NULL) 180 return (EOF); 181 p = buf; 182 if (strncmp(p, "begin-base64 ", 13) == 0) { 183 base64 = 1; 184 p += 13; 185 } else if (strncmp(p, "begin ", 6) == 0) 186 p += 6; 187 else 188 continue; 189 /* p points to mode */ 190 q = strchr(p, ' '); 191 if (q == NULL) 192 continue; 193 *q++ = '\0'; 194 /* q points to filename */ 195 n = strlen(q); 196 while (n > 0 && (q[n-1] == '\n' || q[n-1] == '\r')) 197 q[--n] = '\0'; 198 /* found valid header? */ 199 if (n > 0) 200 break; 201 } 202 203 errno = 0; 204 if ((handle = setmode(p)) == NULL) { 205 if (!errno) 206 warnx("invalid file mode: %s", infile); 207 else 208 warn("setmode malloc failed: %s", infile); 209 210 return (1); 211 } 212 213 mode = getmode(handle, 0) & 0666; 214 free(handle); 215 216 if (sflag) { 217 /* don't strip, so try ~user/file expansion */ 218 p = NULL; 219 pw = NULL; 220 if (*q == '~') 221 p = strchr(q, '/'); 222 if (p != NULL) { 223 *p = '\0'; 224 pw = getpwnam(q + 1); 225 *p = '/'; 226 } 227 if (pw != NULL) { 228 n = strlen(pw->pw_dir); 229 if (buf + n > p) { 230 /* make room */ 231 m = strlen(p); 232 if (sizeof(buf) < n + m) { 233 warnx("%s: bad output filename", 234 infile); 235 return (1); 236 } 237 p = memmove(buf + n, p, m); 238 } 239 q = memcpy(p - n, pw->pw_dir, n); 240 } 241 } else { 242 /* strip down to leaf name */ 243 p = strrchr(q, '/'); 244 if (p != NULL) 245 q = p + 1; 246 } 247 if (!oflag) 248 outfile = q; 249 250 /* POSIX says "/dev/stdout" is a 'magic cookie' not a special file. */ 251 if (pflag || strcmp(outfile, "/dev/stdout") == 0) 252 outfp = stdout; 253 else { 254 flags = O_WRONLY | O_CREAT | O_EXCL; 255 if (lstat(outfile, &st) == 0) { 256 if (iflag) { 257 warnc(EEXIST, "%s: %s", infile, outfile); 258 return (0); 259 } 260 switch (st.st_mode & S_IFMT) { 261 case S_IFREG: 262 case S_IFLNK: 263 /* avoid symlink attacks */ 264 if (unlink(outfile) == 0 || errno == ENOENT) 265 break; 266 warn("%s: unlink %s", infile, outfile); 267 return (1); 268 case S_IFDIR: 269 warnc(EISDIR, "%s: %s", infile, outfile); 270 return (1); 271 default: 272 if (oflag) { 273 /* trust command-line names */ 274 flags &= ~O_EXCL; 275 break; 276 } 277 warnc(EEXIST, "%s: %s", infile, outfile); 278 return (1); 279 } 280 } else if (errno != ENOENT) { 281 warn("%s: %s", infile, outfile); 282 return (1); 283 } 284 if ((fd = open(outfile, flags, mode)) < 0 || 285 (outfp = fdopen(fd, "w")) == NULL) { 286 warn("%s: %s", infile, outfile); 287 return (1); 288 } 289 } 290 291 if (base64) 292 return (base64_decode()); 293 else 294 return (uu_decode()); 295 } 296 297 static int 298 get_line(char *buf, size_t size) 299 { 300 if (fgets(buf, size, infp) != NULL) 301 return (2); 302 if (rflag) 303 return (0); 304 warnx("%s: %s: short file", infile, outfile); 305 return (1); 306 } 307 308 static int 309 checkend(const char *ptr, const char *end, const char *msg) 310 { 311 size_t n; 312 313 n = strlen(end); 314 if (strncmp(ptr, end, n) != 0 || 315 strspn(ptr + n, " \t\r\n") != strlen(ptr + n)) { 316 warnx("%s: %s: %s", infile, outfile, msg); 317 return (1); 318 } 319 if (fclose(outfp) != 0) { 320 warn("%s: %s", infile, outfile); 321 return (1); 322 } 323 return (0); 324 } 325 326 static int 327 uu_decode(void) 328 { 329 int i, ch; 330 char *p; 331 char buf[MAXPATHLEN+1]; 332 333 /* for each input line */ 334 for (;;) { 335 switch (get_line(buf, sizeof(buf))) { 336 case 0: 337 return (0); 338 case 1: 339 return (1); 340 } 341 342 #define DEC(c) (((c) - ' ') & 077) /* single character decode */ 343 #define IS_DEC(c) ( (((c) - ' ') >= 0) && (((c) - ' ') <= 077 + 1) ) 344 345 #define OUT_OF_RANGE do { \ 346 warnx("%s: %s: character out of range: [%d-%d]", \ 347 infile, outfile, 1 + ' ', 077 + ' ' + 1); \ 348 return (1); \ 349 } while (0) 350 351 /* 352 * `i' is used to avoid writing out all the characters 353 * at the end of the file. 354 */ 355 p = buf; 356 if ((i = DEC(*p)) <= 0) 357 break; 358 for (++p; i > 0; p += 4, i -= 3) 359 if (i >= 3) { 360 if (!(IS_DEC(*p) && IS_DEC(*(p + 1)) && 361 IS_DEC(*(p + 2)) && IS_DEC(*(p + 3)))) 362 OUT_OF_RANGE; 363 364 ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4; 365 putc(ch, outfp); 366 ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2; 367 putc(ch, outfp); 368 ch = DEC(p[2]) << 6 | DEC(p[3]); 369 putc(ch, outfp); 370 } else { 371 if (i >= 1) { 372 if (!(IS_DEC(*p) && IS_DEC(*(p + 1)))) 373 OUT_OF_RANGE; 374 ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4; 375 putc(ch, outfp); 376 } 377 if (i >= 2) { 378 if (!(IS_DEC(*(p + 1)) && 379 IS_DEC(*(p + 2)))) 380 OUT_OF_RANGE; 381 382 ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2; 383 putc(ch, outfp); 384 } 385 if (i >= 3) { 386 if (!(IS_DEC(*(p + 2)) && 387 IS_DEC(*(p + 3)))) 388 OUT_OF_RANGE; 389 ch = DEC(p[2]) << 6 | DEC(p[3]); 390 putc(ch, outfp); 391 } 392 } 393 } 394 switch (get_line(buf, sizeof(buf))) { 395 case 0: 396 return (0); 397 case 1: 398 return (1); 399 default: 400 return (checkend(buf, "end", "no \"end\" line")); 401 } 402 } 403 404 static int 405 base64_decode(void) 406 { 407 int n; 408 char inbuf[MAXPATHLEN + 1]; 409 unsigned char outbuf[MAXPATHLEN * 4]; 410 411 for (;;) { 412 switch (get_line(inbuf, sizeof(inbuf))) { 413 case 0: 414 return (0); 415 case 1: 416 return (1); 417 } 418 419 n = b64_pton(inbuf, outbuf, sizeof(outbuf)); 420 421 if (n < 0) 422 break; 423 fwrite(outbuf, 1, n, outfp); 424 } 425 return (checkend(inbuf, "====", 426 "error decoding base64 input stream")); 427 } 428 429 static void 430 usage(void) 431 { 432 (void)fprintf(stderr, 433 "usage: uudecode [-cimprs] [file ...]\n" 434 " uudecode [-i] -o output_file [file]\n" 435 " b64decode [-cimprs] [file ...]\n" 436 " b64decode [-i] -o output_file [file]\n"); 437 exit(1); 438 } 439