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 __FBSDID("$FreeBSD$"); 45 46 /* 47 * uudecode [file ...] 48 * 49 * create the specified file, decoding as you go. 50 * used with uuencode. 51 */ 52 #include <sys/param.h> 53 #include <sys/socket.h> 54 #include <sys/stat.h> 55 56 #include <netinet/in.h> 57 58 #include <ctype.h> 59 #include <err.h> 60 #include <errno.h> 61 #include <fcntl.h> 62 #include <libgen.h> 63 #include <pwd.h> 64 #include <resolv.h> 65 #include <stdbool.h> 66 #include <stdio.h> 67 #include <stdlib.h> 68 #include <string.h> 69 #include <unistd.h> 70 71 extern int main_decode(int, char *[]); 72 extern int main_base64_decode(const char *); 73 74 static const char *infile, *outfile; 75 static FILE *infp, *outfp; 76 static bool base64, cflag, iflag, oflag, pflag, rflag, sflag; 77 78 static void usage(void); 79 static int decode(void); 80 static int decode2(void); 81 static int uu_decode(void); 82 static int base64_decode(void); 83 84 int 85 main_base64_decode(const char *in) 86 { 87 base64 = 1; 88 rflag = 1; 89 if (in != NULL) { 90 infile = in; 91 infp = fopen(infile, "r"); 92 if (infp == NULL) 93 err(1, "%s", in); 94 } else { 95 infile = "stdin"; 96 infp = stdin; 97 } 98 exit(decode()); 99 } 100 101 int 102 main_decode(int argc, char *argv[]) 103 { 104 int rval, ch; 105 106 if (strcmp(basename(argv[0]), "b64decode") == 0) 107 base64 = true; 108 109 while ((ch = getopt(argc, argv, "cimo:prs")) != -1) { 110 switch (ch) { 111 case 'c': 112 if (oflag || rflag) 113 usage(); 114 cflag = true; /* multiple uudecode'd files */ 115 break; 116 case 'i': 117 iflag = true; /* ask before override files */ 118 break; 119 case 'm': 120 base64 = true; 121 break; 122 case 'o': 123 if (cflag || pflag || rflag || sflag) 124 usage(); 125 oflag = true; /* output to the specified file */ 126 sflag = true; /* do not strip pathnames for output */ 127 outfile = optarg; /* set the output filename */ 128 break; 129 case 'p': 130 if (oflag) 131 usage(); 132 pflag = true; /* print output to stdout */ 133 break; 134 case 'r': 135 if (cflag || oflag) 136 usage(); 137 rflag = true; /* decode raw data */ 138 break; 139 case 's': 140 if (oflag) 141 usage(); 142 sflag = true; /* do not strip pathnames for output */ 143 break; 144 default: 145 usage(); 146 } 147 } 148 argc -= optind; 149 argv += optind; 150 151 if (*argv != NULL) { 152 rval = 0; 153 do { 154 infp = fopen(infile = *argv, "r"); 155 if (infp == NULL) { 156 warn("%s", *argv); 157 rval = 1; 158 continue; 159 } 160 rval |= decode(); 161 fclose(infp); 162 } while (*++argv); 163 } else { 164 infile = "stdin"; 165 infp = stdin; 166 rval = decode(); 167 } 168 exit(rval); 169 } 170 171 static int 172 decode(void) 173 { 174 int r, v; 175 176 if (rflag) { 177 /* relaxed alternative to decode2() */ 178 outfile = "/dev/stdout"; 179 outfp = stdout; 180 if (base64) 181 return (base64_decode()); 182 else 183 return (uu_decode()); 184 } 185 v = decode2(); 186 if (v == EOF) { 187 warnx("%s: missing or bad \"begin\" line", infile); 188 return (1); 189 } 190 for (r = v; cflag; r |= v) { 191 v = decode2(); 192 if (v == EOF) 193 break; 194 } 195 return (r); 196 } 197 198 static int 199 decode2(void) 200 { 201 int flags, fd, mode; 202 size_t n, m; 203 char *p, *q; 204 void *handle; 205 struct passwd *pw; 206 struct stat st; 207 char buf[MAXPATHLEN + 1]; 208 209 base64 = false; 210 /* search for header line */ 211 for (;;) { 212 if (fgets(buf, sizeof(buf), infp) == NULL) 213 return (EOF); 214 p = buf; 215 if (strncmp(p, "begin-base64 ", 13) == 0) { 216 base64 = true; 217 p += 13; 218 } else if (strncmp(p, "begin ", 6) == 0) 219 p += 6; 220 else 221 continue; 222 /* p points to mode */ 223 q = strchr(p, ' '); 224 if (q == NULL) 225 continue; 226 *q++ = '\0'; 227 /* q points to filename */ 228 n = strlen(q); 229 while (n > 0 && (q[n-1] == '\n' || q[n-1] == '\r')) 230 q[--n] = '\0'; 231 /* found valid header? */ 232 if (n > 0) 233 break; 234 } 235 236 handle = setmode(p); 237 if (handle == NULL) { 238 warnx("%s: unable to parse file mode", infile); 239 return (1); 240 } 241 mode = getmode(handle, 0) & 0666; 242 free(handle); 243 244 if (sflag) { 245 /* don't strip, so try ~user/file expansion */ 246 p = NULL; 247 pw = NULL; 248 if (*q == '~') 249 p = strchr(q, '/'); 250 if (p != NULL) { 251 *p = '\0'; 252 pw = getpwnam(q + 1); 253 *p = '/'; 254 } 255 if (pw != NULL) { 256 n = strlen(pw->pw_dir); 257 if (buf + n > p) { 258 /* make room */ 259 m = strlen(p); 260 if (sizeof(buf) < n + m) { 261 warnx("%s: bad output filename", 262 infile); 263 return (1); 264 } 265 p = memmove(buf + n, p, m); 266 } 267 q = memcpy(p - n, pw->pw_dir, n); 268 } 269 } else { 270 /* strip down to leaf name */ 271 p = strrchr(q, '/'); 272 if (p != NULL) 273 q = p + 1; 274 } 275 if (!oflag) 276 outfile = q; 277 278 /* POSIX says "/dev/stdout" is a 'magic cookie' not a special file. */ 279 if (pflag || strcmp(outfile, "/dev/stdout") == 0) 280 outfp = stdout; 281 else { 282 flags = O_WRONLY | O_CREAT | O_EXCL; 283 if (lstat(outfile, &st) == 0) { 284 if (iflag) { 285 warnc(EEXIST, "%s: %s", infile, outfile); 286 return (0); 287 } 288 switch (st.st_mode & S_IFMT) { 289 case S_IFREG: 290 case S_IFLNK: 291 /* avoid symlink attacks */ 292 if (unlink(outfile) == 0 || errno == ENOENT) 293 break; 294 warn("%s: unlink %s", infile, outfile); 295 return (1); 296 case S_IFDIR: 297 warnc(EISDIR, "%s: %s", infile, outfile); 298 return (1); 299 default: 300 if (oflag) { 301 /* trust command-line names */ 302 flags &= ~O_EXCL; 303 break; 304 } 305 warnc(EEXIST, "%s: %s", infile, outfile); 306 return (1); 307 } 308 } else if (errno != ENOENT) { 309 warn("%s: %s", infile, outfile); 310 return (1); 311 } 312 if ((fd = open(outfile, flags, mode)) < 0 || 313 (outfp = fdopen(fd, "w")) == NULL) { 314 warn("%s: %s", infile, outfile); 315 return (1); 316 } 317 } 318 319 if (base64) 320 return (base64_decode()); 321 else 322 return (uu_decode()); 323 } 324 325 static int 326 get_line(char *buf, size_t size) 327 { 328 329 if (fgets(buf, size, infp) != NULL) 330 return (2); 331 if (rflag) 332 return (0); 333 warnx("%s: %s: short file", infile, outfile); 334 return (1); 335 } 336 337 static int 338 checkend(const char *ptr, const char *end, const char *msg) 339 { 340 size_t n; 341 342 n = strlen(end); 343 if (strncmp(ptr, end, n) != 0 || 344 strspn(ptr + n, " \t\r\n") != strlen(ptr + n)) { 345 warnx("%s: %s: %s", infile, outfile, msg); 346 return (1); 347 } 348 if (fclose(outfp) != 0) { 349 warn("%s: %s", infile, outfile); 350 return (1); 351 } 352 return (0); 353 } 354 355 static int 356 uu_decode(void) 357 { 358 int i, ch; 359 char *p; 360 char buf[MAXPATHLEN+1]; 361 362 /* for each input line */ 363 for (;;) { 364 switch (get_line(buf, sizeof(buf))) { 365 case 0: 366 return (0); 367 case 1: 368 return (1); 369 } 370 371 #define DEC(c) (((c) - ' ') & 077) /* single character decode */ 372 #define IS_DEC(c) ( (((c) - ' ') >= 0) && (((c) - ' ') <= 077 + 1) ) 373 374 #define OUT_OF_RANGE do { \ 375 warnx("%s: %s: character out of range: [%d-%d]", \ 376 infile, outfile, ' ', 077 + ' ' + 1); \ 377 return (1); \ 378 } while (0) 379 380 /* 381 * `i' is used to avoid writing out all the characters 382 * at the end of the file. 383 */ 384 p = buf; 385 if ((i = DEC(*p)) <= 0) 386 break; 387 for (++p; i > 0; p += 4, i -= 3) 388 if (i >= 3) { 389 if (!(IS_DEC(*p) && IS_DEC(*(p + 1)) && 390 IS_DEC(*(p + 2)) && IS_DEC(*(p + 3)))) 391 OUT_OF_RANGE; 392 393 ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4; 394 putc(ch, outfp); 395 ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2; 396 putc(ch, outfp); 397 ch = DEC(p[2]) << 6 | DEC(p[3]); 398 putc(ch, outfp); 399 } else { 400 if (i >= 1) { 401 if (!(IS_DEC(*p) && IS_DEC(*(p + 1)))) 402 OUT_OF_RANGE; 403 ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4; 404 putc(ch, outfp); 405 } 406 if (i >= 2) { 407 if (!(IS_DEC(*(p + 1)) && 408 IS_DEC(*(p + 2)))) 409 OUT_OF_RANGE; 410 411 ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2; 412 putc(ch, outfp); 413 } 414 if (i >= 3) { 415 if (!(IS_DEC(*(p + 2)) && 416 IS_DEC(*(p + 3)))) 417 OUT_OF_RANGE; 418 ch = DEC(p[2]) << 6 | DEC(p[3]); 419 putc(ch, outfp); 420 } 421 } 422 } 423 switch (get_line(buf, sizeof(buf))) { 424 case 0: 425 return (0); 426 case 1: 427 return (1); 428 default: 429 return (checkend(buf, "end", "no \"end\" line")); 430 } 431 } 432 433 static int 434 base64_decode(void) 435 { 436 int n, count, count4; 437 char inbuf[MAXPATHLEN + 1], *p; 438 unsigned char outbuf[MAXPATHLEN * 4]; 439 char leftover[MAXPATHLEN + 1]; 440 441 leftover[0] = '\0'; 442 for (;;) { 443 strcpy(inbuf, leftover); 444 switch (get_line(inbuf + strlen(inbuf), 445 sizeof(inbuf) - strlen(inbuf))) { 446 case 0: 447 return (0); 448 case 1: 449 return (1); 450 } 451 452 count = 0; 453 count4 = -1; 454 p = inbuf; 455 while (*p != '\0') { 456 /* 457 * Base64 encoded strings have the following 458 * characters in them: A-Z, a-z, 0-9 and +, / and = 459 */ 460 if (isalnum(*p) || *p == '+' || *p == '/' || *p == '=') 461 count++; 462 if (count % 4 == 0) 463 count4 = p - inbuf; 464 p++; 465 } 466 467 strcpy(leftover, inbuf + count4 + 1); 468 inbuf[count4 + 1] = 0; 469 470 n = b64_pton(inbuf, outbuf, sizeof(outbuf)); 471 472 if (n < 0) 473 break; 474 fwrite(outbuf, 1, n, outfp); 475 } 476 return (checkend(inbuf, "====", "error decoding base64 input stream")); 477 } 478 479 static void 480 usage(void) 481 { 482 483 (void)fprintf(stderr, 484 "usage: uudecode [-cimprs] [file ...]\n" 485 " uudecode [-i] -o output_file [file]\n" 486 " b64decode [-cimprs] [file ...]\n" 487 " b64decode [-i] -o output_file [file]\n"); 488 exit(1); 489 } 490