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