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 * $DragonFly: src/usr.bin/uudecode/uudecode.c,v 1.3 2004/12/22 11:25:51 liamfoy Exp $ 33 */ 34 35 /* 36 * uudecode [file ...] 37 * 38 * create the specified file, decoding as you go. 39 * used with uuencode. 40 */ 41 #include <sys/param.h> 42 #include <sys/socket.h> 43 #include <sys/stat.h> 44 45 #include <netinet/in.h> 46 47 #include <err.h> 48 #include <errno.h> 49 #include <fcntl.h> 50 #include <libgen.h> 51 #include <pwd.h> 52 #include <resolv.h> 53 #include <stdio.h> 54 #include <stdlib.h> 55 #include <string.h> 56 #include <unistd.h> 57 58 static const char *infile, *outfile; 59 static FILE *infp, *outfp; 60 static int base64, cflag, iflag, oflag, pflag, rflag, sflag; 61 62 static void usage(void); 63 static int decode(void); 64 static int decode2(void); 65 static int uu_decode(void); 66 static int base64_decode(void); 67 68 int 69 main(int argc, char *argv[]) 70 { 71 int rval, ch; 72 73 if (strcmp(basename(argv[0]), "b64decode") == 0) 74 base64 = 1; 75 76 while ((ch = getopt(argc, argv, "cimo:prs")) != -1) { 77 switch(ch) { 78 case 'c': 79 if (oflag || rflag) 80 usage(); 81 cflag = 1; /* multiple uudecode'd files */ 82 break; 83 case 'i': 84 iflag = 1; /* ask before override files */ 85 break; 86 case 'm': 87 base64 = 1; 88 break; 89 case 'o': 90 if (cflag || pflag || rflag || sflag) 91 usage(); 92 oflag = 1; /* output to the specified file */ 93 sflag = 1; /* do not strip pathnames for output */ 94 outfile = optarg; /* set the output filename */ 95 break; 96 case 'p': 97 if (oflag) 98 usage(); 99 pflag = 1; /* print output to stdout */ 100 break; 101 case 'r': 102 if (cflag || oflag) 103 usage(); 104 rflag = 1; /* decode raw data */ 105 break; 106 case 's': 107 if (oflag) 108 usage(); 109 sflag = 1; /* do not strip pathnames for output */ 110 break; 111 default: 112 usage(); 113 } 114 } 115 argc -= optind; 116 argv += optind; 117 118 if (*argv) { 119 rval = 0; 120 do { 121 infp = fopen(infile = *argv, "r"); 122 if (infp == NULL) { 123 warn("%s", *argv); 124 rval = 1; 125 continue; 126 } 127 rval |= decode(); 128 fclose(infp); 129 } while (*++argv); 130 } else { 131 infile = "stdin"; 132 infp = stdin; 133 rval = decode(); 134 } 135 exit(rval); 136 } 137 138 static int 139 decode(void) 140 { 141 int r, v; 142 143 if (rflag) { 144 /* relaxed alternative to decode2() */ 145 outfile = "/dev/stdout"; 146 outfp = stdout; 147 if (base64) 148 return (base64_decode()); 149 else 150 return (uu_decode()); 151 } 152 v = decode2(); 153 if (v == EOF) { 154 warnx("%s: missing or bad \"begin\" line", infile); 155 return (1); 156 } 157 for (r = v; cflag; r |= v) { 158 v = decode2(); 159 if (v == EOF) 160 break; 161 } 162 return (r); 163 } 164 165 static int 166 decode2(void) 167 { 168 int flags, fd; 169 size_t n, m; 170 char *p, *q; 171 void *handle; 172 mode_t mode; 173 struct passwd *pw; 174 struct stat st; 175 char buf[MAXPATHLEN+1]; 176 177 base64 = 0; 178 /* search for header line */ 179 for (;;) { 180 if (fgets(buf, sizeof(buf), infp) == NULL) 181 return (EOF); 182 p = buf; 183 if (strncmp(p, "begin-base64 ", 13) == 0) { 184 base64 = 1; 185 p += 13; 186 } else if (strncmp(p, "begin ", 6) == 0) 187 p += 6; 188 else 189 continue; 190 /* p points to mode */ 191 q = strchr(p, ' '); 192 if (q == NULL) 193 continue; 194 *q++ = '\0'; 195 /* q points to filename */ 196 n = strlen(q); 197 while (n > 0 && (q[n-1] == '\n' || q[n-1] == '\r')) 198 q[--n] = '\0'; 199 /* found valid header? */ 200 if (n > 0) 201 break; 202 } 203 204 errno = 0; 205 if ((handle = setmode(p)) == NULL) { 206 if (!errno) 207 warnx("invalid file mode: %s", infile); 208 else 209 warn("setmode malloc failed: %s", infile); 210 211 return(1); 212 } 213 214 mode = getmode(handle, 0) & 0666; 215 free(handle); 216 217 if (sflag) { 218 /* don't strip, so try ~user/file expansion */ 219 p = NULL; 220 pw = NULL; 221 if (*q == '~') 222 p = strchr(q, '/'); 223 if (p != NULL) { 224 *p = '\0'; 225 pw = getpwnam(q + 1); 226 *p = '/'; 227 } 228 if (pw != NULL) { 229 n = strlen(pw->pw_dir); 230 if (buf + n > p) { 231 /* make room */ 232 m = strlen(p); 233 if (sizeof(buf) < n + m) { 234 warnx("%s: bad output filename", 235 infile); 236 return (1); 237 } 238 p = memmove(buf + n, p, m); 239 } 240 q = memcpy(p - n, pw->pw_dir, n); 241 } 242 } else { 243 /* strip down to leaf name */ 244 p = strrchr(q, '/'); 245 if (p != NULL) 246 q = p + 1; 247 } 248 if (!oflag) 249 outfile = q; 250 251 /* POSIX says "/dev/stdout" is a 'magic cookie' not a special file. */ 252 if (pflag || strcmp(outfile, "/dev/stdout") == 0) 253 outfp = stdout; 254 else { 255 flags = O_WRONLY|O_CREAT|O_EXCL; 256 if (lstat(outfile, &st) == 0) { 257 if (iflag) { 258 warnc(EEXIST, "%s: %s", infile, outfile); 259 return (0); 260 } 261 switch (st.st_mode & S_IFMT) { 262 case S_IFREG: 263 case S_IFLNK: 264 /* avoid symlink attacks */ 265 if (unlink(outfile) == 0 || errno == ENOENT) 266 break; 267 warn("%s: unlink %s", infile, outfile); 268 return (1); 269 case S_IFDIR: 270 warnc(EISDIR, "%s: %s", infile, outfile); 271 return (1); 272 default: 273 if (oflag) { 274 /* trust command-line names */ 275 flags &= ~O_EXCL; 276 break; 277 } 278 warnc(EEXIST, "%s: %s", infile, outfile); 279 return (1); 280 } 281 } else if (errno != ENOENT) { 282 warn("%s: %s", infile, outfile); 283 return (1); 284 } 285 if ((fd = open(outfile, flags, mode)) < 0 || 286 (outfp = fdopen(fd, "w")) == NULL) { 287 warn("%s: %s", infile, outfile); 288 return (1); 289 } 290 } 291 292 if (base64) 293 return (base64_decode()); 294 else 295 return (uu_decode()); 296 } 297 298 static int 299 getline(char *buf, size_t size) 300 { 301 if (fgets(buf, size, infp) != NULL) 302 return (2); 303 if (rflag) 304 return (0); 305 warnx("%s: %s: short file", infile, outfile); 306 return (1); 307 } 308 309 static int 310 checkend(const char *ptr, const char *end, const char *msg) 311 { 312 size_t n; 313 314 n = strlen(end); 315 if (strncmp(ptr, end, n) != 0 || 316 strspn(ptr + n, " \t\r\n") != strlen(ptr + n)) { 317 warnx("%s: %s: %s", infile, outfile, msg); 318 return (1); 319 } 320 if (fclose(outfp) != 0) { 321 warn("%s: %s", infile, outfile); 322 return (1); 323 } 324 return (0); 325 } 326 327 static int 328 uu_decode(void) 329 { 330 int i, ch; 331 char *p; 332 char buf[MAXPATHLEN+1]; 333 334 /* for each input line */ 335 for (;;) { 336 switch (getline(buf, sizeof(buf))) { 337 case 0: return (0); 338 case 1: return (1); 339 } 340 341 #define DEC(c) (((c) - ' ') & 077) /* single character decode */ 342 #define IS_DEC(c) ( (((c) - ' ') >= 0) && (((c) - ' ') <= 077 + 1) ) 343 344 #define OUT_OF_RANGE do { \ 345 warnx("%s: %s: character out of range: [%d-%d]", \ 346 infile, outfile, 1 + ' ', 077 + ' ' + 1); \ 347 return (1); \ 348 } while (0) 349 350 /* 351 * `i' is used to avoid writing out all the characters 352 * at the end of the file. 353 */ 354 p = buf; 355 if ((i = DEC(*p)) <= 0) 356 break; 357 for (++p; i > 0; p += 4, i -= 3) 358 if (i >= 3) { 359 if (!(IS_DEC(*p) && IS_DEC(*(p + 1)) && 360 IS_DEC(*(p + 2)) && IS_DEC(*(p + 3)))) 361 OUT_OF_RANGE; 362 363 ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4; 364 putc(ch, outfp); 365 ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2; 366 putc(ch, outfp); 367 ch = DEC(p[2]) << 6 | DEC(p[3]); 368 putc(ch, outfp); 369 } 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 (getline(buf, sizeof(buf))) { 395 case 0: return (0); 396 case 1: return (1); 397 default: return (checkend(buf, "end", "no \"end\" line")); 398 } 399 } 400 401 static int 402 base64_decode(void) 403 { 404 int n; 405 char inbuf[MAXPATHLEN+1]; 406 unsigned char outbuf[MAXPATHLEN * 4]; 407 408 for (;;) { 409 switch (getline(inbuf, sizeof(inbuf))) { 410 case 0: return (0); 411 case 1: return (1); 412 } 413 n = b64_pton(inbuf, outbuf, sizeof(outbuf)); 414 if (n < 0) 415 break; 416 fwrite(outbuf, 1, n, outfp); 417 } 418 return (checkend(inbuf, "====", 419 "error decoding base64 input stream")); 420 } 421 422 static void 423 usage(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