usr.bin/uudecode/uudecode.c

   1 /*      $NetBSD: uudecode.c,v 1.28 2013/01/28 19:50:30 apb Exp $        */
   2
   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 HAVE_NBTOOL_CONFIG_H
  33 #include "nbtool_config.h"
  34 #endif
  35
  36 #include <sys/cdefs.h>
  37 #if !defined(lint)
  38 __COPYRIGHT("@(#) Copyright (c) 1983, 1993\
  39  The Regents of the University of California.  All rights reserved.");
  40 #if 0
  41 static char sccsid[] = "@(#)uudecode.c  8.2 (Berkeley) 4/2/94";
  42 #endif
  43 __RCSID("$NetBSD: uudecode.c,v 1.28 2013/01/28 19:50:30 apb Exp $");
  44 #endif /* not lint */
  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/stat.h>
  54 #include <ctype.h>
  55 #include <err.h>
  56 #include <errno.h>
  57 #include <limits.h>
  58 #include <locale.h>
  59 #include <pwd.h>
  60 #include <stdio.h>
  61 #include <stdlib.h>
  62 #include <string.h>
  63 #include <unistd.h>
  64
  65 #ifndef NO_BASE64
  66 #include <netinet/in.h>
  67 #include <resolv.h>
  68 #endif
  69
  70 static int decode(char *);
  71 __dead static void usage(void);
  72 static int checkend(const char *, const char *, const char *);
  73 static int base64_decode(void);
  74
  75 static int base64;
  76 static const char *inputname;
  77
  78 int
  79 main(int argc, char *argv[])
  80 {
  81         int ch, rval;
  82         char *outputname = NULL;
  83
  84         setlocale(LC_ALL, "");
  85         setprogname(argv[0]);
  86
  87         while ((ch = getopt(argc, argv, "mo:p")) != -1)
  88                 switch (ch) {
  89                 case 'm':
  90                         base64 = 1;
  91                         break;
  92                 case 'o':
  93                         outputname = optarg;
  94                         break;
  95                 case 'p':
  96                         outputname = __UNCONST("/dev/stdout");
  97                         break;
  98                 default:
  99                         usage();
 100                 }
 101         argc -= optind;
 102         argv += optind;
 103
 104         if (*argv) {
 105                 rval = 0;
 106                 do {
 107                         if (!freopen(inputname = *argv, "r", stdin)) {
 108                                 warn("%s", *argv);
 109                                 rval = 1;
 110                                 continue;
 111                         }
 112                         rval |= decode(outputname);
 113                 } while (*++argv);
 114         } else {
 115                 inputname = "stdin";
 116                 rval = decode(outputname);
 117         }
 118         exit(rval);
 119 }
 120
 121 /*
 122  * Decode one file from stdin.  If outputname is not NULL
 123  * then it overrides the file name embedded in the input data.
 124  */
 125 static int
 126 decode(char *outputname)
 127 {
 128         struct passwd *pw;
 129         int n;
 130         char ch, *p;
 131         int n1;
 132         long mode;
 133         char *fn;
 134         char buf[MAXPATHLEN];
 135
 136         /* search for header line */
 137         for (;;) {
 138                 if (!fgets(buf, sizeof(buf), stdin)) {
 139                         warnx("%s: no \"%s\" line", inputname, base64 ?
 140                                         "begin-base64" : "begin");
 141                         return(1);
 142                 }
 143                 p = buf;
 144                 if (strncmp(p, "begin-base64", 12) == 0) {
 145                         base64 = 1;
 146                         p += 13;
 147                         break;
 148                 } else if (strncmp(p, "begin", 5) == 0)  {
 149                         p += 6;
 150                         break;
 151                 } else
 152                         continue;
 153         }
 154
 155         /* must be followed by an octal mode and a space */
 156         mode = strtol(p, &fn, 8);
 157         if (fn == (p) || !isspace((unsigned char)*fn) || mode==LONG_MIN || mode==LONG_MAX)
 158         {
 159                 warnx("%s: invalid mode on \"%s\" line", inputname,
 160                         base64 ? "begin-base64" : "begin");
 161                 return(1);
 162         }
 163         /* skip whitespace for file name */
 164         while (*fn && isspace((unsigned char)*fn)) fn++;
 165         if (*fn == 0) {
 166                 warnx("%s: no filename on \"%s\" line", inputname,
 167                         base64 ? "begin-base64" : "begin");
 168                 return(1);
 169         }
 170         /* zap newline */
 171         for (p = fn; *p && *p != '\n'; p++)
 172                 ;
 173         if (*p) *p = 0;
 174
 175         /* outputname overrides fn */
 176         if (outputname)
 177                 fn = outputname;
 178
 179         /* handle ~user/file format */
 180         if (*fn == '~') {
 181                 if (!(p = strchr(fn, '/'))) {
 182                         warnx("%s: illegal ~user.", inputname);
 183                         return(1);
 184                 }
 185                 *p++ = '\0';
 186                 if (!(pw = getpwnam(fn + 1))) {
 187                         warnx("%s: no user %s.", inputname, buf);
 188                         return(1);
 189                 }
 190                 n = strlen(pw->pw_dir);
 191                 n1 = strlen(p);
 192                 if (n + n1 + 2 > MAXPATHLEN) {
 193                         warnx("%s: path too long.", inputname);
 194                         return(1);
 195                 }
 196                 /* make space at beginning of buf by moving end of pathname */
 197                 memmove(buf + n + 1, p, n1 + 1);
 198                 memmove(buf, pw->pw_dir, n);
 199                 buf[n] = '/';
 200                 fn = buf;
 201         }
 202
 203         if (strcmp(fn, "/dev/stdout") == 0 || strcmp(fn, "-") == 0) {
 204                 /*
 205                  * POSIX.1-2008 says that both "-" and "/dev/stdout"
 206                  * refer to standard output when they appear in the file
 207                  * header, but only "/dev/stdout" refers to standard
 208                  * output when it appears as the argument to the "-o"
 209                  * command line option.
 210                  *
 211                  * We handle both special names, regardless of whether
 212                  * they came from the "-o" option or from the header of
 213                  * the input stream.
 214                  */
 215         } else {
 216                 /*
 217                  * Create output file, and set its mode.  POSIX.1-2008
 218                  * requires the mode to be used exactly, ignoring the
 219                  * umask and anything else, but we mask it with 0666.
 220                  */
 221                 if (freopen(fn, "w", stdout) == NULL ||
 222                     fchmod(fileno(stdout), mode & 0666) != 0) {
 223                         warn("%s: %s", fn, inputname);
 224                         return(1);
 225                 }
 226         }
 227
 228         if (base64)
 229                 return base64_decode();
 230         else {
 231                 /* for each input line */
 232                 for (;;) {
 233                         if (!fgets(p = buf, sizeof(buf), stdin)) {
 234                                 warnx("%s: short file.", inputname);
 235                                 return(1);
 236                         }
 237 #define DEC(c)  (((c) - ' ') & 077)             /* single character decode */
 238                         /*
 239                         * `n' is used to avoid writing out all the characters
 240                         * at the end of the file.
 241                         */
 242                         if ((n = DEC(*p)) <= 0)
 243                                 break;
 244                         for (++p; n > 0; p += 4, n -= 3)
 245                                 if (n >= 3) {
 246                                         ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
 247                                         putchar(ch);
 248                                         ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
 249                                         putchar(ch);
 250                                         ch = DEC(p[2]) << 6 | DEC(p[3]);
 251                                         putchar(ch);
 252                                 }
 253                                 else {
 254                                         if (n >= 1) {
 255                                                 ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
 256                                                 putchar(ch);
 257                                         }
 258                                         if (n >= 2) {
 259                                                 ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
 260                                                 putchar(ch);
 261                                         }
 262                                         if (n >= 3) {
 263                                                 ch = DEC(p[2]) << 6 | DEC(p[3]);
 264                                                 putchar(ch);
 265                                         }
 266                                 }
 267                 }
 268                 if (!fgets(buf, sizeof(buf), stdin) || strcmp(buf, "end\n")) {
 269                         warnx("%s: no \"end\" line.", inputname);
 270                         return(1);
 271                 }
 272                 return(0);
 273         }
 274 }
 275
 276 static int
 277 checkend(const char *ptr, const char *end, const char *msg)
 278 {
 279         size_t n;
 280
 281         n = strlen(end);
 282         if (strncmp(ptr, end, n) != 0 ||
 283             strspn(ptr + n, "\t\r\n") != strlen(ptr + n)) {
 284                 warnx("%s", msg);
 285                 return (1);
 286         }
 287         return (0);
 288 }
 289
 290 static int
 291 base64_decode(void)
 292 {
 293         int n;
 294         char inbuf[MAXPATHLEN];
 295         unsigned char outbuf[MAXPATHLEN * 4];
 296
 297         for (;;) {
 298                 if (!fgets(inbuf, sizeof(inbuf), stdin)) {
 299                         warnx("%s: short file.", inputname);
 300                         return (1);
 301                 }
 302 #ifdef NO_BASE64
 303                 warnx("%s: base64 decoding is not supported", inputname);
 304                 return (1);
 305 #else
 306                 n = b64_pton(inbuf, outbuf, sizeof(outbuf));
 307 #endif
 308                 if (n < 0)
 309                         break;
 310                 fwrite(outbuf, 1, n, stdout);
 311         }
 312         return (checkend(inbuf, "====",
 313                         "error decoding base64 input stream"));
 314 }
 315
 316 static void
 317 usage(void)
 318 {
 319         (void)fprintf(stderr,
 320                       "usage: %s [-m] [-p | -o outfile] [encoded-file ...]\n",
 321                       getprogname());
 322         exit(1);
 323 }