usr.bin/uudecode/uudecode.c

   1 /*      $NetBSD: uudecode.c,v 1.24 2008/11/29 22:36:57 dholland 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 1.24 2008/11/29 22:36:57 dholland 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(void);
  71 static void usage(void);
  72 static int checkend(const char *, const char *, const char *);
  73 static int base64_decode(void);
  74 int main(int, char *[]);
  75
  76 int base64, pflag;
  77 const char *filename;
  78
  79 int
  80 main(int argc, char *argv[])
  81 {
  82         int ch, rval;
  83
  84         setlocale(LC_ALL, "");
  85         setprogname(argv[0]);
  86
  87         pflag = 0;
  88         while ((ch = getopt(argc, argv, "mp")) != -1)
  89                 switch (ch) {
  90                 case 'm':
  91                         base64 = 1;
  92                         break;
  93                 case 'p':
  94                         pflag = 1;
  95                         break;
  96                 default:
  97                         usage();
  98                 }
  99         argc -= optind;
 100         argv += optind;
 101
 102         if (*argv) {
 103                 rval = 0;
 104                 do {
 105                         if (!freopen(filename = *argv, "r", stdin)) {
 106                                 warn("%s", *argv);
 107                                 rval = 1;
 108                                 continue;
 109                         }
 110                         rval |= decode();
 111                 } while (*++argv);
 112         } else {
 113                 filename = "stdin";
 114                 rval = decode();
 115         }
 116         exit(rval);
 117 }
 118
 119 static int
 120 decode(void)
 121 {
 122         struct passwd *pw;
 123         int n;
 124         char ch, *p;
 125         int n1;
 126         long mode;
 127         char *fn;
 128         char buf[MAXPATHLEN];
 129
 130         /* search for header line */
 131         for (;;) {
 132                 if (!fgets(buf, sizeof(buf), stdin)) {
 133                         warnx("%s: no \"%s\" line", filename, base64 ?
 134                                         "begin-base64" : "begin");
 135                         return(1);
 136                 }
 137                 p = buf;
 138                 if (strncmp(p, "begin-base64", 12) == 0) {
 139                         base64 = 1;
 140                         p += 13;
 141                         break;
 142                 } else if (strncmp(p, "begin", 5) == 0)  {
 143                         p += 6;
 144                         break;
 145                 } else
 146                         continue;
 147         }
 148
 149         /* must be followed by an octal mode and a space */
 150         mode = strtol(p, &fn, 8);
 151         if (fn == (p) || !isspace((unsigned char)*fn) || mode==LONG_MIN || mode==LONG_MAX)
 152         {
 153                 warnx("%s: invalid mode on \"%s\" line", filename,
 154                         base64 ? "begin-base64" : "begin");
 155                 return(1);
 156         }
 157         /* skip whitespace for file name */
 158         while (*fn && isspace((unsigned char)*fn)) fn++;
 159         if (*fn == 0) {
 160                 warnx("%s: no filename on \"%s\" line", filename,
 161                         base64 ? "begin-base64" : "begin");
 162                 return(1);
 163         }
 164         /* zap newline */
 165         for (p = fn; *p && *p != '\n'; p++)
 166                 ;
 167         if (*p) *p = 0;
 168
 169         /* handle ~user/file format */
 170         if (*fn == '~') {
 171                 if (!(p = strchr(fn, '/'))) {
 172                         warnx("%s: illegal ~user.", filename);
 173                         return(1);
 174                 }
 175                 *p++ = '\0';
 176                 if (!(pw = getpwnam(fn + 1))) {
 177                         warnx("%s: no user %s.", filename, buf);
 178                         return(1);
 179                 }
 180                 n = strlen(pw->pw_dir);
 181                 n1 = strlen(p);
 182                 if (n + n1 + 2 > MAXPATHLEN) {
 183                         warnx("%s: path too long.", filename);
 184                         return(1);
 185                 }
 186                 /* make space at beginning of buf by moving end of pathname */
 187                 memmove(buf + n + 1, p, n1 + 1);
 188                 memmove(buf, pw->pw_dir, n);
 189                 buf[n] = '/';
 190                 fn = buf;
 191         }
 192
 193         /* create output file, set mode */
 194         if (!pflag && (!freopen(fn, "w", stdout) ||
 195             fchmod(fileno(stdout), mode & 0666))) {
 196                 warn("%s: %s", fn, filename);
 197                 return(1);
 198         }
 199
 200         if (base64)
 201                 return base64_decode();
 202         else {
 203                 /* for each input line */
 204                 for (;;) {
 205                         if (!fgets(p = buf, sizeof(buf), stdin)) {
 206                                 warnx("%s: short file.", filename);
 207                                 return(1);
 208                         }
 209 #define DEC(c)  (((c) - ' ') & 077)             /* single character decode */
 210                         /*
 211                         * `n' is used to avoid writing out all the characters
 212                         * at the end of the file.
 213                         */
 214                         if ((n = DEC(*p)) <= 0)
 215                                 break;
 216                         for (++p; n > 0; p += 4, n -= 3)
 217                                 if (n >= 3) {
 218                                         ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
 219                                         putchar(ch);
 220                                         ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
 221                                         putchar(ch);
 222                                         ch = DEC(p[2]) << 6 | DEC(p[3]);
 223                                         putchar(ch);
 224                                 }
 225                                 else {
 226                                         if (n >= 1) {
 227                                                 ch = DEC(p[0]) << 2 | DEC(p[1]) >> 4;
 228                                                 putchar(ch);
 229                                         }
 230                                         if (n >= 2) {
 231                                                 ch = DEC(p[1]) << 4 | DEC(p[2]) >> 2;
 232                                                 putchar(ch);
 233                                         }
 234                                         if (n >= 3) {
 235                                                 ch = DEC(p[2]) << 6 | DEC(p[3]);
 236                                                 putchar(ch);
 237                                         }
 238                                 }
 239                 }
 240                 if (!fgets(buf, sizeof(buf), stdin) || strcmp(buf, "end\n")) {
 241                         warnx("%s: no \"end\" line.", filename);
 242                         return(1);
 243                 }
 244                 return(0);
 245         }
 246 }
 247
 248 static int
 249 checkend(const char *ptr, const char *end, const char *msg)
 250 {
 251         size_t n;
 252
 253         n = strlen(end);
 254         if (strncmp(ptr, end, n) != 0 ||
 255             strspn(ptr + n, "\t\r\n") != strlen(ptr + n)) {
 256                 warnx("%s", msg);
 257                 return (1);
 258         }
 259         return (0);
 260 }
 261
 262 static int
 263 base64_decode(void)
 264 {
 265         int n;
 266         char inbuf[MAXPATHLEN];
 267         unsigned char outbuf[MAXPATHLEN * 4];
 268
 269         for (;;) {
 270                 if (!fgets(inbuf, sizeof(inbuf), stdin)) {
 271                         warnx("%s: short file.", filename);
 272                         return (1);
 273                 }
 274 #ifdef NO_BASE64
 275                 warnx("%s: base64 decoding is not supported", filename);
 276                 return (1);
 277 #else
 278                 n = b64_pton(inbuf, outbuf, sizeof(outbuf));
 279 #endif
 280                 if (n < 0)
 281                         break;
 282                 fwrite(outbuf, 1, n, stdout);
 283         }
 284         return (checkend(inbuf, "====",
 285                         "error decoding base64 input stream"));
 286 }
 287
 288 static void
 289 usage()
 290 {
 291         (void)fprintf(stderr, "usage: %s [-m | -p] [encoded-file ...]\n",
 292                       getprogname());
 293         exit(1);
 294 }