aboutsummaryrefslogtreecommitdiff
path: root/coreutils/uudecode.c
blob: ac33762b0f3f61cea2e9814c5b1fb90c7fb1c52c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
/* uudecode.c -- uudecode utility.
 * Copyright (C) 1994, 1995 Free Software Foundation, Inc.
 *
 * This product is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This product is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this product; see the file COPYING.  If not, write to
 * the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 */

/* Copyright (c) 1983 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *       This product includes software developed by the University of
 *       California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/* Reworked to GNU style by Ian Lance Taylor, ian@airs.com, August 93.  */

#include "internal.h"

#include <stdio.h>
#include <errno.h>
#include <getopt.h>
#include <pwd.h>

/*struct passwd *getpwnam();*/

/* Single character decode.  */
#define	DEC(Char) (((Char) - ' ') & 077)

static int read_stduu (const char *inname)
{
  char buf[2 * BUFSIZ];

  while (1) {
    int n;
    char *p;

    if (fgets (buf, sizeof(buf), stdin) == NULL) {
      errorMsg("%s: Short file\n", inname);
      return FALSE;
    }
    p = buf;

    /* N is used to avoid writing out all the characters at the end of
       the file.  */
    n = DEC (*p);
    if (n <= 0)
      break;
    for (++p; n > 0; p += 4, n -= 3) {
      char ch;

      if (n >= 3) {
        ch = DEC (p[0]) << 2 | DEC (p[1]) >> 4;
        putchar (ch);
        ch = DEC (p[1]) << 4 | DEC (p[2]) >> 2;
        putchar (ch);
        ch = DEC (p[2]) << 6 | DEC (p[3]);
        putchar (ch);
      } else {
        if (n >= 1) {
          ch = DEC (p[0]) << 2 | DEC (p[1]) >> 4;
          putchar (ch);
        }
        if (n >= 2) {
          ch = DEC (p[1]) << 4 | DEC (p[2]) >> 2;
          putchar (ch);
        }
      }
    }
  }

  if (fgets (buf, sizeof(buf), stdin) == NULL
      || strcmp (buf, "end\n")) {
    errorMsg("%s: No `end' line\n", inname);
    return FALSE;
  }

  return TRUE;
}

static int read_base64 (const char *inname)
{
  static const char b64_tab[256] = {
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*000-007*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*010-017*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*020-027*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*030-037*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*040-047*/
    '\177', '\177', '\177', '\76',  '\177', '\177', '\177', '\77',  /*050-057*/
    '\64',  '\65',  '\66',  '\67',  '\70',  '\71',  '\72',  '\73',  /*060-067*/
    '\74',  '\75',  '\177', '\177', '\177', '\100', '\177', '\177', /*070-077*/
    '\177', '\0',   '\1',   '\2',   '\3',   '\4',   '\5',   '\6',   /*100-107*/
    '\7',   '\10',  '\11',  '\12',  '\13',  '\14',  '\15',  '\16',  /*110-117*/
    '\17',  '\20',  '\21',  '\22',  '\23',  '\24',  '\25',  '\26',  /*120-127*/
    '\27',  '\30',  '\31',  '\177', '\177', '\177', '\177', '\177', /*130-137*/
    '\177', '\32',  '\33',  '\34',  '\35',  '\36',  '\37',  '\40',  /*140-147*/
    '\41',  '\42',  '\43',  '\44',  '\45',  '\46',  '\47',  '\50',  /*150-157*/
    '\51',  '\52',  '\53',  '\54',  '\55',  '\56',  '\57',  '\60',  /*160-167*/
    '\61',  '\62',  '\63',  '\177', '\177', '\177', '\177', '\177', /*170-177*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*200-207*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*210-217*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*220-227*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*230-237*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*240-247*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*250-257*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*260-267*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*270-277*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*300-307*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*310-317*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*320-327*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*330-337*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*340-347*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*350-357*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*360-367*/
    '\177', '\177', '\177', '\177', '\177', '\177', '\177', '\177', /*370-377*/
  };
  unsigned char buf[2 * BUFSIZ];

  while (1) {
    int last_data = 0;
    unsigned char *p;

    if (fgets (buf, sizeof(buf), stdin) == NULL) {
      errorMsg("%s: Short file\n", inname);
      return FALSE;
    }
    p = buf;

    if (memcmp (buf, "====", 4) == 0)
      break;
    if (last_data != 0) {
      errorMsg("%s: data following `=' padding character\n", inname);
      return FALSE;
    }

    /* The following implementation of the base64 decoding might look
       a bit clumsy but I only try to follow the POSIX standard:
       ``All line breaks or other characters not found in the table
       [with base64 characters] shall be ignored by decoding
       software.''  */
    while (*p != '\n') {
      char c1, c2, c3;

      while ((b64_tab[*p] & '\100') != 0)
        if (*p == '\n' || *p++ == '=')
          break;
      if (*p == '\n')
        /* This leaves the loop.  */
        continue;
      c1 = b64_tab[*p++];

      while ((b64_tab[*p] & '\100') != 0)
        if (*p == '\n' || *p++ == '=') {
          errorMsg("%s: illegal line\n", inname);
          return FALSE;
        }
      c2 = b64_tab[*p++];

      while (b64_tab[*p] == '\177')
        if (*p++ == '\n') {
          errorMsg("%s: illegal line\n", inname);
          return FALSE;
        }
      if (*p == '=') {
        putchar (c1 << 2 | c2 >> 4);
        last_data = 1;
        break;
      }
      c3 = b64_tab[*p++];

      while (b64_tab[*p] == '\177')
        if (*p++ == '\n') {
          errorMsg("%s: illegal line\n", inname);
          return FALSE;
        }
      putchar (c1 << 2 | c2 >> 4);
      putchar (c2 << 4 | c3 >> 2);
      if (*p == '=') {
        last_data = 1;
        break;
      }
      else
        putchar (c3 << 6 | b64_tab[*p++]);
    }
  }

  return TRUE;
}

static int decode (const char *inname,
                   const char *forced_outname)
{
  struct passwd *pw;
  register int n;
  register char *p;
  int mode, n1;
  char buf[2 * BUFSIZ];
  char *outname;
  int do_base64 = 0;

  /* Search for header line.  */

  while (1) {
    if (fgets (buf, sizeof (buf), stdin) == NULL) {
      errorMsg("%s: No `begin' line\n", inname);
      return FALSE;
    }

    if (strncmp (buf, "begin", 5) == 0) {
      if (sscanf (buf, "begin-base64 %o %s", &mode, buf) == 2) {
        do_base64 = 1;
        break;
      } else if (sscanf (buf, "begin %o %s", &mode, buf) == 2)
        break;
    }
  }

  /* If the output file name is given on the command line this rules.  */
  if (forced_outname != NULL)
    outname = (char *) forced_outname;
  else {
    /* Handle ~user/file format.  */
    if (buf[0] != '~')
      outname = buf;
    else {
      p = buf + 1;
      while (*p != '/')
        ++p;
      if (*p == '\0') {
        errorMsg("%s: Illegal ~user\n", inname);
        return FALSE;
      }
      *p++ = '\0';
      pw = getpwnam (buf + 1);
      if (pw == NULL) {
        errorMsg("%s: No user `%s'\n", inname, buf + 1);
        return FALSE;
      }
      n = strlen (pw->pw_dir);
      n1 = strlen (p);
      outname = (char *) alloca ((size_t) (n + n1 + 2));
      memcpy (outname + n + 1, p, (size_t) (n1 + 1));
      memcpy (outname, pw->pw_dir, (size_t) n);
      outname[n] = '/';
    }
  }

  /* Create output file and set mode.  */
  if (strcmp (outname, "/dev/stdout") != 0 && strcmp (outname, "-") != 0
      && (freopen (outname, "w", stdout) == NULL
	  || chmod (outname, mode & (S_IRWXU | S_IRWXG | S_IRWXO))
         )) {
    errorMsg("uudeoce %s: %s %s\n", outname, inname, strerror(errno)); /* */
    return FALSE;
  }

  /* We differenciate decoding standard UU encoding and base64.  A
     common function would only slow down the program.  */

  /* For each input line:  */
  if (do_base64)
    return read_base64 (inname);
  else
    return read_stduu (inname);
}

static const char uudecode_usage[] =
    "uudecode [FILE]...\n"
#ifndef BB_FEATURE_TRIVIAL_HELP
    "\nUudecode a file that is uuencoded.\n\n"
    "Options:\n"
    "\t-o FILE\tdirect output to FILE\n"
#endif
;

int uudecode_main (int argc,
                   char **argv)
{
  int opt;
  int exit_status;
  const char *outname;
  outname = NULL;

  while ((opt = getopt(argc, argv, "o:")) != EOF) {
    switch (opt) {
     case 0:
      break;

     case 'o':
      outname = optarg;
      break;

     default:
      usage(uudecode_usage);
    }
  }

  if (optind == argc)
    exit_status = decode ("stdin", outname) == 0 ? TRUE : FALSE;
  else {
    exit_status = TRUE;
    do {
      if (freopen (argv[optind], "r", stdin) != NULL) {
        if (decode (argv[optind], outname) != 0)
          exit_status = FALSE;
      } else {
        errorMsg("uudecode: %s: %s\n", argv[optind], strerror(errno));
        exit_status = FALSE;
      }
      optind++;
    }
    while (optind < argc);
  }
  return(exit_status);
}