busybox/uudecode.c

351 lines
11 KiB
C

/* 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 <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);
}
exit(exit_status);
}