3 * MacBinary signature checker and data fork extractor, for files
4 * uploaded from Internet Explorer for Mac.
6 * Copyright (C) 2005 Brion Vibber <brion@pobox.com>
7 * Portions based on Convert::BinHex by Eryq et al
8 * http://www.mediawiki.org/
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License along
21 * with this program; if not, write to the Free Software Foundation, Inc.,
22 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
23 * http://www.gnu.org/copyleft/gpl.html
25 * @ingroup SpecialPage
29 function __construct( $filename ) {
30 $this->open( $filename );
35 * The file must be seekable, such as local filesystem.
36 * Remote URLs probably won't work.
38 * @param string $filename
40 function open( $filename ) {
44 $this->dataLength
= 0;
45 $this->resourceLength
= 0;
46 $this->handle
= fopen( $filename, 'rb' );
50 * Does this appear to be a valid MacBinary archive?
58 * Get length of data fork
61 function dataForkLength() {
62 return $this->dataLength
;
66 * Copy the data fork to an external file or resource.
67 * @param resource $destination
70 function extractData( $destination ) {
71 if( !$this->isValid() ) {
75 // Data fork appears immediately after header
76 fseek( $this->handle
, 128 );
77 return $this->copyBytesTo( $destination, $this->dataLength
);
84 fclose( $this->handle
);
87 // --------------------------------------------------------------
90 * Check if the given file appears to be MacBinary-encoded,
91 * as Internet Explorer on Mac OS may provide for unknown types.
92 * http://www.lazerware.com/formats/macbinary/macbinary_iii.html
93 * If ok, load header data.
98 function loadHeader() {
99 $fname = 'MacBinary::loadHeader';
101 fseek( $this->handle
, 0 );
102 $head = fread( $this->handle
, 128 );
103 #$this->hexdump( $head );
105 if( strlen( $head ) < 128 ) {
106 wfDebug( "$fname: couldn't read full MacBinary header\n" );
110 if( $head{0} != "\x00" ||
$head{74} != "\x00" ) {
111 wfDebug( "$fname: header bytes 0 and 74 not null\n" );
115 $signature = substr( $head, 102, 4 );
116 $a = unpack( "ncrc", substr( $head, 124, 2 ) );
117 $storedCRC = $a['crc'];
118 $calculatedCRC = $this->calcCRC( substr( $head, 0, 124 ) );
119 if( $storedCRC == $calculatedCRC ) {
120 if( $signature == 'mBIN' ) {
126 $crc = sprintf( "%x != %x", $storedCRC, $calculatedCRC );
127 if( $storedCRC == 0 && $head{82} == "\x00" &&
128 substr( $head, 101, 24 ) == str_repeat( "\x00", 24 ) ) {
129 wfDebug( "$fname: no CRC, looks like MacBinary I\n" );
131 } elseif( $signature == 'mBIN' && $storedCRC == 0x185 ) {
132 // Mac IE 5.0 seems to insert this value in the CRC field.
133 // 5.2.3 works correctly; don't know about other versions.
134 wfDebug( "$fname: CRC doesn't match ($crc), looks like Mac IE 5.0\n" );
137 wfDebug( "$fname: CRC doesn't match ($crc) and not MacBinary I\n" );
142 $nameLength = ord( $head{1} );
143 if( $nameLength < 1 ||
$nameLength > 63 ) {
144 wfDebug( "$fname: invalid filename size $nameLength\n" );
147 $this->filename
= substr( $head, 2, $nameLength );
149 $forks = unpack( "Ndata/Nresource", substr( $head, 83, 8 ) );
150 $this->dataLength
= $forks['data'];
151 $this->resourceLength
= $forks['resource'];
152 $maxForkLength = 0x7fffff;
154 if( $this->dataLength
< 0 ||
$this->dataLength
> $maxForkLength ) {
155 wfDebug( "$fname: invalid data fork length $this->dataLength\n" );
159 if( $this->resourceLength
< 0 ||
$this->resourceLength
> $maxForkLength ) {
160 wfDebug( "$fname: invalid resource fork size $this->resourceLength\n" );
164 wfDebug( "$fname: appears to be MacBinary $this->version, data length $this->dataLength\n" );
170 * Calculate a 16-bit CRC value as for MacBinary headers.
171 * Adapted from perl5 Convert::BinHex by Eryq,
172 * based on the mcvert utility (Doug Moore, April '87),
173 * with magic array thingy by Jim Van Verth.
174 * http://search.cpan.org/~eryq/Convert-BinHex-1.119/lib/Convert/BinHex.pm
176 * @param string $data
181 function calcCRC( $data, $seed = 0 ) {
182 # An array useful for CRC calculations that use 0x1021 as the "seed":
184 0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
185 0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
186 0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
187 0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
188 0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
189 0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
190 0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
191 0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
192 0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
193 0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
194 0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12,
195 0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
196 0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
197 0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
198 0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
199 0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
200 0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
201 0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
202 0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
203 0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
204 0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
205 0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
206 0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
207 0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
208 0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
209 0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
210 0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
211 0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92,
212 0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
213 0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
214 0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
215 0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0
217 $len = strlen( $data );
219 for( $i = 0; $i < $len; $i++
) {
220 $crc ^
= ord( $data{$i} ) << 8;
222 $crc = ($crc << 8) ^
$MAGIC[$crc >> 8];
229 * @param resource $destination
230 * @param int $bytesToCopy
234 function copyBytesTo( $destination, $bytesToCopy ) {
236 for( $remaining = $bytesToCopy; $remaining > 0; $remaining -= $bufferSize ) {
237 $thisChunkSize = min( $remaining, $bufferSize );
238 $buffer = fread( $this->handle
, $thisChunkSize );
239 fwrite( $destination, $buffer );
244 * Hex dump of the header for debugging
247 function hexdump( $data ) {
248 global $wgDebugLogFile;
249 if( !$wgDebugLogFile ) return;
253 for( $remaining = strlen( $data ); $remaining > 0; $remaining -= $width ) {
254 $line = sprintf( "%04x:", $at );
256 for( $i = 0; $i < $width && $remaining - $i > 0; $i++
) {
257 $byte = ord( $data{$at++
} );
258 $line .= sprintf( " %02x", $byte );
259 $printable .= ($byte >= 32 && $byte <= 126 )
264 $line .= str_repeat( ' ', $width - $i );
266 wfDebug( "MacBinary: $line $printable\n" );