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 $filename String
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?
59 * Get length of data fork
63 function dataForkLength() {
64 return $this->dataLength;
68 * Copy the data fork to an external file or resource.
70 * @param $destination Ressource
73 function extractData( $destination ) {
74 if( !$this->isValid() ) {
78 // Data fork appears immediately after header
79 fseek( $this->handle, 128 );
80 return $this->copyBytesTo( $destination, $this->dataLength );
87 fclose( $this->handle );
90 // --------------------------------------------------------------
93 * Check if the given file appears to be MacBinary-encoded,
94 * as Internet Explorer on Mac OS may provide for unknown types.
95 * http://www.lazerware.com/formats/macbinary/macbinary_iii.html
96 * If ok, load header data.
101 function loadHeader() {
102 $fname = 'MacBinary::loadHeader';
104 fseek( $this->handle, 0 );
105 $head = fread( $this->handle, 128 );
106 #$this->hexdump( $head );
108 if( strlen( $head ) < 128 ) {
109 wfDebug( "$fname: couldn't read full MacBinary header\n" );
113 if( $head{0} != "\x00" || $head{74} != "\x00" ) {
114 wfDebug( "$fname: header bytes 0 and 74 not null\n" );
118 $signature = substr( $head, 102, 4 );
119 $a = unpack( "ncrc", substr( $head, 124, 2 ) );
120 $storedCRC = $a['crc'];
121 $calculatedCRC = $this->calcCRC( substr( $head, 0, 124 ) );
122 if( $storedCRC == $calculatedCRC ) {
123 if( $signature == 'mBIN' ) {
129 $crc = sprintf( "%x != %x", $storedCRC, $calculatedCRC );
130 if( $storedCRC == 0 && $head{82} == "\x00" &&
131 substr( $head, 101, 24 ) == str_repeat( "\x00", 24 ) ) {
132 wfDebug( "$fname: no CRC, looks like MacBinary I\n" );
134 } elseif( $signature == 'mBIN' && $storedCRC == 0x185 ) {
135 // Mac IE 5.0 seems to insert this value in the CRC field.
136 // 5.2.3 works correctly; don't know about other versions.
137 wfDebug( "$fname: CRC doesn't match ($crc), looks like Mac IE 5.0\n" );
140 wfDebug( "$fname: CRC doesn't match ($crc) and not MacBinary I\n" );
145 $nameLength = ord( $head{1} );
146 if( $nameLength < 1 || $nameLength > 63 ) {
147 wfDebug( "$fname: invalid filename size $nameLength\n" );
150 $this->filename = substr( $head, 2, $nameLength );
152 $forks = unpack( "Ndata/Nresource", substr( $head, 83, 8 ) );
153 $this->dataLength = $forks['data'];
154 $this->resourceLength = $forks['resource'];
155 $maxForkLength = 0x7fffff;
157 if( $this->dataLength < 0 || $this->dataLength > $maxForkLength ) {
158 wfDebug( "$fname: invalid data fork length $this->dataLength\n" );
162 if( $this->resourceLength < 0 || $this->resourceLength > $maxForkLength ) {
163 wfDebug( "$fname: invalid resource fork size $this->resourceLength\n" );
167 wfDebug( "$fname: appears to be MacBinary $this->version, data length $this->dataLength\n" );
173 * Calculate a 16-bit CRC value as for MacBinary headers.
174 * Adapted from perl5 Convert::BinHex by Eryq,
175 * based on the mcvert utility (Doug Moore, April '87),
176 * with magic array thingy by Jim Van Verth.
177 * http://search.cpan.org/~eryq/Convert-BinHex-1.119/lib/Convert/BinHex.pm
179 * @param $data String
180 * @param $seed Integer
184 function calcCRC( $data, $seed = 0 ) {
185 # An array useful for CRC calculations that use 0x1021 as the "seed":
187 0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
188 0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
189 0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
190 0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
191 0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
192 0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
193 0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
194 0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
195 0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
196 0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
197 0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12,
198 0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
199 0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
200 0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
201 0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
202 0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
203 0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
204 0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
205 0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
206 0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
207 0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
208 0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
209 0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
210 0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
211 0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
212 0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
213 0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
214 0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92,
215 0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
216 0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
217 0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
218 0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0
220 $len = strlen( $data );
222 for( $i = 0; $i < $len; $i++ ) {
223 $crc ^= ord( $data{$i} ) << 8;
225 $crc = ($crc << 8) ^ $MAGIC[$crc >> 8];
232 * @param $destination Resource
233 * @param $bytesToCopy Integer
237 function copyBytesTo( $destination, $bytesToCopy ) {
239 for( $remaining = $bytesToCopy; $remaining > 0; $remaining -= $bufferSize ) {
240 $thisChunkSize = min( $remaining, $bufferSize );
241 $buffer = fread( $this->handle, $thisChunkSize );
242 fwrite( $destination, $buffer );
247 * Hex dump of the header for debugging
250 function hexdump( $data ) {
251 global $wgDebugLogFile;
252 if( !$wgDebugLogFile ) return;
256 for( $remaining = strlen( $data ); $remaining > 0; $remaining -= $width ) {
257 $line = sprintf( "%04x:", $at );
259 for( $i = 0; $i < $width && $remaining - $i > 0; $i++ ) {
260 $byte = ord( $data{$at++} );
261 $line .= sprintf( " %02x", $byte );
262 $printable .= ($byte >= 32 && $byte <= 126 )
267 $line .= str_repeat( ' ', $width - $i );
269 wfDebug( "MacBinary: $line $printable\n" );