wiki.techinc.nl/includes/MacBinary.php

271 lines
8.5 KiB
PHP

<?php
/**
* MacBinary signature checker and data fork extractor, for files
* uploaded from Internet Explorer for Mac.
*
* Copyright (C) 2005 Brion Vibber <brion@pobox.com>
* Portions based on Convert::BinHex by Eryq et al
* http://www.mediawiki.org/
*
* This program 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 of the License, or
* (at your option) any later version.
*
* This program 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 program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @addtogroup SpecialPage
*/
class MacBinary {
function __construct( $filename ) {
$this->open( $filename );
$this->loadHeader();
}
/**
* The file must be seekable, such as local filesystem.
* Remote URLs probably won't work.
*
* @param string $filename
*/
function open( $filename ) {
$this->valid = false;
$this->version = 0;
$this->filename = '';
$this->dataLength = 0;
$this->resourceLength = 0;
$this->handle = fopen( $filename, 'rb' );
}
/**
* Does this appear to be a valid MacBinary archive?
* @return bool
*/
function isValid() {
return $this->valid;
}
/**
* Get length of data fork
* @return int
*/
function dataForkLength() {
return $this->dataLength;
}
/**
* Copy the data fork to an external file or resource.
* @param resource $destination
* @return bool
*/
function extractData( $destination ) {
if( !$this->isValid() ) {
return false;
}
// Data fork appears immediately after header
fseek( $this->handle, 128 );
return $this->copyBytesTo( $destination, $this->dataLength );
}
/**
*
*/
function close() {
fclose( $this->handle );
}
// --------------------------------------------------------------
/**
* Check if the given file appears to be MacBinary-encoded,
* as Internet Explorer on Mac OS may provide for unknown types.
* http://www.lazerware.com/formats/macbinary/macbinary_iii.html
* If ok, load header data.
*
* @return bool
* @access private
*/
function loadHeader() {
$fname = 'MacBinary::loadHeader';
fseek( $this->handle, 0 );
$head = fread( $this->handle, 128 );
#$this->hexdump( $head );
if( strlen( $head ) < 128 ) {
wfDebug( "$fname: couldn't read full MacBinary header\n" );
return false;
}
if( $head{0} != "\x00" || $head{74} != "\x00" ) {
wfDebug( "$fname: header bytes 0 and 74 not null\n" );
return false;
}
$signature = substr( $head, 102, 4 );
$a = unpack( "ncrc", substr( $head, 124, 2 ) );
$storedCRC = $a['crc'];
$calculatedCRC = $this->calcCRC( substr( $head, 0, 124 ) );
if( $storedCRC == $calculatedCRC ) {
if( $signature == 'mBIN' ) {
$this->version = 3;
} else {
$this->version = 2;
}
} else {
$crc = sprintf( "%x != %x", $storedCRC, $calculatedCRC );
if( $storedCRC == 0 && $head{82} == "\x00" &&
substr( $head, 101, 24 ) == str_repeat( "\x00", 24 ) ) {
wfDebug( "$fname: no CRC, looks like MacBinary I\n" );
$this->version = 1;
} elseif( $signature == 'mBIN' && $storedCRC == 0x185 ) {
// Mac IE 5.0 seems to insert this value in the CRC field.
// 5.2.3 works correctly; don't know about other versions.
wfDebug( "$fname: CRC doesn't match ($crc), looks like Mac IE 5.0\n" );
$this->version = 3;
} else {
wfDebug( "$fname: CRC doesn't match ($crc) and not MacBinary I\n" );
return false;
}
}
$nameLength = ord( $head{1} );
if( $nameLength < 1 || $nameLength > 63 ) {
wfDebug( "$fname: invalid filename size $nameLength\n" );
return false;
}
$this->filename = substr( $head, 2, $nameLength );
$forks = unpack( "Ndata/Nresource", substr( $head, 83, 8 ) );
$this->dataLength = $forks['data'];
$this->resourceLength = $forks['resource'];
$maxForkLength = 0x7fffff;
if( $this->dataLength < 0 || $this->dataLength > $maxForkLength ) {
wfDebug( "$fname: invalid data fork length $this->dataLength\n" );
return false;
}
if( $this->resourceLength < 0 || $this->resourceLength > $maxForkLength ) {
wfDebug( "$fname: invalid resource fork size $this->resourceLength\n" );
return false;
}
wfDebug( "$fname: appears to be MacBinary $this->version, data length $this->dataLength\n" );
$this->valid = true;
return true;
}
/**
* Calculate a 16-bit CRC value as for MacBinary headers.
* Adapted from perl5 Convert::BinHex by Eryq,
* based on the mcvert utility (Doug Moore, April '87),
* with magic array thingy by Jim Van Verth.
* http://search.cpan.org/~eryq/Convert-BinHex-1.119/lib/Convert/BinHex.pm
*
* @param string $data
* @param int $seed
* @return int
* @access private
*/
function calcCRC( $data, $seed = 0 ) {
# An array useful for CRC calculations that use 0x1021 as the "seed":
$MAGIC = array(
0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7,
0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef,
0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6,
0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de,
0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485,
0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d,
0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4,
0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc,
0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823,
0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b,
0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12,
0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a,
0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41,
0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49,
0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70,
0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78,
0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f,
0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067,
0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e,
0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256,
0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d,
0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c,
0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634,
0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab,
0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3,
0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a,
0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92,
0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9,
0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1,
0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8,
0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0
);
$len = strlen( $data );
$crc = $seed;
for( $i = 0; $i < $len; $i++ ) {
$crc ^= ord( $data{$i} ) << 8;
$crc &= 0xFFFF;
$crc = ($crc << 8) ^ $MAGIC[$crc >> 8];
$crc &= 0xFFFF;
}
return $crc;
}
/**
* @param resource $destination
* @param int $bytesToCopy
* @return bool
* @access private
*/
function copyBytesTo( $destination, $bytesToCopy ) {
$bufferSize = 65536;
for( $remaining = $bytesToCopy; $remaining > 0; $remaining -= $bufferSize ) {
$thisChunkSize = min( $remaining, $bufferSize );
$buffer = fread( $this->handle, $thisChunkSize );
fwrite( $destination, $buffer );
}
}
/**
* Hex dump of the header for debugging
* @access private
*/
function hexdump( $data ) {
global $wgDebugLogFile;
if( !$wgDebugLogFile ) return;
$width = 16;
$at = 0;
for( $remaining = strlen( $data ); $remaining > 0; $remaining -= $width ) {
$line = sprintf( "%04x:", $at );
$printable = '';
for( $i = 0; $i < $width && $remaining - $i > 0; $i++ ) {
$byte = ord( $data{$at++} );
$line .= sprintf( " %02x", $byte );
$printable .= ($byte >= 32 && $byte <= 126 )
? chr( $byte )
: '.';
}
if( $i < $width ) {
$line .= str_repeat( ' ', $width - $i );
}
wfDebug( "MacBinary: $line $printable\n" );
}
}
}