summaryrefslogtreecommitdiff
path: root/includes/MacBinary.php
blob: 05c3ce5cfd992b12357bcb0da4453ca1c9882489 (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
<?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
 *
 * @package MediaWiki
 * @subpackage SpecialPage
 */

class MacBinary {
	function MacBinary( $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" );
		}
	}
}

?>