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mgsmus/MimeReader

Created April 19, 2015 06:20
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MimeReader
<?php
/*************************************************************
* Author: Shane Thompson *
* Date: June 2013 *
* Version: 0.1 *
* Copyright: (c) Shane Thompson 2012 *
* *
* Another quality product of Social-Library.org *
* *
* The code herein comes with NO warranty, implied or *
* otherwise. *
* Neither Shane Thompson or Social-Library will not be held *
* responsible should any problems arise from the use of *
* this code. *
* *
* All rights reserved 2012 *
* Copyright Social-Library.org 2012 *
* *
* This code is free to distribute/copy/re-use. It is *
* released to the public domain and as such has no *
* limitations. Credit appreciated where possible. *
* *
* *
* The following MIME sniffing class is based *
* on the specification published at the following *
* URL: http://mimesniff.spec.whatwg.org/ *
* *
* To use this class, just pass the filename or a file *
* resource to the construct - the class will then examine *
* the file and find the MIME type. *
* *
* The Public API: *
* - get_type: Gets the determined MIME type, returns *
* application/octet-stream if the MIME type *
* is unknown. *
* - is_text: Whether or not the file is plain text *
* (UTF-8 or not) *
* - is_font: Whether the file is a font file *
* - is_zip: Whether the file is zipped *
* - is_archive: Whether the file is an archive *
* - is_scriptable: *
* Determines whether the selected MIME type *
* may contain executable scripts *
************************************************************/
class MimeReader {
protected $file = null, $detected_type = null, $num_bytes = 0, $header = null, $footer = null;
protected static $binary_characters = '', $whitespace_characters = '', $tag_terminating_characters = '';
protected static $image = null, $media = null, $fonts = null, $ms_office = null, $archive = null, $text = null, $others = null, $unknown = null, $html = null;
public function __construct( $file ) {
$this->file = $file;
$this->num_bytes = 512;
if ( empty( self::$binary_characters ) ) {
self::$binary_characters .= "\x00\x01\x02\x03\x04\x05\x06\x07\0x08\x0B\x0E\x0F\x10\x11";
self::$binary_characters .= "\x12\x13\x14\x15\x16\x17\x18\x19\x1A\x1C\x1D\x1E\x1F";
}
if ( empty( self::$whitespace_characters ) ) {
self::$whitespace_characters .= "\x09\x0A\x0C\x0D\x20";
}
if ( empty( self::$tag_terminating_characters ) ) {
self::$tag_terminating_characters .= "\x20\x3E";
}
if ( is_null( self::$image ) ) {
$image = &self::$image;
$image = array();
// Windows Icon
$image[] = array (
'mime' => 'image/vnd.microsoft.icon',
'pattern' => "\x00\x00\x01\x00",
'mask' => "\xFF\xFF\xFF\xFF",
'ignore' => '', // none
);
// "BM" - BMP signature
$image[] = array (
'mime' => 'image/bmp',
'pattern' => "\x42\x4D",
'mask' => "\xFF\xFF",
'ignore' => ''
);
// "GIF87a" - GIF signature
$image[] = array (
'mime' => 'image/gif',
'pattern' => "\x47\x49\x46\x38\x37\x61",
'mask' => "\xFF\xFF\xFF\xFF\xFF\xFF",
'ignore' => ''
);
// "GIF89a" - GIF signature
$image[] = array (
'mime' => 'image/gif',
'pattern' => "\x47\x49\x46\x38\x39\x61",
'mask' => "\xFF\xFF\xFF\xFF\xFF\xFF",
'ignore' => ''
);
// "RIFF" followed by 4 bytes followed by "WEBPVP"
$image[] = array (
'mime' => 'image/webp',
'pattern' => "\x52\x49\x46\x46\x00\x00\x00\x00\x57\x45\x42\x50\x56\x50",
'mask' => "\xFF\xFF\xFF\xFF\x00\x00\x00\x00\xFF\xFF\xFF\xFF\xFF\xFF",
'ignore' => ''
);
// A byte with only the highest bit set followed by the string "PNG" followed by CR LF SUB LF - PNG signature
$image[] = array (
'mime' => 'image/png',
'pattern' => "\x89\x50\x4E\x47\x0D\x0A\x1A\x0A",
'mask' => "\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF",
'ignore' => ''
);
// JPEG start of image marker followed by another marker
$image[] = array (
'mime' => 'image/jpeg',
'pattern' => "\xFF\xD8\xFF",
'mask' => "\xFF\xFF\xFF",
'ignore' => ''
);
// PSD signature
$image[] = array (
'mime' => 'application/psd',
'pattern' => "\x38\x42\x50\x53",
'mask' => "\xFF\xFF\xFF\xFF",
'ignore' => ''
);
}
if ( is_null( self::$media ) ) {
$media = &self::$media;
$media = array();
// The WebM signature
$media[] = array (
'mime' => 'video/webm',
'pattern' => "\x1A\x45\xDF\xA3",
'mask' => "\xFF\xFF\xFF\xFF",
'ignore' => ''
);
// The .snd signature
$media[] = array (
'mime' => 'audio/basic',
'pattern' => "\x2E\x73\x6E\x64",
'mask' => "\xFF\xFF\xFF\xFF",
'ignore' => ''
);
// "FORM" followed by 4 bytes followed by "AIFF" - the AIFF signature
$media[] = array (
'mime' => 'audio/aiff',
'pattern' => "\x46\x4F\x52\x4D\x00\x00\x00\x00\x41\x49\x46\x46",
'mask' => "\xFF\xFF\xFF\xFF\x00\x00\x00\x00\xFF\xFF\xFF\xFF",
'ignore' => ''
);
// MP3 without ID3 tag /****** UNTESTED ******/
$media[] = array (
'mime' => 'audio/mpeg',
'pattern' => "\xFF\xFB",
'mask' => "\xFF\xFF",
'ignore' => ''
);
// "ID3" and the ID3v2-tagged MP3 signature
$media[] = array (
'mime' => 'audio/mpeg',
'pattern' => "\x49\x44\x33",
'mask' => "\xFF\xFF\xFF",
'ignore' => ''
);
// "OggS" followed by NUL - The OGG signature
$media[] = array (
'mime' => 'application/ogg',
'pattern' => "\x4F\x67\x67\x53\x00",
'mask' => "\xFF\xFF\xFF\xFF\xFF",
'ignore' => ''
);
// "MThd" followed by 4 bytes representing the number 6 in 32 bits (big endian) - MIDI signature
$media[] = array (
'mime' => 'audio/midi',
'pattern' => "\x4D\x54\x68\x64\x00\x00\x00\x06",
'mask' => "\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF",
'ignore' => ''
);
// "RIFF" followed by 4 bytes followed by "AVI" - AVI signature
$media[] = array (
'mime' => 'video/avi',
'pattern' => "\x52\x49\x46\x46\x00\x00\x00\x00\x41\x56\x49\x20",
'mask' => "\xFF\xFF\xFF\xFF\x00\x00\x00\x00\xFF\xFF\xFF\xFF",
'ignore' => ''
);
// "RIFF" followed by 4 bytes followed by "WAVE" - WAVE signature
$media[] = array (
'mime' => 'audio/wave',
'pattern' => "\x52\x49\x46\x46\x00\x00\x00\x00\x57\x41\x56\x45",
'mask' => "\xFF\xFF\xFF\xFF\x00\x00\x00\x00\xFF\xFF\xFF\xFF",
'ignore' => ''
);
}
if ( is_null( self::$fonts ) ) {
$fonts = self::$fonts;
$fonts = array();
// 34 bytes followed by "LP" - Opentype signature
$fonts[] = array (
'mime' => 'application/vnd.ms-fontobject',
'pattern' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" .
"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x4C\x50",
'mask' => "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" .
"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xFF\xFF",
'ignore' => ''
);
// 4 bytes representing version type 1 of true type font
$fonts[] = array (
'mime' => 'application/font-ttf',
'pattern' => "\x00\x01\x00\x00",
'mask' => "\xFF\xFF\xFF\xFF",
'ignore' => ''
);
// "OTTO" - Opentype signature
$fonts[] = array (
'mime' => 'application/font-off', // application/vnd.ms-opentype
'pattern' => "\x4F\x54\x54\x4F",
'mask' => "\xFF\xFF\xFF\xFF",
'ignore' => ''
);
// "ttcf" - Truetype Collection signature
$fonts[] = array (
'mime' => 'application/x-font-truetype-collection',
'pattern' => "\x74\x74\x63\x66",
'mask' => "\xFF\xFF\xFF\xFF",
'ignore' => ''
);
// 'wOFF' - Web Open Font Format signature
$fonts[] = array (
'mime' => 'application/font-woff',
'pattern' => "\x77\x4F\x46\x46",
'mask' => "\xFF\xFF\xFF\xFF",
'ignore' => ''
);
}
if ( is_null( self::$archive ) ) {
$archive = &self::$archive;
$archive = array();
// GZIP signature
$archive[] = array (
'mime' => 'application/x-gzip',
'pattern' => "\x1F\x8B\x08",
'mask' => "\xFF\xFF\xFF",
'ignore' => ''
);
// "PK" followed by ETX, EOT - ZIP signature
$archive[] = array (
'mime' => 'application/zip',
'pattern' => "\x50\x4B\x03\x04",
'mask' => "\xFF\xFF\xFF\xFF",
'ignore' => ''
);
// "Rar " followed by SUB, BEL, NUL - RAR signature
$archive[] = array (
'mime' => 'application/x-rar-compressed',
'pattern' => "\x52\x61\x72\x20\x1A\x07\x00",
'mask' => "\xFF\xFF\xFF\xFF\xFF\xFF\xFF",
'ignore' => ''
);
}
if ( is_null( self::$text ) ) {
$text = &self::$text;
$text = array();
// "%!PS-Adobe-" - Postscript signature
$text[] = array (
'mime' => 'application/postscript',
'pattern' => "\x25\x50\x53\x2D\x41\x64\x6F\x62\x65",
'mask' => "\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF",
'ignore' => ''
);
// UTF-16 Big Endian BOM text
$text[] = array (
'mime' => 'text/plain',
'pattern' => "\xFF\xFE",
'mask' => "\xFF\xFF",
'ignore' => ''
);
// UTF-16 Little Endian BOM text
$text[] = array (
'mime' => 'text/plain',
'pattern' => "\xFE\xFF",
'mask' => "\xFF\xFF",
'ignore' => ''
);
// UTF-8 BOM text
$text[] = array (
'mime' => 'text/plain',
'pattern' => "\xEF\xBB\xBF",
'mask' => "\xFF\xFF\xFF",
'ignore' => ''
);
}
if ( is_null( self::$others ) ) {
$others = &self::$others;
$others = array();
/* $others[] = array (
'mime' => 'WINDOWS EXECUTABLE',
'pattern' => "\x4D\x5A",
'mask' => "\xFF\xFF",
'ignore' => ''
);
$others[] = array (
'mime' => 'EXEC_LINKABLE',
'pattern' => "\x7F\x45\x4C\x46",
'mask' => "\xFF\xFF\xFF\xFF",
'ignore' => ''
);
*/
}
if ( is_null( self::$ms_office ) ) {
$office = &self::$ms_office;
$office = array();
$office[] = array (
// application/vnd.openxmlformats-officedocument.wordprocessingml.document
'mime' => 'application/office-x',
'pattern' => "\x50\x4B\x03\x04\x14\x00\x06\x00",
'mask' => "\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF",
'ignore' => ''
);
$office[] = array (
'mime' => 'application/office',
'pattern' => "\xD0\xCF\x11\xE0\xA1\xB1\x1A\xE1",
'mask' => "\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF",
'ignore' => ''
);
}
if ( is_null( self::$unknown ) ) {
$unknown = &self::$unknown;
$unknown = array();
// "<!DOCTYPE HTML"
$unknown[] = array (
'mime' => 'text/html',
'pattern' => "\x3C\x21\x44\x4F\x43\x54\x59\x50\x45\x20\x48\x54\x4D\x4C",
'mask' => "\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF",
'ignore' => self::$whitespace_characters
);
// "<HTML"
$unknown[] = array (
'mime' => 'text/html',
'pattern' => "\x3C\x48\x54\x4D\x4C",
'mask' => "\xFF\xFF\xFF\xFF\xFF",
'ignore' => self::$whitespace_characters
);
// "<HEAD"
$unknown[] = array (
'mime' => 'text/html',
'pattern' => "\x3C\x48\x45\x41\x44",
'mask' => "\xFF\xFF\xFF\xFF\xFF",
'ignore' => self::$whitespace_characters
);
// "<SCRIPT"
$unknown[] = array (
'mime' => 'text/html',
'pattern' => "\x3C\x53\x43\x52\x49\x50\x54",
'mask' => "\xFF\xFF\xFF\xFF\xFF\xFF\xFF",
'ignore' => self::$whitespace_characters
);
// "<IFRAME"
$unknown[] = array (
'mime' => 'text/html',
'pattern' => "\x3C\x49\x46\x52\x41\x4D\x45",
'mask' => "\xFF\xFF\xFF\xFF\xFF\xFF\xFF",
'ignore' => self::$whitespace_characters
);
// "<H1"
$unknown[] = array (
'mime' => 'text/html',
'pattern' => "\x3C\x48\x31",
'mask' => "\xFF\xFF\xFF",
'ignore' => self::$whitespace_characters
);
// "<DIV"
$unknown[] = array (
'mime' => 'text/html',
'pattern' => "\x3C\x44\x49\x56",
'mask' => "\xFF\xFF\xFF\xFF",
'ignore' => self::$whitespace_characters
);
// "<FONT"
$unknown[] = array (
'mime' => 'text/html',
'pattern' => "\x3C\x46\x4F\x4E\x54",
'mask' => "\xFF\xFF\xFF\xFF\xFF",
'ignore' => self::$whitespace_characters
);
// "<TABLE"
$unknown[] = array (
'mime' => 'text/html',
'pattern' => "\x3C\x54\x41\x42\x4C\x45",
'mask' => "\xFF\xFF\xFF\xFF\xFF\xFF",
'ignore' => self::$whitespace_characters
);
// "<A"
$unknown[] = array (
'mime' => 'text/html',
'pattern' => "\x3C\x41",
'mask' => "\xFF\xFF",
'ignore' => self::$whitespace_characters
);
// "<STYLE"
$unknown[] = array (
'mime' => 'text/html',
'pattern' => "\x3C\x53\x54\x59\x4C\x45",
'mask' => "\xFF\xFF\xFF\xFF\xFF\xFF",
'ignore' => self::$whitespace_characters
);
// "<TITLE"
$unknown[] = array (
'mime' => 'text/html',
'pattern' => "\x3C\x54\x49\x54\x4C\x45",
'mask' => "\xFF\xFF\xFF\xFF\xFF\xFF",
'ignore' => self::$whitespace_characters
);
// "<B"
$unknown[] = array (
'mime' => 'text/html',
'pattern' => "\x3C\x42",
'mask' => "\xFF\xFF",
'ignore' => self::$whitespace_characters
);
// "<BODY"
$unknown[] = array (
'mime' => 'text/html',
'pattern' => "\x3C\x42\x4F\x44\x59",
'mask' => "\xFF\xFF\xFF\xFF\xFF",
'ignore' => self::$whitespace_characters
);
// "<BR"
$unknown[] = array (
'mime' => 'text/html',
'pattern' => "\x3C\x42\x52",
'mask' => "\xFF\xFF\xFF",
'ignore' => self::$whitespace_characters
);
// "<P"
$unknown[] = array (
'mime' => 'text/html',
'pattern' => "\x3C\x50",
'mask' => "\xFF\xFF",
'ignore' => self::$whitespace_characters
);
// "<!--"
$unknown[] = array (
'mime' => 'text/html',
'pattern' => "\x3C\x21\x2D\x2D",
'mask' => "\xFF\xFF\xFF\xFF",
'ignore' => self::$whitespace_characters
);
$unknown[] = array (
'mime' => 'text/xml',
'pattern' => "\x3C\x3F\x78\x6D\x6C",
'mask' => "\xFF\xFF\xFF\xFF\xFF",
'ignore' => self::$whitespace_characters
);
// "%PDF" - PDF signature
$unknown[] = array (
'mime' => 'application/pdf',
'pattern' => "\x25\x50\x44\x46",
'mask' => "\xFF\xFF\xFF\xFF",
'ignore' => ''
);
}
$this->read_resource_header();
$this->read_resource_footer();
$this->detect_type();
}
/* The public API */
public function is_text() {
if ( 'application/postscript' === $this->detected_type ) return true;
if ( 'text/plain' === $this->detected_type ) return true;
return false;
}
public function is_font() {
if ( $this->detected_type === 'application/font-ttf' ) return true;
if ( $this->detected_type === 'application/font-cff' ) return true;
if ( $this->detected_type === 'application/font-otf' ) return true;
if ( $this->detected_type === 'application/font-sntf' ) return true;
if ( $this->detected_type === 'application/vds.ms-opentype' ) return true;
if ( $this->detected_type === 'application/font-woff' ) return true;
if ( $this->detected_type === 'application/vnd.ms-fontobject' ) return true;
return false;
}
public function is_zip() {
if ( $this->detected_type === 'application/zip' ) return true;
if ( substr( $this->detected_type, -4 ) === '+zip' ) return true;
return false;
}
public function is_archive() {
if ( $this->detected_type === 'application/x-rar-compressed' ) return true;
if ( $this->detected_type === 'application/zip' ) return true;
if ( $this->detected_type === 'application/x-gzip' ) return true;
return false;
}
public function is_scriptable() {
if ( $this->detected_type === 'text/html' ) return true;
if ( $this->detected_type === 'application/pdf' ) return true;
if ( $this->detected_type === 'application/postscript' ) return true;
return false;
}
public function get_type() {
return $this->detected_type;
}
/**
* Helper functions.
* Execution is passed over to detect_type after the
* construct sets up the data.
*
*/
protected function read_resource_header() {
// We already have that many bytes...
if ( isset( $this->header{$this->num_bytes} ) )
return;
if ( is_string( $this->file ) ) {
$fp = fopen( $this->file, 'rb' );
$header = fread( $fp, $this->num_bytes );
fclose( $fp );
} else {
// The current position may not be at the start. Let's take it then set to
// start of file, read {$num_bytes} bytes then reset to last position.
$position = ftell( $this->file );
fseek( $this->file, 0, SEEK_SET );
$header = fread( $this->file, $this->num_bytes );
fseek( $this->file, $position, SEEK_SET );
}
$this->header = &$header;
}
protected function read_resource_footer() {
if ( isset( $this->footer{$this->num_bytes} ) )
return;
if ( is_string( $this->file ) ) {
$fp = fopen( $this->file, 'rb' );
fseek( $fp, -$this->num_bytes, SEEK_END );
$footer = fread( $fp, $this->num_bytes );
fclose( $fp );
} else {
// The current position may not be at the end. Let's take it then set to
// end of file, read {$num_bytes} bytes then reset to last position.
$position = ftell( $this->file );
fseek( $this->file, -$this->num_bytes, SEEK_END );
$footer = fread( $this->file, $this->num_bytes );
fseek( $this->file, $position, SEEK_SET );
}
$this->footer = &$footer;
}
protected function match_pattern( $pattern, $mask, $ignore ) {
if ( empty( $pattern ) || empty( $mask ) ) {
return false;
}
$s = 0;
$sequence = &$this->header;
$seq_len = strlen( $sequence );
$pattern_len = strlen( $pattern );
$mask_len = strlen( $mask );
if ( $pattern_len !== $mask_len ) {
return false;
}
// First we will set $s so that it ignores the first bytes if it needs to
if ( !empty( $ignore ) ) {
for ( $s = 0; $s < $seq_len; ) {
// This letter should not be ignored.
if ( strpos( $ignore, $sequence{$s} ) === false ) {
break;
}
++$s;
}
}
// Now we will compare. If it doesn't match the mask, we return false.
for ( $i = 0; $i < $pattern_len; ) {
$masked_data = $sequence{$s} & $mask{$i};
if ( $masked_data !== $pattern{$i} ) {
return false;
}
++$i; ++$s;
}
// Mask matched. This pattern matches.
return true;
}
protected function html_match_pattern( $pattern, $mask, $ignore ) {
if ( empty( $pattern ) || empty( $mask ) ) {
return false;
}
$s = 0; $i = 0;
$sequence = &$this->header;
$seq_len = strlen( $sequence );
$pattern_len = strlen( $pattern );
$mask_len = strlen( $mask );
if ( $pattern_len !== $mask_len ) {
return false;
}
// First we will set $s so that it ignores the first bytes if it needs to
if ( !empty( $ignore ) ) {
for (; $s < $seq_len; ) {
// This letter should not be ignored.
if ( strpos( $ignore, $sequence{$s} ) === false ) {
break;
}
++$s;
}
}
// Now we will compare. If it doesn't match the mask, we return false.
for (; $i < $pattern_len; ) {
$masked_data = $sequence{$s} & $mask{$i};
if ( $masked_data !== $pattern{$i} ) {
return false;
}
++$i; ++$s;
}
// Mask matched. This pattern matches if the last character is tag-terminating.
return strpos( self::$tag_terminating_character, $sequence{$s} );
}
protected function detect_type() {
if ( $this->sniff_images() ) return;
if ( $this->sniff_media() ) return;
if ( $this->sniff_fonts() ) return;
if ( $this->sniff_msoffice() ) return;
if ( $this->sniff_archive() ) return;
if ( $this->sniff_text() ) return;
if ( $this->sniff_unknown() ) return;
if ( $this->sniff_others() ) return;
}
/* Sniffer functions */
protected function sniff_images() {
$num_imgs = count( self::$image );
for ( $i = 0; $i < $num_imgs; $i++ ) {
$im = &self::$image[$i];
if ( $this->match_pattern( $im['pattern'], $im['mask'], $im['ignore'] ) ) {
$this->detected_type = $im['mime'];
return true;
}
}
return false;
}
protected function sniff_media() {
$num_media = count( self::$media );
for ( $i = 0; $i < $num_media; $i++ ) {
$m = &self::$media[$i];
if ( $this->match_pattern( $m['pattern'], $m['mask'], $m['ignore'] ) ) {
$this->detected_type = $m['mime'];
return true;
}
}
if ( $this->sniff_mp4() ) {
$this->detected_type = 'video/mp4';
return true;
}
return false;
}
protected function sniff_mp4() {
$sequence = &$this->header;
$seq_len = strlen( $sequence );
if ( $seq_len < 12 ) {
return false;
}
$box_size = substr( $sequence, 0, 4 );
$box_size = unpack( 'N', $box_size );
$box_size = $box_size[1];
if ( $seq_len < $box_size ) return false;
if ( $box_size % 4 ) return false;
if ( substr( $sequence, 4, 4 ) !== "\x66\x74\x79\x70" ) return false;
if ( substr( $sequence, 8, 3 ) === "\x6D\x70\x34" ) return true;
$i = 16;
while ( $i < $box_size ) {
if ( substr( $sequence, $i, 3 ) === "\x6D\x70\x34" ) return true;
$i += 4;
}
return false;
}
protected function sniff_fonts() {
$num_fonts = count( self::$fonts );
for ( $i = 0; $i < $num_fonts; $i++ ) {
$f = &self::$fonts[$i];
if ( $this->match_pattern( $f['pattern'], $f['mask'], $f['ignore'] ) ) {
$this->detected_type = $f['mime'];
return true;
}
}
return false;
}
protected function sniff_msoffice() {
// Yes, this function is a bit of a nightmare as far as code layout...
/// IT WORKS. Please don't change it functionally to "clean" it up.
$type = false;
$num_office = count( self::$ms_office );
for ( $i = 0; $i < $num_office; $i++ ) {
$o = &self::$ms_office[$i];
if ( $this->match_pattern( $o['pattern'], $o['mask'], $o['ignore'] ) ) {
$type = $o['mime'];
break;
}
}
// No match found... Do not continue
if ( $type === false ) {
return false;
}
// Powerpoint requires we read a bit further into the header of the document...
$this->num_bytes = 2056;
$this->read_resource_header();
$eof = trim( $this->footer, chr(0) );
$sof = trim( $this->header, chr(0) );
if ( $type === 'application/office-x' ) {
// [Content_Types].xml
if ( strpos( $sof, "\x5b\x43\x6f\x6e\x74\x65\x6e\x74\x5f\x54\x79\x70\x65\x73\x5d\x2e\x78\x6d\x6c" ) !== false ) {
$f_pos = strpos( $sof, "\x50\x4B\x03\x04", 4 );
if ( $f_pos !== false ) {
$s_pos = strpos( $sof, "\x50\x4B\x03\x04", $f_pos + 4 );
if ( $s_pos !== false ) {
// 26 chars after $s_pos ( 26 + strlen( $s_pos ) ) = 30
$type = substr( $sof, $s_pos + 30, 5 );
if ( strpos( $type, 'word/' ) !== false ) {
$type = 'application/msword';
} else if ( strpos( $type, 'ppt/' ) !== false ) {
$type = 'application/vnd.ms-powerpoint';
} else if ( strpos( $type, 'xl/' ) !== false ) {
$type = 'application/vnd.ms-excel';
} else if ( strpos( $type, 'x/' ) !== false ) {
$type = 'application/ms-office';
} else {
return false;
}
} else {
return false;
}
} else {
return false;
}
} else {
return false;
}
} else if ( $type === 'application/office' ) {
// Word.Document.
if ( strpos( $eof, "\x57\x6F\x72\x64\x2E\x44\x6F\x63\x75\x6D\x65\x6E\x74\x2E" ) !== false ) {
$type = 'application/msword';
// Microsoft Excel
} else if ( strpos( $eof, "\x4D\x69\x63\x72\x6F\x73\x6F\x66\x74\x20\x45\x78\x63\x65\x6C" ) !== false ) {
$type = 'application/vnd.ms-excel';
// P.o.w.e.r.P.o.i.n.t. .D.o.c.u.m.e.n.t.
} else if ( strpos( $sof, "\x50\x00\x6F\x00\x77\x00\x65\x00\x72\x00\x50\x00\x6f\x00\x69\x00\x6e\x00\x74\x00\x20\x00\x44\x00\x6f\x00\x63\x00\x75\x00\x6d\x00\x65\x00\x6e\x00\x74\x00" ) !== false ) {
$type = 'application/vnd.ms-powerpoint';
} else {
return false;
}
// What happended there?
} else {
return false;
}
$this->detected_type = $type;
return true;
}
protected function sniff_archive() {
$num_archives = count( self::$archive );
for ( $i = 0; $i < $num_archives; $i++ ) {
$a = &self::$archive[$i];
if ( $this->match_pattern( $a['pattern'], $a['mask'], $a['ignore'] ) ) {
$this->detected_type = $a['mime'];
return true;
}
}
return false;
}
protected function sniff_text() {
$num_texts = count( self::$text );
for ( $i = 0; $i < $num_texts; $i++ ) {
$t = &self::$text[$i];
if ( $this->match_pattern( $t['pattern'], $t['mask'], $t['ignore'] ) ) {
if ( $this->has_binary_data() ) {
return false;
} else {
$this->detected_type = $t['mime'];
return true;
}
}
}
return false;
}
protected function sniff_unknown() {
$num_unknown = count( self::$unknown );
for ( $i = 0; $i < $num_unknown; $i++ ) {
$u = &self::$unknown[$i];
if ( 'text/html' === $u['mime'] ) {
if ( $this->html_match_pattern( $u['pattern'], $u['mask'], $u['ignore'] ) ) {
$this->detected_type = 'text/html';
return true;
}
} else {
if ( $this->match_pattern( $u['pattern'], $u['mask'], $u['ignore'] ) ) {
$this->detected_type = $u['mime'];
return true;
}
}
}
return false;
}
protected function sniff_others() {
$num_others = count( self::$others );
for ( $i = 0; $i < $num_others; $i++ ) {
$o = &self::$others[$i];
if ( $this->match_pattern( $o['pattern'], $o['mask'], $o['ignore'] ) ) {
$this->detected_type = $o['mime'];
return true;
}
}
return false;
}
protected function has_binary_data() {
static $binary_chars;
if ( is_string( $binary_chars ) )
$binary_chars = str_split( $this->binary_characters );
$num_chars = count( $binary_chars );
for ( $i = 0; $i < $num_chars; $i++ ) {
if ( strpos( $this->header, $binary_chars[$i] ) !== false ) {
return true;
}
}
return false;
}
}
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