MediaWiki  REL1_19
Public Member Functions | Protected Member Functions | Protected Attributes | Private Member Functions
IEContentAnalyzer Class Reference

This class simulates Microsoft Internet Explorer's terribly broken and insecure MIME type detection algorithm. More...

List of all members.

Public Member Functions

 __construct ()
 constructor
 getMimesFromData ($fileName, $chunk, $proposed)
 Get the untranslated MIME types for all known versions.
 getRealMimesFromData ($fileName, $chunk, $proposed)
 Get the MIME types from getMimesFromData(), but convert the result from IE's idiosyncratic private types into something other apps will understand.
 translateMimeType ($type)
 Translate a MIME type from IE's idiosyncratic private types into more commonly understood type strings.

Protected Member Functions

 getDataFormat ($version, $type)
 getMimeTypeForVersion ($version, $fileName, $chunk, $proposed)
 Get the MIME type for a given named version.
 sampleData ($version, $chunk)
 Do heuristic checks on the bulk of the data sample.

Protected Attributes

 $addedTypes
 Changes to the type table in later versions of IE.
 $baseTypeTable
 Relevant data taken from the type table in IE 5.
 $registry
 An approximation of the "Content Type" values in HKEY_CLASSES_ROOT in a typical Windows installation.
 $typeTable = array()
 Type table with versions expanded.
 $versions = array( 'ie05', 'ie06', 'ie07', 'ie07.strict', 'ie07.nohtml' )
 IE versions which have been analysed to bring you this class, and for which some substantive difference exists.

Private Member Functions

 checkBinaryHeaders ($version, $chunk)
 Check for binary headers at the start of the chunk Confirmed same in 5 and 7.
 checkTextHeaders ($version, $chunk)
 Check for text headers at the start of the chunk Confirmed same in 5 and 7.

Detailed Description

This class simulates Microsoft Internet Explorer's terribly broken and insecure MIME type detection algorithm.

It can be used to check web uploads with an apparently safe type, to see if IE will reinterpret them to produce something dangerous.

It is full of bugs and strange design choices should not under any circumstances be used to determine a MIME type to present to a user or client. (Apple Safari developers, this means you too.)

This class is based on a disassembly of IE 5.0, 6.0 and 7.0. Although I have attempted to ensure that this code works in exactly the same way as Internet Explorer, it does not share any source code, or creative choices such as variable names, thus I (Tim Starling) claim copyright on it.

It may be redistributed without restriction. To aid reuse, this class does not depend on any MediaWiki module.

Definition at line 21 of file IEContentAnalyzer.php.

Constructor & Destructor Documentation

IEContentAnalyzer::__construct ( )

constructor

Definition at line 309 of file IEContentAnalyzer.php.

References $addedTypes, and $version.

Member Function Documentation

IEContentAnalyzer::checkBinaryHeaders ( $  version,
$  chunk 
) [private]

Check for binary headers at the start of the chunk Confirmed same in 5 and 7.

Parameters:
$version
$chunk
Returns:
bool|string

Definition at line 580 of file IEContentAnalyzer.php.

Referenced by getMimeTypeForVersion().

Here is the caller graph for this function:

IEContentAnalyzer::checkTextHeaders ( $  version,
$  chunk 
) [private]

Check for text headers at the start of the chunk Confirmed same in 5 and 7.

Parameters:
$version
$chunk
Returns:
bool|string

Definition at line 554 of file IEContentAnalyzer.php.

Referenced by getMimeTypeForVersion().

Here is the caller graph for this function:

IEContentAnalyzer::getDataFormat ( $  version,
$  type 
) [protected]
Parameters:
$version
$type
Returns:
int|string

Definition at line 832 of file IEContentAnalyzer.php.

References $version.

Referenced by getMimeTypeForVersion().

Here is the caller graph for this function:

IEContentAnalyzer::getMimesFromData ( $  fileName,
$  chunk,
$  proposed 
)

Get the untranslated MIME types for all known versions.

Parameters:
$fileNameString: the file name (unused at present)
$chunkString: the first 256 bytes of the file
$proposedString: the MIME type proposed by the server
Returns:
Array: map of IE version to detected mime type

Definition at line 370 of file IEContentAnalyzer.php.

References $version, and getMimeTypeForVersion().

Referenced by getRealMimesFromData().

Here is the call graph for this function:

Here is the caller graph for this function:

IEContentAnalyzer::getMimeTypeForVersion ( $  version,
$  fileName,
$  chunk,
$  proposed 
) [protected]

Get the MIME type for a given named version.

Parameters:
$version
$fileName
$chunk
$proposed
Returns:
bool|string

Definition at line 386 of file IEContentAnalyzer.php.

References $ext, $result, $version, checkBinaryHeaders(), checkTextHeaders(), getDataFormat(), and sampleData().

Referenced by getMimesFromData().

Here is the call graph for this function:

Here is the caller graph for this function:

IEContentAnalyzer::getRealMimesFromData ( $  fileName,
$  chunk,
$  proposed 
)

Get the MIME types from getMimesFromData(), but convert the result from IE's idiosyncratic private types into something other apps will understand.

Parameters:
$fileNameString: the file name (unused at present)
$chunkString: the first 256 bytes of the file
$proposedString: the MIME type proposed by the server
Returns:
Array: map of IE version to detected mime type

Definition at line 332 of file IEContentAnalyzer.php.

References getMimesFromData().

Here is the call graph for this function:

IEContentAnalyzer::sampleData ( $  version,
$  chunk 
) [protected]

Do heuristic checks on the bulk of the data sample.

Search for HTML tags.

Parameters:
$version
$chunk
Returns:
array

Definition at line 681 of file IEContentAnalyzer.php.

References $version.

Referenced by getMimeTypeForVersion().

Here is the caller graph for this function:

IEContentAnalyzer::translateMimeType ( $  type)

Translate a MIME type from IE's idiosyncratic private types into more commonly understood type strings.

Parameters:
$type
Returns:
string

Definition at line 344 of file IEContentAnalyzer.php.

Member Data Documentation

IEContentAnalyzer::$addedTypes [protected]
Initial value:
 array(
                'ie07' => array(
                        'text' => array( 'text/xml', 'application/xml' )
                ),
        )

Changes to the type table in later versions of IE.

Definition at line 49 of file IEContentAnalyzer.php.

Referenced by __construct().

IEContentAnalyzer::$baseTypeTable [protected]
Initial value:
 array(
                'ambiguous'  => array(
                        'text/plain',
                        'application/octet-stream',
                        'application/x-netcdf', 
                ),
                'text'  => array(
                        'text/richtext', 'image/x-bitmap', 'application/postscript', 'application/base64',
                        'application/macbinhex40', 'application/x-cdf', 'text/scriptlet'
                ),
                'binary'  => array(
                        'application/pdf', 'audio/x-aiff', 'audio/basic', 'audio/wav', 'image/gif',
                        'image/pjpeg', 'image/jpeg', 'image/tiff', 'image/x-png', 'image/png', 'image/bmp',
                        'image/x-jg', 'image/x-art', 'image/x-emf', 'image/x-wmf', 'video/avi',
                        'video/x-msvideo', 'video/mpeg', 'application/x-compressed',
                        'application/x-zip-compressed', 'application/x-gzip-compressed', 'application/java',
                        'application/x-msdownload'
                ),
                'html'  => array( 'text/html' ),
        )

Relevant data taken from the type table in IE 5.

Definition at line 25 of file IEContentAnalyzer.php.

IEContentAnalyzer::$registry [protected]

An approximation of the "Content Type" values in HKEY_CLASSES_ROOT in a typical Windows installation.

Used for extension to MIME type mapping if detection fails.

Definition at line 61 of file IEContentAnalyzer.php.

IEContentAnalyzer::$typeTable = array() [protected]

Type table with versions expanded.

Definition at line 306 of file IEContentAnalyzer.php.

IEContentAnalyzer::$versions = array( 'ie05', 'ie06', 'ie07', 'ie07.strict', 'ie07.nohtml' ) [protected]

IE versions which have been analysed to bring you this class, and for which some substantive difference exists.

These will appear as keys in the return value of getRealMimesFromData(). The names are chosen to sort correctly.

Definition at line 301 of file IEContentAnalyzer.php.

The documentation for this class was generated from the following file: