Manual:Configuring file uploads

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MediaWiki supports uploading and integration of media files. This page describes the technical aspects of this feature, see Manual:Image administration and Help:Images for general usage information.

Starting from MediaWiki version 1.1, uploads are initially disabled by default, due to security considerations. Uploads can be enabled via a configuration setting, although it is recommended that you check certain prerequisites first.

Prerequisites

Make sure uploads are enabled in PHP

The following needs to be set in php.ini :

file_uploads = On

If this is not set, PHP scripts cannot use the upload functions, and MediaWiki's uploads will not be enabled.

If the open_basedir directive is set, it must include both the destination upload folder in your MediaWiki installation ("{$IP}/images") and the 'upload_tmp_dir' folder (default system folder if not set). If this is in effect, also check if your hoster has properly configured 'sys_temp_dir', because sometimes they forget about that as well and you cannot write temporary files at all (upload, session or any other tmp file).

The addition of the 'upload_tmp_dir' can avoid messages like "Could not find file "/var/tmp/php31aWnF" (where in this example the 'upload_tmp_dir' is '/var/tmp'). Read more about PHP file uploads at File upload basics and in particular move_uploaded_file().

The formal value for the variable is a boolean expression. PHP treats each string not recognized as a False value as true, hence the often used "on" value yields the same result.

Check for Windows and IIS users

Set %SystemRoot%\TEMP to have permissions for the Internet Guest Account (IUSR_MachineName, or IUSR for IIS 7+): Read, write and execute;

Check directory security

The upload directory needs to be configured so that it is not possible for an end user to upload and execute other scripts, which could then exploit access to your web directory and damage your wiki or web site.

Set the /images folder (or the /uploads folder in previous versions) to have permission "755":

User can read, write and execute;
Group can read and execute;
World can read and execute.

Only the folders must have executable permissions. Files must not have the executable permission. In Linux, to remove executable permissions from all files in a folder, and to add executable permissions to the folder and all sub folders: chmod -x+X uploads_folder -R

If using SELinux , make sure to adjust the ACLs accordingly (see there).

Check webserver security

See Manual:Security#Upload security for changes to make to your webserver configuration to prevent uploaded files from executing code or having browsers execute malicious files.

Restrict directory listing on images folder

If you don't want a public user to list your images folder, an option is to set this up in your apache configuration:

        <Directory /var/www/wiki/images>
                Options -Indexes
        </Directory>

Check .htaccess file

The images directory in the MediaWiki installation folder contains an .htaccess file with some configurations on it. The goal of this file is to make the upload folder more secure, and if you place your upload directory somewhere else, it's recommended to also copy the .htaccess file to the new location, or apply that configuration on the server directly. However, some of those configurations may cause conflicts or errors, depending on how the server is configured.

Some things to take into account:

If the server doesn't allow to set or override directives in .htaccess files, accessing any file under that folder may result in a generic "HTTP 500 error". If that's the case, you should comment-out the lines, and apply those directives directly on the server configuration files. The directives that are most likely causing the problems are AddType —which prevents HTML and PHP files from being served as HTML—, and php_admin_flag —which would prevent PHP files from being parsed and executed on the server as such.

Setting uploads on/off

MediaWiki version:

≥ 1.5

In MediaWiki version 1.5 and later, the attribute to be set resides in LocalSettings.php and $wgEnableUploads is set as follows:

$wgEnableUploads = true; # Enable uploads

To disable upload functionality, set the attribute to false:

$wgEnableUploads = false; # Disable uploads

Using a central repository

InstantCommons is a feature, enabled with a configuration change, which gives you immediate access to the millions of free (freely licensed) files in Wikimedia Commons.

Upload permissions

Per default, all registered users can upload files. To restrict this, you have to change $wgGroupPermissions :

To prevent normal users from uploading files:
$wgGroupPermissions['user']['upload'] = false;
To create a special group called "uploadaccess", and allow members of that group to upload files:
$wgGroupPermissions['uploadaccess']['upload'] = true;
To allow "autoconfirmed" (non-newbie) users to upload files:
$wgGroupPermissions['autoconfirmed']['upload'] = true;

The right to replace existing files is handled by an extra permission, called reupload:

To prevent normal users from overriding existing files:
$wgGroupPermissions['user']['reupload'] = false;
To allow "autoconfirmed" (non-newbie) users to replace existing files:
$wgGroupPermissions['autoconfirmed']['reupload'] = true;

If a ForeignFileRepo is set, the right to replace those files locally is handled by an special permission, called reupload-shared:

To prevent normal users from overriding filerepo files locally:
$wgGroupPermissions['user']['reupload-shared'] = false;
To allow "autoconfirmed" (non-newbie) users to replace filerepo files locally:
$wgGroupPermissions['autoconfirmed']['reupload-shared'] = true;

See Manual:User rights for details on user rights, and Manual:Preventing access for more information about restricting access.

Configuring file types

You can add $wgFileExtensions in LocalSettings.php to allow uploads of other desired file types. For example, you can change the $wgFileExtensions line to look something like

$wgFileExtensions = [ 'png', 'gif', 'jpg', 'jpeg', 'doc',
	'xls', 'mpp', 'pdf', 'ppt', 'tiff', 'bmp', 'docx', 'xlsx',
	'pptx', 'ps', 'odt', 'ods', 'odp', 'odg'
];

or

$wgFileExtensions = array_merge( $wgFileExtensions, [
	'doc', 'xls', 'mpp', 'pdf', 'ppt', 'xlsx', 'jpg', 
	'tiff', 'odt', 'odg', 'ods', 'odp'
] );

or

# Add new types to the existing list from the default settings.
$wgFileExtensions[] = 'docx';
$wgFileExtensions[] = 'xls';
$wgFileExtensions[] = 'pdf';
$wgFileExtensions[] = 'mpp';
$wgFileExtensions[] = 'odt';
$wgFileExtensions[] = 'ods';

However, certain file extensions are prohibited ($wgProhibitedFileExtensions , formerly $wgFileBlacklist for MediaWiki 1.36 and earlier) and cannot be uploaded even if added to $wgFileExtensions. To upload files with prohibited extensions, you must modify $wgProhibitedFileExtensions . For instance, to allow users to upload Windows executables:

$wgFileExtensions[] = 'exe';
$wgProhibitedFileExtensions = array_diff( $wgProhibitedFileExtensions, [ 'exe' ] );

In addition, $wgMimeTypeExclusions (formerly $wgMimeTypeBlacklist ) prevents certain file types based on MIME type; .zip files, for example, are prohibited based on MIME type (MediaWiki version 1.14 up to 1.17).

You can also set $wgStrictFileExtensions

$wgStrictFileExtensions = false;

to allow most types of file to be uploaded. However, prohibited file types and MIME types will still not be permitted.

Warning: Setting $wgStrictFileExtensions to false, or altering $wgProhibitedFileExtensions could result in either you or your users being exposed to security risks.

If you are getting the error "The file is corrupt or has an incorrect extension", make sure MIME type detection is working properly.

If you decide to allow any kind of file, make sure your mime detection is working and think about enabling virus scans for uploads .

To enable zip extension (tested in MediaWiki v1.19.23) the following will be necessary in the LocalSettings.php file:

$wgFileExtensions[] = 'zip';
// $wgTrustedMediaFormats[] = 'ARCHIVE';
$wgTrustedMediaFormats[] = 'application/zip';

Log in

By default anonymous uploads are not allowed. You must register and log in before the upload file link appears in the toolbox.

Thumbnailing

For information about automatic rendering/thumbnailing of images, see Image thumbnailing . For problems with thumbnailing, see Image Thumbnails not working and/or appearing.

MediaWiki version:

≥ 1.11

If the file is not visual (like an Image or Video) a fileicon is used instead. These are generated by the iconThumb() function in the File class in the FileRepo group. Icons stored in "$wgStyleDirectory/common/images/icons/" in a "fileicon-$extension.png"-format.

Set maximum size for file uploads

Browsers tell the server the size of the file to be uploaded before it actually sends the file.

If the upload is too big, it is rejected by the target (server) and the upload fails providing multiple errors depending at which layer the limit was imposed:

If it's a server limit (nginx, Apache) on the maximum amount of transmitted data, it may simply fail with a HTTP 500 error or HTTP 413 – Request entity too large.
If the limit it's at the PHP level, if post_max_size is hit, you may get a generic HTTP 500 error (or simply a blank page) otherwise, MediaWiki should give a more meaningful error message.

post_max_size and upload_max_filesize in php.ini

By default, the configuration code in php.ini limits the size of files to be uploaded to 2 megabytes (and the maximum size of a post operation to 8 megabytes). To allow uploading of larger files, edit these parameters in php.ini:

post_max_size, 8 megabytes large by default
upload_max_filesize, 2 megabytes large by default

This may require root access to the server. (If you are on a shared host, contact your server administrator.)

If you are increasing the maximum upload filesize to a value greater than 100MB, you will need to add $wgMaxUploadSize with the new upload filesize value to LocalSettings.php.

Locating the php.ini file

The location of the php.ini file varies on the distribution you are using. See Manual:Php.ini for instructions for locating the correct php.ini used by your web server (as opposed to the php.ini used by the command line binary).

Multiple websites hosted on a server

If you have more than one website hosted on a server and want to change only for MediaWiki, insert into your /etc/apache2/sites-enabled/your_wiki_site.com inside <Virtual Host>:

php_value upload_max_filesize 100M
php_value post_max_size 100M

Both above settings also work in a .htaccess file if your site uses mod_php. If your site uses PHP >= 5.3 and allows it, you can place php.ini directives in .user.ini files instead.

web server limits

Your web server may impose further limits on the size of files allowed for upload. For Apache, one of the relevant settings is LimitRequestBody. ^[1] For Nginx, client_max_body_size is the relevant setting.^[2] For Lighttpd, server.max-request-size is what may need modification.^[3]

After editing your php.ini or web server configuration, you will need to restart Apache or IIS.

Ubuntu 16.04: sudo service apache2 restart

You may also need to restart php5-fpm after altering your PHP (or nginx server) configuration.

(sudo /etc/init.d/php5-fpm restart in Linux, for example.)

uploading too large of files warning

MediaWiki itself issues a warning if you try to upload files larger than what is specified by $wgUploadSizeWarning option. This is independent of the hard limit imposed by PHP.

temporary upload limits

Temporary changes to upload limits (when using multiple wikis on a farm, for example) can be altered by adding the lines:

ini_set( 'post_max_size', '50M' );
ini_set( 'upload_max_filesize', '50M' );

to the MediaWiki LocalSettings.php configuration file for each wiki. In this example the PHP limit is set at 50 Mb. Note that these settings will not override the maximum settings set above (since the core php.ini and apache2 php.ini files set the absolute maximum). This method sets maximums that are less than the absolute maximum.

IIS7 upload limit

By default, IIS7^[4] on Windows 2008 allows only 30MB to be uploaded via a web application. Larger files will return a 404 error after the upload. If you have this problem, you can solve it by increasing the maximum file size by adding the following code to ‎<system.webServer> in the web.config file:

<security>
  <requestFiltering>
    <requestLimits maxAllowedContentLength="50000000" />
  </requestFiltering>
</security>

With the above maxAllowedContentLength, users can upload files that are 50,000,000 bytes (50 MB) in size. This setting will work immediately without restarting IIS services. The web.config file is located in the root directory of your web site.

To allow uploading files up to 2G:

add the following lines to LocalSettings.php:

$wgUploadSizeWarning = 2147483647;
$wgMaxUploadSize = 2147483647;

Also, modify the following lines in php.ini :

memory_limit = 2048M (this line may not be necessary)
post_max_size = 2048M
upload_max_filesize = 2048M

In the IIS web.config file, override the value of maxRequestLength. For example, the following entry in web.config allows files that are less than or equal to 2 gigabytes (GB) to be uploaded:

<httpRuntime maxRequestLength="2097151" executionTimeout="18000"/>

With IIS 7, you also need to configure it to allow large uploads. This is found by clicking “Request Filtering > Edit Feature Settings” in the IIS section in the middle of the window. Set the ”Maximum allowed content length (Bytes)” field to 2147482624. If you don’t see "Request Filtering" in the IIS section, it needs enabled via Internet Information Services > World Wide Web Services > Security in the "Turn Windows features on or off" area in Control Panel.

If the above tip does not enable large uploads, then open a command prompt and execute this command as well:

%windir%\system32\inetsrv\appcmd set config -section:requestFiltering -requestLimits.maxAllowedContentLength: 2147482624

Allowing Java JAR Uploads

The details described in this section may no longer work. $wgAllowJavaUploads variable has been removed in MW 1.39.0.

By default, MediaWiki will scan all uploads that appear to be ZIP archives and reject any that contain Java .class files. This is a security measure to prevent users uploading a malicious Java applet. For non-public sites only, use the following to disable this check:

$wgAllowJavaUploads = true;

This setting can be used as a work around for allowing MIME types to be accepted indiscriminately. For example, if you attempt to upload a .doc file created by Word 2007, no matter the text list you provide and MIME type checking you invoke or prohibit, you will receive the message:

The file is a corrupt or otherwise unreadable ZIP file. It cannot be properly checked for security.

.doc files saved by Word 2007 (and possibly later versions) contain a small embedded ZIP archive storing metadata that is not representable in the binary .doc format as used by earlier versions of Word. This embedded ZIP data confuses the Java archive scanner, causing the .doc file to be rejected. Files in the newer .docx file format are valid ZIP archives in their entirety, and can be uploaded successfully without setting $wgAllowJavaUploads .

Uploading directly from a URL ("Sideloading")

If you want to allow a user to directly upload files from a URL, instead of from a file on their local computer, set $wgAllowCopyUploads = true.

By default, upload by URL are only possible using the API (or extensions such as UploadWizard ). To make the option usable from Special:Upload, you need to set $wgCopyUploadsFromSpecialUpload to true as well. On the upload form, you will then see an additional field for the URL, below the usual filename field. The URL field is greyed out per default, but can be activated by activating the radiobutton (checkbox) to the left of the field.

In order to use this feature, users must have the user right upload_by_url. This right was granted to sysops by default until MediaWiki 1.20 but it now needs to be granted explicitly. To allow this to normal users, set

 $wgGroupPermissions['user']['upload_by_url'] = true;

Keep in mind that allowing uploads directly from an arbitrary location on the web makes it easier to upload random, unwanted material, and it might be misunderstood as an invitation to upload anything that people might come across on the web.

PHP's cURL support must be enabled to support this feature. Configure your PHP when installing using the --with-curl option.

If your server is accessing internet through a proxy then $wgHTTPProxy needs to be set accordingly. Either you supply it directly or, if your server supplies the environment variable http_proxy see your phpinfo(), then you could use the following code in your LocalSettings.php:

/*
 * Proxy to use for CURL requests.
 */
if ( isset( $_ENV['http_proxy'] )) $wgHTTPProxy = $_ENV['http_proxy'];

Mass uploading

A number of tools are available for uploading multiple files in one go rather than each file separately:

Extension	Description	Release status	Requirements
Extension:UploadWizard	Used on Wikimedia Commons	Stable	MediaWiki 1.23+
Extension:MsUpload	Allows a user to upload multiple files including by dragging & dropping files.	Stable	1.32+
Extension:SimpleBatchUpload	Basic, no-frills uploading of multiple files to MediaWiki	Stable	1.31+
Extension:VisualData/File_upload	Includes a fully-configurable multiple file upload with filename formula and CRUD operations	Stable	1.35+
Commonist (external link to Wikimedia Commons)			Requires file upload via `api.php`. with python: m:Uploadmultiple.py imageharvest.py - copy multiple images to a wiki from a specified URL. imagetransfer.py - copies images to another wiki
importImages.php	"Place the files on the server in a readable location and execute the `maintenance/importImages.php` script from the command line."^[5]

Upload directory

Whenever an image is uploaded, several things are created:

An article in the file namespace with the name of the file, e.g. File:MyPicture.png. This page is stored and can be edited like any other page.
The file itself is stored into the folder on the file system, which is configured in $wgUploadDirectory or into one if its subfolders (see below).
If thumbnailing is available, thumbnailed versions of the file will be created when necessary (such as for the usage on the file description page. These are stored in the thumb directory of the image directory, in a separate directory for each main file.

If $wgHashedUploadDirectory is enabled (by default), MediaWiki creates several subdirectories in the images directory.

If $wgHashedUploadDirectory is set to true, uploaded files will be distributed into sub-directories of $wgUploadDirectory based on the first two characters of the md5 hash of the filename. (e.g. $IP/images/a/ab/foo.jpg) Creation of such subdirectories is handled automatically. This is used to avoid having too many files in one folder because some filesystems don't perform well with large numbers of files in one folder.

If you only maintain a small wiki with few uploaded images, you could turn this off by setting $wgHashedUploadDirectory = false, all images are uploaded in $wgUploadDirectory itself. (e.g. $IP/images/foo.jpg)

Multiwiki sites

Make sure you've changed the site location in LocalSettings.php from, e.g. /var/lib/mediawiki to wherever your installation is, and created a writeable images directory (most of the rest can be symlinked).

Not doing so will mysteriously break image uploads.

Configuring the upload form

The upload form message provided with the default MediaWiki installation (which appears when you click "Upload file" link or go to Special:Upload link) may not go very well for you.

For that case you can edit MediaWiki:Uploadtext contents and provide your own text. If your wiki site is multilanguage don't forget to edit localized versions like MediaWiki:Uploadtext/de.

On the MediaWiki:Licenses page you can customize a drop-down list of licenses for uploads of your site. See the documentation of this feature.

Take into account that localized versions like MediaWiki:Licenses/de won't work by default. To enable them you must configure the $wgForceUIMsgAsContentMsg variable.

Edit MediaWiki:Upload-default-description to add an initial text to the "Summary" field of your upload form (for example your wiki site has a universal template for upload summaries and you want everyone to use that template).

Known problems on Windows

Running MediaWiki on Windows server has some restrictions in allowed filenames, due to a PHP bug. PHP can't handle filenames with non-ascii characters on it correctly, and MediaWiki will refuse to upload files containing such characters to prevent broken uploads (task T3780), with the message This wiki does not support filenames with special characters..

Since MediaWiki 1.31 MediaWiki can handle filenames with non-ascii characters if it's using PHP 7.1 or later.

Known problems with database names having non-alphanumeric characters

Tracked in Phabricator
Task T46066

If $wgDBname contains non-alphanumeric characters, uploads may fail with errors like Could not create directory "mwstore://local-backend/local-public/<path>".. This is caused by an internal check for valid container name for file backend, but it's constructed using $wgDBname.

Since MediaWiki 1.26, it allows uploads when $wgDBname contains dots.

References

↑ core - Apache HTTP Server Version 2.4 - LimitRequestBody Directive, Apache manual
↑ client_max_body_size, Nginx manual
↑ server.max-request-size, Lighthttpd manual
↑ IIS7 is a new revision (version 7.0) of the Internet Information Services that is part of Windows Vista and the next Windows Server version.
↑ http://xpt.sourceforge.net/techdocs/language/wiki/wikimedia/wkm07-MediaWikiImport/index.html#mass_image_upload_zip_

[limitrequestbody-1] re - Apache HTTP Server Version 2.4 - LimitRequestBody Directive, Apache manual

[client_max_body_size-2] t_max_body_size, Nginx manual

[server.max-request-size-3] server.max-request-size, Lighthttpd manual

[4] IIS7 is a new revision (version 7.0) of the Internet Information Services that is part of Windows Vista and the next Windows Server version.

[5] ttp://xpt.sourceforge.net/techdocs/language/wiki/wikimedia/wkm07-MediaWikiImport/index.html#mass_image_upload_zip_

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