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Diffstat (limited to 'www/wiki/includes/libs/mime/MimeAnalyzer.php')
| -rw-r--r-- | www/wiki/includes/libs/mime/MimeAnalyzer.php | 1200 |
1 files changed, 1200 insertions, 0 deletions
diff --git a/www/wiki/includes/libs/mime/MimeAnalyzer.php b/www/wiki/includes/libs/mime/MimeAnalyzer.php new file mode 100644 index 00000000..8d842cbb --- /dev/null +++ b/www/wiki/includes/libs/mime/MimeAnalyzer.php @@ -0,0 +1,1200 @@ +<?php +/** + * Module defining helper functions for detecting and dealing with MIME types. + * + * 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 + * + * @file + */ +use Psr\Log\LoggerAwareInterface; +use Psr\Log\LoggerInterface; + +/** + * Implements functions related to MIME types such as detection and mapping to file extension + * + * @since 1.28 + */ +class MimeAnalyzer implements LoggerAwareInterface { + /** @var string */ + protected $typeFile; + /** @var string */ + protected $infoFile; + /** @var string */ + protected $xmlTypes; + /** @var callable */ + protected $initCallback; + /** @var callable */ + protected $detectCallback; + /** @var callable */ + protected $guessCallback; + /** @var callable */ + protected $extCallback; + /** @var array Mapping of media types to arrays of MIME types */ + protected $mediaTypes = null; + /** @var array Map of MIME type aliases */ + protected $mimeTypeAliases = null; + /** @var array Map of MIME types to file extensions (as a space separated list) */ + protected $mimetoExt = null; + + /** @var array Map of file extensions types to MIME types (as a space separated list) */ + public $mExtToMime = null; // legacy name; field accessed by hooks + + /** @var IEContentAnalyzer */ + protected $IEAnalyzer; + + /** @var string Extra MIME types, set for example by media handling extensions */ + private $extraTypes = ''; + /** @var string Extra MIME info, set for example by media handling extensions */ + private $extraInfo = ''; + + /** @var LoggerInterface */ + private $logger; + + /** + * Defines a set of well known MIME types + * This is used as a fallback to mime.types files. + * An extensive list of well known MIME types is provided by + * the file mime.types in the includes directory. + * + * This list concatenated with mime.types is used to create a MIME <-> ext + * map. Each line contains a MIME type followed by a space separated list of + * extensions. If multiple extensions for a single MIME type exist or if + * multiple MIME types exist for a single extension then in most cases + * MediaWiki assumes that the first extension following the MIME type is the + * canonical extension, and the first time a MIME type appears for a certain + * extension is considered the canonical MIME type. + * + * (Note that appending the type file list to the end of self::$wellKnownTypes + * sucks because you can't redefine canonical types. This could be fixed by + * appending self::$wellKnownTypes behind type file list, but who knows + * what will break? In practice this probably isn't a problem anyway -- Bryan) + */ + protected static $wellKnownTypes = <<<EOT +application/ogg ogx ogg ogm ogv oga spx opus +application/pdf pdf +application/vnd.oasis.opendocument.chart odc +application/vnd.oasis.opendocument.chart-template otc +application/vnd.oasis.opendocument.database odb +application/vnd.oasis.opendocument.formula odf +application/vnd.oasis.opendocument.formula-template otf +application/vnd.oasis.opendocument.graphics odg +application/vnd.oasis.opendocument.graphics-template otg +application/vnd.oasis.opendocument.image odi +application/vnd.oasis.opendocument.image-template oti +application/vnd.oasis.opendocument.presentation odp +application/vnd.oasis.opendocument.presentation-template otp +application/vnd.oasis.opendocument.spreadsheet ods +application/vnd.oasis.opendocument.spreadsheet-template ots +application/vnd.oasis.opendocument.text odt +application/vnd.oasis.opendocument.text-master otm +application/vnd.oasis.opendocument.text-template ott +application/vnd.oasis.opendocument.text-web oth +application/javascript js +application/x-shockwave-flash swf +audio/midi mid midi kar +audio/mpeg mpga mpa mp2 mp3 +audio/x-aiff aif aiff aifc +audio/x-wav wav +audio/ogg oga spx ogg opus +audio/opus opus ogg oga ogg spx +image/x-bmp bmp +image/gif gif +image/jpeg jpeg jpg jpe +image/png png +image/svg+xml svg +image/svg svg +image/tiff tiff tif +image/vnd.djvu djvu +image/x.djvu djvu +image/x-djvu djvu +image/x-portable-pixmap ppm +image/x-xcf xcf +text/plain txt +text/html html htm +video/ogg ogv ogm ogg +video/mpeg mpg mpeg +EOT; + + /** + * Defines a set of well known MIME info entries + * This is used as a fallback to mime.info files. + * An extensive list of well known MIME types is provided by + * the file mime.info in the includes directory. + */ + protected static $wellKnownInfo = <<<EOT +application/pdf [OFFICE] +application/vnd.oasis.opendocument.chart [OFFICE] +application/vnd.oasis.opendocument.chart-template [OFFICE] +application/vnd.oasis.opendocument.database [OFFICE] +application/vnd.oasis.opendocument.formula [OFFICE] +application/vnd.oasis.opendocument.formula-template [OFFICE] +application/vnd.oasis.opendocument.graphics [OFFICE] +application/vnd.oasis.opendocument.graphics-template [OFFICE] +application/vnd.oasis.opendocument.image [OFFICE] +application/vnd.oasis.opendocument.image-template [OFFICE] +application/vnd.oasis.opendocument.presentation [OFFICE] +application/vnd.oasis.opendocument.presentation-template [OFFICE] +application/vnd.oasis.opendocument.spreadsheet [OFFICE] +application/vnd.oasis.opendocument.spreadsheet-template [OFFICE] +application/vnd.oasis.opendocument.text [OFFICE] +application/vnd.oasis.opendocument.text-template [OFFICE] +application/vnd.oasis.opendocument.text-master [OFFICE] +application/vnd.oasis.opendocument.text-web [OFFICE] +application/javascript text/javascript application/x-javascript [EXECUTABLE] +application/x-shockwave-flash [MULTIMEDIA] +audio/midi [AUDIO] +audio/x-aiff [AUDIO] +audio/x-wav [AUDIO] +audio/mp3 audio/mpeg [AUDIO] +application/ogg audio/ogg video/ogg [MULTIMEDIA] +image/x-bmp image/x-ms-bmp image/bmp [BITMAP] +image/gif [BITMAP] +image/jpeg [BITMAP] +image/png [BITMAP] +image/svg+xml [DRAWING] +image/tiff [BITMAP] +image/vnd.djvu [BITMAP] +image/x-xcf [BITMAP] +image/x-portable-pixmap [BITMAP] +text/plain [TEXT] +text/html [TEXT] +video/ogg [VIDEO] +video/mpeg [VIDEO] +unknown/unknown application/octet-stream application/x-empty [UNKNOWN] +EOT; + + /** + * @param array $params Configuration map, includes: + * - typeFile: path to file with the list of known MIME types + * - infoFile: path to file with the MIME type info + * - xmlTypes: map of root element names to XML MIME types + * - initCallback: initialization callback that is passed this object [optional] + * - detectCallback: alternative to finfo that returns the mime type for a file. + * For example, the callback can return the output of "file -bi". [optional] + * - guessCallback: callback to improve the guessed MIME type using the file data. + * This is intended for fixing mistakes in fileinfo or "detectCallback". [optional] + * - extCallback: callback to improve the guessed MIME type using the extension. [optional] + * - logger: PSR-3 logger [optional] + * @note Constructing these instances is expensive due to file reads. + * A service or singleton pattern should be used to avoid creating instances again and again. + */ + public function __construct( array $params ) { + $this->typeFile = $params['typeFile']; + $this->infoFile = $params['infoFile']; + $this->xmlTypes = $params['xmlTypes']; + $this->initCallback = isset( $params['initCallback'] ) + ? $params['initCallback'] + : null; + $this->detectCallback = isset( $params['detectCallback'] ) + ? $params['detectCallback'] + : null; + $this->guessCallback = isset( $params['guessCallback'] ) + ? $params['guessCallback'] + : null; + $this->extCallback = isset( $params['extCallback'] ) + ? $params['extCallback'] + : null; + $this->logger = isset( $params['logger'] ) + ? $params['logger'] + : new \Psr\Log\NullLogger(); + + $this->loadFiles(); + } + + protected function loadFiles() { + /** + * --- load mime.types --- + */ + + # Allow media handling extensions adding MIME-types and MIME-info + if ( $this->initCallback ) { + call_user_func( $this->initCallback, $this ); + } + + $types = self::$wellKnownTypes; + + $mimeTypeFile = $this->typeFile; + if ( $mimeTypeFile ) { + if ( is_file( $mimeTypeFile ) && is_readable( $mimeTypeFile ) ) { + $this->logger->info( __METHOD__ . ": loading mime types from $mimeTypeFile\n" ); + $types .= "\n"; + $types .= file_get_contents( $mimeTypeFile ); + } else { + $this->logger->info( __METHOD__ . ": can't load mime types from $mimeTypeFile\n" ); + } + } else { + $this->logger->info( __METHOD__ . + ": no mime types file defined, using built-ins only.\n" ); + } + + $types .= "\n" . $this->extraTypes; + + $types = str_replace( [ "\r\n", "\n\r", "\n\n", "\r\r", "\r" ], "\n", $types ); + $types = str_replace( "\t", " ", $types ); + + $this->mimetoExt = []; + $this->mExtToMime = []; + + $lines = explode( "\n", $types ); + foreach ( $lines as $s ) { + $s = trim( $s ); + if ( empty( $s ) ) { + continue; + } + if ( strpos( $s, '#' ) === 0 ) { + continue; + } + + $s = strtolower( $s ); + $i = strpos( $s, ' ' ); + + if ( $i === false ) { + continue; + } + + $mime = substr( $s, 0, $i ); + $ext = trim( substr( $s, $i + 1 ) ); + + if ( empty( $ext ) ) { + continue; + } + + if ( !empty( $this->mimetoExt[$mime] ) ) { + $this->mimetoExt[$mime] .= ' ' . $ext; + } else { + $this->mimetoExt[$mime] = $ext; + } + + $extensions = explode( ' ', $ext ); + + foreach ( $extensions as $e ) { + $e = trim( $e ); + if ( empty( $e ) ) { + continue; + } + + if ( !empty( $this->mExtToMime[$e] ) ) { + $this->mExtToMime[$e] .= ' ' . $mime; + } else { + $this->mExtToMime[$e] = $mime; + } + } + } + + /** + * --- load mime.info --- + */ + + $mimeInfoFile = $this->infoFile; + + $info = self::$wellKnownInfo; + + if ( $mimeInfoFile ) { + if ( is_file( $mimeInfoFile ) && is_readable( $mimeInfoFile ) ) { + $this->logger->info( __METHOD__ . ": loading mime info from $mimeInfoFile\n" ); + $info .= "\n"; + $info .= file_get_contents( $mimeInfoFile ); + } else { + $this->logger->info( __METHOD__ . ": can't load mime info from $mimeInfoFile\n" ); + } + } else { + $this->logger->info( __METHOD__ . + ": no mime info file defined, using built-ins only.\n" ); + } + + $info .= "\n" . $this->extraInfo; + + $info = str_replace( [ "\r\n", "\n\r", "\n\n", "\r\r", "\r" ], "\n", $info ); + $info = str_replace( "\t", " ", $info ); + + $this->mimeTypeAliases = []; + $this->mediaTypes = []; + + $lines = explode( "\n", $info ); + foreach ( $lines as $s ) { + $s = trim( $s ); + if ( empty( $s ) ) { + continue; + } + if ( strpos( $s, '#' ) === 0 ) { + continue; + } + + $s = strtolower( $s ); + $i = strpos( $s, ' ' ); + + if ( $i === false ) { + continue; + } + + # print "processing MIME INFO line $s<br>"; + + $match = []; + if ( preg_match( '!\[\s*(\w+)\s*\]!', $s, $match ) ) { + $s = preg_replace( '!\[\s*(\w+)\s*\]!', '', $s ); + $mtype = trim( strtoupper( $match[1] ) ); + } else { + $mtype = MEDIATYPE_UNKNOWN; + } + + $m = explode( ' ', $s ); + + if ( !isset( $this->mediaTypes[$mtype] ) ) { + $this->mediaTypes[$mtype] = []; + } + + foreach ( $m as $mime ) { + $mime = trim( $mime ); + if ( empty( $mime ) ) { + continue; + } + + $this->mediaTypes[$mtype][] = $mime; + } + + if ( count( $m ) > 1 ) { + $main = $m[0]; + $mCount = count( $m ); + for ( $i = 1; $i < $mCount; $i += 1 ) { + $mime = $m[$i]; + $this->mimeTypeAliases[$mime] = $main; + } + } + } + } + + public function setLogger( LoggerInterface $logger ) { + $this->logger = $logger; + } + + /** + * Adds to the list mapping MIME to file extensions. + * As an extension author, you are encouraged to submit patches to + * MediaWiki's core to add new MIME types to mime.types. + * @param string $types + */ + public function addExtraTypes( $types ) { + $this->extraTypes .= "\n" . $types; + } + + /** + * Adds to the list mapping MIME to media type. + * As an extension author, you are encouraged to submit patches to + * MediaWiki's core to add new MIME info to mime.info. + * @param string $info + */ + public function addExtraInfo( $info ) { + $this->extraInfo .= "\n" . $info; + } + + /** + * Returns a list of file extensions for a given MIME type as a space + * separated string or null if the MIME type was unrecognized. Resolves + * MIME type aliases. + * + * @param string $mime + * @return string|null + */ + public function getExtensionsForType( $mime ) { + $mime = strtolower( $mime ); + + // Check the mime-to-ext map + if ( isset( $this->mimetoExt[$mime] ) ) { + return $this->mimetoExt[$mime]; + } + + // Resolve the MIME type to the canonical type + if ( isset( $this->mimeTypeAliases[$mime] ) ) { + $mime = $this->mimeTypeAliases[$mime]; + if ( isset( $this->mimetoExt[$mime] ) ) { + return $this->mimetoExt[$mime]; + } + } + + return null; + } + + /** + * Returns a list of MIME types for a given file extension as a space + * separated string or null if the extension was unrecognized. + * + * @param string $ext + * @return string|null + */ + public function getTypesForExtension( $ext ) { + $ext = strtolower( $ext ); + + $r = isset( $this->mExtToMime[$ext] ) ? $this->mExtToMime[$ext] : null; + return $r; + } + + /** + * Returns a single MIME type for a given file extension or null if unknown. + * This is always the first type from the list returned by getTypesForExtension($ext). + * + * @param string $ext + * @return string|null + */ + public function guessTypesForExtension( $ext ) { + $m = $this->getTypesForExtension( $ext ); + if ( is_null( $m ) ) { + return null; + } + + // TODO: Check if this is needed; strtok( $m, ' ' ) should be sufficient + $m = trim( $m ); + $m = preg_replace( '/\s.*$/', '', $m ); + + return $m; + } + + /** + * Tests if the extension matches the given MIME type. Returns true if a + * match was found, null if the MIME type is unknown, and false if the + * MIME type is known but no matches where found. + * + * @param string $extension + * @param string $mime + * @return bool|null + */ + public function isMatchingExtension( $extension, $mime ) { + $ext = $this->getExtensionsForType( $mime ); + + if ( !$ext ) { + return null; // Unknown MIME type + } + + $ext = explode( ' ', $ext ); + + $extension = strtolower( $extension ); + return in_array( $extension, $ext ); + } + + /** + * Returns true if the MIME type is known to represent an image format + * supported by the PHP GD library. + * + * @param string $mime + * + * @return bool + */ + public function isPHPImageType( $mime ) { + // As defined by imagegetsize and image_type_to_mime + static $types = [ + 'image/gif', 'image/jpeg', 'image/png', + 'image/x-bmp', 'image/xbm', 'image/tiff', + 'image/jp2', 'image/jpeg2000', 'image/iff', + 'image/xbm', 'image/x-xbitmap', + 'image/vnd.wap.wbmp', 'image/vnd.xiff', + 'image/x-photoshop', + 'application/x-shockwave-flash', + ]; + + return in_array( $mime, $types ); + } + + /** + * Returns true if the extension represents a type which can + * be reliably detected from its content. Use this to determine + * whether strict content checks should be applied to reject + * invalid uploads; if we can't identify the type we won't + * be able to say if it's invalid. + * + * @todo Be more accurate when using fancy MIME detector plugins; + * right now this is the bare minimum getimagesize() list. + * @param string $extension + * @return bool + */ + function isRecognizableExtension( $extension ) { + static $types = [ + // Types recognized by getimagesize() + 'gif', 'jpeg', 'jpg', 'png', 'swf', 'psd', + 'bmp', 'tiff', 'tif', 'jpc', 'jp2', + 'jpx', 'jb2', 'swc', 'iff', 'wbmp', + 'xbm', + + // Formats we recognize magic numbers for + 'djvu', 'ogx', 'ogg', 'ogv', 'oga', 'spx', 'opus', + 'mid', 'pdf', 'wmf', 'xcf', 'webm', 'mkv', 'mka', + 'webp', 'mp3', + + // XML formats we sure hope we recognize reliably + 'svg', + + // 3D formats + 'stl', + ]; + return in_array( strtolower( $extension ), $types ); + } + + /** + * Improves a MIME type using the file extension. Some file formats are very generic, + * so their MIME type is not very meaningful. A more useful MIME type can be derived + * by looking at the file extension. Typically, this method would be called on the + * result of guessMimeType(). + * + * @param string $mime The MIME type, typically guessed from a file's content. + * @param string $ext The file extension, as taken from the file name + * + * @return string The MIME type + */ + public function improveTypeFromExtension( $mime, $ext ) { + if ( $mime === 'unknown/unknown' ) { + if ( $this->isRecognizableExtension( $ext ) ) { + $this->logger->info( __METHOD__ . ': refusing to guess mime type for .' . + "$ext file, we should have recognized it\n" ); + } else { + // Not something we can detect, so simply + // trust the file extension + $mime = $this->guessTypesForExtension( $ext ); + } + } elseif ( $mime === 'application/x-opc+zip' ) { + if ( $this->isMatchingExtension( $ext, $mime ) ) { + // A known file extension for an OPC file, + // find the proper MIME type for that file extension + $mime = $this->guessTypesForExtension( $ext ); + } else { + $this->logger->info( __METHOD__ . + ": refusing to guess better type for $mime file, " . + ".$ext is not a known OPC extension.\n" ); + $mime = 'application/zip'; + } + } elseif ( $mime === 'text/plain' && $this->findMediaType( ".$ext" ) === MEDIATYPE_TEXT ) { + // Textual types are sometimes not recognized properly. + // If detected as text/plain, and has an extension which is textual + // improve to the extension's type. For example, csv and json are often + // misdetected as text/plain. + $mime = $this->guessTypesForExtension( $ext ); + } + + # Media handling extensions can improve the MIME detected + $callback = $this->extCallback; + if ( $callback ) { + $callback( $this, $ext, $mime /* by reference */ ); + } + + if ( isset( $this->mimeTypeAliases[$mime] ) ) { + $mime = $this->mimeTypeAliases[$mime]; + } + + $this->logger->info( __METHOD__ . ": improved mime type for .$ext: $mime\n" ); + return $mime; + } + + /** + * MIME type detection. This uses detectMimeType to detect the MIME type + * of the file, but applies additional checks to determine some well known + * file formats that may be missed or misinterpreted by the default MIME + * detection (namely XML based formats like XHTML or SVG, as well as ZIP + * based formats like OPC/ODF files). + * + * @param string $file The file to check + * @param string|bool $ext The file extension, or true (default) to extract + * it from the filename. Set it to false to ignore the extension. DEPRECATED! + * Set to false, use improveTypeFromExtension($mime, $ext) later to improve MIME type. + * + * @return string The MIME type of $file + */ + public function guessMimeType( $file, $ext = true ) { + if ( $ext ) { // TODO: make $ext default to false. Or better, remove it. + $this->logger->info( __METHOD__ . + ": WARNING: use of the \$ext parameter is deprecated. " . + "Use improveTypeFromExtension(\$mime, \$ext) instead.\n" ); + } + + $mime = $this->doGuessMimeType( $file, $ext ); + + if ( !$mime ) { + $this->logger->info( __METHOD__ . + ": internal type detection failed for $file (.$ext)...\n" ); + $mime = $this->detectMimeType( $file, $ext ); + } + + if ( isset( $this->mimeTypeAliases[$mime] ) ) { + $mime = $this->mimeTypeAliases[$mime]; + } + + $this->logger->info( __METHOD__ . ": guessed mime type of $file: $mime\n" ); + return $mime; + } + + /** + * Guess the MIME type from the file contents. + * + * @todo Remove $ext param + * + * @param string $file + * @param mixed $ext + * @return bool|string + * @throws UnexpectedValueException + */ + private function doGuessMimeType( $file, $ext ) { + // Read a chunk of the file + Wikimedia\suppressWarnings(); + $f = fopen( $file, 'rb' ); + Wikimedia\restoreWarnings(); + + if ( !$f ) { + return 'unknown/unknown'; + } + + $fsize = filesize( $file ); + if ( $fsize === false ) { + return 'unknown/unknown'; + } + + $head = fread( $f, 1024 ); + $tailLength = min( 65558, $fsize ); // 65558 = maximum size of a zip EOCDR + if ( fseek( $f, -1 * $tailLength, SEEK_END ) === -1 ) { + throw new UnexpectedValueException( + "Seeking $tailLength bytes from EOF failed in " . __METHOD__ ); + } + $tail = $tailLength ? fread( $f, $tailLength ) : ''; + fclose( $f ); + + $this->logger->info( __METHOD__ . + ": analyzing head and tail of $file for magic numbers.\n" ); + + // Hardcode a few magic number checks... + $headers = [ + // Multimedia... + 'MThd' => 'audio/midi', + 'OggS' => 'application/ogg', + 'ID3' => 'audio/mpeg', + "\xff\xfb" => 'audio/mpeg', // MPEG-1 layer 3 + "\xff\xf3" => 'audio/mpeg', // MPEG-2 layer 3 (lower sample rates) + "\xff\xe3" => 'audio/mpeg', // MPEG-2.5 layer 3 (very low sample rates) + + // Image formats... + // Note that WMF may have a bare header, no magic number. + "\x01\x00\x09\x00" => 'application/x-msmetafile', // Possibly prone to false positives? + "\xd7\xcd\xc6\x9a" => 'application/x-msmetafile', + '%PDF' => 'application/pdf', + 'gimp xcf' => 'image/x-xcf', + + // Some forbidden fruit... + 'MZ' => 'application/octet-stream', // DOS/Windows executable + "\xca\xfe\xba\xbe" => 'application/octet-stream', // Mach-O binary + "\x7fELF" => 'application/octet-stream', // ELF binary + ]; + + foreach ( $headers as $magic => $candidate ) { + if ( strncmp( $head, $magic, strlen( $magic ) ) == 0 ) { + $this->logger->info( __METHOD__ . + ": magic header in $file recognized as $candidate\n" ); + return $candidate; + } + } + + /* Look for WebM and Matroska files */ + if ( strncmp( $head, pack( "C4", 0x1a, 0x45, 0xdf, 0xa3 ), 4 ) == 0 ) { + $doctype = strpos( $head, "\x42\x82" ); + if ( $doctype ) { + // Next byte is datasize, then data (sizes larger than 1 byte are stupid muxers) + $data = substr( $head, $doctype + 3, 8 ); + if ( strncmp( $data, "matroska", 8 ) == 0 ) { + $this->logger->info( __METHOD__ . ": recognized file as video/x-matroska\n" ); + return "video/x-matroska"; + } elseif ( strncmp( $data, "webm", 4 ) == 0 ) { + // XXX HACK look for a video track, if we don't find it, this is an audio file + $videotrack = strpos( $head, "\x86\x85V_VP" ); + + if ( $videotrack ) { + // There is a video track, so this is a video file. + $this->logger->info( __METHOD__ . ": recognized file as video/webm\n" ); + return "video/webm"; + } + + $this->logger->info( __METHOD__ . ": recognized file as audio/webm\n" ); + return "audio/webm"; + } + } + $this->logger->info( __METHOD__ . ": unknown EBML file\n" ); + return "unknown/unknown"; + } + + /* Look for WebP */ + if ( strncmp( $head, "RIFF", 4 ) == 0 && + strncmp( substr( $head, 8, 7 ), "WEBPVP8", 7 ) == 0 + ) { + $this->logger->info( __METHOD__ . ": recognized file as image/webp\n" ); + return "image/webp"; + } + + /** + * Look for PHP. Check for this before HTML/XML... Warning: this is a + * heuristic, and won't match a file with a lot of non-PHP before. It + * will also match text files which could be PHP. :) + * + * @todo FIXME: For this reason, the check is probably useless -- an attacker + * could almost certainly just pad the file with a lot of nonsense to + * circumvent the check in any case where it would be a security + * problem. On the other hand, it causes harmful false positives (bug + * 16583). The heuristic has been cut down to exclude three-character + * strings like "<? ", but should it be axed completely? + */ + if ( ( strpos( $head, '<?php' ) !== false ) || + ( strpos( $head, "<\x00?\x00p\x00h\x00p" ) !== false ) || + ( strpos( $head, "<\x00?\x00 " ) !== false ) || + ( strpos( $head, "<\x00?\x00\n" ) !== false ) || + ( strpos( $head, "<\x00?\x00\t" ) !== false ) || + ( strpos( $head, "<\x00?\x00=" ) !== false ) + ) { + $this->logger->info( __METHOD__ . ": recognized $file as application/x-php\n" ); + return 'application/x-php'; + } + + /** + * look for XML formats (XHTML and SVG) + */ + $xml = new XmlTypeCheck( $file ); + if ( $xml->wellFormed ) { + $xmlTypes = $this->xmlTypes; + if ( isset( $xmlTypes[$xml->getRootElement()] ) ) { + return $xmlTypes[$xml->getRootElement()]; + } else { + return 'application/xml'; + } + } + + /** + * look for shell scripts + */ + $script_type = null; + + # detect by shebang + if ( substr( $head, 0, 2 ) == "#!" ) { + $script_type = "ASCII"; + } elseif ( substr( $head, 0, 5 ) == "\xef\xbb\xbf#!" ) { + $script_type = "UTF-8"; + } elseif ( substr( $head, 0, 7 ) == "\xfe\xff\x00#\x00!" ) { + $script_type = "UTF-16BE"; + } elseif ( substr( $head, 0, 7 ) == "\xff\xfe#\x00!" ) { + $script_type = "UTF-16LE"; + } + + if ( $script_type ) { + if ( $script_type !== "UTF-8" && $script_type !== "ASCII" ) { + // Quick and dirty fold down to ASCII! + $pack = [ 'UTF-16BE' => 'n*', 'UTF-16LE' => 'v*' ]; + $chars = unpack( $pack[$script_type], substr( $head, 2 ) ); + $head = ''; + foreach ( $chars as $codepoint ) { + if ( $codepoint < 128 ) { + $head .= chr( $codepoint ); + } else { + $head .= '?'; + } + } + } + + $match = []; + + if ( preg_match( '%/?([^\s]+/)(\w+)%', $head, $match ) ) { + $mime = "application/x-{$match[2]}"; + $this->logger->info( __METHOD__ . ": shell script recognized as $mime\n" ); + return $mime; + } + } + + // Check for ZIP variants (before getimagesize) + if ( strpos( $tail, "PK\x05\x06" ) !== false ) { + $this->logger->info( __METHOD__ . ": ZIP header present in $file\n" ); + return $this->detectZipType( $head, $tail, $ext ); + } + + // Check for STL (3D) files + // @see https://en.wikipedia.org/wiki/STL_(file_format) + if ( $fsize >= 15 && + stripos( $head, 'SOLID ' ) === 0 && + preg_match( '/\RENDSOLID .*$/i', $tail ) ) { + // ASCII STL file + return 'application/sla'; + } elseif ( $fsize > 84 ) { + // binary STL file + $triangles = substr( $head, 80, 4 ); + $triangles = unpack( 'V', $triangles ); + $triangles = reset( $triangles ); + if ( $triangles !== false && $fsize === 84 + ( $triangles * 50 ) ) { + return 'application/sla'; + } + } + + Wikimedia\suppressWarnings(); + $gis = getimagesize( $file ); + Wikimedia\restoreWarnings(); + + if ( $gis && isset( $gis['mime'] ) ) { + $mime = $gis['mime']; + $this->logger->info( __METHOD__ . ": getimagesize detected $file as $mime\n" ); + return $mime; + } + + # Media handling extensions can guess the MIME by content + # It's intentionally here so that if core is wrong about a type (false positive), + # people will hopefully nag and submit patches :) + $mime = false; + # Some strings by reference for performance - assuming well-behaved hooks + $callback = $this->guessCallback; + if ( $callback ) { + $callback( $this, $head, $tail, $file, $mime /* by reference */ ); + }; + + return $mime; + } + + /** + * Detect application-specific file type of a given ZIP file from its + * header data. Currently works for OpenDocument and OpenXML types... + * If can't tell, returns 'application/zip'. + * + * @param string $header Some reasonably-sized chunk of file header + * @param string|null $tail The tail of the file + * @param string|bool $ext The file extension, or true to extract it from the filename. + * Set it to false (default) to ignore the extension. DEPRECATED! Set to false, + * use improveTypeFromExtension($mime, $ext) later to improve MIME type. + * + * @return string + */ + function detectZipType( $header, $tail = null, $ext = false ) { + if ( $ext ) { # TODO: remove $ext param + $this->logger->info( __METHOD__ . + ": WARNING: use of the \$ext parameter is deprecated. " . + "Use improveTypeFromExtension(\$mime, \$ext) instead.\n" ); + } + + $mime = 'application/zip'; + $opendocTypes = [ + 'chart-template', + 'chart', + 'formula-template', + 'formula', + 'graphics-template', + 'graphics', + 'image-template', + 'image', + 'presentation-template', + 'presentation', + 'spreadsheet-template', + 'spreadsheet', + 'text-template', + 'text-master', + 'text-web', + 'text' ]; + + // https://lists.oasis-open.org/archives/office/200505/msg00006.html + $types = '(?:' . implode( '|', $opendocTypes ) . ')'; + $opendocRegex = "/^mimetype(application\/vnd\.oasis\.opendocument\.$types)/"; + + $openxmlRegex = "/^\[Content_Types\].xml/"; + + if ( preg_match( $opendocRegex, substr( $header, 30 ), $matches ) ) { + $mime = $matches[1]; + $this->logger->info( __METHOD__ . ": detected $mime from ZIP archive\n" ); + } elseif ( preg_match( $openxmlRegex, substr( $header, 30 ) ) ) { + $mime = "application/x-opc+zip"; + # TODO: remove the block below, as soon as improveTypeFromExtension is used everywhere + if ( $ext !== true && $ext !== false ) { + /** This is the mode used by getPropsFromPath + * These MIME's are stored in the database, where we don't really want + * x-opc+zip, because we use it only for internal purposes + */ + if ( $this->isMatchingExtension( $ext, $mime ) ) { + /* A known file extension for an OPC file, + * find the proper mime type for that file extension + */ + $mime = $this->guessTypesForExtension( $ext ); + } else { + $mime = "application/zip"; + } + } + $this->logger->info( __METHOD__ . + ": detected an Open Packaging Conventions archive: $mime\n" ); + } elseif ( substr( $header, 0, 8 ) == "\xd0\xcf\x11\xe0\xa1\xb1\x1a\xe1" && + ( $headerpos = strpos( $tail, "PK\x03\x04" ) ) !== false && + preg_match( $openxmlRegex, substr( $tail, $headerpos + 30 ) ) ) { + if ( substr( $header, 512, 4 ) == "\xEC\xA5\xC1\x00" ) { + $mime = "application/msword"; + } + switch ( substr( $header, 512, 6 ) ) { + case "\xEC\xA5\xC1\x00\x0E\x00": + case "\xEC\xA5\xC1\x00\x1C\x00": + case "\xEC\xA5\xC1\x00\x43\x00": + $mime = "application/vnd.ms-powerpoint"; + break; + case "\xFD\xFF\xFF\xFF\x10\x00": + case "\xFD\xFF\xFF\xFF\x1F\x00": + case "\xFD\xFF\xFF\xFF\x22\x00": + case "\xFD\xFF\xFF\xFF\x23\x00": + case "\xFD\xFF\xFF\xFF\x28\x00": + case "\xFD\xFF\xFF\xFF\x29\x00": + case "\xFD\xFF\xFF\xFF\x10\x02": + case "\xFD\xFF\xFF\xFF\x1F\x02": + case "\xFD\xFF\xFF\xFF\x22\x02": + case "\xFD\xFF\xFF\xFF\x23\x02": + case "\xFD\xFF\xFF\xFF\x28\x02": + case "\xFD\xFF\xFF\xFF\x29\x02": + $mime = "application/vnd.msexcel"; + break; + } + + $this->logger->info( __METHOD__ . + ": detected a MS Office document with OPC trailer\n" ); + } else { + $this->logger->info( __METHOD__ . ": unable to identify type of ZIP archive\n" ); + } + return $mime; + } + + /** + * Internal MIME type detection. Detection is done using the fileinfo + * extension if it is available. It can be overriden by callback, which could + * use an external program, for example. If detection fails and $ext is not false, + * the MIME type is guessed from the file extension, using guessTypesForExtension. + * + * If the MIME type is still unknown, getimagesize is used to detect the + * MIME type if the file is an image. If no MIME type can be determined, + * this function returns 'unknown/unknown'. + * + * @param string $file The file to check + * @param string|bool $ext The file extension, or true (default) to extract it from the filename. + * Set it to false to ignore the extension. DEPRECATED! Set to false, use + * improveTypeFromExtension($mime, $ext) later to improve MIME type. + * + * @return string The MIME type of $file + */ + private function detectMimeType( $file, $ext = true ) { + /** @todo Make $ext default to false. Or better, remove it. */ + if ( $ext ) { + $this->logger->info( __METHOD__ . + ": WARNING: use of the \$ext parameter is deprecated. " + . "Use improveTypeFromExtension(\$mime, \$ext) instead.\n" ); + } + + $callback = $this->detectCallback; + $m = null; + if ( $callback ) { + $m = $callback( $file ); + } else { + $m = mime_content_type( $file ); + } + + if ( $m ) { + # normalize + $m = preg_replace( '![;, ].*$!', '', $m ); # strip charset, etc + $m = trim( $m ); + $m = strtolower( $m ); + + if ( strpos( $m, 'unknown' ) !== false ) { + $m = null; + } else { + $this->logger->info( __METHOD__ . ": magic mime type of $file: $m\n" ); + return $m; + } + } + + // If desired, look at extension as a fallback. + if ( $ext === true ) { + $i = strrpos( $file, '.' ); + $ext = strtolower( $i ? substr( $file, $i + 1 ) : '' ); + } + if ( $ext ) { + if ( $this->isRecognizableExtension( $ext ) ) { + $this->logger->info( __METHOD__ . ": refusing to guess mime type for .$ext file, " + . "we should have recognized it\n" ); + } else { + $m = $this->guessTypesForExtension( $ext ); + if ( $m ) { + $this->logger->info( __METHOD__ . ": extension mime type of $file: $m\n" ); + return $m; + } + } + } + + // Unknown type + $this->logger->info( __METHOD__ . ": failed to guess mime type for $file!\n" ); + return 'unknown/unknown'; + } + + /** + * Determine the media type code for a file, using its MIME type, name and + * possibly its contents. + * + * This function relies on the findMediaType(), mapping extensions and MIME + * types to media types. + * + * @todo analyse file if need be + * @todo look at multiple extension, separately and together. + * + * @param string $path Full path to the image file, in case we have to look at the contents + * (if null, only the MIME type is used to determine the media type code). + * @param string $mime MIME type. If null it will be guessed using guessMimeType. + * + * @return string A value to be used with the MEDIATYPE_xxx constants. + */ + function getMediaType( $path = null, $mime = null ) { + if ( !$mime && !$path ) { + return MEDIATYPE_UNKNOWN; + } + + // If MIME type is unknown, guess it + if ( !$mime ) { + $mime = $this->guessMimeType( $path, false ); + } + + // Special code for ogg - detect if it's video (theora), + // else label it as sound. + if ( $mime == 'application/ogg' && file_exists( $path ) ) { + // Read a chunk of the file + $f = fopen( $path, "rt" ); + if ( !$f ) { + return MEDIATYPE_UNKNOWN; + } + $head = fread( $f, 256 ); + fclose( $f ); + + $head = str_replace( 'ffmpeg2theora', '', strtolower( $head ) ); + + // This is an UGLY HACK, file should be parsed correctly + if ( strpos( $head, 'theora' ) !== false ) { + return MEDIATYPE_VIDEO; + } elseif ( strpos( $head, 'vorbis' ) !== false ) { + return MEDIATYPE_AUDIO; + } elseif ( strpos( $head, 'flac' ) !== false ) { + return MEDIATYPE_AUDIO; + } elseif ( strpos( $head, 'speex' ) !== false ) { + return MEDIATYPE_AUDIO; + } elseif ( strpos( $head, 'opus' ) !== false ) { + return MEDIATYPE_AUDIO; + } else { + return MEDIATYPE_MULTIMEDIA; + } + } + + $type = null; + // Check for entry for full MIME type + if ( $mime ) { + $type = $this->findMediaType( $mime ); + if ( $type !== MEDIATYPE_UNKNOWN ) { + return $type; + } + } + + // Check for entry for file extension + if ( $path ) { + $i = strrpos( $path, '.' ); + $e = strtolower( $i ? substr( $path, $i + 1 ) : '' ); + + // TODO: look at multi-extension if this fails, parse from full path + $type = $this->findMediaType( '.' . $e ); + if ( $type !== MEDIATYPE_UNKNOWN ) { + return $type; + } + } + + // Check major MIME type + if ( $mime ) { + $i = strpos( $mime, '/' ); + if ( $i !== false ) { + $major = substr( $mime, 0, $i ); + $type = $this->findMediaType( $major ); + if ( $type !== MEDIATYPE_UNKNOWN ) { + return $type; + } + } + } + + if ( !$type ) { + $type = MEDIATYPE_UNKNOWN; + } + + return $type; + } + + /** + * Returns a media code matching the given MIME type or file extension. + * File extensions are represented by a string starting with a dot (.) to + * distinguish them from MIME types. + * + * This function relies on the mapping defined by $this->mMediaTypes + * @access private + * @param string $extMime + * @return int|string + */ + function findMediaType( $extMime ) { + if ( strpos( $extMime, '.' ) === 0 ) { + // If it's an extension, look up the MIME types + $m = $this->getTypesForExtension( substr( $extMime, 1 ) ); + if ( !$m ) { + return MEDIATYPE_UNKNOWN; + } + + $m = explode( ' ', $m ); + } else { + // Normalize MIME type + if ( isset( $this->mimeTypeAliases[$extMime] ) ) { + $extMime = $this->mimeTypeAliases[$extMime]; + } + + $m = [ $extMime ]; + } + + foreach ( $m as $mime ) { + foreach ( $this->mediaTypes as $type => $codes ) { + if ( in_array( $mime, $codes, true ) ) { + return $type; + } + } + } + + return MEDIATYPE_UNKNOWN; + } + + /** + * Returns an array of media types (MEDIATYPE_xxx constants) + * + * @return array + */ + public function getMediaTypes() { + return array_keys( $this->mediaTypes ); + } + + /** + * Get the MIME types that various versions of Internet Explorer would + * detect from a chunk of the content. + * + * @param string $fileName The file name (unused at present) + * @param string $chunk The first 256 bytes of the file + * @param string $proposed The MIME type proposed by the server + * @return array + */ + public function getIEMimeTypes( $fileName, $chunk, $proposed ) { + $ca = $this->getIEContentAnalyzer(); + return $ca->getRealMimesFromData( $fileName, $chunk, $proposed ); + } + + /** + * Get a cached instance of IEContentAnalyzer + * + * @return IEContentAnalyzer + */ + protected function getIEContentAnalyzer() { + if ( is_null( $this->IEAnalyzer ) ) { + $this->IEAnalyzer = new IEContentAnalyzer; + } + return $this->IEAnalyzer; + } +} |