array(), 'COM' => array(), 'PSIR' => array(), ); if ( !$filename ) { throw new MWException( "No filename specified for " . __METHOD__ ); } if ( !file_exists( $filename ) || is_dir( $filename ) ) { throw new MWException( "Invalid file $filename passed to " . __METHOD__ ); } $fh = fopen( $filename, "rb" ); if ( !$fh ) { throw new MWException( "Could not open file $filename" ); } $buffer = fread( $fh, 2 ); if ( $buffer !== "\xFF\xD8" ) { throw new MWException( "Not a jpeg, no SOI" ); } while ( !feof( $fh ) ) { $buffer = fread( $fh, 1 ); $segmentCount++; if ( $segmentCount > self::MAX_JPEG_SEGMENTS ) { // this is just a sanity check throw new MWException( 'Too many jpeg segments. Aborting' ); } if ( $buffer !== "\xFF" ) { throw new MWException( "Error reading jpeg file marker. " . "Expected 0xFF but got " . bin2hex( $buffer ) ); } $buffer = fread( $fh, 1 ); while ( $buffer === "\xFF" && !feof( $fh ) ) { // Skip through any 0xFF padding bytes. $buffer = fread( $fh, 1 ); } if ( $buffer === "\xFE" ) { // COM section -- file comment // First see if valid utf-8, // if not try to convert it to windows-1252. $com = $oldCom = trim( self::jpegExtractMarker( $fh ) ); UtfNormal::quickIsNFCVerify( $com ); // turns $com to valid utf-8. // thus if no change, its utf-8, otherwise its something else. if ( $com !== $oldCom ) { wfSuppressWarnings(); $com = $oldCom = iconv( 'windows-1252', 'UTF-8//IGNORE', $oldCom ); wfRestoreWarnings(); } // Try it again, if its still not a valid string, then probably // binary junk or some really weird encoding, so don't extract. UtfNormal::quickIsNFCVerify( $com ); if ( $com === $oldCom ) { $segments["COM"][] = $oldCom; } else { wfDebug( __METHOD__ . " Ignoring JPEG comment as is garbage.\n" ); } } elseif ( $buffer === "\xE1" ) { // APP1 section (Exif, XMP, and XMP extended) // only extract if XMP is enabled. $temp = self::jpegExtractMarker( $fh ); // check what type of app segment this is. if ( substr( $temp, 0, 29 ) === "http://ns.adobe.com/xap/1.0/\x00" && $showXMP ) { $segments["XMP"] = substr( $temp, 29 ); } elseif ( substr( $temp, 0, 35 ) === "http://ns.adobe.com/xmp/extension/\x00" && $showXMP ) { $segments["XMP_ext"][] = substr( $temp, 35 ); } elseif ( substr( $temp, 0, 29 ) === "XMP\x00://ns.adobe.com/xap/1.0/\x00" && $showXMP ) { // Some images (especially flickr images) seem to have this. // I really have no idea what the deal is with them, but // whatever... $segments["XMP"] = substr( $temp, 29 ); wfDebug( __METHOD__ . ' Found XMP section with wrong app identifier ' . "Using anyways.\n" ); } elseif ( substr( $temp, 0, 6 ) === "Exif\0\0" ) { // Just need to find out what the byte order is. // because php's exif plugin sucks... // This is a II for little Endian, MM for big. Not a unicode BOM. $byteOrderMarker = substr( $temp, 6, 2 ); if ( $byteOrderMarker === 'MM' ) { $segments['byteOrder'] = 'BE'; } elseif ( $byteOrderMarker === 'II' ) { $segments['byteOrder'] = 'LE'; } else { wfDebug( __METHOD__ . " Invalid byte ordering?!\n" ); } } } elseif ( $buffer === "\xED" ) { // APP13 - PSIR. IPTC and some photoshop stuff $temp = self::jpegExtractMarker( $fh ); if ( substr( $temp, 0, 14 ) === "Photoshop 3.0\x00" ) { $segments["PSIR"][] = $temp; } } elseif ( $buffer === "\xD9" || $buffer === "\xDA" ) { // EOI - end of image or SOS - start of scan. either way we're past any interesting segments return $segments; } else { // segment we don't care about, so skip $size = wfUnpack( "nint", fread( $fh, 2 ), 2 ); if ( $size['int'] <= 2 ) { throw new MWException( "invalid marker size in jpeg" ); } fseek( $fh, $size['int'] - 2, SEEK_CUR ); } } // shouldn't get here. throw new MWException( "Reached end of jpeg file unexpectedly" ); } /** * Helper function for jpegSegmentSplitter * @param resource &$fh File handle for JPEG file * @throws MWException * @return string Data content of segment. */ private static function jpegExtractMarker( &$fh ) { $size = wfUnpack( "nint", fread( $fh, 2 ), 2 ); if ( $size['int'] <= 2 ) { throw new MWException( "invalid marker size in jpeg" ); } $segment = fread( $fh, $size['int'] - 2 ); if ( strlen( $segment ) !== $size['int'] - 2 ) { throw new MWException( "Segment shorter than expected" ); } return $segment; } /** * This reads the photoshop image resource. * Currently it only compares the iptc/iim hash * with the stored hash, which is used to determine the precedence * of the iptc data. In future it may extract some other info, like * url of copyright license. * * This should generally be called by BitmapMetadataHandler::doApp13() * * @param string $app13 Photoshop psir app13 block from jpg. * @throws MWException (It gets caught next level up though) * @return string If the iptc hash is good or not. One of 'iptc-no-hash', * 'iptc-good-hash', 'iptc-bad-hash'. */ public static function doPSIR( $app13 ) { if ( !$app13 ) { throw new MWException( "No App13 segment given" ); } // First compare hash with real thing // 0x404 contains IPTC, 0x425 has hash // This is used to determine if the iptc is newer than // the xmp data, as xmp programs update the hash, // where non-xmp programs don't. $offset = 14; // skip past PHOTOSHOP 3.0 identifier. should already be checked. $appLen = strlen( $app13 ); $realHash = ""; $recordedHash = ""; // the +12 is the length of an empty item. while ( $offset + 12 <= $appLen ) { $valid = true; if ( substr( $app13, $offset, 4 ) !== '8BIM' ) { // its supposed to be 8BIM // but apparently sometimes isn't esp. in // really old jpg's $valid = false; } $offset += 4; $id = substr( $app13, $offset, 2 ); // id is a 2 byte id number which identifies // the piece of info this record contains. $offset += 2; // some record types can contain a name, which // is a pascal string 0-padded to be an even // number of bytes. Most times (and any time // we care) this is empty, making it two null bytes. $lenName = ord( substr( $app13, $offset, 1 ) ) + 1; // we never use the name so skip it. +1 for length byte if ( $lenName % 2 == 1 ) { $lenName++; } // pad to even. $offset += $lenName; // now length of data (unsigned long big endian) $lenData = wfUnpack( 'Nlen', substr( $app13, $offset, 4 ), 4 ); // PHP can take issue with very large unsigned ints and make them negative. // Which should never ever happen, as this has to be inside a segment // which is limited to a 16 bit number. if ( $lenData['len'] < 0 ) { throw new MWException( "Too big PSIR (" . $lenData['len'] . ')' ); } $offset += 4; // 4bytes length field; // this should not happen, but check. if ( $lenData['len'] + $offset > $appLen ) { throw new MWException( "PSIR data too long. (item length=" . $lenData['len'] . "; offset=$offset; total length=$appLen)" ); } if ( $valid ) { switch ( $id ) { case "\x04\x04": // IPTC block $realHash = md5( substr( $app13, $offset, $lenData['len'] ), true ); break; case "\x04\x25": $recordedHash = substr( $app13, $offset, $lenData['len'] ); break; } } // if odd, add 1 to length to account for // null pad byte. if ( $lenData['len'] % 2 == 1 ) { $lenData['len']++; } $offset += $lenData['len']; } if ( !$realHash || !$recordedHash ) { return 'iptc-no-hash'; } elseif ( $realHash === $recordedHash ) { return 'iptc-good-hash'; } else { /*$realHash !== $recordedHash */ return 'iptc-bad-hash'; } } }