includes/media/Exif.php
<?php
/**
* Extraction and validation of image metadata.
*
* 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
*
* @ingroup Media
* @author Ævar Arnfjörð Bjarmason <avarab@gmail.com>
* @copyright Copyright © 2005, Ævar Arnfjörð Bjarmason, 2009 Brent Garber
* @license GPL-2.0-or-later
* @see http://exif.org/Exif2-2.PDF The Exif 2.2 specification
* @file
*/
use MediaWiki\Config\ConfigException;
use Wikimedia\AtEase\AtEase;
/**
* Class to extract and validate Exif data from jpeg (and possibly tiff) files.
* @ingroup Media
*/
class Exif {
/** An 8-bit (1-byte) unsigned integer. */
private const BYTE = 1;
/** An 8-bit byte containing one 7-bit ASCII code.
* The final byte is terminated with NULL.
*/
private const ASCII = 2;
/** A 16-bit (2-byte) unsigned integer. */
private const SHORT = 3;
/** A 32-bit (4-byte) unsigned integer. */
private const LONG = 4;
/** Two LONGs. The first LONG is the numerator and the second LONG expresses
* the denominator
*/
private const RATIONAL = 5;
/** A 16-bit (2-byte) or 32-bit (4-byte) unsigned integer. */
private const SHORT_OR_LONG = 6;
/** An 8-bit byte that can take any value depending on the field definition */
private const UNDEFINED = 7;
/** A 32-bit (4-byte) signed integer (2's complement notation), */
private const SLONG = 9;
/** Two SLONGs. The first SLONG is the numerator and the second SLONG is
* the denominator.
*/
private const SRATIONAL = 10;
/** A fake value for things we don't want or don't support. */
private const IGNORE = -1;
/** @var array Exif tags grouped by category, the tagname itself is the key
* and the type is the value, in the case of more than one possible value
* type they are separated by commas.
*/
private $mExifTags;
/** @var array The raw Exif data returned by exif_read_data() */
private $mRawExifData;
/** @var array A Filtered version of $mRawExifData that has been pruned
* of invalid tags and tags that contain content they shouldn't contain
* according to the Exif specification
*/
private $mFilteredExifData;
/** @var string The file being processed */
private $file;
/** @var string The basename of the file being processed */
private $basename;
/** @var string|false The private log to log to, e.g. 'exif' */
private $log = false;
/** @var string The byte order of the file. Needed because php's extension
* doesn't fully process some obscure props.
*/
private $byteOrder;
/**
* @param string $file Filename.
* @param string $byteOrder Type of byte ordering either 'BE' (Big Endian)
* or 'LE' (Little Endian). Default ''.
* @todo FIXME: The following are broke:
* SubjectArea. Need to test the more obscure tags.
* DigitalZoomRatio = 0/0 is rejected. need to determine if that's valid.
* Possibly should treat 0/0 = 0. need to read exif spec on that.
*/
public function __construct( $file, $byteOrder = '' ) {
/**
* Page numbers here refer to pages in the Exif 2.2 standard
*
* Note, Exif::UNDEFINED is treated as a string, not as an array of bytes
* so don't put a count parameter for any UNDEFINED values.
*
* @link http://exif.org/Exif2-2.PDF The Exif 2.2 specification
*/
$this->mExifTags = [
# TIFF Rev. 6.0 Attribute Information (p22)
'IFD0' => [
# Tags relating to image structure
# Image width
'ImageWidth' => self::SHORT_OR_LONG,
# Image height
'ImageLength' => self::SHORT_OR_LONG,
# Number of bits per component
'BitsPerSample' => [ self::SHORT, 3 ],
# "When a primary image is JPEG compressed, this designation is not"
# "necessary and is omitted." (p23)
# Compression scheme #p23
'Compression' => self::SHORT,
# Pixel composition #p23
'PhotometricInterpretation' => self::SHORT,
# Orientation of image #p24
'Orientation' => self::SHORT,
# Number of components
'SamplesPerPixel' => self::SHORT,
# Image data arrangement #p24
'PlanarConfiguration' => self::SHORT,
# Subsampling ratio of Y to C #p24
'YCbCrSubSampling' => [ self::SHORT, 2 ],
# Y and C positioning #p24-25
'YCbCrPositioning' => self::SHORT,
# Image resolution in width direction
'XResolution' => self::RATIONAL,
# Image resolution in height direction
'YResolution' => self::RATIONAL,
# Unit of X and Y resolution #(p26)
'ResolutionUnit' => self::SHORT,
# Tags relating to recording offset
# Image data location
'StripOffsets' => self::SHORT_OR_LONG,
# Number of rows per strip
'RowsPerStrip' => self::SHORT_OR_LONG,
# Bytes per compressed strip
'StripByteCounts' => self::SHORT_OR_LONG,
# Offset to JPEG SOI
'JPEGInterchangeFormat' => self::SHORT_OR_LONG,
# Bytes of JPEG data
'JPEGInterchangeFormatLength' => self::SHORT_OR_LONG,
# Tags relating to image data characteristics
# Transfer function
'TransferFunction' => self::IGNORE,
# White point chromaticity
'WhitePoint' => [ self::RATIONAL, 2 ],
# Chromaticities of primarities
'PrimaryChromaticities' => [ self::RATIONAL, 6 ],
# Color space transformation matrix coefficients #p27
'YCbCrCoefficients' => [ self::RATIONAL, 3 ],
# Pair of black and white reference values
'ReferenceBlackWhite' => [ self::RATIONAL, 6 ],
# Other tags
# File change date and time
'DateTime' => self::ASCII,
# Image title
'ImageDescription' => self::ASCII,
# Image input equipment manufacturer
'Make' => self::ASCII,
# Image input equipment model
'Model' => self::ASCII,
# Software used
'Software' => self::ASCII,
# Person who created the image
'Artist' => self::ASCII,
# Copyright holder
'Copyright' => self::ASCII,
],
# Exif IFD Attribute Information (p30-31)
'EXIF' => [
# @todo NOTE: Nonexistence of this field is taken to mean non-conformance
# to the Exif 2.1 AND 2.2 standards
'ExifVersion' => self::UNDEFINED,
# Supported Flashpix version #p32
'FlashPixVersion' => self::UNDEFINED,
# Tags relating to Image Data Characteristics
# Color space information #p32
'ColorSpace' => self::SHORT,
# Tags relating to image configuration
# Meaning of each component #p33
'ComponentsConfiguration' => self::UNDEFINED,
# Image compression mode
'CompressedBitsPerPixel' => self::RATIONAL,
# Valid image height
'PixelYDimension' => self::SHORT_OR_LONG,
# Valid image width
'PixelXDimension' => self::SHORT_OR_LONG,
# Tags relating to related user information
# Manufacturer notes
'MakerNote' => self::IGNORE,
# User comments #p34
'UserComment' => self::UNDEFINED,
# Tags relating to related file information
# Related audio file
'RelatedSoundFile' => self::ASCII,
# Tags relating to date and time
# Date and time of original data generation #p36
'DateTimeOriginal' => self::ASCII,
# Date and time of original data generation
'DateTimeDigitized' => self::ASCII,
# DateTime subseconds
'SubSecTime' => self::ASCII,
# DateTimeOriginal subseconds
'SubSecTimeOriginal' => self::ASCII,
# DateTimeDigitized subseconds
'SubSecTimeDigitized' => self::ASCII,
# Tags relating to picture-taking conditions (p31)
# Exposure time
'ExposureTime' => self::RATIONAL,
# F Number
'FNumber' => self::RATIONAL,
# Exposure Program #p38
'ExposureProgram' => self::SHORT,
# Spectral sensitivity
'SpectralSensitivity' => self::ASCII,
# ISO speed rating
'ISOSpeedRatings' => self::SHORT,
# Optoelectronic conversion factor. Note: We don't have support for this atm.
'OECF' => self::IGNORE,
# Shutter speed
'ShutterSpeedValue' => self::SRATIONAL,
# Aperture
'ApertureValue' => self::RATIONAL,
# Brightness
'BrightnessValue' => self::SRATIONAL,
# Exposure bias
'ExposureBiasValue' => self::SRATIONAL,
# Maximum land aperture
'MaxApertureValue' => self::RATIONAL,
# Subject distance
'SubjectDistance' => self::RATIONAL,
# Metering mode #p40
'MeteringMode' => self::SHORT,
# Light source #p40-41
'LightSource' => self::SHORT,
# Flash #p41-42
'Flash' => self::SHORT,
# Lens focal length
'FocalLength' => self::RATIONAL,
# Subject area
'SubjectArea' => [ self::SHORT, 4 ],
# Flash energy
'FlashEnergy' => self::RATIONAL,
# Spatial frequency response. Not supported atm.
'SpatialFrequencyResponse' => self::IGNORE,
# Focal plane X resolution
'FocalPlaneXResolution' => self::RATIONAL,
# Focal plane Y resolution
'FocalPlaneYResolution' => self::RATIONAL,
# Focal plane resolution unit #p46
'FocalPlaneResolutionUnit' => self::SHORT,
# Subject location
'SubjectLocation' => [ self::SHORT, 2 ],
# Exposure index
'ExposureIndex' => self::RATIONAL,
# Sensing method #p46
'SensingMethod' => self::SHORT,
# File source #p47
'FileSource' => self::UNDEFINED,
# Scene type #p47
'SceneType' => self::UNDEFINED,
# CFA pattern. not supported atm.
'CFAPattern' => self::IGNORE,
# Custom image processing #p48
'CustomRendered' => self::SHORT,
# Exposure mode #p48
'ExposureMode' => self::SHORT,
# White Balance #p49
'WhiteBalance' => self::SHORT,
# Digital zoom ratio
'DigitalZoomRatio' => self::RATIONAL,
# Focal length in 35 mm film
'FocalLengthIn35mmFilm' => self::SHORT,
# Scene capture type #p49
'SceneCaptureType' => self::SHORT,
# Scene control #p49-50
'GainControl' => self::SHORT,
# Contrast #p50
'Contrast' => self::SHORT,
# Saturation #p50
'Saturation' => self::SHORT,
# Sharpness #p50
'Sharpness' => self::SHORT,
# Device settings description. This could maybe be supported. Need to find an
# example file that uses this to see if it has stuff of interest in it.
'DeviceSettingDescription' => self::IGNORE,
# Subject distance range #p51
'SubjectDistanceRange' => self::SHORT,
# Unique image ID
'ImageUniqueID' => self::ASCII,
],
# GPS Attribute Information (p52)
'GPS' => [
'GPSVersion' => self::UNDEFINED,
# Should be an array of 4 Exif::BYTE's. However, php treats it as an undefined
# Note exif standard calls this GPSVersionID, but php doesn't like the id suffix
# North or South Latitude #p52-53
'GPSLatitudeRef' => self::ASCII,
# Latitude
'GPSLatitude' => [ self::RATIONAL, 3 ],
# East or West Longitude #p53
'GPSLongitudeRef' => self::ASCII,
# Longitude
'GPSLongitude' => [ self::RATIONAL, 3 ],
'GPSAltitudeRef' => self::UNDEFINED,
# Altitude reference. Note, the exif standard says this should be an EXIF::Byte,
# but php seems to disagree.
# Altitude
'GPSAltitude' => self::RATIONAL,
# GPS time (atomic clock)
'GPSTimeStamp' => [ self::RATIONAL, 3 ],
# Satellites used for measurement
'GPSSatellites' => self::ASCII,
# Receiver status #p54
'GPSStatus' => self::ASCII,
# Measurement mode #p54-55
'GPSMeasureMode' => self::ASCII,
# Measurement precision
'GPSDOP' => self::RATIONAL,
# Speed unit #p55
'GPSSpeedRef' => self::ASCII,
# Speed of GPS receiver
'GPSSpeed' => self::RATIONAL,
# Reference for direction of movement #p55
'GPSTrackRef' => self::ASCII,
# Direction of movement
'GPSTrack' => self::RATIONAL,
# Reference for direction of image #p56
'GPSImgDirectionRef' => self::ASCII,
# Direction of image
'GPSImgDirection' => self::RATIONAL,
# Geodetic survey data used
'GPSMapDatum' => self::ASCII,
# Reference for latitude of destination #p56
'GPSDestLatitudeRef' => self::ASCII,
# Latitude destination
'GPSDestLatitude' => [ self::RATIONAL, 3 ],
# Reference for longitude of destination #p57
'GPSDestLongitudeRef' => self::ASCII,
# Longitude of destination
'GPSDestLongitude' => [ self::RATIONAL, 3 ],
# Reference for bearing of destination #p57
'GPSDestBearingRef' => self::ASCII,
# Bearing of destination
'GPSDestBearing' => self::RATIONAL,
# Reference for distance to destination #p57-58
'GPSDestDistanceRef' => self::ASCII,
# Distance to destination
'GPSDestDistance' => self::RATIONAL,
# Name of GPS processing method
'GPSProcessingMethod' => self::UNDEFINED,
# Name of GPS area
'GPSAreaInformation' => self::UNDEFINED,
# GPS date
'GPSDateStamp' => self::ASCII,
# GPS differential correction
'GPSDifferential' => self::SHORT,
],
];
$this->file = $file;
$this->basename = wfBaseName( $this->file );
if ( $byteOrder === 'BE' || $byteOrder === 'LE' ) {
$this->byteOrder = $byteOrder;
} else {
// Only give a warning for b/c, since originally we didn't
// require this. The number of things affected by this is
// rather small.
wfWarn( 'Exif class did not have byte order specified. ' .
'Some properties may be decoded incorrectly.' );
// BE seems about twice as popular as LE in jpg's.
$this->byteOrder = 'BE';
}
$this->debugFile( __FUNCTION__, true );
if ( function_exists( 'exif_read_data' ) ) {
AtEase::suppressWarnings();
$data = exif_read_data( $this->file, '', true );
AtEase::restoreWarnings();
} else {
throw new ConfigException( "Internal error: exif_read_data not present. " .
"\$wgShowEXIF may be incorrectly set or not checked by an extension." );
}
/**
* exif_read_data() will return false on invalid input, such as
* when somebody uploads a file called something.jpeg
* containing random gibberish.
*/
$this->mRawExifData = $data ?: [];
$this->makeFilteredData();
$this->collapseData();
$this->debugFile( __FUNCTION__, false );
}
/**
* Make $this->mFilteredExifData
*/
private function makeFilteredData() {
$this->mFilteredExifData = [];
foreach ( $this->mRawExifData as $section => $data ) {
if ( !array_key_exists( $section, $this->mExifTags ) ) {
$this->debug( $section, __FUNCTION__, "'$section' is not a valid Exif section" );
continue;
}
foreach ( $data as $tag => $value ) {
if ( !array_key_exists( $tag, $this->mExifTags[$section] ) ) {
$this->debug( $tag, __FUNCTION__, "'$tag' is not a valid tag in '$section'" );
continue;
}
if ( $this->validate( $section, $tag, $value ) ) {
// This is ok, as the tags in the different sections do not conflict.
// except in computed and thumbnail section, which we don't use.
$this->mFilteredExifData[$tag] = $value;
} else {
$this->debug( $value, __FUNCTION__, "'$tag' contained invalid data" );
}
}
}
}
/**
* Collapse some fields together.
* This converts some fields from exif form, to a more friendly form.
* For example GPS latitude to a single number.
*
* The rationale behind this is that we're storing data, not presenting to the user
* For example a longitude is a single number describing how far away you are from
* the prime meridian. Well it might be nice to split it up into minutes and seconds
* for the user, it doesn't really make sense to split a single number into 4 parts
* for storage. (degrees, minutes, second, direction vs single floating point number).
*
* Other things this might do (not really sure if they make sense or not):
* Dates -> mediawiki date format.
* convert values that can be in different units to be in one standardized unit.
*
* As an alternative approach, some of this could be done in the validate phase
* if we make up our own types like Exif::DATE.
*/
private function collapseData() {
$this->exifGPStoNumber( 'GPSLatitude' );
$this->exifGPStoNumber( 'GPSDestLatitude' );
$this->exifGPStoNumber( 'GPSLongitude' );
$this->exifGPStoNumber( 'GPSDestLongitude' );
if ( isset( $this->mFilteredExifData['GPSAltitude'] ) ) {
// We know altitude data is a <num>/<denom> from the validation
// functions ran earlier. But multiplying such a string by -1
// doesn't work well, so convert.
[ $num, $denom ] = explode( '/', $this->mFilteredExifData['GPSAltitude'], 2 );
$this->mFilteredExifData['GPSAltitude'] = (int)$num / (int)$denom;
if ( isset( $this->mFilteredExifData['GPSAltitudeRef'] ) ) {
switch ( $this->mFilteredExifData['GPSAltitudeRef'] ) {
case "\0":
// Above sea level
break;
case "\1":
// Below sea level
$this->mFilteredExifData['GPSAltitude'] *= -1;
break;
default:
// Invalid
unset( $this->mFilteredExifData['GPSAltitude'] );
break;
}
}
}
unset( $this->mFilteredExifData['GPSAltitudeRef'] );
$this->exifPropToOrd( 'FileSource' );
$this->exifPropToOrd( 'SceneType' );
$this->charCodeString( 'UserComment' );
$this->charCodeString( 'GPSProcessingMethod' );
$this->charCodeString( 'GPSAreaInformation' );
// ComponentsConfiguration should really be an array instead of a string...
// This turns a string of binary numbers into an array of numbers.
if ( isset( $this->mFilteredExifData['ComponentsConfiguration'] ) ) {
$val = $this->mFilteredExifData['ComponentsConfiguration'];
$ccVals = [];
$strLen = strlen( $val );
for ( $i = 0; $i < $strLen; $i++ ) {
$ccVals[$i] = ord( substr( $val, $i, 1 ) );
}
// this is for formatting later.
$ccVals['_type'] = 'ol';
$this->mFilteredExifData['ComponentsConfiguration'] = $ccVals;
}
// GPSVersion(ID) is treated as the wrong type by php exif support.
// Go through each byte turning it into a version string.
// For example: "\x02\x02\x00\x00" -> "2.2.0.0"
// Also change exif tag name from GPSVersion (what php exif thinks it is)
// to GPSVersionID (what the exif standard thinks it is).
if ( isset( $this->mFilteredExifData['GPSVersion'] ) ) {
$val = $this->mFilteredExifData['GPSVersion'];
$newVal = '';
$strLen = strlen( $val );
for ( $i = 0; $i < $strLen; $i++ ) {
if ( $i !== 0 ) {
$newVal .= '.';
}
$newVal .= ord( substr( $val, $i, 1 ) );
}
if ( $this->byteOrder === 'LE' ) {
// Need to reverse the string
$newVal2 = '';
for ( $i = strlen( $newVal ) - 1; $i >= 0; $i-- ) {
$newVal2 .= substr( $newVal, $i, 1 );
}
$this->mFilteredExifData['GPSVersionID'] = $newVal2;
} else {
$this->mFilteredExifData['GPSVersionID'] = $newVal;
}
unset( $this->mFilteredExifData['GPSVersion'] );
}
}
/**
* Do userComment tags and similar. See pg. 34 of exif standard.
* basically first 8 bytes is charset, rest is value.
* This has not been tested on any shift-JIS strings.
* @param string $prop Prop name
*/
private function charCodeString( $prop ) {
if ( isset( $this->mFilteredExifData[$prop] ) ) {
if ( strlen( $this->mFilteredExifData[$prop] ) <= 8 ) {
// invalid. Must be at least 9 bytes long.
$this->debug( $this->mFilteredExifData[$prop], __FUNCTION__, false );
unset( $this->mFilteredExifData[$prop] );
return;
}
$charCode = substr( $this->mFilteredExifData[$prop], 0, 8 );
$val = substr( $this->mFilteredExifData[$prop], 8 );
switch ( $charCode ) {
case "JIS\x00\x00\x00\x00\x00":
$charset = "Shift-JIS";
break;
case "UNICODE\x00":
$charset = "UTF-16" . $this->byteOrder;
break;
default:
// ascii or undefined.
$charset = "";
break;
}
if ( $charset ) {
AtEase::suppressWarnings();
$val = iconv( $charset, 'UTF-8//IGNORE', $val );
AtEase::restoreWarnings();
} else {
// if valid utf-8, assume that, otherwise assume windows-1252
$valCopy = $val;
UtfNormal\Validator::quickIsNFCVerify( $valCopy );
if ( $valCopy !== $val ) {
AtEase::suppressWarnings();
$val = iconv( 'Windows-1252', 'UTF-8//IGNORE', $val );
AtEase::restoreWarnings();
}
}
// trim and check to make sure not only whitespace.
$val = trim( $val );
if ( strlen( $val ) === 0 ) {
// only whitespace.
$this->debug( $this->mFilteredExifData[$prop], __FUNCTION__, "$prop: Is only whitespace" );
unset( $this->mFilteredExifData[$prop] );
return;
}
// all's good.
$this->mFilteredExifData[$prop] = $val;
}
}
/**
* Convert an Exif::UNDEFINED from a raw binary string
* to its value. This is sometimes needed depending on
* the type of UNDEFINED field
* @param string $prop Name of property
*/
private function exifPropToOrd( $prop ) {
if ( isset( $this->mFilteredExifData[$prop] ) ) {
$this->mFilteredExifData[$prop] = ord( $this->mFilteredExifData[$prop] );
}
}
/**
* Convert gps in exif form to a single floating point number
* for example 10 degrees 20`40`` S -> -10.34444
* @param string $prop A GPS coordinate exif tag name (like GPSLongitude)
*/
private function exifGPStoNumber( $prop ) {
$loc =& $this->mFilteredExifData[$prop];
$dir =& $this->mFilteredExifData[$prop . 'Ref'];
$res = false;
if ( isset( $loc ) && isset( $dir )
&& ( $dir === 'N' || $dir === 'S' || $dir === 'E' || $dir === 'W' )
) {
[ $num, $denom ] = explode( '/', $loc[0], 2 );
$res = (int)$num / (int)$denom;
[ $num, $denom ] = explode( '/', $loc[1], 2 );
$res += ( (int)$num / (int)$denom ) * ( 1 / 60 );
[ $num, $denom ] = explode( '/', $loc[2], 2 );
$res += ( (int)$num / (int)$denom ) * ( 1 / 3600 );
if ( $dir === 'S' || $dir === 'W' ) {
// make negative
$res *= -1;
}
}
// update the exif records.
// using !== as $res could potentially be 0
if ( $res !== false ) {
$this->mFilteredExifData[$prop] = $res;
} else {
// if invalid
unset( $this->mFilteredExifData[$prop] );
}
unset( $this->mFilteredExifData[$prop . 'Ref'] );
}
/**
* Get $this->mRawExifData
* @return array
*/
public function getData() {
return $this->mRawExifData;
}
/**
* Get $this->mFilteredExifData
* @return array
*/
public function getFilteredData() {
return $this->mFilteredExifData;
}
/**
* The version of the output format
*
* Before the actual metadata information is saved in the database we
* strip some of it since we don't want to save things like thumbnails
* which usually accompany Exif data. This value gets saved in the
* database along with the actual Exif data, and if the version in the
* database doesn't equal the value returned by this function the Exif
* data is regenerated.
*
* @return int
*/
public static function version() {
return 2;
}
/**
* Validates if a tag value is of the type it should be according to the Exif spec
*
* @param mixed $in The input value to check
* @return bool
*/
private function isByte( $in ) {
if ( !is_array( $in ) && sprintf( '%d', $in ) == $in && $in >= 0 && $in <= 255 ) {
$this->debug( $in, __FUNCTION__, true );
return true;
}
$this->debug( $in, __FUNCTION__, false );
return false;
}
/**
* @param mixed $in The input value to check
* @return bool
*/
private function isASCII( $in ) {
if ( is_array( $in ) ) {
return false;
}
if ( preg_match( "/[^\x0a\x20-\x7e]/", $in ) ) {
$this->debug( $in, __FUNCTION__, 'found a character that is not allowed' );
return false;
}
if ( preg_match( '/^\s*$/', $in ) ) {
$this->debug( $in, __FUNCTION__, 'input consisted solely of whitespace' );
return false;
}
return true;
}
/**
* @param mixed $in The input value to check
* @return bool
*/
private function isShort( $in ) {
if ( !is_array( $in ) && sprintf( '%d', $in ) == $in && $in >= 0 && $in <= 65536 ) {
$this->debug( $in, __FUNCTION__, true );
return true;
}
$this->debug( $in, __FUNCTION__, false );
return false;
}
/**
* @param mixed $in The input value to check
* @return bool
*/
private function isLong( $in ) {
if ( !is_array( $in ) && sprintf( '%d', $in ) == $in && $in >= 0 && $in <= 4_294_967_296 ) {
$this->debug( $in, __FUNCTION__, true );
return true;
}
$this->debug( $in, __FUNCTION__, false );
return false;
}
/**
* @param mixed $in The input value to check
* @return bool
*/
private function isRational( $in ) {
$m = [];
# Avoid division by zero
if ( !is_array( $in )
&& preg_match( '/^(\d+)\/(\d+[1-9]|[1-9]\d*)$/', $in, $m )
) {
return $this->isLong( $m[1] ) && $this->isLong( $m[2] );
}
$this->debug( $in, __FUNCTION__, 'fed a non-fraction value' );
return false;
}
/**
* @param mixed $in The input value to check
* @return bool
*/
private function isUndefined( $in ) {
$this->debug( $in, __FUNCTION__, true );
return true;
}
/**
* @param mixed $in The input value to check
* @return bool
*/
private function isSlong( $in ) {
if ( $this->isLong( abs( (float)$in ) ) ) {
$this->debug( $in, __FUNCTION__, true );
return true;
}
$this->debug( $in, __FUNCTION__, false );
return false;
}
/**
* @param mixed $in The input value to check
* @return bool
*/
private function isSrational( $in ) {
$m = [];
# Avoid division by zero
if ( !is_array( $in ) &&
preg_match( '/^(-?\d+)\/(\d+[1-9]|[1-9]\d*)$/', $in, $m )
) {
return $this->isSlong( $m[0] ) && $this->isSlong( $m[1] );
}
$this->debug( $in, __FUNCTION__, 'fed a non-fraction value' );
return false;
}
/**
* Validates if a tag has a legal value according to the Exif spec
*
* @param string $section Section where tag is located.
* @param string $tag The tag to check.
* @param mixed $val The value of the tag.
* @param bool $recursive True if called recursively for array types.
* @return bool
*/
private function validate( $section, $tag, $val, $recursive = false ): bool {
$debug = "tag is '$tag'";
$etype = $this->mExifTags[$section][$tag];
$ecount = 1;
if ( is_array( $etype ) ) {
[ $etype, $ecount ] = $etype;
if ( $recursive ) {
// checking individual elements
$ecount = 1;
}
}
$count = 1;
if ( is_array( $val ) ) {
$count = count( $val );
if ( $ecount !== $count ) {
$this->debug( $val, __FUNCTION__, "Expected $ecount elements for $tag but got $count" );
return false;
}
}
// If there are multiple values, recursively validate each of them.
if ( $count > 1 ) {
foreach ( $val as $v ) {
if ( !$this->validate( $section, $tag, $v, true ) ) {
return false;
}
}
return true;
}
// NULL values are considered valid. T315202.
if ( $val === null ) {
return true;
}
// Does not work if not typecast
switch ( (string)$etype ) {
case (string)self::BYTE:
$this->debug( $val, __FUNCTION__, $debug );
return $this->isByte( $val );
case (string)self::ASCII:
$this->debug( $val, __FUNCTION__, $debug );
return $this->isASCII( $val );
case (string)self::SHORT:
$this->debug( $val, __FUNCTION__, $debug );
return $this->isShort( $val );
case (string)self::LONG:
$this->debug( $val, __FUNCTION__, $debug );
return $this->isLong( $val );
case (string)self::RATIONAL:
$this->debug( $val, __FUNCTION__, $debug );
return $this->isRational( $val );
case (string)self::SHORT_OR_LONG:
$this->debug( $val, __FUNCTION__, $debug );
return $this->isShort( $val ) || $this->isLong( $val );
case (string)self::UNDEFINED:
$this->debug( $val, __FUNCTION__, $debug );
return $this->isUndefined( $val );
case (string)self::SLONG:
$this->debug( $val, __FUNCTION__, $debug );
return $this->isSlong( $val );
case (string)self::SRATIONAL:
$this->debug( $val, __FUNCTION__, $debug );
return $this->isSrational( $val );
case (string)self::IGNORE:
$this->debug( $val, __FUNCTION__, $debug );
return false;
default:
$this->debug( $val, __FUNCTION__, "The tag '$tag' is unknown" );
return false;
}
}
/**
* Convenience function for debugging output
*
* @param mixed $in Arrays will be processed with print_r().
* @param string $fname Function name to log.
* @param string|bool|null $action Default null.
*/
private function debug( $in, $fname, $action = null ) {
if ( !$this->log ) {
return;
}
$type = gettype( $in );
$class = ucfirst( __CLASS__ );
if ( is_array( $in ) ) {
$in = print_r( $in, true );
}
if ( $action === true ) {
wfDebugLog( $this->log, "$class::$fname: accepted: '$in' (type: $type)" );
} elseif ( $action === false ) {
wfDebugLog( $this->log, "$class::$fname: rejected: '$in' (type: $type)" );
} elseif ( $action === null ) {
wfDebugLog( $this->log, "$class::$fname: input was: '$in' (type: $type)" );
} else {
wfDebugLog( $this->log, "$class::$fname: $action (type: $type; content: '$in')" );
}
}
/**
* Convenience function for debugging output
*
* @param string $fname The name of the function calling this function
* @param bool $io Specify whether we're beginning or ending
*/
private function debugFile( $fname, $io ) {
if ( !$this->log ) {
return;
}
$class = ucfirst( __CLASS__ );
if ( $io ) {
wfDebugLog( $this->log, "$class::$fname: begin processing: '{$this->basename}'" );
} else {
wfDebugLog( $this->log, "$class::$fname: end processing: '{$this->basename}'" );
}
}
}