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Merge pull request #38364 from joshtrichards/jr-preview-libgd-webp-animation-bypass

pull/40427/head
John Molakvoæ 2024-08-06 17:56:14 +07:00 committed by GitHub
parent 4642d82e8b 046fe8d404
commit 8a5bc4778b
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1 changed files with 49 additions and 2 deletions
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51
lib/private/legacy/OC_Image.php
Unescape Escape View File

@ -691,9 +691,56 @@ class OC_Image implements \OCP\IImage {
if (!$this->checkImageSize($imagePath)) {
return false;
}
$this->resource = @imagecreatefromwebp($imagePath);
// Check for animated header before generating preview since libgd does not handle them well
// Adapted from here: https://stackoverflow.com/a/68491679/4085517 (stripped to only to check for animations + added additional error checking)
// Header format details here: https://developers.google.com/speed/webp/docs/riff_container
// Load up the header data, if any
$fp = fopen($imagePath, 'rb');
if (!$fp) {
return false;
}
$data = fread($fp, 90);
if (!$data) {
return false;
}
fclose($fp);
unset($fp);
$headerFormat = 'A4Riff/' . // get n string
'I1Filesize/' . // get integer (file size but not actual size)
'A4Webp/' . // get n string
'A4Vp/' . // get n string
'A74Chunk';
$header = unpack($headerFormat, $data);
unset($data, $headerFormat);
if (!$header) {
return false;
}
// Check if we're really dealing with a valid WEBP header rather than just one suffixed ".webp"
if (!isset($header['Riff']) || strtoupper($header['Riff']) !== 'RIFF') {
return false;
}
if (!isset($header['Webp']) || strtoupper($header['Webp']) !== 'WEBP') {
return false;
}
if (!isset($header['Vp']) || strpos(strtoupper($header['Vp']), 'VP8') === false) {
return false;
}
// Check for animation indicators
if (strpos(strtoupper($header['Chunk']), 'ANIM') !== false || strpos(strtoupper($header['Chunk']), 'ANMF') !== false) {
// Animated so don't let it reach libgd
$this->logger->debug('OC_Image->loadFromFile, animated WEBP images not supported: ' . $imagePath, ['app' => 'core']);
} else {
// We're safe so give it to libgd
$this->resource = @imagecreatefromwebp($imagePath);
}
} else {
$this->logger->debug('OC_Image->loadFromFile, webp images not supported: ' . $imagePath, ['app' => 'core']);
$this->logger->debug('OC_Image->loadFromFile, WEBP images not supported: ' . $imagePath, ['app' => 'core']);
}
break;
/*