cURL file uploads not working anymore after upgrade from PHP 5.5 to 5.6

Question

I've got a cURL upload that fails after upgrading from PHP 5.5 to 5.6:

$aPost = array(
    'file' => "@".$localFile,
    'default_file' => 'html_version.html',
    'expiration' => (2*31*24*60*60)
)

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $apiurl);
curl_setopt($ch, CURLOPT_TIMEOUT, 120);
curl_setopt($ch, CURLOPT_BUFFERSIZE, 128);
curl_setopt($ch, CURLOPT_POSTFIELDS, $aPost);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$sResponse = curl_exec ($ch);

The file seems to be empty on the target system.

Answer 1

Actually I found the answer while starting the question. There is a new Variable included with curl in PHP 5.5: CURLOPT_SAFE_UPLOAD this is set to false by default in PHP 5.5 and is switched to a default of true in PHP 5.6.

This will prevent the '@' upload modifier from working for security reasons - user input could contain malicious upload requests. You can use the CURLFile class to upload files while CURLOPT_SAFE_UPLOAD is set to true or (if you're sure your variables are safe you can switch the CURLOPT_SAFE_UPLOAD to false manually):

 curl_setopt($ch, CURLOPT_SAFE_UPLOAD, false);

Here's a source for the information that got me searching in the right direction: http://comments.gmane.org/gmane.comp.php.devel/87521

It's mentioned in the changed functions too: http://php.net/manual/en/migration56.changed-functions.php But not in the backward incompatible changes, really tripped me off...

Answer 2

Just do following changes for PHP 5.5 or greater

Instead of "@" . $localFile just use new CurlFile($localFile)

And set

curl_setopt($ch, CURLOPT_SAFE_UPLOAD, true);

Answer 3

Include a runtime check to make your code compatible with lower versions too like below

$aPost = array(
    'default_file' => 'html_version.html',
    'expiration' => (2*31*24*60*60)
)
if ((version_compare(PHP_VERSION, '5.5') >= 0)) {
    $aPost['file'] = new CURLFile($localFile);
    curl_setopt($ch, CURLOPT_SAFE_UPLOAD, true);
} else {
    $aPost['file'] = "@".$localFile;
}

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $apiurl);
curl_setopt($ch, CURLOPT_TIMEOUT, 120);
curl_setopt($ch, CURLOPT_BUFFERSIZE, 128);
curl_setopt($ch, CURLOPT_POSTFIELDS, $aPost);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$sResponse = curl_exec ($ch);