AS2Secure drops multipart/signed content-type from headers

Question

I'm trying to received an AS2 MDN using the PHP lib AS2Secure. The message arrives and decodes just fine, but when the response goes out it strips the main "multipart/signed" value from the Content-Type.

For instance, something like this should be in the main header to designate a multipart message:

Content-Type: multipart/signed; boundary="----=_Part_8f23d0b4-8a42-4946-9928-4d12d9f7fc66.63"; protocol="application/pkcs7-signature"; micalg=SHA1

However, when the response for the multipart message goes out, I only see this in the main headers:

Content-Type: text/html; charset=UTF-8

This triggers an error in the remote server, which expects the message to designate its content-type as multipart.

I tracked the stripping of the multipart content-type down to this code in AS2MDN.php:

// TODO : replace with futur AS2MimePart to separate content from header
if (strpos($content, "\n\n") !== false) $content = substr($content, strpos($content, "\n\n") + 2);

If I remove this code, the missing Content-Type: multipart/signed line shows up in the body but Content-Type: text/html still shows in the headers.

Any ideas?

Answer 1

This was caused by the PHP Laravel framework (which handles the app's routing) overwriting headers during output.

Changing this code in the handle() method in AS2server.php:

ob_end_clean();
// send headers
foreach ($mdn->getHeaders() as $key => $value) {
    $header = str_replace(["\r", "\n", "\r\n"], '', $key . ': ' . $value);
    header($header);
}

// output MDN
echo $mdn->getContent();

...to this Laravel friendly code:

$headers = [];

foreach ($mdn->getHeaders() as $key => $value) {
    $headers[str_replace(["\r", "\n", "\r\n"], '', $key)] = str_replace(["\r", "\n", "\r\n"], '', $value);
}

return \Response::make($mdn->getContent(), 200, $headers); // Use native Laravel response.

...solved the problem!