Openssl_pkcs7_sign(): error opening file - php

Question

it's my first time doing signing of cert using openssl. Keep hitting the above error and tried realpath() and appending file:// but still can't get openssl to sign the profile. I don't understand how this works. Any insights would be appreciated.
Edit1: I'm not sure which file is the problematic one. The error messages wasn't specific enough. Is there a way to tell?
Code and screenshots below:
function signProfile()
{
$filename = "./template.mobileconfig";
$filename = realpath($filename);
$outFilename = $filename . ".tmp";
$pkey = dirname(__FILE__) . "/PteKey.key";
$pkey = realpath($pkey);
$certFile = dirname(__FILE__) . "/CertToSign.crt";
$certFile = realpath($certFile);
// try signing the plain XML profile
if (openssl_pkcs7_sign($filename, $outFilename, 'file://'.$certFile, array('file://'.$pkey, ""), array(), 0, ""))
{
// get the data back from the filesystem
$signedString = file_get_contents($outFilename);
// trim the fat
$trimmedString = preg_replace('/(.+\n)+\n/', '', $signedString, 1);
// convert to binary (DER)
$decodedString = base64_decode($trimmedString);
// write the file back to the filesystem (using the filename originally given)
$fh = fopen($filename, 'w');
fwrite($fh, $decodedString);
fclose($fh);
// delete the temporary file
unlink($outFilename);
return TRUE;
}
else
{
return FALSE;
}
}

Answer 1

Remove unwanted fields if not used in
openssl_pkcs7_sign($mobileConfig, $tmpMobileConfig, $certFile, array($pkey, ""), array());
Make sure file paths are correctly supplied.
require_once('variables.php'); //stores abs path to $tmpMobileConfig/$pteKeyPath/$CertToSignPath
$prepend = "file://";
$mobileConfig = realpath("./template.mobileconfig");
$pkey = $prepend . $pteKeyPath;
$pkey = str_replace('\\', '/', $pkey);
$certFile = $prepend . $CertToSignPath;
$certFile = str_replace('\\', '/', $certFile);
$isSignedCert = openssl_pkcs7_sign($mobileConfig, $tmpMobileConfig, $certFile, array($pkey, ""), array());