PHP Extension

Get Certificate CRL Distribution Points

See more Certificates Examples

Demonstrates how to get a certificate's CRL Distribution Points extension data (assuming it exists). In the vast majority of cases, there will be one CRL Distribution Point.

Note: This example requires Chilkat v9.5.0.76 or greater.

PHP Extension

<?php

include("chilkat.php");

$success = false;

$cert = new CkCert();

$success = $cert->LoadFromFile('qa_data/certs/test_haswdt.cer');
if ($success != true) {
    print $cert->lastErrorText() . "\n";
    exit;
}

// Get the CRL Distribution Points extension, which is at OID 2.5.29.31
$extensionXmlStr = $cert->getExtensionAsXml('2.5.29.31');
if ($cert->get_LastMethodSuccess() == false) {
    print 'Certificate does not have the CDP extension.' . "\n";
    exit;
}

$xml = new CkXml();
$xml->LoadXml($extensionXmlStr);

// See what we have..
print $xml->getXml() . "\n";

// We should get XML like this:

// <?xml version="1.0" encoding="utf-8" ?>
// <sequence>
//     <sequence>
//         <contextSpecific tag="0" constructed="1">
//             <contextSpecific tag="0" constructed="1">
//                 <contextSpecific tag="6" constructed="0">aHR0cDovL2NybC5jb21vZG9jYS5jb20vQ09NT0RPUlNBQ2xpZW50QXV0aGVudGljYXRpb25hbmRTZWN1
// cmVFbWFpbENBLmNybA==</contextSpecific>
//             </contextSpecific>
//         </contextSpecific>
//     </sequence>
// </sequence>
// 

// Assuming there is one CRL Distribution Point...
$sbDistPoint = new CkStringBuilder();
$success = $xml->GetChildContentSb('sequence|contextSpecific|contextSpecific|contextSpecific',$sbDistPoint);
if ($success == true) {
    $sbDistPoint->Decode('base64','utf-8');
    print 'CRL Distribution Point:  ' . $sbDistPoint->getAsString() . "\n";
}

// Sample output:
// CRL Distribution Point:  http://crl.comodoca.com/COMODORSAClientAuthenticationandSecureEmailCA.crl

?>