(PHP Extension) Get Certificate CRL Distribution Points

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.

Chilkat PHP Downloads PHP Extension for Windows, Linux, MacOS, Alpine Linux, Solaris

<?php

// The version number (9_5_0) should match version of the Chilkat extension used, omitting the micro-version number.
// For example, if using Chilkat v9.5.0.48, then include as shown here:
include("chilkat_9_5_0.php");

$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

?>