PHP Extension

Get Certificate Authority Information Access

See more Certificates Examples

Demonstrates how to get a certificate's Authority Information Access extension data (if it exists).

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 Authority Information Access extension, which is at OID 1.3.6.1.5.5.7.1.1
$extensionXmlStr = $cert->getExtensionAsXml('1.3.6.1.5.5.7.1.1');
if ($cert->get_LastMethodSuccess() == false) {
    print 'Certificate does not have the AuthInfoAccess 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>
//         <oid>1.3.6.1.5.5.7.48.2</oid>
//         <contextSpecific tag="6" constructed="0">aHR0cDovL2NydC5jb21vZG9jYS5jb20vQ09NT0RPUlNBQ2xpZW50QXV0aGVudGljYXRpb25hbmRTZWN1
// cmVFbWFpbENBLmNydA==</contextSpecific>
//     </sequence>
//     <sequence>
//         <oid>1.3.6.1.5.5.7.48.1</oid>
//         <contextSpecific tag="6" constructed="0">aHR0cDovL29jc3AuY29tb2RvY2EuY29t</contextSpecific>
//     </sequence>
// </sequence>

// Typically, a certificate AIA(Authority Information access) contains 2 parts:
// 
//     On-line Certificate Status Protocol (1.3.6.1.5.5.7.48.1)
//     Certification Authority Issuer (1.3.6.1.5.5.7.48.2)
// 
// The base64 content for each OID (in this case) is just a string.  
// The data can be accessed and decoded like this:

$sbOcsp = new CkStringBuilder();
$success = $xml->GetChildContentSb('/C/oid,1.3.6.1.5.5.7.48.1|++',$sbOcsp);
if ($success == true) {
    $sbOcsp->Decode('base64','utf-8');
    print '1.3.6.1.5.5.7.48.1:  ' . $sbOcsp->getAsString() . "\n";
}

$sbIssuer = new CkStringBuilder();
$success = $xml->GetChildContentSb('/C/oid,1.3.6.1.5.5.7.48.2|++',$sbIssuer);
if ($success == true) {
    $sbIssuer->Decode('base64','utf-8');
    print '1.3.6.1.5.5.7.48.2:  ' . $sbIssuer->getAsString() . "\n";
}

// The output looks like this:

// 1.3.6.1.5.5.7.48.1:  http://ocsp.comodoca.com
// 1.3.6.1.5.5.7.48.2:  http://crt.comodoca.com/COMODORSAClientAuthenticationandSecureEmailCA.crt

// -------------------------------------------------------------------------------
// Note: The Chilkat path passed to GetChildContentSb is composed of two commands:
// The first command is "/C/oid,1.3.6.1.5.5.7.48.1".   It says "traverse the XML tree from the caller
// node and stop at the 1st node having tag = "oid" and content = "1.3.6.1.5.5.7.48.1".
// The "|" char separates the 1st command from the 2nd.
// The 2nd command is "++" and says "move to the next sibling".

?>