Xojo Plugin

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.

Xojo Plugin

Dim success As Boolean
success = False

Dim cert As New Chilkat.Cert

success = cert.LoadFromFile("qa_data/certs/test_haswdt.cer")
If (success <> True) Then
    System.DebugLog(cert.LastErrorText)
    Return
End If

// Get the CRL Distribution Points extension, which is at OID 2.5.29.31
Dim extensionXmlStr As String
extensionXmlStr = cert.GetExtensionAsXml("2.5.29.31")
If (cert.LastMethodSuccess = False) Then
    System.DebugLog("Certificate does not have the CDP extension.")
    Return
End If

Dim xml As New Chilkat.Xml
success = xml.LoadXml(extensionXmlStr)

// See what we have..
System.DebugLog(xml.GetXml())

// 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...
Dim sbDistPoint As New Chilkat.StringBuilder
success = xml.GetChildContentSb("sequence|contextSpecific|contextSpecific|contextSpecific",sbDistPoint)
If (success = True) Then
    success = sbDistPoint.Decode("base64","utf-8")
    System.DebugLog("CRL Distribution Point:  " + sbDistPoint.GetAsString())
End If

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