B4X

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.

B4X

Dim success As Boolean = False

Dim cert As ChilkatCert
cert.Initialize("cert")

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


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


Dim xml As ChilkatXml
xml.Initialize
xml.LoadXml(extensionXmlStr)

'  See what we have..
Log(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 ChilkatStringBuilder
sbDistPoint.Initialize
success = xml.GetChildContentSb("sequence|contextSpecific|contextSpecific|contextSpecific", sbDistPoint)
If success = True Then
    sbDistPoint.Decode("base64", "utf-8")
    Log("CRL Distribution Point:  " & sbDistPoint.GetAsString)
End If


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