(CkPython) 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 Python Downloads install with pip pip3 install chilkat or download... Python Module for Windows, MacOS, Linux, Alpine Linux, Solaris

import sys
import chilkat

cert = chilkat.CkCert()

success = cert.LoadFromFile("qa_data/certs/test_haswdt.cer")
if (success != True):
    print(cert.lastErrorText())
    sys.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.")
    sys.exit()

xml = chilkat.CkXml()
xml.LoadXml(extensionXmlStr)

#  See what we have..
print(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...
sbDistPoint = chilkat.CkStringBuilder()
success = xml.GetChildContentSb("sequence|contextSpecific|contextSpecific|contextSpecific",sbDistPoint)
if (success == True):
    sbDistPoint.Decode("base64","utf-8")
    print("CRL Distribution Point:  " + sbDistPoint.getAsString())

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