This is a Quick and dirty Python script for checking if a domain properly implements Certificate Transparency. If so, it is possible to observe how Certificate Transparency is implemented on the server side. When a server implements Certificate Transparency, it must offer at least one SCT (a proof of inclusion of the server TLS Certificate into a Transparency Log). A SCT can be offered by three different ways: embedded in the certificate, as a TLS extension and via OCSP Stapling. Using PySCTChecker is possible to identify the delivery options that the server uses and the logs the certificate has been sent to. Also, it is possible to check if the offered SCTs are valid and legitimately signed by logs.

• Usage:

   python PySCTChecker/ct_domains_sct_checker.py [domain1 domain2 ...]
  

• Output example:

  user@ubuntu:~/Desktop/PySCTChecker$ python ct_domains_sct_checker.py elevenpaths.com

  ** Connecting to host: elevenpaths.com... **

  ** Looking for embedded SCT in certificate **

  ** Looking for SCTs in TLS extensions**

  No sct found on TLS

  ** Looking for SCTs in OCSP response **

  OCSP address not found No sct found in OCSP response

  ** Logs detected in SCTs **

  Symantec log (precert) └─ Verified signature: True

  Google 'Pilot' log (precert) └─ Verified signature: True

  Google 'Rocketeer' log (precert) └─ Verified signature: True

• Dependencies:

  • To run PySCTChecker, OpenSSL is required.

  • To install python modules dependencies, run:

    sudo pip install -r PySCTChecker/requirements.txt
    

• https://www.elevenpaths.com/labstools/certificate-transparency-checker-firefox/index.html
• https://github.com/Torvel/ct-tools/blob/master/submit-cert.py