SSL Errors for ssl.get_server_certificate on some websites but not on others

Question

So I am trying to get some domains certificates using: (port is first retrieved from a nmap and secondly I try to use 443)

ssl.get_server_certificate((hostname, port))

But for some domains, like the following ones(only a couple of them): q1.insightsnow.redbull.com, mib-cdn.redbull.com, internalauditdb-uux-d.redbull.com, smg20.redbull.com, ssmg11-q.redbull.com, pm.redbull.com. For this subdomains and many other ones I am getting a bunch of different errors:

• [SSL: WRONG_VERSION_NUMBER] wrong version number
• timed out
• EOF occurred in violation of protocol
• [SSL: SSLV3_ALERT_HANDSHAKE_FAILURE] sslv3 alert handshake failure

I need to mention that for a lot of other subdomains (somewhere around 1000), everything works fine and I can get their certificate. But for ~200 of them I am getting the errors from above repeatedly and I can not find their source on the internet.

Do you happen to know why I can not use ssl.get_server_certificate on those website or where am I doing something wrong?

Thanks!

Answer 1

Most if the sites here require SNI. It was a long standing issue that SNI was not done with ssl.get_server_certificate - see ssl.get_server_certificate for sites with SNI (Server Name Indication) and Python issue 36076 . It is finally solved with 3.10:

$ python3.8 -c 'import ssl; print(ssl.get_server_certificate(("q1.insightsnow.redbull.com", 443)))'
...
ssl.SSLError: [SSL: WRONG_VERSION_NUMBER] wrong version number (_ssl.c:1123)


$ python3.10 -c 'import ssl; print(ssl.get_server_certificate(("q1.insightsnow.redbull.com", 443)))'
-----BEGIN CERTIFICATE-----
MIIHnjCCBoagAwIBAgIRAPcBO50Fz5QaF+JxeyoL1vEwDQYJKoZIhvcNAQELBQAw
gZUxCzAJBgNVBAYTAkdCMRswGQYDVQQIExJHcmVhdGVyIE1hbmNoZXN0ZXIxEDAO
...

For older Python versions see the answers to this question on how to get the certificate without using ssl.get_server_certificate .

As for smg20.redbull.com and ssmg11-q.redbull.com - these sites do not seem to be reachable from the internet in the first place, ie they are also not accessible by other tools or the browser.