Are there any public web services that will check for an MTLS cert and response with application/json

Question

A different thread pointed out a couple of services that would require a client MTLS certificate, accept any cert, and then respond with information about the SSL handshake/certs.

HTTPS test server that checks client certificates

These endpoints both return HTML. Does anyone know of anything similar that returns application/json?

I never found such a service so I ended up creating my own. If there is much interest I can see about making it public. — Jason Mathison, Mar 03 '20 at 21:15
I am working on releasing it, but it may be another couple of weeks before I make much progress on it. — Jason Mathison, Nov 04 '20 at 12:38

score 4 · Answer 1 · edited Mar 26 '21 at 22:25

The URLs below will return application/json content upon successfully mutual TLS client certificate authentication. If no authentication is peformed, then HTTP error 403 is returned in the HTTP headers and the response is empty:

https://certauth.idrix.fr/json (TLS 1.2 only)
https://certauth.cryptomix.com/json (TLS 1.2 and TLS 1.3)

The json returned in case of success contains various technical information about the established connection.

Are there any public web services that will check for an MTLS cert and response with application/json

1 Answers1