[keycloak-user] Authentication (Node.JS) Microservice to pass User x.509 certificate to Keycloak

[Daniel Scheiner]

Hi!

I am currently trying to have a Node.JS application between the User and Keycloak.
Keycloak is running in a Docker container (with the option "-e PROXY_ADDRESS_FORWARDING=true").
The Node.JS microservice connects to Keycloak via HTTPS and wants to offer the User x.509 certificate.

How do I have to configure Keycloak (Docker image) to accept the user cert?
- certificate is PEM
- we have a CA set up and can provide the ca-chain
- Node.JS currently tries connecting via 'isomorphic-fetch' and passing cert in headers...

All I get so far with headers:
- SSL_CLIENT_CERT
- X-Client-Certificate
- USER_CERT
- javax.servlet.request.X509Certificate
--> { error_description: 'X509 client certificate is missing.',  error: 'invalid_request' }

Thank you sincerely!
Daniel