TLS inside TLS configuration

[opnsensler]

Hi together,

we use a OPNsense with SQUID Proxy as a non transparent Proxy.
We have SQUID as https froward proxy in our network. One of our application sends a API request out of the network. The webservice needs a client certificate for auth. Application is working fine directly without SQUID proxy.

We need SQUID to decrypt SSL traffic and also authenticate and pass the authentication certificate (client certificate) to webservice server. What are the possible configurations for SQUID for this case?

Greetz
opnsensler