Can the Application Gateway passthrough a client certificate so it can be recognised by APIM?

Question

Can the Application Gateway passthrough a client certificate so it can be recognised by APIM?
in our case it is not validating the certs

Answer 1

Hello @gaur

Application Gateway allows you to add, remove, or update HTTP request and response headers while the request and response packets move between the client and back-end pools.

You are using Mutual Authentication and have set your SSL profile to mutually validate client request, but the request sent to the APIM does not consists of X-ARR-ClientCert header.

Application Gateway can passthrough a client certificate but you need to rewrite HTTP header with a Custom Header name X-ARR-ClientCert with value {var_client_certificate} in Application Gateway.

As the Mutual Authentication is still in preview some features might not work as expected and it is currently not recommended for production environments.

https://stackoverflow.com/questions/69166457/azure-application-gateway-client-certificates-headers

https://learn.microsoft.com/en-us/answers/questions/554635/azure-application-gateway-client-certificates-head.html