Apache proxy: passing on REMOTE_USER to backend server

apache-2.2environment-variablesPROXYreverse-proxy

We are using shibboleth for authentication. Our shibboleth Service provider is running on a host that is running apache with reverse proxy configuration (mod_proxy). The applications using shibboleth are running in the backend, no SP is installed on these servers. We are getting all shibboleth headers on the backend servers.

Now I need the REMOTE_USER variable that is filled by shibboleth authentication on the proxy server to be available on the backend server. I"ve managed to get the value into HTTP_REMOTE_USER and pass it on the the backend servers but i'm struggling to put this value into REMOTE_USER on the backend server.

I would like to know what the difference is between HTTP_REMOTE_USER and REMOTE_USER and how to manipulate REMOTE_USER from the apache config without doing actual authentication.

Best Answer

I wanted to do exactly the same as you with shibboleth. But unfortunately I found this on the corresponding apache docs. REMOTE_USER is part of the CGI standard therefore cannot be modified with apache directives.

It is not possible to override or change the standard CGI variables using the environment manipulation directives.