When the Identity Service runs in apache-httpd, you can use external authentication methods that differ from the authentication provided by the identity store back-end. For example, you can use an SQL identity back-end together with X.509 authentication, Kerberos, and so on instead of using the user name and password combination.

Web servers, like Apache HTTP, support many methods of authentication. The Identity Service can allow the web server to perform the authentication. The web server then passes the authenticated user to the Identity Service by using the REMOTE_USER environment variable. This user must already exist in the Identity Service back-end so as to get a token from the controller. To use this method, the Identity Service should run on apache-httpd.

The following Apache configuration snippet authenticates the user based on a valid X.509 certificate from a known CA: <VirtualHost _default_:5000> SSLEngine on SSLCertificateFile /etc/ssl/certs/ssl.cert SSLCertificateKeyFile /etc/ssl/private/ssl.key SSLCACertificatePath /etc/ssl/allowed_cas SSLCARevocationPath /etc/ssl/allowed_cas SSLUserName SSL_CLIENT_S_DN_CN SSLVerifyClient require SSLVerifyDepth 10 (...) </VirtualHost>