public URI getClientAuthenticationURI(String subdomain) throws GuacamoleException {

        URI authURI = environment.getRequiredProperty(SSL_AUTH_URI);
        String baseHostname = authURI.getHost();

        // Add provided subdomain to auth URI
        return UriBuilder.fromUri(authURI)
                .host(subdomain + "." + baseHostname)
                .build();

    }
Returns a URI that should be used to authenticate users with SSL/TLS
client authentication. The returned URI will consist of the configured
client authentication URI with the wildcard portion ("*.") replaced with
the given subdomain.

@param subdomain
    The subdomain that should replace the wildcard portion of the
    configured client authentication URI.

@return
    A URI that should be used to authenticate users with SSL/TLS
    client authentication.

@throws GuacamoleException
    If the required property for configuring the client authentication
    URI is missing or cannot be parsed.
extensions/guacamole-auth-sso/modules/guacamole-auth-sso-ssl/src/main/java/org/apache/guacamole/auth/ssl/conf/ConfigurationService.java