Web UI Pre-Authentication

It is possible to configure Meridian to run behind a proxy that provides authentication, and then pass the pre-authenticated user to the Meridianwebapp using a header.

Define the pre-authentication configuration in $OPENNMS_HOME/jetty-webapps/opennms/WEB-INF/spring-security.d/header-preauth.xml. This file is automatically included in the Spring security context, but is not enabled by default.

Do not configure Meridian this way unless you are certain the web UI is accessible only to the proxy and not to end users. Otherwise, malicious attackers can craft queries that include the pre-authentication header and get full control of the web UI and REST APIs.

Enabling pre-authentication

Edit the header-preauth.xml file, and set the enabled property:

<beans:property name="enabled" value="true" />

Configuring pre-authentication

You can also set the following properties to change the behavior of the pre-authentication plugin:

Property	Description	Default
enabled	Whether the pre-authentication plugin is active.	false
failOnError	If true, disallow login if the header is not set or the user does not exist. If false, fall through to other mechanisms (basic auth, form login, and so on.)	false
userHeader	The HTTP header that will specify the user to authenticate as.	X-Remote-User
credentialsHeader	A comma-separated list of additional credentials (roles) the user should have.	n/a
authoritiesHeader	The HTTP header that will contain a comma-separated list of authorities (roles) the user will have.	n/a

Property

Description

Default

enabled

Whether the pre-authentication plugin is active.

false

failOnError

If true, disallow login if the header is not set or the user does not exist. If false, fall through to other mechanisms (basic auth, form login, and so on.)

false

userHeader

The HTTP header that will specify the user to authenticate as.

X-Remote-User

credentialsHeader

A comma-separated list of additional credentials (roles) the user should have.

n/a

authoritiesHeader

The HTTP header that will contain a comma-separated list of authorities (roles) the user will have.

n/a

Enabling pre-authorization

Modify jetty-webapps/opennms/WEB-INF/applicationContext-spring-security.xml, and set:

---
<beans:bean id="preauthAuthProvider" class="org.springframework.security.web.authentication.preauth.PreAuthenticatedAuthenticationProvider">
  <beans:property name="preAuthenticatedUserDetailsService">
    <beans:bean id="preAuthUserDetailsService" class="org.springframework.security.web.authentication.preauth.PreAuthenticatedGrantedAuthoritiesUserDetailsService"/>
  </beans:property>
</beans:bean>
---

You can then try testing with:

curl -H "X-Remote-User: myuser" -H "X-Remote-Role: ROLE_USER,ROLE_REST" http://localhost:8980/opennms/rest/whoami