# documentation:2.0:applications:tomcat
Keywords: documentation,2.0,applications,tomcat

# Apache Tomcat

The Tomcat Valve is only available for tomcat 5.5 or greater.

## Presentation

Apache Tomcat is an open source software implementation of the Java Servlet and JavaServer Pages technologies.

As J2EE servlet container, Tomcat provides standard security feature, like authentication: the application deployed in Tomcat can delegate its authentication to Tomcat.

By default, Tomcat provides a file called `users.xml` to manage authentication:

    <?xml version='1.0' encoding='utf-8'?>
    <tomcat-users>
      <role rolename="tomcat"/>
      <role rolename="role1"/>
      <user username="tomcat" password="tomcat" roles="tomcat"/>
      <user username="role1" password="tomcat" roles="role1"/>
      <user username="both" password="tomcat" roles="tomcat,role1"/>
    </tomcat-users>

LL::NG provides a valve, available on download page. This valve will check an HTTP header to set the authenticated user on the J2EE container.

## Installation

Copy `ValveLemonLDAPNG.jar` in `<TOMCAT_HOME>/server/lib`:

    cp ValveLemonLDAPNG.jar server/lib/

If needed, you can recompile the valve from the sources.

## Configuration

Add on your `server.xml` file a new valve entry like this (in host section):

    <Valve className="org.lemonLDAPNG.SSOValve" userKey="AUTH-USER" roleKey="AUTH-ROLE" roleSeparator="," allows="127.0.0.1"/>

Configure attributes:

- userKey: key in the HTTP header containing user login.
- roleKey: key in the HTTP header containing roles. If LL::NG send some roles split by some commas, configure roleSeparator.
- roleSeparator (optional): role values separator.
- allows (optional): Define allowed remote IP (use “,” separator for multiple IP). Just set the LL::NG Handler IP on this attribute in order to add more security. If this attribute is missed all hosts are allowed.
- passThrough (optional): Allow anonymous access or not. When it takes “false”, HTTP headers have to be sent by LL::NG to make authentication. So, if the user is not recognized or HTTP headers not present, a 403 error is sent.

For debugging, this valve can print some helpful information in debug level. See how configure logging in Tomcat .

## Compilation

The sources are available on download page.

Required :

- ant
- jre > 1.4
- tomcat >= 5.5

Configure your tomcat home in `build.properties` files.

Be careful for Windows user, path must contains “/”. Example:

    c:/my hardisk/tomcat/

Next run ant command:

    ant

`ValveLemonLDAPNG.jar` is created under `/dist` directory.