## Jakarta Authentication (formerly JASPIC)

### Table of Contents

- Introduction
- Static configuration
  1. AuthConfigProvider
  2. ServerAuthModule
- Dynamic configuration
- 3rd party modules
  1. Philip Green II's module for Google OAuth 2

### Introduction

Tomcat implements Jakarta Authentication 3.0. The implementation is primarily intended to enable the integration of 3rd party authentication implementations with Tomcat.

Jakarta Authentication may be configured in one of two ways:

- At the container level via the static configuration file `$CATALINA_BASE/conf/jaspic-providers.xml`. With this approach all required classes must be visible to Tomcat's Common class loader which normally means placing a JAR in `$CATALINA_BASE/lib`.
- At the web application level via dynamic configuration using the Jakarta Authentication API. With this approach all required classes must be visible to the web application class loader which normally means placing a JAR in the web application's `WEB-INF/lib` directory.

Users should be aware that if the static Jakarta Authentication configuration file configures Jakarta Authentication for a given web application then the Jakarta Authentication configuration will take precendence over any `<login-config>` present in the web application's `WEB-INF/web.xml` file.

### Static configuration

#### AuthConfigProvider

If the 3rd party implementation includes an `AuthConfigProvider` then a web application can be configured to use it by nesting the following inside the `<jaspic-providers>` element in `$CATALINA_BASE/conf/jaspic-providers.xml`.

    <provider name="any"
              className="fully.qualified.implementation.class.Name"
              layer="HttpServlet"
              appContext="Catalina/localhost /contextPath"
              description="any">
      <property name="see-provider-documentation"
                value="see-provider-documentation" />
    </provider>

The `name` and `description` attributes are not used by Tomcat.

The `className` attribute must be the fully qualified class name of the `AuthConfigProvider`. The implementation may be packaged with the web application or in Tomcat's `$CATALINA_BASE/lib` directory.

The `layer` attribute must be `HttpServlet`.

The `appContext` attribute must be exactly the concatenation of:

- The engine name
- The forward slash character
- The host name
- A single space
- The context path

If the `AuthConfigProvider` supports configuration via properties these may be specified via `<property>` elements nesting inside the `<provide>` element.

#### ServerAuthModule

If the 3rd party implementation only provides an `ServerAuthModule` then it will be necessary to provide a number of supporting classes. These may be a custom implementation or, alternatively, Tomcat provides a simple wrapper implementation for `ServerAuthModule`s.

Tomcat's wrapper for `ServerAuthModule` can be configured by nesting the following inside the `<jaspic-providers>` element in `$CATALINA_BASE/conf/jaspic-providers.xml`.

    <provider name="any"
              className="org.apache.catalina.authenticator.jaspic.SimpleAuthConfigProvider"
              layer="HttpServlet"
              appContext="Catalina/localhost /contextPath"
              description="any">
      <property name="org.apache.catalina.authenticator.jaspic.ServerAuthModule.1"
                value="fully.qualified.implementation.class.Name" />
      <property name="see-provider-documentation"
                value="see-provider-documentation" />
    </provider>

The configuration is similar to the `AuthConfigProvider` in the previous section but with some key differences.

The `className` attribute must be `org.apache.catalina.authenticator.jaspic.SimpleAuthConfigProvider`.

The `ServerAuthModule`(s) are specified via properties. The property name must be `org.apache.catalina.authenticator.jaspic.ServerAuthModule.n` where `n` is the index of the module. The index must start at 1 an increment in steps of 1 until all modules are defined. The value of the property must be the fully qualified class name of the module.

### Dynamic configuration

Jakarta Authentication modules and configuration can be packaged within a WAR file with the web application. The web application can then register the required Jakarta Authentication configuration when it starts using the standard Jakarta Authentication APIs.

If parallel deployment is being used then dynamic configuration should not be used. The Jakarta Authentication API assumes that a context path is unique for any given host which is not the case when using parallel deployment. When using parallel deployment, static Jakarta Authentication configuration should be used. This will require that all versions of the application use the same Jakarta Authentication configuration.

### 3rd party modules

This is not an exhaustive list. The Tomcat community welcomes contributions that add to this section.

#### Philip Green II's module for Google OAuth 2

The source code for this module along with the documentation which includes details of the necessary Google API configuration is available on GitHub.

A sample configuration for using this module with Tomcat would look like this:

    <jaspic-providers xmlns="https://tomcat.apache.org/xml"
                      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                      xsi:schemaLocation="https://tomcat.apache.org/xml jaspic-providers.xsd"
                      version="1.0">
      <provider name="google-oauth"
                className="org.apache.catalina.authenticator.jaspic.SimpleAuthConfigProvider"
                layer="HttpServlet"
                appContext="Catalina/localhost /contextPath"
                description="Google OAuth test">
        <property name="org.apache.catalina.authenticator.jaspic.ServerAuthModule.1"
                  value="com.idmworks.security.google.GoogleOAuthServerAuthModule" />
        <property name="oauth.clientid"
                  value="obtained-from-Google-console" />
        <property name="oauth.clientsecret"
                  value="obtained-from-Google-console" />
        <property name="ignore_missing_login_context"
                  value="true" />
      </provider>
    </jaspic-providers>