02. Authentication

The act of processing a submitted username and password is called authentication. Note that authentication is a prerequisite to authorization. The Pentaho BI Platform uses Acegi Security to process authentication requests. Out-of-the-box authentication mechanisms provided by the platform are form, basic, and request parameter.

The vast majority of the configuration contained in the applicationContext-acegi-security.xml is a standard Acegi Security setup and is well-documented in the Acegi Security documentation. Where the configuration strays from the Acegi Security documentation, it is documented below.

Form-Based Authentication

Form-based authentication lets developers customize the authentication user interface. While the J2EE specifications provide a standard way to specify the login page URL as well as URL authorization rules, there is still container-specific configuration to specify how to read usernames and passwords from a security datastore. This is one reason that the platform uses Acegi Security. The Acegi Security class that processes form posts is AuthenticationProcessingFilter.

Login Handling

SecurityStartupFilter

SecurityStartupFilter allows the Pentaho BI Platform to obtain a user's credentials (java.security.Principal) and inject it into the Pentaho user session. This requires a new bean definition:

<bean id="pentahoSecurityStartupFilter"
  class="com.pentaho.security.SecurityStartupFilter" />

This bean is then added to the filterChainProxy bean (shown later).

HttpSessionReuseDetectionFilter

HttpSessionReuseDetectionFilter detects when an HTTP session which contains a authenticated user is attempting to authenticate again without logging out. Upon detecting this condition, the session is invalidated, the security context is cleared, and the user is redirected to sessionReuseDetectedUrl. This prevents reuse of an HTTP session which contains potentially sensitive, user-specific data. The filterProcessesUrl value should match the value of the same property in AuthenticationProcessingFilter.

Notice the login_error=2 parameter on the filterProcessesUrl? The login page should test for login_error=2 and print the appropriate message describing what just happened.

<bean id="httpSessionReuseDetectionFilter" class="com.pentaho.security.HttpSessionReuseDetectionFilter">
  <property name="filterProcessesUrl" value="/j_acegi_security_check" />
  <property name="sessionReuseDetectedUrl" value="/Login?login_error=2" />
</bean>

Login Page

Below are some screenshots of the login page in different states. To customize this page, including changing strings, see Customizing the Login Page.

Logout Handling

ProPentahoLogoutHandler

ProPentahoLogoutHandler executes various cleanup tasks when the user logs out.

<bean id="logoutFilter"
  class="org.acegisecurity.ui.logout.LogoutFilter">
  <constructor-arg value="/index.jsp" />
  <constructor-arg>
    <list>
      <bean
        class="com.pentaho.security.ProPentahoLogoutHandler" />
        <ref bean="rememberMeServices" />
      <bean
        class="org.acegisecurity.ui.logout.SecurityContextLogoutHandler" />
    </list>
  </constructor-arg>
  <property name="filterProcessesUrl" value="/Logout" />
</bean>

Logout Page

There is no logout page. The page to which a user is redirected after a logout is specified in the first constructor argument in the logoutFilter bean above.

Basic Authentication

Basic authentication is part of the HTTP specification. It is simple but relatively inflexible. Acegi Security implements Basic authentication using BasicProcessingFilter and BasicProcessingFilterEntryPoint.

Request Parameter Authentication

RequestParameterAuthenticationFilter provides security services for Pentaho Spreadsheet Services (PSS). It allows the user requesting access to provide his or her username and password on the query string of the URL. The credentials are unencrypted.

The parameters to pass on the query string are:

• userid=value - the userid to authenticate
• password=value - the user's password (clear-text)

RequestParameterAuthenticationFilter

RequestParameterAuthenticationFilter provides security services for Pentaho Spreadsheet Services (PSS). If you are using PSS, add this filter, along with the associated RequestParameterFilterEntryPoint bean to your Spring config.

<bean id="requestParameterProcessingFilter"
  class="com.pentaho.security.RequestParameterAuthenticationFilter">
  <property name="authenticationManager">
    <ref local="authenticationManager" />
  </property>
  <property name="authenticationEntryPoint">
    <ref local="requestParameterProcessingFilterEntryPoint" />
  </property>
</bean>

<bean id="requestParameterProcessingFilterEntryPoint"
  class="com.pentaho.security.RequestParameterFilterEntryPoint" />

FilterChainProxy

The FilterChainProxy with the Pentaho BI Platform filters is shown below.

Warning: Note that the end-of-line backslashes that occur in the excerpt below are present for formatting purposes only and should not be present in the actual file.

<bean id="filterChainProxy"
  class="org.acegisecurity.util.FilterChainProxy">
  <property name="filterInvocationDefinitionSource">
    <value>
      <![CDATA[CONVERT_URL_TO_LOWERCASE_BEFORE_COMPARISON
      PATTERN_TYPE_APACHE_ANT
      /**=securityContextHolderAwareRequestFilter,httpSessionContextIntegrationFilter, \
      httpSessionReuseDetectionFilter,logoutFilter,authenticationProcessingFilter, \
      basicProcessingFilter,requestParameterProcessingFilter,rememberMeProcessingFilter, \
      anonymousProcessingFilter,pentahoSecurityStartupFilter,switchUserProcessingFilter, \
      exceptionTranslationFilter,filterInvocationInterceptor]]>
    </value>
  </property>
</bean>