Authentication

Overview

IMPORTANT: THIS IS A BETA VERSION

It is under active development and may contain unstable or incomplete features. Use it at your own risk.

Authentication is the act verifying a user's identity. This can be done by asking for Username & Password and verify it against the built-in AD_User table or any other mechanism.

How Authentication Works in Etendo

When a user wants to have access to an Etendo resource. Etendo asks to the authentication manager the application User Id of the user that request access to the Etendo resource. If the user has not been authenticated before, the authentication provider has the responsibility of authenticating this user.

The following describes the flow of events happening when using the DefaultAuthenticationManager:

Visit any Etendo URL for the first time, a cookie is send back to the browser to allow the usual creation of a HTTP-Session to allow to group the users' request together.
The Authentication Manager's authenticate method is called to check if the session has been already authenticated. The DefaultAuthenticationManagers implementation checks for a special attribute in the HTTP-Session object to decide if this session is authenticated or not. As it is not yet it redirects the user to the standard Etendo Login-Page asking for User & Password.
When the Login Form is submitted the LoginHandler class verifies those credentials against the AD_User table and if accepted sets special attribute HttpSession to mark this session as authenticated and to store the userID of the authenticated user.
Then a redirect to the previously requested page is done.
For this request the AuthenticationManagers' authenticate Method is called again. As now the attribute is set in the HttpSession corresponding to this request it returns the userID of the authenticated User and the request continues to be handled in the usual way.
The same now happens for any following request while normally using the application.
This session will be invalidated by any of the following three events:
- Explicit logout by the user
- Session-Timeout (invalidating the HttpSession)
- Clear Browser-Cookie by the User
In that case, the flow is back to the first step and the same cycle begins again.

Note

This only described the flow of events when using the DefaultAuthenticationManager. Any other implementation may implement this different by i.e. not using the standard Etendo Login-page at all or using another mechanism to mark the HTTP-Session as authenticated.

How to Configure the Authentication Manager in Etendo

The authentication manager used in Etendo is defined in the configuration file gradle.properties. In the property authentication.class you have to write the class name of the authentication provider that Etendo will use for this purpose.

Etendo includes three AuthenticationManager implementations:

Default Authentication Manager

This is the default authentication manager provided by Etendo. It is the classic authentication method that uses the Etendo current login page to authenticate users.

After installing Etendo, you do not need to configure anything if you want to use this authentication manager that is the classic method Etendo authenticates application users.

Getting Authentication Manager

Info

To obtain an instance of the Authentication Manager defined in the gradle.properties, it is possible to use the AuthenticationManager.getAuthenticationManager method.

Develop your own Authentication Manager

You can also develop your own Authentication manager. To do this, you have to create a new java class that extends the abstract class org.openbravo.authentication.AuthenticationManager. This interface has the following methods:

```
public void init(HttpServlet s) throws AuthenticationException;
 
public final String authenticate(HttpServletRequest request, HttpServletResponse response)
    throws AuthenticationException, ServletException, IOException

public final String webServiceAuthenticate(HttpServletRequest request)
    throws AuthenticationException

public final String webServiceAuthenticate(String user, String password)
    throws AuthenticationException

public final String connectorAuthenticate(HttpServletRequest request)
    throws AuthenticationException

public final String connectorAuthenticate(String user, String password)
    throws AuthenticationException

protected abstract String doAuthenticate(HttpServletRequest request, HttpServletResponse response)
    throws AuthenticationException, ServletException, IOException

protected String doWebServiceAuthenticate(HttpServletRequest request)

protected String doWebServiceAuthenticate(String user, String password)

public final void logout(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException

protected abstract void doLogout(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException
```

The method init is called after the class is instantiated. It can be used to read the configuration parameters of the authentication manager if needed.

The method authenticate is called for each single request done which requires authentication. It invokes the abstract doAuthenticate method which if this request is authenticated, must the return the userid of the authenticated user. This id must be a valid ad_user_id of a existing entry in the AD_User table.

Otherwise the method must perform the needed steps to acquire some authentication and then return null' as return-value for the function. Usually this consists of redirecting the user to some kind of Login-Page and asking for credentials. After these have been verified the authenticate method will be called again for the next request an now will succeed and return the userId as described above.

The method logout is called when the user requests to close the current session. This method invokes the abstract doLogout. The work expected to be done by the authentication manager is to invalidate the existing session and redirect the user to a page where a new login page be done.

Info

AuthenticationManager is where authentication page is served outside Etendo code, for example from a Single Sign On service, must override useExternalLoginPage method, returning true.

Note

For implementation: The authenticate method is always called with DAL adminMode being active, so code inside it does not need to manage the adminMode on its own.

Web Services and Connectors

Info

All external authenticated services must make use of webServiceAuthenticate authentication. Authorized Connectors can use connectorAuthenticate.

Web Service authentication invokes webServiceAuthenticate and connectors invoke connectorAuthenticate, both of them call doWebServiceAuthenticate. This method is implemented to do standard authentication, it first looks whether user l and password p are sent as request parameters, if not basic authentication is performed. doWebServiceAuthenticate method can be implemented by authentication managers in case different authentication is needed.

webServiceAuthenticate and connectorAuthenticate are overloaded to accept both HttpServletRequest parameter (default one) or String, String parameters. This second one should be used by other services where the default one is not suitable, this one receives user and password parameters.

This work is a derivative of Authentication by Openbravo Wiki, used under CC BY-SA 2.5 ES. This work is licensed under CC BY-SA 2.5 by Etendo.