> How do I login in the portal using this users?

I have solved a similar problem after some tests, implementing my MyLoginModule that extends UsersRolesLoginModule and in this redefined some methds:
(only some part of code)

// to save locally the user
protected String[] getUsernameAndPassword() throws LoginException {
String[] userAndPassword = super.getUsernameAndPassword();
this.user = userAndPassword[0];
return userAndPassword;
}

// to use my validation
protected boolean validatePassword(String arg0, String arg1) {
boolean result = myValidation.login(this.user, arg0);
return result;
}

remember you have to configure portal to use your class:
in jbPortal/server/default/conf/login-config.xml
add you application policy like


<application-policy name = "My_Authentication">

<login-module code ="it.deltadator.security.auth.spi.MyLoginModule"
flag = "required" >
<module-option name="additionalRole">Authenticated</module-option>
</login-module>

</application-policy>

and then use it as security domain changing reference in
server\default\deploy\jboss-portal.sar\portal-server.war\WEB-INF\jboss-web.xml

> How i get the user logged?

In your class you can access to user logged using getUserPrincipal from ProtletRequest


hope you get it useful

> Ok...but where i put that implementation?

It is indipendend from portlet, i mean this way is always used to log in portal so you just need to make a jar and put into server/default/lib of jbossportal ( i made like this and it works)