def process_post(self):
        """
            Analyse the POST request:

                * check that the LoginTicket is valid
                * check that the user sumited credentials are valid

            :return:
                * :attr:`INVALID_LOGIN_TICKET` if the POSTed LoginTicket is not valid
                * :attr:`USER_ALREADY_LOGGED` if the user is already logged and do no request
                  reauthentication.
                * :attr:`USER_LOGIN_FAILURE` if the user is not logged or request for
                  reauthentication and his credentials are not valid
                * :attr:`USER_LOGIN_OK` if the user is not logged or request for
                  reauthentication and his credentials are valid
            :rtype: int
        """
        if not self.check_lt():
            self.init_form(self.request.POST)
            logger.warning("Received an invalid login ticket")
            return self.INVALID_LOGIN_TICKET
        elif not self.request.session.get("authenticated") or self.renew:
            # authentication request receive, initialize the form to use
            self.init_form(self.request.POST)
            if self.form.is_valid():
                self.request.session.set_expiry(0)
                self.request.session["username"] = self.form.cleaned_data['username']
                self.request.session["warn"] = True if self.form.cleaned_data.get("warn") else False
                self.request.session["authenticated"] = True
                self.renewed = True
                self.warned = True
                logger.info("User %s successfully authenticated" % self.request.session["username"])
                return self.USER_LOGIN_OK
            else:
                logger.warning("A login attempt failed")
                return self.USER_LOGIN_FAILURE
        else:
            logger.warning("Received a login attempt for an already-active user")
            return self.USER_ALREADY_LOGGED
Analyse the POST request:

                * check that the LoginTicket is valid
                * check that the user sumited credentials are valid

            :return:
                * :attr:`INVALID_LOGIN_TICKET` if the POSTed LoginTicket is not valid
                * :attr:`USER_ALREADY_LOGGED` if the user is already logged and do no request
                  reauthentication.
                * :attr:`USER_LOGIN_FAILURE` if the user is not logged or request for
                  reauthentication and his credentials are not valid
                * :attr:`USER_LOGIN_OK` if the user is not logged or request for
                  reauthentication and his credentials are valid
            :rtype: int