.. _eventhandler: Event Handler ============= .. index:: Event Handler, events Added in version 2.12. What is the difference between :ref:`policies` and event handlers? Policies are used to define the behaviour of the system. With policies you can *change* the way the system reacts. With event handlers you do not change the way the system reacts. But on certain events you can *trigger a new action* in addition to the behaviour defined in the policies. These additional actions are also logged to the audit log. These actions are marked as *EVENT* in the audit log and you can see, which event triggered these actions. Thus a single API call can cause several audit log entries: One for the API call and more for the triggered actions. Events ------ Each **API call** is an **event** and you can bind arbitrary actions to each event as you like. Internally events are marked by a decorator "event" with an *event identifier*. At the moment not all events might be tagged. Please drop us a note to tag all further API calls. .. figure:: event-list.png :width: 500 *An action is bound to the event* token_init. Pre and Post Handling --------------------- .. index:: Pre Handling, Post Handling Added in Version 2.23. With most event handlers you can decide if you want the action to be taken before the actual event or after the actual event. I.e. if all conditions would trigger certain actions the action is either triggered before (*pre*) the API request is processed or after (*post*) the request is processed. Up to version 2.22 all actions where triggered after the request. In this case additional information from the response is available. E.g. if a user successfully authenticated the event will know the serial number of the token, which the user used to authenticate. If the action is triggered before the API request is processed, the event can not know if the authentication request will be successful or which serial number a token would have. However, triggering the action *before* the API request is processed can have some interesting other advantages: Example for Pre Handling ~~~~~~~~~~~~~~~~~~~~~~~~ The administrator can define an event definition that would trigger on the event ``validate/check`` in case the the authenticating user does not have any token assigned. The *pre* event definition could call the Tokenhandler with the *enroll* action and enroll an email token with *dynamic_email* for this very user. When the API request ``validate/check`` is now processed, the user actually now has an email token and can authenticate via challenge response with this very email token without an administrator ever enrolling or assigning a token for this user. .. _handlermodules: Handler Modules and Actions --------------------------- .. index:: Handler Modules, Actions The actions are defined in handler modules. So you bind a handler module and the action, defined in the handler module, to the events. The handler module can define several actions and each action in the handler module can require additional options. .. figure:: event-details.png :width: 500 *The event* sendmail *requires the option* emailconfig. Conditions ---------- .. index:: Event Handler, conditions Added in version 2.14 An event handler module may also contain conditions. Only if all conditions are fullfilled, the action is triggered. Conditions are defined in the class property *conditions* and checked in the method *check_condition*. The UserNotification Event Handler defines such conditions. Basic conditions ~~~~~~~~~~~~~~~~ The basic event handler module has the following conditions. **last_auth** This condition checks if the last authentication is older than the specified time delta. The timedelta is specified with "h" (hours), "d" (days) or "y" (years). Specifying *180d* would mean, that the action is triggered if the last successful authentication witht he token was berformed more than 180 days ago. This can be used to send notifications to users or administrators to inform them, that there is a token, that might be orphaned. **logged_in_user** This condition checks if the logged in user is either an administrator or a normal user. This way the administrator can bind actions to events triggered by normal users or e.g. by help desk users. If a help desk user enrolls a token for a user, the user might get notified. If a normal user enrolls some kind of token, the administrator might get notified. **otp_counter** The action is triggered, if the otp counter of a token has reached the given value. The administrator can use this condition to e.g. automatically enroll a new paper token for the user or notify the user that nearly all OTP values of a paper token have been spent. **realm** The condition *realm* matches the user realm. The action will only trigger, if the user in this event is located in the given realm. This way the administrator can bind certain actions to specific realms. E.g. some actions will only be triggered, if the event happens for normal users, but not for users in admin- or helpdesk realms. **result_value** This condition checks the result of an event. E.g. the result of the event *validate_check* can be a failed authentication. This can be the trigger to notify either the token owner or the administrator. **serial** The action will only be triggered, if the serial number of the token in the event does match the regular expression. This is a good idea to combine with other conditions. E.g. only tokens with a certain kind of serial number like Google Authenticator will be deleted automatically. **tokenrealm** In contrast to the *realm* this is the realm of the token - the *tokenrealm*. The action is only triggerd, if the token within the event has the given tokenrealm. This can be used in workflows, when e.g. hardware tokens which are not assigned to a user are pushed into a kind of storage realm. **tokentype** The action is only triggered if the token in this event is of the given type. This way the administrator can design workflows for enrolling and reenrolling tokens. E.g. the tokentype can be a registration token and the registration code can be easily and automatically sent to the user. **token_locked** The action is only triggered, if the token in the event is locked, i.e. the maximum failcounter is reached. In such a case the user can not use the token to authenticate anymore. So an action to notify the user or enroll a new token can be triggered. **token_has_owner** The action is only triggered, if the token is or is not assigned to a user. **token_is_orphaned** The action is only triggered, if the user, to whom the token is assigned, does not exist anymore. This can be used to trigger the deletion of the token, if the token owner was removed from the userstore. **token_validity_period** Checks if the token is in the current validity period or not. Can be set to *True* or *False*. .. note:: ``token_validity_period==False`` will trigger an action if either the validitiy period is either *over* or has not *started*, yet. **user_token_number** The action is only triggered, if the user in the event has the given number of tokens assigned. This can be used to e.g. automatically enroll a token for the user if the user has no tokens left (token_number == 0) of to notify the administrator if the user has to many tokens assigned. **tokeninfo** The tokeninfo condition can compare any arbitrary tokeninfo field against a fixed value. You can compare strings and integers. Integers are converted automatically. Valid compares are: myValue == 1000 myValue > 1000 myValue < 99 myTokenInfoField == EnrollmentState myTokenInfoField < ABC myTokenInfoField > abc "myValue" and "myTokenInfoField" being any possible tokeninfo fields. Starting with version 2.20 you can also compare dates in the isoformat like that: myValue > 2017-10-12T10:00+0200 myValue < 2020-01-01T00:00+0000 In addition you can also use the tag *{now}* to compare to the curren time *and* you can add offsets to *{now}* in seconds, minutes, hours or days: myValue < {now} myValue > {now}+10d myValue < {now}-5h Which would match if the tokeninfo *myValue* is a date, which is later than 10 days from now or it the tokeninfo *myValue* is a date, which is 5 more than 5 hours in the past. **detail_error_message** This condition checks a regular expression against the ``detail`` section in the API response. The field ``detail->error->message`` is evaluated. Error messages can be manyfold. In case of authentication you could get error messages like: "The user can not be found in any resolver in this realm!" With ``token/init`` you could get: "missing Authorization header" ..note:: The field ``detail->error->message is only available in case of an internal error, i.e. if the response status is ``False``. **detail_message** This condition checks a regular expression against the ``detail`` section in the API response. The field ``detail->message`` is evaluated. Those messages can be manyfold like: "wrong otp pin" "wrong otp value" "Only 2 failed authentications per 1:00:00" ..note:: The field ``detail->message`` is available in case of status ``True``, like an authentication request that was handled successfully but failed. Managing Events --------------- Using the command ``pi-manage events`` you can list, delete, enable and disable events. You can also export the complete event definitions to a file or import the event definitions from a file again. During import you can specify if you want to remove all existing events or if you want to add the events from the file to the existing events in the database. .. note:: Events are identified by an *id*! Due to database restrictions the id is ignored during import. So importing an event with the same name will create a second event with the same name but another id. Available Handler Modules ------------------------- .. toctree:: :maxdepth: 1 usernotification tokenhandler scripthandler counterhandler federationhandler