9. Event Handler

Added in version 2.12.

What is the difference between 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.

9.1. 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.

../_images/event-list.png

An action is bound to the event token_init.

9.2. Handler Modules and 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.

../_images/event-details.png

The event sendmail requires the option emailconfig.

9.3. 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.

9.3.1. 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 HTTP 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 HTTP 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.