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Interception Scripts#

Overview#

Interception scripts allow you to customize many aspects of your Gluu Server identity and access management service.

For example, if you want to use an external authentication service, like Duo or Yubikey, you would use an interception script. Or if you wanted to perform fraud detection during login, you would write an interception script to call the API of your fraud detection service.

These are just a couple examples demonstrating how interception scripts can be used to customize the behavior of the Gluu Server. Both examples focus on login, but the Gluu Server supports interception scripts for many aspects of the service including registration, user updates, authorization and more.

The web interface for Custom Scripts can be accessed by navigating to Configuration > Manage Custom Scritps.

Jython#

Interception scripts are written in Jython.

Jython was chosen because an interpreted language facilitates dynamic creation of business logic, and makes it easier to distribute this logic to a cluster of Gluu servers.

Jython enables developers to use either Java or Python classes. You can use the full power of java in your scripts, including iterators, converting Set to List, manipulating data as you wish--literally everything that is accessible in context.

Combined with the option of calling web services from Python or Java, this enables the Gluu Server to support any business-driven policy requirement.

Interception Script Methods#

There are three methods that inherit a base interface

Inherited Methods Method description
def init(self, configurationAttributes) This method is only called once during the script initialization. It can be used for global script initialization, initiate objects etc
def destroy(self, configurationAttributes) This method is called once to destroy events. It can be used to free resource and objects created in the init() method
def getApiVersion(self) The getApiVersion method allows API changes in order to do transparent migration from an old script to a new API. Currently all scripts should return 1

The configurationAttributes parameter is java.util.Map<String, SimpleCustomProperty> with properties specified in oxConfigurationProperty attributes.

The script manager only loads enabled scripts. Hence, after enabling or disabling a script, the script manager should trigger an event to either load or destroy a script, respectively. All scripts are stored in LDAP in the ou=scripts,o=<org_inum>,o=gluu branch.

Here is a sample entry:

    dn: inum=@!1111!031C.4A65,ou=scripts,o=@!1111,o=gluu
    objectClass: oxCustomScript
    objectClass: top
    description: <custom_script_description>
    displayName: <display_name>
    gluuStatus: true
    inum: @!1111!031C.4A65
    oxLevel: <priority>
    oxModuleProperty: {"value1":"module_property_name","value2":"module_property_value","description":""}
    oxConfigurationProperty: {"value1":"configuration_property_name","value2":"configuration_property_value","description":""}
    oxRevision: <revision>
    oxScript: <custom_script>
    oxScriptType: <script_type>
    programmingLanguage: python

The script manager reloads scripts automatically without needing to restart the application once oxRevision is increased.

Interception Script Logs#

The log files regarding interception scripts are stored in the oxauth.log file. The logs are separated according to the module they affect. The oxAuth custom script logs are stored in oxauth_script.log and the oxTrust custom script logs are stored in the oxtrust_script.log. Please refer to these log files to troubleshoot errors in the interception scripts or following the workflow of the script.

Note

A print statement may not work on some environments if the PYTHON_HOME environment variable is not set. Make sure it points to a valid python installation.

More details on Logs can be found in Log Management

Person Authentication#

An authentication script enables you to customize the user experience for authentication. For example, you can write a script that enables a two-factor authentication mechanism like Duo Security or FIDO U2F tokens. Or you could call external security services like fraud detection or DDoS protection.

The authentication interception script extends the base script type with the init, destroy and getApiVersion methods but also adds the following methods:

Method isValidAuthenticationMethod(self, usageType, configurationAttributes)
Description This method is used to check if the authentication method is in a valid state. For example we can check there if a 3rd party mechanism is available to authenticate users. As a result it should either return True or False
Method Parameter usageType is org.xdi.model.AuthenticationScriptUsageType
configurationAttributes is java.util.Map<String, SimpleCustomProperty>
Method def getAlternativeAuthenticationMethod(self, usageType, configurationAttributes)
Description This method is called only if the current authentication method is in an invalid state. Hence authenticator calls it only if isValidAuthenticationMethod returns False. As a result it should return the reserved authentication method name
Method Parameter uageType is org.xdi.model.AuthenticationScriptUsageType
configurationAttributes is java.util.Map<String, SimpleCustomProperty>
Method def authenticate(self, configurationAttributes, requestParameters, step)
Description This method is the key method within the person authentication script. It checks if the user has passed the specified step or not. As a result it should either return True or False
Method Parameter requestParameters is java.util.Map<String, String[]>
step is java integer
configurationAttributes is java.util.Map<String, SimpleCustomProperty>
Method def prepareForStep(self, configurationAttributes, requestParameters, step)
Description This method can be used to prepare variables needed to render the login page and store them in an according event context. As a result it should either return True or False
Method Parameter requestParameters is java.util.Map<String, String[]>
step is a java integer
configurationAttributes is java.util.Map<String, SimpleCustomProperty>
Method def getCountAuthenticationSteps(self, configurationAttributes)
Description This method should return an integer value with the number of steps in the authentication workflow
Method Parameter configurationAttributes is java.util.Map<String, SimpleCustomProperty>
Method def getExtraParametersForStep(self, configurationAttributes, step)
Description This method provides a way to notify the authenticator that it should store specified event context parameters event in the oxAuth session. It is needed in a few cases, for example when an authentication script redirects the user to a 3rd party authentication system and expects the workflow to resume after that. As a result it should return a java array of strings
Method Parameter configurationAttributes is java.util.Map<String, SimpleCustomProperty>
step is a java integer
Method def getPageForStep(self, configurationAttributes, step)
Description This method allows the admin to render a required page for a specified authentication step. It should return a string value with a path to an XHTML page. If the return value is empty or null, the authenticator should render the default log in page /login.xhtml
Method Parameter configurationAttributes is java.util.Map<String, SimpleCustomProperty>
step is a java integer
Method def logout(self, configurationAttributes, requestParameters)
Description This method is not mandatory. It can be used in cases when you need to execute specific logout logic within the authentication script when oxAuth receives an end session request. Also, it allows oxAuth to stop processing the end session request workflow if it returns False. As a result it should either return True or False
Method Parameters configurationAttributes is java.util.Map<String, SimpleCustomProperty>
requestParameters is java.util.Map<String, String[]>

Every deployment of the Gluu Server includes a number of pre-written authentication scripts out-of-the-box. Learn more in the authentication guide.

For a complete list of pre-written, open source authentication scripts, view our server integrations.

Update User#

oxTrust allows an admin to add and modify users which belong to groups. In order to simplify this process and apply repeating actions, oxTrust supports an Update User script. In this script it is possible to modify a person entry before it is stored in LDAP.

This script type adds only one method to the base script type:

Method def updateUser(self, user, persisted, configurationAttributes)
Description This method updates the user
Method Parameter user is org.gluu.oxtrust.model.GluuCustomPerson
persisted is a boolean value to specify the operation type: add/modify
configurationAttributes is java.util.Map<String, SimpleCustomProperty>

This script can be used in an oxTrust application only.

User Registration#

oxTrust allows users to perform self-registration. In order to control/validate user registrations there is the user registration script type.

This script type adds three methods to the base script type:

Methods def initRegistration(self, user, requestParameters, configurationAttributes)
def preRegistration(self, user, requestParameters, configurationAttributes)
def postRegistration(self, user, requestParameters, configurationAttributes)
Description This method enables/disables user account based on the custom property's value
Method Parameters user is org.gluu.oxtrust.model.GluuCustomPerson
requestParameters is java.util.Map<String, String[]>
configurationAttributes is java.util.Map<String, SimpleCustomProperty>
Custom Property enable_user--> defaults to false
Description It controls whether or not this user account will be ready for loggin into the Gluu Server CE instance

The methods are executed in the following order:

Order Method Expected Return
First initRegistration() True/False
Second preRegistration() True/False
Third postRegistration() True/False

First oxTrust executes the initRegistration method to do an initial user entry update. The preRegistration method is called before storing the user entry in LDAP. Hence in this script it is possible to validate the user entry. The postRegistration method is called after successfully storing the user entry in LDAP. In this method, for example, the script can send an e-mail or send notifications to other organization systems about the new user entry.

Client Registration#

oxAuth implements the OpenID Connect dynamic client registration specification. All new clients have the same default access scopes and attributes except password and client ID. The Client Registration script allows an admin to modify this limitation. In this script it is possible to get a registration request, analyze it, and apply customizations to registered clients. For example, a script can give access to specified scopes if redirect_uri belongs to a specified service or domain.

This script type adds only one method to the base script type:

Method def updateClient(self, registerRequest, client, configurationAttributes)
Method Parameter registerRequest is org.xdi.oxauth.client.RegisterRequest
client is org.xdi.oxauth.model.registration.Client
configurationAttributes is java.util.Map<String, SimpleCustomProperty>

This script can be used in an oxAuth application only.

Dynamic Scopes#

The dynamic scope custom script allows to generate list of claims (and their values) on the fly, depending on cirtumstances like id of client requesting it, logged user's session parameters, values of other user's attributes, results of some caclucations implementing specific business logic and/or requests to remote APIs or databases. Claims are then returned the usual way in a response to a call to the userinfo endpoint.

Two parameters are passed to the script:

In order to configure a dynamic scope next steps are required:

  • Dynamic scope custom script must be configured and enabled at "Manage custom scripts" page, "Dynamic scopes" tab
  • A scope has to be defined at the "OpenID Connect -> Scopes" page
  • Scope's type must be set to "Dynamic"
  • Corresponding dynamic script must be linked to that scope (Add dynamic script button)
  • The scope must be added to the client which will be using it at the "OpenID Connect -> Clients" page (using the "Add Scope" button), and the scope must be included by the client in "scope=" url query parameter

More detailed explanation about adding scopes can be found under Openid scopes

ID Generator#

By default oxAuth/oxTrust uses an internal method to generate unique identifiers for new person/client, etc. entries. In most cases the format of the ID is:

'!' + idType.getInum() + '!' + four_random_HEX_characters + '.' + four_random_HEX_characters.

The ID generation script enables an admin to implement custom ID generation rules.

This script type adds only one method to the base script type:

Method def generateId(self, appId, idType, idPrefix, configurationAttributes)
Method Parameter appId is application ID
idType is ID Type
idPrefix is ID Prefix
user is org.gluu.oxtrust.model.GluuCustomPerson
configurationAttributes is java.util.Map<String, SimpleCustomProperty>

This script can be used in an oxTrust application only.

Cache Refresh#

In order to integrate your Gluu instance with backend LDAP servers handling authentication in your existing network environment, oxTrust provides a mechanism called Cache Refresh to copy user data to the Gluu Server's local LDAP server. During this process it is possible to specify key attribute(s) and specify attribute name transformations. There are also cases when it can be used to overwrite attribute values or to add new attributes based on other attribute values.

This script type adds only one method to the base script type:

Method def updateUser(self, user, configurationAttributes)
Method Parameter user is org.gluu.oxtrust.model.GluuCustomPerson
configurationAttributes is java.util.Map<String, SimpleCustomProperty>

This script can be used in an oxTrust application only.

UMA 2 RPT Authorization Policies#

This is a special script for UMA. It allows an admin to protect UMA scopes with policies. It is possible to add more than one UMA policy to an UMA scope. On requesting access to a specified resource, the application should call specified UMA policies in order to grant or deny access.

This script type adds only one method to the base script type:

Method def authorize(self, authorizationContext, configurationAttributes)
Method Parameter authorizationContext is org.xdi.oxauth.service.uma.authorization.AuthorizationContext
configurationAttributes is java.util.Map<String, SimpleCustomProperty>

This script can be used in an oxAuth application only.

UMA 2 Claims-Gathering#

This is a special script for UMA 2. It allows an admin to code logic for gathering additional claims (required by UMA RPT Authorization Policy).

This script can be used in an oxAuth application only.

Application Session Management#

This script allows an admin to notify 3rd party systems about requests to end an OAuth session. This method is triggered by an oxAuth call to the end_session endpoint. It's possible to add multiple scripts with this type. The application should call all of them according to the level.

This script type adds only one method to the base script type:

Method def endSession(self, httpRequest, authorizationGrant, configurationAttributes)
Method Parameter httpRequest is javax.servlet.http.HttpServletRequest
authorizationGrant is org.xdi.oxauth.model.common.AuthorizationGrant
configurationAttributes is java.util.Map<String, SimpleCustomProperty>

This script can be used in an oxAuth application only.