Interception Scripts#

Overview#

Interception scripts can be used to implement custom business logic for authentication, authorization and more in a way that is upgrade-proof and doesn't require forking the Gluu Server code. Each type of script is described by a Java interface -- i.e. which methods are required.

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

Jython#

Interception scripts are written in Jython, enabling Java or Python classes to be imported.

While the syntax of the script requires Python, most of the functionality can be written in Java.

Note

If Python classes are imported, they must be "pure Python." For example, a class that wraps C libraries can not be imported. The same goes for Python packages which require cython during compiling.

Manually installing additional Python code#

For the benefit of modularity and code reuse, Python code for interception scripts may be split in different files. An example would be code that's used by multiple interception scripts to communicate with a REST service for different purposes (e.g. additional user authentication against a legacy system).

Copy the code for such a module or package to /opt/gluu/python/libs/ in Gluu Server's container.

Using pip to install additional Python packages#

Sometimes, it saves time to use an existing Python package and the way to install it is with pip. As already stated above, Python packages and modules which are not "pure Python" will simply not work, so keep that in mind. An example would be the psycopg2 library used to connect to PostgreSQL from Python. Since it's basically a C wrapper around libpq, it won't work with Jython. Also, Python 3 packages / modules are not supported.

In order to install additional modules via pip , do the following:

Find out about your Jython version first. cd into the /opt directory in your Gluu Server container and run ls. A directory named jython-<version> should be listed too where <version> will correspond to the Jython version. Note the version.
Open the file /etc/gluu/conf/gluu.properties and look for the line starting with pythonModulesDir=. Append the value /opt/jython-<version>/Lib/site-packages to any existing value. Each value is separater by a colon (:). It should look something like this pythonModulesDir=/opt/gluu/python/libs:/opt/jython-2.7.2a/Lib/site-packages
Run the following command /opt/jython-<version>/bin/jython -m ensurepip
Install your library with /opt/jython-<version>/bin/pip install <library_name> where <library_name> is the name of the library to install.
Restart the oxauth service.

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.

Script Naming#

New custom scripts should be given a descriptive displayName, as that is how they are listed in oxTrust. The displayName is limited to 60 characters.

Note

The name given to each Person Authentication script is also used as its OpenID Connect acr_value. Learn more in the OpenID Connect docs.

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 about Logs can be found in the Log Management portion of the docs.

Debugging#

As scripts are developed, they need to be debugged. Check the debugging tutorial to learn more.

Person Authentication#

Authentication scripts can be used to implement complex multi-step, multi-factor authentication workflows.

In each script, authentication steps and mechanisms are defined, external APIs can be called, and user experience can be adjusted dynamically based on contextual factors. For example, a fraud detection API can be called in step one. If it indicates unacceptable risk, a second step can be added to prompt the user for a stronger authentication credential.

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

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.gluu.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.gluu.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 in the authentication script when oxAuth receives an end session request to the /oxauth/logout.htm endpoint (which receives the same set of parameters than the usual end_session endpoint). This method should return True or False; when False oxAuth stops processing the end session request workflow.

If getApiVersion() returns "3" for this script, logout() will call an external end session API at a 3rd party service before terminating sessions at Gluu Server. To do so it calls getLogoutExternalUrl() method and redirects the user agent to the URL returned by such method (note at this point Gluu's sessions are not yet killed). After the 3rd-party service has completed its end session routines, it must re-direct user back to /oxauth/logout.htm again with empty URL query string - that's enough for oxAuth to recognize it as a continuation of the extended logout flow, restore the original URL query string, and send user to /oxauth/end_session to complete it

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.

View a sample Authentication Script.

OAuth 2.0 allows providers to prompt users for consent before releasing their personal information to a client (application). The standard consent process is binary: approve or deny. Using the consent gathering interception script, the consent flow can be customized to meet unique business requirements, for instance to support payment authorization, where you need to present transactional information, or where you need to step-up authentication to add security.

Consent Gathering can be enabled via oxTrust UI as shown below

consent

Users will be prompted for consent as below.

consent1

consent2

view a sample Consent Gathering Script

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 the database.

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.

Sample Update User Script

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 the database. Hence in this script it is possible to validate the user entry. The postRegistration method is called after successfully storing the user entry in the database. In this method, for example, the script can send an e-mail or send notifications to other organization systems about the new user entry.

Sample User Registration Script

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.gluu.oxauth.client.RegisterRequest` `client` is `org.gluu.oxauth.model.registration.Client` `configurationAttributes` is `java.util.Map<String, SimpleCustomProperty>`

This script can be used in an oxAuth application only.

Sample Client Registration Script

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 calculations implementing specific buisness 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:

dynamicScopeContext is org.gluu.oxauth.service.external.context.DynamicScopeExternalContext class
configurationAttributes is java.util.Map dictionary carring script's custom properties

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

Sample Dynamic Scope Script

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.

Sample ID Generation Script

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.

Sample Cache Refresh Script

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.gluu.oxauth.service.uma.authorization.AuthorizationContext` `configurationAttributes` is `java.util.Map<String, SimpleCustomProperty>`

This script can be used in an oxAuth application only.

Sample RPT Authorization Policy Script

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.

Sample UMA2 Claims-Gathering Script

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.gluu.oxauth.model.common.AuthorizationGrant` `configurationAttributes` is `java.util.Map<String, SimpleCustomProperty>`

This script can be used in an oxAuth application only.

Sample Application Session Management Script

SCIM#

SCIM script allows you to execute custom logic when certain SCIM API operations are invoked. Particularly for create, update, and delete users and groups, custom code can be called just before and after data is persisted to the database.

To enable this feature, SCIM script needs to be enabled from the SCIM tab:

Click on Manage Custom Scripts > SCIM
Click on Enabled check box
Click on update at the bottom of the page

SCIM

Introspection#

Introspection scripts allows to modify response of Introspection Endpoint (spec).

The introspection interception script extends the base script type with the init, destroy and getApiVersion methods but also adds the following method(s):

Method	`def modifyResponse(self, responseAsJsonObject, context)`
Method Parameter	`responseAsJsonObject` is `org.codehaus.jettison.json.JSONObject` `context` is `org.gluu.oxauth.service.external.context.ExternalIntrospectionContext`

Snippet

    # Returns boolean, true - apply introspection method, false - ignore it.
    # This method is called after introspection response is ready. This method can modify introspection response.
    # Note :
    # responseAsJsonObject - is org.codehaus.jettison.json.JSONObject, you can use any method to manipulate json
    # context is reference of org.gluu.oxauth.service.external.context.ExternalIntrospectionContext (in https://github.com/GluuFederation/oxauth project, )
    def modifyResponse(self, responseAsJsonObject, context):
        responseAsJsonObject.put("key_from_script", "value_from_script")
        return True

Full version of introspection script example can be found here.

It is also possible to run introspection script during access_token creation as JWT. It can be controlled by run_introspection_script_before_access_token_as_jwt_creation_and_include_claims client property which is set to false by default.

If run_introspection_script_before_access_token_as_jwt_creation_and_include_claims set to true and access_token_as_jwt set to true then introspection script will be run before JWT (access_token) is created and all JSON values will be transfered to JWT. Also context inside script has additional method which allows to cancel transfering of claims if needed context.setTranferIntrospectionPropertiesIntoJwtClaims(false)

Resource Owner Password Credentials#

Resource Owner Password Credentials script allows modifying the behavior of Resource Owner Password Credentials Grant.

The script is invoked after normal authentication and can either leave current result or change it - authenticate if not authenticated - it should return True and optionally set user (via context.setUser(user))

The script extends the base script type with the init, destroy and getApiVersion methods but also adds the following method(s):

Method	`def authenticate(self, context)`
Method Parameter	`context` is `org.gluu.oxauth.service.external.context.ExternalResourceOwnerPasswordCredentialsContext`

Snippet

    # Returns boolean, true - authenticate user, false - ignore script and do not authenticate user.
    # This method is called after normal ROPC authentication. This method can cancel normal authentication if it returns false and sets `context.setUser(null)`.
    # Note :
    # context is reference of org.gluu.oxauth.service.external.context.ExternalResourceOwnerPasswordCredentialsContext#ExternalResourceOwnerPasswordCredentialsContext (in https://github.com/GluuFederation/oxauth project, )
    def authenticate(self, context):
        if (context.getHttpRequest().getParameterValues("device_id")[0] == "device_id_1"):
            return True
        return False

Full version of the script example can be found here.

Additional Tips#

Visit this page for code references on building custom scripts and pages.

Interception Scripts#

Overview#

Jython#

Manually installing additional Python code#

Using pip to install additional Python packages#

Methods#

Script Naming#

Logs#

Debugging#

Person Authentication#

Consent Gathering#

Update User#

User Registration#

Client Registration#

Dynamic Scopes#

ID Generator#

Cache Refresh#

UMA 2 RPT Authorization Policies#

UMA 2 Claims-Gathering#

Application Session Management#

SCIM#

Introspection#

Resource Owner Password Credentials#

Additional Tips#