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User Journeys

Janssen's authentication server can integrate with any number of authentication mechanisms from different vendors. Factoring the pros and cons of each method, organizations can offer a diverse set of options. A users can register multiple types of credentials and use any preferred credential to perform a login.

An ACRouter Script is a PersonAuthenticationType script orchestrates a 2FA flow by delegating specific implementation details of authentication methods to other scripts. This allows the flow to present users with alternatives in case some credential is not working as expected or is lost.

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Authentication flow#


sequenceDiagram
autonumber

    title User selects authentication mechanism
    User agent->>Jans AS: Invoke /authorize endpoint
    Jans AS->>User agent: Present "username" only screen <br/> OR <br/>username - password screen
    User agent->>Jans AS: Present username <br/> OR username and  password
    Jans AS ->> Jans AS: verify user
    Jans AS->>User agent: Show UI for preferred authentication method, <br>and also a link "Alternate way to sign in"
    loop n times - (enter creds or select alternate way to sign in)
        User agent->>Jans AS: Enter credentials (Or click on "Alternate way to sign in")
        Jans AS->>User agent: Present page for authentication <br/> or <br/> present alternate authentication mechanisms
    end

    Jans AS->Jans AS: 8. validate id_token,<br/>create internal Jans session
    opt if new user
        Jans AS->Jans AS: 9. Dynamic enrollment or registration
    end
    Jans AS->User agent: 10. write Jans session cookie

An ACRouter script:#

Currently, the Jans Auth server comes with 2 PersonAuthenticationType interception scripts that integrate multiple authentication methods and offer alternative options to users for sign-in.

  1. Casa Script The casa script offers a 2 steps authentication flow with login and password prompted in the first step and a user-preferred authentication mechanism in the second step.

  2. Passwordless script The passwordless script offers a 2 steps authentication flow with username prompted in the first step and a user-preferred authentication mechanism in the second step.

Casa App for enrollment of a variety of credentials:#

Casa is a self-service web portal for end-users can be used to 1. Enroll, delete and manage two-factor authentication (2FA) credentials for their account (e.g. FIDO security keys, mobile apps, phone numbers, etc.) 1. Turn 2FA on and off

Adding a new authentication method as an "alternative authentication method":#

Step 1: Write a custom script:#

Ensure the following preconditions are met so that the authentication mehtod integrates seamlessly within flow: 1. The orchestrator script looks for authentication method scripts under /opt/jans/python/libs. Write a custom script that focuses only on authentication. The script file name should follow naming convention like orchestratorName-external_acrName e.g. casa-external_fido2 or pwdless-external_fido2 1. For step 1, prepareForStep must only return True
1. For step 1, getExtraParametersForStep must only return None
1. For step 1, the authenticate routine must check if there is already an authenticated user, and if so bypass validating the username and password. This is because a user may have previously attempted authentication with a different method. 1. Keep in mind that getPageForStep won't be called when step=1 in your script. The orchestrator script i.e. casa or passwordless script takes charge of this specific step/method combination
1. Add a hasEnrollments routine with a signature like this def hasEnrollments(self, configurationAttributes, user):
hasEnrollments must return True or False, describing whether user has one or more credentials enrolled for the type you are interested in
Objects:

Object name Object description
customScript The custom script object. Reference
configurationAttributes configurationProperties passed in when adding custom script. Map<String, SimpleCustomProperty> configurationAttributes
SimpleCustomProperty Map of configuration properties. Reference
User User object Reference

Step2: Modification to web-pages:#

  1. Ensure that custom pages returned by getPageForStep for step 2 (or higher) contain the fragment: 
        <ui:include src="/casa/casa.xhtml" />
    This will display a set of links for the user to navigate to alternate 2FA pages. The list will be shown when clicking on a link which should be provided this way: 
        <a href="javascript:showAlternative('ELEMENT_ID')" id="alter_link" class="green hover-green f7-cust">#{msgs['casa.alternative']}</a>
    Here ELEMENT_ID is the identifier for the HTML node that wraps all visual elements of your page (excluding casa.xhtml). It is required to preserve alter_link as id for the a tag.
  2. Place the modified xhtml page under the path specified in getPageForStep, for e.g. /opt/jans/jetty/jans-auth/custom/pages/casa/fido2.xhtml

Step3: Handle enrollment using the Casa app#

Step 4: Enable the ACRouter script i.e. passwordless or casa script#

Once your script is enabled in the Jans-auth server, you can test it for authentication purposes. Try your script by creating an authentication request passing casa or passwordless as acr value.

Last update: 2023-05-29
Created: 2023-05-29