Adding Multi-Factor Authentication (MFA) challenge with Auth0 Actions

Question

Pulumi · Accepted Answer

To add a Multi-Factor Authentication (MFA) challenge with Auth0 Actions using Pulumi in TypeScript, you would typically have to create an Auth0 action script that triggers MFA, depending on your custom logic or conditions. Auth0 allows you to use Actions, which are JavaScript functions that are executed in Auth0's environment, to customize and extend Auth0's capabilities.

Below, I will outline how you can use Pulumi to automate the creation of an Auth0 Action that triggers MFA. We'll be using the Auth0 Pulumi provider which interacts with your Auth0 account to manage its resources.

First, you need to ensure that you have the Pulumi CLI installed and that you are logged into your Auth0 account. You'll also need an Auth0 tenant where you can deploy this new action.

Here's a step-by-step guide with a TypeScript Pulumi program that defines an Auth0 action for triggering MFA:

Define the Auth0 Action: You will write code that defines what the action will do. In this case, it should enforce MFA.
Create the Action with Pulumi: Use the auth0.Action resource provided by Pulumi's Auth0 provider to create a new action.
Deploy the Action: Once the action is defined, you can use Pulumi's CLI to deploy the action to your Auth0 tenant.

Let's write the TypeScript Pulumi code for this:

import * as pulumi from '@pulumi/pulumi';
import * as auth0 from '@pulumi/auth0';

// Ensure to replace `<YOUR_ACTION_NAME>` with a meaningful name for your action.
// Define the JavaScript code for the Auth0 action.
const mfaActionCode = `
exports.onExecutePostLogin = async (event, api) => {
  if (event.transaction.geoip.country_code !== 'US') {
    api.multifactor.enable('any');
  }
};
`;

// Create a new Auth0 action to enforce MFA based on the country.
const mfaAction = new auth0.Action('<YOUR_ACTION_NAME>', {
    name: '<YOUR_ACTION_NAME>',
    supportedTriggers: [{
        id: "post-login",
        version: "v2"
    }],
    code: mfaActionCode,
    runtime: 'node12',
    // Here, the action is set to be deployed.
    // In a production setup, you may want to set this to `false` for manual deployment.
    deploy: true, 
});

// Export the action ID for reference
export const actionId = mfaAction.id;

Explanation:

auth0.Action: This is the Pulumi resource used to create an Auth0 Action.
mfaActionCode: A variable that holds the JavaScript code to be executed by Auth0 when the action is triggered. In this example, multifactor authentication is enabled for any login attempt that originates outside of the United States.
supportedTriggers: Indicates the points at which this action is to be executed. In this case, the action is set up for the post-login trigger indicating it should run after a successful login.
deploy: A parameter that indicates if the action should be immediately deployed to Auth0 on creation. Carefully control this in a production environment, as it may be more appropriate to deploy changes manually through the Auth0 dashboard or a CI/CD pipeline.

To deploy the action, first, you will navigate to the directory of your Pulumi project in the command line and then run the following commands:

pulumi up

This command will prompt you to review and confirm the actions Pulumi will perform, in this case, creating an Auth0 Action.

Please replace <YOUR_ACTION_NAME> with a name of your choice that describes your action. Keep in mind this guide provides only the basic setup, and you may need to customize the action code according to your specific business logic surrounding multi-factor authentication.