The Duo authenticator can be used to log users in using Duo, from Cisco. This service provides two-factor authentication using various methods, including:
Other factors are also available and it is possible for this selection to be automatic based on heuristics and configuration.
The integration with the Curity Authentication Server is similar to that of Encap, BankID, SMS, and other authentication providers. The integration model is shown in Fig. 58:
Fig. 58 Overview of Duo integration
This diagram is showing that the end user is redirected to the Curity Authentication Server from a service provider application in their user agent, typically a browser (1). This service provider may be a SAML service provider, OAuth client or OpenID Connect Relying Party. Whatever kind of provider, the user is then prompted to identify themselves. Authentication at Duo is then initiated for this user (2). While this takes place, the flow at the Curity Authentication Server is left pending (3). The user authenticates, e.g., by responding to the push notification received to the Duo mobile app (4). When this happens, the the Curity Authentication Server observes this (by making a Web service call to the Duo API) (5). Finally, the user is redirected back to the application that initiated the flow using whatever protocol the service provider was integrated with (6).
To setup and configure a Duo authenticator instance, only a few settings are needed:
The first setting, Duo API hostname, is the same host for both the admin and auth APIs. It is something in the form xyz.duosecurity.com. It and the API integration and secret keys can be obtained from the Duo admin console under Applications. This is shown in Fig. 59:
Fig. 59 Auth API configuration in the Duo admin console
For more details about setting up this application in Duo, refer to the auth API documentation.
The admin API integration and secret keys can be found in the same place in the Duo admin console – under Applications. However, it may need to be enabled by contacting Duo support. Consult the admin API documentation for the details.
“Factors” are the allowed login methods. These include:
The last setting is the account manager. This manages where users will be looked up in the Curity Authentication Server. Users must exist in this data source in order to login with Duo.
Refer to the configuration reference for more details.
The general process for setting up a Duo authenticator is the same as other types of authenticators. The Duo-specific settings described above must also be configure. This can be done using any of the management interfaces, including the UI, CLI, XML files, and RESTCONF API. In the UI, this page is shown in Fig. 60:
Fig. 60 Configuring a Duo Authenticator in the Admin UI
The required configuration settings are marked with an asterisk and validation is in place to ensure that all fields are properly configure before being committed. Some important parts to take note of include:
Show Info Before Registration
Add a New Device
After configuring all the required settings, the changes can be committed and the new Duo authenticator can be used by any service provider or OAuth client that is allowed to use it.
To see the entire flow described below, checkout the demonstration video in the resource section of the Curity website.
The login experience of the end user is similar to other authenticators that have a comparable integration pattern to that of Duo (shown in Fig. 58 above), like SMS, Encap, email, etc. The first thing that a user must do is identify themselves. This step involves the user entering their username.
Fig. 61 Entering a username
This first step is not shown if some other authenticator has been configured to run prior to the Duo authenticator. In any event, the next screen the user will see is the device selection page:
Fig. 62 Selecting a Duo device and registering a new one when none exist
The pages shown in this section can be fully customized like any other. Refer to the developer guide for details.
If the user does not have any devices registered, the page in Fig. 62 is shown. If the user has a registered device, they can still register another on a screen that looks like this:
Fig. 63 Using an existing, registered device or adding a new one
In the former case where the user does not have any devices registered yet, when a new one is added, they will be shown a interstitial page containing information about the use of Duo (if configured). By default, it looks like this:
Fig. 64 Interstitial information page describing how to download the Duo app and register
On this page, the user can:
If the user clicks the QR code, they will be taken to a simple (unauthenticated) page that includes links to download the Duo app for their mobile device. The QR code can be helpful when the user is registering a device other than the one they are on. An example of this page is shown in Fig. 65:
Fig. 65 Duo app download page on a mobile device
After authenticating and downloading the app, the user must activate their device. This is done by proving that they are in control of it. For this to happen, the user needs to provide the phone number of the device. They can also provide an alias and specify the device type if they wish:
Fig. 66 Entering data about a new device
After doing this, they are presented with the following screen:
Fig. 67 Linking (i.e., activating or pairing) a device by proving possession of it
On this screen, the user has to prove that they control the device that they are activating. They can do this in a number of ways:
Any of these techniques will pair the device with the user.
After one of these is done, they will see the following screen, concluding the activation / pairing process:
Fig. 68 Successful completion of device pairing which takes place when a new device is added by a user
After register a new device or if one is already registered, the screen depicted in Fig. 63 will be shown. Here, a user can authenticate using the Duo app on their device by:
When the later is used, the user will be presented with a screen similar to the following:
Fig. 69 Receiving a push notification in the Duo mobile app
Regardless of which method is used to authenticate, after doing so, the flow will complete and the user will be logged in at the Curity Authentication Server.
To see the entire flow described above, checkout the demonstration video in the resource section of the Curity website.