Implementing single sign-on in Studio Server using Amazon Cognito with an external SAML identity provider

Info: The described steps can only be performed on the on-premise version of Studio Server, not on the cloud version.

Logging in to Studio Server using single sign-on (SSO) via Amazon Cognito is one of the ways of logging in to Studio Server using SSO.

This article describes how to implement Cognito in Studio Server in combination with an external SAML identity provider.

Before you start

Before you start, make sure that:

• You have an active Amazon AWS account.
• You have an active Microsoft Azure account.
• The Studio Server environment in which Cognito is implemented has a fully working Studio Server and fully working client applications.
• When making use of LDAP, disable it.

Implementation

The implementation consists of the following steps:

1. Setting up Cognito
2. Setting up the external identity provider
3. Setting up Azure in Cognito
4. Setting up application roles in Azure
5. Configuring Studio Server
6. Testing the implementation

1. Setting up Cognito

This step consists of creating a user pool and defining a domain name.

Step 1. On the AWS Management Console page, enter Cognito in the Find Services list and click the found result.

The Amazon Cognito page appears.

Step 2. Click Manage User Pools.

The User Pools page appears.

Step 3. In the top right corner, click Create a users pool.

Setting up a users pool involves various steps. Each step has its own page. Refer to the navigation menu on the left side of the page.

• Name. Enter a pool name and click Step through settings.

• Attributes. Use this page to set up how you want your end users to sign in. When done, click Next step.

• Set up the following pages as required:
• Policies
• MFA and verifications
• Message customizations
• Tags
• Devices
• Triggers

For more information about these pages, see the Amazon documentation.

• App clients. Click Add an app client, add a name and set the other options to your needs. When done, click Create app client:

• Review. Review your settings and click Create pool.

Step 4. In the menu under App integration, click Domain name and follow the instructions on the page. When done, click Save changes.

2. Setting up the external identity provider

Here, Microsoft Azure Active Director is used.

Step 1. Open the Azure Portal and navigate to Azure Active Directory.

Step 2. Go to Enterprise Applications and choose New application followed by Non-gallery application and give the application a name. Click Add to create the new application.

Step 3. In the newly created App, choose Single sign-on, followed by SAML.

Step 4. Edit the options as follows. When finished, click Save.

• Identifier: The ID of the Cognito user pool. Get this by accessing the General settings of your Cognito user pool. Enter it in the following format:

urn:amazon:cognito:sp:<AWS Cognito user pool ID>

• Reply URL: The Cognito Domain URL. Get this in the Domain name section of your Cognito user pool. Enter it in the following format:

<AWS Cognito Domain URL>/saml2/idpresponse

Step 5. Go to the next step 2 User Attributes & Claims. Add a new claim with the following settings. Leave all other claims as-is. When done, click Save.

• Name: roles
• Namespace: leave empty
• Source attribute: user.assignedroles

Step 6. In the SAML settings, go to step 3 SAML Signing Certificate and click Download for the option Federation Metadata XML. Save the file somewhere on your system, it is needed later in the process.

3. Setting up Azure in Cognito

Step 1. In Cognito, go to Federation > Identity Providers > SAML. Upload the previously downloaded XML file and add a name. When done, click Create provider.

Step 2. Click Configure attribute mapping and set up the following configuration. When done click Save changes.

Step 3. Go to App integration > App client settings and make the following changes. When finished click Save changes.

• Enabled Identity Provider: select Azure-AD (the name that was used in step 1).

• Sign in and sign out URLs:
• Callback URL: This URL consists of 2 parts: the URL of Studio Server followed by /idpcallback.php

Example: https://studio-server.mycompany.com/idpcallback.php

Note: Make sure to check if you are pointing to the directory of Studio Server in your Web server which actually includes the idpcallback.php file.

• Sign out URL: The URL of your Studio Server.

Tip: Concatenate multiple URLs by separating them with a comma.

• OAuth 2.0:
• Allowed OAuth Flows: select Authorization code grant.
• Allowed OAuth Scopes: select all options:
• phone
• email
• openid
• aws.cognito.signin.user.admin
• profile

4. Setting up application roles in Azure

Step 1. In Azure, go to App registrations, choose the previously created App. In the menu, choose Manifest.

Step 2. In the appRoles section, add the following JSON. Verify each property and configure it to your needs. When done, click Save.

{
    "allowedMemberTypes": [
        "User"
    ],
    "description": "Designers role",
    "displayName": "Designers",
    "id": "YOUR GUID HERE",
    "isEnabled": true,
    "lang": null,
    "origin": "Application",
    "value": "Designers"
},
{
    "allowedMemberTypes": [
        "User"
    ],
    "description": "Editors role",
    "displayName": "Editors",
    "id": "YOUR GUID HERE",
    "isEnabled": true,
    "lang": null,
    "origin": "Application",
    "value": "Editors"
},

Step 3. Assign the role to an Active Directory user or group by doing the following:

Note: When no users exist yet, create these first.

1. Go to Enterprise Applications > your App > Users and groups.
2. Choose Add user.
3. Select Users and groups, select one or multiple users or groups and click Select.
4. Click Select Role, select one of the previously created roles and then click Assign.
5. Repeat these steps to assign additional roles.

5. Configuring Studio Server

In Studio Server, a connection to the Enterprise application in Cognito needs to be configured and SSO users need to be mapped to Studio Server user accounts.

1. Configuring a connection to the Enterprise application in Cognito

For this, we need information from Cognito.

Step 1. In Cognito, do the following:

• Under General settings, click App clients followed by Show details. Note down the App client id and the App client secret.

Step 2. In Studio Server, add and configure the following settings in the config_overrule.php file:

• OPENID_ISSUER_URL. The main URL of your Cognito account has a fixed format:

Format: https://cognito-idp.region.amazonaws.com/userPoolId

• OPENID_CLIENT_ID. The client ID as copied in step 1.

• OPENID_CLIENT_SECRET. The App client secret as copied in step 1

• OPENID_SCOPES. Unlike Okta, Cognito only uses the scopes 'openid profile email'.

2. Mapping SSO users to Studio Server user accounts

Mapping a Cognito user with the properties for a user in Studio Server is done through the 'OPENID_FIELD_MAPPING' setting in the config_overrule.php file.

The following Studio Server properties can be mapped:

• Name
• FullName
• EmailAddress
• Language
• TrackChangesColor
• Organization
• Location

However, we advise to start with one of the following basic configurations which are certain to work and have often been tested:

Configuration 1

• Name
• FullName
• EmailAddress

define( 'OPENID_FIELD_MAPPING', serialize ( [
        'Name' => 'given_name',
        'FullName' => 'name',
        'EmailAddress' => 'email',
] ) );

Configuration 2

• Name
• FullName
• EmailAddress
• Language

define( 'OPENID_FIELD_MAPPING', serialize ( [
	 'Name' => 'preferred_username',
	 'FullName' => 'name',
	 'EmailAddress' => 'email',
	 'Language' => 'locale',
] ) );

6. Testing the implementation

Test the implementation by logging in to Studio Server using the various applications:

• The Studio Server Maintenance pages
• Studio
• Studio for InDesign and InCopy

Test the scenario where the user is not yet logged in to Cognito and where the user is already logged in to Cognito. Follow the steps on screen.

Troubleshooting

Error appears when testing the Single Sign-On configuration in Azure: "Required String parameter ‘RelayState’ is not present"

This is a known issue but it does not affect the actual working of the integration. Please ignore this error.

Logging in to Studio Server works, but the assigned permissions are not applied

This is probably caused by the roles that are not correctly passed from Azure to Cognito.

Validate this by navigating to the auto-generated user in Cognito: go to Users and groups, select the user and make sure that custom:groups contains the groups (roles) that were assigned in Azure.

If the custom:groups property is not shown, validate both Azure and Cognito settings. If the issue is not resolved, try re-creating the Cognito User Pool from scratch.

Azure users are unable to log in to Studio Server or the user field values are incorrectly set during login

This happens when SSO users are not correctly mapped with their Studio Server user accounts.

FAQs

Can Azure groups be passed instead of creating application roles?

This is possible but not advisable. The reason is that only Azure AD group GUIDs can be passed as SAML attributes. This would result in creating a group named '9cd1c033-efad-4a96-9e8f-1650dc4137b0' in Studio Server instead of 'Designers'.

Are there limitations to the groups mapping, for example the number of groups?

Yes, the total length of the comma-separated custom groups string must not exceed 2048 characters; this is a limitation in Cognito.

Revisions

• 8 June 2022: Updated step 5 'Configuring Studio Server' with information about mapping SSO users to Studio Server user accounts.
• 8 June 2022: Updated section 'Troubleshooting' with information about Azure users not being able to log in.
• 30 March 2022: Added information about mapping SSO users with their Studio Server user accounts.