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page_type name description languages products urlFragment extensions
sample
Authenticate a user with Azure AD using msal.js and call an Azure AD protected Node.js Web Api using on-behalf of flow
Handling Conditional Access challenges in an Azure AD protected Node.js web API calling another protected Node.js web API on behalf of a user using the on-behalf of flow
javascript
azure-active-directory
msal-js
msal-react
passport-azure-ad
ms-identity-javascript-react-tutorial
services
ms-identity
platform
javascript
endpoint
AAD v2.0
level
300
client
React SPA
service
Node.js web API

Authenticate a user with Azure AD using msal.js and call an Azure AD protected Node.js Web Api using on-behalf of flow

Overview

This sample demonstrates a React single-page application (SPA) which lets a user authenticate with their Azure AD tenant and obtains an access token to call a Node.js web API, protected by passport-azure-ad. The web API then proceeds to obtain another access token for Microsoft Graph API using the OAuth 2.0 on-behalf-of flow. The web API's call to Microsoft Graph is made using the Microsoft Graph SDK

ℹ️ To learn how to integrate a JavaScript React application with Azure AD, consider going through the recorded session: Deep dive on using MSAL.js to integrate React single-page applications with Azure Active Directory

Scenario

  1. The client app uses MSAL React to sign-in a user and obtain a JWT Access Token from Azure AD for the API.
  2. The access token is used as a bearer token to authorize the user to call the Node.js API protected by Azure AD.
  3. This access token is also used by the Node.js API to obtain another Access token to call the MS Graph API on user's behalf using the OAuth 2.0 on-behalf-of flow.
  4. The Node.js API uses the Microsoft Graph SDK to call MS Graph

Scenario Image

Contents

File/folder Description
AppCreationScripts/ Contains Powershell scripts to automate app registration.
SPA/src/authConfig.js Contains configuration parameters for the SPA.
API/authConfig.json Contains authentication parameters for the API.
API/auth/onBehalfOfClient.js Contains logic to acquire an access token for Graph API using OBO flow.

Prerequisites

This sample will not work with a personal Microsoft account. If you're signed in to the Azure portal with a personal Microsoft account and have not created a user account in your directory before, you will need to create one before proceeding.

Setup the sample

Step 1: Clone or download this repository

From your shell or command line:

git clone https://github.com/Azure-Samples/ms-identity-javascript-react-tutorial.git

or download and extract the repository .zip file.

⚠️ To avoid path length limitations on Windows, we recommend cloning into a directory near the root of your drive.

Step 2: Install project dependencies

    cd 6-AdvancedScenarios\1-call-api-obo\API
    npm install
    cd 6-AdvancedScenarios\1-call-api-obo\SPA
    npm install

Step 3: Register the sample application(s) in your tenant

There are two projects in this sample. Each needs to be separately registered in your Azure AD tenant. To register these projects, you can:

  • follow the steps below for manually register your apps
  • or use PowerShell scripts that:
    • automatically creates the Azure AD applications and related objects (passwords, permissions, dependencies) for you.
    • modify the projects' configuration files.
Expand this section if you want to use this automation: > ⚠️ If you have never used **Microsoft Graph PowerShell** before, we recommend you go through the [App Creation Scripts Guide](./AppCreationScripts/AppCreationScripts.md) once to ensure that your environment is prepared correctly for this step.

  1. On Windows, run PowerShell as Administrator and navigate to the root of the cloned directory

  2. In PowerShell run:

    Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope Process -Force

  3. Run the script to create your Azure AD application and configure the code of the sample application accordingly.

  4. For interactive process -in PowerShell, run:

    cd .\AppCreationScripts\
.\Configure.ps1 -TenantId "[Optional] - your tenant id" -AzureEnvironmentName "[Optional] - Azure environment, defaults to 'Global'"

Other ways of running the scripts are described in App Creation Scripts guide. The scripts also provide a guide to automated application registration, configuration and removal which can help in your CI/CD scenarios.

Choose the Azure AD tenant where you want to create your applications

To manually register the apps, as a first step you'll need to:

  1. Sign in to the Azure portal.
  2. If your account is present in more than one Azure AD tenant, select your profile at the top right corner in the menu on top of the page, and then switch directory to change your portal session to the desired Azure AD tenant.

Register the service app (msal-node-api)

  1. Navigate to the Azure portal and select the Azure Active Directory service.
  2. Select the App Registrations blade on the left, then select New registration.
  3. In the Register an application page that appears, enter your application's registration information:
    1. In the Name section, enter a meaningful application name that will be displayed to users of the app, for example msal-node-api.
    2. Under Supported account types, select Accounts in this organizational directory only
    3. Select Register to create the application.
  4. In the Overview blade, find and note the Application (client) ID. You use this value in your app's configuration file(s) later in your code.
  5. In the app's registration screen, select the Certificates & secrets blade in the left to open the page where you can generate secrets and upload certificates.
  6. In the Client secrets section, select New client secret:
    1. Type a key description (for instance app secret).
    2. Select one of the available key durations (6 months, 12 months or Custom) as per your security posture.
    3. The generated key value will be displayed when you select the Add button. Copy and save the generated value for use in later steps.
    4. You'll need this key later in your code's configuration files. This key value will not be displayed again, and is not retrievable by any other means, so make sure to note it from the Azure portal before navigating to any other screen or blade.
  7. Since this app signs-in users, we will now proceed to select delegated permissions, which is is required by apps signing-in users.
    1. In the app's registration screen, select the API permissions blade in the left to open the page where we add access to the APIs that your application needs:
    2. Select the Add a permission button and then:
    3. Ensure that the Microsoft APIs tab is selected.
    4. In the Commonly used Microsoft APIs section, select Microsoft Graph
    5. In the Delegated permissions section, select User.Read, offline_access in the list. Use the search box if necessary.
    6. Select the Add permissions button at the bottom.
  8. In the app's registration screen, select the Expose an API blade to the left to open the page where you can publish the permission as an API for which client applications can obtain access tokens for. The first thing that we need to do is to declare the unique resource URI that the clients will be using to obtain access tokens for this API. To declare an resource URI(Application ID URI), follow the following steps:
    1. Select Set next to the Application ID URI to generate a URI that is unique for this app.
    2. For this sample, accept the proposed Application ID URI (api://{clientId}) by selecting Save.

      ℹ️ Read more about Application ID URI at Validation differences by supported account types (signInAudience).

Publish Delegated Permissions
  1. All APIs must publish a minimum of one scope, also called Delegated Permission, for the client apps to obtain an access token for a user successfully. To publish a scope, follow these steps:
  2. Select Add a scope button open the Add a scope screen and Enter the values as indicated below:
    1. For Scope name, use access_graph_on_behalf_of_user.
    2. Select Admins and users options for Who can consent?.
    3. For Admin consent display name type in Access Microsoft Graph as the signed-in user.
    4. For Admin consent description type in Allow the app to access Microsoft Graph Api as the signed-in user.
    5. For User consent display name type in Access Microsoft Graph on your behalf.
    6. For User consent description type in Allow the Microsoft Graph APi on your behalf..
    7. Keep State as Enabled.
    8. Select the Add scope button on the bottom to save this scope.
  3. Select the Manifest blade on the left.
    1. Set accessTokenAcceptedVersion property to 2.
    2. Select on Save.

ℹ️ Follow the principle of least privilege when publishing permissions for a web API.

Configure Optional Claims

  1. Still on the same app registration, select the Token configuration blade to the left.

  2. Select Add optional claim:

    1. Select optional claim type, then choose Access.
      1. Select the optional claim idtyp.

      Indicates token type. This claim is the most accurate way for an API to determine if a token is an app token or an app+user token. This is not issued in tokens issued to users.

    2. Select Add to save your changes.

  3. Still on the same app registration, select the Manifest blade to the left.

    1. Set the optionalClaims property as shown below to request client capabilities claim xms_cc:
         "optionalClaims": {
         "accessToken": [
             {
                 "additionalProperties": [],
                 "essential": false,
                 "name": "xms_cc",
                 "source": null
             }
         ],
         "idToken": [],
         "saml2Token": []
     }
Configure the service app (msal-node-api) to use your app registration

Open the project in your IDE (like Visual Studio or Visual Studio Code) to configure the code.

In the steps below, "ClientID" is the same as "Application ID" or "AppId".

  1. Open the API\authConfig.js file.
  2. Find the key Enter_the_Application_Id_Here and replace the existing value with the application ID (clientId) of msal-node-api app copied from the Azure portal.
  3. Find the key Enter_the_Tenant_Id_Here and replace the existing value with your Azure AD tenant/directory ID.
  4. Find the key Enter_the_Client_Secret_Here and replace the existing value with the generated secret that you saved during the creation of msal-node-api copied from the Azure portal.

Register the client app (msal-react-spa)

  1. Navigate to the Azure portal and select the Azure Active Directory service.
  2. Select the App Registrations blade on the left, then select New registration.
  3. In the Register an application page that appears, enter your application's registration information:
    1. In the Name section, enter a meaningful application name that will be displayed to users of the app, for example msal-react-spa.
    2. Under Supported account types, select Accounts in this organizational directory only
    3. Select Register to create the application.
  4. In the Overview blade, find and note the Application (client) ID. You use this value in your app's configuration file(s) later in your code.
  5. In the app's registration screen, select the Authentication blade to the left.
  6. If you don't have a platform added, select Add a platform and select the Single-page application option.
    1. In the Redirect URI section enter the following redirect URIs:
      1. http://localhost:3000/
      2. http://localhost:3000/redirect
    2. Click Save to save your changes.
  7. Since this app signs-in users, we will now proceed to select delegated permissions, which is is required by apps signing-in users.
    1. In the app's registration screen, select the API permissions blade in the left to open the page where we add access to the APIs that your application needs:
    2. Select the Add a permission button and then:
    3. Ensure that the My APIs tab is selected.
    4. In the list of APIs, select the API msal-node-api.
    5. In the Delegated permissions section, select access_graph_on_behalf_of_user in the list. Use the search box if necessary.
    6. Select the Add permissions button at the bottom.
Configure Optional Claims
  1. Still on the same app registration, select the Token configuration blade to the left.
  2. Select Add optional claim:
    1. Select optional claim type, then choose Access.
    2. Select the optional claim acct.

    Provides user's account status in tenant. If the user is a member of the tenant, the value is 0. If they're a guest, the value is 1.

    1. Select Add to save your changes.
Configure the client app (msal-react-spa) to use your app registration

Open the project in your IDE (like Visual Studio or Visual Studio Code) to configure the code.

In the steps below, "ClientID" is the same as "Application ID" or "AppId".

  1. Open the SPA\src\authConfig.js file.
  2. Find the key Enter_the_Application_Id_Here and replace the existing value with the application ID (clientId) of msal-react-spa app copied from the Azure portal.
  3. Find the key Enter_the_Tenant_Id_Here and replace the existing value with your Azure AD tenant/directory ID.
  4. Find the key Enter_the_Web_Api_Application_Id_Here and replace the existing value with the application ID (clientId) of msal-node-api app copied from the Azure portal.

Configure Known Client Applications for service (msal-node-api)

For a middle-tier web API (msal-node-api) to be able to call a downstream web API, the middle tier app needs to be granted the required permissions as well. However, since the middle-tier cannot interact with the signed-in user, it needs to be explicitly bound to the client app in its Azure AD registration. This binding merges the permissions required by both the client and the middle-tier web API and presents it to the end user in a single consent dialog. The user then consent to this combined set of permissions. To achieve this, you need to add the Application Id of the client app to the knownClientApplications property in the manifest of the web API. Here's how:

  1. In the Azure portal, navigate to your msal-node-api app registration, and select the Manifest blade.
  2. In the manifest editor, change the knownClientApplications: [] line so that the array contains the Client ID of the client application (msal-react-spa) as an element of the array.

For instance:

    "knownClientApplications": ["ca8dca8d-f828-4f08-82f5-325e1a1c6428"],
  1. Save the changes to the manifest.

Step 4: Running the sample

    cd 6-AdvancedScenarios\1-call-api-obo\API
    npm start
    cd 6-AdvancedScenarios\1-call-api-obo\SPA
    npm start

Explore the sample

  1. Open your browser and navigate to http://localhost:3000.
  2. Click the sign-in button on the top right corner.
  3. Once you authenticate, Select the Profile button on the navigation bar.

ℹ️ Did the sample not work for you as expected? Then please reach out to us using the GitHub Issues page.

We'd love your feedback!

Were we successful in addressing your learning objective? Consider taking a moment to share your experience with us.

Troubleshooting

Expand for troubleshooting info
  • Use Stack Overflow to get support from the community. Ask your questions on Stack Overflow first and browse existing issues to see if someone has asked your question before. Ask your questions on Stack Overflow first and browse existing issues to see if someone has asked your question before. Make sure that your questions or comments are tagged with [azure-active-directory node ms-identity adal msal-js msal-react react].

To provide feedback on or suggest features for Azure Active Directory, visit User Voice page.

About the code

Gaining consent for the web API

The middle-tier application adds the client to the knownClientApplications list in its manifest, and then the client app can trigger a combined consent flow for both itself and the middle-tier application. On the Microsoft identity platform, this is done using the /.default scope. When triggering a consent screen using known client applications and /.default, the consent screen will show permissions for both the client to the middle-tier API, and also request whatever permissions are required by the middle-tier API. The user provides consent for both applications, and then the OBO flow works.

ℹ️ KnownClientApplications is an attribute in application manifest. It is used for bundling consent if you have a solution that contains two (or more) parts: a client app and a custom web API. If you enter the appID (clientID) of the client app into this array, the user will have to consent only once to the client app. Azure AD will know that consenting to the client means implicitly consenting to the web API. It will automatically provision service principals for both the client and web API at the same time. Both the client and the web API app must be registered in the same tenant.

Acquire an access token with the OBO flow

To get the access token for Graph API using the OBO flow, the middle-tier web API will initialize a ConfidentialClientApplication to exchange the access token using the acquireTokenOnBehalfOf API to get a new access token for the down-stream resource in the case Graph API. This is shown in onBehalfOfClient.js:

const getOboToken = async (oboAssertion) => {
    const oboRequest = {
        oboAssertion: oboAssertion,
        scopes: config.resources.downstreamAPI.scopes,
    };

    try {
        const response = await cca.acquireTokenOnBehalfOf(oboRequest);
        return response.accessToken;
    } catch (error) {
        throw error;
    }
};

Calling the Microsoft Graph API

After receiving the access token for Graph, we will initialize the Graph SDK client with an authProvider function. In this case, the user has to provide their implementation for getting and refreshing accessToken. A callback will be passed into this authProvider function; an access token or error needs to be passed into that callback as shown in graphClient.js file.

const getGraphClient = (accessToken) => {
    // Initialize Graph client
    const client = graph.Client.init({
        // Use the provided access token to authenticate requests
        authProvider: (done) => {
            done(null, accessToken);
        },
    });

    return client;
};

Handle Continuous Access Evaluation (CAE) challenges from Microsoft Graph

Continuous access evaluation (CAE) enables applications to do just-in time token validation, for instance enforcing user session revocation in the case of password change/reset but there are other benefits. For details, see Continuous access evaluation.

Microsoft Graph is now CAE-enabled. This means that it can ask its client apps for more claims when conditional access policies require it. Your can enable your application to be ready to consume CAE-enabled APIs by:

  1. Declaring that the client app is capable of handling claims challenges.
  2. Processing the claim challenge when they are thrown by MS Graph Api.

Declare the CAE capability in the configuration

Apps using MSAL can declare CAE-capability by adding the clientCapabilities property in the configuration object. This is shown in authConfig.js:

    const msalConfig = {
        auth: {
            clientId: 'Enter_the_Application_Id_Here', 
            authority: 'https://login.microsoftonline.com/Enter_the_Tenant_Info_Here',
            redirectUri: "/", 
            postLogoutRedirectUri: "/",
            navigateToLoginRequestUrl: true, 
            clientCapabilities: ["CP1"] // this lets the resource owner know that this client is capable of handling claims challenge.
        }
    }

    const msalInstance = new PublicClientApplication(msalConfig);

Note that both the SPA and the web API projects need to declare this, since the web API in this sample also obtains tokens via the on-behalf-of flow (see onBehalfOfClient.js).

Processing the CAE challenge from Microsoft Graph

Once the middle-tier web API (msal-node-api) app receives the CAE claims challenge from Microsoft Graph, it needs to process the challenge and redirect the user back to Azure AD for re-authorization. However, since the middle-tier web API does not have UI to carry out this, it needs to propagate the error to the client app (msal-react-spa) instead, where it can be handled. This is shown in profileController.js:

exports.getProfile = async (req, res, next) => {
    if (isAppOnlyToken(req.authInfo)) {
        return next(new Error('This route requires a user token'));
    }

    const userToken = req.get('authorization');
    const [bearer, tokenValue] = userToken.split(' ');

    if (hasRequiredDelegatedPermissions(req.authInfo, authConfig.protectedRoutes.profile.delegatedPermissions.scopes)) {
        try {
            const accessToken = await getOboToken(tokenValue);

            const graphResponse = await getGraphClient(accessToken)
                .api('/me')
                .responseType(ResponseType.RAW)
                .get();

            if (graphResponse.status === 401) {
                if (graphResponse.headers.get('WWW-Authenticate')) {

                    if (isClientCapableOfClaimsChallenge(req.authInfo)) {
                        /**
                         * Append the WWW-Authenticate header from the Microsoft Graph response to the response to 
                         * the client app. To learn more, visit: https://learn.microsoft.com/azure/active-directory/develop/app-resilience-continuous-access-evaluation
                         */
                        return res.status(401)
                            .set('WWW-Authenticate', graphResponse.headers.get('WWW-Authenticate').toString())
                            .json({ errorMessage: 'Continuous access evaluation resulted in claims challenge' });
                    }

                    return res.status(401).json({ errorMessage: 'Continuous access evaluation resulted in claims challenge but the client is not capable. Please enable client capabilities and try again' });
                }

                throw new Error('Unauthorized');
            }

            const graphData = await graphResponse.json();
            res.status(200).json(graphData);
        } catch (error) {
            if (error instanceof msal.InteractionRequiredAuthError) {
                if (error.claims) {
                    const claimsChallenge = generateClaimsChallenge(error.claims);

                    return res.status(401)
                        .set(claimsChallenge.headers[0], claimsChallenge.headers[1])
                        .json({ errorMessage: error.errorMessage });
                }

                return res.status(401).json(error);
            }

            next(error);
        }
    } else {
        next(new Error('User does not have the required permissions'));
    }
};

On the client side, we use MSAL's acquireToken API and provide the claims challenge as a parameter in the token request (see Profile.jsx). To retrieve the claims challenge from the API response, refer to the fetch.js, where we handle the response with the handleClaimsChallenge method:

export const callApiWithToken = async (accessToken, apiEndpoint, account) => {
    const headers = new Headers();
    const bearer = `Bearer ${accessToken}`;

    headers.append("Authorization", bearer);

    const options = {
        method: "GET",
        headers: headers
    };

    const response = await fetch(apiEndpoint, options);
    return handleClaimsChallenge(response, apiEndpoint, account);
}

export const handleClaimsChallenge = async (response, apiEndpoint, account) => {
    if (response.status === 200) {
        return response.json();
    } else if (response.status === 401) {
        if (response.headers.get('WWW-Authenticate')) {
            const authenticateHeader = response.headers.get('WWW-Authenticate');
            const claimsChallenge = parseChallenges(authenticateHeader);

            /**
             * This method stores the claim challenge to the session storage in the browser to be used when acquiring a token.
             * To ensure that we are fetching the correct claim from the storage, we are using the clientId
             * of the application and oid (user’s object id) as the key identifier of the claim with schema
             * cc.<clientId>.<oid>.<resource.hostname>
             */
            addClaimsToStorage(
                `cc.${msalConfig.auth.clientId}.${account.idTokenClaims.oid}.${new URL(apiEndpoint).hostname}`,
                claimsChallenge.claims,
            );

            throw new Error(`claims_challenge_occurred`);
        }

        throw new Error(`Unauthorized: ${response.status}`);
    } else {
        throw new Error(`Something went wrong with the request: ${response.status}`);
    }
};

Contributing

If you'd like to contribute to this sample, see CONTRIBUTING.MD.

This project has adopted the Microsoft Open Source Code of Conduct. For more information, see the Code of Conduct FAQ or contact [email protected] with any additional questions or comments.

Learn More