BotFramework-WebChat

Single sign-on demo for Intranet apps using OAuth

Deploy Status

Description

In this demo, we will show you how to authorize a user to access resources on an Intranet app with a bot. We will use Azure Active Directory for OAuth provider and Microsoft Graph for the protected resources.

When dealing with personal data, please respect user privacy. Follow platform guidelines and post your privacy statement online.

Background

This sample is a simplified and reduced version of the sample “Single sign-on demo for enterprise apps using OAuth”. There are notable differences:

This demo does not include any threat models and is designed for educational purposes only. When you design a production system, threat-modelling is an important task to make sure your system is secure and provide a way to quickly identify potential source of data breaches. IETF RFC 6819 and OAuth 2.0 for Browser-Based Apps is a good starting point for threat-modelling when using OAuth 2.0.

Test out the hosted sample

You can browse to https://webchat-sample-sso-intranet.azurewebsites.net/ to try out this demo.

How to run locally

This demo integrates with Azure Active Directory. You will need to set it up in order to host the demo.

  1. Clone the code
  2. Setup OAuth via Azure Active Directory
  3. Setup Azure Bot Services
  4. Prepare and run the code

Clone the code

To host this demo, you will need to clone the code and run locally.

  1. Clone this repository
  2. Create two files for environment variables, /bot/.env and /web/.env
    • In /web/.env:
      • Write OAUTH_REDIRECT_URI=http://localhost:5000/api/oauth/callback
        • When Azure Active Directory completes the authorization flow, it will send the browser to this URL. This URL must be accessible by the browser from the end-user machine

Setup OAuth via Azure Active Directory

If you want to authenticate on Azure Active Directory, follow the steps below.

Setup Azure Bot Services

We prefer using Bot Channel Registration during development. This will help you diagnose problems locally without deploying to the server and speed up development.

You can follow our instructions on how to setup a new Bot Channel Registration.

  1. Save the Microsoft App ID and password to /bot/.env
    • MICROSOFT_APP_ID=12345678-1234-5678-abcd-12345678abcd
    • MICROSOFT_APP_PASSWORD=a1b2c3d4e5f6
  2. Save the Web Chat secret to /web/.env
    • DIRECT_LINE_SECRET=a1b2c3.d4e5f6g7h8i9j0

When you are building your production bot, never expose your Web Chat or Direct Line secret to the client. Instead, you should use the secret to generate a limited token and send it to the client. For information, please refer to this page on how to generate a Direct Line token and Enhanced Direct Line Authentication feature.

During development, you will run your bot locally. Azure Bot Services will send activities to your bot through a public URL. You can use ngrok to expose your bot server on a public URL.

  1. Run ngrok http -host-header=localhost:3978 3978
  2. Update your Bot Channel Registration. You can use Azure CLI or Azure Portal
    • Via Azure CLI
      • Run az bot update --resource-group <your-bot-rg> --name <your-bot-name> --subscription <your-subscription-id> --endpoint "https://a1b2c3d4.ngrok.io/api/messages"
    • Via Azure Portal
      • Browse to your Bot Channel Registration
      • Select “Settings”
      • In “Configuration” section, set “Messaging Endpoint” to https://a1b2c3d4.ngrok.io/api/messages

Prepare and run the code

  1. Under both the bot, and web folder, run the following:
    1. npm install
    2. npm start
  2. Browse to http://localhost:5000/ to start the demo

Things to try out

Code

Overview

This sample includes multiple parts:

Assumptions

Goals

Content of the .env files

The .env files hold the environment variables critical to run the service. These are usually security-sensitive information and must not be committed to version control. Although we recommend keeping these keys in Azure Vault, for simplicity of this sample, we would keep them in .env files.

To ease the setup of this sample, here is the template of .env files.

/bot/.env

MICROSOFT_APP_ID=12345678-1234-5678-abcd-12345678abcd
MICROSOFT_APP_PASSWORD=a1b2c3d4e5f6

/web/.env

OAUTH_CLIENT_ID=12345678abcd-1234-5678-abcd-12345678abcd
OAUTH_REDIRECT_URI=http://localhost:5000/api/oauth/callback
DIRECT_LINE_SECRET=a1b2c3.d4e5f6g7h8i9j0

Frequently asked questions

How can I reset my authorization?

To reset application authorization, please follow the steps below.

  1. On the AAD dashboard page, wait until “App permissions” loads. Here you see how many apps you have authorized
  2. Click “Change app permissions”
  3. In the “You can revoke permission for these apps” section, click the “Revoke” button below your app registration

Further reading

OAuth access token vs. refresh token

To make this demo simpler to understand, instead of refresh token, we are obtaining the access token via Authorization Code Grant flow. Access token is short-lived and considered secure to live inside the browser.

In your production scenario, you may want to obtain the refresh token with “Authorization Code Grant” flow instead of using the access token. We did not use the refresh token in this sample as it requires server-to-server communications and secured persistent storage, it would greatly increase the complexity of this demo.

Threat model

To reduce complexity, this sample is limited in scope. In your production system, you should consider enhancing it and review its threat model.