Are you tired of manually logging in to your React Native app every time you want to access a web page that requires authentication? Do you want to provide a seamless Single Sign-On (SSO) experience for your users? Look no further! In this article, we’ll show you how to pass the Keycloak token in React Native to achieve automatic login in a WebView.
What is Keycloak?
Keycloak is an open-source Identity and Access Management (IAM) solution that provides a robust and scalable way to manage user identities and authenticate applications. It offers a wide range of features, including SSO, OAuth 2.0, and OpenID Connect (OIDC) protocols.
What is React Native?
React Native is a popular framework for building cross-platform mobile apps using JavaScript and React. It provides a unique approach to building mobile apps by allowing developers to write native mobile applications for Android and iOS using a single codebase.
The Problem: Manual Login in WebView
When you open a web page in a WebView within a React Native app, the user is prompted to enter their login credentials every time. This can be frustrating, especially if the user has already logged in to the app. This is where SSO comes in – to provide a seamless authentication experience across multiple applications.
The Solution: Passing the Keycloak Token in React Native
To achieve automatic login in a WebView, we need to pass the Keycloak token as a bearer token in the WebView’s request headers. Here’s a step-by-step guide to help you achieve this:
Step 1: Set up Keycloak and React Native
Before we dive into the implementation, make sure you have Keycloak set up and running, and a React Native app created with the necessary dependencies installed.
Create a new React Native project using the following command:
npx react-native init MySSOApp
Install the necessary dependencies, including `react-native-webview`:
npm install react-native-webview
Step 2: Configure Keycloak
Create a new realm in Keycloak and set up an OIDC client with the following settings:
Setting | Value |
---|---|
Realm | MyRealm |
Client ID | my-client |
Client Protocol | openid-connect |
Valid Redirect URIs | http://localhost:8080/* |
Step 3: Authenticate with Keycloak in React Native
In your React Native app, add the following code to authenticate with Keycloak using the OIDC client:
import React, { useState, useEffect } from 'react'; import { WebView } from 'react-native-webview'; import { LoginManager, AccessToken, GraphRequest, GraphRequestManager, } from 'react-native-fbsdk'; const App = () => { const [token, setToken] = useState(null); useEffect(() => { LoginManager.logInWithPermissions(['public_profile', 'email']).then( async result => { if (result.isCancelled) { console.log('User cancelled login'); } else { const accessToken = await AccessToken.getCurrentAccessToken(); const token = accessToken.accessToken; setToken(token); } }, error => { console.error(`Login failed with error: ${error}`); }, ); }, []); return (response.json()) .then(data => { const token = data.access_token; // Set the token in the WebView's request headers WebView.postMessage('setToken', token); }); `} /> ); }; export default App;
Step 4: Pass the Keycloak Token to the WebView
In the `injectedJavaScript` prop, we’re sending a POST request to the Keycloak token endpoint to obtain an access token. We then use the `WebView.postMessage` method to send the token to the native side of the app.
In the native side, we’ll use the `onMessage` prop to receive the token and set it in the WebView’s request headers:
import { WebView } from 'react-native-webview'; const App = () => { const webViewRef = React.createRef(); const handleWebViewMessage = event => { if (event.nativeEvent.data === 'setToken') { const token = event.nativeEvent.data; // Set the token in the WebView's request headers webViewRef.current.injectJavaScript(` document.querySelector('meta[name="csrf-token"]').content = '${token}'; `); } }; return (); };
Step 5: Configure the WebView to Use the Keycloak Token
In the `handleWebViewMessage` function, we’re setting the Keycloak token in the WebView’s request headers using the `injectJavaScript` method. We’re also setting the CSRF token meta tag in the WebView’s HTML to prevent cross-site request forgery (CSRF) attacks.
Now, when the user navigates to a web page that requires authentication, the WebView will automatically include the Keycloak token in the request headers, allowing the user to access the page without entering their login credentials again.
Conclusion
In this article, we’ve demonstrated how to pass the Keycloak token in React Native to achieve automatic login in a WebView. By following these steps, you can provide a seamless SSO experience for your users, allowing them to access multiple applications without entering their login credentials multiple times.
Remember to adapt the code to your specific use case and Keycloak configuration. Happy coding!
Frequently Asked Questions
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What is the purpose of the CSRF token in the WebView?
The CSRF token is used to prevent cross-site request forgery (CSRF) attacks. By setting the token in the WebView’s HTML, we ensure that the web page can verify the authenticity of the request and prevent unauthorized access.
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How does the WebView inject the JavaScript code?
The WebView injects the JavaScript code by executing the `injectJavaScript` method, which allows us to execute arbitrary JavaScript code in the WebView’s context. This code is executed after the WebView has finished loading the page.
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What if I’m using a different authentication provider?
This article focuses on Keycloak, but the principles apply to other authentication providers as well. You’ll need to adapt the code to your specific provider’s API and configuration. Consult your provider’s documentation for more information.
Additional Resources
For more information on Keycloak and React Native, check out the following resources:
I hope this article has helped you achieve automatic login in your React Native app using Keycloak tokens. Happy coding, and don’t hesitate to reach out if you have any further questions or need more clarification on any of the steps!
Frequently Asked Question
Get ready to unlock the secrets of seamless authentication with Keycloak tokens in React Native!
Q: How do I obtain a Keycloak token in my React Native app?
To obtain a Keycloak token, you’ll need to implement the authentication flow using the Keycloak SDK for React Native. This typically involves redirecting the user to the Keycloak authorization endpoint, where they’ll enter their credentials. After a successful login, Keycloak will redirect the user back to your app with an authorization code, which can be exchanged for an access token.
Q: How do I store the Keycloak token securely in my React Native app?
To store the Keycloak token securely, consider using a secure storage solution like React Native Keychain or a library like react-native-secure-storage. These solutions provide a secure way to store sensitive data, such as the access token, on the device. Make sure to follow best practices for secure storage and token handling.
Q: How do I pass the Keycloak token to the WebView in my React Native app?
To pass the Keycloak token to the WebView, you can use the `injectJavaScript` method provided by the React Native WebView component. This method allows you to inject a JavaScript script into the WebView, which can then set the token as a cookie or header. Alternatively, you can use a library like react-native-webview-inject-js to simplify the process.
Q: How do I configure the WebView to use the Keycloak token for automatic login?
To configure the WebView to use the Keycloak token for automatic login, you’ll need to set the token as a cookie or header in the WebView’s request. This can be done using the `injectJavaScript` method or by modifying the WebView’s navigation state. You may also need to configure the WebView’s cache and cookie storage to persist the token across sessions.
Q: What are some common obstacles to watch out for when implementing Keycloak token-based SSO in React Native?
Some common obstacles to watch out for when implementing Keycloak token-based SSO in React Native include token expiration and refresh, WebView cookie management, and secure storage of the token. Additionally, be aware of potential security vulnerabilities, such as token leakage or unauthorized access, and take necessary precautions to mitigate these risks.