react-native-ssl-public-key-pinning

Simple and secure SSL public key pinning for React Native. Uses OkHttp CertificatePinner on Android and TrustKit on iOS.

🔍Overview

• ✅ Supports SSL public key pinning using the base64-encoded SHA-256 hash of a certificate's Subject Public Key Info.
• ✅ No native configuration needed. Simply install and configure through the provided JS API.
• ✅ No modification of existing network request code needed. All network requests done through the standard Networking APIs will have the certificate pinning configuration automatically enabled after initialization.
• ✅ Compatible with Flipper Network plugin for easier debugging of network requests.

🧰Installation

React Native

npm install react-native-ssl-public-key-pinning

OR for Yarn use:

yarn add react-native-ssl-public-key-pinning

Before building for iOS, make sure to run the following commands:

cd ios && pod install && cd ..

Expo Managed Workflow

npx expo install react-native-ssl-public-key-pinning

and then follow the steps to create a development build or production build

Disable expo-dev-client Network Inspector on iOS (Optional)

If you are building an iOS Expo development build and want to test out your pinning configuration, you will need to disable expo-dev-client's network inspector as it interferes with the pinning setup. Note that the network inspector is automatically disabled on production builds and so this library would function properly on production builds without needing to go through the following steps.

1. Install expo-build-properties

   npx expo install expo-build-properties

2. Add the following plugin configuration to your app.json

   
   {
   "expo": {
   "plugins": [
     [
       "expo-build-properties",
       {
         "ios": {
           "networkInspector": false
         } 
       }
     ]
   ]
   }
   }

3. Run prebuild to update native files

npx expo prebuild

## 🚀Usage

1. Retrieve the base64-encoded SHA-256 public key hash of the certificates you want to pin. [More details on how to do this](#public-key-hash)
2. Call `initializeSslPinning` as early as possible in your App entry point with your SSL pinning configuration.
3. All network requests in your app should now have SSL pinning enabled!

### Pinning Example

```js
import { initializeSslPinning } from 'react-native-ssl-public-key-pinning';

await initializeSslPinning({
  'google.com': {
    includeSubdomains: true,
    publicKeyHashes: [
      'CLOmM1/OXvSPjw5UOYbAf9GKOxImEp9hhku9W90fHMk=',
      'hxqRlPTu1bMS/0DITB1SSu0vd4u/8l8TjPgfaAp63Gc=',
      'Vfd95BwDeSQo+NUYxVEEIlvkOlWY2SalKK1lPhzOx78=',
      'QXnt2YHvdHR3tJYmQIr0Paosp6t/nggsEGD4QJZ3Q0g=',
      'mEflZT5enoR1FuXLgYYGqnVEoZvmf9c2bVBpiOjYQ0c=',
    ],
  },
});

// ...

// This request will have public key pinning enabled
const response = await fetch('https://www.google.com');

Listener Example

import { addSslPinningErrorListener } from 'react-native-ssl-public-key-pinning';

useEffect(() => {
  const subscription = addSslPinningErrorListener((error) => {
    // Triggered when an SSL pinning error occurs due to pin mismatch
    console.log(error.serverHostname);
  });
  return () => {
    subscription.remove();
  };
}, []);

💡API Reference

⚙️Options

📝Additional Notes

Known Issues

• This library should support all currently supported versions of React Native. However, older RN versions should also be compatible with this library, though it might be untested. You should go through the process to check your setup on both Android and iOS to ensure it works as expected. Do note that on Android React Native versions below v65, includeSubdomains: true is not supported and you have to match your domains exactly. This is because wildcard domain support (which this library uses for includeSubdomains) was only introduced in OkHttp v4.3, and RN v65 is the first version that upgraded OkHttp to v4.
• On iOS, SSL/TLS sessions are cached. If a connection to your site previously succeeded, setting a pinning configuration that should fail the following request would not actually fail it since the previous session is used. You will need to restart your app to clear out this cache.
• Third-party libraries that use fetch or XMLHttpRequest would also be affected by the pinning (e.g. axios). However, native libraries that implement their own methods of performing network requests would not be affected by the pinning configuration.

Best Practices

• To prevent accidentally locking users out of your site, ensure you have at least one backup pin and have procedures in place to transition to using the backup pin if your primary pin can no longer be used. Read more about this here. Further, TrustKit (native iOS library) enforces two pins which will cause initializeSslPinning to throw an exception if only one pin is provided.
• You can also implement an OTA update mechanism through libraries like react-native-code-push or expo-updates. Doing this will help ensure your key hashes are up to date without needing users to download a new version from the Play Store/App Store since all pinning configurations are done through the JS API.

🤔FAQ

📚References

• OWASP
• OkHttp
• TrustKit

🤝Contributing

See the contributing guide to learn how to contribute to the repository and the development workflow.