What is the proper way to store sensitive data in react native app?

When storing sensitive data in React Native, it is crucial to ensure its security to prevent leaks and other potential security threats. The correct approach typically involves using encryption and secure storage tools. The following are some recommended methods and tools:

1. Using Secure Storage Libraries

A widely adopted and commonly used library is react-native-secure-storage, which provides a secure storage solution based on iOS's Keychain and Android's Keystore. These systems offer hardware-level security, effectively protecting sensitive data such as tokens, passwords, and other private information.

For example, storing a sensitive user token can be done as follows:

javascript
import SecureStorage from 'react-native-secure-storage';

const saveToken = async (userToken) => {
  await SecureStorage.setItem('user_token', userToken, {accessible: SecureStorage.ACCESSIBLE.WHEN_UNLOCKED});
}

const getToken = async () => {
  return await SecureStorage.getItem('user_token');
}

2. Encrypting Data

Encrypting sensitive data before storing it on the device is a best practice. Libraries such as react-native-crypto or react-native-aes-crypto can be used to implement data encryption.

For example, using AES to encrypt a string:

javascript
import { NativeModules } from 'react-native';
const { Aes } = NativeModules;

const encryptData = async (text, key) => {
  const iv = await Aes.randomKey(16);
  const cipher = await Aes.encrypt(text, key, iv, 'aes-256-cbc');
  return { cipher, iv };
}

const decryptData = async (encryptedData, key) => {
  const { cipher, iv } = encryptedData;
  const text = await Aes.decrypt(cipher, key, iv, 'aes-256-cbc');
  return text;
}

3. Using Environment Variables

For configuration data such as API keys, environment variables can be used to manage them, avoiding hardcoding in the code. Libraries like react-native-config can be used to manage environment variables.

javascript
import Config from 'react-native-config';

const API_KEY = Config.API_KEY;

4. Using Native Modules

For extremely sensitive data, consider using native modules (e.g., modules written in Swift or Kotlin/Java) to leverage higher-level security features provided by iOS and Android.

5. Managing Permissions

Ensure proper management of application permissions to avoid unnecessary permission requests, which may compromise application security.

Summary

When storing sensitive data, appropriate encryption and the use of dedicated secure storage libraries are key. Additionally, developers should continuously monitor the latest security practices and vulnerabilities to ensure application security. During implementation, thorough testing should be conducted to verify the effectiveness of security measures.