📦 react-native-aes-lite

Lightweight AES encryption/decryption utility for React Native and Expo. No native modules, no linking — just pure JavaScript.

📖 Overview

react-native-aes-lite provides simple AES block-based text encryption and decryption using a 128-bit key. It is ideal for app-side data scrambling, offline encoding, demos, and educational use.

✔ Encrypt text → hex
✔ Decrypt hex → text
✔ Generate AES keys
✔ Works offline
✔ No native dependencies
✔ React Native CLI support
✔ Expo app support
✔ Expo web support

🚨 Security Warning

This library is not suitable for securing sensitive data.

It does not implement:

• IV / salt
• AES-GCM
• AES-CBC
• key derivation
• authenticated encryption
• secure storage

If you need production-grade crypto → use a native AES solution.

📦 Install

npm install react-native-aes-lite

or

yarn add react-native-aes-lite

🚀 Usage

import { AES, generateKey } from "react-native-aes-lite";

const aes = new AES();
const key = generateKey("hex", { length: 16 });

const encrypted = aes.encrypt("hello world", key);
console.log("Encrypted:", encrypted);

const decrypted = aes.decrypt(encrypted, key);
console.log("Decrypted:", decrypted);

Example output:

Encrypted: f52066d59d6c581c3918e652efe8cb45
Decrypted: hello world

🔑 Key Generation

const key = generateKey("hex", { length: 16 });

Formats supported:

• hex (recommended)
• base64
• ascii

Key lengths:

• 16 bytes (AES-128)
• 24 bytes (AES-192)
• 32 bytes (AES-256)

📘 API Reference

class AES

new AES()
encrypt(text: string, key: string): string
decrypt(cipherHex: string, key: string): string

generateKey(format?, options?)

generateKey(
  format?: "hex" | "base64" | "ascii",
  options?: { length?: number; readable?: boolean }
): string

📌 Example: Saving encrypted text

const aes = new AES();
const key = generateKey("hex");

const token = "USER_SESSION_XYZ";
const encrypted = aes.encrypt(token, key);

await AsyncStorage.setItem("token", encrypted);

const stored = await AsyncStorage.getItem("token");
const decrypted = aes.decrypt(stored, key);

⚡ Performance Notes

AES operations are synchronous.
Works best for short strings.

| Device | Speed | |--------|-------| | New iOS / Android | fast | | Mid-range phones | good | | Old hardware | slower |

Not recommended for large blobs.

🧭 Roadmap

Planned:

• AES-256 support
• Async API
• CBC mode
• IV generation
• UTF-8 optimization
• bundle size reduction

Not planned:

• secure storage
• authenticated encryption
• native rewrite

🧩 Platform Support

| Platform | Status | |------------------|--------| | React Native CLI | ✅ | | Expo app | ✅ | | Expo web | ✅ | | Expo Snack | ❌ (npm modules unsupported) | | TypeScript | ⚠ static warnings may appear |

⚠ Expo Snack

Expo Snack does not support npm installation, so this package cannot run inside Snack. Use Expo locally instead:

expo start

🐞 Troubleshooting

Error: AES is not a constructor

Use default import fallback:

import aesKit from "react-native-aes-lite";
const { AES } = aesKit;

TS2305 — generateKey missing

Ensure latest version is installed.

📜 License

MIT © 2025 Ammachi