AesBridge is a modern, secure, and cross-language AES encryption library. It offers a unified interface for encrypting and decrypting data across multiple programming languages. Supports GCM, CBC, and legacy AES Everywhere modes.

This is the JavaScript implementation of the core project.
👉 Main repository: https://github.com/mervick/aes-bridge

• 🔐 AES-256 encryption in GCM and CBC modes
• 🌍 Unified cross-language design
• 📦 Compact binary format or base64 output
• ✅ HMAC Integrity: CBC mode includes HMAC verification
• 🔄 Backward Compatible: Supports legacy AES Everywhere format
• 💻 Works in both Node.js and browsers (UMD + ESM + CJS)

npm install aes-bridge
# or
yarn add aes-bridge

<script src="aes-bridge.umd.js"></script>
<script>
  const { encrypt, decrypt } = window.aes_bridge;

  const ciphertext = await encrypt("My secret message", "MyStrongPass")
  const plaintext = await decrypt(ciphertext, "MyStrongPass")
</script>

<script src="https://cdn.jsdelivr.net/npm/aes-bridge@v2.0.5/dist/aes-bridge.umd.js"></script>

For Node.js applications using ES Modules:

import { encrypt, decrypt } from 'aes-bridge';

const ciphertext = await encrypt('My secret message', 'MyStrongPass');
const plaintext = await decrypt(ciphertext, 'MyStrongPass');

• encrypt(data, passphrase)
  Encrypts a string using AES-GCM (default).
  Returns: Promise<string> - base64-encoded string.

• decrypt(ciphertext, passphrase)
  Decrypts a base64-encoded string encrypted with AES-GCM.
  Returns: Promise<Uint8Array> - raw binary data.

• encryptGcm(data, passphrase)
  Encrypts a string using AES-GCM.
  Returns: Promise<string> - base64-encoded string.

• decryptGcm(ciphertext, passphrase)
  Decrypts a base64-encoded string encrypted with encryptGcm.
  Returns: Promise<Uint8Array> - raw binary data.

• encryptGcmBin(data, passphrase)
  Returns encrypted binary data using AES-GCM.
  Returns: Promise<Uint8Array> - raw binary data.

• decryptGcmBin(ciphertext, passphrase)
  Decrypts binary data encrypted with encryptGcmBin.
  Returns: Promise<Uint8Array> - raw binary data.

• encryptCbc(data, passphrase)
  Encrypts a string using AES-CBC. HMAC is used for integrity verification.
  Returns: Promise<string> - base64-encoded string.

• decryptCbc(ciphertext, passphrase)
  Decrypts a base64-encoded string encrypted with encryptCbc and verifies HMAC.
  Returns: Promise<Uint8Array> - raw binary data.

• encryptCbcBin(data, passphrase)
  Returns encrypted binary data using AES-CBC with HMAC.
  Returns: Promise<Uint8Array> - raw binary data.

• decryptCbcBin(ciphertext, passphrase)
  Decrypts binary data encrypted with encryptCbcBin and verifies HMAC.
  Returns: Promise<Uint8Array> - raw binary data.

⚠️ These functions are kept for backward compatibility only. Their usage is strongly discouraged in new applications.

• encryptLegacy(data, passphrase)
  Encrypts a string in the legacy AES Everywhere format.
  Returns: Promise<string> - base64-encoded string.

• decryptLegacy(ciphertext, passphrase)
  Decrypts a string encrypted in the legacy AES Everywhere format.
  Returns: Promise<Uint8Array> - raw binary data.

All functions in this library return a Promise. Specifically:

• encrypt, encryptGcm, encryptCbc, encryptLegacy
  Returns: Promise<string> - typically base64-encoded string.

• encryptGcmBin, encryptCbcBin,
  Returns: Promise<Uint8Array> - raw binary data.

• decrypt, decryptGcm, decryptGcmBin, decryptCbc, decryptCbcBin, decryptLegacy
  Returns: Promise<Uint8Array> - raw binary data.

As noted above, decryption functions and binary encryption functions (those with decrypt or Bin in their name) return a Promise<Uint8Array>. If you need to convert this Uint8Array back into a human-readable string, you'll typically use the TextDecoder API, especially if the original data was a UTF-8 encoded string.

Here's an example of how you can convert the Uint8Array to a string:

// Assuming decryptedResult is a Promise<Uint8Array> from a decryption function
const decryptedUint8Array = await decryptedResult; 
const decoder = new TextDecoder('utf-8', { fatal: true });
let finalStringResult;

try {
  finalStringResult = decoder.decode(decryptedUint8Array);
  console.log("Decrypted string:", finalStringResult);
} catch (e) {
  console.error("Decoding failed:", e);
  // Handle decoding errors, e.g., if the data is not valid UTF-8
}

The fatal: true option in TextDecoder will throw an error if the input contains malformed UTF-8 sequences, which can be helpful for debugging or ensuring data integrity.