AES Encryption

Since version 1.6.0 - Gen 3 and Gen 4 devices only

The AES API provides cryptographic functions for encrypting and decrypting data using the Advanced Encryption Standard (AES) algorithm.

Overview

AES encryption allows scripts to:

• Encrypt sensitive data before transmission
• Decrypt received encrypted data
• Support multiple AES modes (CBC, CFB, CTR, OFB, ECB)
• Use 128, 192, or 256-bit keys

API Reference

AES.encrypt()

Encrypts plain text message to encrypted cipher text.

Property	Type	Description
plainText	ArrayBuffer	Data to be encrypted
key	ArrayBuffer	Encryption key (128, 192, or 256 bits)
mode	string	Optional: AES mode - "CBC", "CFB", "CTR", "OFB", or "ECB"

Returns: Encrypted message as ArrayBuffer

AES.decrypt()

Decrypts encrypted message to plain text.

Property	Type	Description
cypherText	ArrayBuffer	Data to be decrypted
key	ArrayBuffer	Decryption key (128, 192, or 256 bits)
mode	string	Optional: AES mode - "CBC", "CFB", "CTR", "OFB", or "ECB"

Returns: Decrypted message as ArrayBuffer

Complete Example

// AES encryption/decryption example using CBC mode

// Helper functions for hex conversion
function hex2a(hex) {
  hex = hex.toString();
  let str = "";
  for (let i = 0; i < hex.length; i += 2) {
    str += String.fromCharCode(parseInt(hex.substr(i, 2), 16));
  }
  return str;
}

function toHex(buffer) {
  let s = "";
  for (let i = 0; i < buffer.length; i++) {
    s += (256 + buffer[i]).toString(16).substr(-2);
  }
  return s;
}

function fromHex(hex) {
  const arr = new ArrayBuffer(hex.length / 2);
  for (let i = 0; i < hex.length; i += 2) {
    arr[i >> 1] = parseInt(hex.substr(i, 2), 16);
  }
  return arr;
}

// 256-bit key
const key = fromHex("dd469421e5f4089a1418ea24ba37c61bdd469421e5f4089a1418ea24ba37c61b");

function encrypt() {
  const plainText = "This is one big, big secret no one should know!!";
  console.log("Message to encrypt:", plainText);

  const cypherText = AES.encrypt(plainText, key, {
    mode: "CBC"
  });

  // Decrypt to verify
  const decrypted = AES.decrypt(cypherText, key, {
    mode: "CBC"
  });

  // Convert from ArrayBuffer to String
  const decryptedText = hex2a(toHex(decrypted));
  console.log("Decrypted message:", decryptedText);
  
  return cypherText;
}

// Run encryption example
encrypt();

Supported Modes

Mode	Description	Use Case
CBC	Cipher Block Chaining	General purpose, most common
CFB	Cipher Feedback	Stream-like encryption
CTR	Counter	Parallel encryption/decryption
OFB	Output Feedback	Stream cipher mode
ECB	Electronic Codebook	Simple but less secure

Key Sizes

• 128-bit (16 bytes): Basic security
• 192-bit (24 bytes): Enhanced security
• 256-bit (32 bytes): Maximum security