crypto.js

const crypto = require("crypto");

const algorithm = "aes-256-ctr";
const password = "Password used to generate key";
// Key length is dependent on the algorithm. In this case for aes192, it is
// 24 bytes (192 bits). For ae256, 32 bytes.
// Use async `crypto.scrypt()` instead.
const key = crypto.scryptSync(password, "salt", 32);
// Use `crypto.randomBytes()` to generate a random iv instead of the static iv
// shown here.
// const iv = Buffer.alloc(16, 0); // Initialization vector.
const iv = crypto.randomBytes(16).toString("hex").slice(0, 16);

const cipher = crypto.createCipheriv(algorithm, key, iv);

let encrypted = "";
cipher.on("readable", () => {
  let chunk;q
  while (null !== (chunk = cipher.read())) {
    encrypted += chunk.toString("hex");
  }
});
cipher.on("end", () => {
  console.log("encrypted:", encrypted);
  // Prints: e5f79c5915c02171eec6b212d5520d44480993d7d622a7c4c2da32f6efda0ffa
});

cipher.write("some clear text data");
cipher.end();

// ------
// ------
// ------
// ------
// ------
// ------
// ------

const decipher = crypto.createDecipheriv(algorithm, key, iv);

let decrypted = "";
decipher.on("readable", () => {
  while (null !== (chunk = decipher.read())) {
    decrypted += chunk.toString("utf8");
  }
});
decipher.on("end", () => {
  console.log("decrypted:", decrypted);
  // Prints: some clear text data
});

// Encrypted with same algorithm, key and iv.
// const encrypted = "e5f79c5915c02171eec6b212d5520d44480993d7d622a7c4c2da32f6efda0ffa";
decipher.write(encrypted, "hex");
decipher.end();