index.js

index.js

const buffer = require('buffer');
const crypto = require('crypto');

const aes256gcm = (key, iv) => {
  const ALGO = 'aes-256-gcm';

  const encrypt = (str) => {

    const cipher = crypto.createCipheriv(ALGO, key, iv);
    let enc = cipher.update(str, 'utf8', 'hex');
    enc += cipher.final('hex');
    return [enc, iv, cipher.getAuthTag()];
  };

  const decrypt = (enc, iv, authTag) => {
    const decipher = crypto.createDecipheriv(ALGO, key, iv);
    decipher.setAuthTag(authTag);
    let str = decipher.update(enc, 'hex', 'utf8');
    str += decipher.final('utf8');
    return str;
  };

  return {
    encrypt,
    decrypt,
  };
};

const KEY = Buffer.from('3a7bd3e2360a3d29eea436fcfb7e44c7', 'utf8');
const IV = Buffer.from('35d117c42d1c1835420b6b9942dd4f1b', 'utf8');

const aesCipher = aes256gcm(KEY, IV);

const [encrypted, iv, authTag] = aesCipher.encrypt('BPJ1AXL5TXAoBcEhHXEvHx==');
console.log("encrypted:");
console.log(encrypted)
console.log("authTag:");
console.log(authTag)
const decrypted = aesCipher.decrypt(encrypted, iv, authTag);
console.log("decrypted:");
console.log(decrypted);