crypto encrypt decrypt class

safe.js

const crypto    = require('crypto');
const key       = crypto.randomBytes(32);
const iv        = crypto.randomBytes(16);
const algorithm = 'aes-256-cbc'
class Safe {
    constructor(key, iv) {
        this.key = key,
        this.iv  = iv
    }
    encrypt (text) {
        let cipher    = crypto.createCipheriv(algorithm, Buffer.from(this.key), this.iv);
        let encrypted = cipher.update(text);
            encrypted = Buffer.concat([encrypted, cipher.final()]);
        return encrypted.toString('hex')
    }
    decrypt (text) {
        let iv           = Buffer.from(this.iv);
        let encryptedTxt = Buffer.from(text, 'hex');
        let decipher     = crypto.createDecipheriv(algorithm, Buffer.from(key), iv);
        let decrypted    = decipher.update(encryptedTxt);
            decrypted    = Buffer.concat([decrypted, decipher.final()]);
        return decrypted.toString();
    };
}
module.exports = new Safe(key, iv)