nodejs chacha20-poly1305 encrypt decrypt example

chacha20-poly1305.js

const crypto = require('crypto');

let key = crypto.randomBytes(32),
text = 'test';

function encChaPoly(key, data, cb){
  try {
    let iv = crypto.randomBytes(12),
    cipher = crypto.createCipheriv('chacha20-poly1305', key, iv, {
      authTagLength: 16
    }),
    encrypted = Buffer.concat([
      cipher.update(
        Buffer.from(data), 'utf8'),
        cipher.final()
    ]),
    tag = cipher.getAuthTag(),
    final = Buffer.concat([iv, tag, encrypted]).toString('hex');
    cb(false, final)
  } catch (err) {
    if(err){
      cb(err,null)
    }
  }
}

function decChaPoly(key, data, cb){
  try {
    let decipher = crypto.createDecipheriv(
      'chacha20-poly1305',
      key,
      Buffer.from(data.substring(0, 24), 'hex'),
      {
        authTagLength: 16
      }
    );
    decipher.setAuthTag(
      Buffer.from(data.substring(24, 56), 'hex')
    ),
    decrypted = [
      decipher.update(
        Buffer.from(data.substring(56), 'hex'),
        'binary',
        'utf8'
      ), decipher.final('utf8')
    ].join('');
    cb(false, decrypted)
  } catch (err) {
    if(err){
      cb(err,null)
    }
  }
}

encChaPoly(key, text, function(err,res){
  if(err){return console.log(err)}
  console.log(res)
  decChaPoly(key, res, function(err,res){
    if(err){return console.log(err)}
    console.log(res)
  })
})