pbkdf2 for modern browsers' JavaScript

pbkdf2.js

async function pbkdf2(message, salt, iterations, keyLen, algorithm) {
    const msgBuffer = new TextEncoder('utf-8').encode(message)
    const msgUint8Array = new Uint8Array(msgBuffer)
    const saltBuffer = new TextEncoder('utf-8').encode(salt)
    const saltUint8Array = new Uint8Array(saltBuffer)
    const key = await crypto.subtle.importKey('raw', msgUint8Array, { name: 'PBKDF2' }, false, ['deriveBits'])
    const buffer = await crypto.subtle.deriveBits({ "name": 'PBKDF2', "salt": saltUint8Array, "iterations": iterations, "hash": algorithm }, key, keyLen * 8)
    const hashArray = Array.from(new Uint8Array(buffer))
    const hashHex = hashArray.map(b => ('00' + b.toString(16)).slice(-2)).join('')
    return hashHex
}