<script type="text/javascript">

		let form=document.querySelector("form[name='chacha']");

		let input=form.querySelector("textarea[name='input']");

		let output=form.querySelector("textarea[name='output']");

		let password=form.querySelector("input[name='password']");

		form.querySelector("button[name='encrypt']").addEventListener("click",function(){

			output.value=cryptoJS.encrypt(input.value,password.value);

		});

		form.querySelector("button[name='decrypt']").addEventListener("click",function(){

			let res=cryptoJS.decrypt(input.value,password.value);

			output.value=res;

		});

	</script>

</body>

</html>

import * as util from "./util.js";

import {blake2s} from "./blake.js";

import {pbkdf2} from "./pbkdf2.js";

import {Chacha20,encrypt as _encrypt,decrypt as _decrypt} from "./chacha.js";

const VERSION=1;

function encrypt(s,password){

	let bs=util.str2utf8(s);

	let pass=util.str2utf8(password);

	let salt=util.createRandomNonce(12);

	let [iters,key]=stretchKey(pass,salt);

	let [_,ciphertext]=_encrypt(bs,key,salt);

	let signature=blake2s([VERSION,iters].concat(salt,ciphertext),16,key);

	let arr=[VERSION,iters].concat(signature,salt,ciphertext);

	return util.bytes2base64(arr);

}

function decrypt(s,password){

	let pass=util.str2utf8(password);

	let arr=util.base642bytes(s);

	let version=arr[0];

	let iters=arr[1];

	let signature=arr.slice(2,18);

	let salt=arr.slice(18,30);

	let ciphertext=arr.slice(30);

	let key=pbkdf2(pass,salt,1<<iters,32);

	let check=blake2s([version,iters].concat(salt,ciphertext),16,key);

	if(!signature.every((b,i)=>b===check[i])){return 1;}

	let plainbytes=_decrypt(ciphertext,key,salt);

	return util.utf82str(plainbytes);

}

function stretchKey(password,salt){

	let start=Date.now(); // ms

	let i,key;

		key=pbkdf2(password,salt,1<<i,32);

		if(Date.now()-start>=500){break;}

	}

	return [i,key];

}

export default {util,blake2s,pbkdf2,Chacha20,encrypt,decrypt};

// export for tests running on Node

if(typeof module!=='undefined'&&module.hasOwnProperty('exports')){

	module.exports.util=util;

	module.exports.blake2s=blake2s;