msf/chacha20-roundtrip.html

## chacha20-roundtrip.html
<!DOCTYPE html>
<html>
<body>

<h2>My Heading</h2>

<p>Play around with the code and click on the "Run" button to view the result.</p>

<p id="demo"></p>

<script>

/* chacha20 - 256 bits */

// Written in 2014 by Devi Mandiri. Public domain.
//
// Implementation derived from chacha-ref.c version 20080118
// See for details: http://cr.yp.to/chacha/chacha-20080128.pdf

function U8TO32_LE(x, i) {
  return x[i] | (x[i+1]<<8) | (x[i+2]<<16) | (x[i+3]<<24);
}

function U32TO8_LE(x, i, u) {
  x[i]   = u; u >>>= 8;
  x[i+1] = u; u >>>= 8;
  x[i+2] = u; u >>>= 8;
  x[i+3] = u;
}

function ROTATE(v, c) {
  return (v << c) | (v >>> (32 - c));
}

var Chacha20 = function(key, nonce, counter) {
  this.input = new Uint32Array(16);

  // https://tools.ietf.org/html/draft-irtf-cfrg-chacha20-poly1305-01#section-2.3
  this.input[0] = 1634760805;
  this.input[1] =  857760878;
  this.input[2] = 2036477234;
  this.input[3] = 1797285236;
  this.input[4] = U8TO32_LE(key, 0);
  this.input[5] = U8TO32_LE(key, 4);
  this.input[6] = U8TO32_LE(key, 8);
  this.input[7] = U8TO32_LE(key, 12);
  this.input[8] = U8TO32_LE(key, 16);
  this.input[9] = U8TO32_LE(key, 20);
  this.input[10] = U8TO32_LE(key, 24);
  this.input[11] = U8TO32_LE(key, 28);
  this.input[12] = counter;
  this.input[13] = U8TO32_LE(nonce, 0);
  this.input[14] = U8TO32_LE(nonce, 4);
  this.input[15] = U8TO32_LE(nonce, 8);
};

Chacha20.prototype.quarterRound = function(x, a, b, c, d) {
  x[a] += x[b]; x[d] = ROTATE(x[d] ^ x[a], 16);
  x[c] += x[d]; x[b] = ROTATE(x[b] ^ x[c], 12);
  x[a] += x[b]; x[d] = ROTATE(x[d] ^ x[a],  8);
  x[c] += x[d]; x[b] = ROTATE(x[b] ^ x[c],  7);
};

Chacha20.prototype.encrypt = function(dst, src, len) {
  var x = new Uint32Array(16);
  var output = new Uint8Array(64);
  var i, dpos = 0, spos = 0;

  while (len > 0 ) {
    for (i = 16; i--;) x[i] = this.input[i];
    for (i = 20; i > 0; i -= 2) {
      this.quarterRound(x, 0, 4, 8,12);
      this.quarterRound(x, 1, 5, 9,13);
      this.quarterRound(x, 2, 6,10,14);
      this.quarterRound(x, 3, 7,11,15);
      this.quarterRound(x, 0, 5,10,15);
      this.quarterRound(x, 1, 6,11,12);
      this.quarterRound(x, 2, 7, 8,13);
      this.quarterRound(x, 3, 4, 9,14);
    }
    for (i = 16; i--;) x[i] += this.input[i];
    for (i = 16; i--;) U32TO8_LE(output, 4*i, x[i]);

    this.input[12] += 1;
    if (!this.input[12]) {
      this.input[13] += 1;
    }
    if (len <= 64) {
      for (i = len; i--;) {
        dst[i+dpos] = src[i+spos] ^ output[i];
      }
      return;
    }
    for (i = 64; i--;) {
      dst[i+dpos] = src[i+spos] ^ output[i];
    }
    len -= 64;
    spos += 64;
    dpos += 64;
  }
};

Chacha20.prototype.keystream = function(dst, len) {
  for (var i = 0; i < len; ++i) dst[i] = 0;
  this.encrypt(dst, dst, len);
};

function fromHex(h) {
  h = h.replace(/([^0-9a-f])/g, '');
  var out = [], len = h.length, w = '';
  for (var i = 0; i < len; i += 2) {
    w = h[i];
    if (((i+1) >= len) || typeof h[i+1] === 'undefined') {
        w += '0';
    } else {
        w += h[i+1];
    }
    out.push(parseInt(w, 16));
  }
  return out;
}

const textEncoder = new TextEncode

const textEncoder = new TextEncoder();
const textDecoder = new TextDecoder();

let text = "testing encryption!!";


const key =fromHex('1c 92 40 a5 eb 55 d3 f3 33 88 86 04 f6 b5 f0 47 39 17 c1 40 2b 80 09 9d ca 5c bc 20 70 75 c0');
const nonce = fromHex('00 00 00 00 01 02 03 04 05 06 07 08');


function msf_encrypt(key, nonce, text) {
  var plaintext = textEncoder.encode(text);
  var plen = plaintext.length,
      buf = new Uint8Array(plen),
      ciphertext = new Uint8Array(plen),
      ctx = new Chacha20(key, nonce, 0);


  ctx.keystream(buf, plen);

  for (var i = 0; i < plen; i++) {
    ciphertext[i] = buf[i] ^ plaintext[i];
  }

  return ciphertext;
}

function msf_decrypt(key, nonce, ciphertext) {
  var plen = ciphertext.length,
      buf = new Uint8Array(plen),
      plaintext = new Uint8Array(plen),
      ctx = new Chacha20(key, nonce, 0);

  ctx.keystream(buf, plen);

  for (var i = 0; i < plen; i++) {
    plaintext[i] = buf[i] ^ ciphertext[i];
  }
  return textDecoder.decode(plaintext);
}

function roundtrip(text) {
var out = msf_encrypt(key, nonce, text);
var cleartext = msf_decrypt(key, nonce, out);

  return cleartext;
}
let x = 5;
let y = 6;
let z = roundtrip(text);
let a = roundtrip("o");

document.getElementById("demo").innerHTML = text +  " roundtrip: "+ roundtrip(text) + " The value of z is: " +a;

</script>

</body>
</html>
	<!DOCTYPE html>
	<html>
	<body>

	<h2>My Heading</h2>

	<p>Play around with the code and click on the "Run" button to view the result.</p>

	<p id="demo"></p>

	<script>

	/* chacha20 - 256 bits */

	// Written in 2014 by Devi Mandiri. Public domain.
	//
	// Implementation derived from chacha-ref.c version 20080118
	// See for details: http://cr.yp.to/chacha/chacha-20080128.pdf

	function U8TO32_LE(x, i) {
	return x[i] \| (x[i+1]<<8) \| (x[i+2]<<16) \| (x[i+3]<<24);
	}

	function U32TO8_LE(x, i, u) {
	x[i] = u; u >>>= 8;
	x[i+1] = u; u >>>= 8;
	x[i+2] = u; u >>>= 8;
	x[i+3] = u;
	}

	function ROTATE(v, c) {
	return (v << c) \| (v >>> (32 - c));
	}

	var Chacha20 = function(key, nonce, counter) {
	this.input = new Uint32Array(16);

	// https://tools.ietf.org/html/draft-irtf-cfrg-chacha20-poly1305-01#section-2.3
	this.input[0] = 1634760805;
	this.input[1] = 857760878;
	this.input[2] = 2036477234;
	this.input[3] = 1797285236;
	this.input[4] = U8TO32_LE(key, 0);
	this.input[5] = U8TO32_LE(key, 4);
	this.input[6] = U8TO32_LE(key, 8);
	this.input[7] = U8TO32_LE(key, 12);
	this.input[8] = U8TO32_LE(key, 16);
	this.input[9] = U8TO32_LE(key, 20);
	this.input[10] = U8TO32_LE(key, 24);
	this.input[11] = U8TO32_LE(key, 28);
	this.input[12] = counter;
	this.input[13] = U8TO32_LE(nonce, 0);
	this.input[14] = U8TO32_LE(nonce, 4);
	this.input[15] = U8TO32_LE(nonce, 8);
	};

	Chacha20.prototype.quarterRound = function(x, a, b, c, d) {
	x[a] += x[b]; x[d] = ROTATE(x[d] ^ x[a], 16);
	x[c] += x[d]; x[b] = ROTATE(x[b] ^ x[c], 12);
	x[a] += x[b]; x[d] = ROTATE(x[d] ^ x[a], 8);
	x[c] += x[d]; x[b] = ROTATE(x[b] ^ x[c], 7);
	};

	Chacha20.prototype.encrypt = function(dst, src, len) {
	var x = new Uint32Array(16);
	var output = new Uint8Array(64);
	var i, dpos = 0, spos = 0;

	while (len > 0 ) {
	for (i = 16; i--;) x[i] = this.input[i];
	for (i = 20; i > 0; i -= 2) {
	this.quarterRound(x, 0, 4, 8,12);
	this.quarterRound(x, 1, 5, 9,13);
	this.quarterRound(x, 2, 6,10,14);
	this.quarterRound(x, 3, 7,11,15);
	this.quarterRound(x, 0, 5,10,15);
	this.quarterRound(x, 1, 6,11,12);
	this.quarterRound(x, 2, 7, 8,13);
	this.quarterRound(x, 3, 4, 9,14);
	}
	for (i = 16; i--;) x[i] += this.input[i];
	for (i = 16; i--;) U32TO8_LE(output, 4*i, x[i]);

	this.input[12] += 1;
	if (!this.input[12]) {
	this.input[13] += 1;
	}
	if (len <= 64) {
	for (i = len; i--;) {
	dst[i+dpos] = src[i+spos] ^ output[i];
	}
	return;
	}
	for (i = 64; i--;) {
	dst[i+dpos] = src[i+spos] ^ output[i];
	}
	len -= 64;
	spos += 64;
	dpos += 64;
	}
	};

	Chacha20.prototype.keystream = function(dst, len) {
	for (var i = 0; i < len; ++i) dst[i] = 0;
	this.encrypt(dst, dst, len);
	};

	function fromHex(h) {
	h = h.replace(/([^0-9a-f])/g, '');
	var out = [], len = h.length, w = '';
	for (var i = 0; i < len; i += 2) {
	w = h[i];
	if (((i+1) >= len) \|\| typeof h[i+1] === 'undefined') {
	w += '0';
	} else {
	w += h[i+1];
	}
	out.push(parseInt(w, 16));
	}
	return out;
	}

	const textEncoder = new TextEncode

	const textEncoder = new TextEncoder();
	const textDecoder = new TextDecoder();

	let text = "testing encryption!!";


	const key =fromHex('1c 92 40 a5 eb 55 d3 f3 33 88 86 04 f6 b5 f0 47 39 17 c1 40 2b 80 09 9d ca 5c bc 20 70 75 c0');
	const nonce = fromHex('00 00 00 00 01 02 03 04 05 06 07 08');


	function msf_encrypt(key, nonce, text) {
	var plaintext = textEncoder.encode(text);
	var plen = plaintext.length,
	buf = new Uint8Array(plen),
	ciphertext = new Uint8Array(plen),
	ctx = new Chacha20(key, nonce, 0);


	ctx.keystream(buf, plen);

	for (var i = 0; i < plen; i++) {
	ciphertext[i] = buf[i] ^ plaintext[i];
	}

	return ciphertext;
	}

	function msf_decrypt(key, nonce, ciphertext) {
	var plen = ciphertext.length,
	buf = new Uint8Array(plen),
	plaintext = new Uint8Array(plen),
	ctx = new Chacha20(key, nonce, 0);

	ctx.keystream(buf, plen);

	for (var i = 0; i < plen; i++) {
	plaintext[i] = buf[i] ^ ciphertext[i];
	}
	return textDecoder.decode(plaintext);
	}

	function roundtrip(text) {
	var out = msf_encrypt(key, nonce, text);
	var cleartext = msf_decrypt(key, nonce, out);

	return cleartext;
	}
	let x = 5;
	let y = 6;
	let z = roundtrip(text);
	let a = roundtrip("o");

	document.getElementById("demo").innerHTML = text + " roundtrip: "+ roundtrip(text) + " The value of z is: " +a;

	</script>

	</body>
	</html>