// Copyright 2019 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

/*
 * A JavaScript implementation of the RSA Data Security, Inc. MD5 Message
 * Digest Algorithm, as defined in RFC 1321.
 * Version 2.1 Copyright (C) Paul Johnston 1999 - 2002.
 * Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
 * Distributed under the BSD License
 * See http://pajhome.org.uk/crypt/md5 for more info.
 */
function md5(s) {
  return binl2hex(core_md5(str2binl(s), s.length * 8));
}

function core_md5(x, len) {
  /* append padding */
  x[len >> 5] |= 0x80 << ((len) % 32);
  x[(((len + 64) >>> 9) << 4) + 14] = len;

  var a = 1732584193;
  var b = -271733879;
  var c = -1732584194;
  var d = 271733878;

  for (var i = 0; i < x.length; i += 16) {
    var olda = a;
    var oldb = b;
    var oldc = c;
    var oldd = d;

    a = md5_ff(a, b, c, d, x[i + 0], 7, -680876936);
    d = md5_ff(d, a, b, c, x[i + 1], 12, -389564586);
    c = md5_ff(c, d, a, b, x[i + 2], 17, 606105819);
    b = md5_ff(b, c, d, a, x[i + 3], 22, -1044525330);
    a = md5_ff(a, b, c, d, x[i + 4], 7, -176418897);
    d = md5_ff(d, a, b, c, x[i + 5], 12, 1200080426);
    c = md5_ff(c, d, a, b, x[i + 6], 17, -1473231341);
    b = md5_ff(b, c, d, a, x[i + 7], 22, -45705983);
    a = md5_ff(a, b, c, d, x[i + 8], 7, 1770035416);
    d = md5_ff(d, a, b, c, x[i + 9], 12, -1958414417);
    c = md5_ff(c, d, a, b, x[i + 10], 17, -42063);
    b = md5_ff(b, c, d, a, x[i + 11], 22, -1990404162);
    a = md5_ff(a, b, c, d, x[i + 12], 7, 1804603682);
    d = md5_ff(d, a, b, c, x[i + 13], 12, -40341101);
    c = md5_ff(c, d, a, b, x[i + 14], 17, -1502002290);
    b = md5_ff(b, c, d, a, x[i + 15], 22, 1236535329);

    a = md5_gg(a, b, c, d, x[i + 1], 5, -165796510);
    d = md5_gg(d, a, b, c, x[i + 6], 9, -1069501632);
    c = md5_gg(c, d, a, b, x[i + 11], 14, 643717713);
    b = md5_gg(b, c, d, a, x[i + 0], 20, -373897302);
    a = md5_gg(a, b, c, d, x[i + 5], 5, -701558691);
    d = md5_gg(d, a, b, c, x[i + 10], 9, 38016083);
    c = md5_gg(c, d, a, b, x[i + 15], 14, -660478335);
    b = md5_gg(b, c, d, a, x[i + 4], 20, -405537848);
    a = md5_gg(a, b, c, d, x[i + 9], 5, 568446438);
    d = md5_gg(d, a, b, c, x[i + 14], 9, -1019803690);
    c = md5_gg(c, d, a, b, x[i + 3], 14, -187363961);
    b = md5_gg(b, c, d, a, x[i + 8], 20, 1163531501);
    a = md5_gg(a, b, c, d, x[i + 13], 5, -1444681467);
    d = md5_gg(d, a, b, c, x[i + 2], 9, -51403784);
    c = md5_gg(c, d, a, b, x[i + 7], 14, 1735328473);
    b = md5_gg(b, c, d, a, x[i + 12], 20, -1926607734);

    a = md5_hh(a, b, c, d, x[i + 5], 4, -378558);
    d = md5_hh(d, a, b, c, x[i + 8], 11, -2022574463);
    c = md5_hh(c, d, a, b, x[i + 11], 16, 1839030562);
    b = md5_hh(b, c, d, a, x[i + 14], 23, -35309556);
    a = md5_hh(a, b, c, d, x[i + 1], 4, -1530992060);
    d = md5_hh(d, a, b, c, x[i + 4], 11, 1272893353);
    c = md5_hh(c, d, a, b, x[i + 7], 16, -155497632);
    b = md5_hh(b, c, d, a, x[i + 10], 23, -1094730640);
    a = md5_hh(a, b, c, d, x[i + 13], 4, 681279174);
    d = md5_hh(d, a, b, c, x[i + 0], 11, -358537222);
    c = md5_hh(c, d, a, b, x[i + 3], 16, -722521979);
    b = md5_hh(b, c, d, a, x[i + 6], 23, 76029189);
    a = md5_hh(a, b, c, d, x[i + 9], 4, -640364487);
    d = md5_hh(d, a, b, c, x[i + 12], 11, -421815835);
    c = md5_hh(c, d, a, b, x[i + 15], 16, 530742520);
    b = md5_hh(b, c, d, a, x[i + 2], 23, -995338651);

    a = md5_ii(a, b, c, d, x[i + 0], 6, -198630844);
    d = md5_ii(d, a, b, c, x[i + 7], 10, 1126891415);
    c = md5_ii(c, d, a, b, x[i + 14], 15, -1416354905);
    b = md5_ii(b, c, d, a, x[i + 5], 21, -57434055);
    a = md5_ii(a, b, c, d, x[i + 12], 6, 1700485571);
    d = md5_ii(d, a, b, c, x[i + 3], 10, -1894986606);
    c = md5_ii(c, d, a, b, x[i + 10], 15, -1051523);
    b = md5_ii(b, c, d, a, x[i + 1], 21, -2054922799);
    a = md5_ii(a, b, c, d, x[i + 8], 6, 1873313359);
    d = md5_ii(d, a, b, c, x[i + 15], 10, -30611744);
    c = md5_ii(c, d, a, b, x[i + 6], 15, -1560198380);
    b = md5_ii(b, c, d, a, x[i + 13], 21, 1309151649);
    a = md5_ii(a, b, c, d, x[i + 4], 6, -145523070);
    d = md5_ii(d, a, b, c, x[i + 11], 10, -1120210379);
    c = md5_ii(c, d, a, b, x[i + 2], 15, 718787259);
    b = md5_ii(b, c, d, a, x[i + 9], 21, -343485551);

    a = safe_add(a, olda);
    b = safe_add(b, oldb);
    c = safe_add(c, oldc);
    d = safe_add(d, oldd);
  }
  return Array(a, b, c, d);
}

function md5_cmn(q, a, b, x, s, t) {
  return safe_add(bit_rol(safe_add(safe_add(a, q), safe_add(x, t)), s), b);
}

function md5_ff(a, b, c, d, x, s, t) {
  return md5_cmn((b & c) | ((~b) & d), a, b, x, s, t);
}

function md5_gg(a, b, c, d, x, s, t) {
  return md5_cmn((b & d) | (c & (~d)), a, b, x, s, t);
}

function md5_hh(a, b, c, d, x, s, t) {
  return md5_cmn(b ^ c ^ d, a, b, x, s, t);
}

function md5_ii(a, b, c, d, x, s, t) {
  return md5_cmn(c ^ (b | (~d)), a, b, x, s, t);
}

function safe_add(x, y) {
  var lsw = (x & 0xFFFF) + (y & 0xFFFF);
  var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
  return (msw << 16) | (lsw & 0xFFFF);
}

function bit_rol(num, cnt) {
  return (num << cnt) | (num >>> (32 - cnt));
}

function str2binl(str) {
  var bin = Array();
  var mask = (1 << 8) - 1;
  for (var i = 0; i < str.length * 8; i += 8)
    bin[i >> 5] |= (str.charCodeAt(i / 8) & mask) << (i % 32);
  return bin;
}

function binl2hex(binarray) {
  var hex_tab = '0123456789abcdef';
  var str = '';
  for (var i = 0; i < binarray.length * 4; i++) {
    str += hex_tab.charAt((binarray[i >> 2] >> ((i % 4) * 8 + 4)) & 0xF) +
        hex_tab.charAt((binarray[i >> 2] >> ((i % 4) * 8)) & 0xF);
  }
  return str;
}

module.exports = md5;