/src/php/strings/md5.js

module.exports = function md5 (str) {
  //  discuss at: http://locutus.io/php/md5/
  // original by: Webtoolkit.info (http://www.webtoolkit.info/)
  // improved by: Michael White (http://getsprink.com)
  // improved by: Jack
  // improved by: Kevin van Zonneveld (http://kvz.io)
  //    input by: Brett Zamir (http://brett-zamir.me)
  // bugfixed by: Kevin van Zonneveld (http://kvz.io)
  //      note 1: Keep in mind that in accordance with PHP, the whole string is buffered and then
  //      note 1: hashed. If available, we'd recommend using Node's native crypto modules directly
  //      note 1: in a steaming fashion for faster and more efficient hashing
  //   example 1: md5('Kevin van Zonneveld')
  //   returns 1: '6e658d4bfcb59cc13f96c14450ac40b9'

  var hash
  try {
    var crypto = require('crypto')
    var md5sum = crypto.createHash('md5')
    md5sum.update(str)
    hash = md5sum.digest('hex')
  } catch (e) {
    hash = undefined
  }

  if (hash !== undefined) {
    return hash
  }

  var utf8Encode = require('../xml/utf8_encode')
  var xl

  var _rotateLeft = function (lValue, iShiftBits) {
    return (lValue << iShiftBits) | (lValue >>> (32 - iShiftBits))
  }

  var _addUnsigned = function (lX, lY) {
    var lX4, lY4, lX8, lY8, lResult
    lX8 = (lX & 0x80000000)
    lY8 = (lY & 0x80000000)
    lX4 = (lX & 0x40000000)
    lY4 = (lY & 0x40000000)
    lResult = (lX & 0x3FFFFFFF) + (lY & 0x3FFFFFFF)
    if (lX4 & lY4) {
      return (lResult ^ 0x80000000 ^ lX8 ^ lY8)
    }
    if (lX4 | lY4) {
      if (lResult & 0x40000000) {
        return (lResult ^ 0xC0000000 ^ lX8 ^ lY8)
      } else {
        return (lResult ^ 0x40000000 ^ lX8 ^ lY8)
      }
    } else {
      return (lResult ^ lX8 ^ lY8)
    }
  }

  var _F = function (x, y, z) {
    return (x & y) | ((~x) & z)
  }
  var _G = function (x, y, z) {
    return (x & z) | (y & (~z))
  }
  var _H = function (x, y, z) {
    return (x ^ y ^ z)
  }
  var _I = function (x, y, z) {
    return (y ^ (x | (~z)))
  }

  var _FF = function (a, b, c, d, x, s, ac) {
    a = _addUnsigned(a, _addUnsigned(_addUnsigned(_F(b, c, d), x), ac))
    return _addUnsigned(_rotateLeft(a, s), b)
  }

  var _GG = function (a, b, c, d, x, s, ac) {
    a = _addUnsigned(a, _addUnsigned(_addUnsigned(_G(b, c, d), x), ac))
    return _addUnsigned(_rotateLeft(a, s), b)
  }

  var _HH = function (a, b, c, d, x, s, ac) {
    a = _addUnsigned(a, _addUnsigned(_addUnsigned(_H(b, c, d), x), ac))
    return _addUnsigned(_rotateLeft(a, s), b)
  }

  var _II = function (a, b, c, d, x, s, ac) {
    a = _addUnsigned(a, _addUnsigned(_addUnsigned(_I(b, c, d), x), ac))
    return _addUnsigned(_rotateLeft(a, s), b)
  }

  var _convertToWordArray = function (str) {
    var lWordCount
    var lMessageLength = str.length
    var lNumberOfWordsTemp1 = lMessageLength + 8
    var lNumberOfWordsTemp2 = (lNumberOfWordsTemp1 - (lNumberOfWordsTemp1 % 64)) / 64
    var lNumberOfWords = (lNumberOfWordsTemp2 + 1) * 16
    var lWordArray = new Array(lNumberOfWords - 1)
    var lBytePosition = 0
    var lByteCount = 0
    while (lByteCount < lMessageLength) {
      lWordCount = (lByteCount - (lByteCount % 4)) / 4
      lBytePosition = (lByteCount % 4) * 8
      lWordArray[lWordCount] = (lWordArray[lWordCount] |
        (str.charCodeAt(lByteCount) << lBytePosition))
      lByteCount++
    }
    lWordCount = (lByteCount - (lByteCount % 4)) / 4
    lBytePosition = (lByteCount % 4) * 8
    lWordArray[lWordCount] = lWordArray[lWordCount] | (0x80 << lBytePosition)
    lWordArray[lNumberOfWords - 2] = lMessageLength << 3
    lWordArray[lNumberOfWords - 1] = lMessageLength >>> 29
    return lWordArray
  }

  var _wordToHex = function (lValue) {
    var wordToHexValue = ''
    var wordToHexValueTemp = ''
    var lByte
    var lCount

    for (lCount = 0; lCount <= 3; lCount++) {
      lByte = (lValue >>> (lCount * 8)) & 255
      wordToHexValueTemp = '0' + lByte.toString(16)
      wordToHexValue = wordToHexValue + wordToHexValueTemp.substr(wordToHexValueTemp.length - 2, 2)
    }
    return wordToHexValue
  }

  var x = []
  var k
  var AA
  var BB
  var CC
  var DD
  var a
  var b
  var c
  var d
  var S11 = 7
  var S12 = 12
  var S13 = 17
  var S14 = 22
  var S21 = 5
  var S22 = 9
  var S23 = 14
  var S24 = 20
  var S31 = 4
  var S32 = 11
  var S33 = 16
  var S34 = 23
  var S41 = 6
  var S42 = 10
  var S43 = 15
  var S44 = 21

  str = utf8Encode(str)
  x = _convertToWordArray(str)
  a = 0x67452301
  b = 0xEFCDAB89
  c = 0x98BADCFE
  d = 0x10325476

  xl = x.length
  for (k = 0; k < xl; k += 16) {
    AA = a
    BB = b
    CC = c
    DD = d
    a = _FF(a, b, c, d, x[k + 0], S11, 0xD76AA478)
    d = _FF(d, a, b, c, x[k + 1], S12, 0xE8C7B756)
    c = _FF(c, d, a, b, x[k + 2], S13, 0x242070DB)
    b = _FF(b, c, d, a, x[k + 3], S14, 0xC1BDCEEE)
    a = _FF(a, b, c, d, x[k + 4], S11, 0xF57C0FAF)
    d = _FF(d, a, b, c, x[k + 5], S12, 0x4787C62A)
    c = _FF(c, d, a, b, x[k + 6], S13, 0xA8304613)
    b = _FF(b, c, d, a, x[k + 7], S14, 0xFD469501)
    a = _FF(a, b, c, d, x[k + 8], S11, 0x698098D8)
    d = _FF(d, a, b, c, x[k + 9], S12, 0x8B44F7AF)
    c = _FF(c, d, a, b, x[k + 10], S13, 0xFFFF5BB1)
    b = _FF(b, c, d, a, x[k + 11], S14, 0x895CD7BE)
    a = _FF(a, b, c, d, x[k + 12], S11, 0x6B901122)
    d = _FF(d, a, b, c, x[k + 13], S12, 0xFD987193)
    c = _FF(c, d, a, b, x[k + 14], S13, 0xA679438E)
    b = _FF(b, c, d, a, x[k + 15], S14, 0x49B40821)
    a = _GG(a, b, c, d, x[k + 1], S21, 0xF61E2562)
    d = _GG(d, a, b, c, x[k + 6], S22, 0xC040B340)
    c = _GG(c, d, a, b, x[k + 11], S23, 0x265E5A51)
    b = _GG(b, c, d, a, x[k + 0], S24, 0xE9B6C7AA)
    a = _GG(a, b, c, d, x[k + 5], S21, 0xD62F105D)
    d = _GG(d, a, b, c, x[k + 10], S22, 0x2441453)
    c = _GG(c, d, a, b, x[k + 15], S23, 0xD8A1E681)
    b = _GG(b, c, d, a, x[k + 4], S24, 0xE7D3FBC8)
    a = _GG(a, b, c, d, x[k + 9], S21, 0x21E1CDE6)
    d = _GG(d, a, b, c, x[k + 14], S22, 0xC33707D6)
    c = _GG(c, d, a, b, x[k + 3], S23, 0xF4D50D87)
    b = _GG(b, c, d, a, x[k + 8], S24, 0x455A14ED)
    a = _GG(a, b, c, d, x[k + 13], S21, 0xA9E3E905)
    d = _GG(d, a, b, c, x[k + 2], S22, 0xFCEFA3F8)
    c = _GG(c, d, a, b, x[k + 7], S23, 0x676F02D9)
    b = _GG(b, c, d, a, x[k + 12], S24, 0x8D2A4C8A)
    a = _HH(a, b, c, d, x[k + 5], S31, 0xFFFA3942)
    d = _HH(d, a, b, c, x[k + 8], S32, 0x8771F681)
    c = _HH(c, d, a, b, x[k + 11], S33, 0x6D9D6122)
    b = _HH(b, c, d, a, x[k + 14], S34, 0xFDE5380C)
    a = _HH(a, b, c, d, x[k + 1], S31, 0xA4BEEA44)
    d = _HH(d, a, b, c, x[k + 4], S32, 0x4BDECFA9)
    c = _HH(c, d, a, b, x[k + 7], S33, 0xF6BB4B60)
    b = _HH(b, c, d, a, x[k + 10], S34, 0xBEBFBC70)
    a = _HH(a, b, c, d, x[k + 13], S31, 0x289B7EC6)
    d = _HH(d, a, b, c, x[k + 0], S32, 0xEAA127FA)
    c = _HH(c, d, a, b, x[k + 3], S33, 0xD4EF3085)
    b = _HH(b, c, d, a, x[k + 6], S34, 0x4881D05)
    a = _HH(a, b, c, d, x[k + 9], S31, 0xD9D4D039)
    d = _HH(d, a, b, c, x[k + 12], S32, 0xE6DB99E5)
    c = _HH(c, d, a, b, x[k + 15], S33, 0x1FA27CF8)
    b = _HH(b, c, d, a, x[k + 2], S34, 0xC4AC5665)
    a = _II(a, b, c, d, x[k + 0], S41, 0xF4292244)
    d = _II(d, a, b, c, x[k + 7], S42, 0x432AFF97)
    c = _II(c, d, a, b, x[k + 14], S43, 0xAB9423A7)
    b = _II(b, c, d, a, x[k + 5], S44, 0xFC93A039)
    a = _II(a, b, c, d, x[k + 12], S41, 0x655B59C3)
    d = _II(d, a, b, c, x[k + 3], S42, 0x8F0CCC92)
    c = _II(c, d, a, b, x[k + 10], S43, 0xFFEFF47D)
    b = _II(b, c, d, a, x[k + 1], S44, 0x85845DD1)
    a = _II(a, b, c, d, x[k + 8], S41, 0x6FA87E4F)
    d = _II(d, a, b, c, x[k + 15], S42, 0xFE2CE6E0)
    c = _II(c, d, a, b, x[k + 6], S43, 0xA3014314)
    b = _II(b, c, d, a, x[k + 13], S44, 0x4E0811A1)
    a = _II(a, b, c, d, x[k + 4], S41, 0xF7537E82)
    d = _II(d, a, b, c, x[k + 11], S42, 0xBD3AF235)
    c = _II(c, d, a, b, x[k + 2], S43, 0x2AD7D2BB)
    b = _II(b, c, d, a, x[k + 9], S44, 0xEB86D391)
    a = _addUnsigned(a, AA)
    b = _addUnsigned(b, BB)
    c = _addUnsigned(c, CC)
    d = _addUnsigned(d, DD)
  }

  var temp = _wordToHex(a) + _wordToHex(b) + _wordToHex(c) + _wordToHex(d)

  return temp.toLowerCase()
}