overleaf/services/web/frontend/js/shared/utils/md5.js

/**
 * Inspired by https://stackoverflow.com/a/60467595/237917
 * A JavaScript implementation of the RSA Data Security, Inc. MD5 Message
 * Digest Algorithm, as defined in RFC 1321.
 * Version 2.2 Copyright (C) Paul Johnston 1999 - 2009
 * Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
 * Distributed under the BSD License
 * See http://pajhome.org.uk/crypt/md5 for more info.
 */

export function generateMD5Hash(inputString) {
  const hc = '0123456789abcdef'
  function rh(n) {
    let j
    let s = ''
    for (j = 0; j <= 3; j++)
      s +=
        hc.charAt((n >> (j * 8 + 4)) & 0x0f) + hc.charAt((n >> (j * 8)) & 0x0f)
    return s
  }
  function ad(x, y) {
    const l = (x & 0xffff) + (y & 0xffff)
    const m = (x >> 16) + (y >> 16) + (l >> 16)
    return (m << 16) | (l & 0xffff)
  }
  function rl(n, c) {
    return (n << c) | (n >>> (32 - c))
  }
  function cm(q, a, b, x, s, t) {
    return ad(rl(ad(ad(a, q), ad(x, t)), s), b)
  }
  function ff(a, b, c, d, x, s, t) {
    return cm((b & c) | (~b & d), a, b, x, s, t)
  }
  function gg(a, b, c, d, x, s, t) {
    return cm((b & d) | (c & ~d), a, b, x, s, t)
  }
  function hh(a, b, c, d, x, s, t) {
    return cm(b ^ c ^ d, a, b, x, s, t)
  }
  function ii(a, b, c, d, x, s, t) {
    return cm(c ^ (b | ~d), a, b, x, s, t)
  }
  function sb(x) {
    let i
    const nblk = ((x.length + 8) >> 6) + 1
    const blks = new Array(nblk * 16)
    for (i = 0; i < nblk * 16; i++) blks[i] = 0
    for (i = 0; i < x.length; i++)
      blks[i >> 2] |= x.charCodeAt(i) << ((i % 4) * 8)
    blks[i >> 2] |= 0x80 << ((i % 4) * 8)
    blks[nblk * 16 - 2] = x.length * 8
    return blks
  }
  let i
  const x = sb('' + inputString)
  let a = 1732584193
  let b = -271733879
  let c = -1732584194
  let d = 271733878
  let olda
  let oldb
  let oldc
  let oldd
  for (i = 0; i < x.length; i += 16) {
    olda = a
    oldb = b
    oldc = c
    oldd = d
    a = ff(a, b, c, d, x[i + 0], 7, -680876936)
    d = ff(d, a, b, c, x[i + 1], 12, -389564586)
    c = ff(c, d, a, b, x[i + 2], 17, 606105819)
    b = ff(b, c, d, a, x[i + 3], 22, -1044525330)
    a = ff(a, b, c, d, x[i + 4], 7, -176418897)
    d = ff(d, a, b, c, x[i + 5], 12, 1200080426)
    c = ff(c, d, a, b, x[i + 6], 17, -1473231341)
    b = ff(b, c, d, a, x[i + 7], 22, -45705983)
    a = ff(a, b, c, d, x[i + 8], 7, 1770035416)
    d = ff(d, a, b, c, x[i + 9], 12, -1958414417)
    c = ff(c, d, a, b, x[i + 10], 17, -42063)
    b = ff(b, c, d, a, x[i + 11], 22, -1990404162)
    a = ff(a, b, c, d, x[i + 12], 7, 1804603682)
    d = ff(d, a, b, c, x[i + 13], 12, -40341101)
    c = ff(c, d, a, b, x[i + 14], 17, -1502002290)
    b = ff(b, c, d, a, x[i + 15], 22, 1236535329)
    a = gg(a, b, c, d, x[i + 1], 5, -165796510)
    d = gg(d, a, b, c, x[i + 6], 9, -1069501632)
    c = gg(c, d, a, b, x[i + 11], 14, 643717713)
    b = gg(b, c, d, a, x[i + 0], 20, -373897302)
    a = gg(a, b, c, d, x[i + 5], 5, -701558691)
    d = gg(d, a, b, c, x[i + 10], 9, 38016083)
    c = gg(c, d, a, b, x[i + 15], 14, -660478335)
    b = gg(b, c, d, a, x[i + 4], 20, -405537848)
    a = gg(a, b, c, d, x[i + 9], 5, 568446438)
    d = gg(d, a, b, c, x[i + 14], 9, -1019803690)
    c = gg(c, d, a, b, x[i + 3], 14, -187363961)
    b = gg(b, c, d, a, x[i + 8], 20, 1163531501)
    a = gg(a, b, c, d, x[i + 13], 5, -1444681467)
    d = gg(d, a, b, c, x[i + 2], 9, -51403784)
    c = gg(c, d, a, b, x[i + 7], 14, 1735328473)
    b = gg(b, c, d, a, x[i + 12], 20, -1926607734)
    a = hh(a, b, c, d, x[i + 5], 4, -378558)
    d = hh(d, a, b, c, x[i + 8], 11, -2022574463)
    c = hh(c, d, a, b, x[i + 11], 16, 1839030562)
    b = hh(b, c, d, a, x[i + 14], 23, -35309556)
    a = hh(a, b, c, d, x[i + 1], 4, -1530992060)
    d = hh(d, a, b, c, x[i + 4], 11, 1272893353)
    c = hh(c, d, a, b, x[i + 7], 16, -155497632)
    b = hh(b, c, d, a, x[i + 10], 23, -1094730640)
    a = hh(a, b, c, d, x[i + 13], 4, 681279174)
    d = hh(d, a, b, c, x[i + 0], 11, -358537222)
    c = hh(c, d, a, b, x[i + 3], 16, -722521979)
    b = hh(b, c, d, a, x[i + 6], 23, 76029189)
    a = hh(a, b, c, d, x[i + 9], 4, -640364487)
    d = hh(d, a, b, c, x[i + 12], 11, -421815835)
    c = hh(c, d, a, b, x[i + 15], 16, 530742520)
    b = hh(b, c, d, a, x[i + 2], 23, -995338651)
    a = ii(a, b, c, d, x[i + 0], 6, -198630844)
    d = ii(d, a, b, c, x[i + 7], 10, 1126891415)
    c = ii(c, d, a, b, x[i + 14], 15, -1416354905)
    b = ii(b, c, d, a, x[i + 5], 21, -57434055)
    a = ii(a, b, c, d, x[i + 12], 6, 1700485571)
    d = ii(d, a, b, c, x[i + 3], 10, -1894986606)
    c = ii(c, d, a, b, x[i + 10], 15, -1051523)
    b = ii(b, c, d, a, x[i + 1], 21, -2054922799)
    a = ii(a, b, c, d, x[i + 8], 6, 1873313359)
    d = ii(d, a, b, c, x[i + 15], 10, -30611744)
    c = ii(c, d, a, b, x[i + 6], 15, -1560198380)
    b = ii(b, c, d, a, x[i + 13], 21, 1309151649)
    a = ii(a, b, c, d, x[i + 4], 6, -145523070)
    d = ii(d, a, b, c, x[i + 11], 10, -1120210379)
    c = ii(c, d, a, b, x[i + 2], 15, 718787259)
    b = ii(b, c, d, a, x[i + 9], 21, -343485551)
    a = ad(a, olda)
    b = ad(b, oldb)
    c = ad(c, oldc)
    d = ad(d, oldd)
  }
  return rh(a) + rh(b) + rh(c) + rh(d)
}