Browser and device fingerprinting - a MD5 checksum generator to identify a device-browser-combination

md5_device_fingerprint.js

(function(window, document, JSON){
  "use strict";
  var SEP = '|', ua, opera, ie;
  /* 
   * Collect Browser & Device Data
   */
  var Collector = {
    /*
     * MD5 Checksum calculation
     */
    stringToMD5 : function (s) {/*get a MD5Hash out of a string provided*/ var hexcase = 0, chrsz = 8, cmc5 = function (x, e) {x[e >> 5] |= 0x80 << ((e) % 32); x[(((e + 64) >>> 9) << 4) + 14] = e; var a = 1732584193; var b = -271733879; var c = -1732584194; var d = 271733878; for (var i = 0; i < x.length; i += 16) {var f = a; var g = b; var h = c; var j = 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, f); b = safe_add(b, g); c = safe_add(c, h); d = safe_add(d, j) } return Array(a, b, c, d) }, md5_cmn = function (q, a, b, x, s, t) {return safe_add(bit_rol(safe_add(safe_add(a, q), safe_add(x, t)), s), b) }, md5_ff = function (a, b, c, d, x, s, t) {return md5_cmn((b & c) | ((~b) & d), a, b, x, s, t) }, md5_gg = function (a, b, c, d, x, s, t) {return md5_cmn((b & d) | (c & (~d)), a, b, x, s, t) }, md5_hh = function (a, b, c, d, x, s, t) {return md5_cmn(b ^ c ^ d, a, b, x, s, t) }, md5_ii = function (a, b, c, d, x, s, t) {return md5_cmn(c ^ (b | (~d)), a, b, x, s, t) }, safe_add = function (x, y) {var a = (x & 0xFFFF) + (y & 0xFFFF); var b = (x >> 16) + (y >> 16) + (a >> 16); return (b << 16) | (a & 0xFFFF) }, bit_rol = function (a, b) {return (a << b) | (a >>> (32 - b)) }, s2b = function (a) {var b = Array(); var c = (1 << chrsz) - 1; for (var i = 0; i < a.length * chrsz; i += chrsz) b[i >> 5] |= (a.charCodeAt(i / chrsz) & c) << (i % 32); return b }, b2h = function (a) {var b = hexcase ? "0123456789ABCDEF" : "0123456789abcdef"; var c = ""; for (var i = 0; i < a.length * 4; i++) {c += b.charAt((a[i >> 2] >> ((i % 4) * 8 + 4)) & 0xF) + b.charAt((a[i >> 2] >> ((i % 4) * 8)) & 0xF) } return c; }; return b2h(cmc5(s2b(s), s.length * chrsz))},
   
    activeXDetect : function(componentClassID) {
      var componentVersion = document.body.getComponentVersion('{' + componentClassID + '}', 'ComponentID');
      return (componentVersion !== null) ? componentVersion : false;
    },

    stripIllegalChars : function(value) {
      var t = "",
          i;

      value = value.toLowerCase();
      for (i = 0; i < value.length; i++) {
        if (value.charAt(i) !== '\n' && value.charAt(i) !== '/' && value.charAt(i) !== "\\") {
          t += value.charAt(i);
        } else if (value.charAt(i) === '\n') {
          t += "n";
        }
      }
      return t;
    },

    stripFullPath : function(tempFileName, lastDir) {
      var fileName = tempFileName,
          filenameStart = fileName.lastIndexOf(lastDir),
          filenameFinish = fileName.length;

      if (filenameStart < 0) {
        filenameStart = 0;
      }

      fileName = fileName.substring(filenameStart + lastDir.length, filenameFinish);

      return fileName;
    },

    userAgent : function () {
      return window.navigator.userAgent || "unknown user agent";
    },

    display : function () {
      var screen = window.screen || screen || {};
      return JSON.stringify(screen);
    },

    software : function() {
      var i, t = "",
          isFirst = true,
          temp = "",
          lastDir = "Plugins",
          plugin, mimeType, components, ver;

      if (window.navigator.plugins.length > 0) {
        if (opera) {
          temp = "";
          lastDir = "Plugins";

          for (i = 0; i < window.navigator.plugins.length; i++) {
            plugin = window.navigator.plugins[i];
            if (isFirst === true) {
              temp += this.stripFullPath(plugin.filename, lastDir);
              isFirst = false;
            } else {
              temp += SEP + this.stripFullPath(plugin.filename, lastDir);
            }
          }
          t = this.stripIllegalChars(temp);
        } else {
          for (i = 0; i < window.navigator.plugins.length; i++) {
            plugin = window.navigator.plugins[i];
            if (isFirst === true) {
              t += plugin.filename;
              isFirst = false;
            } else {
              t += SEP + plugin.filename;
            }
          }
        }
      } else if (window.navigator.mimeTypes.length > 0) {
        for (i = 0; i < window.navigator.mimeTypes.length; i++) {
          mimeType = window.navigator.mimeTypes[i];
          if (isFirst === true) {
            t += mimeType.type;
            isFirst = false;
          } else {
            t += SEP + mimeType.type;
          }
        }
      } else if (ie) {
        components = new Array("7790769C-0471-11D2-AF11-00C04FA35D02", "89820200-ECBD-11CF-8B85-00AA005B4340", "283807B5-2C60-11D0-A31D-00AA00B92C03", "4F216970-C90C-11D1-B5C7-0000F8051515", "44BBA848-CC51-11CF-AAFA-00AA00B6015C", "9381D8F2-0288-11D0-9501-00AA00B911A5", "4F216970-C90C-11D1-B5C7-0000F8051515", "5A8D6EE0-3E18-11D0-821E-444553540000", "89820200-ECBD-11CF-8B85-00AA005B4383", "08B0E5C0-4FCB-11CF-AAA5-00401C608555", "45EA75A0-A269-11D1-B5BF-0000F8051515", "DE5AED00-A4BF-11D1-9948-00C04F98BBC9", "22D6F312-B0F6-11D0-94AB-0080C74C7E95", "44BBA842-CC51-11CF-AAFA-00AA00B6015B", "3AF36230-A269-11D1-B5BF-0000F8051515", "44BBA840-CC51-11CF-AAFA-00AA00B6015C", "CC2A9BA0-3BDD-11D0-821E-444553540000", "08B0E5C0-4FCB-11CF-AAA5-00401C608500", "D27CDB6E-AE6D-11CF-96B8-444553540000", "2A202491-F00D-11CF-87CC-0020AFEECF20");
        document.body.addBehavior("#default#clientCaps");
        for (i = 0; i < components.length; i++) {
          ver = this.activeXDetect(components[i]);
          if (ver) {
            if (isFirst === true) {
              t += ver;
              isFirst = false;
            } else {
              t += SEP + ver;
            }
          } else {
            t += SEP + "null";
          }
        }
      }

      return t;
    },

    myDeviceHash : function () {
      return this.stringToMD5(this.userAgent() + this.display() + this.software());
    }

    // to be extended with canvas fingerprinting etc ...
    // font lists etc ...
  };
  
  // storing information in global object
  // for demo purpose
  window.fingerprint = {
    md5hash : Collector.myDeviceHash(),
    collection : {
      userAgent : Collector.userAgent(),
      display   : Collector.display(),
      software  : Collector.software()
    }
  };

}(window, document, JSON ));

@khanhvuNOIS That's a pretty tall order. Most fingerprinting techniques rely on the myriad ways browsers can be configured (or influenced by other software on the same computer). Each individual piece doesn't provide much information, but in aggregate there's a fair amount of data there to fingerprint off of.

When it comes to fingerprinting the whole PC you just don't have much to go off of. You've basically got OS and screen resolution, which doesn't really narrow it down much. There are MILLIONS of Windows 10 computers from the Surface line kicking around with 2736x1824 screens, for example.

Adding data points to fingerprinting increases their amount of entropy exponentially, which is why what seems like so few pieces of information in a browser can yield dozens or even hundreds of identifying bits. The converse is that losing data points also drops the number of useful identifying bits exponentially. So losing a few dozen data points can take you from useful fingerprinting to ... basically zero information.