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uuid.js

superscore uuid.js 0.2.2
(c) 2012 David Souther
superscore is freely distributable under the MIT license.
For all details and documentation:
https://github.com/DavidSouther/superscore
(function(_){

Build several namespaces, globally...

var UUID = {};
var Sha1 = function(str){return Sha1.hash(str, true);};
var Utf8 = {};


UUID.rvalid = /^\{?[0-9a-f]{8}\-?[0-9a-f]{4}\-?[0-9a-f]{4}\-?[0-9a-f]{4}\-?[0-9a-f]{12}\}?$/i;

UUID.v4 = function() {
  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
    var r = Math.random()*16|0, v = c === 'x' ? r : (r&0x3|0x8);
    return v.toString(16);
  });
};

UUID.v5 = function(msg, namespace) {
  var nst = bin(namespace || '00000000-0000-0000-0000-000000000000');

  var hash = Sha1.hash(nst + msg, true);
  var uuid =  hash.substring(0, 8) +  //8 digits
    '-' + hash.substring(8, 12) + //4 digits
    // four most significant bits holds version number 5
    '-' + ((parseInt(hash.substring(12, 16), 16) & 0x0fff) | 0x5000).toString(16) +
    // two most significant bits holds zero and one for variant DCE1.1
    '-' + ((parseInt(hash.substring(16, 20), 16) & 0x3fff) | 0x8000).toString(16) +
    '-' + hash.substring(20, 32); //12 digits
  return uuid;
};

Convert a string UUID to binary format.

@param string uuid @return string

var bin = function(uuid) {
  if ( ! uuid.match(UUID.rvalid))
  { //Need a real UUID for this...
    return false;
  }

Get hexadecimal components of uuid

  var hex = uuid.replace(/[\-{}]/g, '');

Binary Value

  var bin = '';

  for (var i = 0; i < hex.length; i += 2)
  { // Convert each character to a bit
    bin += String.fromCharCode(parseInt(hex.charAt(i) + hex.charAt(i + 1), 16));
  }

  return bin;
};

SHA-1 implementation in JavaScript | (c) Chris Veness 2002-2010 | www.movable-type.co.uk/scripts/sha256.html - see http://csrc.nist.gov/groups/ST/toolkit/secure_hashing.html http://csrc.nist.gov/groups/ST/toolkit/examples.html

var Sha1 = {}; // Sha1 namespace

Generates SHA-1 hash of string

@param {String} msg String to be hashed @param {Boolean} [utf8encode=true] Encode msg as UTF-8 before generating hash @returns {String} Hash of msg as hex character string

Sha1.hash = function(msg, utf8encode) {
  var i, t;
  utf8encode =  (typeof utf8encode === 'undefined') ? true : utf8encode;

convert string to UTF-8, as SHA only deals with byte-streams

  if (utf8encode){ msg = Utf8.encode(msg); }

constants [§4.2.1]

  var K = [0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xca62c1d6];

PREPROCESSING

  msg += String.fromCharCode(0x80);  // add trailing '1' bit (+ 0's padding) to string [§5.1.1]

convert string msg into 512-bit/16-integer blocks arrays of ints [§5.2.1]

  var l = msg.length/4 + 2;  // length (in 32-bit integers) of msg + ‘1’ + appended length
  var N = Math.ceil(l/16);   // number of 16-integer-blocks required to hold 'l' ints
  var M = new Array(N);

  for (i=0; i<N; i++) {
    M[i] = new Array(16);
    for (var j=0; j<16; j++) {  // encode 4 chars per integer, big-endian encoding
      M[i][j] = (msg.charCodeAt(i*64+j*4)<<24) | (msg.charCodeAt(i*64+j*4+1)<<16) |
        (msg.charCodeAt(i*64+j*4+2)<<8) | (msg.charCodeAt(i*64+j*4+3));
    } // note running off the end of msg is ok 'cos bitwise ops on NaN return 0
  }

add length (in bits) into final pair of 32-bit integers (big-endian) [§5.1.1] note: most significant word would be (len-1)*8 >>> 32, but since JS converts bitwise-op args to 32 bits, we need to simulate this by arithmetic operators

  M[N-1][14] = ((msg.length-1)*8) / Math.pow(2, 32); M[N-1][14] = Math.floor(M[N-1][14]);
  M[N-1][15] = ((msg.length-1)*8) & 0xffffffff;

set initial hash value [§5.3.1]

  var H0 = 0x67452301;
  var H1 = 0xefcdab89;
  var H2 = 0x98badcfe;
  var H3 = 0x10325476;
  var H4 = 0xc3d2e1f0;

HASH COMPUTATION [§6.1.2]

  var W = new Array(80); var a, b, c, d, e;
  for (i=0; i<N; i++) {

1 - prepare message schedule 'W'

    for (t=0;  t<16; t++){ W[t] = M[i][t]; }
    for (t=16; t<80; t++){ W[t] = Sha1.ROTL(W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16], 1); }

2 - initialise five working variables a, b, c, d, e with previous hash value

    a = H0; b = H1; c = H2; d = H3; e = H4;

3 - main loop

    for (t=0; t<80; t++) {
      var s = Math.floor(t/20); // seq for blocks of 'f' functions and 'K' constants
      var T = (Sha1.ROTL(a,5) + Sha1.f(s,b,c,d) + e + K[s] + W[t]) & 0xffffffff;
      e = d;
      d = c;
      c = Sha1.ROTL(b, 30);
      b = a;
      a = T;
    }

4 - compute the new intermediate hash value

    H0 = (H0+a) & 0xffffffff;  // note 'addition modulo 2^32'
    H1 = (H1+b) & 0xffffffff;
    H2 = (H2+c) & 0xffffffff;
    H3 = (H3+d) & 0xffffffff;
    H4 = (H4+e) & 0xffffffff;
  }

  return Sha1.toHexStr(H0) + Sha1.toHexStr(H1) +
    Sha1.toHexStr(H2) + Sha1.toHexStr(H3) + Sha1.toHexStr(H4);
};

/**
 * function 'f' [§4.1.1]
 */
Sha1.f = function(s, x, y, z)  {
  switch (s) {
  case 0: return (x & y) ^ (~x & z);           // Ch()
  case 1: return x ^ y ^ z;                    // Parity()
  case 2: return (x & y) ^ (x & z) ^ (y & z);  // Maj()
  case 3: return x ^ y ^ z;                    // Parity()
  }
};

/**
 * rotate left (circular left shift) value x by n positions [§3.2.5]
 */
Sha1.ROTL = function(x, n) {
  return (x<<n) | (x>>>(32-n));
};

/**
 * hexadecimal representation of a number
 *   (note toString(16) is implementation-dependant, and
 *   in IE returns signed numbers when used on full words)
 */
Sha1.toHexStr = function(n) {
  var s="", v;
  for (var i=7; i>=0; i--) { v = (n>>>(i*4)) & 0xf; s += v.toString(16); }
  return s;
};

Utf8 class: encode / decode between multi-byte Unicode characters and UTF-8 multiple single-byte character encoding (c) Chris Veness 2002-2010

var Utf8 = {}; // Utf8 namespace

Encode multi-byte Unicode string into utf-8 multiple single-byte characters (BMP / basic multilingual plane only)

Chars in range U+0080 - U+07FF are encoded in 2 chars, U+0800 - U+FFFF in 3 chars

@param {String} strUni Unicode string to be encoded as UTF-8 @returns {String} encoded string

Utf8.encode = function(strUni) {

use regular expressions & String.replace callback function for better efficiency than procedural approaches

  var strUtf = strUni.replace(
      /[\u0080-\u07ff]/g,  // U+0080 - U+07FF => 2 bytes 110yyyyy, 10zzzzzz
      function(c) {
        var cc = c.charCodeAt(0);
        return String.fromCharCode(0xc0 | cc>>6, 0x80 | cc&0x3f); }
    );
  strUtf = strUtf.replace(
      /[\u0800-\uffff]/g,  // U+0800 - U+FFFF => 3 bytes 1110xxxx, 10yyyyyy, 10zzzzzz
      function(c) {
        var cc = c.charCodeAt(0);
        return String.fromCharCode(0xe0 | cc>>12, 0x80 | cc>>6&0x3F, 0x80 | cc&0x3f); }
    );
  return strUtf;
};

Decode utf-8 encoded string back into multi-byte Unicode characters

@param {String} strUtf UTF-8 string to be decoded back to Unicode @returns {String} decoded string

Utf8.decode = function(strUtf) {

note: decode 3-byte chars first as decoded 2-byte strings could appear to be 3-byte char!

  var strUni = strUtf.replace(
      /[\u00e0-\u00ef][\u0080-\u00bf][\u0080-\u00bf]/g,  // 3-byte chars
      function(c) {  // (note parentheses for precence)
        var cc = ((c.charCodeAt(0)&0x0f)<<12) | ((c.charCodeAt(1)&0x3f)<<6) | ( c.charCodeAt(2)&0x3f);
        return String.fromCharCode(cc); }
    );
  strUni = strUni.replace(
      /[\u00c0-\u00df][\u0080-\u00bf]/g,                 // 2-byte chars
      function(c) {  // (note parentheses for precence)
        var cc = (c.charCodeAt(0)&0x1f)<<6 | c.charCodeAt(1)&0x3f;
        return String.fromCharCode(cc); }
    );
  return strUni;
};

UUID, etc are objects that need to be attached to _, not functions to be mixed in.

_.extend(_, {
  'UUID': UUID,
  'Utf8': Utf8,
  'Sha1': Sha1
});

}.call(this, _));