uuid.js | |
---|---|
| (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 |
| '-' + ((parseInt(hash.substring(12, 16), 16) & 0x0fff) | 0x5000).toString(16) + |
| '-' + ((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, _));
|