/**
* SHA1
*
* An ActionScript 3 implementation of Secure Hash Algorithm, SHA-1, as defined
* in FIPS PUB 180-1
* Copyright (c) 2007 Henri Torgemane
*
* Derived from:
* A JavaScript implementation of the Secure Hash Algorithm, SHA-1, as defined
* in FIPS PUB 180-1
* Version 2.1a Copyright Paul Johnston 2000 - 2002.
* Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
*
* See LICENSE.txt for full license information.
*/
package com.hurlant.crypto.hash
{
public class SHA1 extends SHABase implements IHash
{
public static const HASH_SIZE:int = 20;
public override function getHashSize():uint {
return HASH_SIZE;
}
protected override function core(x:Array, len:uint):Array
{
/* append padding */
x[len >> 5] |= 0x80 << (24 - len % 32);
x[((len + 64 >> 9) << 4) + 15] = len;
var w:Array = [];
var a:uint = 0x67452301; //1732584193;
var b:uint = 0xEFCDAB89; //-271733879;
var c:uint = 0x98BADCFE; //-1732584194;
var d:uint = 0x10325476; //271733878;
var e:uint = 0xC3D2E1F0; //-1009589776;
for(var i:uint = 0; i < x.length; i += 16)
{
var olda:uint = a;
var oldb:uint = b;
var oldc:uint = c;
var oldd:uint = d;
var olde:uint = e;
for(var j:uint = 0; j < 80; j++)
{
if (j < 16) {
w[j] = x[i + j] || 0;
} else {
w[j] = rol(w[j-3] ^ w[j-8] ^ w[j-14] ^ w[j-16], 1);
}
var t:uint = rol(a,5) + ft(j,b,c,d) + e + w[j] + kt(j);
e = d;
d = c;
c = rol(b, 30);
b = a;
a = t;
}
a += olda;
b += oldb;
c += oldc;
d += oldd;
e += olde;
}
return [ a, b, c, d, e ];
}
/*
* Bitwise rotate a 32-bit number to the left.
*/
private function rol(num:uint, cnt:uint):uint
{
return (num << cnt) | (num >>> (32 - cnt));
}
/*
* Perform the appropriate triplet combination function for the current
* iteration
*/
private function ft(t:uint, b:uint, c:uint, d:uint):uint
{
if(t < 20) return (b & c) | ((~b) & d);
if(t < 40) return b ^ c ^ d;
if(t < 60) return (b & c) | (b & d) | (c & d);
return b ^ c ^ d;
}
/*
* Determine the appropriate additive constant for the current iteration
*/
private function kt(t:uint):uint
{
return (t < 20) ? 0x5A827999 : (t < 40) ? 0x6ED9EBA1 :
(t < 60) ? 0x8F1BBCDC : 0xCA62C1D6;
}
public override function toString():String {
return "sha1";
}
}
}
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