/js/lib/Socket.IO-node/support/socket.io-client/lib/vendor/web-socket-js/flash-src/com/hurlant/crypto/prng/Random.as

/**

 * Random

 * 

 * An ActionScript 3 implementation of a Random Number Generator

 * Copyright (c) 2007 Henri Torgemane

 * 

 * Derived from:

 * 		The jsbn library, Copyright (c) 2003-2005 Tom Wu

 * 

 * See LICENSE.txt for full license information.

 */

package com.hurlant.crypto.prng

{

	import flash.utils.ByteArray;

	import com.hurlant.util.Memory;

	import flash.system.System;

	import flash.system.Capabilities;

	import flash.accessibility.AccessibilityProperties;

	import flash.display.SWFVersion;

	import flash.display.Stage;

	import flash.utils.getTimer;

	import flash.text.Font;

	

	public class Random

	{

		private var state:IPRNG;

		private var ready:Boolean = false;

		private var pool:ByteArray;

		private var psize:int;

		private var pptr:int;

		private var seeded:Boolean = false;

		

		public function Random(prng:Class = null) {

			if (prng==null) prng = ARC4;

			state = new prng as IPRNG;

			psize= state.getPoolSize();

			pool = new ByteArray;

			pptr = 0;

			while (pptr <psize) {

				var t:uint = 65536*Math.random();

				pool[pptr++] = t >>> 8;

				pool[pptr++] = t&255;

			}

			pptr=0;

			seed();

		}

		

		public function seed(x:int = 0):void {

			if (x==0) {

				x = new Date().getTime();

			}

			pool[pptr++] ^= x & 255;

			pool[pptr++] ^= (x>>8)&255;

			pool[pptr++] ^= (x>>16)&255;

			pool[pptr++] ^= (x>>24)&255;

			pptr %= psize;

			seeded = true;

		}

		

		/**

		 * Gather anything we have that isn't entirely predictable:

		 *  - memory used

		 *  - system capabilities

		 *  - timing stuff

		 *  - installed fonts

		 */

		public function autoSeed():void {

			var b:ByteArray = new ByteArray;

			b.writeUnsignedInt(System.totalMemory);

			b.writeUTF(Capabilities.serverString);

			b.writeUnsignedInt(getTimer());

			b.writeUnsignedInt((new Date).getTime());

			var a:Array = Font.enumerateFonts(true);

			for each (var f:Font in a) {

				b.writeUTF(f.fontName);

				b.writeUTF(f.fontStyle);

				b.writeUTF(f.fontType);

			}

			b.position=0;

			while (b.bytesAvailable>=4) {

				seed(b.readUnsignedInt());

			}

		}

		

		

		public function nextBytes(buffer:ByteArray, length:int):void {

			while (length--) {

				buffer.writeByte(nextByte());

			}

		}

		public function nextByte():int {

			if (!ready) {

				if (!seeded) {

					autoSeed();

				}

				state.init(pool);

				pool.length = 0;

				pptr = 0;

				ready = true;

			}

			return state.next();

		}

		public function dispose():void {

			for (var i:uint=0;i<pool.length;i++) {

				pool[i] = Math.random()*256;

			}

			pool.length=0;

			pool = null;

			state.dispose();

			state = null;

			psize = 0;

			pptr = 0;

			Memory.gc();

		}

		public function toString():String {

			return "random-"+state.toString();

		}

	}

}