/*

Copyright 2008-2011 Clipperz Srl

This file is part of Clipperz's Javascript Crypto Library.
Javascript Crypto Library provides web developers with an extensive
and efficient set of cryptographic functions. The library aims to
obtain maximum execution speed while preserving modularity and
reusability.
For further information about its features and functionalities please
refer to http://www.clipperz.com

* Javascript Crypto Library is free software: you can redistribute
  it and/or modify it under the terms of the GNU Affero General Public
  License as published by the Free Software Foundation, either version
  3 of the License, or (at your option) any later version.

* Javascript Crypto Library is distributed in the hope that it will
  be useful, but WITHOUT ANY WARRANTY; without even the implied
  warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  See the GNU Affero General Public License for more details.

* You should have received a copy of the GNU Affero General Public
  License along with Javascript Crypto Library.  If not, see
  <http://www.gnu.org/licenses/>.

*/

try { if (typeof(Clipperz.ByteArray) == 'undefined') { throw ""; }} catch (e) {
	throw "Clipperz.Crypto.PRNG depends on Clipperz.ByteArray!";
}  

try { if (typeof(Clipperz.Crypto.SHA) == 'undefined') { throw ""; }} catch (e) {
	throw "Clipperz.Crypto.PRNG depends on Clipperz.Crypto.SHA!";
}  

try { if (typeof(Clipperz.Crypto.AES) == 'undefined') { throw ""; }} catch (e) {
	throw "Clipperz.Crypto.PRNG depends on Clipperz.Crypto.AES!";
}  

if (typeof(Clipperz.Crypto.PRNG) == 'undefined') { Clipperz.Crypto.PRNG = {}; }

//#############################################################################

Clipperz.Crypto.PRNG.EntropyAccumulator = function(args) {
	args = args || {};
//	MochiKit.Base.bindMethods(this);

	this._stack = new Clipperz.ByteArray();
	this._maxStackLengthBeforeHashing = args.maxStackLengthBeforeHashing || 256;
	return this;
}

Clipperz.Crypto.PRNG.EntropyAccumulator.prototype = MochiKit.Base.update(null, {

	'toString': function() {
		return "Clipperz.Crypto.PRNG.EntropyAccumulator";
	},

	//-------------------------------------------------------------------------

	'stack': function() {
		return this._stack;
	},
	
	'setStack': function(aValue) {
		this._stack = aValue;
	},

	'resetStack': function() {
		this.stack().reset();
	},
	
	'maxStackLengthBeforeHashing': function() {
		return this._maxStackLengthBeforeHashing;
	},

	//-------------------------------------------------------------------------

	'addRandomByte': function(aValue) {
		this.stack().appendByte(aValue);
				
		if (this.stack().length() > this.maxStackLengthBeforeHashing()) {
			this.setStack(Clipperz.Crypto.SHA.sha_d256(this.stack()));
		}
	},
	
	//-------------------------------------------------------------------------
	__syntaxFix__: "syntax fix"
});

//#############################################################################

Clipperz.Crypto.PRNG.RandomnessSource = function(args) {
	args = args || {};
	MochiKit.Base.bindMethods(this);

	this._generator = args.generator || null;
	this._sourceId = args.sourceId || null;
	this._boostMode = args.boostMode || false;
	
	this._nextPoolIndex = 0;
	
	return this;
}

Clipperz.Crypto.PRNG.RandomnessSource.prototype = MochiKit.Base.update(null, {

	'generator': function() {
		return this._generator;
	},

	'setGenerator': function(aValue) {
		this._generator = aValue;
	},

	//-------------------------------------------------------------------------

	'boostMode': function() {
		return this._boostMode;
	},
	
	'setBoostMode': function(aValue) {
		this._boostMode = aValue;
	},
	
	//-------------------------------------------------------------------------
	
	'sourceId': function() {
		return this._sourceId;
	},

	'setSourceId': function(aValue) {
		this._sourceId = aValue;
	},
	
	//-------------------------------------------------------------------------

	'nextPoolIndex': function() {
		return this._nextPoolIndex;
	},
	
	'incrementNextPoolIndex': function() {
		this._nextPoolIndex = ((this._nextPoolIndex + 1) % this.generator().numberOfEntropyAccumulators());
	},
	
	//-------------------------------------------------------------------------

	'updateGeneratorWithValue': function(aRandomValue) {
		if (this.generator() != null) {
			this.generator().addRandomByte(this.sourceId(), this.nextPoolIndex(), aRandomValue);
			this.incrementNextPoolIndex();
		}
	},
	
	//-------------------------------------------------------------------------
	__syntaxFix__: "syntax fix"
});

//#############################################################################
	
Clipperz.Crypto.PRNG.TimeRandomnessSource = function(args) {
	args = args || {};
//	MochiKit.Base.bindMethods(this);

	this._intervalTime = args.intervalTime || 1000;
	
	Clipperz.Crypto.PRNG.RandomnessSource.call(this, args);

	this.collectEntropy();
	return this;
}

Clipperz.Crypto.PRNG.TimeRandomnessSource.prototype = MochiKit.Base.update(new Clipperz.Crypto.PRNG.RandomnessSource, {

	'intervalTime': function() {
		return this._intervalTime;
	},
	
	//-------------------------------------------------------------------------

	'collectEntropy': function() {
		var	now;
		var	entropyByte;
		var intervalTime;
		now = new Date();
		entropyByte = (now.getTime() & 0xff);
		
		intervalTime = this.intervalTime();
		if (this.boostMode() == true) {
			intervalTime = intervalTime / 9;
		}
		
		this.updateGeneratorWithValue(entropyByte);
		setTimeout(this.collectEntropy, intervalTime);
	},
	
	//-------------------------------------------------------------------------

	'numberOfRandomBits': function() {
		return 5;
	},
	
	//-------------------------------------------------------------------------

	'pollingFrequency': function() {
		return 10;
	},

	//-------------------------------------------------------------------------
	__syntaxFix__: "syntax fix"
});

//*****************************************************************************

Clipperz.Crypto.PRNG.MouseRandomnessSource = function(args) {
	args = args || {};

	Clipperz.Crypto.PRNG.RandomnessSource.call(this, args);

	this._numberOfBitsToCollectAtEachEvent = 4;
	this._randomBitsCollector = 0;
	this._numberOfRandomBitsCollected = 0;
	
	MochiKit.Signal.connect(document, 'onmousemove', this, 'collectEntropy');

	return this;
}

Clipperz.Crypto.PRNG.MouseRandomnessSource.prototype = MochiKit.Base.update(new Clipperz.Crypto.PRNG.RandomnessSource, {

	//-------------------------------------------------------------------------

	'numberOfBitsToCollectAtEachEvent': function() {
		return this._numberOfBitsToCollectAtEachEvent;
	},
	
	//-------------------------------------------------------------------------

	'randomBitsCollector': function() {
		return this._randomBitsCollector;
	},

	'setRandomBitsCollector': function(aValue) {
		this._randomBitsCollector = aValue;
	},

	'appendRandomBitsToRandomBitsCollector': function(aValue) {
		var collectedBits;
		var numberOfRandomBitsCollected;
		
		numberOfRandomBitsCollected = this.numberOfRandomBitsCollected();
		collectetBits = this.randomBitsCollector() | (aValue << numberOfRandomBitsCollected);
		this.setRandomBitsCollector(collectetBits);
		numberOfRandomBitsCollected += this.numberOfBitsToCollectAtEachEvent();
		
		if (numberOfRandomBitsCollected == 8) {
			this.updateGeneratorWithValue(collectetBits);
			numberOfRandomBitsCollected = 0;
			this.setRandomBitsCollector(0);
		}
		
		this.setNumberOfRandomBitsCollected(numberOfRandomBitsCollected)
	},
	
	//-------------------------------------------------------------------------

	'numberOfRandomBitsCollected': function() {
		return this._numberOfRandomBitsCollected;
	},

	'setNumberOfRandomBitsCollected': function(aValue) {
		this._numberOfRandomBitsCollected = aValue;
	},

	//-------------------------------------------------------------------------

	'collectEntropy': function(anEvent) {
		var mouseLocation;
		var randomBit;
		var mask;
		
		mask = 0xffffffff >>> (32 - this.numberOfBitsToCollectAtEachEvent());
		
		mouseLocation = anEvent.mouse().client;
		randomBit = ((mouseLocation.x ^ mouseLocation.y) & mask);
		this.appendRandomBitsToRandomBitsCollector(randomBit)
	},
	
	//-------------------------------------------------------------------------

	'numberOfRandomBits': function() {
		return 1;
	},
	
	//-------------------------------------------------------------------------

	'pollingFrequency': function() {
		return 10;
	},

	//-------------------------------------------------------------------------
	__syntaxFix__: "syntax fix"
});

//*****************************************************************************

Clipperz.Crypto.PRNG.KeyboardRandomnessSource = function(args) {
	args = args || {};
	Clipperz.Crypto.PRNG.RandomnessSource.call(this, args);

	this._randomBitsCollector = 0;
	this._numberOfRandomBitsCollected = 0;
	
	MochiKit.Signal.connect(document, 'onkeypress', this, 'collectEntropy');

	return this;
}

Clipperz.Crypto.PRNG.KeyboardRandomnessSource.prototype = MochiKit.Base.update(new Clipperz.Crypto.PRNG.RandomnessSource, {

	//-------------------------------------------------------------------------

	'randomBitsCollector': function() {
		return this._randomBitsCollector;
	},

	'setRandomBitsCollector': function(aValue) {
		this._randomBitsCollector = aValue;
	},

	'appendRandomBitToRandomBitsCollector': function(aValue) {
		var collectedBits;
		var numberOfRandomBitsCollected;
		
		numberOfRandomBitsCollected = this.numberOfRandomBitsCollected();
		collectetBits = this.randomBitsCollector() | (aValue << numberOfRandomBitsCollected);
		this.setRandomBitsCollector(collectetBits);
		numberOfRandomBitsCollected ++;
		
		if (numberOfRandomBitsCollected == 8) {
			this.updateGeneratorWithValue(collectetBits);
			numberOfRandomBitsCollected = 0;
			this.setRandomBitsCollector(0);
		}
		
		this.setNumberOfRandomBitsCollected(numberOfRandomBitsCollected)
	},
	
	//-------------------------------------------------------------------------

	'numberOfRandomBitsCollected': function() {
		return this._numberOfRandomBitsCollected;
	},

	'setNumberOfRandomBitsCollected': function(aValue) {
		this._numberOfRandomBitsCollected = aValue;
	},

	//-------------------------------------------------------------------------

	'collectEntropy': function(anEvent) {
/*
		var mouseLocation;
		var randomBit;
		
		mouseLocation = anEvent.mouse().client;
			
		randomBit = ((mouseLocation.x ^ mouseLocation.y) & 0x1);
		this.appendRandomBitToRandomBitsCollector(randomBit);
*/
	},
	
	//-------------------------------------------------------------------------

	'numberOfRandomBits': function() {
		return 1;
	},
	
	//-------------------------------------------------------------------------

	'pollingFrequency': function() {
		return 10;
	},

	//-------------------------------------------------------------------------
	__syntaxFix__: "syntax fix"
});

//#############################################################################

Clipperz.Crypto.PRNG.Fortuna = function(args) {
	var	i,c;
	
	args = args || {};

	this._key = args.seed || null;
	if (this._key == null) {
		this._counter = 0;
		this._key = new Clipperz.ByteArray();
	} else {
		this._counter = 1;
	}
	
	this._aesKey = null;
	
	this._firstPoolReseedLevel = args.firstPoolReseedLevel || 32 || 64;
	this._numberOfEntropyAccumulators = args.numberOfEntropyAccumulators || 32;
	
	this._accumulators = [];
	c = this.numberOfEntropyAccumulators();
	for (i=0; i<c; i++) {
		this._accumulators.push(new Clipperz.Crypto.PRNG.EntropyAccumulator());
	}

	this._randomnessSources = [];
	this._reseedCounter = 0;
	
	return this;
}

Clipperz.Crypto.PRNG.Fortuna.prototype = MochiKit.Base.update(null, {

	'toString': function() {
		return "Clipperz.Crypto.PRNG.Fortuna";
	},

	//-------------------------------------------------------------------------

	'key': function() {
		return this._key;
	},

	'setKey': function(aValue) {
		this._key = aValue;
		this._aesKey = null;
	},
	
	'aesKey': function() {
		if (this._aesKey == null) {
			this._aesKey = new Clipperz.Crypto.AES.Key({key:this.key()});
		}
		
		return this._aesKey;
	},
	
	'accumulators': function() {
		return this._accumulators;
	},
	
	'firstPoolReseedLevel': function() {
		return this._firstPoolReseedLevel;
	},
	
	//-------------------------------------------------------------------------

	'reseedCounter': function() {
		return this._reseedCounter;
	},

	'incrementReseedCounter': function() {
		this._reseedCounter = this._reseedCounter +1;
	},

	//-------------------------------------------------------------------------

	'reseed': function() {
		var	newKeySeed;
		var reseedCounter;
		var	reseedCounterMask;
		var i, c;
		
		newKeySeed = this.key();
		this.incrementReseedCounter();
		reseedCounter = this.reseedCounter();
		
		c = this.numberOfEntropyAccumulators();
		reseedCounterMask = 0xffffffff >>> (32 - c);
		for (i=0; i<c; i++) {
			if ((i == 0) || ((reseedCounter & (reseedCounterMask >>> (c - i))) == 0)) {
				newKeySeed.appendBlock(this.accumulators()[i].stack());
				this.accumulators()[i].resetStack();
			} 
		}
		
		if (reseedCounter == 1) {
			c = this.randomnessSources().length;
			for (i=0; i<c; i++) {
				this.randomnessSources()[i].setBoostMode(false);
			}
		}
		
		this.setKey(Clipperz.Crypto.SHA.sha_d256(newKeySeed));
		if (reseedCounter == 1) {
MochiKit.Logging.logDebug("### PRNG.readyToGenerateRandomBytes");
			MochiKit.Signal.signal(this, 'readyToGenerateRandomBytes');
		}
		MochiKit.Signal.signal(this, 'reseeded');
	},
	
	//-------------------------------------------------------------------------

	'isReadyToGenerateRandomValues': function() {
		return this.reseedCounter() != 0;
	},
	
	//-------------------------------------------------------------------------

	'entropyLevel': function() {
		return this.accumulators()[0].stack().length() + (this.reseedCounter() * this.firstPoolReseedLevel());
	},
	
	//-------------------------------------------------------------------------

	'counter': function() {
		return this._counter;
	},
	
	'incrementCounter': function() {
		this._counter += 1;
	},
	
	'counterBlock': function() {
		var result;

		result = new Clipperz.ByteArray().appendWords(this.counter(), 0, 0, 0);
		
		return result;
	},

	//-------------------------------------------------------------------------

	'getRandomBlock': function() {
		var result;

		result = new Clipperz.ByteArray(Clipperz.Crypto.AES.encryptBlock(this.aesKey(), this.counterBlock().arrayValues()));
		this.incrementCounter();
		
		return result;
	},
	
	//-------------------------------------------------------------------------

	'getRandomBytes': function(aSize) {
		var result;

		if (this.isReadyToGenerateRandomValues()) {
			var i,c;
			var newKey;
			
			result = new Clipperz.ByteArray();
		
			c = Math.ceil(aSize / (128 / 8));
			for (i=0; i<c; i++) {
				result.appendBlock(this.getRandomBlock());
			}

			if (result.length() != aSize) {
				result = result.split(0, aSize);
			}
			
			newKey = this.getRandomBlock().appendBlock(this.getRandomBlock());
			this.setKey(newKey);
		} else {
MochiKit.Logging.logWarning("Fortuna generator has not enough entropy, yet!");
			throw Clipperz.Crypto.PRNG.exception.NotEnoughEntropy;
		}

		return result;
	},

	//-------------------------------------------------------------------------

	'addRandomByte': function(aSourceId, aPoolId, aRandomValue) {
		var	selectedAccumulator;

		selectedAccumulator = this.accumulators()[aPoolId];
		selectedAccumulator.addRandomByte(aRandomValue);

		if (aPoolId == 0) {
			MochiKit.Signal.signal(this, 'addedRandomByte')
			if (selectedAccumulator.stack().length() > this.firstPoolReseedLevel()) {
				this.reseed();
			}
		}
	},

	//-------------------------------------------------------------------------
	
	'numberOfEntropyAccumulators': function() {
		return this._numberOfEntropyAccumulators;
	},

	//-------------------------------------------------------------------------

	'randomnessSources': function() {
		return this._randomnessSources;
	},
	
	'addRandomnessSource': function(aRandomnessSource) {
		aRandomnessSource.setGenerator(this);
		aRandomnessSource.setSourceId(this.randomnessSources().length);
		this.randomnessSources().push(aRandomnessSource);
		
		if (this.isReadyToGenerateRandomValues() == false) {
			aRandomnessSource.setBoostMode(true);
		}
	},

	//-------------------------------------------------------------------------

	'deferredEntropyCollection': function(aValue) {
		var result;

//MochiKit.Logging.logDebug(">>> PRNG.deferredEntropyCollection");

		if (this.isReadyToGenerateRandomValues()) {
//MochiKit.Logging.logDebug("--- PRNG.deferredEntropyCollection - 1");
			result = aValue;
		} else {
//MochiKit.Logging.logDebug("--- PRNG.deferredEntropyCollection - 2");
			var deferredResult;

			Clipperz.NotificationCenter.notify(this, 'updatedProgressState', 'collectingEntropy', true);

			deferredResult = new MochiKit.Async.Deferred();
//			deferredResult.addBoth(function(res) {MochiKit.Logging.logDebug("1.2.1 - PRNG.deferredEntropyCollection - 1: " + res); return res;});
			deferredResult.addCallback(MochiKit.Base.partial(MochiKit.Async.succeed, aValue));
//			deferredResult.addBoth(function(res) {MochiKit.Logging.logDebug("1.2.2 - PRNG.deferredEntropyCollection - 2: " + res); return res;});
			MochiKit.Signal.connect(this,
									'readyToGenerateRandomBytes',
									deferredResult,
									'callback');
									
			result = deferredResult;
		}
//MochiKit.Logging.logDebug("<<< PRNG.deferredEntropyCollection - result: " + result);

		return result;
	},
	
	//-------------------------------------------------------------------------

	'fastEntropyAccumulationForTestingPurpose': function() {
		while (! this.isReadyToGenerateRandomValues()) {
			this.addRandomByte(Math.floor(Math.random() * 32), Math.floor(Math.random() * 32), Math.floor(Math.random() * 256));
		}
	},
	
	//-------------------------------------------------------------------------

	'dump': function(appendToDoc) {
		var tbl;
		var i,c;
		
		tbl = document.createElement("table");
		tbl.border = 0;
		with (tbl.style) {
			border = "1px solid lightgrey";
			fontFamily = 'Helvetica, Arial, sans-serif';
			fontSize = '8pt';
			//borderCollapse = "collapse";
		}
		var hdr = tbl.createTHead();
		var hdrtr = hdr.insertRow(0);
		// document.createElement("tr");
		{
			var ntd;
			
			ntd = hdrtr.insertCell(0);
			ntd.style.borderBottom = "1px solid lightgrey";
			ntd.style.borderRight = "1px solid lightgrey";
			ntd.appendChild(document.createTextNode("#"));

			ntd = hdrtr.insertCell(1);
			ntd.style.borderBottom = "1px solid lightgrey";
			ntd.style.borderRight = "1px solid lightgrey";
			ntd.appendChild(document.createTextNode("s"));

			ntd = hdrtr.insertCell(2);
			ntd.colSpan = this.firstPoolReseedLevel();
			ntd.style.borderBottom = "1px solid lightgrey";
			ntd.style.borderRight = "1px solid lightgrey";
			ntd.appendChild(document.createTextNode("base values"));
			
			ntd = hdrtr.insertCell(3);
			ntd.colSpan = 20;
			ntd.style.borderBottom = "1px solid lightgrey";
			ntd.appendChild(document.createTextNode("extra values"));

		}

		c = this.accumulators().length;
		for (i=0; i<c ; i++) {
			var	currentAccumulator;
			var bdytr;
			var bdytd;
			var ii, cc;

			currentAccumulator = this.accumulators()[i]
			
			bdytr = tbl.insertRow(true);
			
			bdytd = bdytr.insertCell(0);
			bdytd.style.borderRight = "1px solid lightgrey";
			bdytd.style.color = "lightgrey";
			bdytd.appendChild(document.createTextNode("" + i));

			bdytd = bdytr.insertCell(1);
			bdytd.style.borderRight = "1px solid lightgrey";
			bdytd.style.color = "gray";
			bdytd.appendChild(document.createTextNode("" + currentAccumulator.stack().length()));


			cc = Math.max(currentAccumulator.stack().length(), this.firstPoolReseedLevel());
			for (ii=0; ii<cc; ii++) {
				var cellText;
				
				bdytd = bdytr.insertCell(ii + 2);
				
				if (ii < currentAccumulator.stack().length()) {
					cellText = Clipperz.ByteArray.byteToHex(currentAccumulator.stack().byteAtIndex(ii));
				} else {
					cellText = "_";
				}
				
				if (ii == (this.firstPoolReseedLevel() - 1)) {
					bdytd.style.borderRight = "1px solid lightgrey";
				}
				
				bdytd.appendChild(document.createTextNode(cellText));
			}
			
		}
		

		if (appendToDoc) {
			var ne = document.createElement("div");
			ne.id = "entropyGeneratorStatus";
			with (ne.style) {
				fontFamily = "Courier New, monospace";
				fontSize = "12px";
				lineHeight = "16px";
				borderTop = "1px solid black";
				padding = "10px";
			}
			if (document.getElementById(ne.id)) {
				MochiKit.DOM.swapDOM(ne.id, ne);
			} else {
				document.body.appendChild(ne);
			}
			ne.appendChild(tbl);
		}

		return tbl;
	},

	//-----------------------------------------------------------------------------
	__syntaxFix__: "syntax fix"
});

//#############################################################################

Clipperz.Crypto.PRNG.Random = function(args) {
	args = args || {};
//	MochiKit.Base.bindMethods(this);

	return this;
}

Clipperz.Crypto.PRNG.Random.prototype = MochiKit.Base.update(null, {

	'toString': function() {
		return "Clipperz.Crypto.PRNG.Random";
	},

	//-------------------------------------------------------------------------

	'getRandomBytes': function(aSize) {
//Clipperz.Profile.start("Clipperz.Crypto.PRNG.Random.getRandomBytes");
		var	result;
		var i,c;
		
		result = new Clipperz.ByteArray()
		c = aSize || 1;
		for (i=0; i<c; i++) {
			result.appendByte((Math.random()*255) & 0xff);
		}
		
//Clipperz.Profile.stop("Clipperz.Crypto.PRNG.Random.getRandomBytes");
		return result;
	},

	//-------------------------------------------------------------------------
	__syntaxFix__: "syntax fix"
});

//#############################################################################

_clipperz_crypt_prng_defaultPRNG = null;

Clipperz.Crypto.PRNG.defaultRandomGenerator = function() {
	if (_clipperz_crypt_prng_defaultPRNG == null) {
		_clipperz_crypt_prng_defaultPRNG = new Clipperz.Crypto.PRNG.Fortuna();

		//.............................................................
		//
		//		TimeRandomnessSource
		//
		//.............................................................
		{
			var newRandomnessSource;
		
			newRandomnessSource = new Clipperz.Crypto.PRNG.TimeRandomnessSource({intervalTime:111});
			_clipperz_crypt_prng_defaultPRNG.addRandomnessSource(newRandomnessSource);
		}

		//.............................................................
		//
		//		MouseRandomnessSource
		//
		//.............................................................
		{
			var	newRandomnessSource;
			
			newRandomnessSource = new Clipperz.Crypto.PRNG.MouseRandomnessSource();
			_clipperz_crypt_prng_defaultPRNG.addRandomnessSource(newRandomnessSource);
		}

		//.............................................................
		//
		//		KeyboardRandomnessSource
		//
		//.............................................................
		{
			var	newRandomnessSource;
			
			newRandomnessSource = new Clipperz.Crypto.PRNG.KeyboardRandomnessSource();
			_clipperz_crypt_prng_defaultPRNG.addRandomnessSource(newRandomnessSource);
		}

	}

	return _clipperz_crypt_prng_defaultPRNG;
};

//#############################################################################

Clipperz.Crypto.PRNG.exception =  {
	NotEnoughEntropy: new MochiKit.Base.NamedError("Clipperz.Crypto.PRNG.exception.NotEnoughEntropy") 
};


MochiKit.DOM.addLoadEvent(Clipperz.Crypto.PRNG.defaultRandomGenerator);