Merge pull request #5 from jjsullivan5196/gh-pages

Channel auto select/detect
jjsullivan5196 · Dec 14, 2015 · f04385b · f04385b
2 parents e406992 + c871b9a
commit f04385b
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Showing 4 changed files with 80 additions and 2 deletions.
diff --git a/index.html b/index.html
@@ -13,6 +13,7 @@
 		<script type="text/javascript" src="js/mime.js"></script>
 		<script type="text/javascript" src="js/bloburl.js"></script>
 		<script type="text/javascript" src="js/functions.js"></script>
+		<script type="text/javascript" src="js/magic.js"></script>
 		<script type="text/javascript" src="js/stego.js"></script>
 	</head>
 	<body>
@@ -40,7 +41,7 @@
 							<button class="btn btn-primary" id="stegoInject" type="button" >Inject</button>
 							<button class="btn btn-primary" id="stegoRetrieve" type="button">Retrieve</button>
 						</div>
-						<input class="form-control" id="xthPixel" type="number" size="1" maxlength="2" value="3" min="3" max="20"/>
+						<input class="form-control" id="xthPixel" type="number" size="1" maxlength="2" value="2" min="2" max="20"/>
 					</div>
 					<br>
 					<a id="stegoFile" href="" download=""></a>

diff --git a/js/magic.js b/js/magic.js
@@ -0,0 +1,72 @@
+function determineBestChannel(fileSize, imageX, imageY)
+{
+	var s = 0;
+	for(var x = 4; x <= imageX * imageY; x++)
+	{
+		if(x%2 == 0)
+		{
+			s++;
+		}
+	}
+	if(s < fileSize)
+	{
+		return -1;
+	}
+	var best = 2;//max
+	for (var x = 3; x <= 20; x++)
+	{
+		var next = ((imageX*imageY) - 3) / x;
+		if(next > fileSize)
+		{
+			best = x;
+		}
+		else
+		{
+			break;
+		}	
+	}
+	return best;
+}
+
+function scanXth(data)
+{
+	for (var xth = 2; xth <= 20; xth++)// in range(2, 21):
+	{
+		//console.log("--------------------------------------------------------------------")
+		//prvar("Checking channel " + str(xth))
+		var arr = new Array();
+		for(var i = 4; arr.length < 300; i++) {
+			if(xthPattern(i, xth)) {
+				var	baseColor	=	avgColor(getPixel(data, (i-1)), getPixel(data, (i+1))),
+					dataColor	=	retrieveColor(getPixel(data, i), baseColor, 7),
+					inData		=	rgbaToVal(dataColor, 7);
+				arr.push(inData);
+			}
+		}
+		//Split off the non-filename component
+		try{
+			//////////////Filename Length Validity Check////////////
+			if(arr[0] > 300 || arr[0] < 1)
+			{
+				throw "Filename Too Long or too short" + arr[0];
+			}
+			//////////////////////////////////////////////////////////////////////////////////////
+			rawName = arr.slice(1, arr[0] + 1)
+			////////////////Filename Prvarability Check////////////////
+			for(var i = 0; i < rawName.length; i++)
+			{
+				if(rawName[i] < 32 || rawName[i] > 126)
+				{
+					throw "Unprintable character";
+				}
+			}
+			//////////////////////////////////////////////////////////////////////////////////////
+			return (xth)
+		}catch(e)
+		{
+			//console.log(e)
+			continue
+		}
+	}
+	return (0)
+}
diff --git a/js/stego.js b/js/stego.js
@@ -38,6 +38,8 @@ function inject(ev) {
 
 	if(link.href) URL.revokeObjectURL(link.href);
 
+	if(xth < 3) xth = determineBestChannel(byteNum, canvas.width, canvas.height);
+
 	reader.onload = function(e) {
 		var	fileCont	=	Array.from(new Uint8Array(e.target.result)),
 			fileName	=	[file.name.length];
@@ -98,6 +100,8 @@ function retrieve(ev) {
 		col2	=	retrieveColor(getPixel(data, 1),getPixel(data, 3),10),
 		col3	=	retrieveColor(getPixel(data, 2),getPixel(data, 3),10),
 		byteNum	=	(rgbaToVal(col3, 10)*1000000) + (rgbaToVal(col2, 10)*1000) + rgbaToVal(col1, 10);
+
+	if(xth < 3) xth = scanXth(data);
 
 	for(var i = 4; buffer.length < byteNum; i++) {
 		if(xthPattern(i, xth)) {

diff --git a/js/titler.js b/js/titler.js
@@ -9,7 +9,8 @@ function titler() {
 		"Use any image of the President for a surprise.",
 		"Why are you here?",
 		"We don't negotiate with terrorists.",
-		"Your packets have been diverted, consequences will never be the same."
+		"Your packets have been diverted, consequences will never be the same.",
+		"Nobody cared what the file was until you hid it."
 	];
 	document.title = "Steganosaurus: " + titleArray[parseInt(Math.random() * titleArray.length)];
 }