= 4.3.0
// -disruptiv 2007
if(isset($_GET['display'])) displayImage($_GET['display']);
if(isset($_GET['dl'])) downloadFile($_GET['dl'], $_GET['dlname']);
$submitted = false; // # Display the forms
$image_url = "http://www.example.com/image.png";
$hideme = "http://www.example.com/somefile.txt";
$key = "7:eXaMpLe";
$newfile = "somefile.txt";
if(isset($_POST['submit'])) {
$submitted = true;
$image_url = $_POST['image_url'];
if(isset($_POST['hideme'])) $hideme = $_POST['hideme'];
if(isset($_POST['key'])) $key = $_POST['key'];
if(isset($_POST['newfile'])) $newfile = $_POST['newfile'];
}
echo "
";
echo "
";
if($submitted) { // # Encrypt / Decrypt something
if($_POST['action'] == "encrypt") hideString($_POST['image_url'], $_POST['hideme']);
else showString($_POST['image_url'], $_POST['key'], $_POST['newfile']);
}
// Converts decimal into binary string of a FIXED SIZE
function d2b($var, $len) {
if($len == 8) $output .= ($var & 128) ? '1' : '0';
$output .= ($var & 64) ? '1' : '0';
$output .= ($var & 32) ? '1' : '0';
$output .= ($var & 16) ? '1' : '0';
$output .= ($var & 8) ? '1' : '0';
$output .= ($var & 4) ? '1' : '0';
$output .= ($var & 2) ? '1' : '0';
$output .= ($var & 1) ? '1' : '0';
return $output;
}
// Returns random lowercase string
function randomString($length) {
for($i = 0; $i < $length; $i++) $string .= chr(rand(97,122));
return $string;
}
// Return an array of rgb values for each pixel
function getPixels($image, $width, $height) {
for($y = 0; $y < $height; $y++) {
for($x = 0; $x < $width; $x++) {
$pixels[] = imagecolorsforindex($image, imagecolorat($image, $x, $y));
}
}
return $pixels;
}
// Saves an image created from $newPixels
function savePixels($newPixels, $width, $height, $filename) {
$curx = 0;
$cury = 0;
$image = imagecreatetruecolor($width, $height);
foreach($newPixels as $pixel) {
if($curx > $width-1) {
$cury++;
$curx = 0;
}
if($cury > $height-1) break 2;
$color = imagecolorallocate($image, $pixel["red"], $pixel["green"], $pixel["blue"]);
imagesetpixel($image, $curx, $cury, $color);
$curx++;
}
imagepng($image, $filename);
}
// Replace the 3 least significant image bits
// With the 3 most significant string bits
function hideBits($pixels, $hideString) {
$colors = array("red", "green", "blue");
$imagelen = count($pixels);
$stringlen = strlen($hideString);
for($i = 0; $i < $stringlen; $i++) $binstr .= d2b(ord($hideString[$i]), 7);
$stringlen *= 7;
$curpixel = 0;
$curcolor = 0;
$curbit = 0;
for($i = 0; $i < $stringlen; $i++) {
if($curpixel > $imagelen) {
echo "
FATAL ERROR: Hidden data is larger than image can hide";
die;
}
if($curbit == 3) {
$curbit = 0;
$curcolor++;
}
if($curcolor == 3) {
$curcolor = 0;
$curpixel++;
}
$binpixel = d2b($pixels[$curpixel][$colors[$curcolor]], 8);
$binpixel[strlen($binpixel)-(1+$curbit)] = $binstr[$i];
$pixels[$curpixel][$colors[$curcolor]] = bindec($binpixel);
$curbit++;
}
return $pixels;
}
// Combine the 3 least significant bits of an image to form a string
function showBits($pixels, $hidelen) {
$colors = array("red", "green", "blue");
$imagelen = count($pixels);
$hidelen *= 7;
$curpixel = 0;
$curcolor = 0;
$curbit = 0;
for($i = 0; $i < $hidelen; $i++) {
if($curpixel > $imagelen) {
echo "
FATAL ERROR: Hidden data is larger than image can hide";
die;
}
if($curbit == 3) {
$curbit = 0;
$curcolor++;
}
if($curcolor == 3) {
$curcolor = 0;
$curpixel++;
}
$binpixel = d2b($pixels[$curpixel][$colors[$curcolor]],8);
$binstr .= $binpixel[strlen($binpixel)-(1+$curbit)];
$curbit++;
}
for($i = 0; $i < $hidelen; $i+=7) $string .= chr(bindec(substr($binstr, $i, 7)));
return $string;
}
function displayImage($imagepath) {
header("Content-type: image/png");
echo file_get_contents($imagepath);
unlink($imagepath);
die;
}
function downloadFile($filepath, $dlname) {
header("Content-type: application/octet-stream");
header("Content-length: ".filesize($filepath));
header("Content-disposition: attachment; filename=\"".$dlname."\";");
$file = fopen($filepath, "rb");
echo fread($file, filesize($filepath));
fclose($file);
unlink($filepath);
die;
}
function hideString($imagepath, $hidemepath) {
$image = imagecreatefrompng($imagepath);
$width = imagesx($image);
$height = imagesy($image);
$pixels = getPixels($image, $width, $height);
$file = @fopen($hidemepath, "rb");
if(!$file) {
echo "
FATAL ERROR: Can't open file $hideme
";
die;
}
while(!feof($file)) $hideme .= fread($file, 8192);
fclose($file);
$hiddenlen = strlen($hideme);
$key = randomString($hiddenlen);
for($i = 0; $i < $hiddenlen; $i++) $xored .= $hideme[$i] ^ $key[$i];
$hideme = base64_encode($xored);
$hiddenlen = strlen($hideme);
$pixels = hideBits($pixels, $hideme);
$filename = randomString(8).".png";
savePixels($pixels, $width, $height, $filename);
echo "
Key:
";
echo "Stego-Image:
";
echo "![](".$_SERVER[)
";
}
function showString($imagepath, $key, $dlname) {
$image = @imagecreatefrompng($imagepath);
if(!$image) {
echo "
FATAL ERROR: Can't open image $imagepath
";
die;
}
$width = imagesx($image);
$height = imagesy($image);
$pixels = getPixels($image, $width, $height);
list($hiddenlen,$key) = explode(":", $key);
$keylen = strlen($key);
$hidden = base64_decode(showBits($pixels, $hiddenlen));
for($i = 0; $i < $keylen; $i++) $xored .= $hidden[$i] ^ $key[$i];
$filename = randomString(8);
$file = fopen($filename, "wb");
fwrite($file, $xored, $keylen);
echo "