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PHP Steganography program not working - XAMPP

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PHP Steganography program not working - XAMPP

Postby aswin001 » Thu Apr 12, 2012 9:18 am

Hello friends!

I am trying to do something with the script I`ve got from a site for my college Project. Actually it`s actually working in the site where we can demonstrate. but when I download to work Off line, it is not working properly in XAMPP. Can someone help me out please?

Here`s the script

ini_set("max_execution_time",3000);

function is_even($num)
{
// returns true if $num is even, false if not
return ($num%2==0);
}

function asc2bin($char)
{
// returns 8bit binary value from ASCII char
// eg; asc2bin("a") returns 01100001
return str_pad(decbin(ord($char)), 8, "0", STR_PAD_LEFT);
}

function bin2asc($bin)
{
// returns ASCII char from 8bit binary value
// eg; bin2asc("01100001") returns a
// argument MUST be sent as string
return chr(bindec($bin));
}

function rgb2bin($rgb)
{
// returns binary from rgb value (according to evenness)
// this way, we can store one ascii char in 2.6 pixels
// not a great ratio, but it works (albeit slowly)

$binstream = "";
$red = ($rgb >> 16) & 0xFF;
$green = ($rgb >> 8) & 0xFF;
$blue = $rgb & 0xFF;

if(is_even($red))
{
$binstream .= "1";
} else {
$binstream .= "0";
}
if(is_even($green))
{
$binstream .= "1";
} else {
$binstream .= "0";
}
if(is_even($blue))
{
$binstream .= "1";
} else {
$binstream .= "0";
}

return $binstream;
}

function steg_hide($maskfile, $hidefile)
{
// hides $hidefile in $maskfile

// initialise some vars
$binstream = "";
$recordstream = "";
$make_odd = Array();

// ensure a readable mask file has been sent
$extension = strtolower(substr($maskfile['name'],-3));
if($extension=="jpg")
{
$createFunc = "ImageCreateFromJPEG";
/*
}
else if($extension=="png")
{
$createFunc = "ImageCreateFromPNG";
} else if($extension=="gif")
{
$createFunc = "ImageCreateFromGIF";
*/
} else {
return "Only .jpg mask files are supported";
}

// create images
$pic = @ImageCreateFromJPEG($maskfile['tmp_name']);
$attributes = @getImageSize($maskfile['tmp_name']);
$outpic = @ImageCreateFromJPEG($maskfile['tmp_name']);

if(!$pic || !$outpic || !$attributes)
{
// image creation failed
return "cannot create images - maybe GDlib not installed?";
}

// read file to be hidden
$data = file_get_contents($hidefile['tmp_name']);

// generate unique boundary that does not occur in $data
// 1 in 16581375 chance of a file containing all possible 3 ASCII char sequences
// 1 in every ~1.65 billion files will not be steganographisable by this script
// though my maths might be wrong.
// if you really want to get silly, add another 3 random chars. (1 in 274941996890625)
// ^^^^^^^^^^^^ would require appropriate modification to decoder.
do
{
$boundary = chr(rand(0,255)).chr(rand(0,255)).chr(rand(0,255));
} while(strpos($data,$boundary)!==false && strpos($hidefile['name'],$boundary)!==false);

// add boundary to data
$data = $boundary.$hidefile['name'].$boundary.$data.$boundary;
// you could add all sorts of other info here (eg IP of encoder, date/time encoded, etc, etc)
// decoder reads first boundary, then carries on reading until boundary encountered again
// saves that as filename, and carries on again until final boundary reached

// check that $data will fit in maskfile
if(strlen($data)*8 > ($attributes[0]*$attributes[1])*3)
{
// remove images
ImageDestroy($outpic);
ImageDestroy($pic);
return "Cannot fit ".$hidefile['name']." in ".$maskfile['name'].".<br />".$hidefile['name']." requires mask to contain at least ".(intval((strlen($data)*8)/3)+1)." pixels.<br />Maximum filesize that ".$maskfile['name']." can hide is ".intval((($attributes[0]*$attributes[1])*3)/8)." bytes";
}

// convert $data into array of true/false
// pixels in mask are made odd if true, even if false
for($i=0; $i<strlen($data) ; $i++)
{
// get 8bit binary representation of each char
$char = $data{$i};
$binary = asc2bin($char);

// save binary to string
$binstream .= $binary;

// create array of true/false for each bit. confusingly, 0=true, 1=false
for($j=0 ; $j<strlen($binary) ; $j++)
{
$binpart = $binary{$j};
if($binpart=="0")
{
$make_odd[] = true;
} else {
$make_odd[] = false;
}
}
}

// now loop through each pixel and modify colour values according to $make_odd array
$y=0;
for($i=0,$x=0; $i<sizeof($make_odd) ; $i+=3,$x++)
{
// read RGB of pixel
$rgb = ImageColorAt($pic, $x,$y);
$cols = Array();
$cols[] = ($rgb >> 16) & 0xFF;
$cols[] = ($rgb >> 8) & 0xFF;
$cols[] = $rgb & 0xFF;

for($j=0 ; $j<sizeof($cols) ; $j++)
{
if($make_odd[$i+$j]===true && is_even($cols[$j]))
{
// is even, should be odd
$cols[$j]++;
} else if($make_odd[$i+$j]===false && !is_even($cols[$j])){
// is odd, should be even
$cols[$j]--;
} // else colour is fine as is
}

// modify pixel
$temp_col = ImageColorAllocate($outpic,$cols[0],$cols[1],$cols[2]);
ImageSetPixel($outpic,$x,$y,$temp_col);

// if at end of X, move down and start at x=0
if($x==($attributes[0]-1))
{
$y++;
// $x++ on next loop converts x to 0
$x=-1;
}
}

// output modified image as PNG (or other *LOSSLESS* format)
header("Content-type: image/png");
header("Content-Disposition: attachment; filename=encoded.png");
ImagePNG($outpic);

// remove images
ImageDestroy($outpic);
ImageDestroy($pic);
exit();
}

function steg_recover($maskfile)
{
// recovers file hidden in a PNG image

$binstream = "";
$filename = "";

// get image and width/height
$attributes = @getImageSize($maskfile['tmp_name']);
$pic = @ImageCreateFromPNG($maskfile['tmp_name']);

if(!$pic || !$attributes)
{
return "could not read image";
}

// get boundary
$bin_boundary = "";
for($x=0 ; $x<8 ; $x++)
{
$bin_boundary .= rgb2bin(ImageColorAt($pic, $x,0));
}

// convert boundary to ascii
for($i=0 ; $i<strlen($bin_boundary) ; $i+=8)
{
$binchunk = substr($bin_boundary,$i,8);
$boundary .= bin2asc($binchunk);
}


// now convert RGB of each pixel into binary, stopping when we see $boundary again

// do not process first boundary
$start_x = 8;

for($y=0 ; $y<$attributes[1] ; $y++)
{
for($x=$start_x ; $x<$attributes[0] ; $x++)
{
// generate binary
$binstream .= rgb2bin(ImageColorAt($pic, $x,$y));

// convert to ascii
if(strlen($binstream)>=8)
{
$binchar = substr($binstream,0,8);
$ascii .= bin2asc($binchar);
$binstream = substr($binstream,8);
}

// test for boundary
if(strpos($ascii,$boundary)!==false)
{
// remove boundary
$ascii = substr($ascii,0,strlen($ascii)-3);

if(empty($filename))
{
$filename = $ascii;
$ascii = "";
} else {
// final boundary; exit both 'for' loops
break 2;
}
}
}
// on second line of pixels or greater; we can start at x=0 now
$start_x = 0;
}

// remove image from memory
ImageDestroy($pic);

// and output result (retaining original filename)
header("Content-type: text/plain");
header("Content-Disposition: attachment; filename=".$filename);
echo $ascii;
exit();
}

$result = true;
if(!empty($_FILES['hidefile']['tmp_name']))
{
// encode
$result = steg_hide($_FILES['maskfile'],$_FILES['hidefile']);
} else if(!empty($_FILES['maskfile']['tmp_name'])) {
// decode
$result = steg_recover($_FILES['maskfile']);
}

if($result!==true)
{
$error = "<br /><b>Error: </b><br />".$result."<br />";
}
?>
<html>
<head>
<title>PHP-Steg</title>
<style>
body{
background: white;
color: black;
font-family: verdana;
font-size: 12px;
}
b{
font-size: 14px;
}
</style>
</head>
<body>
<b>PHP-Steg - <a href="http://www.puremango.co.uk" target="_blank">www.puremango.co.uk</a></b><br />
<br />
This is application is totally insecure(*) and is a 'concept' application rather than something to actually be employed for security.<br />
Download the <a href="php_steg_src.txt" target="_blank">source code</a> here.<br />
<?=$error?>
<form action="<?=$_SERVER['PHP_SELF']?>" method="post" enctype="multipart/form-data">
<table>
<tr><td>Image</td><td><input type="file" name="maskfile"></td><td> - <b>jpg</b> for encoding, <b>png</b> for decoding</td></tr>
<tr><td>Hide file</td><td><input type="file" name="hidefile"></td><td> - leave blank if you're just decoding</td></tr>
<tr><td colspan="2" align="center"><input type="submit" value="--- go ---" onClick="this.value='processing...';"></td><td>&nbsp;</td></tr>
</table>
</form>
* - for explanation, see the PHP-steg page on puremango.co.uk (under projects)
</body>
</html>
aswin001
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Posts: 1
Joined: Thu Apr 12, 2012 9:14 am

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