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Hi,
This example shows you how to add dynamic image security system in signup pages like yahoo, hotmail etc. It will make your webpages more secured.
See the attached zip file and run login.php
dynamicimage.php
| <?php
$data = base64_decode($HTTP_GET_VARS['dt']);
$im = imagecreate(65,20);
$white = imagecolorallocate($im,255,255,255);
$gray = imagecolorallocate($im, 210,210,210);
$black = imagecolorallocate($im, 0,0,0);
imagestring($im,4,8,2,$data,$black);
imageline($im,0,10,65,10,$gray);
imagepng($im);
?> | |
login.php
| <! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Dynamic Image Creation</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
</head>
<body>
This script shows how to implement a strong authentication scheme using dynamically generated image. This small snippet is extremely helpful for creating your signup script.
<form name="form1" method="post" action="">
<table width="42%" border="0" align="center" cellpadding="1" cellspacing="0" bgcolor="#990000">
<tr>
<td><table width="100%" border="0" align="center" cellpadding="2" cellspacing="2" bgcolor="#FFFFFF">
<tr>
<td width="64%">Type the following Image Data : <br>
<input name="data" type="text" id="data3"></td>
</tr>
<?
global $data;
$data = mt_rand(100000,1000000);
?>
<tr>
<td>Image : <br>
<img src=dynamicImage.php?dt=<? global $data; echo base64_encode($data);?> border="1">
<input type=hidden name='md5' value =<? echo md5($data);?>></td>
</tr>
<tr>
<td> </td>
</tr>
<tr>
<td><input type="submit" name="Submit" value="Submit"></td>
</tr>
<tr>
<td>Result : <b>
<?
if (count($HTTP_POST_VARS)>0)
{
if (md5($HTTP_POST_VARS['data']) == $HTTP_POST_VARS['md5'])
{
echo "Its Alright";
}
else
{
echo "Wrong";
}
}
?>
<br>
</b></td>
</tr>
</table></td>
</tr>
</table>
</form>
</body>
</html> | |
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