Example analysis of CAPtcha of php ci framework
- 2020-06-23 00:01:01
- OfStack
php code:
Call php code:
html code:
js code:
<?php
class Captcha_code
{
var $width='60';
var $num='4';
var $height='20';
var $name='randcode';
public function __construct($conf="")
{
if($conf!="")
{
foreach($conf as $key=>$value)
{
$this->$key=$value;
}
}
}
function show()
{
Header("Content-type: image/gif");
/*
* Initialize the
*/
$border = 0; // Whether you want a border 1 to :0 Don't
$how = $this->num; // Verification code number
$w = $this->width; // Image width
$h = $this->height; // Picture height
$fontsize = 5; // The font size
$alpha = "abcdefghijkmnopqrstuvwxyz"; // Captcha content 1: The letter
$number = "023456789"; // Captcha content 2: digital
$randcode = ""; // Validation code string initialization
srand((double)microtime()*1000000); // Initializes the random number seed
$im = ImageCreate($w, $h); // Create a verification image
/*
* Draw the basic frame
*/
$bgcolor = ImageColorAllocate($im, 255, 255, 255); // Set the background color
ImageFill($im, 0, 0, $bgcolor); // Fill background color
if($border)
{
$black = ImageColorAllocate($im, 0, 0, 0); // Set the border color
ImageRectangle($im, 0, 0, $w-1, $h-1, $black);// Draw the border
}
/*
* Produces random characters bit by bit
*/
for($i=0; $i<$how; $i++)
{
$alpha_or_number = mt_rand(0, 1); // Letters or Numbers
$str = $alpha_or_number ? $alpha : $number;
$which = mt_rand(0, strlen($str)-1); // Which character to take
$code = substr($str, $which, 1); // Take a character
$j = !$i ? 4 : $j+15; // Glyph position
$color3 = ImageColorAllocate($im, mt_rand(0,100), mt_rand(0,100), mt_rand(0,100)); // Character random color
ImageChar($im, $fontsize, $j, 3, $code, $color3); // Draw characters
$randcode .= $code; // Add the captcha string bit by bit
}
/*
* Add interference
*/
for($i=0; $i<5; $i++)// Draw background interference lines
{
$color1 = ImageColorAllocate($im, mt_rand(0,255), mt_rand(0,255), mt_rand(0,255)); // Interference line color
ImageArc($im, mt_rand(-5,$w), mt_rand(-5,$h), mt_rand(20,300), mt_rand(20,200), 55, 44, $color1); // Interference lines
}
for($i=0; $i<$how*15; $i++)// Paint the background noise
{
$color2 = ImageColorAllocate($im, mt_rand(0,255), mt_rand(0,255), mt_rand(0,255)); // Interference point color
ImageSetPixel($im, mt_rand(0,$w), mt_rand(0,$h), $color2); // Noise points
}
// Writes the captcha string session
//$this->session->set_userdata(array($this->name=>$randcode));
$_SESSION[$this->name]=$randcode;
/* End of the drawing */
Imagegif($im);
ImageDestroy($im);
/* End of the drawing */
}
}
?>
Call php code:
function verify_image() {
$conf['name'] = 'verify_code'; // As a configuration parameter
$this->load->library('lib_captcha', $conf);
$this->lib_captcha->show();
$yzm_session = $this->session->userdata('verify_code');
echo $yzm_session;
}
html code:
<dl>
<dt> Verification code: </dt>
<dd>
<input type="text" name="verify_text" id="verify_text" class="yzma" value="">
<img src="/user/verify_image" alt=" Verification code " id="verify_code" class="yz_img" />
<a href="javascript:changeCode();" class="change_yz"> in 1 zhang </a>
</dd>
<dd class="tips_wrong"><b> The captcha is incorrect </b></dd>
<dd class="tips_correct"></dd>
</dl>
js code:
<script type="text/javascript">
function changeCode(){
FS.query("#verify_code").src ="/user/verify_image?r=" + Math.random();
}
</script>