<?php
/*
Jax Captcha Class v1.o1 - Copyright (c) 2005, Andreas John aka Jack (tR)
This program and it's moduls are Open Source in terms of General Public License (GPL) v2.0
class.captcha.php (captcha class module)
Last modification: 2005-09-05
*/
class captcha
{
var $session_key = null;
var $temp_dir = null;
var $width = 170;
var $height = 60;
var $jpg_quality = 15;
/**
* Constructor - Initializes Captcha class!
*
* @param string $session_key
* @param string $temp_dir
* @return captcha
*/
function captcha( $session_key, $temp_dir )
{
$this->session_key = $session_key;
$this->temp_dir = $temp_dir;
}
/**
* Generates Image file for captcha
*
* @param string $location
* @param string $char_seq
* @return unknown
*/
function _generate_image( $location, $char_seq )
{
$num_chars = strlen($char_seq);
$img = imagecreatetruecolor( $this->width, $this->height );
imagealphablending($img, 1);
imagecolortransparent( $img );
// generate background of randomly built ellipses
for ($i=1; $i<=200; $i++)
{
$r = round( rand( 0, 100 ) );
$g = round( rand( 0, 100 ) );
$b = round( rand( 0, 100 ) );
$color = imagecolorallocate( $img, $r, $g, $b );
imagefilledellipse( $img,round(rand(0,$this->width)), round(rand(0,$this->height)), round(rand(0,$this->width/16)), round(rand(0,$this->height/4)), $color );
}
$start_x = round($this->width / $num_chars);
$max_font_size = $start_x;
$start_x = round(0.5*$start_x);
$max_x_ofs = round($max_font_size*0.9);
// set each letter with random angle, size and color
for ($i=0;$i<=$num_chars;$i++)
{
$r = round( rand( 127, 255 ) );
$g = round( rand( 127, 255 ) );
$b = round( rand( 127, 255 ) );
$y_pos = ($this->height/2)+round( rand( 5, 20 ) );
$fontsize = round( rand( 18, $max_font_size) );
$color = imagecolorallocate( $img, $r, $g, $b);
$presign = round( rand( 0, 1 ) );
$angle = round( rand( 0, 25 ) );
if ($presign==true) $angle = -1*$angle;
ImageTTFText( $img, $fontsize, $angle, $start_x+$i*$max_x_ofs, $y_pos, $color, '/home/boogicby/www.boogie-palace.com/guestbook/amrtypebf', substr($char_seq,$i,1) );
}
// create image file
imagejpeg( $img, $location, $this->jpg_quality );
flush();
imagedestroy( $img );
return true;
}
/**
* Returns name of the new generated captcha image file
*
* @param unknown_type $num_chars
* @return unknown
*/
function get_pic( $num_chars=8 )
{
// define characters of which the captcha can consist
$alphabet = array(
'a','b','c','d','e','f','g','h','i','j','k','l','m',
'n','o','p','q','r','s','t','u','v','w','x','y','z',
'1','2','3','4','5','6','7','8','9','0' );
$max = sizeof( $alphabet );
// generate random string
$captcha_str = '';
for ($i=1;$i<=$num_chars;$i++) // from 1..$num_chars
{
// choose randomly a character from alphabet and append it to string
$chosen = rand( 1, $max );
$captcha_str .= $alphabet[$chosen-1];
}
// generate a picture file that displays the random string
if ( $this->_generate_image( $this->temp_dir.'/'.'cap_'.md5( strtolower( $captcha_str )).'.jpg' , $captcha_str ) )
{
$fh = fopen( $this->temp_dir.'/'.'cap_'.$this->session_key.'.txt', "w" );
fputs( $fh, md5( strtolower( $captcha_str ) ) );
return( md5( strtolower( $captcha_str ) ) );
}
else
{
return false;
}
}
/**
* check hash of password against hash of searched characters
*
* @param string $char_seq
* @return boolean
*/
function verify( $char_seq )
{
$fh = fopen( $this->temp_dir.'/'.'cap_'.$this->session_key.'.txt', "r" );
$hash = fgets( $fh );
if (md5(strtolower($char_seq)) == $hash)
return true;
else
return false;
}
}
?>
