456 lines
14 KiB
PHP
456 lines
14 KiB
PHP
<?php
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/*
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*
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* @(#) $Id: form_captcha.php,v 1.23 2012/07/14 08:39:44 mlemos Exp $
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*
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*/
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class form_captcha_class extends form_custom_class
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{
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var $format="{image} {text} {redraw}{validation}";
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var $image_parameter="___image";
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var $image_width=80;
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var $image_height=20;
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var $image_align="top";
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var $image_format="gif";
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var $verification_style="";
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var $verification_class="";
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var $text_color="#000000";
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var $background_color="";
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var $noise_image="";
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var $noise_image_format="";
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var $text_length=4;
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var $text_characters="0123456789abcdefghijklmnopqrstuvwxyz";
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var $font=2;
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var $expiry_time=0;
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var $expiry_time_validation_error_message="";
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var $validation_error_message="It was not entered the correct text.";
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var $reset_incorrect_text=0;
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var $key="";
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var $text="";
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var $redraw_text="Redraw";
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var $redraw_sub_form="redraw";
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var $validation="";
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var $loaded_text="";
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var $remaining_time=0;
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var $requirements=array(
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"imagecreate"=>"the GD extension is not available",
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"imagegif"=>"the GD extension is not able to save in the GIF format",
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"imagecreatefromgif"=>"the GD extension is not able to read image files in the GIF format",
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"mcrypt_cfb"=>"the mcrypt extension is not available"
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);
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Function CheckRequirements()
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{
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if(IsSet($this->requirements["imagegif"])
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&& strcmp($this->image_format,"gif"))
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{
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$this->requirements["image".$this->image_format]="the GD extension is not able to save in the ".strtoupper($this->image_format)." format";
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UnSet($this->requirements["imagegif"]);
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}
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if(IsSet($this->requirements["imagecreatefromgif"])
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&& strcmp($this->noise_image_format,"gif"))
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{
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if(strlen($this->noise_image_format))
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$this->requirements["imagecreatefrom".$this->noise_image_format]="the GD extension is not able to read image files in the ".strtoupper($this->noise_image_format)." format";
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UnSet($this->requirements["imagecreatefromgif"]);
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}
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Reset($this->requirements);
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$end=(GetType($function=Key($this->requirements))!="string");
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for(;!$end;)
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{
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if(!function_exists($function))
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return($this->requirements[$function]);
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Next($this->requirements);
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$end=(GetType($function=Key($this->requirements))!="string");
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}
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return("");
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}
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Function EncodeText($text)
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{
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$encode_time=time();
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$iv_size=mcrypt_get_iv_size(MCRYPT_3DES,MCRYPT_MODE_CFB);
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$iv=str_repeat(chr(0),$iv_size);
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$key_size=mcrypt_get_key_size(MCRYPT_3DES,MCRYPT_MODE_CFB);
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$key=$encode_time.$this->key;
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if(strlen($key)>$key_size)
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$key=substr($key,0,$key_size);
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return(base64_encode(mcrypt_cfb(MCRYPT_3DES,$key,$text,MCRYPT_ENCRYPT,$iv)).":".$encode_time);
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}
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Function DecodeText($encoded, &$encode_time)
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{
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if(GetType($colon=strpos($encoded,":"))!="integer"
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|| ($encode_time=intval(substr($encoded,$colon+1)))==0
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|| $encode_time>time()
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|| !($encrypted=base64_decode(substr($encoded,0,$colon))))
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return("");
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$iv_size=mcrypt_get_iv_size(MCRYPT_3DES,MCRYPT_MODE_CFB);
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$iv=str_repeat(chr(0),$iv_size);
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$key_size=mcrypt_get_key_size(MCRYPT_3DES,MCRYPT_MODE_CFB);
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$key=$encode_time.$this->key;
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if(strlen($key)>$key_size)
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$key=substr($key,0,$key_size);
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return(mcrypt_cfb(MCRYPT_3DES,$key,$encrypted,MCRYPT_DECRYPT,$iv));
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}
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Function GenerateText()
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{
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for($text="",$c=0;$c<$this->text_length;$c++)
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$text.=substr($this->text_characters,rand(0,strlen($this->text_characters)-1),1);
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return($text);
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}
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Function ValidateText($text)
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{
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if(strlen($text) != $this->text_length)
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return('the verification text length is not '.$this->text_length.' as required');
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for($c=0;$c<$this->text_length;$c++)
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if(GetType(strpos($this->text_characters,$text[$c])) != 'integer')
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return('the character '.$c.' of the verification text is invalid');
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return('');
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}
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Function SetKey(&$form,$encrypted,$format)
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{
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if(strlen($error=$form->GetInputEventURL($this->input,"getimage",array($this->image_parameter=>$encrypted),$image_url)))
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return($error);
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$this->valid_marks["data"]["image"]="<img alt=\"CAPTCHA image\" width=\"".$this->image_width."\" height=\"".$this->image_height."\"".(strlen($this->image_align) ? " align=\"".$this->image_align."\"" : "").(strlen($this->verification_style) ? " style=\"".$this->verification_style."\"" : "").(strlen($this->verification_class) ? " class=\"".$this->verification_class."\"" : "")." src=\"".HtmlEntities($image_url)."\" />";
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if(strlen($error=$form->SetInputValue($this->validation,$encrypted)))
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return($error);
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return($this->DefaultSetInputProperty($form, "Format", $format));
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}
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Function DrawNoiseImage($image,$noise_image,$noise_image_format)
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{
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$function="imagecreatefrom".$noise_image_format;
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if(!@($noise=$function($noise_image)))
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return("could not read the noise ".strtoupper($noise_image_format)." image file ".$noise_image);
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$width=imagesx($noise);
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$height=imagesy($noise);
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$offset_x=-rand(0,$width/2);
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$offset_y=-rand(0,$height/2);
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for($x=$offset_x;$x<$this->image_width;$x+=$width)
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for($y=$offset_y;$y<$this->image_height;$y+=$height)
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imagecopy($image,$noise,$x,$y,0,0,$width,$height);
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imagedestroy($noise);
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return("");
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}
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Function ClearImage($image,$color)
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{
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$rgb=(strlen($color) ? $color : "#FFFFFF");
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if(($background_color=imagecolorallocate($image, HexDec(substr($rgb,1,2)), HexDec(substr($rgb,3,2)), HexDec(substr($rgb,5,2))))==-1)
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return("could not allocate the background color");
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if(strlen($color)==0)
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$background_color=imagecolortransparent($image,$background_color);
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imagefilledrectangle($image, 0, 0, $this->image_width-1, $this->image_height-1, $background_color);
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return("");
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}
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Function DrawText($image,$text,$color)
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{
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$rgb=(strlen($color) ? $color : "#000000");
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if(($text_color=imagecolorallocate($image, HexDec(substr($rgb,1,2)), HexDec(substr($rgb,3,2)), HexDec(substr($rgb,5,2))))==-1)
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return("could not allocate the text color");
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if(strlen($color)==0)
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$text_color=imagecolortransparent($image,$text_color);
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$text_width=strlen($text)*imagefontwidth($this->font);
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$text_height=imagefontheight($this->font);
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imagestring($image, $this->font, rand(0,$this->image_width-$text_width), rand(0,$this->image_height-$text_height), $text, $text_color);
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return("");
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}
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Function SetInputProperty(&$form, $property, $value)
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{
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switch($property)
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{
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case "TextLength":
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case "ImageWidth":
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case "ImageHeight":
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if(strcmp($value,intval($value))
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|| intval($value)<=0)
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return("it was not specified a valid ".$property." value");
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switch($property)
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{
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case "TextLength":
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$this->text_length=intval($value);
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break;
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case "ImageWidth":
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$this->image_width=intval($value);
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break;
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case "ImageHeight":
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$this->image_height=intval($value);
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break;
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}
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break;
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case "Font":
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if(strcmp($value,intval($value))
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|| intval($value)<0)
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return("it was not specified a valid ".$property." value");
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$this->font=intval($value);
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break;
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case "TextColor":
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case "BackgroundColor":
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if(!preg_match('/^#[0-9a-fA-F]{6}$/', $value))
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return("it was not specified a valid ".$property." value");
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switch($property)
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{
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case "TextColor":
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$this->text_color=$value;
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break;
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case "BackgroundColor":
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$this->background_color=$value;
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break;
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}
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break;
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case "ImageFormat":
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switch($value)
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{
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case "gif":
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case "jpeg":
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case "png":
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$this->image_format=$value;
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break;
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default:
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return($value." is not a supported image format");
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}
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break;
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case "ImageAlign":
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$this->image_align=$value;
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break;
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case "VerificationStyle":
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$this->verification_style=$value;
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break;
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case "VerificationClass":
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$this->verification_class=$value;
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break;
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case "NoiseFromGIFImage":
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$this->noise_image=$value;
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$this->noise_image_format="gif";
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break;
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case "NoiseFromPNGImage":
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$this->noise_image=$value;
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$this->noise_image_format="png";
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break;
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case "RedrawText":
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if(strlen($value)==0)
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return("it was not specified a valid redraw button text value");
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$this->redraw_text=$value;
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break;
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case "RedrawSubForm":
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if(strlen($value)==0)
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return("it was not specified a valid redraw button sub-form value");
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$this->redraw_sub_form=$value;
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break;
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case "ResetIncorrectText":
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$this->reset_incorrect_text=(intval($value)!=0);
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break;
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case 'VALUE':
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if(strlen($value))
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{
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if(strlen($error = $this->ValidateText($value)))
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return($error);
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}
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else
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$value = $this->GenerateText();
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$form->SetInputValue($this->text, $this->loaded_text = '');
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return($this->SetKey($form,$this->EncodeText($value),$this->format));
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default:
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return($this->DefaultSetInputProperty($form, $property, $value));
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}
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return("");
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}
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Function SetInputProperties(&$form, $arguments)
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{
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$properties=array(
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"TextLength",
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"TextColor",
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"BackgroundColor",
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"ImageFormat",
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"ImageHeight",
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"ImageWidth",
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"ImageAlign",
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"VerificationStyle",
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"VerificationClass",
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"NoiseFromGIFImage",
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"NoiseFromJPEGImage",
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"NoiseFromPNGImage",
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"RedrawText",
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"RedrawSubForm",
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"Font",
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"ResetIncorrectText",
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);
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for($property=0; $property<count($properties); $property++)
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{
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$name=$properties[$property];
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if(IsSet($arguments[$name])
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&& strlen($error=$this->SetInputProperty($form,$name,$arguments[$name])))
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return($error);
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}
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return("");
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}
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Function AddInput(&$form, $arguments)
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{
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if(!IsSet($arguments["Key"])
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|| strlen($arguments["Key"])==0)
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return("it was not specified a valid key");
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$this->key=$arguments["Key"];
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if(IsSet($arguments["ExpiryTime"]))
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{
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if(($this->expiry_time=intval($arguments["ExpiryTime"]))<=0)
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return("it was not specified a valid expiry time value");
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if(IsSet($arguments["ExpiryTimeValidationErrorMessage"])
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&& strlen($arguments["ExpiryTimeValidationErrorMessage"]))
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$this->expiry_time_validation_error_message=$arguments["ExpiryTimeValidationErrorMessage"];
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else
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return("it was not specified a valid expiry time validation error message");
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}
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if(IsSet($arguments["ValidationErrorMessage"])
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&& strlen($arguments["ValidationErrorMessage"]))
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$this->validation_error_message=$arguments["ValidationErrorMessage"];
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else
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return("it was not specified a valid validation error message");
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if(strlen($error=$this->SetInputProperties($form,$arguments)))
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return($error);
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if(strlen($error=$this->CheckRequirements()))
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return($error);
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$this->text=$this->GenerateInputID($form, $this->input, "text");
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$this->redraw=$this->GenerateInputID($form, $this->input, "redraw");
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$this->validation=$this->GenerateInputID($form, $this->input, "validation");
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$this->valid_marks=array(
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"input"=>array(
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"text"=>$this->text,
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"redraw"=>$this->redraw,
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"validation"=>$this->validation
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),
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"data"=>array(
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"image"=>""
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)
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);
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$input_arguments=array(
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"NAME"=>$this->text,
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"ID"=>$this->text,
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"TYPE"=>"text",
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"ValidateAsNotEmpty"=>1,
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"ValidationErrorMessage"=>$this->validation_error_message,
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"ONKEYPRESS"=>"return(event.keyCode!=13)"
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);
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if(IsSet($arguments['DependentValidation']))
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$input_arguments['DependentValidation'] = $arguments['DependentValidation'];
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if(IsSet($arguments["InputClass"]))
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$input_arguments["CLASS"]=$arguments["InputClass"];
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if(IsSet($arguments["InputStyle"]))
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$input_arguments["STYLE"]=$arguments["InputStyle"];
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if(IsSet($arguments["InputTabIndex"]))
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$input_arguments["TABINDEX"]=$arguments["InputTabIndex"];
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if(IsSet($arguments["InputExtraAttributes"]))
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$input_arguments["ExtraAttributes"]=$arguments["InputExtraAttributes"];
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if(strlen($error=$form->AddInput($input_arguments)))
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return($error);
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$redraw_arguments=array(
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"NAME"=>$this->redraw,
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"ID"=>$this->redraw,
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"TYPE"=>"submit",
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"VALUE"=>$this->redraw_text,
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"SubForm"=>$this->redraw_sub_form
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);
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if(IsSet($arguments["RedrawClass"]))
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$redraw_arguments["CLASS"]=$arguments["RedrawClass"];
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if(IsSet($arguments["RedrawStyle"]))
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$redraw_arguments["STYLE"]=$arguments["RedrawStyle"];
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if(strlen($error=$form->AddInput($redraw_arguments)))
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return($error);
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if(strlen($error=$form->AddInput(array(
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"NAME"=>$this->validation,
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"ID"=>$this->validation,
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"TYPE"=>"hidden",
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"VALUE"=>""
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))))
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return($error);
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if(IsSet($arguments["Format"]))
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$this->format = $arguments["Format"];
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if(IsSet($arguments['VALUE'])
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&& strlen($text = $arguments['VALUE']))
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{
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if(strlen($error = $this->ValidateText($text)))
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return($error);
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}
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else
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$text = $this->GenerateText();
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return($this->SetKey($form,$this->EncodeText($text),$this->format));
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}
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Function LoadInputValues(&$form, $submitted)
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{
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if(IsSet($form->Changes[$this->validation]))
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{
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$encrypted=$form->GetInputValue($this->validation);
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$this->loaded_text=$this->DecodeText($encrypted,$encode_time);
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$this->remaining_time=$encode_time+$this->expiry_time-time();
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if(strlen($this->loaded_text)==$this->text_length
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&& ($this->expiry_time==0
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|| $this->remaining_time>0))
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$this->SetKey($form, $encrypted,$this->format);
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else
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{
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$form->SetInputValue($this->validation,$form->Changes[$this->validation]);
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$this->loaded_text="";
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}
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}
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return('');
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}
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Function ValidateInput(&$form)
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{
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if($this->expiry_time
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&& $this->remaining_time<=0)
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return($this->expiry_time_validation_error_message);
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if(strcmp($this->loaded_text,$form->GetInputValue($this->text)))
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{
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if($this->reset_incorrect_text)
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{
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$this->SetKey($form,$this->EncodeText($this->GenerateText()),$this->format);
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$form->SetInputValue($this->text, $this->loaded_text="");
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}
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return($this->validation_error_message);
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}
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return("");
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}
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Function HandleEvent(&$form, $event, $parameters, &$processed)
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{
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switch($event)
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{
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case "getimage":
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if(!IsSet($parameters[$this->image_parameter]))
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return("the image parameter is not being passed to the captcha input getimage event handler");
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$text=$this->DecodeText(strval($parameters[$this->image_parameter]),$encode_time);
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if(!($image=imagecreate($this->image_width,$this->image_height)))
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return("could not create the CAPTCHA image");
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if(strlen($error=$this->ClearImage($image,$this->background_color)))
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return($error);
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if(strlen($this->noise_image)
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&& strlen($error=$this->DrawNoiseImage($image,$this->noise_image,$this->noise_image_format)))
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return($error);
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if(strlen($error=$this->DrawText($image,$text,$this->text_color)))
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return($error);
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Header("Content-Type: image/".$this->image_format);
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$function="image".$this->image_format;
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$function($image);
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imagedestroy($image);
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$processed=1;
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break;
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default:
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return($this->DefaultHandleEvent($form,$event,$parameters,$processed));
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}
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return("");
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}
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};
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?>
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