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