现在好多网站使用的验证码非常容易被软件自动识别到,本文介绍了一种PHP生成复杂验证码加入倾斜,弦干扰线,黏贴,旋转等效果
常见的软件不容易自动识别的验证码做法有以下3种:
1、字体变型 (一般通过算法,进行扭曲)
2、字体黏贴 (这里面以qq验证码为代表了,目前网上还是很难找到,破解qq验证码的)
3、干扰线,噪点 (这种识别起来相当容易,很容易被程序自动化识别)
对于上面提到,第1,2 二种方法,在识别时候,是比较困难的。
具体实现代码:
php;" style="margin: 3px auto 0px; padding: 0px 0px 0px 5px; outline: none; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial; width: 640px; line-height: 20px; clear: both; border-left: 3px solid rgb(108, 226, 108);"> <?php /** *带文字旋转,倾斜,黏贴,加正弦干扰线验证码* */ class Utils_Caption { var $Width = 60; //图片宽 var $Height = 30; //图片高 var $Length = 4; //验证码位数 var $BgColor = "#FFFFFF"; //背景色 var $TFonts = array("font.ttf"); var $TFontSize=array(17,20); //字体大小范围 var $TFontAngle=array(-20,20); //旋转角度 var $Chars = "0123456789"; //验证码范围(字母数字) var $Code = array(); //验证码 var $Image = ""; //图形对象 var $FontColors=array('#f36161','#6bc146','#5368bd'); //字体颜色,红绿蓝 var $TPadden = 0.75;///字符间距,多少个字符 var $Txbase = 5;///x轴两边距离 var $Tybase =5 ;///y轴两边距离 var $TLine =true; ///画干扰线 public function RandRSI() ///生成验证码 { $this->TFontAngle=range($this->TFontAngle[0],$this->TFontAngle[1]); $this->TFontSize=range($this->TFontSize[0],$this->TFontSize[1]); $arr=array(); $Chars=$this->Chars; $TFontAngle=$this->TFontAngle; $TFontSize=$this->TFontSize; $FontColors=$this->FontColors; $code=""; $font=dirname(__FILE__)."/font/".$this->TFonts[0]; $charlen=strlen($Chars)-1; $anglelen=count($TFontAngle)-1; // 角度范围 $fontsizelen=count($TFontSize)-1; // 角度范围 $fontcolorlen=count($FontColors)-1; // 角度范围 for($i=0;$i<$this->Length;$i++) ///得到字符与颜色 { $char=$Chars[rand(0,$charlen)]; ///得到字符 $angle=$TFontAngle[rand(0,$anglelen)]; ///旋转角度 $fontsize=$TFontSize[rand(0,$fontsizelen)]; ///字体大小 $fontcolor=$FontColors[rand(0,$fontcolorlen)]; ///字体大小 $bound=$this->_calculateTextBox($fontsize,$angle,$font,$char); ///得到范围 $arr[]=array($fontsize,$angle,$fontcolor,$char,$font,$bound); ///得到矩形框 $code.=$char; } $this->Code=$arr; //验证码 return $code; } public function Draw() ///画图 { if(empty($this->Code)) $this->RandRSI(); $codes=$this->Code; ///用户验证码 $wh=$this->_getImageWH($codes); $width=$wh[0]; $height=$wh[1]; ///高度 $this->Width=$width; $this->Height=$height; $this->Image = imageCreate( $width, $height ); $image=$this->Image; $back = $this->_getColor2($this->_getColor( $this->BgColor)); ///背景颜色 imageFilledRectangle($image, 0, 0, $width, $height, $back); ///填充背景 $TPadden=$this->TPadden; $basex=$this->Txbase; $color=null; foreach ($codes as $v) ///逐个画字符 { $bound=$v[5]; $color=$this->_getColor2($this->_getColor($v[2])); imagettftext($image, $v[0], $v[1], $basex, $bound['height'],$color , $v[4], $v[3]); $basex=$basex+$bound['width']*$TPadden-$bound['left'];///计算下一个左边距 } $this->TLine?$this->_wirteSinLine($color,$basex):null; ///画干扰线 header("Content-type: image/png"); imagepng( $image); imagedestroy($image); } /** *通过字体角度得到字体矩形宽度* * * @param int $font_size 字体尺寸 * @param float $font_angle 旋转角度 * @param string $font_file 字体文件路径 * @param string $text 写入字符 * @return array 返回长宽高 */ private function _calculateTextBox($font_size, $font_angle, $font_file, $text) { $box = imagettfbbox($font_size, $font_angle, $font_file, $text); $min_x = min(array($box[0], $box[2], $box[4], $box[6])); $max_x = max(array($box[0], $box[2], $box[4], $box[6])); $min_y = min(array($box[1], $box[3], $box[5], $box[7])); $max_y = max(array($box[1], $box[3], $box[5], $box[7])); return array( 'left' => ($min_x >= -1) ? -abs($min_x + 1) : abs($min_x + 2), 'top' => abs($min_y), 'width' => $max_x - $min_x, 'height' => $max_y - $min_y, 'box' => $box ); } private function _getColor( $color ) //#ffffff { return array(hexdec($color[1].$color[2]),hexdec($color[3].$color[4]),hexdec($color[5].$color[6])); } private function _getColor2( $color ) //#ffffff { return imagecolorallocate ($this->Image, $color[0], $color[1], $color[2]); } private function _getImageWH($data) { $TPadden=$this->TPadden; $w=$this->Txbase; $h=0; foreach ($data as $v) { $w=$w+$v[5]['width']*$TPadden-$v[5]['left']; $h=$h>$v[5]['height']?$h:$v[5]['height']; } return array(max($w,$this->Width),max($h,$this->Height)); } //画正弦干扰线 private function _wirteSinLine($color,$w) { $img=$this->Image; $h=$this->Height; $h1=rand(-5,5); $h2=rand(-1,1); $w2=rand(10,15); $h3=rand(4,6); for($i=-$w/2;$i<$w/2;$i=$i+0.1) { $y=$h/$h3*sin($i/$w2)+$h/2+$h1; imagesetpixel($img,$i+$w/2,$y,$color); $h2!=0?imagesetpixel($img,$i+$w/2,$y+$h2,$color):null; } } }
DEMO代码:
$rsi = new Utils_Caption(); $rsi->TFontSize=array(15,17); $rsi->Width=50; $rsi->Height=25; $code = $rsi->RandRSI(); session_start(); $_SESSION["CHECKCODE"] = $code; $rsi->Draw();
运行效果:
大家可以修改代码中的相应数值达到自己需要的复杂度