Simple and secure PHP code-attached invocation method _php Tips

Example of a verification code

Second, PHP Verification code class, secoder.class.php

<?php/** * Security Verification Code: Verify code text is distorted, rotated, using different fonts, add interference code * * @author Running water Mengchun <cmpan (at) qq.com> * @link HT Tp://labs.yulans.cn/yl_security_secoder * @link Http://wiki.yulans.cn/docs/yl/security/secoder * * Class Yl_security_ 
  Secoder {/** * Verification Code of the session of the subscript * * @var string///public static $seKey = ' Sid.sek ey.ylans.cn '; 
  public static $seKey = ' Sid ';   public static $expire = 3000; Authenticode expiration (s)/** * code used in the character, 01IO easy to confuse, recommended not * * @var string/public static $codeSet = ' 346789ABCDE 
  Fghjklmnpqrtuvwxy ';   public static $fontSize = 25;  Authenticode font size (px) public static $useCurve = true;  Whether to draw a confusing curve public static $useNoise = true;    Add pragma public static $imageH = 0;    Verify code picture wide public static $imageL = 0;    Verify code picture long public static $length = 4; Verify the number of code digits public static $BG = Array (243, 251, 254);   Background protected static $_image = NULL;   Verification code picture instance protected static $_color = NULL; 
 Verify Code Font Color  
  /** * Output Verification code and the value of the validation code saved in the session of the session * Verification code saved to the format of the session: $_session[self:: $seKey] = array (' Code ' => ' Verification Code value ', ' time 
   ' => ' Verification Code creation time '); */public static function entry () {//Picture width (px) Self:: $imageL | | self:: $imageL = self:: $length * Self:: $fontSi  
    Ze * 1.5 + self:: $fontSize *1.5; Picture High (px) Self:: $imageH | | 
    Self:: $imageH = self:: $fontSize * 2;  
    Establish a self:: $imageL x Self:: $imageH image self::$_image = Imagecreate (self:: $imageL, Self:: $imageH);  
    Set Background imagecolorallocate (Self::$_image, Self:: $BG [0], Self:: $BG [1], Self:: $BG [2]); 
    CAPTCHA font random Color Self::$_color = imagecolorallocate (Self::$_image, Mt_rand (1,120), Mt_rand (1,120), Mt_rand (1,120)); The validation code uses a random font//$ttf = DirName (__file__). '/ttfs/'. Mt_rand (1, 20). '. TTF '; 4 $ttf = dirname (__file__).  
     
    '/ttfs/4.ttf '; 
    if (self:: $useNoise) {//Paint Miscellaneous point self::_writenoise (); } if (self:: $useCurve) {//Paint interference line Self::_writecurve (); //Draw Verification Code $code = Array (); Verification code $codeNX = 0; 
      The left margin for the nth character of the authentication code for ($i = 0; $i <self:: $length; $i + +) {$code [$i] = self:: $codeSet [Mt_rand (0, 27)]; 
      $codeNX + + Mt_rand (self:: $fontSize *1.2, Self:: $fontSize *1.6); Write a captcha character imagettftext (Self::$_image, Self:: $fontSize, Mt_rand ( -40), $codeNX, self:: $fontSize *1.5, Self::$_co 
    Lor, $ttf, $code [$i]); }//Save Verification Code isset ($_session) | | 
    Session_Start (); $_session[self:: $seKey] [' code '] = Join (", $code); Save the check code to session $_session[self:: $seKey [' time '] = time (); 
    Verify Code creation Time Header (' Cache-control:private, max-age=0, No-store, No-cache, Must-revalidate ');    
    Header (' cache-control:post-check=0, pre-check=0 ', false);    
    Header (' Pragma:no-cache '); 
   
    Header ("Content-type:image/png");  
    Output Image imagepng (self::$_image); 
  Imagedestroy (Self::$_image); 
   /** * Draw a random sine function curve that is composed of two lines (you can change to a more handsome curve function)* I forgot the math formula for the high school. * sinusoidal function Analytic formula: Y=asin (ωx+φ) +b * Effects of various constant values on function images: * A: Determining peak (i.e., multiple of longitudinal tensile compression) * b : Indicates the position of the waveform in the y-axis or the longitudinal distance (up and down) *φ: Determines the waveform and the position of the x axis or the transverse moving distance (left plus right minus) *ω: Decision period (minimum positive period t=2π/∣ω∣) * * * * * Protected St         atic function _writecurve () {$A = Mt_rand (1, Self:: $imageH/2);  Amplitude $b = Mt_rand (-self:: $imageH/4, Self:: $imageH/4);  Y-axis Offset $f = Mt_rand (-self:: $imageH/4, Self:: $imageH/4); X axis Offset $T = Mt_rand (self:: $imageH *1.5, Self:: $imageL *2); 
             
    Cycle $w = (2* m_pi)/$T; $px 1 = 0; The starting position of the curve axis $px 2 = Mt_rand (self:: $imageL/2, Self:: $imageL * 0.667); The end position of the curve axis for ($px = $px 1; $px <= $px 2; $px = $px + 0.9) {if ($w!=0) {$py = $A * Sin ($w * $px + $f) + $b + self:: $imageH/2; 
        y = Asin (ωx+φ) + b $i = (int) (self:: $fontSize-6)/4); while ($i > 0) {imagesetpixel (self::$_image, $px + $i, $py + $i, self::$_color);//Here's a portrait of a vegetarian dot than imagettftext and IM AgesTring performance is much better $i--;         }} $A = Mt_rand (1, Self:: $imageH/2);  Amplitude $f = Mt_rand (-self:: $imageH/4, Self:: $imageH/4); X axis Offset $T = Mt_rand (self:: $imageH *1.5, Self:: $imageL *2);    
    Cycle $w = (2* m_pi)/$T; 
    $b = $py-$A * sin ($w * $px + $f)-Self:: $imageH/2; 
    $PX 1 = $px 2; 
    $px 2 = self:: $imageL; for ($px = $px 1; $px <= $px 2; $px = $px + 0.9) {if ($w!=0) {$py = $A * Sin ($w * $px + $f) + $b + self:: $imageH/ 2; 
        y = Asin (ωx+φ) + b $i = (int) (self:: $fontSize-8)/4); while ($i > 0) {imagesetpixel (self::$_image, $px + $i, $py + $i, self::$_color);//here (while) loop portrait dot more than IM 
        Agettftext and imagestring use font size to draw (without this while loop) performance is much better $i-; 
    /** * Draw Miscellaneous points * Write different color letters or numbers to the picture * * protected static function _writenoise () { for ($i = 0; $i < $i + +) {//Miscellaneous point color $noiseColor = Imagecolorallocate ( 
               Self::$_image, Mt_rand (150,225), Mt_rand (150,225), Mt_ 
      Rand (150,225)); for ($j = 0; $j < 5 $j + +) {//Paint Miscellaneous point imagestring (Self::$_image, 5, M T_rand ( -10, Self:: $imageL), Mt_rand ( -10, Self:: $imageH), Self:: $codeSet [Mt_rand (0, 27)],//Miscellaneous point text with 
      The letter or number $noiseColor) of the machine; /** * Verify that the verification code is correct * * @param string $code user authentication code * @param BOOL user authentication code is correct/publi 
    C static function Check ($code) {isset ($_session) | | session_start (); Authenticode cannot be empty if (empty ($code) | | empty ($_session[self:: $seKey]) {//echo $_session[self:: $seKey [' Code ']. ' 
      1 '; 
           
    return false; //Session expiration if (time ()-$_session[self:: $seKey] [' time '] > Self:: $expire) {unset ($_session[self::$ 
      Sekey]); echo $_session[self:: $seKey] [' Code ']. ' 
   2 ';   return false; 
    return 0; }//if ($code = = $_session[self:: $seKey [' Code ']) {if strtoupper ($code) = = $_session[self:: $seKey [' Code ']) {/ /case-insensitive comparison//echo $_session[self:: $seKey [' Code ']. ' 
      3 ';     
    return true; }//echo $_session[self:: $seKey [' Code ']. ' 
    4 '; 
         
  return false; }//useage/* Yl_security_secoder:: $useNoise = false; 
To be more secure, change to True yl_security_secoder:: $useCurve = true; 
Yl_security_secoder::entry (); */*//Verify code if (! 
Yl_security_secoder::check (@$_post[' Secode ')) {print ' Error secode '; 

 } 
*/

Third, call the method

1. Display Verification code page code.php

<?php  
  session_start (); 
  Require ' secoder.class.php '; First the class is included, the actual path is modified according to the actual situation.  
  $vcode = new Yl_security_secoder ();   Instantiate an object  
  $vcode->entry ();  
? >  

2, check the verification code is correct

<?php  
  session_start (); 
  Require ' secoder.class.php '; First the class is included, the actual path is modified according to the actual situation.  
  $vcode = new Yl_security_secoder ();   Instantiate an object  
  //$vcode->entry ();  
  $code = $_get[' code '];  
  echo $vcode->check ($code);     
  $_session[' Code ' = $VC->getcode ()//Verify code is saved to session 
?>  

3. Verification Code Input Box call page

 click the picture to retrieve the verification code <br> 

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