Home  >  Article  >  Backend Development  >  How to write registration login verification code in php

How to write registration login verification code in php

尚
Original
2019-10-28 17:38:443253browse

How to write registration login verification code in php

authimg.php The file that generates the verification code:

<?

 $IsLetter = false; //是否出现字母
 session_start();
 $Num  = $_GET["n"];
 
 //生成验证码图片
 header("Content-type: image/PNG");
 $im   = imagecreate(46,20);
 srand((double)microtime()*1000000);
 $Red  = rand(0,200);
 $Green  = rand(0,200);
 $Blue  = rand(0,200);
 $Color  = imagecolorallocate($im, $Red, $Green, $Blue);
 $BackGround = imagecolorallocate($im, 255,255,255);
 imagefill($im,0,0,$BackGround);
 
 if($IsLetter)
 {
  $a = substr(md5($Num*10000000000000000),0,1);
  $b = substr(md5($Num*10000000000000000),4,1);
  $c = substr(md5($Num*10000000000000000),8,1);
  $d = substr(md5($Num*10000000000000000),12,1);
 }
 else
 {
  $a = substr(hexdec(md5($Num*10000000000000000)),2,1);
  $b = substr(hexdec(md5($Num*10000000000000000)),3,1);
  $c = substr(hexdec(md5($Num*10000000000000000)),4,1);
  $d = substr(hexdec(md5($Num*10000000000000000)),5,1);
 }
 
 $Authnum    = strtoupper($a.$b.$c.$d);
 
 $_SESSION["Authnum"] = $Authnum;
 
 imagestring($im, 5, 5, 2, $Authnum, $Color);
 for($i=0;$i<200;$i++)   //加入干扰象素
 {
     $randcolor = imagecolorallocate($im,rand(0,255),rand(0,255),rand(0,255));
     imagesetpixel($im, rand()p , rand()0 , $randcolor);
 }
 imagepng($im);
 imagedestroy($im);
?>

The file that needs to display the verification code:

<?
session_start();
$AuthInput = $_POST["AuthInput"];
$action = $_GET["action"];
?>
<script language="javascript">
function lyalert(){
if( addform.AuthInput.value=="") {
alert("请填写验证码");
document.addform.AuthInput.focus();
return false;
} 
}
</script>
<form name="addform" method="post" action="?action=save" id="addform" onsubmit="return lyalert()">
<table width="500" border="1" cellpadding="5" cellspacing="0">
<tr><td>验证码:</td>
<td><input name="AuthInput" type="text" id="AuthInput"  size="8" maxlength="4" /><script>document.write("<img src=\"authimg.php?n=",Math.random(),"\" />");</script></td></tr>
<tr><td colspan="2" align="center"><input type="submit" name="Button1" value="确定" id="Button1" /></td>
</tr>
</table>
<p> </p>
</form>
  
<?
if($action==&#39;save&#39;)
{
if ($_SESSION["Authnum"] != $AuthInput)
{
?>
<script language="javascript">
alert("验证码输入不正确");
</script>
<? 
}
else
{
 ?>  
<script language="javascript">
 alert("提交成功!");
</script>
<?
 
 
 
} 
}
?>

Recommendation: php server

The above is the detailed content of How to write registration login verification code in php. For more information, please follow other related articles on the PHP Chinese website!

Statement:
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn