PHP验证码生成程序几种方法

发布:smiling　来源: PHP粉丝网　添加日期：2014-08-22 10:33:40　浏览: 评论：0　

PHP验证码生这个功能常用于用用户注册登录或发布信息时一个安全验证的基本功能,下面小编来给大家介绍一些常用的PHP验证码生成代码与应用实例.

例1,直接使用数组,此方法比较简单,代码如下:

<html>

<head>

<meta http-equiv="Content-Type" content="text/html; charset=utf-8">

</head>

<body>

<?php

$arr=array(2,3,4,5,8,1,9,7,"a","b","c","d","e","f","中","国","南","北","大","小","多","少");

$b=array_rand($arr,3);

?>

<form action="yz.php" method="post">

<input type="text" name="code" />

<input type="hidden" name="yanzhengma" value="<?php foreach($b  as $key)

         {

          echo $arr[$key];

         }

       ?>"

/>

<input type="submit" name="submit" value="do" />

</form>

<?php

echo “code:";

foreach($b  as $key)

{

echo $arr[$key];

}

?>

</body>

</html>（以上语句另存为一个php文件）

<?php

header(“Content-Type:text/html;charset=utf-8");

echo $_POST["yanzhengma"];

echo $_POST["code"];

if($_POST["yanzhengma"]==$_POST["code"])

{

echo “验证码正确";

}//开源代码phpfensi.com

else

{

die(“<script>alert(‘验证码不正确");location="array_rand.php";</script>");

}

?>

以上语句另存为yz.php

例2,也是用数组只不是数据多了一点,代码如下:

function UPCAbarcode($code) {

  $lw = 2; $hi = 100;

  $Lencode = array('0001101','0011001','0010011','0111101','0100011',

                   '0110001','0101111','0111011','0110111','0001011');

  $Rencode = array('1110010','1100110','1101100','1000010','1011100',

                   '1001110','1010000','1000100','1001000','1110100');

  $ends = '101'; $center = '01010';

  /* UPC-A Must be 11 digits, we compute the checksum. */

  if ( strlen($code) != 11 ) { die("UPC-A Must be 11 digits."); }

  /* Compute the EAN-13 Checksum digit */

  $ncode = '0'.$code;

  $even = 0; $odd = 0;

  for ($x=0;$x<12;$x++) {

    if ($x % 2) { $odd += $ncode[$x]; } else { $even += $ncode[$x]; }

  }

  $code.=(10 - (($odd * 3 + $even) % 10)) % 10;

  /* Create the bar encoding using a binary string */

  $bars=$ends;

  $bars.=$Lencode[$code[0]];

  for($x=1;$x<6;$x++) {

    $bars.=$Lencode[$code[$x]];

  }

  $bars.=$center;

  for($x=6;$x<12;$x++) {

    $bars.=$Rencode[$code[$x]];

  }

  $bars.=$ends;

  /* Generate the Barcode Image */

  $img = ImageCreate($lw*95+30,$hi+30);

  $fg = ImageColorAllocate($img, 0, 0, 0);

  $bg = ImageColorAllocate($img, 255, 255, 255);

  ImageFilledRectangle($img, 0, 0, $lw*95+30, $hi+30, $bg);

  $shift=10;

  for ($x=0;$x    if (($x<10) || ($x>=45 && $x<50) || ($x >=85)) { $sh=10; } else { $sh=0; }

    if ($bars[$x] == '1') { $color = $fg; } else { $color = $bg; }

    ImageFilledRectangle($img, ($x*$lw)+15,5,($x+1)*$lw+14,$hi+5+$sh,$color);

  }

  /* Add the Human Readable Label */

  ImageString($img,4,5,$hi-5,$code[0],$fg);

  for ($x=0;$x<5;$x++) {

    ImageString($img,5,$lw*(13+$x*6)+15,$hi+5,$code[$x+1],$fg);

    ImageString($img,5,$lw*(53+$x*6)+15,$hi+5,$code[$x+6],$fg);

  }

  ImageString($img,4,$lw*95+17,$hi-5,$code[11],$fg);

  /* Output the Header and Content. */

  header("Content-Type: image/png");

  ImagePNG($img);

}

UPCAbarcode('12345678901');

?>

例3,这个是一个比较完整的ajax刷新验证码实例.

vcode.php,代码如下:

<?php

session_start();//开启session功能

header("Cache-Control: no-cache, must-revalidate");

$im = imagecreate(60,30);//定义图片宽度和高度

$vcode=getVCode();//获取要显示的字符

$bg = imagecolorallocate($im, 255, 255, 255);//定义图片背景

$txt = imagecolorallocate($im, rand(0,255), rand(0,255), rand(0,255));//定义要显示字符的颜色

imagestring($im, 8, 0, 0, $vcode, $txt);//写入字符串到图片

header(Content-type: image/jpeg);//定义Content-type

imagejpeg($im);//以JPEG格式显示图片

$_SESSION[vcode]=$vcode;//写入SESSION

function getVCode(){    //随机生成用户指定个数的字符串

  $codenum=4;

  $checkcode="";

  $string="";//要显示的可选字符串，请自行定义；

  for($i=0;$i<$codenum;$i  ) {

  $number=rand(0,2);

  switch($number){  //根据可选字符串可灵活定义；

       case 0 : $rand_number=rand(0,10);break;

       case 1 : $rand_number=rand(11,36);break;

       case 2 : $rand_number=rand(37,62);break;

  }

  $code=substr($string,$rand_number,1);

  $checkcode=$checkcode.$code;

  }

  return  $checkcode;

}

?>

loginform.html,代码如下:

<form name="loginform">

<table class="dtable">

        <tr>

          <td width="100"> 用户名 </td><td><input class="txtbox" name="loginname" type=text size="30"/></td>

        </tr>

        <tr>

          <td width="100"> 密码 </td><td><input class="txtbox" name="loginpwd" type=password size="30"/></td>

        </tr>

        <tr>

          <td width="100"> 验证码 </td>

          <td><input class="txtbox" name="loginvcode" type=text size="10"/>

          <img id="vcode" src="vcode.php" alt="验证码" align="absmiddle"/>

          <a href="javascript：getVCode();">换一张</a></td>

        </tr>

</table>

<table>

        <tr><td colspan="2">

          <input class="btn" name="ok" type="button" value="登录" onclick="setType('usr');usrVCode();">

          <input class="btn" name="reset" type="reset" value="重写">

          <input class="btn" name="exit" type="button" value="退出" onclick="Hide();">

        </td></tr>

</table>

<table>

        <tr><td colspan="2">

          还没有注册? <a href="javascript：setType('usr');Show('0','addform');">马上注册</a>

          忘记密码? <a href="javascript：setType('usr');Show('0','pwdform');">取回密码</a>

        </td></tr>

</table>

</form>

vcode.js,代码如下:

//该函数用来获取验证码

function getVCode() {

        var vcode=document.getElementById('vcode');

        vcode.src = 'vcode.php?nocache='+new Date().getTime();

}

//该函数用来验证验证码

function usrVCode() {

        if(!checkLogin())return false;

        var loginvcode=document.loginform.loginvcode.value;

        var xmlhttp1=createAjax();

        var data='&loginvcode='+loginvcode;

if (xmlhttp1) {

  var state=document.getElementById('state');

          xmlhttp1.open('get',?do=vcodedo'+data,true);

  xmlhttp1.send(null);

  xmlhttp1.onreadystatechange=function() {

    if (xmlhttp1.readyState==4 && xmlhttp1.status==200) {

             setTimeout("state.style.display = 'none';",1000);

     var myres=xmlhttp1.responseText;

             var result=(myres==1)?"恭喜您,验证码输入正确!":"很抱歉,验证码输入错误!";

             if(myres==0)alert(result);

             if(myres==1)usrLogin();

            }

    else {

             state.style.display = "";

     state.style.left=(document.body.offsetWidth-350)/2;

             state.style.top=(document.body.offsetHeight-235)/2+document.body.scrollTop;

    }

          }

}

}