验证码实现及简单验证码校对

来源：互联网发布：公安部网络安全保卫局编辑：程序博客网时间：2024/06/06 00:03

前端代码:

<?php session_start(); ?><!DOCTYPE html><html><head><meta http-equiv="content-type" content="text/html;charset=utf-8"><title>This is a test!</title></head><body><form method="post" name="form"><input type="text" placeholder="账号"/><br/><input type="password" placeholder="密码"/><br/><input type="text" placeholder="验证码" name="yzm"/><img id="verImg" src="ceshi2.php"/><a href="#" class="change" onclick="changeVer()">点击刷新</a><br/><input type="submit" name="denglu" value="登录"/></form><script type="text/javascript">//刷新验证码function changeVer(){document.getElementById("verImg").src="ceshi2.php?tmp="+Math.random();}</script><?php//验证码的值保存在 验证码 $_SESSION["VerifyCode"]if(@$_POST[denglu]){if(@$_POST[yzm]==""){echo "请输入验证码";}else{if(@strtolower($_POST[yzm])==@strtolower($_SESSION["VerifyCode"])){//strtolower()将函数转换成小写 实现不区分大小写echo "验证码输入正确";}else{echo "验证码输入错误";}}}?></body></html>

php脚本文件验证码的代码如下:

<?phpsession_start();//开启session记录验证码数据vCode(4, 15);//设置验证码的字符个数和图片基础宽度//vCode 字符数目，字体大小，图片宽度、高度function vCode($num = 4, $size = 20, $width = 0, $height = 0) {!$width && $width = $num * $size * 4 / 5 + 15;!$height && $height = $size + 10;//设置验证码字符集合$str = "23456789abcdefghijkmnpqrstuvwxyzABCDEFGHIJKLMNPQRSTUVW";//保存获取的验证码$code = '';//随机选取字符for ($i = 0; $i < $num; $i++) {$code .= $str[mt_rand(0, strlen($str)-1)];}//创建验证码画布$im = imagecreatetruecolor($width, $height);//背景色$back_color = imagecolorallocate($im, mt_rand(0,100),mt_rand(0,100), mt_rand(0,100));//文本色$text_color = imagecolorallocate($im, mt_rand(100, 255), mt_rand(100, 255), mt_rand(100, 255));imagefilledrectangle($im, 0, 0, $width, $height, $back_color);// 画干扰线for($i = 0;$i < 5;$i++) {$font_color = imagecolorallocate($im, mt_rand(0, 255), mt_rand(0, 255), mt_rand(0, 255));imagearc($im, mt_rand(- $width, $width), mt_rand(- $height, $height), mt_rand(30, $width * 2), mt_rand(20, $height * 2), mt_rand(0, 360), mt_rand(0, 360), $font_color);}// 画干扰点for($i = 0;$i < 50;$i++) {$font_color = imagecolorallocate($im, mt_rand(0, 255), mt_rand(0, 255), mt_rand(0, 255));imagesetpixel($im, mt_rand(0, $width), mt_rand(0, $height), $font_color);}//随机旋转角度数组$array=array(5,4,3,2,1,0,-1,-2,-3,-4,-5);// 输出验证码// imagefttext(image, size, angle, x, y, color, fontfile, text)@imagefttext($im, $size , array_rand($array), 12, $size + 6, $text_color, 'c:\WINDOWS\Fonts\simsun.ttc', $code);$_SESSION["VerifyCode"]=$code;//no-cache在每次请求时都会访问服务器//max-age在请求1s后再次请求会再次访问服务器，must-revalidate则第一发送请求会访问服务器，之后不会再访问服务器// header("Cache-Control: max-age=1, s-maxage=1, no-cache, must-revalidate");header("Cache-Control: no-cache");header("Content-type: image/png;charset=gb2312");//将图片转化为png格式imagepng($im);imagedestroy($im);}?>

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