php防止远程提交表单的有关问题

php防止远程提交表单的问题。
在网上找到一段防止远程提交表单的demo，它用的是md5(uniqid(rand()))生成令牌验证的方法，如下：

PHP code

<!--

Code highlighting produced by Actipro CodeHighlighter (freeware)
http://www.CodeHighlighter.com/

-->
<?php
session_start();

if ($_POST['submit'] == “go"){
    //check token
    if ($_POST['token'] == $_SESSION['token']){
        //strip_tags
        $name = strip_tags($_POST['name']);
        $name = substr($name,0,40);
        //clean out any potential hexadecimal characters
        $name = cleanHex($name);
        //continue processing….
    }else{
        //stop all processing! remote form posting attempt!
    }
}

$token = md5(uniqid(rand(), true));
$_SESSION['token']= $token;

function cleanHex($input){
    $clean = preg_replace("![\][xX]([A-Fa-f0-9]{1,3})!", "",$input);
    return $clean;
}

<form action="<?php echo $_SERVER['PHP_SELF'];?>" method="post">
<p><label for="name">Name</label>
<input type="text" name="name" id="name" size="20″ maxlength="40″/></p>
<input type="hidden" name="token" value="<?php echo $token;?>"/>
<p><input type="submit" name="submit" value="go"/></p>
                    <div class="aritcle_card">
                        <a class="aritcle_card_img" href="/ai/2085">
                            <img src="https://img.php.cn/upload/ai_manual/000/000/000/175679986390996.png" alt="表单大师AI">
                        </a>
                        <div class="aritcle_card_info">
                            <a href="/ai/2085">表单大师AI</a>
                            <p>一款基于自然语言处理技术的智能在线表单创建工具，可以帮助用户快速、高效地生成各类专业表单。</p>
                            <div class="">
                                <img src="/static/images/card_xiazai.png" alt="表单大师AI">
                                <span>74</span>
                            </div>
                        </div>
                        <a href="/ai/2085" class="aritcle_card_btn">
                            <span>查看详情</span>
                            <img src="/static/images/cardxiayige-3.png" alt="表单大师AI">
                        </a>
                    </div>
                
</form>
?>

登录后复制