php – 表单提交w /验证后提供下载

我在.php中创建了一个非常简单的下载代码救赎者(感谢此处的帮助),并且我很难弄清楚如果验证成功,下载服务的最佳方式是什么.基本上 –

用户输入无效代码 – >页面刷新并显示错误消息.
用户输入有效代码 – >下载“另存为” – >刷新页面.

在我使用http://www.zubrag.com/scripts/download.php来提供文件的那一刻,但是一旦开始下载,我的表单刷新页面,但只有一半加载内容？！

这是我用PHP脚本的表单.

<div class="dcrForm">
    <p>Have a physical copy of this release? Claim your digital download by entering your Download Code below.</p>
    <form  action="index.php" method="post">
        <input type="text" name="code" class="dcrInput" value="">
        <input type="submit" name="harrisSubmit" class="dcrSubmit" value="Submit">
    </form>
<?php
    include("scripts/dcr_config.php");
    $code="";
    $log="";

    if (isset($_POST['harrisSubmit']))
    {
        $code=$_POST['code'];

        $link = mysql_connect($hostname, $dbusername, $dbpassword);
        mysql_select_db("$databasename");

        $query = "select count from $harris where code='$code'";
        if ($q=mysql_query($query))
            if ($r=mysql_fetch_array($q)){
                if ($r[0]<3)
                {
                    $subquery="update $tbname set count='".($r[0]+1)."' where code='$code'";
                    mysql_query($subquery);
                    ?><script>window.location.href="download.php?f=test.txt";</script><?php
                }
            }
        $log="<p>Invalid code. Try Again.</p>";
    }
    echo $log."";
?>
</div>

有没有人对下载服务的最佳方式有什么想法？我知道目前任何拥有该文件位置的人都可以下载该文件,但我不知道如何保护我

解决方法:

我很高兴你能做到这一点！

如果您要将用户重定向到下载脚本,则该脚本需要附加某种令牌以防止未经授权的下载,基本上会重新验证给定的代码或令牌.

在上面的脚本中,您可以执行以下操作,而不是输出javascript以重定向到下载脚本：

<?php

include "scripts/dcr_config.php";
$code = "";
$log  = "";

if (isset($_POST['harrisSubmit'])) {
    $code = trim($_POST['code']);

    $link = mysql_connect ( $hostname, $dbusername, $dbpassword );
    mysql_select_db ( "$databasename" );

    $code = mysql_real_escape_string($code); // very important! protects against exploits

    $query = "select count from $harris where code='$code'";
    if ($q = mysql_query ( $query )) {
        if ($r = mysql_fetch_array ( $q )) {
            if ($r [0] < 3) {
                $subquery = "update $tbname set count='" . ($r [0] + 1) . "' where code='$code'";
                mysql_query ( $subquery );

                $file = '/path/to/protecteddownload.txt';

                // send file to browser as a download dialog
                // no content can be output prior to these header() calls
                header('Content-type: application/octet-stream');
                header('Content-Disposition: attachment; filename="file.txt"');
                header('Content-Length: ' . filesize($file));
                header("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1
                header("Expires: Sat, 26 Jul 1997 05:00:00 GMT");

                echo file_get_contents($file);
                exit; // terminate script
            } else {
                $log = 'Sorry, this code has already been redeemed.';
            }
        } else {
            $log = 'Invalid download code.  Try again.';
        }
    } else {
        // query failed
        $log = 'An error occurred validating your code, please try again later.';
    }

    $log = "<p>Invalid code. Try Again.</p>";
}

?>

<?php if (isset($log) && $log != ''): ?>
<strong class="error"><?php echo $log ?></strong>
<?php endif; ?>

<div class="dcrForm">
<p>Have a physical copy of this release? Claim your digital download by
entering your Download Code below.</p>
<form action="index.php" method="post"><input type="text" name="code"
    class="dcrInput" value=""> <input type="submit" name="harrisSubmit"
    class="dcrSubmit" value="Submit"></form>
</div>

下载脚本可能类似于我上面的一些内容.
关于此示例的关键是,无法从Web访问您使用file_get_contents提供的文件.您只能在输入有效代码时发送它.

标签：php,http-headers,download,page-refresh
来源： https://codeday.me/bug/20190521/1147538.html