登录系统报错

Question

我有一个登录系统，应该可以用，但我得到 "Check your login details"。

我确定细节没问题，但是它给出了错误。

dologin.php

<?php

include('includes/functions.php');

if(isset($_POST['login'])) {
  if(isset($_POST['username'])) {
    if(isset($_POST['password'])) {
        $username = $_POST['username'];
        $query = mysql_query("SELECT * FROM cm_users WHERE Username = '$username'") or die(mysql_error());
        $user = mysql_fetch_array($query);

        if(md5($_POST['password']) == $user['Password']) {
            echo "Login successful";
            $_SESSION['user'] = $user['Username'];
            header("Location: index.php");
        } else {
            echo "Please check your login details!";
            include('login.php');
        }
    } else {
            echo "Please check your password!";
            include('login.php');
    }
    } else {
    echo "Please check your username!";
    include('login.php');
    }
    } else {
    echo "Please check that you filled out the login form!";
    include('login.php');
    }
?>

Answer 1

你的假设都是正确的很容易测试，毕竟这是调试101。

<?php

include('includes/functions.php');

if(isset($_POST['login'])) {
  if(isset($_POST['username'])) {
    if(isset($_POST['password'])) {
        $username = $_POST['username'];
        $query = mysql_query("SELECT * FROM cm_users WHERE Username = '$username'") or die(mysql_error());
        $user = mysql_fetch_array($query);

        //Proof debug code

        echo 'Database password = ' . $user['Password'] . '<br>';
        echo 'md5 of input password = ' . md5($_POST['password']) . '<br>';
        echo 'ARE THEY THE SAME' . '<br>';



        if(md5($_POST['password']) == $user['Password']) {
            echo "Login successful";
            $_SESSION['user'] = $user['Username'];
            header("Location: index.php");
        } else {
            echo "Please check your login details!";
            include('login.php');
        }
    } else {
            echo "Please check your password!";
            include('login.php');
    }
    } else {
    echo "Please check your username!";
    include('login.php');
    }
    } else {
    echo "Please check that you filled out the login form!";
    include('login.php');
    }
?>

哦，顺便说一下，MD5 不再被认为是安全的。看看这个manual page for how it should be done now