Question

我正在创建一个登录页面，其中输入了用户名和密码，然后根据数据库进行检查以查看它们是否匹配（我之前发布了此信息，但我的代码完全不正确，所以我不得不重新开始）单击提交按钮时，如果两个值匹配，则应将用户定向到主页（index.php），或者出现错误消息，指出＆＃34;登录无效。请再试一次。＆＃34;很简单的基本东西。然而，我无法获得任何变化。

这是我没有验证检查的代码。我相信这段代码是对的，但如果没有，有人可以解释为什么。我不是要求任何人编写任何代码，只是解释它为什么不能正常工作。

<?php

function Password($UserName)
{   

//database login
$dsn = 'mysql:host=XXX;dbname=XXX';
$username='*****';
$password='*****';
//variable for errors
$options = array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION);
//try to run code
try {
//object to open database
$db = new PDO($dsn,$username,$password, $options);
//check username against password
    $SQL = $db->prepare("Select USER_PASSWORD FROM user WHERE USER_NAME = :USER_NAME");
    $SQL->bindValue(':USER_NAME', $UserName);
    $SQL->execute();
    $username = $SQL->fetch();

    if($username === false)
        {
            $Password = null;
        }
    else
        {
            $Password = $username['USER_PASSWORD'];
        }

    return $Password;
    $SQL->closeCursor();
    $db = null;

    } catch(PDOException $e){
        $error_message = $e->getMessage();
        echo("<p>Database Error: $error_message</p>");
        exit();
    }
?>

现在验证码。我已经用Google搜索了这个并找到了几百种方法，但这种方法最符合我的编码风格。它是不完整的，我想要一些帮助，如何正确完成它，然后将其放在上面的代码中。我的假设恰好在此评论之后：＆＃34; //检查用户名对密码＆＃34;。现在我已经看过两次这个版本，在一个版本中，检查是针对txtUserName而另一个是用户名。我相信在每个if语句之后应该有else语句将它们引导到index.php页面。此外，第三个if语句是检查密码是否与用户名匹配。我没理解这个变化。他们太复杂了。

function Login()
{     
if(empty($_POST['txtUserName']))     
{         
    $this->HandleError("UserName is empty!");         
    return false;     
}          
if(empty($_POST['txtPassword']))     
{         
    $this->HandleError("Password is empty!");
            return false;     
}           

$username = trim($_POST['txtUserName']);
    $password = trim($_POST['txtPassword']);           

if(!$this->($username,$password))     
{         
    return false;     
}           
}

我知道我在这里问了很多。但我对PHP很新，我真的很努力学习它。并且有太多的信息，其中大部分都不适合初学者。任何和所有的帮助将不胜感激。

Answer 1

首先，让我们假设我们有一个PDO连接，就像你已经这样，例如使用这个函数：

您可以执行以下操作：

// Usage:   $db = connectToDataBase($dbHost, $dbName, $dbUsername, $dbPassword);
// Pre:     $dbHost is the database hostname, 
//          $dbName is the name of the database itself,
//          $dbUsername is the username to access the database,
//          $dbPassword is the password for the user of the database.
// Post:    $db is an PDO connection to the database, based on the input parameters.
function connectToDataBase($dbHost, $dbName, $dbUsername, $dbPassword)
{
    try
    {
         return new PDO("mysql:host=$dbHost;dbname=$dbName;charset=UTF-8", $dbUsername, $dbPassword);
    }
    catch(Exception $PDOexception)
    {
        exit("<p>An error ocurred: Can't connect to database. </p><p>More preciesly: ". $PDOexception->getMessage(). "</p>");
    }
}

这样你就可以拥有这样的数据库连接：

$host = 'localhost';
$user = 'root';
$dataBaseName = 'databaseName';
$pass = '';

$db = connectToDataBase($host, $databaseName, $user, $pass);

到目前为止，我们和你一样。

现在，我假设我们在PHP页面上，用户提交了他的用户名和密码，首先：检查我们是否真的收到了用户名和密码，以及三元oprator：

// receive parameters to log in with.
$userName = isset($_POST['userName']) ? $_POST['userName'] : false;
$password = isset($_POST['password']) ? $_POST['password'] : false;

现在您可以验证这些输入是否实际发布：

// Check if all required parameters are set and make sure
// that a user is not logged in already

if(isset($_SESSION['loggedIn']))
{
    // You don't want an already logged in user to try to log in.
    $alrLogged = "You're already logged in.";
    $_SESSION['warningMessage'] = $alrLogged;
    header("Location: ../index.php");
}
else if($userName && $password)
{
    // Verify an user by the email address and password
    // submitted to this page
    verifyUser($userName, $password, $db);
}
else if($userName && (!($password)))
{
    $noPass = "You didn't fill out your password.";
    $_SESSION['warningMessage'] = $noPass;
    header("Location: ../index.php");
}
else if((!$userName) && $password)
{
    $noUserName = "You didn't fill out your user name.";
    $_SESSION['warningMessage'] = $noUserName;
    header("Location: ../index.php");
}
else if((!$userName) && (!($password)))
{
    $neither = "You didn't fill out your user name nor did you fill out your password.";
    $_SESSION['warningMessage'] = $neither;
    header("Location: ../index.php");
}
else
{
    $unknownError = "An unknown error occurred.". NL. "Try again or <a href='../sites/contact.php' title='Contact us' target='_blank'>contact us</a>.";
    $_SESSION['warningMessage'] = $unknownError;
    header("Location: ../index.php");
}

现在，让我们假设一切顺利，你已经在变量$ db中存储了数据库连接，那么你可以使用函数

verifyUser($userName, $password, $db);

就像第一个if语句中已经提到的那样：

// Usage:   verifyUser($userName, $password, $db);
// Pre:     $db has already been defined and is a reference
//          to a PDO connection.
//          $userName is of type string.
//          $password is of type string.
// Post:    $user exists and has been granted a session that declares
//          the fact that he is logged in.
function verifyUser($userName, $password, $db)
{
    $userExists = userExists($userName, $db); // Check if user exists with that username.
    if(!($user))
    {
        // User not found.
        // Create warning message.
        $notFound= "User not found.";
        $_SESSION['warningMessage'] = $notFound;
        header("Location: ../index.php");
    }
    else
    {
        // The user exists, here you can use your smart function which receives
        // the hash of the password of the user:
        $passwordHash = Password($UserName);
        // If you have PHPass, an awesome hashing library for PHP
        // http://www.openwall.com/phpass/
        // Then you can do this:
        $passwordMatch = PHPhassMatch($passwordHash , $password);
        // Or you can just create a basic functions which does the same;
        // Receive 1 parameter which is a hashed password, one which is not hashed,
        // so you hash the second one and check if the hashes match.

        if($passwordMatch)
        {
            // The user exists and he entered the correct password.
            $_SESSION['isLoggedIn'] = true;
            header("Location: ../index.php");
            // Whatever more you want to do.
        }
        else
        {
            // Password incorrect.
            // Create warning message.
            $wrongPass = "Username or password incorrect."; // Don't give to much info.
            $_SESSION['warningMessage'] = $wrongPass;
            header("Location: ../index.php");
        }
    }
}

函数userExists（$ userName，$ db）可以是：

function userExists($userName, $db)
{
    $stmt = $db->prepare("SELECT * FROM users WHERE USER_NAME = :USER_NAME;");
    $stmt->execute(array(":USER_NAME "=>$userName));
    $result = $stmt->fetch(PDO::FETCH_ASSOC);
    if($result)
    {
        // User exists.
        return true;
    }
    // User doesn't exist.
    return false;
}

功能密码如下：

function Password($UserName)
{
    $stmt = $db->prepare("Select USER_PASSWORD FROM user WHERE USER_NAME = :USER_NAME;");
    $stmt->execute(array(":USER_NAME"=>UserName));
    $result = $stmt->fetch(PDO::FETCH_ASSOC);
    if($result)
    {
        return $result['USER_PASSWORD'];
    }
    // No result.
    return false;
}

再次确保您不匹配纯文本密码或基本shai1，md5加密等。我真的建议您查看PHPass。

我希望我能说清楚。

PHP用户名和密码验证检查

1 个答案: