php登录保持登录(会话)

bis0qfac  于 2021-06-18  发布在  Mysql
关注(0)|答案(1)|浏览(382)

在下面的php代码中,我想包含一个函数,将cookie设置为保持登录状态。问题是,我在谷歌上找到的样本不起作用。如果用户已经登录,则应该获得一个cookie,而不需要额外的“保持登录”按钮。在每个新请求中,cookie都应该立即登录用户。

<?php
// Initialize the session
session_start();

// Check if the user is already logged in, if yes then redirect him to welcome page
if(isset($_SESSION["loggedin"]) && $_SESSION["loggedin"] === true){
  header("location: index.php");
  exit;
}

// Include config file
require_once "configuser.php";

// Define variables and initialize with empty values
$username = $password = "";
$username_err = $password_err = "";

// Processing form data when form is submitted
if($_SERVER["REQUEST_METHOD"] == "POST"){

    // Check if username is empty
    if(empty(trim($_POST["username"]))){
        $username_err = "Bitte Benutzernamen eingeben.";
    } else{
        $username = trim($_POST["username"]);
    }

    // Check if password is empty
    if(empty(trim($_POST["password"]))){
        $password_err = "Bitte Passwort eingeben.";
    } else{
        $password = trim($_POST["password"]);
    }

    // Validate credentials
    if(empty($username_err) && empty($password_err)){
        // Prepare a select statement
        $sql = "SELECT id, username, password FROM users WHERE username = ?";

        if($stmt = mysqli_prepare($link, $sql)){
            // Bind variables to the prepared statement as parameters
            mysqli_stmt_bind_param($stmt, "s", $param_username);

            // Set parameters
            $param_username = $username;

            // Attempt to execute the prepared statement
            if(mysqli_stmt_execute($stmt)){
                // Store result
                mysqli_stmt_store_result($stmt);

                // Check if username exists, if yes then verify password
                if(mysqli_stmt_num_rows($stmt) == 1){                    
                    // Bind result variables
                    mysqli_stmt_bind_result($stmt, $id, $username, $hashed_password);
                    if(mysqli_stmt_fetch($stmt)){
                        if(password_verify($password, $hashed_password)){
                            // Password is correct, so start a new session
                            session_start();

                            // Store data in session variables
                            $_SESSION["loggedin"] = true;
                            $_SESSION["id"] = $id;
                            $_SESSION["username"] = $username;

                            //Angemeldet bleiben:

                            // Redirect user to welcome page
                            header("location: index.php");
                        } else{
                            // Display an error message if password is not valid
                            $password_err = "Passwort falsch.";
                        }
                    }
                } else{
                    // Display an error message if username doesn't exist
                    $username_err = "Benutzername oder Passwort falsch.";
                }
            } else{
                echo "Störung.";
            }
        }

        // Close statement
        mysqli_stmt_close($stmt);
    }

    // Close connection
    mysqli_close($link);
}
?>

<!DOCTYPE html>
mgdq6dx1

mgdq6dx11#

验证密码后设置cookie:

if(password_verify($password, $hashed_password)) {
    // Password is correct, so start a new session
    session_start();

    // store user data in cookie
    setcookie('user', json_encode([
        'username' => $username,
        'password' => $password
    ]), time() + 3600 * 24 * 30);

在检查之前 loggedin 在会话中,检查cookie(请密切注意此处的注解行):

// Check if there is an already logged in user in the cookie and then set its data to the session
if(isset($_COOKIE['user']) && !isset($_SESSION["loggedin"])) {
    $user = json_decode($_COOKIE['user'], true);

    // do the stuff to check if there is a user with $user['username'] and $user['password'] in the database, then if there is one, do as below :
    $_SESSION["loggedin"] = true;
    $_SESSION["id"] = $userId; // retrieved from database
    $_SESSION["username"] = $user['username'];
    // else if there is no user with that credentials from cookie, do the following to prevent further checking on database :
    $_SESSION["loggedin"] = false;

}

// Check if the user is already logged in, if yes then redirect him to welcome page
if(isset($_SESSION["loggedin"]) && $_SESSION["loggedin"] === true){

为了在注销用户时销毁cookie,请使用 unset 正如@dakshmehta已经说过的:

unset($_COOKIE['user']);

注意:由于安全问题,不建议将用户密码存储在cookie中。因此,您可能希望实现一个基于令牌的身份验证,在短时间内或至少在每次登录时刷新令牌。使用json web tokens(jwt)在这个主题上可能会很有帮助,有一个在php中实现jwt的包:firebase/php jwt您应该知道令牌的行为与密码完全一样,所以当您将其存储在cookie中时,您应该考虑本文最后一节中提到的一些安全提示:在何处存储jwts–cookies与html5web存储

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