PHP 的登录问题

Question

我还不能修复它，我不知道是什么问题。我在 xampp 上使用它。我在 register.php 中将哈希更改为 sha256。现在，如果我尝试使用我注册的密码和用户名登录，它会说用户名和密码错误。

那是我的 login.php

 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;                            
                        
                        // Redirect user to welcome page
                        header("location: welcome.php");
                    } else{
                        // Password is not valid, display a generic error message
                        $login_err = "Invalid username or password.";
                    }
                }
            } else{
                // Username doesn't exist, display a generic error message
                $login_err = "Invalid username or password.";
            }
        } else{
            echo "Oops! Something went wrong. Please try again later.";
        }

        // Close statement
        mysqli_stmt_close($stmt);
    }
}

// Close connection
mysqli_close($link);

那是我的 register.php 我只改变了。

if(empty($username_err) && empty($password_err) && empty($confirm_password_err)){
    
    // Prepare an insert statement
    $sql = "INSERT INTO users (username, password) VALUES (?, ?)";
     
    if($stmt = mysqli_prepare($link, $sql)){
        // Bind variables to the prepared statement as parameters
        mysqli_stmt_bind_param($stmt, "ss", $param_username, $param_password);
        
        // Set parameters
        $param_username = $username;
        $param_password = hash("sha256" , $_POST['password']); // Creates a password hash //<------------------THAT IS CHANGED
        
        // Attempt to execute the prepared statement
        if(mysqli_stmt_execute($stmt)){
            // Redirect to login page
            header("location: login.php");
        } else{
            echo "Oops! Something went wrong. Please try again later.";
        }

        // Close statement
        mysqli_stmt_close($stmt);
    }
}

// Close connection
mysqli_close($link);
}

Answer 1

那是因为您的纯密码永远不会匹配 SHA256 加密文本您可以尝试再次将普通密码转换为 sha256 并进行比较，但这是一种不好的做法，就像劳伦斯所说的那样，您真的不应该以这种格式存储密码

password_verify 与 password_hash 一起工作，您可以在其中提供纯密码和哈希算法，请参阅文档 here

PHP 的登录问题

Login Problems with PHP

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authentication

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