PHP Session cross-domain data consistency verification mechanism

PHP Session cross-domain data consistency verification mechanism

With the development of the Internet, cross-domain access has become a common requirement, and when performing cross-domain access , maintaining data consistency has become an important challenge. PHP provides a Session mechanism to maintain data consistency between different requests, but by default, cross-domain access to Session is not possible. This article will introduce a Token-based mechanism to achieve data consistency verification of PHP Session in cross-domain access by adding a custom verification mechanism, and provide specific code examples.

1. Introduction to Session Mechanism

Session is a data storage method maintained on the server side, which can persistently save user data and realize cross-request data transfer. In PHP, Session generates a unique Session ID and stores the data in a file or database on the server side. When the user accesses other pages, the original session data is restored through the Session ID.

2. Cross-domain access issues

By default, PHP's Session mechanism can only share data between the same domain name or subdomain name. When cross-domain access is required between different domain names, the Session ID cannot be shared between requests, resulting in the inability to obtain the original session data.

3. Token-based data consistency verification mechanism

In order to solve the data consistency problem of Session cross-domain access, you can verify the same user under different domain names by adding a Token mechanism. Whether the session ID is valid. The specific implementation steps are as follows:

1. When the user logs in, the Session ID and user-related data are stored in the database, and a unique Token is generated.
2. Return the Token to the user and set a cross-domain access identifier in the cookie (such as setting domain as the main domain name instead of the currently visited subdomain name).
3. When the user makes a cross-domain request, the Token is obtained through the cross-domain identification in the cookie and passed to the server of the target domain name.
4. After receiving the Token, the server of the target domain name compares it with the Token in the database.
5. If the Token matches successfully, the user's Session ID will be returned to the server of the target domain name.
6. The server of the target domain name obtains user-related data through the Session ID and processes it accordingly.

4. Code Example

The following is a simple code example to demonstrate the Token-based data consistency verification mechanism. Suppose there are two domain names: www.example.com and app.example.com.

1. When the user logs in, a Token is generated and stored in the database.

// Generate unique token
$token = uniqid();

// Store token along with user data in database
$db->query("INSERT INTO users (token, username) VALUES ('$token', '$username')");

2. After successful login, the Token will be fed back to the user and the cross-domain identification will be set in the Cookie.

setcookie('token', $token, time()+3600, '/', 'example.com', false, true);

3. In a cross-domain request, pass the Token in the cookie to the server of the target domain name.

// Retrieve token from cookie
var token = document.cookie.match('(^|;) ?token=([^;]*)(;|$)')[2];

// Make cross-domain request with token
fetch('https://app.example.com/api', {
    headers: {
        'Authorization': 'Bearer ' + token
    }
})
.then(response => response.json())
.then(data => {
    // Handle response data
})
.catch(error => {
    // Handle error
});

4. Compare the server of the target domain name with the Token in the database.

// Retrieve token from request
$token = $_SERVER['HTTP_AUTHORIZATION'];

// Query token from database
$result = $db->query("SELECT * FROM users WHERE token = '$token'");

if ($result->num_rows > 0) {
    // Token is valid, retrieve session ID
    $session_id = session_id();
    // Perform operations with session data
} else {
    // Token is invalid, handle unauthorized access
}

5. Summary

By adding a token-based verification mechanism, the data consistency verification of PHP Session in cross-domain access can be achieved. Although this mechanism has certain complexity compared to directly sharing Session ID, it can effectively solve the data consistency problem in cross-domain access and improve user experience and system security.

The above is the detailed content of PHP Session cross-domain data consistency verification mechanism. For more information, please follow other related articles on the PHP Chinese website!