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php实现ua绑定

2026-02-16 20:46:06PHP

PHP实现UA绑定

UA（User Agent）绑定是一种通过识别和验证用户浏览器的User Agent字符串来限制或允许访问的技术。以下是几种实现UA绑定的方法：

获取User Agent字符串

在PHP中，可以通过$_SERVER['HTTP_USER_AGENT']获取客户端的User Agent字符串：

$userAgent = $_SERVER['HTTP_USER_AGENT'];
echo "User Agent: " . $userAgent;

验证User Agent

通过检查User Agent字符串是否匹配预设的值，可以实现简单的UA绑定：

$allowedUserAgents = [
    'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36',
    'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36'
];

$currentUserAgent = $_SERVER['HTTP_USER_AGENT'];

if (!in_array($currentUserAgent, $allowedUserAgents)) {
    header('HTTP/1.0 403 Forbidden');
    echo 'Access Denied: Unsupported User Agent';
    exit;
}

使用正则表达式匹配

如果需要更灵活的匹配（如部分匹配或模式匹配），可以使用正则表达式：

$pattern = '/^Mozilla\/5\.0 \(Windows NT 10\.0; Win64; x64\) AppleWebKit\/537\.36/';

if (!preg_match($pattern, $_SERVER['HTTP_USER_AGENT'])) {
    header('HTTP/1.0 403 Forbidden');
    echo 'Access Denied: Unsupported User Agent';
    exit;
}

结合数据库存储

可以将允许的User Agent字符串存储在数据库中，动态验证：

// 假设数据库中有表 `allowed_user_agents` 存储合法的UA字符串
$pdo = new PDO('mysql:host=localhost;dbname=your_db', 'username', 'password');
$stmt = $pdo->prepare('SELECT COUNT(*) FROM allowed_user_agents WHERE user_agent = ?');
$stmt->execute([$_SERVER['HTTP_USER_AGENT']]);
$count = $stmt->fetchColumn();

if ($count == 0) {
    header('HTTP/1.0 403 Forbidden');
    echo 'Access Denied: Unsupported User Agent';
    exit;
}

加密或哈希验证

为防止User Agent伪造，可以结合其他信息（如IP、Cookie）生成哈希值进行验证：

$secretKey = 'your_secret_key';
$userAgentHash = hash_hmac('sha256', $_SERVER['HTTP_USER_AGENT'], $secretKey);

// 存储或验证哈希值
if ($userAgentHash !== $expectedHash) {
    header('HTTP/1.0 403 Forbidden');
    echo 'Access Denied: Invalid User Agent';
    exit;
}