无法通过fsockopen连接WebSocket服务器，求PHP连接WebSocket解决方案

Your current code sends a plain HTTP GET request, but WebSocket connections require a specific handshake process with mandatory headers. That’s exactly why you’re hitting a 400 error—the server doesn’t recognize your request as a valid WebSocket initiation.

Let’s break down what’s missing and fix the code step by step:

Key Issues in Your Original Code #

• You’re using fsockopen for an HTTPS (443) connection, which doesn’t handle SSL/TLS encryption. You need to use stream_socket_client with an SSL context instead.
• Critical WebSocket handshake headers are missing: Upgrade, Connection, Sec-WebSocket-Key, and Sec-WebSocket-Version are required for the server to switch protocols to WebSocket.

Corrected Working Code #

// Create an SSL context for secure HTTPS connection
$context = stream_context_create([
    'ssl' => [
        'verify_peer' => false, // Disable for testing; enable this in production
        'verify_peer_name' => false,
    ]
]);

// Connect to the WebSocket server over SSL
$fp = stream_socket_client('ssl://cs.money:443', $errno, $errstr, 30, STREAM_CLIENT_CONNECT, $context);

if (!$fp) {
    echo "$errstr ($errno)<br />";
} else {
    // Generate a random key required for WebSocket handshake
    $websocketKey = base64_encode(random_bytes(16));
    
    // Build the proper WebSocket handshake request
    $handshakeRequest = "GET / HTTP/1.1\r\n";
    $handshakeRequest .= "Host: cs.money\r\n";
    $handshakeRequest .= "Upgrade: websocket\r\n";
    $handshakeRequest .= "Connection: Upgrade\r\n";
    $handshakeRequest .= "Sec-WebSocket-Key: $websocketKey\r\n";
    $handshakeRequest .= "Sec-WebSocket-Version: 13\r\n";
    $handshakeRequest .= "\r\n"; // Mark end of headers
    
    // Send the handshake request
    fwrite($fp, $handshakeRequest);
    
    // Read the server's handshake response
    $response = '';
    while (!feof($fp)) {
        $response .= fgets($fp, 1024);
        // Stop reading once we reach the end of headers (double newline)
        if (strpos($response, "\r\n\r\n") !== false) {
            break;
        }
    }
    
    // Verify if handshake was successful
    if (strpos($response, 'HTTP/1.1 101 Switching Protocols') !== false) {
        echo "WebSocket handshake successful!\n";
        // Note: After this, you need to encode/decode messages per WebSocket framing rules
        // (client messages must be masked, server messages are unmasked)
    } else {
        echo "Handshake failed. Server response:\n$response";
    }
    
    fclose($fp);
}

Important Post-Handshake Notes #

1. SSL Security: In production, enable verify_peer and verify_peer_name to ensure secure, verified connections—disabling them is only for testing.
2. WebSocket Framing: Once the handshake succeeds, you can’t send plain text directly. You need to wrap messages in WebSocket frames (with opcode, length, and masking key for client-to-server messages).
3. Server-Specific Headers: Some servers may require additional headers like Origin—if you still get errors, inspect browser WebSocket requests (via DevTools) to match the exact headers the server expects.

内容的提问来源于stack exchange，提问作者Mike Reacher