tlsSocket.authorized Property in Node.js

Node.js provides robust support for secure network communications through its tls module. When working with secure sockets, verifying whether the connection is properly authenticated is crucial. That’s where the tlsSocket.authorized property comes into play.

What is tlsSocket.authorized?

The tlsSocket.authorized property is a Boolean value that tells you if the TLS connection has been successfully authorized. Specifically, it indicates whether the peer’s certificate passed verification against the trusted certificate authorities (CAs).

If the connection is authorized, the value will be true; otherwise, it will be false. This is particularly useful in scenarios where client certificates are required and must be validated during the handshake process.

Syntax

The syntax to access the property is straightforward:

        
        tlsSocket.authorized
        
        

It can be accessed after the secure connection is established, typically inside a TLS server or client event callback.

Example: Checking TLS Authorization

Here’s a simple example of using tlsSocket.authorized in a TLS server:

        
        const tls = require('tls');
        const fs = require('fs');

        const options = {
            key: fs.readFileSync('server-key.pem'),
            cert: fs.readFileSync('server-cert.pem'),
            ca: fs.readFileSync('client-cert.pem'),
            requestCert: true,
            rejectUnauthorized: false
        };

        const server = tls.createServer(options, (socket) => {
            console.log('Client connected');
            console.log('Authorized:', socket.authorized);
            if (!socket.authorized) {
                console.log('Authorization error:', socket.authorizationError);
            }
        });

        server.listen(8000, () => {
            console.log('TLS server running on port 8000');
        });
        
        

Output

When a client connects, the server will log whether the client’s certificate is authorized. If authorization fails, you can also inspect the authorizationError property for the reason.

Use Cases

• Mutual TLS authentication between servers and clients
• Building secure APIs that require client certificate verification
• Auditing or logging failed certificate verifications
• Creating custom logic for handling unauthorized connections

Handling Unauthorized Connections

In many scenarios, it’s not enough to just log whether the connection is authorized—you may want to close unauthorized connections or respond differently. For example:

        
        if (!socket.authorized) {
            socket.write('Connection rejected: Invalid certificate');
            socket.destroy();
        }
        
        

Important Notes

By default, if you want to verify client certificates, you must set requestCert: true and handle authorized manually unless rejectUnauthorized is set to true, in which case unauthorized clients are automatically rejected.

Conclusion

The tlsSocket.authorized property is an essential feature for developers working with secure communication in Node.js. It helps confirm whether a TLS connection is authenticated, ensuring that only trusted parties are able to communicate. Use this property to build safer, more secure Node.js applications that handle certificates responsibly.

---