How do you implement a custom TLS/SSL server in Node.js?

Question

Accepted Answer

**TLS/SSL** — encrypted communication.

```javascript
const https = require("https");
const fs = require("fs");

const options = {
    key: fs.readFileSync("server.key"),
    cert: fs.readFileSync("server.cert"),
    // Mutual TLS (mTLS)
    requestCert: true,
    rejectUnauthorized: true,
    ca: [fs.readFileSync("ca.cert")],
};

const server = https.createServer(options, (req, res) => {
    // Verify client certificate
    const cert = req.socket.getPeerCertificate();
    if (!cert.subject) {
        return res.status(401).json({ error: "No certificate" });
    }

res.json({ cn: cert.subject.CN });
});

server.listen(443);
```

**Generate certificates:**
```bash
# Generate CA
openssl genrsa -out ca.key 2048
openssl req -new -x509 -days 365 -key ca.key -out ca.cert

# Generate server cert
openssl genrsa -out server.key 2048
openssl req -new -key server.key -out server.csr
openssl x509 -req -days 365 -in server.csr -CA ca.cert -CAkey ca.key -out server.cert
```

Node.js: How do you implement a custom TLS/SSL server in Node.js?