method TLSSocket.prototype.getProtocol
Usage in Deno
```typescript import { TLSSocket } from "node:node__tls.d.ts"; ```
TLSSocket.prototype.getProtocol(): string | null
Returns a string containing the negotiated SSL/TLS protocol version of the
current connection. The value `'unknown'` will be returned for connected
sockets that have not completed the handshaking process. The value `null` will
be returned for server sockets or disconnected client sockets.
Protocol versions are:
* `'SSLv3'`
* `'TLSv1'`
* `'TLSv1.1'`
* `'TLSv1.2'`
* `'TLSv1.3'`
See the OpenSSL [`SSL_get_version`](https://www.openssl.org/docs/man1.1.1/man3/SSL_get_version.html) documentation for more information.
string | null