Deno.connectTls
UNSTABLE New API, yet to be vetted.
Create a TLS connection with an attached client certificate.
const conn = await Deno.connectTls({
  hostname: "deno.land",
  port: 443,
  certChain: "---- BEGIN CERTIFICATE ----\n ...",
  privateKey: "---- BEGIN PRIVATE KEY ----\n ...",
});
Requires allow-net permission.