dtls.connect

History

dtls.connect(host, port, options?): DTLSSession

Attributes

host:string

Remote host to connect to, as an IPv4 or IPv6 literal. Host names are not resolved.

port:number

Remote port to connect to.

options:Object

ca:string | Buffer | string[] | Buffer[]

CA certificates in PEM format.

cert:string | Buffer

Client certificate in PEM format.

key:string | Buffer

Client private key in PEM format.

secureContext:DTLSSecureContext

A context from dtls.createSecureContext() to use instead of building one from the credential options below. Must not have been created with isServer: true. Cannot be combined with any option the context already carries.

psk:Object | Function

A pre-shared key as { identity, key }, or a function returning one. See Pre-shared keys.

session:Buffer

A session from session.session on an earlier connection, to resume rather than handshake in full. See Session resumption.

passphrase:string

Passphrase to decrypt key, if it is encrypted. Ignored when key is not encrypted. Unlike key and cert, this must be a string, matching tls.createSecureContext().

rejectUnauthorized?:boolean

When true, the server's certificate must both chain to a trusted CA and match the expected identity (servername, or host when servername is not set); otherwise the handshake is aborted and session.opened rejects. When false, the certificate is still verified and the handshake completes regardless, leaving the decision to the application via session.authorized and session.authorizationError. Default: true.

servername?:string

Server name used for the SNI (Server Name Indication) extension and as the identity checked during certificate verification. Default: the host argument. Set to '' to disable SNI. SNI is never sent for IP address literals.

bindHost?:string

Local bind address. Default: '::' when host is an IPv6 literal, otherwise '0.0.0.0'. The local socket must be in the same address family as the peer.

bindPort?:number

Local bind port. Default: 0 (ephemeral).

alpn:string[] | Buffer

ALPN protocol names. Each name must be between 1 and 255 bytes. A Buffer must already be in ALPN wire format: one length byte followed by that many bytes, repeated.

srtp:string

SRTP protection profile names.

mtu?:number

Maximum size in bytes of a DTLS datagram. Default: 1200.

handshakeTimeout?:number

Milliseconds a handshake may take before it is abandoned and session.opened rejects. 0 disables it. Default: 60000. See Handshake timeout.

Returns:DTLSSession

Connects to a DTLS server. Returns a DTLSSession whose opened property is a Promise that resolves when the handshake completes.

import { connect } from 'node:dtls';
import { readFileSync } from 'node:fs';

const session = connect('127.0.0.1', 4433, {
  ca: [readFileSync('ca-cert.pem')],
});

await session.opened;
session.send('hello');

session.onmessage = (data) => {
  console.log('Received:', data.toString());
};

JavaScript