Add support for OAuth 2.0 authentication

lib/client.js

@@ -122,6 +122,7 @@ export default class Client extends EventTarget {
 		pass: null,
 		saslPlain: null,
 		saslExternal: false,
+		saslOauthBearer: null,
 		bouncerNetwork: null,
 		ping: 0,
 		eventPlayback: true,
@@ -467,6 +468,10 @@ export default class Client extends EventTarget {
 		case "EXTERNAL":
 			initialResp = { command: "AUTHENTICATE", params: [base64.encode("")] };
 			break;
+		case "OAUTHBEARER":
+			let raw = "n,,\x01auth=Bearer " + params.token + "\x01\x01";
+			initialResp = { command: "AUTHENTICATE", params: [base64.encode(raw)] };
+			break;
 		default:
 			throw new Error(`Unknown authentication mechanism '${mechanism}'`);
 		}
@@ -658,6 +663,8 @@ export default class Client extends EventTarget {
 						promise = this.authenticate("PLAIN", this.params.saslPlain);
 					} else if (this.params.saslExternal) {
 						promise = this.authenticate("EXTERNAL");
+					} else if (this.params.saslOauthBearer) {
+						promise = this.authenticate("OAUTHBEARER", this.params.saslOauthBearer);
 					}
 					(promise || Promise.resolve()).catch((err) => {
 						this.dispatchError(err);