Add support for OAuth 2.0 authentication

README.md

@@ -103,8 +103,9 @@ gamja default settings can be set using a `config.json` file at the root:
 		"autojoin": "#gamja",
 		// Controls how the password UI is presented to the user. Set to
 		// "mandatory" to require a password, "optional" to accept one but not
-		// require it, "disabled" to never ask for a password, or "external" to
-		// use SASL EXTERNAL. Defaults to "optional".
+		// require it, "disabled" to never ask for a password, "external" to
+		// use SASL EXTERNAL, "oauth2" to use SASL OAUTHBEARER. Defaults to
+		// "optional".
 		"auth": "optional",
 		// Default nickname (string). If it contains a "*" character, it will
 		// be replaced with a random string.
@@ -116,6 +117,19 @@ gamja default settings can be set using a `config.json` file at the root:
 		// disable. Enabling PINGs can have an impact on client power usage and
 		// should only be enabled if necessary.
 		"ping": 60
+	},
+	// OAuth 2.0 settings.
+	"oauth2": {
+		// OAuth 2.0 server URL (string). The server must support OAuth 2.0
+		// Authorization Server Metadata (RFC 8414) or OpenID Connect
+		// Discovery.
+		"url": "https://auth.example.org",
+		// OAuth 2.0 client ID (string).
+		"client_id": "asdf",
+		// OAuth 2.0 client secret (string).
+		"client_secret": "ghjk",
+		// OAuth 2.0 scope (string).
+		"scope": "profile"
 	}
 }
 ```