From fec30b7ec94a689ccc6899427a1da430e365d28e Mon Sep 17 00:00:00 2001
From: hippoz <10706925-hippoz@users.noreply.gitlab.com>
Date: Thu, 14 Apr 2022 21:10:05 +0300
Subject: [PATCH] backend: disallow gateway clients from authenticating if
 they're already authenticated

---
 src/errors.ts        | 1 +
 src/gateway/index.ts | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/src/errors.ts b/src/errors.ts
index 1769d5b..1e7e259 100644
--- a/src/errors.ts
+++ b/src/errors.ts
@@ -13,4 +13,5 @@ export const gatewayErrors = {
     AUTHENTICATION_TIMEOUT: { code: 4003, message: "Authentication timeout" },
     NO_PING: { code: 4004, message: "No ping" },
     FLOODING: { code: 4005, message: "Flooding (exceeded maximum messages per batch)" },
+    ALREADY_AUTHENTICATED: { code: 4006, message: "Already authenticated" },
 };
diff --git a/src/gateway/index.ts b/src/gateway/index.ts
index 8337dcc..a2eb33e 100644
--- a/src/gateway/index.ts
+++ b/src/gateway/index.ts
@@ -178,6 +178,10 @@ export default function(server: Server) {
 
             switch (payload.t) {
                 case GatewayPayloadType.Authenticate: {
+                    if (ws.state.ready) {
+                        return closeWithError(ws, gatewayErrors.ALREADY_AUTHENTICATED);
+                    }
+
                     const token = payload.d;
                     if (typeof token !== "string") {
                         return closeWithBadPayload(ws, "d: expected string");