fix(websocket): add support for WSS in WebSocket URL construction based on forwarded headers

web/backend/api/gateway_host.go

@@ -75,6 +75,29 @@ func requestHostName(r *http.Request) string {
 	return "127.0.0.1"
 }
 
+// forwardedRFC7239Proto returns the proto value from the first Forwarded element (RFC 7239), or "".
+func forwardedRFC7239Proto(r *http.Request) string {
+	raw := strings.TrimSpace(r.Header.Get("Forwarded"))
+	if raw == "" {
+		return ""
+	}
+	first := strings.TrimSpace(strings.Split(raw, ",")[0])
+	for _, part := range strings.Split(first, ";") {
+		part = strings.TrimSpace(part)
+		idx := strings.IndexByte(part, '=')
+		if idx <= 0 {
+			continue
+		}
+		key := strings.ToLower(strings.TrimSpace(part[:idx]))
+		if key != "proto" {
+			continue
+		}
+		v := strings.Trim(strings.TrimSpace(part[idx+1:]), `"'`)
+		return strings.ToLower(v)
+	}
+	return ""
+}
+
 func requestWSScheme(r *http.Request) string {
 	if forwarded := strings.TrimSpace(r.Header.Get("X-Forwarded-Proto")); forwarded != "" {
 		proto := strings.ToLower(strings.TrimSpace(strings.Split(forwarded, ",")[0]))
@@ -86,6 +109,19 @@ func requestWSScheme(r *http.Request) string {
 		}
 	}
 
+	if p := forwardedRFC7239Proto(r); p != "" {
+		if p == "https" || p == "wss" {
+			return "wss"
+		}
+		if p == "http" || p == "ws" {
+			return "ws"
+		}
+	}
+
+	if strings.EqualFold(strings.TrimSpace(r.Header.Get("X-Forwarded-Ssl")), "on") {
+		return "wss"
+	}
+
 	if r.TLS != nil {
 		return "wss"
 	}
@@ -100,6 +136,12 @@ func requestHTTPScheme(r *http.Request) string {
 			return "https"
 		}
 	}
+	if p := forwardedRFC7239Proto(r); p == "https" {
+		return "https"
+	}
+	if strings.EqualFold(strings.TrimSpace(r.Header.Get("X-Forwarded-Ssl")), "on") {
+		return "https"
+	}
 	if r.TLS != nil {
 		return "https"
 	}

web/backend/api/gateway_host_test.go

@@ -186,3 +186,37 @@ func TestBuildWsURLPrefersForwardedHTTPOverTLS(t *testing.T) {
 		t.Fatalf("buildWsURL() = %q, want %q", got, "ws://chat.example.com:18800/pico/ws")
 	}
 }
+
+func TestBuildWsURLUsesWSSWhenForwardedHeaderProtoIsHTTPS(t *testing.T) {
+	configPath := filepath.Join(t.TempDir(), "config.json")
+	h := NewHandler(configPath)
+
+	cfg := config.DefaultConfig()
+	cfg.Gateway.Host = "0.0.0.0"
+	cfg.Gateway.Port = 18790
+
+	req := httptest.NewRequest("GET", "http://10.0.0.1/api/pico/token", nil)
+	req.Host = "chat.example.com"
+	req.Header.Set("Forwarded", `for=203.0.113.1;proto=https;host=chat.example.com`)
+
+	if got := h.buildWsURL(req, cfg); got != "wss://chat.example.com:18800/pico/ws" {
+		t.Fatalf("buildWsURL() = %q, want %q", got, "wss://chat.example.com:18800/pico/ws")
+	}
+}
+
+func TestBuildWsURLUsesWSSWhenXForwardedSslOn(t *testing.T) {
+	configPath := filepath.Join(t.TempDir(), "config.json")
+	h := NewHandler(configPath)
+
+	cfg := config.DefaultConfig()
+	cfg.Gateway.Host = "0.0.0.0"
+	cfg.Gateway.Port = 18790
+
+	req := httptest.NewRequest("GET", "http://10.0.0.1/api/pico/token", nil)
+	req.Host = "chat.example.com"
+	req.Header.Set("X-Forwarded-Ssl", "on")
+
+	if got := h.buildWsURL(req, cfg); got != "wss://chat.example.com:18800/pico/ws" {
+		t.Fatalf("buildWsURL() = %q, want %q", got, "wss://chat.example.com:18800/pico/ws")
+	}
+}

web/frontend/src/features/chat/websocket.ts

@@ -13,8 +13,15 @@ export function normalizeWsUrlForBrowser(wsUrl: string): string {
 
     if (isLocalHost && !isBrowserLocal) {
       parsedUrl.hostname = window.location.hostname
-      finalWsUrl = parsedUrl.toString()
     }
+
+    // HTTPS pages cannot open ws:// (mixed content). Backend may still return ws
+    // when TLS terminates at a reverse proxy without X-Forwarded-Proto.
+    if (window.location.protocol === "https:" && parsedUrl.protocol === "ws:") {
+      parsedUrl.protocol = "wss:"
+    }
+
+    finalWsUrl = parsedUrl.toString()
   } catch (error) {
     console.warn("Could not parse ws_url:", error)
   }