nixos/galene: systemd unit hardening

nixos/modules/services/web-apps/galene.nix

@@ -164,6 +164,35 @@ in
             optional (cfg.dataDir == defaultdataDir) "galene/data" ++
             optional (cfg.groupsDir == defaultgroupsDir) "galene/groups" ++
             optional (cfg.recordingsDir == defaultrecordingsDir) "galene/recordings";
+
+          # Hardening
+          CapabilityBoundingSet = [ "" ];
+          DeviceAllow = [ "" ];
+          LockPersonality = true;
+          MemoryDenyWriteExecute = true;
+          NoNewPrivileges = true;
+          PrivateDevices = true;
+          PrivateTmp = true;
+          PrivateUsers = true;
+          ProcSubset = "pid";
+          ProtectClock = true;
+          ProtectControlGroups = true;
+          ProtectHome = true;
+          ProtectHostname = true;
+          ProtectKernelLogs = true;
+          ProtectKernelModules = true;
+          ProtectKernelTunables = true;
+          ProtectProc = "invisible";
+          ProtectSystem = "strict";
+          ReadWritePaths = cfg.recordingsDir;
+          RemoveIPC = true;
+          RestrictAddressFamilies = [ "AF_INET" "AF_INET6" ];
+          RestrictNamespaces = true;
+          RestrictRealtime = true;
+          RestrictSUIDSGID = true;
+          SystemCallArchitectures = "native";
+          SystemCallFilter = [ "@system-service" "~@privileged" "~@resources" ];
+          UMask = "0077";
         }
       ];
     };