From 1ac86e14c746140a7fa9a6e81a3471739655366b Mon Sep 17 00:00:00 2001
From: Daniel Frank <git@danielfrank.net>
Date: Fri, 18 Oct 2019 00:53:48 +0200
Subject: [PATCH] swap: depend on rngd if enabled and randomEncryption is
 configured to avoid entropy starvation during boot

---
 nixos/modules/config/swap.nix | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/nixos/modules/config/swap.nix b/nixos/modules/config/swap.nix
index d0fc0d4a3ea4..adb4e2294213 100644
--- a/nixos/modules/config/swap.nix
+++ b/nixos/modules/config/swap.nix
@@ -185,6 +185,8 @@ in
           { description = "Initialisation of swap device ${sw.device}";
             wantedBy = [ "${realDevice'}.swap" ];
             before = [ "${realDevice'}.swap" ];
+            # If swap is encrypted, depending on rngd resolves a possible entropy starvation during boot
+            after = mkIf (config.security.rngd.enable && sw.randomEncryption.enable) [ "rngd.service" ];
             path = [ pkgs.utillinux ] ++ optional sw.randomEncryption.enable pkgs.cryptsetup;
 
             script =