testing the new config before pushing to main

system/modules/security.nix

@@ -0,0 +1,100 @@
+{ lib, config, pkgs, ... }:
+
+let
+  cfg = config.systemModules.security;
+in
+
+{
+  config = lib.mkIf cfg.enable {
+
+    environment.systemPackages = with pkgs; [
+      polkit_gnome
+    ];
+
+    programs = {
+      gnupg.agent = {
+        enable = true;
+        enableSSHSupport = true;
+      };
+      _1password = {
+        enable = true;
+      };
+      _1password-gui = {
+        enable = true;
+        polkitPolicyOwners = [ "ooks" ];
+      };
+    };
+    security = {
+      polkit = {
+        enable = true;
+      };
+      pam.services = { swaylock = { }; };
+      sudo = {
+        enable = true;
+        wheelNeedsPassword = false;
+      };
+      rtkit.enable = true;
+    };
+
+    # security tweaks borrowed from @hlissner
+    boot.kernel.sysctl = {
+      # The Magic SysRq key is a key combo that allows users connected to the
+      # system console of a Linux kernel to perform some low-level commands.
+      # Disable it, since we don't need it, and is a potential security concern.
+      "kernel.sysrq" = 0;
+
+      ## TCP hardening
+      # Prevent bogus ICMP errors from filling up logs.
+      "net.ipv4.icmp_ignore_bogus_error_responses" = 1;
+      # Reverse path filtering causes the kernel to do source validation of
+      # packets received from all interfaces. This can mitigate IP spoofing.
+      "net.ipv4.conf.default.rp_filter" = 1;
+      "net.ipv4.conf.all.rp_filter" = 1;
+      # Do not accept IP source route packets (we're not a router)
+      "net.ipv4.conf.all.accept_source_route" = 0;
+      "net.ipv6.conf.all.accept_source_route" = 0;
+      # Don't send ICMP redirects (again, we're not a router)
+      "net.ipv4.conf.all.send_redirects" = 0;
+      "net.ipv4.conf.default.send_redirects" = 0;
+      # Refuse ICMP redirects (MITM mitigations)
+      "net.ipv4.conf.all.accept_redirects" = 0;
+      "net.ipv4.conf.default.accept_redirects" = 0;
+      "net.ipv4.conf.all.secure_redirects" = 0;
+      "net.ipv4.conf.default.secure_redirects" = 0;
+      "net.ipv6.conf.all.accept_redirects" = 0;
+      "net.ipv6.conf.default.accept_redirects" = 0;
+      # Protects against SYN flood attacks
+      "net.ipv4.tcp_syncookies" = 1;
+      # Incomplete protection again TIME-WAIT assassination
+      "net.ipv4.tcp_rfc1337" = 1;
+
+      ## TCP optimization
+      # TCP Fast Open is a TCP extension that reduces network latency by packing
+      # data in the sender’s initial TCP SYN. Setting 3 = enable TCP Fast Open for
+      # both incoming and outgoing connections:
+      "net.ipv4.tcp_fastopen" = 3;
+      # Bufferbloat mitigations + slight improvement in throughput & latency
+      "net.ipv4.tcp_congestion_control" = "bbr";
+      "net.core.default_qdisc" = "cake";
+    };
+
+    boot.kernelModules = ["tcp_bbr"];  
+
+    systemd = {
+      user.services.polkit-gnome-authentication-agent-1 = {
+        description = "polkit-gnome-authentication-agent-1";
+        wantedBy = [ "graphical-session.target" ];
+        wants = [ "graphical-session.target" ];
+        after = [ "graphical-session.target" ];
+        serviceConfig = {
+          Type = "simple";
+          ExecStart = "${pkgs.polkit_gnome}/libexec/polkit-gnome-authentication-agent-1";
+          Restart = "on-failure";
+          RestartSec = 1;
+          TimeoutStopSec = 10;
+
+        };
+      };
+    };
+  };
+}