sneeuwvlok/_modules/system/security.nix
2025-07-28 14:34:09 +02:00

77 lines
2.3 KiB
Nix

{ inputs, pkgs, ... }:
{
imports = [
inputs.sops-nix.nixosModules.sops
];
config = {
environment.systemPackages = with pkgs; [
bitwarden
sops
];
sops = {
defaultSopsFile = ../../secrets/secrets.yaml;
defaultSopsFormat = "yaml";
age.keyFile = "/home/";
};
security = {
sudo.execWheelOnly = true;
acme.acceptTerms = true;
polkit.enable = true;
pam = {
u2f = {
enable = true;
settings.cue = true;
};
};
};
networking.firewall.enable = true;
programs.gnupg.agent.enable = true;
boot = {
loader.systemd-boot = {
editor = false;
configurationLimit = 50;
};
kernelModules = [ "tcp_bbr" ];
kernel.sysctl = {
## 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 on 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
# Enable TCP Fast Open for 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";
};
};
};
}