infra/modules/networking.nix

45 lines
1.7 KiB
Nix

{ pkgs, lib, ... }: {
# Don't expose SSH via public interfaces
networking.firewall.interfaces.wg-ssh.allowedTCPPorts = [ 22 ];
services.openssh = {
enable = true;
openFirewall = lib.mkDefault false;
settings = {
PermitRootLogin = "prohibit-password";
PasswordAuthentication = false;
# Add back openssh MACs that got removed from defaults
# for backwards compatibility
#
# NixOS default openssh MACs have changed to use "encrypt-then-mac" only.
# This breaks compatibilty with clients that do not offer these MACs. For
# compatibility reasons, we add back the old defaults.
# See: https://github.com/NixOS/nixpkgs/pull/231165
#
# https://blog.stribik.technology/2015/01/04/secure-secure-shell.html
# https://infosec.mozilla.org/guidelines/openssh#modern-openssh-67
Macs = [
"hmac-sha2-512-etm@openssh.com"
"hmac-sha2-256-etm@openssh.com"
"umac-128-etm@openssh.com"
"hmac-sha2-512"
"hmac-sha2-256"
"umac-128@openssh.com"
];
};
};
services.resolved = {
enable = true;
# DNSSEC=false because of random SERVFAIL responses with Greenbaum DNS
# when using allow-downgrade, see https://github.com/systemd/systemd/issues/10579
extraConfig = ''
DNS=193.110.81.0#dns0.eu 185.253.5.0#dns0.eu 2a0f:fc80::#dns0.eu 2a0f:fc81::#dns0.eu 9.9.9.9#dns.quad9.net 149.112.112.112#dns.quad9.net 2620:fe::fe#dns.quad9.net 2620:fe::9#dns.quad9.net
FallbackDNS=5.1.66.255#dot.ffmuc.net 185.150.99.255#dot.ffmuc.net 2001:678:e68:f000::#dot.ffmuc.net 2001:678:ed0:f000::#dot.ffmuc.net
Domains=~.
DNSOverTLS=yes
DNSSEC=false
'';
};
}