58 lines
1.5 KiB
Nix
58 lines
1.5 KiB
Nix
{ lib
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, config
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, ...
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}:
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{
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services.openssh = {
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enable = true;
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settings = {
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KbdInteractiveAuthentication = false;
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Ciphers = [
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"aes256-gcm@openssh.com"
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];
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# Use key exchange algorithms recommended by `nixpkgs#ssh-audit`
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KexAlgorithms = [
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"sntrup761x25519-sha512@openssh.com"
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"mlkem768x25519-sha256"
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];
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PasswordAuthentication = false;
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StreamLocalBindUnlink = true; # unbind gnupg sockets if they exists
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UseDns = false;
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X11Forwarding = false;
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};
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hostKeys = [
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{
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path = "/etc/ssh/ssh_host_ed25519_key";
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type = "ed25519";
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}
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];
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authorizedKeysFiles = lib.mkForce [ "/etc/ssh/authorized_keys.d/%u" ];
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};
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networking.nftables.tables."nixos-fw".content = lib.mkOrder 20 ''
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set ssh-ratelimit-v4 {
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type ipv4_addr
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timeout 60s
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flags dynamic
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}
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set ssh-ratelimit-v6 {
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type ipv6_addr
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timeout 60s
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flags dynamic
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}
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'';
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# Implement connection rate limit
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services.openssh.openFirewall = false;
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networking.firewall.extraInputRules = lib.mkOrder 5 (
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let
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ports = builtins.concatStringsSep ", " (map builtins.toString config.services.openssh.ports);
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in
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''
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tcp dport { ${ports} } update @ssh-ratelimit-v4 { ip saddr limit rate 1/second burst 10 packets } accept
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tcp dport { ${ports} } update @ssh-ratelimit-v6 { ip6 saddr limit rate 1/second burst 10 packets } accept
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''
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);
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}
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