51d63a1829
* Updated agenix: github:ryantm/agenix/ed7e69bff3c17671349839f696e88e345eb9eb24 -> github:ryantm/agenix/9eb981eeb552e0856cb562b7643b311933a0e992 * Updated emacs-overlay: github:nix-community/emacs-overlay/063ee066b5095dd2f21f47c582b04024674974a8 -> github:nix-community/emacs-overlay/daa4b15755f6cccb462efed696abceee0994bb96 * Updated home-manager: github:rycee/home-manager/f45c7000d544f17e5499e2ae6b505b5f705c5d61 -> github:rycee/home-manager/040ea28e448a93d24540b7cf2eda4b25300c5ab1 * Updated nixos-hardware: github:nixos/nixos-hardware/c9b965a43e582765f797f8b75d50cb2874b30f30 -> github:nixos/nixos-hardware/831de9cac9ff2ea8cf4c3742020ea92e82ac8ac3 * Updated nixpkgs: github:NixOS/nixpkgs/ff96a0fa5635770390b184ae74debea75c3fd534 -> github:NixOS/nixpkgs/29b0d4d0b600f8f5dd0b86e3362a33d4181938f9 * Updated nixpkgs-unstable: github:NixOS/nixpkgs/07b0c7bc4104b87cb5223ec10e32b863d10768ad -> github:NixOS/nixpkgs/d02b1cc8ed29b6967119fd95267ee1a955015d59 Also, removed noexec from /tmp because it screws with build processes that deploy/execute scripts to/out of /tmp, causing permission errors while building.
71 lines
2.9 KiB
Nix
71 lines
2.9 KiB
Nix
{ config, lib, ... }:
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{
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## System security tweaks
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# sets hidepid=2 on /proc (make process info visible only to owning user)
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# NOTE Was removed on nixpkgs-unstable because it doesn't do anything
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# security.hideProcessInformation = true;
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# Prevent replacing the running kernel w/o reboot
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security.protectKernelImage = true;
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# tmpfs = /tmp is mounted in ram. Doing so makes temp file management speedy
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# on ssd systems, and volatile! Because it's wiped on reboot.
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boot.tmpOnTmpfs = lib.mkDefault true;
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# If not using tmpfs, which is naturally purged on reboot, we must clean it
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# /tmp ourselves. /tmp should be volatile storage!
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boot.cleanTmpDir = lib.mkDefault (!config.boot.tmpOnTmpfs);
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# Fix a security hole in place for backwards compatibility. See desc in
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# nixpkgs/nixos/modules/system/boot/loader/systemd-boot/systemd-boot.nix
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boot.loader.systemd-boot.editor = false;
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boot.kernel.sysctl = {
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# The Magic SysRq key is a key combo that allows users connected to the
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# system console of a Linux kernel to perform some low-level commands.
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# Disable it, since we don't need it, and is a potential security concern.
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"kernel.sysrq" = 0;
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## TCP hardening
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# Prevent bogus ICMP errors from filling up logs.
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"net.ipv4.icmp_ignore_bogus_error_responses" = 1;
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# Reverse path filtering causes the kernel to do source validation of
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# packets received from all interfaces. This can mitigate IP spoofing.
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"net.ipv4.conf.default.rp_filter" = 1;
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"net.ipv4.conf.all.rp_filter" = 1;
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# Do not accept IP source route packets (we're not a router)
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"net.ipv4.conf.all.accept_source_route" = 0;
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"net.ipv6.conf.all.accept_source_route" = 0;
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# Don't send ICMP redirects (again, we're on a router)
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"net.ipv4.conf.all.send_redirects" = 0;
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"net.ipv4.conf.default.send_redirects" = 0;
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# Refuse ICMP redirects (MITM mitigations)
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"net.ipv4.conf.all.accept_redirects" = 0;
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"net.ipv4.conf.default.accept_redirects" = 0;
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"net.ipv4.conf.all.secure_redirects" = 0;
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"net.ipv4.conf.default.secure_redirects" = 0;
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"net.ipv6.conf.all.accept_redirects" = 0;
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"net.ipv6.conf.default.accept_redirects" = 0;
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# Protects against SYN flood attacks
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"net.ipv4.tcp_syncookies" = 1;
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# Incomplete protection again TIME-WAIT assassination
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"net.ipv4.tcp_rfc1337" = 1;
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## TCP optimization
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# TCP Fast Open is a TCP extension that reduces network latency by packing
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# data in the sender’s initial TCP SYN. Setting 3 = enable TCP Fast Open for
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# both incoming and outgoing connections:
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"net.ipv4.tcp_fastopen" = 3;
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# Bufferbloat mitigations + slight improvement in throughput & latency
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"net.ipv4.tcp_congestion_control" = "bbr";
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"net.core.default_qdisc" = "cake";
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};
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boot.kernelModules = [ "tcp_bbr" ];
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# Change me later!
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user.initialPassword = "nixos";
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users.users.root.initialPassword = "nixos";
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# So we don't have to do this later...
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security.acme.acceptTerms = true;
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}
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