From 1bea49d3bf339a708dc8724a9f2ebd3047e212b5 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Janne=20He=C3=9F?= Date: Wed, 13 Apr 2022 19:45:29 +0100 Subject: [PATCH] nixos/stage-1-systemd: Add LUKS w/ password support --- nixos/modules/system/boot/luksroot.nix | 78 ++++++++++++++++++-- nixos/tests/all-tests.nix | 1 + nixos/tests/systemd-initrd-luks-password.nix | 48 ++++++++++++ 3 files changed, 121 insertions(+), 6 deletions(-) create mode 100644 nixos/tests/systemd-initrd-luks-password.nix diff --git a/nixos/modules/system/boot/luksroot.nix b/nixos/modules/system/boot/luksroot.nix index dde07571b3e7..57fc02a2e322 100644 --- a/nixos/modules/system/boot/luksroot.nix +++ b/nixos/modules/system/boot/luksroot.nix @@ -1,10 +1,11 @@ -{ config, lib, pkgs, ... }: +{ config, options, lib, pkgs, ... }: with lib; let luks = config.boot.initrd.luks; kernelPackages = config.boot.kernelPackages; + defaultPrio = (mkOptionDefault {}).priority; commonFunctions = '' die() { @@ -474,6 +475,16 @@ let preLVM = filterAttrs (n: v: v.preLVM) luks.devices; postLVM = filterAttrs (n: v: !v.preLVM) luks.devices; + stage1Crypttab = pkgs.writeText "initrd-crypttab" (lib.concatStringsSep "\n" (lib.mapAttrsToList (n: v: let + opts = v.crypttabExtraOpts + ++ optional v.allowDiscards "discard" + ++ optionals v.bypassWorkqueues [ "no-read-workqueue" "no-write-workqueue" ] + ++ optional (v.header != null) "header=${v.header}" + ++ optional (v.keyFileOffset != null) "keyfile-offset=${v.keyFileOffset}" + ++ optional (v.keyFileSize != null) "keyfile-size=${v.keyFileSize}" + ; + in "${n} ${v.device} ${if v.keyFile == null then "-" else v.keyFile} ${lib.concatStringsSep "," opts}") luks.devices)); + in { imports = [ @@ -802,6 +813,18 @@ in Commands that should be run right after we have mounted our LUKS device. ''; }; + + crypttabExtraOpts = mkOption { + type = with types; listOf singleLineStr; + default = []; + example = [ "_netdev" ]; + visible = false; + description = '' + Only used with systemd stage 1. + + Extra options to append to the last column of the generated crypttab file. + ''; + }; }; })); }; @@ -853,6 +876,31 @@ in -> versionAtLeast kernelPackages.kernel.version "5.9"; message = "boot.initrd.luks.devices..bypassWorkqueues is not supported for kernels older than 5.9"; } + + { assertion = config.boot.initrd.systemd.enable -> all (dev: !dev.fallbackToPassword) (attrValues luks.devices); + message = "boot.initrd.luks.devices..fallbackToPassword is implied by systemd stage 1."; + } + { assertion = config.boot.initrd.systemd.enable -> all (dev: dev.preLVM) (attrValues luks.devices); + message = "boot.initrd.luks.devices..preLVM is not used by systemd stage 1."; + } + { assertion = config.boot.initrd.systemd.enable -> options.boot.initrd.luks.reusePassphrases.highestPrio == defaultPrio; + message = "boot.initrd.luks.reusePassphrases has no effect with systemd stage 1."; + } + { assertion = config.boot.initrd.systemd.enable -> all (dev: dev.preOpenCommands == "" && dev.postOpenCommands == "") (attrValues luks.devices); + message = "boot.initrd.luks.devices..preOpenCommands and postOpenCommands is not supported by systemd stage 1. Please bind a service to cryptsetup.target or cryptsetup-pre.target instead."; + } + # TODO + { assertion = config.boot.initrd.systemd.enable -> !luks.gpgSupport; + message = "systemd stage 1 does not support GPG smartcards yet."; + } + # TODO + { assertion = config.boot.initrd.systemd.enable -> !luks.fido2Support; + message = "systemd stage 1 does not support FIDO2 yet."; + } + # TODO + { assertion = config.boot.initrd.systemd.enable -> !luks.yubikeySupport; + message = "systemd stage 1 does not support Yubikeys yet."; + } ]; # actually, sbp2 driver is the one enabling the DMA attack, but this needs to be tested @@ -867,7 +915,7 @@ in ++ (if builtins.elem "xts" luks.cryptoModules then ["ecb"] else []); # copy the cryptsetup binary and it's dependencies - boot.initrd.extraUtilsCommands = '' + boot.initrd.extraUtilsCommands = mkIf (!config.boot.initrd.systemd.enable) '' copy_bin_and_libs ${pkgs.cryptsetup}/bin/cryptsetup copy_bin_and_libs ${askPass}/bin/cryptsetup-askpass sed -i s,/bin/sh,$out/bin/sh, $out/bin/cryptsetup-askpass @@ -915,7 +963,7 @@ in ''} ''; - boot.initrd.extraUtilsCommandsTest = '' + boot.initrd.extraUtilsCommandsTest = mkIf (!config.boot.initrd.systemd.enable) '' $out/bin/cryptsetup --version ${optionalString luks.yubikeySupport '' $out/bin/ykchalresp -V @@ -932,9 +980,27 @@ in ''} ''; - boot.initrd.preFailCommands = postCommands; - boot.initrd.preLVMCommands = commonFunctions + preCommands + concatStrings (mapAttrsToList openCommand preLVM) + postCommands; - boot.initrd.postDeviceCommands = commonFunctions + preCommands + concatStrings (mapAttrsToList openCommand postLVM) + postCommands; + boot.initrd.systemd = { + contents."/etc/crypttab".source = stage1Crypttab; + + extraBin.systemd-cryptsetup = "${config.boot.initrd.systemd.package}/lib/systemd/systemd-cryptsetup"; + + additionalUpstreamUnits = [ + "cryptsetup-pre.target" + "cryptsetup.target" + "remote-cryptsetup.target" + ]; + storePaths = [ + "${config.boot.initrd.systemd.package}/lib/systemd/systemd-cryptsetup" + ]; + + }; + # We do this because we need the udev rules from the package + boot.initrd.services.lvm.enable = true; + + boot.initrd.preFailCommands = mkIf (!config.boot.initrd.systemd.enable) postCommands; + boot.initrd.preLVMCommands = mkIf (!config.boot.initrd.systemd.enable) (commonFunctions + preCommands + concatStrings (mapAttrsToList openCommand preLVM) + postCommands); + boot.initrd.postDeviceCommands = mkIf (!config.boot.initrd.systemd.enable) (commonFunctions + preCommands + concatStrings (mapAttrsToList openCommand postLVM) + postCommands); environment.systemPackages = [ pkgs.cryptsetup ]; }; diff --git a/nixos/tests/all-tests.nix b/nixos/tests/all-tests.nix index 57c17508aab6..3f3e672d6fd5 100644 --- a/nixos/tests/all-tests.nix +++ b/nixos/tests/all-tests.nix @@ -524,6 +524,7 @@ in systemd-confinement = handleTest ./systemd-confinement.nix {}; systemd-cryptenroll = handleTest ./systemd-cryptenroll.nix {}; systemd-escaping = handleTest ./systemd-escaping.nix {}; + systemd-initrd-luks-password = handleTest ./systemd-initrd-luks-password.nix {}; systemd-initrd-shutdown = handleTest ./systemd-shutdown.nix { systemdStage1 = true; }; systemd-initrd-simple = handleTest ./systemd-initrd-simple.nix {}; systemd-initrd-swraid = handleTest ./systemd-initrd-swraid.nix {}; diff --git a/nixos/tests/systemd-initrd-luks-password.nix b/nixos/tests/systemd-initrd-luks-password.nix new file mode 100644 index 000000000000..e8e651f7b35f --- /dev/null +++ b/nixos/tests/systemd-initrd-luks-password.nix @@ -0,0 +1,48 @@ +import ./make-test-python.nix ({ lib, pkgs, ... }: { + name = "systemd-initrd-luks-password"; + + nodes.machine = { pkgs, ... }: { + # Use systemd-boot + virtualisation = { + emptyDiskImages = [ 512 512 ]; + useBootLoader = true; + useEFIBoot = true; + }; + boot.loader.systemd-boot.enable = true; + + environment.systemPackages = with pkgs; [ cryptsetup ]; + boot.initrd.systemd = { + enable = true; + emergencyAccess = true; + }; + + specialisation.boot-luks.configuration = { + boot.initrd.luks.devices = lib.mkVMOverride { + # We have two disks and only type one password - key reuse is in place + cryptroot.device = "/dev/vdc"; + cryptroot2.device = "/dev/vdd"; + }; + virtualisation.bootDevice = "/dev/mapper/cryptroot"; + }; + }; + + testScript = '' + # Create encrypted volume + machine.wait_for_unit("multi-user.target") + machine.succeed("echo -n supersecret | cryptsetup luksFormat -q --iter-time=1 /dev/vdc -") + machine.succeed("echo -n supersecret | cryptsetup luksFormat -q --iter-time=1 /dev/vdd -") + + # Boot from the encrypted disk + machine.succeed("bootctl set-default nixos-generation-1-specialisation-boot-luks.conf") + machine.succeed("sync") + machine.crash() + + # Boot and decrypt the disk + machine.start() + machine.wait_for_console_text("Please enter passphrase for disk cryptroot") + machine.send_console("supersecret\n") + machine.wait_for_unit("multi-user.target") + + assert "/dev/mapper/cryptroot on / type ext4" in machine.succeed("mount") + ''; +})