lanzaboote/nix/tests/lanzaboote.nix

260 lines
8.1 KiB
Nix

{ pkgs
, testPkgs
, lanzabooteModule
}:
let
inherit (pkgs) lib;
mkSecureBootTest = { name, machine ? { }, useSecureBoot ? true, testScript }: testPkgs.nixosTest {
inherit name testScript;
nodes.machine = { lib, ... }: {
imports = [
lanzabooteModule
machine
];
virtualisation = {
useBootLoader = true;
useEFIBoot = true;
inherit useSecureBoot;
};
boot.loader.efi = {
canTouchEfiVariables = true;
};
boot.lanzaboote = {
enable = true;
enrollKeys = lib.mkDefault true;
pkiBundle = ./fixtures/uefi-keys;
};
};
};
# Execute a boot test that has an intentionally broken secure boot
# chain. This test is expected to fail with Secure Boot and should
# succeed without.
#
# Takes a set `path` consisting of a `src` and a `dst` attribute. The file at
# `src` is copied to `dst` inside th VM. Optionally append some random data
# ("crap") to the end of the file at `dst`. This is useful to easily change
# the hash of a file and produce a hash mismatch when booting the stub.
mkHashMismatchTest = { name, path, appendCrap ? false, useSecureBoot ? true }: mkSecureBootTest {
inherit name;
inherit useSecureBoot;
testScript = ''
import json
import os.path
bootspec = None
def convert_to_esp(store_file_path):
store_dir = os.path.basename(os.path.dirname(store_file_path))
filename = os.path.basename(store_file_path)
return f'/boot/EFI/nixos/{store_dir}-{filename}.efi'
machine.start()
bootspec = json.loads(machine.succeed("cat /run/current-system/boot.json")).get('v1')
assert bootspec is not None, "Unsupported bootspec version!"
src_path = ${path.src}
dst_path = ${path.dst}
machine.succeed(f"cp -rf {src_path} {dst_path}")
'' + lib.optionalString appendCrap ''
machine.succeed(f"echo Foo >> {dst_path}")
'' +
''
machine.succeed("sync")
machine.crash()
machine.start()
'' + (if useSecureBoot then ''
machine.wait_for_console_text("Hash mismatch")
'' else ''
# Just check that the system came up.
print(machine.succeed("bootctl", timeout=120))
'');
};
# The initrd is not directly signed. Its hash is embedded into
# lanzaboote. To make integrity verification fail, we actually have
# to modify the initrd. Appending crap to the end is a harmless way
# that would make the kernel still accept it.
mkModifiedInitrdTest = { name, useSecureBoot }: mkHashMismatchTest {
inherit name useSecureBoot;
path = {
src = "bootspec.get('initrd')";
dst = "convert_to_esp(bootspec.get('initrd'))";
};
appendCrap = true;
};
mkModifiedKernelTest = { name, useSecureBoot }: mkHashMismatchTest {
inherit name useSecureBoot;
path = {
src = "bootspec.get('kernel')";
dst = "convert_to_esp(bootspec.get('kernel'))";
};
appendCrap = true;
};
in
{
# TODO: user mode: OK
# TODO: how to get in: {deployed, audited} mode ?
basic = mkSecureBootTest {
name = "lanzaboote";
testScript = ''
machine.start()
assert "Secure Boot: enabled (user)" in machine.succeed("bootctl status")
'';
};
systemd-initrd = mkSecureBootTest {
name = "lanzaboote-systemd-initrd";
machine = { ... }: {
boot.initrd.systemd.enable = true;
};
testScript = ''
machine.start()
assert "Secure Boot: enabled (user)" in machine.succeed("bootctl status")
'';
};
# Test that a secret is appended to the initrd during installation. Smilar to
# the initrd-secrets test in Nixpkgs:
# https://github.com/NixOS/nixpkgs/blob/master/nixos/tests/initrd-secrets.nix
initrd-secrets =
let
secret = (pkgs.writeText "oh-so-secure" "uhh-ooh-uhh-security");
in
mkSecureBootTest {
name = "lanzaboote-initrd-secrets";
machine = { ... }: {
boot.initrd.secrets = {
"/test" = secret;
};
boot.initrd.postMountCommands = ''
cp /test /mnt-root/secret-from-initramfs
'';
};
testScript = ''
machine.start()
machine.wait_for_unit("multi-user.target")
machine.succeed("cmp ${secret} /secret-from-initramfs")
assert "Secure Boot: enabled (user)" in machine.succeed("bootctl status")
'';
};
# Test that the secrets configured to be appended to the initrd get updated
# when installing a new generation even if the initrd itself (i.e. its store
# path) does not change.
#
# An unfortunate result of this NixOS feature is that updating the secrets
# without creating a new initrd might break previous generations. Lanzaboote
# has no control over that.
#
# This tests uses a specialisation to imitate a newer generation. This works
# because `lzbt` installs the specialisation of a generation AFTER installing
# the generation itself (thus making the specialisation "newer").
initrd-secrets-update =
let
originalSecret = (pkgs.writeText "oh-so-secure" "uhh-ooh-uhh-security");
newSecret = (pkgs.writeText "newly-secure" "so-much-better-now");
in
mkSecureBootTest {
name = "lanzaboote-initrd-secrets-update";
machine = { pkgs, lib, ... }: {
boot.initrd.secrets = {
"/test" = lib.mkDefault originalSecret;
};
boot.initrd.postMountCommands = ''
cp /test /mnt-root/secret-from-initramfs
'';
specialisation.variant.configuration = {
boot.initrd.secrets = {
"/test" = newSecret;
};
};
};
testScript = ''
machine.start()
machine.wait_for_unit("multi-user.target")
# Assert that only two boot files exists (a single kernel and a single
# initrd). If there are two initrds, the test would not be able to test
# updating the secret of an already existing initrd.
assert int(machine.succeed("ls -1 /boot/EFI/nixos | wc -l")) == 2
# It is expected that the initrd contains the new secret.
machine.succeed("cmp ${newSecret} /secret-from-initramfs")
'';
};
modified-initrd-doesnt-boot-with-secure-boot = mkModifiedInitrdTest {
name = "modified-initrd-doesnt-boot-with-secure-boot";
useSecureBoot = true;
};
modified-initrd-boots-without-secure-boot = mkModifiedInitrdTest {
name = "modified-initrd-boots-without-secure-boot";
useSecureBoot = false;
};
modified-kernel-doesnt-boot-with-secure-boot = mkModifiedKernelTest {
name = "modified-kernel-doesnt-boot-with-secure-boot";
useSecureBoot = true;
};
modified-kernel-boots-without-secure-boot = mkModifiedKernelTest {
name = "modified-kernel-boots-without-secure-boot";
useSecureBoot = false;
};
specialisation-works = mkSecureBootTest {
name = "specialisation-still-boot-under-secureboot";
machine = { pkgs, ... }: {
specialisation.variant.configuration = {
environment.systemPackages = [
pkgs.efibootmgr
];
};
};
testScript = ''
machine.start()
print(machine.succeed("ls -lah /boot/EFI/Linux"))
# TODO: make it more reliable to find this filename, i.e. read it from somewhere?
machine.succeed("bootctl set-default nixos-generation-1-specialisation-variant.efi")
machine.succeed("sync")
machine.fail("efibootmgr")
machine.crash()
machine.start()
print(machine.succeed("bootctl"))
# Only the specialisation contains the efibootmgr binary.
machine.succeed("efibootmgr")
'';
};
systemd-boot-loader-config = mkSecureBootTest {
name = "lanzaboote-systemd-boot-loader-config";
machine = {
boot.loader.timeout = 0;
boot.loader.systemd-boot.consoleMode = "auto";
};
testScript = ''
machine.start()
actual_loader_config = machine.succeed("cat /boot/loader/loader.conf")
expected_loader_config = "timeout 0\nconsole-mode auto\n"
assert actual_loader_config == expected_loader_config, \
f"Actual: '{actual_loader_config}' is not equal to expected: '{expected_loader_config}'"
'';
};
}