454 lines
17 KiB
Nix
454 lines
17 KiB
Nix
{ pkgs
|
|
, lanzabooteModule
|
|
}:
|
|
|
|
let
|
|
inherit (pkgs) lib system;
|
|
defaultTimeout = 5 * 60; # = 5 minutes
|
|
|
|
mkSecureBootTest = { name, machine ? { }, useSecureBoot ? true, useTPM2 ? false, readEfiVariables ? false, testScript }:
|
|
let
|
|
tpmSocketPath = "/tmp/swtpm-sock";
|
|
tpmDeviceModels = {
|
|
x86_64-linux = "tpm-tis";
|
|
aarch64-linux = "tpm-tis-device";
|
|
};
|
|
# Should go to nixpkgs.
|
|
efiVariablesHelpers = ''
|
|
import struct
|
|
|
|
SD_LOADER_GUID = "4a67b082-0a4c-41cf-b6c7-440b29bb8c4f"
|
|
def read_raw_variable(var: str) -> bytes:
|
|
attr_var = machine.succeed(f"cat /sys/firmware/efi/efivars/{var}-{SD_LOADER_GUID}").encode('raw_unicode_escape')
|
|
_ = attr_var[:4] # First 4 bytes are attributes according to https://www.kernel.org/doc/html/latest/filesystems/efivarfs.html
|
|
value = attr_var[4:]
|
|
return value
|
|
def read_string_variable(var: str, encoding='utf-16-le') -> str:
|
|
return read_raw_variable(var).decode(encoding).rstrip('\x00')
|
|
# By default, it will read a 4 byte value, read `struct` docs to change the format.
|
|
def assert_variable_uint(var: str, expected: int, format: str = 'I'):
|
|
with subtest(f"Is `{var}` set to {expected} (uint)"):
|
|
value, = struct.unpack(f'<{format}', read_raw_variable(var))
|
|
assert value == expected, f"Unexpected variable value in `{var}`, expected: `{expected}`, actual: `{value}`"
|
|
def assert_variable_string(var: str, expected: str, encoding='utf-16-le'):
|
|
with subtest(f"Is `{var}` correctly set"):
|
|
value = read_string_variable(var, encoding)
|
|
assert value == expected, f"Unexpected variable value in `{var}`, expected: `{expected.encode(encoding)!r}`, actual: `{value.encode(encoding)!r}`"
|
|
def assert_variable_string_contains(var: str, expected_substring: str):
|
|
with subtest(f"Do `{var}` contain expected substrings"):
|
|
value = read_string_variable(var).strip()
|
|
assert expected_substring in value, f"Did not find expected substring in `{var}`, expected substring: `{expected_substring}`, actual value: `{value}`"
|
|
'';
|
|
tpm2Initialization = ''
|
|
import subprocess
|
|
from tempfile import TemporaryDirectory
|
|
|
|
# From systemd-initrd-luks-tpm2.nix
|
|
class Tpm:
|
|
def __init__(self):
|
|
self.state_dir = TemporaryDirectory()
|
|
self.start()
|
|
|
|
def start(self):
|
|
self.proc = subprocess.Popen(["${pkgs.swtpm}/bin/swtpm",
|
|
"socket",
|
|
"--tpmstate", f"dir={self.state_dir.name}",
|
|
"--ctrl", "type=unixio,path=${tpmSocketPath}",
|
|
"--tpm2",
|
|
])
|
|
|
|
# Check whether starting swtpm failed
|
|
try:
|
|
exit_code = self.proc.wait(timeout=0.2)
|
|
if exit_code is not None and exit_code != 0:
|
|
raise Exception("failed to start swtpm")
|
|
except subprocess.TimeoutExpired:
|
|
pass
|
|
|
|
"""Check whether the swtpm process exited due to an error"""
|
|
def check(self):
|
|
exit_code = self.proc.poll()
|
|
if exit_code is not None and exit_code != 0:
|
|
raise Exception("swtpm process died")
|
|
|
|
tpm = Tpm()
|
|
|
|
@polling_condition
|
|
def swtpm_running():
|
|
tpm.check()
|
|
'';
|
|
in
|
|
pkgs.nixosTest {
|
|
inherit name;
|
|
globalTimeout = defaultTimeout;
|
|
|
|
testScript = ''
|
|
${lib.optionalString useTPM2 tpm2Initialization}
|
|
${lib.optionalString readEfiVariables efiVariablesHelpers}
|
|
${testScript}
|
|
'';
|
|
|
|
nodes.machine = { pkgs, lib, ... }: {
|
|
imports = [
|
|
lanzabooteModule
|
|
machine
|
|
];
|
|
|
|
virtualisation = {
|
|
useBootLoader = true;
|
|
useEFIBoot = true;
|
|
|
|
# We actually only want to enable features in OVMF, but at
|
|
# the moment edk2 202308 is also broken. So we downgrade it
|
|
# here as well. How painful!
|
|
#
|
|
# See #240.
|
|
efi.OVMF =
|
|
let
|
|
edk2Version = "202305";
|
|
edk2Src = pkgs.fetchFromGitHub {
|
|
owner = "tianocore";
|
|
repo = "edk2";
|
|
rev = "edk2-stable${edk2Version}";
|
|
fetchSubmodules = true;
|
|
hash = "sha256-htOvV43Hw5K05g0SF3po69HncLyma3BtgpqYSdzRG4s=";
|
|
};
|
|
|
|
edk2 = pkgs.edk2.overrideAttrs (old: rec {
|
|
version = edk2Version;
|
|
src = edk2Src;
|
|
});
|
|
in
|
|
(pkgs.OVMF.override {
|
|
secureBoot = useSecureBoot;
|
|
tpmSupport = useTPM2; # This is needed otherwise OVMF won't initialize the TPM2 protocol.
|
|
|
|
edk2 = edk2;
|
|
}).overrideAttrs (old: {
|
|
src = edk2Src;
|
|
});
|
|
|
|
qemu.options = lib.mkIf useTPM2 [
|
|
"-chardev socket,id=chrtpm,path=${tpmSocketPath}"
|
|
"-tpmdev emulator,id=tpm_dev_0,chardev=chrtpm"
|
|
"-device ${tpmDeviceModels.${system}},tpmdev=tpm_dev_0"
|
|
];
|
|
|
|
inherit useSecureBoot;
|
|
};
|
|
|
|
boot.initrd.availableKernelModules = lib.mkIf useTPM2 [ "tpm_tis" ];
|
|
|
|
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, appendCrapGlob, useSecureBoot ? true }: mkSecureBootTest {
|
|
inherit name;
|
|
inherit useSecureBoot;
|
|
|
|
testScript = ''
|
|
machine.start()
|
|
machine.succeed("echo some_garbage_to_change_the_hash | tee -a ${appendCrapGlob} > /dev/null")
|
|
machine.succeed("sync")
|
|
machine.crash()
|
|
machine.start()
|
|
'' + (if useSecureBoot then ''
|
|
machine.wait_for_console_text("hash does not match")
|
|
'' 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;
|
|
appendCrapGlob = "/boot/EFI/nixos/initrd-*.efi";
|
|
};
|
|
|
|
mkModifiedKernelTest = { name, useSecureBoot }: mkHashMismatchTest {
|
|
inherit name useSecureBoot;
|
|
appendCrapGlob = "/boot/EFI/nixos/kernel-*.efi";
|
|
};
|
|
|
|
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. Verify that
|
|
# a new initrd (which is supposed to only differ by the secrets) is created
|
|
# in this case.
|
|
#
|
|
# 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 three boot files exists (a single kernel and a two
|
|
# initrds).
|
|
assert int(machine.succeed("ls -1 /boot/EFI/nixos | wc -l")) == 3
|
|
|
|
# It is expected that the initrd contains the original secret.
|
|
machine.succeed("cmp ${originalSecret} /secret-from-initramfs")
|
|
|
|
machine.succeed("bootctl set-default nixos-generation-1-specialisation-variant-\*.efi")
|
|
machine.succeed("sync")
|
|
machine.crash()
|
|
machine.start()
|
|
machine.wait_for_unit("multi-user.target")
|
|
# It is expected that the initrd of the specialisation 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")
|
|
'';
|
|
};
|
|
|
|
# We test if we can install Lanzaboote without Bootspec support.
|
|
synthesis = mkSecureBootTest {
|
|
name = "lanzaboote-synthesis";
|
|
machine = { lib, ... }: {
|
|
boot.bootspec.enable = lib.mkForce false;
|
|
};
|
|
testScript = ''
|
|
machine.start()
|
|
assert "Secure Boot: enabled (user)" in machine.succeed("bootctl status")
|
|
'';
|
|
};
|
|
|
|
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").split("\n")
|
|
expected_loader_config = ["timeout 0", "console-mode auto"]
|
|
|
|
assert all(cfg in actual_loader_config for cfg in expected_loader_config), \
|
|
f"Expected: {expected_loader_config} is not included in actual config: '{actual_loader_config}'"
|
|
'';
|
|
};
|
|
|
|
export-efi-variables = mkSecureBootTest {
|
|
name = "lanzaboote-exports-efi-variables";
|
|
machine.environment.systemPackages = [ pkgs.efibootmgr ];
|
|
readEfiVariables = true;
|
|
testScript = ''
|
|
# We will choose to boot directly on the stub.
|
|
# To perform this trick, we will boot first with systemd-boot.
|
|
# Then, we will add a new boot entry in EFI with higher priority
|
|
# pointing to our stub.
|
|
# Finally, we will reboot.
|
|
# We will also assert that systemd-boot is not running
|
|
# by checking for the sd-boot's specific EFI variables.
|
|
machine.start()
|
|
|
|
# By construction, nixos-generation-1.efi is the stub we are interested in.
|
|
# TODO: this should work -- machine.succeed("efibootmgr -d /dev/vda -c -l \\EFI\\Linux\\nixos-generation-1.efi") -- efivars are not persisted
|
|
# across reboots atm?
|
|
# cheat code no 1
|
|
machine.succeed("cp /boot/EFI/Linux/nixos-generation-1-*.efi /boot/EFI/BOOT/BOOTX64.EFI")
|
|
machine.succeed("cp /boot/EFI/Linux/nixos-generation-1-*.efi /boot/EFI/systemd/systemd-bootx64.efi")
|
|
|
|
# Let's reboot.
|
|
machine.succeed("sync")
|
|
machine.crash()
|
|
machine.start()
|
|
|
|
# This is the sd-boot EFI variable indicator, we should not have it at this point.
|
|
print(machine.execute("bootctl")[1]) # Check if there's incorrect value in the output.
|
|
machine.succeed(
|
|
"test -e /sys/firmware/efi/efivars/LoaderEntrySelected-4a67b082-0a4c-41cf-b6c7-440b29bb8c4f && false || true"
|
|
)
|
|
|
|
expected_variables = ["LoaderDevicePartUUID",
|
|
"LoaderImageIdentifier",
|
|
"LoaderFirmwareInfo",
|
|
"LoaderFirmwareType",
|
|
"StubInfo",
|
|
"StubFeatures"
|
|
]
|
|
|
|
# Debug all systemd loader specification GUID EFI variables loaded by the current environment.
|
|
print(machine.succeed(f"ls /sys/firmware/efi/efivars/*-{SD_LOADER_GUID}"))
|
|
with subtest("Check if supported variables are exported"):
|
|
for expected_var in expected_variables:
|
|
machine.succeed(f"test -e /sys/firmware/efi/efivars/{expected_var}-{SD_LOADER_GUID}")
|
|
|
|
with subtest("Is `StubInfo` correctly set"):
|
|
assert "lanzastub" in read_string_variable("StubInfo"), "Unexpected stub information, provenance is not lanzaboote project!"
|
|
|
|
assert_variable_string("LoaderImageIdentifier", "\\EFI\\BOOT\\BOOTX64.EFI")
|
|
# TODO: exploit QEMU test infrastructure to pass the good value all the time.
|
|
assert_variable_string("LoaderDevicePartUUID", "1c06f03b-704e-4657-b9cd-681a087a2fdc")
|
|
# OVMF tests are using EDK II tree.
|
|
assert_variable_string_contains("LoaderFirmwareInfo", "EDK II")
|
|
assert_variable_string_contains("LoaderFirmwareType", "UEFI")
|
|
|
|
with subtest("Is `StubFeatures` non-zero"):
|
|
assert struct.unpack('<Q', read_raw_variable("StubFeatures")) != 0
|
|
'';
|
|
};
|
|
|
|
tpm2-export-efi-variables = mkSecureBootTest {
|
|
name = "lanzaboote-tpm2-exports-efi-variables";
|
|
useTPM2 = true;
|
|
readEfiVariables = true;
|
|
testScript = ''
|
|
machine.start()
|
|
|
|
# TODO: the other variables are not yet supported.
|
|
expected_variables = [
|
|
"StubPcrKernelImage"
|
|
]
|
|
|
|
# Debug all systemd loader specification GUID EFI variables loaded by the current environment.
|
|
print(machine.succeed(f"ls /sys/firmware/efi/efivars/*-{SD_LOADER_GUID}"))
|
|
with subtest("Check if supported variables are exported"):
|
|
for expected_var in expected_variables:
|
|
machine.succeed(f"test -e /sys/firmware/efi/efivars/{expected_var}-{SD_LOADER_GUID}")
|
|
|
|
# "Static" parts of the UKI is measured in PCR11
|
|
assert_variable_uint("StubPcrKernelImage", 11)
|
|
'';
|
|
};
|
|
|
|
}
|