From 0963ba83dd92fefbc914bbde419bb613fbe5fa15 Mon Sep 17 00:00:00 2001
From: Julian Stecklina <js@alien8.de>
Date: Thu, 2 Feb 2023 14:38:34 +0100
Subject: [PATCH] tests: check whether disabled secure boot relaxes hash checks

---
 nix/tests/lanzaboote.nix | 85 ++++++++++++++++++++++++++++------------
 1 file changed, 59 insertions(+), 26 deletions(-)

diff --git a/nix/tests/lanzaboote.nix b/nix/tests/lanzaboote.nix
index d8f0781..cc79538 100644
--- a/nix/tests/lanzaboote.nix
+++ b/nix/tests/lanzaboote.nix
@@ -6,7 +6,7 @@
 let
   inherit (pkgs) lib;
 
-  mkSecureBootTest = { name, machine ? { }, testScript }: testPkgs.nixosTest {
+  mkSecureBootTest = { name, machine ? { }, useSecureBoot ? true, testScript }: testPkgs.nixosTest {
     inherit name testScript;
     nodes.machine = { lib, ... }: {
       imports = [
@@ -17,7 +17,8 @@ let
       virtualisation = {
         useBootLoader = true;
         useEFIBoot = true;
-        useSecureBoot = true;
+
+        inherit useSecureBoot;
       };
 
       boot.loader.efi = {
@@ -31,14 +32,18 @@ let
     };
   };
 
-  # Execute a SB test that is expected to fail because of a hash mismatch.
+  # 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 }: mkSecureBootTest {
+  mkHashMismatchTest = { name, path, appendCrap ? false, useSecureBoot ? true }: mkSecureBootTest {
     inherit name;
+    inherit useSecureBoot;
+
     testScript = ''
       import json
       import os.path
@@ -62,9 +67,40 @@ let
       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
@@ -109,31 +145,28 @@ in
     '';
   };
 
-  # The initrd is not directly signed. Its hash is embedded
-  # into the UKI. 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.
-  secured-initrd = mkHashMismatchTest {
-    name = "lanzaboote-secured-initrd";
-    path = {
-      src = "bootspec.get('initrd')";
-      dst = "convert_to_esp(bootspec.get('initrd'))";
-    };
-    appendCrap = true;
+  modified-initrd-doesnt-boot-with-secure-boot = mkModifiedInitrdTest {
+    name = "modified-initrd-doesnt-boot-with-secure-boot";
+    useSecureBoot = true;
   };
 
-  secured-kernel = mkHashMismatchTest {
-    name = "lanzaboote-secured-kernel";
-    path = {
-      src = "bootspec.get('kernel')";
-      dst = "convert_to_esp(bootspec.get('kernel'))";
-    };
-    appendCrap = true;
+  modified-initrd-boots-without-secure-boot = mkModifiedInitrdTest {
+    name = "modified-initrd-boots-without-secure-boot";
+    useSecureBoot = false;
   };
 
-  specialisation = mkSecureBootTest {
-    name = "lanzaboote-specialisation";
+  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 = [