pyrox.dev
1{ lib, pkgs, ... }:
2{
3 name = "systemd-credentials-tpm2";
4
5 meta = {
6 maintainers = with pkgs.lib.maintainers; [ tmarkus ];
7 };
8
9 nodes.machine =
10 { pkgs, ... }:
11 {
12 virtualisation.tpm.enable = true;
13 environment.systemPackages = with pkgs; [ diffutils ];
14 };
15
16 testScript = ''
17 CRED_NAME = "testkey"
18 CRED_RAW_FILE = f"/root/{CRED_NAME}"
19 CRED_FILE = f"/root/{CRED_NAME}.cred"
20
21 def systemd_run(machine, cmd):
22 machine.log(f"Executing command (via systemd-run): \"{cmd}\"")
23
24 (status, out) = machine.execute( " ".join([
25 "systemd-run",
26 "--service-type=exec",
27 "--quiet",
28 "--wait",
29 "-E PATH=\"$PATH\"",
30 "-p StandardOutput=journal",
31 "-p StandardError=journal",
32 f"-p LoadCredentialEncrypted={CRED_NAME}:{CRED_FILE}",
33 f"$SHELL -c '{cmd}'"
34 ]) )
35
36 if status != 0:
37 raise Exception(f"systemd_run failed (status {status})")
38
39 machine.log("systemd-run finished successfully")
40
41 machine.wait_for_unit("multi-user.target")
42
43 with subtest("Check whether TPM device exists"):
44 machine.succeed("test -e /dev/tpm0")
45 machine.succeed("test -e /dev/tpmrm0")
46
47 with subtest("Check whether systemd-creds detects TPM2 correctly"):
48 cmd = "systemd-creds has-tpm2"
49 machine.log(f"Running \"{cmd}\"")
50 (status, _) = machine.execute(cmd)
51
52 # Check exit code equals 0 or 1 (1 means firmware support is missing, which is OK here)
53 if status != 0 and status != 1:
54 raise Exception("systemd-creds failed to detect TPM2")
55
56 with subtest("Encrypt credential using systemd-creds"):
57 machine.succeed(f"dd if=/dev/urandom of={CRED_RAW_FILE} bs=1k count=16")
58 machine.succeed(f"systemd-creds --with-key=host+tpm2 encrypt --name=testkey {CRED_RAW_FILE} {CRED_FILE}")
59
60 with subtest("Write provided credential and check for equality"):
61 CRED_OUT_FILE = f"/root/{CRED_NAME}.out"
62 systemd_run(machine, f"systemd-creds cat testkey > {CRED_OUT_FILE}")
63 machine.succeed(f"cmp --silent -- {CRED_RAW_FILE} {CRED_OUT_FILE}")
64
65 with subtest("Check whether systemd service can see credential in systemd-creds list"):
66 systemd_run(machine, f"systemd-creds list | grep {CRED_NAME}")
67
68 with subtest("Check whether systemd service can access credential in $CREDENTIALS_DIRECTORY"):
69 systemd_run(machine, f"cmp --silent -- $CREDENTIALS_DIRECTORY/{CRED_NAME} {CRED_RAW_FILE}")
70 '';
71}