The current TPM2 PIN mode is flawed as a compromised TPM directly exposes
the sealed secret which is the LUKS volume key itself (#27502 and #37386).
Goal: add Argon2id-based PIN hardening to TPM2 enrollment, making
the TPM a second factor rather than a single point of failure:
1. Password + salt -> Argon2id -> 512-bit key split into Key1 + Key2
2. Key2 (base64-encoded) is used as the PIN to seal a random secret
in the TPM
3. Key1 + unsealed secret -> HKDF-SHA256 -> final LUKS volume key
This implementation ensures that if the TPM is compromised, an attacker
still needs the password to derive Key1 and combine it with the unsealed
secret.
The --tpm2-with-pin= option now accepts three values:
- false (no PIN used)
- true (PIN hardened with Argon2id - default)
- "direct" (legacy PIN without Argon2id for backward compatibility)
Argon2id parameters are customizable via:
--tpm2-argon2id-memory=
--tpm2-argon2id-iterations=
--tpm2-argon2id-parallelism=
--tpm2-argon2id-iter-time=
These default to a function of available CPUs and physical memory, with
a benchmark that scales iterations to the target time (default: 2s) and
falls back to ARGON2ID_PARAMETERS_DEFAULT (64 MiB, 8 iter, 4 lanes) when
auto detection fails.
Also if the runtime OpenSSL lacks Argon2id support (< 3.2), the feature
silently falls back to direct PIN mode with a warning.
Added includes:
- src/cryptenroll/cryptenroll.c: cpu-set-util.h, limits-util.h, time-util.h
for Argon2id benchmark auto-tuning (cpus_online, physical_memory_scale,
now/usec_t)
- src/cryptenroll/cryptenroll-tpm2.c: crypto-util.h for Argon2IdParameters
struct in load_volume_key_tpm2()
- src/shared/tpm2-util.h: crypto-util.h for Argon2IdParameters in
tpm2_make_luks2_json() API
- src/shared/tpm2-util.c: limits-util.h, tpm2-util.h for physical_memory() validation
of Argon2id memory cost and function prototypes
- src/cryptsetup/cryptsetup-tokens/luks2-tpm2.c: crypto-util.h for
kdf_argon2id_derive()/kdf_hkdf_sha256() on the token unlock path
This introduces a test utility to validate the presence and correctness
of dlopen ELF notes.
The test extracts and compares dlopen ELF notes between the dynamic and
static versions of target binaries to catch missing entries. Furthermore,
it scans the code for dlopen_foo() invocations to ensure that no stale or
unused notes remain in the final binary, thereby verifying the linker's
garbage-collection integration.
