On Wed, 2021-11-24 at 19:38 -0500, Stefan Berger wrote:
From: Stefan Berger stefanb@linux.ibm.com
Probe for an available PCR bank to accommodate devices that do not have a
What does "probing for an vailable PCR bank" even mean?
SHA-1 PCR bank or whose SHA-1 bank is deactivated. Use the bank that can be used for the TPM2 commands, such as the SHA-256 bank.
This is incorrect, as the patch does not have code to query available hash algorithms.
What the code does, and only does that, is to use SHA-256 as a fallback when SHA-1 is not enabled.
/Jarkko
Signed-off-by: Stefan Berger stefanb@linux.ibm.com
tools/testing/selftests/tpm2/tpm2_tests.py | 35 +++++++++++++++++----- 1 file changed, 27 insertions(+), 8 deletions(-)
diff --git a/tools/testing/selftests/tpm2/tpm2_tests.py b/tools/testing/selftests/tpm2/tpm2_tests.py index 9d764306887b..6b88ff0e47b9 100644 --- a/tools/testing/selftests/tpm2/tpm2_tests.py +++ b/tools/testing/selftests/tpm2/tpm2_tests.py @@ -27,7 +27,23 @@ class SmokeTest(unittest.TestCase): result = self.client.unseal(self.root_key, blob, auth, None) self.assertEqual(data, result) + def determine_bank_alg(self): + # Probe for available PCR bank + for bank_alg in [tpm2.TPM2_ALG_SHA1, tpm2.TPM2_ALG_SHA256]: + try: + handle = self.client.start_auth_session(tpm2.TPM2_SE_TRIAL) + self.client.policy_pcr(handle, [17], bank_alg=bank_alg) + return bank_alg + except tpm2.UnknownPCRBankError: + pass + finally: + self.client.flush_context(handle) + return None
def test_seal_with_policy(self): + bank_alg = self.determine_bank_alg() + self.assertIsNotNone(bank_alg)
handle = self.client.start_auth_session(tpm2.TPM2_SE_TRIAL) data = ('X' * 64).encode() @@ -35,7 +51,7 @@ class SmokeTest(unittest.TestCase): pcrs = [16] try: - self.client.policy_pcr(handle, pcrs) + self.client.policy_pcr(handle, pcrs, bank_alg=bank_alg) self.client.policy_password(handle) policy_dig = self.client.get_policy_digest(handle) @@ -47,7 +63,7 @@ class SmokeTest(unittest.TestCase): handle = self.client.start_auth_session(tpm2.TPM2_SE_POLICY) try: - self.client.policy_pcr(handle, p"Use SHA-256 as a fallback crs) + self.client.policy_pcr(handle, pcrs, bank_alg=bank_alg) self.client.policy_password(handle) result = self.client.unseal(self.root_key, blob, auth, handle) @@ -72,6 +88,9 @@ class SmokeTest(unittest.TestCase): self.assertEqual(rc, tpm2.TPM2_RC_AUTH_FAIL) def test_unseal_with_wrong_policy(self): + bank_alg = self.determine_bank_alg() + self.assertIsNotNone(bank_alg)
handle = self.client.start_auth_session(tpm2.TPM2_SE_TRIAL) data = ('X' * 64).encode() @@ -79,7 +98,7 @@ class SmokeTest(unittest.TestCase): pcrs = [16] try: - self.client.policy_pcr(handle, pcrs) + self.client.policy_pcr(handle, pcrs, bank_alg=bank_alg) self.client.policy_password(handle) policy_dig = self.client.get_policy_digest(handle) @@ -91,13 +110,13 @@ class SmokeTest(unittest.TestCase): # Extend first a PCR that is not part of the policy and try to unseal. # This should succeed. - ds = tpm2.get_digest_size(tpm2.TPM2_ALG_SHA1) - self.client.extend_pcr(1, ('X' * ds).encode()) + ds = tpm2.get_digest_size(bank_alg) + self.client.extend_pcr(1, ('X' * ds).encode(), bank_alg=bank_alg) handle = self.client.start_auth_session(tpm2.TPM2_SE_POLICY) try: - self.client.policy_pcr(handle, pcrs) + self.client.policy_pcr(handle, pcrs, bank_alg=bank_alg) self.client.policy_password(handle) result = self.client.unseal(self.root_key, blob, auth, handle) @@ -109,14 +128,14 @@ class SmokeTest(unittest.TestCase): # Then, extend a PCR that is part of the policy and try to unseal. # This should fail. - self.client.extend_pcr(16, ('X' * ds).encode()) + self.client.extend_pcr(16, ('X' * ds).encode(), bank_alg=bank_alg) handle = self.client.start_auth_session(tpm2.TPM2_SE_POLICY) rc = 0 try: - self.client.policy_pcr(handle, pcrs) + self.client.policy_pcr(handle, pcrs, bank_alg=bank_alg) self.client.policy_password(handle) result = self.client.unseal(self.root_key, blob, auth, handle)