From 0d060f230fa06c32d91e67978a3088be9635848e Mon Sep 17 00:00:00 2001 From: Stefan Berger Date: Sat, 27 Nov 2021 23:10:51 -0500 Subject: [PATCH] selftests: tpm2: Determine available PCR bank Determine an available PCR bank to be used by a test case by querying the capability TPM2_GET_CAP. The TPM2 returns TPML_PCR_SELECTIONS that contains an array of TPMS_PCR_SELECTIONs indicating available PCR banks and the bitmasks that show which PCRs are enabled in each bank. Collect the data in a dictionary. From the dictionary determine the PCR bank that has the PCRs enabled that the test needs. This avoids test failures with TPM2's that either to not have a SHA-1 bank or whose SHA-1 bank is disabled. Signed-off-by: Stefan Berger Tested-by: Jarkko Sakkinen Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- tools/testing/selftests/tpm2/tpm2.py | 31 ++++++++++++++++++++++ tools/testing/selftests/tpm2/tpm2_tests.py | 29 ++++++++++++++------ 2 files changed, 52 insertions(+), 8 deletions(-) diff --git a/tools/testing/selftests/tpm2/tpm2.py b/tools/testing/selftests/tpm2/tpm2.py index f34486cd7342..057a4f49c79d 100644 --- a/tools/testing/selftests/tpm2/tpm2.py +++ b/tools/testing/selftests/tpm2/tpm2.py @@ -56,6 +56,7 @@ TSS2_RESMGR_TPM_RC_LAYER = (11 << TSS2_RC_LAYER_SHIFT) TPM2_CAP_HANDLES = 0x00000001 TPM2_CAP_COMMANDS = 0x00000002 +TPM2_CAP_PCRS = 0x00000005 TPM2_CAP_TPM_PROPERTIES = 0x00000006 TPM2_PT_FIXED = 0x100 @@ -712,3 +713,33 @@ class Client: pt += 1 return handles + + def get_cap_pcrs(self): + pcr_banks = {} + + fmt = '>HII III' + + cmd = struct.pack(fmt, + TPM2_ST_NO_SESSIONS, + struct.calcsize(fmt), + TPM2_CC_GET_CAPABILITY, + TPM2_CAP_PCRS, 0, 1) + rsp = self.send_cmd(cmd)[10:] + _, _, cnt = struct.unpack('>BII', rsp[:9]) + rsp = rsp[9:] + + # items are TPMS_PCR_SELECTION's + for i in range(0, cnt): + hash, sizeOfSelect = struct.unpack('>HB', rsp[:3]) + rsp = rsp[3:] + + pcrSelect = 0 + if sizeOfSelect > 0: + pcrSelect, = struct.unpack('%ds' % sizeOfSelect, + rsp[:sizeOfSelect]) + rsp = rsp[sizeOfSelect:] + pcrSelect = int.from_bytes(pcrSelect, byteorder='big') + + pcr_banks[hash] = pcrSelect + + return pcr_banks diff --git a/tools/testing/selftests/tpm2/tpm2_tests.py b/tools/testing/selftests/tpm2/tpm2_tests.py index 9d764306887b..e63a37819978 100644 --- a/tools/testing/selftests/tpm2/tpm2_tests.py +++ b/tools/testing/selftests/tpm2/tpm2_tests.py @@ -27,7 +27,17 @@ class SmokeTest(unittest.TestCase): result = self.client.unseal(self.root_key, blob, auth, None) self.assertEqual(data, result) + def determine_bank_alg(self, mask): + pcr_banks = self.client.get_cap_pcrs() + for bank_alg, pcrSelection in pcr_banks.items(): + if pcrSelection & mask == mask: + return bank_alg + return None + def test_seal_with_policy(self): + bank_alg = self.determine_bank_alg(1 << 16) + self.assertIsNotNone(bank_alg) + handle = self.client.start_auth_session(tpm2.TPM2_SE_TRIAL) data = ('X' * 64).encode() @@ -35,7 +45,7 @@ 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 +57,7 @@ class SmokeTest(unittest.TestCase): 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) @@ -72,6 +82,9 @@ 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(1 << 16 | 1 << 1) + self.assertIsNotNone(bank_alg) + handle = self.client.start_auth_session(tpm2.TPM2_SE_TRIAL) data = ('X' * 64).encode() @@ -79,7 +92,7 @@ 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 +104,13 @@ 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 +122,14 @@ 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)