| Message ID | 20211125003827.1360432-2-stefanb@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | selftests: tpm2: Probe for available PCR bank | expand |
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)
On 11/26/21 19:29, Jarkko Sakkinen wrote: > 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? Checking ? Testing ? What's the difference to those words? > >> 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. I am not sure I understand. The new function determines which PCR banks (SHA-1 or SHA-256) the subsequent tests can use. It tries to execute the policy_pcr command with the given hash bank algorithm (SHA-256 or SHA-1) and if it returns an UnknowPcrBankError it tries the next one in the list. It doesn't need to query available hash algorithms. A TPM 2 may support SHA 256 and yet its SHA 256 bank may be deactivate. > 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)
On Fri, Nov 26, 2021 at 10:43:42PM -0500, Stefan Berger wrote: > > On 11/26/21 19:29, Jarkko Sakkinen wrote: > > 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? > > Checking ? Testing ? What's the difference to those words? This would an exact description: "Some devices do not have SHA1 bank available. Try to use SHA256 as a fallback when this occurs." It does not leave any open territory what the patch does. It does exactly this, not more or less. /Jarkko
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, 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 +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)