vmsdk/python/tests: add tests for TDX (#57)

* docs(contributor): contrib-readme-action has updated readme

* vmsdk/python/tests: add tests for TDX

This patch mainly adds some tests for TDX.
And it refactors some corresponding code accordingly.

Signed-off-by: zhongjie <[email protected]>

* docs(contributor): contrib-readme-action has updated readme

---------

Signed-off-by: zhongjie <[email protected]>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

.github/workflows/vmsdk-test-python.yaml

@@ -19,4 +19,12 @@ jobs:
       - name: Run PyTest for VMSDK
         run: |
           set -ex
-          sudo su -c "source setupenv.sh && python3 -m pytest -v ./vmsdk/python/tests/test_sdk.py"
+          # Set the "PYTHONDONTWRITEBYTECODE" and "no:cacheprovider" to prevent
+          # generated some intermediate files by root. Othwerwise, these
+          # files will fail the action/checkout in the next round of running
+          # due to the permission issue.
+          sudo su -c "source setupenv.sh && \
+                      pushd vmsdk/python/tests && \
+                      export PYTHONDONTWRITEBYTECODE=1 && \
+                      python3 -m pytest -p no:cacheprovider -v test_sdk.py && \
+                      popd"

common/python/cctrusted_base/api.py

@@ -66,7 +66,12 @@ def get_measurement(self, imr_select:[int, int]) -> TcgIMR:
         raise NotImplementedError("Inherited SDK class should implement this.")
 
     @abstractmethod
-    def get_quote(self, nonce: bytearray, data: bytearray, extraArgs=None) -> Quote:
+    def get_quote(
+        self,
+        nonce: bytearray = None,
+        data: bytearray = None,
+        extraArgs = None
+    ) -> Quote:
         """Get the quote for given nonce and data.
 
         The quote is signing of attestation data (IMR values or hashes of IMR

common/python/cctrusted_base/imr.py

@@ -3,7 +3,7 @@
 """
 
 from abc import ABC, abstractmethod
-from cctrusted_base.tcg import TcgDigest, TcgAlgorithmRegistry
+from cctrusted_base.tcg import TcgDigest
 
 class TcgIMR(ABC):
     """Common Integrated Measurement Register class."""
@@ -56,21 +56,3 @@ def is_valid(self):
         """
         return self._index != TcgIMR._INVALID_IMR_INDEX and \
             self._index <= self.max_index
-
-class TdxRTMR(TcgIMR):
-    """RTMR class defined for Intel TDX."""
-
-    @property
-    def max_index(self):
-        return 3
-
-    def __init__(self, index, digest_hash):
-        super().__init__(index, TcgAlgorithmRegistry.TPM_ALG_SHA384,
-                        digest_hash)
-
-class TpmPCR(TcgIMR):
-    """PCR class defined for TPM"""
-
-    @property
-    def max_index(self):
-        return 23

common/python/cctrusted_base/tdx/rtmr.py

@@ -0,0 +1,23 @@
+"""
+RTMR (Runtime Measurement Register).
+"""
+
+from cctrusted_base.imr import TcgIMR
+from cctrusted_base.tcg import TcgAlgorithmRegistry
+
+class TdxRTMR(TcgIMR):
+    """RTMR class defined for Intel TDX."""
+
+    RTMR_COUNT = 4
+    """Intel TDX TDREPORT provides the 4 measurement registers by default."""
+
+    RTMR_LENGTH_BY_BYTES = 48
+    """RTMR length by bytes."""
+
+    @property
+    def max_index(self):
+        return 3
+
+    def __init__(self, index, digest_hash):
+        super().__init__(index, TcgAlgorithmRegistry.TPM_ALG_SHA384,
+                        digest_hash)

common/python/cctrusted_base/tpm/pcr.py

@@ -0,0 +1,12 @@
+"""
+PCR (Platform Configuration Register).
+"""
+
+from cctrusted_base.imr import TcgIMR
+
+class TpmPCR(TcgIMR):
+    """PCR class defined for TPM"""
+
+    @property
+    def max_index(self):
+        return 23

vmsdk/python/cc_imr_cli.py

@@ -12,7 +12,8 @@
 count = CCTrustedVmSdk.inst().get_measurement_count()
 for index in range(CCTrustedVmSdk.inst().get_measurement_count()):
     alg = CCTrustedVmSdk.inst().get_default_algorithms()
-    digest_obj = CCTrustedVmSdk.inst().get_measurement([index, alg.alg_id])
+    imr = CCTrustedVmSdk.inst().get_measurement([index, alg.alg_id])
+    digest_obj = imr.digest(alg.alg_id)
 
     hash_str = ""
     for hash_item in digest_obj.hash:

vmsdk/python/cc_quote_cli.py

@@ -42,7 +42,7 @@ def main():
         level=logging.NOTSET,
         format="%(name)s %(levelname)-8s %(message)s"
     )
-    quote = CCTrustedVmSdk.inst().get_quote(None, None, None)
+    quote = CCTrustedVmSdk.inst().get_quote()
     if quote is not None:
         quote.dump(args.out_format == OUT_FORMAT_RAW)
     else:

vmsdk/python/cctrusted_vm/cvm.py

@@ -13,10 +13,11 @@
 import struct
 import fcntl
 from abc import abstractmethod
-from cctrusted_base.imr import TdxRTMR,TcgIMR
+from cctrusted_base.imr import TcgIMR
 from cctrusted_base.quote import Quote
 from cctrusted_base.tcg import TcgAlgorithmRegistry
 from cctrusted_base.tdx.common import TDX_VERSION_1_0, TDX_VERSION_1_5
+from cctrusted_base.tdx.rtmr import TdxRTMR
 from cctrusted_base.tdx.quote import TdxQuoteReq10, TdxQuoteReq15
 from cctrusted_base.tdx.report import TdxReportReq10, TdxReportReq15
 

vmsdk/python/cctrusted_vm/sdk.py

@@ -86,9 +86,14 @@ def get_measurement(self, imr_select:[int, int]) -> TcgIMR:
         if algo_id is None or algo_id is TcgAlgorithmRegistry.TPM_ALG_ERROR:
             algo_id = self._cvm.default_algo_id
 
-        return self._cvm.imrs[imr_index].digest(algo_id)
-
-    def get_quote(self, nonce: bytearray, data: bytearray, extraArgs=None) -> Quote:
+        return self._cvm.imrs[imr_index]
+
+    def get_quote(
+        self,
+        nonce: bytearray = None,
+        data: bytearray = None,
+        extraArgs = None
+    ) -> Quote:
         """Get the quote for given nonce and data.
 
         The quote is signing of attestation data (IMR values or hashes of IMR

vmsdk/python/tests/conftest.py

@@ -0,0 +1,66 @@
+"""Local conftest.py containing directory-specific hook implementations."""
+
+import pytest
+from cctrusted_base.tcg import TcgAlgorithmRegistry
+from cctrusted_base.tdx.rtmr import TdxRTMR
+from cctrusted_vm.cvm import ConfidentialVM
+from cctrusted_vm.sdk import CCTrustedVmSdk
+import tdx_check
+
+cnf_default_alg = {
+    ConfidentialVM.TYPE_CC_TDX: TcgAlgorithmRegistry.TPM_ALG_SHA384
+}
+"""Configurations of default algorithm.
+The configurations could be different for different confidential VMs.
+e.g. TDX use sha384 as the default.
+"""
+
+cnf_measurement_cnt = {
+    ConfidentialVM.TYPE_CC_TDX: TdxRTMR.RTMR_COUNT
+}
+"""Configurations of measurement count.
+The configurations could be different for different confidential VMs.
+"""
+
+cnf_measurement_check = {
+    ConfidentialVM.TYPE_CC_TDX: tdx_check.tdx_check_measurement_imrs
+}
+"""Configurations of measurement check functions.
+The configurations could be different for different confidential VMs.
+"""
+
+cnf_quote_check = {
+    ConfidentialVM.TYPE_CC_TDX: tdx_check.tdx_check_quote_rtmrs
+}
+"""Configurations of quote check functions.
+The configurations could be different for different confidential VMs.
+"""
+
+@pytest.fixture(scope="module")
+def vm_sdk():
+    """Get VMSDK instance."""
+    return CCTrustedVmSdk.inst()
+
+@pytest.fixture(scope="module")
+def default_alg_id():
+    """Get default algorithm."""
+    cc_type = ConfidentialVM.detect_cc_type()
+    return cnf_default_alg[cc_type]
+
+@pytest.fixture(scope="module")
+def measurement_count():
+    """Get measurement count."""
+    cc_type = ConfidentialVM.detect_cc_type()
+    return cnf_measurement_cnt[cc_type]
+
+@pytest.fixture(scope="module")
+def check_measurement():
+    """Return checker for measurement."""
+    cc_type = ConfidentialVM.detect_cc_type()
+    return cnf_measurement_check[cc_type]
+
+@pytest.fixture(scope="module")
+def check_quote():
+    """Return checker for quote."""
+    cc_type = ConfidentialVM.detect_cc_type()
+    return cnf_quote_check[cc_type]

vmsdk/python/tests/tdx_check.py

@@ -0,0 +1,77 @@
+"""TDX specific test."""
+
+from hashlib import sha384
+from cctrusted_base.tcg import TcgAlgorithmRegistry, TcgImrEvent
+from cctrusted_base.tdx.quote import TdxQuote, TdxQuoteBody
+from cctrusted_base.tdx.rtmr import TdxRTMR
+from cctrusted_vm.sdk import CCTrustedVmSdk
+
+def _replay_eventlog():
+    """Get RTMRs from event log by replay."""
+    rtmr_len = TdxRTMR.RTMR_LENGTH_BY_BYTES
+    rtmr_cnt = TdxRTMR.RTMR_COUNT
+    rtmrs = [bytearray(rtmr_len)] * rtmr_cnt
+    event_logs = CCTrustedVmSdk.inst().get_eventlog().event_logs
+    assert event_logs is not None
+    for event in event_logs:
+        if isinstance(event, TcgImrEvent):
+            sha384_algo = sha384()
+            sha384_algo.update(rtmrs[event.imr_index] + event.digests[0].hash)
+            rtmrs[event.imr_index] = sha384_algo.digest()
+    return rtmrs
+
+def _check_imr(imr_index: int, alg_id: int, rtmr: bytes):
+    """Check individual IMR.
+    Compare the 4 IMR hash with the hash derived by replay event log. They are
+    expected to be same.
+    Args:
+        imr_index: an integer specified the IMR index.
+        alg_id: an integer specified the hash algorithm.
+        rtmr: bytes of RTMR data for comparison.
+    """
+    assert 0 <= imr_index < TdxRTMR.RTMR_COUNT
+    assert rtmr is not None
+    assert alg_id == TcgAlgorithmRegistry.TPM_ALG_SHA384
+    imr = CCTrustedVmSdk.inst().get_measurement([imr_index, alg_id])
+    assert imr is not None
+    digest_obj = imr.digest(alg_id)
+    assert digest_obj is not None
+    digest_alg_id = digest_obj.alg.alg_id
+    assert digest_alg_id == TcgAlgorithmRegistry.TPM_ALG_SHA384
+    digest_hash = digest_obj.hash
+    assert digest_hash is not None
+    assert digest_hash == rtmr, \
+        f"rtmr {rtmr.hex()} doesn't equal digest {digest_hash.hex()}"
+
+def tdx_check_measurement_imrs():
+    """Test measurement result.
+    The test is done by compare the measurement register against the value
+    derived by replay eventlog.
+    """
+    alg = CCTrustedVmSdk.inst().get_default_algorithms()
+    rtmrs = _replay_eventlog()
+    _check_imr(0, alg.alg_id, rtmrs[0])
+    _check_imr(1, alg.alg_id, rtmrs[1])
+    _check_imr(2, alg.alg_id, rtmrs[2])
+    _check_imr(3, alg.alg_id, rtmrs[3])
+
+def tdx_check_quote_rtmrs():
+    """Test quote result.
+    The test is done by compare the RTMRs in quote body against the value
+    derived by replay eventlog.
+    """
+    quote = CCTrustedVmSdk.inst().get_quote()
+    assert quote is not None
+    assert isinstance(quote, TdxQuote)
+    body = quote.body
+    assert body is not None
+    assert isinstance(body, TdxQuoteBody)
+    rtmrs = _replay_eventlog()
+    assert body.rtmr0 == rtmrs[0], \
+        "RTMR0 doesn't equal the replay from event log!"
+    assert body.rtmr1 == rtmrs[1], \
+        "RTMR1 doesn't equal the replay from event log!"
+    assert body.rtmr2 == rtmrs[2], \
+        "RTMR2 doesn't equal the replay from event log!"
+    assert body.rtmr3 == rtmrs[3], \
+        "RTMR3 doesn't equal the replay from event log!"

vmsdk/python/tests/test_sdk.py

@@ -1,55 +1,55 @@
 """Containing unit test cases for sdk class"""
 
 import pytest
-from cctrusted_vm import CCTrustedVmSdk
-
-class TestCCTrustedVmSdk():
-    """Unit tests for CCTrustedVmSdk class."""
-
-    def test_get_default_algorithms(self):
-        """Test get_default_algorithms() function."""
-        algo = CCTrustedVmSdk.inst().get_default_algorithms()
-        assert algo is not None
-
-    def test_get_measurement_count(self):
-        """Test get_measurement_count() function."""
-        count = CCTrustedVmSdk.inst().get_measurement_count()
-        assert count is not None
-
-    def test_get_measurement_with_invalid_input(self):
-        """Test get_measurement() function with invalid input."""
-        # calling get_measurement() with invalid IMR index
-        measurement = CCTrustedVmSdk.inst().get_measurement([-1, 0xC])
-        assert measurement is None
-
-        # calling get_measurement() with invalid algorithm ID
-        measurement = CCTrustedVmSdk.inst().get_measurement([0, None])
-        assert measurement is not None
-
-    def test_get_measurement_with_valid_input(self):
-        """Test get_measurement() function with valid input."""
-        count = CCTrustedVmSdk.inst().get_measurement_count()
-        for index in range(count):
-            alg = CCTrustedVmSdk.inst().get_default_algorithms()
-            digest_obj = CCTrustedVmSdk.inst().get_measurement([index, alg.alg_id])
-            assert digest_obj is not None
-
-    def test_get_eventlog_with_invalid_input(self):
-        """Test get_eventlog() function with invalid input."""
-        # calling get_eventlog with count < 0
-        with pytest.raises(ValueError):
-            CCTrustedVmSdk.inst().get_eventlog(start=1, count=-1)
-
-        # calling get_eventlog with start < 1
-        with pytest.raises(ValueError):
-            CCTrustedVmSdk.inst().get_eventlog(start=0)
-
-    def test_get_eventlog_with_valid_input(self):
-        """Test get_eventlog() funtion with valid input."""
-        event_logs = CCTrustedVmSdk.inst().get_eventlog()
-        assert event_logs is not None
-
-    def test_get_quote_with_valid_input(self):
-        """Test get_quote() function with valid input."""
-        quote = CCTrustedVmSdk.inst().get_quote(None, None, None)
-        assert quote is not None
+
+def test_get_default_algorithms(vm_sdk, default_alg_id):
+    """Test get_default_algorithms() function."""
+    algo = vm_sdk.get_default_algorithms()
+    assert algo is not None
+    assert algo.alg_id == default_alg_id
+
+def test_get_measurement_count(vm_sdk, measurement_count):
+    """Test get_measurement_count() function."""
+    count = vm_sdk.get_measurement_count()
+    assert count is not None
+    assert count == measurement_count
+
+def test_get_measurement_with_invalid_input(vm_sdk):
+    """Test get_measurement() function with invalid input."""
+    # calling get_measurement() with invalid IMR index
+    measurement = vm_sdk.get_measurement([-1, 0xC])
+    assert measurement is None
+
+    # calling get_measurement() with invalid algorithm ID
+    measurement = vm_sdk.get_measurement([0, None])
+    assert measurement is not None
+
+def test_get_measurement_with_valid_input(vm_sdk, check_measurement):
+    """Test get_measurement() function with valid input."""
+    count = vm_sdk.get_measurement_count()
+    for index in range(count):
+        alg = vm_sdk.get_default_algorithms()
+        digest_obj = vm_sdk.get_measurement([index, alg.alg_id])
+        assert digest_obj is not None
+    check_measurement()
+
+def test_get_eventlog_with_invalid_input(vm_sdk):
+    """Test get_eventlog() function with invalid input."""
+    # calling get_eventlog with count < 0
+    with pytest.raises(ValueError):
+        vm_sdk.get_eventlog(start=1, count=-1)
+
+    # calling get_eventlog with start < 1
+    with pytest.raises(ValueError):
+        vm_sdk.get_eventlog(start=0)
+
+def test_get_eventlog_with_valid_input(vm_sdk):
+    """Test get_eventlog() funtion with valid input."""
+    event_logs = vm_sdk.get_eventlog()
+    assert event_logs is not None
+
+def test_get_quote_with_valid_input(vm_sdk, check_quote):
+    """Test get_quote() function with valid input."""
+    quote = vm_sdk.get_quote(None, None, None)
+    assert quote is not None
+    check_quote()