tests: change test_mba_parsing to not need keylime installed

This test needs the verifier configuration file available, and on
systems that do not have keylime installed (hence, no config file),
it would fail.

This commit changes the test so that it creates a verifier conf file
in a temporary directory with default values, so that it can use it.

Signed-off-by: Sergio Correia <scorreia@redhat.com>

test/test_mba_parsing.py

@@ -1,27 +1,51 @@
 import os
+import tempfile
 import unittest
+from configparser import RawConfigParser
 
+from keylime import config
+from keylime.cmd import convert_config
 from keylime.common.algorithms import Hash
 from keylime.mba import mba
 
+TEMPLATES_DIR = os.path.abspath(os.path.join(os.path.dirname(__file__), "..", "templates"))
+
 
 class TestMBAParsing(unittest.TestCase):
     def test_parse_bootlog(self):
         """Test parsing binary measured boot event log"""
-        mba.load_imports()
-        # Use the file that triggered https://github.com/keylime/keylime/issues/1153
-        mb_log_path = os.path.abspath(os.path.join(os.path.dirname(__file__), "data/mb_log.b64"))
-        with open(mb_log_path, encoding="utf-8") as f:
-            # Read the base64 input and remove the newlines
-            b64 = "".join(f.read().splitlines())
-            pcr_hashes, boot_aggregates, measurement_data, failure = mba.bootlog_parse(b64, Hash.SHA256)
-
-            self.assertFalse(
-                failure, f"Parsing of measured boot log failed with: {list(map(lambda x: x.context, failure.events))}"
-            )
-            self.assertTrue(isinstance(pcr_hashes, dict))
-            self.assertTrue(isinstance(boot_aggregates, dict))
-            self.assertTrue(isinstance(measurement_data, dict))
+        # This test requires the verifier configuration file, so let's create
+        # one with the default values to use, so that we do not depend on the
+        # configuration files existing in the test system.
+        with tempfile.TemporaryDirectory() as config_dir:
+            # Let's write the config file for the verifier.
+            verifier_config = convert_config.process_versions(["verifier"], TEMPLATES_DIR, RawConfigParser(), True)
+            convert_config.output(["verifier"], verifier_config, TEMPLATES_DIR, config_dir)
+
+            # As we want to use a config file from a different location, the
+            # proper way would be to define an environment variable for the
+            # module of interest, e.g. in our case it would be the
+            # KEYLIME_VERIFIER_CONFIG variable. However, the config module
+            # reads such env vars at first load, and there is no clean way
+            # to have it re-read them, so for this test we will override it
+            # manually.
+            config.CONFIG_ENV["verifier"] = os.path.abspath(os.path.join(config_dir, "verifier.conf"))
+
+            mba.load_imports()
+            # Use the file that triggered https://github.com/keylime/keylime/issues/1153
+            mb_log_path = os.path.abspath(os.path.join(os.path.dirname(__file__), "data/mb_log.b64"))
+            with open(mb_log_path, encoding="utf-8") as f:
+                # Read the base64 input and remove the newlines
+                b64 = "".join(f.read().splitlines())
+                pcr_hashes, boot_aggregates, measurement_data, failure = mba.bootlog_parse(b64, Hash.SHA256)
+
+                self.assertFalse(
+                    failure,
+                    f"Parsing of measured boot log failed with: {list(map(lambda x: x.context, failure.events))}",
+                )
+                self.assertTrue(isinstance(pcr_hashes, dict))
+                self.assertTrue(isinstance(boot_aggregates, dict))
+                self.assertTrue(isinstance(measurement_data, dict))
 
 
 if __name__ == "__main__":