Add tests for SSlibKey

Tests to check equalities, serialization and verify method of SSlibKey
are added to ensure integritry of Key interfaces.

Signed-off-by: Pradyumna Krishna <git@onpy.in>

tests/test_key.py

@@ -0,0 +1,128 @@
+#!/usr/bin/env python
+
+"""Test cases for "key.py". """
+
+import copy
+import unittest
+
+import securesystemslib.formats
+import securesystemslib.keys as KEYS
+from securesystemslib.exceptions import (
+    CryptoError,
+    FormatError,
+    UnsupportedAlgorithmError,
+)
+from securesystemslib.key import SSlibKey
+from securesystemslib.signer import SSlibSigner
+
+
+class TestSSlibKey(unittest.TestCase):
+    """SSlibKey Test Case."""
+
+    @classmethod
+    def setUpClass(cls):
+        cls.dicts = [
+            KEYS.generate_rsa_key(),
+            KEYS.generate_ed25519_key(),
+            KEYS.generate_ecdsa_key(),
+        ]
+        cls.DATA_STR = "SOME DATA REQUIRING AUTHENTICITY."
+        cls.DATA = securesystemslib.formats.encode_canonical(cls.DATA_STR).encode(
+            "utf-8"
+        )
+
+    def test_sslib_verify(self):
+        """Test to check verify method of key."""
+
+        for scheme_dict in self.dicts:
+            sslib_signer = SSlibSigner(scheme_dict)
+            sig_obj = sslib_signer.sign(self.DATA)
+
+            # Verify signature.
+            sslib_key = SSlibKey.from_securesystemslib_key(scheme_dict)
+            verified = sslib_key.verify(sig_obj, self.DATA)
+            self.assertTrue(verified, "Incorrect signature.")
+
+            # Test for invalid public key.
+            public = scheme_dict["keyval"]["public"]
+            scheme_dict["keyval"]["public"] = ""
+            sslib_key = SSlibKey.from_securesystemslib_key(scheme_dict)
+
+            with self.assertRaises(
+                (CryptoError, UnsupportedAlgorithmError, FormatError)
+            ):
+                sslib_key.verify(sig_obj, self.DATA)
+
+            scheme_dict["keyval"]["public"] = public
+
+    def test_sslib_serialization(self):
+        """Test to check serialization methods of key."""
+
+        for scheme_dict in self.dicts:
+            # Format key.
+            key_dict = KEYS.format_keyval_to_metadata(
+                scheme_dict["keytype"],
+                scheme_dict["scheme"],
+                scheme_dict["keyval"],
+            )
+            # key_dict contains keyid_hash_algorithms.
+            key_dict.pop("keyid_hash_algorithms")
+
+            keyid = scheme_dict["keyid"]
+
+            # Test for load and dump key_dict.
+            sslib_key = SSlibKey.from_dict(copy.copy(key_dict), keyid)
+            self.assertEqual(key_dict, sslib_key.to_dict())
+
+            # Test for load and dump securesystemslib_key.
+            key_dict["keyid"] = keyid
+            sslib_key = SSlibKey.from_securesystemslib_key(key_dict)
+            self.assertEqual(key_dict, sslib_key.to_securesystemslib_key())
+
+            # Test for invalid keytype.
+            valid_keytype = scheme_dict["keytype"]
+            scheme_dict["keytype"] = "invalid_keytype"
+            with self.assertRaises((ValueError, FormatError)):
+                SSlibKey.from_securesystemslib_key(scheme_dict)
+
+            scheme_dict["keytype"] = valid_keytype
+
+    def test_sslib_equality(self):
+        """Test to check equality of key."""
+
+        for scheme_dict in self.dicts:
+            # Create two keys.
+            sslib_key = SSlibKey.from_securesystemslib_key(scheme_dict)
+            sslib_key_2 = SSlibKey.from_securesystemslib_key(scheme_dict)
+
+            # Assert not equal with scheme_dict.
+            self.assertNotEqual(scheme_dict, sslib_key)
+
+            # Assert equality of two keys created from same securesystemslib_key.
+            self.assertEqual(sslib_key_2, sslib_key)
+
+            # Assert equality of key created from dict of first sslib_key.
+            sslib_key_2 = SSlibKey.from_securesystemslib_key(
+                sslib_key.to_securesystemslib_key()
+            )
+            self.assertEqual(sslib_key_2, sslib_key)
+
+            # Assert inequalities.
+            sslib_key_2.scheme = "invalid"
+            self.assertNotEqual(sslib_key_2, sslib_key)
+            sslib_key_2.scheme = sslib_key.scheme
+
+            sslib_key_2.keytype = "invalid"
+            self.assertNotEqual(sslib_key_2, sslib_key)
+            sslib_key_2.keytype = sslib_key.keytype
+
+            sslib_key_2.keyval = {"public": "invalid"}
+            self.assertNotEqual(sslib_key_2, sslib_key)
+            sslib_key_2.keyval = sslib_key.keyval
+
+            self.assertEqual(sslib_key_2, sslib_key)
+
+
+# Run the unit tests.
+if __name__ == "__main__":
+    unittest.main()