Island: Add ResetKeyError

monkey/monkey_island/cc/server_utils/encryption/__init__.py

@@ -7,7 +7,7 @@ from .password_based_bytes_encryptor import (
     InvalidCredentialsError,
     InvalidCiphertextError,
 )
-from .i_lockable_encryptor import ILockableEncryptor, LockedKeyError, UnlockError
+from .i_lockable_encryptor import ILockableEncryptor, LockedKeyError, UnlockError, ResetKeyError
 from .repository_encryptor import RepositoryEncryptor
 from .data_store_encryptor import (
     get_datastore_encryptor,

monkey/monkey_island/cc/server_utils/encryption/i_lockable_encryptor.py

@@ -27,6 +27,12 @@ class UnlockError(Exception):
     """
 
 
+class ResetKeyError(Exception):
+    """
+    Raised if an error occurs while attempting to reset an ILockableEncryptor's key
+    """
+
+
 class ILockableEncryptor(IEncryptor):
     """
     An encryptor that can be locked or unlocked.
@@ -54,6 +60,10 @@ class ILockableEncryptor(IEncryptor):
     def reset_key(self):
         """
         Reset the encryptor's key
+
+        Remove the existing key material so that it can never be used again.
+
+        :raises ResetKeyError: If an error occurred while attemping to reset the key
         """
 
     @abstractmethod

monkey/monkey_island/cc/server_utils/encryption/repository_encryptor.py

@@ -3,7 +3,7 @@ from pathlib import Path
 
 from monkey_island.cc.server_utils.file_utils import open_new_securely_permissioned_file
 
-from . import ILockableEncryptor, LockedKeyError, UnlockError
+from . import ILockableEncryptor, LockedKeyError, ResetKeyError, UnlockError
 from .key_based_encryptor import KeyBasedEncryptor
 from .password_based_bytes_encryptor import PasswordBasedBytesEncryptor
 
@@ -49,8 +49,11 @@ class RepositoryEncryptor(ILockableEncryptor):
         self._key_based_encryptor = None
 
     def reset_key(self):
-        if self._key_file.is_file():
-            self._key_file.unlink()
+        try:
+            if self._key_file.is_file():
+                self._key_file.unlink()
+        except Exception as err:
+            raise ResetKeyError(err)
 
         self._password_based_encryptor = None
         self._key_based_encryptor = None

monkey/tests/unit_tests/monkey_island/cc/server_utils/encryption/test_repository_encryptor.py

@@ -7,6 +7,7 @@ from common.utils.file_utils import get_file_sha256_hash
 from monkey_island.cc.server_utils.encryption import (
     LockedKeyError,
     RepositoryEncryptor,
+    ResetKeyError,
     UnlockError,
 )
 
@@ -110,3 +111,16 @@ def test_encrypt_after_reset(encryptor, key_file):
 def test_reset_before_unlock(encryptor):
     # Test will fail if an exception is raised
     encryptor.reset_key()
+
+
+def test_reset_key_error(key_file):
+    class UnlinkErrorWrapper(key_file.__class__):
+        def unlink(self):
+            raise OSError("Can't delete file")
+
+    encryptor = RepositoryEncryptor(UnlinkErrorWrapper(key_file))
+    encryptor.unlock(SECRET)
+    encryptor.lock()
+
+    with pytest.raises(ResetKeyError):
+        encryptor.reset_key()