test(utils): Add test and error handling for wiped InMemorySecret

- Updated `InMemorySecret.get_bytes()` in `src/utils/memory_protection.py` to raise a `RuntimeError` if the secret has been wiped, replacing the previous `AttributeError`.
- Added `test_access_after_wipe_raises_error` to `src/tests/test_memory_protection.py` to verify this behavior.

Co-authored-by: PR0M3TH3AN <[email protected]>

src/tests/test_memory_protection.py

@@ -27,3 +27,16 @@ def test_inmemory_secret_wipe_clears_attributes():
     assert secret._nonce is None
     assert secret._cipher is None
     assert secret._encrypted is None
+
+
+def test_access_after_wipe_raises_error():
+    secret = InMemorySecret(b"secret data")
+    secret.wipe()
+
+    with pytest.raises(RuntimeError) as excinfo:
+        secret.get_bytes()
+    assert str(excinfo.value) == "Secret has been wiped"
+
+    with pytest.raises(RuntimeError) as excinfo:
+        secret.get_str()
+    assert str(excinfo.value) == "Secret has been wiped"

src/utils/memory_protection.py

@@ -17,6 +17,8 @@ class InMemorySecret:
 
     def get_bytes(self) -> bytes:
         """Decrypt and return the plaintext bytes."""
+        if self._cipher is None:
+            raise RuntimeError("Secret has been wiped")
         return self._cipher.decrypt(self._nonce, self._encrypted, None)
 
     def wipe(self) -> None: