Fix KDF metadata handling and headless password prompts

src/tests/test_legacy_migration.py

@@ -1,4 +1,5 @@
 import json
+import base64
 import hashlib
 from pathlib import Path
 
@@ -99,7 +100,8 @@ def test_migrated_index_has_v2_prefix(monkeypatch, tmp_path: Path):
     vault.load_index()
 
     new_file = tmp_path / "seedpass_entries_db.json.enc"
-    assert new_file.read_bytes().startswith(b"V2:")
+    payload = json.loads(new_file.read_text())
+    assert base64.b64decode(payload["ct"]).startswith(b"V2:")
     assert vault.migrated_from_legacy
 
 

src/tests/test_legacy_migration_iterations.py

@@ -66,5 +66,5 @@ def test_migrate_iterations(tmp_path, monkeypatch, iterations):
     cfg = ConfigManager(vault, tmp_path)
     assert cfg.get_kdf_iterations() == iterations
 
-    content = (tmp_path / "seedpass_entries_db.json.enc").read_bytes()
-    assert content.startswith(b"V2:")
+    payload = json.loads((tmp_path / "seedpass_entries_db.json.enc").read_text())
+    assert base64.b64decode(payload["ct"]).startswith(b"V2:")

src/tests/test_legacy_migration_prompt.py

@@ -50,6 +50,6 @@ def test_migrate_legacy_sets_flag(tmp_path, monkeypatch):
     monkeypatch.setattr(vault_module, "prompt_existing_password", lambda _: password)
     monkeypatch.setattr("builtins.input", lambda _: "2")
     vault.load_index()
-    content = (tmp_path / "seedpass_entries_db.json.enc").read_bytes()
-    assert content.startswith(b"V2:")
+    payload = json.loads((tmp_path / "seedpass_entries_db.json.enc").read_text())
+    assert base64.b64decode(payload["ct"]).startswith(b"V2:")
     assert vault.encryption_manager.last_migration_performed is True

src/tests/test_legacy_migration_second_session.py

@@ -1,4 +1,5 @@
 import json
+import base64
 import hashlib
 from pathlib import Path
 from types import SimpleNamespace
@@ -34,7 +35,8 @@ def test_legacy_migration_second_session(monkeypatch, tmp_path: Path) -> None:
     monkeypatch.setattr("builtins.input", lambda *_a, **_k: "y")
     vault.load_index()
     new_file = fp_dir / "seedpass_entries_db.json.enc"
-    assert new_file.read_bytes().startswith(b"V2:")
+    payload = json.loads(new_file.read_text())
+    assert base64.b64decode(payload["ct"]).startswith(b"V2:")
 
     new_enc_mgr = EncryptionManager(key, fp_dir)
     new_vault = Vault(new_enc_mgr, fp_dir)
@@ -59,4 +61,5 @@ def test_legacy_migration_second_session(monkeypatch, tmp_path: Path) -> None:
     )
 
     pm.initialize_managers()
-    assert new_file.read_bytes().startswith(b"V2:")
+    payload = json.loads(new_file.read_text())
+    assert base64.b64decode(payload["ct"]).startswith(b"V2:")

src/tests/test_seed_migration.py

@@ -1,4 +1,6 @@
 import sys
+import json
+import base64
 from pathlib import Path
 from cryptography.fernet import Fernet
 
@@ -28,4 +30,5 @@ def test_parent_seed_migrates_from_fernet(tmp_path: Path) -> None:
 
     assert new_file.exists()
     assert new_file.read_bytes() != encrypted
-    assert new_file.read_bytes().startswith(b"V2:")
+    payload = json.loads(new_file.read_text())
+    assert base64.b64decode(payload["ct"]).startswith(b"V2:")