char[] decrypted = storage.decryptCredentials(null);
        assertNull(decrypted, "Decrypting null should return null");
    }

    @Test
    public void testEncryptDecryptLongPassword() throws Exception {
        // Test with very long password
        char[] plaintext = new char[10000];
        Arrays.fill(plaintext, 'X');

        byte[] encrypted = storage.encryptCredentials(plaintext);