SQLCipher .NET with Entity Core - set or remove password

SQLCipher
1

I’m using SQLCipher (community edition) running with .NET and Entity Core. Everything works perfectly including changing a password on existing database.

For example, if DB is protected with password ‘1’ it is no issue to change (rekey) it to ‘2’ or anything else. However, there is an issue when I want to protect unprotected database or remove protection from a database that has password.

At the moment the code that changes password for a DB looks like:

public bool Rekey(string oldKey, string newKey)
    {
        SqliteConnection conn = GetConnection(oldKey);

        try
        {
            conn.Open();
            using (var command = conn.CreateCommand())
            {
                command.CommandText = $"PRAGMA rekey = '{newKey}';";
                int rowsChanged = command.ExecuteNonQuery();
            }
            conn.Close();
        }
        catch
        {
            return false;
        }
        return true;
    }

private SqliteConnection GetConnection(string key)
    {
        SqliteConnection conn;
        if (_dbaccessBytes == null)
        {
            conn = new SqliteConnection
            {
                ConnectionString = new SqliteConnectionStringBuilder()
                {
                    DataSource = _databasePath,
                    Mode = SqliteOpenMode.ReadWriteCreate
                }.ToString()
            };
        }
        else
        {
            conn = new SqliteConnection
            {
                ConnectionString = new SqliteConnectionStringBuilder()
                {
                    DataSource = _databasePath,
                    Mode = SqliteOpenMode.ReadWriteCreate,
                    Password = key
                }.ToString()
            };
        }

        return conn;
    }

So when we don’t have password protection and send oldKey as NULL and newKey as some value - it would just run, but will not set password. No errors. I tried to look up solution, but no luck yet. May be I’m missing some understanding and setting and removing key should be done not like ‘PRAGMA rekey’, but in some other method?

Thanks in advance.

2

Hi @alex

The PRAGMA rekey command should only be used change the password being used for deriving an encryption key to another password value. To convert a plaintext SQLite database to use SQLCipher, or to export a SQLCipher encrypted database to a plaintext database, you will need to utilize the convenience function sqlcipher_export(...). This function is addressed within our documentation with several examples here.

3

Thanks a lot for pointing this out! It works perfectly.