Xamarin, SQLite and encryption (SQLCipher)

Question

I should have my SQLite database protected by password. I found SqlCipher but I don't understand how I can use it.

I defined my database

public class MyDatabase
{
    /// <summary>
    /// The database
    /// </summary>
    SQLiteConnection database;

    /// <summary>
    /// The locker
    /// </summary>
    static object locker = new object();

    /// <summary>
    /// Initializes a new instance of the <see cref="Database"/> class.
    /// </summary>
    public MyDatabase()
    {
        SetDatabase();
        InitDatabase();
    }

    public async Task SetDatabase() {
        database = await DependencyService.Get<ISQLite>().GetConnectionAsync();
    }

    /// <summary>
    /// Init the database.
    /// </summary>
    public void InitDatabase()
    {
        if (database != null)
        {
            database.CreateTable<Answer>();
        }
    }

    /// <summary>
    /// Gets the items
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <returns>All items from a table without deleted records</returns>
    public List<T> GetItems<T>() where T : ITableEntity, new()
    {
        lock (locker)
        {
            List<T> rtn = null;
            return (from i in database.Table<T>() select i).ToList();
        }
    }

    /// <summary>
    /// Gets the items.
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="func">The function.</param>
    /// <returns>List&lt;T&gt;.</returns>
    public List<T> GetItems<T>(Expression<Func<T, bool>> func) 
           where T : ITableEntity, new()
    {
        lock (locker)
        {
            return database.Table<T>().Where(func).ToList();
        }
    }

    /// <summary>
    /// Gets the item.
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="id">The identifier.</param>
    /// <returns></returns>
    public T GetItem<T>(int id) where T : ITableEntity, new()
    {
        lock (locker)
        {
            return database.Table<T>().FirstOrDefault(x => x.Id == id);
        }
    }

    /// <summary>
    /// Saves the item.
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="item">The item.</param>
    /// <returns></returns>
    public int SaveItem<T>(T item) where T : ITableEntity
    {
        lock (locker)
        {
            if (item.Id != 0)
            {
                database.Update(item);
                return item.Id;
            }
            else
            {
                return database.Insert(item);
            }
        }
    }

    /// <summary>
    /// Deletes the item.
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="id">The identifier.</param>
    /// <returns></returns>
    public int DeleteItem<T>(int id) where T : ITableEntity, new()
    {
        lock (locker)
        {
            T tmpRecord = GetItem<T>(id);
            return database.Delete<T>(id);
        }
    }
}

Also, I defined my repository with all functions for each table. I understood I have to execute this code before any requests

var t = conn.Query<int>("PRAGMA key=xzy1921");

to set the password. All example I found use conn.Query<int>("<query>"). How can I use that?

Thank you in advance.

Xamarin, SQLite and encryption (SQLCipher)

0 Answers0