sqlite - Encrypted cookies in Chrome

Question

I am currently working on a C# forms application that needs to access a specific cookie on my computer, which I can do perfectly fine. Here's the issue:

Google stores cookies in SQLite, and I've downloaded Sqlite database browser to help me look at these values. What surprises me is that about half of the cookie values shows as empty (including the one I need), even though they are obviously not.

The db file is located at:

C:Users\%username%AppDataLocalGoogleChromeUser DataDefaultCookies

On Chrome I have an addon called "Edit This Cookie" which allows me to directly modify cookies on the website I'm on. This addon can read these cookies, and the web browser can parse values through HTTP when needed for different requests, so they are definitely there - still, the SQLite browser, and my custom code both come to the conclusion that the particular value field is empty.

Why is that? What is it that somehow prevents the field from being read by certain applications?

Answer 1

I've run into this same problem, and the code below provides a working example for anyone who is interested. All credit to Scherling, as the DPAPI was spot on.

public class ChromeCookieReader
{
    public IEnumerable<Tuple<string,string>> ReadCookies(string hostName)
    {
        if (hostName == null) throw new ArgumentNullException("hostName");

        var dbPath = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData) + @"GoogleChromeUser DataDefaultCookies";
        if (!System.IO.File.Exists(dbPath)) throw new System.IO.FileNotFoundException("Cant find cookie store",dbPath); // race condition, but i'll risk it

        var connectionString = "Data Source=" + dbPath + ";pooling=false";

        using (var conn = new System.Data.SQLite.SQLiteConnection(connectionString))
        using (var cmd = conn.CreateCommand())
        {
            var prm = cmd.CreateParameter();
            prm.ParameterName = "hostName";
            prm.Value = hostName;
            cmd.Parameters.Add(prm);

            cmd.CommandText = "SELECT name,encrypted_value FROM cookies WHERE host_key = @hostName";

            conn.Open();
            using (var reader = cmd.ExecuteReader())
            {
                while (reader.Read())
                {
                    var encryptedData = (byte[]) reader[1];
                    var decodedData = System.Security.Cryptography.ProtectedData.Unprotect(encryptedData, null, System.Security.Cryptography.DataProtectionScope.CurrentUser);
                    var plainText = Encoding.ASCII.GetString(decodedData); // Looks like ASCII

                    yield return Tuple.Create(reader.GetString(0), plainText);
                }
            }
            conn.Close();
        }
    }
}