Programmatically set browser cookie (Firefox)

Question

I know from this question that Firefox 3.0 and up stores its cookies in an SQLite database. My question is: can you access this database from other desktop programs in such a way that you could add a cookie?

I realize this has security implications. However, I do not want to read them at all. I want to be able to set one cookie if possible. I don't even want to overwrite a cookie. I just want to add it if it isn't there already. This is sort of a personal project I'm working on for fun.

This question is mostly language agnostic. I would prefer a solution in C#, but proof of concept in any language will suffice.

Extra credit: It would be cool to set the same cookie in Internet Explorer, too

Answer 1

For FF3, you can access the cookies.sqlite file with any SQLite wrapper - however, check whether FF is running - it may be write-locking the file (not tested).

The database contains this:

TABLE moz_cookies (
    id INTEGER PRIMARY KEY, 
    name TEXT, 
    value TEXT, 
    host TEXT, 
    path TEXT,
    expiry INTEGER, 
    lastAccessed INTEGER, 
    isSecure INTEGER, 
    isHttpOnly INTEGER
)

Not sure about the primary key, it looks like it is a unix timestamp of when the cookie was created; expiry and lastAccessed are also unix timestamps, the rest is self-explanatory.

Try an INSERT INTO moz_cookies and see if FF becomes immediately aware of the new cookie or if it requires a restart.

Answer 2

I know this question is really old, but I had the same problem and never really found a complete sample of code (though the answers on this page pointed me in the right direction). HTH!

public static void ClearFirefoxCookies()
{
    int procCount = Process.GetProcessesByName("firefox").Length;
    if (procCount > 0)
        throw new ApplicationException(string.Format("There are {0} instances of Firefox still running", procCount));

    try
    {
        using (SQLiteConnection conn = new SQLiteConnection("Data Source=" + GetFirefoxCookiesFileName()))
        { 
            conn.Open();
            SQLiteCommand command = conn.CreateCommand();
            command.CommandText = "delete from moz_cookies";
            int count = command.ExecuteNonQuery();
        }
    }
    catch (SQLiteException ex)
    {
        if (!(ex.ErrorCode == SQLiteErrorCode.Busy || ex.ErrorCode == SQLiteErrorCode.Locked))
            throw new ApplicationException("The Firefox cookies.sqlite file is locked");
    }
}

private static string GetFirefoxCookiesFileName()
{
    string path = System.IO.Path.Combine(System.Environment.GetFolderPath(System.Environment.SpecialFolder.ApplicationData), @"Mozilla\Firefox\Profiles");
    if (!System.IO.Directory.Exists(path))
        throw new ApplicationException("Firefox profiles folder not found");

    string[] fileNames = System.IO.Directory.GetFiles(path, "cookies.sqlite", System.IO.SearchOption.AllDirectories);
    if (fileNames.Length != 1 || !System.IO.File.Exists(fileNames[0]))
        throw new ApplicationException("Firefox cookies.sqlite file not found");
    return fileNames[0];
}