如何将Google凭证存储到SQLite？GenerateStoredKey参数及DataStore使用疑问

我之前使用GoogleWebAuthorizationBroker将用户凭证保存至本地文件，为提升应用安全性，计划将凭证存储到SQLite数据库。已参考相关内容实现了Entity Framework相关类，但不清楚如何正确使用这些类完成数据库存储，尤其是GenerateStoredKey方法的参数应传入什么值。

当前调用代码 #

return GoogleWebAuthorizationBroker.AuthorizeAsync(
                    GoogleClientSecrets.FromStream(stream).Secrets,
                    _scopes,
                    "user",
                    CancellationToken.None,
                    GoogleCredentialsDataStore.GenerateStoredKey("What string value goes here")
);

数据接口实现类 #

public class GoogleCredentialsDataStore : SqLiteDbContext, IDataStore
{
    /// <summary>
    /// Database context to access database
    /// </summary>
    private readonly SqLiteDbContext _context;
    public GoogleCredentialsDataStore(SqLiteDbContext context)
    {
        _context = context;
    }

    /// <summary>
    /// Stores the given value for the given key. It creates a new row in the database with the user id of
    /// (primary key <see cref="GenerateStoredKey"/>) in <see cref="GoogleUserCredentials"/>.
    /// </summary>
    /// <typeparam name="T">The type to store in the data store.</typeparam>
    /// <param name="key">The key.</param>
    /// <param name="value">The value to store in the data store.</param>
    Task IDataStore.StoreAsync<T>(string key, T value)
    {
        if (string.IsNullOrEmpty(key))
        {
            throw new ArgumentNullException("key Must have a value");
        }

        var serialized = NewtonsoftJsonSerializer.Instance.Serialize(value);

        _context.GoogleCredentials.Add(new()
        {
            Key = GenerateStoredKey(key),
            Credentials = serialized
        });
        _context.SaveChanges();
        return Task.Delay(0);
    }
    /// <summary>
    /// Deletes the given key. It deletes the <see cref="GenerateStoredKey"/> row in
    /// <see cref="GoogleCredentials"/>.
    /// </summary>
    /// <param name="key">The key to delete from the data store.</param>
    Task IDataStore.DeleteAsync<T>(string key)
    {
        if (string.IsNullOrEmpty(key))
        {
            throw new ArgumentException("Key MUST have a value");
        }

        try
        {
            var hold = _context.GoogleCredentials.Where(a => a.Key == key).FirstOrDefault();
            _context.GoogleCredentials.Remove(hold);
            _context.SaveChangesAsync();
        }
        catch (Exception)
        {
            throw new Exception("Failed to delete credentials");
        }

        return Task.Delay(0);
    }

    /// <summary>
    /// Returns the stored value for the given key or <c>null</c> if the matching row (<see cref="GenerateStoredKey"/>
    /// in <see cref="GoogleCredentials"/> doesn't exist.
    /// </summary>
    /// <typeparam name="T">The type to retrieve.</typeparam>
    /// <param name="key">The key to retrieve from the data store.</param>
    /// <returns>The stored object.</returns>
    Task<T> IDataStore.GetAsync<T>(string key)
    {
        if (string.IsNullOrEmpty(key))
        {
            throw new ArgumentException("Key MUST have a value");
        }

        TaskCompletionSource<T> tcs = new TaskCompletionSource<T>();
        var user = GetUserByKey(GenerateStoredKey(key));
        if (user != null)
        {
            try
            {
                tcs.SetResult(NewtonsoftJsonSerializer.Instance.Deserialize<T>(user.Credentials));
            }
            catch (Exception ex)
            {
                tcs.SetException(ex);
            }
        }
        else
        {
            tcs.SetResult(default(T));
        }
        return tcs.Task;
    }

    /// <summary>
    /// Clears all values in the data store. This method deletes all files in <see cref="GoogleCredentials"/>.
    /// </summary>
    Task IDataStore.ClearAsync()
    {
        try
        {
            foreach (var item in _context.GoogleCredentials)
            {
                _context.GoogleCredentials.Remove(item);
            }
        }
        catch (Exception)
        {
            throw new Exception("Failed to clear credentials");
        }

        return Task.Delay(0);
    }

    /// <summary>
    /// Checks if the user exists <see cref="GenerateStoredKey"/>.
    /// </summary>
    private GoogleCredentials GetUserByKey(string key)
    {
        try
        {
            var user = _context.GoogleCredentials.Where(a => a.Key == key).FirstOrDefault();

            if (user != null)
                return user;

            return null;
        }
        catch (Exception)
        {
            return null;
        }
    }

    /// <summary>
    /// Save the credentials.  If the user <see cref="GenerateStoredKey"/> does not exists we insert it other wise we will do an update.
    /// </summary>
    /// <param name="key"></param>
    /// <param name="serialized"></param>
    private void save(string key, string serialized)
    {
        try
        {
            var user = _context.GoogleCredentials.Where(a => a.Key == key).FirstOrDefault();
            if (user == null)
            {
                var hold = new GoogleCredentials { Key = key, Credentials = serialized };
                _context.GoogleCredentials.Add(hold);
            }
            else
            {
                var aUser = _context.GoogleCredentials.Where(a => a.Key == key).FirstOrDefault();
                aUser.Credentials = serialized;
            }
            _context.SaveChanges();
        }
        catch (Exception)
        {
            throw;
        }
    }

    /// <summary>Creates a unique stored key based on the key and the current project name.</summary>
    /// <param name="key">The object key.</param>
    public static string GenerateStoredKey(string key)
    {
        return string.Format("{0}-{1}", Assembly.GetCallingAssembly().GetName().Name, key);
    }
}

Google凭证模型类 #

public class GoogleCredentials
{
    [Key]
    public int Id { get; set; }
    [Required, StringLength(500)]
    public string Key { get; set; }
    [Required]
    public string Credentials { get; set; }
}

我是新手，目前认为方向正确，但希望得到资深开发者的指导，帮我走上正确路径。

内容的提问来源于stack exchange，提问作者DRW