/// <summary>
        /// Get identity by credentials
        /// </summary>
        /// <param name="userLogin">user's login</param>
        /// <param name="password">user's password</param>
        /// <returns>user</returns>
        public async Task <ClaimsIdentity> GetClaimsIdentity(string userLogin, string password)
        {
            if (string.IsNullOrEmpty(userLogin) || string.IsNullOrEmpty(password))
            {
                return(null);
            }

            var userToVerify = await _appDbContext.FindByLogin(userLogin);

            if (userToVerify == 0)
            {
                return(null);
            }

            if (await _appDbContext.CheckPassword(password, userToVerify))
            {
                return(await GetIdentity(userLogin, userToVerify));
            }

            return(null);
        }