public async Task <UserEntity> Authenticate(UserEntity user, CancellationToken cancellationToken)
{
if (user == null)
{
throw new ArgumentNullException(nameof(user));
}
if (string.IsNullOrEmpty(user.Username))
{
throw new ArgumentException("Username is null!");
}
if (string.IsNullOrEmpty(user.Password))
{
throw new ArgumentException("Password is null!");
}
UserEntity userEntity = await _repository.GetByUsername(user.Username, cancellationToken);
if (userEntity == null || !_dataProtection.VerifyPassword(user.Password, userEntity.Password))
{
// authentication failed
return(null);
}
return(userEntity);
}