public static void StoreParametersForRoundTrip(OpenAuthenticationParameters parameters)
 {
     var session = GetSession();
     session["Muh.externalauth.parameters"] = parameters;
 }
        public virtual AuthorizationResult Authorize(OpenAuthenticationParameters parameters)
        {
            var userFound = _openAuthenticationService.GetUser(parameters);

            var userLoggedIn = _workContext.CurrentCustomer.IsRegistered() ? _workContext.CurrentCustomer : null;

            if (AccountAlreadyExists(userFound, userLoggedIn))
            {
                if (AccountIsAssignedToLoggedOnAccount(userFound, userLoggedIn))
                {
                    // The person is trying to log in as himself.. bit weird
                    return new AuthorizationResult(OpenAuthenticationStatus.Authenticated);
                }

                var result = new AuthorizationResult(OpenAuthenticationStatus.Error);
                result.AddError("Account is already assigned");
                return result;
            }
            if (AccountDoesNotExistAndUserIsNotLoggedOn(userFound, userLoggedIn))
            {
                ExternalAuthorizerHelper.StoreParametersForRoundTrip(parameters);

                if (AutoRegistrationIsEnabled())
                {
                    #region Register user

                    var currentCustomer = _workContext.CurrentCustomer;
                    var details = new RegistrationDetails(parameters);
                    var randomPassword = CommonHelper.GenerateRandomDigitCode(20);

                    bool isApproved =
                        //standard registration
                        (_customerSettings.UserRegistrationType == UserRegistrationType.Standard) ||
                        //skip email validation?
                        (_customerSettings.UserRegistrationType == UserRegistrationType.EmailValidation &&
                         !_externalAuthenticationSettings.RequireEmailValidation);

                    var registrationRequest = new CustomerRegistrationRequest(currentCustomer, details.EmailAddress,
                        _customerSettings.UsernamesEnabled ? details.UserName : details.EmailAddress, randomPassword, PasswordFormat.Clear, isApproved);
                    var registrationResult = _customerRegistrationService.RegisterCustomer(registrationRequest);
                    if (registrationResult.Success)
                    {

                        userFound = currentCustomer;
                        _openAuthenticationService.AssociateExternalAccountWithUser(currentCustomer, parameters);
                        ExternalAuthorizerHelper.RemoveParameters();

                        //code below is copied from CustomerController.Register method

                        //authenticate
                        if (isApproved)
                            _authenticationService.SignIn(userFound ?? userLoggedIn, false);

                        if (isApproved)
                        {
                            //standard registration
                            //or
                            //skip email validation

                            //result
                            return new AuthorizationResult(OpenAuthenticationStatus.AutoRegisteredStandard);
                        }
                        else if (_customerSettings.UserRegistrationType == UserRegistrationType.EmailValidation)
                        {

                            //result
                            return new AuthorizationResult(OpenAuthenticationStatus.AutoRegisteredEmailValidation);
                        }
                        else if (_customerSettings.UserRegistrationType == UserRegistrationType.AdminApproval)
                        {
                            //result
                            return new AuthorizationResult(OpenAuthenticationStatus.AutoRegisteredAdminApproval);
                        }
                    }
                    else
                    {
                        ExternalAuthorizerHelper.RemoveParameters();

                        var result = new AuthorizationResult(OpenAuthenticationStatus.Error);
                        foreach (var error in registrationResult.Errors)
                            result.AddError(string.Format(error));
                        return result;
                    }

                    #endregion
                }
                else if (RegistrationIsEnabled())
                {
                    return new AuthorizationResult(OpenAuthenticationStatus.AssociateOnLogon);
                }
                else
                {
                    ExternalAuthorizerHelper.RemoveParameters();

                    var result = new AuthorizationResult(OpenAuthenticationStatus.Error);
                    result.AddError("Registration is disabled");
                    return result;
                }
            }
            if (userFound == null)
            {
                _openAuthenticationService.AssociateExternalAccountWithUser(userLoggedIn, parameters);
            }

            //authenticate
            _authenticationService.SignIn(userFound ?? userLoggedIn, false);
            //activity log
            _customerActivityService.InsertActivity("PublicStore.Login", _localizationService.GetResource("ActivityLog.PublicStore.Login"),
                userFound ?? userLoggedIn);

            return new AuthorizationResult(OpenAuthenticationStatus.Authenticated);
        }