public async Task <IActionResult> OnGetCallbackAsync(string returnUrl = null, string remoteError = null) { returnUrl = returnUrl ?? Url.Content("~/"); if (remoteError != null) { ErrorMessage = $"Error from external provider: {remoteError}"; return(RedirectToPage("./Login", new { ReturnUrl = returnUrl })); } var info = await _signInManager.GetExternalLoginInfoAsync(); if (info == null) { ErrorMessage = "Error loading external login information."; return(RedirectToPage("./Login", new { ReturnUrl = returnUrl })); } _tokenStore.HarvestAndStore(); // this is so that downstream handler in the pipeline can get access to the current Info. _externalLoginProvider.ExternalLoginInfo = info; // Sign in the user with this external login provider if the user already has a login. var result = await _signInManager.ExternalLoginSignInAsync(info.LoginProvider, info.ProviderKey, isPersistent : false, bypassTwoFactor : true); if (result.Succeeded) { _logger.LogInformation("{Name} logged in with {LoginProvider} provider.", info.Principal.Identity.Name, info.LoginProvider); return(LocalRedirect(returnUrl)); } if (result.IsLockedOut) { return(RedirectToPage("./Lockout")); } else { var user = await _userManager.FindByIdAsync(info.ProviderKey); if (user != null) { var addResult = await _userManager.AddLoginAsync(user, info); if (!addResult.Succeeded) { throw new InvalidOperationException($"Unexpected error occurred adding external login for user with ID '{user.Id}'."); } result = await _signInManager.ExternalLoginSignInAsync(info.LoginProvider, info.ProviderKey, isPersistent : false, bypassTwoFactor : true); if (result.Succeeded) { _logger.LogInformation("{Name} logged in with {LoginProvider} provider.", info.Principal.Identity.Name, info.LoginProvider); return(LocalRedirect(returnUrl)); } throw new InvalidOperationException($"Unexpected error occurred adding external login for user with ID '{user.Id}'."); } // If the user does not have an account, then ask the user to create an account. ReturnUrl = returnUrl; LoginProvider = info.LoginProvider; if (info.Principal.HasClaim(c => c.Type == ClaimTypes.Email)) { Input = new InputModel { Email = info.Principal.FindFirstValue(ClaimTypes.Email) }; } return(Page()); } }