IdentityServer4 Windows Authentication Missing Callback implementation - identityserver4

Question

The documentation to setup Windows Authentication is here: https://docs.identityserver.io/en/latest/topics/windows.html
But I have no idea how to configure the Callback() method referred to in the line RedirectUri = Url.Action("Callback"), or wethere or not I'm even supposed to use that.
I tried manually redirecting back to the https://<client:port>/auth-callback route of my angular app but I get the error:
Error: No state in response
at UserManager.processSigninResponse (oidc-client.js:8308)
Does someone have a suggested Callback method I can use with an SPA using code + pkce ? I've tried searching Google but there are no current example apps using Windows Authentication and the ones that do exist are old.

Answer 1

Take a look at the ExternalLoginCallback method. I've also pasted the version of the code as of 26 Oct 2020 below for future reference incase the repo goes away.
/// <summary>
/// Post processing of external authentication
/// </summary>
[HttpGet]
public async Task<IActionResult> ExternalLoginCallback()
{
// read external identity from the temporary cookie
var result = await HttpContext.AuthenticateAsync(IdentityConstants.ExternalScheme);
if (result?.Succeeded != true)
{
throw new Exception("External authentication error");
}
// lookup our user and external provider info
var (user, provider, providerUserId, claims) = await FindUserFromExternalProviderAsync(result);
if (user == null)
{
// this might be where you might initiate a custom workflow for user registration
// in this sample we don't show how that would be done, as our sample implementation
// simply auto-provisions new external user
user = await AutoProvisionUserAsync(provider, providerUserId, claims);
}
// this allows us to collect any additonal claims or properties
// for the specific prtotocols used and store them in the local auth cookie.
// this is typically used to store data needed for signout from those protocols.
var additionalLocalClaims = new List<Claim>();
additionalLocalClaims.AddRange(claims);
var localSignInProps = new AuthenticationProperties();
ProcessLoginCallbackForOidc(result, additionalLocalClaims, localSignInProps);
ProcessLoginCallbackForWsFed(result, additionalLocalClaims, localSignInProps);
ProcessLoginCallbackForSaml2p(result, additionalLocalClaims, localSignInProps);
// issue authentication cookie for user
// we must issue the cookie maually, and can't use the SignInManager because
// it doesn't expose an API to issue additional claims from the login workflow
var principal = await _signInManager.CreateUserPrincipalAsync(user);
additionalLocalClaims.AddRange(principal.Claims);
var name = principal.FindFirst(JwtClaimTypes.Name)?.Value ?? user.Id;
await _events.RaiseAsync(new UserLoginSuccessEvent(provider, providerUserId, user.Id, name));
// issue authentication cookie for user
var isuser = new IdentityServerUser(principal.GetSubjectId())
{
DisplayName = name,
IdentityProvider = provider,
AdditionalClaims = additionalLocalClaims
};
await HttpContext.SignInAsync(isuser, localSignInProps);
// delete temporary cookie used during external authentication
await HttpContext.SignOutAsync(IdentityConstants.ExternalScheme);
// validate return URL and redirect back to authorization endpoint or a local page
var returnUrl = result.Properties.Items["returnUrl"];
if (_interaction.IsValidReturnUrl(returnUrl) || Url.IsLocalUrl(returnUrl))
{
return Redirect(returnUrl);
}
return Redirect("~/");
}