Advice on cross-domain localization

[Ponant]

Hello,
I have two websites and one is used as an IdentityServer, where user login to enter credentials or register and where he is redirected back to the second website after. Each website lives on a different domain but I can also target them to sub-domains of a main domain if that is a needed.

Localization is implemented successfully on each website with a dropdown button for the cultures. What I would like is, when a user comes to the website 2, chooses a culture (say DE) and decides to login, I want him to be redirected to IdentityServer with culture DE instead of the default.
I welcome any hint on how to achieve this?

[hishamco]

Frankly I didn't work with Identity server, but if there's a way to pass the culture to the identity server, you could simply append the culture to the querystring when you redirect to other website

I'm happy to hear from @damienbod which wrote a lot of great blog posts about the Identity Server and localization

[Ponant]

@hishamco , thank you for your answer and hint. Any link to blog posts on identityserver+localzation would be great as a start; a quick google search returns nothing at first attempt.

[Eilon]

Using a query string parameter is probably the best approach here. I think that the security middleware has callback events where you can add additional data to the authentication process, which would get transferred to the authentication server.

@Tratcher - do you know the secret sauce to pass additional data to the auth server? It seems that there are OAuth-standard request parameters for things like "ui locale".

[Tratcher]

OAuth2 or OpenIdConnect? The process is similar.

For OAuth2 you implement the OnRedirectToAuthorizationEndpoint event and tack your parameters onto the already assembled RedirectUri.
https://github.com/aspnet/Security/blob/rel/1.1.2/src/Microsoft.AspNetCore.Authentication.OAuth/Events/OAuthEvents.cs#L23

For OpenIdConnect it's OnRedirectToIdentityProvider where you add your custom parameters to the ProtocolMessage.
https://github.com/aspnet/Security/blob/rel/1.1.2/src/Microsoft.AspNetCore.Authentication.OpenIdConnect/Events/OpenIdConnectEvents.cs#L33

[Ponant]

Thanks @Eilon and @Tratcher , I thought that modifying the endpoint is not a secure procedure. I recall having read something like this on the IdenttityServer repo but cannot find the thread anymore. Perhaps @leastprivilege could comment on the reliability of the procedures mentioned above.

[Ponant]

Hi @Tratcher, can you point to some example using the Funcs you refer to? Cheers

[hishamco]

Have a look to the test project here and there

[Ponant]

Thanks @hishamco I will look at that, then.

[aspnet-hello]

This issue was moved to dotnet/aspnetcore#2637