Post-logout redirect support

[omon77]

This PR adds support for auto-redirecting the user after signing out of STS, if the client has PostLogoutRedirectUri configured.
Resolves issue #226 .

[omon77]

Due to Duende.IdentityServer project switching from MVC to Razor Pages, it didn't make sense to try to retrofit just the post-logout redirect changes.

Perhaps it would be a good idea to catch up STS project to Razor Pages as original project transitioned to them with v6.0.0.

[skoruba]

Hi @omon77 - I fully agree with you, I have not had a time to do it. Can you help me with this migration from MVC to Razor Pages for STS?
Thanks!

[omon77]

Might be a while, but I can give it a shot...

I added an issue/enhancement request #245 so that it can be tracked...

[apetrut]

@omon77 @skoruba The PostLogoutRedirectUri is always empty even if I set it up in the [ClientPostLogoutRedirectUris] db table. Did you experience the same issue?

Also, what if I want to pass a different logout redirect uri based on the environment I am running in? The Duende instance is the same, but it's being called from dev and prod environments separately and each is having its own redirect uri.

[omon77]

@omon77 @skoruba The PostLogoutRedirectUri is always empty even if I set it up in the [ClientPostLogoutRedirectUris] db table. Did you experience the same issue?

Also, what if I want to pass a different logout redirect uri based on the environment I am running in? The Duende instance is the same, but it's being called from dev and prod environments separately and each is having its own redirect uri.

@apetrut ,
This PR should solve the client's post logout uri being empty, even though populated in config table.

As for different logout uris, wouldn't having a different client per logical environment, solve it? Or if you have to have only one client, specify all post logout uris. If the one requested by the logout process matches, the redirect will work.

[apetrut]

@omon77 It turns out that I had to specify the redirect uri in this format: http://[subdomain].[domain]/signout-callback-oidc and it worked.