Transforming Open Id Connect claims in ASP.Net Core

Question

I\'m writing an ASP.Net Core Web Application and using UseOpenIdConnectAuthentication to connect it to IdentityServer3. Emulating their ASP.Net MVC 5 sample I\'

Answer 1

Thank you Adem for your reply... it solved the vast majority of the problem... the only issue being that identity.Claim is a read only property. I found creating a new Principal did work though:

Events = new CookieAuthenticationEvents()
{
    OnSigningIn = (context) =>
    {
        ClaimsIdentity identity = (ClaimsIdentity)context.Principal.Identity;

        var givenName = identity.FindFirst(Constants.ClaimTypes.GivenName);
        var familyName = identity.FindFirst(Constants.ClaimTypes.FamilyName);
        var sub = identity.FindFirst(Constants.ClaimTypes.Subject);

        var claimsToKeep = new List {givenName, familyName, sub};

        var newIdentity = new ClaimsIdentity(claimsToKeep, identity.AuthenticationType);

        context.Principal = new ClaimsPrincipal(newIdentity);

        return Task.FromResult(0);
    }
}

Whether this is the correct approach I'm not sure, but it appears to work.