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

I personally prefer to do the claims transformation in the middleware where the actual authentication happens.

You can use the OnTicketReceived event on the OIDC middleware for that.

var oidcOptions = new OpenIdConnectOptions
{
   AuthenticationScheme = "oidc",
   SignInScheme = "cookies",

   Authority = Clients.Constants.BaseAddress,

   ClientId = "mvc.hybrid",
   ClientSecret = "secret",
   ResponseType = "code id_token",
   SaveTokens = true,

   TokenValidationParameters = new TokenValidationParameters
   {
      NameClaimType = JwtClaimTypes.Name,
      RoleClaimType = JwtClaimTypes.Role,
   },

   Events = new OpenIdConnectEvents
   {
       OnTicketReceived = e =>
       {
           ClaimsPrincipal p = TransformClaims(e.Ticket.Principal);
           e.Ticket = new AuthenticationTicket(
            p,
            e.Ticket.Properties,
            e.Ticket.AuthenticationScheme);

        return Task.CompletedTask;
    }
  }
};