Is there any way to change client_id and client_secret on the fly in IdentityServer4

Question

We created a multi-tenant SaaS application and I need to change client_id dynamically. How can i change client_id and client_secret in OnRedirectToIdentityProvider event ?

Answer 1

As mentioned in the comment for @d_f it's a wrong approach. The right approach to do that is passing the tenant id from client to IdentityServer using the event : OnRedirectToIdentityProvider
Example

    options.Events.OnRedirectToIdentityProvider = (loginRedirectContext) =>
                {
                    var servicesProvider = loginRedirectContext.HttpContext.RequestServices;
                    var tenantInfo = servicesProvider.GetRequiredService<IRequestContextTenantInfo>();

loginRedirectContext.ProtocolMessage.SetParameter("tenantId", tenantInfo.Id);


                    return Task.FromResult(0);
                };

In The Identity Server You can read it in Login Action method like this :

var _interaction = context.RequestServices.GetRequiredService<IIdentityServerInteractionService>();
                var returnUrl = context.Request.Query["ReturnUrl"].ToString();

                var authContext = await _interaction.GetAuthorizationContextAsync(returnUrl);
                tenantId = authContext.Parameters["tenantid"];

Now based on tenant id you have to know which tenant you have to connect with to verify the login process.

It's also a good practice to inject a specific custom middleware in IdentityServer4 to handle the multitenancy in the early stage in the request pipeline Example in Configure method in Startup :

 app.UseMultiTenancy();
 app.UseIdentityServer();

and UseMultiTenancy() method will read the tenant parameter that is sent from client.