Added Custom Claim, showing in ID token missing in Access token - identityserver4

Question

I have a .NET Core Identity Provider (which also uses IdentityServer4) which authenticates SPA applications with Azure AD. I am adding an "oid" claim with the object identifier value received from Azure. The problem is that from the SPA application I can see the "oid" claim in the ID token but cannot see it in the access token. I need the oid in the access token as well. Here is the relevant code:
Startup.cs
services.AddAuthentication()
.AddCookie("Cookies", options =>
{
options.ExpireTimeSpan = TimeSpan.FromMinutes(10);
})
.AddOpenIdConnect(ActiveDirectoryTenants.TenantA, ActiveDirectoryTenants.TenantA, options => Configuration.Bind("TenantAAzureAd", options))
.AddOpenIdConnect(ActiveDirectoryTenants.TenantB, ActiveDirectoryTenants.TenantB, options => Configuration.Bind("TenantBAzureAd", options));
AddActiveDirectoryOpenIdConnectOptions(services, ActiveDirectoryTenants.TenantA);
AddActiveDirectoryOpenIdConnectOptions(services, ActiveDirectoryTenants.TenantB);
I have a common function to add other options to these configurations. I tried to add the oid claim in OnTokenValidated but didn't receive the oid claim in the access token.
protected virtual void AddActiveDirectoryOpenIdConnectOptions(IServiceCollection services, string tenant)
{
services.Configure<OpenIdConnectOptions>(tenant, options =>
{
options.Authority = options.Authority + "/v2.0/";
options.TokenValidationParameters.ValidateIssuer = false;
options.Events = new OpenIdConnectEvents
{
OnRedirectToIdentityProvider = ctx =>
{
ctx.ProtocolMessage.LoginHint = ctx.Properties.GetString("username");
return Task.CompletedTask;
},
OnTokenValidated = ctx =>
{
//Maybe need to add oid here???
}
};
});
}
The oid claim is being added after successfully logging in to Azure AD.
AccountController.cs
public async Task<IActionResult> ExternalLoginCallback(string returnUrl, string remoteError = null, string openIdScheme = null)
{
var authResult = await HttpContext.AuthenticateAsync(openIdScheme ?? ActiveDirectoryTenants.TenantA);
var externalUser = authResult.Principal;
var claims = externalUser.Claims.ToList();
var applicationUser = //gets the user based on the email found in claims, omitted for brevity
await userManager.AddClaimAsync(applicationUser, new Claim("oid", claims.First(x => x.Type == http://schemas.microsoft.com/identity/claims/objectidentifier).Value));
await signInManager.SignInAsync(applicationUser, false, "AzureAD");
return Redirect("~/");
}
The ID token received in the SPA application (note the oid claim):
{
"nbf": xxx,
"exp": xxx,
"iss": "https://localhost:3000",
"aud": "xxx-spa-test",
"iat": xxx,
"at_hash": "",
"s_hash": "",
"sid": "",
"sub": "guid",
"auth_time": 1620026953,
"idp": "AzureAD",
"display_name": "Test User",
"oid": "guid",
"role": [
"Staff",
],
"name": "test#azureaddomain",
"amr": [
"external"
]
}
The access token received in the SPA application (note the missing oid claim):
{
"nbf": xxx,
"exp": xxx,
"iss": "https://localhost:3000",
"aud": [
"https://localhost:3000/resources",
"xxx-api-test-scope"
],
"client_id": "xxx-spa-test",
"sub": "guid",
"auth_time": 1620026953,
"idp": "AzureAD",
"role": [
"Staff",
],
"name": "test#azureaddomain",
"scope": [
"openid",
"profile",
"xxx-api-test-scope"
],
"amr": [
"external"
]
}

Answer 1

For the claim to end up in the access token, you need to add a ApiScope and add the Userclaim name to it. Alternatively, add an ApiScope and an ApiResource that contains the UserClaim.
Like
var apiresource1 = new ApiResource()
{
Name = "apiresource1", //This is the name of the API
ApiSecrets = new List<Secret>
{
new Secret("myapisecret".Sha256())
},
Description = "This is the order Api-resource description",
Enabled = true,
DisplayName = "Orders API Service",
Scopes = new List<string> { "apiscope1"},
UserClaims = new List<string>
{
//Custom user claims that should be provided when requesting access to this API.
//These claims will be added to the access token, not the ID-token!
"apiresource1-userclaim3",
}
};
See my answer here for more details
To complement this answer, I write a blog post that goes into more detail about this topic:
IdentityServer – IdentityResource vs. ApiResource vs. ApiScope