How to access and use Delegated Adal token - authentication

Question

The reason there is no info on this is probably because it should be obvious, but I am struggling nonetheless.
After I sign in to my AAD-tenant using ADAL in StartUp.Auth.cs Isuccessfully get a token:
private async Task OnAuthorizationCodeReceivedAAD(AuthorizationCodeReceivedNotification notification)
{
var code = notification.Code;
var credential = new ClientCredential(appId, appSecret);
var userObjectId = notification.AuthenticationTicket.Identity.FindFirst("http://schemas.microsoft.com/identity/claims/objectidentifier").Value;
var context = new Microsoft.IdentityModel.Clients.ActiveDirectory.AuthenticationContext("https://login.microsoftonline.com/tenant.onmicrosoft.com/");
var uri = new Uri(HttpContext.Current.Request.Url.GetLeftPart(UriPartial.Path));
var result = await context.AcquireTokenByAuthorizationCodeAsync(code, uri, credential);
}
I can add a breakpoint here and view the token. My question is, how do I now access this token through my code from other classes? for example to call an API. The token needs to be delegated, so Client Credentials are not going to work, which is all I can find docs on.

Answer 1

The AuthenticationContext class will store the the token in the cache by default when we acquire the token using it.
Then we can retrieve the token from cache based on the resource and user using AcquireTokenSilentAsync. This method will acquire the token from cache and renew the token if it is necessary. Here is an example for your reference:
AuthenticationContext authContext = new AuthenticationContext(authority);
ClientCredential credential = new ClientCredential(clientId, secret);
string userObjectID = ClaimsPrincipal.Current.FindFirst("http://schemas.microsoft.com/identity/claims/objectidentifier").Value;
AuthenticationResult result = await authContext.AcquireTokenSilentAsync(resource,credential, new UserIdentifier(userObjectID, UserIdentifierType.UniqueId));