Caching Issue: ASP.NET Core, failed to get access token - asp.net-core

Question

GetUserAccessTokenAsync by using this method I am trying to get the Token, The same code working fine in POC App, where as in the real application I am getting TokenNotFound.
User is authenticated and able to get the userId too, at the end I am getting account as null, it leads to the main error.
public async Task<string> GetUserAccessTokenAsync(string userId)
{
var account = await _app.GetAccountAsync(userId);
if (account == null) throw new ServiceException(new Error
{
Code = "TokenNotFound",
Message = "User not found in token cache. Maybe the server was restarted."
});
try
{
var result = await _app.AcquireTokenSilent(_scopes, account).ExecuteAsync();
return result.AccessToken;
}
// Unable to retrieve the access token silently.
catch (Exception)
{
throw new ServiceException(new Error
{
Code = GraphErrorCode.AuthenticationFailure.ToString(),
Message = "Caller needs to authenticate. Unable to retrieve the access token silently."
});
}
}
Note: The same code working fine in POC application, I tried with same app resource and created new app resource too.
Please help me what exactly I am missing...

Answer 1

I have a sample with asp.net core mvc, which integrate MSAL to obtain access token for calling Ms graph api. I don't know what is POC App actually, but per my searching, AcquireTokenSilent may from MSAL.js
Here's the detail.
Adding configurations in appsetting file about azure ad:
"AzureAd": {
"Instance": "https://login.microsoftonline.com/",
"Domain": "your_tenant_name.onmicrosoft.com",
"TenantId": "tenant_id",
"ClientId": "azure_ad_client_id",
"ClientSecret": "client_secret",
"CallbackPath": "/signin-oidc",//don't forget to set redirect url in azure portal
"SignedOutCallbackPath ": "/signout-callback-oidc"
}
installing packages:
<PackageReference Include="Microsoft.Identity.Web" Version="1.23.1" />
<PackageReference Include="Microsoft.Identity.Web.UI" Version="1.23.1" />
StartUp.cs, don't forget to add app.UseAuthentication();app.UseAuthorization(); in Configure method:
public void ConfigureServices(IServiceCollection services)
{
services.AddMicrosoftIdentityWebAppAuthentication(Configuration)
.EnableTokenAcquisitionToCallDownstreamApi(new string[] { "user.read" })
.AddInMemoryTokenCaches();
// Require authentication
services.AddControllersWithViews(options =>
{
var policy = new AuthorizationPolicyBuilder()
.RequireAuthenticatedUser()
.Build();
options.Filters.Add(new AuthorizeFilter(policy));
})
// Add the Microsoft Identity UI pages for signin/out
.AddMicrosoftIdentityUI();
}
And my test Controller:
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;
using Microsoft.Identity.Web;
using System.Diagnostics;
using System.Threading.Tasks;
using WebAppMvc.Models;
namespace WebAppMvc.Controllers
{
[Authorize]
public class HomeController : Controller
{
private readonly ITokenAcquisition _tokenAcquisition;
public HomeController(ITokenAcquisition tokenAcquisition)
{
_tokenAcquisition = tokenAcquisition;
}
public async Task<IActionResult> IndexAsync()
{
string[] scopes = new string[] { "user.read" };
string accessToken = await _tokenAcquisition.GetAccessTokenForUserAsync(scopes);
return View();
}
}
}
If the redirection url is wrong after signing in, just changing the url in browser manually to localhost:xxx/home

Answer 2

At Finally I have followed below link it helped to get rid of my all queries for graph API;
https://github.com/microsoftgraph/msgraph-training-aspnet-core