public async Task GetAsync(string tenantId)
{
try
{
MSALCache appTokenCache = new MSALCache(Startup.clientId);
// Get a token for the Microsoft Graph. If this line throws an exception for
// any reason, we'll just let the exception be returned as a 500 response
// to the caller, and show a generic error message to the user.
ConfidentialClientApplication daemonClient = new ConfidentialClientApplication(Startup.clientId, string.Format(AuthorityFormat, tenantId), Startup.redirectUri,
new ClientCredential(Startup.clientSecret), null, appTokenCache.GetMsalCacheInstance());
AuthenticationResult authResult = await daemonClient.AcquireTokenForClientAsync(new[] { MSGraphScope });
// Query for list of users in the tenant
HttpClient client = new HttpClient();
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Get, MSGraphQuery);
request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", authResult.AccessToken);
HttpResponseMessage response = await client.SendAsync(request);
// If the token we used was insufficient to make the query, drop the token from the cache.
// The Users page of the website will show a message to the user instructing them to grant
// permissions to the app (see User/Index.cshtml).
if (response.StatusCode == System.Net.HttpStatusCode.Forbidden)
{
// BUG: Here, we should clear MSAL's app token cache to ensure that on a subsequent call
// to SyncController, MSAL does not return the same access token that resulted in this 403.
// By clearing the cache, MSAL will be forced to retrieve a new access token from AAD,
// which will contain the most up-to-date set of permissions granted to the app. Since MSAL
// currently does not provide a way to clear the app token cache, we have commented this line
// out. Thankfully, since this app uses the default in-memory app token cache, the app still
// works correctly, since the in-memory cache is not persistent across calls to SyncController
// anyway. If you build a persistent app token cache for MSAL, you should make sure to clear
// it at this point in the code.
//
appTokenCache.Clear();
}
if (!response.IsSuccessStatusCode)
{
throw new HttpResponseException(response.StatusCode);
}
// Record users in the data store (note that this only records the first page of users)
string json = await response.Content.ReadAsStringAsync();
MsGraphUserListResponse users = JsonConvert.DeserializeObject <MsGraphUserListResponse>(json);
usersByTenant[tenantId] = users.value;
}
catch (Exception ex)
{
var e = ex.ToString();
}
}
/// <summary>
/// Remove all cache entries for this user.
/// </summary>
private void RemoveCachedTokens()
{
MSALCache appTokenCache = new MSALCache(Startup.clientId);
appTokenCache.Clear();
}