// Get an access token. First tries to get the token from the token cache.
public async Task<string> GetUserAccessTokenAsync()
{
string signedInUserID = ClaimsPrincipal.Current.FindFirst(ClaimTypes.NameIdentifier).Value;
tokenCache = new SessionTokenCache(
signedInUserID,
HttpContext.Current.GetOwinContext().Environment["System.Web.HttpContextBase"] as HttpContextBase);
//var cachedItems = tokenCache.ReadItems(appId); // see what's in the cache
ConfidentialClientApplication cca = new ConfidentialClientApplication(
appId,
redirectUri,
new ClientCredential(appSecret),
tokenCache);
try
{
AuthenticationResult result = await cca.AcquireTokenSilentAsync(scopes.Split(new char[] { ' ' }));
return result.Token;
}
// Unable to retrieve the access token silently.
catch (MsalSilentTokenAcquisitionException)
{
HttpContext.Current.Request.GetOwinContext().Authentication.Challenge(
new AuthenticationProperties() { RedirectUri = "/" },
OpenIdConnectAuthenticationDefaults.AuthenticationType);
throw new Exception(Resource.Error_AuthChallengeNeeded);
}
}
