Authenticate an EWS WCF service by using OAuth and refresh access token

Question

I am trying to call Exchange web services (EWS) end points from my WCF service using OAuth authentication. I have registered the app on Azure portal and able to generate and authenticate it using access token.

My question is about how I can refresh the token in WCF service. It seems access token has an hour validity.

// Using Microsoft.Identity.Client 4.22.0
var cca = ConfidentialClientApplicationBuilder
    .Create(ConfigurationManager.AppSettings["appId"])
    .WithClientSecret(ConfigurationManager.AppSettings["clientSecret"])
    .WithTenantId(ConfigurationManager.AppSettings["tenantId"])
    .Build();

// The permission scope required for EWS access
var ewsScopes = new string[] { "https://outlook.office365.com/.default" };

//Make the token request
var authResult = await cca.AcquireTokenForClient(ewsScopes).ExecuteAsync();

Followed below link for this. https://docs.microsoft.com/en-us/exchange/client-developer/exchange-web-services/how-to-authenticate-an-ews-application-by-using-oauth

Thanks

What about making a new access token request, a few time before the expiration? — Ortomala Lokni

Glen Scales Glen Scales · Accepted Answer · 2021-03-14T23:06:16

In your WCF client you want to do something like How to add a custom HTTP header to every WCF call? so you have a piece of code that runs before any request is made that calls AcquireTokenForClient which should use the Token Application Cache (so it will either give you the current token if valid or acquire a new token if expired).

Authenticate an EWS WCF service by using OAuth and refresh access token

1 Answers