public string RefreshAccessToken(FormCollection form) { string spWebUrl = form["spWebUrl"]; string tenantId = form["tenantId"]; string refreshTokenContent = _refreshTokenManager.RetrieveToken(HttpContext.Request); var credential = new ClientCredential(SettingsHelper.ClientId, SettingsHelper.ClientKey); var authContext = new AuthenticationContext(SettingsHelper.AUTHORITY + tenantId); try { AuthenticationResult result = authContext.AcquireTokenByRefreshToken(refreshTokenContent, credential, spWebUrl); if (result == null) { throw new Exception("Error acquiring SharePoint AccessToken."); } return(result.AccessToken); } catch (AdalServiceException exception) { throw new Exception("SharePoint RefreshToken is invalid.", exception); } }