/// <summary>
/// Attempts to acquire access token from the token cache silently by calling AcquireTokenSilentAsync
/// </summary>
internal async Task <AuthenticationResult> GetAccessTokenSilentAsync(MsalAuthenticationProviderOption msalAuthProviderOption)
{
IAccount account = null;
if (msalAuthProviderOption.UserAccount?.ObjectId != null)
{
// Parse GraphUserAccount to IAccount instance
account = new GraphAccount(msalAuthProviderOption.UserAccount);
}
else
{
// If no graph user account is passed, try get the one in cache.
IEnumerable <IAccount> accounts = await ClientApplication.GetAccountsAsync();
account = accounts.FirstOrDefault();
}
if (account == null)
{
return(null);
}
try
{
return(await ClientApplication.AcquireTokenSilentAsync(
msalAuthProviderOption.Scopes ?? Scopes,
account,
ClientApplication.Authority,
msalAuthProviderOption.ForceRefresh));
}
catch (MsalUiRequiredException msalUiEx)
{
return(null);
}
catch (MsalServiceException serviceException)
{
throw new AuthenticationException(
new Error
{
Code = ErrorConstants.Codes.GeneralException,
Message = ErrorConstants.Message.UnexpectedMsalException
},
serviceException);
}
catch (Exception exception)
{
throw new AuthenticationException(
new Error
{
Code = ErrorConstants.Codes.GeneralException,
Message = ErrorConstants.Message.UnexpectedException
},
exception);
}
}
/// <summary>
/// Adds an authentication header to the incoming request by checking the application's <see cref="TokenCache"/>
/// for an unexpired access token. If a token is not found or expired, it gets a new one.
/// </summary>
/// <param name="httpRequestMessage">A <see cref="HttpRequestMessage"/> to authenticate.</param>
public async Task AuthenticateRequestAsync(HttpRequestMessage httpRequestMessage)
{
GraphRequestContext requestContext = httpRequestMessage.GetRequestContext();
MsalAuthenticationProviderOption msalAuthProviderOption = httpRequestMessage.GetMsalAuthProviderOption();
IAccount account = new GraphAccount(msalAuthProviderOption.UserAccount);
AuthenticationResult authenticationResult = await this.GetAccessTokenSilentAsync(msalAuthProviderOption);
if (authenticationResult == null)
{
authenticationResult = await GetNewAccessTokenAsync(account, msalAuthProviderOption.Scopes ?? Scopes);
}
if (!string.IsNullOrEmpty(authenticationResult.AccessToken))
{
httpRequestMessage.Headers.Authorization = new AuthenticationHeaderValue(CoreConstants.Headers.Bearer, authenticationResult.AccessToken);
}
}