/// <summary>
/// Click handler for the 'ChangeAdminKey' button.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private async void ChangeAdminKey_Click(object sender, RoutedEventArgs e)
{
if (!rootPage.ValidateTPMSmartCard())
{
rootPage.NotifyUser(
"Use Scenario One to create a TPM virtual smart card.",
NotifyType.ErrorMessage);
return;
}
Button b = sender as Button;
b.IsEnabled = false;
try
{
IBuffer newadminkey = CryptographicBuffer.GenerateRandom(
MainPage.ADMIN_KEY_LENGTH_IN_BYTES);
SmartCard card = await rootPage.GetSmartCard();
SmartCardProvisioning provisioning =
await SmartCardProvisioning.FromSmartCardAsync(card);
rootPage.NotifyUser("Changing smart card admin key...",
NotifyType.StatusMessage);
using (SmartCardChallengeContext context =
await provisioning.GetChallengeContextAsync())
{
IBuffer response =
ChallengeResponseAlgorithm.CalculateResponse(
context.Challenge, rootPage.AdminKey);
await context.ChangeAdministrativeKeyAsync(response,
newadminkey);
rootPage.AdminKey = newadminkey;
}
rootPage.NotifyUser(
"Smart card change admin key operation completed.",
NotifyType.StatusMessage);
}
catch (Exception ex)
{
rootPage.NotifyUser(
"Changing smart card admin key operation failed " +
"with exception: " +
ex.ToString(),
NotifyType.ErrorMessage);
}
finally
{
b.IsEnabled = true;
}
}
/// <summary>
/// Click handler for the 'VerifyResponse' button.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private async void VerifyResponse_Click(object sender, RoutedEventArgs e)
{
if (!rootPage.ValidateTPMSmartCard())
{
rootPage.NotifyUser(
"Use Scenario One to create a TPM virtual smart card.",
NotifyType.ErrorMessage);
return;
}
Button b = sender as Button;
b.IsEnabled = false;
try
{
bool verifyResult = false;
SmartCard card = await rootPage.GetSmartCard();
SmartCardProvisioning provisioning =
await SmartCardProvisioning.FromSmartCardAsync(card);
rootPage.NotifyUser("Verifying smart card response...",
NotifyType.StatusMessage);
using (SmartCardChallengeContext context =
await provisioning.GetChallengeContextAsync())
{
IBuffer response = ChallengeResponseAlgorithm.CalculateResponse(
context.Challenge,
rootPage.AdminKey);
verifyResult = await context.VerifyResponseAsync(response);
}
rootPage.NotifyUser(
"Smart card response verification completed. Result: " +
verifyResult.ToString(),
NotifyType.StatusMessage);
}
catch (Exception ex)
{
rootPage.NotifyUser(
"Verifying smart card response operation failed " +
"with exception: " +
ex.ToString(),
NotifyType.ErrorMessage);
}
finally
{
b.IsEnabled = true;
}
}
/// <summary>
/// Click handler for the 'create' button.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private async void Create_Click(object sender, RoutedEventArgs e)
{
Button b = sender as Button;
b.IsEnabled = false;
rootPage.NotifyUser("Creating TPM virtual smart card...",
NotifyType.StatusMessage);
try
{
SmartCardPinPolicy pinPolicy = ParsePinPolicy();
IBuffer adminkey = CryptographicBuffer.GenerateRandom(
MainPage.ADMIN_KEY_LENGTH_IN_BYTES);
SmartCardProvisioning provisioning = await
SmartCardProvisioning.RequestVirtualSmartCardCreationAsync(
FriendlyNameText.Text,
adminkey,
pinPolicy);
// If card creation is cancelled by the user,
// RequestVirtualSmartCard will return null instead of a
// SmartCardProvisioning object.
if (null == provisioning)
{
rootPage.NotifyUser(
"TPM virtual smart card creation was canceled by " +
"the user.",
NotifyType.StatusMessage);
b.IsEnabled = true;
return;
}
// The following two lines are not directly related to TPM virtual
// smart card creation, but are used to demonstrate how to handle
// CardAdded events by registering an event handler with a
// SmartCardReader object. Since we are using a TPM virtual smart
// card in this case, the card cannot actually be added to or
// removed from the reader, but a CardAdded event will fire as
// soon as the event handler is added, since the card is already
// inserted.
//
// We must retain a reference to the SmartCardReader object to
// which we are adding the event handler. Hence we assign the
// reader object associated with the SmartCardProvisioning we
// received from RequestVirtualSmartCardCreationAsync to the
// class's "reader" member. Then, we use += to add the
// HandleCardAdded method as an event handler. The function
// will be automatically boxed in a TypedEventHandler, but
// the function signature match the template arguments for
// the specific event - in this case,
// <SmartCardReader, CardAddedEventArgs>
reader = provisioning.SmartCard.Reader;
reader.CardAdded += HandleCardAdded;
// Store the reader's device ID and admin key to enable the
// following scenarios in the sample.
rootPage.SmartCardReaderDeviceId =
provisioning.SmartCard.Reader.DeviceId;
rootPage.AdminKey = adminkey;
// Once RequestVirtualSmartCardCreationAsync has returned, the card
// is already provisioned and ready to use. Therefore, the steps
// in this using block are not actually necessary at this point.
// However, should you want to re-provision the card in the future,
// you would follow this sequence: acquire a challenge context,
// calculate a response, and then call ProvisionAsync on the
// challenge context with the calculated response.
using (var context = await provisioning.GetChallengeContextAsync())
{
IBuffer response =
ChallengeResponseAlgorithm.CalculateResponse(
context.Challenge,
adminkey);
await context.ProvisionAsync(response, true);
}
rootPage.NotifyUser(
"TPM virtual smart card is provisioned and ready for use.",
NotifyType.StatusMessage);
}
catch (Exception ex)
{
// Two potentially common error scenarios when creating a TPM
// virtual smart card are that the user's machine may not have
// a TPM, or the TPM may not be ready for use. It is important
// to explicitly check for these scenarios by checking the
// HResult of any exceptions thrown by
// RequestVirtualSmartCardCreationAsync and gracefully
// providing a suitable message to the user.
if(NTE_DEVICE_NOT_FOUND == ex.HResult)
{
rootPage.NotifyUser(
"We were unable to find a Trusted Platform Module on " +
"your machine. A TPM is required to use a TPM Virtual " +
"Smart Card.",
NotifyType.ErrorMessage);
}
else if (NTE_DEVICE_NOT_READY == ex.HResult)
{
rootPage.NotifyUser(
"Your Trusted Platform Module is not ready for use. " +
"Please contact your administrator for assistance with " +
"initializing your TPM.",
NotifyType.ErrorMessage);
}
else
{
rootPage.NotifyUser(
"TPM virtual smart card creation failed with exception: " +
ex.ToString(),
NotifyType.ErrorMessage);
}
}
finally
{
b.IsEnabled = true;
}
}
/// <summary>
/// Click handler for the 'ResetPin' button.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private async void ResetPin_Click(object sender, RoutedEventArgs e)
{
if (!rootPage.ValidateTPMSmartCard())
{
rootPage.NotifyUser(
"Use Scenario One to create a TPM virtual smart card.",
NotifyType.ErrorMessage);
return;
}
Button b = sender as Button;
b.IsEnabled = false;
try
{
SmartCard card = await rootPage.GetSmartCard();
SmartCardProvisioning provisioning =
await SmartCardProvisioning.FromSmartCardAsync(card);
rootPage.NotifyUser("Resetting smart card PIN...",
NotifyType.StatusMessage);
// When requesting a PIN reset, a SmartCardPinResetHandler must be
// provided as an argument. This handler must use the challenge
// it receives and the card's admin key to calculate and set the
// response.
bool result = await provisioning.RequestPinResetAsync(
(pinResetSender, request) =>
{
SmartCardPinResetDeferral deferral =
request.GetDeferral();
try
{
IBuffer response =
ChallengeResponseAlgorithm.CalculateResponse(
request.Challenge,
rootPage.AdminKey);
request.SetResponse(response);
}
finally
{
deferral.Complete();
}
});
if (result)
{
rootPage.NotifyUser(
"Smart card PIN reset operation completed.",
NotifyType.StatusMessage);
}
else
{
rootPage.NotifyUser(
"Smart card PIN reset operation was canceled by " +
"the user.",
NotifyType.StatusMessage);
}
}
catch (Exception ex)
{
rootPage.NotifyUser(
"Resetting smart card PIN failed with exception: " +
ex.ToString(),
NotifyType.ErrorMessage);
}
finally
{
b.IsEnabled = true;
}
}
