/// <summary>
/// Applies the UI context.
/// </summary>
/// <param name="ngcKeyHandle">The NGC key handle.</param>
/// <param name="uiContext">The UI context.</param>
private static void ApplyUiContext(SafeNCryptHandle ngcKeyHandle, AuthProviderUiContext uiContext)
{
if (uiContext == null)
{
return;
}
var parentWindowHandle = uiContext.ParentWindowHandle;
if (parentWindowHandle != IntPtr.Zero)
{
var handle = BitConverter.GetBytes(IntPtr.Size == 8
? parentWindowHandle.ToInt64()
: parentWindowHandle.ToInt32());
NCryptSetProperty(
ngcKeyHandle,
NCRYPT_WINDOW_HANDLE_PROPERTY,
handle,
handle.Length,
CngPropertyOptions.None)
.CheckStatus("NCRYPT_WINDOW_HANDLE_PROPERTY");
}
var message = uiContext.Message;
if (!string.IsNullOrEmpty(message))
{
NCryptSetProperty(
ngcKeyHandle,
NCRYPT_USE_CONTEXT_PROPERTY,
message,
(message.Length + 1) * 2,
CngPropertyOptions.None)
.CheckStatus("NCRYPT_USE_CONTEXT_PROPERTY");
}
}
/// <summary>
/// Creates a new instance of the <see cref="WinHelloProvider"/> class.
/// </summary>
/// <param name="message">The message.</param>
/// <param name="windowHandle">The window handle.</param>
/// <returns>A new instance of the <see cref="WinHelloProvider"/> class.</returns>
// ReSharper disable once UnusedMember.Global
public static WinHelloProvider CreateInstance(string message, IntPtr windowHandle)
{
if (!IsAvailable())
{
throw new AuthProviderIsUnavailableException("Windows Hello is not available.");
}
lock (Mutex)
{
if (!TryOpenPersistentKey(out var ngcKeyHandle))
{
CreatePersistentKey(true, AuthProviderUiContext.With(message, windowHandle)).Dispose();
}
ngcKeyHandle.Dispose();
var winHelloProvider = new WinHelloProvider(AuthProviderUiContext.With(message, windowHandle));
return(_instance ?? (_instance = winHelloProvider));
}
}
private WinHelloProvider(AuthProviderUiContext uIContext)
{
if (!TryOpenPersistentKey(out var ngcKeyHandle))
{
throw new AuthProviderInvalidKeyException("Persistent key does not exist.");
}
using (ngcKeyHandle)
{
if (!VerifyPersistentKeyIntegrity(ngcKeyHandle))
{
ngcKeyHandle.Close();
DeletePersistentKey();
throw new AuthProviderInvalidKeyException(InvalidatedKeyMessage);
}
}
_uiContext = uIContext;
_currentKeyName = _persistentKeyName.Value;
}
private static SafeNCryptKeyHandle CreatePersistentKey(bool overwriteExisting, AuthProviderUiContext uIContext)
{
NCryptOpenStorageProvider(
out var ngcProviderHandle,
MS_NGC_KEY_STORAGE_PROVIDER,
0).CheckStatus("NCryptOpenStorageProvider");
SafeNCryptKeyHandle ngcKeyHandle;
using (ngcProviderHandle)
{
NCryptCreatePersistedKey(
ngcProviderHandle,
out ngcKeyHandle,
BCRYPT_RSA_ALGORITHM,
_persistentKeyName.Value,
0,
overwriteExisting ? CngKeyCreationOptions.OverwriteExistingKey : CngKeyCreationOptions.None)
.CheckStatus("NCryptCreatePersistedKey");
var lengthProp = BitConverter.GetBytes(2048);
NCryptSetProperty(
ngcKeyHandle,
NCRYPT_LENGTH_PROPERTY,
lengthProp,
lengthProp.Length,
CngPropertyOptions.None)
.CheckStatus("NCRYPT_LENGTH_PROPERTY");
var keyUsage = BitConverter.GetBytes(NCRYPT_ALLOW_DECRYPT_FLAG | NCRYPT_ALLOW_SIGNING_FLAG);
NCryptSetProperty(
ngcKeyHandle,
NCRYPT_KEY_USAGE_PROPERTY,
keyUsage,
keyUsage.Length,
CngPropertyOptions.None)
.CheckStatus("NCRYPT_KEY_USAGE_PROPERTY");
var cacheType = BitConverter.GetBytes(NCRYPT_NGC_CACHE_TYPE_PROPERTY_AUTH_MANDATORY_FLAG);
try
{
NCryptSetProperty(
ngcKeyHandle,
NCRYPT_NGC_CACHE_TYPE_PROPERTY,
cacheType,
cacheType.Length,
CngPropertyOptions.None)
.CheckStatus("NCRYPT_NGC_CACHE_TYPE_PROPERTY");
}
catch
{
NCryptSetProperty(
ngcKeyHandle,
NCRYPT_NGC_CACHE_TYPE_PROPERTY_DEPRECATED,
cacheType,
cacheType.Length,
CngPropertyOptions.None)
.CheckStatus("NCRYPT_NGC_CACHE_TYPE_PROPERTY_DEPRECATED");
}
ApplyUiContext(ngcKeyHandle, uIContext);
NCryptFinalizeKey(ngcKeyHandle, 0).CheckStatus("NCryptFinalizeKey");
}
return(ngcKeyHandle);
}
