C# CngKey.Dispose方法代碼示例

        private static X509Certificate2 CreateSelfSignedCertificate(CngKey key, X500DistinguishedName subjectName)
        {
            using (SafeCertContextHandle selfSignedCertHandle = CreateSelfSignedCertificate(key,
                                                                                            true,
                                                                                            subjectName.RawData,
                                                                                            X509CertificateCreationOptions.None, // NONE
                                                                                            RsaSha1Oid,
                                                                                            DateTime.UtcNow,
                                                                                            DateTime.UtcNow.AddYears(1)))
            {
                X509Certificate2 certificate = null;
                bool addedRef = false;
                RuntimeHelpers.PrepareConstrainedRegions();
                try
                {
                    selfSignedCertHandle.DangerousAddRef(ref addedRef);
                    certificate = new X509Certificate2(selfSignedCertHandle.DangerousGetHandle());
                }
                finally
                {
                    if (addedRef)
                    {
                        selfSignedCertHandle.DangerousRelease();
                    }
                }

                key.Dispose();

                return certificate;
            }
        }

        /// <summary>
        ///     Wrap an existing key handle with a CngKey object
        /// </summary>
        public static CngKey Open(SafeNCryptKeyHandle keyHandle, CngKeyHandleOpenOptions keyHandleOpenOptions)
        {
            if (keyHandle == null)
                throw new ArgumentNullException("keyHandle");
            if (keyHandle.IsClosed || keyHandle.IsInvalid)
                throw new ArgumentException(SR.Cryptography_OpenInvalidHandle, "keyHandle");

            SafeNCryptKeyHandle keyHandleCopy = keyHandle.Duplicate();

            // Get a handle to the key's provider.
            SafeNCryptProviderHandle providerHandle = new SafeNCryptProviderHandle();
            IntPtr rawProviderHandle = keyHandle.GetPropertyAsIntPtr(KeyPropertyName.ProviderHandle, CngPropertyOptions.None);
            providerHandle.SetHandleValue(rawProviderHandle);

            // Set up a key object wrapping the handle
            CngKey key = null;
            try
            {
                key = new CngKey(providerHandle, keyHandleCopy);
                bool openingEphemeralKey = (keyHandleOpenOptions & CngKeyHandleOpenOptions.EphemeralKey) == CngKeyHandleOpenOptions.EphemeralKey;

                //
                // If we're wrapping a handle to an ephemeral key, we need to make sure that IsEphemeral is
                // set up to return true.  In the case that the handle is for an ephemeral key that was created
                // by the CLR, then we don't have anything to do as the IsEphemeral CLR property will already
                // be setup.  However, if the key was created outside of the CLR we will need to setup our
                // ephemeral detection property.
                // 
                // This enables consumers of CngKey objects to always be able to rely on the result of
                // calling IsEphemeral, and also allows them to safely access the Name property.
                // 
                // Finally, if we detect that this is an ephemeral key that the CLR created but we were not
                // told that it was an ephemeral key we'll throw an exception.  This prevents us from having
                // to decide who to believe -- the key property or the caller of the API.  Since other code
                // relies on the ephemeral flag being set properly to avoid tripping over bugs in CNG, we
                // need to reject the case that we suspect that the flag is incorrect.
                // 

                if (!key.IsEphemeral && openingEphemeralKey)
                {
                    key.IsEphemeral = true;
                }
                else if (key.IsEphemeral && !openingEphemeralKey)
                {
                    throw new ArgumentException(SR.Cryptography_OpenEphemeralKeyHandleWithoutEphemeralFlag, "keyHandleOpenOptions");
                }
            }
            catch
            {
                // Make sure that we don't leak the handle the CngKey duplicated
                if (key != null)
                    key.Dispose();

                throw;
            }

            return key;
        }

 public static CngKey Open(SafeNCryptKeyHandle keyHandle, CngKeyHandleOpenOptions keyHandleOpenOptions)
 {
     if (keyHandle == null)
     {
         throw new ArgumentNullException("keyHandle");
     }
     if (keyHandle.IsClosed || keyHandle.IsInvalid)
     {
         throw new ArgumentException(System.SR.GetString("Cryptography_OpenInvalidHandle"), "keyHandle");
     }
     SafeNCryptKeyHandle handle = keyHandle.Duplicate();
     SafeNCryptProviderHandle kspHandle = new SafeNCryptProviderHandle();
     RuntimeHelpers.PrepareConstrainedRegions();
     try
     {
     }
     finally
     {
         IntPtr newHandleValue = NCryptNative.GetPropertyAsIntPtr(keyHandle, "Provider Handle", CngPropertyOptions.None);
         kspHandle.SetHandleValue(newHandleValue);
     }
     CngKey key = null;
     bool flag = false;
     try
     {
         key = new CngKey(kspHandle, handle);
         bool flag2 = (keyHandleOpenOptions & CngKeyHandleOpenOptions.EphemeralKey) == CngKeyHandleOpenOptions.EphemeralKey;
         if (!key.IsEphemeral && flag2)
         {
             key.IsEphemeral = true;
         }
         else if (key.IsEphemeral && !flag2)
         {
             throw new ArgumentException(System.SR.GetString("Cryptography_OpenEphemeralKeyHandleWithoutEphemeralFlag"), "keyHandleOpenOptions");
         }
         flag = true;
     }
     finally
     {
         if (!flag && (key != null))
         {
             key.Dispose();
         }
     }
     return key;
 }