private static SafeBCryptKeyHandle ImportPublicKeyInfo(SafeCertContextHandle certContext)
{
IntPtr certHandle = certContext.DangerousGetHandle();
//Read the public key blob from the certificate
X509Native.CERT_CONTEXT pCertContext = (X509Native.CERT_CONTEXT)Marshal.PtrToStructure(certHandle, typeof(X509Native.CERT_CONTEXT));
IntPtr pSubjectPublicKeyInfo = new IntPtr((long)pCertContext.pCertInfo +
(long)Marshal.OffsetOf(typeof(X509Native.CERT_INFO), "SubjectPublicKeyInfo"));
X509Native.CERT_PUBLIC_KEY_INFO certPublicKeyInfo =
(X509Native.CERT_PUBLIC_KEY_INFO)Marshal.PtrToStructure(pSubjectPublicKeyInfo, typeof(X509Native.CERT_PUBLIC_KEY_INFO));
SafeBCryptKeyHandle publicKeyInfo = BCryptNative.ImportAsymmetricPublicKey(certPublicKeyInfo, 0);
// certContext needs to be valid through the call to BCryptNative.ImportAsymmetricPublicKey
// because certPublicKeyInfo structure contains pointers.
GC.KeepAlive(certContext);
return(publicKeyInfo);
}
private static ECDsa LegacyGetECDsaPublicKey(X509Certificate2 certificate)
{
if (certificate == null)
{
throw new ArgumentNullException("certificate");
}
if (!IsECDsa(certificate))
{
return(null);
}
SafeCertContextHandle safeCertContext = X509Native.GetCertificateContext(certificate);
IntPtr certHandle = safeCertContext.DangerousGetHandle();
//Read the public key blob from the certificate
X509Native.CERT_CONTEXT pCertContext = (X509Native.CERT_CONTEXT)Marshal.PtrToStructure(certHandle, typeof(X509Native.CERT_CONTEXT));
IntPtr pSubjectPublicKeyInfo = new IntPtr((long)pCertContext.pCertInfo +
(long)Marshal.OffsetOf(typeof(X509Native.CERT_INFO), "SubjectPublicKeyInfo"));
X509Native.CERT_PUBLIC_KEY_INFO certPublicKeyInfo = (X509Native.CERT_PUBLIC_KEY_INFO)Marshal.PtrToStructure(pSubjectPublicKeyInfo,
typeof(X509Native.CERT_PUBLIC_KEY_INFO));
CngKey key;
//Import the public key blob to BCRYPT_KEY_HANDLE
using (SafeBCryptKeyHandle bcryptKeyHandle = BCryptNative.ImportAsymmetricPublicKey(certPublicKeyInfo, 0))
{
if (bcryptKeyHandle.IsInvalid)
{
throw new CryptographicException("SR.GetString(SR.Cryptography_OpenInvalidHandle)");
}
key = LegacyBCryptHandleToNCryptHandle(bcryptKeyHandle);
}
GC.KeepAlive(safeCertContext);
return(new ECDsaCng(key));
}
