private static ECDiffieHellmanCngPublicKey GetECDiffieHellmanCngPublicKey(X509Certificate2 cert)
{
var keyAlgoDerBytes = cert.GetKeyAlgorithmParameters();
var keyAlgoAsn1 = new Asn1InputStream(keyAlgoDerBytes).ReadObject();
var keyAlgoOid = new DerObjectIdentifier(keyAlgoAsn1.ToString());
var xmlImport = Rfc4050XmlMaker("ECDH", keyAlgoOid, cert);
var ecDiffieHellmanCngPublicKey = ECDiffieHellmanCngPublicKey.FromXmlString(xmlImport);
return ecDiffieHellmanCngPublicKey;
}
public static DSA GetDSAPublicKey(this X509Certificate2 certificate)
{
if (certificate == null)
{
throw new ArgumentNullException("certificate");
}
if (!IsDSA(certificate))
{
return(null);
}
unsafe
{
DSAParameters dp = new DSAParameters();
SafeLocalAllocHandle dssKeyLocalAlloc = null;
try
{
byte[] encodedPublicKey = certificate.PublicKey.EncodedKeyValue.RawData;
uint cbDSSKey;
if (!CapiNative.DecodeObject((IntPtr)(CapiNative.X509_DSS_PUBLICKEY), encodedPublicKey, out dssKeyLocalAlloc, out cbDSSKey))
{
throw new CryptographicException(Marshal.GetLastWin32Error());
}
if (cbDSSKey < Marshal.SizeOf(typeof(CapiNative.CRYPTOAPI_BLOB)))
{
throw new CryptographicException();
}
CapiNative.CRYPTOAPI_BLOB *pDssKeyBlob = (CapiNative.CRYPTOAPI_BLOB *)(dssKeyLocalAlloc.DangerousGetHandle());
dp.Y = ToBigEndianByteArray(*pDssKeyBlob);
}
finally
{
if (dssKeyLocalAlloc != null)
{
dssKeyLocalAlloc.Dispose();
dssKeyLocalAlloc = null;
}
}
SafeLocalAllocHandle dssParametersLocalHandle = null;
try
{
byte[] encodedKeyAlgorithmParameters = certificate.GetKeyAlgorithmParameters();
uint cbDSSParams;
if (!CapiNative.DecodeObject((IntPtr)(CapiNative.X509_DSS_PARAMETERS), encodedKeyAlgorithmParameters, out dssParametersLocalHandle, out cbDSSParams))
{
throw new CryptographicException(Marshal.GetLastWin32Error());
}
if (cbDSSParams < Marshal.SizeOf(typeof(CapiNative.CERT_DSS_PARAMETERS)))
{
throw new CryptographicException();
}
CapiNative.CERT_DSS_PARAMETERS *pDssParameters = (CapiNative.CERT_DSS_PARAMETERS *)(dssParametersLocalHandle.DangerousGetHandle());
dp.P = ToBigEndianByteArray(pDssParameters->p);
dp.Q = ToBigEndianByteArray(pDssParameters->q);
dp.G = ToBigEndianByteArray(pDssParameters->g);
}
finally
{
if (dssParametersLocalHandle != null)
{
dssParametersLocalHandle.Dispose();
dssParametersLocalHandle = null;
}
}
DSACng dsaCng = new DSACng();
dsaCng.ImportParameters(dp);
return(dsaCng);
}
}