private CngKey ImportGenericPrivateKey(EcKeyCurveParameters curveParameters, byte[] x, byte[] y, byte[] d)
{
/* struct BCRYPT_ECCFULLKEY_BLOB
* {
* ULONG dwMagic; // BCRYPT_ECDSA_PUBLIC_GENERIC_MAGIC or BCRYPT_ECDSA_PRIVATE_GENERIC_MAGIC
* BCRYPT_ECC_PARAMETER_HEADER curveParameters;
* BYTE Qx[cbFieldLength] // X-coordinate of the public point.
* BYTE Qy[cbFieldLength] // Y-coordinate of the public point.
* BYTE d[cbSubgroupOrder] // Private key. Zero if only public key is required.
* }
*/
var keyBlob = new byte[curveParameters.KeyBlobSize];
using (var writer = new BinaryWriter(new MemoryStream(keyBlob)))
{
writer.Write(NativeMethods.BCRYPT_ECDSA_PRIVATE_GENERIC_MAGIC);
curveParameters.WriteTo(writer);
var size = curveParameters.KeySizeInBytes;
AlignAndWrite(writer, x, size, nameof(x));
AlignAndWrite(writer, y, size, nameof(y));
AlignAndWrite(writer, d, size, nameof(d));
}
return(CngKey.Import(keyBlob, CngKeyBlobFormat_Generic_Private));
}
private CngKey ImportGenericKey(EcKeyCurveParameters curveParameters, byte[] x, byte[] y, byte[] d)
{
if (d == null || IsZero(d))
{
return(ImportGenericPublicKey(curveParameters, x, y));
}
return(ImportGenericPrivateKey(curveParameters, x, y, d));
}
