public static byte[] DeriveKey(CngKey externalPubKey, CngKey privateKey, int keyBitLength, byte[] algorithmId, byte[] partyVInfo, byte[] partyUInfo, byte[] suppPubInfo)
{
#if NET40 || NET461
using (var cng = new ECDiffieHellmanCng(privateKey))
{
using (SafeNCryptSecretHandle hSecretAgreement = cng.DeriveSecretAgreementHandle(externalPubKey))
{
using (var algIdBuffer = new NCrypt.NCryptBuffer(NCrypt.KDF_ALGORITHMID, algorithmId))
using (var pviBuffer = new NCrypt.NCryptBuffer(NCrypt.KDF_PARTYVINFO, partyVInfo))
using (var pvuBuffer = new NCrypt.NCryptBuffer(NCrypt.KDF_PARTYUINFO, partyUInfo))
using (var spiBuffer = new NCrypt.NCryptBuffer(NCrypt.KDF_SUPPPUBINFO, suppPubInfo))
{
using (var parameters = new NCrypt.NCryptBufferDesc(algIdBuffer, pviBuffer, pvuBuffer, spiBuffer))
{
uint derivedSecretByteSize;
uint status = NCrypt.NCryptDeriveKey(hSecretAgreement, "SP800_56A_CONCAT", parameters, null, 0, out derivedSecretByteSize, 0);
if (status != BCrypt.ERROR_SUCCESS)
{
throw new CryptographicException(string.Format("NCrypt.NCryptDeriveKey() failed with status code:{0}", status));
}
var secretKey = new byte[derivedSecretByteSize];
status = NCrypt.NCryptDeriveKey(hSecretAgreement, "SP800_56A_CONCAT", parameters, secretKey, derivedSecretByteSize, out derivedSecretByteSize, 0);
if (status != BCrypt.ERROR_SUCCESS)
{
throw new CryptographicException(string.Format("NCrypt.NCryptDeriveKey() failed with status code:{0}", status));
}
return(Arrays.LeftmostBits(secretKey, keyBitLength));
}
}
}
}
#elif NETSTANDARD1_4
throw new NotImplementedException("not yet");
#endif
}
public static byte[] DeriveKey(CngKey externalPubKey, CngKey privateKey, int keyBitLength, byte[] algorithmId, byte[] partyVInfo, byte[] partyUInfo, byte[] suppPubInfo)
{
uint num;
byte[] numArray;
using (ECDiffieHellmanCng eCDiffieHellmanCng = new ECDiffieHellmanCng(privateKey))
{
using (SafeNCryptSecretHandle safeNCryptSecretHandle = eCDiffieHellmanCng.DeriveSecretAgreementHandle(externalPubKey))
{
using (NCrypt.NCryptBuffer nCryptBuffer = new NCrypt.NCryptBuffer(8, algorithmId))
{
using (NCrypt.NCryptBuffer nCryptBuffer1 = new NCrypt.NCryptBuffer(10, partyVInfo))
{
using (NCrypt.NCryptBuffer nCryptBuffer2 = new NCrypt.NCryptBuffer(9, partyUInfo))
{
using (NCrypt.NCryptBuffer nCryptBuffer3 = new NCrypt.NCryptBuffer(11, suppPubInfo))
{
using (NCrypt.NCryptBufferDesc nCryptBufferDesc = new NCrypt.NCryptBufferDesc(new NCrypt.NCryptBuffer[] { nCryptBuffer, nCryptBuffer1, nCryptBuffer2, nCryptBuffer3 }))
{
uint num1 = NCrypt.NCryptDeriveKey(safeNCryptSecretHandle, "SP800_56A_CONCAT", nCryptBufferDesc, null, 0, out num, 0);
if (num1 != 0)
{
throw new CryptographicException(string.Format("NCrypt.NCryptDeriveKey() failed with status code:{0}", num1));
}
byte[] numArray1 = new byte[num];
num1 = NCrypt.NCryptDeriveKey(safeNCryptSecretHandle, "SP800_56A_CONCAT", nCryptBufferDesc, numArray1, num, out num, 0);
if (num1 != 0)
{
throw new CryptographicException(string.Format("NCrypt.NCryptDeriveKey() failed with status code:{0}", num1));
}
numArray = Arrays.LeftmostBits(numArray1, keyBitLength);
}
}
}
}
}
}
}
return(numArray);
}
