public byte[] GetPrivateKeyBlob(IntPtr context, KeyDerivation derive)
{
bool result, shouldFree = false;
NativeMethods.KeySpec addInfo = 0;
IntPtr hProv = IntPtr.Zero, hExportKey = IntPtr.Zero,
phSessionKey = IntPtr.Zero, userKey = IntPtr.Zero;
try {
result = NativeMethods.CryptAcquireCertificatePrivateKey(context, 0, IntPtr.Zero, ref hProv, ref addInfo, ref shouldFree);
if (!result)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
result = NativeMethods.CryptGetUserKey(hProv, (uint)addInfo, ref userKey);
if (!result)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
CheckPermission(userKey);
result = NativeMethods.CryptGenKey(hProv, EphemAlgId, 0, out phSessionKey);
if (!result)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
uint dhOIDsz = 50;
var dhOID = new byte[dhOIDsz];
result = NativeMethods.CryptGetKeyParam(phSessionKey, NativeMethods.KP_DHOID, dhOID, ref dhOIDsz, 0);
if (!result)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
dhOID = dhOID.Take((int)dhOIDsz - 1).ToArray();
var dhOIDstr = Encoding.ASCII.GetString(dhOID);
uint hashOIDsz = 50;
var hashOID = new byte[hashOIDsz];
result = NativeMethods.CryptGetKeyParam(phSessionKey, NativeMethods.KP_HASHOID, hashOID, ref hashOIDsz, 0);
if (!result)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
hashOID = hashOID.Take((int)hashOIDsz - 1).ToArray();
var hashOIDstr = Encoding.ASCII.GetString(hashOID);
uint pbdatalen = 0;
result = NativeMethods.CryptExportKey(phSessionKey, IntPtr.Zero, NativeMethods.PUBLICKEYBLOB, 0, null, ref pbdatalen);
if (!result)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
SessionKey = new byte[pbdatalen];
result = NativeMethods.CryptExportKey(phSessionKey, IntPtr.Zero, NativeMethods.PUBLICKEYBLOB, 0, SessionKey, ref pbdatalen);
if (!result)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
var blob = new CRYPT_PUBLICKEYBLOB {
reserved = 0,
bType = 6,
aiKeyAlg = (uint)KeyAlgId,
bVersion = 0x20,
Magic = NativeMethods.GR3410_1_MAGIC,
BitLen = PublicKeyLength
};
var dhOid = new DerObjectIdentifier(dhOIDstr);
var hashOid = new DerObjectIdentifier(hashOIDstr);
var seq = new DerSequence(dhOid, hashOid);
var keyData = seq.GetDerEncoded();
Array.Resize(ref keyData, 24);
blob.KeyData1 = BitConverter.ToUInt64(keyData, 0);
blob.KeyData2 = BitConverter.ToUInt64(keyData, 8);
blob.KeyData3 = BitConverter.ToUInt64(keyData, 16);
var blobData = blob.GetBytes();
var pbdata2 = new byte[BlobLength];
for (int i = 0; i < KeyOffset; ++i)
{
pbdata2[i] = blobData[i];
}
derive.Init(dhOid, hashOid);
var genkey = derive.GetPublicKeyBytes();
for (int i = 0, j = KeyOffset; i < genkey.Length; ++i, ++j)
{
pbdata2[j] = genkey[i];
}
result = NativeMethods.CryptImportKey(hProv, pbdata2, BlobLength, phSessionKey, 0, ref hExportKey);
if (!result)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
result = NativeMethods.CryptSetKeyParam(hExportKey, (int)NativeMethods.KP_ALGID, BitConverter.GetBytes((uint)ExportAlgId), 0);
if (!result)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
uint pkSize = 0;
result = NativeMethods.CryptExportKey(userKey, hExportKey, NativeMethods.PRIVATEKEYBLOB, 0, null, ref pkSize);
if (!result)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
var ret = new byte[pkSize];
result = NativeMethods.CryptExportKey(userKey, hExportKey, NativeMethods.PRIVATEKEYBLOB, 0, ret, ref pkSize);
if (!result)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
return(ret);
} catch (Win32Exception e) {
throw new CryptographicException(e.Message, e);
} finally {
if (shouldFree)
{
NativeMethods.CryptReleaseContext(hProv, 0);
}
if (hExportKey != IntPtr.Zero)
{
NativeMethods.CryptDestroyKey(hExportKey);
}
if (phSessionKey != IntPtr.Zero)
{
NativeMethods.CryptDestroyKey(phSessionKey);
}
if (userKey != IntPtr.Zero)
{
NativeMethods.CryptDestroyKey(userKey);
}
}
}
private static void ExportPrivateKey(SafeHandle context, byte[] genkey, out byte[] sessionKeyData, out byte[] privKeyData)
{
bool result, shouldFree = false;
NativeMethods.KeySpec addInfo = 0;
IntPtr provOrKey = IntPtr.Zero, hExportKey = IntPtr.Zero,
phSessionKey = IntPtr.Zero, provInfoPtr = IntPtr.Zero, userKey = IntPtr.Zero;
try {
result = NativeMethods.CryptAcquireCertificatePrivateKey(context, 0, IntPtr.Zero, ref provOrKey, ref addInfo, ref shouldFree);
if (!result)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
uint pcbData = 0;
result = NativeMethods.CertGetCertificateContextProperty(context, NativeMethods.CERT_KEY_PROV_INFO_PROP_ID, provInfoPtr, ref pcbData);
if (!result)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
provInfoPtr = Marshal.AllocHGlobal((int)pcbData);
result = NativeMethods.CertGetCertificateContextProperty(context, NativeMethods.CERT_KEY_PROV_INFO_PROP_ID, provInfoPtr, ref pcbData);
if (!result)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
var provInfo = (NativeMethods.CRYPT_KEY_PROV_INFO)Marshal.PtrToStructure(provInfoPtr, typeof(NativeMethods.CRYPT_KEY_PROV_INFO));
result = NativeMethods.CryptGetUserKey(provOrKey, (uint)addInfo, ref userKey);
if (!result)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
CheckPermission(userKey);
result = NativeMethods.CryptGenKey(provOrKey, NativeMethods.ALG_ID.CALG_DH_EL_EPHEM, 0, out phSessionKey);
if (!result)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
uint pbdatalen = 100;
sessionKeyData = new byte[pbdatalen];
result = NativeMethods.CryptExportKey(phSessionKey, IntPtr.Zero, NativeMethods.PUBLICKEYBLOB, 0, sessionKeyData, ref pbdatalen);
if (!result)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
var blob = new CRYPT_PUBLICKEYBLOB
{
reserved = 0,
bType = 6,
aiKeyAlg = (uint)NativeMethods.ALG_ID.CALG_GR3410EL,
bVersion = 0x20,
Magic = NativeMethods.GR3410_1_MAGIC,
BitLen = 512,
// bASN1GostR3410_94_PublicKeyParameters
KeyData1 = 0x07061230,
KeyData2 = 0x0203852A,
KeyData3 = 0x06002402,
KeyData4 = 0x03852A07,
KeyData5 = 0x011E0202
};
var blobData = blob.GetBytes();
var pbdata2 = new byte[100];
for (int i = 0; i < blobData.Length; ++i)
{
pbdata2[i] = blobData[i];
}
for (int i = 0, j = 36; i < genkey.Length; ++i, ++j)
{
pbdata2[j] = genkey[i];
}
result = NativeMethods.CryptImportKey(provOrKey, pbdata2, pbdatalen, phSessionKey, 0, ref hExportKey);
if (!result)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
// export wrapped key
var alg = BitConverter.GetBytes((uint)NativeMethods.ALG_ID.CALG_PRO_EXPORT);
result = NativeMethods.CryptSetKeyParam(hExportKey, (int)NativeMethods.KP_ALGID, alg, 0);
if (!result)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
uint pkSize = 0;
result = NativeMethods.CryptExportKey(userKey, hExportKey, NativeMethods.PRIVATEKEYBLOB, 0, null, ref pkSize);
if (!result)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
privKeyData = new byte[pkSize];
result = NativeMethods.CryptExportKey(userKey, hExportKey, NativeMethods.PRIVATEKEYBLOB, 0, privKeyData, ref pkSize);
if (!result)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
} catch (Win32Exception e) {
throw new CryptographicException(e.Message, e);
} finally {
if (shouldFree)
{
NativeMethods.CryptReleaseContext(provOrKey, 0);
}
if (provInfoPtr != IntPtr.Zero)
{
Marshal.FreeHGlobal(provInfoPtr);
}
if (hExportKey != IntPtr.Zero)
{
NativeMethods.CryptDestroyKey(hExportKey);
}
if (phSessionKey != IntPtr.Zero)
{
NativeMethods.CryptDestroyKey(phSessionKey);
}
if (userKey != IntPtr.Zero)
{
NativeMethods.CryptDestroyKey(userKey);
}
}
}
