public static ByteString DecryptString(Hash em, ECKeyPair keyPair)
{
#if NETCOREAPP
throw new NotImplementedException();
#else
ECParameters parameters = new ECParameters();
byte[] ems = em;
parameters.Q.X = ems.Skip(1).Take(32).ToArray();
parameters.Q.Y = ems.Skip(33).Take(32).ToArray();
parameters.D = keyPair.D;
parameters.Curve = keyPair.ECParameters.Curve;
parameters.Validate();
using (var ecDiffieHellmanCng = new ECDiffieHellmanCng())
{
ecDiffieHellmanCng.ImportParameters(parameters);
var ek = ecDiffieHellmanCng.DeriveKeyFromHash(ecDiffieHellmanCng.PublicKey, HashAlgorithmName.SHA256, null, new byte[] { 0, 0, 0, 1 });
using (RijndaelManaged aes = new RijndaelManaged())
{
aes.Padding = PaddingMode.PKCS7;
var d = aes.CreateDecryptor(ek, new byte[16]);
var bs = d.TransformFinalBlock(ems.Skip(65).Take(ems.Length - 65 - 32).ToArray(), 0,
ems.Length - 65 - 32);
return(bs);
}
}
#endif
}
public static void HashAlgorithm_SupportsOtherECDHImplementations()
{
using ECDiffieHellman ecdh = ECDiffieHellman.Create(ECCurve.NamedCurves.nistP256);
using ECDiffieHellmanCng ecdhCng = new ECDiffieHellmanCng(ECCurve.NamedCurves.nistP256);
byte[] key1 = ecdhCng.DeriveKeyFromHash(ecdh.PublicKey, HashAlgorithmName.SHA256);
byte[] key2 = ecdh.DeriveKeyFromHash(ecdhCng.PublicKey, HashAlgorithmName.SHA256);
Assert.Equal(key1, key2);
}
public static void Equivalence_Hash(HashAlgorithmName algorithm, bool prepend, bool append)
{
using (ECDiffieHellmanCng ecdh = NewDefaultECDHCng())
using (ECDiffieHellmanPublicKey publicKey = ecdh.PublicKey)
{
byte[] secretPrepend = prepend ? new byte[3] : null;
byte[] secretAppend = append ? new byte[4] : null;
byte[] newWay = ecdh.DeriveKeyFromHash(publicKey, algorithm, secretPrepend, secretAppend);
ecdh.HashAlgorithm = new CngAlgorithm(algorithm.Name);
ecdh.SecretPrepend = secretPrepend;
ecdh.SecretAppend = secretAppend;
ecdh.KeyDerivationFunction = ECDiffieHellmanKeyDerivationFunction.Hash;
byte[] oldWay = ecdh.DeriveKeyMaterial(publicKey);
Assert.Equal(newWay, oldWay);
}
}
