private static byte[] EncryptKey(byte[] keyhalf1, byte[] keyhalf2, byte[] derived)
{
var derivedhalf1 = derived.SafeSubarray(0, 32);
var derivedhalf2 = derived.SafeSubarray(32, 32);
var encryptedhalf1 = new byte[16];
var encryptedhalf2 = new byte[16];
#if USEBC || WINDOWS_UWP
var aes = BitcoinEncryptedSecret.CreateAES256(true, derivedhalf2);
#else
var aes = CreateAES256();
aes.Key = derivedhalf2;
var encrypt = aes.CreateEncryptor();
#endif
for (int i = 0; i < 16; i++)
{
derivedhalf1[i] = (byte)(keyhalf1[i] ^ derivedhalf1[i]);
}
#if USEBC || WINDOWS_UWP
aes.ProcessBytes(derivedhalf1, 0, 16, encryptedhalf1, 0);
aes.ProcessBytes(derivedhalf1, 0, 16, encryptedhalf1, 0);
#else
encrypt.TransformBlock(derivedhalf1, 0, 16, encryptedhalf1, 0);
#endif
for (int i = 0; i < 16; i++)
{
derivedhalf1[16 + i] = (byte)(keyhalf2[i] ^ derivedhalf1[16 + i]);
}
#if USEBC || WINDOWS_UWP
aes.ProcessBytes(derivedhalf1, 16, 16, encryptedhalf2, 0);
aes.ProcessBytes(derivedhalf1, 16, 16, encryptedhalf2, 0);
#else
encrypt.TransformBlock(derivedhalf1, 16, 16, encryptedhalf2, 0);
#endif
return(encryptedhalf1.Concat(encryptedhalf2).ToArray());
}
