public static ExtendedKey from_slice(Secp256K1 secp, byte[] slice)
{
// TODO change when ser. ext. size is fixed
if (slice.Length != 79)
{
throw new Exception("InvalidSliceSize");
}
var ext = new ExtendedKey {
Depth = slice[0]
};
var rootKeyBytes = slice.Skip(1).Take(10).ToArray();
ext.RootKeyId = ExtKey.Identifier.From_bytes(rootKeyBytes);
var nchildBytes = slice.Skip(11).Take(4).ToArray();
Array.Reverse(nchildBytes);
ext.NChild = BitConverter.ToUInt32(nchildBytes, 0);
ext.Chaincode = slice.Skip(15).Take(32).ToArray();
var keyBytes = slice.Skip(47).Take(32).ToArray();
ext.Key = SecretKey.From_slice(secp, keyBytes);
return(ext);
}
/// Creates a new extended master key from a seed
public static ExtendedKey from_seed(Secp256K1 secp, byte[] seed)
{
switch (seed.Length)
{
case 16:
case 32:
case 64:
break;
default:
throw new Exception("InvalidSeedSize");
}
var keyData = Encoding.ASCII.GetBytes("Mimble seed");
var blake2B = new HMACBlake2B(keyData, 512);
var derived = blake2B.ComputeHash(seed);
var chaincode = derived.Skip(32).ToArray();
var secretKeyBytes = derived.Take(32).ToArray();
var secretKey = SecretKey.From_slice(secp, secretKeyBytes);
var ext = new ExtendedKey
{
Depth = 0,
RootKeyId = ExtKey.Identifier.Zero(),
NChild = 0,
Chaincode = chaincode,
Key = secretKey,
};
ext.RootKeyId = ext.Identifier(secp);
return(ext);
}
