/// <summary> /// Recreates the private key of the parent from the private key of the child /// combinated with the public key of the parent (hardened children cannot be /// used to recreate the parent). /// </summary> public ExtKey GetParentExtKey(ExtPubKey parent) { if (parent == null) { throw new ArgumentNullException(nameof(parent)); } if (Depth == 0) { throw new InvalidOperationException("This ExtKey is the root key of the HD tree"); } if (IsHardened) { throw new InvalidOperationException("This private key is hardened, so you can't get its parent"); } var expectedFingerPrint = parent.CalculateChildFingerprint(); if (parent.Depth != Depth - 1 || !expectedFingerPrint.SequenceEqual(_vchFingerprint)) { throw new ArgumentException("The parent ExtPubKey is not the immediate parent of this ExtKey", nameof(parent)); } byte[] l = null; var ll = new byte[32]; var lr = new byte[32]; var pubKey = parent.PubKey.ToBytes(); l = Hashes.BIP32Hash(parent._vchChainCode, _nChild, pubKey[0], pubKey.SafeSubArray(1)); Array.Copy(l, ll, 32); Array.Copy(l, 32, lr, 0, 32); var ccChild = lr; var parse256LL = new BigInteger(1, ll); var N = ECKey.Curve.N; if (!ccChild.SequenceEqual(_vchChainCode)) { throw new InvalidOperationException( "The derived chain code of the parent is not equal to this child chain code"); } var keyBytes = PrivateKey.ToBytes(); var key = new BigInteger(1, keyBytes); var kPar = key.Add(parse256LL.Negate()).Mod(N); var keyParentBytes = kPar.ToByteArrayUnsigned(); if (keyParentBytes.Length < 32) { keyParentBytes = new byte[32 - keyParentBytes.Length].Concat(keyParentBytes).ToArray(); } var parentExtKey = new ExtKey { _vchChainCode = parent._vchChainCode, _nDepth = parent.Depth, _vchFingerprint = parent.Fingerprint, _nChild = parent._nChild, _key = new Key(keyParentBytes) }; return(parentExtKey); }
/// <summary> /// Constructor. Creates a representation of an extended key, within the specified network. /// </summary> public BitcoinExtKey(ExtKey key, Network network) : base(key, network) { }
public bool IsParentOf(ExtKey childKey) { return(childKey.IsChildOf(this)); }