Beispiel #1
0
 private static RawKeyBytes deriveChildKeyBytesFromPublic(
     DeterministicKey parent, ChildNumber childNumber) throws HDDerivationException {
   checkArgument(!childNumber.isHardened(), "Can't use private derivation with public keys only.");
   byte[] parentPublicKey = ECKey.compressPoint(parent.getPubKeyPoint()).getEncoded();
   assert parentPublicKey.length == 33 : parentPublicKey.length;
   ByteBuffer data = ByteBuffer.allocate(37);
   data.put(parentPublicKey);
   data.putInt(childNumber.i());
   byte[] i = HDUtils.hmacSha512(parent.getChainCode(), data.array());
   assert i.length == 64 : i.length;
   byte[] il = Arrays.copyOfRange(i, 0, 32);
   byte[] chainCode = Arrays.copyOfRange(i, 32, 64);
   BigInteger ilInt = new BigInteger(1, il);
   assertLessThanN(ilInt, "Illegal derived key: I_L >= n");
   ECPoint Ki = ECKey.CURVE.getG().multiply(ilInt).add(parent.getPubKeyPoint());
   assertNonInfinity(Ki, "Illegal derived key: derived public key equals infinity.");
   return new RawKeyBytes(Ki.getEncoded(true), chainCode);
 }
Beispiel #2
0
 private static RawKeyBytes deriveChildKeyBytesFromPrivate(
     DeterministicKey parent, ChildNumber childNumber) throws HDDerivationException {
   checkArgument(parent.hasPrivKey(), "Parent key must have private key bytes for this method.");
   byte[] parentPublicKey = ECKey.compressPoint(parent.getPubKeyPoint()).getEncoded();
   assert parentPublicKey.length == 33 : parentPublicKey.length;
   ByteBuffer data = ByteBuffer.allocate(37);
   if (childNumber.isHardened()) {
     data.put(parent.getPrivKeyBytes33());
   } else {
     data.put(parentPublicKey);
   }
   data.putInt(childNumber.i());
   byte[] i = HDUtils.hmacSha512(parent.getChainCode(), data.array());
   assert i.length == 64 : i.length;
   byte[] il = Arrays.copyOfRange(i, 0, 32);
   byte[] chainCode = Arrays.copyOfRange(i, 32, 64);
   BigInteger ilInt = new BigInteger(1, il);
   assertLessThanN(ilInt, "Illegal derived key: I_L >= n");
   final BigInteger priv = parent.getPrivKey();
   BigInteger ki = priv.add(ilInt).mod(ECKey.CURVE.getN());
   assertNonZero(ki, "Illegal derived key: derived private key equals 0.");
   return new RawKeyBytes(ki.toByteArray(), chainCode);
 }