BIP32

An implementation of the BIP32 spec for Hierarchical Deterministic Bitcoin addresses. No superimposing wallet structure has been defined.

Examples

You can use this library in two ways; one with a serialized public or private HD key or with a hex encoded seed.

Look at the tests to see more elaborate uses.

With a seed

  Chain chain = Chain.seed(hex.encode(utf8.encode("some seed")));
  ExtendedPrivateKey key = chain.forPath("m/0/100");
  print(key);
  // => xprv9ww7sMFLzJN5LhdyGB9zfhm9MAVZ8P97iTWQtVeAg2rA9MPZfJUESWe6NaSu44zz44QBjWtwH9HNfJ4vFiUwfrTCvf7AGrgYpXe17bfh2Je

The key has a field called key which contains a BigInt. This is the actual key.

Importing a HD private key

  Chain chain = Chain.import("xprv9s21ZrQH143K3QTDL4LXw2F7HEK3wJUD2nW2nRk4stbPy6cq3jPPqjiChkVvvNKmPGJxWUtg6LnF5kejMRNNU3TGtRBeJgk33yuGBxrMPHi");
  ExtendedPrivateKey childKey = chain.forPath("m/0/100");

Importing a HD public key

  Chain chain = Chain.import("xpub661MyMwAqRbcFtXgS5sYJABqqG9YLmC4Q1Rdap9gSE8NqtwybGhePY2gZ29ESFjqJoCu1Rupje8YtGqsefD265TMg7usUDFdp6W1EGMcet8");
  ExtendedPublic childKey = chain.forPath("M/0/100");

The key has a field called q which contains a ECPoint. This is the actual key.

Please note that trying to generate a private key from a public key will throw an exception.

Exceptions

There is a tiny chance a child key derivation fails. Please catch the appropriate exceptions in your code.

These exceptions are:

KeyZero
KeyBiggerThanOrder
KeyInfinite

Installing

Add it to your pubspec.yaml:

dependencies:
  bip32: ^0.1.0

Licence overview

All files in this repository fall under the license specified in COPYING. The project is licensed as AGPL with a lesser clause. It may be used within a proprietary project, but the core library and any changes to it must be published online. Source code for this library must always remain free for everybody to access.

Thanks

Without the guiding code of go-bip32 and money-tree projects this library would have been a significantly bigger struggle.