How to iterate through BIP44 addresses?

[shayanb]

I'm trying to use eth-lightwallet to generate BIP32/44 style addresses using custom paths, let's say:

BasePath = m'/0'/0''

Address 1= m'/0'/0'/1
Address 2= m'/0'/0'/2
Address 3= m'/0'/0'/3
...

The way eth-lightwallet seems to be working is by using ks.generateNewAddress(pwDerivedKey, 1); you'd get the next address but I couldn't find a way to get either the path for that address or input the custom path to generate the address in the path I want.

There's a way to iterate through the addresses which is a bit hacky, something like the following:

BasePath = m'/0'/0'/0'

Address 1= m'/0'/0'/1/1
Address 2= m'/0'/0'/2/1
Address 3= m'/0'/0'/3/1
...

Here is the source code for such iteration:

function generateNewAddress (seed, password, HdPathString, newAddressIdentifier, done) {
  // newAddressIdentifier is the incremental value for new address
  // the final path is basically HdPathString/newAddressIdentifier
  const finalHdPath = HdPathString + '/' + newAddressIdentifier.toString() + "'";
  console.log('finalHdPath', finalHdPath);

  lightwallet.keystore.deriveKeyFromPassword(password, function (err, pwDerivedKey) {
    var ks = new lightwallet.keystore(secretSeed, pwDerivedKey, finalHdPath);

    ks.generateNewAddress(pwDerivedKey, 1);
    var addr = ks.getAddresses()[0];
    console.log('addr', addr);
    var privKey = ks.exportPrivateKey(addr, pwDerivedKey, finalHdPath);
    const retObj = {address: addr,
      privateKey: privKey};
    done(null, retObj);
  });
}

The ^ solution is using the deprecated function which will be removed on next updates.

However using the new method KeyStore.createVault() even this hack is not possible as it would throw exception.

this works fine when the finalHdPath is m/0'/0'/0'. but fails as soon as we try to run it using any other default path:

function generateNewAddress (seed, password, HdPathString, newAddressIdentifier, done) {
  // newAddressIdentifier is the incremental value for new address
  // the final path is basically HdPathString/newAddressIdentifier
  const finalHdPath = HdPathString + '/' + newAddressIdentifier.toString() + "'";
  console.log('finalHdPath', finalHdPath);

  lightwallet.keystore.createVault({
    password: password,
    seedPhrase: secretSeed,
    HdPathString: finalHdPath
  }, function (err, ks) {
    if (err) done(err);
    ks.keyFromPassword(password, function (err, pwDerivedKey) {
      if (err) done(err);
      ks.generateNewAddress(pwDerivedKey, 1, finalHdPath); // generateNewAddress(pwDerivedKey, [num,] [hdPathString])
      console.log(ks.getAddresses());
      var addr = ks.getAddresses()[0];
      var privKey = ks.exportPrivateKey(addr, pwDerivedKey, finalHdPath);
      console.log(ks.defaultHdPathString);
      console.log('addr', addr);
      const retObj = {address: addr,
        privateKey: privKey};
      done(null, retObj);
    });
  });
}

for input m/0'/0'/0':

[ 'fff3a90735a619bd1a5780450b446d1515928b68' ]
m/0'/0'/0'
addr fff3a90735a619bd1a5780450b446d1515928b68
{ address: 'fff3a90735a619bd1a5780450b446d1515928b68',
  privateKey: 'fa746519af5b0bb64163d96bb13548e7e15410080e45ac8df388b9568f01042a' }

for input m/0'/0'/1':

hdPathString m/0'/0'/1'
this.ksData[hdPathString] undefined
/token_eth_sweeper/testFlow.js:43
  if (err) throw err;
           ^

TypeError: Cannot read property 'info' of undefined
    at KeyStore.generateNewAddress (/token_eth_sweeper/node_modules/eth-lightwallet/lib/keystore.js:443:32)
    at /token_eth_sweeper/testFlow.js:29:10
    at cb (/token_eth_sweeper/node_modules/eth-lightwallet/lib/keystore.js:524:7)
    at /token_eth_sweeper/node_modules/scrypt-async/scrypt-async.js:518:13
    at Immediate._onImmediate (/token_eth_sweeper/node_modules/scrypt-async/scrypt-async.js:481:11)
    at runCallback (timers.js:800:20)
    at tryOnImmediate (timers.js:762:5)
    at processImmediate [as _immediateCallback] (timers.js:733:5)

[coder5876]

@shayanb Right now we don't really support iterations beyond HdPathString/i where i is an integer 0, 1, 2, ....

You say you want to generate

Address 1= m'/0'/0'/1
Address 2= m'/0'/0'/2
Address 3= m'/0'/0'/3

and this is very easy to do by using m'/0'/0' as hdPathString and then you can do

ks.generateNewAddress(pwDerivedKey, 4)

to generate m'/0'/0'/0 as well as the 3 addresses in your example.

[shayanb]

@christianlundkvist Thanks, the way ks.generateNewAddress(pwDerivedKey, 4) works is that if you generate 4 for now and later on you want to continue on the path using another instance of the app, you have to generate let's say 10 and don't use the first 4 that you've already used. This solution would not be really scalable.

I made a pull request to add this feature so you can derive any path you need: https://github.com/ConsenSys/eth-lightwallet/pull/156

keystore.generateNewAddressOnPath(pwDerivedKey, [hdPathString], [index])

Please take a look and merge.