Account derivation not according to EIP 2334

[alonmuroch]

When creating a wallet the derivation path for new accounts is /m/12381/3600/i/0
https://github.com/wealdtech/go-eth2-wallet-hd/blob/master/wallet.go#L339

EIP 2334 defines the derivation to be:
/m/12381/3600/i/0 for withdrawal keys
/m/12381/3600/i/0/z for signing keys
https://github.com/ethereum/EIPs/pull/2334/files

[mcdee]

Those pieces of EIP-2334 are not a good idea. I've created a pull request to remove those restrictions, as they will preclude adherence to the EIP in many common staking situations.

ethereum/EIPs#2670

[alonmuroch]

That's open for discussion I guess but for now the implementation also prohibits multi wallet support from 1 seed.

derivation, as a minimum, should be m/12381/3600/{wallet_index}/{account_index}
Maybe even m/12381/3600/{wallet_index}/{0 for withdrawal, 1 for signing}/{account_index}

[alonmuroch]

@mcdee made a fix multi account support, let me know what you think
https://github.com/alonmuroch/go-eth2-wallet-hd/tree/fix/EIP2334

[mcdee]

Thanks for the idea. Wallets are a level of separation, adding the ability to create multiple wallets from a single HD seed breaks that separation.

If multiple wallets are required, different seeds can be used. If multiple accounts with the same seed are required, they can all be in the same wallet. Creating two wallets from the same seed could cause confusion. If, for example, a 'withdrawal' and a 'validator' wallet created from the same seed and the 'validator' wallet copied to an internet-connected server, the user may believe that their 'withdrawal' wallet is safe but in fact the seed will be exposed on the internet-connected server.