How could we restore the private key from extended private key in bip32.py about btclib HOT 3 CLOSED

good point. We should probably implement

pubkey_from_xpub(xpub: octets) -> Point:
prvkey_from_xpriv(xprv: octets) -> int:

and then rely on the wifaddress module for converting the public key point to address and the private key int to wif.
Does it make sense to you?

from btclib.

You mean use bip32 to manipulate the extended private key and extended public key, and use wifaddress to convert the Point (pubKey) and Int (prvKey) to other formats, that makes a lot of sense to me.

One other topic is using the generated private key to generate the second layer of the extended private/public key.

seed=bip39.seed_from_mnemonic('xyz')

// Generate the first layer address
mprv=bip32.mprv_from_seed(seed, xkey_version.hex())
dmprv=bip32.derive(mprv, layer1_path)
dprv=bip32.prvkey_from_xpriv(dmprv)

// Generate the second layer address
mprv2=bip32.mprv_from_pri(dprv)  # or could we use bip32.mprv_from_seed here?
dmprv2=bip32.derive(mprv, layer2_path)

from btclib.

with next release (later this month or early February, check the current master branch at fametrano/btclib) you will be able to use wif_from_xprv:

from btclib import bip32
from btclib.wif import p2pkh_address_from_wif
seed = b"00"*32  # better be random
rxprv = bip32.rootxprv_from_seed(seed)
path = "m/0h/0h/12"
xprv = bip32.derive(rxprv, path)
wif = bip32.wif_from_xprv(xprv)
address = p2pkh_address_from_wif(wif)
address2 = bip32.address_from_xpub(bip32.xpub_from_xprv(xprv))

with WIF being b'KyLk7s6Z1FtgYEVp3bPckPVnXvLUWNCcVL6wNt3gaT96EmzTKZwP' and both addresses being b'1Lbn3TbfPzM5AjQn84d4bugQN8W4bS1WAQ'

from btclib.