Golang BIP32 private key to Web3 Secret Storage conversion

bip32_web3secret.go

package main

import (
	"fmt"
	"io/ioutil"

	"github.com/ethereum/go-ethereum/accounts/keystore"
	"github.com/ethereum/go-ethereum/crypto"
	"github.com/jbenet/go-base58"
	"github.com/tyler-smith/go-bip32"
	"github.com/tyler-smith/go-bip39"
)

func generateSeed(passphrase string) []byte {
	// Generate a mnemonic for memorization or user-friendly seeds
	entropy, _ := bip39.NewEntropy(256)
	mnemonic, _ := bip39.NewMnemonic(entropy)

	fmt.Println("Mnemonic: ", mnemonic)
	return bip39.NewSeed(mnemonic, passphrase)
}

func newKs(keydir string) *keystore.KeyStore {
	return keystore.NewKeyStore(keydir, keystore.StandardScryptN, keystore.StandardScryptP)
}

func main() {

	// Generate a new seed
	seed := generateSeed("") // or seed := bip39.NewSeed(mnemonic, "") to recover from a mnemonic

	// Get the master key
	masterKey, _ := bip32.NewMasterKey(seed)
	publicKey := masterKey.PublicKey()
	fmt.Println("BIP32 Master private key: ", masterKey)
	fmt.Println("BIP32 Master public key: ", publicKey)

	// To use derivate child keys instead, see:
	// https://gist.github.com/miguelmota/f56fa0b01e8c6c649a6c4f0ee7337aab#file-bip32_ecdsa-go-L24

	// Extract the private key
	decoded := base58.Decode(masterKey.B58Serialize())
	privateKey := decoded[46:78]

	// Hex private key to ECDSA private key
	privateKeyECDSA, err := crypto.ToECDSA(privateKey)
	if err != nil {
		panic(err)
	}

	// Import ECDSA key into the keystore
	ks := newKs(".")
	account, err := ks.ImportECDSA(privateKeyECDSA, "")
	if err != nil {
		panic(err)
	}

	// A Web3 Secret Storage JSON file is now stored in account.URL.Path, just print it out
	b, err := ioutil.ReadFile(account.URL.Path)
	if err != nil {
		panic(err)
	}
	fmt.Println("Web3 Secret Storage:")
	fmt.Print(string(b))
}