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Manual Creation of Public-Private Key Pairs using AvalancheJS

Generate a Mnemonic​

To begin, we'll create a mnemonic phrase with AvalancheJS. Mnemonics enable us to encode strong security into a human-readable phrase. AvalancheJS supports 10 languages including English, Japanese, Spanish, Italian, French, Korean, Czech, Portuguese, Chinese Simplified and Chinese Traditional.

First, generate a 24 word english BIP39-compliant mnemonic via AvalancheJS.

import { Mnemonic } from "avalanche"
const mnemonic: Mnemonic = Mnemonic.getInstance()
const strength: number = 256
const wordlist = mnemonic.getWordlists("english") as string[]
const m: string = mnemonic.generateMnemonic(strength, randomBytes, wordlist)
console.log(m)
// "chimney asset heavy ecology accuse window gold weekend annual oil emerge alley retreat rabbit seed advance define off amused board quick wealth peasant disorder"

Derive Addresses​

After generating a mnemonic we can use AvalancheJS to derive BIP32-compliant hierarchical deterministic (HD) Keypairs.

import HDNode from "avalanche/dist/utils/hdnode"
import { Avalanche, Mnemonic, Buffer } from "avalanche"
import { EVMAPI, KeyChain } from "avalanche/dist/apis/evm"
import { ethers } from "ethers"

const ip: string = "api.avax-test.network"
const port: number = 443
const protocol: string = "https"
const networkID: number = 5
const avalanche: Avalanche = new Avalanche(ip, port, protocol, networkID)
const cchain: EVMAPI = avalanche.CChain()

const mnemonic: Mnemonic = Mnemonic.getInstance()
const m: string =
  "chimney asset heavy ecology accuse window gold weekend annual oil emerge alley retreat rabbit seed advance define off amused board quick wealth peasant disorder"
const seed: Buffer = mnemonic.mnemonicToSeedSync(m)
const hdnode: HDNode = new HDNode(seed)

const keyChain: KeyChain = cchain.newKeyChain()

const cAddresses: string[] = []

for (let i: number = 0; i <= 2; i++) {
  const child: HDNode = hdnode.derive(`m/44'/60'/0'/0/${i}`)
  keyChain.importKey(child.privateKey)
  const cchainAddress = ethers.utils.computeAddress(child.privateKey)
  cAddresses.push(cchainAddress)
}
console.log(cAddresses)
// [
//   '0x2d1d87fF3Ea2ba6E0576bCA4310fC057972F2559',
//   '0x25d83F090D842c1b4645c1EFA46B15093d4CaC7C',
//   '0xa14dFb7d8593c44a47A07298eCEA774557036ff3'
// ]

Generate Private Keys from a Mnemonic​

As long as you have the mnemonic phrase, you can re-generate your private keys and the addresses they control.

For example, if you want to generate the private keys for the first 3 address in the C Chain keychain:

you might update the example script above to the following:

const cAddresses: string[] = []
const privateKeys: string[] = []
for (let i: number = 0; i <= 2; i++) {
  // Deriving the _i_th external BIP44 C-Chain address
  const child: HDNode = hdnode.derive(`m/44'/60'/0'/0/${i}`)
  keyChain.importKey(child.privateKey)
  // Converting the BIP44 addresses to hexadecimal addresses
  const cchainAddress = ethers.utils.computeAddress(child.privateKey)
  privateKeys.push(child.privateKey.toString("hex"))
  cAddresses.push(cchainAddress)
}
console.log({ cAddresses, privateKeys })
// {
//   cAddresses: [
//     '0x2d1d87fF3Ea2ba6E0576bCA4310fC057972F2559',
//     '0x25d83F090D842c1b4645c1EFA46B15093d4CaC7C',
//     '0xa14dFb7d8593c44a47A07298eCEA774557036ff3'
//   ],
//   privateKeys: [
//     'cd30aef1af167238c627593537e162ecf5aad1d4ab4ea98ed2f96ad4e47006dc',
//     'b85479b26bc8fbada4737e90ab2133204f2fa2a9ea33c1e0de4452cbf8fa3be4',
//     'c72e18ea0f9aa5457396e3bf810e9de8df0177c8e4e5bf83a85f871512d645a9'
//   ]
// }