Javascript function that generates an Ethereum wallet (address, pubKey and privKey) using a random private key

ethwallet-generator.js

/**
 * MIT License
 *
 * Copyright (c) 2021 Giuseppe Eletto <[email protected]>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

/*
// Browser version:
    $ browserify -p tinyify ethwallet-generator.js --s genEthereumWallet | uglifyjs > ethwallet-generator.bundle.js
// Browser version usage:
    <script src="ethwallet-generator.bundle.js"></script>
    <script>
        const wallet = genEthereumWallet()
        console.log(wallet)
    </script>
*/

/**
 * Create a wallet from a random private key
 * @returns {{address: String, pubKey: String, privKey: String}}
 */
module.exports = () => {
    const { Buffer } = require('safe-buffer')
    const randomBytes = require('randombytes')
    const { privateKeyVerify, publicKeyCreate } = require('secp256k1')
    const keccak = require('keccak')

    /**
     * Generates a random private key
     * @returns Buffer
     */
    const genPrivateKey = () => {
        for (let privKey; (privKey = randomBytes(32)); )
            if (privateKeyVerify(privKey)) return privKey
    }

    /**
     * Generates the public key for the given private key
     * @param Buffer privKey
     * @returns Buffer
     */
    const genPublicKey = (privKey) => {
        const pubKey = publicKeyCreate(privKey, false).slice(1)
        return Buffer.from(pubKey)
    }

    /**
     * Generates the address based on the given public key
     * @param Buffer pubKey
     * @returns String
     */
    const genAddress = (pubKey) => {
        const address = keccak('keccak256').update(pubKey).digest('hex').slice(24)
        const hash = keccak('keccak256').update(address).digest('hex')

        let result = ''
        for (let i = 0; i < address.length; i++) {
            result += parseInt(hash[i], 16) >= 0x08 ? address[i].toUpperCase() : address[i]
        }
        return result
    }

    // Private & Public keys
    const privKey = genPrivateKey()
    const pubKey = genPublicKey(privKey)

    // Address
    const address = genAddress(pubKey)

    // Return Wallet object
    return {
        address: `0x${address}`,
        pubKey: pubKey.toString('hex'),
        privKey: privKey.toString('hex'),
    }
}