Managing account against an Ethereum client

account-mgmt.js

const Web3 = require('web3');
const web3 = new Web3(new Web3.providers.HttpProvider('http://localhost:8545'));

/*
* Creating account
*/
const passphrase = 'my-super-secret-passphrase'; // Get the passphrase from HTML form or any other way
web3.personal.newAccount(passphrase, (error, address) => {
    user.setAddress(address);
});

/*
* Unlocking account
*/
const passphrase = 'my-super-secret-passphrase'; // Get the passphrase from HTML form or any other way
const address = '0x3eca3...23abe2'; // Get user's address from DB or user input
const isUnlocked = web3.personal.unlockAccount(address, passphrase, 100); // Use Geth API for unlocking the account

if (isUnlocked) {
    // Send transaction...
}