Ethereum simple wallet

simple-wallet.js

const web3 = new Web3('https://ropsten.infura.io/your-id');

// Create a account and store it encrypted in the localStorage
function createAndSaveAccount() {
    const password = prompt('Mot de passe encrypter le compte');
    const account = web3.eth.accounts.create();
    const keystore = account.encrypt(password);
    localStorage.setItem('keystore', JSON.stringify(keystore));
}

// Get the account in the localStorage and decrypt if with the password
function getAccount(password) {
    const keystoreStr = localStorage.getItem('keystore');
    const keystore = JSON.parse(keystoreStr);
    return web3.eth.accounts.decrypt(keystore, password);
}

// Get the account and sign a message
function signMessage(message) {
    const password = prompt('Sign a message');
    return getAccount(password).sign(message);
}