hpcore/examples/hpclient/client.js

//
// HotPocket client example code adopted from:
// https://github.com/codetsunami/hotpocket/blob/master/hp_client.js
//

const fs = require('fs')
const ws_api = require('ws');
const sodium = require('libsodium-wrappers')
const readline = require('readline')

// sodium has a trigger when it's ready, we will wait and execute from there
sodium.ready.then(main).catch((e) => { console.log(e) })


function main() {

    var keys = sodium.crypto_sign_keypair()


    // check for client keys
    if (!fs.existsSync('.hp_client_keys')) {
        keys.privateKey = sodium.to_hex(keys.privateKey)
        keys.publicKey = sodium.to_hex(keys.publicKey)
        fs.writeFileSync('.hp_client_keys', JSON.stringify(keys))
    } else {
        keys = JSON.parse(fs.readFileSync('.hp_client_keys'))
        keys.privateKey = Uint8Array.from(Buffer.from(keys.privateKey, 'hex'))
        keys.publicKey = Uint8Array.from(Buffer.from(keys.publicKey, 'hex'))
    }


    var server = 'ws://localhost:8080'

    if (process.argv.length == 3) server = 'ws://localhost:' + process.argv[2]

    if (process.argv.length == 4) server = 'ws://' + process.argv[2] + ':' + process.argv[3]

    var ws = new ws_api(server, {
        rejectUnauthorized: false
    })

    /* anatomy of a public challenge
       {
       version: '0.1',
       type: 'public_challenge',
       challenge: '<hex string>'
       }
     */


    // if the console ctrl + c's us we should close ws gracefully
    process.once('SIGINT', function (code) {
        console.log('SIGINT received...');
        ws.close()
    });

    function create_input_container(inp) {
        let inp_container = {
            nonce: (new Date()).getTime().toString(),
            input: Buffer.from(inp).toString('hex'),
            max_ledger_seqno: 9999999
        }
        let inp_container_bytes = JSON.stringify(inp_container);
        let sig_bytes = sodium.crypto_sign_detached(inp_container_bytes, keys.privateKey);

        let signed_inp_container = {
            type: "contract_input",
            content: inp_container_bytes.toString('hex'),
            sig: Buffer.from(sig_bytes).toString('hex')
        }

        return JSON.stringify(signed_inp_container);
    }

    function create_status_request() {
        let statreq = { type: 'stat' }
        return JSON.stringify(statreq);
    }

    ws.on('message', (m) => {
        console.log("-----Received raw message-----")
        console.log(m.toString())
        console.log("------------------------------")

        try {
            m = JSON.parse(m)
        } catch (e) {
            return
        }

        if (m.type != 'public_challenge') return

        console.log("Received challenge message")
        console.log(m)

        let pkhex = 'ed' + Buffer.from(keys.publicKey).toString('hex');
        console.log('My public key is: ' + pkhex);

        // sign the challenge and send back the response
        var sigbytes = sodium.crypto_sign_detached(m.challenge, keys.privateKey);
        var response = {
            type: 'challenge_resp',
            challenge: m.challenge,
            sig: Buffer.from(sigbytes).toString('hex'),
            pubkey: pkhex
        }

        console.log('Sending challenge response.');
        ws.send(JSON.stringify(response))

        // start listening for stdin
        const rl = readline.createInterface({
            input: process.stdin,
            output: process.stdout
        });

        // Capture user input from the console.
        var input_pump = () => {
            rl.question('\nProvide an input: ', (inp) => {

                let msgtosend = "";

                if (inp == "stat")
                    msgtosend = create_status_request();
                else
                    msgtosend = create_input_container(inp);
                    
                console.log("Sending message: " + msgtosend);
                ws.send(msgtosend)

                input_pump()
            })
        }
        input_pump()

    });

    ws.on('close', () => {
        console.log('Server disconnected.');
    });
}