repro.js

repro.js

const net = require('net');
const { URL } = require('url');

const proxy = new URL('socks5://USERNAME:PASSWORD@rp.scrapegw.com:6060');
const targetHost = '18.117.245.0';
const targetPort = 43594;
const iterations = 10;
const probe = Buffer.from('0000000100', 'hex');

if (proxy.hostname === 'PROXY_HOST') {
  console.error('Set SOCKS5_PROXY first. Example: socks5://user:pass@host:port');
  process.exit(1);
}

(async () => {
  for (let i = 0; i < iterations; i++) {
    const sock = net.connect(Number(proxy.port), proxy.hostname);

    try {
      await connected(sock);

      const user = Buffer.from(decodeURIComponent(proxy.username));
      const pass = Buffer.from(decodeURIComponent(proxy.password));

      sock.write(Buffer.from([5, 2, 0, 2]));
      let r = await read(sock);
      if (r[0] !== 5) return print(i, 'not-socks-greeting', r);

      if (r[1] === 2) {
        sock.write(Buffer.concat([Buffer.from([1, user.length]), user, Buffer.from([pass.length]), pass]));
        r = await read(sock);
        if (r[1] !== 0) return print(i, 'auth-failed', r);
      }

      sock.write(Buffer.concat([
        Buffer.from([5, 1, 0]),
        socksHost(targetHost),
        Buffer.from([targetPort >> 8, targetPort & 255])
      ]));

      r = await read(sock);
      if (r[0] !== 5 || r[1] !== 0) return print(i, 'connect-failed', r);

      sock.write(probe);
      r = await read(sock, true);
      print(i, startsWithHttp(r) ? 'http-response' : 'tcp-or-empty', r);
    } catch (e) {
      console.log(JSON.stringify({ attempt: i, result: 'error', error: e.message }));
    } finally {
      sock.destroy();
      await sleep(250);
    }
  }
})();

function socksHost(host) {
  if (net.isIP(host) === 4) return Buffer.from([1, ...host.split('.').map(Number)]);
  const b = Buffer.from(host);
  return Buffer.concat([Buffer.from([3, b.length]), b]);
}

function connected(sock) {
  return new Promise((resolve, reject) => {
    const t = setTimeout(() => reject(new Error('connect timeout')), 8000);
    sock.once('connect', () => { clearTimeout(t); resolve(); });
    sock.once('error', reject);
  });
}

function read(sock, allowTimeout = false) {
  return new Promise((resolve, reject) => {
    const t = setTimeout(() => allowTimeout ? resolve(Buffer.alloc(0)) : reject(new Error('read timeout')), 8000);
    sock.once('data', (b) => { clearTimeout(t); resolve(b); });
    sock.once('error', reject);
  });
}

function print(attempt, result, buf) {
  const ascii = buf.toString('latin1').replace(/[^\x09\x0a\x0d\x20-\x7e]/g, '.').slice(0, 120);
  console.log(JSON.stringify({
    attempt,
    result,
    bytes: buf.length,
    http: (ascii.match(/^HTTP\/\d(?:\.\d)?\s+\d{3}[^\r\n]*/) || [null])[0],
    ascii,
    hex: buf.slice(0, 80).toString('hex')
  }));
}

function startsWithHttp(buf) {
  return /^HTTP\/\d(?:\.\d)?\s+\d{3}/.test(buf.toString('latin1'));
}

function sleep(ms) {
  return new Promise((resolve) => setTimeout(resolve, ms));
}