Function onProxyData

lib/https.js:243–290

(chunk)

  // clean up the socket and return an error. Otherwise we establish the tunnel.
  let buffer = '';
  function onProxyData(chunk) {
    const str = chunk.toString();
    debug('onProxyData', str);
    buffer += str;
    const headerEndIndex = buffer.indexOf('\r\n\r\n');
    if (headerEndIndex === -1) return headerEndIndex;
    const statusLine = buffer.substring(0, buffer.indexOf('\r\n'));
    const statusCode = statusLine.split(' ')[1];
    if (statusCode !== '200') {
      debug(`onProxyData receives ${statusCode}, cleaning up`);
      cleanup();
      const targetHost = proxyTunnelPayload.split('\r')[0].split(' ')[1];
      const message = `Failed to establish tunnel to ${targetHost} via ${agent[kProxyConfig].href}: ${statusLine}`;
      const err = new ERR_PROXY_TUNNEL(message);
      err.statusCode = NumberParseInt(statusCode);
      afterSocket(err, socket);
    } else {
      // https://datatracker.ietf.org/doc/html/rfc9110#CONNECT
      // RFC 9110 says that it can be 2xx but in the real world, proxy clients generally only
      // accepts 200.
      // Proxy servers are not supposed to send anything after the headers - the payload must be
      // be empty. So after this point we will proceed with the tunnel e.g. starting TLS handshake.
      debug('onProxyData receives 200, establishing tunnel');
      cleanup();

      // Reuse the tunneled socket to perform the TLS handshake with the endpoint,
      // then send the request.
      const { requestOptions } = tunnelConfig;
      tunnelConfig.requestOptions = null;
      requestOptions.socket = socket;
      let tunneldSocket;
      const onTLSHandshakeError = (err) => {
        debug('Propagate error event from tunneled socket to tunnel socket');
        afterSocket(err, tunneldSocket);
      };
      tunneldSocket = tls.connect(requestOptions, () => {
        debug('TLS handshake over tunnel succeeded');
        tunneldSocket.removeListener('error', onTLSHandshakeError);
        afterSocket(null, tunneldSocket);
      });
      tunneldSocket.on('free', () => {
        debug('Propagate free event from tunneled socket to tunnel socket');
        socket.emit('free');
      });
      tunneldSocket.on('error', onTLSHandshakeError);
    }
    return headerEndIndex;
  }

  function onProxyEnd() {
    cleanup();