Proxy adding a client certificate

proxy.js

var http = require('http');
var httpProxy = require('http-proxy');

var caCert =
  '-----BEGIN CERTIFICATE-----\n' +
  'MIIDajCCAlICCQDgeRZY85PN7TANBgkqhkiG9w0BAQUFADB2MQswCQYDVQQGEwJV\n' +
  'UzETMBEGA1UECBMKQ2FsaWZvcm5pYTEWMBQGA1UEBxMNU2FuIEZyYW5jaXNjbzEh\n' +
  'MB8GA1UEChMYSW50ZXJuZXQgV2lkZ2l0cyBQdHkgTHRkMRcwFQYDVQQDEw5EZW1v\n' +
  'IEF1dGhvcml0eTAgFw0xNTA3MDQyMTQxNDlaGA8yMTE1MDYxMDIxNDE0OVowdjEL\n' +
  'MAkGA1UEBhMCVVMxEzARBgNVBAgTCkNhbGlmb3JuaWExFjAUBgNVBAcTDVNhbiBG\n' +
  'cmFuY2lzY28xITAfBgNVBAoTGEludGVybmV0IFdpZGdpdHMgUHR5IEx0ZDEXMBUG\n' +
  'A1UEAxMORGVtbyBBdXRob3JpdHkwggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEK\n' +
  'AoIBAQC+kP1Zn05sixEGRQ9waRZtAEb2MBYtrebUkh6ogNiVCFfo6qWp9gmqeucU\n' +
  'PGl4cEMyVIJNqvURFsYwTmMQwGsoT7ek9rgGcdr/DSrqClq+micRalORrmYzUZ1W\n' +
  'cY5GwYdLv+fFbOKb4/sQY5XnS7pUp23Pc+AIAB7O29gWdDcPF1wuA3NU+rvuopkN\n' +
  'pYN5FPFViqOAxHffT3bAFF3LAPN3YS0zqjXNlM2zM58kfyRvMvE9fotbjfX8LWms\n' +
  'Je6kD4AYmcehcHvkBeKyvKa5Zh90uNdgC6wmtUHZ+sqt5a02mE+uHongLCMME3bP\n' +
  '2F+ov3fbEsPng4bLcgsLy/R4MB0pAgMBAAEwDQYJKoZIhvcNAQEFBQADggEBAJ2K\n' +
  'RscR2O97SW+hnWBrHgNGHsMvsFel0Ne2X6IJ7AJmir0eIVgG22U9BkevMKvC9dOZ\n' +
  '9k9sgQsIVSvcMCIXZaCMEvTli65SxHE55OJdWIeBn/6vNysX2gSDxDmxGUnWpHHe\n' +
  'JALL57Fp4GKAvEKnnvvM7WyACReluDTwweQn2W4cXwaOrs37cF22CaQljJfdhZfS\n' +
  'KkJ/R9OGW0fSefebH6ofsVWD2aOzWPGj2mIxQhcjoa1XTEZu37Ab0290KIWUOMCA\n' +
  'XNWIq782dRGWOpm653cvdgkDijeU821dddJR7qb/WrTODhnI3N28lxC6kfl3Wawr\n' +
  'vnEg2nF657AcrlZHImM=\n' +
  '-----END CERTIFICATE-----';

var clientKey =
  '-----BEGIN RSA PRIVATE KEY-----\n' +
  'MIIEpgIBAAKCAQEA7Gc7QlrFW8XikIfMsqL/wcxn6pS2AZmNNEUEqS4H2wtfZP6U\n' +
  'w8JeDACUGMkgelt/5HisbZgO0RnlJ+0gXZqWKV96n/OGrB8ju1C/6P6P9lkcYByZ\n' +
  'KLF9rAiNcL5dy6VSAPTvokCL+5XZl1yjBTSeJjXTocjLVM6IB5dMO+GyFuFkaZUU\n' +
  '4CHtAKEyE+nQ+9uOmDQfB5Ijp1KZFN+U3CE99Wel8FEno1QKjlXAGk8hiIaW3nDX\n' +
  'YmRxwVUajDfUvJ3hpzIu0zOZf4oVAPt+FozK4zaXvg0E71kNJooYrcyr7dUD6Mkm\n' +
  'xg8MJrgQnRPlYzhldEZYOG1su0BrpCnOjIA75wIDAQABAoIBAQDe/eVlCvBdSAUV\n' +
  '5jMNUjnEGcbv/MTOL4SFiJED8JqSYWDjiEzVdzN1SNppotaS9FpoLfggDK31SeLh\n' +
  'zYiZIueAMUMfO/yNwXXYDCxqYC1158qfUnqaaworS4n3jmo1XUVEB8c/GnmwoEI2\n' +
  'x7gygdaoHl/5nMlHvuWLm4jad2OgtbyxLVW/BG8d2f9OG1P4N2inE8kZVfkDvX21\n' +
  'qnlFf8HWUGpMxHwjcNN6DD+42kD1pKqRVkHCGXHRztOHRhr2VzDPssSLU7rd/Yjv\n' +
  'hPcUj34J+2WL+rpfKNFsDeqA/eA03whID1AOaPKGfjGklsbvzoBf4a/6CkWBomxu\n' +
  'IRh9XGnBAoGBAP82BkTO1g4lD8SuSAlQAX1Ob/SiF+ps+Cvhqz2evG9Dkd1LnC2O\n' +
  'CGYWJUyNUMQLsT+E3pNYilMgfY+fZILD8Pzl7hsPCF2DKiiQDhdGaKWbAgYMCxrY\n' +
  'Ye8cRbHTBmLrHOoa1H2JQzUm4Q8JvRjWDQWlZayVw9nxuEw3ufeI1KbhAoGBAO0i\n' +
  'UojwLde72LuPa+l02h4mAYDQFQArKmd9H2p71V/GQQDN9SGsMJfOdEAyP9Md2qlj\n' +
  'vy8jAzy3dUXAWwDJeFeUls/KFM4hnkfqBK9FsE7FHchQr5M1nfov0lYe5gjLmH7A\n' +
  'k9IKheR12K/X1vocEcb4W+X9M+4drOulFML7WePHAoGBAJ4xL5uRFe/4mxiP6wkS\n' +
  'tYmliBH8M5TU7NPOcyWj8iuJl62zQ2CdbKlSytXztn9+u+SiiJCOzlcOiaXv6A6C\n' +
  'RCuOnpPZMpc8SXKRMJrOwuj79zomVu/R9oqPXMgIBSplkCuwa8xQu/8DVXfL0pHF\n' +
  'hJbeWfKrdpXulg1wcW51O1MhAoGBAN13e6vG3JmqJ41sMjVz263igu7h52sj5VOH\n' +
  'yQpzIuFy0AzHTZQoM63jtDCsfW1XaXtf3BNS2Ngg4tbFAnjmsIzjCkKAEhQ904yI\n' +
  'Y92p8TJv6BPIP2H15lfdx8yEyQQX2ZEvnB7Dky6+XSRFKdKm2neARpuycYiGkJP3\n' +
  'tj8v7lDLAoGBAJLnvMH3bmzezgpQHZ2hlQ58nrHfBcD2wrILaXylsUgA4ddjWhAP\n' +
  'iSe8ie3UEkHjzSWRzj4cQvgZjqdgScg4XVMxMnaxUia5yVVJAWtLmoCFTjT/ZJgM\n' +
  'MsS2LGlPYBwDeHW7i7vYwMX8aU0huBpo/CxZnB8BzJgqj/NSEAtclBux\n' +
  '-----END RSA PRIVATE KEY-----\n';

var clientCert =
  '-----BEGIN CERTIFICATE-----\n' +
  'MIIDZTCCAk0CCQC+bRt5zDRK+zANBgkqhkiG9w0BAQUFADB2MQswCQYDVQQGEwJV\n' +
  'UzETMBEGA1UECBMKQ2FsaWZvcm5pYTEWMBQGA1UEBxMNU2FuIEZyYW5jaXNjbzEh\n' +
  'MB8GA1UEChMYSW50ZXJuZXQgV2lkZ2l0cyBQdHkgTHRkMRcwFQYDVQQDEw5EZW1v\n' +
  'IEF1dGhvcml0eTAgFw0xNTA3MDQyMTU3MjJaGA8yMTE1MDYxMDIxNTcyMlowcTEL\n' +
  'MAkGA1UEBhMCVVMxEzARBgNVBAgTCkNhbGlmb3JuaWExFjAUBgNVBAcTDVNhbiBG\n' +
  'cmFuY2lzY28xITAfBgNVBAoTGEludGVybmV0IFdpZGdpdHMgUHR5IEx0ZDESMBAG\n' +
  'A1UEAxMJbG9jYWxob3N0MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA\n' +
  '7Gc7QlrFW8XikIfMsqL/wcxn6pS2AZmNNEUEqS4H2wtfZP6Uw8JeDACUGMkgelt/\n' +
  '5HisbZgO0RnlJ+0gXZqWKV96n/OGrB8ju1C/6P6P9lkcYByZKLF9rAiNcL5dy6VS\n' +
  'APTvokCL+5XZl1yjBTSeJjXTocjLVM6IB5dMO+GyFuFkaZUU4CHtAKEyE+nQ+9uO\n' +
  'mDQfB5Ijp1KZFN+U3CE99Wel8FEno1QKjlXAGk8hiIaW3nDXYmRxwVUajDfUvJ3h\n' +
  'pzIu0zOZf4oVAPt+FozK4zaXvg0E71kNJooYrcyr7dUD6Mkmxg8MJrgQnRPlYzhl\n' +
  'dEZYOG1su0BrpCnOjIA75wIDAQABMA0GCSqGSIb3DQEBBQUAA4IBAQBDu0nppbbO\n' +
  'tPweh4LiHlk4efjiepWTLolD7FHyj1c5cCg4Ml3+XmRd3jTvXEgqMKsw4OYQsGFy\n' +
  'pfV5W2ehwQnGEBtgGAixMAjj6+GTk53oYRjwW8QxM4MaxJio7guPavvjtUoLR5mf\n' +
  'vMtRw90zI75wB0U+D4c1AHF5LxRoSQN/n1bN0NStxgPKEWQdvqXwo3G5u/dibjC3\n' +
  '7iYFI2XhKHg5FBG0xrrA9xArJigA1TS3yq5tAFLOR22wla/fSqlxV3mCkUfJCKka\n' +
  'jUa7eC1K/+0IAssrazo/ND2H5brcmGXvJaiNPRAjrxPF32DqpwzVNcspJ7KzCWif\n' +
  'immNPLi3ksvI\n' +
  '-----END CERTIFICATE-----\n';

var proxy = httpProxy.createServer();

// https://github.com/nodejitsu/node-http-proxy/issues/734
proxy.on('proxyRes', function(proxyRes, req, res) {
  if (res.shouldKeepAlive) {
    proxyRes.headers.connection = 'keep-alive';
  }
});

var httpServer = http.createServer(function(req, res) {
  var options = {
    target: {
      host: 'api.example.com',
      port: 443,
      protocol: 'https:',
      key: clientKey,
      cert: clientCert,
      ca: caCert,
    },
    changeOrigin: true
  };

  proxy.web(req, res, options, function(err) {
    console.log('oh nooooo: ' + err.toString());

    if (!res.headersSent) {
      res.statusCode = 502;
      res.end('bad gateway');
    }
  });
});

httpServer.listen(8080, function() {
  console.log('proxy server on port 8080');
});