Attaching a refreshed certificate

[denchen]

Is this a question?

I asked this over on StackOverflow but haven't gotten a response

I'm using this library to create a proxy to a server that requires certificates (cert, ca, and key). The problem is, these certs expire over time, so I need to retrieve new certificates. However, I'm unsure how to attach a new certificate to an existing proxy.

My basic setup is similar to the following:

app.use(
  '/api',
  proxy({
    target: {
      protocol: 'https:',
      host: 'another.domain.com',
      port: 443,
      cert: cert,
      ca: ca_cert,
      key: key
    },
    secure: false,
    changeOrigin: true
  })
);

Is it possible to insert a middleware before the proxy() to retrieve new certs and have proxy() use the new certs? Something like

app.use(
  '/api',
  (req, res, next) => {
    if (/* cert has expired */) {
      cert = /* get new cert */
    }
  },
  proxy({
    target: {
      protocol: 'https:',
      host: 'another.domain.com',
      port: 443,
      cert: cert,
      ca: ca_cert,
      key: key
    },
    secure: false,
    changeOrigin: true
  })
);

Or will that not work? Can I use onProxyReq() to manipulate the certs? Or can I tear down the original proxy() instance and instantiate a new one?

Setup

• http-proxy-middleware: 0.19.0
• http-proxy-middleware configuration
• server: express@4.16.4

[iverberk]

I know this is old but we have a similar use-case. We need to fetch/check the client certificates on-the-fly (when the request is made) and they are only valid for five minutes. Statically configuring the certificates won't work for us. Is there any way that we can alter/set the client certificates in the onProxyReq event handler?

@chimurai can you please tell us if this is (im)possible? If it is not possible we need to rethink our solution.

[chimurai]

You could try the router option. (router recipes)

It'll allow you to return a dynamic target; Before returning the target you can fetch/check certs and configure them in the target object.

// Asynchronous router function which returns promise
router: async function(req) {
    const target = await doSomeIO();
    return target;
}

target can be an string or an target object.

[iverberk]

Thanks a lot @chimurai, your suggestion works like a charm!