http - Node.js HTTP2 server Error: socket hang up

Question

Given the latest version of Node.js with experimental HTTP2 support:

$ node -v
v9.2.0

An HTTP2 server:

var options = {
  key: getKey(),
  cert: getCert(),
  allowHTTP1: true
}

var server = http2.createSecureServer(options)
server.on('stream', onstream)
server.on('error', onerror)
server.on('connect', onconnect)
server.on('socketError', onsocketerror)
server.on('frameError', onframeerror)
server.on('remoteSettings', onremotesettings)
server.listen(8443)

function onconnect() {
  console.log('connect')
}

function onremotesettings(settings) {
  console.log('remote settings', settings)
}

function onframeerror(error) {
  console.log('frame error', error)
}

function onsocketerror(error) {
  console.log('socket error', error)
}

function onerror(error) {
  console.log(error)
}

function onstream(stream, headers) {
  console.log('stream')
}

And a request made to it:

var https = require('https')

var options = {
  method: 'GET',
  hostname: 'localhost',
  port: '8443',
  path: '/',
  protocol: 'https:',
  rejectUnauthorized: false,
  agent: false
}

var req = https.request(options, function(res){
  var body = ''
  res.setEncoding('utf8')
  res.on('data', function(data){
    body += data;
  });
  res.on('end', function(){
    callback(null, body)
  })
})

req.end()

It just hangs and eventually says:

Error: socket hang up
at createHangUpError (_http_client.js:330:15)
    at TLSSocket.socketOnEnd (_http_client.js:423:23)
    at TLSSocket.emit (events.js:164:20)
    at endReadableNT (_stream_readable.js:1054:12)
    at _combinedTickCallback (internal/process/next_tick.js:138:11)
    at process._tickCallback (internal/process/next_tick.js:180:9)

If rejectUnauthorized: true is set, then it errors:

Error: self signed certificate
    at TLSSocket.onConnectSecure (_tls_wrap.js:1036:34)
    at TLSSocket.emit (events.js:159:13)
    at TLSSocket._finishInit (_tls_wrap.js:637:8)

Not sure what is going wrong and why it won't get to the point of logging stream.

If I go in the browser and visit https://localhost:8443, and click through the warning messages, it does actually log stream and successfully make the request. But haven't been able to get node to make the request.

I would like to treat this as an HTTP1 server, so don't want to use the HTTP2 client to make the request. But tried using that and same thing.

Answer 1

HTTP/1 doesn't share the same request semantics as HTTP/2 so HTTP/1 clients need to be detected and handled in a HTTP/2 server. To support both you need to use the HTTP2 Compatibility API.

The "hang" occurs when a HTTP1 client connects to a HTTP/2 server with allowHTTP1: true set but doesn't handle the HTTP/1 request.

The examples are based on the Node documentation example code.

HTTP/1 and /2 Mixed Server

const http2 = require('http2')
const fs = require('fs')

var options = {
  key: fs.readFileSync('server-key.pem'), 
  cert: fs.readFileSync('server-crt.pem'), 
  //ca: fs.readFileSync('ca-crt.pem'), 
  allowHTTP1: true,
}

var server = http2.createSecureServer(options, (req, res) => {
  // detects if it is a HTTPS request or HTTP/2
  const { socket: { alpnProtocol } } = (req.httpVersion === '2.0')
    ? req.stream.session 
    : req

  res.writeHead(200, { 'content-type': 'application/json' })
  res.end(JSON.stringify({
    alpnProtocol,
    httpVersion: req.httpVersion
  }))
})

server.listen(8443)

HTTP/2 Client

const http2 = require('http2')
const fs = require('fs')

const client = http2.connect('https://localhost:8443', {
    ca: fs.readFileSync('ca-crt.pem'),
    rejectUnauthorized: true,
})
client.on('socketError', (err) => console.error(err))
client.on('error', (err) => console.error(err))

const req = client.request({ ':path': '/' })

req.on('response', (headers, flags) => {
  for (const name in headers) {
    console.log('Header: "%s" "%s"', name, headers[name])
  }
})

req.setEncoding('utf8')
let data = ''
req.on('data', chunk => data += chunk)
req.on('end', () => {
  console.log('Data:', data)
  client.destroy()
})
req.end()

Then running:

→ node http2_client.js 
(node:34542) ExperimentalWarning: The http2 module is an experimental API.
Header: ":status" "200"
Header: "content-type" "application/json"
Header: "date" "Sat, 02 Dec 2017 23:27:21 GMT"
Data: {"alpnProtocol":"h2","httpVersion":"2.0"}

HTTP/1 Client

const https = require('https')
const fs = require('fs')

var options = {
  method: 'GET',
  hostname: 'localhost',
  port: '8443',
  path: '/',
  protocol: 'https:',
  ca: fs.readFileSync('ca-crt.pem'),
  rejectUnauthorized: true,
  //agent: false
}

var req = https.request(options, function(res){
  var body = ''
  res.setEncoding('utf8')
  res.on('data', data => body += data)
  res.on('end', ()=> console.log('Body:', body))
})

req.on('response', response => {
  for (const name in response.headers) {
    console.log('Header: "%s" "%s"', name, response.headers[name])
  }
})

req.end()

Then running

→ node http1_client.js 
Header: "content-type" "application/json"
Header: "date" "Sat, 02 Dec 2017 23:27:08 GMT"
Header: "connection" "close"
Header: "transfer-encoding" "chunked"
Body: {"alpnProtocol":false,"httpVersion":"1.1"}

HTTP/2 Server

Using the plain HTTP/2 Server will work with the http2_client but will "hang" for a http1_client. The TLS connection from a HTTP/1 client will be closed when you remove allowHTTP1: true.

const http2 = require('http2')
const fs = require('fs')

var options = {
  key: fs.readFileSync('server-key.pem'), 
  cert: fs.readFileSync('server-crt.pem'), 
  ca: fs.readFileSync('ca-crt.pem'), 
  allowHTTP1: true,
}

var server = http2.createSecureServer(options)
server.on('error', error => console.log(error))
server.on('connect', conn => console.log('connect', conn))
server.on('socketError', error => console.log('socketError', error))
server.on('frameError', error => console.log('frameError', error))
server.on('remoteSettings', settings => console.log('remote settings', settings))

server.on('stream', (stream, headers) => {
  console.log('stream', headers)
  stream.respond({
    'content-type': 'application/html',
    ':status': 200
  })
  console.log(stream.session)
  stream.end(JSON.stringify({
    alpnProtocol: stream.session.socket.alpnProtocol,
    httpVersion: "2"
  }))
})

server.listen(8443)

Certs

With the extended intermediate certificate setup detailed in the gist, the complete certificate chain for the CA needs to be supplied to the clients.

cat ca/x/certs/x.public.pem > caxy.pem
cat ca/y/certs/y.public.pem >> caxy.pem

Then in the clients use this ca in the options.

{ 
  ca: fs.readFileSync('caxy.pem'),
}

These examples were run withe the following simple CA setup from this circle.com article:

To simplify the configuration, let’s grab the following CA configuration file.

wget https://raw.githubusercontent.com/anders94/https-authorized-clients/master/keys/ca.cnf

Next, we’ll create a new certificate authority using this configuration.

openssl req -new -x509 
  -days 9999 
  -config ca.cnf 
  -keyout ca-key.pem 
  -out ca-crt.pem

Now that we have our certificate authority in ca-key.pem and ca-crt.pem, let’s generate a private key for the server.

openssl genrsa 
  -out server-key.pem 
  4096

Our next move is to generate a certificate signing request. Again to simplify configuration, let’s use server.cnf as a configuration shortcut.

wget https://raw.githubusercontent.com/anders94/https-authorized-clients/master/keys/server.cnf

Now we’ll generate the certificate signing request.

openssl req -new 
  -config server.cnf 
  -key server-key.pem 
  -out server-csr.pem

Now let’s sign the request.

openssl x509 -req -extfile server.cnf 
  -days 999 
  -passin "pass:password" 
  -in server-csr.pem 
  -CA ca-crt.pem 
  -CAkey ca-key.pem 
  -CAcreateserial 
  -out server-crt.pem