How do I use a self signed certificate for a HTTPS Node.js server?

Update (Nov 2018): Do you need self-signed certs?

Or would real certificates get the job done better? Have you considered any of these?

(Note: Let’s Encrypt can also issue certificates to private networks)

ScreenCast

https://coolaj86.com/articles/how-to-create-a-csr-for-https-tls-ssl-rsa-pems/

Full, Working example

  • creates certificates
  • runs node.js server
  • no warnings or errors in node.js client
  • no warnings or errors in cURL

https://github.com/coolaj86/nodejs-self-signed-certificate-example

Using localhost.greenlock.domains as an example (it points to 127.0.0.1):

server.js

'use strict';

var https = require('https')
  , port = process.argv[2] || 8043
  , fs = require('fs')
  , path = require('path')
  , server
  , options
  ;

require('ssl-root-cas')
  .inject()
  .addFile(path.join(__dirname, 'server', 'my-private-root-ca.cert.pem'))
  ;

options = {
  // this is ONLY the PRIVATE KEY
  key: fs.readFileSync(path.join(__dirname, 'server', 'privkey.pem'))
  // You DO NOT specify `ca`, that's only for peer authentication
//, ca: [ fs.readFileSync(path.join(__dirname, 'server', 'my-private-root-ca.cert.pem'))]
  // This should contain both cert.pem AND chain.pem (in that order) 
, cert: fs.readFileSync(path.join(__dirname, 'server', 'fullchain.pem'))
};


function app(req, res) {
  res.setHeader('Content-Type', 'text/plain');
  res.end('Hello, encrypted world!');
}

server = https.createServer(options, app).listen(port, function () {
  port = server.address().port;
  console.log('Listening on https://127.0.0.1:' + port);
  console.log('Listening on https://' + server.address().address + ':' + port);
  console.log('Listening on https://localhost.greenlock.domains:' + port);
});

client.js

'use strict';

var https = require('https')
  , fs = require('fs')
  , path = require('path')
  , ca = fs.readFileSync(path.join(__dirname, 'client', 'my-private-root-ca.cert.pem'))
  , port = process.argv[2] || 8043
  , hostname = process.argv[3] || 'localhost.greenlock.domains'
  ;

var options = {
  host: hostname
, port: port
, path: "https://stackoverflow.com/"
, ca: ca
};
options.agent = new https.Agent(options);

https.request(options, function(res) {
  res.pipe(process.stdout);
}).end();

And the script that makes the certificate files:

make-certs.sh

#!/bin/bash
FQDN=$1

# make directories to work from
mkdir -p server/ client/ all/

# Create your very own Root Certificate Authority
openssl genrsa \
  -out all/my-private-root-ca.privkey.pem \
  2048

# Self-sign your Root Certificate Authority
# Since this is private, the details can be as bogus as you like
openssl req \
  -x509 \
  -new \
  -nodes \
  -key all/my-private-root-ca.privkey.pem \
  -days 1024 \
  -out all/my-private-root-ca.cert.pem \
  -subj "/C=US/ST=Utah/L=Provo/O=ACME Signing Authority Inc/CN=example.com"

# Create a Device Certificate for each domain,
# such as example.com, *.example.com, awesome.example.com
# NOTE: You MUST match CN to the domain name or ip address you want to use
openssl genrsa \
  -out all/privkey.pem \
  2048

# Create a request from your Device, which your Root CA will sign
openssl req -new \
  -key all/privkey.pem \
  -out all/csr.pem \
  -subj "/C=US/ST=Utah/L=Provo/O=ACME Tech Inc/CN=${FQDN}"

# Sign the request from Device with your Root CA
openssl x509 \
  -req -in all/csr.pem \
  -CA all/my-private-root-ca.cert.pem \
  -CAkey all/my-private-root-ca.privkey.pem \
  -CAcreateserial \
  -out all/cert.pem \
  -days 500

# Put things in their proper place
rsync -a all/{privkey,cert}.pem server/
cat all/cert.pem > server/fullchain.pem         # we have no intermediates in this case
rsync -a all/my-private-root-ca.cert.pem server/
rsync -a all/my-private-root-ca.cert.pem client/

# create DER format crt for iOS Mobile Safari, etc
openssl x509 -outform der -in all/my-private-root-ca.cert.pem -out client/my-private-root-ca.crt

For example:

bash make-certs.sh 'localhost.greenlock.domains'

Hopefully this puts the nail in the coffin on this one.

And some more explanation: https://github.com/coolaj86/node-ssl-root-cas/wiki/Painless-Self-Signed-Certificates-in-node.js

Install private cert on iOS Mobile Safari

You need to create a copy of the root ca certificate a DER format with a .crt extension:

# create DER format crt for iOS Mobile Safari, etc
openssl x509 -outform der -in all/my-private-root-ca.cert.pem -out client/my-private-root-ca.crt

Then you can simply serve that file with your webserver. When you click the link you should be asked if you want to install the certificate.

For an example of how this works you can try installing MIT’s Certificate Authority: https://ca.mit.edu/mitca.crt

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