Creating self signed certificate for domain and su

Question

I followed this tutorial for creating Signed SSL certificates on Windows for development purposes, and it worked great for one of my domains(I'm using hosts file to simulate dns). Then I figured that I have a lot of subdomains, and that would be a pain in the ass to create a certificate for each of them. So I tried creating a certificate using wildcard in Common field as suggested in some of the answers at serverfault. Like this:

Common Name: *.myserver.net/CN=myserver.net

However, after importing this certificate into Trusted Root Certification Authority, I'm getting NET::ERR_CERT_COMMON_NAME_INVALID error in Chrome, for main domain and all of its subodmains, for example: https://sub1.myserver.net and https://myserver.net.

This server could not prove that it is myserver.net; its security certificate is from *.myserver.net/CN=myserver.net.

This may be caused by a misconfiguration or an attacker intercepting your connection.

Is there something wrong in Common Name field that is causing this error?

Answer 1

As Rahul stated, it is a common Chrome and an OSX bug. I was having similar issues in the past. In fact I finally got tired of making the 2 [yes I know it is not many] additional clicks when testing a local site for work.

As for a possible workaround to this issue [using Windows], I would using one of the many self signing certificate utilities available.

Recommended Steps:

1. Create a Self Signed Cert
2. Import Certificate into Windows Certificate Manager
3. Import Certificate in Chrome Certificate Manager
   NOTE: Step 3 will resolve the issue experienced once Google addresses the bug...considering the time in has been stale there is no ETA in the foreseeable future.**
   
   As much as I prefer to use Chrome for development, I have found myself in Firefox Developer Edition lately. which does not have this issue.
   
   Hope this helps :)

Answer 2

Create openssl.conf file:

[req]
default_bits = 2048
default_keyfile = oats.key
encrypt_key = no
utf8 = yes
distinguished_name = req_distinguished_name
x509_extensions = v3_req
prompt = no

[req_distinguished_name]
C = US
ST = Cary
L = Cary
O  = BigCompany
CN = *.myserver.net

[v3_req]
keyUsage = critical, digitalSignature, keyAgreement
extendedKeyUsage = serverAuth
subjectAltName = @alt_names

[alt_names]
DNS.1 = myserver.net
DNS.2 = *.myserver.net

Run this comand:

openssl req -x509 -sha256 -nodes -days 3650 -newkey rsa:2048 -keyout app.key -out app.crt  -config openssl.conf

Output files app.crt and app.key work for me.

Answer 3

The answers provided did not work for me (Chrome or Firefox) while creating PWA for local development and testing. DO NOT USE FOR PRODUCTION! I was able to use the following:

1. Online certificate tools site with the following options:
   • Common Names: Add both the "localhost" and IP of your system e.g. 192.168.1.12
   • Subject Alternative Names: Add "DNS" = "localhost" and "IP" = <your ip here, e.g. 192.168.1.12>
   • "CRS" drop down options set to "Self Sign"
   • all other options were defaults
2. Download all links
3. Import .p7b cert into Windows by double clicking and select "install"/ OSX?/Linux?
4. Added certs to node app... using Google's PWA example
   • add const https = require('https'); const fs = require('fs'); to the top of the server.js file
   • comment out return app.listen(PORT, () => { ... }); at the bottom of server.js file
   • add below https.createServer({ key: fs.readFileSync('./cert.key','utf8'), cert: fs.readFileSync('./cert.crt','utf8'), requestCert: false, rejectUnauthorized: false }, app).listen(PORT)

I have no more errors in Chrome or Firefox