Hello friends,
Just about every guide that comes up on my Google search for "How to create certificate authority with OpenSSL" seems to be out-of-date. Particularly, they all guide me towards creating a certificate that gets rejected by the browser due to the "Common Name" field deprecation, and the requirement of "Subject Alternative Name" field.
Does someone know a tool that creates a Certificate Authority and signs certificates with that CA? A tool that follows modern standards, gets accepted by browsers and other common web tools. Preferably something based on OpenSSL.
If you know a guide that does this using OpenSSL, even better! But I have low hopes for this after going through dozens of guides all having the same issue I mentioned above.
Replies to Some Questions you Might Ask Me
Why not just correct those two fields you mention?
I want to make sure I am doing this right. I don't want to keep running into errors in the future. For example, I actually did try that, and npm CLI rejected my certs without a good explanation (through browser accepts it).
Why not Let's Encrypt?
This is for private services that are only accessible on a private network or VPN
If this is for LAN and VPN only services, why do you need TLS?
TLS still has benefits. Any device on the same network could still compromise the security of the communication without TLS. Examples: random webcam or accessory at your house, a Meta Quest VR headset, or even a compromised smartphone or computer.
Use small step CA (or other ACME tools)
I am not sure I want the added complexity of this. I only have 2 services requiring TLS now, and I don't believe I will need to scale that much. I will have setup a way to consume the ACME server. I am happier with just a tool that spits out the certificates and I manage them that way, instead of a whole service for managing certs.
If I am over estimating the difficulty for this, please correct me.
I used this guide a few times and it's pretty well made and general, doesn't focus on just one task or end goal, just lets you set up a proper CA with intermediates and all: https://jamielinux.com/docs/openssl-certificate-authority/
I should've linked it in my post, but unfortunately that's the first guide I tried which gave me the issues I mentioned in first paragraph :(
Did it work for you?? Browser would not accept my certs even if I trust them locally.
Did you install the certificates at all the appropriate locations?
No certs like that will ever be recognized by browsers by default. You need to add your CA to your browser, and also every other applicable certificate stores. Usually that'd be
/usr/share/ca-certificatesor command line flags to explicitly define the chain of trust (for example,curl --cacert), or sometimes environment variables likeSSL_CERT_FILE.Also if you have an intermediate CA and only trust the root CA, the intermediate certificate needs to be bundled with the server's certificate so the browser can trace the chain of trust all the way to something it already trusts (ie. your root CA).
That's kind of a rabbit hole on its own since it varies from software to software how it's done, and also OS to OS. On Mac for example, that's managed through Keychain.