This letter was originally published in our 2024 Annual Report.
The past year at ISRG has been a great one and I couldn’t be more proud of our staff, community, funders, and other partners that made it happen. Let’s Encrypt continues to thrive, serving more websites around the world than ever before with excellent security and stability. Our understanding of what it will take to make more privacy-preserving metrics more mainstream via our Divvi Up project is evolving in important ways.
I’m saying that if you’re a developer of software that communicates between two nodes across the internet, you shouldn’t rely on X.509 because the common root stores have historically been filled with compromised CAs, which would let someone with that CA decrypt and view the messages you send with TLS.
You should mint your own certs and pin their fingerprints so that your application will only send messages if the fingerprint of the cert on the other end matches your trusted cert.
Technically all certificates are pinned, especially with public CAs, most OS package the latest CA certs which will all go out of style within 10 years or so. You can see this by loading up any old distro or defunct version of windows.
Yeah, fuck the users. We can just slap “100% secure” on the box and who cares if some woman is raped and murdered because we decided not to follow best security practices, right? /s
Yeah, now imagine pinning certs that change weekly.
My first thought is that old school secure software (like claws-mail) treats a cert change as a minor security incident, asking you to confirm every time. Completely different school of thought.
Yes X.509 is broken. If you’re a developer and not pinning certs, you’re doing it wrong.
What
What part are you confused about, and are you a developer?
Edit: why was I downvoted for asking this?
I’m a developer and would appreciate you going into more specifics about which certificates you suggest pinning.
I’m saying that if you’re a developer of software that communicates between two nodes across the internet, you shouldn’t rely on X.509 because the common root stores have historically been filled with compromised CAs, which would let someone with that CA decrypt and view the messages you send with TLS.
You should mint your own certs and pin their fingerprints so that your application will only send messages if the fingerprint of the cert on the other end matches your trusted cert.
OK, so cases where you control both ends of the communication. Thanks for the clarification.
And your software stops functioning after X years due to this.
Don’t do this, this is a bad idea.
Technically all certificates are pinned, especially with public CAs, most OS package the latest CA certs which will all go out of style within 10 years or so. You can see this by loading up any old distro or defunct version of windows.
Yeah, fuck the users. We can just slap “100% secure” on the box and who cares if some woman is raped and murdered because we decided not to follow best security practices, right? /s
That’s a hell of a leap there chief.
Yeah, now imagine pinning certs that change weekly.
My first thought is that old school secure software (like claws-mail) treats a cert change as a minor security incident, asking you to confirm every time. Completely different school of thought.
You can pin to your own CA. Then it doesn’t matter if you want to update your certs frequently.
Right