OpenVPN Support Forum

Last year I setup a new server with the at that time actual easyrsa software to generate new certificates that would satisfy the security requirements.
It has generated CA, SERVER and CLIENT certificates with RSA 2048-bit modulus and SHA256 as hash.

And now, that is again considered "too weak"!!!
I think this is going way too far. It is not upon software authors to decide security policies for the users of their software.
Everyone has different requirements, and when you are not some secret service then these parameters are secure enough, IMHO.

As it is really difficult to smoothly migrate to a new CA cert, I would need to AGAIN (for the second time in a year) need to setup a new server and re-issue and re-distribute all certificates (well over 100).
I hope that the maintainers can convert that fatal "OpenSSL: error:0A00018E:SSL routines::ca md too weak" error into a warning (by enabling tls-cert-profile insecure when that error is encountered) to give us more time to migrate.

Hey @rob-pe1chl,
I get your frustration - having to update certificates and set up a new server is a big task, especially if it's for the second time in a year!
The increase in security requirements can seem a bit over the top sometimes.
That said, your suggestion of turning the error message into a warning makes sense and could provide a smoother transition period for many users.
I recommend reaching out directly to the OpenVPN maintainers with your suggestion. They're usually pretty responsive to user feedback and it might lead to some changes in future updates.

It is my understanding that posting a message here (and in the announce topic) IS "reaching out to the maintainers".
If not, through which hoop do I need to jump to do that?

The OpenSSL 3.x library deems 2048bit-CA keys too weak internally for server verification (not the user certificate).
Having a 2048bit CA for server verification will be rejected by any modern OpenSSL3-based client.

The ca option in the client config has nothing to do with user certs, it's just used to verify the OpenVPN server cert.

1) Setting the tls-cert-profile in client configs can be used as a (bad) mitigation.
2) What you can do is just use a different CA as root for the server cert chain than for issuing user certs.
3) Or you forego the CA-based server authentication and use the (OpenVPN 2.6+ only) new peer-fingerprint option.

In either case, all that is needed on user side is to update the client config accordingly.