If CAs don't want hostility from browser companies for using https certificate for non-http/browser applications, they should build their own thing.
I put "HTTPS certificates" in quotes in this comment because it is not a technical term defined anywhere, just a concept that "these certificates should only be used for HTTPS". The core specifications talk about "TLS servers" and "TLS clients".
There's loads of non web, non HTTPS TLS use cases, it's just the CAB doesn't care about those (why should it?).
However, eventually, the CABF started imposing restrictions on the public CA operators regarding the issuance of non-HTTPS certificates. Nominally, the CAs are still offering "TLS certificates", but due to the pressure from the CABF, the allowed certificates are getting more and more limited, with the removal of SRVname a few years ago, and the removal of clientAuth that this thread is about.
I can understand the CABF position of "just make your own PKI" to a degree, but in practice that would require a LetsEncrypt level of effort for something that is already perfectly provided by LetsEncrypt, if it wouldn't be for the CABF lobbying.
The restriction is on signing non web certificates with the same root/intermediate as is part of the WebPKI.
There's no rule (that I'm aware of?) that says the CAs can't have different signing roots for whatever use-case that are then trusted by people who need that use case.
[citation needed]
The title of their current (2.2.2) standard is "Baseline Requirements for the Issuance and Management of Publicly‐Trusted TLS Server Certificates":
* https://cabforum.org/working-groups/server/baseline-requirem...
§1.3, "PKI Participants", states:
> The CA/Browser Forum is a voluntary organization of Certification Authorities and suppliers of Internet browser and other relying‐party software applications.
IMHO "other relying-party software applications" can include XMPP servers (also perhaps SMTP, IMAP, FTPS, NNTP, etc).
My citation is the membership of the CAB.
> IMHO "other relying-party software applications" can include XMPP servers (also perhaps SMTP, IMAP, FTPS, NNTP, etc).
This may be your opinion, but what's the representation of XMPP etc. software maintainers at the CAB?
> My citation is the membership of the CAB.
It is a single member of the CAB that is insisting on changing the MAY to a MUST NOT for clientAuth. Why does that single member, Google-Chrome, get to dictate this?
Has Mozilla insisted on changing the meaning of §1.3 to basically remove "other relying‐party software applications"? Apple-Safari? Or any other of the "Certificate Consumers":
* https://cabforum.org/working-groups/server/#certificate-cons...
The membership of CAB collectively agree to the requirements/restrictions they places on themselves, and those requirements (a) state both browser and non-browser use cases, and (b) explicitly allow clientAuth usage as a MAY; see §7.1.2.10.6, §7.1.2.7.10:
* https://cabforum.org/working-groups/server/baseline-requirem...
A serious problem with traditional CAs, which was partly solved by Let's Encrypt just giving them away. Everyone gradually realized that the "tying to real identity" function was both very expensive and of little value, compared to what people actually want which is "encryption, with reasonable certainty that it's not MITMd suddenly".
> Welcome to the CA/Browser Forum > > The Certification Authority Browser Forum (CA/Browser Forum) is a voluntary gathering of Certificate Issuers and suppliers of Internet browser software and other applications that use certificates (Certificate Consumers).
From https://letsencrypt.org/docs/faq/
> Does Let’s Encrypt issue certificates for anything other than SSL/TLS for websites? > > Let’s Encrypt certificates are standard Domain Validation certificates, so you can use them for any server that uses a domain name, like web servers, mail servers, FTP servers, and many more.
Are we really at an age where people don’t remember that SSL was intended for many protocols, including MAIL?!
Do you think email works on web technology because you use a web-client to access your mailbox?
Jesus christ, formal education needs to come quickly to our industry.
X.509 was published in November 25, 1988 ; version 3 added support for "the web" as it was known at the time. One obvious use was for X.400 e-mail systems in the 1980s. Novell Netware adopted x.509.
It was originally intended to use with X.511 "Directory Access Protocol", which LDAP was based on. You can still find X.500 heritage in Microsft Exchange and Active Directory, although it's getting less over time and e.g. EntraID only has some affordances for backward compatibility.
It just went away, upset. It might never come back.