is SFTPv4 support possible?

[Damien Miller]

On Wed, 29 Sep 2021, Stef Bon wrote:

> What are you doing? You are reinventing SFTP. The features you want
> are in the higher versions of SFTP. Just start supporting versions
> higher than 3, and you are there. And openssh is not the only server
> and client.

"just" implementing later sftp revisions means promising to support all
the mandatory features in them, as well as providing compatibility for
the current version.

The sftp standardisation process was a trainwreck of accepting poorly-
justified features that made the later versions of the protocol bloated
and unwieldy. OpenSSH jumped off the train fairly early and have no
desire to get back on it.

So, we've been demonstrably willing to consider extensions that fill in
missing information for _well-justified_ use-cases (e.g. the statvfs
extension doesn't even exist in later filexfer drafts) , but have no
desire to adopt the whole mess that protocol became.

-d