Hi, the higher versions (like 6) have a supported structure with all the flags and features the servers support, see: https://datatracker.ietf.org/doc/html/draft-ietf-secsh-filexfer-13#section-5.4 The server can simply set the valid attributes like size, permissions, type, owner and group and times, and so thus ignoring everything else. But the standard answer is use a different sftp subsystem than the one provided by openssh. I'm writing one which supports at least version 6, and possibly uses some extensions. See for example: https://www.greenend.org.uk/rjk/sftpserver/ There is a lot of info about sftp implementations. Stef Bon Op ma 27 sep. 2021 om 10:56 schreef Mike Frysinger <vapier@xxxxxxxxxx>: > > would SFTPv4 support be acceptable in OpenSSH's server & client ? > > SFTPv4 supports higher stat fidelity & user/group names (not just numeric): > https://datatracker.ietf.org/doc/html/draft-ietf-secsh-filexfer-04#section-10.1 > > iiuc, some of the newer features are a bit contentious, like the NFS ACL models > (which only get worse it seems with SFTPv5 & SFTPv6). from a quick scan, it > seems these only show up in the file attrs operations, and the server could > just not return any (never set SSH_FILEXFER_ATTR_ACL). if the client were to > set file attrs and they have SSH_FILEXFER_ATTR_ACL set, then the server could > also ignore it, or have it return SSH_FX_OP_UNSUPPORTED. > > the other feature that looks a bit dicey is opening files in text mode. the > caveats the spec sprinkles around makes it sound like it too would be easier > to simply return SSH_FX_OP_UNSUPPORTED. > > requiring filenames be UTF-8 sounds fine ... the code already treats paths as > a series of bytes (effectively ignoring the encoding), so can just keep doing > that. if the client sends invalid UTF-8, that's a client bug. if the server > has a path that is invalid UTF-8, then the client can decide to ignore it, or > process it. > > everything else looks pretty straight forward. > -mike > _______________________________________________ > openssh-unix-dev mailing list > openssh-unix-dev@xxxxxxxxxxx > https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev _______________________________________________ openssh-unix-dev mailing list openssh-unix-dev@xxxxxxxxxxx https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev
