Re: Comments on draft-ietf-secsh-filexfer-05.txt

[Damien Miller <djm%mindrot.org@localhost>]

Another comment/query on the filexfer draft:

I think that SSH_FXP_OPEN should support a flag to stop it from
following symlinks, like O_NOFOLLOW on some Unices.

Without something like this, I believe that SSH_FXP_FSTAT isn't very
useful as a race-free means to collect attributes. One could end up
following a symlink unless one checks it first - which opens another race.

Even using the hypothetical nofollow isn't entirely race-free, but it
enables a server to not chase symlinks (e.g. to /dev/st0) if it doesn't
want to.

-d