[scponly] SIGPIPE when trying to connect to chrooted scponly host

[Christopher Barry]

> -----Original Message-----
> From: scponly-bounces at lists.ccs.neu.edu [mailto:scponly-
> bounces at lists.ccs.neu.edu] On Behalf Of Mark Trolley
> Sent: Monday, April 06, 2009 10:30 AM
> To: scponly at lists.ccs.neu.edu
> Subject: Re: [scponly] SIGPIPE when trying to connect to chrooted
> scponly host
> 
> I can check. Which logs in particular should I be looking at? The
> information below is from auth.log. I tried grepping for scponly and
> that was the only log file I found with reference to it. I don't know
> syslog very well though.
> 
> Thanks,
> Mark
> 
> On Mon, Apr 6, 2009 at 10:25 AM, Kaleb Pederson
> <kaleb.pederson at gmail.com> wrote:
> > Mark,
> >
> > On Sunday 05 April 2009 03:29:23 pm Mark Trolley wrote:
> >>Sorry, didn't realize my reply went straight to you.
> >
> > It's alright, that happens.
> >
> >>I don't know why it wasn't working but when I tried testing by
> >>connecting locally (# sftp user at localhost) I got that in my log.
> >>
> >>Here's what I get when I try from Filezilla from a remote host:
> > ...
> >
> >> Apr  5 18:27:38 hanzy sshd[13628]: subsystem request for sftp
> >> Apr  5 18:27:38 hanzy sshd[13628]: debug1: subsystem: exec()
> >> /usr/lib/sftp-server
> >> Apr  5 18:27:38 hanzy scponly[13629]: chrooted binary in place, will
> chroot()
> >> Apr  5 18:27:38 hanzy scponly[13629]: 3 arguments in total.
> >> Apr  5 18:27:38 hanzy scponly[13629]: ^Iarg 0 is scponlyc
> >> Apr  5 18:27:38 hanzy scponly[13629]: ^Iarg 1 is -c
> >> Apr  5 18:27:38 hanzy scponly[13629]: ^Iarg 2 is /usr/lib/sftp-
> server
> >> Apr  5 18:27:38 hanzy scponly[13629]: opened log at LOG_AUTHPRIV,
> opts
> >> 0x00000029
> >
> > Are you sure that's the only output being generated by scponly?  You
> might check a couple of the other log files as we should see something
> indicating that scponly chrooted to the correct directory, changed
> directory, etc., but none of those is present in the above.
> >
> > Thanks.
> >
> > --Kaleb
> >


I've been working with logging myself a lot lately, and one thing on Debian/Ubuntu I found necessary was in the file /etc/default/syslogd add in:
SYSLOGD="-a /path/to/chroot/dev/log"

This will auto-create a syslog socket for you so sftp-server can write to the log.

This will give data from the moment scponly spawns the sftp-server. But from looking at your earlier logs, it appeared that the handoff was not actually occurring. It seemed also like you were using rhosts-type auth from the sshd logs. Is that true? Not purporting to know any answers here though ;)

-C