data loss with ssh -n

[Markus Friedl]

the data get's truncated? who's sending EOF? the client?

so
	$ ssh -n host cat file > file2
fails on linux?
every time?

On Fri, Jul 20, 2001 at 01:22:24PM +0300, Pekka Savola wrote:
> Hi,
> 
> Using OpenSSH 2.9p2 (2.5.2 was also bad), I've noticed data loss on
> Linux when:
>  1) ssh -n flag is used, and
>  2) ssh jobs are run from cron (effectively causing the same as above).
> 
> What is done, is a command basically like:
> 
> ssh [-n] -c blowfish -p 722 -i rsakey -l pwget passwdserver passwd > passwd.tmp 2> /tmp/log
> 
> ie, retrieve dynamically created passwd-file from passwdserver using rsa
> keys.
> 
> The server is SSH 1.2.25 or the like (yeah, I know it's broken, but can't
> be changed at the moment).
> 
> The diff of ssh -v -v -v is:
> 
> --- log	Fri Jul 20 13:18:42 2001
> +++ log.cron	Fri Jul 20 13:02:01 2001
> @@ -41,13 +41,12 @@
>  debug3: clear hostkey 0
>  debug3: clear hostkey 1
>  debug3: clear hostkey 2
> -debug1: Requesting X11 forwarding with authentication spoofing.
> -debug1: Remote: X11 forwarding disabled in server configuration file.
> -Warning: Remote host denied X11 forwarding.
>  debug1: Sending command: passwd
>  debug1: Entering interactive session.
> +debug1: fd 0 setting O_NONBLOCK
>  debug1: fd 1 setting O_NONBLOCK
>  debug1: fd 2 setting O_NONBLOCK
> -debug1: Transferred: stdin 0, stdout 155303, stderr 0 bytes in 1.6 seconds
> -debug1: Bytes per second: stdin 0.0, stdout 95576.3, stderr 0.0
> +debug1: Sending eof.
> +debug1: Transferred: stdin 0, stdout 155303, stderr 0 bytes in 1.5 seconds
> +debug1: Bytes per second: stdin 0.0, stdout 100654.4, stderr 0.0
>  debug1: Exit status 0
> 
> When run from cron, or with -n, you get "Sending eof." which truncates the
> data.
> 
> Any ideas?
> 
> -- 
> Pekka Savola                 "Tell me of difficulties surmounted,
> Netcore Oy                   not those you stumble over and fall"
> Systems. Networks. Security.  -- Robert Jordan: A Crown of Swords
> 
>