ssh-sftp-perl-users — For users and developers of the Perl SSH and SFTP modules

[Marschall P. <pet...@is...>]

Hi
,
I have a problem with Net::SFTP / Net::SSH::Perl (both the old and the current versions) on Perl 5.6.0 and Linux 2.4.x

The attached program sftptest.pl tries to connect to a server and do a simple 'ls' there.
It works absolutely flawlessly when run interactively by a regular user, but when the very same user tries to run it from cron he does not get any answers from the server.
Another strange behaviour: when root tries to run the program from cron it works as expected.

It happens on three machines with similar (but not identical) setup.

The attached files sftptest-interactive.log and sftptest-via-cron.log show the differences.
They result from a shell script that calls sftptest.pl after setting all environment variables to the values from the cron environment.
Somehow the connection seems to get closed at about the time when SSH2_FXP_INIT gets sent.

Can you give me any hint or clue how to make Net::SFTP run from cron too ?

I'd really love to use Net::SFTP instead of doing some dirty tricks with Expect or calling the sftp program directly.

Thanks in advance for your help
Peter Marschall

-------------- sftptest.pl ------------------

#!/usr/bin/perl -w

use Net::SFTP;
use strict;

my $server = $ARGV[0] || '';
my $user = $ARGV[1] || '';
my $password = $ARGV[2] || '';
my $dir = $ARGV[3] || '';

my @result = ();

print STDERR "Environment:\n";
map { print STDERR "\t$_ = $ENV{$_}\n"; } keys(%ENV);

print STDERR "Specials:\n";
print STDERR "\t\$\$ = ". (defined($$) ? $$ : '<undef>') ."\n";
print STDERR "\t\$\< = ". (defined($<) ? $< : '<undef>') ."\n";
print STDERR "\t\$\> = ". (defined($>) ? $> : '<undef>') ."\n";
print STDERR "\t\$\/ = ". (defined($/) ? $/ : '<undef>') ."\n";
print STDERR "\t\$\\ = ". (defined($\) ? $\ : '<undef>') ."\n";
print STDERR "\t\$\~ = ". (defined($~) ? $~ : '<undef>') ."\n";
print STDERR "\t\$\% = ". (defined($%) ? $% : '<undef>') ."\n";
print STDERR "\t\$\= = ". (defined($=) ? $= : '<undef>') ."\n";
print STDERR "\t\$\- = ". (defined($-) ? $- : '<undef>') ."\n";
print STDERR "\t\$\, = ". (defined($,) ? $, : '<undef>') ."\n";
print STDERR "\t\$\| = ". (defined($|) ? $| : '<undef>') ."\n";
print STDERR "\t\$\! = ". (defined($!) ? $! : '<undef>') ."\n";
print STDERR "\t\$\? = ". (defined($?) ? $? : '<undef>') ."\n";

my $sftp = Net::SFTP->new($server,
                          user => $user || '',
                          password => $password || '',
                          debug => 1)
    or  die "error creating SFTP object: $@";

die "ls: $@"
  if (!defined(eval { @result = $sftp->ls($dir) }));

print STDERR "Files:\n";
map { print STDERR "\t".$_->{filename}."\n"; } @result;

# EOF

-------------- sftptest-interactive.log ------------------

Environment:
	_ = /usr/local/src/Meta/test/sftptest.pl
	HOSTTYPE = i386
	HOME = /home/metaconn
	SHLVL = 1
	OSTYPE = linux
	TERM = dumb
	PWD = /home/metaconn
	HOSTNAME = lx0042
	MACHTYPE = i386-suse-linux
	LOGNAME = metaconn
	PATH = /usr/bin:/bin
	SHELL = /bin/sh
Specials:
	$$ = 22827
	$< = 500
	$> = 500
	$/ = 

	$\ = <undef>
	$~ = STDOUT
	$% = 0
	$= = 60
	$- = 0
	$, = <undef>
	$| = 0
	$! = 
	$? = 0
lx0042: Reading configuration data /home/metaconn/.ssh/config
lx0042: Reading configuration data /etc/ssh_config
lx0042: Connecting to sl00028.weimar.teagnetkom.de, port 22.
lx0042: Remote protocol version 1.99, remote software version OpenSSH_3.5p1
lx0042: Net::SSH::Perl Version 1.24, protocol version 2.0.
lx0042: No compat match: OpenSSH_3.5p1.
lx0042: Connection established.
lx0042: Sent key-exchange init (KEXINIT), wait response.
lx0042: Algorithms, c->s: 3des-cbc hmac-sha1 none
lx0042: Algorithms, s->c: 3des-cbc hmac-sha1 none
lx0042: Entering Diffie-Hellman Group 1 key exchange.
lx0042: Sent DH public key, waiting for reply.
lx0042: Received host key, type 'ssh-dss'.
lx0042: Host 'sl00028.weimar.teagnetkom.de' is known and matches the host key.
lx0042: Computing shared secret key.
lx0042: Verifying server signature.
lx0042: Waiting for NEWKEYS message.
lx0042: Enabling incoming encryption/MAC/compression.
lx0042: Send NEWKEYS, enable outgoing encryption/MAC/compression.
lx0042: Sending request for user-authentication service.
lx0042: Service accepted: ssh-userauth.
lx0042: Trying empty user-authentication request.
lx0042: Authentication methods that can continue: publickey,password.
lx0042: Next method to try is publickey.
lx0042: Next method to try is password.
lx0042: Trying password authentication.
lx0042: Login completed, opening dummy shell channel.
lx0042: channel 0: new [client-session]
lx0042: Requesting channel_open for channel 0.
lx0042: channel 0: open confirm rwindow 0 rmax 32768
lx0042: Got channel open confirmation, requesting shell.
lx0042: Requesting service shell on channel 0.
lx0042: channel 1: new [client-session]
lx0042: Requesting channel_open for channel 1.
lx0042: Sending subsystem: sftp
lx0042: Requesting service subsystem on channel 1.
lx0042: channel 1: open confirm rwindow 0 rmax 32768
lx0042: sftp: Sending SSH2_FXP_INIT
lx0042: sftp: Remote version: 3
lx0042: sftp: Sent message T:11 I:0
lx0042: sftp: Sent message T:12 I:1
lx0042: sftp: Received reply T:104 I:1
lx0042: sftp: Received 30 SSH2_FXP_NAME responses
lx0042: sftp: Sent message T:12 I:2
lx0042: sftp: Received reply T:101 I:2
lx0042: sftp: Received SSH2_FXP_STATUS 1
lx0042: sftp: Sent message T:4 I:3
Files:
	.
	..
	dms_mobil_031101223038.txt
	dms_mobil_031106223039.txt
	dms_mobil_031102223038.txt
	dms_mobil_031103223037.txt
	dms_mobil_031108223038.txt
	dms_mobil_031104223037.txt
	dms_mobil_031112223038.txt
	dms_mobil_031105223042.txt
	dms_mobil_031109223043.txt
	dms_mobil_031110223040.txt
	dms_mobil_031113223038.txt
	dms_mobil_031114223041.txt
	dms_mobil_031115223040.txt
	dms_mobil_031116223040.txt
	dms_mobil_031117223040.txt

-------------- sftptest-via-cron.log ------------------

Environment:
	_ = /usr/local/src/Meta/test/sftptest.pl
	HOSTTYPE = i386
	HOME = /home/metaconn
	SHLVL = 1
	OSTYPE = linux
	TERM = dumb
	PWD = /home/metaconn
	HOSTNAME = lx0042
	MACHTYPE = i386-suse-linux
	LOGNAME = metaconn
	PATH = /usr/bin:/bin
	SHELL = /bin/sh
Specials:
	$$ = 22796
	$< = 500
	$> = 500
	$/ = 

	$\ = <undef>
	$~ = STDOUT
	$% = 0
	$= = 60
	$- = 0
	$, = <undef>
	$| = 0
	$! = 
	$? = 0
lx0042: Reading configuration data /home/metaconn/.ssh/config
lx0042: Reading configuration data /etc/ssh_config
lx0042: Connecting to sl00028.weimar.teagnetkom.de, port 22.
lx0042: Remote protocol version 1.99, remote software version OpenSSH_3.5p1
lx0042: Net::SSH::Perl Version 1.24, protocol version 2.0.
lx0042: No compat match: OpenSSH_3.5p1.
lx0042: Connection established.
lx0042: Sent key-exchange init (KEXINIT), wait response.
lx0042: Algorithms, c->s: 3des-cbc hmac-sha1 none
lx0042: Algorithms, s->c: 3des-cbc hmac-sha1 none
lx0042: Entering Diffie-Hellman Group 1 key exchange.
lx0042: Sent DH public key, waiting for reply.
lx0042: Received host key, type 'ssh-dss'.
lx0042: Host 'sl00028.weimar.teagnetkom.de' is known and matches the host key.
lx0042: Computing shared secret key.
lx0042: Verifying server signature.
lx0042: Waiting for NEWKEYS message.
lx0042: Enabling incoming encryption/MAC/compression.
lx0042: Send NEWKEYS, enable outgoing encryption/MAC/compression.
lx0042: Sending request for user-authentication service.
lx0042: Service accepted: ssh-userauth.
lx0042: Trying empty user-authentication request.
lx0042: Authentication methods that can continue: publickey,password.
lx0042: Next method to try is publickey.
lx0042: Next method to try is password.
lx0042: Trying password authentication.
lx0042: Login completed, opening dummy shell channel.
lx0042: channel 0: new [client-session]
lx0042: Requesting channel_open for channel 0.
lx0042: channel 0: open confirm rwindow 0 rmax 32768
lx0042: Got channel open confirmation, requesting shell.
lx0042: Requesting service shell on channel 0.
lx0042: channel 1: new [client-session]
lx0042: Requesting channel_open for channel 1.
lx0042: Sending subsystem: sftp
lx0042: Requesting service subsystem on channel 1.
lx0042: channel 1: open confirm rwindow 0 rmax 32768
lx0042: sftp: Sending SSH2_FXP_INIT
Use of uninitialized value in numeric eq (==) at /usr/lib/perl5/site_perl/5.6.0/Net/SSH/Perl/SSH2.pm line 309.
Connection closed at /usr/local/src/Meta/test/sftptest.pl line 31



-- 
Peter Marschall
> is:energy  GmbH
Verzeichnisdienste
http://www.is-energy.de