Unable to ssh in linux box

pinnacle has asked for the wisdom of the Perl Monks concerning the following question:

I am getting "cipher" error while logging into linux box

#!/usr/bin/perl

use Net::SSH::Perl;
use Math::BigInt::GMP;
use strict;
use warnings;

my $host = "xx.xx.xx.xx";
print "SSHing into $host...\n";
my $user = "xxxx";
my $passwd = "xxxxx";
my $cmd = "ls -l /root";

my $ssh = Net::SSH::Perl->new($host);
 $ssh->login($user,$passwd);
my ($output, $error, $exit) = $ssh->cmd($cmd);
print $output;
[download]

Error Message

SSHing into xx.xx.xx.xx... No matching cipher found: client 3des-cbc,blowfish-cbc,arcfour server aes256-cbc at /usr/lib/perl5/vendor_perl/5.8.5/Net/SSH/Perl/SSH2.pm line 92

Comment on Unable to ssh in linux box Download Code

Replies are listed 'Best First'.
Re: Unable to ssh in linux box by JavaFan (Canon) on May 18, 2011 at 00:50 UTC
So, what happens if you manually ssh to said box? Does running it with one or more `-v`'s reveal anything? Instead of outcommenting the Ciphers line on the server side, what happens if you set them to the same values? (Don't forget to restart the server).	[reply] [d/l]
Re: Unable to ssh in linux box by Argel (Prior) on May 17, 2011 at 23:04 UTC
The error message appears to be saying your client is trying: 3des-cbc, blowfish-cbc, and arcfour but the server is only using aes256-cbc. So you need to either modify the server to use e.g. 3des-cbc or modify your client to use aes256-cbc. If Net::SSH::Perl is shelling out to run ssh then check your ssh_config file (or sshd_config on the server). Elda Taluta; Sarks Sark; Ark Arks	[reply]
Re^2: Unable to ssh in linux box by pinnacle (Acolyte) on May 18, 2011 at 00:08 UTC
I already checked it On my server in file "/etc/ssh/sshd_config" I have setting like `Ciphers aes256-cbc,3des-cbc,blowfish-cbc,arcfour` On my client in file "/etc/ssh/ssh_config" I have setting like `# Cipher 3des,aes128-cbc,3des-cbc,blowfish-cbc` So on client it's commented out So if I comment out client and server cipher lines it still does not work Also I tried to login other server from same client I was able to login, in this case both client and server cipher setting is commented out Please Assist	[reply] [d/l] [select]
Re^3: Unable to ssh in linux box by Bloodnok (Vicar) on May 18, 2011 at 15:13 UTC
Have you tried copying the config file from the server to which you successfully logged in onto the server that failed the attempt ? Also, how do the versions of the servers compare ? JAT ... A user level that continues to overstate my experience :-))	[reply]
Re^4: Unable to ssh in linux box by pinnacle (Acolyte) on May 19, 2011 at 16:24 UTC
Re: Unable to ssh in linux box by salva (Canon) on May 18, 2011 at 08:34 UTC
If you are able to connect to that host using the command line ssh client, then try using Net::OpenSSH instead of Net::SSH::Perl. Net::SSH2 may also be another good alternative.	[reply]
Re: Unable to ssh in linux box by Argel (Prior) on May 18, 2011 at 19:19 UTC
I mentioned earlier to check the configs "If Net::SSH::Perl is shelling out". I just looked at Net::SSH::Perl and it's a pure Perl implementation (i.e. not shelling out). That means you need to tell it what ciphers to use (i.e. it is not using ssh_config). You might try running the server in debug mode (without forking) on a different port to get a better idea on what is going on. Seems like what your server is responding back with doesn't match the sshd_config file. Elda Taluta; Sarks Sark; Ark Arks	[reply]