Re^4: Establishing SSH tunnel and opening another SSH connection through it

[tehcook]

I think the root of my issues is no clear understanding of how authentication works along with ProxyCommand. In my setup I have public key auth with host that I use in ProxyCommand to run nc. And the destination host needs password auth. So when I supply username/password - which host does it apply to ? One that is serving as a relay and running nc or the final destination ?

Here is relevant part of my code. May be I need properly destroy $ssh before opening new connection too. To not stumble upon remains of the previous failed public key attempt.

while ( GO OVER ALL HOSTS I HAVE ) {

        // FIGURE OUT IF CAN BE REACHED DIRECT

        my $ssh;

        my @pw_opts = (
                -o      => "CheckHostIP no",
                -o      => "ConnectionAttempts 1",
                -o      => "ForwardAgent yes",
                -o      => "HashKnownHosts no",
                -o      => "StrictHostKeyChecking=no",
                -o      => "VerifyHostKeyDNS no",
                -o      => "UserKnownHostsFile /dev/null",
                -o      => "ConnectTimeout 5",
                -o      => "HostbasedAuthentication no",
                -o      => "ChallengeResponseAuthentication no",
                -o      => "RhostsRSAAuthentication no",
                -o      => "GSSAPIAuthentication no",
        );

        my @pubkey_opts = @pw_opts;

        push @pubkey_opts, ( -o => "PasswordAuthentication no");
        push @pubkey_opts, ( -o => "PubkeyAuthentication yes");
        push @pubkey_opts, ( -o => "PreferredAuthentications publickey
+");

        push @pw_opts, ( -o => "PreferredAuthentications=password");
        push @pw_opts, ( -o => "NumberOfPasswordPrompts=1");


        if( NOT REACHABLE DIRECT ) {
                push @pw_opts, (-o => 'ProxyCommand=ssh root@'.$sshgw.
+' nc %h 22');
                push @pubkey_opts, (-o => 'ProxyCommand=ssh root@'.$ss
+hgw.' nc %h 22');
        }

        $ssh = Net::OpenSSH->new(
                $user.'@'.$host,
                master_opts             => \@pubkey_opts,
                master_stdout_discard   => 1,
                master_stderr_discard   => 1,
        );

        if($ssh->error) {

                print "SSH key auth didn't work for $host, will try pa
+sswords...\n";

                foreach my $pass (@passwords) {

                        $ssh = Net::OpenSSH->new(
                                $user.'@'.$host,
                                password                => $pass,
                                master_opts             => \@pw_opts,
                                kill_ssh_on_timeout     => 1,
                        #       master_stdout_discard   => 1,
                        #       master_stderr_discard   => 1,
                        );

                        if(!$ssh->error) {
                                print "Authenticated with password to 
+$host\n" if($debug);
                                last;
                        } else {
                                print "SSH returned : ".$ssh->error."\
+n" if($debug);
                        }
                }

                if($ssh->error) {
                        print "Can not login into $host : ".$ssh->erro
+r."\n";
                        next;
                }

        } else {
                print "SSH key accepted at $host\n";
        }
}