[Ssh-sftp-perl-users] Slow Authentication

[Eric L. <net...@er...>]

I'm having some trouble with slow logins using Net::SSH::Perl. I've used =
the module on other machines in the past and love what I can do with it, =
but the slow authentication I'm seeing currently is a pain.=20

I'm using Perl 5.8.0 with the latest versions of the modules downloaded =
from CPAN. Machine is a dual XEON with 64 Bit Redhat Enterprise 3.1 =
installed. Tried installing using MCPAN and also manually downloading =
and installing each module. Didn't seem to help.=20

To try and narrow things down, I've put a little script together that =
simply goes and performs an 'ls' on the remote machine.=20

use strict;
use Net::SSH::Perl;
use vars qw($ssh);


my @ident =3D ( "/home/user/.ssh/id_dsa");
my %params =3D (
        protocol =3D> 2,
        interactive =3D> 0,
        identity_files =3D> [@ident],
        debug =3D> 1,
        options =3D> [
                "BatchMode yes",
                "AuthenticationSuccessMsg no",
                "ForwardX11 no",
                "ForwardAgent no"
        ]
);

my $server =3D $ARGV[0];
&sshconnect($server);
my ($stdout, $stderr, $exit) =3D $ssh->cmd("ls");
print "$stdout\n";
if (! $ssh) {
        print "Unable to establish ssh connection to: $server\n";
} else {
        print "Successfully established ssh connection to: $server\n";
}

sub sshconnect {
        my $server =3D $_[0];
        our $ssh =3D Net::SSH::Perl->new("$server", %params);
        $ssh->login("user");
}


Output with the debug flag is as follows:

d: Reading configuration data /root/.ssh/config
d: Reading configuration data /etc/ssh_config
d: Allocated local port 1022.
d: Connecting to remote1, port 22.
d: Remote protocol version 2.0, remote software version OpenSSH_3.6.1p2
d: Net::SSH::Perl Version 1.28, protocol version 2.0.
d: No compat match: OpenSSH_3.6.1p2.
d: Connection established.
d: Sent key-exchange init (KEXINIT), wait response.
d: Algorithms, c->s: 3des-cbc hmac-sha1 none
d: Algorithms, s->c: 3des-cbc hmac-sha1 none
d: Entering Diffie-Hellman Group 1 key exchange.
d: Sent DH public key, waiting for reply.
d: Received host key, type 'ssh-dss'.
d: Host 'remote1' is known and matches the host key.
d: Computing shared secret key.
d: Verifying server signature.
d: Waiting for NEWKEYS message.
d: Enabling incoming encryption/MAC/compression.
d: Send NEWKEYS, enable outgoing encryption/MAC/compression.
d: Sending request for user-authentication service.
d: Service accepted: ssh-userauth.
d: Trying empty user-authentication request.
d: Authentication methods that can continue: =
publickey,password,keyboard-interactive.
d: Next method to try is publickey.
d: Trying pubkey authentication with key file '/home/user/.ssh/id_dsa'
d: Login completed, opening dummy shell channel.
d: channel 0: new [client-session]
d: Requesting channel_open for channel 0.
d: channel 0: open confirm rwindow 0 rmax 32768
d: Got channel open confirmation, requesting shell.
d: Requesting service shell on channel 0.
d: channel 1: new [client-session]
d: Requesting channel_open for channel 1.
d: Entering interactive session.
d: Sending command: ls
d: Requesting service exec on channel 1.
d: channel 1: open confirm rwindow 0 rmax 32768
d: input_channel_request: rtype exit-status reply 0
d: channel 1: rcvd eof
d: channel 1: output open -> drain
d: channel 1: rcvd close
d: channel 1: input open -> closed
d: channel 1: close_read
d: channel 1: obuf empty
d: channel 1: output drain -> closed
d: channel 1: close_write
d: channel 1: send close
d: channel 1: full closed
authorized_keys
sites

Successfully established ssh connection to: remote1


The delay seems to happen primarily in two places. First at the line: d: =
Algorithms, s->c: 3des-cbc hmac-sha1 none
which takes 10 seconds or so, then again at: d: Computing shared secret =
key.=20

Which again takes 10 or 15 seconds.=20

Any help would be greatly appreciated. I'd like to not have to rewrite =
the whole process to use Net::SSH