Perl

Continue SSH Tunnel Keyboard-Interactive Authentication

Demonstrates the Chilkat SshTunnel.ContinueKeyboardAuth method, which submits a response to a keyboard-interactive prompt. The only argument is the response text; for a request with multiple prompts, an XML response is supplied instead. It returns XML indicating the next prompt or the final result.

Background: This is the second half of the exchange started by StartKeyboardAuth. A server may issue several rounds of prompts, so a robust client loops: submit answers, read the returned XML, and continue until it sees success or failure. On success, BeginAccepting still must be called before the tunnel forwards traffic.

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Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

# Demonstrates the SshTunnel.ContinueKeyboardAuth method, which submits a response to a
# keyboard-interactive prompt.  The only argument is the response.  For multiple prompts, an XML
# response is supplied instead.

my $tunnel = Chilkat2::SshTunnel->new;

# The tunnel forwards accepted local connections to this destination through the SSH server.
$tunnel->DestHostname('db.internal.example.com');
$tunnel->DestPort(5432);

# Connect to the SSH server.  This performs the TCP/proxy connection and SSH handshake, but
# does not authenticate yet.
my $sshPort = 22;
my $success = $tunnel->Connect('ssh.example.com', $sshPort);
if (!$success) {
    print $tunnel->LastErrorText, "\n";
    exit;
}

# Begin keyboard-interactive authentication to receive the server's prompt(s).
my $infoRequestXml = $tunnel->StartKeyboardAuth('mySshLogin');
if (!$tunnel->LastMethodSuccess) {
    print $tunnel->LastErrorText, "\n";
    exit;
}

# Normally you would not hard-code the password in source.  You should instead obtain it
# from an interactive prompt, environment variable, or a secrets vault.
my $password = 'mySshPassword';

# Submit the response (typically the password).  The returned XML indicates the next prompt or
# the final result.
my $result = $tunnel->ContinueKeyboardAuth($password);
if (!$tunnel->LastMethodSuccess) {
    print $tunnel->LastErrorText, "\n";
    exit;
}

print $result, "\n";

my $waitForThreadExit = 1;
$success = $tunnel->CloseTunnel($waitForThreadExit);
if (!$success) {
    print $tunnel->LastErrorText, "\n";
    exit;
}