check_cas

#! /usr/bin/perl -w

# Prevent Nagios from using the Embedded Perl Interpreter for this module
# as per http://nagios.sourceforge.net/docs/3_0/embeddedperl.html
# nagios: -epn

# Nagios CAS (Central Autentication Service) plugin
#
# This plugin makes a CAS authentication to display service status, so you need
# a valid CAS account for make it working. For retrieving performance data it
# does a login into the CAS service managment application and look for the
# "<nagiosPerformanceData></nagiosPerformanceData>" tags. The user account needs
# rights to acces the service managment application to get performance data.
#
# Author: Christophe Marteau
#
# Usage:
#   perl check_cas.pl -H cas.example.fr -u "/cas/login" -p 443 -l username -a password -r "Log In Successful"

use strict;
use Getopt::Std;
use Getopt::Long qw(:config no_ignore_case);
use Pod::Usage;
use vars qw($PROGNAME);
use lib "/usr/lib/nagios/plugins";
use lib "/usr/lib64/nagios/plugins";
use utils qw (%ERRORS &print_revision);
use IO::Socket;
use Net::SSLeay qw(&post_https &make_form &make_headers &get_https4 &get_https);

my %h_Option = ();

$h_Option{'version'}{'value'}   = 0;
$h_Option{'version'}{'options'} = '.*';

$h_Option{'help'}{'value'}   = 0;
$h_Option{'help'}{'options'} = '.*';

$h_Option{'debug'}{'value'}   = 0;
$h_Option{'debug'}{'options'} = '[0-9]+';

$h_Option{'timeout'}{'value'}   = 30;
$h_Option{'timeout'}{'options'} = '[0-9]+';

$h_Option{'hostname'}{'value'}   = '';
$h_Option{'hostname'}{'options'} = '[-a-zA-Z0-9_.]+';

$h_Option{'port'}{'value'}   = 80;
$h_Option{'port'}{'options'} = '[0-9]+';

$h_Option{'url'}{'value'}   = '/cas/login';
$h_Option{'url'}{'options'} = '[-a-zA-Z0-9_./]+';

$h_Option{'ltregex'}{'value'}   = 'input type="hidden" name="lt" value="([-a-zA-Z0-9_]+)';
$h_Option{'ltregex'}{'options'} = '.+';

$h_Option{'login'}{'value'}   = '';
$h_Option{'login'}{'options'} = '.+';

$h_Option{'authentication'}{'value'}   = '';
$h_Option{'authentication'}{'options'} = '.+';

$h_Option{'regex'}{'value'}   = '';
$h_Option{'regex'}{'options'} = '.+';

$h_Option{'npd-url'}{'value'}   = '/cas/services/viewStatistics.html';
$h_Option{'npd-url'}{'options'} = '[-a-zA-Z0-9_./]+';

$h_Option{'npd-regex'}{'value'}   = '<nagiosPerformanceData>(.*)</nagiosPerformanceData>';
$h_Option{'npd-regex'}{'options'} = '.+';

my $result  = 'UNKNOWN';
my $message = 'Bad option or unknown error';

# debug function
# [in] $level :debug level
# [in] $functionName : The function name in which the debug function is call
# [in] @a_String : String array to display
my $debugCurrentDecalage = 0;

sub debug () {
  my ($level, $functionName, @a_String) = @_;

  if (($level == 9) && (join('', @a_String) =~ /^END /)) {
    $debugCurrentDecalage--;
  }

  my $space = '>';
  for (my $i = 0; $i < $debugCurrentDecalage; $i++) {
    $space = '==' . $space;
  }

  if ($h_Option{'debug'}{'value'} >= $level) {
    my @a_StringDisplayed = split("\n", join('', @a_String));

    for (my $i = 0; $i < scalar(@a_StringDisplayed); $i++) {
      print(  '# DEBUG [' 
            . $level . '] ('
            . $functionName . ') :'
            . $space . '{'
            . $a_StringDisplayed[$i] . '} '
            . "\n");
    }
  }

  if (($level == 9) && (join('', @a_String) =~ /^BEGIN /)) {
    $debugCurrentDecalage++;
  }
}

# Fonction qui teste les options pass�es en parametres du
# programme et g�n�re une aide si l'option n'est pas valide
sub parse_option {
  &debug(9, 'parse_option', 'BEGIN parse_option');

  if ($h_Option{'help'}{value}) {
    print($result. ' - Displaying help' . "\n");
    pod2usage(-verbose => 2, -exitval => $ERRORS{$result});
  }

  if ($h_Option{'version'}{'value'}) {
    print($result. ' - check_cas.pl v1.0' . "\n");
    print_revision($PROGNAME, 'check_cas.pl, v1.0');
    exit $ERRORS{$result};
  }

  foreach my $option (sort (keys(%h_Option))) {
    &debug(9, 'parse_option',
            'Parsing option "' 
          . $option . '" = {'
          . $h_Option{$option}{'value'}
          . '} with /^'
          . $h_Option{$option}{'options'}
          . '$/');
    if (exists($h_Option{$option}{'options'})) {
      if ($h_Option{$option}{'value'} !~ /^$h_Option{$option}{'options'}$/) {
        print($result. ' - Option "' . $option . '" incorrecte.' . "\n");
        pod2usage(
          -message => 'Option "' . $option . '" incorrecte.' . "\n",
          -exitval => $ERRORS{$result}
        );
      }
    }
    &debug(5, 'parse_option', 'Option "' . $option . '" = {' . $h_Option{$option}{'value'} . '}');
  }
  &debug(9, 'parse_option', 'END parse_option');
}

my $optionNumber = scalar(@ARGV);

my $options = GetOptions(
  "V|version!"          => \$h_Option{'version'}{'value'},
  "h|help!"             => \$h_Option{'help'}{'value'},
  "d|v|debug|verbose:i" => \$h_Option{'debug'}{'value'},
  "t|timeout=i"         => \$h_Option{'timeout'}{'value'},
  "H|hostname=s"        => \$h_Option{'hostname'}{'value'},
  "p|port=i"            => \$h_Option{'port'}{'value'},
  "u|url=s"             => \$h_Option{'url'}{'value'},
  "x|ltregex=s"         => \$h_Option{'ltregex'}{'value'},
  "l|login=s"           => \$h_Option{'login'}{'value'},
  "a|authentication=s"  => \$h_Option{'authentication'}{'value'},
  "r|regex=s"           => \$h_Option{'regex'}{'value'},
  "s|npd-url=s"         => \$h_Option{'npd-url'}{'value'},
  "n|npd-regex=s"       => \$h_Option{'npd-regex'}{'value'}
);

if (($options) && ($optionNumber > 0)) {
  &parse_option();
}
else {
  print($result. ' - ' . $message . ' (options found [' . $optionNumber . '])' . "\n");
  pod2usage(-verbose => 2, -exitval => $ERRORS{$result});
}

# Main program
&debug(9, 'main', 'BEGIN main');

my $serviceAlive = IO::Socket::INET->new(
  PeerAddr => $h_Option{'hostname'}{'value'},
  PeerPort => $h_Option{'port'}{'value'},
  Proto    => 'tcp',
  Timeout  => $h_Option{'timeout'}{'value'}
);

if ($serviceAlive && $serviceAlive->connected()) {

  # ToDo : Verify server certificate

  # Step 1 : Connection to the CAS login page and retrieving useful data
  #          to estabish a connection
  #           - LT : Login ticket
  #           - cookie : session cookie
  &debug(1, 'main',
          'Connection to "'
        . $h_Option{'hostname'}{'value'}
        . '" on port "'
        . $h_Option{'port'}{'value'}
        . '" => [OK]');
  close $serviceAlive;
  &debug(1, 'main',
          'Login to "https://'
        . $h_Option{'hostname'}{'value'} . ':'
        . $h_Option{'port'}{'value'}
        . $h_Option{'url'}{'value'}
        . '"');
  my ($content, $response, %h_Header, $certificat) = post_https(
    $h_Option{'hostname'}{'value'},
    $h_Option{'port'}{'value'},
    $h_Option{'url'}{'value'},
    make_headers('User-Agent' => 'nagios/check_cas')
  );

  # Verifying server response when conection is done to the login page
  &debug(1, 'main', 'Login response : {' . $response . '}');
  if ($response =~ /^HTTP\/1\.[01] 200 OK$/) {
    &debug(3, 'main', 'Login headers : ');
    foreach my $headerName (keys(%h_Header)) {
      &debug(3, 'main', '[' . $headerName . '] = {' . $h_Header{$headerName} . '}');
    }
    &debug(9, 'main', 'Login page content : ' . "\n" . $content);

    # Retreiving Login Ticket (if available)
    if ($content =~ /$h_Option{'ltregex'}{'value'}/) {
      my $loginTicket = "$1";
      &debug(1, 'main', 'CAS Login Ticket (lt) found : {' . $loginTicket . '}');

      # Retreiving session cookie (if available)
      if ($h_Header{'SET-COOKIE'} =~ /^JSESSIONID=([A-Za-z0-9_:.-]+); Path=\//) {

        my $cookie = "$1";
        &debug(1, 'main', 'CAS session Cookie found : {' . $cookie . '}');

        # Step 2 : CAS server authentication with form args
        #            - User name (login)
        #            - User passord (authentication)
        #            - Login ticket (lt)
        #            - Session cookie (cookie)
        &debug(3, 'main',
                'Authenticate to "https://'
              . $h_Option{'hostname'}{'value'} . ':'
              . $h_Option{'port'}{'value'}
              . $h_Option{'url'}{'value'}
              . '" with username "'
              . $h_Option{'login'}{'value'}
              . '" and password "'
              . $h_Option{'authentication'}{'value'}
              . '"');
        my $entity = "OTHER";
        &debug(7, 'main', 'Parsing [' . $h_Option{'url'}{'value'} . '] to retrieve entity ...');
        if ($h_Option{'url'}{'value'} =~ /\/(UT|UT1|UT2|UT3|INSA|ISAE|UNR|INP)(\/|$)/) {
          $entity = "$1";
        }
        &debug(1, 'main',
                'Login to "https://'
              . $h_Option{'hostname'}{'value'} . ':'
              . $h_Option{'port'}{'value'}
              . $h_Option{'url'}{'value'}
              . '"');
        &debug(1, 'main', 'Sending headers "[COOKIE]=>JSESSIONID=' . $cookie . '"');
        &debug(1, 'main',
                'Sending form "entity=>' 
              . $entity
              . ', username=>'
              . $h_Option{'login'}{'value'}
              . ', password=>'
              . $h_Option{'authentication'}{'value'}
              . ', lt=>'
              . $loginTicket
              . ', _eventId=>submit"');
        ($content, $response, %h_Header, $certificat) = post_https(
          $h_Option{'hostname'}{'value'},
          $h_Option{'port'}{'value'},
          $h_Option{'url'}{'value'},
          make_headers('COOKIE' => 'JSESSIONID=' . $cookie, 'User-Agent' => 'nagios/check_cas'),
          make_form(
            entity   => $entity,
            username => $h_Option{'login'}{'value'},
            password => $h_Option{'authentication'}{'value'},
            lt       => $loginTicket,
            _eventId => 'submit'
          )
        );

        &debug(1, 'main', 'Login response : {' . $response . '}');
        if ($response =~ /^HTTP\/1\.[01] 200 OK$/) {
          &debug(3, 'main', 'Login headers : ');

          # Printing headers (debug mode)
          foreach my $headerName (keys(%h_Header)) {
            &debug(3, 'main', '[' . $headerName . '] = {' . $h_Header{$headerName} . '}');
          }
          &debug(9, 'main', 'Authentication result page content : ' . "\n" . $content);

          # Verifying authentication succesful by searching a string
          # in the result page
          if ($content =~ /$h_Option{'regex'}{'value'}/) {
            $result  = 'OK';
            $message = "CAS authentication successful";

          # Getting performance DATA if available
          # Check services/viewStatistics.html (--npd-url) to retrieve performance data for nagios
            &debug(3, 'main', 'Retrieving performande DATA');

            # Getting CAS Granting Cookie
            if ($h_Header{'SET-COOKIE'} =~ /^CASTGC=([^;]+); Domain=[^;]+; Path=\/[^;]+; Secure$/)
            {
              my $casGrantingCookie = "$1";
              &debug(1, 'main', 'CAS Granting Cookie found : {' . $casGrantingCookie . '}');

              # Accessing statistics page
              &debug(1, 'main',
                      'Login to "https://'
                    . $h_Option{'hostname'}{'value'} . ':'
                    . $h_Option{'port'}{'value'}
                    . $h_Option{'npd-url'}{'value'}
                    . '"');
              &debug(1, 'main',
                      'Sending headers "[COOKIE]=>JSESSIONID=' 
                    . $cookie
                    . '; CASTGC='
                    . $casGrantingCookie
                    . '"');
              ($content, $response, %h_Header, $certificat) = post_https(
                $h_Option{'hostname'}{'value'},
                $h_Option{'port'}{'value'},
                $h_Option{'npd-url'}{'value'},
                make_headers(
                  'COOKIE' => 'JSESSIONID=' . $cookie . '; CASTGC=' . $casGrantingCookie
                )
              );

              # We are redirected to acegi security check
              &debug(1, 'main', 'Login response : {' . $response . '}');
              if ($response =~ /^HTTP\/1.1 302 Moved Temporarily$/) {
                &debug(3, 'main', 'Login headers : ');

                # Printing headers (debug mode)
                foreach my $headerName (keys(%h_Header)) {
                  &debug(3, 'main', '[' . $headerName . '] = {' . $h_Header{$headerName} . '}');
                }
                &debug(9, 'main', 'Service result page content : ' . "\n" . $content);

                # Getting acegi security check location
                if ($h_Header{'LOCATION'} =~ /^https:\/\/[^\/]+(\/.*)$/) {
                  my $acegiURL = "$1";
                  &debug(1, 'main',
                          'Login to "https://'
                        . $h_Option{'hostname'}{'value'} . ':'
                        . $h_Option{'port'}{'value'}
                        . $acegiURL
                        . '"');
                  &debug(1, 'main',
                          'Sending headers "[COOKIE]=>JSESSIONID=' 
                        . $cookie
                        . '; CASTGC='
                        . $casGrantingCookie
                        . '"');
                  ($content, $response, %h_Header, $certificat) = post_https(
                    $h_Option{'hostname'}{'value'},
                    $h_Option{'port'}{'value'},
                    $acegiURL,
                    make_headers(
                      'COOKIE' => 'JSESSIONID=' . $cookie . '; CASTGC=' . $casGrantingCookie
                    )
                  );

                  # Are we redirected to acegi security check CAS Ticket validation ? (first time)
                  &debug(1, 'main', 'Login response : {' . $response . '}');
                  if ($response =~ /^HTTP\/1.1 302 Moved Temporarily$/) {
                    &debug(3, 'main', 'Login headers : ');

                    # Printing headers (debug mode)
                    foreach my $headerName (keys(%h_Header)) {
                      &debug(3, 'main',
                        '[' . $headerName . '] = {' . $h_Header{$headerName} . '}');
                    }
                    &debug(9, 'main', 'Service result page content : ' . "\n" . $content);

                    # Getting acegi security check CAS Ticket validation location
                    if ($h_Header{'LOCATION'} =~ /^https:\/\/[^\/]+(\/.*)$/) {
                      my $acegiTicketValidateURL = "$1";
                      &debug(1, 'main',
                              'Login to "https://'
                            . $h_Option{'hostname'}{'value'} . ':'
                            . $h_Option{'port'}{'value'}
                            . $acegiTicketValidateURL
                            . '"');
                      &debug(1, 'main',
                              'Sending headers "[COOKIE]=>JSESSIONID=' 
                            . $cookie
                            . '; CASTGC='
                            . $casGrantingCookie
                            . '"');
                      ($content, $response, %h_Header, $certificat) = post_https(
                        $h_Option{'hostname'}{'value'},
                        $h_Option{'port'}{'value'},
                        $acegiTicketValidateURL,
                        make_headers(
                          'COOKIE' => 'JSESSIONID=' . $cookie . '; CASTGC=' . $casGrantingCookie
                        )
                      );

                      # Are we redirected to acegi security check CAS Ticket validation ?
                      &debug(1, 'main', 'Login response : {' . $response . '}');
                      &debug(3, 'main', 'Login headers : ');

                      # Printing headers (debug mode)
                      foreach my $headerName (keys(%h_Header)) {
                        &debug(3, 'main',
                          '[' . $headerName . '] = {' . $h_Header{$headerName} . '}');
                      }
                      &debug(9, 'main', 'Service result page content : ' . "\n" . $content);
                      if ($response =~ /^HTTP\/1.1 302 Moved Temporarily$/) {
                        &debug(1, 'main',
                                'Login to "https://'
                              . $h_Option{'hostname'}{'value'} . ':'
                              . $h_Option{'port'}{'value'}
                              . $h_Option{'npd-url'}{'value'}
                              . '"');
                        &debug(1, 'main',
                                'Sending headers "[COOKIE]=>JSESSIONID=' 
                              . $cookie
                              . '; CASTGC='
                              . $casGrantingCookie
                              . '"');
                        ($content, $response, %h_Header, $certificat) = post_https(
                          $h_Option{'hostname'}{'value'},
                          $h_Option{'port'}{'value'},
                          $h_Option{'npd-url'}{'value'},
                          make_headers(
                            'COOKIE' => 'JSESSIONID=' . $cookie . '; CASTGC=' . $casGrantingCookie
                          )
                        );
                        &debug(1, 'main', 'Login response : {' . $response . '}');
                        if ($response =~ /^HTTP\/1\.1 200 OK$/) {
                          &debug(3, 'main', 'Login headers : ');

                          # Printing headers (debug mode)
                          foreach my $headerName (keys(%h_Header)) {
                            &debug(3, 'main',
                              '[' . $headerName . '] = {' . $h_Header{$headerName} . '}');
                          }
                          &debug(9, 'main', 'Service result page content : ' . "\n" . $content);
                          if ($content =~ /$h_Option{'npd-regex'}{'value'}/) {
                            my $nagiosperformancedata = $1;
                            $result  = 'OK';
                            $message = "$message|$nagiosperformancedata";
                          }
                          else {
                            &debug(1, 'main', 'Unable get statistic page');
                            &debug(1, 'main', 'No stats available');
                          }
                        }
                        else {
                          &debug(1, 'main', 'Unable get statistic page');
                          &debug(1, 'main', 'No stats available');
                        }
                      }
                      else {
                        &debug(1, 'main',
                          'Not redirected to acegi security check CAS Ticket validation');
                        &debug(1, 'main', 'No stats available');
                      }
                    }
                    else {
                      &debug(1, 'main', 'Unable to redirect to CAS service manage');
                      &debug(1, 'main', 'No stats available');
                    }
                  }
                  else {
                    &debug(1, 'main',
                      'Not redirected to acegi security check CAS Ticket validation (first time)'
                    );
                    &debug(1, 'main', 'No stats available');
                  }
                }
                else {
                  &debug(1, 'main', 'Unable to find location for acegi security check page');
                  &debug(1, 'main', 'No stats available');
                }
              }
              else {
                &debug(1, 'main', 'Not redirected to acegi security check');
                &debug(1, 'main', 'No stats available');
              }
            }
            else {
              &debug(1, 'main', 'Unable to retrieve CAS Granting Cookie');
              &debug(1, 'main', 'No stats available');
            }
          }
          else {
            &debug(2, 'main',
                    'No match for "'
                  . $h_Option{'regex'}{'value'}
                  . '" in authentication result request.');
            $result  = 'CRITICAL';
            $message = "CAS login failed ";
          }
        }
        else {
          $result  = 'CRITICAL';
          $message = 'Cannot access to CAS authentication result ' . 'page (' . $response . ')';
          &debug(3, 'main', 'Authentication result page headers : ');
          foreach my $headerName (keys(%h_Header)) {
            &debug(3, 'main', '[' . $headerName . '] = {' . $h_Header{$headerName} . '}');
          }
          &debug(8, 'main', 'Authentication result page content : ' . "\n" . $content);
        }
      }
      else {
        $result  = 'CRITICAL';
        $message = 'CAS session cookie not found';
      }
    }
    else {
      &debug(2, 'main',
        'No match for "' . $h_Option{'ltregex'}{'value'} . '" in login result request.');
      $result  = 'CRITICAL';
      $message = 'CAS Login Ticket (lt) not found in login result ' . 'request';
    }
  }
  else {
    $result  = 'CRITICAL';
    $message = 'Cannot access to CAS login page (' . $response . ')';
  }
}
else {
  $result = 'CRITICAL';
  $message =
        'Cannot connect to CAS host "'
      . $h_Option{'hostname'}{'value'}
      . '" on port "'
      . $h_Option{'port'}{'value'} . '"';
}

print "$result - $message\n";
&debug(9, 'main', 'END main');
exit $ERRORS{$result};

__END__

=head1 NAME

  check-cas.pl - Nagios CAS (Central authentication Service) check plugins.

=cut

=head1 DESCRIPTION

  Nagios CAS (Central authentication Service) check plugins. First it does 
a request to get the CAS Login Ticket (lt) and the CAS Cookie from the login 
page. Then it does a request to authenticate with the Login ticket, the 
cookie, the username and the password. No support for http redirection in 
request, login page and authentication page must be directly accessible. if
exists, it also retreive performance data for nagios. 

=cut

=head1 SYNOPSIS

  check-cas.pl [--version] [--help] [--verbose <level>] [--debug <level>] 
               [--timeout <threshold> ] --hostname <host> [--port <port>]
               [--url <URL>] [--ltregex <regex>] --login <username> 
               --authentication <password> --regex <regex>
               [--npd-url <nagios performance data url>]
               [--npd-regex <nagios performance data regex>]
  
  Options:
   --version      : Display plugins version.
   --help         : Display this help.
   --verbose      : Same as debug option (0-9).
   --debug        : Increase debug (0-9).
   --timeout      : Time threshold to wait before timeout (in second).

   --hostname     : The CAS server host <name or IP).
   --port         : The CAS server port.
   --url          : The CAS server login URL.
   --ltregex      : Regex to find the CAS login token.

   --login        : The username used to authenticate.
   --authenticate : The password for the user to authenticate.
   --regex        : The matching regex to validate a success.
   --npd-url      : The url where to find nagios performance data.
   --npd-regex    : Regex matching the nagios performance data.

=cut

=head1 OPTIONS

=over 5

=item B<--version>

Display plugins version.

=item B<--help>

Display this help.

=item B<--verbose [0-9]>

Same as debug option.

=item B<--debug [0-9]>

Define a debug level between 0 and 9.
 0 means no debug and 9 means full debug (default to 0).

=item B<--timeout>

Time threshold in second to wait before timeout (default to 30). 

=item B<--hostname <host>>

The CAS server host. It can be a DNS name or an IP address.

=item B<--port <port>

The CAS server port (default to 80).

=item B<--url <URL>

The CAS server login URL (default to "/cas/login").

=item B<--ltregex <regex>

Regex to find the CAS login token 
(default to "input type="hidden" name="lt" value="([-a-zA-Z0-9_]+)").

=item B<--login <username>

The username used to authenticate.

=item B<--authenticate <password>>

The password for the user to authenticate.

=item B<--regex <regex>>

The matching regex to validate a success.

=item B<--npd-url <nagios performance data url>

The url where to find nagios performance data.
(default to "/cas/services/viewStatistics.html").

=item B<--npd-regex <nagios performance data regex>

Regex matching the nagios performance data.
(default to "<nagiosPerformanceData>(.*)</nagiosPerformanceData>").

=back

=cut

=head1 EXAMPLES

  Using check_cas.pl script:
perl check_cas.pl -H cas.example.fr -u "/cas/login" -p 443 
-l username -a password -r "Log In Successful"  

=cut