#!/usr/bin/perl use strict; my $VERSION = '0.1'; my $COPYRIGHT = 'Copyright (C) 2005-2011 Jonathan Buhacoff '; my $LICENSE = 'http://www.gnu.org/licenses/gpl.txt'; my %status = ( 'OK' => 0, 'WARNING' => 1, 'CRITICAL' => 2, 'UNKNOWN' => 3 ); use Getopt::Long; use Mail::IMAPClient; use IO::Socket::SSL; use Net::SSLeay; # get options from command line Getopt::Long::Configure("bundling"); my $verbose = 0; my $help = ""; my $help_usage = ""; my $show_version = ""; my $imap_server = ""; my $default_imap_port = "143"; my $default_imap_ssl_port = "993"; my $imap_port = ""; my $timeout = 60; my $ok; $ok = Getopt::Long::GetOptions( "V|version"=>\$show_version, "v|verbose+"=>\$verbose,"h|help"=>\$help,"usage"=>\$help_usage, # imap settings "H|hostname=s"=>\$imap_server,"p|port=i"=>\$imap_port, # time "t|timeout=i"=>\$timeout ); if( $show_version ) { print "$VERSION\n"; exit $status{UNKNOWN}; } if( $help ) { exec "perldoc", $0 or print "Try `perldoc $0`\n"; exit $status{UNKNOWN}; } if( $help_usage || ( $imap_server eq "" ) ) { print "Usage: $0 -H host [-p port]\n"; exit $status{UNKNOWN}; } my @certs = (); # we have to store the certs we get Net::SSLeay here so that we can output them in REVERSE order (server cert first, root cert last) # connect to IMAP server print "connecting to server $imap_server\n" if $verbose > 2; my $imap; eval { local $SIG{ALRM} = sub { die "exceeded timeout $timeout seconds\n" }; # NB: \n required, see `perldoc -f alarm` alarm $timeout; $imap_port = $default_imap_ssl_port unless $imap_port; my $socket = IO::Socket::SSL->new( PeerAddr => "$imap_server:$imap_port", SSL_verify_mode => 1, SSL_ca_file => undef, SSL_verifycn_scheme => 'imap', SSL_verifycn_name => $imap_server, SSL_verify_callback => \&ssl_printer ); die IO::Socket::SSL::errstr() unless $socket; $socket->autoflush(1); $imap = Mail::IMAPClient->new(Socket=>$socket, Debug => 0 ); $imap->State(Mail::IMAPClient->Connected); $imap->_read_line() if "$Mail::IMAPClient::VERSION" le "2.2.9"; # necessary to remove the server's "ready" line from the input buffer for old versions of Mail::IMAPClient. Using string comparison for the version check because the numeric didn't work on Darwin and for Mail::IMAPClient the next version is 2.3.0 and then 3.00 so string comparison works # $imap->User($username); # $imap->Password($password); # $imap->login() or die "Cannot login: $@"; print join("\n",reverse(@certs)); alarm 0; }; if( $@ ) { chomp $@; print "Could not connect to $imap_server port $imap_port: $@\n"; exit $status{CRITICAL}; } unless( $imap ) { print "Could not connect to $imap_server port $imap_port: $@\n"; exit $status{CRITICAL}; } # deselect the mailbox $imap->close(); # disconnect from IMAP server print "disconnecting from server\n" if $verbose > 2; $imap->logout(); exit $status{OK}; # see IO::Socket::SSL documentation for SSL_verify_callback: sub ssl_printer { my ($boolOpenSSLResult, $cmemCertificateStore, $strCertIssuerOwnerAttr, $strError, $cmemPeerCertificate) = @_; warn "OpenSSL says certificate is " . ( $boolOpenSSLResult ? "valid" : "invalid" ) if $verbose > 0; warn "Peer certificate: $strCertIssuerOwnerAttr" if $verbose > 0; warn "Errors: $strError" if $verbose > 0; #print Net::SSLeay::PEM_get_string_X509($cmemPeerCertificate); push @certs, $strCertIssuerOwnerAttr . "\n" . Net::SSLeay::PEM_get_string_X509($cmemPeerCertificate); } package main; 1; __END__ =pod =head1 NAME imap_ssl_cert - connects to an IMAP server using SSL and saves the server certificate into a .pem file =head1 SYNOPSIS imap_ssl_cert -H imap.server.com > server_ca_file.pem imap_ssl_cert -? imap_ssl_cert --help =head1 DEPENDENCIES This utility requires the following perl modules to be installed: Getopt::Long Mail::IMAPClient IO::Socket::SSL Net::SSLeay =head1 OPTIONS =over =item --timeout Abort with critical status if it takes longer than to connect to the IMAP server. Default is 60 seconds. The difference between timeout and critical is that, with the default settings, if it takes 45 seconds to connect to the server then the connection will succeed but the plugin will return CRITICAL because it took longer than 30 seconds. Also known as: -t =item --hostname Address or name of the IMAP server. Examples: mail.server.com, localhost, 192.168.1.100 Also known as: -H =item --port Service port on the IMAP server. Default is 143. If you use SSL, default is 993. Also known as: -p =item --verbose Display additional information. Useful for troubleshooting. Also known as: -v =item --version Display plugin version and exit. Also known as: -V =item --help Display this documentation and exit. Also known as: -h =item --usage Display a short usage instruction and exit. =back =head1 EXAMPLES =head2 Print the server's SSL certificate chain $ perl imap_ssl_cert.pl -H imap.server.com > ca_file.pem $ cat ca_file.pem -----BEGIN CERTIFICATE----- MIID1zCCAr+gAwIBAgIQPr3bVk0SkuXygjxgA7EVGDANBgkqhkiG9w0BAQUFADA8 [...snip...] 0FF4warjskrfqaVtWeIV58LJheaM4cPJkc2M -----END CERTIFICATE----- $ openssl x509 -in ca_file.pem -text =head1 SEE ALSO http://en.wikipedia.org/wiki/X.509 http://en.wikipedia.org/wiki/Privacy_Enhanced_Mail http://tools.ietf.org/html/rfc1422 http://search.cpan.org/~mikem/Net-SSLeay-1.42/lib/Net/SSLeay.pm http://search.cpan.org/~plobbes/Mail-IMAPClient-3.29/lib/Mail/IMAPClient.pod =head1 CHANGES Fri Nov 11 03:38:13 AST 2011 + version 0.1 =head1 AUTHOR Jonathan Buhacoff =head1 COPYRIGHT AND LICENSE Copyright (C) 2011 Jonathan Buhacoff This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . http://www.gnu.org/licenses/gpl.txt =cut