config/cfgroot/ids-functions.pl

   1 #!/usr/bin/perl -w
   2 ############################################################################
   3 #                                                                          #
   4 # This file is part of the IPFire Firewall.                                #
   5 #                                                                          #
   6 # IPFire is free software; you can redistribute it and/or modify           #
   7 # it under the terms of the GNU General Public License as published by     #
   8 # the Free Software Foundation; either version 2 of the License, or        #
   9 # (at your option) any later version.                                      #
  10 #                                                                          #
  11 # IPFire is distributed in the hope that it will be useful,                #
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of           #
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the            #
  14 # GNU General Public License for more details.                             #
  15 #                                                                          #
  16 # You should have received a copy of the GNU General Public License        #
  17 # along with IPFire; if not, write to the Free Software                    #
  18 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA #
  19 #                                                                          #
  20 # Copyright (C) 2018-2019 IPFire Team <info@ipfire.org>                    #
  21 #                                                                          #
  22 ############################################################################
  23
  24 use strict;
  25
  26 package IDS;
  27
  28 require '/var/ipfire/general-functions.pl';
  29 require "${General::swroot}/network-functions.pl";
  30 require "${General::swroot}/suricata/ruleset-sources";
  31
  32 # Location where all config and settings files are stored.
  33 our $settingsdir = "${General::swroot}/suricata";
  34
  35 # File where the used rulefiles are stored.
  36 our $used_rulefiles_file = "$settingsdir/suricata-used-rulefiles.yaml";
  37
  38 # File where the addresses of the homenet are stored.
  39 our $homenet_file = "$settingsdir/suricata-homenet.yaml";
  40
  41 # File where the addresses of the used DNS servers are stored.
  42 our $dns_servers_file = "$settingsdir/suricata-dns-servers.yaml";
  43
  44 # File where the HTTP ports definition is stored.
  45 our $http_ports_file = "$settingsdir/suricata-http-ports.yaml";
  46
  47 # File which contains the enabled sids.
  48 our $enabled_sids_file = "$settingsdir/oinkmaster-enabled-sids.conf";
  49
  50 # File which contains the disabled sids.
  51 our $disabled_sids_file = "$settingsdir/oinkmaster-disabled-sids.conf";
  52
  53 # File which contains wheater the rules should be changed.
  54 our $modify_sids_file = "$settingsdir/oinkmaster-modify-sids.conf";
  55
  56 # File which stores the configured IPS settings.
  57 our $ids_settings_file = "$settingsdir/settings";
  58
  59 # DEPRECATED - File which stores the configured rules-settings.
  60 our $rules_settings_file = "$settingsdir/rules-settings";
  61
  62 # File which stores the used and configured ruleset providers.
  63 our $providers_settings_file = "$settingsdir/providers-settings";
  64
  65 # File which stores the configured settings for whitelisted addresses.
  66 our $ignored_file = "$settingsdir/ignored";
  67
  68 # DEPRECATED - Location and name of the tarball which contains the ruleset.
  69 our $rulestarball = "/var/tmp/idsrules.tar.gz";
  70
  71 # Location where the downloaded rulesets are stored.
  72 our $dl_rules_path = "/var/tmp";
  73
  74 # File to store any errors, which also will be read and displayed by the wui.
  75 our $storederrorfile = "/tmp/ids_storederror";
  76
  77 # File to lock the WUI, while the autoupdate script runs.
  78 our $ids_page_lock_file = "/tmp/ids_page_locked";
  79
  80 # Location where the rulefiles are stored.
  81 our $rulespath = "/var/lib/suricata";
  82
  83 # Location of the classification file.
  84 our $classification_file = "$rulespath/classification.config";
  85
  86 # Location to store local rules. This file will not be touched.
  87 our $local_rules_file = "$rulespath/local.rules";
  88
  89 # File which contains the rules to whitelist addresses on suricata.
  90 our $whitelist_file = "$rulespath/whitelist.rules";
  91
  92 # File which contains a list of all supported ruleset sources.
  93 # (Sourcefire, Emergingthreads, etc..)
  94 our $rulesetsourcesfile = "$settingsdir/ruleset-sources";
  95
  96 # The pidfile of the IDS.
  97 our $idspidfile = "/var/run/suricata.pid";
  98
  99 # Location of suricatactrl.
 100 my $suricatactrl = "/usr/local/bin/suricatactrl";
 101
 102 # Prefix for each downloaded ruleset.
 103 my $dl_rulesfile_prefix = "idsrules";
 104
 105 # Temporary directory where the rulesets will be extracted.
 106 my $tmp_directory = "/tmp/ids_tmp";
 107
 108 # Array with allowed commands of suricatactrl.
 109 my @suricatactrl_cmds = ( 'start', 'stop', 'restart', 'reload', 'fix-rules-dir', 'cron' );
 110
 111 # Array with supported cron intervals.
 112 my @cron_intervals = ('off', 'daily', 'weekly' );
 113
 114 # Array which contains the HTTP ports, which statically will be declared as HTTP_PORTS in the
 115 # http_ports_file.
 116 my @http_ports = ('80', '81');
 117
 118 # Hash which allows to convert the download type (dl_type) to a file suffix.
 119 my %dl_type_to_suffix = (
 120         "archive" => ".tar.gz",
 121         "plain" => ".rules",
 122 );
 123
 124 #
 125 ## Function to check and create all IDS related files, if the does not exist.
 126 #
 127 sub check_and_create_filelayout() {
 128         # Check if the files exist and if not, create them.
 129         unless (-f "$enabled_sids_file") { &create_empty_file($enabled_sids_file); }
 130         unless (-f "$disabled_sids_file") { &create_empty_file($disabled_sids_file); }
 131         unless (-f "$modify_sids_file") { &create_empty_file($modify_sids_file); }
 132         unless (-f "$used_rulefiles_file") { &create_empty_file($used_rulefiles_file); }
 133         unless (-f "$ids_settings_file") { &create_empty_file($ids_settings_file); }
 134         unless (-f "$providers_settings_file") { &create_empty_file($providers_settings_file); }
 135         unless (-f "$ignored_file") { &create_empty_file($ignored_file); }
 136         unless (-f "$whitelist_file" ) { &create_empty_file($whitelist_file); }
 137 }
 138
 139 #
 140 ## Function to get a list of all available ruleset providers.
 141 ##
 142 ## They will be returned as a sorted array.
 143 #
 144 sub get_ruleset_providers() {
 145         my @providers;
 146
 147         # Loop through the hash of providers.
 148         foreach my $provider ( keys %IDS::Ruleset::Providers ) {
 149                 # Add the provider to the array.
 150                 push(@providers, $provider);
 151         }
 152
 153         # Sort and return the array.
 154         return sort(@providers);
 155 }
 156
 157 #
 158 ## Function for checking if at least 300MB of free disk space are available
 159 ## on the "/var" partition.
 160 #
 161 sub checkdiskspace () {
 162         # Call diskfree to gather the free disk space of /var.
 163         my @df = &General::system_output("/bin/df", "-B", "M", "/var");
 164
 165         # Loop through the output.
 166         foreach my $line (@df) {
 167                 # Ignore header line.
 168                 next if $line =~ m/^Filesystem/;
 169
 170                 # Search for a line with the device information.
 171                 if ($line =~ m/dev/ ) {
 172                         # Split the line into single pieces.
 173                         my @values = split(' ', $line);
 174                         my ($filesystem, $blocks, $used, $available, $used_perenctage, $mounted_on) = @values;
 175
 176                         # Check if the available disk space is more than 300MB.
 177                         if ($available < 300) {
 178                                 # Log error to syslog.
 179                                 &_log_to_syslog("Not enough free disk space on /var. Only $available MB from 300 MB available.");
 180
 181                                 # Exit function and return "1" - False.
 182                                 return 1;
 183                         }
 184                 }
 185         }
 186
 187         # Everything okay, return nothing.
 188         return;
 189 }
 190
 191 #
 192 ## This function is responsible for downloading the configured IDS rulesets or if no one is specified
 193 ## all configured rulesets will be downloaded.
 194 ##
 195 ## * At first it gathers all configured ruleset providers, initialize the downloader and sets an
 196 ##   upstream proxy if configured.
 197 ## * After that, the given ruleset or in case all rulesets should be downloaded, it will determine wether it
 198 ##   is enabled or not.
 199 ## * The next step will be to generate the final download url, by obtaining the URL for the desired
 200 ##   ruleset, add the settings for the upstream proxy.
 201 ## * Finally the function will grab all the rules files or tarballs from the servers.
 202 #
 203 sub downloadruleset ($) {
 204         my ($provider) = @_;
 205
 206         # If no provider is given default to "all".
 207         $provider //= 'all';
 208
 209         # Hash to store the providers and access id's, for which rules should be downloaded.
 210         my %sheduled_providers = ();
 211
 212         # Get used provider settings.
 213         my %used_providers = ();
 214         &General::readhasharray("$providers_settings_file", \%used_providers);
 215
 216         # Check if a ruleset has been configured.
 217         unless(%used_providers) {
 218                 # Log that no ruleset has been configured and abort.
 219                 &_log_to_syslog("No ruleset provider has been configured.");
 220
 221                 # Return "1".
 222                 return 1;
 223         }
 224
 225         # Read proxysettings.
 226         my %proxysettings=();
 227         &General::readhash("${General::swroot}/proxy/settings", \%proxysettings);
 228
 229         # Load required perl module to handle the download.
 230         use LWP::UserAgent;
 231
 232         # Init the download module.
 233         my $downloader = LWP::UserAgent->new;
 234
 235         # Set timeout to 10 seconds.
 236         $downloader->timeout(10);
 237
 238         # Check if an upstream proxy is configured.
 239         if ($proxysettings{'UPSTREAM_PROXY'}) {
 240                 my $proxy_url;
 241
 242                 $proxy_url = "http://";
 243
 244                 # Check if the proxy requires authentication.
 245                 if (($proxysettings{'UPSTREAM_USER'}) && ($proxysettings{'UPSTREAM_PASSWORD'})) {
 246                         $proxy_url .= "$proxysettings{'UPSTREAM_USER'}\:$proxysettings{'UPSTREAM_PASSWORD'}\@";
 247                 }
 248
 249                 # Add proxy server address and port.
 250                 $proxy_url .= $proxysettings{'UPSTREAM_PROXY'};
 251
 252                 # Setup proxy settings.
 253                 $downloader->proxy(['http', 'https'], $proxy_url);
 254         }
 255
 256         # Loop through the hash of configured providers.
 257         foreach my $id ( keys %used_providers ) {
 258                 # Skip providers which are not enabled.
 259                 next if ($used_providers{$id}[3] ne "enabled");
 260
 261                 # Obtain the provider handle.
 262                 my $provider_handle = $used_providers{$id}[0];
 263
 264                 # Handle update off all providers.
 265                 if (($provider eq "all") || ($provider_handle eq "$provider")) {
 266                         # Add provider handle and it's id to the hash of sheduled providers.
 267                         $sheduled_providers{$provider_handle} = $id;
 268                 }
 269         }
 270
 271         # Loop through the hash of sheduled providers.
 272         foreach my $provider ( keys %sheduled_providers) {
 273                 # Grab the download url for the provider.
 274                 my $url = $IDS::Ruleset::Providers{$provider}{'dl_url'};
 275
 276                 # Check if the provider requires a subscription.
 277                 if ($IDS::Ruleset::Providers{$provider}{'requires_subscription'} eq "True") {
 278                         # Grab the previously stored access id for the provider from hash.
 279                         my $id = $sheduled_providers{$provider};
 280
 281                         # Grab the subscription code.
 282                         my $subscription_code = $used_providers{$id}[1];
 283
 284                         # Add the subscription code to the download url.
 285                         $url =~ s/\<subscription_code\>/$subscription_code/g;
 286
 287                 }
 288
 289                 # Abort if no url could be determined for the provider.
 290                 unless ($url) {
 291                         # Log error and abort.
 292                         &_log_to_syslog("Unable to gather a download URL for the selected ruleset provider.");
 293                         return 1;
 294                 }
 295
 296                 # Variable to store the filesize of the remote object.
 297                 my $remote_filesize;
 298
 299                 # The sourcfire (snort rules) does not allow to send "HEAD" requests, so skip this check
 300                 # for this webserver.
 301                 #
 302                 # Check if the ruleset source contains "snort.org".
 303                 unless ($url =~ /\.snort\.org/) {
 304                         # Pass the requrested url to the downloader.
 305                         my $request = HTTP::Request->new(HEAD => $url);
 306
 307                         # Accept the html header.
 308                         $request->header('Accept' => 'text/html');
 309
 310                         # Perform the request and fetch the html header.
 311                         my $response = $downloader->request($request);
 312
 313                         # Check if there was any error.
 314                         unless ($response->is_success) {
 315                                 # Obtain error.
 316                                 my $error = $response->status_line();
 317
 318                                 # Log error message.
 319                                 &_log_to_syslog("Unable to download the ruleset. \($error\)");
 320
 321                                 # Return "1" - false.
 322                                 return 1;
 323                         }
 324
 325                         # Assign the fetched header object.
 326                         my $header = $response->headers();
 327
 328                         # Grab the remote file size from the object and store it in the
 329                         # variable.
 330                         $remote_filesize = $header->content_length;
 331                 }
 332
 333                 # Load perl module to deal with temporary files.
 334                 use File::Temp;
 335
 336                 # Generate temporary file name, located in "/var/tmp" and with a suffix of ".tmp".
 337                 my $tmp = File::Temp->new( SUFFIX => ".tmp", DIR => "/var/tmp/", UNLINK => 0 );
 338                 my $tmpfile = $tmp->filename();
 339
 340                 # Pass the requested url to the downloader.
 341                 my $request = HTTP::Request->new(GET => $url);
 342
 343                 # Perform the request and save the output into the tmpfile.
 344                 my $response = $downloader->request($request, $tmpfile);
 345
 346                 # Check if there was any error.
 347                 unless ($response->is_success) {
 348                         # Obtain error.
 349                         my $error = $response->content;
 350
 351                         # Log error message.
 352                         &_log_to_syslog("Unable to download the ruleset. \($error\)");
 353
 354                         # Return "1" - false.
 355                         return 1;
 356                 }
 357
 358                 # Load perl stat module.
 359                 use File::stat;
 360
 361                 # Perform stat on the tmpfile.
 362                 my $stat = stat($tmpfile);
 363
 364                 # Grab the local filesize of the downloaded tarball.
 365                 my $local_filesize = $stat->size;
 366
 367                 # Check if both file sizes match.
 368                 if (($remote_filesize) && ($remote_filesize ne $local_filesize)) {
 369                         # Log error message.
 370                         &_log_to_syslog("Unable to completely download the ruleset. ");
 371                         &_log_to_syslog("Only got $local_filesize Bytes instead of $remote_filesize Bytes. ");
 372
 373                         # Delete temporary file.
 374                         unlink("$tmpfile");
 375
 376                         # Return "1" - false.
 377                         return 1;
 378                 }
 379
 380                 # Genarate and assign file name and path to store the downloaded rules file.
 381                 my $dl_rulesfile = &_get_dl_rulesfile($provider);
 382
 383                 # Check if a file name could be obtained.
 384                 unless ($dl_rulesfile) {
 385                         # Log error message.
 386                         &_log_to_syslog("Unable to store the downloaded rules file. ");
 387
 388                         # Delete downloaded temporary file.
 389                         unlink("$tmpfile");
 390
 391                         # Return "1" - false.
 392                 }
 393
 394                 # Load file copy module, which contains the move() function.
 395                 use File::Copy;
 396
 397                 # Overwrite the may existing rulefile or tarball with the downloaded one.
 398                 move("$tmpfile", "$dl_rulesfile");
 399
 400                 # Delete temporary file.
 401                 unlink("$tmpfile");
 402
 403                 # Set correct ownership for the tarball.
 404                 set_ownership("$dl_rulesfile");
 405         }
 406
 407         # If we got here, everything worked fine. Return nothing.
 408         return;
 409 }
 410
 411 #
 412 ## Function to extract a given ruleset.
 413 #
 414 sub extractruleset ($) {
 415         my ($provider) = @_;
 416
 417         # Load perl module to deal with archives.
 418         use Archive::Tar;
 419
 420         # Load perl module to deal with files and path.
 421         use File::Basename;
 422
 423         # Get full path and downloaded rulesfile for the given provider.
 424         my $tarball = &_get_dl_rulesfile($provider);
 425
 426         # Check if the file exists.
 427         unless (-f $tarball) {
 428                 &_log_to_syslog("Could not extract ruleset file: $tarball");
 429
 430                 # Return nothing.
 431                 return;
 432         }
 433
 434         # Destination directories, where the files will be extracted.
 435         my $rules_destdir = "$tmp_directory/rules";
 436         my $conf_destdir = "$tmp_directory/conf";
 437
 438         # Check if the temporary directories exist, otherwise create them.
 439         mkdir("$tmp_directory") unless (-d "$tmp_directory");
 440         mkdir("$rules_destdir") unless (-d "$rules_destdir");
 441         mkdir("$conf_destdir") unless (-d "$conf_destdir");
 442
 443         # Initialize the tar module.
 444         my $tar = Archive::Tar->new($tarball);
 445
 446         # Get the filelist inside the tarball.
 447         my @packed_files = $tar->list_files;
 448
 449         # Loop through the filelist.
 450         foreach my $packed_file (@packed_files) {
 451                 my $destination;
 452
 453                 # Splitt the packed file into chunks.
 454                 my $file = fileparse($packed_file);
 455
 456                 # Handle msg-id.map file.
 457                 if ("$file" eq "sid-msg.map") {
 458                         # Set extract destination to temporary config_dir.
 459                         $destination = "$conf_destdir/$provider\-sid-msg.map";
 460                 # Handle classification.conf
 461                 } elsif ("$file" eq "classification.config") {
 462                         # Set extract destination to temporary config_dir.
 463                         $destination = "$conf_destdir/$provider\-classification.config";
 464                 # Handle rules files.
 465                 } elsif ($file =~ m/\.rules$/) {
 466                         my $rulesfilename;
 467
 468                         # Splitt the filename into chunks.
 469                         my @filename = split("-", $file);
 470
 471                         # Reverse the array.
 472                         @filename = reverse(@filename);
 473
 474                         # Get the amount of elements in the array.
 475                         my $elements = @filename;
 476
 477                         # Remove last element of the hash.
 478                         # It contains the vendor name, which will be replaced.
 479                         if ($elements >= 3) {
 480                                 # Remove last element from hash.
 481                                 pop(@filename);
 482                         }
 483
 484                         # Check if the last element of the filename does not
 485                         # contain the providers name.
 486                         if (@filename[-1] ne "$provider") {
 487                                 # Add provider name as last element.
 488                                 push(@filename, $provider);
 489                         }
 490
 491                         # Reverse the array back.
 492                         @filename = reverse(@filename);
 493
 494                         # Generate the name for the rulesfile.
 495                         $rulesfilename = join("-", @filename);
 496
 497                         # Set extract destination to temporaray rules_dir.
 498                         $destination = "$rules_destdir/$rulesfilename";
 499                 } else {
 500                         # Skip all other files.
 501                         next;
 502                 }
 503
 504                 # Extract the file to the temporary directory.
 505                 $tar->extract_file("$packed_file", "$destination");
 506         }
 507 }
 508
 509 #
 510 ## A tiny wrapper function to call the oinkmaster script.
 511 #
 512 sub oinkmaster () {
 513         # Check if the files in rulesdir have the correct permissions.
 514         &_check_rulesdir_permissions();
 515
 516         # Cleanup the rules directory before filling it with the new rulest.
 517         &_cleanup_rulesdir();
 518
 519         # Load perl module to talk to the kernel syslog.
 520         use Sys::Syslog qw(:DEFAULT setlogsock);
 521
 522         # Establish the connection to the syslog service.
 523         openlog('oinkmaster', 'cons,pid', 'user');
 524
 525         # Call oinkmaster to generate ruleset.
 526         open(OINKMASTER, "/usr/local/bin/oinkmaster.pl -s -u file://$rulestarball -C $settingsdir/oinkmaster.conf -o $rulespath 2>&1 |") or die "Could not execute oinkmaster $!\n";
 527
 528         # Log output of oinkmaster to syslog.
 529         while(<OINKMASTER>) {
 530                 # The syslog function works best with an array based input,
 531                 # so generate one before passing the message details to syslog.
 532                 my @syslog = ("INFO", "$_");
 533
 534                 # Send the log message.
 535                 syslog(@syslog);
 536         }
 537
 538         # Close the pipe to oinkmaster process.
 539         close(OINKMASTER);
 540
 541         # Close the log handle.
 542         closelog();
 543 }
 544
 545 #
 546 ## Function to merge the classifications for a given amount of providers and write them
 547 ## to the classifications file.
 548 #
 549 sub merge_classifications(@) {
 550         my @providers = @_;
 551
 552         # Hash to store all collected classifications.
 553         my %classifications = ();
 554
 555         # Loop through the given array of providers.
 556         foreach my $provider (@providers) {
 557                 # Generate full path to classification file.
 558                 my $classification_file = "$tmp_directory/conf/$provider\-classification.config";
 559
 560                 # Skip provider if no classification file exists.
 561                 next unless (-f "$classification_file");
 562
 563                 # Open the classification file.
 564                 open(CLASSIFICATION, $classification_file) or die "Could not open file $classification_file. $!\n";
 565
 566                 # Loop through the file content.
 567                 while(<CLASSIFICATION>) {
 568                         # Parse the file and grab the classification details.
 569                         if ($_ =~/.*config classification\: (.*)/) {
 570                                 # Split the grabbed details.
 571                                 my ($short_name, $short_desc, $priority) = split("\,", $1);
 572
 573                                 # Check if the grabbed classification is allready known and the priority value is greater
 574                                 # than the stored one (which causes less priority in the IDS).
 575                                 if (($classifications{$short_name}) && ($classifications{$short_name}[1] >= $priority)) {
 576                                         #Change the priority value to the stricter one.
 577                                         $classifications{$short_name} = [ "$classifications{$short_name}[0]", "$priority" ];
 578                                 } else {
 579                                         # Add the classification to the hash.
 580                                         $classifications{$short_name} = [ "$short_desc", "$priority" ];
 581                                 }
 582                         }
 583                 }
 584
 585                 # Close the file.
 586                 close(CLASSIFICATION);
 587         }
 588
 589         # Open classification file for writing.
 590         open(FILE, ">", "$classification_file") or die "Could not write to $classification_file. $!\n";
 591
 592         # Print notice about autogenerated file.
 593         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n\n";
 594
 595         # Sort and loop through the hash of classifications.
 596         foreach my $key (sort keys %classifications) {
 597                 # Assign some nice variable names for the items.
 598                 my $short_name = $key;
 599                 my $short_desc = $classifications{$key}[0];
 600                 my $priority = $classifications{$key}[1];
 601
 602                 # Write the classification to the file.
 603                 print FILE "config classification: $short_name,$short_desc,$priority\n";
 604         }
 605
 606         # Close file handle.
 607         close(FILE);
 608 }
 609
 610 #
 611 ## Function to do all the logging stuff if the downloading or updating of the ruleset fails.
 612 #
 613 sub log_error ($) {
 614         my ($error) = @_;
 615
 616         # Remove any newline.
 617         chomp($error);
 618
 619         # Call private function to log the error message to syslog.
 620         &_log_to_syslog($error);
 621
 622         # Call private function to write/store the error message in the storederrorfile.
 623         &_store_error_message($error);
 624 }
 625
 626 #
 627 ## Function to log a given error message to the kernel syslog.
 628 #
 629 sub _log_to_syslog ($) {
 630         my ($message) = @_;
 631
 632         # Load perl module to talk to the kernel syslog.
 633         use Sys::Syslog qw(:DEFAULT setlogsock);
 634
 635         # The syslog function works best with an array based input,
 636         # so generate one before passing the message details to syslog.
 637         my @syslog = ("ERR", "<ERROR> $message");
 638
 639         # Establish the connection to the syslog service.
 640         openlog('oinkmaster', 'cons,pid', 'user');
 641
 642         # Send the log message.
 643         syslog(@syslog);
 644
 645         # Close the log handle.
 646         closelog();
 647 }
 648
 649 #
 650 ## Private function to write a given error message to the storederror file.
 651 #
 652 sub _store_error_message ($) {
 653         my ($message) = @_;
 654
 655         # Remove any newline.
 656         chomp($message);
 657
 658         # Open file for writing.
 659         open (ERRORFILE, ">$storederrorfile") or die "Could not write to $storederrorfile. $!\n";
 660
 661         # Write error to file.
 662         print ERRORFILE "$message\n";
 663
 664         # Close file.
 665         close (ERRORFILE);
 666
 667         # Set correct ownership for the file.
 668         &set_ownership("$storederrorfile");
 669 }
 670
 671 #
 672 ## Private function to get the path and filename for a downloaded ruleset by a given provider.
 673 #
 674 sub _get_dl_rulesfile($) {
 675         my ($provider) = @_;
 676
 677         # Gather the download type for the given provider.
 678         my $dl_type = $IDS::Ruleset::Providers{$provider}{'dl_type'};
 679
 680         # Obtain the file suffix for the download file type.
 681         my $suffix = $dl_type_to_suffix{$dl_type};
 682
 683         # Check if a suffix has been found.
 684         unless ($suffix) {
 685                 # Abort return - nothing.
 686                 return;
 687         }
 688
 689         # Generate the full filename and path for the stored rules file.
 690         my $rulesfile = "$dl_rules_path/$dl_rulesfile_prefix-$provider$suffix";
 691
 692         # Return the generated filename.
 693         return $rulesfile;
 694 }
 695
 696 #
 697 ## Function to check if the IDS is running.
 698 #
 699 sub ids_is_running () {
 700         if(-f $idspidfile) {
 701                 # Open PID file for reading.
 702                 open(PIDFILE, "$idspidfile") or die "Could not open $idspidfile. $!\n";
 703
 704                 # Grab the process-id.
 705                 my $pid = <PIDFILE>;
 706
 707                 # Close filehandle.
 708                 close(PIDFILE);
 709
 710                 # Remove any newline.
 711                 chomp($pid);
 712
 713                 # Check if a directory for the process-id exists in proc.
 714                 if(-d "/proc/$pid") {
 715                         # The IDS daemon is running return the process id.
 716                         return $pid;
 717                 }
 718         }
 719
 720         # Return nothing - IDS is not running.
 721         return;
 722 }
 723
 724 #
 725 ## Function to call suricatactrl binary with a given command.
 726 #
 727 sub call_suricatactrl ($) {
 728         # Get called option.
 729         my ($option, $interval) = @_;
 730
 731         # Loop through the array of supported commands and check if
 732         # the given one is part of it.
 733         foreach my $cmd (@suricatactrl_cmds) {
 734                 # Skip current command unless the given one has been found.
 735                 next unless($cmd eq $option);
 736
 737                 # Check if the given command is "cron".
 738                 if ($option eq "cron") {
 739                         # Check if an interval has been given.
 740                         if ($interval) {
 741                                 # Check if the given interval is valid.
 742                                 foreach my $element (@cron_intervals) {
 743                                         # Skip current element until the given one has been found.
 744                                         next unless($element eq $interval);
 745
 746                                         # Call the suricatactrl binary and pass the "cron" command
 747                                         # with the requrested interval.
 748                                         &General::system("$suricatactrl", "$option", "$interval");
 749
 750                                         # Return "1" - True.
 751                                         return 1;
 752                                 }
 753                         }
 754
 755                         # If we got here, the given interval is not supported or none has been given. - Return nothing.
 756                         return;
 757                 } else {
 758                         # Call the suricatactrl binary and pass the requrested
 759                         # option to it.
 760                         &General::system("$suricatactrl", "$option");
 761
 762                         # Return "1" - True.
 763                         return 1;
 764                 }
 765         }
 766
 767         # Command not found - return nothing.
 768         return;
 769 }
 770
 771 #
 772 ## Function to create a new empty file.
 773 #
 774 sub create_empty_file($) {
 775         my ($file) = @_;
 776
 777         # Check if the given file exists.
 778         if(-e $file) {
 779                 # Do nothing to prevent from overwriting existing files.
 780                 return;
 781         }
 782
 783         # Open the file for writing.
 784         open(FILE, ">$file") or die "Could not write to $file. $!\n";
 785
 786         # Close file handle.
 787         close(FILE);
 788
 789         # Return true.
 790         return 1;
 791 }
 792
 793 #
 794 ## Private function to check if the file permission of the rulespath are correct.
 795 ## If not, call suricatactrl to fix them.
 796 #
 797 sub _check_rulesdir_permissions() {
 798         # Check if the rulepath main directory is writable.
 799         unless (-W $rulespath) {
 800                 # If not call suricatctrl to fix it.
 801                 &call_suricatactrl("fix-rules-dir");
 802         }
 803
 804         # Open snort rules directory and do a directory listing.
 805         opendir(DIR, $rulespath) or die $!;
 806         # Loop through the direcory.
 807         while (my $file = readdir(DIR)) {
 808                 # We only want files.
 809                 next unless (-f "$rulespath/$file");
 810
 811                 # Check if the file is writable by the user.
 812                 if (-W "$rulespath/$file") {
 813                         # Everything is okay - go on to the next file.
 814                         next;
 815                 } else {
 816                         # There are wrong permissions, call suricatactrl to fix it.
 817                         &call_suricatactrl("fix-rules-dir");
 818                 }
 819         }
 820 }
 821
 822 #
 823 ## Private function to cleanup the directory which contains
 824 ## the IDS rules, before extracting and modifing the new ruleset.
 825 #
 826 sub _cleanup_rulesdir() {
 827         # Open rules directory and do a directory listing.
 828         opendir(DIR, $rulespath) or die $!;
 829
 830         # Loop through the direcory.
 831         while (my $file = readdir(DIR)) {
 832                 # We only want files.
 833                 next unless (-f "$rulespath/$file");
 834
 835                 # Skip element if it has config as file extension.
 836                 next if ($file =~ m/\.config$/);
 837
 838                 # Skip rules file for whitelisted hosts.
 839                 next if ("$rulespath/$file" eq $whitelist_file);
 840
 841                 # Skip rules file with local rules.
 842                 next if ("$rulespath/$file" eq $local_rules_file);
 843
 844                 # Delete the current processed file, if not, exit this function
 845                 # and return an error message.
 846                 unlink("$rulespath/$file") or return "Could not delete $rulespath/$file. $!\n";
 847         }
 848
 849         # Return nothing;
 850         return;
 851 }
 852
 853 #
 854 ## Function to generate the file which contains the home net information.
 855 #
 856 sub generate_home_net_file() {
 857         my %netsettings;
 858
 859         # Read-in network settings.
 860         &General::readhash("${General::swroot}/ethernet/settings", \%netsettings);
 861
 862         # Get available network zones.
 863         my @network_zones = &Network::get_available_network_zones();
 864
 865         # Temporary array to store network address and prefix of the configured
 866         # networks.
 867         my @networks;
 868
 869         # Loop through the array of available network zones.
 870         foreach my $zone (@network_zones) {
 871                 # Check if the current processed zone is red.
 872                 if($zone eq "red") {
 873                         # Grab the IP-address of the red interface.
 874                         my $red_address = &get_red_address();
 875
 876                         # Check if an address has been obtained.
 877                         if ($red_address) {
 878                                 # Generate full network string.
 879                                 my $red_network = join("/", $red_address, "32");
 880
 881                                 # Add the red network to the array of networks.
 882                                 push(@networks, $red_network);
 883                         }
 884
 885                         # Check if the configured RED_TYPE is static.
 886                         if ($netsettings{'RED_TYPE'} eq "STATIC") {
 887                                 # Get configured and enabled aliases.
 888                                 my @aliases = &get_aliases();
 889
 890                                 # Loop through the array.
 891                                 foreach my $alias (@aliases) {
 892                                         # Add "/32" prefix.
 893                                         my $network = join("/", $alias, "32");
 894
 895                                         # Add the generated network to the array of networks.
 896                                         push(@networks, $network);
 897                                 }
 898                         }
 899                 # Process remaining network zones.
 900                 } else {
 901                         # Convert current zone name into upper case.
 902                         $zone = uc($zone);
 903
 904                         # Generate key to access the required data from the netsettings hash.
 905                         my $zone_netaddress = $zone . "_NETADDRESS";
 906                         my $zone_netmask = $zone . "_NETMASK";
 907
 908                         # Obtain the settings from the netsettings hash.
 909                         my $netaddress = $netsettings{$zone_netaddress};
 910                         my $netmask = $netsettings{$zone_netmask};
 911
 912                         # Convert the subnetmask into prefix notation.
 913                         my $prefix = &Network::convert_netmask2prefix($netmask);
 914
 915                         # Generate full network string.
 916                         my $network = join("/", $netaddress,$prefix);
 917
 918                         # Check if the network is valid.
 919                         if(&Network::check_subnet($network)) {
 920                                 # Add the generated network to the array of networks.
 921                                 push(@networks, $network);
 922                         }
 923                 }
 924         }
 925
 926         # Format home net declaration.
 927         my $line = "\"[" . join(',', @networks) . "]\"";
 928
 929         # Open file to store the addresses of the home net.
 930         open(FILE, ">$homenet_file") or die "Could not open $homenet_file. $!\n";
 931
 932         # Print yaml header.
 933         print FILE "%YAML 1.1\n";
 934         print FILE "---\n\n";
 935
 936         # Print notice about autogenerated file.
 937         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
 938
 939         # Print the generated and required HOME_NET declaration to the file.
 940         print FILE "HOME_NET:\t$line\n";
 941
 942         # Close file handle.
 943         close(FILE);
 944 }
 945
 946 #
 947 # Function to generate and write the file which contains the configured and used DNS servers.
 948 #
 949 sub generate_dns_servers_file() {
 950         # Get the used DNS servers.
 951         my @nameservers = &General::get_nameservers();
 952
 953         # Get network settings.
 954         my %netsettings;
 955         &General::readhash("${General::swroot}/ethernet/settings", \%netsettings);
 956
 957         # Format dns servers declaration.
 958         my $line = "";
 959
 960         # Check if the system has configured nameservers.
 961         if (@nameservers) {
 962                 # Add the GREEN address as DNS servers.
 963                 push(@nameservers, $netsettings{'GREEN_ADDRESS'});
 964
 965                 # Check if a BLUE zone exists.
 966                 if ($netsettings{'BLUE_ADDRESS'}) {
 967                         # Add the BLUE address to the array of nameservers.
 968                         push(@nameservers, $netsettings{'BLUE_ADDRESS'});
 969                 }
 970
 971                 # Generate the line which will be written to the DNS servers file.
 972                 $line = join(",", @nameservers);
 973         } else {
 974                 # External net simply contains (any).
 975                 $line = "\$EXTERNAL_NET";
 976         }
 977
 978         # Open file to store the used DNS server addresses.
 979         open(FILE, ">$dns_servers_file") or die "Could not open $dns_servers_file. $!\n";
 980
 981         # Print yaml header.
 982         print FILE "%YAML 1.1\n";
 983         print FILE "---\n\n";
 984
 985         # Print notice about autogenerated file.
 986         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
 987
 988         # Print the generated DNS declaration to the file.
 989         print FILE "DNS_SERVERS:\t\"[$line]\"\n";
 990
 991         # Close file handle.
 992         close(FILE);
 993 }
 994
 995 #
 996 # Function to generate and write the file which contains the HTTP_PORTS definition.
 997 #
 998 sub generate_http_ports_file() {
 999         my %proxysettings;
1000
1001         # Read-in proxy settings
1002         &General::readhash("${General::swroot}/proxy/advanced/settings", \%proxysettings);
1003
1004         # Check if the proxy is enabled.
1005         if (( -e "${General::swroot}/proxy/enable") || (-e "${General::swroot}/proxy/enable_blue")) {
1006                 # Add the proxy port to the array of HTTP ports.
1007                 push(@http_ports, $proxysettings{'PROXY_PORT'});
1008         }
1009
1010         # Check if the transparent mode of the proxy is enabled.
1011         if ((-e "${General::swroot}/proxy/transparent") || (-e "${General::swroot}/proxy/transparent_blue")) {
1012                 # Add the transparent proxy port to the array of HTTP ports.
1013                 push(@http_ports, $proxysettings{'TRANSPARENT_PORT'});
1014         }
1015
1016         # Format HTTP_PORTS declaration.
1017         my $line = "";
1018
1019         # Generate line which will be written to the http ports file.
1020         $line = join(",", @http_ports);
1021
1022         # Open file to store the HTTP_PORTS.
1023         open(FILE, ">$http_ports_file") or die "Could not open $http_ports_file. $!\n";
1024
1025         # Print yaml header.
1026         print FILE "%YAML 1.1\n";
1027         print FILE "---\n\n";
1028
1029         # Print notice about autogenerated file.
1030         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1031
1032         # Print the generated HTTP_PORTS declaration to the file.
1033         print FILE "HTTP_PORTS:\t\"[$line]\"\n";
1034
1035         # Close file handle.
1036         close(FILE);
1037 }
1038
1039 #
1040 ## Function to generate and write the file for used rulefiles.
1041 #
1042 sub write_used_rulefiles_file(@) {
1043         my @files = @_;
1044
1045         # Open file for used rulefiles.
1046         open (FILE, ">$used_rulefiles_file") or die "Could not write to $used_rulefiles_file. $!\n";
1047
1048         # Write yaml header to the file.
1049         print FILE "%YAML 1.1\n";
1050         print FILE "---\n\n";
1051
1052         # Write header to file.
1053         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1054
1055         # Allways use the whitelist.
1056         print FILE " - whitelist.rules\n";
1057
1058         # Loop through the array of given files.
1059         foreach my $file (@files) {
1060                 # Check if the given filename exists and write it to the file of used rulefiles.
1061                 if(-f "$rulespath/$file") {
1062                         print FILE " - $file\n";
1063                 }
1064         }
1065
1066         # Close file after writing.
1067         close(FILE);
1068 }
1069
1070 #
1071 ## Function to generate and write the file for modify the ruleset.
1072 #
1073 sub write_modify_sids_file() {
1074         # Get configured settings.
1075         my %idssettings=();
1076         my %rulessettings=();
1077         &General::readhash("$ids_settings_file", \%idssettings);
1078         &General::readhash("$rules_settings_file", \%rulessettings);
1079
1080         # Gather the configured ruleset.
1081         my $ruleset = $rulessettings{'RULES'};
1082
1083         # Open modify sid's file for writing.
1084         open(FILE, ">$modify_sids_file") or die "Could not write to $modify_sids_file. $!\n";
1085
1086         # Write file header.
1087         print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
1088
1089         # Check if the traffic only should be monitored.
1090         unless($idssettings{'MONITOR_TRAFFIC_ONLY'} eq 'on') {
1091                 # Suricata is in IPS mode, which means that the rule actions have to be changed
1092                 # from 'alert' to 'drop', however not all rules should be changed.  Some rules
1093                 # exist purely to set a flowbit which is used to convey other information, such
1094                 # as a specific type of file being downloaded, to other rulewhich then check for
1095                 # malware in that file.  Rules which fall into the first category should stay as
1096                 # alert since not all flows of that type contain malware.
1097
1098                 if($ruleset eq 'registered' or $ruleset eq 'subscripted' or $ruleset eq 'community') {
1099                         # These types of rulesfiles contain meta-data which gives the action that should
1100                         # be used when in IPS mode.  Do the following:
1101                         #
1102                         # 1. Disable all rules and set the action to 'drop'
1103                         # 2. Set the action back to 'alert' if the rule contains 'flowbits:noalert;'
1104                         #    This should give rules not in the policy a reasonable default if the user
1105                         #    manually enables them.
1106                         # 3. Enable rules and set actions according to the meta-data strings.
1107
1108                         my $policy = 'balanced';  # Placeholder to allow policy to be changed.
1109
1110                         print FILE <<END;
1111 modifysid * "^#?(?:alert|drop)" | "#drop"
1112 modifysid * "^#drop(.+flowbits:noalert;)" | "#alert\${1}"
1113 modifysid * "^#(?:alert|drop)(.+policy $policy-ips alert)" | "alert\${1}"
1114 modifysid * "^#(?:alert|drop)(.+policy $policy-ips drop)" | "drop\${1}"
1115 END
1116                 } else {
1117                         # These rulefiles don't have the metadata, so set rules to 'drop' unless they
1118                         # contain the string 'flowbits:noalert;'.
1119                         print FILE <<END;
1120 modifysid * "^(#?)(?:alert|drop)" | "\${1}drop"
1121 modifysid * "^(#?)drop(.+flowbits:noalert;)" | "\${1}alert\${2}"
1122 END
1123                 }
1124         }
1125
1126         # Close file handle.
1127         close(FILE);
1128 }
1129
1130 #
1131 ## Function to gather the version of suricata.
1132 #
1133 sub get_suricata_version($) {
1134         my ($format) = @_;
1135
1136         # Execute piped suricata command and return the version information.
1137         open(SURICATA, "suricata -V |") or die "Couldn't execute program: $!";
1138
1139         # Grab and store the output of the piped program.
1140         my $version_string = <SURICATA>;
1141
1142         # Close pipe.
1143         close(SURICATA);
1144
1145         # Remove newlines.
1146         chomp($version_string);
1147
1148         # Grab the version from the version string.
1149         $version_string =~ /([0-9]+([.][0-9]+)+)/;
1150
1151         # Splitt the version into single chunks.
1152         my ($major_ver, $minor_ver, $patchlevel) = split(/\./, $1);
1153
1154         # Check and return the requested version sheme.
1155         if ($format eq "major") {
1156                 # Return the full version.
1157                 return "$major_ver";
1158         } elsif ($format eq "minor") {
1159                 # Return the major and minor part.
1160                 return "$major_ver.$minor_ver";
1161         } else {
1162                 # Return the full version string.
1163                 return "$major_ver.$minor_ver.$patchlevel";
1164         }
1165 }
1166
1167 #
1168 ## Function to generate the rules file with whitelisted addresses.
1169 #
1170 sub generate_ignore_file() {
1171         my %ignored = ();
1172
1173         # SID range 1000000-1999999 Reserved for Local Use
1174         # Put your custom rules in this range to avoid conflicts
1175         my $sid = 1500000;
1176
1177         # Read-in ignoredfile.
1178         &General::readhasharray($IDS::ignored_file, \%ignored);
1179
1180         # Open ignorefile for writing.
1181         open(FILE, ">$IDS::whitelist_file") or die "Could not write to $IDS::whitelist_file. $!\n";
1182
1183         # Config file header.
1184         print FILE "# Autogenerated file.\n";
1185         print FILE "# All user modifications will be overwritten.\n\n";
1186
1187         # Add all user defined addresses to the whitelist.
1188         #
1189         # Check if the hash contains any elements.
1190         if (keys (%ignored)) {
1191                 # Loop through the entire hash and write the host/network
1192                 # and remark to the ignore file.
1193                 while ( (my $key) = each %ignored) {
1194                         my $address = $ignored{$key}[0];
1195                         my $remark = $ignored{$key}[1];
1196                         my $status = $ignored{$key}[2];
1197
1198                         # Check if the status of the entry is "enabled".
1199                         if ($status eq "enabled") {
1200                                 # Check if the address/network is valid.
1201                                 if ((&General::validip($address)) || (&General::validipandmask($address))) {
1202                                         # Write rule line to the file to pass any traffic from this IP
1203                                         print FILE "pass ip $address any -> any any (msg:\"pass all traffic from/to $address\"\; sid:$sid\;)\n";
1204
1205                                         # Increment sid.
1206                                         $sid++;
1207                                 }
1208                         }
1209                 }
1210         }
1211
1212         close(FILE);
1213 }
1214
1215 #
1216 ## Function to set correct ownership for single files and directories.
1217 #
1218
1219 sub set_ownership($) {
1220         my ($target) = @_;
1221
1222         # User and group of the WUI.
1223         my $uname = "nobody";
1224         my $grname = "nobody";
1225
1226         # The chown function implemented in perl requies the user and group as nummeric id's.
1227         my $uid = getpwnam($uname);
1228         my $gid = getgrnam($grname);
1229
1230         # Check if the given target exists.
1231         unless ($target) {
1232                 # Stop the script and print error message.
1233                 die "The $target does not exist. Cannot change the ownership!\n";
1234         }
1235
1236         # Check weather the target is a file or directory.
1237         if (-f $target) {
1238                 # Change ownership ot the single file.
1239                 chown($uid, $gid, "$target");
1240         } elsif (-d $target) {
1241                 # Do a directory listing.
1242                 opendir(DIR, $target) or die $!;
1243                         # Loop through the direcory.
1244                         while (my $file = readdir(DIR)) {
1245
1246                                 # We only want files.
1247                                 next unless (-f "$target/$file");
1248
1249                                 # Set correct ownership for the files.
1250                                 chown($uid, $gid, "$target/$file");
1251                         }
1252
1253                 closedir(DIR);
1254
1255                 # Change ownership of the directory.
1256                 chown($uid, $gid, "$target");
1257         }
1258 }
1259
1260 #
1261 ## Function to read-in the aliases file and returns all configured and enabled aliases.
1262 #
1263 sub get_aliases() {
1264         # Location of the aliases file.
1265         my $aliases_file = "${General::swroot}/ethernet/aliases";
1266
1267         # Array to store the aliases.
1268         my @aliases;
1269
1270         # Check if the file is empty.
1271         if (-z $aliases_file) {
1272                 # Abort nothing to do.
1273                 return;
1274         }
1275
1276         # Open the aliases file.
1277         open(ALIASES, $aliases_file) or die "Could not open $aliases_file. $!\n";
1278
1279         # Loop through the file content.
1280         while (my $line = <ALIASES>) {
1281                 # Remove newlines.
1282                 chomp($line);
1283
1284                 # Splitt line content into single chunks.
1285                 my ($address, $state, $remark) = split(/\,/, $line);
1286
1287                 # Check if the state of the current processed alias is "on".
1288                 if ($state eq "on") {
1289                         # Check if the address is valid.
1290                         if(&Network::check_ip_address($address)) {
1291                                 # Add the alias to the array of aliases.
1292                                 push(@aliases, $address);
1293                         }
1294                 }
1295         }
1296
1297         # Close file handle.
1298         close(ALIASES);
1299
1300         # Return the array.
1301         return @aliases;
1302 }
1303
1304 #
1305 ## Function to grab the current assigned IP-address on red.
1306 #
1307 sub get_red_address() {
1308         # File, which contains the current IP-address of the red interface.
1309         my $file = "${General::swroot}/red/local-ipaddress";
1310
1311         # Check if the file exists.
1312         if (-e $file) {
1313                 # Open the given file.
1314                 open(FILE, "$file") or die "Could not open $file.";
1315
1316                 # Obtain the address from the first line of the file.
1317                 my $address = <FILE>;
1318
1319                 # Close filehandle
1320                 close(FILE);
1321
1322                 # Remove newlines.
1323                 chomp $address;
1324
1325                 # Check if the grabbed address is valid.
1326                 if (&General::validip($address)) {
1327                         # Return the address.
1328                         return $address;
1329                 }
1330         }
1331
1332         # Return nothing.
1333         return;
1334 }
1335
1336 #
1337 ## Function to write the lock file for locking the WUI, while
1338 ## the autoupdate script runs.
1339 #
1340 sub lock_ids_page() {
1341         # Call subfunction to create the file.
1342         &create_empty_file($ids_page_lock_file);
1343 }
1344
1345 #
1346 ## Function to release the lock of the WUI, again.
1347 #
1348 sub unlock_ids_page() {
1349         # Delete lock file.
1350         unlink($ids_page_lock_file);
1351 }
1352
1353 1;