# Location where all config and settings files are stored.
our $settingsdir = "${General::swroot}/suricata";
+# File where the used rulefiles are stored.
+our $used_rulefiles_file = "$settingsdir/suricata-used-rulefiles.yaml";
+
+# File where the addresses of the homenet are stored.
+our $homenet_file = "$settingsdir/suricata-homenet.yaml";
+
+# File which contains the enabled sids.
+our $enabled_sids_file = "$settingsdir/oinkmaster-enabled-sids.conf";
+
+# File which contains the disabled sids.
+our $disabled_sids_file = "$settingsdir/oinkmaster-disabled-sids.conf";
+
+# File which contains wheater the rules should be changed.
+our $modify_sids_file = "$settingsdir/oinkmaster-modify-sids.conf";
+
+# File which stores the configured IPS settings.
+our $ids_settings_file = "$settingsdir/settings";
+
+# File which stores the configured rules-settings.
+our $rules_settings_file = "$settingsdir/rules-settings";
+
+# File which stores the configured settings for whitelisted addresses.
+our $ignored_file = "$settingsdir/ignored";
+
# Location and name of the tarball which contains the ruleset.
our $rulestarball = "/var/tmp/idsrules.tar.gz";
# File to store any errors, which also will be read and displayed by the wui.
our $storederrorfile = "/tmp/ids_storederror";
+# File to lock the WUI, while the autoupdate script runs.
+our $ids_page_lock_file = "/tmp/ids_page_locked";
+
# Location where the rulefiles are stored.
our $rulespath = "/var/lib/suricata";
+# File which contains the rules to whitelist addresses on suricata.
+our $whitelist_file = "$rulespath/whitelist.rules";
+
# File which contains a list of all supported ruleset sources.
# (Sourcefire, Emergingthreads, etc..)
our $rulesetsourcesfile = "$settingsdir/ruleset-sources";
# Array with supported cron intervals.
my @cron_intervals = ('off', 'daily', 'weekly' );
+#
+## Function to check and create all IDS related files, if the does not exist.
+#
+sub check_and_create_filelayout() {
+ # Check if the files exist and if not, create them.
+ unless (-f "$enabled_sids_file") { &create_empty_file($enabled_sids_file); }
+ unless (-f "$disabled_sids_file") { &create_empty_file($disabled_sids_file); }
+ unless (-f "$modify_sids_file") { &create_empty_file($modify_sids_file); }
+ unless (-f "$used_rulefiles_file") { &create_empty_file($used_rulefiles_file); }
+ unless (-f "$ids_settings_file") { &create_empty_file($ids_settings_file); }
+ unless (-f "$rules_settings_file") { &create_empty_file($rules_settings_file); }
+ unless (-f "$ignored_file") { &create_empty_file($ignored_file); }
+ unless (-f "$whitelist_file" ) { &create_empty_file($whitelist_file); }
+}
+
#
## Function for checking if at least 300MB of free disk space are available
## on the "/var" partition.
}
#
-## This function is responsible for downloading the configured snort ruleset.
+## This function is responsible for downloading the configured IDS ruleset.
##
-## * At first it obtains from the stored snortsettings which ruleset should be downloaded.
+## * At first it obtains from the stored rules settings which ruleset should be downloaded.
## * The next step is to get the download locations for all available rulesets.
## * After that, the function will check if an upstream proxy should be used and grab the settings.
## * The last step will be to generate the final download url, by obtaining the URL for the desired
## ruleset, add the settings for the upstream proxy and final grab the rules tarball from the server.
#
sub downloadruleset {
- # Get snort settings.
- my %snortsettings=();
- &General::readhash("$settingsdir/settings", \%snortsettings);
+ # Get rules settings.
+ my %rulessettings=();
+ &General::readhash("$rules_settings_file", \%rulessettings);
# Check if a ruleset has been configured.
- unless($snortsettings{'RULES'}) {
+ unless($rulessettings{'RULES'}) {
# Log that no ruleset has been configured and abort.
&_log_to_syslog("No ruleset source has been configured.");
# Check if an upstream proxy is configured.
if ($proxysettings{'UPSTREAM_PROXY'}) {
- my ($peer, $peerport) = (/^(?:[a-zA-Z ]+\:\/\/)?(?:[A-Za-z0-9\_\.\-]*?(?:\:[A-Za-z0-9\_\.\-]*?)?\@)?([a-zA-Z0-9\.\_\-]*?)(?:\:([0-9]{1,5}))?(?:\/.*?)?$/);
my $proxy_url;
- # Check if we got a peer.
- if ($peer) {
- $proxy_url = "http://";
-
- # Check if the proxy requires authentication.
- if (($proxysettings{'UPSTREAM_USER'}) && ($proxysettings{'UPSTREAM_PASSWORD'})) {
- $proxy_url .= "$proxysettings{'UPSTREAM_USER'}\:$proxysettings{'UPSTREAM_PASSWORD'}\@";
- }
+ $proxy_url = "http://";
- # Add proxy server address and port.
- $proxy_url .= "$peer\:$peerport";
- } else {
- # Log error message and break.
- &_log_to_syslog("Could not proper configure the proxy server access.");
-
- # Return "1" - false.
- return 1;
+ # Check if the proxy requires authentication.
+ if (($proxysettings{'UPSTREAM_USER'}) && ($proxysettings{'UPSTREAM_PASSWORD'})) {
+ $proxy_url .= "$proxysettings{'UPSTREAM_USER'}\:$proxysettings{'UPSTREAM_PASSWORD'}\@";
}
+ # Add proxy server address and port.
+ $proxy_url .= $proxysettings{'UPSTREAM_PROXY'};
+
# Setup proxy settings.
- $downloader->proxy('http', $proxy_url);
+ $downloader->proxy(['http', 'https'], $proxy_url);
}
# Grab the right url based on the configured vendor.
- my $url = $rulesetsources{$snortsettings{'RULES'}};
+ my $url = $rulesetsources{$rulessettings{'RULES'}};
# Check if the vendor requires an oinkcode and add it if needed.
- $url =~ s/\<oinkcode\>/$snortsettings{'OINKCODE'}/g;
+ $url =~ s/\<oinkcode\>/$rulessettings{'OINKCODE'}/g;
# Abort if no url could be determined for the vendor.
unless ($url) {
return 1;
}
+ # Variable to store the filesize of the remote object.
+ my $remote_filesize;
+
+ # The sourcfire (snort rules) does not allow to send "HEAD" requests, so skip this check
+ # for this webserver.
+ #
+ # Check if the ruleset source contains "snort.org".
+ unless ($url =~ /\.snort\.org/) {
+ # Pass the requrested url to the downloader.
+ my $request = HTTP::Request->new(HEAD => $url);
+
+ # Accept the html header.
+ $request->header('Accept' => 'text/html');
+
+ # Perform the request and fetch the html header.
+ my $response = $downloader->request($request);
+
+ # Check if there was any error.
+ unless ($response->is_success) {
+ # Obtain error.
+ my $error = $response->status_line();
+
+ # Log error message.
+ &_log_to_syslog("Unable to download the ruleset. \($error\)");
+
+ # Return "1" - false.
+ return 1;
+ }
+
+ # Assign the fetched header object.
+ my $header = $response->headers();
+
+ # Grab the remote file size from the object and store it in the
+ # variable.
+ $remote_filesize = $header->content_length;
+ }
+
+ # Load perl module to deal with temporary files.
+ use File::Temp;
+
+ # Generate temporary file name, located in "/var/tmp" and with a suffix of ".tar.gz".
+ my $tmp = File::Temp->new( SUFFIX => ".tar.gz", DIR => "/var/tmp/", UNLINK => 0 );
+ my $tmpfile = $tmp->filename();
+
# Pass the requested url to the downloader.
my $request = HTTP::Request->new(GET => $url);
- # Perform the request and save the output into the "$rulestarball" file.
- my $response = $downloader->request($request, $rulestarball);
+ # Perform the request and save the output into the tmpfile.
+ my $response = $downloader->request($request, $tmpfile);
# Check if there was any error.
unless ($response->is_success) {
return 1;
}
+ # Load perl stat module.
+ use File::stat;
+
+ # Perform stat on the tmpfile.
+ my $stat = stat($tmpfile);
+
+ # Grab the local filesize of the downloaded tarball.
+ my $local_filesize = $stat->size;
+
+ # Check if both file sizes match.
+ if (($remote_filesize) && ($remote_filesize ne $local_filesize)) {
+ # Log error message.
+ &_log_to_syslog("Unable to completely download the ruleset. ");
+ &_log_to_syslog("Only got $local_filesize Bytes instead of $remote_filesize Bytes. ");
+
+ # Delete temporary file.
+ unlink("$tmpfile");
+
+ # Return "1" - false.
+ return 1;
+ }
+
+ # Load file copy module, which contains the move() function.
+ use File::Copy;
+
+ # Overwrite existing rules tarball with the new downloaded one.
+ move("$tmpfile", "$rulestarball");
+
+ # Set correct ownership for the rulesdir and files.
+ set_ownership("$rulestarball");
+
# If we got here, everything worked fine. Return nothing.
return;
}
# Check if the files in rulesdir have the correct permissions.
&_check_rulesdir_permissions();
+ # Cleanup the rules directory before filling it with the new rulest.
+ &_cleanup_rulesdir();
+
# Load perl module to talk to the kernel syslog.
use Sys::Syslog qw(:DEFAULT setlogsock);
openlog('oinkmaster', 'cons,pid', 'user');
# Call oinkmaster to generate ruleset.
- open(OINKMASTER, "/usr/local/bin/oinkmaster.pl -v -s -u file://$rulestarball -C $settingsdir/oinkmaster.conf -o $rulespath|") or die "Could not execute oinkmaster $!\n";
+ open(OINKMASTER, "/usr/local/bin/oinkmaster.pl -s -u file://$rulestarball -C $settingsdir/oinkmaster.conf -o $rulespath 2>&1 |") or die "Could not execute oinkmaster $!\n";
# Log output of oinkmaster to syslog.
while(<OINKMASTER>) {
# Close file.
close (ERRORFILE);
+
+ # Set correct ownership for the file.
+ &set_ownership("$storederrorfile");
}
#
}
}
+#
+## Private function to cleanup the directory which contains
+## the IDS rules, before extracting and modifing the new ruleset.
+#
+sub _cleanup_rulesdir() {
+ # Open rules directory and do a directory listing.
+ opendir(DIR, $rulespath) or die $!;
+
+ # Loop through the direcory.
+ while (my $file = readdir(DIR)) {
+ # We only want files.
+ next unless (-f "$rulespath/$file");
+
+ # Skip element if it has config as file extension.
+ next if ($file =~ m/\.config$/);
+
+ # Skip rules file for whitelisted hosts.
+ next if ("$rulespath/$file" eq $whitelist_file);
+
+ # Delete the current processed file, if not, exit this function
+ # and return an error message.
+ unlink("$rulespath/$file") or return "Could not delete $rulespath/$file. $!\n";
+ }
+
+ # Return nothing;
+ return;
+}
+
+#
+## Function to generate the file which contains the home net information.
+#
+sub generate_home_net_file() {
+ my %netsettings;
+
+ # Read-in network settings.
+ &General::readhash("${General::swroot}/ethernet/settings", \%netsettings);
+
+ # Get available network zones.
+ my @network_zones = &get_available_network_zones();
+
+ # Temporary array to store network address and prefix of the configured
+ # networks.
+ my @networks;
+
+ # Loop through the array of available network zones.
+ foreach my $zone (@network_zones) {
+ # Check if the current processed zone is red.
+ if($zone eq "red") {
+ # Grab the IP-address of the red interface.
+ my $red_address = &get_red_address();
+
+ # Check if an address has been obtained.
+ if ($red_address) {
+ # Generate full network string.
+ my $red_network = join("/", $red_address, "32");
+
+ # Add the red network to the array of networks.
+ push(@networks, $red_network);
+ }
+
+ # Check if the configured RED_TYPE is static.
+ if ($netsettings{'RED_TYPE'} eq "STATIC") {
+ # Get configured and enabled aliases.
+ my @aliases = &get_aliases();
+
+ # Loop through the array.
+ foreach my $alias (@aliases) {
+ # Add "/32" prefix.
+ my $network = join("/", $alias, "32");
+
+ # Add the generated network to the array of networks.
+ push(@networks, $network);
+ }
+ }
+ # Process remaining network zones.
+ } else {
+ # Convert current zone name into upper case.
+ $zone = uc($zone);
+
+ # Generate key to access the required data from the netsettings hash.
+ my $zone_netaddress = $zone . "_NETADDRESS";
+ my $zone_netmask = $zone . "_NETMASK";
+
+ # Obtain the settings from the netsettings hash.
+ my $netaddress = $netsettings{$zone_netaddress};
+ my $netmask = $netsettings{$zone_netmask};
+
+ # Convert the subnetmask into prefix notation.
+ my $prefix = &Network::convert_netmask2prefix($netmask);
+
+ # Generate full network string.
+ my $network = join("/", $netaddress,$prefix);
+
+ # Check if the network is valid.
+ if(&Network::check_subnet($network)) {
+ # Add the generated network to the array of networks.
+ push(@networks, $network);
+ }
+ }
+ }
+
+ # Format home net declaration.
+ my $line = "\"\[";
+
+ # Loop through the array of networks.
+ foreach my $network (@networks) {
+ # Add the network to the line.
+ $line = "$line" . "$network";
+
+ # Check if the current network was the last in the array.
+ if ($network eq $networks[-1]) {
+ # Close the line.
+ $line = "$line" . "\]\"";
+ } else {
+ # Add "," for the next network.
+ $line = "$line" . "\,";
+ }
+ }
+
+ # Open file to store the addresses of the home net.
+ open(FILE, ">$homenet_file") or die "Could not open $homenet_file. $!\n";
+
+ # Print yaml header.
+ print FILE "%YAML 1.1\n";
+ print FILE "---\n\n";
+
+ # Print notice about autogenerated file.
+ print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
+
+ # Print the generated and required HOME_NET declaration to the file.
+ print FILE "HOME_NET:\t$line\n";
+
+ # Close file handle.
+ close(FILE);
+}
+
+#
+## Function to generate and write the file for used rulefiles.
+#
+sub write_used_rulefiles_file(@) {
+ my @files = @_;
+
+ # Open file for used rulefiles.
+ open (FILE, ">$used_rulefiles_file") or die "Could not write to $used_rulefiles_file. $!\n";
+
+ # Write yaml header to the file.
+ print FILE "%YAML 1.1\n";
+ print FILE "---\n\n";
+
+ # Write header to file.
+ print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
+
+ # Allways use the whitelist.
+ print FILE " - whitelist.rules\n";
+
+ # Loop through the array of given files.
+ foreach my $file (@files) {
+ # Check if the given filename exists and write it to the file of used rulefiles.
+ if(-f "$rulespath/$file") {
+ print FILE " - $file\n";
+ }
+ }
+
+ # Close file after writing.
+ close(FILE);
+}
+
+#
+## Function to generate and write the file for modify the ruleset.
+#
+sub write_modify_sids_file() {
+ # Get configured settings.
+ my %idssettings=();
+ my %rulessettings=();
+ &General::readhash("$ids_settings_file", \%idssettings);
+ &General::readhash("$rules_settings_file", \%rulessettings);
+
+ # Gather the configured ruleset.
+ my $ruleset = $rulessettings{'RULES'};
+
+ # Open modify sid's file for writing.
+ open(FILE, ">$modify_sids_file") or die "Could not write to $modify_sids_file. $!\n";
+
+ # Write file header.
+ print FILE "#Autogenerated file. Any custom changes will be overwritten!\n";
+
+ # Check if the traffic only should be monitored.
+ unless($idssettings{'MONITOR_TRAFFIC_ONLY'} eq 'on') {
+ # Suricata is in IPS mode, which means that the rule actions have to be changed
+ # from 'alert' to 'drop', however not all rules should be changed. Some rules
+ # exist purely to set a flowbit which is used to convey other information, such
+ # as a specific type of file being downloaded, to other rulewhich then check for
+ # malware in that file. Rules which fall into the first category should stay as
+ # alert since not all flows of that type contain malware.
+
+ if($ruleset eq 'registered' or $ruleset eq 'subscripted' or $ruleset eq 'community') {
+ # These types of rulesfiles contain meta-data which gives the action that should
+ # be used when in IPS mode. Do the following:
+ #
+ # 1. Disable all rules and set the action to 'drop'
+ # 2. Set the action back to 'alert' if the rule contains 'flowbits:noalert;'
+ # This should give rules not in the policy a reasonable default if the user
+ # manually enables them.
+ # 3. Enable rules and set actions according to the meta-data strings.
+
+ my $policy = 'balanced'; # Placeholder to allow policy to be changed.
+
+ print FILE <<END;
+modifysid * "^#?(?:alert|drop)" | "#drop"
+modifysid * "^#drop(.+flowbits:noalert;)" | "#alert\${1}"
+modifysid * "^#(?:alert|drop)(.+policy $policy-ips alert)" | "alert\${1}"
+modifysid * "^#(?:alert|drop)(.+policy $policy-ips drop)" | "drop\${1}"
+END
+ } else {
+ # These rulefiles don't have the metadata, so set rules to 'drop' unless they
+ # contain the string 'flowbits:noalert;'.
+ print FILE <<END;
+modifysid * "^(#?)(?:alert|drop)" | "\${1}drop"
+modifysid * "^(#?)drop(.+flowbits:noalert;)" | "\${1}alert\${2}"
+END
+ }
+ }
+
+ # Close file handle.
+ close(FILE);
+}
+
+#
+## Function to gather the version of suricata.
+#
+sub get_suricata_version($) {
+ my ($format) = @_;
+
+ # Execute piped suricata command and return the version information.
+ open(SURICATA, "suricata -V |") or die "Couldn't execute program: $!";
+
+ # Grab and store the output of the piped program.
+ my $version_string = <SURICATA>;
+
+ # Close pipe.
+ close(SURICATA);
+
+ # Remove newlines.
+ chomp($version_string);
+
+ # Grab the version from the version string.
+ $version_string =~ /([0-9]+([.][0-9]+)+)/;
+
+ # Splitt the version into single chunks.
+ my ($major_ver, $minor_ver, $patchlevel) = split(/\./, $1);
+
+ # Check and return the requested version sheme.
+ if ($format eq "major") {
+ # Return the full version.
+ return "$major_ver";
+ } elsif ($format eq "minor") {
+ # Return the major and minor part.
+ return "$major_ver.$minor_ver";
+ } else {
+ # Return the full version string.
+ return "$major_ver.$minor_ver.$patchlevel";
+ }
+}
+
+#
+## Function to generate the rules file with whitelisted addresses.
+#
+sub generate_ignore_file() {
+ my %ignored = ();
+
+ # SID range 1000000-1999999 Reserved for Local Use
+ # Put your custom rules in this range to avoid conflicts
+ my $sid = 1500000;
+
+ # Read-in ignoredfile.
+ &General::readhasharray($IDS::ignored_file, \%ignored);
+
+ # Open ignorefile for writing.
+ open(FILE, ">$IDS::whitelist_file") or die "Could not write to $IDS::whitelist_file. $!\n";
+
+ # Config file header.
+ print FILE "# Autogenerated file.\n";
+ print FILE "# All user modifications will be overwritten.\n\n";
+
+ # Add all user defined addresses to the whitelist.
+ #
+ # Check if the hash contains any elements.
+ if (keys (%ignored)) {
+ # Loop through the entire hash and write the host/network
+ # and remark to the ignore file.
+ while ( (my $key) = each %ignored) {
+ my $address = $ignored{$key}[0];
+ my $remark = $ignored{$key}[1];
+ my $status = $ignored{$key}[2];
+
+ # Check if the status of the entry is "enabled".
+ if ($status eq "enabled") {
+ # Check if the address/network is valid.
+ if ((&General::validip($address)) || (&General::validipandmask($address))) {
+ # Write rule line to the file to pass any traffic from this IP
+ print FILE "pass ip $address any -> any any (msg:\"pass all traffic from/to $address\"\; sid:$sid\;)\n";
+
+ # Increment sid.
+ $sid++;
+ }
+ }
+ }
+ }
+
+ close(FILE);
+}
+
+#
+## Function to set correct ownership for single files and directories.
+#
+
+sub set_ownership($) {
+ my ($target) = @_;
+
+ # User and group of the WUI.
+ my $uname = "nobody";
+ my $grname = "nobody";
+
+ # The chown function implemented in perl requies the user and group as nummeric id's.
+ my $uid = getpwnam($uname);
+ my $gid = getgrnam($grname);
+
+ # Check if the given target exists.
+ unless ($target) {
+ # Stop the script and print error message.
+ die "The $target does not exist. Cannot change the ownership!\n";
+ }
+
+ # Check weather the target is a file or directory.
+ if (-f $target) {
+ # Change ownership ot the single file.
+ chown($uid, $gid, "$target");
+ } elsif (-d $target) {
+ # Do a directory listing.
+ opendir(DIR, $target) or die $!;
+ # Loop through the direcory.
+ while (my $file = readdir(DIR)) {
+
+ # We only want files.
+ next unless (-f "$target/$file");
+
+ # Set correct ownership for the files.
+ chown($uid, $gid, "$target/$file");
+ }
+
+ closedir(DIR);
+
+ # Change ownership of the directory.
+ chown($uid, $gid, "$target");
+ }
+}
+
+#
+## Function to read-in the aliases file and returns all configured and enabled aliases.
+#
+sub get_aliases() {
+ # Location of the aliases file.
+ my $aliases_file = "${General::swroot}/ethernet/aliases";
+
+ # Array to store the aliases.
+ my @aliases;
+
+ # Check if the file is empty.
+ if (-z $aliases_file) {
+ # Abort nothing to do.
+ return;
+ }
+
+ # Open the aliases file.
+ open(ALIASES, $aliases_file) or die "Could not open $aliases_file. $!\n";
+
+ # Loop through the file content.
+ while (my $line = <ALIASES>) {
+ # Remove newlines.
+ chomp($line);
+
+ # Splitt line content into single chunks.
+ my ($address, $state, $remark) = split(/\,/, $line);
+
+ # Check if the state of the current processed alias is "on".
+ if ($state eq "on") {
+ # Check if the address is valid.
+ if(&Network::check_ip_address($address)) {
+ # Add the alias to the array of aliases.
+ push(@aliases, $address);
+ }
+ }
+ }
+
+ # Close file handle.
+ close(ALIASES);
+
+ # Return the array.
+ return @aliases;
+}
+
+#
+## Function to grab the current assigned IP-address on red.
+#
+sub get_red_address() {
+ # File, which contains the current IP-address of the red interface.
+ my $file = "${General::swroot}/red/local-ipaddress";
+
+ # Check if the file exists.
+ if (-e $file) {
+ # Open the given file.
+ open(FILE, "$file") or die "Could not open $file.";
+
+ # Obtain the address from the first line of the file.
+ my $address = <FILE>;
+
+ # Close filehandle
+ close(FILE);
+
+ # Remove newlines.
+ chomp $address;
+
+ # Check if the grabbed address is valid.
+ if (&General::validip($address)) {
+ # Return the address.
+ return $address;
+ }
+ }
+
+ # Return nothing.
+ return;
+}
+
+#
+## Function to write the lock file for locking the WUI, while
+## the autoupdate script runs.
+#
+sub lock_ids_page() {
+ # Call subfunction to create the file.
+ &create_empty_file($ids_page_lock_file);
+}
+
+#
+## Function to release the lock of the WUI, again.
+#
+sub unlock_ids_page() {
+ # Delete lock file.
+ unlink($ids_page_lock_file);
+}
+
1;