diff options
Diffstat (limited to 'config/snort/snort.inc')
| -rwxr-xr-x | config/snort/snort.inc | 938 |
1 files changed, 928 insertions, 10 deletions
diff --git a/config/snort/snort.inc b/config/snort/snort.inc index e442755a..abe2f9ad 100755 --- a/config/snort/snort.inc +++ b/config/snort/snort.inc @@ -41,7 +41,7 @@ require_once("pkg-utils.inc"); require_once("filter.inc"); // Snort GUI needs some extra PHP memory space to manipulate large rules arrays -ini_set("memory_limit", "192M"); +ini_set("memory_limit", "256M"); // Explicitly declare this as global so it works through function call includes global $rebuild_rules, $pfSense_snort_version; @@ -82,6 +82,7 @@ define("GPL_FILE_PREFIX", "GPLv2_"); define("ET_OPEN_FILE_PREFIX", "emerging-"); define("ET_PRO_FILE_PREFIX", "etpro-"); define("IPREP_PATH", "/var/db/snort/iprep/"); +define('SID_MODS_PATH', '/var/db/snort/sidmods/'); /* Rebuild Rules Flag -- if "true", rebuild enforcing rules and flowbit-rules files */ $rebuild_rules = false; @@ -1157,11 +1158,11 @@ function snort_load_rules_map($rules_path) { if (empty($rules_path)) return $map_ref; - /*************************************************************** + /************************************************************************************ * Read all the rules into the map array. * The structure of the map array is: * - * map[gid][sid]['rule']['category']['disabled']['action']['flowbits'] + * map[gid][sid]['rule']['category']['action']['disabled']['managed']['flowbits'] * * where: * gid = Generator ID from rule, or 1 if general text @@ -1169,12 +1170,14 @@ function snort_load_rules_map($rules_path) { * sid = Signature ID from rule * rule = Complete rule text * category = File name of file containing the rule + * action = alert, drop, reject or pass * disabled = 1 if rule is disabled (commented out), 0 if * rule is enabled - * action = alert|log|pass|drop|reject|sdrop + * managed = 1 if rule is auto-managed by SID MGMT process, + * 0 if not auto-managed * flowbits = Array of applicable flowbits if rule contains * flowbits options - ***************************************************************/ + ************************************************************************************/ /* First check if we were passed a directory, a single file */ /* or an array of filenames to read. Set our $rule_files */ @@ -1697,6 +1700,854 @@ function snort_write_enforcing_rules_file($rule_map, $rule_path) { } } +function snort_parse_sidconf_file($sidconf_file) { + + /**********************************************/ + /* This function loads and processes the file */ + /* specified by '$sidconf_file'. The file is */ + /* assumed to contain valid instructions for */ + /* matching rule SIDs as supported by the */ + /* Oinkmaster and PulledPork utilities. */ + /* */ + /* $sidconf_file ==> full path and name of */ + /* file to process */ + /* */ + /* Returns ==> an array containing */ + /* SID modifier tokens */ + /**********************************************/ + + $buf = ""; + $sid_mods = array(); + + $fd = fopen("{$sidconf_file}", "r"); + if ($fd == FALSE) { + log_error("[Snort] Failed to open SID MGMT file '{$sidconf_file}' for processing."); + return $sid_mods; + } + + // Read and parse the conf file line-by-line + while (($buf = fgets($fd)) !== FALSE) { + $line = array(); + + // Skip any lines that may be just spaces. + if (trim($buf, " \r\n") == "") + continue; + + // Skip line with leading "#" since it's a comment + if (preg_match('/^\s*#/', $buf)) + continue; + + // Trim off any trailing comment + $line = explode("#", $buf); + + // Trim leading and trailing spaces plus newline and any carriage returns + $buf = trim($line[0], ' \r\n'); + + // Now split the SID mod arguments at the commas, if more than one + // per line, and add to our $sid_mods array. + $line = explode(",", $buf); + foreach ($line as $ent) + $sid_mods[] = trim($ent); + } + + // Close the file, release unneeded memory and return + // the array of SID mod tokens parsed from the file. + fclose($fd); + unset($line, $buf); + return $sid_mods; +} + +function snort_sid_mgmt_auto_categories($snortcfg, $log_results = FALSE) { + + /****************************************************/ + /* This function parses any auto-SID conf files */ + /* configured for the interface and returns an */ + /* array of rule categories adjusted from the */ + /* ['enabled_rulesets'] element in the config for */ + /* the interface in accordance with the contents */ + /* of the SID Mgmt conf files. */ + /* */ + /* The returned array shows which files should be */ + /* removed and which should be added to the list */ + /* used when building the enforcing ruleset. */ + /* */ + /* $snortcfg ==> pointer to interface */ + /* configuration info */ + /* $log_results ==> [optional] log results to */ + /* 'sid_changes.log' in the */ + /* interface directory in */ + /* /var/log/snort when TRUE */ + /* */ + /* Returns ==> array of category file names */ + /* for the interface. The keys */ + /* are category file names and */ + /* the corresponding values show */ + /* if the file should be added */ + /* or removed from the enabled */ + /* rulesets list. */ + /* */ + /* Example - */ + /* $changes[file] = 'enabled' */ + /* */ + /****************************************************/ + + global $config; + $snort_sidmods_dir = SID_MODS_PATH; + $sid_mods = array(); + $enables = array(); + $disables = array(); + + // Check if auto-mgmt of SIDs is enabled, exit if not + if ($config['installedpackages']['snortglobal']['auto_manage_sids'] != 'on') + return array(); + if (empty($snortcfg['disable_sid_file']) && empty($snortcfg['enable_sid_file'])) + return array(); + + // Configure the interface's logging subdirectory if log results is enabled + if ($log_results == TRUE) + $log_file = SNORTLOGDIR . "/snort_" . get_real_interface($snortcfg['interface']) . "{$snortcfg['uuid']}/sid_changes.log"; + else + $log_file = NULL; + + // Get the list of currently enabled categories for the interface + if (!empty($snortcfg['rulesets'])) + $enabled_cats = explode("||", $snortcfg['rulesets']); + + if ($log_results == TRUE) { + error_log(gettext("********************************************************\n"), 3, $log_file); + error_log(gettext("Starting auto RULE CATEGORY management for " . convert_friendly_interface_to_friendly_descr($snortcfg['interface']) ."\n"), 3, $log_file); + error_log(gettext("Start Time: " . date("Y-m-d H:i:s") . "\n"), 3, $log_file); + } + + switch ($snortcfg['sid_state_order']) { + case "disable_enable": + if (!empty($snortcfg['disable_sid_file'])) { + if ($log_results == TRUE) + error_log(gettext("Processing disable_sid file: {$snortcfg['disable_sid_file']}\n"), 3, $log_file); + + // Attempt to open the 'disable_sid_file' for the interface + if (!file_exists("{$snort_sidmods_dir}{$snortcfg['disable_sid_file']}")) { + log_error(gettext("[Snort] Error - unable to open 'disable_sid_file' \"{$snortcfg['disable_sid_file']}\" specified for " . convert_friendly_interface_to_friendly_descr($snortcfg['interface']))); + if ($log_results == TRUE) + error_log(gettext("Unable to open disable_sid file \"{$snortcfg['disable_sid_file']}\".\n"), 3, $log_file); + } + else + $sid_mods = snort_parse_sidconf_file("{$snort_sidmods_dir}{$snortcfg['disable_sid_file']}"); + + if (!empty($sid_mods)) + $disables = snort_get_auto_category_mods($enabled_cats, $sid_mods, "disable", $log_results, $log_file); + elseif ($log_results == TRUE && !empty($log_file)) { + error_log(gettext("WARNING: no valid SID match tokens found in file \"{$snortcfg['disable_sid_file']}\".\n"), 3, $log_file); + } + } + if (!empty($snortcfg['enable_sid_file'])) { + if ($log_results == TRUE) + error_log(gettext("Processing enable_sid file: {$snortcfg['enable_sid_file']}\n"), 3, $log_file); + + // Attempt to open the 'enable_sid_file' for the interface + if (!file_exists("{$snort_sidmods_dir}{$snortcfg['enable_sid_file']}")) { + log_error(gettext("[Snort] Error - unable to open 'enable_sid_file' \"{$snortcfg['enable_sid_file']}\" specified for " . convert_friendly_interface_to_friendly_descr($snortcfg['interface']))); + if ($log_results == TRUE) + error_log(gettext("Unable to open enable_sid file \"{$snortcfg['enable_sid_file']}\".\n"), 3, $log_file); + } + else + $sid_mods = snort_parse_sidconf_file("{$snort_sidmods_dir}{$snortcfg['enable_sid_file']}"); + + if (!empty($sid_mods)) + $enables = snort_get_auto_category_mods($enabled_cats, $sid_mods, "enable", $log_results, $log_file); + elseif ($log_results == TRUE && !empty($log_file)) { + error_log(gettext("WARNING: no valid SID match tokens found in file \"{$snortcfg['enable_sid_file']}\".\n"), 3, $log_file); + } + } + break; + + case "enable_disable": + if (!empty($snortcfg['enable_sid_file'])) { + if ($log_results == TRUE) + error_log(gettext("Processing enable_sid file: {$snortcfg['enable_sid_file']}\n"), 3, $log_file); + + // Attempt to open the 'enable_sid_file' for the interface + if (!file_exists("{$snort_sidmods_dir}{$snortcfg['enable_sid_file']}")) { + log_error(gettext("[Snort] Error - unable to open 'enable_sid_file' \"{$snortcfg['enable_sid_file']}\" specified for " . convert_friendly_interface_to_friendly_descr($snortcfg['interface']))); + if ($log_results == TRUE) + error_log(gettext("Unable to open enable_sid file \"{$snortcfg['enable_sid_file']}\".\n"), 3, $log_file); + } + else + $sid_mods = snort_parse_sidconf_file("{$snort_sidmods_dir}{$snortcfg['enable_sid_file']}"); + + if (!empty($sid_mods)) + $enables = snort_get_auto_category_mods($enabled_cats, $sid_mods, "enable", $log_results, $log_file); + elseif ($log_results == TRUE && !empty($log_file)) { + error_log(gettext("WARNING: no valid SID match tokens found in file \"{$snortcfg['enable_sid_file']}\".\n"), 3, $log_file); + } + } + if (!empty($snortcfg['disable_sid_file'])) { + if ($log_results == TRUE) + error_log(gettext("Processing disable_sid file: {$snortcfg['disable_sid_file']}\n"), 3, $log_file); + + // Attempt to open the 'disable_sid_file' for the interface + if (!file_exists("{$snort_sidmods_dir}{$snortcfg['disable_sid_file']}")) { + log_error(gettext("[Snort] Error - unable to open 'disable_sid_file' \"{$snortcfg['disable_sid_file']}\" specified for " . convert_friendly_interface_to_friendly_descr($snortcfg['interface']))); + if ($log_results == TRUE) + error_log(gettext("Unable to open disable_sid file \"{$snortcfg['disable_sid_file']}\".\n"), 3, $log_file); + } + else + $sid_mods = snort_parse_sidconf_file("{$snort_sidmods_dir}{$snortcfg['disable_sid_file']}"); + + if (!empty($sid_mods)) + $disables = snort_get_auto_category_mods($enabled_cats, $sid_mods, "disable", $log_results, $log_file); + elseif ($log_results == TRUE && !empty($log_file)) { + error_log(gettext("WARNING: no valid SID match tokens found in file \"{$snortcfg['disable_sid_file']}\".\n"), 3, $log_file); + } + } + break; + + default: + log_error(gettext("[Snort] Unrecognized 'sid_state_order' value. Skipping auto CATEGORY mgmt step for " . convert_friendly_interface_to_friendly_descr($snortcfg['interface']))); + if ($log_results == TRUE) { + error_log(gettext("ERROR: unrecognized 'sid_state_order' value. Skipping auto CATEGORY mgmt step for ") . convert_friendly_interface_to_friendly_descr($snortcfg['interface']). ".\n", 3, $log_file); + } + } + + if ($log_results == TRUE) { + error_log(gettext("End Time: " . date("Y-m-d H:i:s") . "\n"), 3, $log_file); + error_log(gettext("********************************************************\n\n"), 3, $log_file); + } + + // Return the required rule category modifications as an array; + return array_merge($enables, $disables); +} + +function snort_get_auto_category_mods($categories, $sid_mods, $action, $log_results = FALSE, $log_file = NULL) { + + /****************************************************/ + /* This function parses the provided SID mod tokens */ + /* in $sid_mods and returns an array of category */ + /* files that must be added ('enabled') or removed */ + /* ('disabled') from the provided $categories list */ + /* of enabled rule categories as determined by the */ + /* content of the SID Mgmt tokens in $sid_mods. */ + /* */ + /* The returned array shows which files should be */ + /* removed and which should be added to the list */ + /* used when building the enforcing ruleset. */ + /* */ + /* $categories ==> array of currently enabled */ + /* ruleset categories */ + /* $sid_mods ==> array of SID modification */ + /* tokens */ + /* $action ==> modification action for */ + /* matching category targets: */ + /* 'enable' or 'disable' */ + /* $log_results ==> [optional] 'yes' to log */ + /* results to $log_file */ + /* $log_file ==> full path and filename of log */ + /* file to write to */ + /* */ + /* Returns ==> array of category file names */ + /* for the interface. The keys */ + /* are category file names and */ + /* the corresponding values show */ + /* if the file should be added */ + /* or removed from the enabled */ + /* rulesets list. */ + /* */ + /* Example - */ + /* $changes[file] = 'enabled' */ + /* */ + /****************************************************/ + + $snortdir = SNORTDIR; + $all_cats = array(); + $changes = array(); + $counter = 0; + $matchcount = 0; + + // Get a list of all possible categories by loading all rules files + foreach (array( VRT_FILE_PREFIX, ET_OPEN_FILE_PREFIX, ET_PRO_FILE_PREFIX, GPL_FILE_PREFIX ) as $prefix) { + $files = glob("{$snortdir}/rules/{$prefix}*.rules"); + foreach ($files as $file) + $all_cats[] = basename($file); + } + + // Walk the SID mod tokens and decode looking for rule + // category enable/disable changes. + foreach ($sid_mods as $tok) { + $matches = array(); + // Test the SID token for a GID:SID range and skip if true + if (preg_match('/^(\d+):(\d+)-\1:(\d+)/', $tok)) + continue; + // Test the token for a single GID:SID and skip if true + elseif (preg_match('/^(\d+):(\d+)$/', $tok)) + continue; + // Test the token for the PCRE: keyword and skip if true + elseif (preg_match('/(^pcre\:)(.+)/i', $tok)) + continue; + // Test the token for the MS reference keyword and skip if true + elseif (preg_match('/^MS\d+-.+/i', $tok)) + continue; + // Test the token for other keywords delimited with a colon and skip if true + elseif (preg_match('/^[a-xA-X]+\:.+/', $tok)) + continue; + // Test the SID token for a rule category name. Anything that + // failed to match above is considered a potential category name. + elseif (preg_match('/[a-xA-X]+(-|\w).*/', $tok, $matches)) { + $counter++; + $regex = "/" . preg_quote(trim($matches[0]), '/') . "/i"; + // Search through the $all_cats array for any matches to the regex + $matches = preg_grep($regex, $all_cats); + + // See if any matches are in the $categories array + foreach ($matches as $cat) { + switch ($action) { + case 'enable': + if (!isset($changes[$cat])) { + $changes[$cat] = 'enabled'; + if ($log_results == TRUE && !empty($log_file)) + error_log(gettext(" Enabled rule category: {$cat}\n"), 3, $log_file); + $matchcount++; + } + break; + + case 'disable': + if (!isset($changes[$cat])) { + $changes[$cat] = 'disabled'; + if ($log_results == TRUE && !empty($log_file)) + error_log(gettext(" Disabled rule category: {$cat}\n"), 3, $log_file); + $matchcount++; + } + break; + + default: + break; + } + } + } + else { + if ($log_results == TRUE && !empty($log_file)) + error_log(gettext("WARNING: unrecognized token '{$tok}' encountered while processing an automatic SID MGMT file.\n"), 3, $log_file); + } + } + + if ($log_results == TRUE && !empty($log_file)) { + error_log(gettext(" Parsed {$counter} potential Rule Categories to match from the list of tokens.\n"), 3, $log_file); + error_log(gettext(" " . ucfirst($action) . "d {$matchcount} matching Rule Categories.\n"), 3, $log_file); + } + + // Release memory no longer needed + unset($all_cats, $matches); + + // Return array of rule category file changes + return $changes; +} + +function snort_modify_sid_state(&$rule_map, $sid_mods, $action, $log_results = FALSE, $log_file = NULL) { + + /**********************************************/ + /* This function walks the provided array of */ + /* SID modification tokens and locates the */ + /* target SID or SIDs in the $rule_map array. */ + /* It then performs the change specified by */ + /* $action on the target SID or SIDs. */ + /* */ + /* $rule_map ==> reference to array of */ + /* current rules */ + /* $sid_mods ==> array of SID modification */ + /* tokens */ + /* $action ==> modification action for */ + /* matching SID targets: */ + /* 'enable' or 'disable' */ + /* $log_results ==> [optional] 'yes' to log */ + /* results to $log_file */ + /* $log_file ==> full path and filename */ + /* of log file to write to */ + /* */ + /* On Return ==> $rule_map array modified */ + /* by changing state for */ + /* matching SIDs. */ + /* */ + /* Returns a two-dimension */ + /* array of matching GID:SID */ + /* pairs. */ + /**********************************************/ + + $sids = array(); + + // If no rules in $rule_map or mods in $sid_mods, + // then nothing to do. + if (empty($rule_map) || empty($sid_mods)) + return $sids; + + // Validate the action keyword as we only accept + // 'enable' and 'disable' as valid. + switch ($action) { + + case "enable": + break; + + case "disable": + break; + + default: + log_error(gettext("[Snort] Error - unknown action '{$action}' supplied to snort_modify_sid_state() function...no SIDs modified.")); + return $sids; + } + + // Walk the SID mod tokens and decode each one + foreach ($sid_mods as $tok) { + $matches = array(); + // Test the SID token for a GID:SID range + if (preg_match('/^(\d+):(\d+)-\1:(\d+)/', $tok, $matches)) { + // It was a range, so find all the intervening SIDs + $gid = trim($matches[1]); + $lsid = trim($matches[2]); + $usid = trim($matches[3]); + $sids[$gid][$lsid] = $action; + while ($lsid < $usid) { + $lsid++; + $sids[$gid][$lsid] = $action; + } + } + // Test the SID token for a single GID:SID + elseif (preg_match('/^(\d+):(\d+)$/', $tok, $matches)) { + // It's a single GID:SID, so grab it + $sids[$matches[1]][$matches[2]] = $action; + } + // Test the SID token for the PCRE: keyword + elseif (preg_match('/(^pcre\:)(.+)/i', $tok, $matches)) { + $regex = '/' . preg_quote($matches[2], '/') . '/i'; + + // Now search through the $rule_map in the 'rule' + // element for any matches to the regex and get + // the GID:SID. + foreach ($rule_map as $k1 => $rulem) { + foreach ($rulem as $k2 => $v) { + if (preg_match($regex, $v['rule'])) { + $sids[$k1][$k2] = $action; + } + } + } + } + // Test the SID token for the MS reference keyword + elseif (preg_match('/^MS\d+-.+/i', $tok, $matches)) { + $regex = "/" . preg_quote($matches[0], '/') . "/i"; + + // Now search through the $rule_map in the 'rule' + // element for any matches to the regex and get + // the GID:SID. + foreach ($rule_map as $k1 => $rulem) { + foreach ($rulem as $k2 => $v) { + if (preg_match($regex, $v['rule'])) { + $sids[$k1][$k2] = $action; + } + } + } + } + // Test the SID token for other keywords delimited with a colon + elseif (preg_match('/^[a-xA-X]+\:.+/', $tok, $matches)) { + $regex = "/" . str_replace(':', ",", preg_quote($matches[0], '/')) . "/i"; + + // Now search through the $rule_map in the 'rule' + // element for any matches to the regex and get + // the GID:SID. + foreach ($rule_map as $k1 => $rulem) { + foreach ($rulem as $k2 => $v) { + if (preg_match($regex, $v['rule'])) { + $sids[$k1][$k2] = $action; + } + } + } + } + // Test the SID token for a rule category name. Anything that + // failed to match above is considered a potential category name. + elseif (preg_match('/[a-xA-X]+(-|\w).*/', $tok, $matches)) { + $regex = "/" . preg_quote(trim($matches[0]), '/') . "/i"; + // Now search through the $rule_map in the 'category' + // element for any matches to the regex and get + // the GID:SID. + foreach ($rule_map as $k1 => $rulem) { + foreach ($rulem as $k2 => $v) { + if (preg_match($regex, $v['category'] . ".rules")) { + $sids[$k1][$k2] = $action; + } + } + } + } + else { + if ($log_results == TRUE && !empty($log_file)) + error_log(gettext("WARNING: unrecognized token '{$tok}' encountered while processing an automatic SID MGMT file.\n"), 3, $log_file); + } + } + + // Change state of all the matching GID:SID pairs we found + // above in the $rule_map array passed to us. + $modcount = $changecount = 0; + $counter = count($sids, COUNT_RECURSIVE) - count($sids); + + if ($log_results == TRUE && !empty($log_file)) + error_log(gettext(" Parsed {$counter} potential SIDs to match from the provided list of tokens.\n"), 3, $log_file); + + foreach (array_keys($sids) as $k1) { + foreach (array_keys($sids[$k1]) as $k2) { + if (isset($rule_map[$k1][$k2])) { + if ($action == 'enable' && $rule_map[$k1][$k2]['disabled'] == 1) { + $rule_map[$k1][$k2]['rule'] = ltrim($rule_map[$k1][$k2]['rule'], " \t#"); + $rule_map[$k1][$k2]['disabled'] = 0; + $rule_map[$k1][$k2]['managed'] = 1; + $changecount++; + $modcount++; + } + elseif ($action == 'disable' && $rule_map[$k1][$k2]['disabled'] == 0) { + $rule_map[$k1][$k2]['rule'] = "# " . $rule_map[$k1][$k2]['rule']; + $rule_map[$k1][$k2]['disabled'] = 1; + $rule_map[$k1][$k2]['managed'] = 1; + $changecount++; + $modcount++; + } + } + } + } + + if ($log_results == TRUE && !empty($log_file)) { + error_log(gettext(" Found {$modcount} matching SIDs in the active rules.\n"), 3, $log_file); + error_log(gettext(" Changed state for {$changecount} SIDs to '{$action}d'.\n"), 3, $log_file); + } + + // Return the array of matching SIDs + return $sids; +} + +function snort_modify_sid_content(&$rule_map, $sid_mods, $log_results = FALSE, $log_file = NULL) { + + /************************************************/ + /* This function walks the provided array of */ + /* SID modification tokens and locates the */ + /* target SID or SIDs in the $rule_map array. */ + /* It then modifies the content of the target */ + /* SID or SIDs. Modifications are only valid */ + /* for normal GID=1 text rules. */ + /* */ + /* $rule_map ==> reference to array of */ + /* current rules */ + /* $sid_mods ==> array of SID modification */ + /* tokens */ + /* $log_results ==> [optional] 'yes' to log */ + /* results to $log_file */ + /* $log_file ==> full path and filename */ + /* of log file to write to */ + /* */ + /* On Return ==> $rule_map array modified */ + /* by changing content for */ + /* matching SIDs. */ + /* */ + /* Returns a two-dimension */ + /* array of matching */ + /* GID:SID pairs. */ + /************************************************/ + + $sids = array(); + $tokencounter = $modcount = $modifiedcount = 0; + + // If no rules in $rule_map or mods in $sid_mods, + // then nothing to do. + if (empty($rule_map) || empty($sid_mods)) + return $sids; + + // Walk the SID mod tokens and decode each one + foreach ($sid_mods as $tok) { + $matches = array(); + if (preg_match('/([\d+|,|\*]*)\s+"(.+)"\s+"(.*)"/', $tok, $matches)) { + $tokencounter++; + $sidlist = explode(",", $matches[1]); + $from = '/' . preg_quote($matches[2], '/') . '/'; + $to = $matches[3]; + $count = 0; + + // Now walk the provided rule map and make the modifications + if ($matches[1] == "*") { + // If wildcard '*' provided for SID, then check them all + foreach ($rule_map[1] as $rulem) { + foreach ($rulem as $k2 => $v) { + $modcount++; + $rule_map[1][$k2]['rule'] = preg_replace($from, $to, $v['rule'], -1, $count); + if ($count > 0) { + $rule_map[1][$k2]['managed'] = 1; + $sids[1][$k2] = 'modify'; + $modifiedcount++; + } + } + } + } + else { + // Otherwise just check the provided SIDs + foreach ($sidlist as $sid) { + if (isset($rule_map[1][$sid])) { + $modcount++; + $rule_map[1][$sid]['rule'] = preg_replace($from, $to, $rule_map[1][$sid]['rule'], -1, $count); + if ($count > 0) { + $rule_map[1][$sid]['managed'] = 1; + $sids[1][$sid] = 'modify'; + $modifiedcount++; + } + } + } + } + } + else { + if ($log_results == TRUE && !empty($log_file)) + error_log(gettext("WARNING: unrecognized token '{$tok}' encountered while processing an automatic SID MGMT file.\n"), 3, $log_file); + } + } + + if ($log_results == TRUE && !empty($log_file)) { + error_log(gettext(" Parsed {$tokencounter} potential SIDs to match from the provided list of tokens.\n"), 3, $log_file); + error_log(gettext(" Found {$modcount} matching SIDs in the active rules.\n"), 3, $log_file); + error_log(gettext(" Modified rule text for {$modifiedcount} SIDs.\n"), 3, $log_file); + } + + // Return the array of matching SIDs + return $sids; +} + +function snort_process_enablesid(&$rule_map, $snortcfg, $log_results = FALSE, $log_file = NULL) { + + /**********************************************/ + /* This function loads and processes the file */ + /* specified by 'enable_sid_file' for the */ + /* interface. The file is assumed to be a */ + /* valid enablesid.conf file containing */ + /* instructions for enabling matching rule */ + /* SIDs. */ + /* */ + /* $rule_map ==> reference to array of */ + /* current rules */ + /* $snortcfg ==> interface config params */ + /* $log_results ==> [optional] 'yes' to log */ + /* results to $log_file */ + /* $log_file ==> full path and filename */ + /* of log file to write to */ + /* */ + /* On Return ==> suitably modified */ + /* $rule_map array */ + /**********************************************/ + + $snort_sidmods_dir = SID_MODS_PATH; + $snortlogdir = SNORTLOGDIR; + $sid_mods = array(); + + // If no rules in $rule_map, then nothing to do + if (empty($rule_map)) + return; + + // Attempt to open the 'enable_sid_file' for the interface + if (!file_exists("{$snort_sidmods_dir}{$snortcfg['enable_sid_file']}")) { + log_error(gettext("[Snort] Error - unable to open 'enable_sid_file' \"{$snortcfg['enable_sid_file']}\" specified for " . convert_friendly_interface_to_friendly_descr($snortcfg['interface']))); + return; + } + else + $sid_mods = snort_parse_sidconf_file("{$snort_sidmods_dir}{$snortcfg['enable_sid_file']}"); + + if (!empty($sid_mods)) + snort_modify_sid_state($rule_map, $sid_mods, "enable", $log_results, $log_file); + elseif ($log_results == TRUE && !empty($log_file)) { + error_log(gettext("WARNING: no valid SID match tokens found in file \"{$snortcfg['enable_sid_file']}\".\n"), 3, $log_file); + } + + unset($sid_mods); +} + +function snort_process_disablesid(&$rule_map, $snortcfg, $log_results = FALSE, $log_file = NULL) { + + /**********************************************/ + /* This function loads and processes the file */ + /* specified by 'disable_sid_file' for the */ + /* interface. The file is assumed to be a */ + /* valid disablesid.conf file containing */ + /* instructions for disabling matching rule */ + /* SIDs. */ + /* */ + /* $rule_map ==> reference to array of */ + /* current rules */ + /* $snortcfg ==> interface config params */ + /* $log_results ==> [optional] 'yes' to log */ + /* results to $log_file */ + /* $log_file ==> full path and filename */ + /* of log file to write to */ + /* */ + /* On Return ==> suitably modified */ + /* $rule_map array */ + /**********************************************/ + + $snort_sidmods_dir = SID_MODS_PATH; + $snortlogdir = SNORTLOGDIR; + $sid_mods = array(); + + // If no rules in $rule_map, then nothing to do + if (empty($rule_map)) + return; + + // Attempt to open the 'disable_sid_file' for the interface + if (!file_exists("{$snort_sidmods_dir}{$snortcfg['disable_sid_file']}")) { + log_error(gettext("[Snort] Error - unable to open 'disable_sid_file' \"{$snortcfg['disable_sid_file']}\" specified for " . convert_friendly_interface_to_friendly_descr($snortcfg['interface']))); + return; + } + else + $sid_mods = snort_parse_sidconf_file("{$snort_sidmods_dir}{$snortcfg['disable_sid_file']}"); + + if (!empty($sid_mods)) + snort_modify_sid_state($rule_map, $sid_mods, "disable", $log_results, $log_file); + elseif ($log_results == TRUE && !empty($log_file)) { + error_log(gettext("WARNING: no valid SID match tokens found in file \"{$snortcfg['disable_sid_file']}\".\n"), 3, $log_file); + } + + unset($sid_mods); +} + +function snort_process_modifysid(&$rule_map, $snortcfg, $log_results = FALSE, $log_file = NULL) { + + /**********************************************/ + /* This function loads and processes the file */ + /* specified by 'modify_sid_file' for the */ + /* interface. The file is assumed to be a */ + /* valid modifysid.conf file containing */ + /* instructions for modifying matching rule */ + /* SIDs. */ + /* */ + /* $rule_map ==> reference to array of */ + /* current rules */ + /* $snortcfg ==> interface config params */ + /* $log_results ==> [optional] 'yes' to log */ + /* results to $log_file */ + /* $log_file ==> full path and filename */ + /* of log file to write to */ + /* */ + /* On Return ==> suitably modified */ + /* $rule_map array */ + /**********************************************/ + + $snort_sidmods_dir = SID_MODS_PATH; + $snortlogdir = SNORTLOGDIR; + $sid_mods = array(); + + // If no rules in $rule_map, then nothing to do + if (empty($rule_map)) + return; + + // Attempt to open the 'modify_sid_file' for the interface + if (!file_exists("{$snort_sidmods_dir}{$snortcfg['modify_sid_file']}")) { + log_error(gettext("[Snort] Error - unable to open 'modify_sid_file' \"{$snortcfg['modify_sid_file']}\" specified for " . convert_friendly_interface_to_friendly_descr($snortcfg['interface']))); + return; + } + else + $sid_mods = snort_parse_sidconf_file("{$snort_sidmods_dir}{$snortcfg['modify_sid_file']}"); + + if (!empty($sid_mods)) + snort_modify_sid_content($rule_map, $sid_mods, $log_results, $log_file); + elseif ($log_results == TRUE && !empty($log_file)) { + error_log(gettext("WARNING: no valid SID match tokens found in file \"{$snortcfg['modify_sid_file']}\".\n"), 3, $log_file); + } + + unset($sid_mods); +} + +function snort_auto_sid_mgmt(&$rule_map, $snortcfg, $log_results = FALSE) { + + /**************************************************/ + /* This function modifies the rules in the */ + /* passed rule_map array based on values in the */ + /* files 'enable_sid_file', 'disable_sid_file' */ + /* and 'modify_sid_file' for the interface. */ + /* */ + /* If auto-mgmt of SIDs is enabled via the */ + /* settings on the UPDATE RULES tab, then the */ + /* rules are processed against these settings. */ + /* */ + /* $rule_map ==> array of current rules */ + /* $snortcfg ==> interface config settings */ + /* $log_results ==> [optional] log results to */ + /* 'sid_changes.log' in the */ + /* interface directory in */ + /* /var/log/snort when TRUE */ + /* */ + /* Returns ==> TRUE if rules were changed; */ + /* otherwise FALSE */ + /**************************************************/ + + global $config; + $result = FALSE; + + // Configure the interface's logging subdirectory if log results is enabled + if ($log_results == TRUE) + $log_file = SNORTLOGDIR . "/snort_" . get_real_interface($snortcfg['interface']) . "{$snortcfg['uuid']}/sid_changes.log"; + else + $log_file = NULL; + + // Check if auto-mgmt of SIDs is enabled and files are specified + // for the interface. + if ($config['installedpackages']['snortglobal']['auto_manage_sids'] == 'on' && + (!empty($snortcfg['disable_sid_file']) || !empty($snortcfg['enable_sid_file']) || + !empty($snortcfg['modify_sid_file']))) { + if ($log_results == TRUE) { + error_log(gettext("********************************************************\n"), 3, $log_file); + error_log(gettext("Starting auto SID management for " . convert_friendly_interface_to_friendly_descr($snortcfg['interface']) ."\n"), 3, $log_file); + error_log(gettext("Start Time: " . date("Y-m-d H:i:s") . "\n"), 3, $log_file); + } + + switch ($snortcfg['sid_state_order']) { + case "disable_enable": + if (!empty($snortcfg['disable_sid_file'])) { + if ($log_results == TRUE) + error_log(gettext("Processing disable_sid file: {$snortcfg['disable_sid_file']}\n"), 3, $log_file); + snort_process_disablesid($rule_map, $snortcfg, $log_results, $log_file); + } + if (!empty($snortcfg['enable_sid_file'])) { + if ($log_results == TRUE) + error_log(gettext("Processing enable_sid file: {$snortcfg['enable_sid_file']}\n"), 3, $log_file); + snort_process_enablesid($rule_map, $snortcfg, $log_results, $log_file); + } + if (!empty($snortcfg['modify_sid_file'])) { + if ($log_results == TRUE) + error_log(gettext("Processing modify_sid file: {$snortcfg['modify_sid_file']}\n"), 3, $log_file); + snort_process_modifysid($rule_map, $snortcfg, $log_results, $log_file); + } + $result = TRUE; + break; + + case "enable_disable": + if (!empty($snortcfg['enable_sid_file'])) { + if ($log_results == TRUE) + error_log(gettext("Processing enable_sid file: {$snortcfg['enable_sid_file']}\n"), 3, $log_file); + snort_process_enablesid($rule_map, $snortcfg, $log_results, $log_file); + } + if (!empty($snortcfg['disable_sid_file'])) { + if ($log_results == TRUE) + error_log(gettext("Processing disable_sid file: {$snortcfg['disable_sid_file']}\n"), 3, $log_file); + snort_process_disablesid($rule_map, $snortcfg, $log_results, $log_file); + } + if (!empty($snortcfg['modify_sid_file'])) { + if ($log_results == TRUE) + error_log(gettext("Processing modify_sid file: {$snortcfg['modify_sid_file']}\n"), 3, $log_file); + snort_process_modifysid($rule_map, $snortcfg, $log_results, $log_file); + } + $result = TRUE; + break; + + default: + log_error(gettext("[Snort] Unrecognized 'sid_state_order' value. Skipping auto SID mgmt step for " . convert_friendly_interface_to_friendly_descr($snortcfg['interface']))); + if ($log_results == TRUE) { + error_log(gettext("ERROR: unrecognized 'sid_state_order' value. Skipping auto SID mgmt step for ") . convert_friendly_interface_to_friendly_descr($snortcfg['interface']). ".\n", 3, $log_file); + } + $result = FALSE; + } + + if ($log_results == TRUE) { + error_log(gettext("End Time: " . date("Y-m-d H:i:s") . "\n"), 3, $log_file); + error_log(gettext("********************************************************\n\n"), 3, $log_file); + } + } + return $result; +} + function snort_load_sid_mods($sids) { /*****************************************/ @@ -2226,6 +3077,9 @@ function snort_prepare_rule_files($snortcfg, $snortcfgdir) { $snortdir = SNORTDIR; $flowbit_rules_file = FLOWBITS_FILENAME; $snort_enforcing_rules_file = ENFORCING_RULES_FILENAME; + $enabled_files = array(); + $all_rules = array(); + $cat_mods = array(); $no_rules_defined = true; $enabled_rules = array(); @@ -2236,6 +3090,10 @@ function snort_prepare_rule_files($snortcfg, $snortcfgdir) { /* Log a message for rules rebuild in progress */ log_error(gettext("[Snort] Updating rules configuration for: " . convert_friendly_interface_to_friendly_descr($snortcfg['interface']) . " ...")); + // Get any automatic rule category enable/disable modifications + // if auto-SID Mgmt is enabled and conf files exist for the interface. + $cat_mods = snort_sid_mgmt_auto_categories($snortcfg, TRUE); + /* Enable all, some or none of the SDF rules depending on setting. */ if ($snortcfg['sensitive_data'] == 'on' && $snortcfg['protect_preproc_rules'] != 'on') { if (file_exists(SNORTDIR."/preproc_rules/sensitive-data.rules")) { @@ -2262,8 +3120,6 @@ function snort_prepare_rule_files($snortcfg, $snortcfgdir) { /* Only rebuild rules if some are selected or an IPS Policy is enabled */ if (!empty($snortcfg['rulesets']) || $snortcfg['ips_policy_enable'] == 'on') { - $enabled_files = array(); - $all_rules = array(); $no_rules_defined = false; /* Load up all the text rules into a Rules Map array. */ @@ -2279,6 +3135,28 @@ function snort_prepare_rule_files($snortcfg, $snortcfgdir) { $enabled_files[$category] = $file; } + // Now adjust the list using any required changes as + // determined by auto-SID Mgmt policy files. + if (!empty($cat_mods)) { + foreach ($cat_mods as $k => $action) { + $key = basename($k, ".rules"); + switch ($action) { + case 'enabled': + if (!isset($enabled_files[$key])) + $enabled_files[$key] = $k; + break; + + case 'disabled': + if (isset($enabled_files[$key])) + unset($enabled_files[$key]); + break; + + default: + break; + } + } + } + /****************************************************/ /* Walk the ALL_RULES map array and copy the rules */ /* matching our selected file categories to the */ @@ -2301,7 +3179,7 @@ function snort_prepare_rule_files($snortcfg, $snortcfgdir) { } /* Release memory we no longer need. */ - unset($enabled_files, $rulem, $v); + unset($enabled_files, $cat_mods, $rulem, $v); } /* Check if a pre-defined Snort VRT policy is selected. If so, */ @@ -2324,7 +3202,9 @@ function snort_prepare_rule_files($snortcfg, $snortcfgdir) { unset($policy_rules, $policy, $p); } - /* Process any enablesid or disablesid modifications for the selected rules. */ + // Process any enablesid or disablesid modifications for the selected rules. + // Do the auto-SID managment first, if enabled, then do any manual SID state changes. + snort_auto_sid_mgmt($enabled_rules, $snortcfg, TRUE); snort_modify_sids($enabled_rules, $snortcfg); /* Check for and disable any rules dependent upon disabled preprocessors if */ @@ -2357,7 +3237,45 @@ function snort_prepare_rule_files($snortcfg, $snortcfgdir) { } else /* Just put an empty file to always have the file present */ snort_write_flowbit_rules_file(array(), "{$snortcfgdir}/rules/{$flowbit_rules_file}"); - } else { + unset($all_rules); + } + // If no rule categories were enabled, then use auto-SID management if enabled, since it may enable some rules + elseif ($config['installedpackages']['snortglobal']['auto_manage_sids'] == 'on' && + (!empty($snortcfg['disable_sid_file']) || !empty($snortcfg['enable_sid_file']) || + !empty($snortcfg['modify_sid_file']))) { + + snort_auto_sid_mgmt($enabled_rules, $snortcfg, TRUE); + if (!empty($enabled_rules)) { + // Auto-SID management generated some rules, so use them + $no_rules_defined = false; + snort_modify_sids($enabled_rules, $snortcfg); + + // Write the enforcing rules file to the Suricata interface's "rules" directory. + snort_write_enforcing_rules_file($enabled_rules, "{$snortcfgdir}/rules/{$snort_enforcing_rules_file}"); + + // If auto-flowbit resolution is enabled, generate the dependent flowbits rules file. + if ($snortcfg['autoflowbitrules'] == 'on') { + log_error('[Suricata] Enabling any flowbit-required rules for: ' . convert_friendly_interface_to_friendly_descr($snortcfg['interface']) . '...'); + + // Load up all rules into a Rules Map array for flowbits assessment + $all_rules = snort_load_rules_map("{$snortdir}/rules/"); + $fbits = snort_resolve_flowbits($all_rules, $enabled_rules); + + // Check for and disable any flowbit-required rules the + // user has manually forced to a disabled state. + snort_modify_sids($fbits, $snortcfg); + snort_write_flowbit_rules_file($fbits, "{$snortcfgdir}/rules/{$flowbit_rules_file}"); + unset($all_rules, $fbits); + } else + // Just put an empty file to always have the file present + snort_write_flowbit_rules_file(array(), "{$snortcfgdir}/rules/{$flowbit_rules_file}"); + } + else { + snort_write_enforcing_rules_file(array(), "{$snortcfgdir}/rules/{$snort_enforcing_rules_file}"); + snort_write_flowbit_rules_file(array(), "{$snortcfgdir}/rules/{$flowbit_rules_file}"); + } + } + else { /* No regular rules or policy were selected, so just use the decoder and preproc rules */ snort_write_enforcing_rules_file($enabled_rules, "{$snortcfgdir}/rules/{$snort_enforcing_rules_file}"); snort_write_flowbit_rules_file(array(), "{$snortcfgdir}/rules/{$flowbit_rules_file}"); |