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|
#!/usr/bin/perl -w
#
########################################################################
#
# File: snort_opts.pl
#
# Purpose: To parse snort rules and display a listing of snort fields
# along with how many snort rules in which each field is
# found.
#
########################################################################
#
use Getopt::Long;
use strict;
my $sig_file = '';
my $help = 0;
die "[*] Use --help for usage information.\n" unless (GetOptions(
'file=s' => \$sig_file,
'help' => \$help
));
&usage() if $help;
my %options = (
'flow' => 0,
'flowbits' => 0,
'msg' => 0,
'logto' => 0,
'ttl' => 0,
'tos' => 0,
'id' => 0,
'ipopts' => 0,
'fragbits' => 0,
'dsize' => 0,
'flags' => 0,
'seq' => 0,
'ack' => 0,
'itype' => 0,
'icode' => 0,
'icmp_id' => 0,
'icmp_seq' => 0,
'content' => 0,
'uricontent' => 0,
'content-list' => 0,
'offset' => 0,
'depth' => 0,
'nocase' => 0,
'file_data' => 0,
'rawbytes' => 0,
'session' => 0,
'rpc' => 0,
'resp' => 0,
'react' => 0,
'reference' => 0,
'sid' => 0,
'rev' => 0,
'classtype' => 0,
'priority' => 0,
'tag' => 0,
'ip_proto' => 0,
'sameip' => 0,
'asn1' => 0,
'stateless' => 0,
'regex' => 0,
'window' => 0,
'isdataat' => 0,
'distance' => 0,
'within' => 0,
'byte_jump' => 0,
'byte_test' => 0,
'byte_extract' => 0,
'pcre' => 0,
'ftpbounce' => 0,
'base64_data' => 0,
'base64_decode' => 0,
'http_header' => 0,
'http_cookie' => 0,
'http_uri' => 0,
'http_raw_uri' => 0,
'urilen' => 0,
'http_method' => 0,
'http_stat_code' => 0,
'http_stat_msg' => 0,
'http_client_body' => 0,
'fast_pattern' => 0,
'metadata' => 0,
'threshold' => 0,
'detection_filter' => 0,
);
my %unrecognized = ();
my $total_rules = 0;
my $dir = 'deps/snort_rules';
my @rfiles = ();
if ($sig_file) {
push @rfiles, $sig_file;
} else {
opendir D, $dir or die "[*] Could not open $dir: $!";
@rfiles = readdir D;
closedir D;
}
print "[+] Calculating snort rule keyword percentages:\n";
for my $rfile (@rfiles) {
my @lines = ();
if ($sig_file) {
open R, "< $sig_file" or die $!;
@lines = <R>;
close R;
} else {
next unless $rfile =~ /\.rules/;
open R, "< $dir/$rfile" or die $!;
@lines = <R>;
close R;
}
for my $line (@lines) {
chomp $line;
next unless $line =~ /\S/;
next if $line =~ /^#/;
$total_rules++;
if ($line =~ /^\s*alert/) {
for my $opt (keys %options) {
if ($line =~ /\s$opt[:;]/) {
$options{$opt}++;
} elsif ($line =~ /\($opt[:;]/) {
$options{$opt}++;
} elsif ($line =~ /;$opt[:;]/) {
$options{$opt}++;
}
}
while ($line =~ m/[\s;](\w+)[:;]/g) {
next if $1 =~ /^\d+$/;
unless (defined $options{$1}) {
$unrecognized{$1}++;
}
}
}
}
}
my $max_opt_len = 0;
for my $opt (keys %options) {
$max_opt_len = length($opt) if length($opt) > $max_opt_len;
}
for my $opt (sort {$options{$b} <=> $options{$a}} keys %options) {
printf("%${max_opt_len}s %13s", $opt, "$options{$opt}/$total_rules ");
print sprintf("%.1f", $options{$opt} / $total_rules * 100) . "%\n";
}
print "\n[-] Potentially unrecognized options:\n";
for my $opt (keys %unrecognized) {
print " $opt\n";
}
exit 0;
sub usage() {
print <<_USAGE_;
Usage: $0 [-f <sig file>] [-h]
_USAGE_
exit 0;
}
|
