mirror of
https://github.com/Ponce/slackbuilds
synced 2024-11-29 13:00:32 +01:00
179 lines
4.8 KiB
Smarty
179 lines
4.8 KiB
Smarty
#!/usr/bin/perl -wT
|
|
|
|
# Copyright 2009 Kagan D. MacTane
|
|
#
|
|
# Licensed under the Apache License, Version 2.0 (the "License");
|
|
# you may not use this file except in compliance with the License.
|
|
# You may obtain a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing, software
|
|
# distributed under the License is distributed on an "AS IS" BASIS,
|
|
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
# See the License for the specific language governing permissions and
|
|
# limitations under the License.
|
|
|
|
require 5.004;
|
|
use strict;
|
|
use Sys::Syslog;
|
|
|
|
# -------------------------------------------------------------------
|
|
|
|
# This option *MUST* match the corresponding value in sshblock.pl!
|
|
my $history_file = '/etc/ssh/block-history';
|
|
|
|
|
|
# Blocking duration formula: If blocking for the Nth time, and
|
|
# b = $base and m = $mult, then block for:
|
|
#
|
|
# T = m * ( b ^ (N-1) )
|
|
#
|
|
# Time T is expressed in hours.
|
|
my $base = 4;
|
|
my $mult = 3;
|
|
|
|
my $Syslog_Level = 'info';
|
|
my $Syslog_Facility = 'user';
|
|
my $Syslog_Options = '';
|
|
|
|
my $VERSION = 0.5;
|
|
|
|
$ENV{'PATH'} = '/bin:/usr/bin:/usr/sbin:/sbin';
|
|
|
|
# -------------------------------------------------------------------
|
|
|
|
# Abort if you're not running as root
|
|
if ($>) {
|
|
print "Only root can run this program.\n";
|
|
exit 1;
|
|
}
|
|
|
|
my $now = time();
|
|
|
|
my @history;
|
|
open FH, "$history_file" || exit 7;
|
|
@history = <FH>;
|
|
close FH;
|
|
|
|
my @input_chain = `iptables -nL INPUT | tail +3`;
|
|
|
|
# Your iptables output needs to look like:
|
|
# DROP tcp -- 1.2.3.4 0.0.0.0/0 tcp dpt:22 flags:0x17/0x02
|
|
|
|
if (scalar @input_chain > 0) {
|
|
LogMessage("Checking ".scalar @input_chain." blocked IPs against ".scalar @history." block-history entries.");
|
|
}
|
|
|
|
foreach my $item (@input_chain) {
|
|
my @stats = split(/\s+/, $item);
|
|
next unless ($stats[0] eq 'DROP');
|
|
next unless ($stats[1] eq 'tcp');
|
|
next unless ($stats[6] eq 'dpt:22');
|
|
next unless ($stats[7] eq 'flags:0x17/0x02');
|
|
my $curr_ip = $stats[3];
|
|
|
|
if ($curr_ip =~ /^(\b(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b)$/) {
|
|
$curr_ip = $1;
|
|
} else {
|
|
LogMessage("Invalid IP address in output from iptables?!?");
|
|
next;
|
|
}
|
|
for ( my $i = 0; $i < scalar @history; $i++ ) {
|
|
my $hist_ip = (split(/\t/, $history[$i]))[0];
|
|
if ((split(/\t/, $history[$i]))[0] eq $curr_ip) {
|
|
my ($times_blocked, $blocked_since) = (split(/\t/, $history[$i]))[1,2];
|
|
my $duration = $now - $blocked_since;
|
|
$duration /= 3600;
|
|
$duration = sprintf("%.2f", $duration);
|
|
my $block_for = $mult * ($base ** ($times_blocked - 1));
|
|
if ($duration > $block_for) {
|
|
`iptables -D INPUT -p tcp -s $curr_ip --dport 22 --syn -j DROP`;
|
|
if ($?) {
|
|
LogMessage("Couldn't unblock IP $curr_ip (now blocked for $duration hours)! Error $?: $!");
|
|
} else {
|
|
LogMessage("Unblocked IP $curr_ip after $duration hours.");
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
exit 0;
|
|
|
|
|
|
|
|
sub is_blocked {
|
|
my $ip_addr = shift;
|
|
return grep /^$ip_addr/, split /\n/, `iptables -nL | grep DROP | grep 'dpt:22' | grep '0x17/0x02' | awk '{print \$4}'`;
|
|
}
|
|
|
|
|
|
sub LogMessage {
|
|
my $format = shift;
|
|
openlog('sshblock', $Syslog_Options, $Syslog_Facility);
|
|
syslog($Syslog_Level, $format, @_);
|
|
closelog();
|
|
}
|
|
|
|
|
|
__END__
|
|
|
|
=head1 NAME
|
|
|
|
sshunblock.pl - SSH dictionary attack (un)blocker
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
B<sshblock.pl>
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
This is part of the SSHblock system; the B<sshunblock.pl> executable is responsible for unblocking blocked IP addresses after a suitable length of time has passed. It does this by removing the B<iptables> firewall rules created by B<sshblock.pl>. In order to use iptables, sshunblock.pl must be run as root.
|
|
|
|
=head1 INVOCATION
|
|
|
|
B<sshunblock.pl> is intended to be called as an hourly cron(8) job. Calling it more or less frequently will not interfere with its operation.
|
|
|
|
By default, SSHblock logs its activity to syslog(8), using the "user" facility at level "info".
|
|
|
|
=head1 CONFIGURATION
|
|
|
|
F<sshunblock.pl> can be configured by changing the following options in the program's source code.
|
|
|
|
=over
|
|
|
|
=item B<$history_file>
|
|
|
|
Note that B<this option MUST match the value in sshblock.pl!> This is where SSHblock should store its history file. This file keeps a record of all IP addresses SSHblock has ever blocked, one per line. Each line consists of three tab-delimited fields: the IP address; the total number of times it's been blocked; and the timestamp it was last blocked at.
|
|
|
|
=item B<$base, $mult>
|
|
|
|
These control the behavior of SSHblock's exponential increase algorithm. By tweaking these, you can make SSHblock block attacking IP addresses for longer or shorter periods of time.
|
|
|
|
=back
|
|
|
|
=head1 FILES
|
|
|
|
=over
|
|
|
|
=item F</etc/ssh/block-history>
|
|
|
|
=back
|
|
|
|
|
|
=head1 BUGS
|
|
|
|
Please let me know if you find any.
|
|
|
|
=head1 AUTHOR
|
|
|
|
Kagan D. MacTane (kai@mactane.org)
|
|
|
|
=head1 SEE ALSO
|
|
|
|
sshblock(8), iptables(8), L<http://sourceforge.net/projects/swatch/>
|
|
|
|
=cut
|
|
|