This commit is contained in:
Gregory Colpart 2009-08-10 19:02:09 +02:00
commit b3fb2ce6b9
2 changed files with 367 additions and 0 deletions

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# Fichier de configuration
# pour minifirewall
# version 0.1 - 12 juillet 2007 $Id: firewall.rc,v 1.2 2007/07/12 19:08:59 reg Exp $
# Interface concernee
INT='eth0'
# IP associee
INTIP='192.168.0.2'
INTLAN='192.168.0.0/24'
# trusted ip addresses
TRUSTEDIPS='62.212.121.90 62.212.111.216'
# privilegied ip addresses
# (trusted ip addresses *are* privilegied)
PRIVILEGIEDIPS=''
# Services "publics"
SERVICESTCP1='21 25 53 993 995'
SERVICESUDP1='53'
# Services "semi-publics"
SERVICESTCP2='22 25 53 80 110 143 443'
SERVICESUDP2=''
# Services "prives"
SERVICESTCP3='636 5666'
SERVICESUDP3=''
################### SORTANTS
# DNS
DNSSERVEURS='85.31.205.33 78.153.240.29'
# HTTP : security.d.o x3, zidane, modsecurity www.debian.org
# /!\ Possibilite d'utiliser des noms de domaines
# mais il est conseiller de placer un rechargement
# du minifirewall en crontab
HTTPSITES='security.debian.org 85.31.205.33 80.25.139.226 www.debian.org'
# HTTPS
HTTPSSITES=''
# FTP
FTPSITES=''
# SSH
SSHOK='0.0.0.0/0'
# SMTP
SMTPOK='0.0.0.0/0'
# NTP
NTPOK='78.153.240.29'
################### Specific rules
# /sbin/iptables ....
# /sbin/iptables ....
# /sbin/iptables ....

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#!/bin/sh
# version 0.1.1 - 13 avril 2009 : firewall.rc est charge un peu plus loin
# version 0.1 - 12 juillet 2007 $Id: minifirewall,v 1.6 2007/07/12 19:08:59 reg Exp $
# Copyright (c) 2007 Gregory Colpart
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License.
# Script netfilter/iptables
# http://netfilter.org/
#
# Designed for Linux kernel 2.4/2.6
# http://www.kernel.org/
# Description
# script pour machine unique
###
# Configuration des variables
###
# chemin iptables
IPT=/sbin/iptables
# variables TCP/IP
LOOPBACK='127.0.0.0/8'
CLASSA='10.0.0.0/8'
CLASSB='172.16.0.0/12'
CLASSC='192.168.0.0/16'
CLASSD='224.0.0.0/4'
CLASSE='240.0.0.0/5'
ALL='0.0.0.0'
BROAD='255.255.255.255'
PORTSROOT='0:1023'
PORTSUSER='1024:65535'
case "$1" in
start)
echo "Demarrage regles IPTables..."
# 1.Protections diverses
# ne pas repondre aux ping broadcast
echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_broadcasts
# Ignorer les mauvais messages d'erreurs ICMP
echo 1 > /proc/sys/net/ipv4/icmp_ignore_bogus_error_responses
# effacer la source des paquets routés
for i in /proc/sys/net/ipv4/conf/*/accept_source_route; do
echo 0 > $i
done
# activer les TCP SYN cookies evitant des attaques DoS de type TCP-SYN-FLOOD
# cf http://cr.yp.to/syncookies.html
echo 1 > /proc/sys/net/ipv4/tcp_syncookies
# desactiver les messages ICMP d'information de redirection
# potentiellement dangereux
for i in /proc/sys/net/ipv4/conf/*/accept_redirects; do
echo 0 > $i
done
for i in /proc/sys/net/ipv4/conf/*/send_redirects; do
echo 0 > $i
done
# filtrage par chemin inverse: verifie que les reponses sortent bien de l'interface d'arrivee
for i in /proc/sys/net/ipv4/conf/*/rp_filter; do
echo 1 > $i
done
# log des paquets avec adresse incoherente
for i in /proc/sys/net/ipv4/conf/*/log_martians; do
echo 1 > $i
done
# 2. Sur la machine
$IPT -N LOG_DROP
$IPT -A LOG_DROP -j LOG --log-prefix '[IPTABLES DROP] : '
$IPT -A LOG_DROP -j DROP
$IPT -N LOG_ACCEPT
$IPT -A LOG_ACCEPT -j LOG --log-prefix '[IPTABLES ACCEPT] : '
$IPT -A LOG_ACCEPT -j ACCEPT
test -f /etc/firewall.rc && . /etc/firewall.rc
# trusted ip addresses
$IPT -N ONLYTRUSTED
$IPT -A ONLYTRUSTED -j LOG_DROP
for x in $TRUSTEDIPS
do
$IPT -I ONLYTRUSTED -s $x -j ACCEPT
done
# privilegied ip addresses
# (trusted ip addresses *are* privilegied)
$IPT -N ONLYPRIVILEGIED
$IPT -A ONLYPRIVILEGIED -j ONLYTRUSTED
for x in $PRIVILEGIEDIPS
do
$IPT -I ONLYPRIVILEGIED -s $x -j ACCEPT
done
# politique
# par defaut rien ne rentre
$IPT -P INPUT DROP
# par defaut rien ne transite
$IPT -P FORWARD DROP
# par defaut tout peut sortir (sinon voir OUTPUTDROP)
$IPT -P OUTPUT ACCEPT
# On autorise tout sur l'interface loopback
$IPT -A INPUT -i lo -j ACCEPT
# if OUTPUTDROP
#$IPT -A OUTPUT -o lo -j ACCEPT
# on evite pas mal de paquets "martiens" effet de bord de virus
# notamment W32/Blaster qui attaquait windowsupdate.com
# et dont l'enregistrement DNS a ete change pour 127.0.0.1
# $IPT -t NAT -I PREROUTING -s $LOOPBACK -i ! lo -j DROP
$IPT -A INPUT -s $LOOPBACK -i ! lo -j DROP
#################################################################
# Les services accessibles
#################################################################
# Les services accessibles en local ?
#$IPT -A INPUT -i $INT2 -j ACCEPT
$IPT -A INPUT -s $INTLAN -j ACCEPT
# Services publics
for x in $SERVICESTCP1
do
$IPT -A INPUT -p tcp --dport $x -j ACCEPT
done
for x in $SERVICESUDP1
do
$IPT -A INPUT -p udp --dport $x -j ACCEPT
done
# Services semi-publics
for x in $SERVICESTCP2
do
$IPT -A INPUT -p tcp --dport $x -j ONLYPRIVILEGIED
done
for x in $SERVICESUDP2
do
$IPT -A INPUT -p udp --dport $x -j ONLYPRIVILEGIED
done
# Services prives
for x in $SERVICESTCP3
do
$IPT -A INPUT -p tcp --dport $x -j ONLYTRUSTED
done
for x in $SERVICESUDP3
do
$IPT -A INPUT -p udp --dport $x -j ONLYTRUSTED
done
#################################################################
# Les services auxquels la machine peut acceder
#################################################################
# DNS
# autoriser a recevoir des reponses DNS
for x in $DNSSERVEURS
do
$IPT -A INPUT -p tcp ! --syn --sport 53 --dport $PORTSUSER -s $x -j ACCEPT
$IPT -A INPUT -p udp --sport 53 --dport $PORTSUSER -s $x -m state --state ESTABLISHED,RELATED -j ACCEPT
done
# HTTP
# autoriser a se connecter a certaines IP en http (miroirs debian par exemple)
for x in $HTTPSITES
do
$IPT -A INPUT -p tcp ! --syn --sport 80 --dport $PORTSUSER -s $x -j ACCEPT
done
# HTTPS
for x in $HTTPSSITES
do
$IPT -A INPUT -p tcp ! --syn --sport 443 --dport $PORTSUSER -s $x -j ACCEPT
done
# FTP
# autoriser a se connecter a certaines IP en ftp (miroirs debian par exemple)
for x in $FTPSITES
do
# requetes exterieures sur le canal de controle
$IPT -A INPUT -p tcp ! --syn --sport 21 --dport $PORTSUSER -s $x -j ACCEPT
# FTP port-mode sur le canal de donnees
$IPT -A INPUT -p tcp --sport 20 --dport $PORTSUSER -s $x -j ACCEPT
# FTP passive-mode sur le canal de donnees
# ATTENTION, cela active aussi les connexions sur tous les ports TCP > 1024 pour cette machine
$IPT -A INPUT -p tcp ! --syn --sport $PORTSUSER --dport $PORTSUSER -s $x -j ACCEPT
done
# autoriser a se connecter sur certaines IP par SSH
for x in $SSHOK
do
$IPT -A INPUT -p tcp ! --syn --sport 22 -s $x -j ACCEPT
done
# SMTP
for x in $SMTPOK
do
$IPT -A INPUT -p tcp ! --syn --sport 25 --dport $PORTSUSER -j ACCEPT
done
# NTP
# autoriser synchronisation ntpdate
for x in $NTPOK
do
$IPT -A INPUT -p udp --sport 123 -s $x -j ACCEPT
done
# ICMP
$IPT -N ICMP_STACK
$IPT -A INPUT -p icmp -j ICMP_STACK
# Gestion des Pings de l'exterieur (on autorise 3 Pings/s)
$IPT -A ICMP_STACK -p icmp --icmp-type echo-request -m limit --limit 3/s -i $INT -j ACCEPT
$IPT -A ICMP_STACK -p icmp --icmp-type echo-reply -m limit --limit 3/s -i $INT -j ACCEPT
$IPT -A ICMP_STACK -p icmp --icmp-type echo-request -i $INT -j DROP
$IPT -A ICMP_STACK -p icmp --icmp-type echo-reply -i $INT -j DROP
$IPT -A ICMP_STACK -j ACCEPT
# 3.Forward
# On autorise pas le forward a priori
echo 0 > /proc/sys/net/ipv4/ip_forward
echo "Fin du chargement des regles... "
;;
stop)
echo "On vide toutes les regles et on accepte tout..."
# On supprime toutes les regles
$IPT -F
#$IPT -t nat -F
$IPT -t mangle -F
# On accepte tout
$IPT -P INPUT ACCEPT
$IPT -P OUTPUT ACCEPT
$IPT -P FORWARD ACCEPT
#$IPT -t nat -P PREROUTING ACCEPT
#$IPT -t nat -P POSTROUTING ACCEPT
# On supprime les tables creees
$IPT -X LOG_DROP
$IPT -X LOG_ACCEPT
$IPT -X ONLYPRIVILEGIED
$IPT -X ONLYTRUSTED
$IPT -X ICMP_STACK
echo "OK"
;;
status)
$IPT -L -n -v --line-numbers
#$IPT -t nat -L -n -v --line-numbers
$IPT -t mangle -L -n -v --line-numbers
;;
reset)
echo "On remet les compteurs a zero..."
$IPT -Z
#$IPT -t nat -Z
$IPT -t mangle -Z
;;
restart)
$0 stop
$0 start
;;
*)
echo "Usage: $0 {start|stop|restart|status|reset|squid}"
exit 1
esac
exit 0