Subversion Repositories ALCASAR

Rev

Rev 688 | Rev 726 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log

Rev Author Line No. Line
675 richard 1 
#!/bin/sh
64 franck 2 
# $Id: alcasar-iptables.sh 694 2011-08-03 04:38:09Z franck $
675 richard 3 
# Script de mise en place des regles du parefeu d'Alcasar (mode normal)
568 richard 4 
# This script write the netfilter rules for ALCASAR
675 richard 5 
# Rexy - 3abtux - CPN
6 
#
7 
# Reminders
568 richard 8 
# There are three channels for log :
498 richard 9 
#	1 (default) for tracability;
10 
#	2 for secure admin (ssh);
11 
#	3 for exterior access attempts.
568 richard 12 
# The French Security Agency (ANSSI) rules was applied by 'alcasar.sh' script
675 richard 13 
# The bootps/dhcp (67) port is always open on tun0/eth1 by coova
1 root 14 
 
612 richard 15 
conf_file="/usr/local/etc/alcasar.conf"
16 
private_ip_mask=`grep PRIVATE_IP $conf_file|cut -d"=" -f2`
615 richard 17 
private_ip_mask=${private_ip_mask:=192.168.182.1/24}
604 richard 18 
private_network=`/bin/ipcalc -n $private_ip_mask|cut -d"=" -f2`		# LAN IP address (ie.: 192.168.182.0)
19 
private_prefix=`/bin/ipcalc -p $private_ip_mask|cut -d"=" -f2`		# LAN prefix (ie. 24)
612 richard 20 
dns1=`grep DNS1 $conf_file|cut -d"=" -f2`				# first public DNS server
615 richard 21 
dns1=${dns1:=208.67.220.220}
612 richard 22 
dns2=`grep DNS2 $conf_file|cut -d"=" -f2`				# second public DNS server
615 richard 23 
dns2=${dns2:=208.67.222.222}
24 
PROTOCOLS_FILTERING=`grep PROTOCOLS_FILTERING $conf_file|cut -d"=" -f2`	# Network protocols filter (on/off)
25 
PROTOCOLS_FILTERING=${PROTOCOLS_FILTERING:=off}
26 
DNS_FILTERING=`grep DNS_FILTERING $conf_file|cut -d"=" -f2`		# DNS and URLs filter (on/off)
27 
DNS_FILTERING=${DNS_FILTERING:=off}
28 
QOS=`grep QOS $conf_file|cut -d"=" -f2`					# QOS (on/off)
29 
QOS=${QOS:=off}
30 
SSH=`grep SSH $conf_file|cut -d"=" -f2`					# sshd active (on/off)
31 
SSH=${SSH:=off}
694 franck 32 
Admin_from_IP=${Admin_from_IP:="0.0.0.0/0.0.0.0"}			# Une @IP fixe peut-être fournie pour restreindre l'accès en ssh depuis l'extérieur (ex: 80.22.21.53/24) ( 0.0.0.0/0.0.0.0  = de n'importe où ! )
615 richard 33 
LDAP=`grep LDAP $conf_file|cut -d"=" -f2`				# ldap external server active (on/off)
34 
LDAP=${LDAP:=off}
694 franck 35 
LDAP_IP=${LDAP_IP:="0.0.0.0"}
612 richard 36 
PRIVATE_NETWORK_MASK=$private_network/$private_prefix			# Lan IP address + prefix (192.168.182.0/24)
37 
PRIVATE_IP=`echo $private_ip_mask | cut -d"/" -f1`			# ALCASAR LAN IP address
38 
DNSSERVERS="$dns1,$dns2"						# first and second DNS IP servers addresses
675 richard 39 
EXTIF="eth0"
1 root 40 
INTIF="eth1"
604 richard 41 
TUNIF="tun0"								# listen card for chilli daemon
612 richard 42 
IPTABLES="/sbin/iptables"
1 root 43 
 
498 richard 44 
# Effacement des règles existantes
476 richard 45 
# Flush all existing rules
1 root 46 
$IPTABLES -F
47 
$IPTABLES -t nat -F
48 
$IPTABLES -t mangle -F
49 
$IPTABLES -F INPUT
50 
$IPTABLES -F FORWARD
51 
$IPTABLES -F OUTPUT
52 
 
498 richard 53 
# Suppression des chaines utilisateurs sur les tables filter et nat
54 
# Flush non default rules on filter and nat tables
55 
$IPTABLES -X
56 
$IPTABLES -t nat -X
57 
 
58 
# Stratégies par défaut
476 richard 59 
# Default policies
1 root 60 
$IPTABLES -P INPUT DROP
61 
$IPTABLES -P FORWARD DROP
498 richard 62 
$IPTABLES -P OUTPUT DROP
1 root 63 
$IPTABLES -t nat -P PREROUTING ACCEPT
64 
$IPTABLES -t nat -P POSTROUTING ACCEPT
65 
$IPTABLES -t nat -P OUTPUT ACCEPT
66 
 
498 richard 67 
# Tout passe sur loopback
476 richard 68 
# accept all on loopback
1 root 69 
$IPTABLES -A INPUT -i lo -j ACCEPT
492 franck 70 
 
472 richard 71 
#############################
72 
#       INTIF rules         #
73 
#############################
675 richard 74 
# interdit l'accès à INTIF (n'est utile que lorsque chilli est arrêté).
75 
# Reject INTIF access (only when chilli is down)
1 root 76 
$IPTABLES -A INPUT -i $INTIF -j ULOG --ulog-prefix "RULE Protect1 -- REJECT "
77 
$IPTABLES -A INPUT -i $INTIF -j REJECT
78 
 
472 richard 79 
#############################
80 
#  Local protection rules   #
81 
#############################
675 richard 82 
# On stoppe les demande de connexions non conformes (NullScan, XMAS (tous flags à 1), NEW not SYN, etc.)
83 
# Drop non standard connexions (NULLscans, XMAS, "NEW not SYN", etc.)
472 richard 84 
$IPTABLES -A INPUT -p tcp --tcp-flags FIN,URG,PSH FIN,URG,PSH -j DROP
85 
$IPTABLES -A INPUT -p tcp --tcp-flags ALL ALL -j DROP
86 
$IPTABLES -A INPUT -p tcp --tcp-flags ALL NONE -j DROP
87 
$IPTABLES -A INPUT -p tcp --tcp-flags SYN,RST SYN,RST -j DROP
675 richard 88 
$IPTABLES -A INPUT -p tcp -m tcp ! --syn -m state --state NEW -j DROP
498 richard 89 
 
675 richard 90 
# On ne traite pas les broadcasts et multicast
476 richard 91 
# Drop broadcast & multicast
472 richard 92 
$IPTABLES -A INPUT -m addrtype --dst-type BROADCAST,MULTICAST -j DROP
498 richard 93 
 
94 
# Rejet des tentatives de création de tunnels DNS (même pour les utilisateurs authentifiés)
476 richard 95 
# Deny forward DNS (even for authenticated users ...)
373 richard 96 
$IPTABLES -A FORWARD -i $TUNIF -p udp --dport domain -j REJECT --reject-with icmp-port-unreachable
97 
$IPTABLES -A FORWARD -i $TUNIF -p tcp --dport domain -j REJECT --reject-with tcp-reset
98 
 
498 richard 99 
# On autorise les retours de connexions légitimes par FORWARD
476 richard 100 
# Conntrack on forward
373 richard 101 
$IPTABLES -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
102 
 
520 richard 103 
###############################
104 
#  If DNS filter is activate  #
105 
###############################
106 
# Redirection des flux DNS vers le port 54 (dns+blackhole) sauf pour les IP en exceptions
612 richard 107 
if [ $DNS_FILTERING = on ]; then
520 richard 108 
	# Compute exception IP
688 richard 109 
	nb_exceptions=`wc -l /usr/local/etc/alcasar-filter-exceptions | cut -d" " -f1`
520 richard 110 
	if [ $nb_exceptions != "0" ]
111 
	then
112 
		while read ip_exception
113 
		do
114 
			$IPTABLES -A PREROUTING -t nat -i $TUNIF -p udp -s $ip_exception -d $PRIVATE_IP --dport domain -j ACCEPT
115 
		done < /usr/local/etc/alcasar-filter-exceptions
116 
	fi
117 
		$IPTABLES -A PREROUTING -t nat -i $TUNIF -p udp -d $PRIVATE_IP --dport domain -j REDIRECT --to-port 54
118 
fi
476 richard 119 
#####################################
120 
#  If protocols filter is activate  #
121 
#####################################
612 richard 122 
if [ $PROTOCOLS_FILTERING = on ]; then
688 richard 123 
	# Compute exception IP (IP addresses that shouldn't be filtered)
124 
	nb_exceptions=`wc -l /usr/local/etc/alcasar-filter-exceptions | cut -d" " -f1`
373 richard 125 
	if [ $nb_exceptions != "0" ]
126 
	then
127 
		while read ip_exception
128 
		do
129 
			$IPTABLES -A FORWARD -i $TUNIF -s $ip_exception -m state --state NEW -j ULOG --ulog-prefix "RULE IP-exception -- ACCEPT "
130 
			$IPTABLES -A FORWARD -i $TUNIF -s $ip_exception -m state --state NEW -j ACCEPT
131 
		done < /usr/local/etc/alcasar-filter-exceptions
132 
	fi
688 richard 133 
	# Compute uamallowed IP (IP address of equipments connect between ALCASAR and Internet (DMZ, own servers, ...)
134 
	nb_exceptions=`wc -l /usr/local/etc/alcasar-uamallowed | cut -d" "  -f1`
135 
	if [ $nb_exceptions != "0" ]
136 
	then
137 
		while read ip_allowed_line
138 
		do
139 
			ip_allowed=`echo $ip_allowed_line|cut -d"\"" -f2`
140 
			$IPTABLES -A FORWARD -i $TUNIF -d $ip_allowed -m state --state NEW -j ULOG --ulog-prefix "RULE IP-allowed -- ACCEPT "
141 
			$IPTABLES -A FORWARD -i $TUNIF -d $ip_allowed -m state --state NEW -j ACCEPT
142 
		done < /usr/local/etc/alcasar-uamallowed
143 
	fi
520 richard 144 
	# Autorisation des protocoles non commentés
476 richard 145 
	# Allow non comment protocols
373 richard 146 
	while read svc_line
147 
	do
148 
		svc_on=`echo $svc_line|cut -b1`
149 
		if [ $svc_on != "#" ]
150 
		then
151 
			svc_name=`echo $svc_line|cut -d" " -f1`
152 
			svc_port=`echo $svc_line|cut -d" " -f2`
153 
			if [ $svc_name = "icmp" ]
154 
			then
155 
				$IPTABLES -A FORWARD -i $TUNIF -p icmp -j ACCEPT
156 
			else
157 
				$IPTABLES -A FORWARD -i $TUNIF -p tcp --dport $svc_port -m state --state NEW -j ULOG --ulog-prefix "RULE F_$svc_name -- ACCEPT "
158 
				$IPTABLES -A FORWARD -i $TUNIF -p tcp --dport $svc_port -m state --state NEW -j ACCEPT
159 
			fi
160 
		fi
161 
	done < /usr/local/etc/alcasar-services
498 richard 162 
	# Rejet explicite (vers le LAN) des autres protocoles
476 richard 163 
	# reject the others
373 richard 164 
	$IPTABLES -A FORWARD -i $TUNIF -p tcp -j ULOG --ulog-prefix "RULE F_filter -- REJECT "
165 
	$IPTABLES -A FORWARD -i $TUNIF -p tcp -j REJECT --reject-with tcp-reset
166 
	$IPTABLES -A FORWARD -i $TUNIF -p udp -j REJECT --reject-with icmp-port-unreachable
167 
	$IPTABLES -A FORWARD -i $TUNIF -p icmp -j REJECT
1 root 168 
fi
492 franck 169 
 
170 
########################
171 
#  If QOS is activate  #
172 
########################
612 richard 173 
if [ $QOS = on ] && [ -e /usr/local/etc/alcasar-iptables-qos.sh ]; then
492 franck 174 
	. /usr/local/etc/alcasar-iptables-qos.sh
175 
fi
176 
 
498 richard 177 
# Autorisation des connections sortant du LAN
476 richard 178 
# Allow forward connections with log
179 
$IPTABLES -A FORWARD -i $TUNIF -m state --state NEW -j ULOG --ulog-prefix "RULE F_all -- ACCEPT "
411 richard 180 
$IPTABLES -A FORWARD -i $TUNIF -m state --state NEW -j ACCEPT
1 root 181 
 
604 richard 182 
#################################################################################################
183 
#  Direct input from local network (icmp, dns, ntp, https, http, ssh and 3990 (user disconnect) #
184 
#################################################################################################
185 
$IPTABLES -A INPUT -i $TUNIF -s $PRIVATE_NETWORK_MASK -p icmp --icmp-type 0 -j ACCEPT # ping reply
186 
$IPTABLES -A INPUT -i $TUNIF -s $PRIVATE_NETWORK_MASK -p icmp --icmp-type 8 -j ACCEPT # ping request
520 richard 187 
$IPTABLES -A INPUT -i $TUNIF -d $PRIVATE_IP -p udp --dport domain -j ACCEPT # dnsmasq without forward
188 
$IPTABLES -A INPUT -i $TUNIF -d $PRIVATE_IP -p udp --dport 54 -j ACCEPT # dnsmasq with blackhole
339 richard 189 
$IPTABLES -A INPUT -i $TUNIF -d $PRIVATE_IP -p udp --dport ntp -j ACCEPT
190 
$IPTABLES -A INPUT -i $TUNIF -d $PRIVATE_IP -p tcp --dport https -j ACCEPT
191 
$IPTABLES -A INPUT -i $TUNIF -d $PRIVATE_IP -p tcp --dport http -j ACCEPT
192 
$IPTABLES -A INPUT -i $TUNIF -d $PRIVATE_IP -p tcp --dport 3990 -j ACCEPT
604 richard 193 
# SSHD rules if activate
612 richard 194 
if [ $SSH = on ]
604 richard 195 
	then
196 
	$IPTABLES -A INPUT -i $TUNIF -d $PRIVATE_IP -p tcp --dport ssh -m state --state NEW -j ULOG --ulog-nlgroup 2 --ulog-prefix "RULE ssh-from-LAN -- ACCEPT"
197 
	$IPTABLES -A INPUT -i $TUNIF -d $PRIVATE_IP -p tcp --dport ssh -j ACCEPT
198 
	$IPTABLES -A INPUT -i $EXTIF -p tcp --dport ssh -s $Admin_from_IP -m state --state NEW --syn -j ULOG --ulog-nlgroup 2 --ulog-prefix "RULE ssh-from-WAN -- ACCEPT"
199 
	$IPTABLES -A INPUT -i $EXTIF -p tcp --dport ssh -s $Admin_from_IP -m state --state NEW,ESTABLISHED -j ACCEPT
200 
	$IPTABLES -A OUTPUT -o $EXTIF -p tcp --sport ssh -m state --state ESTABLISHED -j ACCEPT
201 
fi
202 
 
203 
# Insertion de règles locales
694 franck 204 
# Here, we add local rules (i.e. VPN from Internet)
604 richard 205 
if [ -f /usr/local/etc/alcasar-iptables-local.sh ]; then
206 
        . /usr/local/etc/alcasar-iptables-local.sh
207 
fi
208 
 
498 richard 209 
# On autorise les retours de connexions légitimes par INPUT
476 richard 210 
# Conntrack on INPUT
1 root 211 
$IPTABLES -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
212 
 
520 richard 213 
# On interdit les connexions directes au port utilisé par DansGuardian (8080)
498 richard 214 
# Les packets concernés ont fait l'objet d'un marquage dans la table mangle
215 
# lors d'une règle de PREROUTING (voir plus bas)
520 richard 216 
# Deny direct connections on DansGuardian port (8080)
476 richard 217 
# The concerned paquets are marked by a pre-routing rule (see further)
1 root 218 
$IPTABLES -A INPUT -i $TUNIF -p tcp --dport 8080 -m mark --mark 1 -j DROP
520 richard 219 
# Autorisation des connexions à DansGuardian
220 
# Allow connections for DansGuardian
1 root 221 
$IPTABLES -A INPUT -i $TUNIF -p tcp --dport 8080 -m state --state NEW --syn -j ACCEPT
222 
 
498 richard 223 
# Journalisation des requètes HTTP (seulement des paquets SYN)
476 richard 224 
# Log HTTP requests (only syn)
225 
$IPTABLES -A PREROUTING -t nat -i $TUNIF -p tcp ! -d $PRIVATE_IP --dport http -m state --state NEW -j ULOG --ulog-prefix "RULE F_http -- ACCEPT "
498 richard 226 
# On redirige les requêtes HTTP vers DansGuardian (transparent pour les utilisateurs)
476 richard 227 
# Redirect HTTP request in DansGuardian (transparent proxy)
1 root 228 
$IPTABLES -A PREROUTING -t nat -i $TUNIF -p tcp ! -d $PRIVATE_IP --dport http -j REDIRECT --to-port 8080
520 richard 229 
# Journalisation et marquage des paquets qui tentent d'accéder directement à DansGuardian
498 richard 230 
# pour pouvoir les supprimer en INPUT (voir plus haut)
520 richard 231 
# Mark the dansguardian bypass attempts
1 root 232 
$IPTABLES -A PREROUTING -t nat -i $TUNIF -p tcp -d $PRIVATE_IP -m tcp --dport 8080 -j ULOG --ulog-prefix "RULE direct-proxy -- DENY "
233 
$IPTABLES -A PREROUTING -t mangle -i $TUNIF -p tcp -d $PRIVATE_IP -m tcp --dport 8080 -j MARK --set-mark 1
234 
 
498 richard 235 
# Journalisation et rejet des connexions (autres que celles autorisées) effectuées depuis le LAN
476 richard 236 
# Deny and log on INPUT from the LAN
237 
$IPTABLES -A INPUT -i $TUNIF -m state --state NEW -j ULOG --ulog-prefix "RULE rej-int -- REJECT "
472 richard 238 
$IPTABLES -A INPUT -i $TUNIF -p tcp -j REJECT --reject-with tcp-reset
239 
$IPTABLES -A INPUT -i $TUNIF -p udp -j REJECT --reject-with icmp-port-unreachable
492 franck 240 
 
498 richard 241 
# Journalisation et rejet des connexions initiées depuis le réseau extérieur (test des effets du paramètre --limit en cours)
476 richard 242 
# On EXTIF, the access attempts are log in channel 2 (we should test --limit option to avoid deny of service)
243 
$IPTABLES -A INPUT -i $EXTIF -m state --state NEW -j ULOG --ulog-nlgroup 3 --ulog-qthreshold 10 --ulog-prefix "RULE rej-ext -- DROP"
1 root 244 
 
498 richard 245 
#############################
246 
# filtering outside OUTPUT. #
247 
#############################
248 
# On laisse tout sortir sur toutes les cartes sauf celle qui est connectée sur l'extérieur
249 
# Everything is allowed but traffic through outside network interface
250 
$IPTABLES -A OUTPUT ! -o $EXTIF -j ACCEPT
520 richard 251 
 
503 richard 252 
# On autorise les requêtes DNS vers les serveurs DNS identifiés
498 richard 253 
# Allow DNS requests to identified DNS servers
254 
$IPTABLES -A OUTPUT -o $EXTIF -d $DNSSERVERS -p udp --dport domain -m state --state NEW -j ACCEPT
615 richard 255 
# On autorise les requêtes HTTP sortantes
498 richard 256 
# HTTP requests are allowed
257 
$IPTABLES -A OUTPUT -o $EXTIF -p tcp --dport http -j ACCEPT
615 richard 258 
# On autorise les requêtes NTP
498 richard 259 
# NTP requests are allowed
260 
$IPTABLES -A OUTPUT -o $EXTIF -p udp --dport ntp -j ACCEPT
503 richard 261 
# On autorise les requêtes ICMP (ping)
262 
# ICMP (ping) requests are allowed
263 
$IPTABLES -A OUTPUT -o $EXTIF -p icmp --icmp-type 8 -j ACCEPT
615 richard 264 
# On autorise les requêtes LDAP si un serveur externe est configué
265 
# LDAP requests are allowed if an external server is declared
266 
if [ $LDAP = on ]
267 
	then
694 franck 268 
	$IPTABLES -A OUTPUT -p tcp -d $LDAP_IP -m multiport --dports ldap,ldaps -m state --state NEW,ESTABLISHED -j ACCEPT
269 
	$IPTABLES -A OUTPUT -p udp -d $LDAP_IP -m multiport --dports ldap,ldaps -m state --state NEW,ESTABLISHED -j ACCEPT
270 
#	$IPTABLES -A INPUT  -p tcp -s $LDAP_IP -m multiports --sports ldap,ldaps -m state --state ESTABLISHED -j ACCEPT
271 
#	$IPTABLES -A INPUT  -p udp -s $LDAP_IP -m multiports --sports ldap,ldaps -m state --state ESTABLISHED -j ACCEPT
615 richard 272 
fi
498 richard 273 
# Traduction dynamique d'adresse en sortie
476 richard 274 
# Dynamic NAT on EXTIF
1 root 275 
$IPTABLES -A POSTROUTING -t nat -o $EXTIF -j MASQUERADE
276 
 
476 richard 277 
# Save all rules
1 root 278 
/etc/init.d/iptables save
279 
 
476 richard 280 
# End of script
1 root 281