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lundi 24 août 2015

:: SSH brute force banning script ::

Références

Installation et configuration

Note : Ce script est une version modifiée de celui fourni par robzr sur le forum OpenWrt.

Créer le fichier /usr/sbin/dropBrute.sh et copier le contenu suivant :

#!/bin/sh
# ------------------------------------------------------------------------------
# dropBrute.sh : minimalist OpenWRT/dropbear ssh brute force attack banning script
# ------------------------------------------------------------------------------
# initial release by robzr
# ------------------------------------------------------------------------------
# Installation steps:
# 1) Edit the variables in the header of this script to customise for your environment.
# 2) Insert a reference for this rule in your firewall script before you accept ssh.
#    This will block the brute force attack until the IP is banned by the script.
#      iptables -N logndrop
#      iptables -N dropBrute
#      iptables -A logndrop -j LOG
#      iptables -A logndrop -j DROP
#      iptables -A input_rule -p tcp --dport 22 -i eth1 -m state --state NEW -m recent --set
#      iptables -A input_rule -p tcp --dport 22 -i eth1 -m state --state NEW -m recent --update --seconds 60 --hitcount 4 -j logndrop
#      iptables -A input_rule -p tcp --dport 22 -j dropBrute
# 3) Run the script periodically out of cron:
#      echo '*/10 * * * * /usr/sbin/dropBrute.sh 2>&1 >> /tmp/dropBrute.log' >> /etc/crontabs/root
# 4) If cron is not enabled, you'll also need to run the following:
#      /etc/init.d/cron enable && /etc/init.d/cron start
# ------------------------------------------------------------------------------
# To whitelist hosts or networks, simply add a manual entry to the lease
# file with a leasetime of -1.  This can be done with the following syntax:
#    echo -1 192.168.1.0/24 >> /tmp/dropBrute.leases
# A static, or non-expiring blacklist of a host or network can also be
# added, just use a lease time of 0.  This can be done with the following syntax:
#    echo 0 1.2.3.0/24 >> /tmp/dropBrute.leases
# ------------------------------------------------------------------------------

# =========================== CUSTOMIZABLE VARIABLES =========================== 
# Debug mode (let empty to disable, debug = '')
debug='1'
# How many bad attempts before banning.
allowedAttempts=3
# How long IPs are banned for (in seconds)
secondsToBan=86400
# the "lease" file - defaults to /tmp which does not persist across reboots
# Note: here, USB key is mounted on /tmp/cache. This way, leases file persists across reboots
leaseFile=/tmp/cache/dropBrute.leases
# Iptables chain that drop commands will go into.
iptChain=dropBrute
# IP Tables drop & whitelist rules
iptDropRule='-j DROP'
iptWhiteRule='-j RETURN'
# Default leasefile entries
[ -f $leaseFile ] || cat <<__EOF__>>$leaseFile
-1 192.168.1.0/24
__EOF__
# Path to iptables command
ipt='/usr/sbin/iptables'
# ======================= END OF CUSTOMIZABLE VARIABLES ========================

# ------------------------------------------------------------------------------
[ `date +'%s'` -lt 1320000000 ] && echo System date not set, aborting. && exit -1
$ipt -N $iptChain >&/dev/null
now=`date +'%s'`
nowPlus=$((now + secondsToBan))
echo ------ Starting dropBrute on `date` \($now\)

# find new badIPs (method 1)
[ "$debug" ] && echo Looking for bad IPs \(method 1\)
for badIP in `logread | fgrep dropbear | egrep -i 'login attempt for nonexistent user'\|'bad password attempt for'| sed 's/^.*from //' | sed 's/:.*$//' | sort -u` ; do
  [ "$debug" ] && echo  - Working on $badIP
  n=`logread | fgrep dropbear | egrep -i 'login attempt for nonexistent user'\|'bad password attempt for'|sed 's/^.*from //'|sed 's/:.*$//' | fgrep $badIP | wc -l`
  if [ $n -ge $allowedAttempts ] ; then
    [ "$debug" ] && echo ... KO \($n occurences\)
    # if there is not a lease, add it
    if [ $(egrep -c $badIP$ $leaseFile) -eq 0 ] ; then
      echo $nowPlus $badIP >> $leaseFile
      [ "$debug" ] && echo ... Adding new lease for $badIP
    else
      [ "$debug" ] && echo ... Lease for $badIP already exists
    fi
  else
    [ "$debug" ] && echo ... Ok \($n occurences\)
  fi
done

# find new badIPs (Method 2)
[ "$debug" ] && echo Looking for bad IPs \(method 2\)
for fuzzyIP in `logread | fgrep dropbear | egrep -i 'Child connection from' | sed 's/^.*from //' | sed 's/:.*$//' | sort -u` ; do
  n=0
  [ "$debug" ] && echo - Working on $fuzzyIP
  for fuzzyPs in `logread | fgrep dropbear | egrep -i 'Child connection from' | fgrep  $fuzzyIP | sed 's/^.*dropbear\[//' | sed 's/\]:.*$//' | sort -u` ; do
    nbPs=`logread | egrep -i 'Exit before auth' | fgrep $fuzzyPs | wc -l`
    n=$((n+nbPs))
  done
  if [ $n -ge $allowedAttempts ] ; then
    [ "$debug" ] && echo ... KO \($n occurences\)
    # if there is not a lease, add it
    if [ $(egrep -c $fuzzyIP $leaseFile) -eq 0 ] ; then
      echo $nowPlus $fuzzyIP >> $leaseFile
      [ "$debug" ] && echo ... Adding new lease for $fuzzyIP
    else
      [ "$debug" ] && echo ... Lease for $fuzzyIP already exists
    fi
  else
    [ "$debug" ] && echo ... Ok \($n occurences\)
  fi
done

# now parse the leaseFile
[ "$debug" ] && echo Parsing the leasefile
cat $leaseFile | while read lease ; do
  leaseTime=`echo $lease|cut -f1 -d\ `
  leaseIP=`echo $lease|cut -f2 -d\ `
  # when used with the iptables example on the top a return rule is not needed
  if [ $leaseTime -lt 0 ] ; then
    if [ `$ipt -S $leaseChain|egrep \ $leaseIP/32\ \|\ $leaseIP\ |fgrep -- "$iptWhiteRule"| wc -l` -lt 1 ] ; then
      #[ "$debug" ] && echo Adding new whitelist rule for $leaseIP
      #$ipt -I $iptChain -s $leaseIP $iptWhiteRule
      true
    fi
  elif [ $leaseTime -ge 1 -a $now -gt $leaseTime ] ; then
    [ "$debug" ] && echo  - Expiring lease for $leaseIP
    $ipt -D $iptChain -s $leaseIP $iptDropRule
    $ipt -D $iptChain -s $leaseIP -j LOG --log-prefix "dropBrute "
    sed -i /$leaseIP/d $leaseFile
  elif [ $leaseTime -ge 0 -a `$ipt -S $leaseChain|egrep \ $leaseIP/32\ \|\ $leaseIP\ |wc -l` -lt 1 ] ; then
    [ "$debug" ] && echo  - Adding new rule for $leaseIP
    $ipt -I $iptChain -s $leaseIP $iptDropRule
    $ipt -I $iptChain -s $leaseIP -j LOG --log-prefix "dropBrute "
  fi
done < $leaseFile

echo ------ Ending dropBrute on `date` \(`date +'%s'`\)

mercredi 29 octobre 2014

:: Installation de rTorrent sur OpenWRT ::

Références

Introduction

rTorrent est un client bitorrent basé sur libtorrent et que l'on peut lancer en mode daemon à l'aide de screen.
Il existe de nombreuses interfaces (GUi et webUi) disponibles pour Windows, Linux, Mac et Android.

Ici, je l'installe sur un routeur Netgear WNDR3800 sous OpenWRT ATTITUDE ADJUSTMENT (12.09, r36088).

Installation et configuration

Installation de rTorrent et de screen

# opkg install rtorrent screen

Création du fichier de configuration rTorrent

# cd /root
# vi .rtorrent.rc

Ma configuration après modification :

# Nombre de pairs en téléchargement
min_peers = 40
max_peers = 120

# Nombre de pairs en téléversement
min_peers_seed = 2
max_peers_seed = 6
max_uploads = 4

# Limite de bande passante
download_rate = 0
upload_rate = 20

# Répertoires contenant les fichiers téléchargés
directory = /mnt/torrent

# Répertoire de stockage de l'état des sessions
session = /mnt/torrent/session

# Ajout automatique de torrents
schedule = watch_directory,15,15,load_start=/mnt/torrent/torrent_active/*.torrent

# Ports utilisables par rtorrent
port_range = 6881-6999
port_random = no

# Vérification des données à la fin du téléchargement
check_hash = yes

# Activation de DHT pour les torrents sans tracker
dht = auto

# Port UDP pour l'utilisation de DHT.
dht_port = 6880

# Forcer l'utilisation de transactions chiffrées, pour ne recevoir et n'envoyer que des données protégées
encryption = allow_incoming,require,require_rc4

Script d'init

# vi /etc/init.d/rtorrent

Copier le contenu suivant :

#!/bin/sh /etc/rc.common
# Copyright (C) 2006-2012 OpenWrt.org

START=99

boot() {
     HOME=/root screen -dmS rtorrent rtorrent
}

start() {
     HOME=/root screen -dmS rtorrent rtorrent
}

stop() {
     killall rtorrent
}

Rendre le script exécutable et l'activer

# chmod 755 /etc/init.d/rtorrent
# /etc/init.d/rtorrent enable
# /etc/init.d/rtorrent start

Utilisation

rTorrent s'exécute dans screen en arrière-plan. Pour le faire revenir au premier plan, on ré-attache la session screen :

# screen -r

et pour le remettre à l'arrière-plan, on s'en détache :

CTRL+A+D