#!/bin/bash

# Fail2ban for NextCloudPi
#
# Copyleft 2017 by Ignacio Nunez Hernanz <nacho _a_t_ ownyourbits _d_o_t_ com>
# GPL licensed (see end of file) * Use at your own risk!
#
# More at: https://ownyourbits.com/2017/02/24/nextcloudpi-fail2ban-installer/
#


# time to ban an IP that exceeded attempts

# cooldown time for incorrect passwords

# bad attempts before banning an IP


# Option to activate email notifications

# email to send notifications to


install()
{
  apt-get update
  apt-get install --no-install-recommends -y python3-systemd
  apt-get install --no-install-recommends -y fail2ban whois
  update-rc.d fail2ban disable
  rm -f /etc/fail2ban/jail.d/defaults-debian.conf

  # tweak fail2ban email
  local F=/etc/fail2ban/action.d/sendmail-common.conf
  sed -i 's|Fail2Ban|NextCloudPi|' /etc/fail2ban/action.d/sendmail-whois-lines.conf
  grep -q actionstart_ "$F" || sed -i 's|actionstart|actionstart_|' "$F"
  grep -q actionstop_  "$F" || sed -i 's|actionstop|actionstop_|'   "$F"

}

configure()
{
  [[ $ACTIVE != "yes" ]] && {
    service fail2ban stop
    update-rc.d fail2ban disable
    echo "fail2ban disabled"
    return
  }

  local NCLOG="/var/www/nextcloud/data/nextcloud.log"
  local NCLOG1="$(ncc config:system:get logfile)"

  [[ "$NCLOG1" != "" ]] && NCLOG="$NCLOG1"

  local BASEDIR=$( dirname "$NCLOG" )
  [ -d "$BASEDIR" ] || { echo -e "directory $BASEDIR not found"; return 1; }

  sudo -u www-data touch "$NCLOG" || { echo -e "ERROR: user www-data does not have write permissions on $NCLOG"; return 1; }

  ncc config:system:set loglevel --value=2
  ncc config:system:set log_type --value=file

  # Filters
  cat > /etc/fail2ban/filter.d/nextcloud.conf <<'EOF'
[INCLUDES]
before = common.conf

[Definition]
_groupsre = (?:(?:,?\s*"\w+":(?:"[^"]+"|\w+))*)
failregex = ^\{%(_groupsre)s,?\s*"remoteAddr":"<HOST>"%(_groupsre)s,?\s*"message":"Login failed:
datepattern = ,?\s*"time"\s*:\s*"%%Y-%%m-%%d[T ]%%H:%%M:%%S(%%z)?"
ignoreregex =
EOF

  cat > /etc/fail2ban/filter.d/ufwban.conf <<'EOF'
[INCLUDES]
before = common.conf

[Definition]
failregex = UFW BLOCK.* SRC=<HOST>
ignoreregex =
EOF
  mkdir -p /etc/systemd/system/fail2ban.service.d
  cat > /etc/systemd/system/fail2ban.service.d/touch-ufw-log.conf <<'EOF'
[Service]
ExecStartPre=/bin/touch /var/log/ufw.log
EOF

  [[ "$MAILALERTS" == "yes" ]] && local ACTION=action_mwl || local ACTION=action_

  # Jails
  cat > /etc/fail2ban/jail.conf <<EOF
# The DEFAULT allows a global definition of the options. They can be overridden
# in each jail afterwards.
[DEFAULT]

# "ignoreip" can be an IP address, a CIDR mask or a DNS host. Fail2ban will not
# ban a host which matches an address in this list. Several addresses can be
# defined using space separator.
ignoreip = 127.0.0.1/8

# "bantime" is the number of seconds that a host is banned.
bantime  = $BANTIME

# A host is banned if it has generated "maxretry" during the last "findtime"
# seconds.
findtime = $FINDTIME
maxretry = $MAXRETRY

#
# ACTIONS
#
banaction  = iptables-multiport
protocol   = tcp
chain      = INPUT
action_    = %(banaction)s[name=%(__name__)s, port="%(port)s", protocol="%(protocol)s", chain="%(chain)s"]
action_mwl = %(banaction)s[name=%(__name__)s, port="%(port)s", protocol="%(protocol)s", chain="%(chain)s"]
           sendmail-whois-lines[name=%(__name__)s, dest=$EMAIL, sender=ncp-fail2ban@ownyourbits.com]
action = %($ACTION)s

#
# SSH
#
[ssh]
enabled  = true
port     = ssh
filter   = sshd
backend  = systemd
logpath  = /var/log/auth.log
maxretry = $MAXRETRY

#
# HTTP servers
#
[nextcloud]
enabled  = true
port     = http,https
filter   = nextcloud
logpath  = $NCLOG
maxretry = $MAXRETRY
backend  = auto

#
# UFW
#
[ufwban]
enabled = true
port    = ssh, http, https
filter  = ufwban
logpath = /var/log/ufw.log
action  = ufw
backend = auto
EOF

  cp /etc/fail2ban/jail.conf /etc/fail2ban/jail.local
  touch /var/log/ufw.log
  update-rc.d fail2ban defaults
  update-rc.d fail2ban enable
  systemctl daemon-reload
  service fail2ban restart
  echo "fail2ban enabled"
}

# License
#
# This script 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, or
# (at your option) any later version.
#
# This script is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this script; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place, Suite 330,
# Boston, MA  02111-1307  USA

