#!/bin/bash

# Author: Christophe Casalegno / Brain 0verride
# Contact: brain@christophe-casalegno.com
# Version 0.1
#
# Copyright (c) 2020 Christophe Casalegno
# 
# 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 3 of the License, or
#    (at your option) any later version.
#
#    This program 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 program.  If not, see <https://www.gnu.org/licenses/>
#
# The license is available on this server here: 
# https://www.christophe-casalegno.com/licences/gpl-3.0.txt


OPTION=$1
HOSTNAME=$(hostname)
DATE=$(date +%Y-%m-%d-%H-%M-%S)
REPORT_FILE="report-${HOSTNAME}-${DATE}.txt"
INTERESTING_FILES='.bash_history .bash_logout .bashrc .ssh known_hosts authorized_keys id_rsa id_rsa.pub authorized_keys2'
INTERESTING_PLACES='/var /tmp /dev/shm'
COMPRESSED_FILE_EXTENSIONS='.zip .tar .gz .rar'

function title () 
{
  TITLE=$1
  echo -e "-----------------------------------------------------"
  echo -e "CHECKING FOR ${TITLE}..."
  echo -e "-----------------------------------------------------"
}

function end () 
{
echo -e "-----------------------------------------------------"
echo -e ""
}

function check_permission () 
{
  PERMISSION=$1
  PERMISSION_TEXT=$2
  
  title ${PERMISSION_TEXT}
  echo "${PERMISSION_TEXT} is ${PERMISSION}"
  find / -type f -perm ${PERMISSION} -exec ls -ld {} \; 2>/dev/null 
  end
}


function check_writable_directories () 
{
  title "world-writable directories"
  find / -type d -perm -2 -exec ls -ld {} \; 2>/dev/null
  end
}

function check_file () 
{
  FILE_NAME=$1
  FILE_DESCRIPTION=$2
  title "${FILE_NAME} file"
  echo ${FILE_DESCRIPTION}
  find / -name ${FILE_NAME} -exec ls -ld {} \; 2>/dev/null
  end
}

function interesting_files ()
{
    INTERESTING_FILES=$1
    for FILE in ${INTERESTING_FILES}
    do
        check_file ${FILE}
    done
}

function check_writable_files ()
{
    INTERESTING_PLACES=$1
    
    title "writable files in interesting places : ${INTERESTING_PLACES}"
    for PLACE in ${INTERESTING_PLACES}
    do
        find ${PLACE} -writable -printf '%p\n' 2>/dev/null
    done
    end
}

function check_compressed_files ()
{
    COMPRESSED_FILE_EXTENSIONS=$1
    
    for EXT in ${COMPRESSED_FILE_EXTENSIONS}
    do
        title "readable ${EXT} files"
        find / -type f -name "*${EXT}" -readable 2>/dev/null
        end
    done
}
        
function check_sudo ()
{
    title "sudo avalaible commands"
    sudo -l
    end
}

function check_process ()
{
    title "process list"
    ps auxwwf
    end
}

function check_crontab ()
{
    title "crontab content"
    crontab -l
    end
}

function check_connections ()
{
    title "connections"
    ss -tunapo
    end
}

if [[ ${OPTION} == "--save" ]]
then
  exec > >(tee ${REPORT_FILE})
fi

check_permission "-u+s" "SUID executables"
check_permission "-g+s" "SGID executables"

check_writable_directories
interesting_files "${INTERESTING_FILES}"
check_writable_files "${INTERESTING_PLACES}"
check_compressed_files "${COMPRESSED_FILE_EXTENSIONS}"

check_sudo
check_crontab
check_connections 
check_process