#!/bin/bash
set -e

# This is the Raspberry Pi Kali ARM build script - https://www.kali.org/downloads
# A trusted Kali Linux image created by Offensive Security - https://www.offensive-security.com

if [[ $EUID -ne 0 ]]; then
   echo "This script must be run as root"
   exit 1
fi

if [[ $# -eq 0 ]] ; then
    echo "Please pass version number, e.g. $0 2.0, and (if you want) a hostname, default is kali"
    exit 0
fi

basedir=`pwd`/rpi-hyperpixel-$1

# Custom hostname variable
hostname=${2:-kali}
# Custom image file name variable - MUST NOT include .img at the end.
imagename=${3:-kali-linux-$1-rpi-hyperpixel}
# Size of image in megabytes (Default is 4500=4.5GB)
size=4500
# Suite to use.
# Valid options are:
# kali-rolling, kali-dev, kali-bleeding-edge, kali-dev-only, kali-experimental, kali-last-snapshot
# A release is done against kali-last-snapshot, but if you're building your own, you'll probably want to build
# kali-rolling.
suite=kali-rolling

# Generate a random machine name to be used.
machine=$(cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 16 | head -n 1)

# Package installations for various sections.
# This will build a minimal XFCE Kali system with the top 10 tools.
# This is the section to edit if you would like to add more packages.
# See http://www.kali.org/new/kali-linux-metapackages/ for meta packages you can
# use. You can also install packages, using just the package name, but keep in
# mind that not all packages work on ARM! If you specify one of those, the
# script will throw an error, but will still continue on, and create an unusable
# image, keep that in mind.

arm="abootimg cgpt fake-hwclock ntpdate u-boot-tools vboot-utils vboot-kernel-utils"
base="apt-transport-https apt-utils console-setup e2fsprogs firmware-linux firmware-realtek firmware-atheros firmware-libertas firmware-brcm80211 ifupdown initramfs-tools iw kali-defaults man-db mlocate netcat-traditional net-tools parted psmisc rfkill screen snmpd snmp sudo tftp tmux unrar usbutils vim wget zerofree"
desktop="kali-menu fonts-croscore fonts-crosextra-caladea fonts-crosextra-carlito kali-desktop-xfce kali-root-login lightdm network-manager network-manager-gnome xfce4 xserver-xorg-video-fbdev xserver-xorg-input-evdev xserver-xorg-input-synaptics"
tools="aircrack-ng crunch cewl dnsrecon dnsutils ethtool exploitdb hydra john libnfc-bin medusa metasploit-framework mfoc ncrack nmap passing-the-hash proxychains recon-ng sqlmap tcpdump theharvester tor tshark usbutils whois windows-binaries winexe wpscan wireshark"
services="apache2 atftpd openssh-server openvpn tightvncserver"
extras="bluez bluez-firmware i2c-tools python3-configobj python3-evdev python3-pip python3-requests python3-rpi.gpio python3-smbus xfonts-terminus triggerhappy wpasupplicant xfce4-terminal"

# Git commit hash to check out for the kernel
#kernel_commit=20fe468

packages="${arm} ${base} ${services}"
architecture="armel"
# If you have your own preferred mirrors, set them here.
# After generating the rootfs, we set the sources.list to the default settings.
mirror=http.kali.org

# Check to ensure that the architecture is set to ARMEL since the RPi is the
# only board that is armel.
if [[ ${architecture} != "armel" ]] ; then
    echo "The Raspberry Pi cannot run Debian armhf binaries"
    exit 0
fi

# Set this to use an http proxy, like apt-cacher-ng, and uncomment further down
# to unset it.
#export http_proxy="http://localhost:3142/"

mkdir -p "${basedir}"
cd "${basedir}"

# create the rootfs - not much to modify here, except maybe throw in some more packages if you want.
debootstrap --foreign --keyring=/usr/share/keyrings/kali-archive-keyring.gpg --include=kali-archive-keyring --arch ${architecture} ${suite} kali-${architecture} http://${mirror}/kali

cp /usr/bin/qemu-arm-static kali-${architecture}/usr/bin/

LANG=C systemd-nspawn -M ${machine} -D kali-${architecture} /debootstrap/debootstrap --second-stage

mkdir -p kali-${architecture}/etc/apt/
cat << EOF > kali-${architecture}/etc/apt/sources.list
deb http://${mirror}/kali ${suite} main contrib non-free
EOF

# Set hostname
echo "${hostname}" > kali-${architecture}/etc/hostname
# So X doesn't complain, we add $hostname to hosts
cat << EOF > kali-${architecture}/etc/hosts
127.0.0.1       ${hostname}    localhost
::1             localhost ip6-localhost ip6-loopback
fe00::0         ip6-localnet
ff00::0         ip6-mcastprefix
ff02::1         ip6-allnodes
ff02::2         ip6-allrouters
EOF

mkdir -p kali-${architecture}/etc/network/
cat << EOF > kali-${architecture}/etc/network/interfaces
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp
EOF

cat << EOF > kali-${architecture}/etc/resolv.conf
nameserver 8.8.8.8
EOF

cat << EOF > kali-${architecture}/debconf.set
console-common console-data/keymap/policy select Select keymap from full list
console-common console-data/keymap/full select en-latin1-nodeadkeys
EOF

mkdir -p kali-${architecture}/usr/lib/systemd/system/
cat << 'EOF' > kali-${architecture}/usr/lib/systemd/system/regenerate_ssh_host_keys.service
[Unit]
Description=Regenerate SSH host keys
Before=ssh.service
[Service]
Type=oneshot
ExecStartPre=-/bin/dd if=/dev/hwrng of=/dev/urandom count=1 bs=4096
ExecStartPre=-/bin/sh -c "/bin/rm -f -v /etc/ssh/ssh_host_*_key*"
ExecStart=/usr/bin/ssh-keygen -A -v
ExecStartPost=/bin/sh -c "for i in /etc/ssh/ssh_host_*_key*; do actualsize=$(wc -c <\"$i\") ;if [ $actualsize -eq 0 ]; then echo size is 0 bytes ; exit 1 ; fi ; done ; /bin/systemctl disable regenerate_ssh_host_keys"
[Install]
WantedBy=multi-user.target
EOF
chmod 644 kali-${architecture}/usr/lib/systemd/system/regenerate_ssh_host_keys.service

cat << EOF > kali-${architecture}/usr/lib/systemd/system/smi-hack.service
[Unit]
Description=shared-mime-info update hack
Before=regenerate_ssh_host_keys.service
[Service]
Type=oneshot
Environment=DEBIAN_FRONTEND=noninteractive
ExecStart=/bin/sh -c "rm -rf /etc/ssl/certs/*.pem && dpkg -i /root/*.deb"
ExecStart=/bin/sh -c "dpkg-reconfigure shared-mime-info"
ExecStart=/bin/sh -c "dpkg-reconfigure xfonts-base"
ExecStart=/bin/sh -c "rm -f /root/*.deb"
ExecStartPost=/bin/systemctl disable smi-hack

[Install]
WantedBy=multi-user.target
EOF
chmod 644 kali-${architecture}/usr/lib/systemd/system/smi-hack.service

cat << EOF > kali-${architecture}/usr/lib/systemd/system/rpiwiggle.service
[Unit]
Description=Resize filesystem
After=regenerate_ssh_host_keys.service
[Service]
Type=oneshot
ExecStart=/root/scripts/rpi-wiggle.sh
ExecStartPost=/bin/systemctl disable rpiwiggle
[Install]
WantedBy=multi-user.target
EOF
chmod 644 kali-${architecture}/usr/lib/systemd/system/rpiwiggle.service

cat << EOF > "${basedir}"/kali-${architecture}/usr/lib/systemd/system/enable-ssh.service
[Unit]
Description=Turn on SSH if /boot/ssh is present
ConditionPathExistsGlob=/boot/ssh{,.txt}
After=regenerate_ssh_host_keys.service

[Service]
Type=oneshot
ExecStart=/bin/sh -c "update-rc.d ssh enable && invoke-rc.d ssh start && rm -f /boot/ssh ; rm -f /boot/ssh.txt"

[Install]
WantedBy=multi-user.target
EOF
chmod 644 "${basedir}"/kali-${architecture}/usr/lib/systemd/system/enable-ssh.service

cat << EOF > "${basedir}"/kali-${architecture}/usr/lib/systemd/system/copy-user-wpasupplicant.service
[Unit]
Description=Copy user wpa_supplicant.conf
ConditionPathExists=/boot/wpa_supplicant.conf
Before=dhcpcd.service

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/bin/mv /boot/wpa_supplicant.conf /etc/wpa_supplicant/wpa_supplicant.conf
ExecStartPost=/bin/chmod 600 /etc/wpa_supplicant/wpa_supplicant.conf

[Install]
WantedBy=multi-user.target
EOF
chmod 644 "${basedir}"/kali-${architecture}/usr/lib/systemd/system/copy-user-wpasupplicant.service

# Download the hyperpixel's service files here so we can enable them in the third stage with the rest of the services
wget https://raw.githubusercontent.com/pimoroni/hyperpixel/master/requirements/usr/lib/systemd/system/hyperpixel-touch.service -O kali-${architecture}/usr/lib/systemd/system/hyperpixel-touch.service
wget https://raw.githubusercontent.com/pimoroni/hyperpixel/master/requirements/usr/lib/systemd/system/hyperpixel-init.service -O kali-${architecture}/usr/lib/systemd/system/hyperpixel-init.service
wget https://raw.githubusercontent.com/pimoroni/hyperpixel/master/requirements/usr/bin/hyperpixel-init -O kali-${architecture}/usr/bin/hyperpixel-init
chmod 755 kali-${architecture}/usr/bin/hyperpixel-init
wget https://raw.githubusercontent.com/pimoroni/hyperpixel/master/requirements/usr/bin/hyperpixel-touch -O kali-${architecture}/usr/bin/hyperpixel-touch
chmod 755 kali-${architecture}/usr/bin/hyperpixel-touch

cat << EOF > kali-${architecture}/third-stage
#!/bin/bash
set -e
dpkg-divert --add --local --divert /usr/sbin/invoke-rc.d.chroot --rename /usr/sbin/invoke-rc.d
cp /bin/true /usr/sbin/invoke-rc.d
echo -e "#!/bin/sh\nexit 101" > /usr/sbin/policy-rc.d
chmod 755 /usr/sbin/policy-rc.d

apt-get update
apt-get --yes --allow-change-held-packages install locales-all

debconf-set-selections /debconf.set
rm -f /debconf.set
apt-get -y install git-core binutils ca-certificates initramfs-tools u-boot-tools
apt-get -y install locales console-common less nano git
echo "root:toor" | chpasswd
rm -f /etc/udev/rules.d/70-persistent-net.rules
export DEBIAN_FRONTEND=noninteractive
# This looks weird, but we do it twice because every so often, there's a failure to download from the mirror
# So to workaround it, we attempt to install them twice.
apt-get --yes --allow-change-held-packages -o dpkg::options::=--force-confnew install ${packages} || apt-get --yes --fix-broken install
apt-get --yes --allow-change-held-packages -o dpkg::options::=--force-confnew install ${packages} || apt-get --yes --fix-broken install
apt-get --yes --allow-change-held-packages -o dpkg::options::=--force-confnew install ${desktop} ${extras} ${tools} || apt-get --yes --fix-broken install
apt-get --yes --allow-change-held-packages -o dpkg::options::=--force-confnew install ${desktop} ${extras} ${tools} || apt-get --yes --fix-broken install
apt-get --yes --allow-change-held-packages -o dpkg::options::=--force-confnew dist-upgrade
apt-get --yes --allow-change-held-packages -o dpkg::options::=--force-confnew autoremove

# Because copying in authorized_keys is hard for people to do, let's make the
# image insecure and enable root login with a password.

echo "Making the image insecure"
sed -i -e 's/^#PermitRootLogin prohibit-password/PermitRootLogin yes/' /etc/ssh/sshd_config

# Resize FS on first run (hopefully)
systemctl enable rpiwiggle

# Enable copying of user wpa_supplicant.conf file
systemctl enable copy-user-wpasupplicant

# Regenerated the shared-mime-info database on the first boot
# since it fails to do so properly in a chroot.
systemctl enable smi-hack

# Generate SSH host keys on first run
systemctl enable regenerate_ssh_host_keys
systemctl enable ssh

# Enable the hyperpixel display
systemctl enable hyperpixel-init
systemctl enable hyperpixel-touch

# Copy over the default bashrc to root
cp  /etc/skel/.bashrc /root/.bashrc

cd /root
apt download ca-certificates
apt download libgdk-pixbuf2.0-0
apt download fontconfig

# Fix startup time from 5 minutes to 15 secs on raise interface wlan0
sed -i 's/^TimeoutStartSec=5min/TimeoutStartSec=15/g' "/lib/systemd/system/networking.service"

# Try and make the console a bit nicer
# Set the terminus font for a bit nicer display.
sed -i -e 's/FONTFACE=.*/FONTFACE="Terminus"/' /etc/default/console-setup
sed -i -e 's/FONTSIZE=.*/FONTSIZE="6x12"/' /etc/default/console-setup

# Fix startup time from 5 minutes to 15 secs on raise interface wlan0
sed -i 's/^TimeoutStartSec=5min/TimeoutStartSec=15/g' "/lib/systemd/system/networking.service"

rm -f /usr/sbin/policy-rc.d
rm -f /usr/sbin/invoke-rc.d
dpkg-divert --remove --rename /usr/sbin/invoke-rc.d

rm -rf /root/.bash_history
apt-get update
apt-get clean
rm -f /0
rm -f /hs_err*
rm -f cleanup
rm -f /usr/bin/qemu*

rm -f /third-stage
EOF

export MALLOC_CHECK_=0 # workaround for LP: #520465
export LC_ALL=C
export DEBIAN_FRONTEND=noninteractive

#mount -t proc proc kali-$architecture/proc
#mount -o bind /dev/ kali-$architecture/dev/
#mount -o bind /dev/pts kali-$architecture/dev/pts

chmod 755 kali-${architecture}/third-stage

LANG=C systemd-nspawn -M ${machine} -D kali-${architecture} /third-stage
if [[ $? > 0 ]]; then
  echo "Third stage failed"
  exit 1
fi


#umount kali-$architecture/dev/pts
#umount kali-$architecture/dev/
#umount kali-$architecture/proc

# Enable login over serial
echo "T0:23:respawn:/sbin/agetty -L ttyAMA0 115200 vt100" >> "${basedir}"/kali-${architecture}/etc/inittab

# Uncomment this if you use apt-cacher-ng otherwise git clones will fail.
#unset http_proxy

# Kernel section. If you want to use a custom kernel, or configuration, replace
# them in this section.
# Kernel section. If you want to use a custom kernel, or configuration, replace
# them in this section.
git clone --depth 1 https://github.com/raspberrypi/firmware.git rpi-firmware
cp -rf rpi-firmware/boot/* "${basedir}"/kali-${architecture}/boot/
# copy over Pi specific libs (video core) and binaries (dtoverlay,dtparam ...)
cp -rf rpi-firmware/opt/* "${basedir}"/kali-${architecture}/opt/
rm -rf rpi-firmware
git clone --depth 1 https://github.com/nethunteros/re4son-raspberrypi-linux.git -b rpi-4.14.80-re4son "${basedir}"/kali-${architecture}/usr/src/kernel
cd "${basedir}"/kali-${architecture}/usr/src/kernel
export ARCH=arm
export CROSS_COMPILE=arm-linux-gnueabi-
make re4son_pi1_defconfig

# Build kernel
make -j $(grep -c processor /proc/cpuinfo)
make modules_install INSTALL_MOD_PATH="${basedir}"/kali-${architecture}

# Copy kernel to boot
perl scripts/mkknlimg --dtok arch/arm/boot/zImage "${basedir}"/kali-${architecture}/boot/kernel.img
cp arch/arm/boot/dts/*.dtb "${basedir}"/kali-${architecture}/boot/
cp arch/arm/boot/dts/overlays/*.dtb* "${basedir}"/kali-${architecture}/boot/overlays/
cp arch/arm/boot/dts/overlays/README "${basedir}"/kali-${architecture}/boot/overlays/

make mrproper
make re4son_pi1_defconfig
cd "${basedir}"

# Fix up the symlink for building external modules
# kernver is used so we don't need to keep track of what the current compiled
# version is
kernver=$(ls "${basedir}"/kali-${architecture}/lib/modules/)
cd "${basedir}"/kali-${architecture}/lib/modules/${kernver}
rm build
rm source
ln -s /usr/src/kernel build
ln -s /usr/src/kernel source
cd "${basedir}"

# Create cmdline.txt file
cat << EOF > "${basedir}"/kali-${architecture}/boot/cmdline.txt
dwc_otg.lpm_enable=0 console=ttyAMA0,115200 kgdboc=ttyAMA0,115200 console=tty1 elevator=deadline root=/dev/mmcblk0p2 rootfstype=ext3 rootwait net.ifnames=0
EOF

# systemd doesn't seem to be generating the fstab properly for some people, so
# let's create one.
cat << EOF > "${basedir}"/kali-${architecture}/etc/fstab
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc /proc proc nodev,noexec,nosuid 0  0
/dev/mmcblk0p2  / ext3 errors=remount-ro 0 1
# Change this if you add a swap partition or file
#/dev/SWAP none swap sw 0 0
/dev/mmcblk0p1 /boot vfat noauto 0 0
EOF

# Re4son's rpi-tft configurator
wget https://raw.githubusercontent.com/Re4son/RPi-Tweaks/master/kalipi-tft-config/kalipi-tft-config -O "${basedir}"/kali-${architecture}/usr/bin/kalipi-tft-config
chmod 755 "${basedir}"/kali-${architecture}/usr/bin/kalipi-tft-config

# rpi-wiggle
mkdir -p "${basedir}"/kali-${architecture}/root/scripts
wget https://raw.github.com/steev/rpiwiggle/master/rpi-wiggle -O "${basedir}"/kali-${architecture}/root/scripts/rpi-wiggle.sh
chmod 755 "${basedir}"/kali-${architecture}/root/scripts/rpi-wiggle.sh

cd "${basedir}"

# Copy a default config, with everything commented out so people find it when
# they go to add something when they are following instructions on a website.
cp "${basedir}"/../misc/config.txt "${basedir}"/kali-${architecture}/boot/config.txt

cat << EOF >> "${basedir}"/kali-${architecture}/boot/config.txt

# HyperPixel LCD Settings
dtoverlay=hyperpixel
overscan_left=0
overscan_right=0
overscan_top=0
overscan_bottom=0
framebuffer_width=800
framebuffer_height=480
enable_dpi_lcd=1
display_default_lcd=1
dpi_group=2
dpi_mode=87
dpi_output_format=0x6f016
display_rotate=2
hdmi_timings=800 0 50 20 50 480 1 3 2 3 0 0 0 60 0 32000000 6
# Use a basic GPIO backlight driver with on/off support
dtoverlay=hyperpixel-gpio-backlight
EOF

cp "${basedir}"/../misc/zram "${basedir}"/kali-${architecture}/etc/init.d/zram
chmod 755 "${basedir}"/kali-${architecture}/etc/init.d/zram

echo "Running du to see how big kali-${architecture} is"
du -sh "${basedir}"/kali-${architecture}
echo "the above is how big the sdcard needs to be"

# Create the disk and partition it
echo "Creating image file ${imagename}.img"
dd if=/dev/zero of="${basedir}"/${imagename}.img bs=1M count=${size}
parted ${imagename}.img --script -- mklabel msdos
parted ${imagename}.img --script -- mkpart primary fat32 0 128
parted ${imagename}.img --script -- mkpart primary ext3 128 -1

# Set the partition variables
loopdevice=`losetup -f --show "${basedir}"/${imagename}.img`
device=`kpartx -va ${loopdevice} | sed 's/.*\(loop[0-9]\+\)p.*/\1/g' | head -1`
sleep 5
device="/dev/mapper/${device}"
bootp=${device}p1
rootp=${device}p2

# Create file systems
mkfs.vfat ${bootp}
mkfs.ext3 ${rootp}

# Create the dirs for the partitions and mount them
mkdir -p "${basedir}"/root
mount ${rootp} "${basedir}"/root
mkdir -p "${basedir}"/root/boot
mount ${bootp} "${basedir}"/root/boot

# We do this down here to get rid of the build system's resolv.conf after running through the build.
cat << EOF > kali-${architecture}/etc/resolv.conf
nameserver 8.8.8.8
EOF

echo "Rsyncing rootfs into image file"
rsync -HPavz -q "${basedir}"/kali-${architecture}/ "${basedir}"/root/

# Unmount partitions
# Sync before unmounting to ensure everything is written
sync
umount -l ${bootp}
umount -l ${rootp}
kpartx -dv ${loopdevice}
losetup -d ${loopdevice}

# Don't pixz on 32bit, there isn't enough memory to compress the images.
MACHINE_TYPE=`uname -m`
if [ ${MACHINE_TYPE} == 'x86_64' ]; then
echo "Compressing ${imagename}.img"
pixz "${basedir}"/${imagename}.img "${basedir}"/../${imagename}.img.xz
rm "${basedir}"/${imagename}.img
fi

# Clean up all the temporary build stuff and remove the directories.
# Comment this out to keep things around if you want to see what may have gone
# wrong.
echo "Cleaning up the temporary build files..."
rm -rf "${basedir}"