#!/bin/bash
#
# .---.                  .              .
# |                      |              |
# |--- .--. .-.  .-.  .-.|  .-. .--.--. |.-.  .-. .--.  .-.
# |    |   (.-' (.-' (   | (   )|  |  | |   )(   )|  | (.-'
# '    '     --'  --'  -' -  -' '  '   -' -'   -' '   -  --'
#
#                    Freedom in the Cloud
#
# License
# =======
#
# Copyright (C) 2015-2016 Bob Mottram <bob@freedombone.net>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

PROJECT_NAME='freedombone'

export TEXTDOMAIN=${PROJECT_NAME}-client
export TEXTDOMAINDIR="/usr/share/locale"

CURR_USER=$USER
CURR_GROUP=$USER
if [ -f /usr/bin/pacman ]; then
    CURR_GROUP='users'
fi
MESH_CLIENT_INSTALL=
ENABLE_MONKEYSPHERE=

# Version number of this script
VERSION="1.01"

# get the main project file, so that some values can be extracted
MAIN_PROJECT_FILE=/usr/local/bin/${PROJECT_NAME}
if [ ! -f $MAIN_PROJECT_FILE ]; then
    MAIN_PROJECT_FILE=/usr/bin/${PROJECT_NAME}
fi
if [ ! -f $MAIN_PROJECT_FILE ]; then
    echo "The main project file $MAIN_PROJECT_FILE was not found"
    exit 72529
fi

# ssh (from https://stribika.github.io/2015/01/04/secure-secure-shell.html)
UTILS_SSH=/usr/share/${PROJECT_NAME}/utils/${PROJECT_NAME}-utils-ssh
SSH_CIPHERS=$(cat $UTILS_SSH | grep 'SSH_CIPHERS=' | head -n 1 | awk -F '"' '{print $2}')
SSH_MACS=$(cat $UTILS_SSH | grep 'SSH_MACS=' | head -n 1 | awk -F '"' '{print $2}')
SSH_KEX=$(cat $UTILS_SSH | grep 'SSH_KEX=' | head -n 1 | awk -F '"' '{print $2}')
SSH_HOST_KEY_ALGORITHMS=$(cat $UTILS_SSH | grep 'SSH_HOST_KEY_ALGORITHMS=' | head -n 1 | awk -F '"' '{print $2}')

# refresh gpg keys every few hours
REFRESH_GPG_KEYS_HOURS=2

function global_rate_limit {
    SYSCTL_FILE=/etc/sysctl.conf
    if [ -f /usr/bin/pacman ]; then
        SYSCTL_FILE=/etc/sysctl.d/99-sysctl.conf
    fi
    if [ ! -f $SYSCTL_FILE ]; then
        sudo touch $SYSCTL_FILE
    fi

    sudo cp $SYSCTL_FILE ~/sysctl.conf
    sudo chown $CURR_USER:$CURR_GROUP ~/sysctl.conf
    if ! grep -q "tcp_challenge_ack_limit" ~/sysctl.conf; then
        echo 'net.ipv4.tcp_challenge_ack_limit = 999999999' >> ~/sysctl.conf
    else
        sed -i 's|net.ipv4.tcp_challenge_ack_limit.*|net.ipv4.tcp_challenge_ack_limit = 999999999|g' ~/sysctl.conf
    fi
    sudo cp ~/sysctl.conf $SYSCTL_FILE
    sudo rm ~/sysctl.conf
    sudo sysctl -p -q $SYSCTL_FILE
}

function refresh_gpg_keys {
    if [ ! -f /usr/bin/gpg ]; then
        if [ ! -f /usr/bin/pacman ]; then
            sudo apt-get -yq install gnupg
        else
            sudo pacman -S --noconfirm gnupg
        fi
    fi
    sudo cp /etc/crontab ~/temp_crontab
    sudo chown $CURR_USER:$CURR_GROUP ~/temp_crontab
    if ! grep -q "gpg --refresh-keys" ~/temp_crontab; then
        echo "0            */$REFRESH_GPG_KEYS_HOURS *   *   *   $CURR_USER /usr/bin/gpg --refresh-keys > /dev/null" >> ~/temp_crontab
        sudo cp ~/temp_crontab /etc/crontab
        sudo chown root:root /etc/crontab
    fi
    rm ~/temp_crontab
}

# see https://stribika.github.io/2015/01/04/secure-secure-shell.html
function ssh_remove_small_moduli {
    sudo awk '$5 > 2000' /etc/ssh/moduli > /home/$CURR_USER/moduli
    sudo mv /home/$CURR_USER/moduli /etc/ssh/moduli
}

function configure_ssh_client {
    if [ -f /usr/bin/pacman ]; then
        sudo pacman --noconfirm -S openbsd-netcat
    else
        sudo apt-get -yq install tor connect-proxy
    fi

    #sudo sed -i 's/#   PasswordAuthentication.*/   PasswordAuthentication no/g' /etc/ssh/ssh_config
    #sudo sed -i 's/#   ChallengeResponseAuthentication.*/   ChallengeResponseAuthentication no/g' /etc/ssh/ssh_config
    sudo sed -i "s/#   HostKeyAlgorithms.*/   HostKeyAlgorithms $SSH_HOST_KEY_ALGORITHMS/g" /etc/ssh/ssh_config
    sudo sed -i "s/#   Ciphers.*/   Ciphers $SSH_CIPHERS/g" /etc/ssh/ssh_config
    sudo sed -i "s/#   MACs.*/   MACs $SSH_MACS/g" /etc/ssh/ssh_config
    sudo sed -i "s/HostKeyAlgorithms.*/HostKeyAlgorithms $SSH_HOST_KEY_ALGORITHMS/g" /etc/ssh/ssh_config
    if ! grep -q "HostKeyAlgorithms" /etc/ssh/ssh_config; then
        sudo cp /etc/ssh/ssh_config ~/ssh_config
        sudo chown $CURR_USER:$CURR_GROUP ~/ssh_config
        echo "   HostKeyAlgorithms $SSH_HOST_KEY_ALGORITHMS" >> ~/ssh_config
        sudo mv ~/ssh_config /etc/ssh/ssh_config
        sudo chown root:root /etc/ssh/ssh_config
    fi
    sudo sed -i "s/HostKeyAlgorithms.*/#HostKeyAlgorithms $SSH_HOST_KEY_ALGORITHMS/g" /etc/ssh/ssh_config

    sudo sed -i "s/Ciphers.*/Ciphers $SSH_CIPHERS/g" /etc/ssh/ssh_config
    if ! grep -q "Ciphers " /etc/ssh/ssh_config; then
        sudo cp /etc/ssh/ssh_config ~/ssh_config
        sudo chown $CURR_USER:$CURR_GROUP ~/ssh_config
        echo "   Ciphers $SSH_CIPHERS" >> ~/ssh_config
        sudo mv ~/ssh_config /etc/ssh/ssh_config
        sudo chown root:root /etc/ssh/ssh_config
    fi
    sudo sed -i "s/MACs.*/MACs $SSH_MACS/g" /etc/ssh/ssh_config
    if ! grep -q "MACs " /etc/ssh/ssh_config; then
        sudo cp /etc/ssh/ssh_config ~/ssh_config
        sudo chown $CURR_USER:$CURR_GROUP ~/ssh_config
        echo "   MACs $SSH_MACS" >> ~/ssh_config
        sudo mv ~/ssh_config /etc/ssh/ssh_config
        sudo chown root:root /etc/ssh/ssh_config
    fi

    # Create ssh keys
    if [ ! -f /home/$CURR_USER/.ssh/id_ed25519 ]; then
        ssh-keygen -t ed25519 -o -a 100
    fi
    if [ ! -f /home/$CURR_USER/.ssh/id_rsa ]; then
        ssh-keygen -t rsa -b 4096 -o -a 100
    fi

    ssh_remove_small_moduli

    if [ ! -d ~/.ssh ]; then
        mkdir ~/.ssh
    fi
    echo 'Host *.onion' > ~/.ssh/config
    echo '  ServerAliveInterval 60' >> ~/.ssh/config
    echo '  ServerAliveCountMax 3' >> ~/.ssh/config

    proxycmd="connect -R remote -5 -S 127.0.0.1:9050 %h %p"
    if [ -f /usr/bin/pacman ]; then
        proxycmd="/usr/bin/nc -X 5 -x 127.0.0.1:9050 %h %p"
    fi

    if [[ $ENABLE_MONKEYSPHERE == $'yes' || $ENABLE_MONKEYSPHERE == $'y' ]]; then
        echo "  ProxyCommand sh -c 'monkeysphere ssh-proxycommand --no-connect %h %p ; $proxycmd'" >> ~/.ssh/config
    else
        echo "  ProxyCommand $proxycmd" >> ~/.ssh/config
    fi
    echo 'Host *' >> ~/.ssh/config
    echo '  ServerAliveInterval 60' >> ~/.ssh/config
    echo '  ServerAliveCountMax 3' >> ~/.ssh/config
    if [[ $ENABLE_MONKEYSPHERE == $'yes' || $ENABLE_MONKEYSPHERE == $'y' ]]; then
        echo '  ProxyCommand monkeysphere ssh-proxycommand %h %p' >> ~/.ssh/config
    fi

    echo ''
    echo $'Copy the following into a file called /home/username/.ssh/authorized_keys on the Freedombone server'
    echo ''
    echo $(cat /home/$CURR_USER/.ssh/id_rsa.pub)
    echo $(cat /home/$CURR_USER/.ssh/id_ed25519.pub)
    echo ''
}

function configure_monkeysphere {
    if [ -f /usr/bin/pacman ]; then
        return
    fi
    sudo apt-get -yq install monkeysphere
}

function show_help {
    echo ''
    echo $"${PROJECT_NAME}-client --mesh [yes|no] --monkeysphere [yes|no]"
    echo ''
    exit 0
}

while [[ $# > 1 ]]
do
    key="$1"

    case $key in
        -h|--help)
            show_help
            ;;
        --essid)
            shift
            WIFI_SSID="$1"
            ;;
        --channel)
            shift
            WIFI_CHANNEL=${1}
            ;;
        -m|--mesh)
            shift
            MESH_CLIENT_INSTALL=${1}
            ;;
        --monkeysphere|--ms|--monkey)
            shift
            ENABLE_MONKEYSPHERE=${1}
            ;;
        *)
            # unknown option
            ;;
    esac
    shift
done

echo $'Configuring client'
refresh_gpg_keys
configure_ssh_client
global_rate_limit
configure_monkeysphere
if [[ $MESH_CLIENT_INSTALL == $'yes' || $MESH_CLIENT_INSTALL == $'y' || $MESH_CLIENT_INSTALL == $'on' ]]; then
    echo $'Installing mesh packages'
    if [ ! -f /usr/bin/pacman ]; then
        sudo apt-get -yq install avahi-utils avahi-autoipd avahi-dnsconfd
    else
        sudo pacman -S --noconfirm avahi nss-mdns
        sudo sed -i 's|hosts:.*|hosts: files mdns_minimal [NOTFOUND=return] dns myhostname|g' /etc/nsswitch.conf
    fi
    sudo ${PROJECT_NAME}-mesh-install -f tox_node
    sudo ${PROJECT_NAME}-mesh-install -f toxic
    ${PROJECT_NAME}-mesh-install -f qtox
    sudo ${PROJECT_NAME}-mesh-install -f zeronet
fi
echo $'Configuration complete'
exit 0