#!/bin/bash
#
# .---.                  .              .
# |                      |              |
# |--- .--. .-.  .-.  .-.|  .-. .--.--. |.-.  .-. .--.  .-.
# |    |   (.-' (.-' (   | (   )|  |  | |   )(   )|  | (.-'
# '    '     --'  --'  -' -  -' '  '   -' -'   -' '   -  --'
#
#                    Freedom in the Cloud
#
# Onion functions
#
# License
# =======
#
# Copyright (C) 2014-2018 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/>.

# The maximum amount of traffic per day in gigabytes
TOR_MAX_TRAFFIC_PER_MONTH_GB=10

USE_V2_ONION_ADDRESS=
HIDDEN_SERVICE_PATH='/var/lib/tor/hidden_service_'

function add_email_hostname {
    extra_email_hostname="$1"
    email_hostnames=$(cat /etc/exim4/update-exim4.conf.conf | grep "dc_other_hostnames" | awk -F "'" '{print $2}')
    if [[ "$email_hostnames" != *"$extra_email_hostname"* ]]; then
        sed -i "s|dc_other_hostnames=.*|dc_other_hostnames='$emailhostnames;extra_email_hostname'|g" /etc/exim4/update-exim4.conf.conf
        update-exim4.conf
        dpkg-reconfigure --frontend noninteractive exim4-config
        systemctl restart saslauthd
    fi
}

function onion_update {
    # update so that new onion services appear
    systemctl restart tor
}

function wait_for_onion_service_base {
    onion_service_name="$1"

    sleep_ctr=0
    while [ ! -f ${HIDDEN_SERVICE_PATH}${onion_service_name}/hostname ]; do
        sleep 1
        sleep_ctr=$((sleep_ctr + 1))
        if [ $sleep_ctr -gt 10 ]; then
            break
        fi
    done
}

function wait_for_onion_service {
    onion_service_name="$1"

    wait_for_onion_service_base ${onion_service_name}

    if [ ! -f ${HIDDEN_SERVICE_PATH}${onion_service_name}/hostname ]; then
        # try a second time
        onion_update
        wait_for_onion_service_base ${onion_service_name}
    fi
    sync
}

function remove_onion_service {
    onion_service_name="$1"
    onion_service_port_to=$2
    nick="$3"

    if [ ${#nick} -gt 0 ]; then
        sed -i "/stealth ${nick}/d" /etc/tor/torrc
    fi
    sed -i "/hidden_service_${onion_service_name}/,+1 d" /etc/tor/torrc
    sed -i "/hidden_service_${onion_service_name}_mobile/,+1 d" /etc/tor/torrc
    sed -i "/127.0.0.1:${onion_service_port_to}/d" /etc/tor/torrc
    if [ $3 ]; then
        sed -i "/127.0.0.1:${3}/d" /etc/tor/torrc
        if [ $4 ]; then
            sed -i "/127.0.0.1:${4}/d" /etc/tor/torrc
            if [ $5 ]; then
                sed -i "/127.0.0.1:${5}/d" /etc/tor/torrc
            fi
        fi
    fi
    if [ -d ${HIDDEN_SERVICE_PATH}${onion_service_name} ]; then
        shred -zu ${HIDDEN_SERVICE_PATH}${onion_service_name}/*
        rm -rf ${HIDDEN_SERVICE_PATH}${onion_service_name}
    fi
    if [ -d ${HIDDEN_SERVICE_PATH}${onion_service_name}_mobile ]; then
        shred -zu ${HIDDEN_SERVICE_PATH}${onion_service_name}_mobile/*
        rm -rf ${HIDDEN_SERVICE_PATH}${onion_service_name}_mobile
    fi
    remove_completion_param "${onion_service_name} onion domain"
    onion_update
}

function add_onion_service {
    onion_service_name="$1"
    onion_service_port_from=$2
    onion_service_port_to=$3
    onion_stealth_name="$4"

    if [ -f ${HIDDEN_SERVICE_PATH}${onion_service_name}/hostname ]; then
        echo $(cat ${HIDDEN_SERVICE_PATH}${onion_service_name}/hostname)
        USE_V2_ONION_ADDRESS=
        return
    fi

    if [ ! -d /var/lib/tor ]; then
        echo $"No Tor installation found. ${onion_service_name} onion site cannot be configured."
        USE_V2_ONION_ADDRESS=
        exit 877367
    fi
    if ! grep -q "hidden_service_${onion_service_name}" /etc/tor/torrc; then
        echo "HiddenServiceDir ${HIDDEN_SERVICE_PATH}${onion_service_name}/" >> /etc/tor/torrc
        if [ ! $USE_V2_ONION_ADDRESS ]; then
            echo 'HiddenServiceVersion 3' >> /etc/tor/torrc
        else
            echo 'HiddenServiceVersion 2' >> /etc/tor/torrc
        fi
        echo "HiddenServicePort ${onion_service_port_from} 127.0.0.1:${onion_service_port_to}" >> /etc/tor/torrc
        if [ ${#onion_stealth_name} -gt 0 ]; then
            echo "HiddenServiceAuthorizeClient stealth ${onion_stealth_name}" >> /etc/tor/torrc
        fi
    fi

    USE_V2_ONION_ADDRESS=

    onion_update

    function_check wait_for_onion_service
    wait_for_onion_service ${onion_service_name}

    if [ ! -f ${HIDDEN_SERVICE_PATH}${onion_service_name}/hostname ]; then
        ls -lh ${HIDDEN_SERVICE_PATH}${onion_service_name}/hostname
        echo $"${onion_service_name} onion site hostname not found"
        exit 763624
    fi

    onion_address=$(cat ${HIDDEN_SERVICE_PATH}${onion_service_name}/hostname)

    # Record the domain in the completion file
    set_completion_param "${onion_service_name} onion domain" "${onion_address}"

    echo $onion_address
}

function set_default_onion_domains {
    # If sites are only visible via Tor then for installation
    # purposes assign them some default domain names
    if [[ $ONION_ONLY == "no" ]]; then
        return
    fi

    POSTACTIV_DOMAIN_NAME='postactiv.local'
    GNUSOCIAL_DOMAIN_NAME='gnusocial.local'
    HTMLY_DOMAIN_NAME='htmly.local'
    GHOST_DOMAIN_NAME='ghost.local'
    DOKUWIKI_DOMAIN_NAME='dokuwiki.local'
    DEFAULT_DOMAIN_NAME="${LOCAL_NAME}.local"
    GIT_DOMAIN_NAME='gogs.local'
}

function create_avahi_onion_domains {
    if [[ $SYSTEM_TYPE == "mesh"* ]]; then
        return
    fi
    if [ ! -d /etc/avahi/services ]; then
        return
    fi
    if [ $GNUSOCIAL_DOMAIN_NAME ]; then
        function_check create_avahi_service
        create_avahi_service gnusocial http tcp $GNUSOCIAL_ONION_PORT
    fi
    if [ $HTMLY_DOMAIN_NAME ]; then
        function_check create_avahi_service
        create_avahi_service blog http tcp $HTMLY_ONION_PORT
    fi
    if [ $GIT_DOMAIN_NAME ]; then
        function_check create_avahi_service
        create_avahi_service git http tcp $GIT_ONION_PORT
    fi
    if [ $DOKUWIKI_DOMAIN_NAME ]; then
        function_check create_avahi_service
        create_avahi_service dokuwiki http tcp $DOKUWIKI_ONION_PORT
    fi
}

function allow_ssh_to_onion_address {
    if [[ $SYSTEM_TYPE == "mesh"* ]]; then
        return
    fi
    if [ ! -d /home/$MY_USERNAME/.ssh ]; then
        mkdir /home/$MY_USERNAME/.ssh
    fi
    if [ ! -d /etc/tor ]; then
        echo $'Tor not found when updating ssh'
        exit 528257
    fi
    if ! grep -q "onion" /home/$MY_USERNAME/.ssh/config; then
        echo 'Host *.onion' >> /home/$MY_USERNAME/.ssh/config
        echo 'ProxyCommand connect -R remote -5 -S 127.0.0.1:9050 %h %p' >> /home/$MY_USERNAME/.ssh/config
    fi
}

function enable_ssh_via_onion {
    if [[ $SYSTEM_TYPE == "mesh"* ]]; then
        return
    fi
    if [[ $(is_completed "${FUNCNAME[0]}") == "1" ]]; then
        return
    fi
    apt-get -yq install tor connect-proxy
    if ! grep -q 'Host *.onion' /home/$MY_USERNAME/.ssh/config; then
        if [ ! -d /home/$MY_USERNAME/.ssh ]; then
            mkdir /home/$MY_USERNAME/.ssh
        fi
        echo 'Host *.onion' >> /home/$MY_USERNAME/.ssh/config
        echo 'ProxyCommand connect -R remote -5 -S 127.0.0.1:9050 %h %p' >> /home/$MY_USERNAME/.ssh/config
        chown $MY_USERNAME:$MY_USERNAME /home/$MY_USERNAME/.ssh
        chown $MY_USERNAME:$MY_USERNAME /home/$MY_USERNAME/.ssh/config
    fi
    if ! grep -q 'Host *.onion' /root/.ssh/config; then
        if [ ! -d /root/.ssh ]; then
            mkdir /root/.ssh
        fi
        echo 'Host *.onion' >> /root/.ssh/config
        echo 'ProxyCommand connect -R remote -5 -S 127.0.0.1:9050 %h %p' >> /root/.ssh/config
    fi
    if ! grep -q 'Host *.onion' /etc/skel/.ssh/config; then
        if [ ! -d /etc/skel/.ssh ]; then
            mkdir /etc/skel/.ssh
        fi
        echo 'Host *.onion' >> /etc/skel/.ssh/config
        echo 'ProxyCommand connect -R remote -5 -S 127.0.0.1:9050 %h %p' >> /etc/skel/.ssh/config
    fi
    mark_completed "${FUNCNAME[0]}"
}

function configure_ssh_onion {
    if [[ $(is_completed "${FUNCNAME[0]}") == "1" ]]; then
        return
    fi
    if [[ $SYSTEM_TYPE == "mesh"* ]]; then
        return
    fi

    SSH_ONION_HOSTNAME=$(add_onion_service ssh ${SSH_PORT} ${SSH_PORT})
    if [[ "$SSH_ONION_HOSTNAME" != *'.onion' ]]; then
        echo $'ssh onion site not generated'
        exit 624128
    fi

    set_completion_param "ssh onion domain" "${SSH_ONION_HOSTNAME}"
    add_email_hostname "${SSH_ONION_HOSTNAME}"

    mark_completed "${FUNCNAME[0]}"
}

function install_tor {
    if [[ $SYSTEM_TYPE == "mesh*" ]]; then
        return
    fi
    if [[ $(is_completed "${FUNCNAME[0]}") == "1" ]]; then
        return
    fi

    apt-get -yq -t stretch-backports install tor
    if [ ! -f /etc/tor/torrc ]; then
        echo 'Tor failed to install'
        exit 38259
    fi

    # For torify
    apt-get -yq install torsocks

    # turn off logging
    sed -i 's|#Log notice file.*|Log notice file /dev/null|g' /etc/tor/torrc
    sed -i 's|Log notice file.*|Log notice file /dev/null|g' /etc/tor/torrc

    # Restrict traffic
    sed -i "s|#AccountingMax.*|AccountingMax $TOR_MAX_TRAFFIC_PER_MONTH_GB GBytes|g" /etc/tor/torrc
    sed -i "s|AccountingMax.*|AccountingMax $TOR_MAX_TRAFFIC_PER_MONTH_GB GBytes|g" /etc/tor/torrc

    mark_completed "${FUNCNAME[0]}"
}

function resolve_dns_via_tor {
    if [[ $SYSTEM_TYPE == "mesh"* ]]; then
        return
    fi
    if [[ $(is_completed "${FUNCNAME[0]}") == "1" ]]; then
        return
    fi
    if [ ! -f /etc/tor/torrc ]; then
        echo $'tor was not installed'
        exit 52952
    fi

    # resolve DNS via tor
    if ! grep -q 'DNSPort 53' /etc/tor/torrc; then
        echo 'DNSPort 53' >> /etc/tor/torrc
        echo 'AutomapHostsOnResolve 1' >> /etc/tor/torrc
        echo 'AutomapHostsSuffixes .exit,.onion' >> /etc/tor/torrc
        onion_update
    fi

    # don't change resolv.conf
    sed -i 's|, domain-name-servers||g' /etc/dhcp/dhclient.conf

    # point resolv.conf to tor
    resolvconf=/etc/resolvconf/resolv.conf.d/head
    echo 'nameserver 127.0.0.1:53' > $resolvconf
    resolvconf -u

    mark_completed "${FUNCNAME[0]}"
}

# see https://trac.torproject.org/projects/tor/wiki/doc/TransparentProxy
# Local Redirection and Anonymizing Middlebox
function route_outgoing_traffic_through_tor {
    if [[ $(is_completed "${FUNCNAME[0]}") == "1" ]]; then
        return
    fi
    if [[ $ROUTE_THROUGH_TOR != "yes" ]]; then
        return
    fi
    apt-get -yq install tor tor-arm

    ### set variables
    # Destinations you don't want routed through Tor
    _non_tor="192.168.1.0/24 192.168.0.0/24"

    # The user that Tor runs as
    _tor_uid="debian-tor"

    # Tor's TransPort
    _trans_port="9040"

    # Your internal interface
    _int_if="eth0"

    ### Set iptables *nat
    iptables -t nat -A OUTPUT -o lo -j RETURN
    iptables -t nat -A OUTPUT -m owner --uid-owner $_tor_uid -j RETURN
    iptables -t nat -A OUTPUT -p udp --dport 53 -j REDIRECT --to-ports 53

    # Allow clearnet access for hosts in $_non_tor
    for _clearnet in $_non_tor; do
        iptables -t nat -A OUTPUT -d $_clearnet -j RETURN
        iptables -t nat -A PREROUTING -i $_int_if -d $_clearnet -j RETURN
    done

    # Redirect all other pre-routing and output to Tor
    iptables -t nat -A OUTPUT -p tcp --syn -j REDIRECT --to-ports $_trans_port
    iptables -t nat -A PREROUTING -i $_int_if -p udp --dport 53 -j REDIRECT --to-ports 53
    iptables -t nat -A PREROUTING -i $_int_if -p tcp --syn -j REDIRECT --to-ports $_trans_port

    ### set iptables *filter
    iptables -A OUTPUT -m state --state ESTABLISHED,RELATED -j ACCEPT

    # Allow clearnet access for hosts in $_non_tor
    for _clearnet in $_non_tor 127.0.0.0/8; do
        iptables -A OUTPUT -d $_clearnet -j ACCEPT
    done

    # Allow only Tor output
    iptables -A OUTPUT -m owner --uid-owner $_tor_uid -j ACCEPT
    iptables -A OUTPUT -j REJECT

    function_check save_firewall_settings
    save_firewall_settings

    if ! grep -q "fs.file-max" /etc/sysctl.conf; then
        echo "fs.file-max=100000" >> /etc/sysctl.conf
        /sbin/sysctl -p -q
    fi

    resolvconf=/etc/resolvconf/resolv.conf.d/head
    echo 'domain localdomain' > $resolvconf
    echo 'search localdomain' >> $resolvconf
    echo 'nameserver 127.0.0.1' >> $resolvconf
    resolvconf -u

    if ! grep -q "VirtualAddrNetworkIPv4" /etc/tor/torrc; then
        echo 'VirtualAddrNetworkIPv4 10.192.0.0/10' >> /etc/tor/torrc
    fi

    if ! grep -q "AutomapHostsOnResolve" /etc/tor/torrc; then
        echo 'AutomapHostsOnResolve 1' >> /etc/tor/torrc
    fi

    if ! grep -q "TransPort" /etc/tor/torrc; then
        echo 'TransPort 9040' >> /etc/tor/torrc
    fi

    if ! grep -q "TransListenAddress 127.0.0.1" /etc/tor/torrc; then
        echo 'TransListenAddress 127.0.0.1' >> /etc/tor/torrc
    fi

    if ! grep -q "TransListenAddress $LOCAL_NETWORK_STATIC_IP_ADDRESS" /etc/tor/torrc; then
        echo "TransListenAddress $LOCAL_NETWORK_STATIC_IP_ADDRESS" >> /etc/tor/torrc
    fi

    if ! grep -q "DNSPort" /etc/tor/torrc; then
        echo 'DNSPort 53' >> /etc/tor/torrc
    fi

    if ! grep -q "DNSListenAddress 127.0.0.1" /etc/tor/torrc; then
        echo 'DNSListenAddress 127.0.0.1' >> /etc/tor/torrc
    fi

    if ! grep -q "DNSListenAddress $LOCAL_NETWORK_STATIC_IP_ADDRESS" /etc/tor/torrc; then
        echo "DNSListenAddress $LOCAL_NETWORK_STATIC_IP_ADDRESS" >> /etc/tor/torrc
    fi

    mark_completed "${FUNCNAME[0]}"
}

function get_app_onion_address {
    app_name="$1"
    mobilestr="$2"

    if [ ${#mobilestr} -gt 0 ]; then
        app_name="mobile${app_name}"
    fi
    if grep -q "${app_name} onion domain" $COMPLETION_FILE; then
        if grep -q "${app_name} onion domain" $COMPLETION_FILE; then
            echo $(cat ${COMPLETION_FILE} | grep "${app_name} onion domain" | head -n 1 | awk -F ':' '{print $2}')
            return
        fi
    fi
    echo ""
}

function tor_add_bridge {
    bridge_ip_address="$1"
    bridge_port="$2"
    bridge_key="$3"
    bridge_type='obfs4'

    if [[ "$bridge_ip_address" != *"."* ]]; then
        return
    fi
    if [ ${#bridge_port} -eq 0 ]; then
        return
    fi
    if [ ${#bridge_key} -eq 0 ]; then
        return
    fi

    apt-get -yq install obfs4proxy

    if grep -q "ClientTransportPlugin" /etc/tor/torrc; then
        sed -i 's|#ClientTransportPlugin|ClientTransportPlugin|g' /etc/tor/torrc
        sed -i 's|# ClientTransportPlugin|ClientTransportPlugin|g' /etc/tor/torrc
        sed -i 's|ClientTransportPlugin.*|ClientTransportPlugin obfs4 exec /usr/bin/obfs4proxy managed|g' /etc/tor/torrc
    else
        echo 'ClientTransportPlugin obfs4 exec /usr/bin/obfs4proxy managed' >> /etc/tor/torrc
    fi
    if grep -q "UseBridges" /etc/tor/torrc; then
        sed -i 's|#UseBridges|UseBridges|g' /etc/tor/torrc
        sed -i 's|# UseBridges|UseBridges|g' /etc/tor/torrc
        sed -i 's|UseBridges.*|UseBridges 1|g' /etc/tor/torrc
    else
        echo 'UseBridges 1' >> /etc/tor/torrc
    fi

    bridge_str="Bridge $bridge_type ${bridge_ip_address}:${bridge_port} ${bridge_key}"
    if ! grep -q "${bridge_str}" /etc/tor/torrc; then
        sed -i "/UseBridges/a ${bridge_str}" >> /etc/tor/torrc
    fi

    systemctl restart tor
}

function tor_remove_bridge {
    bridge_ip_address="$1"
    bridge_type='obfs4'

    if [[ "$bridge_ip_address" == *"."* ]]; then
        bridge_str="Bridge $bridge_type ${bridge_ip_address}"
    else
        if grep -q " ${bridge_ip_address}" /etc/tor/torrc; then
            bridge_str=" ${bridge_ip_address}"
        else
            return
        fi
    fi
    if grep -q "${bridge_str}" /etc/tor/torrc; then
        sed -i "/${bridge_str}/d" /etc/tor/torrc
    fi

    # If there are no bridges remaining then remove UseBridges
    if ! grep -q "Bridge " /etc/tor/torrc; then
        if ! grep -q "#UseBridges" /etc/tor/torrc; then
            sed -i 's|UseBridges|#UseBridges|g' /etc/tor/torrc
        fi
        if ! grep -q "#ClientTransportPlugin" /etc/tor/torrc; then
            sed -i 's|ClientTransportPlugin|#ClientTransportPlugin|g' /etc/tor/torrc
        fi
    fi

    systemctl restart tor
}

function tor_create_bridge_relay {
    read_config_param 'TOR_BRIDGE_PORT'
    read_config_param 'TOR_BRIDGE_NICKNAME'
    if [ ! $TOR_BRIDGE_PORT ]; then
        return
    fi
    if [ ${#TOR_BRIDGE_PORT} -eq 0 ]; then
        return
    fi
    if [ ${#TOR_BRIDGE_NICKNAME} -eq 0 ]; then
        return
    fi

    apt-get -yq install obfs4proxy

    sed -i 's|#BridgeRelay.*|BridgeRelay 1|g' /etc/tor/torrc
    sed -i 's|BridgeRelay.*|BridgeRelay 1|g' /etc/tor/torrc
    sed -i 's|#ServerTransportPlugin.*|ServerTransportPlugin obfs4 exec /usr/bin/obfs4proxy|g' /etc/tor/torrc
    sed -i 's|ServerTransportPlugin.*|ServerTransportPlugin obfs4 exec /usr/bin/obfs4proxy|g' /etc/tor/torrc

    if ! grep -q 'ExtORPort ' /etc/tor/torrc; then
        echo "ExtORPort $TOR_BRIDGE_PORT" >> /etc/tor/torrc
    else
        sed -i "s|#ExtORPort .*|ExtORPort $TOR_BRIDGE_PORT|g" /etc/tor/torrc
        sed -i "s|ExtORPort .*|ExtORPort $TOR_BRIDGE_PORT|g" /etc/tor/torrc
    fi

    read_config_param 'MY_EMAIL_ADDRESS'

    sed -i "s|#ContactInfo.*|ContactInfo $MY_EMAIL_ADDRESS|g" /etc/tor/torrc
    if [ $TOR_BRIDGE_NICKNAME ]; then
        sed -i "s|#Nickname.*|Nickname $TOR_BRIDGE_NICKNAME|g" /etc/tor/torrc
        sed -i "s|Nickname.*|Nickname $TOR_BRIDGE_NICKNAME|g" /etc/tor/torrc
    fi
    firewall_add tor_bridge $TOR_BRIDGE_PORT tcp
    systemctl restart tor
}

function tor_remove_bridge_relay {
    if ! grep -q '#BridgeRelay ' /etc/tor/torrc; then
        sed -i 's|BridgeRelay |#BridgeRelay |g' /etc/tor/torrc
    fi
    if ! grep -q '#ServerTransportPlugin ' /etc/tor/torrc; then
        sed -i 's|ServerTransportPlugin |#ServerTransportPlugin |g' /etc/tor/torrc
    fi
    if ! grep -q '#ExtORPort ' /etc/tor/torrc; then
        sed -i 's|ExtORPort |#ExtORPort |g' /etc/tor/torrc
    fi
    if ! grep -q '#ContactInfo ' /etc/tor/torrc; then
        sed -i "s|ContactInfo |#ContactInfo |g" /etc/tor/torrc
    fi
    if ! grep -q '#Nickname ' /etc/tor/torrc; then
        sed -i "s|Nickname |#Nickname |g" /etc/tor/torrc
    fi
    read_config_param 'TOR_BRIDGE_PORT'
    firewall_remove $TOR_BRIDGE_PORT tcp
    systemctl restart tor
}

# NOTE: deliberately no exit 0