#!/bin/bash
#
# .---.                  .              .
# |                      |              |
# |--- .--. .-.  .-.  .-.|  .-. .--.--. |.-.  .-. .--.  .-.
# |    |   (.-' (.-' (   | (   )|  |  | |   )(   )|  | (.-'
# '    '     --'  --'  -' -  -' '  '   -' -'   -' '   -  --'
#
#                    Freedom in the Cloud
#
# Backup to remote servers - the web of backups

# 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'
COMPLETION_FILE=$HOME/${PROJECT_NAME}-completed.txt
CONFIGURATION_FILE=$HOME/${PROJECT_NAME}.cfg
BACKUP_EXTRA_DIRECTORIES=/root/backup-extra-dirs.csv
ENABLE_VERIFICATION="no"

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

PROJECT_INSTALL_DIR=/usr/local/bin
if [ -f /usr/bin/${PROJECT_NAME} ]; then
    PROJECT_INSTALL_DIR=/usr/bin
fi

source $PROJECT_INSTALL_DIR/${PROJECT_NAME}-vars

# utilities needed for backup commands
UTILS_FILES=/usr/share/${PROJECT_NAME}/utils/${PROJECT_NAME}-utils-*
for f in $UTILS_FILES
do
  source $f
done

# Temporary location for data to be backed up to other servers
SERVER_DIRECTORY=/root/remotebackup

# get the version of Go being used
GO_VERSION=$(cat /usr/share/${PROJECT_NAME}/utils/${PROJECT_NAME}-utils-go | grep 'GO_VERSION=' | head -n 1 | awk -F '=' '{print $2}')

ADMIN_USERNAME=$(get_completion_param "Admin user")
ADMIN_NAME=$(getent passwd $ADMIN_USERNAME | cut -d: -f5 | cut -d, -f1)
ADMIN_EMAIL_ADDRESS=${ADMIN_USERNAME}@${HOSTNAME}
if [ ! -f /etc/ssl/private/backup.key ]; then
    echo $"Creating backup key"
    ${PROJECT_NAME}-addcert -h backup --dhkey 2048
fi

if [ ! -f /home/${ADMIN_USERNAME}/backup.list ]; then
    exit 1
fi

# MariaDB password
DATABASE_PASSWORD=''
if [ -f /root/dbpass ]; then
    DATABASE_PASSWORD=$(cat /root/dbpass)
fi

# local directory where the backup will be made
if [ ! -d $SERVER_DIRECTORY ]; then
    mkdir $SERVER_DIRECTORY
fi

if [ ! -d $SERVER_DIRECTORY/backup ]; then
    mkdir -p $SERVER_DIRECTORY/backup
fi

# The name of a currently suspended site
# Sites are suspended so that verification should work
SUSPENDED_SITE=

function suspend_site {
    # suspends a given website
    if [[ $ENABLE_VERIFICATION != "yes" ]]; then
        return
    fi
    SUSPENDED_SITE="$1"
    nginx_dissite $SUSPENDED_SITE
    service nginx reload
}

function restart_site {
    # restarts a given website
    if [ ! $SUSPENDED_SITE ]; then
        return
    fi
    nginx_ensite $SUSPENDED_SITE
    service nginx reload
    SUSPENDED_SITE=
}

function backup_configfiles {
    echo $"Backing up ${PROJECT_NAME} configuration files"
    temp_backup_dir=/root/tempbackupconfig
    if [ ! -d $temp_backup_dir ]; then
        mkdir -p $temp_backup_dir
    fi
    cp -f $CONFIGURATION_FILE $temp_backup_dir
    cp -f $COMPLETION_FILE $temp_backup_dir
    if [ -f $BACKUP_EXTRA_DIRECTORIES ]; then
        cp -f $BACKUP_EXTRA_DIRECTORIES $temp_backup_dir
    fi
    # nginx password hashes
    if [ -f /etc/nginx/.htpasswd ]; then
        cp -f /etc/nginx/.htpasswd $temp_backup_dir/htpasswd
    fi
    backup_directory_to_friend $temp_backup_dir configfiles
}

function backup_users {
    for d in /home/*/ ; do
        USERNAME=$(echo "$d" | awk -F '/' '{print $3}')
        if [[ $(is_valid_user "$USERNAME") == "1" ]]; then

            # personal settings
            if [ -d /home/$USERNAME/personal ]; then
                echo $"Backing up personal settings for $USERNAME"
                backup_directory_to_friend /home/$USERNAME/personal personal/$USERNAME
            fi

            # gpg keys
            if [ -d /home/$USERNAME/.gnupg ]; then
                echo $"Backing up gpg keys for $USERNAME"
                backup_directory_to_friend /home/$USERNAME/.gnupg gnupg/$USERNAME
            fi

            # ssh keys
            if [ -d /home/$USERNAME/.ssh ]; then
                echo $"Backing up ssh keys for $USERNAME"
                backup_directory_to_friend /home/$USERNAME/.ssh ssh/$USERNAME
            fi

            # syncthing files
            if [ -d /home/$USERNAME/Sync ]; then
                echo $"Backing up syncthing files for $USERNAME"
                backup_directory_to_friend /home/$USERNAME/Sync syncthing/$USERNAME
                # ensure that device IDs will be backed up as part of user config settings
                if [ ! -d /home/$USERNAME/.config/syncthing ]; then
                    mkdir -p /home/$USERNAME/.config/syncthing
                    chown -R $USERNAME:$USERNAME /home/$USERNAME/.config
                fi
                if [ -f /home/$USERNAME/.syncthing-server-id ]; then
                    cp /home/$USERNAME/.syncthing-server-id /home/$USERNAME/.config/syncthing
                    chown -R $USERNAME:$USERNAME /home/$USERNAME/.config
                fi
                if [ -f /home/$USERNAME/.syncthingids ]; then
                    cp /home/$USERNAME/.syncthingids /home/$USERNAME/.config/syncthing
                    chown -R $USERNAME:$USERNAME /home/$USERNAME/.config
                fi
            fi

            # config files
            if [ -d /home/$USERNAME/.config ]; then
                echo $"Backing up config files for $USERNAME"
                backup_directory_to_friend /home/$USERNAME/.config config/$USERNAME
            fi

            # monkeysphere files
            if [ -d /home/$USERNAME/.monkeysphere ]; then
                echo $"Backing up monkeysphere files for $USERNAME"
                backup_directory_to_friend /home/$USERNAME/.monkeysphere monkeysphere/$USERNAME
            fi

            # fin files
            if [ -d /home/$USERNAME/.fin ]; then
                echo $"Backing up fin files for $USERNAME"
                backup_directory_to_friend /home/$USERNAME/.fin fin/$USERNAME
            fi

            # local files
            if [ -d /home/$USERNAME/.local ]; then
                echo $"Backing up local files for $USERNAME"
                backup_directory_to_friend /home/$USERNAME/.local local/$USERNAME
            fi

            # mutt settings
            if [ -f /home/$USERNAME/.muttrc ]; then
                echo $"Backing up Mutt settings for $USERNAME"
                if [ ! -d /home/$USERNAME/tempbackup ]; then
                    mkdir -p /home/$USERNAME/tempbackup
                fi
                cp /home/$USERNAME/.muttrc /home/$USERNAME/tempbackup
                if [ -f /etc/Muttrc ]; then
                    cp /etc/Muttrc /home/$USERNAME/tempbackup
                fi
                backup_directory_to_friend /home/$USERNAME/tempbackup mutt/$USERNAME
            fi

            # procmail settings
            if [ -f /home/$USERNAME/.procmailrc ]; then
                echo $"Backing up procmail settings for $USERNAME"
                if [ ! -d /home/$USERNAME/tempbackup ]; then
                    mkdir -p /home/$USERNAME/tempbackup
                fi
                cp /home/$USERNAME/.procmailrc /home/$USERNAME/tempbackup
                backup_directory_to_friend /home/$USERNAME/tempbackup procmail/$USERNAME
            fi

            # spamassassin settings
            if [ -d /home/$USERNAME/.spamassassin ]; then
                echo $"Backing up spamassassin settings for $USERNAME"
                backup_directory_to_friend /home/$USERNAME/.spamassassin spamassassin/$USERNAME
            fi

            # email
            if [ -d /home/$USERNAME/Maildir ]; then
                echo $"Stopping mail server"
                systemctl stop exim4
                echo $"Creating an email archive"
                if [ ! -d /root/backupemail/$USERNAME ]; then
                    mkdir -p /root/backupemail/$USERNAME
                fi
                tar -czvf /root/backupemail/$USERNAME/maildir.tar.gz /home/$USERNAME/Maildir
                echo $"Restarting mail server"
                systemctl start exim4
                echo $"Backing up emails for $USERNAME"
                backup_directory_to_friend /root/backupemail/$USERNAME mail/$USERNAME
            fi
        fi
    done
}

function backup_letsencrypt {
    if [ -d /etc/letsencrypt ]; then
        echo $"Backing up Lets Encrypt settings"
        backup_directory_to_friend /etc/letsencrypt letsencrypt
    fi
}

function backup_tor {
    if [ -d /etc/letsencrypt ]; then
        echo $"Backing up Tor settings"
        backup_directory_to_friend /var/lib/tor tor
    fi
}

function backup_certs {
    if [ -d /etc/ssl ]; then
        echo $"Backing up certificates"
        backup_directory_to_friend /etc/ssl ssl
    fi
}

function backup_mailing_list {
    if [ -d /var/spool/mlmmj ]; then
        echo $"Backing up the public mailing list"
        backup_directory_to_friend /var/spool/mlmmj mailinglist
    fi
}

function backup_web_server {
    if [ -d /etc/nginx ]; then
        echo $"Backing up web settings"
        backup_directory_to_friend /etc/nginx/sites-available web
    fi
}

function backup_admin_readme {
    if [ -f /home/$ADMIN_USERNAME/README ]; then
        echo $"Backing up README"
        if [ ! -d /home/$ADMIN_USERNAME/tempbackup ]; then
            mkdir -p /home/$ADMIN_USERNAME/tempbackup
        fi
        cp -f /home/$ADMIN_USERNAME/README /home/$ADMIN_USERNAME/tempbackup
        backup_directory_to_friend /home/$ADMIN_USERNAME/tempbackup readme
    fi
}

function backup_mariadb {
    if [ ${#DATABASE_PASSWORD} -gt 1 ]; then
        temp_backup_dir=/root/tempmariadb
        if [ ! -d $temp_backup_dir ]; then
            mkdir $temp_backup_dir
        fi
        mysqldump --password=$DATABASE_PASSWORD mysql user > $temp_backup_dir/mysql.sql
        if [ ! -s $temp_backup_dir/mysql.sql ]; then
            echo $"Unable to backup MariaDB settings"
            rm -rf $temp_backup_dir
            # Send a warning email
            echo $"Unable to export database settings" | mail -s "${PROJECT_NAME} backup to friends" $ADMIN_EMAIL_ADDRESS
            exit 653
        fi
        echo "$DATABASE_PASSWORD" > $temp_backup_dir/db
        chmod 400 $temp_backup_dir/db
        backup_directory_to_friend $temp_backup_dir mariadb
    fi
}

# Returns the filename of a key share
function get_key_share {
    no_of_shares=$1
    USERNAME="$2"
    REMOTE_DOMAIN="$3"

    # Get a share index based on the supplied domain name
    # This ensures that the same share is always given to the same domain
    sharenumstr=$(md5sum <<< "$REMOTE_DOMAIN")
    share_index=$(echo $((0x${sharenumstr%% *} % ${no_of_shares})) | tr -d -)

    # get the filename
    share_files=(/home/$USERNAME/.gnupg_fragments/keyshare.asc.*)
    share_filename=${share_files[share_index]}

    echo "$share_filename"
}

function disperse_key_shares {
    USERNAME=$1
    REMOTE_DOMAIN=$2
    REMOTE_SSH_PORT=$3
    REMOTE_PASSWORD=$4
    REMOTE_SERVER=$5

    if [ -d /home/$USERNAME/.gnupg_fragments ]; then
        if [ $REMOTE_DOMAIN ]; then
            cd /home/$USERNAME/.gnupg_fragments
            no_of_shares=$(ls -afq keyshare.asc.* | wc -l)
            if (( no_of_shares > 1 )); then
                share_filename=$(get_key_share $no_of_shares "$USERNAME" "$REMOTE_DOMAIN")

                # create a temp directory containing the share
                temp_key_share_dir=/home/$USERNAME/tempkey
                temp_key_share_fragments=$temp_key_share_dir/.gnupg_fragments_${USERNAME}
                mkdir -p $temp_key_share_fragments
                cp $share_filename $temp_key_share_fragments/

                # copy the fragments directory to the remote server
                /usr/bin/sshpass -p "$REMOTE_PASSWORD" \
                                 scp -r -P $REMOTE_SSH_PORT $temp_key_share_fragments $REMOTE_SERVER
                if [ ! "$?" = "0" ]; then
                    # Send a warning email
                    echo "Key share to $REMOTE_SERVER failed" | \
                        mail -s "${PROJECT_NAME} social key management" $MY_EMAIL_ADDRESS
                else
                    # Send a confirmation email
                    echo "Key ${share_filename} shared to $REMOTE_SERVER" | \
                        mail -s "${PROJECT_NAME} social key management" $MY_EMAIL_ADDRESS
                fi

                # remove the temp file/directory
                shred -zu $temp_key_share_fragments/*
                rm -rf $temp_key_share_dir
            fi
        fi
    fi
}

TEST_MODE="no"
if [[ "$1" == "test" ]]; then
    TEST_MODE="yes"
fi

backup_configfiles
if [[ $TEST_MODE == "no" ]]; then
    backup_users
    backup_letsencrypt
    backup_tor
    backup_web_server
    backup_admin_readme
    backup_mariadb
    backup_certs
    backup_mailing_list
    backup_apps remote
    backup_extra_directories remote
fi

# For each remote server
while read remote_server
do
    # Get the server and its password
    # Format is:
    #   username@domain <port number> /home/username <ssh password>
    REMOTE_SERVER=$(echo "${remote_server}" | awk -F ' ' '{print $1}')
    if [ $REMOTE_SERVER ]; then
        REMOTE_DOMAIN=$(echo "${remote_server}" | awk -F ' ' '{print $1}' | awk -F '@' '{print $2}')
        REMOTE_SSH_PORT=$(echo "${remote_server}" | awk -F ' ' '{print $2}')
        REMOTE_DIRECTORY=$(echo "${remote_server}" | awk -F ' ' '{print $3}')
        REMOTE_PASSWORD=$(echo "${remote_server}" | awk -F ' ' '{print $4}')
        NOW=$(date +"%Y-%m-%d %H:%M:%S")
        REMOTE_SERVER=$REMOTE_SERVER:$REMOTE_DIRECTORY

        echo "$NOW Starting backup to $REMOTE_SERVER" >> /var/log/remotebackups.log

        # Social key management
        for d in /home/*/ ; do
            USERNAME=$(echo "$d" | awk -F '/' '{print $3}')
            if [[ $(is_valid_user "$USERNAME") == "1" ]]; then
                disperse_key_shares $USERNAME $REMOTE_DOMAIN $REMOTE_SSH_PORT "$REMOTE_PASSWORD" $REMOTE_SERVER
            fi
        done

        if [[ $TEST_MODE == "yes" ]]; then
            echo "rsync -ratlzv --rsh=\"/usr/bin/sshpass -p '$REMOTE_PASSWORD' ssh -p $REMOTE_SSH_PORT -o StrictHostKeyChecking=no\" $SERVER_DIRECTORY/backup $REMOTE_SERVER"
        fi
        rsync -ratlzv --rsh="/usr/bin/sshpass -p \"$REMOTE_PASSWORD\" ssh -p $REMOTE_SSH_PORT -o StrictHostKeyChecking=no" $SERVER_DIRECTORY/backup $REMOTE_SERVER
        if [ ! "$?" = "0" ]; then
            echo "$NOW Backup to $REMOTE_SERVER failed" >> /var/log/remotebackups.log
            # Send a warning email
            echo "Backup to $REMOTE_SERVER failed" | mail -s "${PROJECT_NAME} backup to friends" $ADMIN_EMAIL_ADDRESS
        else
            echo "$NOW Backed up to $REMOTE_SERVER" >> /var/log/remotebackups.log
        fi
    fi

done < /home/${ADMIN_USERNAME}/backup.list

exit 0