#!/bin/bash
#
# .---.                  .              .
# |                      |              |
# |--- .--. .-.  .-.  .-.|  .-. .--.--. |.-.  .-. .--.  .-.
# |    |   (.-' (.-' (   | (   )|  |  | |   )(   )|  | (.-'
# '    '     --'  --'  -' -  -' '  '   -' -'   -' '   -  --'
#
#                    Freedom in the Cloud
#
# Encryption key related functions

# 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/>.

function interactive_gpg_from_usb {
    dialog --title $"Recover Encryption Keys" \
           --msgbox $'Plug in a USB keydrive containing a copy of your full key or key fragment' 6 70

    HOME_DIR=/home/$MY_USERNAME
    GPG_LOADING="yes"
    SSH_IMPORTED="no"
    GPG_CTR=0

    while [[ $GPG_LOADING == "yes" ]]
    do
        detect_usb_drive

        if [ ! -b $USB_DRIVE ]; then
            if (( GPG_CTR > 0 )); then
                gpg_reconstruct_key $MY_USERNAME interactive
                gpg_update_mutt $MY_USERNAME
                return 0
            fi
            dialog --title $"Recover Encryption Keys" --msgbox $'No USB drive found' 6 30
            exit 739836
        fi

        backup_mount_drive ${USB_DRIVE} ${MY_USERNAME}

        if [ ! -d $USB_MOUNT ]; then
            if (( GPG_CTR > 0 )); then
                backup_unmount_drive ${USB_DRIVE}
                gpg_reconstruct_key $MY_USERNAME interactive
                return 0
            fi
            dialog --title $"Recover Encryption Keys" \
                   --msgbox $"There was a problem mounting the USB drive $USB_DRIVE to $USB_MOUNT" 6 70
            backup_unmount_drive ${USB_DRIVE}
            exit 74393
        fi

        if [ ! -d $USB_MOUNT/.gnupg ]; then
            if [ ! -d $USB_MOUNT/.gnupg_fragments ]; then
                if (( GPG_CTR > 0 )); then
                    backup_unmount_drive ${USB_DRIVE}
                    gpg_reconstruct_key $MY_USERNAME interactive
                    gpg_update_mutt $MY_USERNAME
                    return 0
                fi
                dialog --title $"Recover Encryption Keys" \
                       --msgbox $"The directory $USB_MOUNT/.gnupg or $USB_MOUNT/.gnupg_fragments was not found" 6 70
                backup_unmount_drive ${USB_DRIVE}
                exit 723814
            fi
        fi

        if [ -d $USB_MOUNT/letsencrypt ]; then
            if [ ! -d /etc/letsencrypt ]; then
                mkdir /etc/letsencrypt
            fi
            echo $'Recovering LetsEncrypt keys'
            cp -r $USB_MOUNT/letsencrypt/* /etc/letsencrypt
            addgroup ssl-cert
            chown -R root:ssl-cert /etc/letsencrypt
        fi

        if [ -f $USB_MOUNT/.mastergpgkey ]; then
            # Recovering keys from file rather than just copying the gnupg
            # directory may help to avoid problems during upgrades/reinstalls
            if [ ! -f $USB_MOUNT/.backupgpgkey ]; then
                echo $'No backup key file found on USB drive'
                exit 725729
            fi
            CURR_EMAIL_ADDRESS=$MY_USERNAME@$HOSTNAME
            CURR_GPG_ID=$(gpg --homedir=$HOME_DIR/.gnupg --list-keys $CURR_EMAIL_ADDRESS | sed -n '2p' | sed 's/^[ \t]*//')
            CURR_GPG_BACKUP_ID=$(gpg --homedir=$HOME_DIR/.gnupg --list-keys "(backup key)" | sed -n '2p' | sed 's/^[ \t]*//')

            echo $'Making backup copy of existing gpg keys'
            if [ -d $HOME_DIR/.gnupg ]; then
                if [ -d $HOME_DIR/.gnupg_old ]; then
                    rm -rf $HOME_DIR/.gnupg_old
                fi
                cp -r $HOME_DIR/.gnupg $HOME_DIR/.gnupg_old
                chmod 700 $HOME_DIR/.gnupg_old
                chmod -R 600 $HOME_DIR/.gnupg_old/*
                chown -R $MY_USERNAME:$MY_USERNAME $HOME_DIR/.gnupg_old
            fi
            echo $'Removing old gpg keys'
            gpg_delete_key $MY_USERNAME $CURR_GPG_BACKUP_ID
            gpg_delete_key $MY_USERNAME $CURR_GPG_ID
            echo $'Importing master keys'
            gpg --homedir=$HOME_DIR/.gnupg --allow-secret-key-import --import $USB_MOUNT/.mastergpgkey
            echo "$BACKUP_DUMMY_PASSWORD" | gpg --batch --passphrase-fd 0 --homedir=$HOME_DIR/.gnupg --allow-secret-key-import --import $USB_MOUNT/.backupgpgkey
            if [ -d $HOME_DIR/.gnupg ]; then
                echo $'Setting permissions'
                gpg_set_permissions $MY_USERNAME
                echo $"Updating muttrc for $MY_USERNAME"
                gpg_update_mutt $MY_USERNAME
            fi
            GPG_LOADING="no"
            dialog --title $"Recover Encryption Keys" \
                   --msgbox $"GPG Keyring loaded to $HOME_DIR from master keydrive" 6 70
        else
            if [ -d $USB_MOUNT/.gnupg ]; then
                if [ ! -d $HOME_DIR/.gnupg ]; then
                    mkdir $HOME_DIR/.gnupg
                fi
                echo $'Recovering GPG keys'
                cp -r $USB_MOUNT/.gnupg/* $HOME_DIR/.gnupg
                GPG_LOADING="no"
                dialog --title $"Recover Encryption Keys" \
                       --msgbox $"GPG Keyring directory loaded to $HOME_DIR" 6 70
            else
                # Collect fragments from the USB drive
                if [ ! -d $HOME_DIR/.gnupg_fragments ]; then
                    mkdir $HOME_DIR/.gnupg_fragments
                fi
                cp -r $USB_MOUNT/.gnupg_fragments/* $HOME_DIR/.gnupg_fragments
            fi
        fi

        if [[ $SSH_IMPORTED == "no" ]]; then
            if [ -d $USB_MOUNT/.ssh ]; then
                if [ ! -d $HOME_DIR/.ssh ]; then
                    mkdir $HOME_DIR/.ssh
                fi
                cp $USB_MOUNT/.ssh/* $HOME_DIR/.ssh
                dialog --title $"Recover Encryption Keys" \
                       --msgbox $"ssh keys imported" 6 70
                SSH_IMPORTED="yes"
            fi
        fi

        if [ -d $USB_MOUNT ]; then
            backup_unmount_drive ${USB_DRIVE}
        fi
        if [[ $GPG_LOADING == "yes" ]]; then
            dialog --title $"Recover Encryption Keys" \
                   --msgbox $"Now remove the USB drive. Insert the next drive containing a key fragment, or select Ok to finish" 6 70
        fi
        GPG_CTR=$((GPG_CTR + 1))
    done
}

function interactive_gpg_from_remote {
    REMOTE_SERVERS_LIST=/home/$MY_USERNAME/keyshareservers.txt

    # get a list of remote servers
    ${PROJECT_NAME}-remote -u $MY_USERNAME -l $REMOTE_SERVERS_LIST -t "Remote server"

    if [ ! -f $REMOTE_SERVERS_LIST ]; then
        dialog --title $"Encryption Keys Recovery" --msgbox $'Error obtaining server list' 6 70
        return 1
    fi

    # check the number of entries in the file
    no_of_servers=$(cat $REMOTE_SERVERS_LIST | wc -l)
    if (( no_of_servers < 3 )); then
        dialog --title $"Encryption Keys Recovery" \
               --msgbox $'There must be at least three servers to recover the key' 6 70
        return 2
    fi

    # try to recover the key from the servers
    ${PROJECT_NAME}-recoverkey -u $MY_USERNAME -l $REMOTE_SERVERS_LIST
    if [ ! "$?" = "0" ]; then
        dialog --title $"Encryption Keys Recovery" --msgbox $'Your key could not be recovered' 6 70
        return 3
    fi

    dialog --title $"Encryption Keys Recovery" --msgbox $'Your key has been recovered' 6 70

    return 0
}

function interactive_gpg {
    GPG_CONFIGURED="no"
    while [[ $GPG_CONFIGURED != "yes" ]]
    do
        GPG_CONFIGURED="yes"
        data=$(tempfile 2>/dev/null)
        trap "rm -f $data" 0 1 2 5 15
        dialog --backtitle $"Freedombone Configuration" \
               --radiolist $"GPG/PGP keys for your system:" 13 70 3 \
               1 $"Generate new keys (new user)" on \
               2 $"Import keys from USB drive/s" off \
               3 $"Retrieve keys from friends servers" off 2> $data
        sel=$?
        case $sel in
            1) exit 1;;
            255) exit 2;;
        esac
        case $(cat $data) in
            1) if [ -d /home/${MY_USERNAME}/.gnupg ]; then
                   rm -rf /home/${MY_USERNAME}/.gnupg
               fi
               break;;
            2) interactive_gpg_from_usb
               break;;
            3) interactive_gpg_from_remote
               if [ ! "$?" = "0" ]; then
                   GPG_CONFIGURED="no"
               fi;;
        esac
    done
}

function interactive_key_recovery {
    data=$(tempfile 2>/dev/null)
    trap "rm -f $data" 0 1 2 5 15

    dialog --title $"Encryption Keys Recovery" \
           --backtitle $"Freedombone Configuration" \
           --defaultno \
           --yesno $"Do you wish to recover your previous encryption keys from a USB master keydrive?" 7 60
    sel=$?
    case $sel in
        1) return;;
        255) return;;
    esac
    clear
    apt-get -yq install cryptsetup
    ${PROJECT_NAME}-recoverkey -u $MY_USERNAME
    if [ -d /home/$MY_USERNAME/.gnupg ]; then
        cp -rf /home/$MY_USERNAME/.gnupg /root
        chmod 700 /root/.gnupg
        chmod 600 /root/.gnupg/*
    fi
}

function set_password_for_all_users {
    app_name="$1"
    change_password="$2"

    for d in /home/*/ ; do
        USERNAME=$(echo "$d" | awk -F '/' '{print $3}')
        if [[ $(is_valid_user "$USERNAME") == "1" ]]; then
            ${PROJECT_NAME}-pass -u "${USERNAME}" -a "${app_name}" -p "${change_password}"
        fi
    done
}

# NOTE: deliberately there is no "exit 0"
