#!/usr/bin/bash

# vim:ft=sh:fdm=marker:fmr={,}

# archlabs installer library script file
# this file is not meant to be run directly
# sourcing this file in a non bash shell is not advised

declare -g LUKS=0
declare -g LUKS_DEV=""
declare -g LUKS_PART=""
declare -g LUKS_PASS=""
declare -g LUKS_UUID=""
declare -g LUKS_NAME="cryptroot"

luks_open() {
    LUKS_PART=""
    modprobe -a dm-mod dm_crypt
    unmount_partitions
    find_partitions 'part|crypt|lvm' || return 1
    tput civis

    if (( COUNT == 1 )); then
        LUKS_PART="$(awk 'NF > 0 {print $1}' <<< "$PARTS")"
        infobox "$_LuksOpen" "${_OnlyOne}: $LUKS_PART\n" 1
    else
        tput civis
        LUKS_PART="$(dialog --cr-wrap --stdout --backtitle "$BT" \
            --title " $_LuksOpen " --menu "$_LuksMenuBody" 0 0 0 $PARTS)"
        [[ $? != 0 || $LUKS_PART == "" ]] && return 1
    fi

    # get password and name for encryption
    luks_pass "$_LuksOpen" "$LUKS_NAME" || return 1

    infobox "$_LuksOpen" "$_LuksWaitBody $LUKS_NAME $_LuksWaitBody2 $LUKS_PART\n" 0
    cryptsetup open --type luks $LUKS_PART "$LUKS_NAME" <<< "$(openssl enc -pbkdf2 -a -d -salt -pass pass:$SALT <<< "$LUKS_PASS")" 2>$ERR
    check_for_errors "cryptsetup open --type luks $LUKS_PART $LUKS_NAME"

    LUKS=1
    luks_show
    return 0
}

luks_pass() {
    local title="$1"
    local name="$2"
    LUKS_PASS=""
    LUKS_NAME=""

    tput cnorm
    local values
    values="$(dialog --stdout --separator '~' --ok-label "Submit" --backtitle "$BT" \
        --title " $title " --insecure --mixedform "$_LuksOpenBody" 16 75 4 \
        "$_Name"      1 1 "$name" 1 $((${#_Name} + 2))      71 0 0 \
        "$_Password"  2 1 ""      2 $((${#_Password} + 2))  71 0 1 \
        "$_Password2" 3 1 ""      3 $((${#_Password2} + 2)) 71 0 1 |
        openssl enc -pbkdf2 -a -salt -pass pass:$SALT)"
    [[ $? != 0 || $values == "" ]] && return 1

    name="$(openssl enc -pbkdf2 -a -d -salt -pass pass:$SALT <<< "$values" |
        awk -F'~' '{print $1}')"

    # all of this is a bit hacky, but we don't ever want the passwords to be stored in plain text
    # so it decrypts the string '$values', gets the field we want, and re-encrypts it
    local pass pass2
    pass="$(openssl enc -pbkdf2 -a -d -salt -pass pass:$SALT <<< "$values" |
        awk -F'~' '{print $2}' | openssl enc -pbkdf2 -a -salt -pass pass:$SALT)"
    pass2="$(openssl enc -pbkdf2 -a -d -salt -pass pass:$SALT <<< "$values" |
        awk -F'~' '{print $3}' | openssl enc -pbkdf2 -a -salt -pass pass:$SALT)"

    # due to the encryption the string while encrypted will not be empty
    local empty
    empty="$(openssl enc -pbkdf2 -a -salt -pass pass:$SALT <<< "")"

    if [[ $pass == "$empty" || "$pass" != "$pass2" ]]; then
        msgbox "$_ErrTitle" "$_PassErr\n$_TryAgain"
        luks_pass "$title" "$name" || return 1
    fi

    LUKS_PASS="$pass"
    LUKS_NAME="$name"
    return 0
}

luks_setup() {
    LUKS_PART=""
    modprobe -a dm-mod dm_crypt
    unmount_partitions

    if [[ $ROOT_PART == "" || $LVM -eq 1 ]]; then
        find_partitions 'part|lvm' || return 1
        [[ $BOOT_PART != "" ]] && decr_count "$BOOT_PART"

        if (( COUNT == 1 )); then
            LUKS_PART="$(awk 'NF > 0 {print $1}' <<< "$PARTS")"
            infobox "$_LuksEncrypt" "${_OnlyOne}: $LUKS_PART\n" 1
        else
            tput civis
            LUKS_PART="$(dialog --cr-wrap --stdout --backtitle "$BT" \
                --title " $_LuksEncrypt " --menu "$_LuksEncryptBody" 0 0 0 $PARTS)"
            [[ $? != 0 || $LUKS_PART == "" ]] && return 1
        fi
    else
        infobox "$_PrepMount" "\nUsing root partition created earlier: $ROOT_PART\n" 1
        LUKS_PART="$ROOT_PART"
    fi

    # get password and name for encrypted device
    luks_pass "$_LuksEncrypt" "$LUKS_NAME" || return 1
    return 0
}

luks_default() {
    luks_setup || return 1
    infobox "$_LuksEncrypt" "$_LuksWaitBody $LUKS_NAME $_LuksWaitBody2 $LUKS_PART\n" 0

    cryptsetup -q luksFormat $LUKS_PART <<< "$(openssl enc -pbkdf2 -a -d -salt -pass pass:$SALT <<< "$LUKS_PASS")" 2>$ERR
    check_for_errors "cryptsetup -q luksFormat $LUKS_PART"

    cryptsetup open $LUKS_PART "$LUKS_NAME" <<< "$(openssl enc -pbkdf2 -a -d -salt -pass pass:$SALT <<< "$LUKS_PASS")" 2>$ERR
    check_for_errors "cryptsetup open $LUKS_PART $LUKS_NAME"

    LUKS=1
    luks_show
    return 0
}

luks_keycmd() {
    if luks_setup; then
        tput cnorm
        local cipher
        cipher="$(getinput "$_PrepLUKS" "$_LuksCipherKey" "-s 512 -c aes-xts-plain64")"
        [[ $? != 0 || $cipher == "" ]] && return 1

        infobox "$_LuksEncryptAdv" "$_LuksWaitBody $LUKS_NAME $_LuksWaitBody2 $LUKS_PART\n" 0

        cryptsetup -q $cipher luksFormat $LUKS_PART <<< "$(openssl enc -pbkdf2 -a -d -salt -pass pass:$SALT <<< "$LUKS_PASS")" 2>$ERR
        check_for_errors "cryptsetup -q $cipher luksFormat $LUKS_PART"

        cryptsetup open $LUKS_PART "$LUKS_NAME" <<< "$(openssl enc -pbkdf2 -a -d -salt -pass pass:$SALT <<< "$LUKS_PASS")" 2>$ERR
        check_for_errors "cryptsetup open $LUKS_PART $LUKS_NAME"

        luks_show
        return 0
    fi
    return 1
}

luks_show() {
    tput civis
    sleep 0.5
    echo -e "$_LuksEncryptSucc" > /tmp/.devlist
    lsblk -o NAME,TYPE,FSTYPE,SIZE $LUKS_PART >> /tmp/.devlist
    dialog --cr-wrap --backtitle "$BT" --title " $_LuksEncrypt " --textbox /tmp/.devlist 0 0
}

luks_menu() {
    tput civis
    local choice
    choice="$(dialog --cr-wrap --stdout --backtitle "$BT" --title " $_PrepLUKS " \
        --menu "${_LuksMenuBody}${_LuksMenuBody2}${_LuksMenuBody3}" 0 0 0 \
        "$_LuksEncrypt"    "cryptsetup -q luksFormat" \
        "$_LuksOpen"       "cryptsetup open --type luks" \
        "$_LuksEncryptAdv" "cryptsetup -q -s -c luksFormat" \
        "$_Back"           "-")"

    case $choice in
        "$_LuksEncrypt") luks_default && return 0 ;;
        "$_LuksOpen") luks_open && return 0 ;;
        "$_LuksEncryptAdv") luks_keycmd && return 0 ;;
        *) return 0
    esac

    luks_menu
}

luks_keyfile() {
    # Only used when choosing grub as bootloader.
    # Without a keyfile, during boot the user will be asked
    # to enter password for decryption twice, this is annoying

    if [[ ! -e $MNT/crypto_keyfile.bin ]]; then
        infobox "$_LuksKeyFileTitle" "$_LuksKeyFileCreate" 0
        echo -e "$_LuksKeyFileCreate"

        local n
        n="$(lsblk -lno NAME,UUID,TYPE | awk "/$LUKS_UUID/"' && /part|crypt|lvm/ {print $1}')"

        local mkkey="dd bs=512 count=8 if=/dev/urandom of=/crypto_keyfile.bin"
        mkkey="$mkkey && chmod 000 /crypto_keyfile.bin"
        mkkey="$mkkey && cryptsetup luksAddKey /dev/$n /crypto_keyfile.bin <<< '$(openssl enc -pbkdf2 -a -d -salt -pass pass:$SALT <<< "$LUKS_PASS")'"

        chroot_cmd "$mkkey"
        sed -i 's/FILES=()/FILES=(\/crypto_keyfile.bin)/g' $MNT/etc/mkinitcpio.conf 2>$ERR
    fi

    return 0
}