#!/bin/sh
# Boot from a local disk installation

CONFIG_BOOT_GUI_MENU_NAME='Heads Boot Menu'

. /etc/functions
. /etc/config

mount_boot()
{
  # Mount local disk if it is not already mounted
  if ! grep -q /boot /proc/mounts ; then
    mount -o ro /boot \
      || recovery "Unable to mount /boot"
  fi
}


last_half=X
while true; do
  MAIN_MENU_OPTIONS=""
  unset totp_confirm
  # update the TOTP code every thirty seconds
  date=`date "+%Y-%m-%d %H:%M:%S"`
  seconds=`date "+%s"`
  half=`expr \( $seconds % 60 \) / 30`
  if [ "$CONFIG_TPM" = n ]; then
    TOTP="NO TPM"
  elif [ "$half" != "$last_half" ]; then
    last_half=$half;
    TOTP=`unseal-totp`
    if [ $? -ne 0 ]; then
      whiptail --clear --title "ERROR: TOTP Generation Failed!" \
        --menu "ERROR: Heads couldn't generate the TOTP code.\n\nIf you have just reflashed your BIOS, you will need to generate a new TOTP secret.\n\nIf you have not just reflashed your BIOS, THIS COULD INDICATE TAMPERING!\n\nIf this is the first time the system has booted, you should reset the TPM and set your own password\n\nHow would you like to proceed?" 30 80 4 \
        'g' ' Generate new TOTP secret' \
        'i' ' Ignore error and continue to default boot menu' \
        'p' ' Reset the TPM' \
        'x' ' Exit to recovery shell' \
        2>/tmp/whiptail || recovery "GUI menu failed"

      totp_confirm=$(cat /tmp/whiptail)
    fi
  fi

  if [ "$totp_confirm" = "i" -o -z "$totp_confirm" ]; then 
    whiptail --clear --title "$CONFIG_BOOT_GUI_MENU_NAME" \
      --menu "$date\nTOTP code: $TOTP" 20 80 10 \
      'y' ' Default boot' \
      'r' ' TOTP does not match, refresh code' \
      'n' ' TOTP does not match after refresh, troubleshoot' \
      'm' ' Show OS boot menu' \
      'u' ' USB boot' \
      'g' ' Generate new TOTP secret' \
      'i' ' Ignore tampering and force a boot (Unsafe!)' \
      'p' ' Reset the TPM' \
      'x' ' Exit to recovery shell' \
      2>/tmp/whiptail || recovery "GUI menu failed"

    totp_confirm=$(cat /tmp/whiptail)
  fi

  if [ "$totp_confirm" = "x" ]; then
    recovery "User requested recovery shell"
  fi

  if [ "$totp_confirm" = "r" ]; then
    continue
  fi

  if [ "$totp_confirm" = "n" ]; then
    if (whiptail --title "TOTP code mismatched" \
      --yesno "TOTP code mismatches could indicate either TPM tampering or clock drift:\n\nTo correct clock drift: 'date -s HH:MM:SS'\nand save it to the RTC: 'hwclock -w'\nthen reboot and try again.\n\nWould you like to exit to a recovery console?" 30 80) then
      echo ""
      echo "To correct clock drift: 'date -s HH:MM:SS'"
      echo "and save it to the RTC: 'hwclock -w'"
      echo "then reboot and try again"
      echo ""
      recovery "TOTP mismatch"
    else
      continue
    fi
  fi

  if [ "$totp_confirm" = "u" ]; then
    exec /bin/usb-init
    continue
  fi

  if [ "$totp_confirm" = "g" ]; then
    if (whiptail --title 'Generate new TOTP secret' \
        --yesno "This will erase your old secret and replace it with a new one!\n\nDo you want to proceed?" 16 80) then
      echo "Scan the QR code to add the new TOTP secret"
      /bin/seal-totp
      echo "Once you have scanned the QR code, hit Enter to reboot"
      read
      /bin/reboot
    else
      echo "Returning to the main menu"
    fi
    continue
  fi

  if [ "$totp_confirm" = "p" ]; then
    if (whiptail --title 'Reset the TPM' \
        --yesno "This will clear the TPM, erase the old TPM password and replace it with a new one!\n\nDo you want to proceed?" 16 80) then
      /bin/tpm-reset
      echo "Scan the QR code to add the new TOTP secret"
      /bin/seal-totp
      echo "Once you have scanned the QR code, hit Enter to reboot"
      read
      /bin/reboot
    else
      echo "Returning to the main menu"
    fi
    continue
  fi

  if [ "$totp_confirm" = "m" ]; then
    # Try to select a kernel from the menu
    mount_boot
    kexec-select-boot -m -b /boot -c "grub.cfg" -g
    continue
  fi

  if [ "$totp_confirm" = "i" ]; then
    # Run the menu selection in "force" mode, bypassing hash checks
    if (whiptail --title 'Unsafe Forced Boot Selected!' \
        --yesno "WARNING: You have chosen to skip all tamper checks and boot anyway.\n\nThis is an unsafe option!\n\nDo you want to proceed?" 16 80) then
      mount_boot
      kexec-select-boot -m -b /boot -c "grub.cfg" -g -f
    else
      echo "Returning to the main menu"
    fi
    continue
  fi

  if [ "$totp_confirm" = "y" -o -n "$totp_confirm" ]; then
    # Try to boot the default
    mount_boot
	  DEFAULT_FILE=`find /boot/kexec_default.*.txt 2>/dev/null | head -1`
    if [ -r "$DEFAULT_FILE" ]; then
      kexec-select-boot -b /boot -c "grub.cfg" -g \
      || recovery "Failed default boot"
    else
      if (whiptail --title 'No Default Boot Option Configured' \
          --yesno "There is no default boot option configured yet. Would you like to load a menu of boot options? Otherwise you will return to the main menu." 16 80) then
        kexec-select-boot -m -b /boot -c "grub.cfg" -g
      else
        echo "Returning to the main menu"
      fi
      continue
    fi
  fi

done

recovery "Something failed during boot"