nixfiles/presets/nixos/encryptedDrive.nix

{
  self,
  config,
  pkgs,
  lib,
  ...
}: let
  inherit (lib.modules) mkBefore;

  encryptedUSB = import "${self}/data/drives/encryptedUSB.nix";
  driveData = import "${self}/data/drives/encryptedDrive.nix";
in {
  boot = {
    initrd.availableKernelModules = [
      # For USB w/ Encryption Key
      "usb_storage"
      "usbcore"
      "uas"
      "sd_mod"
      # For USB Keyboards
      "usbhid"
      # For Cryptography
      "aesni_intel"
      "cryptd"
    ];
    initrd.postDeviceCommands = mkBefore ''
      mkdir -m 0755 -p /keys
      mkdir -m 0755 -p ${encryptedUSB.mountpoint}

      while !(test -b ${encryptedUSB.encryptedPath})
      do
        ${
        if config.boot.plymouth.enable
        then ''
          ${pkgs.plymouth}/bin/plymouth display-message --text="Please Plug In USB"
        ''
        else ''
          echo "Please Plug In USB"
        ''
      }
        sleep 1
      done

      ${
        if config.boot.plymouth.enable
        then ''
          ${pkgs.plymouth}/bin/plymouth hide-message --text="Please Plug In USB"

          ${pkgs.plymouth}/bin/plymouth ask-for-password \
            --prompt="Please Decrypt USB" \
            --command="cryptsetup -T1 open ${encryptedUSB.encryptedPath} ${encryptedUSB.preBootMapperName}" \
            --number-of-tries=3
        ''
        else ''
          echo "Please Decrypt USB"
          cryptsetup open ${encryptedUSB.encryptedPath} ${encryptedUSB.preBootMapperName}
        ''
      }

      mount -n -t ${encryptedUSB.unencryptedFSType} -o ro ${encryptedUSB.preBootMapperPath} ${encryptedUSB.mountpoint}

      cp ${encryptedUSB.encryptionKeysPath}/${config.networking.hostName}.key /keys

      umount -f ${encryptedUSB.mountpoint}

      cryptsetup close ${encryptedUSB.preBootMapperName}
    '';

    initrd.luks.devices = {
      "${driveData.mapperName}" = {
        device = "${driveData.encryptedPath}";
        keyFile = "/keys/${config.networking.hostName}.key";
        preLVM = false;
        allowDiscards = true;
      };
    };
  };

  fileSystems = {
    "/" = {
      device = "${driveData.decryptedPath}";
      fsType = "${driveData.unencryptedFSType}";
    };
    "/boot" = {
      device = "${driveData.bootPath}";
      fsType = "${driveData.bootFSType}";
    };
  };
}