add nix flake

.gitignore

@@ -5,4 +5,6 @@
 fido2luks.bash
 fido2luks.elv
 fido2luks.fish
-fido2luks.zsh
+fido2luks.zsh
+result
+result-*

flake.nix

@@ -0,0 +1,61 @@
+{
+  description = "Decrypt your LUKS partition using a FIDO2 compatible authenticator";
+
+  inputs = {
+    utils.url = "github:numtide/flake-utils";
+    naersk = {
+      url = "github:nmattia/naersk";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
+  };
+
+  outputs = { self, nixpkgs, utils, naersk }:
+    let
+      root = ./.;
+      pname = (builtins.fromTOML (builtins.readFile ./Cargo.toml)).package.name;
+      forPkgs = pkgs:
+        let
+          naersk-lib = naersk.lib."${pkgs.system}";
+          buildInputs = with pkgs; [ cryptsetup ];
+          LIBCLANG_PATH = "${pkgs.clang.cc.lib}/lib";
+          nativeBuildInputs = with pkgs; [
+            pkgconfig
+            clang
+          ];
+        in
+        rec {
+          # `nix build`
+          packages.${pname} = naersk-lib.buildPackage {
+            inherit pname root buildInputs nativeBuildInputs LIBCLANG_PATH;
+          };
+          defaultPackage = packages.${pname};
+
+          # `nix run`
+          apps.${pname} = utils.lib.mkApp {
+            drv = packages.${pname};
+          };
+          defaultApp = apps.${pname};
+
+          # `nix flake check`
+          checks = {
+            fmt = with pkgs; runCommandLocal "${pname}-fmt" { buildInputs = [ cargo rustfmt nixpkgs-fmt ]; } ''
+              cd ${root}
+              cargo fmt -- --check
+              nixpkgs-fmt --check *.nix
+              touch $out
+            '';
+          };
+
+          # `nix develop`
+          devShell = pkgs.mkShell {
+            nativeBuildInputs = with pkgs; [ rustc cargo rustfmt nixpkgs-fmt ] ++ nativeBuildInputs;
+            inherit buildInputs LIBCLANG_PATH;
+          };
+        };
+      forSystem = system: forPkgs nixpkgs.legacyPackages."${system}";
+    in
+    (utils.lib.eachSystem [ "aarch64-linux" "i686-linux" "x86_64-linux" ] forSystem) // {
+      overlay = final: prev: (forPkgs final).packages;
+    };
+
+}