Add nix derivation

.gitignore

@@ -1,2 +1,3 @@
 /target
 *.csv
+/result

default.nix

@@ -0,0 +1,18 @@
+{ pkgs ? import <nixpkgs> {
+    overlays = [
+      (import (fetchTarball "https://github.com/oxalica/rust-overlay/archive/master.tar.gz"))
+    ];
+  }
+}:
+with pkgs;
+rustPlatform.buildRustPackage
+{
+  name = "wireguard-client";
+  src = nix-gitignore.gitignoreSource [ ] ./.;
+
+  nativeBuildInputs = [ 
+    (rust-bin.fromRustupToolchainFile ./rust-toolchain.toml)    
+  ];
+
+  cargoSha256 = "sha256-3FnWeoFeD9/q16J0CpXL4/lIlP34jf1aUN6I8fBFZ0g=";
+}