asset.php: load asset from repository

asset.php

@@ -0,0 +1,23 @@
+<?php include "conf.php"; /* load a local configuration */ ?>
+<?php session_start(); ?>
+<?php require 'vendor/autoload.php'; /* composer includes */ ?>
+<?php include "modulekit/loader.php"; /* loads all php-includes */ ?>
+<?php call_hooks("init"); /* initialize submodules */ ?>
+<?php
+$allRepositories = getRepositories();
+
+$repoId = $_REQUEST['repo'];
+if (!array_key_exists($repoId, $allRepositories)) {
+  Header("HTTP/1.1 404 Repository not found");
+  exit(0);
+}
+
+$repoData = $allRepositories[$repoId];
+$repo = getRepo($repoId, $repoData);
+
+$tmpfile = tempnam('/tmp', 'osb-asset-');
+file_put_contents($tmpfile, $repo->file_get_contents($_REQUEST['file']));
+$mime_type = mime_content_type($tmpfile);
+
+Header("Content-Type: {$mime_type}; charset=utf-8");
+readfile($tmpfile);