Burn asset-hash utility

refs #9178

- Ghost uses the Node crypto lib always direct (require('crypto'))
- it doesn't make sense to outsource a single crypto statement (for the asset hash)
- we either have to write a crypto wrapper to avoid writing long crypto statements or we keep the direct usages for every case
- for now, wrapping the crypto calls into a lib/crypto has no priority

core/server/data/meta/asset_url.js

@@ -1,7 +1,10 @@
-var config = require('../../config'),
+'use strict';
+
+const crypto = require('crypto'),
+    config = require('../../config'),
     blogIconUtils = require('../../utils/blog-icon'),
     urlService = require('../../services/url'),
-    globalUtils = require('../../utils');
+    packageInfo = require('../../../../package.json');
 
 /**
  * Serve either uploaded favicon or default
@@ -38,7 +41,7 @@ function getAssetUrl(path, hasMinFile) {
     // Ensure we have an assetHash
     // @TODO rework this!
     if (!config.get('assetHash')) {
-        config.set('assetHash', globalUtils.generateAssetHash());
+        config.set('assetHash', (crypto.createHash('md5').update(packageInfo.version + Date.now()).digest('hex')).substring(0, 10));
     }
 
     // Finally add the asset hash to the output URL

core/server/utils/asset-hash.js

@@ -1,6 +0,0 @@
-var crypto        = require('crypto'),
-    packageInfo   = require('../../../package.json');
-
-module.exports = function generateAssetHash() {
-    return (crypto.createHash('md5').update(packageInfo.version + Date.now()).digest('hex')).substring(0, 10);
-};

core/server/utils/index.js

@@ -133,7 +133,6 @@ utils = {
 
     readCSV: require('./read-csv'),
     zipFolder: require('./zip-folder'),
-    generateAssetHash: require('./asset-hash'),
     tokens: require('./tokens'),
     sequence: require('../lib/promise/sequence'),
     ghostVersion: require('./ghost-version'),