Adopt a portion of SRI for our implementation

* This was already implemented pre W3C recommendation in our form but normalizing to their syntax.
* UI and DB remaining non-base64 encoded... semver limitation with extra characters that violate that spec.
* Change caching mechanism... unfortunately traffic for a while will be increased while syncing with browsers. Also because spec doesn't use hex, which it probably should, the eTag header value will be bigger. Hashes, so far, are always "hex-able" by design of SHA but that could change in the future... who knows.
* Base62 being dropped in favor of Base64 for cache mechanism. Should be okay with extra `+/` in base64 since that falls within ASCII limitations.
* Any .user.js utilizing the .meta.json, or other language, will need to modify to check for the `sha512-` prefix and decode the value appropriately.
* If .meta.json shows empty `hash` clear browser cache *(weird Fx issue perhaps)*
* Bugfix on local copy of metadata script access... non-fatal atm just incorrect live copy referenced.

Post OpenUserJS#1076 and applies to OpenUserJS#432 OpenUserJS#249

Ref(s):
* https://developer.mozilla.org/docs/Web/HTTP/Headers/ETag
* https://developer.mozilla.org/docs/Web/Security/Subresource_Integrity
* https://w3c.github.io/webappsec-subresource-integrity/
* https://www.srihash.org/

Author: Martii

README.md

@@ -24,7 +24,6 @@ Repository | Reference | Recent Version
 [ansi-colors][ansi-colorsGHUrl] | [Documentation][ansi-colorsDOCUrl] | [![NPM version][ansi-colorsNPMVersionImage]][ansi-colorsNPMUrl]
 [async][asyncGHUrl] | [Documentation][asyncDOCUrl] | [![NPM version][asyncNPMVersionImage]][asyncNPMUrl]
 [aws-sdk][aws-sdkGHUrl] | [Documentation][aws-sdkDOCUrl] | [![NPM version][aws-sdkNPMVersionImage]][aws-sdkNPMUrl]
-[base62][base62GHUrl] | [Documentation][base62DOCUrl] | [![NPM version][base62NPMVersionImage]][base62NPMUrl]
 [body-parser][body-parserGHUrl] | [Documentation][body-parserDOCUrl] | [![NPM version][body-parserNPMVersionImage]][body-parserNPMUrl]
 [bootstrap][bootstrapGHUrl] | [Documentation][bootstrapDOCUrl] | [![NPM version][bootstrapNPMVersionImage]][bootstrapNPMUrl]
 [bootstrap-markdown][bootstrap-markdownGHUrl] | [Documentation][bootstrap-markdownDOCUrl] | [![NPM version][bootstrap-markdownNPMVersionImage]][bootstrap-markdownNPMUrl]
@@ -147,11 +146,6 @@ Outdated dependencies list can also be achieved with `$ npm outdated`
 [aws-sdkNPMUrl]: https://www.npmjs.com/package/aws-sdk
 [aws-sdkNPMVersionImage]: https://img.shields.io/npm/v/aws-sdk.svg?style=flat
 
-[base62GHUrl]: https://github.com/base62/base62.js
-[base62DOCUrl]: https://github.com/base62/base62.js/blob/master/Readme.md
-[base62NPMUrl]: https://www.npmjs.com/package/base62
-[base62NPMVersionImage]: https://img.shields.io/npm/v/base62.svg?style=flat
-
 [body-parserGHUrl]: https://github.com/expressjs/body-parser
 [body-parserDOCUrl]: https://github.com/expressjs/body-parser/blob/master/README.md
 [body-parserNPMUrl]: https://www.npmjs.com/package/body-parser

controllers/scriptStorage.js

@@ -27,7 +27,6 @@ var mediaType = require('media-type');
 var mediaDB = require('mime-db');
 var async = require('async');
 var moment = require('moment');
-var Base62 = require('base62/lib/ascii');
 var SPDX = require('spdx-license-ids');
 var sizeOf = require('image-size');
 var ipRangeCheck = require("ip-range-check");
@@ -570,6 +569,7 @@ exports.sendScript = function (aReq, aRes, aNext) {
 
     var lastModified = null;
     var eTag = null;
+    var hashSRI = null;
     var maxAge = 7 * 60 * 60 * 24; // nth day(s) in seconds
     var now = null;
     var continuation = true;
@@ -628,6 +628,10 @@ exports.sendScript = function (aReq, aRes, aNext) {
       }
     }
 
+    hashSRI = aScript.hash
+      ? 'sha512-' + Buffer.from(aScript.hash).toString('base64')
+      : 'undefined';
+
     // HTTP/1.1 Caching
     aRes.set('Cache-Control', 'public, max-age=' + maxAge +
       ', no-cache, no-transform, must-revalidate');
@@ -639,8 +643,8 @@ exports.sendScript = function (aReq, aRes, aNext) {
       lastModified = moment(aScript.updated)
         .utc().format('ddd, DD MMM YYYY HH:mm:ss') + ' GMT';
 
-      // Convert a based representation of the hex sha512sum
-      eTag = '"'  + Base62.encode(parseInt('0x' + aScript.hash, 16)) + ' .user.js"';
+      // Use SRI of the stored sha512sum
+      eTag = '"'  + hashSRI + ' .user.js"';
 
       // If already client-side... HTTP/1.1 Caching
       if (aReq.get('if-none-match') === eTag || aReq.get('if-modified-since') === lastModified) {
@@ -796,10 +800,12 @@ exports.sendScript = function (aReq, aRes, aNext) {
             } else {
               source = result.code;
 
-              // Calculate a based representation of the hex sha512sum
-              eTag = '"'  + Base62.encode(
-                parseInt('0x' + crypto.createHash('sha512').update(source).digest('hex'), 16)) +
-                  ' .min.user.js"';
+              // Calculate SRI of the source sha512sum
+              eTag = '"sha512-' +
+                Buffer.from(
+                  crypto.createHash('sha512').update(source).digest('hex')
+                ).toString('base64') + ' .min.user.js"';
+
             }
           } catch (aE) { // On any failure default to unminified
             if (isDev) {
@@ -827,8 +833,8 @@ exports.sendScript = function (aReq, aRes, aNext) {
             lastModified = moment(aScript.updated)
               .utc().format('ddd, DD MMM YYYY HH:mm:ss') + ' GMT';
 
-            // Reset to convert a based representation of the hex sha512sum
-            eTag = '"'  + Base62.encode(parseInt('0x' + aScript.hash, 16)) + ' .user.js"';
+            // Reset SRI of the stored sha512sum
+            eTag = '"'  + hashSRI + ' .user.js"';
           }
 
           // If already client-side... partial HTTP/1.1 Caching
@@ -928,8 +934,8 @@ exports.sendMeta = function (aReq, aRes, aNext) {
       meta = script.meta; // NOTE: Watchpoint
 
       if (/\.json$/.test(aReq.params.scriptname)) {
-        // Create a based representation of the hex sha512sum
-        eTag = '"'  + Base62.encode(parseInt('0x' + aScript.hash, 16)) + ' .meta.json"';
+        // Use SRI of the stored sha512sum
+        eTag = '"'  + script.hashSRI + ' .meta.json"';
 
         // If already client-side... HTTP/1.1 Caching
         if (aReq.get('if-none-match') === eTag) {
@@ -955,7 +961,7 @@ exports.sendMeta = function (aReq, aRes, aNext) {
         // Overwrite any keys found with the following...
         meta.OpenUserJS.installs = [{ value: script.installs }];
         meta.OpenUserJS.issues =  [{ value: 'n/a' }];
-        meta.OpenUserJS.hash = aScript.hash ? [{ value: aScript.hash }] : undefined;
+        meta.OpenUserJS.hash = script.hash ? [{ value: script.hashSRI }] : 'undefined';
 
         // Get the number of open issues
         scriptOpenIssueCountQuery = Discussion.find({ category: exports
@@ -966,8 +972,8 @@ exports.sendMeta = function (aReq, aRes, aNext) {
         async.parallel(tasks, asyncComplete);
 
       } else {
-        // Create a based representation of the hex sha512sum
-        eTag = '"'  + Base62.encode(parseInt('0x' + aScript.hash, 16)) + ' .meta.js"';
+        // Use SRI of the stored sha512sum
+        eTag = '"'  + script.hashSRI + ' .meta.js"';
 
         // If already client-side... HTTP/1.1 Caching
         if (aReq.get('if-none-match') === eTag) {

libs/modelParser.js

@@ -489,7 +489,14 @@ var parseScript = function (aScript) {
   parseDateProperty(script, 'updated');
 
   // Hash
-  script.hashShort = script.hash ? script.hash.substr(0, 7) : 'undefined';
+  script.hashShort = 'undefined';
+  script.hashSRI = 'undefined';
+
+  if (script.hash) {
+     // NOTE: May be absent in dev DB but should not be in pro DB
+    script.hashShort = script.hash.substr(0, 7);
+    script.hashSRI = 'sha512-' + Buffer.from(script.hash).toString('base64');
+  }
 
   if (script.created && script.updated && script.created.toString() !== script.updated.toString()) {
     script.isUpdated = true;

package.json

@@ -9,7 +9,6 @@
     "async": "3.2.0",
     "@octokit/auth-oauth-app": "4.3.0",
     "aws-sdk": "2.944.0",
-    "base62": "2.0.1",
     "body-parser": "1.19.0",
     "bootstrap": "3.4.1",
     "bootstrap-markdown": "2.10.0",

views/pages/scriptPage.html

@@ -27,7 +27,7 @@
 
             <div class="script-meta">
               <p><i class="fa fa-fw fa-clock-o"></i> <b>Published:</b> <time datetime="{{script.createdISOFormat}}" title="{{script.created}}">{{script.createdHumanized}}</time></p>
-              <p><i class="fa fa-fw fa-history"></i> <b>Version:</b> <code>{{script.meta.UserScript.version.0.value}}<span title="SHA-512 {{script.hash}}">+{{script.hashShort}}</span></code>{{#script.isUpdated}} updated <time class="script-updated" datetime="{{script.updatedISOFormat}}" title="{{script.updated}}">{{script.updatedHumanized}}</time>{{/script.isUpdated}}</p>
+              <p><i class="fa fa-fw fa-history"></i> <b>Version:</b> <code>{{script.meta.UserScript.version.0.value}}<span title="{{script.hashSRI}}">+{{script.hashShort}}</span></code>{{#script.isUpdated}} updated <time class="script-updated" datetime="{{script.updatedISOFormat}}" title="{{script.updated}}">{{script.updatedHumanized}}</time>{{/script.isUpdated}}</p>
               {{#script.description}}<p><i class="fa fa-fw fa-info"></i> <b>Summary:</b> {{script.description}}</p>{{/script.description}}
               {{#script.hasGroups}}
                 <span>