fix(cve-2023-29827): replace EJS with Handlebars to resolve security …

…warning

Relates to: loopbackio/loopback-next#9867

Signed-off-by: KalleV <kvirtaneva@gmail.com>

lib/send-html.js

@@ -4,7 +4,7 @@
 // License text available at https://opensource.org/licenses/MIT
 
 'use strict';
-const ejs = require('ejs');
+const handlebars = require('handlebars');
 const fs = require('fs');
 const path = require('path');
 
@@ -16,13 +16,49 @@ const compiledTemplates = {
 
 module.exports = sendHtml;
 
+/**
+ * Sends HTML response to the client.
+ *
+ * @param {Object} res - The response object.
+ * @param {Object} data - The data object to be rendered in the HTML.
+ * @param {Object} options - The options object.
+ */
 function sendHtml(res, data, options) {
   const toRender = {options, data};
   // TODO: ability to call non-default template functions from options
   const body = compiledTemplates.default(toRender);
   sendResponse(res, body);
 }
 
+/**
+ * Returns the content of a Handlebars partial file as a string.
+ * @param {string} name - The name of the Handlebars partial file.
+ * @returns {string} The content of the Handlebars partial file as a string.
+ */
+function partial(name) {
+  const partialPath = path.resolve(assetDir, `${name}.hbs`);
+  const partialContent = fs.readFileSync(partialPath, 'utf8');
+  return partialContent;
+}
+
+handlebars.registerHelper('partial', partial);
+
+/**
+ * Checks if the given property is a standard property.
+ * @param {string} prop - The property to check.
+ * @param {Object} options - The Handlebars options object.
+ * @returns {string} - The result of the Handlebars template.
+ */
+function standardProps(prop, options) {
+  const standardProps = ['name', 'statusCode', 'message', 'stack'];
+  if (standardProps.indexOf(prop) === -1) {
+    return options.fn(this);
+  }
+  return options.inverse(this);
+}
+
+handlebars.registerHelper('standardProps', standardProps);
+
 /**
  * Compile and cache the file with the `filename` key in options
  *
@@ -32,15 +68,23 @@ function sendHtml(res, data, options) {
 function compileTemplate(filepath) {
   const options = {cache: true, filename: filepath};
   const fileContent = fs.readFileSync(filepath, 'utf8');
-  return ejs.compile(fileContent, options);
+  return handlebars.compile(fileContent, options);
 }
 
-// loads and cache default error templates
+/**
+ * Loads the default error handlebars template from the asset directory and compiles it.
+ * @returns {Function} The compiled handlebars template function.
+ */
 function loadDefaultTemplates() {
-  const defaultTemplate = path.resolve(assetDir, 'default-error.ejs');
+  const defaultTemplate = path.resolve(assetDir, 'default-error.hbs');
   return compileTemplate(defaultTemplate);
 }
 
+/**
+ * Sends an HTML response with the given body to the provided response object.
+ * @param {Object} res - The response object to send the HTML response to.
+ * @param {string} body - The HTML body to send in the response.
+ */
 function sendResponse(res, body) {
   res.setHeader('Content-Type', 'text/html; charset=utf-8');
   res.end(body);