From dcc477acbc0735c04cb555c708b916a18e115d5a Mon Sep 17 00:00:00 2001
From: antelle <dmitryvit@gmail.com>
Date: Sun, 11 Apr 2021 11:44:51 +0200
Subject: [PATCH] tightened content security policy to prevent browser
 extension from adding scripts to KeeWeb

---
 app/index.html                  |  2 +-
 app/scripts/plugins/plugin.js   | 40 +++++++++++++++++----------------
 build/tasks/grunt-csp-hashes.js |  4 ++--
 release-notes.md                |  1 +
 4 files changed, 25 insertions(+), 22 deletions(-)

diff --git a/app/index.html b/app/index.html
index f556a310..a20ffa13 100644
--- a/app/index.html
+++ b/app/index.html
@@ -8,7 +8,7 @@
             content="
                             default-src 'self';
                             font-src data:;
-                            script-src 'self' blob: 'unsafe-eval';
+                            script-src 'self' 'unsafe-eval';
                             style-src 'self' blob:;
                             connect-src 'self' ws: https:;
                             child-src 'self' blob:;
diff --git a/app/scripts/plugins/plugin.js b/app/scripts/plugins/plugin.js
index 71ec2f28..9787e4a8 100644
--- a/app/scripts/plugins/plugin.js
+++ b/app/scripts/plugins/plugin.js
@@ -373,25 +373,27 @@ class Plugin extends Model {
                 };
                 text = `(function(require, module){${text}})(window["${jsVar}"].require,window["${jsVar}"].module);`;
                 const ts = this.logger.ts();
-                const blob = new Blob([text], { type: 'text/javascript' });
-                const objectUrl = URL.createObjectURL(blob);
-                const elId = 'plugin-js-' + name;
-                const el = this.createElementInHead('script', elId, {
-                    src: objectUrl
-                });
-                el.addEventListener('load', () => {
-                    URL.revokeObjectURL(objectUrl);
-                    setTimeout(() => {
-                        delete global[jsVar];
-                        if (this.module.exports.uninstall) {
-                            this.logger.debug('Plugin script installed', this.logger.ts(ts));
-                            this.loadPluginSettings();
-                            resolve();
-                        } else {
-                            reject('Plugin script installation failed');
-                        }
-                    }, 0);
-                });
+
+                // Note that here we're calling eval to run the plugin code,
+                // previously it was loaded as 'blob:' scheme (see the code below), however:
+                // 1. we need to have eval enabled in our CSP anyway for WASM,
+                //      see https://github.com/WebAssembly/content-security-policy/issues/7
+                // 2. we would like to prevent Chrome extensions from injecting scripts to our page,
+                //      which is possible to do if we have 'blob:', but they can't call eval
+                // Previous implementation with 'blob:' can be found in git, if we ever need to restore it.
+
+                // eslint-disable-next-line no-eval
+                eval(text);
+                setTimeout(() => {
+                    delete global[jsVar];
+                    if (this.module.exports.uninstall) {
+                        this.logger.debug('Plugin script installed', this.logger.ts(ts));
+                        this.loadPluginSettings();
+                        resolve();
+                    } else {
+                        reject('Plugin script installation failed');
+                    }
+                }, 0);
             } catch (e) {
                 this.logger.error('Error installing plugin script', e);
                 reject(e);
diff --git a/build/tasks/grunt-csp-hashes.js b/build/tasks/grunt-csp-hashes.js
index 1e05982d..fa49889d 100644
--- a/build/tasks/grunt-csp-hashes.js
+++ b/build/tasks/grunt-csp-hashes.js
@@ -41,12 +41,12 @@ module.exports = function (grunt) {
 
             let htmlStr = html.toString('latin1');
             for (const [type, digests] of Object.entries(hashes)) {
-                const cspIndex = htmlStr.indexOf(`${type}-src`);
+                const cspIndex = htmlStr.indexOf(`${type}-src 'self'`);
                 if (cspIndex < 0) {
                     grunt.warn(`Not found: ${type}-src`);
                 }
                 const digestsList = digests.map((digest) => `'${algo}-${digest}'`).join(' ');
-                htmlStr = htmlStr.replace(`${type}-src`, `${type}-src ${digestsList}`);
+                htmlStr = htmlStr.replace(`${type}-src 'self'`, `${type}-src ${digestsList}`);
             }
 
             grunt.log.writeln(
diff --git a/release-notes.md b/release-notes.md
index 2cc5f6dd..9c633fe0 100644
--- a/release-notes.md
+++ b/release-notes.md
@@ -8,6 +8,7 @@ Release notes
 `+` better Touch ID error messages  
 `-` legacy auto-type removed  
 `-` fixed a crash after disabling USB devices on Linux    
+`+` tightened content security policy  
 
 ##### v1.17.6 (2021-04-09)
 `+` team drives support in Google Drive