Support resolution of unencrypted code from plaintext asar file (closes

#41)

README.md

@@ -169,13 +169,12 @@ Don't forget to update `package.json` as well:
 - "main": "./dist/main/main.js",
 ```
 
-4. Load any hooks at the start of the [main process](https://github.com/sleeyax/asarmor/blob/master/example/electron/src/main/main.ts) file (optional):
+4. **Optional**: load configuration hooks at the start of the [main process](https://github.com/sleeyax/asarmor/blob/master/example/electron/src/main/main.ts) file:
 ```ts
 // main.ts
-import { hookNodeModulesAsar } from 'asarmor/encryption/hooks';
+import { allowUnencrypted } from 'asarmor';
 
-// load hooks at the start of the file
-hookNodeModulesAsar(); // enables resolution of non-encrypted dependencies from node_modules.asar
+allowUnencrypted(['node_modules']); // enables resolution of non-encrypted dependencies from `node_modules.asar`
 ```
 
 5. Update your `BrowserWindow.webPreferences` configuration settings:

example/electron/src/main/main.ts

@@ -14,7 +14,9 @@ import { autoUpdater } from 'electron-updater';
 import log from 'electron-log';
 import MenuBuilder from './menu';
 import { resolveHtmlPath } from './util';
-import { hookNodeModulesAsar } from '../../../../build/src/encryption/hooks';
+import { allowUnencrypted } from '../../../../build/src';
+
+allowUnencrypted(['node_modules']);
 
 export default class AppUpdater {
   constructor() {
@@ -24,8 +26,6 @@ export default class AppUpdater {
   }
 }
 
-hookNodeModulesAsar();
-
 let mainWindow: BrowserWindow | null = null;
 
 ipcMain.on('ipc-example', async (event, arg) => {

src/encryption/allowlist.ts

@@ -0,0 +1,61 @@
+/* eslint-disable no-plusplus */
+/* eslint-disable func-names */
+/* eslint-disable no-underscore-dangle */
+/* eslint-disable @typescript-eslint/ban-ts-comment */
+import path from 'path';
+import Module from 'module';
+
+// @ts-ignore
+const originalResolveLookupPaths = Module._resolveLookupPaths;
+
+/**
+ * Hooks into `Module._resolveLookupPaths` so it can resolve unencrypted source files.
+ * @example
+ * allowUnencrypted(['node_modules']); // This will allow resolution of unencrypted code from `node_modules.asar`.
+ */
+export function allowUnencrypted(allowedPaths: string[]) {
+  function override2args(request: unknown, parent: unknown) {
+    // @ts-ignore
+    const result = originalResolveLookupPaths.call(this, request, parent);
+
+    if (!result) return result;
+
+    for (let i = 0; i < result.length; i++) {
+      if (allowedPaths.includes(path.basename(result[i]))) {
+        result.splice(i + 1, 0, `${result[i]}.asar`);
+        i++;
+      }
+    }
+
+    return result;
+  }
+
+  function override3args(
+    request: unknown,
+    parent: unknown,
+    newReturn: unknown
+  ) {
+    const result = originalResolveLookupPaths.call(
+      // @ts-ignore
+      this,
+      request,
+      parent,
+      newReturn
+    );
+
+    const paths = newReturn ? result : result[1];
+
+    for (let i = 0; i < paths.length; i++) {
+      if (allowedPaths.includes(path.basename(paths[i]))) {
+        paths.splice(i + 1, 0, `${paths[i]}.asar`);
+        i++;
+      }
+    }
+
+    return result;
+  }
+
+  // @ts-ignore
+  Module._resolveLookupPaths =
+    originalResolveLookupPaths.length === 2 ? override2args : override3args;
+}

src/encryption/index.ts

@@ -1 +1,2 @@
-export { encrypt, EncryptionOptions } from './encryption';
+export * from './encryption';
+export * from './allowlist';