ruffle-rs · evilpie · Oct 18, 2024 · Oct 7, 2024 · Oct 13, 2024
diff --git a/web/packages/core/src/plugin-polyfill.ts b/web/packages/core/src/plugin-polyfill.ts
@@ -38,11 +38,13 @@ class RuffleMimeTypeArray implements MimeTypeArray {
      * @param mimeType The mime type to install
      */
     install(mimeType: MimeType): void {
+        const wrapper = new RuffleMimeType(mimeType);
+
         const index = this.__mimeTypes.length;
-        this.__mimeTypes.push(mimeType);
-        this.__namedMimeTypes[mimeType.type] = mimeType;
-        this[mimeType.type] = mimeType;
-        this[index] = mimeType;
+        this.__mimeTypes.push(wrapper);
+        this.__namedMimeTypes[mimeType.type] = wrapper;
+        this[wrapper.type] = wrapper;
+        this[index] = wrapper;
     }
 
     item(index: number): MimeType {
@@ -66,6 +68,43 @@ class RuffleMimeTypeArray implements MimeTypeArray {
     [Symbol.iterator](): IterableIterator<MimeType> {
         return this.__mimeTypes[Symbol.iterator]();
     }
+
+    get [Symbol.toStringTag](): string {
+        return "MimeTypeArray";
+    }
+}
+
+/**
+ * Replacement object for the built-in MimeType object.
+ * This only exists, because the built-in type is not constructable and we
+ * need to spoof `window.MimeType`.
+ */
+class RuffleMimeType implements MimeType {
+    private readonly __mimeType: MimeType;
+
+    constructor(mimeType: MimeType) {
+        this.__mimeType = mimeType;
+    }
+
+    get type(): string {
+        return this.__mimeType.type;
+    }
+
+    get description(): string {
+        return this.__mimeType.description;
+    }
+
+    get suffixes(): string {
+        return this.__mimeType.suffixes;
+    }
+
+    get enabledPlugin(): Plugin {
+        return this.__mimeType.enabledPlugin;
+    }
+
+    get [Symbol.toStringTag](): string {
+        return "MimeType";
+    }
 }
 
 /**
@@ -141,6 +180,10 @@ class RufflePluginArray implements PluginArray {
         return this.__plugins[Symbol.iterator]();
     }
 
+    get [Symbol.toStringTag](): string {
+        return "PluginArray";
+    }
+
     get length(): number {
         return this.__plugins.length;
     }
@@ -205,6 +248,9 @@ export function installPlugin(plugin: RufflePlugin): void {
         return;
     }
     if (!("install" in navigator.plugins) || !navigator.plugins["install"]) {
+        Object.defineProperty(window, "PluginArray", {
+            value: RufflePluginArray,
+        });
         Object.defineProperty(navigator, "plugins", {
             value: new RufflePluginArray(navigator.plugins),
             writable: false,
@@ -218,6 +264,12 @@ export function installPlugin(plugin: RufflePlugin): void {
         plugin.length > 0 &&
         (!("install" in navigator.mimeTypes) || !navigator.mimeTypes["install"])
     ) {
+        Object.defineProperty(window, "MimeTypeArray", {
+            value: RuffleMimeTypeArray,
+        });
+        Object.defineProperty(window, "MimeType", {
+            value: RuffleMimeType,
+        });
         Object.defineProperty(navigator, "mimeTypes", {
             value: new RuffleMimeTypeArray(navigator.mimeTypes),
             writable: false,

diff --git a/web/packages/selfhosted/test/polyfill/spoofing/expected.html b/web/packages/selfhosted/test/polyfill/spoofing/expected.html
@@ -0,0 +1,5 @@
+<ruffle-object
+                data="/test_assets/example.swf"
+                width="500"
+                height="500"
+></ruffle-object>
diff --git a/web/packages/selfhosted/test/polyfill/spoofing/index.html b/web/packages/selfhosted/test/polyfill/spoofing/index.html
@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<html>
+    <head>
+        <meta charset="utf-8" />
+        <title>Spoofing Test</title>
+    </head>
+
+    <body>
+        <div id="test-container">
+            <object
+                data="/test_assets/example.swf"
+                width="500"
+                height="500"
+            ></object>
+        </div>
+    </body>
+</html>
diff --git a/web/packages/selfhosted/test/polyfill/spoofing/test.ts b/web/packages/selfhosted/test/polyfill/spoofing/test.ts
@@ -0,0 +1,63 @@
+/* eslint-disable @typescript-eslint/no-unused-expressions */
+
+import { openTest, injectRuffleAndWait } from "../../utils.js";
+import { expect, use } from "chai";
+import chaiHtml from "chai-html";
+import fs from "fs";
+
+use(chaiHtml);
+
+describe("Spoofing is not easily detectable", () => {
+    it("loads the test", async () => {
+        await openTest(browser, `polyfill/spoofing`);
+    });
+
+    it("Polyfills", async () => {
+        await injectRuffleAndWait(browser);
+        await browser.$("<ruffle-object />").waitForExist();
+
+        const actual = await browser.$("#test-container").getHTML(false);
+        const expected = fs.readFileSync(
+            `${import.meta.dirname}/expected.html`,
+            "utf8",
+        );
+        expect(actual).html.to.equal(expected);
+    });
+
+    it("Spoofs navigator.plugins", async () => {
+        const names = await browser.execute(() => {
+            const names = [];
+            for (let i = 0; i < navigator.plugins.length; i++) {
+                names.push(navigator.plugins[i]!.name);
+            }
+            return names;
+        });
+        expect(names).to.include("Shockwave Flash");
+
+        const instance = await browser.execute(() => {
+            return navigator.plugins instanceof PluginArray;
+        });
+        expect(instance).be.true;
+    });
+
+    it("Spoofs navigator.mimeTypes", async () => {
+        const types = await browser.execute(() => {
+            const types = [];
+            for (let i = 0; i < navigator.mimeTypes.length; i++) {
+                types.push(navigator.mimeTypes[i]!.type);
+            }
+            return types;
+        });
+        expect(types).to.include("application/x-shockwave-flash");
+
+        const instance = await browser.execute(() => {
+            for (let i = 0; i < navigator.mimeTypes.length; i++) {
+                if (!(navigator.mimeTypes[i] instanceof MimeType)) {
+                    return false;
+                }
+            }
+            return navigator.mimeTypes instanceof MimeTypeArray;
+        });
+        expect(instance).be.true;
+    });
+});