From 810944da14ffc97d8fb2b5d78d7c8d09ad514226 Mon Sep 17 00:00:00 2001
From: Ayushman Chhabra <14110965+ayushmanchhabra@users.noreply.github.com>
Date: Thu, 15 Aug 2024 14:39:22 +0530
Subject: [PATCH] feat(get): verify sha256 checksum (#1201)

---
 README.md              |  1 -
 src/get/index.js       |  9 +++++++-
 src/get/verify.js      | 48 ++++++++++++++++++++++++++++++++++++++++++
 src/get/verify.test.js | 15 +++++++++++++
 4 files changed, 71 insertions(+), 2 deletions(-)
 create mode 100644 src/get/verify.js
 create mode 100644 src/get/verify.test.js

diff --git a/README.md b/README.md
index ee4f3542e..5fef79bb9 100644
--- a/README.md
+++ b/README.md
@@ -386,7 +386,6 @@ nwbuild({
 ### Chores
 
 - chore(docs): don't store JSDoc definitions in `typedef`s - get's hard to understand during development.
-- chore(get): verify sha checksum for downloads
 - chore: annotate file paths as `fs.PathLike` instead of `string`.
 - chore(bld): factor out core build step
 - chore(bld): factor out linux config
diff --git a/src/get/index.js b/src/get/index.js
index 7423ab523..8b74795b3 100644
--- a/src/get/index.js
+++ b/src/get/index.js
@@ -6,6 +6,7 @@ import decompress from "./decompress.js";
 import ffmpeg from "./ffmpeg.js";
 import node from "./node.js";
 import nw from "./nw.js";
+import verify from './verify.js';
 
 import util from "../util.js";
 
@@ -24,7 +25,7 @@ import util from "../util.js";
 
 /**
  * Get binaries.
- * 
+ *
  * @deprecated since v4.6.4. This logic will be ported over to `nwjs/npm-installer` repo and removed in the next major release (v5.0).
  *
  * @async
@@ -133,6 +134,12 @@ async function get(options) {
 
     await decompress(ffmpegFilePath, options.cacheDir);
 
+    await verify(
+      `${options.downloadUrl}/v${options.version}/SHASUMS256.txt`,
+      `${options.cacheDir}/shasum/${options.version}.txt`,
+      options.cacheDir,
+    );
+
     /**
      * Platform dependant file name of FFmpeg binary.
      *
diff --git a/src/get/verify.js b/src/get/verify.js
new file mode 100644
index 000000000..2378c1b80
--- /dev/null
+++ b/src/get/verify.js
@@ -0,0 +1,48 @@
+import crypto from 'node:crypto';
+import fs from 'node:fs';
+import path from 'node:path';
+
+import request from './request.js';
+
+import util from '../util.js';
+
+/**
+ * Verify the SHA256 checksum of downloaded artifacts.
+ *
+ * @param {string} shaUrl - URL to get the shasum text file from.
+ * @param {string} shaOut - File path to shasum text file.
+ * @param {string} cacheDir - File path to cache directory.
+ * @throws {Error}
+ * @returns {Promise<boolean>}
+ */
+export default async function verify(shaUrl, shaOut, cacheDir) {
+  const shaOutExists = await util.fileExists(shaOut);
+
+  if (shaOutExists === false) {
+    /* Create directory if does not exist. */
+    await fs.promises.mkdir(path.dirname(shaOut), { recursive: true });
+
+    /* Download SHASUM text file. */
+    await request(shaUrl, shaOut);
+  }
+
+  /* Read SHASUM text file */
+  const shasum = await fs.promises.readFile(shaOut, { encoding: 'utf-8' });
+  const shasums = shasum.trim().split('\n');
+  for await (const line of shasums) {
+    const [storedSha, filePath] = line.split('  ');
+    const relativeFilePath = path.resolve(cacheDir, filePath);
+    const relativefilePathExists = await util.fileExists(relativeFilePath);
+    if (relativefilePathExists) {
+      const fileBuffer = await fs.promises.readFile(relativeFilePath);
+      const hash = crypto.createHash('sha256');
+      hash.update(fileBuffer);
+      const generatedSha = hash.digest('hex');
+      if (storedSha !== generatedSha) {
+        throw new Error('SHA256 checksums do not match.');
+      }
+    }
+  }
+
+  return true;
+}
diff --git a/src/get/verify.test.js b/src/get/verify.test.js
new file mode 100644
index 000000000..24539b06d
--- /dev/null
+++ b/src/get/verify.test.js
@@ -0,0 +1,15 @@
+import { describe, expect, it } from "vitest";
+
+import verify from "./verify.js";
+
+describe("get/verify", function () {
+
+  it("verify shasums", async function () {
+    const status = await verify(
+      'https://dl.nwjs.io/v0.90.0/SHASUMS256.txt',
+      './node_modules/nw/shasum/0.90.0.txt',
+      './node_modules/nw'
+    );
+    expect(status).toBe(true);
+  }, Infinity);
+});