From 5fea75b151dd3fffe05b34a222759f3120c28ba6 Mon Sep 17 00:00:00 2001
From: Julian Waller <git@julusian.co.uk>
Date: Sun, 15 Dec 2024 19:42:13 +0000
Subject: [PATCH] wip: check download checksum

---
 .../lib/Instance/InstalledModulesManager.ts      | 16 +++++++++++++++-
 shared-lib/lib/Model/ModulesStore.ts             |  1 +
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/companion/lib/Instance/InstalledModulesManager.ts b/companion/lib/Instance/InstalledModulesManager.ts
index ef3ab6e46f..90aabb5e12 100644
--- a/companion/lib/Instance/InstalledModulesManager.ts
+++ b/companion/lib/Instance/InstalledModulesManager.ts
@@ -15,6 +15,7 @@ import type { ModuleStoreModuleInfoVersion } from '@companion-app/shared/Model/M
 import { MultipartUploader } from '../Resources/MultipartUploader.js'
 import type { DataDatabase } from '../Data/Database.js'
 import { ConnectionConfigStore } from './ConnectionConfigStore.js'
+import crypto from 'node:crypto'
 
 const gunzipP = promisify(zlib.gunzip)
 
@@ -332,6 +333,11 @@ export class InstanceInstalledModulesManager {
 			return `Module ${moduleId} v${moduleVersion} has no download URL`
 		}
 
+		if (!versionInfo.tarSha) {
+			this.#logger.error(`Module ${moduleId} v${moduleVersion} has no download checksum`)
+			return `Module ${moduleId} v${moduleVersion} has no download checksum`
+		}
+
 		const timeBeforeDownload = Date.now()
 
 		const abortControl = new AbortController()
@@ -363,7 +369,15 @@ export class InstanceInstalledModulesManager {
 			`Downloaded ${moduleId} v${moduleVersion} in ${Date.now() - timeBeforeDownload}ms (${bytesReceived} bytes)`
 		)
 
-		const decompressedData = await gunzipP(Buffer.concat(chunks))
+		const fullTarBuffer = Buffer.concat(chunks)
+
+		const bufferChecksum = crypto.createHash('sha256').update(fullTarBuffer).digest('hex')
+		if (bufferChecksum !== versionInfo.tarSha) {
+			this.#logger.error(`Downlod did not match checksum`)
+			return 'Download did not match checksum'
+		}
+
+		const decompressedData = await gunzipP(fullTarBuffer)
 		if (!decompressedData) {
 			this.#logger.error(`Failed to decompress module data`)
 			return 'Failed to decompress data'
diff --git a/shared-lib/lib/Model/ModulesStore.ts b/shared-lib/lib/Model/ModulesStore.ts
index 274d6cb8d1..27413aa5c8 100644
--- a/shared-lib/lib/Model/ModulesStore.ts
+++ b/shared-lib/lib/Model/ModulesStore.ts
@@ -46,6 +46,7 @@ export interface ModuleStoreModuleInfoVersion {
 	releasedAt: number // unix timestamp
 
 	tarUrl: string | null
+	tarSha: string | null
 	deprecationReason: string | null
 
 	apiVersion: string