feat: add file hashes to asar header

lib/asar.js

@@ -157,6 +157,10 @@ module.exports.statFile = function (archive, filename, followLinks) {
   return filesystem.getFile(filename, followLinks)
 }
 
+module.exports.getRawHeader = function (archive) {
+  return disk.readArchiveHeaderSync(archive)
+}
+
 module.exports.listPackage = function (archive, options) {
   return disk.readFilesystemSync(archive).listFiles(options)
 }

lib/disk.js

@@ -76,7 +76,7 @@ module.exports.readArchiveHeaderSync = function (archive) {
 
   const headerPickle = pickle.createFromBuffer(headerBuf)
   const header = headerPickle.createIterator().readString()
-  return { header: JSON.parse(header), headerSize: size }
+  return { headerString: header, header: JSON.parse(header), headerSize: size }
 }
 
 module.exports.readFilesystemSync = function (archive) {

lib/filesystem.js

@@ -5,6 +5,7 @@ const os = require('os')
 const path = require('path')
 const { promisify } = require('util')
 const stream = require('stream')
+const hashFile = require('./hash')
 
 const UINT32_MAX = 2 ** 32 - 1
 
@@ -57,6 +58,7 @@ class Filesystem {
     if (shouldUnpack || dirNode.unpacked) {
       node.size = file.stat.size
       node.unpacked = true
+      node.hashes = await hashFile(p)
       return Promise.resolve()
     }
 
@@ -86,6 +88,7 @@ class Filesystem {
 
     node.size = size
     node.offset = this.offset.toString()
+    node.hashes = await hashFile(p)
     if (process.platform !== 'win32' && (file.stat.mode & 0o100)) {
       node.executable = true
     }

lib/hash.js

@@ -0,0 +1,28 @@
+const crypto = require('crypto')
+const fs = require('fs')
+const stream = require('stream')
+const { promisify } = require('util')
+
+const ALGORITHMS = ['SHA256']
+
+const pipeline = promisify(stream.pipeline)
+
+async function hashFile (path) {
+  const hashes = {}
+
+  await Promise.all(ALGORITHMS.map(async (algo) => {
+    const read = fs.createReadStream(path)
+    const hash = crypto.createHash(algo)
+    hash.setEncoding('base64')
+    await pipeline(
+      read,
+      hash
+    )
+
+    hashes[algo] = hash.read()
+  }))
+
+  return hashes
+}
+
+module.exports = hashFile

lib/index.d.ts

@@ -44,6 +44,13 @@ export type InputMetadata = {
   }
 };
 
+export type ArchiveHeader = {
+  // The JSON parsed header string
+  header: any;
+  headerString: string;
+  headerSize: number;
+}
+
 export function createPackage(src: string, dest: string): Promise<void>;
 export function createPackageWithOptions(
   src: string,
@@ -59,6 +66,7 @@ export function createPackageFromFiles(
 ): Promise<void>;
 
 export function statFile(archive: string, filename: string, followLinks?: boolean): Metadata;
+export function getRawHeader(archive: string): ArchiveHeader;
 export function listPackage(archive: string, options?: ListOptions): string[];
 export function extractFile(archive: string, filename: string): Buffer;
 export function extractAll(archive: string, dest: string): void;