build(manager): 👷 sign Windows apps during electron build (#1104)

#### Description

In this PR, I introduced the cross-platform Windows binary signing tools to the server manager. [Jsign](https://ebourg.github.io/jsign/) is included as one of the `third_party` dependencies. In the future, we can leverage GCP KMS based certificate to do the signing as well.

#### Environment Variables

- `WINDOWS_SIGNING_CERT_TYPE`: `none|pfx|digicert-usb`
- `WINDOWS_SIGNING_CERT_PASSWORD`: password of the certificate (store)
- `WINDOWS_SIGNING_PFX_CERT`: ".pfx" certificate path if the type is `pfx`
- `WINDOWS_SIGNING_EV_CERT_SUBJECT`: [optional] subject of the EV certificate if type is `digicert-usb` (in our case, you can use `Jigsaw Operations LLC`)

src/server_manager/electron_app/windows/digicert-usb-config/eToken-macos.cfg

@@ -0,0 +1,3 @@
+name=eToken
+description=SunPKCS11 via Digicert SafeNet Authentication Client
+library=/usr/local/lib/libeTPkcs11.dylib

src/server_manager/electron_app/windows/digicert-usb-config/eToken-windows.cfg

@@ -0,0 +1,3 @@
+name=eToken
+description=SunPKCS11 via Digicert SafeNet Authentication Client
+library=c:\WINDOWS\system32\eTPKCS11.dll

src/server_manager/electron_app/windows/electron_builder_signing_plugin.cjs

@@ -0,0 +1,29 @@
+// Copyright 2022 The Outline Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/**
+ * The entry point which will be called by electron-builder signing module.
+ * @param {Object} configuration a configuration containing signing information
+ * @param {string} configuration.path the executable file path to be signed
+ * @param {'sha1'|'sha256'} configuration.hash requested hash algorithm
+ * @param {boolean} configuration.isNest whether it is a secondary signature
+ * @param {Object} configuration.options a duplication of electron-builder.json
+ */
+async function electronBuilderEntryPoint(configuration) {
+  // CommonJS module is required, ES6 module is not supported by electron-builder
+  const {signWindowsExecutable} = await import('./sign_windows_executable.mjs');
+  await signWindowsExecutable(configuration.path, configuration.hash, null);
+}
+
+exports.default = electronBuilderEntryPoint;

src/server_manager/electron_app/windows/sign_windows_executable.mjs

@@ -0,0 +1,211 @@
+// Copyright 2022 The Outline Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import {spawn} from 'child_process';
+import {constants} from 'fs';
+import {access} from 'fs/promises';
+import minimist from 'minimist';
+import {dirname, resolve} from 'path';
+import {fileURLToPath, pathToFileURL} from 'url';
+import {format} from 'util';
+
+/**
+ * Get the parent folder path of this script.
+ * @returns the folder path containing the current script.
+ */
+function currentDirname() {
+  return dirname(fileURLToPath(import.meta.url));
+}
+
+/**
+ * Get the outline-server root folder path.
+ * @returns the folder path of outline-client root.
+ */
+function outlineDirname() {
+  return resolve(currentDirname(), '..', '..', '..', '..');
+}
+
+function assert(condition, msg) {
+  if (!condition) {
+    throw new Error(msg);
+  }
+}
+
+async function assertFileExists(file, msg) {
+  try {
+    await access(file, constants.R_OK | constants.W_OK);
+  } catch (err) {
+    throw new Error(format(msg, file), {cause: err});
+  }
+}
+
+/**
+ * Get the required option value from either cliValue or environment variable.
+ * @param {object} options the CLI options object.
+ * @param {string} argName the CLI argument name.
+ * @param {string} envName the environment variable name for this option.
+ * @param {boolean} required indicates whether this option is required.
+ * @returns {string} the value of the option
+ */
+function getOptionValue(options, argName, envName, required) {
+  const cliValue = options ? options[argName] : null;
+  const v = cliValue ?? process.env[envName];
+  if (required) {
+    assert(!!v, `either --${argName} or ${envName} is required`);
+  }
+  return v;
+}
+
+function appendPfxJsignArgs(args, options) {
+  // self-signed development certificate
+  args.push('--storetype', 'PKCS12');
+
+  const pfxCert = getOptionValue(options, 'pfx', 'WINDOWS_SIGNING_PFX_CERT', true);
+  args.push('--keystore', pfxCert);
+}
+
+function appendDigicertUsbJsignArgs(args, options) {
+  // extended validation certificate stored in USB drive
+  args.push('--storetype', 'PKCS11');
+
+  const subject = getOptionValue(options, 'subject', 'WINDOWS_SIGNING_EV_CERT_SUBJECT', false);
+  if (subject) {
+    args.push('--alias', subject);
+  }
+
+  var eTokenCfg;
+  switch (process.platform) {
+    case 'win32':
+      eTokenCfg = resolve(currentDirname(), 'digicert-usb-config', 'eToken-windows.cfg');
+      break;
+    case 'darwin':
+      eTokenCfg = resolve(currentDirname(), 'digicert-usb-config', 'eToken-macos.cfg');
+      break;
+    default:
+      throw new Error(`we do not support ev signing on ${process.platform}`);
+  }
+  args.push('--keystore', eTokenCfg);
+}
+
+/**
+ * Run jsign.jar according to the corresponding options targeting fileToSign.
+ * @param {string} fileToSign The path string of a file to be signed.
+ * @param {string[]} options The options to be passed to jsign. see https://ebourg.github.io/jsign/
+ * @returns {Promise<number>} A promise containing the exit code of jsign.
+ */
+function jsign(fileToSign, options) {
+  if (!options) {
+    throw new Error('options are required by jsign');
+  }
+  if (!fileToSign) {
+    throw new Error('fileToSign is required by jsign');
+  }
+
+  const jSignJarPath = resolve(outlineDirname(), 'third_party', 'jsign', 'jsign-4.0.jar');
+  const jsignProc = spawn('java', ['-jar', jSignJarPath, ...options, fileToSign], {
+    stdio: 'inherit',
+  });
+  return new Promise((resolve, reject) => {
+    jsignProc.on('error', reject);
+    jsignProc.on('exit', resolve);
+  });
+}
+
+/**
+ * Sign the target exeFile using a specific algorithm and options.
+ * @param {string} exeFile the full path of the exe file to be signed.
+ * @param {'sha1'|'sha256'} algorithm the algorithm used for signing.
+ * @param {object} options additional options (cli arguments) for signing.
+ *                         the options will also be read from environment
+ *                         variables.
+ */
+export async function signWindowsExecutable(exeFile, algorithm, options) {
+  const type = getOptionValue(options, 'certtype', 'WINDOWS_SIGNING_CERT_TYPE', false);
+  if (!type || type === 'none') {
+    console.info(`skip signing "${exeFile}"`);
+    return;
+  }
+
+  assert(!!exeFile, 'executable path is required');
+  assert(algorithm === 'sha1' || algorithm === 'sha256', 'hashing algorithm must be either "sha1" or "sha256"');
+
+  exeFile = resolve(exeFile);
+  await assertFileExists(exeFile, 'executable file "%s" does not exist');
+
+  const password = getOptionValue(options, 'password', 'WINDOWS_SIGNING_CERT_PASSWORD', true);
+
+  const jsignArgs = [
+    '--alg',
+    algorithm === 'sha256' ? 'SHA-256' : 'SHA-1',
+    '--tsaurl',
+    'http://timestamp.digicert.com',
+    '--storepass',
+    password,
+  ];
+
+  switch (type) {
+    case 'pfx':
+      appendPfxJsignArgs(jsignArgs, options);
+      break;
+    case 'digicert-usb':
+      appendDigicertUsbJsignArgs(jsignArgs, options);
+      break;
+    default:
+      throw new Error(`cert type ${type} is not supported`);
+  }
+
+  var exitCode;
+  try {
+    exitCode = await jsign(exeFile, jsignArgs);
+  } catch (err) {
+    console.error('failed to start java, please make sure you have installed java');
+    throw new Error(err);
+  }
+
+  if (exitCode === 0) {
+    console.info(`successfully signed "${exeFile}"`);
+  } else {
+    console.error(`jsign exited with error code ${exitCode}`);
+    throw new Error(`failed to sign "${exeFile}"`);
+  }
+}
+
+async function main() {
+  const {target, algorithm, ...options} = minimist(process.argv);
+  await signWindowsExecutable(target, algorithm, options);
+}
+
+// Call this script through CLI to sign a Windows executable:
+//   node sign_windows_executable.mjs
+//     --target <exe-path-to-sign>
+//     --algorithm <sha1|sha256>
+//     --certtype <none|pfx|digicert-usb>
+//     --password <cert-store-password>
+// The following options are for --certtype == pfx
+//     --pfx <pfx-cert-path>
+// The following options are for --certtype == digicert-usb
+//     [--subject <cert-subject-name>]
+//
+// You can also use environment variables to specify some arguments:
+//   WINDOWS_SIGNING_CERT_TYPE       <=> --certtype
+//   WINDOWS_SIGNING_CERT_PASSWORD   <=> --password
+//   WINDOWS_SIGNING_PFX_CERT        <=> --pfx
+//   WINDOWS_SIGNING_EV_CERT_SUBJECT <=> --subject
+if (import.meta.url === pathToFileURL(process.argv[1]).href) {
+  try {
+    await main();
+  } catch (err) {
+    console.error(err);
+  }
+}

src/server_manager/scripts/get_electron_build_flags.mjs

@@ -32,7 +32,11 @@ export async function getElectronBuildFlags(platform, buildMode) {
       ];
       break;
     case 'windows':
-      buildFlags = ['--win', '--ia32', '--config.win.icon=icons/win/icon.ico', ...buildFlags];
+      buildFlags = [
+        '--win', '--ia32',
+        '--config.win.icon=icons/win/icon.ico',
+        '--config.win.sign=src/server_manager/electron_app/windows/electron_builder_signing_plugin.cjs',
+        ...buildFlags];
       break;
     case 'macos':
       buildFlags = ['--mac', '--config.mac.icon=icons/mac/icon.icns', ...buildFlags];
@@ -50,10 +54,6 @@ export async function getElectronBuildFlags(platform, buildMode) {
     ];
   }
 
-  if (buildMode === 'release' && platform === 'windows') {
-    buildFlags.push("--config.win.certificateSubjectName='Jigsaw Operations LLC'");
-  }
-
   return buildFlags;
 }
 

third_party/jsign/LICENSE.txt

@@ -0,0 +1,201 @@
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third_party/jsign/METADATA

@@ -0,0 +1,17 @@
+name: "Jsign"
+description:
+    "Java implementation of Microsoft Authenticode for signing Windows "
+    "executable files, installers and scripts."
+
+third_party {
+  url {
+    type: HOMEPAGE
+    value: "https://ebourg.github.io/jsign/"
+  }
+  url {
+    type: GIT
+    value: "https://github.com/ebourg/jsign"
+  }
+  version: "4.0"
+  last_upgrade_date { year: 2022 month: 5 day: 27 }
+}