From 496ebf2a47b9f2f5652fa66cb41dacbde8eb4243 Mon Sep 17 00:00:00 2001 From: Scott Nonnenberg Date: Thu, 16 Aug 2018 10:07:38 -0700 Subject: [PATCH] Store SQLCipher decryption key in separate file First, we write the key a whole lot less. We write it on creation, then never again. Second, it's in a file we control very closely. Instead of blindly regenerating the key if the target file generates an error on read, we block startup unless the error is 'ENOENT' - the file isn't there at all. This still allows for the key.txt file to be deleted or corrupted somehow, but it should be a lot less common than the high-traffic config.json used for window location and media permissions. --- app/key_management.js | 62 +++++++++++++++++++++++++++++++++++++++++++ app/sql_channel.js | 9 +++---- main.js | 61 +++++++++++++++++++----------------------- 3 files changed, 93 insertions(+), 39 deletions(-) create mode 100644 app/key_management.js diff --git a/app/key_management.js b/app/key_management.js new file mode 100644 index 000000000..83a471f34 --- /dev/null +++ b/app/key_management.js @@ -0,0 +1,62 @@ +const fs = require('fs'); +const path = require('path'); +const crypto = require('crypto'); + +const { app } = require('electron'); + +const ENCODING = 'utf8'; +const userDataPath = app.getPath('userData'); +const targetPath = path.join(userDataPath, 'key.txt'); + +module.exports = { + get, + set, + initialize, + remove, +}; + +function get() { + try { + const key = fs.readFileSync(targetPath, ENCODING); + console.log('key/get: Successfully read key file'); + return key; + } catch (error) { + if (error.code === 'ENOENT') { + console.log('key/get: Could not find key file, returning null'); + return null; + } + + throw error; + } +} + +function set(key) { + console.log('key/set: Saving key to disk'); + fs.writeFileSync(targetPath, key, ENCODING); +} + +function remove() { + console.log('key/remove: Deleting key from disk'); + fs.unlinkSync(targetPath); +} + +function initialize({ userConfig }) { + const keyFromConfig = userConfig.get('key'); + const keyFromStore = get(); + + let key = keyFromStore || keyFromConfig; + if (!key) { + console.log( + 'key/initialize: Generating new encryption key, since we did not find it on disk' + ); + // https://www.zetetic.net/sqlcipher/sqlcipher-api/#key + key = crypto.randomBytes(32).toString('hex'); + set(key); + } else if (keyFromConfig) { + set(key); + console.log('key/initialize: Removing key from config.json'); + userConfig.delete('key'); + } + + return key; +} diff --git a/app/sql_channel.js b/app/sql_channel.js index c375b222c..46d74c31b 100644 --- a/app/sql_channel.js +++ b/app/sql_channel.js @@ -1,5 +1,6 @@ const electron = require('electron'); const sql = require('./sql'); +const { remove } = require('./key_management'); const { ipcMain } = electron; @@ -12,16 +13,12 @@ let initialized = false; const SQL_CHANNEL_KEY = 'sql-channel'; const ERASE_SQL_KEY = 'erase-sql-key'; -function initialize({ userConfig }) { +function initialize() { if (initialized) { throw new Error('sqlChannels: already initialized!'); } initialized = true; - if (!userConfig) { - throw new Error('initialize: userConfig is required!'); - } - ipcMain.on(SQL_CHANNEL_KEY, async (event, jobId, callName, ...args) => { try { const fn = sql[callName]; @@ -44,7 +41,7 @@ function initialize({ userConfig }) { ipcMain.on(ERASE_SQL_KEY, async event => { try { - userConfig.set('key', null); + remove(); event.sender.send(`${ERASE_SQL_KEY}-done`); } catch (error) { const errorForDisplay = error && error.stack ? error.stack : error; diff --git a/main.js b/main.js index 763798dbe..53269fbb1 100644 --- a/main.js +++ b/main.js @@ -4,14 +4,17 @@ const path = require('path'); const url = require('url'); const os = require('os'); const fs = require('fs'); -const crypto = require('crypto'); const _ = require('lodash'); const pify = require('pify'); const electron = require('electron'); -const getRealPath = pify(fs.realpath); +const packageJson = require('./package.json'); +const GlobalErrors = require('./app/global_errors'); +GlobalErrors.addHandler(); + +const getRealPath = pify(fs.realpath); const { app, BrowserWindow, @@ -22,26 +25,6 @@ const { shell, } = electron; -const packageJson = require('./package.json'); - -const sql = require('./app/sql'); -const sqlChannels = require('./app/sql_channel'); -const attachments = require('./app/attachments'); -const attachmentChannel = require('./app/attachment_channel'); -const autoUpdate = require('./app/auto_update'); -const createTrayIcon = require('./app/tray_icon'); -const GlobalErrors = require('./app/global_errors'); -const logging = require('./app/logging'); -const windowState = require('./app/window_state'); -const { createTemplate } = require('./app/menu'); -const { - installFileHandler, - installWebHandler, -} = require('./app/protocol_filter'); -const { installPermissionsHandler } = require('./app/permissions'); - -GlobalErrors.addHandler(); - const appUserModelId = `org.whispersystems.${packageJson.name}`; console.log('Set Windows Application User Model ID (AUMID)', { appUserModelId, @@ -64,14 +47,32 @@ const usingTrayIcon = const config = require('./app/config'); +// Very important to put before the single instance check, since it is based on the +// userData directory. +const userConfig = require('./app/user_config'); + const importMode = process.argv.some(arg => arg === '--import') || config.get('import'); const development = config.environment === 'development'; -// Very important to put before the single instance check, since it is based on the -// userData directory. -const userConfig = require('./app/user_config'); +// We generally want to pull in our own modules after this point, after the user +// data directory has been set. +const attachments = require('./app/attachments'); +const attachmentChannel = require('./app/attachment_channel'); +const autoUpdate = require('./app/auto_update'); +const createTrayIcon = require('./app/tray_icon'); +const keyManagement = require('./app/key_management'); +const logging = require('./app/logging'); +const sql = require('./app/sql'); +const sqlChannels = require('./app/sql_channel'); +const windowState = require('./app/window_state'); +const { createTemplate } = require('./app/menu'); +const { + installFileHandler, + installWebHandler, +} = require('./app/protocol_filter'); +const { installPermissionsHandler } = require('./app/permissions'); function showWindow() { if (!mainWindow) { @@ -618,15 +619,9 @@ app.on('ready', async () => { locale = loadLocale({ appLocale, logger }); } - let key = userConfig.get('key'); - if (!key) { - // https://www.zetetic.net/sqlcipher/sqlcipher-api/#key - key = crypto.randomBytes(32).toString('hex'); - userConfig.set('key', key); - } - + const key = keyManagement.initialize({ userConfig }); await sql.initialize({ configDir: userDataPath, key }); - await sqlChannels.initialize({ userConfig }); + await sqlChannels.initialize(); async function cleanupOrphanedAttachments() { const allAttachments = await attachments.getAllAttachments(userDataPath);