diff options
Diffstat (limited to 'services/fxaccounts/FxAccountsCommands.sys.mjs')
| -rw-r--r-- | services/fxaccounts/FxAccountsCommands.sys.mjs | 336 |
1 files changed, 330 insertions, 6 deletions
diff --git a/services/fxaccounts/FxAccountsCommands.sys.mjs b/services/fxaccounts/FxAccountsCommands.sys.mjs index 40fcc7f925..0851906061 100644 --- a/services/fxaccounts/FxAccountsCommands.sys.mjs +++ b/services/fxaccounts/FxAccountsCommands.sys.mjs @@ -5,10 +5,14 @@ import { COMMAND_SENDTAB, COMMAND_SENDTAB_TAIL, + COMMAND_CLOSETAB, + COMMAND_CLOSETAB_TAIL, SCOPE_OLD_SYNC, log, } from "resource://gre/modules/FxAccountsCommon.sys.mjs"; +import { clearTimeout, setTimeout } from "resource://gre/modules/Timer.sys.mjs"; + import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs"; import { Observers } from "resource://services-common/observers.sys.mjs"; @@ -36,18 +40,32 @@ export class FxAccountsCommands { constructor(fxAccountsInternal) { this._fxai = fxAccountsInternal; this.sendTab = new SendTab(this, fxAccountsInternal); + this.closeTab = new CloseRemoteTab(this, fxAccountsInternal); this._invokeRateLimitExpiry = 0; } async availableCommands() { + // Invalid keys usually means the account is not verified yet. const encryptedSendTabKeys = await this.sendTab.getEncryptedSendTabKeys(); - if (!encryptedSendTabKeys) { - // This will happen if the account is not verified yet. - return {}; + let commands = {}; + + if (encryptedSendTabKeys) { + commands[COMMAND_SENDTAB] = encryptedSendTabKeys; } - return { - [COMMAND_SENDTAB]: encryptedSendTabKeys, - }; + + // Close Tab is still a worked-on feature, so we should not broadcast it widely yet + let closeTabEnabled = Services.prefs.getBoolPref( + "identity.fxaccounts.commands.remoteTabManagement.enabled", + false + ); + if (closeTabEnabled) { + const encryptedCloseTabKeys = + await this.closeTab.getEncryptedCloseTabKeys(); + if (encryptedCloseTabKeys) { + commands[COMMAND_CLOSETAB] = encryptedCloseTabKeys; + } + } + return commands; } async invoke(command, device, payload) { @@ -166,6 +184,7 @@ export class FxAccountsCommands { } // We debounce multiple incoming tabs so we show a single notification. const tabsReceived = []; + const tabsToClose = []; for (const { index, data } of messages) { const { command, payload, sender: senderId } = data; const reason = this._getReason(notifiedIndex, index); @@ -179,6 +198,24 @@ export class FxAccountsCommands { ); } switch (command) { + case COMMAND_CLOSETAB: + try { + const { urls } = await this.closeTab.handleTabClose( + senderId, + payload, + reason + ); + log.info( + `Close Tab received with FxA commands: "${urls.length} tabs" + from ${sender ? sender.name : "Unknown device"}.` + ); + // URLs are PII, so only logged at trace. + log.trace(`Close Remote Tabs received URLs: ${urls}`); + tabsToClose.push({ urls, sender }); + } catch (e) { + log.error(`Error while handling incoming Close Tab payload.`, e); + } + break; case COMMAND_SENDTAB: try { const { title, uri } = await this.sendTab.handle( @@ -212,11 +249,18 @@ export class FxAccountsCommands { if (tabsReceived.length) { this._notifyFxATabsReceived(tabsReceived); } + if (tabsToClose.length) { + this._notifyFxATabsClosed(tabsToClose); + } } _notifyFxATabsReceived(tabsReceived) { Observers.notify("fxaccounts:commands:open-uri", tabsReceived); } + + _notifyFxATabsClosed(tabsToClose) { + Observers.notify("fxaccounts:commands:close-uri", tabsToClose); + } } /** @@ -458,6 +502,286 @@ export class SendTab { } } +/** + * Close Tabs is built on-top of device commands and handles + * actions a client wants to perform on tabs found on other devices + * This class is very similar to the Send Tab component in FxAccountsCommands + * + * Devices exchange keys wrapped in the oldsync key between themselves (getEncryptedCloseTabKeys) + * during the device registration flow. The FxA server can theoretically never + * retrieve the close tab keys since it doesn't know the oldsync key. + * + * Note: Close Tabs does things slightly different from SendTab + * The sender encrypts the close-tab command using the receiver's public key, + * and the FxA server stores it (without re-encrypting). + * A web-push notifies the receiver that a new command is available. + * The receiver decrypts the payload using its private key. + */ +export class CloseRemoteTab { + constructor(commands, fxAccountsInternal) { + this._commands = commands; + this._fxai = fxAccountsInternal; + this.pendingClosedTabs = new Map(); + // pushes happen per device, making a timer per device makes sending + // the pushes a little more sane + this.pushTimers = new Map(); + } + + /** + * Sending a push everytime the user wants to close a tab on a remote device + * could lead to excessive notifications to the users device, push throttling, etc + * so we add the tabs to a queue and have a timer that sends the push after a certain + * amount of "inactivity" + */ + /** + * @param {Device} targetDevice - Device object (typically returned by fxAccounts.getDevicesList()). + * @param {String} tab - url for the tab to close + * @param {Integer} how far to delay, in miliseconds, the push for this timer + */ + enqueueTabToClose(targetDevice, tab, pushDelay = 6000) { + if (this.pendingClosedTabs.has(targetDevice.id)) { + this.pendingClosedTabs.get(targetDevice.id).tabs.push(tab); + } else { + this.pendingClosedTabs.set(targetDevice.id, { + device: targetDevice, + tabs: [tab], + }); + } + + // extend the timer + this._refreshPushTimer(targetDevice.id, pushDelay); + } + + async _refreshPushTimer(deviceId, pushDelay) { + // If the user is still performing "actions" for this device + // reset the timer to send the push + if (this.pushTimers.has(deviceId)) { + clearTimeout(this.pushTimers.get(deviceId)); + } + + // There is a possibility that the browser closes before this actually executes + // we should catch the browser as it's closing and immediately fire these + // See https://bugzilla.mozilla.org/show_bug.cgi?id=1888299 + const timerId = setTimeout(async () => { + let { device, tabs } = this.pendingClosedTabs.get(deviceId); + // send a push notification for this specific device + await this._sendCloseTabPush(device, tabs); + + // Clear the timer + this.pushTimers.delete(deviceId); + // We also need to locally store the tabs we sent so the user doesn't + // see these anymore + this.pendingClosedTabs.delete(deviceId); + + // This is used for tests only, to get around timer woes + Observers.notify("test:fxaccounts:commands:close-uri:sent"); + }, pushDelay); + + // Store the new timer with the device + this.pushTimers.set(deviceId, timerId); + } + + /** + * @param {Device} target - Device object (typically returned by fxAccounts.getDevicesList()). + * @param {String[]} urls - array of urls that should be closed on the remote device + */ + async _sendCloseTabPush(target, urls) { + log.info(`Sending tab closures to ${target.id} device.`); + const flowID = this._fxai.telemetry.generateFlowID(); + const encoder = new TextEncoder(); + try { + const streamID = this._fxai.telemetry.generateFlowID(); + const targetData = { flowID, streamID, urls }; + const bytes = encoder.encode(JSON.stringify(targetData)); + const encrypted = await this._encrypt(bytes, target); + // FxA expects an object as the payload, but we only have a single encrypted string; wrap it. + // If you add any plaintext items to this payload, please carefully consider the privacy implications + // of revealing that data to the FxA server. + const payload = { encrypted }; + await this._commands.invoke(COMMAND_CLOSETAB, target, payload); + this._fxai.telemetry.recordEvent( + "command-sent", + COMMAND_CLOSETAB_TAIL, + this._fxai.telemetry.sanitizeDeviceId(target.id), + { flowID, streamID } + ); + } catch (error) { + // We should also show the user there was some kind've error + log.error("Error while invoking a send tab command.", error); + } + } + + // Returns true if the target device is compatible with FxA Commands Send tab. + isDeviceCompatible(device) { + let pref = Services.prefs.getBoolPref( + "identity.fxaccounts.commands.remoteTabManagement.enabled", + false + ); + return ( + pref && + device.availableCommands && + device.availableCommands[COMMAND_CLOSETAB] + ); + } + + // Handle incoming remote tab payload, called by FxAccountsCommands. + async handleTabClose(senderID, { encrypted }, reason) { + const bytes = await this._decrypt(encrypted); + const decoder = new TextDecoder("utf8"); + const data = JSON.parse(decoder.decode(bytes)); + // urls is an array of strings + const { flowID, streamID, urls } = data; + this._fxai.telemetry.recordEvent( + "command-received", + COMMAND_CLOSETAB_TAIL, + this._fxai.telemetry.sanitizeDeviceId(senderID), + { flowID, streamID, reason } + ); + + return { + urls, + }; + } + + async _encrypt(bytes, device) { + let bundle = device.availableCommands[COMMAND_CLOSETAB]; + if (!bundle) { + throw new Error(`Device ${device.id} does not have close tab keys.`); + } + const oldsyncKey = await this._fxai.keys.getKeyForScope(SCOPE_OLD_SYNC); + const json = JSON.parse(bundle); + const wrapper = new lazy.CryptoWrapper(); + wrapper.deserialize({ payload: json }); + const syncKeyBundle = lazy.BulkKeyBundle.fromJWK(oldsyncKey); + let { publicKey, authSecret } = await wrapper.decrypt(syncKeyBundle); + authSecret = urlsafeBase64Decode(authSecret); + publicKey = urlsafeBase64Decode(publicKey); + + const { ciphertext: encrypted } = await lazy.PushCrypto.encrypt( + bytes, + publicKey, + authSecret + ); + return urlsafeBase64Encode(encrypted); + } + + async _getPersistedCloseTabKeys() { + const { device } = await this._fxai.getUserAccountData(["device"]); + return device && device.closeTabKeys; + } + + async _decrypt(ciphertext) { + let { privateKey, publicKey, authSecret } = + await this._getPersistedCloseTabKeys(); + publicKey = urlsafeBase64Decode(publicKey); + authSecret = urlsafeBase64Decode(authSecret); + ciphertext = new Uint8Array(urlsafeBase64Decode(ciphertext)); + return lazy.PushCrypto.decrypt( + privateKey, + publicKey, + authSecret, + // The only Push encoding we support. + { encoding: "aes128gcm" }, + ciphertext + ); + } + + async _generateAndPersistCloseTabKeys() { + let [publicKey, privateKey] = await lazy.PushCrypto.generateKeys(); + publicKey = urlsafeBase64Encode(publicKey); + let authSecret = lazy.PushCrypto.generateAuthenticationSecret(); + authSecret = urlsafeBase64Encode(authSecret); + const closeTabKeys = { + publicKey, + privateKey, + authSecret, + }; + await this._fxai.withCurrentAccountState(async state => { + const { device } = await state.getUserAccountData(["device"]); + await state.updateUserAccountData({ + device: { + ...device, + closeTabKeys, + }, + }); + }); + return closeTabKeys; + } + + async _getPersistedEncryptedCloseTabKey() { + const { encryptedCloseTabKeys } = await this._fxai.getUserAccountData([ + "encryptedCloseTabKeys", + ]); + return encryptedCloseTabKeys; + } + + async _generateAndPersistEncryptedCloseTabKeys() { + let closeTabKeys = await this._getPersistedCloseTabKeys(); + if (!closeTabKeys) { + log.info("Could not find closeTab keys, generating them"); + closeTabKeys = await this._generateAndPersistCloseTabKeys(); + } + // Strip the private key from the bundle to encrypt. + const keyToEncrypt = { + publicKey: closeTabKeys.publicKey, + authSecret: closeTabKeys.authSecret, + }; + if (!(await this._fxai.keys.canGetKeyForScope(SCOPE_OLD_SYNC))) { + log.info("Can't fetch keys, so unable to determine closeTab keys"); + return null; + } + let oldsyncKey; + try { + oldsyncKey = await this._fxai.keys.getKeyForScope(SCOPE_OLD_SYNC); + } catch (ex) { + log.warn( + "Failed to fetch keys, so unable to determine closeTab keys", + ex + ); + return null; + } + const wrapper = new lazy.CryptoWrapper(); + wrapper.cleartext = keyToEncrypt; + const keyBundle = lazy.BulkKeyBundle.fromJWK(oldsyncKey); + await wrapper.encrypt(keyBundle); + const encryptedCloseTabKeys = JSON.stringify({ + // This is expected in hex, due to pre-JWK sync key ids :-( + kid: this._fxai.keys.kidAsHex(oldsyncKey), + IV: wrapper.IV, + hmac: wrapper.hmac, + ciphertext: wrapper.ciphertext, + }); + await this._fxai.withCurrentAccountState(async state => { + await state.updateUserAccountData({ + encryptedCloseTabKeys, + }); + }); + return encryptedCloseTabKeys; + } + + async getEncryptedCloseTabKeys() { + let encryptedCloseTabKeys = await this._getPersistedEncryptedCloseTabKey(); + const closeTabKeys = await this._getPersistedCloseTabKeys(); + if (!encryptedCloseTabKeys || !closeTabKeys) { + log.info("Generating and persisting encrypted closeTab keys"); + // `_generateAndPersistEncryptedCloseTabKeys` requires the sync key + // which cannot be accessed if the login manager is locked + // (i.e when the primary password is locked) or if the sync keys + // aren't accessible (account isn't verified) + // so this function could fail to retrieve the keys + // however, device registration will trigger when the account + // is verified, so it's OK + // Note that it's okay to persist those keys, because they are + // already persisted in plaintext and the encrypted bundle + // does not include the sync-key (the sync key is used to encrypt + // it though) + encryptedCloseTabKeys = + await this._generateAndPersistEncryptedCloseTabKeys(); + } + return encryptedCloseTabKeys; + } +} + function urlsafeBase64Encode(buffer) { return ChromeUtils.base64URLEncode(new Uint8Array(buffer), { pad: false }); } |