diff -r 000000000000 -r 6474c204b198 services/sync/modules/browserid_identity.js --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/services/sync/modules/browserid_identity.js Wed Dec 31 06:09:35 2014 +0100 @@ -0,0 +1,689 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this file, + * You can obtain one at http://mozilla.org/MPL/2.0/. */ + +"use strict"; + +this.EXPORTED_SYMBOLS = ["BrowserIDManager"]; + +const {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components; + +Cu.import("resource://gre/modules/Log.jsm"); +Cu.import("resource://services-common/async.js"); +Cu.import("resource://services-common/utils.js"); +Cu.import("resource://services-common/tokenserverclient.js"); +Cu.import("resource://services-crypto/utils.js"); +Cu.import("resource://services-sync/identity.js"); +Cu.import("resource://services-sync/util.js"); +Cu.import("resource://services-common/tokenserverclient.js"); +Cu.import("resource://gre/modules/Services.jsm"); +Cu.import("resource://services-sync/constants.js"); +Cu.import("resource://gre/modules/Promise.jsm"); +Cu.import("resource://services-sync/stages/cluster.js"); +Cu.import("resource://gre/modules/FxAccounts.jsm"); + +// Lazy imports to prevent unnecessary load on startup. +XPCOMUtils.defineLazyModuleGetter(this, "Weave", + "resource://services-sync/main.js"); + +XPCOMUtils.defineLazyModuleGetter(this, "BulkKeyBundle", + "resource://services-sync/keys.js"); + +XPCOMUtils.defineLazyModuleGetter(this, "fxAccounts", + "resource://gre/modules/FxAccounts.jsm"); + +XPCOMUtils.defineLazyGetter(this, 'log', function() { + let log = Log.repository.getLogger("Sync.BrowserIDManager"); + log.level = Log.Level[Svc.Prefs.get("log.logger.identity")] || Log.Level.Error; + return log; +}); + +// FxAccountsCommon.js doesn't use a "namespace", so create one here. +let fxAccountsCommon = {}; +Cu.import("resource://gre/modules/FxAccountsCommon.js", fxAccountsCommon); + +const OBSERVER_TOPICS = [ + fxAccountsCommon.ONLOGIN_NOTIFICATION, + fxAccountsCommon.ONLOGOUT_NOTIFICATION, +]; + +const PREF_SYNC_SHOW_CUSTOMIZATION = "services.sync.ui.showCustomizationDialog"; + +function deriveKeyBundle(kB) { + let out = CryptoUtils.hkdf(kB, undefined, + "identity.mozilla.com/picl/v1/oldsync", 2*32); + let bundle = new BulkKeyBundle(); + // [encryptionKey, hmacKey] + bundle.keyPair = [out.slice(0, 32), out.slice(32, 64)]; + return bundle; +} + +/* + General authentication error for abstracting authentication + errors from multiple sources (e.g., from FxAccounts, TokenServer). + details is additional details about the error - it might be a string, or + some other error object (which should do the right thing when toString() is + called on it) +*/ +function AuthenticationError(details) { + this.details = details; +} + +AuthenticationError.prototype = { + toString: function() { + return "AuthenticationError(" + this.details + ")"; + } +} + +this.BrowserIDManager = function BrowserIDManager() { + // NOTE: _fxaService and _tokenServerClient are replaced with mocks by + // the test suite. + this._fxaService = fxAccounts; + this._tokenServerClient = new TokenServerClient(); + this._tokenServerClient.observerPrefix = "weave:service"; + // will be a promise that resolves when we are ready to authenticate + this.whenReadyToAuthenticate = null; + this._log = log; +}; + +this.BrowserIDManager.prototype = { + __proto__: IdentityManager.prototype, + + _fxaService: null, + _tokenServerClient: null, + // https://docs.services.mozilla.com/token/apis.html + _token: null, + _signedInUser: null, // the signedinuser we got from FxAccounts. + + // null if no error, otherwise a LOGIN_FAILED_* value that indicates why + // we failed to authenticate (but note it might not be an actual + // authentication problem, just a transient network error or similar) + _authFailureReason: null, + + // it takes some time to fetch a sync key bundle, so until this flag is set, + // we don't consider the lack of a keybundle as a failure state. + _shouldHaveSyncKeyBundle: false, + + get readyToAuthenticate() { + // We are finished initializing when we *should* have a sync key bundle, + // although we might not actually have one due to auth failures etc. + return this._shouldHaveSyncKeyBundle; + }, + + get needsCustomization() { + try { + return Services.prefs.getBoolPref(PREF_SYNC_SHOW_CUSTOMIZATION); + } catch (e) { + return false; + } + }, + + initialize: function() { + for (let topic of OBSERVER_TOPICS) { + Services.obs.addObserver(this, topic, false); + } + return this.initializeWithCurrentIdentity(); + }, + + /** + * Ensure the user is logged in. Returns a promise that resolves when + * the user is logged in, or is rejected if the login attempt has failed. + */ + ensureLoggedIn: function() { + if (!this._shouldHaveSyncKeyBundle) { + // We are already in the process of logging in. + return this.whenReadyToAuthenticate.promise; + } + + // If we are already happy then there is nothing more to do. + if (this._syncKeyBundle) { + return Promise.resolve(); + } + + // Similarly, if we have a previous failure that implies an explicit + // re-entering of credentials by the user is necessary we don't take any + // further action - an observer will fire when the user does that. + if (Weave.Status.login == LOGIN_FAILED_LOGIN_REJECTED) { + return Promise.reject(); + } + + // So - we've a previous auth problem and aren't currently attempting to + // log in - so fire that off. + this.initializeWithCurrentIdentity(); + return this.whenReadyToAuthenticate.promise; + }, + + finalize: function() { + // After this is called, we can expect Service.identity != this. + for (let topic of OBSERVER_TOPICS) { + Services.obs.removeObserver(this, topic); + } + this.resetCredentials(); + this._signedInUser = null; + return Promise.resolve(); + }, + + offerSyncOptions: function () { + // If the user chose to "Customize sync options" when signing + // up with Firefox Accounts, ask them to choose what to sync. + const url = "chrome://browser/content/sync/customize.xul"; + const features = "centerscreen,chrome,modal,dialog,resizable=no"; + let win = Services.wm.getMostRecentWindow("navigator:browser"); + + let data = {accepted: false}; + win.openDialog(url, "_blank", features, data); + + return data; + }, + + initializeWithCurrentIdentity: function(isInitialSync=false) { + // While this function returns a promise that resolves once we've started + // the auth process, that process is complete when + // this.whenReadyToAuthenticate.promise resolves. + this._log.trace("initializeWithCurrentIdentity"); + + // Reset the world before we do anything async. + this.whenReadyToAuthenticate = Promise.defer(); + this.whenReadyToAuthenticate.promise.then(null, (err) => { + this._log.error("Could not authenticate: " + err); + }); + + this._shouldHaveSyncKeyBundle = false; + this._authFailureReason = null; + + return this._fxaService.getSignedInUser().then(accountData => { + if (!accountData) { + this._log.info("initializeWithCurrentIdentity has no user logged in"); + this.account = null; + // and we are as ready as we can ever be for auth. + this._shouldHaveSyncKeyBundle = true; + this.whenReadyToAuthenticate.reject("no user is logged in"); + return; + } + + this.account = accountData.email; + this._updateSignedInUser(accountData); + // The user must be verified before we can do anything at all; we kick + // this and the rest of initialization off in the background (ie, we + // don't return the promise) + this._log.info("Waiting for user to be verified."); + this._fxaService.whenVerified(accountData).then(accountData => { + this._updateSignedInUser(accountData); + this._log.info("Starting fetch for key bundle."); + if (this.needsCustomization) { + let data = this.offerSyncOptions(); + if (data.accepted) { + Services.prefs.clearUserPref(PREF_SYNC_SHOW_CUSTOMIZATION); + + // Mark any non-selected engines as declined. + Weave.Service.engineManager.declineDisabled(); + } else { + // Log out if the user canceled the dialog. + return this._fxaService.signOut(); + } + } + }).then(() => { + return this._fetchTokenForUser(); + }).then(token => { + this._token = token; + this._shouldHaveSyncKeyBundle = true; // and we should actually have one... + this.whenReadyToAuthenticate.resolve(); + this._log.info("Background fetch for key bundle done"); + Weave.Status.login = LOGIN_SUCCEEDED; + if (isInitialSync) { + this._log.info("Doing initial sync actions"); + Svc.Prefs.set("firstSync", "resetClient"); + Services.obs.notifyObservers(null, "weave:service:setup-complete", null); + Weave.Utils.nextTick(Weave.Service.sync, Weave.Service); + } + }).then(null, err => { + this._shouldHaveSyncKeyBundle = true; // but we probably don't have one... + this.whenReadyToAuthenticate.reject(err); + // report what failed... + this._log.error("Background fetch for key bundle failed: " + err); + }); + // and we are done - the fetch continues on in the background... + }).then(null, err => { + this._log.error("Processing logged in account: " + err); + }); + }, + + _updateSignedInUser: function(userData) { + // This object should only ever be used for a single user. It is an + // error to update the data if the user changes (but updates are still + // necessary, as each call may add more attributes to the user). + // We start with no user, so an initial update is always ok. + if (this._signedInUser && this._signedInUser.email != userData.email) { + throw new Error("Attempting to update to a different user.") + } + this._signedInUser = userData; + }, + + logout: function() { + // This will be called when sync fails (or when the account is being + // unlinked etc). It may have failed because we got a 401 from a sync + // server, so we nuke the token. Next time sync runs and wants an + // authentication header, we will notice the lack of the token and fetch a + // new one. + this._token = null; + }, + + observe: function (subject, topic, data) { + this._log.debug("observed " + topic); + switch (topic) { + case fxAccountsCommon.ONLOGIN_NOTIFICATION: + // This should only happen if we've been initialized without a current + // user - otherwise we'd have seen the LOGOUT notification and been + // thrown away. + // The exception is when we've initialized with a user that needs to + // reauth with the server - in that case we will also get here, but + // should have the same identity. + // initializeWithCurrentIdentity will throw and log if these contraints + // aren't met, so just go ahead and do the init. + this.initializeWithCurrentIdentity(true); + break; + + case fxAccountsCommon.ONLOGOUT_NOTIFICATION: + Weave.Service.startOver(); + // startOver will cause this instance to be thrown away, so there's + // nothing else to do. + break; + } + }, + + /** + * Compute the sha256 of the message bytes. Return bytes. + */ + _sha256: function(message) { + let hasher = Cc["@mozilla.org/security/hash;1"] + .createInstance(Ci.nsICryptoHash); + hasher.init(hasher.SHA256); + return CryptoUtils.digestBytes(message, hasher); + }, + + /** + * Compute the X-Client-State header given the byte string kB. + * + * Return string: hex(first16Bytes(sha256(kBbytes))) + */ + _computeXClientState: function(kBbytes) { + return CommonUtils.bytesAsHex(this._sha256(kBbytes).slice(0, 16), false); + }, + + /** + * Provide override point for testing token expiration. + */ + _now: function() { + return this._fxaService.now() + }, + + get _localtimeOffsetMsec() { + return this._fxaService.localtimeOffsetMsec; + }, + + usernameFromAccount: function(val) { + // we don't differentiate between "username" and "account" + return val; + }, + + /** + * Obtains the HTTP Basic auth password. + * + * Returns a string if set or null if it is not set. + */ + get basicPassword() { + this._log.error("basicPassword getter should be not used in BrowserIDManager"); + return null; + }, + + /** + * Set the HTTP basic password to use. + * + * Changes will not persist unless persistSyncCredentials() is called. + */ + set basicPassword(value) { + throw "basicPassword setter should be not used in BrowserIDManager"; + }, + + /** + * Obtain the Sync Key. + * + * This returns a 26 character "friendly" Base32 encoded string on success or + * null if no Sync Key could be found. + * + * If the Sync Key hasn't been set in this session, this will look in the + * password manager for the sync key. + */ + get syncKey() { + if (this.syncKeyBundle) { + // TODO: This is probably fine because the code shouldn't be + // using the sync key directly (it should use the sync key + // bundle), but I don't like it. We should probably refactor + // code that is inspecting this to not do validation on this + // field directly and instead call a isSyncKeyValid() function + // that we can override. + return "99999999999999999999999999"; + } + else { + return null; + } + }, + + set syncKey(value) { + throw "syncKey setter should be not used in BrowserIDManager"; + }, + + get syncKeyBundle() { + return this._syncKeyBundle; + }, + + /** + * Resets/Drops all credentials we hold for the current user. + */ + resetCredentials: function() { + this.resetSyncKey(); + this._token = null; + }, + + /** + * Resets/Drops the sync key we hold for the current user. + */ + resetSyncKey: function() { + this._syncKey = null; + this._syncKeyBundle = null; + this._syncKeyUpdated = true; + this._shouldHaveSyncKeyBundle = false; + }, + + /** + * The current state of the auth credentials. + * + * This essentially validates that enough credentials are available to use + * Sync. + */ + get currentAuthState() { + if (this._authFailureReason) { + this._log.info("currentAuthState returning " + this._authFailureReason + + " due to previous failure"); + return this._authFailureReason; + } + // TODO: need to revisit this. Currently this isn't ready to go until + // both the username and syncKeyBundle are both configured and having no + // username seems to make things fail fast so that's good. + if (!this.username) { + return LOGIN_FAILED_NO_USERNAME; + } + + // No need to check this.syncKey as our getter for that attribute + // uses this.syncKeyBundle + // If bundle creation started, but failed. + if (this._shouldHaveSyncKeyBundle && !this.syncKeyBundle) { + return LOGIN_FAILED_NO_PASSPHRASE; + } + + return STATUS_OK; + }, + + /** + * Do we have a non-null, not yet expired token for the user currently + * signed in? + */ + hasValidToken: function() { + if (!this._token) { + return false; + } + if (this._token.expiration < this._now()) { + return false; + } + return true; + }, + + // Refresh the sync token for our user. + _fetchTokenForUser: function() { + let tokenServerURI = Svc.Prefs.get("tokenServerURI"); + let log = this._log; + let client = this._tokenServerClient; + let fxa = this._fxaService; + let userData = this._signedInUser; + + log.info("Fetching assertion and token from: " + tokenServerURI); + + let maybeFetchKeys = () => { + // This is called at login time and every time we need a new token - in + // the latter case we already have kA and kB, so optimise that case. + if (userData.kA && userData.kB) { + return; + } + return this._fxaService.getKeys().then( + newUserData => { + userData = newUserData; + this._updateSignedInUser(userData); // throws if the user changed. + } + ); + } + + let getToken = (tokenServerURI, assertion) => { + log.debug("Getting a token"); + let deferred = Promise.defer(); + let cb = function (err, token) { + if (err) { + return deferred.reject(err); + } + log.debug("Successfully got a sync token"); + return deferred.resolve(token); + }; + + let kBbytes = CommonUtils.hexToBytes(userData.kB); + let headers = {"X-Client-State": this._computeXClientState(kBbytes)}; + client.getTokenFromBrowserIDAssertion(tokenServerURI, assertion, cb, headers); + return deferred.promise; + } + + let getAssertion = () => { + log.debug("Getting an assertion"); + let audience = Services.io.newURI(tokenServerURI, null, null).prePath; + return fxa.getAssertion(audience); + }; + + // wait until the account email is verified and we know that + // getAssertion() will return a real assertion (not null). + return fxa.whenVerified(this._signedInUser) + .then(() => maybeFetchKeys()) + .then(() => getAssertion()) + .then(assertion => getToken(tokenServerURI, assertion)) + .then(token => { + // TODO: Make it be only 80% of the duration, so refresh the token + // before it actually expires. This is to avoid sync storage errors + // otherwise, we get a nasty notification bar briefly. Bug 966568. + token.expiration = this._now() + (token.duration * 1000) * 0.80; + if (!this._syncKeyBundle) { + // We are given kA/kB as hex. + this._syncKeyBundle = deriveKeyBundle(Utils.hexToBytes(userData.kB)); + } + return token; + }) + .then(null, err => { + // TODO: unify these errors - we need to handle errors thrown by + // both tokenserverclient and hawkclient. + // A tokenserver error thrown based on a bad response. + if (err.response && err.response.status === 401) { + err = new AuthenticationError(err); + // A hawkclient error. + } else if (err.code === 401) { + err = new AuthenticationError(err); + } + + // TODO: write tests to make sure that different auth error cases are handled here + // properly: auth error getting assertion, auth error getting token (invalid generation + // and client-state error) + if (err instanceof AuthenticationError) { + this._log.error("Authentication error in _fetchTokenForUser: " + err); + // set it to the "fatal" LOGIN_FAILED_LOGIN_REJECTED reason. + this._authFailureReason = LOGIN_FAILED_LOGIN_REJECTED; + } else { + this._log.error("Non-authentication error in _fetchTokenForUser: " + err.message); + // for now assume it is just a transient network related problem. + this._authFailureReason = LOGIN_FAILED_NETWORK_ERROR; + } + // Drop the sync key bundle, but still expect to have one. + // This will arrange for us to be in the right 'currentAuthState' + // such that UI will show the right error. + this._shouldHaveSyncKeyBundle = true; + Weave.Status.login = this._authFailureReason; + Services.obs.notifyObservers(null, "weave:service:login:error", null); + throw err; + }); + }, + + // Returns a promise that is resolved when we have a valid token for the + // current user stored in this._token. When resolved, this._token is valid. + _ensureValidToken: function() { + if (this.hasValidToken()) { + this._log.debug("_ensureValidToken already has one"); + return Promise.resolve(); + } + return this._fetchTokenForUser().then( + token => { + this._token = token; + } + ); + }, + + getResourceAuthenticator: function () { + return this._getAuthenticationHeader.bind(this); + }, + + /** + * Obtain a function to be used for adding auth to RESTRequest instances. + */ + getRESTRequestAuthenticator: function() { + return this._addAuthenticationHeader.bind(this); + }, + + /** + * @return a Hawk HTTP Authorization Header, lightly wrapped, for the .uri + * of a RESTRequest or AsyncResponse object. + */ + _getAuthenticationHeader: function(httpObject, method) { + let cb = Async.makeSpinningCallback(); + this._ensureValidToken().then(cb, cb); + try { + cb.wait(); + } catch (ex) { + this._log.error("Failed to fetch a token for authentication: " + ex); + return null; + } + if (!this._token) { + return null; + } + let credentials = {algorithm: "sha256", + id: this._token.id, + key: this._token.key, + }; + method = method || httpObject.method; + + // Get the local clock offset from the Firefox Accounts server. This should + // be close to the offset from the storage server. + let options = { + now: this._now(), + localtimeOffsetMsec: this._localtimeOffsetMsec, + credentials: credentials, + }; + + let headerValue = CryptoUtils.computeHAWK(httpObject.uri, method, options); + return {headers: {authorization: headerValue.field}}; + }, + + _addAuthenticationHeader: function(request, method) { + let header = this._getAuthenticationHeader(request, method); + if (!header) { + return null; + } + request.setHeader("authorization", header.headers.authorization); + return request; + }, + + createClusterManager: function(service) { + return new BrowserIDClusterManager(service); + } + +}; + +/* An implementation of the ClusterManager for this identity + */ + +function BrowserIDClusterManager(service) { + ClusterManager.call(this, service); +} + +BrowserIDClusterManager.prototype = { + __proto__: ClusterManager.prototype, + + _findCluster: function() { + let endPointFromIdentityToken = function() { + let endpoint = this.identity._token.endpoint; + // For Sync 1.5 storage endpoints, we use the base endpoint verbatim. + // However, it should end in "/" because we will extend it with + // well known path components. So we add a "/" if it's missing. + if (!endpoint.endsWith("/")) { + endpoint += "/"; + } + log.debug("_findCluster returning " + endpoint); + return endpoint; + }.bind(this); + + // Spinningly ensure we are ready to authenticate and have a valid token. + let promiseClusterURL = function() { + return this.identity.whenReadyToAuthenticate.promise.then( + () => { + // We need to handle node reassignment here. If we are being asked + // for a clusterURL while the service already has a clusterURL, then + // it's likely a 401 was received using the existing token - in which + // case we just discard the existing token and fetch a new one. + if (this.service.clusterURL) { + log.debug("_findCluster found existing clusterURL, so discarding the current token"); + this.identity._token = null; + } + return this.identity._ensureValidToken(); + } + ).then(endPointFromIdentityToken + ); + }.bind(this); + + let cb = Async.makeSpinningCallback(); + promiseClusterURL().then(function (clusterURL) { + cb(null, clusterURL); + }).then( + null, err => { + // service.js's verifyLogin() method will attempt to fetch a cluster + // URL when it sees a 401. If it gets null, it treats it as a "real" + // auth error and sets Status.login to LOGIN_FAILED_LOGIN_REJECTED, which + // in turn causes a notification bar to appear informing the user they + // need to re-authenticate. + // On the other hand, if fetching the cluster URL fails with an exception, + // verifyLogin() assumes it is a transient error, and thus doesn't show + // the notification bar under the assumption the issue will resolve + // itself. + // Thus: + // * On a real 401, we must return null. + // * On any other problem we must let an exception bubble up. + if (err instanceof AuthenticationError) { + // callback with no error and a null result - cb.wait() returns null. + cb(null, null); + } else { + // callback with an error - cb.wait() completes by raising an exception. + cb(err); + } + }); + return cb.wait(); + }, + + getUserBaseURL: function() { + // Legacy Sync and FxA Sync construct the userBaseURL differently. Legacy + // Sync appends path components onto an empty path, and in FxA Sync the + // token server constructs this for us in an opaque manner. Since the + // cluster manager already sets the clusterURL on Service and also has + // access to the current identity, we added this functionality here. + return this.service.clusterURL; + } +}