Add m-esr52 at 52.6.0

1 files changed, 1756 insertions, 0 deletions

diff --git a/services/sync/modules/service.js b/services/sync/modules/service.js
new file mode 100644
index 000000000..5fc0fa7a7
--- /dev/null
+++ b/services/sync/modules/service.js
@@ -0,0 +1,1756 @@
+/* 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/. */
+
+this.EXPORTED_SYMBOLS = ["Service"];
+
+var Cc = Components.classes;
+var Ci = Components.interfaces;
+var Cr = Components.results;
+var Cu = Components.utils;
+
+// How long before refreshing the cluster
+const CLUSTER_BACKOFF = 5 * 60 * 1000; // 5 minutes
+
+// How long a key to generate from an old passphrase.
+const PBKDF2_KEY_BYTES = 16;
+
+const CRYPTO_COLLECTION = "crypto";
+const KEYS_WBO = "keys";
+
+Cu.import("resource://gre/modules/Preferences.jsm");
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+Cu.import("resource://gre/modules/Log.jsm");
+Cu.import("resource://services-sync/constants.js");
+Cu.import("resource://services-sync/engines.js");
+Cu.import("resource://services-sync/engines/clients.js");
+Cu.import("resource://services-sync/identity.js");
+Cu.import("resource://services-sync/policies.js");
+Cu.import("resource://services-sync/record.js");
+Cu.import("resource://services-sync/resource.js");
+Cu.import("resource://services-sync/rest.js");
+Cu.import("resource://services-sync/stages/enginesync.js");
+Cu.import("resource://services-sync/stages/declined.js");
+Cu.import("resource://services-sync/status.js");
+Cu.import("resource://services-sync/telemetry.js");
+Cu.import("resource://services-sync/userapi.js");
+Cu.import("resource://services-sync/util.js");
+
+const ENGINE_MODULES = {
+  Addons: "addons.js",
+  Bookmarks: "bookmarks.js",
+  Form: "forms.js",
+  History: "history.js",
+  Password: "passwords.js",
+  Prefs: "prefs.js",
+  Tab: "tabs.js",
+  ExtensionStorage: "extension-storage.js",
+};
+
+const STORAGE_INFO_TYPES = [INFO_COLLECTIONS,
+                            INFO_COLLECTION_USAGE,
+                            INFO_COLLECTION_COUNTS,
+                            INFO_QUOTA];
+
+function Sync11Service() {
+  this._notify = Utils.notify("weave:service:");
+}
+Sync11Service.prototype = {
+
+  _lock: Utils.lock,
+  _locked: false,
+  _loggedIn: false,
+
+  infoURL: null,
+  storageURL: null,
+  metaURL: null,
+  cryptoKeyURL: null,
+  // The cluster URL comes via the ClusterManager object, which in the FxA
+  // world is ebbedded in the token returned from the token server.
+  _clusterURL: null,
+
+  get serverURL() {
+    return Svc.Prefs.get("serverURL");
+  },
+  set serverURL(value) {
+    if (!value.endsWith("/")) {
+      value += "/";
+    }
+
+    // Only do work if it's actually changing
+    if (value == this.serverURL)
+      return;
+
+    Svc.Prefs.set("serverURL", value);
+
+    // A new server most likely uses a different cluster, so clear that.
+    this._clusterURL = null;
+  },
+
+  get clusterURL() {
+    return this._clusterURL || "";
+  },
+  set clusterURL(value) {
+    if (value != null && typeof value != "string") {
+      throw new Error("cluster must be a string, got " + (typeof value));
+    }
+    this._clusterURL = value;
+    this._updateCachedURLs();
+  },
+
+  get miscAPI() {
+    // Append to the serverURL if it's a relative fragment
+    let misc = Svc.Prefs.get("miscURL");
+    if (misc.indexOf(":") == -1)
+      misc = this.serverURL + misc;
+    return misc + MISC_API_VERSION + "/";
+  },
+
+  /**
+   * The URI of the User API service.
+   *
+   * This is the base URI of the service as applicable to all users up to
+   * and including the server version path component, complete with trailing
+   * forward slash.
+   */
+  get userAPIURI() {
+    // Append to the serverURL if it's a relative fragment.
+    let url = Svc.Prefs.get("userURL");
+    if (!url.includes(":")) {
+      url = this.serverURL + url;
+    }
+
+    return url + USER_API_VERSION + "/";
+  },
+
+  get pwResetURL() {
+    return this.serverURL + "weave-password-reset";
+  },
+
+  get syncID() {
+    // Generate a random syncID id we don't have one
+    let syncID = Svc.Prefs.get("client.syncID", "");
+    return syncID == "" ? this.syncID = Utils.makeGUID() : syncID;
+  },
+  set syncID(value) {
+    Svc.Prefs.set("client.syncID", value);
+  },
+
+  get isLoggedIn() { return this._loggedIn; },
+
+  get locked() { return this._locked; },
+  lock: function lock() {
+    if (this._locked)
+      return false;
+    this._locked = true;
+    return true;
+  },
+  unlock: function unlock() {
+    this._locked = false;
+  },
+
+  // A specialized variant of Utils.catch.
+  // This provides a more informative error message when we're already syncing:
+  // see Bug 616568.
+  _catch: function _catch(func) {
+    function lockExceptions(ex) {
+      if (Utils.isLockException(ex)) {
+        // This only happens if we're syncing already.
+        this._log.info("Cannot start sync: already syncing?");
+      }
+    }
+
+    return Utils.catch.call(this, func, lockExceptions);
+  },
+
+  get userBaseURL() {
+    if (!this._clusterManager) {
+      return null;
+    }
+    return this._clusterManager.getUserBaseURL();
+  },
+
+  _updateCachedURLs: function _updateCachedURLs() {
+    // Nothing to cache yet if we don't have the building blocks
+    if (!this.clusterURL || !this.identity.username) {
+      // Also reset all other URLs used by Sync to ensure we aren't accidentally
+      // using one cached earlier - if there's no cluster URL any cached ones
+      // are invalid.
+      this.infoURL = undefined;
+      this.storageURL = undefined;
+      this.metaURL = undefined;
+      this.cryptoKeysURL = undefined;
+      return;
+    }
+
+    this._log.debug("Caching URLs under storage user base: " + this.userBaseURL);
+
+    // Generate and cache various URLs under the storage API for this user
+    this.infoURL = this.userBaseURL + "info/collections";
+    this.storageURL = this.userBaseURL + "storage/";
+    this.metaURL = this.storageURL + "meta/global";
+    this.cryptoKeysURL = this.storageURL + CRYPTO_COLLECTION + "/" + KEYS_WBO;
+  },
+
+  _checkCrypto: function _checkCrypto() {
+    let ok = false;
+
+    try {
+      let iv = Svc.Crypto.generateRandomIV();
+      if (iv.length == 24)
+        ok = true;
+
+    } catch (e) {
+      this._log.debug("Crypto check failed: " + e);
+    }
+
+    return ok;
+  },
+
+  /**
+   * Here is a disgusting yet reasonable way of handling HMAC errors deep in
+   * the guts of Sync. The astute reader will note that this is a hacky way of
+   * implementing something like continuable conditions.
+   *
+   * A handler function is glued to each engine. If the engine discovers an
+   * HMAC failure, we fetch keys from the server and update our keys, just as
+   * we would on startup.
+   *
+   * If our key collection changed, we signal to the engine (via our return
+   * value) that it should retry decryption.
+   *
+   * If our key collection did not change, it means that we already had the
+   * correct keys... and thus a different client has the wrong ones. Reupload
+   * the bundle that we fetched, which will bump the modified time on the
+   * server and (we hope) prompt a broken client to fix itself.
+   *
+   * We keep track of the time at which we last applied this reasoning, because
+   * thrashing doesn't solve anything. We keep a reasonable interval between
+   * these remedial actions.
+   */
+  lastHMACEvent: 0,
+
+  /*
+   * Returns whether to try again.
+   */
+  handleHMACEvent: function handleHMACEvent() {
+    let now = Date.now();
+
+    // Leave a sizable delay between HMAC recovery attempts. This gives us
+    // time for another client to fix themselves if we touch the record.
+    if ((now - this.lastHMACEvent) < HMAC_EVENT_INTERVAL)
+      return false;
+
+    this._log.info("Bad HMAC event detected. Attempting recovery " +
+                   "or signaling to other clients.");
+
+    // Set the last handled time so that we don't act again.
+    this.lastHMACEvent = now;
+
+    // Fetch keys.
+    let cryptoKeys = new CryptoWrapper(CRYPTO_COLLECTION, KEYS_WBO);
+    try {
+      let cryptoResp = cryptoKeys.fetch(this.resource(this.cryptoKeysURL)).response;
+
+      // Save out the ciphertext for when we reupload. If there's a bug in
+      // CollectionKeyManager, this will prevent us from uploading junk.
+      let cipherText = cryptoKeys.ciphertext;
+
+      if (!cryptoResp.success) {
+        this._log.warn("Failed to download keys.");
+        return false;
+      }
+
+      let keysChanged = this.handleFetchedKeys(this.identity.syncKeyBundle,
+                                               cryptoKeys, true);
+      if (keysChanged) {
+        // Did they change? If so, carry on.
+        this._log.info("Suggesting retry.");
+        return true;              // Try again.
+      }
+
+      // If not, reupload them and continue the current sync.
+      cryptoKeys.ciphertext = cipherText;
+      cryptoKeys.cleartext  = null;
+
+      let uploadResp = cryptoKeys.upload(this.resource(this.cryptoKeysURL));
+      if (uploadResp.success)
+        this._log.info("Successfully re-uploaded keys. Continuing sync.");
+      else
+        this._log.warn("Got error response re-uploading keys. " +
+                       "Continuing sync; let's try again later.");
+
+      return false;            // Don't try again: same keys.
+
+    } catch (ex) {
+      this._log.warn("Got exception \"" + ex + "\" fetching and handling " +
+                     "crypto keys. Will try again later.");
+      return false;
+    }
+  },
+
+  handleFetchedKeys: function handleFetchedKeys(syncKey, cryptoKeys, skipReset) {
+    // Don't want to wipe if we're just starting up!
+    let wasBlank = this.collectionKeys.isClear;
+    let keysChanged = this.collectionKeys.updateContents(syncKey, cryptoKeys);
+
+    if (keysChanged && !wasBlank) {
+      this._log.debug("Keys changed: " + JSON.stringify(keysChanged));
+
+      if (!skipReset) {
+        this._log.info("Resetting client to reflect key change.");
+
+        if (keysChanged.length) {
+          // Collection keys only. Reset individual engines.
+          this.resetClient(keysChanged);
+        }
+        else {
+          // Default key changed: wipe it all.
+          this.resetClient();
+        }
+
+        this._log.info("Downloaded new keys, client reset. Proceeding.");
+      }
+      return true;
+    }
+    return false;
+  },
+
+  /**
+   * Prepare to initialize the rest of Weave after waiting a little bit
+   */
+  onStartup: function onStartup() {
+    this._migratePrefs();
+
+    // Status is instantiated before us and is the first to grab an instance of
+    // the IdentityManager. We use that instance because IdentityManager really
+    // needs to be a singleton. Ideally, the longer-lived object would spawn
+    // this service instance.
+    if (!Status || !Status._authManager) {
+      throw new Error("Status or Status._authManager not initialized.");
+    }
+
+    this.status = Status;
+    this.identity = Status._authManager;
+    this.collectionKeys = new CollectionKeyManager();
+
+    this.errorHandler = new ErrorHandler(this);
+
+    this._log = Log.repository.getLogger("Sync.Service");
+    this._log.level =
+      Log.Level[Svc.Prefs.get("log.logger.service.main")];
+
+    this._log.info("Loading Weave " + WEAVE_VERSION);
+
+    this._clusterManager = this.identity.createClusterManager(this);
+    this.recordManager = new RecordManager(this);
+
+    this.enabled = true;
+
+    this._registerEngines();
+
+    let ua = Cc["@mozilla.org/network/protocol;1?name=http"].
+      getService(Ci.nsIHttpProtocolHandler).userAgent;
+    this._log.info(ua);
+
+    if (!this._checkCrypto()) {
+      this.enabled = false;
+      this._log.info("Could not load the Weave crypto component. Disabling " +
+                      "Weave, since it will not work correctly.");
+    }
+
+    Svc.Obs.add("weave:service:setup-complete", this);
+    Svc.Obs.add("sync:collection_changed", this); // Pulled from FxAccountsCommon
+    Svc.Prefs.observe("engine.", this);
+
+    this.scheduler = new SyncScheduler(this);
+
+    if (!this.enabled) {
+      this._log.info("Firefox Sync disabled.");
+    }
+
+    this._updateCachedURLs();
+
+    let status = this._checkSetup();
+    if (status != STATUS_DISABLED && status != CLIENT_NOT_CONFIGURED) {
+      Svc.Obs.notify("weave:engine:start-tracking");
+    }
+
+    // Send an event now that Weave service is ready.  We don't do this
+    // synchronously so that observers can import this module before
+    // registering an observer.
+    Utils.nextTick(function onNextTick() {
+      this.status.ready = true;
+
+      // UI code uses the flag on the XPCOM service so it doesn't have
+      // to load a bunch of modules.
+      let xps = Cc["@mozilla.org/weave/service;1"]
+                  .getService(Ci.nsISupports)
+                  .wrappedJSObject;
+      xps.ready = true;
+
+      Svc.Obs.notify("weave:service:ready");
+    }.bind(this));
+  },
+
+  _checkSetup: function _checkSetup() {
+    if (!this.enabled) {
+      return this.status.service = STATUS_DISABLED;
+    }
+    return this.status.checkSetup();
+  },
+
+  _migratePrefs: function _migratePrefs() {
+    // Migrate old debugLog prefs.
+    let logLevel = Svc.Prefs.get("log.appender.debugLog");
+    if (logLevel) {
+      Svc.Prefs.set("log.appender.file.level", logLevel);
+      Svc.Prefs.reset("log.appender.debugLog");
+    }
+    if (Svc.Prefs.get("log.appender.debugLog.enabled")) {
+      Svc.Prefs.set("log.appender.file.logOnSuccess", true);
+      Svc.Prefs.reset("log.appender.debugLog.enabled");
+    }
+
+    // Migrate old extensions.weave.* prefs if we haven't already tried.
+    if (Svc.Prefs.get("migrated", false))
+      return;
+
+    // Grab the list of old pref names
+    let oldPrefBranch = "extensions.weave.";
+    let oldPrefNames = Cc["@mozilla.org/preferences-service;1"].
+                       getService(Ci.nsIPrefService).
+                       getBranch(oldPrefBranch).
+                       getChildList("", {});
+
+    // Map each old pref to the current pref branch
+    let oldPref = new Preferences(oldPrefBranch);
+    for (let pref of oldPrefNames)
+      Svc.Prefs.set(pref, oldPref.get(pref));
+
+    // Remove all the old prefs and remember that we've migrated
+    oldPref.resetBranch("");
+    Svc.Prefs.set("migrated", true);
+  },
+
+  /**
+   * Register the built-in engines for certain applications
+   */
+  _registerEngines: function _registerEngines() {
+    this.engineManager = new EngineManager(this);
+
+    let engines = [];
+    // Applications can provide this preference (comma-separated list)
+    // to specify which engines should be registered on startup.
+    let pref = Svc.Prefs.get("registerEngines");
+    if (pref) {
+      engines = pref.split(",");
+    }
+
+    let declined = [];
+    pref = Svc.Prefs.get("declinedEngines");
+    if (pref) {
+      declined = pref.split(",");
+    }
+
+    this.clientsEngine = new ClientEngine(this);
+
+    for (let name of engines) {
+      if (!name in ENGINE_MODULES) {
+        this._log.info("Do not know about engine: " + name);
+        continue;
+      }
+
+      let ns = {};
+      try {
+        Cu.import("resource://services-sync/engines/" + ENGINE_MODULES[name], ns);
+
+        let engineName = name + "Engine";
+        if (!(engineName in ns)) {
+          this._log.warn("Could not find exported engine instance: " + engineName);
+          continue;
+        }
+
+        this.engineManager.register(ns[engineName]);
+      } catch (ex) {
+        this._log.warn("Could not register engine " + name, ex);
+      }
+    }
+
+    this.engineManager.setDeclined(declined);
+  },
+
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsIObserver,
+                                         Ci.nsISupportsWeakReference]),
+
+  // nsIObserver
+
+  observe: function observe(subject, topic, data) {
+    switch (topic) {
+      // Ideally this observer should be in the SyncScheduler, but it would require
+      // some work to know about the sync specific engines. We should move this there once it does.
+      case "sync:collection_changed":
+        if (data.includes("clients")) {
+          this.sync([]); // [] = clients collection only
+        }
+        break;
+      case "weave:service:setup-complete":
+        let status = this._checkSetup();
+        if (status != STATUS_DISABLED && status != CLIENT_NOT_CONFIGURED)
+            Svc.Obs.notify("weave:engine:start-tracking");
+        break;
+      case "nsPref:changed":
+        if (this._ignorePrefObserver)
+          return;
+        let engine = data.slice((PREFS_BRANCH + "engine.").length);
+        this._handleEngineStatusChanged(engine);
+        break;
+    }
+  },
+
+  _handleEngineStatusChanged: function handleEngineDisabled(engine) {
+    this._log.trace("Status for " + engine + " engine changed.");
+    if (Svc.Prefs.get("engineStatusChanged." + engine, false)) {
+      // The enabled status being changed back to what it was before.
+      Svc.Prefs.reset("engineStatusChanged." + engine);
+    } else {
+      // Remember that the engine status changed locally until the next sync.
+      Svc.Prefs.set("engineStatusChanged." + engine, true);
+    }
+  },
+
+  /**
+   * Obtain a Resource instance with authentication credentials.
+   */
+  resource: function resource(url) {
+    let res = new Resource(url);
+    res.authenticator = this.identity.getResourceAuthenticator();
+
+    return res;
+  },
+
+  /**
+   * Obtain a SyncStorageRequest instance with authentication credentials.
+   */
+  getStorageRequest: function getStorageRequest(url) {
+    let request = new SyncStorageRequest(url);
+    request.authenticator = this.identity.getRESTRequestAuthenticator();
+
+    return request;
+  },
+
+  /**
+   * Perform the info fetch as part of a login or key fetch, or
+   * inside engine sync.
+   */
+  _fetchInfo: function (url) {
+    let infoURL = url || this.infoURL;
+
+    this._log.trace("In _fetchInfo: " + infoURL);
+    let info;
+    try {
+      info = this.resource(infoURL).get();
+    } catch (ex) {
+      this.errorHandler.checkServerError(ex);
+      throw ex;
+    }
+
+    // Always check for errors; this is also where we look for X-Weave-Alert.
+    this.errorHandler.checkServerError(info);
+    if (!info.success) {
+      this._log.error("Aborting sync: failed to get collections.")
+      throw info;
+    }
+    return info;
+  },
+
+  verifyAndFetchSymmetricKeys: function verifyAndFetchSymmetricKeys(infoResponse) {
+
+    this._log.debug("Fetching and verifying -- or generating -- symmetric keys.");
+
+    // Don't allow empty/missing passphrase.
+    // Furthermore, we assume that our sync key is already upgraded,
+    // and fail if that assumption is invalidated.
+
+    if (!this.identity.syncKey) {
+      this.status.login = LOGIN_FAILED_NO_PASSPHRASE;
+      this.status.sync = CREDENTIALS_CHANGED;
+      return false;
+    }
+
+    let syncKeyBundle = this.identity.syncKeyBundle;
+    if (!syncKeyBundle) {
+      this._log.error("Sync Key Bundle not set. Invalid Sync Key?");
+
+      this.status.login = LOGIN_FAILED_INVALID_PASSPHRASE;
+      this.status.sync = CREDENTIALS_CHANGED;
+      return false;
+    }
+
+    try {
+      if (!infoResponse)
+        infoResponse = this._fetchInfo();    // Will throw an exception on failure.
+
+      // This only applies when the server is already at version 4.
+      if (infoResponse.status != 200) {
+        this._log.warn("info/collections returned non-200 response. Failing key fetch.");
+        this.status.login = LOGIN_FAILED_SERVER_ERROR;
+        this.errorHandler.checkServerError(infoResponse);
+        return false;
+      }
+
+      let infoCollections = infoResponse.obj;
+
+      this._log.info("Testing info/collections: " + JSON.stringify(infoCollections));
+
+      if (this.collectionKeys.updateNeeded(infoCollections)) {
+        this._log.info("collection keys reports that a key update is needed.");
+
+        // Don't always set to CREDENTIALS_CHANGED -- we will probably take care of this.
+
+        // Fetch storage/crypto/keys.
+        let cryptoKeys;
+
+        if (infoCollections && (CRYPTO_COLLECTION in infoCollections)) {
+          try {
+            cryptoKeys = new CryptoWrapper(CRYPTO_COLLECTION, KEYS_WBO);
+            let cryptoResp = cryptoKeys.fetch(this.resource(this.cryptoKeysURL)).response;
+
+            if (cryptoResp.success) {
+              let keysChanged = this.handleFetchedKeys(syncKeyBundle, cryptoKeys);
+              return true;
+            }
+            else if (cryptoResp.status == 404) {
+              // On failure, ask to generate new keys and upload them.
+              // Fall through to the behavior below.
+              this._log.warn("Got 404 for crypto/keys, but 'crypto' in info/collections. Regenerating.");
+              cryptoKeys = null;
+            }
+            else {
+              // Some other problem.
+              this.status.login = LOGIN_FAILED_SERVER_ERROR;
+              this.errorHandler.checkServerError(cryptoResp);
+              this._log.warn("Got status " + cryptoResp.status + " fetching crypto keys.");
+              return false;
+            }
+          }
+          catch (ex) {
+            this._log.warn("Got exception \"" + ex + "\" fetching cryptoKeys.");
+            // TODO: Um, what exceptions might we get here? Should we re-throw any?
+
+            // One kind of exception: HMAC failure.
+            if (Utils.isHMACMismatch(ex)) {
+              this.status.login = LOGIN_FAILED_INVALID_PASSPHRASE;
+              this.status.sync = CREDENTIALS_CHANGED;
+            }
+            else {
+              // In the absence of further disambiguation or more precise
+              // failure constants, just report failure.
+              this.status.login = LOGIN_FAILED;
+            }
+            return false;
+          }
+        }
+        else {
+          this._log.info("... 'crypto' is not a reported collection. Generating new keys.");
+        }
+
+        if (!cryptoKeys) {
+          this._log.info("No keys! Generating new ones.");
+
+          // Better make some and upload them, and wipe the server to ensure
+          // consistency. This is all achieved via _freshStart.
+          // If _freshStart fails to clear the server or upload keys, it will
+          // throw.
+          this._freshStart();
+          return true;
+        }
+
+        // Last-ditch case.
+        return false;
+      }
+      else {
+        // No update needed: we're good!
+        return true;
+      }
+
+    } catch (ex) {
+      // This means no keys are present, or there's a network error.
+      this._log.debug("Failed to fetch and verify keys", ex);
+      this.errorHandler.checkServerError(ex);
+      return false;
+    }
+  },
+
+  verifyLogin: function verifyLogin(allow40XRecovery = true) {
+    if (!this.identity.username) {
+      this._log.warn("No username in verifyLogin.");
+      this.status.login = LOGIN_FAILED_NO_USERNAME;
+      return false;
+    }
+
+    // Attaching auth credentials to a request requires access to
+    // passwords, which means that Resource.get can throw MP-related
+    // exceptions!
+    // So we ask the identity to verify the login state after unlocking the
+    // master password (ie, this call is expected to prompt for MP unlock
+    // if necessary) while we still have control.
+    let cb = Async.makeSpinningCallback();
+    this.identity.unlockAndVerifyAuthState().then(
+      result => cb(null, result),
+      cb
+    );
+    let unlockedState = cb.wait();
+    this._log.debug("Fetching unlocked auth state returned " + unlockedState);
+    if (unlockedState != STATUS_OK) {
+      this.status.login = unlockedState;
+      return false;
+    }
+
+    try {
+      // Make sure we have a cluster to verify against.
+      // This is a little weird, if we don't get a node we pretend
+      // to succeed, since that probably means we just don't have storage.
+      if (this.clusterURL == "" && !this._clusterManager.setCluster()) {
+        this.status.sync = NO_SYNC_NODE_FOUND;
+        return true;
+      }
+
+      // Fetch collection info on every startup.
+      let test = this.resource(this.infoURL).get();
+
+      switch (test.status) {
+        case 200:
+          // The user is authenticated.
+
+          // We have no way of verifying the passphrase right now,
+          // so wait until remoteSetup to do so.
+          // Just make the most trivial checks.
+          if (!this.identity.syncKey) {
+            this._log.warn("No passphrase in verifyLogin.");
+            this.status.login = LOGIN_FAILED_NO_PASSPHRASE;
+            return false;
+          }
+
+          // Go ahead and do remote setup, so that we can determine
+          // conclusively that our passphrase is correct.
+          if (this._remoteSetup(test)) {
+            // Username/password verified.
+            this.status.login = LOGIN_SUCCEEDED;
+            return true;
+          }
+
+          this._log.warn("Remote setup failed.");
+          // Remote setup must have failed.
+          return false;
+
+        case 401:
+          this._log.warn("401: login failed.");
+          // Fall through to the 404 case.
+
+        case 404:
+          // Check that we're verifying with the correct cluster
+          if (allow40XRecovery && this._clusterManager.setCluster()) {
+            return this.verifyLogin(false);
+          }
+
+          // We must have the right cluster, but the server doesn't expect us.
+          // The implications of this depend on the identity being used - for
+          // the legacy identity, it's an authoritatively "incorrect password",
+          // (ie, LOGIN_FAILED_LOGIN_REJECTED) but for FxA it probably means
+          // "transient error fetching auth token".
+          this.status.login = this.identity.loginStatusFromVerification404();
+          return false;
+
+        default:
+          // Server didn't respond with something that we expected
+          this.status.login = LOGIN_FAILED_SERVER_ERROR;
+          this.errorHandler.checkServerError(test);
+          return false;
+      }
+    } catch (ex) {
+      // Must have failed on some network issue
+      this._log.debug("verifyLogin failed", ex);
+      this.status.login = LOGIN_FAILED_NETWORK_ERROR;
+      this.errorHandler.checkServerError(ex);
+      return false;
+    }
+  },
+
+  generateNewSymmetricKeys: function generateNewSymmetricKeys() {
+    this._log.info("Generating new keys WBO...");
+    let wbo = this.collectionKeys.generateNewKeysWBO();
+    this._log.info("Encrypting new key bundle.");
+    wbo.encrypt(this.identity.syncKeyBundle);
+
+    this._log.info("Uploading...");
+    let uploadRes = wbo.upload(this.resource(this.cryptoKeysURL));
+    if (uploadRes.status != 200) {
+      this._log.warn("Got status " + uploadRes.status + " uploading new keys. What to do? Throw!");
+      this.errorHandler.checkServerError(uploadRes);
+      throw new Error("Unable to upload symmetric keys.");
+    }
+    this._log.info("Got status " + uploadRes.status + " uploading keys.");
+    let serverModified = uploadRes.obj;   // Modified timestamp according to server.
+    this._log.debug("Server reports crypto modified: " + serverModified);
+
+    // Now verify that info/collections shows them!
+    this._log.debug("Verifying server collection records.");
+    let info = this._fetchInfo();
+    this._log.debug("info/collections is: " + info);
+
+    if (info.status != 200) {
+      this._log.warn("Non-200 info/collections response. Aborting.");
+      throw new Error("Unable to upload symmetric keys.");
+    }
+
+    info = info.obj;
+    if (!(CRYPTO_COLLECTION in info)) {
+      this._log.error("Consistency failure: info/collections excludes " +
+                      "crypto after successful upload.");
+      throw new Error("Symmetric key upload failed.");
+    }
+
+    // Can't check against local modified: clock drift.
+    if (info[CRYPTO_COLLECTION] < serverModified) {
+      this._log.error("Consistency failure: info/collections crypto entry " +
+                      "is stale after successful upload.");
+      throw new Error("Symmetric key upload failed.");
+    }
+
+    // Doesn't matter if the timestamp is ahead.
+
+    // Download and install them.
+    let cryptoKeys = new CryptoWrapper(CRYPTO_COLLECTION, KEYS_WBO);
+    let cryptoResp = cryptoKeys.fetch(this.resource(this.cryptoKeysURL)).response;
+    if (cryptoResp.status != 200) {
+      this._log.warn("Failed to download keys.");
+      throw new Error("Symmetric key download failed.");
+    }
+    let keysChanged = this.handleFetchedKeys(this.identity.syncKeyBundle,
+                                             cryptoKeys, true);
+    if (keysChanged) {
+      this._log.info("Downloaded keys differed, as expected.");
+    }
+  },
+
+  changePassword: function changePassword(newPassword) {
+    let client = new UserAPI10Client(this.userAPIURI);
+    let cb = Async.makeSpinningCallback();
+    client.changePassword(this.identity.username,
+                          this.identity.basicPassword, newPassword, cb);
+
+    try {
+      cb.wait();
+    } catch (ex) {
+      this._log.debug("Password change failed", ex);
+      return false;
+    }
+
+    // Save the new password for requests and login manager.
+    this.identity.basicPassword = newPassword;
+    this.persistLogin();
+    return true;
+  },
+
+  changePassphrase: function changePassphrase(newphrase) {
+    return this._catch(function doChangePasphrase() {
+      /* Wipe. */
+      this.wipeServer();
+
+      this.logout();
+
+      /* Set this so UI is updated on next run. */
+      this.identity.syncKey = newphrase;
+      this.persistLogin();
+
+      /* We need to re-encrypt everything, so reset. */
+      this.resetClient();
+      this.collectionKeys.clear();
+
+      /* Login and sync. This also generates new keys. */
+      this.sync();
+
+      Svc.Obs.notify("weave:service:change-passphrase", true);
+
+      return true;
+    })();
+  },
+
+  startOver: function startOver() {
+    this._log.trace("Invoking Service.startOver.");
+    Svc.Obs.notify("weave:engine:stop-tracking");
+    this.status.resetSync();
+
+    // Deletion doesn't make sense if we aren't set up yet!
+    if (this.clusterURL != "") {
+      // Clear client-specific data from the server, including disabled engines.
+      for (let engine of [this.clientsEngine].concat(this.engineManager.getAll())) {
+        try {
+          engine.removeClientData();
+        } catch(ex) {
+          this._log.warn(`Deleting client data for ${engine.name} failed`, ex);
+        }
+      }
+      this._log.debug("Finished deleting client data.");
+    } else {
+      this._log.debug("Skipping client data removal: no cluster URL.");
+    }
+
+    // We want let UI consumers of the following notification know as soon as
+    // possible, so let's fake for the CLIENT_NOT_CONFIGURED status for now
+    // by emptying the passphrase (we still need the password).
+    this._log.info("Service.startOver dropping sync key and logging out.");
+    this.identity.resetSyncKey();
+    this.status.login = LOGIN_FAILED_NO_PASSPHRASE;
+    this.logout();
+    Svc.Obs.notify("weave:service:start-over");
+
+    // Reset all engines and clear keys.
+    this.resetClient();
+    this.collectionKeys.clear();
+    this.status.resetBackoff();
+
+    // Reset Weave prefs.
+    this._ignorePrefObserver = true;
+    Svc.Prefs.resetBranch("");
+    this._ignorePrefObserver = false;
+    this.clusterURL = null;
+
+    Svc.Prefs.set("lastversion", WEAVE_VERSION);
+
+    this.identity.deleteSyncCredentials();
+
+    // If necessary, reset the identity manager, then re-initialize it so the
+    // FxA manager is used.  This is configurable via a pref - mainly for tests.
+    let keepIdentity = false;
+    try {
+      keepIdentity = Services.prefs.getBoolPref("services.sync-testing.startOverKeepIdentity");
+    } catch (_) { /* no such pref */ }
+    if (keepIdentity) {
+      Svc.Obs.notify("weave:service:start-over:finish");
+      return;
+    }
+
+    try {
+      this.identity.finalize();
+      // an observer so the FxA migration code can take some action before
+      // the new identity is created.
+      Svc.Obs.notify("weave:service:start-over:init-identity");
+      this.identity.username = "";
+      this.status.__authManager = null;
+      this.identity = Status._authManager;
+      this._clusterManager = this.identity.createClusterManager(this);
+      Svc.Obs.notify("weave:service:start-over:finish");
+    } catch (err) {
+      this._log.error("startOver failed to re-initialize the identity manager: " + err);
+      // Still send the observer notification so the current state is
+      // reflected in the UI.
+      Svc.Obs.notify("weave:service:start-over:finish");
+    }
+  },
+
+  persistLogin: function persistLogin() {
+    try {
+      this.identity.persistCredentials(true);
+    } catch (ex) {
+      this._log.info("Unable to persist credentials: " + ex);
+    }
+  },
+
+  login: function login(username, password, passphrase) {
+    function onNotify() {
+      this._loggedIn = false;
+      if (Services.io.offline) {
+        this.status.login = LOGIN_FAILED_NETWORK_ERROR;
+        throw "Application is offline, login should not be called";
+      }
+
+      let initialStatus = this._checkSetup();
+      if (username) {
+        this.identity.username = username;
+      }
+      if (password) {
+        this.identity.basicPassword = password;
+      }
+      if (passphrase) {
+        this.identity.syncKey = passphrase;
+      }
+
+      if (this._checkSetup() == CLIENT_NOT_CONFIGURED) {
+        throw "Aborting login, client not configured.";
+      }
+
+      // Ask the identity manager to explicitly login now.
+      this._log.info("Logging in the user.");
+      let cb = Async.makeSpinningCallback();
+      this.identity.ensureLoggedIn().then(
+        () => cb(null),
+        err => cb(err || "ensureLoggedIn failed")
+      );
+
+      // Just let any errors bubble up - they've more context than we do!
+      cb.wait();
+
+      // Calling login() with parameters when the client was
+      // previously not configured means setup was completed.
+      if (initialStatus == CLIENT_NOT_CONFIGURED
+          && (username || password || passphrase)) {
+        Svc.Obs.notify("weave:service:setup-complete");
+      }
+      this._updateCachedURLs();
+
+      this._log.info("User logged in successfully - verifying login.");
+      if (!this.verifyLogin()) {
+        // verifyLogin sets the failure states here.
+        throw "Login failed: " + this.status.login;
+      }
+
+      this._loggedIn = true;
+
+      return true;
+    }
+
+    let notifier = this._notify("login", "", onNotify.bind(this));
+    return this._catch(this._lock("service.js: login", notifier))();
+  },
+
+  logout: function logout() {
+    // If we failed during login, we aren't going to have this._loggedIn set,
+    // but we still want to ask the identity to logout, so it doesn't try and
+    // reuse any old credentials next time we sync.
+    this._log.info("Logging out");
+    this.identity.logout();
+    this._loggedIn = false;
+
+    Svc.Obs.notify("weave:service:logout:finish");
+  },
+
+  checkAccount: function checkAccount(account) {
+    let client = new UserAPI10Client(this.userAPIURI);
+    let cb = Async.makeSpinningCallback();
+
+    let username = this.identity.usernameFromAccount(account);
+    client.usernameExists(username, cb);
+
+    try {
+      let exists = cb.wait();
+      return exists ? "notAvailable" : "available";
+    } catch (ex) {
+      // TODO fix API convention.
+      return this.errorHandler.errorStr(ex);
+    }
+  },
+
+  createAccount: function createAccount(email, password,
+                                        captchaChallenge, captchaResponse) {
+    let client = new UserAPI10Client(this.userAPIURI);
+
+    // Hint to server to allow scripted user creation or otherwise
+    // ignore captcha.
+    if (Svc.Prefs.isSet("admin-secret")) {
+      client.adminSecret = Svc.Prefs.get("admin-secret", "");
+    }
+
+    let cb = Async.makeSpinningCallback();
+
+    client.createAccount(email, password, captchaChallenge, captchaResponse,
+                         cb);
+
+    try {
+      cb.wait();
+      return null;
+    } catch (ex) {
+      return this.errorHandler.errorStr(ex.body);
+    }
+  },
+
+  // Note: returns false if we failed for a reason other than the server not yet
+  // supporting the api.
+  _fetchServerConfiguration() {
+    // This is similar to _fetchInfo, but with different error handling.
+
+    let infoURL = this.userBaseURL + "info/configuration";
+    this._log.debug("Fetching server configuration", infoURL);
+    let configResponse;
+    try {
+      configResponse = this.resource(infoURL).get();
+    } catch (ex) {
+      // This is probably a network or similar error.
+      this._log.warn("Failed to fetch info/configuration", ex);
+      this.errorHandler.checkServerError(ex);
+      return false;
+    }
+
+    if (configResponse.status == 404) {
+      // This server doesn't support the URL yet - that's OK.
+      this._log.debug("info/configuration returned 404 - using default upload semantics");
+    } else if (configResponse.status != 200) {
+      this._log.warn(`info/configuration returned ${configResponse.status} - using default configuration`);
+      this.errorHandler.checkServerError(configResponse);
+      return false;
+    } else {
+      this.serverConfiguration = configResponse.obj;
+    }
+    this._log.trace("info/configuration for this server", this.serverConfiguration);
+    return true;
+  },
+
+  // Stuff we need to do after login, before we can really do
+  // anything (e.g. key setup).
+  _remoteSetup: function _remoteSetup(infoResponse) {
+    let reset = false;
+
+    if (!this._fetchServerConfiguration()) {
+      return false;
+    }
+
+    this._log.debug("Fetching global metadata record");
+    let meta = this.recordManager.get(this.metaURL);
+
+    // Checking modified time of the meta record.
+    if (infoResponse &&
+        (infoResponse.obj.meta != this.metaModified) &&
+        (!meta || !meta.isNew)) {
+
+      // Delete the cached meta record...
+      this._log.debug("Clearing cached meta record. metaModified is " +
+          JSON.stringify(this.metaModified) + ", setting to " +
+          JSON.stringify(infoResponse.obj.meta));
+
+      this.recordManager.del(this.metaURL);
+
+      // ... fetch the current record from the server, and COPY THE FLAGS.
+      let newMeta = this.recordManager.get(this.metaURL);
+
+      // If we got a 401, we do not want to create a new meta/global - we
+      // should be able to get the existing meta after we get a new node.
+      if (this.recordManager.response.status == 401) {
+        this._log.debug("Fetching meta/global record on the server returned 401.");
+        this.errorHandler.checkServerError(this.recordManager.response);
+        return false;
+      }
+
+      if (this.recordManager.response.status == 404) {
+        this._log.debug("No meta/global record on the server. Creating one.");
+        newMeta = new WBORecord("meta", "global");
+        newMeta.payload.syncID = this.syncID;
+        newMeta.payload.storageVersion = STORAGE_VERSION;
+        newMeta.payload.declined = this.engineManager.getDeclined();
+
+        newMeta.isNew = true;
+
+        this.recordManager.set(this.metaURL, newMeta);
+        let uploadRes = newMeta.upload(this.resource(this.metaURL));
+        if (!uploadRes.success) {
+          this._log.warn("Unable to upload new meta/global. Failing remote setup.");
+          this.errorHandler.checkServerError(uploadRes);
+          return false;
+        }
+      } else if (!newMeta) {
+        this._log.warn("Unable to get meta/global. Failing remote setup.");
+        this.errorHandler.checkServerError(this.recordManager.response);
+        return false;
+      } else {
+        // If newMeta, then it stands to reason that meta != null.
+        newMeta.isNew   = meta.isNew;
+        newMeta.changed = meta.changed;
+      }
+
+      // Switch in the new meta object and record the new time.
+      meta              = newMeta;
+      this.metaModified = infoResponse.obj.meta;
+    }
+
+    let remoteVersion = (meta && meta.payload.storageVersion)?
+      meta.payload.storageVersion : "";
+
+    this._log.debug(["Weave Version:", WEAVE_VERSION, "Local Storage:",
+      STORAGE_VERSION, "Remote Storage:", remoteVersion].join(" "));
+
+    // Check for cases that require a fresh start. When comparing remoteVersion,
+    // we need to convert it to a number as older clients used it as a string.
+    if (!meta || !meta.payload.storageVersion || !meta.payload.syncID ||
+        STORAGE_VERSION > parseFloat(remoteVersion)) {
+
+      this._log.info("One of: no meta, no meta storageVersion, or no meta syncID. Fresh start needed.");
+
+      // abort the server wipe if the GET status was anything other than 404 or 200
+      let status = this.recordManager.response.status;
+      if (status != 200 && status != 404) {
+        this.status.sync = METARECORD_DOWNLOAD_FAIL;
+        this.errorHandler.checkServerError(this.recordManager.response);
+        this._log.warn("Unknown error while downloading metadata record. " +
+                       "Aborting sync.");
+        return false;
+      }
+
+      if (!meta)
+        this._log.info("No metadata record, server wipe needed");
+      if (meta && !meta.payload.syncID)
+        this._log.warn("No sync id, server wipe needed");
+
+      reset = true;
+
+      this._log.info("Wiping server data");
+      this._freshStart();
+
+      if (status == 404)
+        this._log.info("Metadata record not found, server was wiped to ensure " +
+                       "consistency.");
+      else // 200
+        this._log.info("Wiped server; incompatible metadata: " + remoteVersion);
+
+      return true;
+    }
+    else if (remoteVersion > STORAGE_VERSION) {
+      this.status.sync = VERSION_OUT_OF_DATE;
+      this._log.warn("Upgrade required to access newer storage version.");
+      return false;
+    }
+    else if (meta.payload.syncID != this.syncID) {
+
+      this._log.info("Sync IDs differ. Local is " + this.syncID + ", remote is " + meta.payload.syncID);
+      this.resetClient();
+      this.collectionKeys.clear();
+      this.syncID = meta.payload.syncID;
+      this._log.debug("Clear cached values and take syncId: " + this.syncID);
+
+      if (!this.upgradeSyncKey(meta.payload.syncID)) {
+        this._log.warn("Failed to upgrade sync key. Failing remote setup.");
+        return false;
+      }
+
+      if (!this.verifyAndFetchSymmetricKeys(infoResponse)) {
+        this._log.warn("Failed to fetch symmetric keys. Failing remote setup.");
+        return false;
+      }
+
+      // bug 545725 - re-verify creds and fail sanely
+      if (!this.verifyLogin()) {
+        this.status.sync = CREDENTIALS_CHANGED;
+        this._log.info("Credentials have changed, aborting sync and forcing re-login.");
+        return false;
+      }
+
+      return true;
+    }
+    else {
+      if (!this.upgradeSyncKey(meta.payload.syncID)) {
+        this._log.warn("Failed to upgrade sync key. Failing remote setup.");
+        return false;
+      }
+
+      if (!this.verifyAndFetchSymmetricKeys(infoResponse)) {
+        this._log.warn("Failed to fetch symmetric keys. Failing remote setup.");
+        return false;
+      }
+
+      return true;
+    }
+  },
+
+  /**
+   * Return whether we should attempt login at the start of a sync.
+   *
+   * Note that this function has strong ties to _checkSync: callers
+   * of this function should typically use _checkSync to verify that
+   * any necessary login took place.
+   */
+  _shouldLogin: function _shouldLogin() {
+    return this.enabled &&
+           !Services.io.offline &&
+           !this.isLoggedIn;
+  },
+
+  /**
+   * Determine if a sync should run.
+   *
+   * @param ignore [optional]
+   *        array of reasons to ignore when checking
+   *
+   * @return Reason for not syncing; not-truthy if sync should run
+   */
+  _checkSync: function _checkSync(ignore) {
+    let reason = "";
+    if (!this.enabled)
+      reason = kSyncWeaveDisabled;
+    else if (Services.io.offline)
+      reason = kSyncNetworkOffline;
+    else if (this.status.minimumNextSync > Date.now())
+      reason = kSyncBackoffNotMet;
+    else if ((this.status.login == MASTER_PASSWORD_LOCKED) &&
+             Utils.mpLocked())
+      reason = kSyncMasterPasswordLocked;
+    else if (Svc.Prefs.get("firstSync") == "notReady")
+      reason = kFirstSyncChoiceNotMade;
+
+    if (ignore && ignore.indexOf(reason) != -1)
+      return "";
+
+    return reason;
+  },
+
+  sync: function sync(engineNamesToSync) {
+    let dateStr = Utils.formatTimestamp(new Date());
+    this._log.debug("User-Agent: " + Utils.userAgent);
+    this._log.info("Starting sync at " + dateStr);
+    this._catch(function () {
+      // Make sure we're logged in.
+      if (this._shouldLogin()) {
+        this._log.debug("In sync: should login.");
+        if (!this.login()) {
+          this._log.debug("Not syncing: login returned false.");
+          return;
+        }
+      }
+      else {
+        this._log.trace("In sync: no need to login.");
+      }
+      return this._lockedSync(engineNamesToSync);
+    })();
+  },
+
+  /**
+   * Sync up engines with the server.
+   */
+  _lockedSync: function _lockedSync(engineNamesToSync) {
+    return this._lock("service.js: sync",
+                      this._notify("sync", "", function onNotify() {
+
+      let histogram = Services.telemetry.getHistogramById("WEAVE_START_COUNT");
+      histogram.add(1);
+
+      let synchronizer = new EngineSynchronizer(this);
+      let cb = Async.makeSpinningCallback();
+      synchronizer.onComplete = cb;
+
+      synchronizer.sync(engineNamesToSync);
+      // wait() throws if the first argument is truthy, which is exactly what
+      // we want.
+      let result = cb.wait();
+
+      histogram = Services.telemetry.getHistogramById("WEAVE_COMPLETE_SUCCESS_COUNT");
+      histogram.add(1);
+
+      // We successfully synchronized.
+      // Check if the identity wants to pre-fetch a migration sentinel from
+      // the server.
+      // If we have no clusterURL, we are probably doing a node reassignment
+      // so don't attempt to get it in that case.
+      if (this.clusterURL) {
+        this.identity.prefetchMigrationSentinel(this);
+      }
+
+      // Now let's update our declined engines (but only if we have a metaURL;
+      // if Sync failed due to no node we will not have one)
+      if (this.metaURL) {
+        let meta = this.recordManager.get(this.metaURL);
+        if (!meta) {
+          this._log.warn("No meta/global; can't update declined state.");
+          return;
+        }
+
+        let declinedEngines = new DeclinedEngines(this);
+        let didChange = declinedEngines.updateDeclined(meta, this.engineManager);
+        if (!didChange) {
+          this._log.info("No change to declined engines. Not reuploading meta/global.");
+          return;
+        }
+
+        this.uploadMetaGlobal(meta);
+      }
+    }))();
+  },
+
+  /**
+   * Upload meta/global, throwing the response on failure.
+   */
+  uploadMetaGlobal: function (meta) {
+    this._log.debug("Uploading meta/global: " + JSON.stringify(meta));
+
+    // It would be good to set the X-If-Unmodified-Since header to `timestamp`
+    // for this PUT to ensure at least some level of transactionality.
+    // Unfortunately, the servers don't support it after a wipe right now
+    // (bug 693893), so we're going to defer this until bug 692700.
+    let res = this.resource(this.metaURL);
+    let response = res.put(meta);
+    if (!response.success) {
+      throw response;
+    }
+    this.recordManager.set(this.metaURL, meta);
+  },
+
+  /**
+   * Get a migration sentinel for the Firefox Accounts migration.
+   * Returns a JSON blob - it is up to callers of this to make sense of the
+   * data.
+   *
+   * Returns a promise that resolves with the sentinel, or null.
+   */
+  getFxAMigrationSentinel: function() {
+    if (this._shouldLogin()) {
+      this._log.debug("In getFxAMigrationSentinel: should login.");
+      if (!this.login()) {
+        this._log.debug("Can't get migration sentinel: login returned false.");
+        return Promise.resolve(null);
+      }
+    }
+    if (!this.identity.syncKeyBundle) {
+      this._log.error("Can't get migration sentinel: no syncKeyBundle.");
+      return Promise.resolve(null);
+    }
+    try {
+      let collectionURL = this.storageURL + "meta/fxa_credentials";
+      let cryptoWrapper = this.recordManager.get(collectionURL);
+      if (!cryptoWrapper || !cryptoWrapper.payload) {
+        // nothing to decrypt - .decrypt is noisy in that case, so just bail
+        // now.
+        return Promise.resolve(null);
+      }
+      // If the payload has a sentinel it means we must have put back the
+      // decrypted version last time we were called.
+      if (cryptoWrapper.payload.sentinel) {
+        return Promise.resolve(cryptoWrapper.payload.sentinel);
+      }
+      // If decryption fails it almost certainly means the key is wrong - but
+      // it's not clear if we need to take special action for that case?
+      let payload = cryptoWrapper.decrypt(this.identity.syncKeyBundle);
+      // After decrypting the ciphertext is lost, so we just stash the
+      // decrypted payload back into the wrapper.
+      cryptoWrapper.payload = payload;
+      return Promise.resolve(payload.sentinel);
+    } catch (ex) {
+      this._log.error("Failed to fetch the migration sentinel: ${}", ex);
+      return Promise.resolve(null);
+    }
+  },
+
+  /**
+   * Set a migration sentinel for the Firefox Accounts migration.
+   * Accepts a JSON blob - it is up to callers of this to make sense of the
+   * data.
+   *
+   * Returns a promise that resolves with a boolean which indicates if the
+   * sentinel was successfully written.
+   */
+  setFxAMigrationSentinel: function(sentinel) {
+    if (this._shouldLogin()) {
+      this._log.debug("In setFxAMigrationSentinel: should login.");
+      if (!this.login()) {
+        this._log.debug("Can't set migration sentinel: login returned false.");
+        return Promise.resolve(false);
+      }
+    }
+    if (!this.identity.syncKeyBundle) {
+      this._log.error("Can't set migration sentinel: no syncKeyBundle.");
+      return Promise.resolve(false);
+    }
+    try {
+      let collectionURL = this.storageURL + "meta/fxa_credentials";
+      let cryptoWrapper = new CryptoWrapper("meta", "fxa_credentials");
+      cryptoWrapper.cleartext.sentinel = sentinel;
+
+      cryptoWrapper.encrypt(this.identity.syncKeyBundle);
+
+      let res = this.resource(collectionURL);
+      let response = res.put(cryptoWrapper.toJSON());
+
+      if (!response.success) {
+        throw response;
+      }
+      this.recordManager.set(collectionURL, cryptoWrapper);
+    } catch (ex) {
+      this._log.error("Failed to set the migration sentinel: ${}", ex);
+      return Promise.resolve(false);
+    }
+    return Promise.resolve(true);
+  },
+
+  /**
+   * If we have a passphrase, rather than a 25-alphadigit sync key,
+   * use the provided sync ID to bootstrap it using PBKDF2.
+   *
+   * Store the new 'passphrase' back into the identity manager.
+   *
+   * We can check this as often as we want, because once it's done the
+   * check will no longer succeed. It only matters that it happens after
+   * we decide to bump the server storage version.
+   */
+  upgradeSyncKey: function upgradeSyncKey(syncID) {
+    let p = this.identity.syncKey;
+
+    if (!p) {
+      return false;
+    }
+
+    // Check whether it's already a key that we generated.
+    if (Utils.isPassphrase(p)) {
+      this._log.info("Sync key is up-to-date: no need to upgrade.");
+      return true;
+    }
+
+    // Otherwise, let's upgrade it.
+    // N.B., we persist the sync key without testing it first...
+
+    let s = btoa(syncID);        // It's what WeaveCrypto expects. *sigh*
+    let k = Utils.derivePresentableKeyFromPassphrase(p, s, PBKDF2_KEY_BYTES);   // Base 32.
+
+    if (!k) {
+      this._log.error("No key resulted from derivePresentableKeyFromPassphrase. Failing upgrade.");
+      return false;
+    }
+
+    this._log.info("Upgrading sync key...");
+    this.identity.syncKey = k;
+    this._log.info("Saving upgraded sync key...");
+    this.persistLogin();
+    this._log.info("Done saving.");
+    return true;
+  },
+
+  _freshStart: function _freshStart() {
+    this._log.info("Fresh start. Resetting client and considering key upgrade.");
+    this.resetClient();
+    this.collectionKeys.clear();
+    this.upgradeSyncKey(this.syncID);
+
+    // Wipe the server.
+    let wipeTimestamp = this.wipeServer();
+
+    // Upload a new meta/global record.
+    let meta = new WBORecord("meta", "global");
+    meta.payload.syncID = this.syncID;
+    meta.payload.storageVersion = STORAGE_VERSION;
+    meta.payload.declined = this.engineManager.getDeclined();
+    meta.isNew = true;
+
+    // uploadMetaGlobal throws on failure -- including race conditions.
+    // If we got into a race condition, we'll abort the sync this way, too.
+    // That's fine. We'll just wait till the next sync. The client that we're
+    // racing is probably busy uploading stuff right now anyway.
+    this.uploadMetaGlobal(meta);
+
+    // Wipe everything we know about except meta because we just uploaded it
+    let engines = [this.clientsEngine].concat(this.engineManager.getAll());
+    let collections = engines.map(engine => engine.name);
+    // TODO: there's a bug here. We should be calling resetClient, no?
+
+    // Generate, upload, and download new keys. Do this last so we don't wipe
+    // them...
+    this.generateNewSymmetricKeys();
+  },
+
+  /**
+   * Wipe user data from the server.
+   *
+   * @param collections [optional]
+   *        Array of collections to wipe. If not given, all collections are
+   *        wiped by issuing a DELETE request for `storageURL`.
+   *
+   * @return the server's timestamp of the (last) DELETE.
+   */
+  wipeServer: function wipeServer(collections) {
+    let response;
+    let histogram = Services.telemetry.getHistogramById("WEAVE_WIPE_SERVER_SUCCEEDED");
+    if (!collections) {
+      // Strip the trailing slash.
+      let res = this.resource(this.storageURL.slice(0, -1));
+      res.setHeader("X-Confirm-Delete", "1");
+      try {
+        response = res.delete();
+      } catch (ex) {
+        this._log.debug("Failed to wipe server", ex);
+        histogram.add(false);
+        throw ex;
+      }
+      if (response.status != 200 && response.status != 404) {
+        this._log.debug("Aborting wipeServer. Server responded with " +
+                        response.status + " response for " + this.storageURL);
+        histogram.add(false);
+        throw response;
+      }
+      histogram.add(true);
+      return response.headers["x-weave-timestamp"];
+    }
+
+    let timestamp;
+    for (let name of collections) {
+      let url = this.storageURL + name;
+      try {
+        response = this.resource(url).delete();
+      } catch (ex) {
+        this._log.debug("Failed to wipe '" + name + "' collection", ex);
+        histogram.add(false);
+        throw ex;
+      }
+
+      if (response.status != 200 && response.status != 404) {
+        this._log.debug("Aborting wipeServer. Server responded with " +
+                        response.status + " response for " + url);
+        histogram.add(false);
+        throw response;
+      }
+
+      if ("x-weave-timestamp" in response.headers) {
+        timestamp = response.headers["x-weave-timestamp"];
+      }
+    }
+    histogram.add(true);
+    return timestamp;
+  },
+
+  /**
+   * Wipe all local user data.
+   *
+   * @param engines [optional]
+   *        Array of engine names to wipe. If not given, all engines are used.
+   */
+  wipeClient: function wipeClient(engines) {
+    // If we don't have any engines, reset the service and wipe all engines
+    if (!engines) {
+      // Clear out any service data
+      this.resetService();
+
+      engines = [this.clientsEngine].concat(this.engineManager.getAll());
+    }
+    // Convert the array of names into engines
+    else {
+      engines = this.engineManager.get(engines);
+    }
+
+    // Fully wipe each engine if it's able to decrypt data
+    for (let engine of engines) {
+      if (engine.canDecrypt()) {
+        engine.wipeClient();
+      }
+    }
+
+    // Save the password/passphrase just in-case they aren't restored by sync
+    this.persistLogin();
+  },
+
+  /**
+   * Wipe all remote user data by wiping the server then telling each remote
+   * client to wipe itself.
+   *
+   * @param engines [optional]
+   *        Array of engine names to wipe. If not given, all engines are used.
+   */
+  wipeRemote: function wipeRemote(engines) {
+    try {
+      // Make sure stuff gets uploaded.
+      this.resetClient(engines);
+
+      // Clear out any server data.
+      this.wipeServer(engines);
+
+      // Only wipe the engines provided.
+      if (engines) {
+        engines.forEach(function(e) {
+            this.clientsEngine.sendCommand("wipeEngine", [e]);
+          }, this);
+      }
+      // Tell the remote machines to wipe themselves.
+      else {
+        this.clientsEngine.sendCommand("wipeAll", []);
+      }
+
+      // Make sure the changed clients get updated.
+      this.clientsEngine.sync();
+    } catch (ex) {
+      this.errorHandler.checkServerError(ex);
+      throw ex;
+    }
+  },
+
+  /**
+   * Reset local service information like logs, sync times, caches.
+   */
+  resetService: function resetService() {
+    this._catch(function reset() {
+      this._log.info("Service reset.");
+
+      // Pretend we've never synced to the server and drop cached data
+      this.syncID = "";
+      this.recordManager.clearCache();
+    })();
+  },
+
+  /**
+   * Reset the client by getting rid of any local server data and client data.
+   *
+   * @param engines [optional]
+   *        Array of engine names to reset. If not given, all engines are used.
+   */
+  resetClient: function resetClient(engines) {
+    this._catch(function doResetClient() {
+      // If we don't have any engines, reset everything including the service
+      if (!engines) {
+        // Clear out any service data
+        this.resetService();
+
+        engines = [this.clientsEngine].concat(this.engineManager.getAll());
+      }
+      // Convert the array of names into engines
+      else {
+        engines = this.engineManager.get(engines);
+      }
+
+      // Have each engine drop any temporary meta data
+      for (let engine of engines) {
+        engine.resetClient();
+      }
+    })();
+  },
+
+  /**
+   * Fetch storage info from the server.
+   *
+   * @param type
+   *        String specifying what info to fetch from the server. Must be one
+   *        of the INFO_* values. See Sync Storage Server API spec for details.
+   * @param callback
+   *        Callback function with signature (error, data) where `data' is
+   *        the return value from the server already parsed as JSON.
+   *
+   * @return RESTRequest instance representing the request, allowing callers
+   *         to cancel the request.
+   */
+  getStorageInfo: function getStorageInfo(type, callback) {
+    if (STORAGE_INFO_TYPES.indexOf(type) == -1) {
+      throw "Invalid value for 'type': " + type;
+    }
+
+    let info_type = "info/" + type;
+    this._log.trace("Retrieving '" + info_type + "'...");
+    let url = this.userBaseURL + info_type;
+    return this.getStorageRequest(url).get(function onComplete(error) {
+      // Note: 'this' is the request.
+      if (error) {
+        this._log.debug("Failed to retrieve '" + info_type + "'", error);
+        return callback(error);
+      }
+      if (this.response.status != 200) {
+        this._log.debug("Failed to retrieve '" + info_type +
+                        "': server responded with HTTP" +
+                        this.response.status);
+        return callback(this.response);
+      }
+
+      let result;
+      try {
+        result = JSON.parse(this.response.body);
+      } catch (ex) {
+        this._log.debug("Server returned invalid JSON for '" + info_type +
+                        "': " + this.response.body);
+        return callback(ex);
+      }
+      this._log.trace("Successfully retrieved '" + info_type + "'.");
+      return callback(null, result);
+    });
+  },
+};
+
+this.Service = new Sync11Service();
+Service.onStartup();