gecko-dev/services/sync/modules/record.js
Gregory Szorc 6aed806b4c Bug 787273 - Part 2: Refactor Resource and Record to not rely on singletons; r=rnewman
Resource currently relies on the Identity singleton to perform
authentication. This is bad magic behavior. Resource instances should
authenticate according to the service instance they are associated with.

This patch removes Identity magic from Resource. Everything using
Resource now explicitly assigns an authenticator which comes from
the service instance/singleton. This required API changes to Collection
and Record.

The preferred method to obtain a Resource instance is to call
getResource() on a service instance.

The end result of this patch looks a little weird, especially in test
code. You have things like Service.resource(Service.cryptoKeysURL).
This ugliness will go away when a unified storage service client is
used.
2012-09-14 16:02:32 -07:00

636 lines
18 KiB
JavaScript

/* 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/. */
const EXPORTED_SYMBOLS = [
"WBORecord",
"RecordManager",
"CryptoWrapper",
"CollectionKeys",
"Collection",
];
const Cc = Components.classes;
const Ci = Components.interfaces;
const Cr = Components.results;
const Cu = Components.utils;
const CRYPTO_COLLECTION = "crypto";
const KEYS_WBO = "keys";
Cu.import("resource://services-common/log4moz.js");
Cu.import("resource://services-sync/constants.js");
Cu.import("resource://services-sync/keys.js");
Cu.import("resource://services-sync/resource.js");
Cu.import("resource://services-sync/util.js");
function WBORecord(collection, id) {
this.data = {};
this.payload = {};
this.collection = collection; // Optional.
this.id = id; // Optional.
}
WBORecord.prototype = {
_logName: "Sync.Record.WBO",
get sortindex() {
if (this.data.sortindex)
return this.data.sortindex;
return 0;
},
// Get thyself from your URI, then deserialize.
// Set thine 'response' field.
fetch: function fetch(resource) {
if (!resource instanceof Resource) {
throw new Error("First argument must be a Resource instance.");
}
let r = resource.get();
if (r.success) {
this.deserialize(r); // Warning! Muffles exceptions!
}
this.response = r;
return this;
},
upload: function upload(resource) {
if (!resource instanceof Resource) {
throw new Error("First argument must be a Resource instance.");
}
return resource.put(this);
},
// Take a base URI string, with trailing slash, and return the URI of this
// WBO based on collection and ID.
uri: function(base) {
if (this.collection && this.id) {
let url = Utils.makeURI(base + this.collection + "/" + this.id);
url.QueryInterface(Ci.nsIURL);
return url;
}
return null;
},
deserialize: function deserialize(json) {
this.data = json.constructor.toString() == String ? JSON.parse(json) : json;
try {
// The payload is likely to be JSON, but if not, keep it as a string
this.payload = JSON.parse(this.payload);
} catch(ex) {}
},
toJSON: function toJSON() {
// Copy fields from data to be stringified, making sure payload is a string
let obj = {};
for (let [key, val] in Iterator(this.data))
obj[key] = key == "payload" ? JSON.stringify(val) : val;
if (this.ttl)
obj.ttl = this.ttl;
return obj;
},
toString: function toString() {
return "{ " +
"id: " + this.id + " " +
"index: " + this.sortindex + " " +
"modified: " + this.modified + " " +
"ttl: " + this.ttl + " " +
"payload: " + JSON.stringify(this.payload) +
" }";
}
};
Utils.deferGetSet(WBORecord, "data", ["id", "modified", "sortindex", "payload"]);
/**
* An interface and caching layer for records.
*/
function RecordManager(service) {
this.service = service;
this._log = Log4Moz.repository.getLogger(this._logName);
this._records = {};
}
RecordManager.prototype = {
_recordType: WBORecord,
_logName: "Sync.RecordManager",
import: function RecordMgr_import(url) {
this._log.trace("Importing record: " + (url.spec ? url.spec : url));
try {
// Clear out the last response with empty object if GET fails
this.response = {};
this.response = this.service.resource(url).get();
// Don't parse and save the record on failure
if (!this.response.success)
return null;
let record = new this._recordType(url);
record.deserialize(this.response);
return this.set(url, record);
} catch(ex) {
this._log.debug("Failed to import record: " + Utils.exceptionStr(ex));
return null;
}
},
get: function RecordMgr_get(url) {
// Use a url string as the key to the hash
let spec = url.spec ? url.spec : url;
if (spec in this._records)
return this._records[spec];
return this.import(url);
},
set: function RecordMgr_set(url, record) {
let spec = url.spec ? url.spec : url;
return this._records[spec] = record;
},
contains: function RecordMgr_contains(url) {
if ((url.spec || url) in this._records)
return true;
return false;
},
clearCache: function recordMgr_clearCache() {
this._records = {};
},
del: function RecordMgr_del(url) {
delete this._records[url];
}
};
function CryptoWrapper(collection, id) {
this.cleartext = {};
WBORecord.call(this, collection, id);
this.ciphertext = null;
this.id = id;
}
CryptoWrapper.prototype = {
__proto__: WBORecord.prototype,
_logName: "Sync.Record.CryptoWrapper",
ciphertextHMAC: function ciphertextHMAC(keyBundle) {
let hasher = keyBundle.sha256HMACHasher;
if (!hasher) {
throw "Cannot compute HMAC without an HMAC key.";
}
return Utils.bytesAsHex(Utils.digestUTF8(this.ciphertext, hasher));
},
/*
* Don't directly use the sync key. Instead, grab a key for this
* collection, which is decrypted with the sync key.
*
* Cache those keys; invalidate the cache if the time on the keys collection
* changes, or other auth events occur.
*
* Optional key bundle overrides the collection key lookup.
*/
encrypt: function encrypt(keyBundle) {
keyBundle = keyBundle || CollectionKeys.keyForCollection(this.collection);
if (!keyBundle) {
throw new Error("Key bundle is null for " + this.uri.spec);
}
this.IV = Svc.Crypto.generateRandomIV();
this.ciphertext = Svc.Crypto.encrypt(JSON.stringify(this.cleartext),
keyBundle.encryptionKeyB64, this.IV);
this.hmac = this.ciphertextHMAC(keyBundle);
this.cleartext = null;
},
// Optional key bundle.
decrypt: function decrypt(keyBundle) {
if (!this.ciphertext) {
throw "No ciphertext: nothing to decrypt?";
}
keyBundle = keyBundle || CollectionKeys.keyForCollection(this.collection);
if (!keyBundle) {
throw new Error("Key bundle is null for " + this.collection + "/" + this.id);
}
// Authenticate the encrypted blob with the expected HMAC
let computedHMAC = this.ciphertextHMAC(keyBundle);
if (computedHMAC != this.hmac) {
Utils.throwHMACMismatch(this.hmac, computedHMAC);
}
// Handle invalid data here. Elsewhere we assume that cleartext is an object.
let cleartext = Svc.Crypto.decrypt(this.ciphertext,
keyBundle.encryptionKeyB64, this.IV);
let json_result = JSON.parse(cleartext);
if (json_result && (json_result instanceof Object)) {
this.cleartext = json_result;
this.ciphertext = null;
} else {
throw "Decryption failed: result is <" + json_result + ">, not an object.";
}
// Verify that the encrypted id matches the requested record's id.
if (this.cleartext.id != this.id)
throw "Record id mismatch: " + this.cleartext.id + " != " + this.id;
return this.cleartext;
},
toString: function toString() {
let payload = this.deleted ? "DELETED" : JSON.stringify(this.cleartext);
return "{ " +
"id: " + this.id + " " +
"index: " + this.sortindex + " " +
"modified: " + this.modified + " " +
"ttl: " + this.ttl + " " +
"payload: " + payload + " " +
"collection: " + (this.collection || "undefined") +
" }";
},
// The custom setter below masks the parent's getter, so explicitly call it :(
get id() WBORecord.prototype.__lookupGetter__("id").call(this),
// Keep both plaintext and encrypted versions of the id to verify integrity
set id(val) {
WBORecord.prototype.__lookupSetter__("id").call(this, val);
return this.cleartext.id = val;
},
};
Utils.deferGetSet(CryptoWrapper, "payload", ["ciphertext", "IV", "hmac"]);
Utils.deferGetSet(CryptoWrapper, "cleartext", "deleted");
XPCOMUtils.defineLazyGetter(this, "CollectionKeys", function () {
return new CollectionKeyManager();
});
/**
* Keeps track of mappings between collection names ('tabs') and KeyBundles.
*
* You can update this thing simply by giving it /info/collections. It'll
* use the last modified time to bring itself up to date.
*/
function CollectionKeyManager() {
this.lastModified = 0;
this._collections = {};
this._default = null;
this._log = Log4Moz.repository.getLogger("Sync.CollectionKeys");
}
// TODO: persist this locally as an Identity. Bug 610913.
// Note that the last modified time needs to be preserved.
CollectionKeyManager.prototype = {
// Return information about old vs new keys:
// * same: true if two collections are equal
// * changed: an array of collection names that changed.
_compareKeyBundleCollections: function _compareKeyBundleCollections(m1, m2) {
let changed = [];
function process(m1, m2) {
for (let k1 in m1) {
let v1 = m1[k1];
let v2 = m2[k1];
if (!(v1 && v2 && v1.equals(v2)))
changed.push(k1);
}
}
// Diffs both ways.
process(m1, m2);
process(m2, m1);
// Return a sorted, unique array.
changed.sort();
let last;
changed = [x for each (x in changed) if ((x != last) && (last = x))];
return {same: changed.length == 0,
changed: changed};
},
get isClear() {
return !this._default;
},
clear: function clear() {
this._log.info("Clearing CollectionKeys...");
this.lastModified = 0;
this._collections = {};
this._default = null;
},
keyForCollection: function(collection) {
if (collection && this._collections[collection])
return this._collections[collection];
return this._default;
},
/**
* If `collections` (an array of strings) is provided, iterate
* over it and generate random keys for each collection.
* Create a WBO for the given data.
*/
_makeWBO: function(collections, defaultBundle) {
let wbo = new CryptoWrapper(CRYPTO_COLLECTION, KEYS_WBO);
let c = {};
for (let k in collections) {
c[k] = collections[k].keyPairB64;
}
wbo.cleartext = {
"default": defaultBundle ? defaultBundle.keyPairB64 : null,
"collections": c,
"collection": CRYPTO_COLLECTION,
"id": KEYS_WBO
};
return wbo;
},
/**
* Create a WBO for the current keys.
*/
asWBO: function(collection, id)
this._makeWBO(this._collections, this._default),
/**
* Compute a new default key, and new keys for any specified collections.
*/
newKeys: function(collections) {
let newDefaultKey = new BulkKeyBundle(DEFAULT_KEYBUNDLE_NAME);
newDefaultKey.generateRandom();
let newColls = {};
if (collections) {
collections.forEach(function (c) {
let b = new BulkKeyBundle(c);
b.generateRandom();
newColls[c] = b;
});
}
return [newDefaultKey, newColls];
},
/**
* Generates new keys, but does not replace our local copy. Use this to
* verify an upload before storing.
*/
generateNewKeysWBO: function(collections) {
let newDefaultKey, newColls;
[newDefaultKey, newColls] = this.newKeys(collections);
return this._makeWBO(newColls, newDefaultKey);
},
// Take the fetched info/collections WBO, checking the change
// time of the crypto collection.
updateNeeded: function(info_collections) {
this._log.info("Testing for updateNeeded. Last modified: " + this.lastModified);
// No local record of modification time? Need an update.
if (!this.lastModified)
return true;
// No keys on the server? We need an update, though our
// update handling will be a little more drastic...
if (!(CRYPTO_COLLECTION in info_collections))
return true;
// Otherwise, we need an update if our modification time is stale.
return (info_collections[CRYPTO_COLLECTION] > this.lastModified);
},
//
// Set our keys and modified time to the values fetched from the server.
// Returns one of three values:
//
// * If the default key was modified, return true.
// * If the default key was not modified, but per-collection keys were,
// return an array of such.
// * Otherwise, return false -- we were up-to-date.
//
setContents: function setContents(payload, modified) {
if (!modified)
throw "No modified time provided to setContents.";
let self = this;
this._log.info("Setting CollectionKeys contents. Our last modified: " +
this.lastModified + ", input modified: " + modified + ".");
if (!payload)
throw "No payload in CollectionKeys.setContents().";
if (!payload.default) {
this._log.warn("No downloaded default key: this should not occur.");
this._log.warn("Not clearing local keys.");
throw "No default key in CollectionKeys.setContents(). Cannot proceed.";
}
// Process the incoming default key.
let b = new BulkKeyBundle(DEFAULT_KEYBUNDLE_NAME);
b.keyPairB64 = payload.default;
let newDefault = b;
// Process the incoming collections.
let newCollections = {};
if ("collections" in payload) {
this._log.info("Processing downloaded per-collection keys.");
let colls = payload.collections;
for (let k in colls) {
let v = colls[k];
if (v) {
let keyObj = new BulkKeyBundle(k);
keyObj.keyPairB64 = v;
if (keyObj) {
newCollections[k] = keyObj;
}
}
}
}
// Check to see if these are already our keys.
let sameDefault = (this._default && this._default.equals(newDefault));
let collComparison = this._compareKeyBundleCollections(newCollections, this._collections);
let sameColls = collComparison.same;
if (sameDefault && sameColls) {
self._log.info("New keys are the same as our old keys! Bumped local modified time.");
self.lastModified = modified;
return false;
}
// Make sure things are nice and tidy before we set.
this.clear();
this._log.info("Saving downloaded keys.");
this._default = newDefault;
this._collections = newCollections;
// Always trust the server.
self._log.info("Bumping last modified to " + modified);
self.lastModified = modified;
return sameDefault ? collComparison.changed : true;
},
updateContents: function updateContents(syncKeyBundle, storage_keys) {
let log = this._log;
log.info("Updating collection keys...");
// storage_keys is a WBO, fetched from storage/crypto/keys.
// Its payload is the default key, and a map of collections to keys.
// We lazily compute the key objects from the strings we're given.
let payload;
try {
payload = storage_keys.decrypt(syncKeyBundle);
} catch (ex) {
log.warn("Got exception \"" + ex + "\" decrypting storage keys with sync key.");
log.info("Aborting updateContents. Rethrowing.");
throw ex;
}
let r = this.setContents(payload, storage_keys.modified);
log.info("Collection keys updated.");
return r;
}
}
function Collection(uri, recordObj, service) {
if (!service) {
throw new Error("Collection constructor requires a service.");
}
Resource.call(this, uri);
// This is a bit hacky, but gets the job done.
let res = service.resource(uri);
this.authenticator = res.authenticator;
this._recordObj = recordObj;
this._service = service;
this._full = false;
this._ids = null;
this._limit = 0;
this._older = 0;
this._newer = 0;
this._data = [];
}
Collection.prototype = {
__proto__: Resource.prototype,
_logName: "Sync.Collection",
_rebuildURL: function Coll__rebuildURL() {
// XXX should consider what happens if it's not a URL...
this.uri.QueryInterface(Ci.nsIURL);
let args = [];
if (this.older)
args.push('older=' + this.older);
else if (this.newer) {
args.push('newer=' + this.newer);
}
if (this.full)
args.push('full=1');
if (this.sort)
args.push('sort=' + this.sort);
if (this.ids != null)
args.push("ids=" + this.ids);
if (this.limit > 0 && this.limit != Infinity)
args.push("limit=" + this.limit);
this.uri.query = (args.length > 0)? '?' + args.join('&') : '';
},
// get full items
get full() { return this._full; },
set full(value) {
this._full = value;
this._rebuildURL();
},
// Apply the action to a certain set of ids
get ids() this._ids,
set ids(value) {
this._ids = value;
this._rebuildURL();
},
// Limit how many records to get
get limit() this._limit,
set limit(value) {
this._limit = value;
this._rebuildURL();
},
// get only items modified before some date
get older() { return this._older; },
set older(value) {
this._older = value;
this._rebuildURL();
},
// get only items modified since some date
get newer() { return this._newer; },
set newer(value) {
this._newer = value;
this._rebuildURL();
},
// get items sorted by some criteria. valid values:
// oldest (oldest first)
// newest (newest first)
// index
get sort() { return this._sort; },
set sort(value) {
this._sort = value;
this._rebuildURL();
},
pushData: function Coll_pushData(data) {
this._data.push(data);
},
clearRecords: function Coll_clearRecords() {
this._data = [];
},
set recordHandler(onRecord) {
// Save this because onProgress is called with this as the ChannelListener
let coll = this;
// Switch to newline separated records for incremental parsing
coll.setHeader("Accept", "application/newlines");
this._onProgress = function() {
let newline;
while ((newline = this._data.indexOf("\n")) > 0) {
// Split the json record from the rest of the data
let json = this._data.slice(0, newline);
this._data = this._data.slice(newline + 1);
// Deserialize a record from json and give it to the callback
let record = new coll._recordObj();
record.deserialize(json);
onRecord(record);
}
};
},
};