Initial XBR protocol implementation (#424)

* dump current working tree

* improvements

* More seller code

* Do some stuff on the network

* More implementation...

* bring things closer to Python impl

* Call the market maker with right parameters

* add preliminary xbr buyer code

* Bring the XBR Seller near completion

* Make improvements to the Buyer code

* Bring buyer close to the finish line

* Minor improvements here and there

* Actually encrypt/decrypt secretbox

* Move deferred factory to utils and reuse in XBR

* Fix context

* Nothing to resolve

* dont export the private _onRotate

* assign 'self' at a universal place

lib/autobahn.js

@@ -42,6 +42,7 @@ var serializer = require('./serializer.js');
 var persona = require('./auth/persona.js');
 var cra = require('./auth/cra.js');
 var cryptosign = require('./auth/cryptosign.js');
+var xbr = require('./xbr/xbr.js');
 
 exports.version = pjson.version;
 
@@ -71,3 +72,4 @@ exports.nacl = nacl;
 
 exports.util = util;
 exports.log = log;
+exports.xbr = xbr;

lib/connection.js

@@ -28,42 +28,7 @@ var Connection = function (options) {
 
    // Deferred factory
    //
-   if (options && options.use_es6_promises) {
-
-      if ('Promise' in global) {
-         // ES6-based deferred factory
-         //
-         self._defer = function () {
-            var deferred = {};
-
-            deferred.promise = new Promise(function (resolve, reject) {
-               deferred.resolve = resolve;
-               deferred.reject = reject;
-            });
-
-            return deferred;
-         };
-      } else {
-
-         log.debug("Warning: ES6 promises requested, but not found! Falling back to whenjs.");
-
-         // whenjs-based deferred factory
-         //
-         self._defer = when.defer;
-      }
-
-   } else if (options && options.use_deferred) {
-
-      // use explicit deferred factory, e.g. jQuery.Deferred or Q.defer
-      //
-      self._defer = options.use_deferred;
-
-   } else {
-
-      // whenjs-based deferred factory
-      //
-      self._defer = when.defer;
-   }
+   self._defer = util.deferred_factory(options);
 
 
    // WAMP transport

lib/util.js

@@ -289,9 +289,63 @@ var new_global_id = function() {
     return Math.floor(Math.random() * 9007199254740992) + 1;
 };
 
+var deferred_factory = function(options) {
+   var defer = null;
+
+   if (options && options.use_es6_promises) {
+
+      if ('Promise' in global) {
+         // ES6-based deferred factory
+         //
+         defer = function () {
+            var deferred = {};
+
+            deferred.promise = new Promise(function (resolve, reject) {
+               deferred.resolve = resolve;
+               deferred.reject = reject;
+            });
+
+            return deferred;
+         };
+      } else {
+
+         log.debug("Warning: ES6 promises requested, but not found! Falling back to whenjs.");
+
+         // whenjs-based deferred factory
+         //
+         defer = when.defer;
+      }
+
+   } else if (options && options.use_deferred) {
+
+      // use explicit deferred factory, e.g. jQuery.Deferred or Q.defer
+      //
+      defer = options.use_deferred;
+
+   } else {
+
+      // whenjs-based deferred factory
+      //
+      defer = when.defer;
+   }
+
+   return defer;
+};
+
+var promise = function(d) {
+   if (d.promise.then) {
+      // whenjs has the actual user promise in an attribute
+      return d.promise;
+   } else {
+      return d;
+   }
+};
+
 exports.handle_error = handle_error;
 exports.rand_normal = rand_normal;
 exports.assert = assert;
 exports.http_post = http_post;
 exports.defaults = defaults;
 exports.new_global_id = new_global_id;
+exports.deferred_factory = deferred_factory;
+exports.promise = promise;

lib/xbr/buyer.js

@@ -0,0 +1,125 @@
+var cbor = require('cbor');
+var nacl = require('tweetnacl');
+var eth_accounts = require("web3-eth-accounts");
+var eth_util = require("ethereumjs-util");
+var util = require('../util.js');
+
+
+var SimpleBuyer = function (buyerKey, maxPrice) {
+    this._running = false;
+    this._session = null;
+    this._channel = null;
+    this._balance = null;
+    this._keys = {};
+    this._maxPrice = maxPrice;
+    this._deferred_factory = util.deferred_factory();
+
+    var account = new eth_accounts.Accounts().privateKeyToAccount(buyerKey);
+    this._addr = eth_util.toBuffer(account.address);
+
+    this._keyPair = nacl.box.keyPair();
+};
+
+SimpleBuyer.prototype.start = function(session, consumerID) {
+    self = this;
+    self._session = session;
+    self._running = true;
+
+    var d = this._deferred_factory();
+
+    session.call('xbr.marketmaker.get_payment_channel', [self._addr]).then(
+        function (paymentChannel) {
+            self._channel = paymentChannel;
+            self._balance = paymentChannel['remaining'];
+            d.resolve(self._balance);
+        },
+        function (error) {
+            console.log("Call failed:", error);
+            d.reject(error['error']);
+        }
+    );
+
+    return util.promise(d);
+};
+
+SimpleBuyer.prototype.stop = function () {
+    this._running = false;
+};
+
+SimpleBuyer.prototype.balance = function () {
+    var d = this._deferred_factory();
+    this._session.call('xbr.marketmaker.get_payment_channel', [self._addr]).then(
+        function (paymentChannel) {
+            var balance = {
+                amount: paymentChannel['amount'],
+                remaining: paymentChannel['remaining'],
+                inflight: paymentChannel['inflight']
+            };
+            d.resolve(balance);
+        },
+        function (error) {
+            console.log("Call failed:", error);
+            d.reject(error['error']);
+        }
+    );
+    return util.promise(d);
+};
+
+SimpleBuyer.prototype.openChannel = function (buyerAddr, amount) {
+    var signature = nacl.randomBytes(64);
+    var d = this._deferred_factory();
+    this._session.call(
+        'xbr.marketmaker.open_payment_channel',
+        [buyerAddr, this._addr, amount, signature]
+    ).then(
+        function (paymentChannel) {
+            var balance = {
+                amount: paymentChannel['amount'],
+                remaining: paymentChannel['remaining'],
+                inflight: paymentChannel['inflight']
+            };
+            d.resolve(balance);
+        },
+        function (error) {
+            console.log("Call failed:", error);
+            d.reject(error['error']);
+        }
+    );
+    return util.promise(d);
+};
+
+SimpleBuyer.prototype.closeChannel = function () {
+};
+
+SimpleBuyer.prototype.unwrap = function (keyID, ciphertext) {
+    self = this;
+    var d = self._deferred_factory();
+    if (!self._keys.hasOwnProperty(keyID)) {
+        self._keys[keyID] = false;
+        self._session.call(
+            'xbr.marketmaker.buy_key',
+            [self._addr, self._keyPair.publicKey, keyID, self._maxPrice, nacl.randomBytes(64)]
+        ).then(
+            function (receipt) {
+                var sealedKey = receipt['sealed_key'];
+                try {
+                    self._keys[keyID] = nacl.sealedbox.open(sealedKey, self._keyPair.publicKey,
+                        self._keyPair.secretKey);
+                    var nonce = ciphertext.slice(0, nacl.secretbox.nonceLength);
+                    var message = ciphertext.slice(nacl.secretbox.nonceLength, ciphertext.length);
+                    var decrypted = nacl.secretbox.open(message, nonce, self._keys[keyID]);
+                    var payload = cbor.decode(decrypted);
+                    d.resolve(payload);
+                } catch (e) {
+                    d.reject(e)
+                }
+            },
+            function (error) {
+                d.reject(error['error'])
+            }
+        );
+    }
+    return util.promise(d);
+};
+
+exports.SimpleBuyer = SimpleBuyer;

lib/xbr/keyseries.js

@@ -0,0 +1,50 @@
+var cbor = require('cbor');
+var nacl = require('tweetnacl');
+var sealedbox = require('tweetnacl-sealedbox-js');
+
+var KeySeries = function(apiID, prefix, price, interval, onRotate) {
+    this.apiID = apiID;
+    this.price = price;
+    this.interval = interval;
+    this.prefix = prefix;
+    this.onRotate = onRotate;
+    this._archive = {};
+    this._started = false;
+};
+
+KeySeries.prototype.encrypt = function(payload) {
+    var nonce = nacl.randomBytes(nacl.secretbox.nonceLength);
+    var box = nacl.secretbox(cbor.encode(payload), nonce, this._archive[this.keyID]);
+    var fullMessage = new Uint8Array(nonce.length + box.length);
+    fullMessage.set(nonce);
+    fullMessage.set(box, nonce.length);
+    return fullMessage;
+};
+
+KeySeries.prototype.encryptKey = function(keyID, buyerPubKey) {
+    return sealedbox.seal(this._archive[this.keyID], buyerPubKey)
+};
+
+KeySeries.prototype.start = function() {
+    if (!this._started) {
+        this._rotate(this);
+        this._started = true;
+    }
+};
+
+KeySeries.prototype._rotate = function(context) {
+    context.keyID = nacl.randomBytes(16);
+    context._archive[context.keyID] = nacl.randomBytes(nacl.secretbox.keyLength);
+    context.onRotate(context);
+    // Rotate the keys
+    // FIXME: make this to wait for the above onRotate callback to finish
+    setTimeout(context._rotate, context.interval, context);
+};
+
+KeySeries.prototype.stop = function() {
+    if (this._started) {
+        this._started = false;
+    }
+};
+
+exports.KeySeries = KeySeries;

lib/xbr/seller.js

@@ -0,0 +1,89 @@
+var autobahn = require("../autobahn.js");
+var eth_accounts = require("web3-eth-accounts");
+var eth_util = require("ethereumjs-util");
+var key_series = require('./keyseries');
+var util = require('../util.js');
+
+
+var Seller = function (sellerKey) {
+    self = this;
+    this.sellerKey = sellerKey;
+    this.keys = {};
+    this.keysMap = {};
+    this._providerID = eth_util.bufferToHex(eth_util.privateToPublic(sellerKey));
+    this._session = null;
+    this.sessionRegs = [];
+    this._deferred_factory = util.deferred_factory();
+
+    var account = new eth_accounts.Accounts().privateKeyToAccount(sellerKey);
+    this._addr = eth_util.toBuffer(account.address);
+    this._privateKey = eth_util.toBuffer(account.privateKey);
+};
+
+Seller.prototype.start = function (session) {
+    self._session = session;
+
+    var d = this._deferred_factory();
+    var procedure = 'xbr.protocol.' + self._providerID + '.sell';
+    session.register(procedure, self.sell).then(
+        function (registration) {
+            self.sessionRegs.push(registration);
+            for (var key in self.keys) {
+                self.keys[key].start();
+            }
+            d.resolve();
+        },
+        function (error) {
+            console.log("Registration failed:", error);
+            d.reject();
+        }
+    );
+    return util.promise(d);
+};
+
+Seller.prototype.sell = function (key_id, buyer_pubkey) {
+    if (!this.keysMap.hasOwnProperty(key_id)) {
+        throw "no key with ID " + key_id;
+    }
+    return this.keysMap[key_id].encryptKey(key_id, buyer_pubkey)
+};
+
+Seller.prototype.add = function (apiID, prefix, price, interval) {
+    var keySeries = new key_series.KeySeries(apiID, prefix, price, interval, _onRotate);
+    this.keys[apiID] = keySeries;
+    return keySeries;
+};
+
+var _onRotate = function (series) {
+    self.keysMap[series.keyID] = series;
+
+    self._session.call(
+        'xbr.marketmaker.place_offer',
+        [series.keyID, series.apiID, series.prefix, BigInt(Date.now() * 1000000 - 10 * 10 ** 9),
+            self._addr, autobahn.nacl.randomBytes(64)],
+        {price: series.price, provider_id: self._providerID}
+    ).then(
+        function (result) {
+            console.log("Offer placed for key", result['key']);
+        },
+        function (error) {
+            console.log("Call failed:", error);
+        }
+    )
+};
+
+Seller.prototype.stop = function () {
+    for (var key in this.keys) {
+        this.keys[key].stop()
+    }
+
+    for (var i = 0; i < this.sessionRegs.length; i++) {
+        this.sessionRegs[i].unregister()
+    }
+};
+
+Seller.prototype.wrap = function (api_id, uri, payload) {
+    return this.keys[api_id].encrypt(payload)
+};
+
+exports.SimpleSeller = Seller;

lib/xbr/xbr.js

@@ -0,0 +1,2 @@
+exports.SimpleBuyer = require('./buyer.js').SimpleBuyer;
+exports.SimpleSeller = require('./seller.js').SimpleSeller;

package.json

@@ -16,6 +16,7 @@
     "randombytes": ">=2.0.6",
     "tweetnacl": ">= 0.14.3",
     "tweetnacl-sealedbox-js": ">=1.1.0",
+    "web3": ">=1.0.0-beta.53",
     "when": ">= 3.7.7",
     "ws": ">= 1.1.4"
   },