Merge pull request #768 from ryanxcharles/feature/authentication

Authentication

js/models/core/Message.js

@@ -0,0 +1,82 @@
+'use strict';
+
+var imports = require('soop').imports();
+var bitcore = require('bitcore');
+
+/* Encrypted, authenticated messages to be shared between copayers */
+var Message = function() {
+};
+
+Message.encode = function(topubkey, fromkey, payload) {
+  var version = new Buffer([0]);
+  var toencrypt = Buffer.concat([version, payload]);
+  var encrypted = Message._encrypt(topubkey, toencrypt);
+  var sig = Message._sign(fromkey, encrypted);
+  var encoded = {
+    pubkey: fromkey.public.toString('hex'),
+    sig: sig.toString('hex'),
+    encrypted: encrypted.toString('hex')
+  };
+  return encoded;
+};
+
+Message.decode = function(key, encoded) {
+  try {
+    var frompubkey = new Buffer(encoded.pubkey, 'hex');
+  } catch (e) {
+    throw new Error('Error decoding public key: ' + e);
+  }
+
+  try {
+    var sig = new Buffer(encoded.sig, 'hex');
+    var encrypted = new Buffer(encoded.encrypted, 'hex');
+  } catch (e) {
+    throw new Error('Error decoding data: ' + e);
+  }
+  
+  try {
+    var v = Message._verify(frompubkey, sig, encrypted);
+  } catch (e) {
+    throw new Error('Error verifying signature: ' + e);
+  }
+
+  if (!v)
+    throw new Error('Invalid signature');
+
+  try {
+    var decrypted = Message._decrypt(key.private, encrypted);
+  } catch (e) {
+    throw new Error('Cannot decrypt data: ' + e);
+  }
+
+  if (decrypted[0] !== 0)
+    throw new Error('Invalid version number');
+
+  if (decrypted.length === 0)
+    throw new Error('No data present');
+
+  var payload = decrypted.slice(1);
+  return payload;
+};
+
+Message._encrypt = function(topubkey, payload, r, iv) {
+  var encrypted = bitcore.ECIES.encrypt(topubkey, payload, r, iv);
+  return encrypted;
+};
+
+Message._decrypt = function(privkey, encrypted) {
+  var decrypted = bitcore.ECIES.decrypt(privkey, encrypted);
+  return decrypted;
+};
+
+Message._sign = function(key, payload) {
+  var sig = bitcore.Message.sign(payload, key);
+  return sig;
+};
+
+Message._verify = function(pubkey, signature, payload) {
+  var v = bitcore.Message.verifyWithPubKey(pubkey, payload, signature);
+  return v;
+};
+
+module.exports = require('soop')(Message);

js/models/core/PrivateKey.js

@@ -32,9 +32,17 @@ PrivateKey.prototype.getIdPriv = function() {
   return this.idpriv;
 };
 
+PrivateKey.prototype.getIdKey = function() {
+  if (!this.idkey) {
+    this.cacheId();
+  }
+  return this.idkey;
+};
+
 PrivateKey.prototype.cacheId = function() {
   var path = Structure.IdFullBranch;
   var idhk = this.bip.derive(path);
+  this.idkey = idhk.eckey;
   this.id = idhk.eckey.public.toString('hex');
   this.idpriv = idhk.eckey.private.toString('hex');
 };

js/models/core/Wallet.js

@@ -280,6 +280,7 @@ Wallet.prototype.netStart = function(callback) {
 
   var myId = self.getMyCopayerId();
   var myIdPriv = self.getMyCopayerIdPriv();
+
   var startOpts = {
     copayerId: myId,
     privkey: myIdPriv,

js/models/core/WalletFactory.js

@@ -224,7 +224,8 @@ WalletFactory.prototype.joinCreateSession = function(secret, nickname, passphras
   this.log('\t### PrivateKey Initialized');
   var opts = {
     copayerId: privateKey.getId(),
-    privkey: privateKey.getIdPriv()
+    privkey: privateKey.getIdPriv(),
+    key: privateKey.getIdKey()
   };
   self.network.cleanUp();
   self.network.start(opts, function() {

js/models/network/WebRTC.js

@@ -5,6 +5,7 @@ var EventEmitter = imports.EventEmitter || require('events').EventEmitter;
 var bitcore = require('bitcore');
 var util = bitcore.util;
 var extend = require('util')._extend;
+var Message = require('../core/Message');
 /*
  * Emits
  *  'connect'
@@ -45,6 +46,7 @@ Network.prototype.cleanUp = function() {
   this.connectedPeers = [];
   this.peerId = null;
   this.privkey = null; //TODO: hide privkey in a closure
+  this.key = null;
   this.copayerId = null;
   this.signingKey = null;
   this.allowedCopayerIds = null;
@@ -151,16 +153,29 @@ Network.prototype._addConnectedCopayer = function(copayerId, isInbound) {
   this.emit('connect', copayerId);
 };
 
-Network.prototype._onData = function(enchex, isInbound, peerId) {
-  var sig, payload;
-  var encUint8Array = new Uint8Array(enchex);
+Network.prototype.getKey = function() {
+  if (!this.key) {
+    var key = new bitcore.Key();
+    key.private = new Buffer(this.privkey, 'hex');
+    key.regenerateSync();
+    this.key = key;
+  }
+  return this.key;
+};
+
+Network.prototype._onData = function(enc, isInbound, peerId) {
+  var encUint8Array = new Uint8Array(enc);
   var encbuf = new Buffer(encUint8Array);
+  var encstr = encbuf.toString();
 
   var privkey = this.privkey;
+  var key = this.getKey();
 
   try {
-    var data = this._decrypt(privkey, encbuf);
-    payload = JSON.parse(data);
+    var encoded = JSON.parse(encstr);
+    var databuf = this._decode(key, encoded);
+    var datastr = databuf.toString();
+    var payload = JSON.parse(datastr);
   } catch (e) {
     this._deletePeer(peerId);
     return;
@@ -169,6 +184,13 @@ Network.prototype._onData = function(enchex, isInbound, peerId) {
   if (isInbound && payload.type === 'hello') {
     var payloadStr = JSON.stringify(payload);
 
+    //ensure claimed public key is actually the public key of the peer
+    //e.g., their public key should hash to be their peerId
+    if (peerId.toString() !== this.peerFromCopayer(payload.copayerId) || peerId.toString() !== this.peerFromCopayer(encoded.pubkey)) {
+      this._deletePeer(peerId, 'incorrect pubkey for peerId');
+      return;
+    }
+
     if (this.allowedCopayerIds && !this.allowedCopayerIds[payload.copayerId]) {
       this._deletePeer(peerId);
       return;
@@ -349,18 +371,20 @@ Network.prototype.getPeer = function() {
   return this.peer;
 };
 
-Network.prototype._encrypt = function(pubkey, payload) {
-  var encrypted = bitcore.ECIES.encrypt(pubkey, payload);
-  return encrypted;
+Network.prototype._encode = function(topubkey, fromkey, payload) {
+  var encoded = Message.encode(topubkey, fromkey, payload);
+  return encoded;
 };
 
 
-Network.prototype._decrypt = function(privkey, encrypted) {
-  var decrypted = bitcore.ECIES.decrypt(privkey, encrypted);
-  return decrypted;
+Network.prototype._decode = function(key, encoded) {
+  var payload = Message.decode(key, encoded);
+  return payload;
 };
 
-Network.prototype._sendToOne = function(copayerId, payload, sig, cb) {
+Network.prototype._sendToOne = function(copayerId, payload, cb) {
+  if (!Buffer.isBuffer(payload))
+    throw new Error('payload must be a buffer');
   var peerId = this.peerFromCopayer(copayerId);
   if (peerId !== this.peerId) {
     var dataConn = this.connections[peerId];
@@ -383,7 +407,6 @@ Network.prototype.send = function(copayerIds, payload, cb) {
   if (typeof copayerIds === 'string')
     copayerIds = [copayerIds];
 
-  var sig;
   var payloadStr = JSON.stringify(payload);
   var payloadBuf = new Buffer(payloadStr);
 
@@ -391,8 +414,9 @@ Network.prototype.send = function(copayerIds, payload, cb) {
   var i = 0;
   copayerIds.forEach(function(copayerId) {
     var copayerIdBuf = new Buffer(copayerId, 'hex');
-    var encPayload = self._encrypt(copayerIdBuf, payloadBuf);
-    self._sendToOne(copayerId, encPayload, sig, function() {
+    var encPayload = self._encode(copayerIdBuf, self.getKey(), payloadBuf);
+    var enc = new Buffer(JSON.stringify(encPayload));
+    self._sendToOne(copayerId, enc, function() {
       if (++i === l && typeof cb === 'function') cb();
     });
   });