Allow adding other device by address, auto request public key

PROTOCOL.md

@@ -282,6 +282,32 @@ Address is the address that is no longer reachable.
 SeqNum is the sequence number of the route that is no longer available
 (if known). Otherwise, set TargSeqNum = -1. This field is signed.
 
+### PublicKeyRequest (Protocol-Type = 5)
+
+     0                   1                   2                   3
+     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                            Address                            |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    
+Contains an address for which the sender wants the corresponding public
+key.
+
+### PublicKeyReply (Protocol-Type = 6)
+
+     0                   1                   2                   3
+     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                          Key Length                           |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    /                                                               /
+    \                   Key (variable length)                       \
+    /                                                               /
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    
+Contains a node's public key in binary form. Sent in reply to a
+PublicKeyRequest.
+
 Content Messages
 ----------------
 

android/src/main/scala/com/nutomic/ensichat/activities/ConnectionsActivity.scala

@@ -127,7 +127,7 @@ class ConnectionsActivity extends EnsichatActivity with OnItemClickListener {
       .setMessage(getString(R.string.dialog_add_contact, user.name))
       .setPositiveButton(android.R.string.yes, new OnClickListener {
         override def onClick(dialog: DialogInterface, which: Int): Unit = {
-          database.get.addContact(user)
+          service.get.addContact(user)
           Toast.makeText(ConnectionsActivity.this, R.string.toast_contact_added, Toast.LENGTH_SHORT)
             .show()
         }

core/src/main/scala/com/nutomic/ensichat/core/ConnectionHandler.scala

@@ -42,12 +42,17 @@ final class ConnectionHandler(settings: SettingsInterface, database: Database,
 
   private lazy val messageBuffer = new MessageBuffer(crypto.localAddress, requestRoute)
 
+  /**
+    * Messages which we couldn't verify yet because we don't have the sender's public key.
+    */
+  private var unverifiedMessages = Set[Message]()
+
   /**
    * Holds all known users.
    *
    * This is for user names that were received during runtime, and is not persistent.
    */
-  private var knownUsers = Set[util.User]()
+  private var knownUsers = Set[User]()
 
   /**
    * Generates keys and starts Bluetooth interface.
@@ -86,16 +91,28 @@ final class ConnectionHandler(settings: SettingsInterface, database: Database,
     assert(body.contentType != -1)
     FutureHelper {
       val messageId = settings.get("message_id", 0L)
-      val header = new ContentHeader(crypto.localAddress, target, seqNumGenerator.next(),
+      val header = ContentHeader(crypto.localAddress, target, seqNumGenerator.next(),
         body.contentType, Some(messageId), Some(DateTime.now), AbstractHeader.InitialForwardingTokens)
       settings.put("message_id", messageId + 1)
 
       val msg = new Message(header, body)
+      onNewMessage(msg)
+      if (crypto.havePublicKey(target)) {
         val encrypted = crypto.encryptAndSign(msg)
         router.forwardMessage(encrypted)
         forwardMessageToRelays(encrypted)
-      onNewMessage(msg)
       }
+      else {
+        logger.info(s"Public key missing for $target, buffering message and sending key request")
+        requestPublicKey(target)
+      }
+    }
+  }
+
+  private def requestPublicKey(address: Address): Unit = {
+    val header = MessageHeader(PublicKeyRequest.Type, crypto.localAddress, Address.Broadcast, seqNumGenerator.next(), 0)
+    val msg = new Message(header, PublicKeyRequest(address))
+    router.forwardMessage(crypto.sign(msg))
   }
 
   private def requestRoute(target: Address): Unit = {
@@ -205,6 +222,38 @@ final class ConnectionHandler(settings: SettingsInterface, database: Database,
               .foreach(routeError(_, None))
           }
         }
+        return
+      case pkr: PublicKeyRequest =>
+        if (crypto.havePublicKey(pkr.address)) {
+          val header = MessageHeader(PublicKeyReply.Type, crypto.localAddress, msg.header.origin, seqNumGenerator.next(), 0)
+          val msg2 = new Message(header, PublicKeyReply(crypto.getPublicKey(pkr.address)))
+          router.forwardMessage(crypto.sign(msg2), Option(previousHop))
+        }
+        else {
+          router.forwardMessage(msg)
+        }
+        return
+      case pkr: PublicKeyReply =>
+        if (msg.header.target != crypto.localAddress) {
+          router.forwardMessage(msg)
+          return
+        }
+        val address = crypto.calculateAddress(pkr.key)
+        if (crypto.havePublicKey(address))
+          return
+
+        logger.info(s"Received public key for $address, resending and decrypting messages")
+        crypto.addPublicKey(address, pkr.key)
+        database.getMessages(address)
+          .filter(_.header.target == address)
+          .foreach{ m =>
+            sendTo(address, m.body)
+          }
+        val current = unverifiedMessages
+          .filter(_.header.origin == address)
+        current.foreach(decryptMessage)
+        unverifiedMessages --= current
+        return
       case _ =>
     }
 
@@ -214,6 +263,17 @@ final class ConnectionHandler(settings: SettingsInterface, database: Database,
       return
     }
 
+    if (!crypto.havePublicKey(msg.header.origin)) {
+      logger.info(s"Received message from ${msg.header.origin} but don't have public key, buffering")
+      unverifiedMessages += msg
+      requestPublicKey(msg.header.origin)
+      return
+    }
+
+    decryptMessage(msg)
+  }
+
+  private def decryptMessage(msg: Message): Unit = {
     val plainMsg =
       try {
         if (!crypto.verify(msg)) {
@@ -241,7 +301,7 @@ final class ConnectionHandler(settings: SettingsInterface, database: Database,
 
     if (plainMsg.body.contentType == Text.Type) {
       logger.trace(s"Sending confirmation for $plainMsg")
-      sendTo(plainMsg.header.origin, new messages.body.MessageReceived(plainMsg.header.messageId.get))
+      sendTo(plainMsg.header.origin, new MessageReceived(plainMsg.header.messageId.get))
     }
 
     onNewMessage(plainMsg)
@@ -280,13 +340,13 @@ final class ConnectionHandler(settings: SettingsInterface, database: Database,
    */
   private def onNewMessage(msg: Message): Unit = msg.body match {
     case ui: UserInfo =>
-      val contact = new util.User(msg.header.origin, ui.name, ui.status)
+      val contact = User(msg.header.origin, ui.name, ui.status)
       knownUsers += contact
       if (database.getContact(msg.header.origin).nonEmpty)
         database.updateContact(contact)
 
       callbacks.onConnectionsChanged()
-    case mr: messages.body.MessageReceived =>
+    case mr: MessageReceived =>
       database.setMessageConfirmed(mr.messageId)
     case _ =>
       val origin = msg.header.origin
@@ -339,7 +399,7 @@ final class ConnectionHandler(settings: SettingsInterface, database: Database,
     else
       logger.info("Node " + sender + " connected")
 
-    sendTo(sender, new UserInfo(settings.get(SettingsInterface.KeyUserName, ""),
+    sendTo(sender, UserInfo(settings.get(SettingsInterface.KeyUserName, ""),
                             settings.get(SettingsInterface.KeyUserStatus, "")))
     callbacks.onConnectionsChanged()
     resendMissingRouteMessages()
@@ -372,7 +432,7 @@ final class ConnectionHandler(settings: SettingsInterface, database: Database,
   def getUser(address: Address) =
     allKnownUsers()
       .find(_.address == address)
-      .getOrElse(new util.User(address, address.toString(), ""))
+      .getOrElse(User(address, address.toString(), ""))
 
   /**
     * This method should be called when the local device's internet connection has changed in any way.
@@ -382,4 +442,12 @@ final class ConnectionHandler(settings: SettingsInterface, database: Database,
       .find(_.isInstanceOf[InternetInterface])
       .foreach(_.asInstanceOf[InternetInterface].connectionChanged())
   }
+
+  def addContact(user: User): Unit = {
+    database.addContact(user)
+    if (!crypto.havePublicKey(user.address)) {
+      requestPublicKey(user.address)
+    }
+  }
+
 }

core/src/main/scala/com/nutomic/ensichat/core/messages/Message.scala

@@ -50,11 +50,13 @@ object Message {
 
       val body =
         header.protocolType match {
-          case messages.body.ConnectionInfo.Type => messages.body.ConnectionInfo.read(remaining)
+          case ConnectionInfo.Type   => ConnectionInfo.read(remaining)
           case RouteRequest.Type     => RouteRequest.read(remaining)
           case RouteReply.Type       => RouteReply.read(remaining)
           case RouteError.Type       => RouteError.read(remaining)
-          case _                   => new EncryptedBody(remaining)
+          case PublicKeyRequest.Type => PublicKeyRequest.read(remaining)
+          case PublicKeyReply.Type   => PublicKeyReply.read(remaining)
+          case _                     => EncryptedBody(remaining)
         }
 
       new Message(header, crypto, body)

core/src/main/scala/com/nutomic/ensichat/core/messages/body/PublicKeyReply.scala

@@ -0,0 +1,45 @@
+package com.nutomic.ensichat.core.messages.body
+
+import java.nio.ByteBuffer
+import java.security.spec.X509EncodedKeySpec
+import java.security.{KeyFactory, PublicKey}
+
+import com.nutomic.ensichat.core.util.BufferUtils
+import com.nutomic.ensichat.core.util.Crypto
+
+object PublicKeyReply {
+
+  val Type = 6
+
+  /**
+    * Constructs [[ConnectionInfo]] instance from byte array.
+    */
+  def read(array: Array[Byte]): PublicKeyReply = {
+    val b = ByteBuffer.wrap(array)
+    val length = BufferUtils.getUnsignedInt(b).toInt
+    val encoded = new Array[Byte](length)
+    b.get(encoded, 0, length)
+
+    val factory = KeyFactory.getInstance(Crypto.PublicKeyAlgorithm)
+    val key = factory.generatePublic(new X509EncodedKeySpec(encoded))
+    new PublicKeyReply(key)
+  }
+
+}
+
+case class PublicKeyReply(key: PublicKey) extends MessageBody {
+
+  override def protocolType = PublicKeyRequest.Type
+
+  override def contentType = -1
+
+  override def write: Array[Byte] = {
+    val b = ByteBuffer.allocate(length)
+    BufferUtils.putUnsignedInt(b, key.getEncoded.length)
+    b.put(key.getEncoded)
+    b.array()
+  }
+
+  override def length = 4 + key.getEncoded.length
+
+}

core/src/main/scala/com/nutomic/ensichat/core/messages/body/PublicKeyRequest.scala

@@ -0,0 +1,50 @@
+package com.nutomic.ensichat.core.messages.body
+
+import java.nio.ByteBuffer
+
+import com.nutomic.ensichat.core.routing.Address
+import com.nutomic.ensichat.core.util.BufferUtils
+
+object PublicKeyRequest {
+
+  val Type = 5
+
+  /**
+    * Constructs [[Text]] instance from byte array.
+    */
+  def read(array: Array[Byte]): PublicKeyRequest = {
+    val b = ByteBuffer.wrap(array)
+    val length = BufferUtils.getUnsignedInt(b).toInt
+    val bytes = new Array[Byte](length)
+    b.get(bytes, 0, length)
+    new PublicKeyRequest(new Address(bytes))
+  }
+
+}
+
+case class PublicKeyRequest(address: Address) extends MessageBody {
+
+  require(address != Address.Broadcast, "")
+  require(address != Address.Null, "")
+
+  override def protocolType = PublicKeyRequest.Type
+
+  override def contentType = -1
+
+  override def write: Array[Byte] = {
+    val b = ByteBuffer.allocate(length)
+    val bytes = address.bytes
+    BufferUtils.putUnsignedInt(b, bytes.length)
+    b.put(bytes)
+    b.array()
+  }
+
+
+  override def equals(a: Any): Boolean = a match {
+    case o: PublicKeyRequest => address == o.address
+    case _ => false
+  }
+
+  override def length = 4 + address.bytes.length
+
+}

core/src/main/scala/com/nutomic/ensichat/core/routing/Router.scala

@@ -67,6 +67,7 @@ private[core] class Router(routesInfo: LocalRoutesInfo, send: (Address, Message)
         send(a, incHopCount(msg))
         markMessageSeen((msg.header.origin, msg.header.seqNum))
       case None =>
+        if (msg.header.isInstanceOf[ContentHeader])
           noRouteFound(msg)
     }
   }

core/src/main/scala/com/nutomic/ensichat/core/util/Database.scala

@@ -160,7 +160,7 @@ class Database(path: File, settings: SettingsInterface, callbackInterface: Callb
   /**
    * Inserts the user as a new contact.
    */
-  def addContact(contact: User): Unit = {
+  private[core] def addContact(contact: User): Unit = {
     Await.result(db.run(contacts += contact), Duration.Inf)
     callbackInterface.onContactsUpdated()
   }

integration/src/main/scala/com.nutomic.ensichat.integration/Main.scala

@@ -22,6 +22,7 @@ import scalax.file.Path
  */
 object Main extends App {
 
+  /*
   testNeighborSending()
   testMeshMessageSending()
   testIndirectRelay()
@@ -30,6 +31,8 @@ object Main extends App {
   testSendDelayed()
   testRouteChange()
   testMessageConfirmation()
+  */
+  testKeyRequest()
 
   private def testNeighborSending(): Unit = {
     val node1 = Await.result(createNode(1), Duration.Inf)
@@ -169,6 +172,38 @@ object Main extends App {
     nodes.foreach(_.stop())
   }
 
+  private def testKeyRequest(): Unit = {
+    val nodes = createNodes(4)
+    connectNodes(nodes(0), nodes(1))
+    connectNodes(nodes(1), nodes(2))
+    connectNodes(nodes(2), nodes(3))
+
+    val origin = nodes(0)
+    val target = nodes(3)
+
+    System.out.println(s"sendMessage(${origin.index}, ${target.index})")
+    val text = s"${origin.index} to ${target.index}"
+    origin.connectionHandler.sendTo(target.crypto.localAddress, new Text(text))
+
+    val latch = new CountDownLatch(1)
+    Future {
+      val exists =
+        target.eventQueue.toStream.exists { event =>
+          if (event._1 != LocalNode.EventType.MessageReceived)
+            false
+          else {
+            event._2.get.body match {
+              case t: Text => t.text == text
+              case _ => false
+            }
+          }
+        }
+      assert(exists, s"message from ${origin.index} did not arrive at ${target.index}")
+      latch.countDown()
+    }
+    assert(latch.await(3, TimeUnit.SECONDS))
+  }
+
   private def createNodes(count: Int): Seq[LocalNode] = {
     val nodes = Await.result(Future.sequence((0 until count).map(createNode)), Duration.Inf)
     nodes.foreach(n => System.out.println(s"Node ${n.index} has address ${n.crypto.localAddress}"))