Moved remaining messages to binary encoding, removed msgpack dependency.

This seems to have added some random disconnects, but there doesn't
seem to be a reason for this in the code.

PROTOCOL.md

@@ -7,17 +7,17 @@ The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
 document are to be interpreted as described in RFC 2119.
 
-A node is a single device implementing this protocol. Each node has
+A _node_ is a single device implementing this protocol. Each node has
-exactl one node address.
+exactly one node address based on its RSA key pair.
 
-A node address consists of 32 bytes and is the SHA-256 hash of the
+A _node address_ consists of 32 bytes and is the SHA-256 hash of the
 node's public key.
 
-The broadcast address is
+The _broadcast address_ is
 `0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF`
 (i.e. all bits set).
 
-The null address is
+The _null address_ is
 `0x0000000000000000000000000000000000000000000000000000000000000000`
 (i.e. no bits set).
 
@@ -29,6 +29,27 @@ nodes MUST NOT connect to a node with either address.
 Messages
 --------
 
+All messages are signed using RSASSA-PKCS1-v1_5. All messages except
+ConnectionInfo are encrypted using AES/CBC/PKCS5Padding, after which
+the AES key is wrapped with the recipient's public RSA key.
+
+     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
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    /                                                               /
+    \                    Header (variable length)                   \
+    /                                                               /
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    /                                                               /
+    \               Encryption Data (variable length)               \
+    /                                                               /
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    /                                                               /
+    \                    Body (variable length)                     \
+    /                                                               /
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+
 ### Header
 
 Every message starts with one 32 bit word indicating the message
@@ -54,6 +75,8 @@ header is in network byte order, i.e. big endian.
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |        Sequence Number        |     Metric    |   Reserved    |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                         Body Length                           |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 
 Ver specifies the protocol version number. This is currently 0. A
 message with unknown version number MUST be ignored. The connection
@@ -83,17 +106,50 @@ Sequence number is the sequence number of either the source or target
 node for this message, depending on type.
 
 
+### Encryption Data
+
+     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
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                        Signature Length                       |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    /                                                               /
+    \                   Signature (variable length)                 \
+    /                                                               /
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                     Encryption Key Length                     |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    /                                                               /
+    \               Encryption Key (variable length)                \
+    /                                                               /
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+Encryption key is the symmetric key that was used to encrypt the message
+body.
+
+Signature is the cryptographic signature over the (unencrypted) message
+header and message body.
+
+
+
 ConnectionInfo (Type = 0)
 ---------
 
 After successfully connecting to a node via Bluetooth, public keys
-must be exchanged. Each node MUST send this as the first message over
+are exchanged. Each node MUST send this as the first message over
 the connection. Hop Limit MUST be 1 for this message type (i.e. it
 must never be forwarded). Origin Address and Target Address MUST be
 set to all zeros, and MUST be ignored by the receiving node.
 
 A receiving node SHOULD store the key in permanent storage if it
-hasn't already stored it earlier. This key is to be used for message
+hasn't already stored it earlier.  However, a node MAY decide to
+delete these stored keys in a least-recently-used order to adhere
+to storage limitations. If a key has been deleted, messages to
+that node can only be sent once a new ConnectionInfo message
+for it has been received.
+
+
+This key is to be used for message
 encryption when communicating with the sending node.
 
      0                   1                   2                   3
@@ -114,20 +170,46 @@ After this message has been received, communication with normal messages
 may start.
 
 
-### Data (Data Transfer, Type = 255)
+### RequestAddContact (Type = 4)
+
+Sent when a user wants to add another node as a contact. After this,
+a ResultAddContact message should be returned.
 
      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-    |                             Length                            |
+    |                           Reserved                            |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+
+### ResultAddContact (Type = 5)
+
+Sent as response to a RequestAddContact message.
+
+     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
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |A|                          Reserved                           |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+Accepted bit (A) is true if the user accepts the new contact, false
+otherwise. Nodes should only add another node as a contact if both
+users agreed.
+
+### Text (Type = 6)
+
+A simple chat message.
+
+     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
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                            Reserved                           |
+    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+    |                          Text Length                          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     /                                                               /
-    \                       Data (variable length)                  \
+    \                   Text (variable length)                      \
     /                                                               /
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 
-Length is the number of bytes in data.
+Text the string to be transferred, encoded as UTF-8.
-
-Data is any binary data that should be transported.
-
-This message type is deprecated.

app/build.gradle

@@ -6,27 +6,19 @@ buildscript {
         mavenCentral()
     }
     dependencies {
-        classpath "com.android.tools.build:gradle:0.14.4"
         classpath "jp.leafytree.gradle:gradle-android-scala-plugin:1.3.1"
     }
 }
 
 dependencies {
-    compile "com.android.support:support-v4:21.0.0"
+    compile "com.android.support:support-v4:21.0.2"
     // For `flat` debug config, as `flatProvided` is unknown.
     provided "org.scala-lang:scala-library:2.11.4"
     debugCompile "org.scala-lang:scala-library:2.11.4"
     releaseCompile "org.scala-lang:scala-library:2.11.4"
-    compile("org.msgpack:msgpack-scala_2.11:0.6.11") {
-        transitive = false;
-    }
-    compile('org.msgpack:msgpack:0.6.11') {
-        transitive = false;
-    }
     compile 'com.google.guava:guava:18.0'
 }
 
-
 android {
     compileSdkVersion 21
     buildToolsVersion "21.1.1"
@@ -40,13 +32,8 @@ android {
     }
 
     sourceSets {
-        main {
+        main.scala.srcDir "src/main/scala"
-            scala.srcDir "src/main/scala"
+        androidTest.scala.srcDir "src/androidTest/scala"
-        }
-
-        androidTest {
-            scala.srcDir "src/androidTest/scala"
-        }
     }
 
     buildTypes {
@@ -68,11 +55,13 @@ android {
 
     // Needed to rename `app-thin.apk` to `app-debug.apk` (because Android Studio doesn't let us
     // specify a different apk name).
+/*
     applicationVariants.all { variant ->
         def apk = variant.outputFile;
         def newName = apk.name.replace("app-thin", "app-debug");
         variant.outputFile = new File(apk.parentFile, newName);
     }
+*/
 
     // Avoid duplicate file errors during packaging.
     packagingOptions {
@@ -82,3 +71,7 @@ android {
         exclude 'META-INF/NOTICE'
     }
 }
+
+tasks.withType(ScalaCompile) {
+    scalaCompileOptions.useCompileDaemon = true
+}

app/proguard-rules.pro

@@ -18,11 +18,12 @@
 -dontpreverify
 -dontwarn scala.**
 -keep class !scala*.** { *; }
--ignorewarnings
 # Avoid crash when invoking String.toInt (see https://issues.scala-lang.org/browse/SI-5397).
 -keep class scala.collection.SeqLike {
     public protected *;
 }
 
-# Suppress warnings caused by msgpack (code works fine anyway).
+# Disable warnings for Guava annotations.
--dontwarn
+-dontwarn javax.annotation.**
+-dontwarn javax.inject.**
+-dontwarn sun.misc.Unsafe

app/src/androidTest/scala/com/nutomic/ensichat/aodvv2/AddressTest.scala

@@ -14,14 +14,17 @@ object AddressTest {
 
   val a4 = new Address("4444459893F8810C4024CFC951374AABA1F4DE6347A3D7D8E44918AD1FF2BA36")
 
-  val a1Binary: Array[Byte] = Array(-91, 27, 116, 71, 94, -26, 34, -61, -55, 36, -37, 20, 118, 104, -8, 94, 2, 76, -96, -76, 76, -95, 70, -75, -29, -45, -61, 26, 84, -77, 76, 30).map(_.toByte)
+  val a1Binary: Array[Byte] = Array(-91, 27, 116, 71, 94, -26, 34, -61, -55, 36, -37, 20, 118, 104,
+    -8, 94, 2, 76, -96, -76, 76, -95, 70, -75, -29, -45, -61, 26, 84, -77, 76, 30).map(_.toByte)
+
+  val Addresses = Set(a1, a2, a3, a4, Address.Broadcast, Address.Null)
 
 }
 
 class AddressTest extends AndroidTestCase {
 
   def testEncode(): Unit = {
-    Set(Address.Broadcast, Address.Null, a1, a2, a3, a4).foreach{a =>
+    Addresses.foreach{a =>
       val base32 = a.toString
       val read = new Address(base32)
       assertEquals(a, read)

app/src/androidTest/scala/com/nutomic/ensichat/aodvv2/MessageHeaderTest.scala

@@ -1,30 +1,41 @@
 package com.nutomic.ensichat.aodvv2
 
-import java.util.Date
+import java.util.GregorianCalendar
 
 import android.test.AndroidTestCase
-import junit.framework.Assert
+import com.nutomic.ensichat.aodvv2.MessageHeaderTest._
+import junit.framework.Assert._
 
 object MessageHeaderTest {
 
-  val h1 = new MessageHeader(Data.Type, MessageHeader.DefaultHopLimit, new Date(), AddressTest.a3,
+  val h1 = new MessageHeader(Text.Type, MessageHeader.DefaultHopLimit, AddressTest.a1,
-    AddressTest.a4, 456, 123)
+    AddressTest.a2, 1234, 0, new GregorianCalendar(1970, 1, 1).getTime, 567, 8)
 
-  val h2 = new MessageHeader(0xfff, 0, new Date(0xffffffff), Address.Null, Address.Broadcast, 0,
+  val h2 = new MessageHeader(Text.Type, 0, AddressTest.a1, AddressTest.a3, 8765, 234,
-    0xff)
+   new GregorianCalendar(2014, 6, 10).getTime, 0, 0xff)
 
-  val h3 = new MessageHeader(0xfff, 0xff, new Date(0), Address.Broadcast, Address.Null, 0xffff, 0)
+  val h3 = new MessageHeader(Text.Type, 0xff, AddressTest.a4, AddressTest.a2, 0, 56,
+    new GregorianCalendar(2020, 11, 11).getTime, 0xffff, 0)
+
+  val h4 = new MessageHeader(0xfff, 0, Address.Null, Address.Broadcast, 0, 0xff,
+    new GregorianCalendar(1990, 1, 1).getTime, 0, 0xff)
+
+  val h5 = new MessageHeader(ConnectionInfo.Type, 0xff, Address.Broadcast, Address.Null, 0xffff, 0,
+    new GregorianCalendar(2035, 12, 31).getTime, 0xffff, 0)
+
+  val headers = Set(h1, h2, h3, h4, h5)
 
 }
 
 class MessageHeaderTest extends AndroidTestCase {
 
   def testSerialize(): Unit = {
-    val ci = ConnectionInfoTest.generateCi(getContext)
+    headers.foreach{h =>
-    val bytes = MessageHeaderTest.h1.write(ci)
+      val bytes = h.write(0)
-    val header = MessageHeader.read(bytes)
+      val header = MessageHeader.read(bytes)
-    Assert.assertEquals(MessageHeaderTest.h1, header)
+      assertEquals(h, header)
-    Assert.assertEquals(bytes.length, header.Length)
+      assertEquals(bytes.length, header.Length)
+    }
   }
 
 }

app/src/androidTest/scala/com/nutomic/ensichat/aodvv2/MessageTest.scala

@@ -0,0 +1,77 @@
+package com.nutomic.ensichat.aodvv2
+
+import java.io.ByteArrayInputStream
+import java.util.GregorianCalendar
+
+import android.test.AndroidTestCase
+import com.nutomic.ensichat.aodvv2.MessageHeaderTest._
+import com.nutomic.ensichat.aodvv2.MessageTest._
+import com.nutomic.ensichat.messages.Crypto
+import junit.framework.Assert._
+
+import scala.collection.immutable.TreeSet
+
+object MessageTest {
+
+  val m1 = new Message(h1, new Text("first"))
+
+  val m2 = new Message(h2, new Text("second"))
+
+  val m3 = new Message(h3, new Text("third"))
+
+  val messages = Set(m1, m2, m3)
+
+}
+
+class MessageTest extends AndroidTestCase {
+
+  lazy val Crypto: Crypto = new Crypto(getContext)
+
+  override def setUp(): Unit = {
+    super.setUp()
+    if (!Crypto.localKeysExist) {
+      Crypto.generateLocalKeys()
+    }
+  }
+
+  def testOrder(): Unit = {
+    var messages = new TreeSet[Message]()(Message.Ordering)
+    messages += m1
+    messages += m2
+    assertEquals(m1, messages.firstKey)
+
+    messages = new TreeSet[Message]()(Message.Ordering)
+    messages += m2
+    messages += m3
+    assertEquals(m2, messages.firstKey)
+  }
+
+  def testSerializeSigned(): Unit = {
+    val header = new MessageHeader(ConnectionInfo.Type, 0xff, AddressTest.a4, AddressTest.a2, 0, 56,
+      new GregorianCalendar(2020, 11, 11).getTime, 0xffff, 0)
+    val m = new Message(header, ConnectionInfoTest.generateCi(getContext))
+
+    val signed = Crypto.sign(m)
+    val bytes = signed.write
+    val read = Message.read(new ByteArrayInputStream(bytes))
+
+    assertEquals(signed, read)
+    assertTrue(Crypto.verify(read, Crypto.getLocalPublicKey))
+  }
+
+  def testSerializeEncrypted(): Unit = {
+    messages.foreach{ m =>
+      val signed = Crypto.sign(m)
+      val encrypted = Crypto.encrypt(signed, Crypto.getLocalPublicKey)
+      val bytes = encrypted.write
+
+      val read = Message.read(new ByteArrayInputStream(bytes))
+      assertEquals(encrypted.Crypto, read.Crypto)
+      val decrypted = Crypto.decrypt(read)
+      assertEquals(m.Header, decrypted.Header)
+      assertEquals(m.Body, decrypted.Body)
+      assertTrue(Crypto.verify(decrypted, Crypto.getLocalPublicKey))
+    }
+  }
+
+}

app/src/androidTest/scala/com/nutomic/ensichat/aodvv2/ResultAddContactTest.scala

@@ -0,0 +1,18 @@
+package com.nutomic.ensichat.aodvv2
+
+import android.test.AndroidTestCase
+import junit.framework.Assert._
+
+
+class ResultAddContactTest extends AndroidTestCase {
+
+  def testWriteRead(): Unit = {
+    Array(true, false).foreach { a =>
+      val rac = new ResultAddContact(a)
+      val bytes = rac.write
+      val read = ResultAddContact.read(bytes)
+      assertEquals(a, read.Accepted)
+    }
+  }
+
+}

app/src/androidTest/scala/com/nutomic/ensichat/messages/CryptoTest.scala

@@ -1,7 +1,7 @@
 package com.nutomic.ensichat.messages
 
 import android.test.AndroidTestCase
-import com.nutomic.ensichat.messages.MessageTest._
+import com.nutomic.ensichat.aodvv2.MessageTest._
 import junit.framework.Assert._
 
 class CryptoTest extends AndroidTestCase {
@@ -16,15 +16,21 @@ class CryptoTest extends AndroidTestCase {
   }
 
   def testSignVerify(): Unit = {
-    val sig = Crypto.calculateSignature(m1)
+    messages.foreach { m =>
-    assertTrue(Crypto.isValidSignature(m1, sig, Crypto.getLocalPublicKey))
+      val signed = Crypto.sign(m)
+      assertTrue(Crypto.verify(signed, Crypto.getLocalPublicKey))
+      assertEquals(m.Header, signed.Header)
+      assertEquals(m.Body, signed.Body)
+    }
   }
 
   def testEncryptDecrypt(): Unit = {
-    val (encrypted, key) =
+    messages.foreach{ m =>
-      Crypto.encrypt(null, MessageTest.m1.write(Array[Byte]()), Crypto.getLocalPublicKey)
+      val encrypted = Crypto.encrypt(Crypto.sign(m), Crypto.getLocalPublicKey)
-    val decrypted = Crypto.decrypt(encrypted, key)
+      val decrypted = Crypto.decrypt(encrypted)
-    assertEquals(MessageTest.m1, Message.read(decrypted)._1)
+      assertEquals(m.Body, decrypted.Body)
+      assertEquals(m.Header, encrypted.Header)
+    }
   }
 
 }

app/src/androidTest/scala/com/nutomic/ensichat/messages/MessageTest.scala

@@ -1,50 +0,0 @@
-package com.nutomic.ensichat.messages
-
-import java.io.{PipedInputStream, PipedOutputStream}
-import java.util.GregorianCalendar
-
-import android.test.AndroidTestCase
-import com.nutomic.ensichat.aodvv2.AddressTest
-import com.nutomic.ensichat.messages.MessageTest._
-import junit.framework.Assert._
-
-import scala.collection.immutable.TreeSet
-
-object MessageTest {
-
-  val m1 = new TextMessage(AddressTest.a1, AddressTest.a2,
-    new GregorianCalendar(2014, 10, 29).getTime, "first")
-
-  val m2 = new TextMessage(AddressTest.a1, AddressTest.a3,
-    new GregorianCalendar(2014, 10, 30).getTime, "second")
-
-  val m3 = new TextMessage(AddressTest.a4, AddressTest.a2,
-    new GregorianCalendar(2014, 10, 31).getTime, "third")
-
-}
-
-class MessageTest extends AndroidTestCase {
-
-  def testSerialize(): Unit = {
-    Set(m1, m2, m3).foreach { m =>
-      val pis = new PipedInputStream()
-      val pos = new PipedOutputStream(pis)
-      val bytes = m.write(Array[Byte]())
-      val (msg, _) = Message.read(bytes)
-      assertEquals(m, msg)
-    }
-  }
-
-  def testOrder(): Unit = {
-    var messages = new TreeSet[Message]()(Message.Ordering)
-    messages += MessageTest.m1
-    messages += MessageTest.m2
-    assertEquals(MessageTest.m1, messages.firstKey)
-
-    messages = new TreeSet[Message]()(Message.Ordering)
-    messages += MessageTest.m2
-    messages += MessageTest.m3
-    assertEquals(MessageTest.m2, messages.firstKey)
-  }
-
-}

app/src/androidTest/scala/com/nutomic/ensichat/util/DatabaseTest.scala

@@ -9,7 +9,7 @@ import android.database.sqlite.SQLiteDatabase
 import android.test.AndroidTestCase
 import android.test.mock.MockContext
 import com.nutomic.ensichat.aodvv2.AddressTest
-import com.nutomic.ensichat.messages.MessageTest
+import com.nutomic.ensichat.aodvv2.MessageTest._
 import junit.framework.Assert._
 
 class DatabaseTest extends AndroidTestCase {
@@ -27,9 +27,9 @@ class DatabaseTest extends AndroidTestCase {
   private lazy val Database = new Database(new TestContext(getContext))
 
   override def setUp(): Unit = {
-    Database.addMessage(MessageTest.m1)
+    Database.addMessage(m1)
-    Database.addMessage(MessageTest.m2)
+    Database.addMessage(m2)
-    Database.addMessage(MessageTest.m3)
+    Database.addMessage(m3)
   }
 
   override def tearDown(): Unit = {
@@ -38,22 +38,22 @@ class DatabaseTest extends AndroidTestCase {
   }
 
   def testMessageCount(): Unit = {
-    val msg1 = Database.getMessages(MessageTest.m1.sender, 1)
+    val msg1 = Database.getMessages(m1.Header.Origin, 1)
     assertEquals(1, msg1.size)
 
-    val msg2 = Database.getMessages(MessageTest.m1.sender, 3)
+    val msg2 = Database.getMessages(m1.Header.Origin, 3)
     assertEquals(2, msg2.size)
   }
 
   def testMessageOrder(): Unit = {
-    val msg = Database.getMessages(MessageTest.m1.receiver, 1)
+    val msg = Database.getMessages(m1.Header.Target, 1)
-    assertTrue(msg.contains(MessageTest.m3))
+    assertTrue(msg.contains(m3))
   }
 
   def testMessageSelect(): Unit = {
-    val msg = Database.getMessages(MessageTest.m1.receiver, 2)
+    val msg = Database.getMessages(m1.Header.Target, 2)
-    assertTrue(msg.contains(MessageTest.m1))
+    assertTrue(msg.contains(m1))
-    assertTrue(msg.contains(MessageTest.m3))
+    assertTrue(msg.contains(m3))
   }
 
   def testAddContact(): Unit = {

app/src/main/res/xml/settings.xml

@@ -5,7 +5,7 @@
     <EditTextPreference
         android:title="@string/scan_interval_seconds"
         android:key="scan_interval_seconds"
-        android:defaultValue="5"
+        android:defaultValue="15"
         android:inputType="number"
         android:numeric="integer" />
 

app/src/main/scala/com/nutomic/ensichat/activities/AddContactsActivity.scala

@@ -1,7 +1,5 @@
 package com.nutomic.ensichat.activities
 
-import java.util.Date
-
 import android.app.AlertDialog
 import android.content.DialogInterface.OnClickListener
 import android.content.{Context, DialogInterface}
@@ -12,10 +10,10 @@ import android.view._
 import android.widget.AdapterView.OnItemClickListener
 import android.widget._
 import com.nutomic.ensichat.R
-import com.nutomic.ensichat.aodvv2.Address
+import com.nutomic.ensichat.aodvv2.{Address, Message, RequestAddContact, ResultAddContact}
 import com.nutomic.ensichat.bluetooth.ChatService
 import com.nutomic.ensichat.bluetooth.ChatService.OnMessageReceivedListener
-import com.nutomic.ensichat.messages.{Crypto, Message, RequestAddContactMessage, ResultAddContactMessage}
+import com.nutomic.ensichat.messages.Crypto
 import com.nutomic.ensichat.util.{DevicesAdapter, IdenticonGenerator}
 
 import scala.collection.SortedSet
@@ -92,7 +90,7 @@ class AddContactsActivity extends EnsiChatActivity with ChatService.OnNearbyCont
       return
     }
 
-    service.send(new RequestAddContactMessage(Crypto.getLocalAddress, address, new Date()))
+    service.sendTo(address, new RequestAddContact())
     addDeviceDialog(address)
   }
 
@@ -108,12 +106,10 @@ class AddContactsActivity extends EnsiChatActivity with ChatService.OnNearbyCont
           currentlyAdding +=
             (address -> new AddContactInfo(currentlyAdding(address).localConfirmed, true))
           addContactIfBothConfirmed(address)
-          service.send(
+          service.sendTo(address, new ResultAddContact(true))
-            new ResultAddContactMessage(Crypto.getLocalAddress, address, new Date(), true))
         case DialogInterface.BUTTON_NEGATIVE =>
           // Local user denied adding contact, send info to other device.
-          service.send(
+          service.sendTo(address, new ResultAddContact(false))
-            new ResultAddContactMessage(Crypto.getLocalAddress, address, new Date(), false))
       }
     }
 
@@ -137,27 +133,28 @@ class AddContactsActivity extends EnsiChatActivity with ChatService.OnNearbyCont
   }
 
   /**
-   * Handles incoming [[RequestAddContactMessage]] and [[ResultAddContactMessage]] messages.
+   * Handles incoming [[RequestAddContact]] and [[ResultAddContact]] messages.
    *
    * These are only handled here and require user action, so contacts can only be added if
    * the user is in this activity.
    */
   override def onMessageReceived(messages: SortedSet[Message]): Unit = {
-    messages.filter(_.receiver == Crypto.getLocalAddress)
+    messages.filter(_.Header.Target == Crypto.getLocalAddress)
       .foreach{
-        case m: RequestAddContactMessage =>
+        case m if m.Body.isInstanceOf[RequestAddContact] =>
-          Log.i(Tag, "Remote device " + m.sender + " wants to add us as a contact, showing dialog")
+          Log.i(Tag, "Remote device " + m.Header.Origin + " wants to add us as a contact, showing dialog")
-          addDeviceDialog(m.sender)
+          addDeviceDialog(m.Header.Origin)
-        case m: ResultAddContactMessage =>
+        case m if m.Body.isInstanceOf[ResultAddContact] =>
-          if (m.Accepted) {
+          val origin = m.Header.Origin
-            Log.i(Tag, "Remote device " + m.sender + " accepted us as a contact, updating state")
+          if (m.Body.asInstanceOf[ResultAddContact].Accepted) {
-            currentlyAdding += (m.sender ->
+            Log.i(Tag, "Remote device " + origin + " accepted us as a contact, updating state")
-              new AddContactInfo(true, currentlyAdding(m.sender).remoteConfirmed))
+            currentlyAdding += (origin ->
-            addContactIfBothConfirmed(m.sender)
+              new AddContactInfo(true, currentlyAdding(origin).remoteConfirmed))
+            addContactIfBothConfirmed(origin)
           } else {
-            Log.i(Tag, "Remote device " + m.sender + " denied us as a contact, showing toast")
+            Log.i(Tag, "Remote device " + origin + " denied us as a contact, showing toast")
             Toast.makeText(this, R.string.contact_not_added, Toast.LENGTH_LONG).show()
-            currentlyAdding -= m.sender
+            currentlyAdding -= origin
           }
         case _ =>
       }

app/src/main/scala/com/nutomic/ensichat/aodvv2/ConnectionInfo.scala

@@ -34,11 +34,22 @@ object ConnectionInfo {
  */
 class ConnectionInfo(val key: PublicKey) extends MessageBody {
 
+  override def Type = ConnectionInfo.Type
+
   override def write: Array[Byte] = {
-    val b = ByteBuffer.allocate(4 + key.getEncoded.length)
+    val b = ByteBuffer.allocate(length)
     BufferUtils.putUnsignedInt(b, key.getEncoded.length)
     b.put(key.getEncoded)
     b.array()
   }
 
+  override def equals(a: Any): Boolean = a match {
+    case o: ConnectionInfo => key == o.key
+    case _ => false
+  }
+
+  override def toString = "ConnectionInfo(key=" + key + ")"
+
+  override def length = 4 + key.getEncoded.length
+
 }

app/src/main/scala/com/nutomic/ensichat/aodvv2/CryptoData.scala

@@ -0,0 +1,67 @@
+package com.nutomic.ensichat.aodvv2
+
+import java.nio.ByteBuffer
+import java.util.Arrays
+
+import com.nutomic.ensichat.util.BufferUtils
+
+object CryptoData {
+
+  /**
+   * Constructs [[CryptoData]] instance from byte array.
+   */
+  def read(array: Array[Byte]): (CryptoData, Array[Byte]) = {
+    val b = ByteBuffer.wrap(array)
+    val signatureLength = BufferUtils.getUnsignedInt(b).toInt
+    val signature = new Array[Byte](signatureLength)
+    b.get(signature, 0, signatureLength)
+
+    val keyLength = BufferUtils.getUnsignedInt(b).toInt
+    val key =
+      if (keyLength != 0) {
+        val key = new Array[Byte](keyLength)
+        b.get(key, 0, keyLength)
+        Some(key)
+      }
+      else None
+
+    val remaining = new Array[Byte](b.remaining())
+    b.get(remaining, 0, b.remaining())
+    (new CryptoData(Some(signature), key), remaining)
+
+  }
+
+}
+
+/**
+ * Holds the signature and (optional) key that are stored in a message.
+ */
+class CryptoData(val Signature: Option[Array[Byte]], val Key: Option[Array[Byte]]) {
+
+  override def equals(a: Any): Boolean = a match {
+    case o: CryptoData =>
+      Arrays.equals(Signature.orNull, o.Signature.orNull) && Arrays.equals(Key.orNull, o.Key.orNull)
+    case _ => false
+  }
+
+  /**
+   * Writes this object into a new byte array.
+   * @return
+   */
+  def write: Array[Byte] = {
+    val b = ByteBuffer.allocate(length)
+    BufferUtils.putUnsignedInt(b, Signature.get.length)
+    b.put(Signature.get)
+    BufferUtils.putUnsignedInt(b, keyLength)
+    if (Key.nonEmpty) b.put(Key.get)
+    b.array()
+  }
+
+  def length = 8 + Signature.get.length + keyLength
+
+  private def keyLength = if (Key.isDefined) Key.get.length else 0
+
+  override def toString = "CryptoData(Signature.length=" + Signature.foreach(_.length) +
+    ", Key.length=" + Key.foreach(_.length) + ")"
+
+}

app/src/main/scala/com/nutomic/ensichat/aodvv2/Data.scala

@@ -1,37 +0,0 @@
-package com.nutomic.ensichat.aodvv2
-
-import java.nio.ByteBuffer
-
-import com.nutomic.ensichat.util.BufferUtils
-
-object Data {
-
-  val Type = 255
-
-  /**
-   * Constructs [[Data]] object from byte array.
-   */
-  def read(array: Array[Byte]): Data = {
-    val b = ByteBuffer.wrap(array)
-    val length = BufferUtils.getUnsignedInt(b).toInt
-    val data = new Array[Byte](length)
-    b.get(data, 0, length)
-    new Data(data)
-  }
-
-}
-
-/**
- * Container for [[com.nutomic.ensichat.messages.Message]] objects.
- */
-@Deprecated
-class Data(val data: Array[Byte]) extends MessageBody {
-
-  override def write: Array[Byte] = {
-    val b = ByteBuffer.allocate(4 + data.length)
-    BufferUtils.putUnsignedInt(b, data.length)
-    b.put(data)
-    b.array()
-  }
-
-}

app/src/main/scala/com/nutomic/ensichat/aodvv2/EncryptedBody.scala

@@ -0,0 +1,15 @@
+package com.nutomic.ensichat.aodvv2
+
+/**
+ * Represents the data in an encrypted message body.
+ */
+class EncryptedBody(val Data: Array[Byte]) extends MessageBody {
+
+  override def Type = -1
+
+  def write = Data
+
+  override def toString = "EncryptedBody(Data.length=" + Data.length + ")"
+
+  override def length = Data.length
+}

app/src/main/scala/com/nutomic/ensichat/aodvv2/Message.scala

@@ -0,0 +1,50 @@
+package com.nutomic.ensichat.aodvv2
+
+import java.io.InputStream
+
+object Message {
+
+  /**
+   * Orders messages by date, oldest messages first.
+   */
+  val Ordering = new Ordering[Message] {
+    override def compare(m1: Message, m2: Message) =  m1.Header.Time.compareTo(m2.Header.Time)
+  }
+
+  def read(stream: InputStream): Message = {
+    val headerBytes = new Array[Byte](MessageHeader.Length)
+    stream.read(headerBytes, 0, MessageHeader.Length)
+    val header = MessageHeader.read(headerBytes)
+
+    val contentLength = (header.Length - MessageHeader.Length).toInt
+    val contentBytes = new Array[Byte](contentLength)
+    stream.read(contentBytes, 0, contentLength)
+
+    val (crypto, remaining) = CryptoData.read(contentBytes)
+
+    val body =
+      header.MessageType match {
+        case ConnectionInfo.Type => ConnectionInfo.read(remaining)
+        case _                   => new EncryptedBody(remaining)
+      }
+
+    new Message(header, crypto, body)
+  }
+
+}
+
+class Message(val Header: MessageHeader, val Crypto: CryptoData, val Body: MessageBody) {
+
+  def this(header: MessageHeader, body: MessageBody) =
+    this(header, new CryptoData(None, None), body)
+
+  def write = Header.write(Body.length + Crypto.length) ++ Crypto.write ++ Body.write
+
+  override def toString = "Message(Header=" + Header + ", Body=" + Body + ", Crypto=" + Crypto + ")"
+
+  override def equals(a: Any): Boolean = a match {
+    case o: Message => Header == o.Header && Body == o.Body && Crypto == o.Crypto
+    case _ => false
+  }
+
+}

app/src/main/scala/com/nutomic/ensichat/aodvv2/MessageBody.scala

@@ -1,14 +1,19 @@
 package com.nutomic.ensichat.aodvv2
 
+import android.util.Log
+
 /**
  * Holds the actual message content.
  */
 abstract class MessageBody {
 
+  def Type: Int
+
   /**
    * Writes the message contents to a byte array.
-   * @return
    */
   def write: Array[Byte]
 
+  def length: Int
+
 }

app/src/main/scala/com/nutomic/ensichat/aodvv2/MessageHeader.scala

@@ -7,11 +7,11 @@ import com.nutomic.ensichat.util.BufferUtils
 
 object MessageHeader {
 
-  val Length = 16 + 2 * Address.Length
+  val Length = 20 + 2 * Address.Length
 
   val DefaultHopLimit = 20
 
-  val Version = 3
+  val Version = 0
 
   class ParseMessageException(detailMessage: String) extends RuntimeException(detailMessage) {
   }
@@ -38,7 +38,7 @@ object MessageHeader {
     val seqNum = BufferUtils.getUnsignedShort(b)
     val metric = BufferUtils.getUnsignedByte(b)
 
-    new MessageHeader(messageType, hopLimit, time, origin, target, seqNum, metric, length, hopCount)
+    new MessageHeader(messageType, hopLimit, origin, target, seqNum, metric, time, length, hopCount)
   }
 
 }
@@ -48,27 +48,26 @@ object MessageHeader {
  */
 class MessageHeader(val MessageType: Int,
                     val HopLimit: Int,
-                    val Time: Date,
                     val Origin: Address,
                     val Target: Address,
                     val SequenceNumber: Int,
                     val Metric: Int,
+                    val Time: Date = new Date(),
                     val Length: Long = -1,
                     val HopCount: Int = 0) {
 
   /**
    * Writes the header to byte array.
    */
-  def write(body: MessageBody): Array[Byte] = {
+  def write(contentLength: Int): Array[Byte] = {
     val b = ByteBuffer.allocate(MessageHeader.Length)
-    val bodyBytes = body.write
 
     val versionAndType = (MessageHeader.Version << 12) | MessageType
     BufferUtils.putUnsignedShort(b, versionAndType)
     BufferUtils.putUnsignedByte(b, HopLimit)
     BufferUtils.putUnsignedByte(b, HopCount)
 
-    BufferUtils.putUnsignedInt(b, MessageHeader.Length + bodyBytes.length)
+    BufferUtils.putUnsignedInt(b, MessageHeader.Length + contentLength)
     b.putInt((Time.getTime / 1000).toInt)
     b.put(Origin.Bytes)
     b.put(Target.Bytes)
@@ -77,7 +76,7 @@ class MessageHeader(val MessageType: Int,
     BufferUtils.putUnsignedByte(b, Metric)
     BufferUtils.putUnsignedByte(b, 0)
 
-    b.array() ++ bodyBytes
+    b.array()
   }
 
   override def equals(a: Any): Boolean = a match {
@@ -89,9 +88,8 @@ class MessageHeader(val MessageType: Int,
         Target == o.Target &&
         SequenceNumber == o.SequenceNumber &&
         Metric == o.Metric &&
-        // Don't compare length as it may be unknown (when header was just created without a body).
-        //Length == o.Length &&
         HopCount == o.HopCount
+        // Don't compare length as it may be unknown (when header was just created without a body).
     case _ => false
   }
 

app/src/main/scala/com/nutomic/ensichat/aodvv2/RequestAddContact.scala

@@ -0,0 +1,34 @@
+package com.nutomic.ensichat.aodvv2
+
+import java.nio.ByteBuffer
+
+object RequestAddContact {
+
+  val Type = 4
+
+  /**
+   * Constructs [[RequestAddContact]] instance from byte array.
+   */
+  def read(array: Array[Byte]): RequestAddContact = {
+    new RequestAddContact()
+  }
+
+}
+
+/**
+ * Sent when the user initiates adding another device as a contact.
+ */
+class RequestAddContact extends MessageBody {
+
+  override def Type = RequestAddContact.Type
+
+  override def write: Array[Byte] = {
+    val b = ByteBuffer.allocate(length)
+    b.array()
+  }
+
+  override def toString = "RequestAddContact()"
+
+  override def length = 4
+
+}

app/src/main/scala/com/nutomic/ensichat/aodvv2/ResultAddContact.scala

@@ -0,0 +1,41 @@
+package com.nutomic.ensichat.aodvv2
+
+import java.nio.ByteBuffer
+
+import com.nutomic.ensichat.util.BufferUtils
+
+object ResultAddContact {
+
+  val Type = 5
+
+  /**
+   * Constructs [[ResultAddContact]] instance from byte array.
+   */
+  def read(array: Array[Byte]): ResultAddContact = {
+    val b = ByteBuffer.wrap(array)
+    val first = BufferUtils.getUnsignedByte(b)
+    val accepted = (first & 0x80) != 0
+    new ResultAddContact(accepted)
+  }
+
+}
+
+/**
+ * Contains the result of a [[RequestAddContact]] message.
+ */
+class ResultAddContact(val Accepted: Boolean) extends MessageBody {
+
+  override def Type = ResultAddContact.Type
+
+  override def write: Array[Byte] = {
+    val b = ByteBuffer.allocate(length)
+    BufferUtils.putUnsignedByte(b, if (Accepted) 0x80 else 0)
+    (0 to 1).foreach(_ => BufferUtils.putUnsignedByte(b, 0))
+    b.array()
+  }
+
+  override def toString = "ResultAddContact(Accepted=" + Accepted + ")"
+
+  override def length = 4
+
+}

app/src/main/scala/com/nutomic/ensichat/aodvv2/Text.scala

@@ -0,0 +1,50 @@
+package com.nutomic.ensichat.aodvv2
+
+import java.nio.ByteBuffer
+
+import com.nutomic.ensichat.util.BufferUtils
+
+object Text {
+
+  val Type = 6
+
+  val Charset = "UTF-8"
+
+  /**
+   * Constructs [[Text]] instance from byte array.
+   */
+  def read(array: Array[Byte]): Text = {
+    val b = ByteBuffer.wrap(array)
+    val length = BufferUtils.getUnsignedInt(b).toInt
+    val bytes = new Array[Byte](length)
+    b.get(bytes, 0, length)
+    new Text(new String(bytes, Text.Charset))
+  }
+
+}
+
+/**
+ * Holds a plain text message.
+ */
+class Text(val text: String) extends MessageBody {
+
+  override def Type = Text.Type
+
+  override def write: Array[Byte] = {
+    val bytes = text.getBytes(Text.Charset)
+    val b = ByteBuffer.allocate(4 + bytes.length)
+    BufferUtils.putUnsignedInt(b, bytes.length)
+    b.put(bytes)
+    b.array()
+  }
+
+  override def equals(a: Any): Boolean = a match {
+    case o: Text => text == o.text
+    case _ => false
+  }
+
+  override def toString = "Text(" + text + ")"
+
+  override def length = write.length
+
+}

app/src/main/scala/com/nutomic/ensichat/bluetooth/ChatService.scala

@@ -1,6 +1,6 @@
 package com.nutomic.ensichat.bluetooth
 
-import java.util.{Date, UUID}
+import java.util.UUID
 
 import android.app.Service
 import android.bluetooth.{BluetoothAdapter, BluetoothDevice, BluetoothSocket}
@@ -14,7 +14,6 @@ import com.nutomic.ensichat.aodvv2._
 import com.nutomic.ensichat.bluetooth.ChatService.{OnMessageReceivedListener, OnNearbyContactsChangedListener}
 import com.nutomic.ensichat.messages._
 import com.nutomic.ensichat.util.Database
-import org.msgpack.ScalaMessagePack
 
 import scala.collection.SortedSet
 import scala.collection.immutable.{HashMap, HashSet, TreeSet}
@@ -77,6 +76,8 @@ class ChatService extends Service {
 
   private lazy val Crypto = new Crypto(this)
 
+  private var discovered = Set[Device]()
+
   private val AddressDeviceMap = HashBiMap.create[Address, Device.ID]()
 
   /**
@@ -89,6 +90,8 @@ class ChatService extends Service {
 
     registerReceiver(DeviceDiscoveredReceiver, new IntentFilter(BluetoothDevice.ACTION_FOUND))
     registerReceiver(BluetoothStateReceiver, new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED))
+    registerReceiver(DiscoveryFinishedReceiver,
+      new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED))
     if (bluetoothAdapter.isEnabled) {
       startBluetoothConnections()
     }
@@ -116,6 +119,7 @@ class ChatService extends Service {
     cancelDiscovery = true
     unregisterReceiver(DeviceDiscoveredReceiver)
     unregisterReceiver(BluetoothStateReceiver)
+    unregisterReceiver(DiscoveryFinishedReceiver)
   }
 
   /**
@@ -126,12 +130,12 @@ class ChatService extends Service {
       return
 
     if (!bluetoothAdapter.isDiscovering) {
-      Log.v(Tag, "Running discovery")
+      Log.v(Tag, "Starting discovery")
       bluetoothAdapter.startDiscovery()
     }
 
     val scanInterval = PreferenceManager.getDefaultSharedPreferences(this)
-      .getString("scan_interval_seconds", "5").toInt * 1000
+      .getString("scan_interval_seconds", "15").toInt * 1000
     MainHandler.postDelayed(new Runnable {
       override def run(): Unit = discover()
     }, scanInterval)
@@ -142,10 +146,21 @@ class ChatService extends Service {
    */
   private val DeviceDiscoveredReceiver = new BroadcastReceiver() {
     override def onReceive(context: Context, intent: Intent) {
-      val device: Device =
+      discovered += new Device(intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE), false)
-        new Device(intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE), false)
+    }
-      devices += (device.Id -> device)
+  }
-      new ConnectThread(device, onConnectionChanged).start()
+
+  /**
+   * Iniates the actual connection to discovered devices.
+   */
+  private val DiscoveryFinishedReceiver = new BroadcastReceiver() {
+    override def onReceive(context: Context, intent: Intent): Unit = {
+      discovered.filterNot(d => connections.keySet.contains(d.Id))
+        .foreach { d =>
+        new ConnectThread(d, onConnectionChanged).start()
+        devices += (d.Id -> d)
+      }
+      discovered = Set[Device]()
     }
   }
 
@@ -200,7 +215,7 @@ class ChatService extends Service {
   def onConnectionChanged(device: Device, socket: BluetoothSocket): Unit = {
     devices += (device.Id -> device)
 
-    if (device.Connected) {
+    if (device.Connected && !connections.keySet.contains(device.Id)) {
       connections += (device.Id ->
         new TransferThread(device, socket, this, Crypto, onReceiveMessage))
       connections(device.Id).start()
@@ -219,79 +234,75 @@ class ChatService extends Service {
   }
 
   /**
-   * Sends message to the device specified as receiver,
+   * Sends a new message to the given target address.
    */
-  def send(message: Message): Unit = {
+  def sendTo(target: Address, body: MessageBody): Unit = {
-    assert(message.sender == Crypto.getLocalAddress, "Message must be sent from local device")
+    if (!AddressDeviceMap.containsKey(target)) {
-
+      Log.w(Tag, "Receiver " + target + " is not connected, ignoring message")
-    if (!AddressDeviceMap.containsKey(message.receiver)) {
-      Log.w(Tag, "Receiver " + message.receiver + " is not connected, ignoring message")
       return
     }
 
-    val header = new MessageHeader(Data.Type, MessageHeader.DefaultHopLimit,
+    val header = new MessageHeader(body.Type, MessageHeader.DefaultHopLimit,
-      new Date(), Crypto.getLocalAddress, message.receiver, 0, 0)
+      Crypto.getLocalAddress, target, 0, 0)
 
-    val plain = message.write(Crypto.calculateSignature(message))
+    val msg = new Message(header, body)
-    val (encrypted, key) = Crypto.encrypt(message.receiver, plain)
+    val encrypted = Crypto.encrypt(Crypto.sign(msg))
-    val packer = new ScalaMessagePack().createBufferPacker()
+    connections.apply(AddressDeviceMap.get(target)).send(encrypted)
-    packer
+    Database.addMessage(msg)
-      .write(encrypted)
+    callMessageReceivedListeners(msg)
-      .write(key)
-    val body = new Data(packer.toByteArray)
-
-    connections.apply(AddressDeviceMap.get(message.receiver)).send(header, body)
-    Database.addMessage(message)
   }
 
   /**
    * Saves the message to database and sends it to registered listeners.
    *
-   * If you want to send a new message, use [[send]].
+   * If you want to send a new message, use [[sendTo]].
    *
    * Messages must always be sent between local device and a contact.
    *
-   * NOTE: Messages sent from the local node using [[send]] are also passed through this method.
+   * NOTE: Messages sent from the local node using [[sendTo]] are also passed through this method.
    */
-  private def onReceiveMessage(header: MessageHeader, body: MessageBody, device: Device.ID): Unit = {
+  private def onReceiveMessage(message: Message, device: Device.ID): Unit = {
-    assert(header.Origin != Crypto.getLocalAddress)
+    assert(message.Header.Origin != Crypto.getLocalAddress)
 
-    body match {
+    message.Body match {
       case info: ConnectionInfo =>
-        if (header.Origin == Crypto.getLocalAddress)
+        if (message.Header.Origin == Crypto.getLocalAddress)
           return
         onNeighborConnected(info, device)
-      case data: Data =>
+      case _ =>
-        val up = new ScalaMessagePack().createBufferUnpacker(data.data)
+        val decrypted = Crypto.decrypt(message)
-        val encrypted = up.readByteArray()
+        if (!Crypto.verify(decrypted)) {
-        val key = up.readByteArray()
+          Log.i(Tag, "Dropping message with invalid signature from " + message.Header.Origin)
-        val (message, signature) = Message.read(Crypto.decrypt(encrypted, key))
-
-        if (!Crypto.isValidSignature(message, signature)) {
-          Log.i(Tag, "Dropping message with invalid signature from " + header.Origin)
           return
         }
 
-        Database.addMessage(message)
+        callMessageReceivedListeners(decrypted)
-        MainHandler.post(new Runnable {
+        Database.addMessage(decrypted)
-          override def run(): Unit = {
-            messageListeners.foreach(l =>
-              if (l.get != null)
-                l.apply().onMessageReceived(new TreeSet[Message]()(Message.Ordering) + message)
-              else
-                messageListeners -= l)
-          }
-        })
     }
   }
 
+  /**
+   * Calls all [[OnMessageReceivedListener]]s with the new message.
+   */
+  private def callMessageReceivedListeners(message: Message): Unit = {
+    MainHandler.post(new Runnable {
+      override def run(): Unit = {
+        messageListeners.foreach(l =>
+          if (l.get != null)
+            l.apply().onMessageReceived(new TreeSet[Message]()(Message.Ordering) + message)
+          else
+            messageListeners -= l)
+      }
+    })
+  }
+
   /**
    * Called when a [[ConnectionInfo]] message from a new neighbor is received.
    */
   private def onNeighborConnected(info: ConnectionInfo, device: Device.ID): Unit = {
     val sender = Crypto.calculateAddress(info.key)
     if (sender == Address.Broadcast || sender == Address.Null) {
-      connections(device).close()
+      Log.i(Tag, "Received ConnectionInfo message with invalid sender " + sender + ", ignoring")
       return
     }
 

app/src/main/scala/com/nutomic/ensichat/bluetooth/ConnectThread.scala

@@ -22,7 +22,7 @@ class ConnectThread(device: Device, onConnected: (Device, BluetoothSocket) => Un
       Socket.connect()
     } catch {
       case e: IOException =>
-        Log.w(Tag, "Failed to connect to " + device.toString, e)
+        Log.v(Tag, "Failed to connect to " + device.toString, e)
         try {
           Socket.close()
         } catch {

app/src/main/scala/com/nutomic/ensichat/bluetooth/ListenThread.scala

@@ -41,6 +41,7 @@ class ListenThread(name: String, adapter: BluetoothAdapter,
       }
 
       val device: Device = new Device(socket.getRemoteDevice, true)
+      Log.i(Tag, "Incoming connection from " + device.toString)
       onConnected(device, socket)
     }
   }

app/src/main/scala/com/nutomic/ensichat/bluetooth/TransferThread.scala

@@ -1,7 +1,6 @@
 package com.nutomic.ensichat.bluetooth
 
 import java.io._
-import java.util.Date
 
 import android.bluetooth.BluetoothSocket
 import android.util.Log
@@ -18,7 +17,7 @@ import com.nutomic.ensichat.messages.Crypto
  * @param onReceive Called when a message was received from the other device.
  */
 class TransferThread(device: Device, socket: BluetoothSocket, service: ChatService,
-                     crypto: Crypto, onReceive: (MessageHeader, MessageBody, Device.ID) => Unit)
+                     crypto: Crypto, onReceive: (Message, Device.ID) => Unit)
   extends Thread {
 
   private val Tag: String = "TransferThread"
@@ -44,26 +43,16 @@ class TransferThread(device: Device, socket: BluetoothSocket, service: ChatServi
   override def run(): Unit = {
     Log.i(Tag, "Starting data transfer with " + device.toString)
 
-    send(new MessageHeader(ConnectionInfo.Type, ConnectionInfo.HopLimit, new Date(), Address.Null,
+    send(crypto.sign(new Message(new MessageHeader(ConnectionInfo.Type, ConnectionInfo.HopLimit,
-      Address.Null, 0, 0), new ConnectionInfo(crypto.getLocalPublicKey))
+      Address.Null, Address.Null, 0, 0), new ConnectionInfo(crypto.getLocalPublicKey))))
 
     while (socket.isConnected) {
       try {
-        val headerBytes = new Array[Byte](MessageHeader.Length)
+        if (InStream.available() > 0) {
-        InStream.read(headerBytes, 0, MessageHeader.Length)
+          val msg = Message.read(InStream)
-        val header = MessageHeader.read(headerBytes)
-        val bodyLength = (header.Length - MessageHeader.Length).toInt
 
-        val bodyBytes = new Array[Byte](bodyLength)
+          onReceive(msg, device.Id)
-        InStream.read(bodyBytes, 0, bodyLength)
+        }
-
-        val body =
-          header.MessageType match {
-            case ConnectionInfo.Type => ConnectionInfo.read(bodyBytes)
-            case Data.Type           => Data.read(bodyBytes)
-          }
-
-        onReceive(header, body, device.Id)
       } catch {
         case e: RuntimeException =>
           Log.i(Tag, "Received invalid message", e)
@@ -73,11 +62,12 @@ class TransferThread(device: Device, socket: BluetoothSocket, service: ChatServi
       }
     }
     service.onConnectionChanged(new Device(device.bluetoothDevice, false), null)
+    Log.i(Tag, "Neighbor " + device + " has disconnected")
   }
 
-  def send(header: MessageHeader, body: MessageBody): Unit = {
+  def send(msg: Message): Unit = {
     try {
-      OutStream.write(header.write(body))
+      OutStream.write(msg.write)
     } catch {
       case e: IOException => Log.e(Tag, "Failed to write message", e)
     }
@@ -85,6 +75,7 @@ class TransferThread(device: Device, socket: BluetoothSocket, service: ChatServi
 
   def close(): Unit = {
     try {
+      Log.i(Tag, "Closing connection to " + device)
       socket.close()
     } catch {
       case e: IOException => Log.e(Tag, "Failed to close socket", e);

app/src/main/scala/com/nutomic/ensichat/fragments/ChatFragment.scala

@@ -1,7 +1,5 @@
 package com.nutomic.ensichat.fragments
 
-import java.util.Date
-
 import android.app.ListFragment
 import android.os.Bundle
 import android.view.View.OnClickListener
@@ -11,10 +9,9 @@ import android.widget.TextView.OnEditorActionListener
 import android.widget._
 import com.nutomic.ensichat.R
 import com.nutomic.ensichat.activities.EnsiChatActivity
-import com.nutomic.ensichat.aodvv2.Address
+import com.nutomic.ensichat.aodvv2.{Address, Message, Text}
 import com.nutomic.ensichat.bluetooth.ChatService
 import com.nutomic.ensichat.bluetooth.ChatService.OnMessageReceivedListener
-import com.nutomic.ensichat.messages.{Crypto, Message, TextMessage}
 import com.nutomic.ensichat.util.MessagesAdapter
 
 import scala.collection.SortedSet
@@ -43,7 +40,7 @@ class ChatFragment extends ListFragment with OnClickListener
 
   private var listView: ListView = _
 
-  private var adapter: ArrayAdapter[TextMessage] = _
+  private var adapter: ArrayAdapter[Message] = _
 
   override def onActivityCreated(savedInstanceState: Bundle): Unit = {
     super.onActivityCreated(savedInstanceState)
@@ -103,10 +100,8 @@ class ChatFragment extends ListFragment with OnClickListener
     case R.id.send =>
       val text = messageText.getText.toString.trim
       if (!text.isEmpty) {
-        val message =
+        val message = new Text(text.toString)
-          new TextMessage(Crypto.getLocalAddress(getActivity), address, new Date(), text.toString)
+        chatService.sendTo(address, message)
-        chatService.send(message)
-        adapter.add(message)
         messageText.getText.clear()
       }
   }
@@ -115,9 +110,8 @@ class ChatFragment extends ListFragment with OnClickListener
    * Displays new messages in UI.
    */
   override def onMessageReceived(messages: SortedSet[Message]): Unit = {
-    messages.filter(m => m.sender == address || m.receiver == address)
+    messages.filter(m => Set(m.Header.Origin, m.Header.Target).contains(address))
-      .filter(_.isInstanceOf[TextMessage])
+      .foreach(adapter.add)
-      .foreach(m => adapter.add(m.asInstanceOf[TextMessage]))
   }
 
   /**

app/src/main/scala/com/nutomic/ensichat/messages/Crypto.scala

@@ -9,7 +9,7 @@ import javax.crypto.{Cipher, CipherOutputStream, KeyGenerator, SecretKey}
 import android.content.Context
 import android.preference.PreferenceManager
 import android.util.Log
-import com.nutomic.ensichat.aodvv2.Address
+import com.nutomic.ensichat.aodvv2._
 import com.nutomic.ensichat.messages.Crypto._
 import com.nutomic.ensichat.util.PRNGFixes
 
@@ -107,6 +107,7 @@ class Crypto(Context: Context) {
    *
    * @throws RuntimeException If the key does not exist.
    */
+  @throws[RuntimeException]
   def getPublicKey(address: Address): PublicKey = {
     loadKey(address.toString, classOf[PublicKey])
   }
@@ -114,49 +115,32 @@ class Crypto(Context: Context) {
   /**
    * Adds a new public key for a remote device.
    *
-   * If a key for the device already exists, nothing is done.
+   * @throws RuntimeException If a this key
-   *
-   * @param address The device to which the key belongs.
-   * @param key The new key to add.
    */
+  @throws[RuntimeException]
   def addPublicKey(address: Address, key: PublicKey): Unit = {
-    if (!havePublicKey(address)) {
+    if (havePublicKey(address))
-      saveKey(address.toString, key)
+      throw new RuntimeException("Already have key for " + address + ", not overwriting")
-    } else {
+
-      Log.i(Tag, "Already have key for " + address.toString + ", not overwriting")
+    saveKey(address.toString, key)
-    }
   }
 
-  /**
+  def sign(msg: Message): Message = {
-   * Checks if the message was properly signed.
-   *
-   * This is done by signing the output of [[Message.write()]] called with an empty signature.
-   *
-   * @param message The message to verify.
-   * @param signature The signature that was sent
-   * @return True if the signature is valid.
-   */
-  def isValidSignature(message: Message, signature: Array[Byte], key: PublicKey = null): Boolean = {
-    val publicKey =
-      if (key != null) key
-      else loadKey(message.sender.toString, classOf[PublicKey])
-    val sig = Signature.getInstance(SignAlgorithm)
-    sig.initVerify(publicKey)
-    sig.update(message.write(Array[Byte]()))
-    sig.verify(signature)
-  }
-
-  /**
-   * Returns a cryptographic signature for the given message (using local private key).
-   *
-   * This is done by signing the output of [[Message.write()]] called with an empty signature.
-   */
-  def calculateSignature(message: Message): Array[Byte] = {
     val sig = Signature.getInstance(SignAlgorithm)
     val key = loadKey(PrivateKeyAlias, classOf[PrivateKey])
     sig.initSign(key)
-    sig.update(message.write(Array[Byte]()))
+    sig.update(msg.Body.write)
-    sig.sign
+    new Message(msg.Header, new CryptoData(Option(sig.sign), None), msg.Body)
+  }
+
+  def verify(msg: Message, key: PublicKey = null): Boolean = {
+    val publicKey =
+      if (key != null) key
+      else loadKey(msg.Header.Origin.toString, classOf[PublicKey])
+    val sig = Signature.getInstance(SignAlgorithm)
+    sig.initVerify(publicKey)
+    sig.update(msg.Body.write)
+    sig.verify(msg.Crypto.Signature.get)
   }
 
   /**
@@ -239,50 +223,42 @@ class Crypto(Context: Context) {
    */
   private def keyFolder = new File(Context.getFilesDir, "keys")
 
-  /**
+  def encrypt(msg: Message, key: PublicKey = null): Message = {
-   * Encrypts data for the given receiver.
+    assert(msg.Crypto.Signature.isDefined, "Message must be signed before encryption")
-   *
+
-   * @param receiver The device that should be able to decrypt this message.
-   * @param data The message to encrypt.
-   * @param key Optional RSA public key to use for encryption.
-   * @return Pair of AES encrypted data and RSA encrypted AES key.
-   */
-  def encrypt(receiver: Address, data: Array[Byte], key: PublicKey = null):
-      (Array[Byte], Array[Byte]) = {
     // Symmetric encryption of data
     val secretKey = makeSecretKey()
     val symmetricCipher = Cipher.getInstance(SymmetricCipherAlgorithm)
     symmetricCipher.init(Cipher.ENCRYPT_MODE, secretKey)
-    val encryptedData = copyThroughCipher(symmetricCipher, data)
+    val encrypted = new EncryptedBody(copyThroughCipher(symmetricCipher, msg.Body.write))
 
     // Asymmetric encryption of secret key
     val publicKey =
       if (key != null) key
-      else loadKey(receiver.toString, classOf[PublicKey])
+      else loadKey(msg.Header.Target.toString, classOf[PublicKey])
     val asymmetricCipher = Cipher.getInstance(KeyAlgorithm)
     asymmetricCipher.init(Cipher.WRAP_MODE, publicKey)
 
-    (encryptedData, asymmetricCipher.wrap(secretKey))
+    new Message(msg.Header,
+      new CryptoData(msg.Crypto.Signature, Option(asymmetricCipher.wrap(secretKey))), encrypted)
   }
 
-  /**
+  def decrypt(msg: Message): Message = {
-   * Decrypts the output of [[encrypt]].
-   *
-   * @param data The AES encrypted data to decrypt.
-   * @param key The RSA encrypted AES key used to encrypt data.
-   * @return The plain text data.
-   */
-  def decrypt(data: Array[Byte], key: Array[Byte]): Array[Byte] = {
     // Asymmetric decryption of secret key
     val asymmetricCipher = Cipher.getInstance(KeyAlgorithm)
     asymmetricCipher.init(Cipher.UNWRAP_MODE, loadKey(PrivateKeyAlias, classOf[PrivateKey]))
-    val secretKey = asymmetricCipher.unwrap(key, SymmetricKeyAlgorithm, Cipher.SECRET_KEY)
+    val key = asymmetricCipher.unwrap(msg.Crypto.Key.get, SymmetricKeyAlgorithm, Cipher.SECRET_KEY)
 
     // Symmetric decryption of data
     val symmetricCipher = Cipher.getInstance(SymmetricCipherAlgorithm)
-    symmetricCipher.init(Cipher.DECRYPT_MODE, secretKey)
+    symmetricCipher.init(Cipher.DECRYPT_MODE, key)
-    val dec = copyThroughCipher(symmetricCipher, data)
+    val decryped = copyThroughCipher(symmetricCipher, msg.Body.asInstanceOf[EncryptedBody].Data)
-    dec
+    val body = msg.Header.MessageType match {
+      case RequestAddContact.Type => RequestAddContact.read(decryped)
+      case ResultAddContact.Type => ResultAddContact.read(decryped)
+      case Text.Type => Text.read(decryped)
+    }
+    new Message(msg.Header, msg.Crypto, body)
   }
 
   /**

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

@@ -1,122 +0,0 @@
-package com.nutomic.ensichat.messages
-
-import java.io.IOException
-import java.util.{Date, Objects}
-
-import com.nutomic.ensichat.aodvv2.Address
-import org.msgpack.ScalaMessagePack
-import org.msgpack.packer.Packer
-
-object Message {
-
-  /**
-   * Types of messages that can be transfered.
-   *
-   * There must be one type for each implementation and vice versa.
-   */
-  object Type {
-    val Text = 1
-    val RequestAddContact = 2
-    val ResultAddContact = 3
-  }
-
-  /**
-   * Orders messages by date, oldest messages first.
-   */
-  val Ordering = new Ordering[Message] {
-    override def compare(m1: Message, m2: Message) =  m1.date.compareTo(m2.date)
-  }
-
-  /**
-   * Reads a byte array that was written by [[Message.write]] into the correct
-   * message implementation..
-   *
-   * @return Deserialized message and sits signature.
-   */
-  def read(bytes: Array[Byte]): (Message, Array[Byte]) = {
-    val up = new ScalaMessagePack().createBufferUnpacker(bytes)
-
-    @throws[IOException]("If the message can't be parsed")
-    @throws[RuntimeException]("If the message has an unknown type")
-    val messageType = up.readInt()
-    val sender      = new Address(up.readByteArray())
-    val receiver    = new Address(up.readByteArray())
-    val date        = new Date(up.readLong())
-    val sig         = up.readByteArray()
-    (messageType match {
-      case Type.Text              => TextMessage.read(sender, receiver, date, up)
-      case Type.RequestAddContact => RequestAddContactMessage.read(sender, receiver, date, up)
-      case Type.ResultAddContact  => ResultAddContactMessage.read(sender, receiver, date, up)
-      case t =>
-        throw new RuntimeException("Received message of unknown type " + t)
-    }, sig)
-  }
-
-}
-
-/**
- * Message object that can be sent between remote devices.
- *
- * @param messageType One of [[Message.Type]].
- */
-@Deprecated
-abstract class Message(val messageType: Int) {
-
-  /**
-   * Device where the message was sent from.
-   */
-  val sender: Address
-
-  /**
-   * Device the message is addressed to.
-   */
-  val receiver: Address
-
-  /**
-   * Timestamp of message creation.
-   */
-  val date: Date
-
-  /**
-   * Writes this message and the given signature into byte array.
-   *
-   * Signature may not be null, but can be an empty array.
-   */
-  def write(signature: Array[Byte]): Array[Byte] = {
-    val packer = new ScalaMessagePack().createBufferPacker()
-    packer.write(messageType)
-      .write(sender.Bytes)
-      .write(receiver.Bytes)
-      .write(date.getTime)
-      .write(signature)
-    doWrite(packer)
-    packer.toByteArray
-  }
-
-  /**
-   * Serializes any extra data for implementing classes.
-   */
-  protected def doWrite(packer: Packer): Unit
-
-  /**
-   * Returns true if objects are equal.
-   *
-   * Implementations must provide their own implementation to check the result of this
-   * function and their own data.
-   */
-  override def equals(a: Any): Boolean = a match {
-      case o: Message => sender == o.sender && receiver == o.receiver && date == o.date
-      case _ => false
-  }
-
-  /**
-   * Returns a hash code for this object.
-   *
-   * Implementations must provide their own implementation to check the result of this
-   * function and their own data.
-   */
-  override def hashCode: Int = Objects.hash(sender, receiver, date)
-
-  override def toString: String
-
-}

app/src/main/scala/com/nutomic/ensichat/messages/RequestAddContactMessage.scala

@@ -1,30 +0,0 @@
-package com.nutomic.ensichat.messages
-
-import java.util.Date
-
-import com.nutomic.ensichat.activities.AddContactsActivity
-import com.nutomic.ensichat.aodvv2.Address
-import com.nutomic.ensichat.messages.Message._
-import org.msgpack.packer.Packer
-import org.msgpack.unpacker.Unpacker
-
-object RequestAddContactMessage {
-
-  def read(sender: Address, receiver: Address, date: Date, up: Unpacker) =
-    new RequestAddContactMessage(sender, receiver, date)
-
-}
-
-/**
- * Message sent by [[AddContactsActivity]] to notify a device that it should be added as a contact.
- */
-class RequestAddContactMessage(override val sender: Address, override val receiver: Address,
-                               override val date: Date) extends Message(Type.RequestAddContact) {
-
-  override def doWrite(packer: Packer) = {
-  }
-
-  override def toString = "RequestAddContactMessage(" + sender.toString + ", " + receiver.toString +
-    ", " + date.toString + ")"
-
-}

app/src/main/scala/com/nutomic/ensichat/messages/ResultAddContactMessage.scala

@@ -1,37 +0,0 @@
-package com.nutomic.ensichat.messages
-
-import java.util.{Date, Objects}
-
-import com.nutomic.ensichat.activities.AddContactsActivity
-import com.nutomic.ensichat.aodvv2.Address
-import com.nutomic.ensichat.messages.Message._
-import org.msgpack.packer.Packer
-import org.msgpack.unpacker.Unpacker
-
-object ResultAddContactMessage {
-
-  def read(sender: Address, receiver: Address, date: Date, up: Unpacker) =
-    new ResultAddContactMessage(sender, receiver, date, up.readBoolean())
-
-}
-
-/**
- * Message sent by [[AddContactsActivity]] to tell a device whether the user confirmed adding it
- * to contacts.
- */
-class ResultAddContactMessage(override val sender: Address, override val receiver: Address,
-                              override val date: Date, val Accepted: Boolean)
-  extends Message(Type.ResultAddContact) {
-
-  override def doWrite(packer: Packer) = packer.write(Accepted)
-
-  override def equals(a: Any) =
-    super.equals(a) && a.asInstanceOf[ResultAddContactMessage].Accepted == Accepted
-
-  override def hashCode =
-    Objects.hash(super.hashCode: java.lang.Integer, Accepted: java.lang.Boolean)
-
-  override def toString = "ResultAddContactMessage(" + sender.toString + ", " + receiver.toString +
-    ", " + date.toString + ", " + Accepted + ")"
-
-}

app/src/main/scala/com/nutomic/ensichat/messages/TextMessage.scala

@@ -1,32 +0,0 @@
-package com.nutomic.ensichat.messages
-
-import java.util.{Date, Objects}
-
-import com.nutomic.ensichat.aodvv2.Address
-import com.nutomic.ensichat.messages.Message._
-import org.msgpack.packer.Packer
-import org.msgpack.unpacker.Unpacker
-
-object TextMessage {
-
-  def read(sender: Address, receiver: Address, date: Date, up: Unpacker): TextMessage =
-    new TextMessage(sender, receiver, date, up.readString())
-
-}
-
-/**
- * Message that contains text.
- */
-class TextMessage(override val sender: Address, override val receiver: Address,
-                  override val date: Date, val text: String) extends Message(Type.Text) {
-
-  override def doWrite(packer: Packer) = packer.write(text)
-
-  override def equals(a: Any) = super.equals(a) && a.asInstanceOf[TextMessage].text == text
-
-  override def hashCode = Objects.hash(super.hashCode: java.lang.Integer, text)
-
-  override def toString = "TextMessage(" + sender.toString + ", " + receiver.toString +
-    ", " + date.toString + ", " + text + ")"
-
-}

app/src/main/scala/com/nutomic/ensichat/util/BufferUtils.scala

@@ -2,6 +2,9 @@ package com.nutomic.ensichat.util
 
 import java.nio.ByteBuffer
 
+/**
+ * Provides various helper methods for [[ByteBuffer]].
+ */
 object BufferUtils {
 
   def getUnsignedByte(bb: ByteBuffer): Short       = (bb.get & 0xff).toShort
@@ -25,6 +28,6 @@ object BufferUtils {
     b
   }
 
-  def toString(bb: ByteBuffer)= bb.array().slice(0, 4).map("%02X" format _).mkString
+  def toString(array: Array[Byte]) = array.map("%02X".format(_)).mkString
 
 }

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

@@ -4,8 +4,7 @@ import java.util.Date
 
 import android.content.{ContentValues, Context}
 import android.database.sqlite.{SQLiteDatabase, SQLiteOpenHelper}
-import com.nutomic.ensichat.aodvv2.Address
+import com.nutomic.ensichat.aodvv2._
-import com.nutomic.ensichat.messages._
 
 import scala.collection.SortedSet
 import scala.collection.immutable.TreeSet
@@ -18,8 +17,8 @@ object Database {
 
   private val CreateMessagesTable = "CREATE TABLE messages(" +
     "_id integer primary key autoincrement," +
-    "sender text not null," +
+    "origin text not null," +
-    "receiver text not null," +
+    "target text not null," +
     "text text not null," +
     "date integer not null);" // Unix timestamp of message.
 
@@ -35,8 +34,6 @@ object Database {
 class Database(context: Context) extends SQLiteOpenHelper(context, Database.DatabaseName,
                                                           null, Database.DatabaseVersion) {
 
-  private val Tag = "MessageStore"
-
   private var contactsUpdatedListeners = Set[() => Unit]()
 
   override def onCreate(db: SQLiteDatabase): Unit = {
@@ -49,17 +46,21 @@ class Database(context: Context) extends SQLiteOpenHelper(context, Database.Data
    */
   def getMessages(address: Address, count: Int): SortedSet[Message] = {
     val c = getReadableDatabase.query(true,
-      "messages", Array("sender", "receiver", "text", "date"),
+      "messages", Array("origin", "target", "text", "date"),
-      "sender = ? OR receiver = ?", Array(address.toString, address.toString),
+      "origin = ? OR target = ?", Array(address.toString, address.toString),
       null, null, "date DESC", count.toString)
     var messages = new TreeSet[Message]()(Message.Ordering)
     while (c.moveToNext()) {
-      val m = new TextMessage(
+      val header = new MessageHeader(
-        new Address(c.getString(c.getColumnIndex("sender"))),
+        Text.Type,
-        new Address(c.getString(c.getColumnIndex("receiver"))),
+        -1,
-        new Date(c.getLong(c.getColumnIndex("date"))),
+        new Address(c.getString(c.getColumnIndex("origin"))),
-        new String(c.getString(c.getColumnIndex ("text"))))
+        new Address(c.getString(c.getColumnIndex("target"))),
-      messages += m
+        -1,
+        -1,
+        new Date(c.getLong(c.getColumnIndex("date"))))
+      val body = new Text(new String(c.getString(c.getColumnIndex ("text"))))
+      messages += new Message(header, body)
     }
     c.close()
     messages
@@ -68,16 +69,16 @@ class Database(context: Context) extends SQLiteOpenHelper(context, Database.Data
   /**
    * Inserts the given new message into the database.
    */
-  def addMessage(message: Message): Unit = message match {
+  def addMessage(message: Message): Unit = message.Body match {
-    case msg: TextMessage =>
+    case msg: Text =>
       val cv =  new ContentValues()
-      cv.put("sender", msg.sender.toString)
+      cv.put("origin", message.Header.Origin.toString)
-      cv.put("receiver", msg.receiver.toString)
+      cv.put("target", message.Header.Target.toString)
       // toString used as workaround for compile error with Long.
-      cv.put("date", msg.date.getTime.toString)
+      cv.put("date", message.Header.Time.getTime.toString)
       cv.put("text", msg.text)
       getWritableDatabase.insert("messages", null, cv)
-    case _: RequestAddContactMessage | _: ResultAddContactMessage =>
+    case _: ConnectionInfo | _: RequestAddContact | _: ResultAddContact =>
       // Never stored.
   }
 

app/src/main/scala/com/nutomic/ensichat/util/MessagesAdapter.scala

@@ -4,14 +4,13 @@ import android.content.Context
 import android.view.{Gravity, View, ViewGroup}
 import android.widget.{ArrayAdapter, RelativeLayout, TextView}
 import com.nutomic.ensichat.R
-import com.nutomic.ensichat.aodvv2.Address
+import com.nutomic.ensichat.aodvv2.{Address, Message, Text}
-import com.nutomic.ensichat.messages.TextMessage
 
 /**
- * Displays [[TextMessage]]s in ListView.
+ * Displays [[Message]]s in ListView.
  */
 class MessagesAdapter(context: Context, remoteAddress: Address) extends
-  ArrayAdapter[TextMessage](context, R.layout.item_message, android.R.id.text1) {
+  ArrayAdapter[Message](context, R.layout.item_message, android.R.id.text1) {
 
   /**
    * Free space to the right/left to a message depending on who sent it, in dip.
@@ -22,11 +21,11 @@ class MessagesAdapter(context: Context, remoteAddress: Address) extends
     val view = super.getView(position, convertView, parent).asInstanceOf[RelativeLayout]
     val tv = view.findViewById(android.R.id.text1).asInstanceOf[TextView]
 
-    tv.setText(getItem(position).text)
+    tv.setText(getItem(position).Body.asInstanceOf[Text].text)
 
     val lp = new RelativeLayout.LayoutParams(tv.getLayoutParams)
     val margin = (MessageMargin * context.getResources.getDisplayMetrics.density).toInt
-    if (getItem(position).sender != remoteAddress) {
+    if (getItem(position).Header.Origin != remoteAddress) {
       view.setGravity(Gravity.RIGHT)
       lp.setMargins(margin, 0, 0, 0)
     } else {

build.gradle

@@ -7,7 +7,7 @@ buildscript {
     }
     dependencies {
         classpath 'com.android.tools.build:gradle:0.14.2'
-        classpath 'com.github.ben-manes:gradle-versions-plugin:0.5'
+        classpath 'com.github.ben-manes:gradle-versions-plugin:0.6'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files

gradle/gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,6 @@
+#Thu Dec 04 22:57:09 EET 2014
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-2.1-bin.zip

gradle/gradlew

@@ -0,0 +1,164 @@
+#!/usr/bin/env bash
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn ( ) {
+    echo "$*"
+}
+
+die ( ) {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+esac
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched.
+if $cygwin ; then
+    [ -n "$JAVA_HOME" ] && JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
+fi
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >&-
+APP_HOME="`pwd -P`"
+cd "$SAVED" >&-
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=$((i+1))
+    done
+    case $i in
+        (0) set -- ;;
+        (1) set -- "$args0" ;;
+        (2) set -- "$args0" "$args1" ;;
+        (3) set -- "$args0" "$args1" "$args2" ;;
+        (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Split up the JVM_OPTS And GRADLE_OPTS values into an array, following the shell quoting and substitution rules
+function splitJvmOpts() {
+    JVM_OPTS=("$@")
+}
+eval splitJvmOpts $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS
+JVM_OPTS[${#JVM_OPTS[*]}]="-Dorg.gradle.appname=$APP_BASE_NAME"
+
+exec "$JAVACMD" "${JVM_OPTS[@]}" -classpath "$CLASSPATH" org.gradle.wrapper.GradleWrapperMain "$@"

gradle/gradlew.bat

@@ -0,0 +1,90 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windowz variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+if "%@eval[2+2]" == "4" goto 4NT_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+goto execute
+
+:4NT_args
+@rem Get arguments from the 4NT Shell from JP Software
+set CMD_LINE_ARGS=%$
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega

gradle/local.properties

@@ -0,0 +1,11 @@
+## This file is automatically generated by Android Studio.
+# Do not modify this file -- YOUR CHANGES WILL BE ERASED!
+#
+# This file must *NOT* be checked into Version Control Systems,
+# as it contains information specific to your local configuration.
+#
+# Location of the SDK. This is only used by Gradle.
+# For customization when using a Version Control System, please read the
+# header note.
+#Thu Dec 04 22:57:09 EET 2014
+sdk.dir=/home/felix/software/android-sdk

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,6 @@
+#Tue Dec 09 17:41:26 EET 2014
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=http\://services.gradle.org/distributions/gradle-2.1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-2.1-bin.zip