Inbound Path (#38)

* refactor invite

* Update tests

* Cleanups

* Remove ContentFrame references

examples/pingpong.nim

@@ -82,7 +82,7 @@ proc main() {.async.} =
 
   # Perform OOB Introduction: Raya -> Saro
   let raya_bundle = raya.createIntroBundle()
-  discard await saro.newPrivateConversation(raya_bundle)
+  discard await saro.newPrivateConversation(raya_bundle, initTextFrame("Init").toContentFrame().toBytes())
 
   await sleepAsync(20.seconds) # Run for some time 
 

examples/tui/tui.nim

@@ -203,7 +203,7 @@ proc drawStatusBar(app: ChatApp, layout: Pane , fg: ForegroundColor, bg: Backgro
 
   var i = layout.yStart + 1
   var chunk = layout.width - 9
-  tb.write(1, i, "Name: " & app.client.getId())
+  tb.write(1, i, "Name: " & app.client.getName())
   inc i
   tb.write(1, i, fmt"PeerCount: {app.peerCount}")
   inc i

protos/invite.proto

@@ -2,10 +2,13 @@ syntax = "proto3";
 
 package wap.invite;
 
+import "encryption.proto";
+
 message InvitePrivateV1 {
     bytes initiator = 1;
     bytes initiator_ephemeral = 2;
     bytes participant = 3;
     int32 participant_ephemeral_id= 4;
     string discriminator = 5;
+    encryption.EncryptedPayload initial_message = 6;
 }

src/chat/client.nim

@@ -54,6 +54,7 @@ type Client* = ref object
   conversations: Table[string, Conversation] # Keyed by conversation ID
   inboundQueue: QueueRef
   isRunning: bool
+  inbox: Inbox
 
   newMessageCallbacks: seq[MessageCallback]
   newConvoCallbacks: seq[NewConvoCallback]
@@ -71,6 +72,8 @@ proc newClient*(cfg: WakuConfig, ident: Identity): Client {.raises: [IOError,
     let rm = newReliabilityManager().valueOr:
       raise newException(ValueError, fmt"SDS InitializationError")
 
+    let defaultInbox = initInbox(ident)
+
     var q = QueueRef(queue: newAsyncQueue[ChatPayload](10))
     var c = Client(ident: ident,
                   ds: waku,
@@ -78,14 +81,14 @@ proc newClient*(cfg: WakuConfig, ident: Identity): Client {.raises: [IOError,
                   conversations: initTable[string, Conversation](),
                   inboundQueue: q,
                   isRunning: false,
+                  inbox: defaultInbox,
                   newMessageCallbacks: @[],
                   newConvoCallbacks: @[])
 
-    let defaultInbox = initInbox(c.ident.getPubkey())
     c.conversations[defaultInbox.id()] = defaultInbox
 
-    notice "Client started", client = c.ident.getId(),
+    notice "Client started", client = c.ident.getName(),
-        defaultInbox = defaultInbox
+        defaultInbox = defaultInbox, inTopic= topic_inbox(c.ident.get_addr())
     result = c
   except Exception as e:
     error "newCLient", err = e.msg
@@ -95,7 +98,7 @@ proc newClient*(cfg: WakuConfig, ident: Identity): Client {.raises: [IOError,
 #################################################
 
 proc getId*(client: Client): string =
-  result = client.ident.getId()
+  result = client.ident.getName()
 
 proc identity*(client: Client): Identity =
   result = client.ident
@@ -174,7 +177,7 @@ proc createIntroBundle*(self: var Client): IntroBundle =
 #################################################
 
 proc addConversation*(client: Client, convo: Conversation) =
-  notice "Creating conversation", client = client.getId(), topic = convo.id()
+  notice "Creating conversation", client = client.getId(), convoId = convo.id()
   client.conversations[convo.id()] = convo
   client.notifyNewConversation(convo)
 
@@ -183,47 +186,15 @@ proc getConversation*(client: Client, convoId: string): Conversation =
   result = client.conversations[convoId]
 
 proc newPrivateConversation*(client: Client,
-    introBundle: IntroBundle): Future[Option[ChatError]] {.async.} =
+    introBundle: IntroBundle, content: Content): Future[Option[ChatError]] {.async.} =
   ## Creates a private conversation with the given `IntroBundle`.
   ## `IntroBundles` are provided out-of-band.
+  let remote_pubkey = loadPublicKeyFromBytes(introBundle.ident).get()
+  let remote_ephemeralkey = loadPublicKeyFromBytes(introBundle.ephemeral).get()
 
-  notice "New PRIVATE Convo ", client = client.getId(),
+  let convo = await client.inbox.inviteToPrivateConversation(client.ds,remote_pubkey, remote_ephemeralkey, content )
-      fromm = introBundle.ident.mapIt(it.toHex(2)).join("")
+  client.addConversation(convo)     # TODO: Fix re-entrantancy bug. Convo needs to be saved before payload is sent.
 
-  let destPubkey = loadPublicKeyFromBytes(introBundle.ident).valueOr:
-    raise newException(ValueError, "Invalid public key in intro bundle.")
-
-  let convoId = conversationIdFor(destPubkey)
-  let destConvoTopic = topicInbox(destPubkey.getAddr())
-
-  let invite = InvitePrivateV1(
-    initiator: @(client.ident.getPubkey().bytes()),
-    initiatorEphemeral: @[0, 0], # TODO: Add ephemeral
-    participant: @(destPubkey.bytes()),
-    participantEphemeralId: introBundle.ephemeralId,
-    discriminator: "test"
-    )
-
-
-
-  let env = wrapEnv(encrypt(InboxV1Frame(invitePrivateV1: invite,
-      recipient: "")), convoId)
-
-  let deliveryAckCb = proc(
-        conversation: Conversation,
-      msgId: string): Future[void] {.async.} =
-    client.notifyDeliveryAck(conversation, msgId)
-
-  # TODO: remove placeholder key
-  var key : array[32, byte]
-  key[2]=2
-
-  var convo = initPrivateV1Sender(client.identity(), client.ds, destPubkey, key, deliveryAckCb)
-  client.addConversation(convo)
-
-  # TODO: Subscribe to new content topic
-
-  await client.ds.sendPayload(destConvoTopic, env)
   return none(ChatError)
 
 

src/chat/conversations/private_v1.nim

@@ -24,6 +24,7 @@ import message
 
 import ../../naxolotl as nax
 
+const TopicPrefixPrivateV1 = "/convo/private/"
 
 type
   ReceivedPrivateV1Message* = ref object of ReceivedMessage 
@@ -37,17 +38,32 @@ type
     ds: WakuClient
     sdsClient: ReliabilityManager
     owner: Identity
-    topic: string
     participant: PublicKey
     discriminator: string
     doubleratchet: naxolotl.Doubleratchet
 
-const
+proc derive_topic(participant: PublicKey): string =
-  TopicPrefixPrivateV1 = "/convo/private/"
+  ## Derives a topic from the participants' public keys.
+  return TopicPrefixPrivateV1 & participant.get_addr()
 
-proc getTopic*(self: PrivateV1): string =
+proc getTopicInbound*(self: PrivateV1): string =
-  ## Returns the topic for the PrivateV1 conversation.
+  ## Returns the topic where the local client is listening for messages
-  return self.topic
+  return derive_topic(self.owner.getPubkey())
+
+proc getTopicOutbound*(self: PrivateV1): string =
+  ## Returns the topic where the remote recipient is listening for messages
+  return derive_topic(self.participant)
+
+## Parses the topic to extract the conversation ID.
+proc parseTopic*(topic: string): Result[string, ChatError] =
+  if not topic.startsWith(TopicPrefixPrivateV1):
+    return err(ChatError(code: errTopic, context: "Invalid topic prefix"))
+  
+  let id = topic.split('/')[^1]
+  if id == "":
+    return err(ChatError(code: errTopic, context: "Empty conversation ID"))
+  
+  return ok(id)
 
 proc allParticipants(self: PrivateV1): seq[PublicKey] =
   return @[self.owner.getPubkey(), self.participant]
@@ -64,20 +80,6 @@ proc getConvoIdRaw(participants: seq[PublicKey],
 proc getConvoId*(self: PrivateV1): string =
   return getConvoIdRaw(@[self.owner.getPubkey(), self.participant], self.discriminator)
 
-proc derive_topic(participants: seq[PublicKey], discriminator: string): string =
-  ## Derives a topic from the participants' public keys.
-  return TopicPrefixPrivateV1 & getConvoIdRaw(participants, discriminator)
-
-## Parses the topic to extract the conversation ID.
-proc parseTopic*(topic: string): Result[string, ChatError] =
-  if not topic.startsWith(TopicPrefixPrivateV1):
-    return err(ChatError(code: errTopic, context: "Invalid topic prefix"))
-  
-  let id = topic.split('/')[^1]
-  if id == "":
-    return err(ChatError(code: errTopic, context: "Empty conversation ID"))
-  
-  return ok(id)
 
 proc calcMsgId(self: PrivateV1, msgBytes: seq[byte]): string =
   let s = fmt"{self.getConvoId()}|{msgBytes}"
@@ -124,7 +126,7 @@ proc wireCallbacks(convo: PrivateV1, deliveryAckCb: proc(
   let funcDeliveryAck = proc(messageId: SdsMessageID,
       channelId: SdsChannelID) {.gcsafe.} =
     debug "sds message ack", messageId = messageId,
-        channelId = channelId, cb = repr(deliveryAckCb)
+        channelId = channelId
 
     if deliveryAckCb != nil:
       asyncSpawn deliveryAckCb(convo, messageId)
@@ -146,19 +148,21 @@ proc initPrivateV1*(owner: Identity, ds:WakuClient, participant: PublicKey, seed
       msgId: string): Future[void] {.async.} = nil):
           PrivateV1 =
 
-  var participants = @[owner.getPubkey(), participant];
-
   var rm = newReliabilityManager().valueOr:
     raise newException(ValueError, fmt"sds initialization: {repr(error)}")
 
+  let dr = if isSender:
+      initDoubleratchetSender(seedKey, participant.bytes)
+    else:
+      initDoubleratchetRecipient(seedKey, owner.privateKey.bytes)
+
   result = PrivateV1(
     ds: ds,
     sdsClient: rm,
     owner: owner,
-    topic: derive_topic(participants, discriminator),
     participant: participant,
     discriminator: discriminator,
-    doubleratchet: initDoubleratchet(seedKey, owner.privateKey.bytes, participant.bytes, isSender)
+    doubleratchet: dr
   )
 
   result.wireCallbacks(deliveryAckCb)
@@ -166,18 +170,7 @@ proc initPrivateV1*(owner: Identity, ds:WakuClient, participant: PublicKey, seed
   result.sdsClient.ensureChannel(result.getConvoId()).isOkOr:
     raise newException(ValueError, "bad sds channel")
 
-
+proc encodeFrame*(self: PrivateV1, msg: PrivateV1Frame): (MessageId, EncryptedPayload) =
-proc initPrivateV1Sender*(owner:Identity, ds: WakuClient, participant: PublicKey, seedKey: array[32, byte], deliveryAckCb: proc(
-        conversation: Conversation, msgId: string): Future[void] {.async.} = nil): PrivateV1 =
-        initPrivateV1(owner, ds, participant, seedKey, "default", true, deliveryAckCb)
-
-proc initPrivateV1Recipient*(owner:Identity,ds: WakuClient, participant: PublicKey, seedKey: array[32, byte], deliveryAckCb: proc(
-        conversation: Conversation, msgId: string): Future[void] {.async.} = nil): PrivateV1 =
-        initPrivateV1(owner,ds, participant, seedKey, "default", false, deliveryAckCb)
-
-
-proc sendFrame(self: PrivateV1, ds: WakuClient,
-    msg: PrivateV1Frame):  Future[MessageId]{.async.} =
 
   let frameBytes = encode(msg)
   let msgId = self.calcMsgId(frameBytes)
@@ -185,9 +178,12 @@ proc sendFrame(self: PrivateV1, ds: WakuClient,
       self.getConvoId()).valueOr:
     raise newException(ValueError, fmt"sds wrapOutgoingMessage failed: {repr(error)}")
 
-  let encryptedPayload = self.encrypt(sdsPayload)
+  result = (msgId, self.encrypt(sdsPayload))
 
-  discard ds.sendPayload(self.getTopic(), encryptedPayload.toEnvelope(
+proc sendFrame(self: PrivateV1, ds: WakuClient,
+    msg: PrivateV1Frame):  Future[MessageId]{.async.} =
+  let (msgId, encryptedPayload) = self.encodeFrame(msg)
+  discard ds.sendPayload(self.getTopicOutbound(), encryptedPayload.toEnvelope(
       self.getConvoId()))
 
   result = msgId
@@ -197,18 +193,15 @@ method id*(self: PrivateV1): string =
   return getConvoIdRaw(self.allParticipants(), self.discriminator)
 
 proc handleFrame*[T: ConversationStore](convo: PrivateV1, client: T,
-    bytes: seq[byte]) =
+    encPayload: EncryptedPayload) =
   ## Dispatcher for Incoming `PrivateV1Frames`.
   ## Calls further processing depending on the kind of frame.
 
-  let enc = decode(bytes, EncryptedPayload).valueOr:
+  if convo.doubleratchet.dhSelfPublic() == encPayload.doubleratchet.dh:
-    raise newException(ValueError, fmt"Failed to decode EncryptedPayload: {repr(error)}")
-
-  if convo.doubleratchet.dhSelfPublic() == enc.doubleratchet.dh:
     info "outgoing message, no need to handle", convo = convo.id()
     return
 
-  let plaintext = convo.decrypt(enc).valueOr:
+  let plaintext = convo.decrypt(encPayload).valueOr:
     error "decryption failed", error = error
     return
 
@@ -234,6 +227,15 @@ proc handleFrame*[T: ConversationStore](convo: PrivateV1, client: T,
   of typePlaceholder:
     notice "Got Placeholder", text = frame.placeholder.counter
 
+proc handleFrame*[T: ConversationStore](convo: PrivateV1, client: T,
+    bytes: seq[byte]) =
+  ## Dispatcher for Incoming `PrivateV1Frames`.
+  ## Calls further processing depending on the kind of frame.
+  let encPayload = decode(bytes, EncryptedPayload).valueOr:
+    raise newException(ValueError, fmt"Failed to decode EncryptedPayload: {repr(error)}")
+
+  convo.handleFrame(client,encPayload)
+
 
 method sendMessage*(convo: PrivateV1, content_frame: Content) : Future[MessageId] {.async.} =
 
@@ -245,3 +247,36 @@ method sendMessage*(convo: PrivateV1, content_frame: Content) : Future[MessageId
   except Exception as e:
     error "Unknown error in PrivateV1:SendMessage"
 
+
+## Encrypts content without sending it.
+proc encryptMessage*(self: PrivateV1, content_frame: Content) : (MessageId, EncryptedPayload) =
+
+  try:
+    let frame = PrivateV1Frame(
+      sender: @(self.owner.getPubkey().bytes()),
+      timestamp: getCurrentTimestamp(), 
+      content: content_frame
+    )
+
+    result = self.encodeFrame(frame)
+
+  except Exception as e:
+    error "Unknown error in PrivateV1:EncryptMessage"
+
+proc initPrivateV1Sender*(sender:Identity, 
+                          ds: WakuClient, 
+                          participant: PublicKey, 
+                          seedKey: array[32, byte], 
+                          content: Content,
+                          deliveryAckCb: proc(conversation: Conversation, msgId: string): Future[void] {.async.} = nil): (PrivateV1, EncryptedPayload) =
+  let convo = initPrivateV1(sender, ds, participant, seedKey, "default", true, deliveryAckCb)
+
+  # Encrypt Content with Convo
+  let contentFrame = PrivateV1Frame(sender: @(sender.getPubkey().bytes()), timestamp: getCurrentTimestamp(), content: content) 
+  let (msg_id, encPayload) = convo.encryptMessage(content)
+  result = (convo, encPayload)
+
+
+proc initPrivateV1Recipient*(owner:Identity,ds: WakuClient, participant: PublicKey, seedKey: array[32, byte], deliveryAckCb: proc(
+        conversation: Conversation, msgId: string): Future[void] {.async.} = nil): PrivateV1 =
+  initPrivateV1(owner,ds, participant, seedKey, "default", false, deliveryAckCb)

src/chat/identity.nim

@@ -29,5 +29,5 @@ proc getAddr*(self: Identity): string =
   result = get_addr(self.getPubKey())
 
 
-proc getId*(self: Identity): string =
+proc getName*(self: Identity): string =
   result = self.name

src/chat/inbox.nim

@@ -11,16 +11,19 @@ import
   conversations,
   conversation_store,
   crypto,
+  delivery/waku_client,
   errors,
+  identity,
   proto_types,
-  types
+  types,
+  utils
 
 logScope:
   topics = "chat inbox"
 
 type
   Inbox* = ref object of Conversation
-    pubkey: PublicKey
+    identity: Identity
     inbox_addr: string
 
 const
@@ -30,9 +33,9 @@ proc `$`*(conv: Inbox): string =
   fmt"Inbox: addr->{conv.inbox_addr}"
 
 
-proc initInbox*(pubkey: PublicKey): Inbox =
+proc initInbox*(ident: Identity): Inbox =
   ## Initializes an Inbox object with the given address and invite callback.
-  return Inbox(pubkey: pubkey)
+  return Inbox(identity: ident)
 
 proc encrypt*(frame: InboxV1Frame): EncryptedPayload =
   return encrypt_plain(frame)
@@ -73,13 +76,52 @@ proc parseTopic*(topic: string): Result[string, ChatError] =
   return ok(id)
 
 method id*(convo: Inbox): string =
-  return conversation_id_for(convo.pubkey)
+  return conversation_id_for(convo.identity.getPubkey())
 
+## Encrypt and Send a frame to the remote account
+proc sendFrame(ds: WakuClient, remote: PublicKey, frame: InboxV1Frame ): Future[void] {.async.} =
+    let env = wrapEnv(encrypt(frame),conversation_id_for(remote) )
+    await ds.sendPayload(topic_inbox(remote.get_addr()), env)
+
+
+proc newPrivateInvite(initator_static: PublicKey, 
+                      initator_ephemeral: PublicKey, 
+                      recipient_static: PublicKey, 
+                      recipient_ephemeral: uint32, 
+                      payload: EncryptedPayload) : InboxV1Frame =
+
+  let invite = InvitePrivateV1(
+    initiator: @(initator_static.bytes()),
+    initiatorEphemeral: @(initator_ephemeral.bytes()),
+    participant: @(recipient_static.bytes()),
+    participantEphemeralId: 0,
+    discriminator: "",
+    initial_message: payload
+  )
+  result = InboxV1Frame(invitePrivateV1: invite, recipient: "")
 
 #################################################
 # Conversation Creation
 #################################################
 
+## Establish a PrivateConversation with a remote client
+proc inviteToPrivateConversation*(self: Inbox, ds: Wakuclient, remote_static: PublicKey, remote_ephemeral: PublicKey, content: Content ) : Future[PrivateV1] {.async.} =
+  # Create SeedKey
+  # TODO: Update key derivations when noise is integrated
+  var local_ephemeral = generateKey()
+  var sk{.noInit.} : array[32, byte] = default(array[32, byte])
+
+  # Initialize PrivateConversation
+  let (convo, encPayload) = initPrivateV1Sender(self.identity, ds, remote_static, sk, content, nil)
+  result = convo
+
+  # # Build Invite
+  let frame = newPrivateInvite(self.identity.getPubkey(), local_ephemeral.getPublicKey(), remote_static, 0, encPayload)
+  
+  # Send
+  await sendFrame(ds, remote_static, frame)
+
+## Receive am Invitation to create a new private conversation
 proc createPrivateV1FromInvite*[T: ConversationStore](client: T,
     invite: InvitePrivateV1) =
 
@@ -92,12 +134,16 @@ proc createPrivateV1FromInvite*[T: ConversationStore](client: T,
     client.notifyDeliveryAck(conversation, msgId)
 
   # TODO: remove placeholder key
-  var key : array[32, byte]
+  var key : array[32, byte] = default(array[32,byte])
-  key[2]=2
 
   let convo = initPrivateV1Recipient(client.identity(), client.ds, destPubkey, key, deliveryAckCb)
   notice "Creating PrivateV1 conversation", client = client.getId(),
-      topic = convo.getConvoId()
+      convoId = convo.getConvoId()
+  
+  convo.handleFrame(client, invite.initial_message)
+
+  # Calling `addConversation` must only occur after the conversation is completely configured.
+  # The client calls the OnNewConversation callback, which returns execution to the application.
   client.addConversation(convo) 
 
 proc handleFrame*[T: ConversationStore](convo: Inbox, client: T, bytes: seq[

src/chat/proto_types.nim

@@ -10,7 +10,6 @@ export protobuf_serialization
 
 import_proto3 "../../protos/inbox.proto"
 # import_proto3 "../protos/invite.proto"    // Import3 follows protobuf includes so this will result in a redefinition error
-import_proto3 "../../protos/encryption.proto"
 import_proto3 "../../protos/envelope.proto"
 
 import_proto3 "../../protos/private_v1.proto"

src/naxolotl/naxolotl.nim

@@ -50,12 +50,20 @@ proc `$`*(x: DrHeader): string =
   "DrHeader(pubKey=" & hex(x.dhPublic) & ", msgNum=" & $x.msgNumber & ", msgNum=" & $x.prevChainLen & ")"
 
 
+proc `$`*(key: array[32, byte]): string =
+  let byteStr = hex(key)
+  fmt"{byteStr[0..5]}..{byteStr[^6 .. ^1]}"
+
+
+proc generateDhKey() : PrivateKey =
+  result = generateKeypair().get()[0]
+
 #################################################
 # Kdf
 #################################################
 
 
-func kdfRoot(self: var Doubleratchet, rootKey: RootKey, dhOutput:DhDerivedKey): (RootKey, ChainKey) =
+func kdfRoot(rootKey: RootKey, dhOutput:DhDerivedKey): (RootKey, ChainKey) =
 
   var salt = rootKey
   var ikm = dhOutput
@@ -63,7 +71,7 @@ func kdfRoot(self: var Doubleratchet, rootKey: RootKey, dhOutput:DhDerivedKey):
 
   hkdfSplit(salt, ikm, info)
 
-func kdfChain(self: Doubleratchet, chainKey: ChainKey): (MessageKey, ChainKey) =
+func kdfChain(chainKey: ChainKey): (MessageKey, ChainKey) =
 
   let msgKey   = hkdfExtract(chainKey, [0x01u8])
   let chainKey = hkdfExtract(chainKey, [0x02u8])
@@ -73,7 +81,7 @@ func kdfChain(self: Doubleratchet, chainKey: ChainKey): (MessageKey, ChainKey) =
 func dhRatchetSend(self: var Doubleratchet) =
   # Perform DH Ratchet step when receiving a new peer key.
   let dhOutput : DhDerivedKey = dhExchange(self.dhSelf, self.dhRemote).get()
-  let (newRootKey, newChainKeySend) = kdfRoot(self, self.rootKey, dhOutput)
+  let (newRootKey, newChainKeySend) = kdfRoot(self.rootKey, dhOutput)
   self.rootKey = newRootKey
   self.chainKeySend = newChainKeySend
   self.msgCountSend = 0
@@ -86,14 +94,14 @@ proc dhRatchetRecv(self: var Doubleratchet, remotePublickey: PublicKey ) =
   self.dhRemote = remotePublickey
 
   let dhOutputPre = self.dhSelf.dhExchange(self.dhRemote).get()
-  let (newRootKey, newChainKeyRecv) = kdfRoot(self, self.rootKey, dhOutputPre)
+  let (newRootKey, newChainKeyRecv) = kdfRoot(self.rootKey, dhOutputPre)
   self.rootKey = newRootKey
   self.chainKeyRecv = newChainKeyRecv
 
-  self.dhSelf = generateKeypair().get()[0]
+  self.dhSelf = generateDhKey()
 
   let dhOutputPost = self.dhSelf.dhExchange(self.dhRemote).get()
-  (self.rootKey, self.chainKeySend) = kdfRoot(self, self.rootKey, dhOutputPost)
+  (self.rootKey, self.chainKeySend) = kdfRoot(self.rootKey, dhOutputPost)
 
 
 proc skipMessageKeys(self: var Doubleratchet, until: MsgCount): Result[(), string] =
@@ -102,7 +110,7 @@ proc skipMessageKeys(self: var Doubleratchet, until: MsgCount): Result[(), strin
     return err("Too many skipped messages")
 
   while self.msgCountRecv < until:
-    let (msgKey, chainKey) = self.kdfChain(self.chainKeyRecv)
+    let (msgKey, chainKey) = kdfChain(self.chainKeyRecv)
     self.chainKeyRecv = chainKey
 
     let keyId = keyId(self.dhRemote, self.msgCountRecv)
@@ -113,7 +121,7 @@ proc skipMessageKeys(self: var Doubleratchet, until: MsgCount): Result[(), strin
 
 proc encrypt(self: var Doubleratchet, plaintext: var seq[byte], associatedData: openArray[byte]): (DrHeader, CipherText) = 
 
-  let (msgKey, chainKey) = self.kdfChain(self.chainKeySend)
+  let (msgKey, chainKey) = kdfChain(self.chainKeySend)
   self.chainKeySend = chainKey
   let header = DrHeader(  
                 dhPublic: self.dhSelf.public, #TODO Serialize
@@ -130,14 +138,12 @@ proc encrypt(self: var Doubleratchet, plaintext: var seq[byte], associatedData:
   output.add(nonce)
   output.add(ciphertext)
 
-
   (header, output)
 
 
 proc decrypt*(self: var Doubleratchet, header: DrHeader, ciphertext: CipherText, associatedData: openArray[byte] ) : Result[seq[byte], NaxolotlError] =
 
   let peerPublic = header.dhPublic
-
   var msgKey : MessageKey
 
   # Check Skipped Keys
@@ -155,7 +161,7 @@ proc decrypt*(self: var Doubleratchet, header: DrHeader, ciphertext: CipherText,
     if r.isErr:
        error "skipMessages", error = r.error()
 
-    (msgKey, self.chainKeyRecv) = self.kdfChain(self.chainKeyRecv)
+    (msgKey, self.chainKeyRecv) = kdfChain(self.chainKeyRecv)
     inc self.msgCountRecv
 
   var nonce : Nonce
@@ -173,10 +179,10 @@ proc encrypt*(self: var Doubleratchet, plaintext: var seq[byte]) : (DrHeader, Ci
   encrypt(self, plaintext,@[])
 
 
-func initDoubleratchet*(sharedSecret: array[32, byte], dhSelf: PrivateKey, dhRemote: PublicKey, isSending: bool = true): Doubleratchet =
+proc initDoubleratchetSender*(sharedSecret: array[32, byte], dhRemote: PublicKey): Doubleratchet =
 
   result = Doubleratchet(
-      dhSelf: dhSelf,
+      dhSelf: generateDhKey(),
       dhRemote: dhRemote,
       rootKey: RootKey(sharedSecret),
       msgCountSend: 0,
@@ -185,8 +191,20 @@ func initDoubleratchet*(sharedSecret: array[32, byte], dhSelf: PrivateKey, dhRem
       skippedMessageKeys: initTable[(PublicKey, MsgCount), MessageKey]()
   )
 
-  if isSending:
+  # Update RK, CKs
-    result.dhRatchetSend()
+  result.dhRatchetSend()
+
+proc initDoubleratchetRecipient*(sharedSecret: array[32, byte], dhSelf: PrivateKey): Doubleratchet =
+
+  result = Doubleratchet(
+      dhSelf: dhSelf,
+      #dhRemote: None,
+      rootKey: RootKey(sharedSecret),
+      msgCountSend: 0,
+      msgCountRecv: 0,
+      prevChainLen: 0,
+      skippedMessageKeys: initTable[(PublicKey, MsgCount), MessageKey]()
+  )
 
 func dhSelfPublic*(self: Doubleratchet): PublicKey = 
   self.dhSelf.public

tests/test_naxolotl.nim

@@ -31,7 +31,6 @@ proc hexToArray*[N: static[int]](hexStr: string): array[N, byte] =
       "Hex string length (" & $hexStr.len & ") doesn't match array size (" & $(
           N*2) & ")")
           
-  var result: array[N, byte]
   for i in 0..<N:
     result[i] = byte(parseHexInt(hexStr[2*i .. 2*i+1]))
 
@@ -46,9 +45,9 @@ func loadTestKeys() : (array[32,byte],array[32,byte],array[32,byte],array[32,byt
 
     (a_priv, a_pub, b_priv, b_pub)
 
-func createTestInstances(a: array[32, byte], apub: array[32, byte], b: array[32, byte], bpub: array[32, byte],sk: array[32, byte]) : (Doubleratchet, Doubleratchet) =
+proc createTestInstances(b: array[32, byte], bpub: array[32, byte],sk: array[32, byte]) : (Doubleratchet, Doubleratchet) =
-    let adr = initDoubleratchet(sk, a, bpub, true)
+    let adr = initDoubleratchetSender(sk, bpub)
-    let bdr = initDoubleratchet(sk, b, apub, false)
+    let bdr = initDoubleratchetRecipient(sk, b)
     (adr,bdr)
 
 
@@ -60,8 +59,7 @@ suite "Doubleratchet":
 
     let sk = hexToArray[32](ks7748_shared_key)
 
-    var adr = initDoubleratchet(sk, a_priv, b_pub, true)
+    var (adr, bdr) = createTestInstances(b_priv, b_pub, sk)
-    var bdr = initDoubleratchet(sk, b_priv, a_pub, true)
     
     var msg :seq[byte] = @[1,2,3,4,5,6,7,8,9,10]
 
@@ -77,8 +75,7 @@ suite "Doubleratchet":
 
     let sk = hexToArray[32](ks7748_shared_key)
     
-    var adr = initDoubleratchet(sk, a_priv, b_pub, true)
+    var (adr, bdr) = createTestInstances(b_priv, b_pub, sk)
-    var bdr = initDoubleratchet(sk, b_priv, a_pub, true)
 
     var msg0 :seq[byte] = @[1,2,3,4,5,6,7,8,9,10]
     var msg1 :seq[byte] = @[6,7,8,9,10,1,2,3,4,5]
@@ -98,8 +95,7 @@ suite "Doubleratchet":
 
     let sk = hexToArray[32](ks7748_shared_key)
     
-    var adr = initDoubleratchet(sk, a_priv, b_pub, true)
+    var (adr, bdr) = createTestInstances(b_priv, b_pub, sk)
-    var bdr = initDoubleratchet(sk, b_priv, a_pub, true)
 
     var msg : seq[ seq[byte]]= @[
       @[1,2,3,4,5,6,7,8,9,10],
@@ -132,8 +128,7 @@ suite "Doubleratchet":
     let (a_priv, a_pub, b_priv, b_pub) = loadTestKeys()
     let sk = hexToArray[32](ks7748_shared_key)
 
-    var adr = initDoubleratchet(sk, a_priv, b_pub, true)
+    var (adr, bdr) = createTestInstances(b_priv, b_pub, sk)
-    var bdr = initDoubleratchet(sk, b_priv, a_pub, true)
     
     var msg :seq[byte] = @[1,2,3,4,5,6,7,8,9,10]
   
@@ -150,8 +145,7 @@ suite "Doubleratchet":
     let (a_priv, a_pub, b_priv, b_pub) = loadTestKeys()
     let sk = hexToArray[32](ks7748_shared_key)
 
-    var adr = initDoubleratchet(sk, a_priv, b_pub, true)
+    var (adr, bdr) = createTestInstances(b_priv, b_pub, sk)
-    var bdr = initDoubleratchet(sk, b_priv, a_pub, true)
     
     var msg :seq[byte] = @[1,2,3,4,5,6,7,8,9,10]
 
@@ -167,8 +161,7 @@ suite "Doubleratchet":
 
     let sk = hexToArray[32](ks7748_shared_key)
     
-    var adr = initDoubleratchet(sk, a_priv, b_pub, true)
+    var (adr, bdr) = createTestInstances(b_priv, b_pub, sk)
-    var bdr = initDoubleratchet(sk, b_priv, a_pub, true)
 
     var last_dh_a : PublicKey
     var last_dh_b : PublicKey