Started work on websocket communication: Parsing/Serialization of WebSocket packets.

conquest.nimble

@@ -2,7 +2,7 @@
 
 version       = "0.1.0"
 author        = "Jakob Friedl"
-description   = "Command & control framework written in Nim"
+description   = "Conquest command & control/post-exploitation framework"
 license       = "BSD-3-Clause"
 srcDir        = "src"
 
@@ -29,4 +29,5 @@ requires "winim >= 3.9.4"
 requires "ptr_math >= 0.3.0"
 requires "imguin >= 1.92.2.1"
 requires "zippy >= 0.10.16"
-requires "mummy >= 0.4.6"
+requires "mummy >= 0.4.6"
+requires "whisky >= 0.1.3"

src/client/layout.ini

@@ -1,41 +1,41 @@
 [Window][Sessions [Table View]]
 Pos=10,43
-Size=1533,946
+Size=2016,548
 Collapsed=0
 DockId=0x00000003,0
 
 [Window][Listeners]
-Pos=10,43
+Pos=10,593
-Size=1533,946
+Size=2528,804
 Collapsed=0
-DockId=0x00000003,1
+DockId=0x00000006,0
 
 [Window][Eventlog]
-Pos=1545,43
+Pos=2028,43
-Size=353,946
+Size=510,548
 Collapsed=0
 DockId=0x00000004,0
 
 [Window][Dear ImGui Demo]
-Pos=1545,43
+Pos=2028,43
-Size=353,946
+Size=510,548
 Collapsed=0
 DockId=0x00000004,1
 
 [Window][Dockspace]
 Pos=0,0
-Size=1908,999
+Size=2548,1407
 Collapsed=0
 
 [Window][[FACEDEAD] bob@LAPTOP-02]
-Pos=956,326
+Pos=10,593
-Size=942,663
+Size=2528,804
 Collapsed=0
-DockId=0x00000005,0
+DockId=0x00000006,1
 
 [Window][[C9D8E7F6] charlie@SERVER-03]
-Pos=10,434
+Pos=10,593
-Size=1888,555
+Size=2528,804
 Collapsed=0
 DockId=0x00000006,1
 
@@ -45,16 +45,16 @@ Size=400,400
 Collapsed=0
 
 [Window][[G1H2I3J5] diana@WORKSTATION-04]
-Pos=10,434
+Pos=10,593
-Size=1888,555
+Size=2528,804
 Collapsed=0
-DockId=0x00000006,0
+DockId=0x00000006,1
 
 [Window][[DEADBEEF] alice@DESKTOP-01]
-Pos=10,402
+Pos=10,716
-Size=1888,587
+Size=2848,969
 Collapsed=0
-DockId=0x00000005,1
+DockId=0x00000006,2
 
 [Window][Example: Console]
 Pos=10,572
@@ -110,8 +110,8 @@ Size=76,76
 Collapsed=0
 
 [Window][Start Listener]
-Pos=704,387
+Pos=955,591
-Size=500,225
+Size=637,225
 Collapsed=0
 
 [Table][0x32886A44,8]
@@ -136,9 +136,9 @@ Column 3  Weight=0.9746
 
 [Docking][Data]
 DockNode      ID=0x00000009 Pos=100,200 Size=754,103 Selected=0x64D005CF
-DockSpace     ID=0x85940918 Window=0x260A4489 Pos=10,43 Size=1888,946 Split=Y
+DockSpace     ID=0x85940918 Window=0x260A4489 Pos=10,43 Size=2528,1354 Split=Y
-  DockNode    ID=0x00000005 Parent=0x85940918 SizeRef=1888,389 Split=X
+  DockNode    ID=0x00000005 Parent=0x85940918 SizeRef=1888,548 Split=X
-    DockNode  ID=0x00000003 Parent=0x00000005 SizeRef=1533,159 CentralNode=1 Selected=0x61E02D75
+    DockNode  ID=0x00000003 Parent=0x00000005 SizeRef=1376,159 CentralNode=1 Selected=0x61E02D75
-    DockNode  ID=0x00000004 Parent=0x00000005 SizeRef=353,159 Selected=0x5E5F7166
+    DockNode  ID=0x00000004 Parent=0x00000005 SizeRef=510,159 Selected=0x5E5F7166
-  DockNode    ID=0x00000006 Parent=0x85940918 SizeRef=1888,555 Selected=0x65D642C0
+  DockNode    ID=0x00000006 Parent=0x85940918 SizeRef=1888,804 Selected=0x6BE22050
 

src/client/main.nim

@@ -1,6 +1,9 @@
-import tables
+import whisky
+import tables, strutils
 import ./utils/appImGui
 import ./views/[dockspace, sessions, listeners, eventlog, console]
+import ../common/[types, utils]
+import ./websocket
 
 proc main() = 
     var app = createApp(1024, 800, imnodes = true, title = "Conquest", docking = true)
@@ -35,6 +38,10 @@ proc main() =
 
     let io = igGetIO()
 
+    # Initiate WebSocket connection
+    let ws = newWebSocket("ws://localhost:12345")
+    defer: ws.close() 
+
     # main loop
     while not app.handle.windowShouldClose:
         pollEvents()
@@ -44,10 +51,24 @@ proc main() =
             continue 
         newFrame()
 
+        #[
+            WebSocket communication with the team server
+        ]# 
+        # Continuously send heartbeat messages
+        ws.sendHeartbeat()
+
+        # Receive and parse websocket response message 
+        let message = ws.receiveMessage().get()
+        case message.getMessageType()
+        of CLIENT_EVENT_LOG: 
+            message.receiveEventlogItem(addr eventlog)
+        else: discard
+
+
         # Draw/update UI components/views
         dockspace.draw(addr showConquest, views, addr dockTop, addr dockBottom, addr dockTopLeft, addr dockTopRight)
         if showSessionsTable: sessionsTable.draw(addr showSessionsTable)   
-        if showListeners: listenersTable.draw(addr showListeners)
+        if showListeners: listenersTable.draw(addr showListeners, ws)
         if showEventlog: eventlog.draw(addr showEventlog)
 
         # Show console windows
@@ -56,7 +77,7 @@ proc main() =
             if console.showConsole:
                 # Ensure that new console windows are docked to the bottom panel by default
                 igSetNextWindowDockID(dockBottom, ImGuiCond_FirstUseEver.int32)
-                console.draw()
+                console.draw(ws)
                 newConsoleTable[agentId] = console
             
         # Update the consoles table with only those sessions that have not been closed yet

src/client/views/console.nim

@@ -1,3 +1,4 @@
+import whisky
 import strformat, strutils, times
 import imguin/[cimgui, glfw_opengl, simple]
 import ../utils/[appImGui, colors]
@@ -113,11 +114,11 @@ proc callback(data: ptr ImGuiInputTextCallbackData): cint {.cdecl.} =
 #[
     API to add new console item
 ]#
-proc addItem*(component: ConsoleComponent, itemType: LogType, data: string) = 
+proc addItem*(component: ConsoleComponent, itemType: LogType, data: string, timestamp: int64 = now().toTime().toUnix()) = 
 
     for line in data.split("\n"): 
         component.console.items.add(ConsoleItem(
-            timestamp: if itemType == LOG_OUTPUT: 0 else: now().toTime().toUnix(),
+            timestamp: if itemType == LOG_OUTPUT: 0 else: timestamp,
             itemType: itemType,
             text: line
         ))
@@ -148,7 +149,7 @@ proc print(item: ConsoleItem) =
     igSameLine(0.0f, 0.0f)
     igTextUnformatted(item.text.cstring, nil)
 
-proc draw*(component: ConsoleComponent) =
+proc draw*(component: ConsoleComponent, ws: WebSocket) =
     igBegin(fmt"[{component.agent.agentId}] {component.agent.username}@{component.agent.hostname}", addr component.showConsole, 0)
     defer: igEnd()
     
@@ -251,22 +252,25 @@ proc draw*(component: ConsoleComponent) =
     let inputFlags = ImGuiInputTextFlags_EnterReturnsTrue.int32 or ImGuiInputTextFlags_EscapeClearsAll.int32 or ImGuiInputTextFlags_CallbackHistory.int32 or ImGuiInputTextFlags_CallbackCompletion.int32
     if igInputText("##Input", addr component.inputBuffer[0], MAX_INPUT_LENGTH, inputFlags, callback, cast[pointer](component)):
 
-        let command = $(addr component.inputBuffer[0]).cstring
+        let command = ($(addr component.inputBuffer[0])).strip()
-        component.addItem(LOG_COMMAND, command)
+        if not command.isEmptyOrWhitespace(): 
+        
+            component.addItem(LOG_COMMAND, command)
 
-        # For testing
+            # For testing
-        component.addItem(LOG_ERROR, "error message")
+            # component.addItem(LOG_ERROR, "error message")
-        component.addItem(LOG_SUCCESS, "success message")
+            # component.addItem(LOG_SUCCESS, "success message")
-        component.addItem(LOG_INFO, "info message")
+            # component.addItem(LOG_INFO, "info message")
-        component.addItem(LOG_WARNING, "warning message")
+            # component.addItem(LOG_WARNING, "warning message")
-        component.addItem(LOG_OUTPUT, "error message\nLong output\n\tindented output\nasdasd")
+            # component.addItem(LOG_OUTPUT, "error message\nLong output\n\tindented output\nasdasd")
 
-        # TODO: Handle command execution
+            # TODO: Handle command execution
-        # console.handleCommand(command)
+            # console.handleCommand(command)
+            ws.send("CMD:" & component.agent.agentId & ":" & command)
 
-        # Add command to console history
+            # Add command to console history
-        component.history.add(command)
+            component.history.add(command)
-        component.historyPosition = -1 
+            component.historyPosition = -1 
 
         zeroMem(addr component.inputBuffer[0], MAX_INPUT_LENGTH)
         focusInput = true

src/client/views/eventlog.nim

@@ -4,7 +4,7 @@ import ../utils/[appImGui, colors]
 import ../../common/types
 
 type 
-    EventlogComponent = ref object of RootObj
+    EventlogComponent* = ref object of RootObj
         title: string 
         log*: ConsoleItems
         textSelect: ptr TextSelect
@@ -41,11 +41,11 @@ proc Eventlog*(title: string): EventlogComponent =
 #[
     API to add new log entry
 ]#
-proc addItem*(component: EventlogComponent, itemType: LogType, data: string) = 
+proc addItem*(component: EventlogComponent, itemType: LogType, data: string, timestamp: int64 = now().toTime().toUnix()) = 
 
     for line in data.split("\n"): 
         component.log.items.add(ConsoleItem(
-            timestamp: if itemType == LOG_OUTPUT: 0 else: now().toTime().toUnix(),
+            timestamp: if itemType == LOG_OUTPUT: 0 else: timestamp,
             itemType: itemType,
             text: line
         ))

src/client/views/listeners.nim

@@ -3,11 +3,12 @@ import imguin/[cimgui, glfw_opengl, simple]
 import ../utils/appImGui
 import ../../common/[types, utils]
 import ./modals/startListener
+import whisky
 
 type 
-    ListenersTableComponent = ref object of RootObj
+    ListenersTableComponent* = ref object of RootObj
         title: string 
-        listeners: seq[Listener]
+        listeners*: seq[Listener]
         selection: ptr ImGuiSelectionBasicStorage
         startListenerModal: ListenerModalComponent
 
@@ -33,7 +34,7 @@ proc ListenersTable*(title: string): ListenersTableComponent =
     result.selection = ImGuiSelectionBasicStorage_ImGuiSelectionBasicStorage()
     result.startListenerModal = ListenerModal()
 
-proc draw*(component: ListenersTableComponent, showComponent: ptr bool) = 
+proc draw*(component: ListenersTableComponent, showComponent: ptr bool, ws: WebSocket) = 
     igBegin(component.title, showComponent, 0)
     defer: igEnd() 
 
@@ -46,7 +47,7 @@ proc draw*(component: ListenersTableComponent, showComponent: ptr bool) =
     let listener = component.startListenerModal.draw()
     if listener != nil: 
         # TODO: Start listener
-        
+        ws.send("Starting listener: " & listener.listenerId)
         component.listeners.add(listener)    
 
     #[

src/client/views/sessions.nim

@@ -6,9 +6,9 @@ import ../utils/appImGui
 import ../../common/[types, utils]
 
 type 
-    SessionsTableComponent = ref object of RootObj
+    SessionsTableComponent* = ref object of RootObj
         title: string 
-        agents: seq[Agent]
+        agents*: seq[Agent]
         selection: ptr ImGuiSelectionBasicStorage
         consoles: ptr Table[string, ConsoleComponent]
 

src/client/websocket.nim

@@ -0,0 +1,135 @@
+import times, tables
+import ../common/[types, utils, serialize]
+import views/[sessions, listeners, console, eventlog]
+import whisky 
+
+#[
+    [ Sending Functions ]
+    Client -> Server 
+    - Heartbeat 
+    - ListenerStart
+    - ListenerStop
+    - AgentBuild
+    - AgentCommand
+]#
+proc sendHeartbeat*(ws: WebSocket) = 
+    var packer = Packer.init() 
+
+    packer.add(cast[uint8](CLIENT_HEARTBEAT))
+    let data = packer.pack() 
+
+    ws.send(Bytes.toString(data), BinaryMessage)
+
+proc sendStartListener*(ws: WebSocket, listener: Listener) = 
+    var packer = Packer.init() 
+
+    packer.add(cast[uint8](CLIENT_LISTENER_START))
+    packer.add(string.toUUid(listener.listenerId))
+    packer.addDataWithLengthPrefix(string.toBytes(listener.address))
+    packer.add(cast[uint16](listener.port))
+    packer.add(cast[uint8](listener.protocol))
+
+    let data = packer.pack() 
+
+    ws.send(Bytes.toString(data), BinaryMessage)
+
+proc sendStopListener*(ws: WebSocket, listenerId: string) = 
+    var packer = Packer.init() 
+
+    packer.add(cast[uint8](CLIENT_LISTENER_STOP))
+    packer.add(string.toUuid(listenerId))
+    let data = packer.pack() 
+
+    ws.send(Bytes.toString(data), BinaryMessage)
+
+proc sendAgentCommand*(ws: WebSocket, agentId: string, command: string) = 
+    var packer = Packer.init() 
+
+    packer.add(cast[uint8](CLIENT_AGENT_COMMAND))
+    packer.add(string.toUuid(agentId))
+    packer.addDataWithLengthPrefix(string.toBytes(command))
+    let data = packer.pack() 
+
+    ws.send(Bytes.toString(data), BinaryMessage)
+
+proc sendAgentBuild*(ws: WebSocket, listenerId: string, sleepDelay: int, sleepMask: SleepObfuscationTechnique, spoofStack: bool, modules: uint32) = 
+    var packer = Packer.init() 
+
+    packer.add(cast[uint8](CLIENT_AGENT_BUILD))
+    packer.add(string.toUuid(listenerId))
+    packer.add(cast[uint32](sleepDelay))
+    packer.add(cast[uint8](sleepMask))
+    packer.add(cast[uint8](spoofStack))
+    packer.add(modules)
+    let data = packer.pack() 
+
+    ws.send(Bytes.toString(data), BinaryMessage)
+    
+#[
+    [ Retrieval Functions ]
+    Server -> Client 
+]#
+proc getMessageType*(message: Message): WsMessageAction = 
+    var unpacker = Unpacker.init(message.data)
+    return cast[WsMessageAction](unpacker.getUint8()) 
+
+proc receiveAgentPayload*(message: Message): seq[byte] = 
+    var unpacker = Unpacker.init(message.data)
+    
+    discard unpacker.getUint8() 
+    return string.toBytes(unpacker.getDataWithLengthPrefix())
+
+proc receiveAgentConnection*(message: Message, sessions: ptr SessionsTableComponent) = 
+    var unpacker = Unpacker.init(message.data)
+
+    discard unpacker.getUint8() 
+    let agent = Agent(
+        agentId: Uuid.toString(unpacker.getUint32()),
+        listenerId: Uuid.toString(unpacker.getUint32()),
+        username: unpacker.getDataWithLengthPrefix(), 
+        hostname: unpacker.getDataWithLengthPrefix(),
+        domain: unpacker.getDataWithLengthPrefix(),
+        ip: unpacker.getDataWithLengthPrefix(),
+        os: unpacker.getDataWithLengthPrefix(),
+        process: unpacker.getDataWithLengthPrefix(),
+        pid: int(unpacker.getUint32()),
+        elevated: unpacker.getUint8() != 0,
+        sleep: int(unpacker.getUint32()),
+        tasks: @[],  
+        firstCheckin: cast[int64](unpacker.getUint32()).fromUnix().utc(),
+        latestCheckin: now(),
+    )
+
+    sessions.agents.add(agent)
+
+proc receiveAgentCheckin*(message: Message, sessions: ptr SessionsTableComponent)= 
+    var unpacker = Unpacker.init(message.data)
+
+    discard unpacker.getUint8() 
+    let agentId = Uuid.toString(unpacker.getUint32())
+    let timestamp = cast[int64](unpacker.getUint32())
+
+    # TODO: Update checkin 
+
+proc receiveConsoleItem*(message: Message, consoles: ptr Table[string, ConsoleComponent]) = 
+    var unpacker = Unpacker.init(message.data)
+
+    discard unpacker.getUint8() 
+    let 
+        agentId = Uuid.toString(unpacker.getUint32())
+        logType = cast[LogType](unpacker.getUint8())
+        timestamp = cast[int64](unpacker.getUint32())
+        message = unpacker.getDataWithLengthPrefix()
+
+    consoles[][agentId].addItem(logType, message, timestamp)
+
+proc receiveEventlogItem*(message: Message, eventlog: ptr EventlogComponent) = 
+    var unpacker = Unpacker.init(message.data)
+
+    discard unpacker.getUint8() 
+    let 
+        logType = cast[LogType](unpacker.getUint8())
+        timestamp = cast[int64](unpacker.getUint32())
+        message = unpacker.getDataWithLengthPrefix()
+    
+    eventlog[].addItem(logType, message, timestamp)

src/common/types.nim

@@ -81,7 +81,7 @@ type
         CONFIG_PUBLIC_KEY = 4'u8
         CONFIG_PROFILE = 5'u8
 
-    LogType* = enum 
+    LogType* {.size: sizeof(uint8).} = enum 
         LOG_INFO = " [INFO] "
         LOG_ERROR = " [FAIL] "
         LOG_SUCCESS = " [DONE] "
@@ -193,7 +193,7 @@ type
 
 # Listener structure
 type 
-    Protocol* = enum
+    Protocol* {.size: sizeof(uint8).} = enum
         HTTP = "http"
 
     Listener* = ref object of RootObj
@@ -262,4 +262,85 @@ type
         text*: string
 
     ConsoleItems* = ref object
-        items*: seq[ConsoleItem]
+        items*: seq[ConsoleItem]
+
+#[
+    Client <-> Server WebSocket communication
+]#
+type 
+    WsMessageAction* = enum
+        # Sent by client 
+        CLIENT_HEARTBEAT = 0'u8             # Basic checkin 
+        CLIENT_AGENT_COMMAND = 1'u8               # Instruct TS to send queue a command for a specific agent
+        CLIENT_LISTENER_START = 2'u8        # Start a listener on the TS
+        CLIENT_LISTENER_STOP = 3'u8         # Stop a listener
+        CLIENT_AGENT_BUILD = 4'u8           # Generate an agent binary for a specific listener
+
+        # Sent by team server
+        CLIENT_AGENT_BINARY = 100'u8        # Return the agent binary to write to the operator's client machine
+        CLIENT_AGENT_CONNECTION = 101'u8    # Notify new agent connection 
+        CLIENT_AGENT_CHECKIN = 102'u8       # Update agent checkin
+        CLIENT_CONSOLE_LOG = 103'u8         # Add entry to a agent's console 
+        CLIENT_EVENT_LOG = 104'u8           # Add entry to the eventlog
+        
+        CLIENT_CONNECTION = 200'u8          # Return team server profile 
+
+    # Client -> Server 
+    WsHeartbeat* = object 
+        msgType* = CLIENT_HEARTBEAT         
+
+    WsCommand* = object 
+        msgType* = CLIENT_AGENT_COMMAND           
+        agentId*: uint32                    
+        command*: seq[byte]                 # Command input field in the console window, prefixed with length
+
+    WsListenerStart* = object  
+        msgType* = CLIENT_LISTENER_START    
+        listener*: Listener
+
+    WsListenerStop* = object 
+        msgType* = CLIENT_LISTENER_STOP     
+        listenerId*: uint32                 
+
+    WsAgentBuild* = object 
+        msgType* = CLIENT_AGENT_BUILD   
+        listenerId*: uint32                 
+        sleepDelay*: uint32                  
+        sleepMask*: SleepObfuscationTechnique
+        spoofStack*: uint8  
+        modules*: uint64
+
+    # Server -> Client 
+    WsAgentBinary* = object
+        msgType* = CLIENT_AGENT_BINARY 
+        agentPayload*: seq[byte]            # Agent binary in byte-form, opens file browser to select location on the client
+
+    WsAgentConnection* = object
+        msgType* = CLIENT_AGENT_CONNECTION
+        agent*: Agent                      
+    
+    WsAgentCheckin* = object 
+        msgType* = CLIENT_AGENT_CHECKIN
+        agentId*: uint32                   
+        timestamp*: uint32
+
+    WsConsoleLog* = object 
+        msgType* = CLIENT_CONSOLE_LOG
+        agentId*: uint32 
+        logType*: LogType
+        timestamp*: uint32 
+        data*: seq[byte]
+
+    WsEventLog* = object 
+        msgType* = CLIENT_EVENT_LOG
+        logType*: LogType
+        timestamp*: uint32 
+        data*: seq[byte]
+
+    WsClientConnection* = object 
+        msgType* = CLIENT_CONNECTION
+        version: uint8
+        profile*: seq[byte]
+        agents*: seq[Agent]
+        listeners*: seq[Listener] 
+    

src/server/core/server.nim

@@ -1,4 +1,4 @@
-import prompt, terminal, argparse, parsetoml
+import prompt, terminal, argparse, parsetoml, times
 import strutils, strformat, system, tables
 
 import ./[agent, listener, builder]
@@ -6,6 +6,8 @@ import ../globals
 import ../db/database
 import ../core/logger
 import ../../common/[types, crypto, profile]
+import ../protocol/websocket
+import mummy, mummy/routers
 
 #[
     Argument parsing
@@ -137,6 +139,33 @@ proc init*(T: type Conquest, profile: Profile): Conquest =
     cq.dbPath = CONQUEST_ROOT & "/" & profile.getString("database-file")
     return cq
 
+#[
+    WebSocket
+]#
+proc upgradeHandler(request: Request) = 
+    let ws = request.upgradeToWebSocket()
+
+    # Send client connection message
+    ws.sendEventlogItem(LOG_SUCCESS_SHORT, now().toTime().toUnix(), "CQ-V1")
+
+
+proc websocketHandler(ws: WebSocket, event: WebSocketEvent, message: Message) = 
+    case event:
+    of OpenEvent:
+        discard
+    of MessageEvent:
+        ws.sendHeartbeat()
+    of ErrorEvent:
+        discard
+    of CloseEvent:
+        discard
+
+proc serve(server: Server) {.thread.} = 
+    try:
+        server.serve(Port(12345))
+    except Exception:
+        discard 
+    
 proc startServer*(profilePath: string) =
 
     # Ensure that the conquest root directory was passed as a compile-time define 
@@ -167,6 +196,13 @@ proc startServer*(profilePath: string) =
     cq.restartListeners()
     cq.addMultiple(cq.dbGetAllAgents())
 
+    var router: Router
+    router.get("/*", upgradeHandler)
+    let server = newServer(router, websocketHandler)
+    
+    var thread: Thread[Server]
+    createThread(thread, serve, server)
+
     # Main loop
     while true: 
         cq.prompt.setIndicator("[conquest]> ")

src/server/nim.cfg

@@ -1,5 +1,6 @@
 # Compiler flags
 -d:server
 --threads:on
+--mm:orc
 -d:httpxServerName=""
 -o:"bin/server"

src/server/protocol/websocket.nim

@@ -0,0 +1,47 @@
+import times, tables
+import ../../common/[types, utils, serialize]
+import mummy
+
+#[
+    [ Sending functions ]
+    Server -> Client
+]#
+proc sendHeartbeat*(ws: WebSocket) = 
+    var packer = Packer.init() 
+
+    packer.add(cast[uint8](CLIENT_HEARTBEAT))
+    let data = packer.pack() 
+
+    ws.send(Bytes.toString(data), BinaryMessage)
+
+proc sendEventlogItem*(ws: WebSocket, logType: LogType, timestamp: int64, message: string) = 
+    var packer = Packer.init() 
+
+    packer.add(cast[uint8](CLIENT_EVENT_LOG))
+    packer.add(cast[uint8](logType))
+    packer.add(cast[uint32](timestamp))
+    packer.addDataWithLengthPrefix(string.toBytes(message))
+    let data = packer.pack() 
+
+    ws.send(Bytes.toString(data), BinaryMessage)
+
+#[
+    [ Retrieval functions ]
+    Client -> Server
+]#
+proc getMessageType*(message: Message): WsMessageAction = 
+    var unpacker = Unpacker.init(message.data)
+    return cast[WsMessageAction](unpacker.getUint8()) 
+
+proc receiveStartListener*(message: Message): Listener = 
+    var unpacker = Unpacker.init(message.data)
+
+    discard unpacker.getUint8() 
+
+    return Listener(
+        server: nil,
+        listenerId: Uuid.toString(unpacker.getUint32()),
+        address: unpacker.getDataWithLengthPrefix(),
+        port: int(unpacker.getUint16()),
+        protocol: cast[Protocol](unpacker.getUint8())
+    )