"Implement" "login"

config/runtime.exs

@@ -1,4 +1,5 @@
 import Config
 
 config :amethyst,
-  port: 25599 # Bogus port for testing, avoids unexpected conflicts
+  port: 25599, # Bogus port for testing, avoids unexpected conflicts
+  encryption: false

lib/data.ex

@@ -26,6 +26,13 @@ defmodule Amethyst.Minecraft.Write do
     UUID.string_to_binary!(uuid)
   end
 
+  def bool(value) do
+    case value do
+      true -> <<0x01::8>>
+      false -> <<0x00::8>>
+    end
+  end
+
   def varint(value) when value in -2_147_483_648..2_147_483_647 do
     <<value::32-unsigned>> = <<value::32-signed>> # This is a trick to allow the arithmetic shift to act as a logical shift
     varnum("", value)

lib/servers/generic.ex

@@ -24,9 +24,13 @@ defmodule Amethyst.Server.Generic do
 
   def get_packet(client) do
     {[length], ""} = get_varint(client, "")
-    {:ok, full_packet} = :gen_tcp.recv(client, length)
-    {[id], data} = Read.start(full_packet) |> Read.varint() |> Read.stop()
-    {id, data}
+    recv = :gen_tcp.recv(client, length)
+    case recv do
+      {:ok, full_packet} -> ({[id], data} = Read.start(full_packet) |> Read.varint() |> Read.stop()
+                            {id, data})
+      {:error, :closed} -> raise RuntimeError, "TODO: Handle disconnections reasonably"
+      {:error, error} -> raise RuntimeError, "An error has occured while waiting on a packet: #{error}"
+    end
   end
 
   defp get_varint(client, acc) do

lib/servers/login.ex

@@ -72,7 +72,7 @@ defmodule Amethyst.Server.Login do
   end
   # Encryption Request https://wiki.vg/Protocol#Encryption_Request
   def serialize({:encryption_request, id, pubkey, verify_token, auth}) do
-    Write.varint(0x01) <> Write.string(id) <> Write.varint(byte_size(pubkey)) <> pubkey <> Write.varint(byte_size(verify_token)) <> verify_token <> <<auth::8>>
+    Write.varint(0x01) <> Write.string(id) <> Write.varint(byte_size(pubkey)) <> pubkey <> Write.varint(byte_size(verify_token)) <> verify_token <> Write.bool(auth)
   end
   # Login Success https://wiki.vg/Protocol#Login_Success
   def serialize({:login_success, uuid, username, props, strict}) do
@@ -80,7 +80,7 @@ defmodule Amethyst.Server.Login do
     Enum.reduce(props, "", fn {name, value, signature}, acc -> acc <> Write.string(name) <> Write.string(value) <> case signature do
       nil -> <<0x00>>
       signature -> <<0x01>> <> Write.string(signature)
-    end end) <> <<strict::8>>
+    end end) <> Write.bool(strict)
   end
   # Set Compression https://wiki.vg/Protocol#Set_Compression
   def serialize({:set_compression, threshold}) do
@@ -99,6 +99,18 @@ defmodule Amethyst.Server.Login do
   end
 
   ## HANDLING
+  # Login Start https://wiki.vg/Protocol#Login_Start
+  def handle({:login_start, name, uuid}, client) do
+    Logger.info("Logging in #{name} (#{uuid})")
+    if Application.fetch_env!(:amethyst, :encryption) do
+      raise RuntimeError, "Encryption is not currently supported!"
+    else
+      transmit({:login_success, uuid, name, [], false}, client)
+    end
+  end
+  def handle({:login_acknowledged}, _client) do
+    raise RuntimeError, "Configuration stage is not implemented."
+  end
   def handle(tuple, _) do
     Logger.error("Unhandled but known packet #{elem(tuple, 0)}")
   end