[feat] Sockets, i guess mm hmm

# Conflicts:
#	Content.Server/Administration/Systems/BwoinkSystem.cs
#	Content.Server/Chat/Managers/ChatManager.cs
#	Content.Server/Entry/EntryPoint.cs
#	Content.Server/GameTicking/GameTicker.RoundFlow.cs
#	Content.Server/IoC/ServerContentIoC.cs
#	Content.Server/RoundEnd/RoundEndSystem.cs
#	Content.Server/Shuttles/Systems/EmergencyShuttleSystem.Console.cs
#	Content.Server/Shuttles/Systems/EmergencyShuttleSystem.cs
#	Content.Shared/CCVar/CCVars.cs

Content.Server/UtkaIntegration/Commands/UtkaAuthenticationCommand.cs

@@ -0,0 +1,57 @@
+using Content.Server.UtkaIntegration.TCP;
+using Content.Shared.CCVar;
+using Content.Shared.White;
+using Robust.Shared.Configuration;
+
+namespace Content.Server.UtkaIntegration;
+
+public sealed class UtkaAuthenticationCommand : IUtkaCommand
+{
+    [Dependency] private readonly IConfigurationManager _configurationManager = default!;
+    [Dependency] private readonly UtkaTCPWrapper _utkaTcpWrapper = default!;
+
+    public string Name => "handshake";
+    public Type RequestMessageType => typeof(UtkaHandshakeMessage);
+
+    public void Execute(UtkaTCPSession session, UtkaBaseMessage baseMessage)
+    {
+        if (baseMessage is not UtkaHandshakeMessage message)
+            return;
+
+        IoCManager.InjectDependencies(this);
+
+        if (string.IsNullOrWhiteSpace(message.Key))
+        {
+            SendMessage(session, "key_missmatch");
+            return;
+        }
+
+        var key = _configurationManager.GetCVar(WhiteCVars.UtkaSocketKey);
+
+        if (key != message.Key)
+        {
+            SendMessage(session, "key_missmatch");
+            return;
+        }
+
+        if (session.Authenticated)
+        {
+            SendMessage(session, "already_authentificated");
+            return;
+        }
+
+        session.Authenticated = true;
+        SendMessage(session, "handshake_accepted");
+    }
+
+    private void SendMessage(UtkaTCPSession session, string message)
+    {
+        var response = new UtkaHandshakeMessage()
+        {
+            Key = _configurationManager.GetCVar(WhiteCVars.UtkaSocketKey),
+            Message = message
+        };
+
+        _utkaTcpWrapper.SendMessageToClient(session, response);
+    }
+}