1 files changed, 69 insertions, 0 deletions
diff --git a/Program.cs b/Program.cs
new file mode 100644
index 0000000..5f8de30
--- /dev/null
+++ b/Program.cs
@@ -0,0 +1,69 @@
+using System;
+using System.Net;
+using System.Net.Sockets;
+
+const char DELIM = ' ';
+const int DELAY_DURATION_S = 990;
+
+short ReadPort() => args.Length != 0 && short.TryParse(args[0], out var port) ? port : (short)22;
+
+IList<string> ReadBanner() => Console.In.ReadToEnd().Split(DELIM, StringSplitOptions.RemoveEmptyEntries);
+
+async Task SshClientHandler(TcpClient client, IEnumerable<string> banner)
+{
+    var remote = client.Client.RemoteEndPoint;
+    Console.WriteLine($"{remote}: Client connected.");
+
+    try
+    {
+        using (client)
+        {
+            var stream = client.GetStream();
+            var writer = new StreamWriter(stream) { AutoFlush = true };
+
+            while (true)
+            {
+                foreach (var word in banner)
+                {
+                    await writer.WriteAsync($"{word}{DELIM}");
+                    await Task.Delay(DELAY_DURATION_S);
+                }
+
+                Console.WriteLine($"{remote}: Client read it all!");
+            }
+        }
+    }
+    catch (Exception ex)
+    {
+        Console.WriteLine($"{remote}: Client handler error: {ex.Message}");
+    }
+    finally
+    {
+        Console.WriteLine($"{remote}: Client hung up");
+    }
+}
+
+// main 
+var banner = ReadBanner();
+var port = ReadPort();
+var listener = new TcpListener(IPAddress.Any, port);
+
+using (listener)
+{
+    listener.Start();
+    Console.WriteLine($"Listening on port {port}...");
+
+    while (true)
+    {
+        try
+        {
+            var client = await listener.AcceptTcpClientAsync();
+
+            _ = Task.Run(() => SshClientHandler(client, banner));
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"Accept error: {ex.Message}");
+        }
+    }
+}
+\ No newline at end of file