Adjusted BoatCom protocol use, I have not tested this :D

BackupManager/Config.cs

@@ -16,6 +16,7 @@
         public string SatoriHost { get; set; }
         public ushort SatoriPort { get; set; }
         public string SatoriSecret { get; set; }
+        public string SatoriFormat { get; set; } = @"/msg flash {0}";
         public bool SatoriErrorsOnly { get; set; } = true;
     }
 }

BackupManager/Program.cs

@@ -287,39 +287,34 @@ namespace BackupManager {
 
             EndPoint endPoint = new IPEndPoint(ip, Config.SatoriPort);
 
-            StringBuilder textBuilder = new StringBuilder();
+            StringBuilder textBuilder = new();
             textBuilder.AppendFormat(@"[b]Backup System[/b] [{0}]: ", Environment.MachineName);
 
-            if (error)
+            if(error)
                 textBuilder.Append(@"[color=red]");
 
             textBuilder.Append(text);
 
-            if (error)
+            if(error)
                 textBuilder.Append(@"[/color]");
 
-            text = textBuilder.ToString();
+            text = string.Format(Config.SatoriFormat, textBuilder);
 
-            StringBuilder messageBuilder = new StringBuilder();
+            byte[] opcode = new byte[1] { 1 };
-
+            byte[] hash;
-            using (HMACSHA256 hmac = new HMACSHA256(Encoding.UTF8.GetBytes(Config.SatoriSecret))) {
+            using(HMACSHA256 hmac = new(Encoding.UTF8.GetBytes(Config.SatoriSecret))) {
-                byte[] hash = hmac.ComputeHash(Encoding.UTF8.GetBytes(text));
+                hmac.TransformBlock(opcode, 0, opcode.Length, null, 0);
-
+                hash = Encoding.UTF8.GetBytes(text);
-                foreach (byte b in hash)
+                hmac.TransformFinalBlock(hash, 0, hash.Length);
-                    messageBuilder.AppendFormat(@"{0:x2}", b);
+                hash = hmac.Hash;
             }
 
-            messageBuilder.Append(text);
+            using Socket sock = new(endPoint.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
-            string message = messageBuilder.ToString();
+            sock.NoDelay = sock.Blocking = true;
-            byte[] messageBytes = new byte[Encoding.UTF8.GetByteCount(message) + 2];
+            sock.Connect(endPoint);
-            messageBytes[0] = messageBytes[messageBytes.Length - 1] = 0x0F;
+            sock.Send(hash);
-            Encoding.UTF8.GetBytes(message).CopyTo(messageBytes, 1);
+            sock.Send(opcode);
-
+            sock.Send(Encoding.UTF8.GetBytes(text));
-            using (Socket sock = new Socket(endPoint.AddressFamily, SocketType.Stream, ProtocolType.Tcp)) {
-                sock.NoDelay = sock.Blocking = true;
-                sock.Connect(endPoint);
-                sock.Send(messageBytes);
-            }
         }
     }
 }

do-backup.sh

@@ -1,5 +1,5 @@
 cwd="$(pwd)"
 export DOTNET_CLI_TELEMETRY_OPTOUT=1
 cd "$(dirname "$0")"
-dotnet run --project BackupManager -c Release -f net5.0 -- -cron
+dotnet run --project BackupManager -c Release -f net6.0 -- -cron
 cd "$cwd"