Ver 3

2026-06-13 22:48:42 +00:00 · 2026-05-24 18:27:22 +03:00
parent a6e8bed31d
commit eb323e8bf8
69 changed files with 6532 additions and 3371 deletions
@@ -0,0 +1,155 @@
+using Esiur.Core;
+using Esiur.Protocol;
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Esiur.Data
+{
+    public struct PlainTdu
+    {
+        public TduIdentifier Identifier;
+        public int Index;
+        public TduClass Class;
+        public uint TduOffset;
+        public uint PayloadOffset;
+        public ulong PayloadLength;
+        public byte[] Data;
+        public byte Exponent;
+        public ulong TotalLength;
+        public uint Ends;
+
+
+
+        public static PlainTdu Parse(byte[] data, uint offset, uint ends)
+        {
+            var oOffset = offset;
+
+            // @TODO: add protection against memory allocation attacks by checking the length of the data before parsing it.
+
+            var h = data[offset++];
+
+            var cls = (TduClass)(h >> 6);
+
+            if (cls == TduClass.Fixed)
+            {
+                var exp = (h & 0x38) >> 3;
+
+                if (exp == 0)
+                    return new PlainTdu()
+                    {
+                        Identifier = (TduIdentifier)h,
+                        Data = data,
+                        TduOffset = oOffset,
+                        PayloadOffset = offset,
+                        Class = cls,
+                        Exponent = (byte)exp,
+                        Index = (byte)h & 0x7,
+                        PayloadLength = 0,
+                        TotalLength = 1,
+                        Ends = ends
+                    };
+
+                ulong cl = (ulong)(1 << (exp - 1));
+
+                if (ends - offset < cl)
+                    return new PlainTdu()
+                    {
+                        Class = TduClass.Invalid,
+                        TotalLength = (cl - (ends - offset))
+                    };
+
+                //offset += (uint)cl;
+
+                return new PlainTdu()
+                {
+                    Identifier = (TduIdentifier)h,
+                    Data = data,
+                    TduOffset= oOffset,
+                    PayloadOffset = offset,
+                    Class = cls,
+                    PayloadLength = cl,
+                    TotalLength = 1 + cl,
+                    Exponent = (byte)exp,
+                    Index = (byte)h & 0x7,
+                    Ends = ends
+                };
+            }
+            else if (cls == TduClass.Typed)
+            {
+                ulong cll = (ulong)(h >> 3) & 0x7;
+
+                if (ends - offset < cll)
+                    return new PlainTdu()
+                    {
+                        Class = TduClass.Invalid,
+                        TotalLength = (cll - (ends - offset))
+                    };
+
+                ulong cl = 0;
+
+                for (uint i = 0; i < cll; i++)
+                    cl = cl << 8 | data[offset++];
+
+                if (ends - offset < cl)
+                    return new PlainTdu()
+                    {
+                        TotalLength = (cl - (ends - offset)),
+                        Class = TduClass.Invalid,
+                    };
+
+
+                return new PlainTdu()
+                {
+                    Identifier = (TduIdentifier)(h & 0xC7),
+                    Data = data,
+                    TduOffset = oOffset,
+                    PayloadOffset = offset,
+                    Class = cls,
+                    PayloadLength = cl,
+                    TotalLength = 1 + cl + cll,
+                    Index = (byte)h & 0x7,
+                    Ends = ends
+                };
+            }
+            else
+            {
+                ulong cll = (ulong)(h >> 3) & 0x7;
+
+                if (ends - offset < cll)
+                    return new PlainTdu()
+                    {
+                        Class = TduClass.Invalid,
+                        TotalLength = (cll - (ends - offset))
+                    };
+
+                ulong cl = 0;
+
+                for (uint i = 0; i < cll; i++)
+                    cl = cl << 8 | data[offset++];
+
+                if (ends - offset < cl)
+                    return new PlainTdu()
+                    {
+                        Class = TduClass.Invalid,
+                        TotalLength = (cl - (ends - offset))
+                    };
+
+
+                return
+                    new PlainTdu()
+                    {
+                        Identifier = (TduIdentifier)(h & 0xC7),
+                        Data = data,
+                        TduOffset = oOffset,
+                        PayloadOffset = offset,
+                        Class = cls,
+                        PayloadLength = cl,
+                        TotalLength = 1 + cl + cll,
+                        Index = (byte)h & 0x7,
+                        Ends = ends
+                    };
+            }
+        }
+    }
+}