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Libraries/Esiur/Net/Packets/EpAuthPacket.cs

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+/*
+ 
+Copyright (c) 2017-2026 Ahmed Kh. Zamil
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+*/
+
+using Esiur.Data;
+using Esiur.Security.Authority;
+using Esiur.Security.Cryptography;
+using System;
+using System.Collections.Generic;
+using System.Data.Common;
+using System.Linq;
+using System.Security.Cryptography;
+using System.Text;
+using System.Threading.Tasks;
+using System.Timers;
+
+namespace Esiur.Net.Packets;
+
+public class EpAuthPacket : Packet
+{
+    public EpAuthPacketCommand Command
+    {
+        get;
+        set;
+    }
+
+    public EpAuthPacketAction Action
+    {
+        get;
+        set;
+    }
+
+    public EpAuthPacketEvent Event
+    {
+        get;
+        set;
+    }
+
+    public EpAuthPacketAcknowledgement Acknowledgement
+    {
+        get;
+        set;
+    }
+
+
+    public AuthenticationMode AuthMode
+    {
+        get;
+        set;
+    }
+
+    public EncryptionMode EncryptionMode
+    {
+        get;
+        set;
+    }
+
+    //public AuthenticationMethod AuthenticationMethod
+    //{
+    //    get;
+    //    set;
+    //}
+
+
+    public byte ErrorCode
+    {
+        get;
+        set;
+    }
+
+    public string Message
+    {
+        get;
+        set;
+    }
+
+    public byte[] SessionId
+    {
+        get;
+        set;
+    }
+
+
+    public ParsedTdu? Tdu
+    {
+        get;
+        set;
+    }
+
+    // IAuth Reference
+    public uint Reference
+    {
+        get;
+        set;
+    }
+
+
+
+    private uint dataLengthNeeded;
+
+    bool NotEnough(uint offset, uint ends, uint needed)
+    {
+        if (offset + needed > ends)
+        {
+            dataLengthNeeded = needed - (ends - offset);
+            return true;
+        }
+        else
+            return false;
+    }
+
+    public override string ToString()
+    {
+        return Command.ToString() + " " + Action.ToString();
+    }
+
+    public override long Parse(byte[] data, uint offset, uint ends)
+    {
+        var oOffset = offset;
+
+        if (NotEnough(offset, ends, 1))
+            return -dataLengthNeeded;
+
+        Command = (EpAuthPacketCommand)(data[offset] >> 6);
+        var hasTdu = (data[offset] & 0x20) != 0;
+
+        if (Command == EpAuthPacketCommand.Initialize)
+        {
+            AuthMode = (AuthenticationMode)(data[offset] >> 3 & 0x7);
+            EncryptionMode = (EncryptionMode)(data[offset++] & 0x7);
+        }
+        else if (Command == EpAuthPacketCommand.Acknowledge)
+        {
+            // remove last two reserved LSBs
+            Acknowledgement = (EpAuthPacketAcknowledgement)(data[offset++]);// & 0xFC);
+        }
+        else if (Command == EpAuthPacketCommand.Action)
+        {
+            // remove last two reserved LSBs
+            Action = (EpAuthPacketAction)(data[offset++]);// & 0xFC);
+        }
+        else if (Command == EpAuthPacketCommand.Event)
+        {
+            // remove last two reserved LSBs
+            Event = (EpAuthPacketEvent)(data[offset++]);// & 0xFC);
+        }
+        else
+        {
+            return -1; // invalid command
+        }
+
+        if (hasTdu)
+        {
+            if (NotEnough(offset, ends, 1))
+                return -dataLengthNeeded;
+
+            Tdu = ParsedTdu.Parse(data, offset, ends);
+
+            if (Tdu.Value.Class == TduClass.Invalid)
+                return -(int)Tdu.Value.TotalLength;
+
+            offset += (uint)Tdu.Value.TotalLength;
+
+        }
+
+        return offset - oOffset;
+
+    }
+
+}
+