Need help porting functions from c# to Au3.

Luig · June 20, 2010

I am trying to convert 2 functions from c# source which are use to encrypt and decrypt packets.

This is the code for the 2 functions.

/// <summary>
        /// Encrypts the given packet
        /// </summary>
        /// <param name="p">The packet to encrypt</param>
        public static Packet Encrypt(Packet p)
        {
            byte[] buffer = p.GetBuffer();
            buffer[0] = (byte)((int)0x76 ^ (int)buffer[0]);
            for (int i = 1; i != p.Length; i++)
                buffer[i] = (byte)(buffer[i] ^ buffer[i - 1]);

            //Packet length
            byte[] Raw = buffer;
            byte[] NewRaw = new byte[buffer.Length + 4];
            byte[] Length = BitConverter.GetBytes(buffer.Length + 4);
            Array.Copy(Length, NewRaw, 2);
            NewRaw[2] = 0x01;
            NewRaw[3] = 0x00;
            Array.Copy(Raw, 0, NewRaw, 4, buffer.Length);
            Raw = new byte[NewRaw.Length];
            Array.Copy(NewRaw, Raw, NewRaw.Length);

            return new Packet(NewRaw);
        }

/// <summary>
        /// Decrypts the given packet 
        /// </summary>
        /// <param name="p">The packet to decrypt</param>
        public static Packet Decrypt(Packet p)
        {
            byte[] data = p.GetBuffer();
            int i = data.Length - 4;
            byte[] bs = new byte[i];
            Array.Copy(data, 4, bs, 0, i);
            byte b2 = bs[0];
            byte b3 = 0;
            bs[0] = (byte)(bs[0] ^ 118);

            for (int k = 1; k < data.Length - 4; k++)
            {
                byte b1 = b2;
                b2 = bs[k];
                b3 = b2;
                b3 ^= b1;
                bs[k] = b3;
            }
            return new Packet(bs);
            /*int i = data.Length - 4;
            byte[] bs = new byte[i];
            Array.Copy(data, 4, bs, 0, i);

            byte DL = bs[0];
            bs[0] = (byte)((int)bs[0] ^ (int)0x76);
            for (int c = 1; c != i; c++)
            {
                byte AL = bs[c];
                bs[c] = (byte)(bs[c] ^ DL);
                DL = AL;
            }

            Packet n = new Packet(bs);
            return n;*/
        }

The whole source for this section is:

/*
This file is part of LaLore.

LaLore is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

LaLore is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with LaLore.  If not, see <http://www.gnu.org/licenses/>.
*/
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace LaLore
{
    class Packet
    {
        private byte[] BufferData;
        public int Index = 0;
        public int Length = 0;

        /// <summary>
        /// Creates a new buffer
        /// </summary>
        /// <param name="Size">Size of buffer</param>
        public Packet(uint Size)
        {
            try
            {
                BufferData = new byte[Size];
            }
            catch
            {
                BufferData = new byte[Size * 2]; //whatever
            }
            Length = BufferData.GetLength(0);
        }
        /// <summary>
        /// Creates a new buffer
        /// </summary>
        /// <param name="ArrayOfBytes">The byte array the buffer should use</param>
        public Packet(byte[] ArrayOfBytes)
        {
            BufferData = new byte[ArrayOfBytes.Length];
            ArrayOfBytes.CopyTo(BufferData, 0);
            Length = BufferData.Length;
        }
        /// <summary>
        /// Resizes the buffer
        /// </summary>
        /// <param name="Deltasize"></param>
        private void Resize(int Deltasize)
        {
            byte[] newbuffer = new byte[Length + Deltasize];
            BufferData.CopyTo(newbuffer, 0);
            BufferData = newbuffer;
            Length = BufferData.Length;
        }
        /// <summary>
        /// Returns the buffer data
        /// </summary>
        /// <returns>Buffer data</returns>
        public byte[] GetBuffer()
        {
            return BufferData;
        }
        /// <summary>
        /// Returns the buffer data in a byte array
        /// </summary>
        /// <returns>The buffer data</returns>
        public byte[] GetWrittenBuffer()
        {
            try
            {
                if (Index > Length)
                {
                    byte[] result = new byte[Index - 1];
                    System.Buffer.BlockCopy(BufferData, 0, result, 0, Index - 1);
                    return result;
                }
                else
                {
                    byte[] result = new byte[Index];
                    System.Buffer.BlockCopy(BufferData, 0, result, 0, Index);
                    return result;
                }
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
                return new byte[1];
            }
        }
        /// <summary>
        /// Sets the index to the given position
        /// </summary>
        /// <param name="nIndex">New index</param>
        /// <returns>True if the operation completed</returns>
        public bool setIndex(int nIndex)
        {
            if (Index > Length) return false;
            Index = nIndex;
            return true;
        }
        /// <summary>
        /// Sets the index to current pos + new index
        /// </summary>
        /// <param name="nIndex">New index</param>
        /// <returns>True if operation completed</returns>
        public bool addIndex(int nIndex)
        {
            return setIndex(Index + nIndex);
        }
        /// <summary>
        /// Sets the index to 0
        /// </summary>
        public void resetIndex()
        {
            setIndex(0);
        }

        //Write methods

        /// <summary>
        /// Writes a byte to the buffer
        /// </summary>
        /// <param name="Byte">The byte to write</param>
        public void WriteByte(byte Byte)
        {
            if (Index >= Length) Resize((Index - Length) + 1);
            BufferData[Index] = Byte;
            ++Index;
        }

        /// <summary>
        /// Writes a byte to the buffer
        /// </summary>
        /// <param name="Byte">The byte to write</param>
        public void WriteByte(int Int)
        {
            byte Byte = (byte)Int;
            if (Index >= Length) Resize((Index - Length) + 1);
            BufferData[Index] = Byte;
            ++Index;
        }

        /// <summary>
        /// Writes a short (Int16) to the buffer
        /// </summary>
        /// <param name="ShortInteger">The short to write</param>
        public void WriteShort(short ShortInteger)
        {
            if (Index + 2 >= Length) Resize((Index - Length) + 2);
            WriteByte((byte)(ShortInteger & 0xFF));
            WriteByte((byte)((((ushort)ShortInteger) >> 8) & 0xFF));
        }

        /// <summary>
        /// Writes a short (Int16) to the buffer
        /// </summary>
        /// <param name="ShortInteger">The short to write</param>
        public void WriteShort(int Int)
        {
            short ShortInteger = (short)Int;
            if (Index + 2 >= Length) Resize((Index - Length) + 2);
            WriteByte((byte)(ShortInteger & 0xFF));
            WriteByte((byte)((((ushort)ShortInteger) >> 8) & 0xFF));
        }

        /// <summary>
        /// Writes an integer to the buffer
        /// </summary>
        /// <param name="Integer">The int you want to write</param>
        public void WriteInt(int Integer)
        {
            if (Index + 4 >= Length) Resize((Index - Length) + 4);
            WriteByte((byte)(Integer & 0xFF));
            WriteByte((byte)((((uint)Integer) >> 8) & 0xFF));
            WriteByte((byte)((((uint)Integer) >> 16) & 0xFF));
            WriteByte((byte)((((uint)Integer) >> 24) & 0xFF));

        }

        public void WriteLong(long Integer)
        {
            WriteByte((byte)(Integer & 0xFF));
            WriteByte((byte)((((ulong)Integer) >> 8) & 0xFF));
            WriteByte((byte)((((ulong)Integer) >> 16) & 0xFF));
            WriteByte((byte)((((ulong)Integer) >> 24) & 0xFF));
            WriteByte((byte)((((ulong)Integer) >> 32) & 0xFF));
            WriteByte((byte)((((ulong)Integer) >> 40) & 0xFF));
            WriteByte((byte)((((ulong)Integer) >> 48) & 0xFF));
            WriteByte((byte)((((ulong)Integer) >> 56) & 0xFF));
        }

        /// <summary>
        /// Writes a byte n number of times to the buffer
        /// </summary>
        /// <param name="Pad">The byte you want to pad</param>
        /// <param name="nLength">The number of bytes to write</param>
        public void BytePad(byte Pad, int nLength)
        {
            if ((Index + nLength) >= Length) Resize(nLength);
            for (int i = 0; i < nLength; i++)
            {
                BufferData[Index + i] = Pad;
            }
            Index += nLength;
        }
        /// <summary>
        /// Writes a string to the buffer
        /// </summary>
        /// <param name="String">The string you want to write</param>
        public void WriteString(string String)
        {
            if ((Index + String.Length) >= Length) Resize(String.Length);
            for (int i = 0; i < String.Length; i++)
            {
                BufferData[Index + i] = (byte)String[i];
            }
            Index += String.Length;
        }
        /// <summary>
        /// Writes a string preceeded by a short containing its length
        /// </summary>
        /// <param name="String">The string you want to write</param>
        public void WriteStringLen(string String)
        {
            if ((Index + String.Length + 2) >= Length) Resize(String.Length + 2);
            WriteShort((short)String.Length);
            WriteString(String);
        }
        /// <summary>
        /// Writes a padded left string to the buffer
        /// </summary>
        /// <param name="String">The string you want to write</param>
        /// <param name="Pad">The char you want to pad</param>
        /// <param name="PadLength">The number of chars you want to pad</param>
        public void WriteStringPaddedLeft(string String, char Pad, int PadLength)
        {
            String.PadLeft(PadLength, Pad);
            if ((Index + String.Length) >= Length) Resize(String.Length);
            WriteString(String);
        }
        /// <summary>
        /// Writes a padded right string to the buffer
        /// </summary>
        /// <param name="String">The string you want to write</param>
        /// <param name="Pad">The char you want to pad</param>
        /// <param name="PadLength">The number of chars you want to pad</param>
        public void WriteStringPaddedRight(string String, char Pad, int PadLength)
        {
            String.PadRight(PadLength, Pad);
            if ((Index + String.Length) >= Length) Resize(String.Length);
            WriteString(String);
        }
        /// <summary>
        /// Writes an array of bytes to the buffer
        /// </summary>
        /// <param name="Array">The array you want to write</param>
        public void WriteArray(byte[] Array)
        {
            if ((Index + Array.Length) >= Length) Resize(Array.Length);
            for (int i = 0; i < Array.Length; i++)
            {
                BufferData[Index + i] = Array[i];
            }
            Index += Array.Length;
        }
        /// <summary>
        /// Write a hex string to the buffer
        /// </summary>
        /// <param name="HexString">The string containing the hex chain</param>
        public void WriteHexString(string HexString)
        {
            int _out;
            byte[] _byte = HexEncoding.GetBytes(HexString, out _out);
            WriteArray(_byte);
        }

        //Read methods

        /// <summary>
        /// Reads a byte from the buffer
        /// </summary>
        /// <returns>The read byte or 0 if failed</returns>
        public byte ReadByte()
        {
            try
            {
                byte result = BufferData[Index];
                ++Index;
                return result;
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
                ++Index;
                return 0;
            }
        }
        /// <summary>
        /// Reads a byte at a certain position in the buffer
        /// </summary>
        /// <param name="pos">The position to read from</param>
        /// <returns>The read byte or 0 if failed</returns>
        public byte ReadByte(int pos)
        {
            int TempIndex = Index;
            Index = pos;
            byte result = ReadByte();
            Index = TempIndex;
            return result;
        }
        /// <summary>
        /// Reads an unsigned short from the buffer
        /// </summary>
        /// <returns>The read ushort</returns>
        public ushort ReadUShort()
        {
            try
            {
                ushort result = (ushort)((BufferData[Index]) + (BufferData[Index + 1] * 256));
                Index += 2;
                return result;
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
                Index += 2;
                return 0;
            }
        }
        /// <summary>
        /// Reads a short from the buffer
        /// </summary>
        /// <returns>The read short</returns>
        public short ReadShort()
        {
            int byte1, byte2;
            byte1 = ReadByte();
            byte2 = ReadByte();
            return (short)((byte2 << 8) + byte1);
        }
        /// <summary>
        /// Reads a short from the buffer at the given position
        /// </summary>
        /// <param name="pos">Position to read at</param>
        /// <returns>The read short</returns>
        public short ReadShort(int pos)
        {
            int TempIndex = Index;
            Index = pos;
            short result = ReadShort();
            Index = TempIndex;
            return result;
        }


        /// <summary>
        /// Reads an integer from the buffer
        /// </summary>
        /// <returns>The read int</returns>
        public int ReadInt()
        {
            int byte1 = ReadByte();
            int byte2 = ReadByte();
            int byte3 = ReadByte();
            int byte4 = ReadByte();



            return (byte4 << 24) + (byte3 << 16) + (byte2 << 8) + byte1;
        }
        /// <summary>
        /// Reads an unsigned int from the buffer at the given position
        /// </summary>
        /// <param name="Pos">The position to read at</param>
        /// <returns>The read uint</returns>
        public int ReadInt(int Pos)
        {
            int TempIndex = Index;
            Index = Pos;
            int result = ReadInt();
            Index = TempIndex;
            return result;
        }
        /// <summary>
        /// Reads a string that is as long as the provided length from the buffer
        /// </summary>
        /// <param name="_length">Length of the string to be read</param>
        /// <returns>The read string</returns>
        public string ReadString(int _length)
        {
            try
            {
                char[] newbuf = new char[_length];
                for (int i = 0; i < _length; i++)
                {
                    newbuf[i] = (char)BufferData[Index + i];
                }
                Index += _length;
                return new string(newbuf);
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
                return string.Empty;
            }
        }

        /// <summary>
        /// Reads a string that is as long as the provided length from the buffer
        /// </summary>
        /// <param name="_length">Length of the string to be read</param>
        /// <returns>The read string</returns>
        public string ReadStringFrom0(int _length)
        {
            try
            {
                ArrayList a = new ArrayList();
                for (int i = 0; i < _length; i++)
                {
                    if(BufferData[Index + i] != 0x00)
                        a.Add((char)BufferData[Index + i]);
                }
                Index += _length;
                char[] newbuf = new char[a.Count];
                for (int i = 0; i < a.Count; i++)
                    newbuf[i] = (char)a[i];
                return new string(newbuf);
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
                return string.Empty;
            }
        }
        /// <summary>
        /// Reads a string using the short length preceding the string from the buffer
        /// </summary>
        /// <returns>The read string</returns>
        public string ReadStringFromLength()
        {
            int _length = ReadShort();
            return ReadString(_length);
        }
        /// <summary>
        /// Reads a string using the short length preceding the string from the buffer at the given position
        /// </summary>
        /// <param name="Pos">The position to read at</param>
        /// <returns>The read string</returns>
        public string ReadStringFromLength(int Pos)
        {
            int TempIndex = Index;
            Index = Pos;
            string result = ReadStringFromLength();
            Index = TempIndex;
            return result;
        }
        /// <summary>
        /// Reads a string that is as long as the provided length from the buffer at the given position
        /// </summary>
        /// <param name="Pos">The position to read at</param>
        /// <param name="nLength">The length of the string to be read</param>
        /// <returns>The read string</returns>
        public string ReadStringSpecify(int Pos, int nLength)
        {
            int TempIndex = Index;
            Index = Pos;
            string result = ReadString(nLength);
            Index = TempIndex;
            return result;
        }

        /// <summary>
        /// Pads the packet
        /// </summary>
        /// <param name="b"></param>
        /// <param name="amount"></param>
        public void Pad(byte b, int amount)
        {
            for (int i = 0; i < amount; i++)
                WriteByte(b);
        }

        /// <summary>
        /// Encrypts the given packet
        /// </summary>
        /// <param name="p">The packet to encrypt</param>
        public static Packet Encrypt(Packet p)
        {
            byte[] buffer = p.GetBuffer();
            buffer[0] = (byte)((int)0x76 ^ (int)buffer[0]);
            for (int i = 1; i != p.Length; i++)
                buffer[i] = (byte)(buffer[i] ^ buffer[i - 1]);

            //Packet length
            byte[] Raw = buffer;
            byte[] NewRaw = new byte[buffer.Length + 4];
            byte[] Length = BitConverter.GetBytes(buffer.Length + 4);
            Array.Copy(Length, NewRaw, 2);
            NewRaw[2] = 0x01;
            NewRaw[3] = 0x00;
            Array.Copy(Raw, 0, NewRaw, 4, buffer.Length);
            Raw = new byte[NewRaw.Length];
            Array.Copy(NewRaw, Raw, NewRaw.Length);

            return new Packet(NewRaw);
        }

        /// <summary>
        /// Decrypts the given packet 
        /// </summary>
        /// <param name="p">The packet to decrypt</param>
        public static Packet Decrypt(Packet p)
        {
            byte[] data = p.GetBuffer();
            int i = data.Length - 4;
            byte[] bs = new byte[i];
            Array.Copy(data, 4, bs, 0, i);
            byte b2 = bs[0];
            byte b3 = 0;
            bs[0] = (byte)(bs[0] ^ 118);

            for (int k = 1; k < data.Length - 4; k++)
            {
                byte b1 = b2;
                b2 = bs[k];
                b3 = b2;
                b3 ^= b1;
                bs[k] = b3;
            }
            return new Packet(bs);
            /*int i = data.Length - 4;
            byte[] bs = new byte[i];
            Array.Copy(data, 4, bs, 0, i);

            byte DL = bs[0];
            bs[0] = (byte)((int)bs[0] ^ (int)0x76);
            for (int c = 1; c != i; c++)
            {
                byte AL = bs[c];
                bs[c] = (byte)(bs[c] ^ DL);
                DL = AL;
            }

            Packet n = new Packet(bs);
            return n;*/
        }

        public byte[] ReadBytes(int amt)
        {
            byte[] buffer = new byte[amt];
            Array.Copy(this.GetBuffer(), Index, buffer, 0, amt);
            Index += amt;
            return buffer;
        }

        public void Skip(int amt)
        {
            Index += amt;
        }

        public void Skip()
        {
            Index += 1;
        }
    }
    /// <summary>
    /// Hex encoding class
    /// </summary>
    class HexEncoding
    {
        /* External code from http://www.codeproject.com/KB/recipes/hexencoding.aspx */
        /* Author = neilck http://www.codeproject.com/script/Membership/Profiles.aspx?mid=375133 */
        public static bool IsHexDigit(Char c)
        {
            int numChar;
            int numA = Convert.ToInt32('A');
            int num1 = Convert.ToInt32('0');
            c = Char.ToUpper(c);
            numChar = Convert.ToInt32(c);
            if (numChar >= numA && numChar < (numA + 6))
                return true;
            if (numChar >= num1 && numChar < (num1 + 10))
                return true;
            return false;
        }

        private static byte HexToByte(string hex)
        {
            if (hex.Length > 2 || hex.Length <= 0)
                throw new ArgumentException("hex must be 1 or 2 characters in length");
            byte newByte = byte.Parse(hex, System.Globalization.NumberStyles.HexNumber);
            return newByte;
        }

        public static byte[] GetBytes(string hexString, out int discarded)
        {
            discarded = 0;
            string newString = string.Empty;
            char c;
            // remove all none A-F, 0-9, characters
            for (int i = 0; i < hexString.Length; i++)
            {
                c = hexString[i];
                if (IsHexDigit(c))
                    newString += c;
                else
                    discarded++;
            }
            // if odd number of characters, discard last character
            if (newString.Length % 2 != 0)
            {
                discarded++;
                newString = newString.Substring(0, newString.Length - 1);
            }

            int byteLength = newString.Length / 2;
            byte[] bytes = new byte[byteLength];
            string hex;
            int j = 0;
            for (int i = 0; i < bytes.Length; i++)
            {
                hex = new String(new Char[] { newString[j], newString[j + 1] });
                bytes[i] = HexToByte(hex);
                j = j + 2;
            }
            return bytes;
        }
        /* End external code */
    }
}

I have no clue where to start. I am trying my best and will post my progress but suggestions or guidance would help me a lot.

Mat · June 20, 2010

Heres a start. I've done everything except the hex class and the encrypt/decrypt

#cs
This file is part of LaLore.

LaLore is free software: you can redistribute it and/or modIfy
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

LaLore is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with LaLore.  If not, see <http://www.gnu.org/licenses/>.
#ce

Global $BufferData[1]
Global $Index = 0
Global $Length = 0

; Creates a new buffer
; Size - Size of buffer
Func Packet($Size)
    ReDim $BufferData[$Size]
    $Length = $Size
EndFunc

; Creates a new buffer
; ArrayOfBytes - The byte array the buffer should use
Func Packet($ArrayOfBytes)
    $BufferData = $ArrayOfBytes
    $Length = UBound($BufferData)
EndFunc

; Resizes the buffer
; Deltasize -
Func Resize($Deltasize)
    ReDim $BufferData[$Length + $Deltasize]
    $Length += $Deltasize
EndFunc

; Returns the buffer data
; Returns - Buffer data
Func GetBuffer()
    return $BufferData
EndFunc

; Returns the buffer data in a byte array
; Returns - The buffer data
Func GetWrittenBuffer()
    Local $result = $BufferData

    If ($Index > $Length) Then
        ReDim $result[$Index - 1]
    Else
        ReDim $result[$Index]
    EndIf

    Return $result
EndFunc

; Sets the index to the given position
; nIndex - New index
; Returns - True If the operation completed
Func setIndex($nIndex)
    If ($Index > $Length) Then Return False
    $Index = $nIndex
    Return True
EndFunc

; Sets the index to current pos + new index
; nIndex - New index
; Returns - True If operation completed
Func addIndex($nIndex)
    return setIndex($Index + $nIndex)
EndFunc

; Sets the index to 0
Func resetIndex()
    setIndex(0)
EndFunc

; Writes a byte to the buffer
; Byte - The byte to write
Func WriteByte($Byte)
    If ($Index >= $Length) Then Resize(($Index - $Length) + 1)
    $BufferData[$Index] = $Byte
    $Index += 1
EndFunc

; Writes a short (Int16) to the buffer
; ShortInteger - The short to write
Func WriteShort($ShortInteger)
    If ($Index + 2 >= $Length) Then Resize(($Index - $Length) + 2)
    WriteByte(BitAND(ShortInteger, 0xFF))
    WriteByte(BitAND(BitShift($ShortInteger, 8), 0xFF))
EndFunc


; Writes an integer to the buffer
; Integer - The int you want to write
Func WriteInt($Integer)
    If ($Index + 4 >= $Length) Then Resize(($Index - $Length) + 4)
    WriteByte(BitAND($Integer, 0xFF))
    WriteByte(BitAND(BitShift($Integer,  8), 0xFF))
    WriteByte(BitAND(BitShift($Integer, 16), 0xFF))
    WriteByte(BitAND(BitShift($Integer, 24), 0xFF))
EndFunc

Func WriteLong($Integer)
    WriteByte(BitAND($Integer, 0xFF))
    WriteByte(BitAND(BitShift($Integer, 8), 0xFF))
    WriteByte(BitAND(BitShift($Integer, 16), 0xFF))
    WriteByte(BitAND(BitShift($Integer, 24), 0xFF))
    WriteByte(BitAND(BitShift($Integer, 32), 0xFF))
    WriteByte(BitAND(BitShift($Integer, 40), 0xFF))
    WriteByte(BitAND(BitShift($Integer, 48), 0xFF))
    WriteByte(BitAND(BitShift($Integer, 56), 0xFF))
EndFunc

; Writes a byte n number of times to the buffer
; Pad - The byte you want to pad
; nLength - The number of bytes to write
Func BytePad($Pad, $nLength)
    If (($Index + $nLength) >= $Length) Then Resize($nLength)
    For $i = 0 To $nLength - 1
        $BufferData[$Index + $i] = $Pad
    Next
    $Index += $nLength
EndFunc

; Writes a string to the buffer
; String - The string you want to write
Func WriteString($String)
    If (($Index + StringLen($String)) >= $Length) Then Resize(StringLen($String))
    For $i = 0 To StringLen($String) - 1
        $BufferData[$Index + $i] = Asc(StringMid($String, $i, 1))
    Next
    $Index += StringLen($String)
EndFunc

; Writes a string preceeded by a short containing its length
; String - The string you want to write
Func WriteStringLen($String)
    If (($Index + StringLen($String) + 2) >= $Length) Then Resize(StringLen($String) + 2)
    WriteShort(StringLen($String))
    WriteString($String)
EndFunc

; Writes a padded left string to the buffer
; String - The string you want to write
; Pad - The char you want to pad
; PadLength - The number of chars you want to pad
Func WriteStringPaddedLeft($String, $Pad, $PadLength)
    $String = _StringRepeat($Pad, $PadLength) & $String
    If (($Index + StringLen($String)) >= $Length) Then Resize(StringLen($String))
    WriteString($String)
EndFunc

; Writes a padded right string to the buffer
; String - The string you want to write
; Pad - The char you want to pad
; PadLength - The number of chars you want to pad
Func WriteStringPaddedRight($String, $Pad, $PadLength)
    $String &= _StringRepeat($Pad, $PadLength)
    If (($Index + StringLen($String)) >= $Length) Then Resize(StringLen($String))
    WriteString($String)
EndFunc

; Writes an array of bytes to the buffer
; Array - The array you want to write
Func WriteArray($Array)
    If (($Index + UBound($Array)) >= $Length) Then Resize(UBound($Array))
    For $i = 0 To UBound($Array) - 1
        $BufferData[$Index + $i] = $Array[$i]
    Next
    $Index += UBound($Array)
EndFunc

; Write a hex string to the buffer
; HexString - The string containing the hex chain
Func WriteHexString($HexString)
    Local $_byte = HexEncodingGetBytes($HexString)
    WriteArray($_byte)
EndFunc

; Reads a byte from the buffer
; Returns - The read byte or 0 If failed
Func ReadByte()
    Local $result = $BufferData[$Index];
    $Index += 1
    return $result
EndFunc

; Reads a byte at a certain position in the buffer
; pos - The position to read from
; Returns - The read byte or 0 If failed
Func ReadByteAtPos($pos)
    Local $TempIndex = $Index
    $Index = $pos
    Local $result = ReadByte()
    $Index = $TempIndex
    return $result
EndFunc

; Reads an unsigned short from the buffer
; Returns - The read ushort
Func ReadUShort()
    Local $result = $BufferData[$Index] + ($BufferData[$Index + 1] * 256)
    $Index += 2
    return $result
EndFunc

; Reads a short from the buffer
; Returns - The read short
Func ReadShort()
    Local $byte1, $byte2
    $byte1 = ReadByte()
    $byte2 = ReadByte()
    return BitShift($byte2, -8) + $byte1
EndFunc

; Reads a short from the buffer at the given position
; pos - Position to read at
; Returns - The read short
Func ReadShortAtPos($pos)
    Local $TempIndex = $Index
    $Index = $pos
    Local $result = ReadShort()
    $Index = $TempIndex
    Return $result
EndFunc

; Reads an integer from the buffer
; Returns - The read int
Func ReadInt()
    Local $byte1 = ReadByte()
    Local $byte2 = ReadByte()
    Local $byte3 = ReadByte()
    Local $byte4 = ReadByte()

    Return BitShift($byte4, -24) + BitShift($byte3, -16) + BitShift($byte2, -8) + $byte1
EndFunc

; Reads an unsigned int from the buffer at the given position
; Pos - The position to read at
; Returns - The read uint
Func ReadIntAtPos($Pos)
    Local $TempIndex = $Index
    $Index = $Pos
    Local $result = ReadInt()
    $Index = $TempIndex
    Return $result
EndFunc

; Reads a string that is as long as the provided length from the buffer
; _length - Length of the string to be read
; Returns - The read string
Func ReadString($_length)
    Local $ret
    For $i = 0 To $_length - 1
        $ret &= Chr($BufferData[$Index + $i])
    Next
    $Index += $_length
    Return $ret
EndFunc

; Reads a string that is as long as the provided length from the buffer
; _length - Length of the string to be read
; Returns - The read string
Func ReadStringFrom0($_length)
    Local $ret
    For $i = 0 To $_length - 1
        If ($BufferData[$Index + $i] <> 0) Then $ret &= Chr($BufferData[$Index + $i])
    Next
    $Index += $_length
    Return $ret
EndFunc

; Reads a string using the short length preceding the string from the buffer
; Returns - The read string
Func ReadStringFromLength()
    Local $_length = ReadShort()
    Return ReadString($_length)
EndFunc

; Reads a string using the short length preceding the string from the buffer at the given position
; Pos - The position to read at
; Returns - The read string
Func ReadStringFromLengthAtPos($Pos)
    Local $TempIndex = $Index
    $Index = $Pos
    Local $result = ReadStringFromLength()
    $Index = $TempIndex
    Return $result
EndFunc

; Reads a string that is as long as the provided length from the buffer at the given position
; Pos - The position to read at
; nLength - The length of the string to be read
; Returns - The read string
Func ReadStringSpecIfy($Pos, $nLength)
    Local $TempIndex = $Index
    $Index = $Pos
    Local $result = ReadString($nLength)
    $Index = $TempIndex
    Return $result
EndFunc

; Pads the packet
; b -
; amount -
Func Pad($b, $amount)
    For $i = 0 To $amount - 1
        WriteByte($b)
    Next
EndFunc

Func ReadBytes($amt)
    Local $buffer[$amt]
    Array.Copy($BufferData, $Index, $buffer, 0, $amt)
    $Index += $amt
    return $buffer
EndFunc

Func Skip($amt)
    $Index += $amt
EndFunc

Func Skip1()
    Index += 1;
EndFunc

Due to the fact AutoIt does not have classes, there is only one class.

Mat

Luig · June 22, 2010

Thanks for doing all that, I also found another udf in some foreign site that does the same as this but I am making my own basing it on these 2. Now I still don't understand how the encryption and decryption routines work.

I don't understand this:

buffer[0] = (byte)((int)0x76 ^ (int)buffer[0]);

I dont understand the ^ operator. If someone could explain it to me that would be a great help.

It also appears here:

b3 ^= b1;

In the autoit docs it says its a mathematical operator.

Raises a number to the power.  e.g. 2 ^ 4    (equals 16)

If someone can clear this up or better yet port it I would be grateful.

Mat · June 22, 2010

Its ~~BitNOT~~. My bad, its BitXOR...

Edited June 22, 2010 by Mat

Luig · June 22, 2010

Ok now I think I ported the Array.Copy correctly and will try to port the encrypt function first.

Heres how I made the array copy function although I am going to add an array size check to re size the array if its to small.

Func _Array_Copy(ByRef $Source, $SourceIndex, ByRef $DestArray, $DestIndex, $Length)
    Local $TempIndex = $DestIndex
    For $i = $SourceIndex to ($Length + $SourceIndex) - 1
        $DestArray[$TempIndex] = $SourceIndex[$i]
        $TempIndex += 1
    Next
EndFunc

I got the info for the function here.

Luig · June 22, 2010

Ok I ported the decrypt function like so:

Func DecryptPacket($Packet)
    Local $Data = $Packet, $b1, $b2, $b3
    Local $i = UBound($Data) - 4
    Dim $bs[$i]
    _Array_Copy($Data, 4, $bs, 0, $i)
    $b2 = $bs[0]
    $b3 = 0
    $bs[0] = BitXOR($TempPacket[0], 0x76) ; decimal 118 = hex 0x76 
    For $k = 1 to $i
        $b1 = $b2
        $b2 = $bs[$k]
        $b3 = $b2
        $b3 = BitXOR($b3, $b)
        $bs[$k] = $b3
    Next
    Return $bs
EndFunc

Am I right, I'll try to decrypt a packet right now though.

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Need help porting functions from c# to Au3.

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