Help *DLL INJECTOR*

[Repix]

I get some errors with this code, and it was just working!
Also some vars corrupt for no reason.
(I'm a beginner with c++)

#include <iostream>
#include <string>
#include <Windows.h>
#include <TlHelp32.h>
#include <fstream>
#include <stdio.h>
#include <sstream>
#include <direct.h>

using namespace std;
bool InjectDLL(DWORD ProcessId);
typedef HINSTANCE (*fpLoadLibrary)(char*);


int main(){
	//Getting this program's dir
	/*DWORD nBufferLength = MAX_PATH;
	char szCurrentDirectory[MAX_PATH + 1];
	GetCurrentDirectory(nBufferLength, szCurrentDirectory); 
	szCurrentDirectory[MAX_PATH +1 ] = '\0';
	stringstream Dir1;
	string Dir2;
	Dir1 << szCurrentDirectory;
	Dir1 >> Dir2;*/

	//cout<<szCurrentDirectory<<endl;

	//Reading Config File
	ifstream inFile;
	inFile.open("config.txt");
	if(inFile.fail()){
		cerr<<"Error Opening Config.txt"<<endl;
		exit(1);
	}

	
	string File,Process;

	inFile>>File>>Process;
	

	cout<<"DLL to inject: "<<File<<endl;
	cout<<"Process to inject into: "<<Process<<endl;

	char FileToInject[1024]; //Converting File to FileToInject
	strcpy(FileToInject, File.c_str());

	char ProcessName[1024]; //Converting Process to ProcessName
	strcpy(ProcessName, Process.c_str());
	
	//Actually Injecting
	

	DWORD processId = NULL;

	PROCESSENTRY32 pe32 = {sizeof(PROCESSENTRY32)};
	HANDLE hProcSnap;
	
	Sleep(3000);

	while(!processId){
		system("CLS");
		cout<<"Searching for: "<<ProcessName<<endl;
		cout<<"Make sure "<<ProcessName<<" is running!"<<endl;
		hProcSnap = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);

		if(Process32First(hProcSnap, &pe32)){
			do{
				if(!strcmp(pe32.szExeFile, ProcessName)){
					processId = pe32.th32ProcessID;
					break;
				}
			}while(Process32Next(hProcSnap, &pe32));
		}
		Sleep(1000);
	}
	while(!InjectDLL(processId)){
		system("CLS");
		cout<<"DLL failed to inject!"<<endl;
		Sleep(1000);
	}
	cout<<"DLL Injection Successful!"<<endl<<endl;
	cout<<"Closing injector in 3 seconds!"<<endl;
	CloseHandle(hProcSnap);
	Sleep(3000);
	exit(1);
	return 0;
}
 bool InjectDLL(DWORD ProcessId){
	//Reading Config File
	ifstream inFile;
	inFile.open("config.txt");
	if(inFile.fail()){
		cerr<<"Error Opening Config.txt"<<endl;
		exit(1);
	}
	string File,Process;

	inFile>>File>>Process;

	char FileToInject[1024]; //Converting File to FileToInject
	strcpy(FileToInject, File.c_str());

	char ProcessName[1024]; //Converting Process to ProcessName
	strcpy(ProcessName, Process.c_str());

	//Getting this program's dir
	DWORD nBufferLength = MAX_PATH;
	char szCurrentDirectory[MAX_PATH + 10000];
	GetCurrentDirectory(MAX_PATH, szCurrentDirectory); 
	szCurrentDirectory[MAX_PATH +1000 ] = '\0';

	HANDLE hProc;
	LPVOID paramAddr;
	
	HINSTANCE hDll = LoadLibrary("KERNEL32");

	strcat(szCurrentDirectory, "\\");
	strcat(szCurrentDirectory, FileToInject);
	cout<<szCurrentDirectory<<endl;
	
	fpLoadLibrary LoadLibraryAddr = (fpLoadLibrary)GetProcAddress(hDll, "LoadLibraryA");

	hProc = OpenProcess(PROCESS_ALL_ACCESS, false, ProcessId);

	paramAddr = VirtualAllocEx(hProc, 0, strlen(szCurrentDirectory)+10000, MEM_COMMIT, PAGE_READWRITE);
	
	bool memoryWritten = WriteProcessMemory(hProc, paramAddr, szCurrentDirectory, strlen(szCurrentDirectory)+10000, NULL);

	CreateRemoteThread(hProc, 0, 0,(LPTHREAD_START_ROUTINE)LoadLibraryAddr, paramAddr, 0, 0);

	CloseHandle(hProc);
	return memoryWritten;
}

[integralfx]

Why do you unnecessarily open "config.txt" in main() and in InjectDll() ?
- You could either read it in main() and pass the information read to InjectDll() as parameters
OR
- Just read it in InjectDll().

Line 101 to 105
There is no need to allocate 2 extra variables for no reason. If you need to concatenate, use std::string::append().

Line 109, 111 and 126
What are with these magic constants? Namely, 10000 and 1000.

the maximum length for a path is MAX_PATH, which is defined as 260 characters.

https://msdn.microsoft.com/en-au/library/windows/desktop/aa365247%28v=vs.85%29.aspx#maxpath

I would recommend to add some if-else statements for checking the validity of variables.
For example, Line 124, what happens if OpenProcess() fails? Something simple like this would suffice:

hProc = OpenProcess(PROCESS_ALL_ACCESS, false, ProcessId);
if(!hProc || hProc == INVALID_HANDLE_VALUE) {
	std::cout << "Failed to OpenProcess!" << "\t" "Error: " << GetLastError() << "\n";
	return false
}
// otherwise hProc is a valid handle, move on . . . 

Oh and by the way, you forgot to deallocate the memory you allocated.

(I'm a beginner with c++)

- I would recommend you learn the basics first.

while(!InjectDLL(processId)){
		system("CLS");
		cout<<"DLL failed to inject!"<<endl;
		Sleep(1000);
	}

This code keeps calling InjectDLL() until it returns true. So if the injection fails, you have yourself an infinite loop.

HMODULE WINAPI LoadLibrary(
_In_ LPCTSTR lpFileName
);

As you can see LoadLibrary() takes an LPCTSTR.

LPCTSTR is a const TCHAR string, (TCHAR being either a wide char or char depending on whether UNICODE is defined in your project)

http://stackoverflow.com/questions/321413/lpcstr-lpctstr-and-lptstr