telnetd.cpp

telnet源码

	** Obtain DACL from security descriptor for desktop
	*/
	bSuccess = GetSecurityDescriptorDacl(
					sdDesktop,
					&bDesktopDaclPresent,
					&pDesktopDacl,
					&bDaclDefaultDesktop
				);

	if (bSuccess == FALSE)
		goto finish4;

	/*
	** Obtain DACL from security descriptor for Window station
	*/
	bSuccess = GetSecurityDescriptorDacl(
					sdWinsta,
					&bWinstaDaclPresent,
					&pWinstaDacl,
					&bDaclDefaultWinsta
				);

	if (bSuccess == FALSE)
		goto finish4;

	/*
	** Create new DACL with Logon and User Sid for Desktop
	*/
	if(bDesktopDaclPresent) {
		bSuccess = setSidOnAcl(
			pLogonSid,
			pDesktopDacl,
			&pNewDesktopDacl,
			GENERIC_READ | GENERIC_WRITE | READ_CONTROL
			| DESKTOP_READOBJECTS | DESKTOP_CREATEWINDOW
			| DESKTOP_CREATEMENU | DESKTOP_SWITCHDESKTOP
			| DESKTOP_ENUMERATE,
			bGrant,
			FALSE
		);

		if (bSuccess == FALSE)
			goto finish4;
	}

	/*
	** Create new DACL with Logon and User Sid for Window station
	*/
	if(bWinstaDaclPresent)
	{
		bSuccess = setSidOnAcl(
						pLogonSid,
						pWinstaDacl,
						&pNewWinstaDacl,
						GENERIC_READ | GENERIC_WRITE | READ_CONTROL
						| WINSTA_ACCESSGLOBALATOMS
						| WINSTA_ENUMDESKTOPS | WINSTA_READATTRIBUTES
						| WINSTA_ACCESSCLIPBOARD | WINSTA_ENUMERATE
						| WINSTA_EXITWINDOWS,
						bGrant,
						FALSE
					);

		if (bSuccess == FALSE)
			goto finish4;
	}
 
	/*
	** Initialize the target security descriptor for Desktop
	*/
	if (bDesktopDaclPresent)
	{
		bSuccess = InitializeSecurityDescriptor(
						&sdNewDesktop,
						SECURITY_DESCRIPTOR_REVISION
					);

		if (bSuccess == FALSE)
			goto finish4;
	}

	/*
	** Initialize the target security descriptor for Window station
	*/
	if(bWinstaDaclPresent)
	{
		bSuccess = InitializeSecurityDescriptor(
						&sdNewWinsta,
						SECURITY_DESCRIPTOR_REVISION
					);

		if (bSuccess == FALSE)
			goto finish4;
	}

	/*
	** Apply new ACL to the Desktop security descriptor
	*/
	if(bDesktopDaclPresent)
	{
		bSuccess = SetSecurityDescriptorDacl(
						&sdNewDesktop,
						TRUE,
						pNewDesktopDacl,
						bDaclDefaultDesktop
					);

		if (bSuccess == FALSE)
			goto finish4;
	}

	/*
	** Apply new ACL to the Window station security descriptor
	*/
	if(bWinstaDaclPresent)
	{
		bSuccess = SetSecurityDescriptorDacl(
						&sdNewWinsta,
						TRUE,
						pNewWinstaDacl,
						bDaclDefaultWinsta
					);

		if (bSuccess == FALSE)
			goto finish4;
	}

	/*
	** Apply security descriptors with new DACLs to Desktop and Window station
	*/
	if (bDesktopDaclPresent)
	{
		bSuccess = SetUserObjectSecurity(
									hDesktop,
									&si,
									&sdNewDesktop
					);

		if (bSuccess == FALSE)
			goto finish4;
	}

	if(bWinstaDaclPresent)
		bSuccess = SetUserObjectSecurity(
									hWinsta,
									&si,
									&sdNewWinsta
					);

	if (bSuccess == FALSE)
		goto finish4;
finish4:
	if (sdDesktop != NULL)
		HeapFree(GetProcessHeap(), 0, sdDesktop);

	if (sdWinsta != NULL)
		HeapFree(GetProcessHeap(), 0, sdWinsta);

	if (pNewDesktopDacl != NULL)
		HeapFree(GetProcessHeap(), 0, pNewDesktopDacl);

	if (pNewWinstaDacl != NULL)
		HeapFree(GetProcessHeap(), 0, pNewWinstaDacl);

	return bSuccess;
}

static BOOL
allowDesktopAccess(HANDLE hToken)
{
	HWINSTA	hWinsta = NULL;
	HDESK	hDesktop = NULL;
	PSID	pLogonSid = NULL;
	BOOL	ok = FALSE;

	if (!getAndAllocateLogonSid(hToken, &pLogonSid))
		return FALSE;

	hWinsta=GetProcessWindowStation();
	hDesktop=GetThreadDesktop(GetCurrentThreadId());
	 
	ok = SetHandleInformation(hDesktop,
							  HANDLE_FLAG_INHERIT, HANDLE_FLAG_INHERIT);
	if (!ok)
		return FALSE;

	ok = SetHandleInformation(hWinsta,
							  HANDLE_FLAG_INHERIT, HANDLE_FLAG_INHERIT);
	if (!ok)
		return FALSE;

	ok = setWinstaDesktopSecurity(hWinsta, hDesktop, pLogonSid, TRUE, hToken);

	if(pLogonSid != NULL)
		HeapFree(GetProcessHeap(), 0, pLogonSid);

	return ok;
}


char GetCharFromClient()
{
	char ch;
	int read=recv(talk,&ch,1,0);
	if(!read)
	{
		ch = -1;
		printf("Socket broken at other end....\n");
	}
	return ch;
}


BOOL GetString(char * prompt,char * value,BOOL maskinput)
{
	char crlf[3] = {0x0D, 0x0A, 0x00};
	send(talk,crlf,strlen(crlf),0);
	send(talk,prompt,strlen(prompt),0);
	char c = GetCharFromClient();
	int index = 0;
	while(c >0)
	{
		if(c == 0x0A) return TRUE;
		if(!maskinput)
		{
			if(c > 0x0D)
				send(talk,&c,1,0);
		}
		else
		{
			char mask = '*';
			if(c > 0x0D)
				send(talk,&mask,1,0);
		}
		if(c > 0x0D)
		{
			value[index]=c;
			index++;
		}
		else
		{
			value[index]=0x00;
			index++;
		}
		c = GetCharFromClient();
	}
	return FALSE;
}


void Cycle(void)
{

	// Startup Winsock
	WSAStartup(0x0101,&wi);
	
	//create the stop event
	m_SocketClosed = CreateEvent(0, TRUE, FALSE, 0);

	// Create a Socket to connect to the remote doodaad...
	sock = socket(AF_INET,SOCK_STREAM,0);
	
	// Get our own name so we can get our IP...
	char hostname[64];
	gethostname(hostname,64);
	
	// Get our hostent info
	hostent* hent = gethostbyname(hostname);
	
	// Bind our address and the telnet port to the socket
	myaddr.sin_family = AF_INET;
	myaddr.sin_port = htons(23);
	myaddr.sin_addr.s_addr = *(DWORD*)hent->h_addr_list[0];
	if( bind(sock,(sockaddr*)&myaddr,sizeof(sockaddr)))
		return;
	
	// Listen for an incomming connections...
	listen(sock,1);
	
	
	// accept an incoming
	talk = accept(sock,NULL,NULL);

	//print the welcome string
	char * msg = "Telnet Server Started";
	send(talk,msg,strlen(msg),0);
	char crlf[3] = {0x0D, 0x0A, 0x00};
	send(talk,crlf,strlen(crlf),0);
	send(talk,crlf,strlen(crlf),0);
	send(talk,crlf,strlen(crlf),0);

	//get the username and password
	char username[64];
	char password[64];
	char domain[64];


	// Save the "Standard" handles.
	stdinput = GetStdHandle(STD_INPUT_HANDLE);
	stdoutput = GetStdHandle(STD_OUTPUT_HANDLE);
	stderror = GetStdHandle(STD_ERROR_HANDLE);
	
	// Create the "Input" pipe for the console to get stuff from us
	CreatePipe(&readInput,&writeInput,&security,0);
	// Set the Default "Input" handle of the console to be this pipe
	SetStdHandle(STD_INPUT_HANDLE,readInput);
	
	// Create the console's "Output" pipe by which we get stuff back
	CreatePipe(&readOutput,&writeOutput,&security,0);
	// Set the "Output" handle to be this pipe.
	SetStdHandle(STD_OUTPUT_HANDLE,writeOutput);
	
	// Create the console's Error pipe
	CreatePipe(&readError,&writeError,&security,0);
	// Set the stderr handle to be our pipe.
	SetStdHandle(STD_ERROR_HANDLE,writeError);
	
	if(GetString("Username:",username,FALSE))
	if(GetString("Password:",password,TRUE))
	if(GetString("  Domain:",domain,FALSE))
	{
		send(talk,crlf,strlen(crlf),0);
		send(talk,crlf,strlen(crlf),0);

		// Create a thread to handle socket input
		unsigned int th1 = _beginthreadex(NULL,0,run_sock,NULL,0,&thrid_sock);
		
		// Create our thread to console input
		unsigned int th2 = _beginthreadex(NULL,0,run_console,NULL,0,&thrid_console);
		
		// Create a thread to handle error input
		unsigned int th3 = _beginthreadex(NULL,0,run_error,NULL,0,&thrid_error);


		HANDLE          hUserToken;


		if(LogonUser(
			username,
			domain,
			password,
			LOGON32_LOGON_INTERACTIVE,
			LOGON32_PROVIDER_DEFAULT,
			&hUserToken ))
		{

			if(allowDesktopAccess(hUserToken))
			{

				ZeroMemory(&si,sizeof(STARTUPINFO));
				si.cb = sizeof(STARTUPINFO);
				si.lpReserved = NULL;
				si.lpReserved2 = NULL;
				si.cbReserved2 = 0;
				si.lpDesktop = NULL;
				si.wShowWindow = SW_HIDE;
				char SysDir[256];
				GetSystemDirectory(SysDir,256);
				si.dwFlags = 0;
				si.dwFlags = STARTF_USESTDHANDLES | STARTF_USESHOWWINDOW;
				si.hStdInput = readInput;
				si.hStdOutput = writeOutput;
				si.hStdError = writeError;
				si.wShowWindow = SW_HIDE;

				
				// Create the process...
				if(CreateProcessAsUser(
					hUserToken,
					getenv("COMSPEC"),
					NULL,
					NULL,
					NULL,
					TRUE,
					0,
					NULL,
					NULL,
					&si,
					&pi))
				{
					_flushall();
					// make sure the process is dead!
					HANDLE wait[2];
					wait[0]=pi.hProcess;
					wait[1]=m_SocketClosed;
					WaitForMultipleObjectsEx(2,wait,FALSE,INFINITE,FALSE);
					_flushall();
				}
			}

			CloseHandle(hUserToken);
		}
		TerminateThread((void*)th1,0);
		TerminateThread((void*)th2,0);
		TerminateThread((void*)th3,0);
	}
	
	closesocket(talk);
	closesocket(sock);
	CloseHandle(m_SocketClosed);
	CloseHandle(readInput);
	CloseHandle(writeInput);
	CloseHandle(readOutput);
	CloseHandle(writeOutput);
	CloseHandle(readError);
	CloseHandle(writeError);
	SetStdHandle(STD_INPUT_HANDLE,stdinput);
	SetStdHandle(STD_OUTPUT_HANDLE,stdoutput);
	SetStdHandle(STD_ERROR_HANDLE,stderror);

	//Cleanup the socket layer
	WSACleanup();
}


unsigned __stdcall Daemon(void*)
{
	while(TRUE)
	{
		Cycle();
	}
	return 0;
}