#include "Patcher.h"

void Patcher::PatchBytes(BYTE* address, BYTE* shellcode, const int shellCodeSize, bool modifyPageProtection, DWORD newPageProtection, bool restorePageProtection)
{
	DWORD oldProtection;
	if (modifyPageProtection)
	{
		//apply new page protection
		VirtualProtect(address, shellCodeSize, newPageProtection, &oldProtection);
	}
	else
	{
		//there is nothing to restore if page protection wasn't changed
		restorePageProtection = false;
	}

	//apply patch
	memcpy(address, shellcode, shellCodeSize);

	if (restorePageProtection)
	{
		//restore page protection
		VirtualProtect(address, shellCodeSize, oldProtection, &oldProtection);
	}
}

void Patcher::NOPBytes(BYTE* address, const int amount, bool modifyPageProtection, DWORD newPageProtection, bool restorePageProtection)
{
	DWORD oldProtection;
	if (modifyPageProtection)
	{
		//apply new page protection
		VirtualProtect(address, amount, newPageProtection, &oldProtection);
	}
	else
	{
		//there is nothing to restore if page protection wasn't changed
		restorePageProtection = false;
	}

	//apply patch
	for (int i = 0; i < amount; i++)
	{
		address[i] = 0x90; //NOP
	}

	if (restorePageProtection)
	{
		//restore page protection
		VirtualProtect(address, amount, oldProtection, &oldProtection);
	}
}

//Writes a 1 byte value using local endianess
void Patcher::Patch(BYTE* address, int8_t value)
{
	DWORD oldProtection;

	//apply new page protection
	VirtualProtect(address, sizeof(value), PAGE_EXECUTE_READWRITE, &oldProtection);

	//write value
	*(int8_t*)address = value;

	//restore page protection
	VirtualProtect(address, sizeof(value), oldProtection, &oldProtection);
}

//Writes a 2 byte value using local endianess
void Patcher::Patch(BYTE* address, int16_t value)
{
	DWORD oldProtection;

	//apply new page protection
	VirtualProtect(address, sizeof(value), PAGE_EXECUTE_READWRITE, &oldProtection);

	//write value
	*(int16_t*)address = value;

	//restore page protection
	VirtualProtect(address, sizeof(value), oldProtection, &oldProtection);
}

//Writes a 4 byte value using local endianess
void Patcher::Patch(BYTE* address, int32_t value)
{
	DWORD oldProtection;

	//apply new page protection
	VirtualProtect(address, sizeof(value), PAGE_EXECUTE_READWRITE, &oldProtection);

	//write value
	*(int32_t*)address = value;

	//restore page protection
	VirtualProtect(address, sizeof(value), oldProtection, &oldProtection);
}

//Writes a 8 byte value using local endianess
void Patcher::Patch(BYTE* address, int64_t value)
{
	DWORD oldProtection;

	//apply new page protection
	VirtualProtect(address, sizeof(value), PAGE_EXECUTE_READWRITE, &oldProtection);

	//write value
	*(int64_t*)address = value;

	//restore page protection
	VirtualProtect(address, sizeof(value), oldProtection, &oldProtection);
}