PatternScan.h

#include <Windows.h>
#include <vector>

// https://github.com/lguilhermee/Discord-DX11-Overlay-Hook/blob/master/Helper/Helper.cpp 

uintptr_t PatternScan(uintptr_t moduleAdress, const char* signature)
{
	static auto patternToByte = [](const char* pattern)
	{
		auto       bytes = std::vector<int>{};
		const auto start = const_cast<char*>(pattern);
		const auto end = const_cast<char*>(pattern) + strlen(pattern);

		for (auto current = start; current < end; ++current)
		{
			if (*current == '?')
			{
				++current;
				bytes.push_back(-1);
			}
			else { bytes.push_back(strtoul(current, &current, 16)); }
		}
		return bytes;
	};

	const auto dosHeader = (PIMAGE_DOS_HEADER)moduleAdress;
	const auto ntHeaders = (PIMAGE_NT_HEADERS)((std::uint8_t*)moduleAdress + dosHeader->e_lfanew);

	const auto sizeOfImage = ntHeaders->OptionalHeader.SizeOfImage;
	auto       patternBytes = patternToByte(signature);
	const auto scanBytes = reinterpret_cast<std::uint8_t*>(moduleAdress);

	const auto s = patternBytes.size();
	const auto d = patternBytes.data();

	for (auto i = 0ul; i < sizeOfImage - s; ++i)
	{
		bool found = true;
		for (auto j = 0ul; j < s; ++j)
		{
			if (scanBytes[i + j] != d[j] && d[j] != -1)
			{
				found = false;
				break;
			}
		}
		if (found) { return reinterpret_cast<uintptr_t>(&scanBytes[i]); }
	}
	return NULL;
}