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1 files changed, 68 insertions, 0 deletions

diff --git a/internal_rewrite/pattern.hpp b/internal_rewrite/pattern.hpp
new file mode 100644
index 0000000..8b4e17e
--- /dev/null
+++ b/internal_rewrite/pattern.hpp
@@ -0,0 +1,68 @@
+#pragma once
+
+#include <Windows.h>
+#include <stdio.h>
+#include <Psapi.h>
+#include <vector>
+#include <iostream>
+#include <string>
+#include <sstream>
+#include <algorithm>
+#include <iterator>
+
+#pragma warning ( disable : 4018 )
+
+namespace pattern
+{
+	inline bool bin_match( uint8_t* code, uint8_t* pattern, size_t size ) {
+		for( size_t j = 0; j < size; j++ ) {
+			if( pattern[ j ] && code[ j ] != pattern[ j ] ) {
+				return false;
+			}
+		}
+		return true;
+	}
+
+	template< typename t = uintptr_t > static t first_match( uintptr_t start, std::string sig, size_t len, std::ptrdiff_t offset = 0 ) {
+		std::istringstream iss( sig );
+		std::vector< std::string > tokens{ std::istream_iterator< std::string >{ iss }, std::istream_iterator< std::string >{} };
+		std::vector< uint8_t > sig_bytes;
+
+		for( const auto& hex_byte : tokens ) {
+			sig_bytes.push_back( static_cast< uint8_t >( std::strtoul( hex_byte.c_str( ), nullptr, 16 ) ) );
+		}
+
+		if( sig_bytes.empty( ) || sig_bytes.size( ) < 2 ) {
+			return t{ };
+		}
+
+		auto sig_data = sig_bytes.data( );
+		auto sig_size = sig_bytes.size( );
+
+		for( size_t i{ }; i < len; i++ ) {
+			uint8_t* code_ptr = reinterpret_cast< uint8_t* >( start + i );
+
+			if( bin_match( code_ptr, sig_data, sig_size ) ) {
+				return( ( t )( start + i + offset ) );
+			}
+		}
+
+		return t{ };
+	}
+
+	//ultimately the function you want to call to sigscan ( ida style )
+	template< typename t = uintptr_t > static t first_code_match( HMODULE start, std::string sig, std::ptrdiff_t offset = 0 ) {
+		auto dos_hdr = reinterpret_cast< PIMAGE_DOS_HEADER >( start );
+
+		if( !dos_hdr ) return t{ };
+
+		//DOS header, verifies if module is valid
+		if( dos_hdr->e_magic != 0x5a4d ) {
+			return t{ };
+		}
+
+		auto nt_hdrs = reinterpret_cast< PIMAGE_NT_HEADERS >( reinterpret_cast< uintptr_t >( dos_hdr ) + dos_hdr->e_lfanew );
+
+		return first_match< t >( reinterpret_cast< uintptr_t >( dos_hdr ) + nt_hdrs->OptionalHeader.BaseOfCode, sig, nt_hdrs->OptionalHeader.SizeOfCode, offset );
+	}
+};
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