vmassembler/src/main.cpp

#include <Windows.h>
#include <cli-parser.hpp>
#include <fstream>
#include <iostream>
#include <sstream>
#include <transform.hpp>
#include <xtils.hpp>

#include "compiler.h"
#include "parser.h"
#include "parser.tab.h"
#include "vmasm.hpp"

extern FILE *yyin;
extern "C" int yywrap()
{
    return 1;
}

void yyerror( char *msg )
{
    std::printf( "[!] parsing failure: %s\n", msg );
}

void generate_header( std::vector< std::uint8_t > &virt_instrs, std::string image_path )
{

}

int __cdecl main( int argc, const char *argv[] )
{
    argparse::argument_parser_t argp( "vmassembler", "virtual instruction assembler" );

    argp.add_argument()
        .names( { "--input", "--in" } )
        .description( "path to a vasm file to be assembled..." )
        .required( true );

    argp.add_argument().names( { "--vmpbin", "--bin" } ).description( "path to protected binary..." ).required( true );
    argp.add_argument().names( { "--vmentry", "--entry" } ).description( "rva to vm entry..." ).required( true );
    argp.add_argument().name( { "--output" } ).description( "output file name and path..." ).required( true );

    argp.enable_help();
    auto err = argp.parse( argc, argv );

    if ( err )
    {
        std::cout << err << std::endl;
        return -1;
    }

    if ( argp.exists( "help" ) )
    {
        argp.print_help();
        return 0;
    }

    //
    // set yyin to the vasm file...
    //

    if ( ( yyin = fopen( argp.get< std::string >( "input" ).c_str(), "r" ) ) == nullptr )
    {
        std::printf( "[!] failed to open vasm file...\n" );
        return -1;
    }

    //
    // parse vasm file for all of the instructions...
    //

    yyparse();
    std::printf( "[+] finished parsing vasm file...\n" );

    //
    // init vm variables...
    //

    const auto module_base = reinterpret_cast< std::uintptr_t >(
        LoadLibraryExA( argp.get< std::string >( "vmpbin" ).c_str(), NULL, DONT_RESOLVE_DLL_REFERENCES ) );

    const auto vm_entry_rva = std::strtoull( argp.get< std::string >( "vmentry" ).c_str(), nullptr, 16 );
    const auto image_base = xtils::um_t::get_instance()->image_base( argp.get< std::string >( "vmpbin" ).c_str() );
    const auto image_size = NT_HEADER( module_base )->OptionalHeader.SizeOfImage;
    vm::ctx_t vmctx( module_base, image_base, image_size, vm_entry_rva );

    if ( !vmctx.init() )
    {
        std::printf( "> failed to init vmctx... make sure all arguments are valid\n"
                     "and that the binary you are providing is unpacked and protected\n"
                     "by VMProtect 2...\n" );
        return -1;
    }

    vm::compiler_t compiler( &vmctx );

    //
    // encode virtual instructions...
    //

    auto [ encoded_success, vinstrs ] = compiler.encode();
    std::printf( "[+] finished encoding... encoded instructions below...\n" );

    if ( !encoded_success )
    {
        std::printf( "[!] failed to encode virtual instructions...\n" );
        return -1;
    }

    for ( auto &vinstr : *vinstrs )
    {
        if ( vinstr.imm_size )
            std::printf( "> 0x%x - 0x%x\n", vinstr.vm_handler, vinstr.operand );
        else
            std::printf( "> 0x%x\n", vinstr.vm_handler );
    }

    //
    // encrypt virtual instructions...
    //

    auto [ entry_rva, result_buffer ] = compiler.encrypt();
    std::printf( "[+] finished encrypting... encrypted instructions below...\n" );

    if ( !entry_rva )
    {
        std::printf( "[!] failed to encrypt virtual instructions...\n" );
        return -1;
    }

    std::printf( "> virtual instructions must be allocated at = 0x%p\n", entry_rva );
    std::printf( "> " );
    {
        auto idx = 0u;
        for ( auto byte : *result_buffer )
        {
            std::printf( "0x%x ", byte );
            if ( ++idx == 10 )
            {
                std::printf( "\n" );
                idx = 0u;
            }
        }
    }

    std::printf( "\n" );
    generate_header( *result_buffer, argp.get< std::string >( "output" ) );
}