PHP 8.4 FFI Windows Registry Query

ffi-kernel32.h

#define FFI_LIB "kernel32.dll"
#define FFI_SCOPE "kernel32"

typedef unsigned short wchar_t;
typedef int BOOL;
typedef unsigned long DWORD;
typedef void *PVOID;
typedef PVOID HANDLE;
typedef DWORD *LPDWORD;
typedef unsigned short WORD;
typedef wchar_t WCHAR;
typedef short SHORT;
typedef unsigned short USHORT;
typedef unsigned int UINT;
typedef char CHAR;
typedef char BYTE;
typedef unsigned char UBYTE;
typedef WCHAR TCHAR;

typedef long LSTATUS;
typedef long HKEY;
typedef HKEY* PHKEY;
typedef DWORD ACCESS_MASK;
typedef ACCESS_MASK *PACCESS_MASK;
typedef ACCESS_MASK REGSAM;
typedef const char* LPCSTR;
typedef char* LPSTR;
typedef const wchar_t* LPCWSTR;
typedef wchar_t* LPWSTR;
typedef BYTE* LPBYTE;

LSTATUS
RegOpenKeyExA(
    /*_In_*/ HKEY hKey,
    /*_In_opt_*/ LPCSTR lpSubKey,
    /*_In_opt_*/ DWORD ulOptions,
    /*_In_*/ REGSAM samDesired,
    /*_Out_*/ PHKEY phkResult
    );

LSTATUS
RegOpenKeyExW(
    /*_In_*/ HKEY hKey,
    /*_In_opt_*/ LPCWSTR lpSubKey,
    /*_In_opt_*/ DWORD ulOptions,
    /*_In_*/ REGSAM samDesired,
    /*_Out_*/ PHKEY phkResult
);

LSTATUS
RegEnumValueA(
    /*_In_*/ HKEY hKey,
    /*_In_*/ DWORD dwIndex,
    /*_Out_writes_to_opt_(*lpcchValueName,*lpcchValueName + 1)*/ LPSTR lpValueName,
    /*_Inout_*/ LPDWORD lpcchValueName,
    /*_Reserved_*/ LPDWORD lpReserved,
    /*_Out_opt_*/ LPDWORD lpType,
    /*_Out_writes_bytes_to_opt_(*lpcbData, *lpcbData) __out_data_source(REGISTRY)*/ LPBYTE lpData,
    /*_Inout_opt_*/ LPDWORD lpcbData
);

LSTATUS
RegEnumValueW(
    /*_In_*/ HKEY hKey,
    /*_In_*/ DWORD dwIndex,
    /*_Out_writes_to_opt_(*lpcchValueName,*lpcchValueName + 1)*/ LPWSTR lpValueName,
    /*_Inout_*/ LPDWORD lpcchValueName,
    /*_Reserved_*/ LPDWORD lpReserved,
    /*_Out_opt_*/ LPDWORD lpType,
    /*_Out_writes_bytes_to_opt_(*lpcbData, *lpcbData) __out_data_source(REGISTRY)*/ LPBYTE lpData,
    /*_Inout_opt_*/ LPDWORD lpcbData
);

ffi-kernel32.php

<?php

if (!extension_loaded('ffi'))
    die("FFI Extension is not loaded");

const ERROR_SUCCESS = 0;
const ERROR_NO_MORE_ITEMS = 259;

const HKEY_CLASSES_ROOT                   = 0x80000000;
const HKEY_CURRENT_USER                   = 0x80000001;
const HKEY_LOCAL_MACHINE                  = 0x80000002;
const HKEY_USERS                          = 0x80000003;
const HKEY_PERFORMANCE_DATA               = 0x80000004;
const HKEY_PERFORMANCE_TEXT               = 0x80000050;
const HKEY_PERFORMANCE_NLSTEXT            = 0x80000060;
const HKEY_CURRENT_CONFIG                 = 0x80000005;
const HKEY_DYN_DATA                       = 0x80000006;
const HKEY_CURRENT_USER_LOCAL_SETTINGS    = 0x80000007;

const KEY_QUERY_VALUE        =  (0x0001);
const KEY_SET_VALUE          =  (0x0002);
const KEY_CREATE_SUB_KEY     =  (0x0004);
const KEY_ENUMERATE_SUB_KEYS =  (0x0008);
const KEY_NOTIFY             =  (0x0010);
const KEY_CREATE_LINK        =  (0x0020);
const KEY_WOW64_32KEY        =  (0x0200);
const KEY_WOW64_64KEY        =  (0x0100);
const KEY_WOW64_RES          =  (0x0300);

const STANDARD_RIGHTS_READ = 0x00020000;
const KEY_READ = STANDARD_RIGHTS_READ | KEY_QUERY_VALUE | KEY_ENUMERATE_SUB_KEYS | KEY_NOTIFY;

function EnumInstalledEngines() : array
{
    $result = array();

    $ffi = FFI::load(__DIR__ . DIRECTORY_SEPARATOR . 'ffi-kernel32.h');

    $hKey = $ffi->new('HKEY');
    $hResult = $ffi->RegOpenKeyExA(HKEY_CURRENT_USER,
        "SOFTWARE\\Epic Games\\Unreal Engine\\Builds",
        null,
        KEY_READ,
        FFI::addr($hKey)
    );
    if ($hResult == ERROR_SUCCESS)
    {
        for($Index = 0;$Index < 256; ++$Index)
        {
            $ValueName = $ffi->new('CHAR[256]');
            $ValueData = $ffi->new('BYTE[256]');
            $ValueType = $ffi->new('DWORD');
            $ValueType->cdata = 0;
            $ValueNameLength = $ffi->new('DWORD');
            $ValueNameLength->cdata = FFI::sizeof($ValueName);
            $ValueDataLength = $ffi->new('DWORD');
            $ValueDataLength->cdata = FFI::sizeof($ValueData);

            $hResult = $ffi->RegEnumValueA(
                $hKey->cdata,
                $Index,
                $ValueName,
                FFI::addr($ValueNameLength),
                null,
                FFI::addr($ValueType),
                $ffi->cast('LPBYTE', FFI::addr($ValueData)),
                FFI::addr($ValueDataLength)
            );

            if ($hResult == ERROR_SUCCESS)
            {
                $name = FFI::string($ValueName);
                $data = FFI::string($ValueData);

                //echo "$name => $data" . PHP_EOL;

                $result[] = array(
                    'Key' => $name,
                    'Path' => $data
                );
            }
            elseif ($hResult == ERROR_NO_MORE_ITEMS)
            {
                break;
            }

        }
    }

    return $result;
}