1#include "os.h"
  2#include "common/strutil.h"
  3#include "common/windows/registry.h"
  4#include "common/windows/unicode.h"
  5
  6#include <windows.h>
  7
  8PWSTR WINAPI BrandingFormatString(PCWSTR format);
  9
 10static bool getCodeName(FFOSResult* os) {
 11    FF_AUTO_CLOSE_FD HANDLE hKey = nullptr;
 12    if (!ffRegOpenKeyForRead(HKEY_LOCAL_MACHINE, L"SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion", &hKey, nullptr)) {
 13        return false;
 14    }
 15
 16    if (!ffRegReadStrbuf(hKey, L"DisplayVersion", &os->codename, nullptr)) {
 17        if (!ffRegReadStrbuf(hKey, L"CSDVersion", &os->codename, nullptr)) {    // For Windows 7 and Windows 8
 18            if (!ffRegReadStrbuf(hKey, L"ReleaseId", &os->codename, nullptr)) { // For old Windows 10
 19                return false;
 20            }
 21        }
 22    }
 23
 24    return true;
 25}
 26
 27void ffDetectOSImpl(FFOSResult* os) {
 28    // https://dennisbabkin.com/blog/?t=how-to-tell-the-real-version-of-windows-your-app-is-running-on#ver_string
 29
 30    // Reads a single branding field from winbrand.dll. The buffer is allocated with
 31    // GlobalAlloc(GMEM_ZEROINIT) by winbrand, so it is ours to release.
 32    //
 33    // Fields offered by winbrand.dll (enumerated in basebrd.dll's RES_METADATA resource):
 34    //   %WINDOWS_GENERIC%   the OS family, independent of edition and release ("Windows")
 35    //   %WINDOWS_SHORT%     family + release, but hardcoded to "Windows 10" since Windows 10
 36    //   %WINDOWS_LONG%      "<family> <release> <edition> [...]" ("Windows 11 Pro Insider Preview")
 37    //   %WINDOWS_PRODUCT%   the product of the running edition
 38    //   %WINDOWS_COPYRIGHT%, %MICROSOFT_COMPANYNAME%, %MICROSOFT_ACCOUNT(S)%
 39    // There is deliberately no field for the bare release number: basebrd.dll stores it
 40    // inside the same per-edition resource as the rest of %WINDOWS_LONG%
 41    // ("Windows 11 Pro%1%2"), so the release can only be peeled off that string.
 42    const wchar_t* rawName = BrandingFormatString(L"%WINDOWS_LONG%");
 43    ffStrbufSetWS(&os->variant, rawName);
 44    GlobalFree((HGLOBAL) rawName);
 45    ffStrbufSet(&os->prettyName, &os->variant);
 46    ffStrbufTrimRight(&os->variant, ' ');
 47
 48    // WMI returns the "Microsoft" prefix while BrandingFormatString doesn't. Make them consistent.
 49    if (ffStrbufStartsWithS(&os->variant, "Microsoft ")) {
 50        ffStrbufSubstrAfter(&os->variant, strlen("Microsoft ") - 1);
 51    }
 52
 53    if (os->variant.length == 0) // Windows PE?
 54    {
 55        FF_AUTO_CLOSE_FD HANDLE hKey = nullptr;
 56        if (ffRegOpenKeyForRead(HKEY_LOCAL_MACHINE, L"SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion", &hKey, nullptr)) {
 57            ffRegReadStrbuf(hKey, L"ProductName", &os->variant, nullptr);
 58        }
 59    }
 60
 61    ffStrbufSet(&os->prettyName, &os->variant);
 62
 63    if (ffStrbufStartsWithS(&os->variant, "Windows ")) {
 64        ffStrbufAppendS(&os->name, "Windows");
 65
 66        ffStrbufSubstrAfter(&os->variant, strlen("Windows ") - 1);
 67
 68        if (ffStrbufStartsWithS(&os->variant, "Server ")) {
 69            ffStrbufAppendS(&os->name, " Server");
 70            ffStrbufSubstrAfter(&os->variant, strlen(" Server") - 1);
 71        } else if (ffStrbufStartsWithS(&os->variant, "Embedded ")) {
 72            ffStrbufAppendS(&os->name, " Embedded");
 73            ffStrbufSubstrAfter(&os->variant, strlen(" Embedded") - 1);
 74        }
 75
 76        if (ffStrbufStartsWithIgnCaseS(&os->variant, "(TM) ")) {
 77            ffStrbufSubstrAfter(&os->variant, strlen(" (TM)") - 1);
 78        }
 79
 80        uint32_t index = ffStrbufFirstIndexC(&os->variant, ' ');
 81        ffStrbufAppendNS(&os->version, index, os->variant.chars);
 82        ffStrbufSubstrAfter(&os->variant, index);
 83
 84        // Windows Server 20xx Rx
 85        if (ffStrbufEndsWithC(&os->name, 'r')) {
 86            if (os->variant.chars[0] == 'R' &&
 87                ffCharIsDigit(os->variant.chars[1]) &&
 88                (os->variant.chars[2] == '\0' || os->variant.chars[2] == ' ')) {
 89                ffStrbufAppendF(&os->version, " R%c", os->variant.chars[1]);
 90                ffStrbufSubstrAfter(&os->variant, strlen("Rx ") - 1);
 91            }
 92        }
 93    } else {
 94        // Unknown Windows name, please report this
 95        ffStrbufAppend(&os->name, &os->variant);
 96        ffStrbufClear(&os->variant);
 97    }
 98
 99    ffStrbufAppendF(&os->id, "%s %s", os->name.chars, os->version.chars);
100    ffStrbufSetStatic(&os->idLike, "Windows");
101
102    if (getCodeName(os) && os->codename.length > 0) {
103        ffStrbufAppendF(&os->prettyName, " (%s)", os->codename.chars);
104    }
105}