[host][windows] Refactor code to query registry via golang.org/x/sys/windows/registry

host/host_windows.go

@@ -15,7 +15,6 @@ import (
 
 	"github.com/shirou/gopsutil/internal/common"
 	process "github.com/shirou/gopsutil/process"
-	"golang.org/x/sys/windows"
 	"golang.org/x/sys/windows/registry"
 )
 
@@ -94,30 +93,15 @@ func InfoWithContext(ctx context.Context) (*InfoStat, error) {
 }
 
 func getMachineGuid() (string, error) {
-	var h windows.Handle
-	err := windows.RegOpenKeyEx(windows.HKEY_LOCAL_MACHINE, windows.StringToUTF16Ptr(`SOFTWARE\Microsoft\Cryptography`), 0, windows.KEY_READ|windows.KEY_WOW64_64KEY, &h)
+	k, err := registry.OpenKey(registry.LOCAL_MACHINE, `SOFTWARE\Microsoft\Cryptography`, registry.QUERY_VALUE)
 	if err != nil {
 		return "", err
 	}
-	defer windows.RegCloseKey(h)
-
-	const windowsRegBufLen = 74 // len(`{`) + len(`abcdefgh-1234-456789012-123345456671` * 2) + len(`}`) // 2 == bytes/UTF16
-	const uuidLen = 36
-
-	var regBuf [windowsRegBufLen]uint16
-	bufLen := uint32(windowsRegBufLen)
-	var valType uint32
-	err = windows.RegQueryValueEx(h, windows.StringToUTF16Ptr(`MachineGuid`), nil, &valType, (*byte)(unsafe.Pointer(&regBuf[0])), &bufLen)
+	defer k.Close()
+	hostID, _, err := k.GetStringValue("MachineGuid")
 	if err != nil {
 		return "", err
 	}
-
-	hostID := windows.UTF16ToString(regBuf[:])
-	hostIDLen := len(hostID)
-	if hostIDLen != uuidLen {
-		return "", fmt.Errorf("HostID incorrect: %q\n", hostID)
-	}
-
 	return hostID, nil
 }