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@ropnop @ayoul3
// +build windows
package clr
import (
"syscall"
"unsafe"
)
// VARTYPE uint16
// UINT uint32
// VT_UI1 = 0x0011
// ULONG uint32
// LONG int32
// USHORT uint16
// from OAld.h
type SafeArray struct {
cDims uint16
fFeatures uint16
cbElements uint32
cLocks uint32
pvData uintptr
rgsabound [1]SafeArrayBound
}
type SafeArrayBound struct {
cElements uint32
lLbound int32
}
// CreateSafeArray is a wrapper function that takes in a Go byte array and creates a SafeArray containing unsigned bytes
// by making two syscalls and copying raw memory into the correct spot.
func CreateSafeArray(rawBytes []byte) (unsafe.Pointer, error) {
saPtr, err := CreateEmptySafeArray(0x11, len(rawBytes)) // VT_UI1
if err != nil {
return nil, err
}
// now we need to use RtlCopyMemory to copy our bytes to the SafeArray
modNtDll := syscall.MustLoadDLL("ntdll.dll")
procRtlCopyMemory := modNtDll.MustFindProc("RtlCopyMemory")
sa := (*SafeArray)(saPtr)
_, _, err = procRtlCopyMemory.Call(
sa.pvData,
uintptr(unsafe.Pointer(&rawBytes[0])),
uintptr(len(rawBytes)))
if err != syscall.Errno(0) {
return nil, err
}
return saPtr, nil
}
// CreateEmptySafeArray is a wrapper function that takes an array type and a size and creates a safe array with corresponding
// properties. It returns a pointer to that empty array.
func CreateEmptySafeArray(arrayType int, size int) (unsafe.Pointer, error) {
modOleAuto := syscall.MustLoadDLL("OleAut32.dll")
procSafeArrayCreate := modOleAuto.MustFindProc("SafeArrayCreate")
sab := SafeArrayBound{
cElements: uint32(size),
lLbound: 0,
}
vt := uint16(arrayType)
ret, _, err := procSafeArrayCreate.Call(
uintptr(vt),
uintptr(1),
uintptr(unsafe.Pointer(&sab)))
if err != syscall.Errno(0) {
return nil, err
}
return unsafe.Pointer(ret), nil
}
// SysAllocString converts a Go string to a BTSR string, that is a unicode string prefixed with its length.
// It returns a pointer to the string's content.
func SysAllocString(str string) (unsafe.Pointer, error) {
modOleAuto := syscall.MustLoadDLL("OleAut32.dll")
sysAllocString := modOleAuto.MustFindProc("SysAllocString")
input := utf16Le(str)
ret, _, err := sysAllocString.Call(
uintptr(unsafe.Pointer(&input[0])),
)
if err != syscall.Errno(0) {
return nil, err
}
return unsafe.Pointer(ret), nil
}
// SafeArrayPutElement pushes an element to the safe array at a given index
func SafeArrayPutElement(array, btsr unsafe.Pointer, index int) (err error) {
modOleAuto := syscall.MustLoadDLL("OleAut32.dll")
safeArrayPutElement := modOleAuto.MustFindProc("SafeArrayPutElement")
_, _, err = safeArrayPutElement.Call(
uintptr(array),
uintptr(unsafe.Pointer(&index)),
uintptr(btsr),
)
if err != syscall.Errno(0) {
return err
}
return nil
}