Enumerating Registry Values in Go (Golang)

Question

I'm trying to enumerate over a list of values in the Windows registry using Go, but I'm running into some trouble. I've tried two approaches: using both the Go-provided `syscall` library to call into `RegEnumValue`, as well as using a Windows API wrapper by lxn. In both cases, I'm having the same issue. This is the code I'm using (which is currently using the win library from lxn): ``` var root win.HKEY rootpath, _ := syscall.UTF16PtrFromString("HARDWARE\DEVICEMAP\SERIALCOMM") fmt.Println(win.RegOpenKeyEx(win.HKEY_LOCAL_MACHINE, rootpath, 0, win.KEY_READ, &root)) var name_length uint32 = 72 var name *uint16 var key_type uint32 var lpData *byte var lpDataLength uint32 = 72 var zero_uint uint32 = 0 fmt.Println(win.RegEnumValue(root, zero_uint, name, &name_length, nil, &key_type, lpData, &lpDataLength)) win.RegCloseKey(root) ``` In this case, `RegEnumValue` always returns code 87, which MSDN's only explanation is "The parameter is incorrect." Does anyone have any ideas that can point m…

Accepted Answer

A member of the Golang sub-reddit pointed out that I was not actually allocating any memory to the buffers passed in to `RegEnumValue`. As such, I've corrected the above example to the following:

```
var name_length uint32 = 72
var key_type uint32
var lpDataLength uint32 = 72
var zero_uint uint32 = 0
name := make([]uint16, 72)
lpData := make([]byte, 72)

win.RegEnumValue(root, zero_uint, &name[0], &name_length, nil, &key_type, &lpData[0], &lpDataLength)
```

Obviously, the "magic number" of 72 should probably be replaced with something else. There is another method called `RegQueryInfoKey` that can retrieve information about the registry key to allocate the correct number of bytes for the largest name and value in the key.

Enumerating Registry Values in Go (Golang)

Solution

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