Use proper UTF-8 to UTF-16 conversion?

[rgl]

Can

winrm/powershell.go

Lines 10 to 23 in 1d17eaf

	func Powershell(psCmd string) string {
	// 2 byte chars to make PowerShell happy
	wideCmd := ""
	for _, b := range []byte(psCmd) {
	wideCmd += string(b) + "\x00"
	}
	// Base64 encode the command
	input := []uint8(wideCmd)
	encodedCmd := base64.StdEncoding.EncodeToString(input)
	// Create the powershell.exe command line to execute the script
	return fmt.Sprintf("powershell.exe -EncodedCommand %s", encodedCmd)
	}

be changed to use a proper UTF-8 to UTF-16 (the native windows encoding) conversion?

[masterzen]

@rgl,

I'm not really versed into Windows encoding (nor UTF-16). From what I understand this code is building a pure UCS-2 (wide char) string with the topmost byte being always 0. This will indeed fail with any character > 127, which is unfortunate.

I think this can be fixed with this:

 wideCmd := utf16.Encode([]rune(psCmd))

Hopefully the result will be in proper endian for the receiving machine.

Would you mind testing this, as I'm very illiterate about everything related to powershell ?

[rgl]

Windows uses UTF-16LE and utf16.Encode is UTF-16BE. I will submit PR soon.

[rgl]

Oh an I was mistaken, utf16.Encode is really UTF-16LE! We just need to convert the result into a []byte.

[masterzen]

@rgl I'm lost, your PR implements a BE->LE conversion, but your last comment here seems to imply it wasn't needed. Can you elaborate?

[rgl]

Sorry for the confusion... the PR does not really convert from BE to LE.

Let me clarify:

1. utf16.Encode converts from string to a []uint16 encoded as UTF-16LE.
2. encodeUtf16Le converts from []uint16 to a []byte encoded as UTF-16LE, making the entire conversion from string to []byte encoded as UTF-16LE.