build(deps): bump github.com/Microsoft/hcsshim from 0.8.20 to 0.9.6

Bumps [github.com/Microsoft/hcsshim](https://github.com/Microsoft/hcsshim) from 0.8.20 to 0.9.6.
- [Release notes](https://github.com/Microsoft/hcsshim/releases)
- [Commits](https://github.com/Microsoft/hcsshim/compare/v0.8.20...v0.9.6)

---
updated-dependencies:
- dependency-name: github.com/Microsoft/hcsshim
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Signed-off-by: Matthieu MOREL <matthieu.morel35@gmail.com>

vendor/github.com/Microsoft/hcsshim/internal/winapi/utils.go

@@ -20,36 +20,41 @@ func Uint16BufferToSlice(buffer *uint16, bufferLength int) (result []uint16) {
 	return
 }
 
+// UnicodeString corresponds to UNICODE_STRING win32 struct defined here
+// https://docs.microsoft.com/en-us/windows/win32/api/ntdef/ns-ntdef-_unicode_string
 type UnicodeString struct {
 	Length        uint16
 	MaximumLength uint16
 	Buffer        *uint16
 }
 
+// NTSTRSAFE_UNICODE_STRING_MAX_CCH is a constant defined in ntstrsafe.h. This value
+// denotes the maximum number of wide chars a path can have.
+const NTSTRSAFE_UNICODE_STRING_MAX_CCH = 32767
+
 //String converts a UnicodeString to a golang string
 func (uni UnicodeString) String() string {
 	// UnicodeString is not guaranteed to be null terminated, therefore
 	// use the UnicodeString's Length field
-	return syscall.UTF16ToString(Uint16BufferToSlice(uni.Buffer, int(uni.Length/2)))
+	return windows.UTF16ToString(Uint16BufferToSlice(uni.Buffer, int(uni.Length/2)))
 }
 
 // NewUnicodeString allocates a new UnicodeString and copies `s` into
 // the buffer of the new UnicodeString.
 func NewUnicodeString(s string) (*UnicodeString, error) {
-	// Get length of original `s` to use in the UnicodeString since the `buf`
-	// created later will have an additional trailing null character
-	length := len(s)
-	if length > 32767 {
-		return nil, syscall.ENAMETOOLONG
-	}
-
 	buf, err := windows.UTF16FromString(s)
 	if err != nil {
 		return nil, err
 	}
+
+	if len(buf) > NTSTRSAFE_UNICODE_STRING_MAX_CCH {
+		return nil, syscall.ENAMETOOLONG
+	}
+
 	uni := &UnicodeString{
-		Length:        uint16(length * 2),
-		MaximumLength: uint16(length * 2),
+		// The length is in bytes and should not include the trailing null character.
+		Length:        uint16((len(buf) - 1) * 2),
+		MaximumLength: uint16((len(buf) - 1) * 2),
 		Buffer:        &buf[0],
 	}
 	return uni, nil