[deps] Update grpc for CVE-2019-9511 https://nvd.nist.gov/vuln/detail/CVE-2019-9511

vendor/github.com/Microsoft/go-winio/.gitignore

@@ -0,0 +1 @@
+*.exe

vendor/github.com/Microsoft/go-winio/LICENSE

@@ -0,0 +1,22 @@
+The MIT License (MIT)
+
+Copyright (c) 2015 Microsoft
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+

vendor/github.com/Microsoft/go-winio/README.md

@@ -0,0 +1,22 @@
+# go-winio
+
+This repository contains utilities for efficiently performing Win32 IO operations in
+Go. Currently, this is focused on accessing named pipes and other file handles, and
+for using named pipes as a net transport.
+
+This code relies on IO completion ports to avoid blocking IO on system threads, allowing Go
+to reuse the thread to schedule another goroutine. This limits support to Windows Vista and
+newer operating systems. This is similar to the implementation of network sockets in Go's net
+package.
+
+Please see the LICENSE file for licensing information.
+
+This project has adopted the [Microsoft Open Source Code of
+Conduct](https://opensource.microsoft.com/codeofconduct/). For more information
+see the [Code of Conduct
+FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or contact
+[opencode@microsoft.com](mailto:opencode@microsoft.com) with any additional
+questions or comments.
+
+Thanks to natefinch for the inspiration for this library. See https://github.com/natefinch/npipe
+for another named pipe implementation.

vendor/github.com/Microsoft/go-winio/backup.go

@@ -0,0 +1,280 @@
+// +build windows
+
+package winio
+
+import (
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"runtime"
+	"syscall"
+	"unicode/utf16"
+)
+
+//sys backupRead(h syscall.Handle, b []byte, bytesRead *uint32, abort bool, processSecurity bool, context *uintptr) (err error) = BackupRead
+//sys backupWrite(h syscall.Handle, b []byte, bytesWritten *uint32, abort bool, processSecurity bool, context *uintptr) (err error) = BackupWrite
+
+const (
+	BackupData = uint32(iota + 1)
+	BackupEaData
+	BackupSecurity
+	BackupAlternateData
+	BackupLink
+	BackupPropertyData
+	BackupObjectId
+	BackupReparseData
+	BackupSparseBlock
+	BackupTxfsData
+)
+
+const (
+	StreamSparseAttributes = uint32(8)
+)
+
+const (
+	WRITE_DAC              = 0x40000
+	WRITE_OWNER            = 0x80000
+	ACCESS_SYSTEM_SECURITY = 0x1000000
+)
+
+// BackupHeader represents a backup stream of a file.
+type BackupHeader struct {
+	Id         uint32 // The backup stream ID
+	Attributes uint32 // Stream attributes
+	Size       int64  // The size of the stream in bytes
+	Name       string // The name of the stream (for BackupAlternateData only).
+	Offset     int64  // The offset of the stream in the file (for BackupSparseBlock only).
+}
+
+type win32StreamId struct {
+	StreamId   uint32
+	Attributes uint32
+	Size       uint64
+	NameSize   uint32
+}
+
+// BackupStreamReader reads from a stream produced by the BackupRead Win32 API and produces a series
+// of BackupHeader values.
+type BackupStreamReader struct {
+	r         io.Reader
+	bytesLeft int64
+}
+
+// NewBackupStreamReader produces a BackupStreamReader from any io.Reader.
+func NewBackupStreamReader(r io.Reader) *BackupStreamReader {
+	return &BackupStreamReader{r, 0}
+}
+
+// Next returns the next backup stream and prepares for calls to Read(). It skips the remainder of the current stream if
+// it was not completely read.
+func (r *BackupStreamReader) Next() (*BackupHeader, error) {
+	if r.bytesLeft > 0 {
+		if s, ok := r.r.(io.Seeker); ok {
+			// Make sure Seek on io.SeekCurrent sometimes succeeds
+			// before trying the actual seek.
+			if _, err := s.Seek(0, io.SeekCurrent); err == nil {
+				if _, err = s.Seek(r.bytesLeft, io.SeekCurrent); err != nil {
+					return nil, err
+				}
+				r.bytesLeft = 0
+			}
+		}
+		if _, err := io.Copy(ioutil.Discard, r); err != nil {
+			return nil, err
+		}
+	}
+	var wsi win32StreamId
+	if err := binary.Read(r.r, binary.LittleEndian, &wsi); err != nil {
+		return nil, err
+	}
+	hdr := &BackupHeader{
+		Id:         wsi.StreamId,
+		Attributes: wsi.Attributes,
+		Size:       int64(wsi.Size),
+	}
+	if wsi.NameSize != 0 {
+		name := make([]uint16, int(wsi.NameSize/2))
+		if err := binary.Read(r.r, binary.LittleEndian, name); err != nil {
+			return nil, err
+		}
+		hdr.Name = syscall.UTF16ToString(name)
+	}
+	if wsi.StreamId == BackupSparseBlock {
+		if err := binary.Read(r.r, binary.LittleEndian, &hdr.Offset); err != nil {
+			return nil, err
+		}
+		hdr.Size -= 8
+	}
+	r.bytesLeft = hdr.Size
+	return hdr, nil
+}
+
+// Read reads from the current backup stream.
+func (r *BackupStreamReader) Read(b []byte) (int, error) {
+	if r.bytesLeft == 0 {
+		return 0, io.EOF
+	}
+	if int64(len(b)) > r.bytesLeft {
+		b = b[:r.bytesLeft]
+	}
+	n, err := r.r.Read(b)
+	r.bytesLeft -= int64(n)
+	if err == io.EOF {
+		err = io.ErrUnexpectedEOF
+	} else if r.bytesLeft == 0 && err == nil {
+		err = io.EOF
+	}
+	return n, err
+}
+
+// BackupStreamWriter writes a stream compatible with the BackupWrite Win32 API.
+type BackupStreamWriter struct {
+	w         io.Writer
+	bytesLeft int64
+}
+
+// NewBackupStreamWriter produces a BackupStreamWriter on top of an io.Writer.
+func NewBackupStreamWriter(w io.Writer) *BackupStreamWriter {
+	return &BackupStreamWriter{w, 0}
+}
+
+// WriteHeader writes the next backup stream header and prepares for calls to Write().
+func (w *BackupStreamWriter) WriteHeader(hdr *BackupHeader) error {
+	if w.bytesLeft != 0 {
+		return fmt.Errorf("missing %d bytes", w.bytesLeft)
+	}
+	name := utf16.Encode([]rune(hdr.Name))
+	wsi := win32StreamId{
+		StreamId:   hdr.Id,
+		Attributes: hdr.Attributes,
+		Size:       uint64(hdr.Size),
+		NameSize:   uint32(len(name) * 2),
+	}
+	if hdr.Id == BackupSparseBlock {
+		// Include space for the int64 block offset
+		wsi.Size += 8
+	}
+	if err := binary.Write(w.w, binary.LittleEndian, &wsi); err != nil {
+		return err
+	}
+	if len(name) != 0 {
+		if err := binary.Write(w.w, binary.LittleEndian, name); err != nil {
+			return err
+		}
+	}
+	if hdr.Id == BackupSparseBlock {
+		if err := binary.Write(w.w, binary.LittleEndian, hdr.Offset); err != nil {
+			return err
+		}
+	}
+	w.bytesLeft = hdr.Size
+	return nil
+}
+
+// Write writes to the current backup stream.
+func (w *BackupStreamWriter) Write(b []byte) (int, error) {
+	if w.bytesLeft < int64(len(b)) {
+		return 0, fmt.Errorf("too many bytes by %d", int64(len(b))-w.bytesLeft)
+	}
+	n, err := w.w.Write(b)
+	w.bytesLeft -= int64(n)
+	return n, err
+}
+
+// BackupFileReader provides an io.ReadCloser interface on top of the BackupRead Win32 API.
+type BackupFileReader struct {
+	f               *os.File
+	includeSecurity bool
+	ctx             uintptr
+}
+
+// NewBackupFileReader returns a new BackupFileReader from a file handle. If includeSecurity is true,
+// Read will attempt to read the security descriptor of the file.
+func NewBackupFileReader(f *os.File, includeSecurity bool) *BackupFileReader {
+	r := &BackupFileReader{f, includeSecurity, 0}
+	return r
+}
+
+// Read reads a backup stream from the file by calling the Win32 API BackupRead().
+func (r *BackupFileReader) Read(b []byte) (int, error) {
+	var bytesRead uint32
+	err := backupRead(syscall.Handle(r.f.Fd()), b, &bytesRead, false, r.includeSecurity, &r.ctx)
+	if err != nil {
+		return 0, &os.PathError{"BackupRead", r.f.Name(), err}
+	}
+	runtime.KeepAlive(r.f)
+	if bytesRead == 0 {
+		return 0, io.EOF
+	}
+	return int(bytesRead), nil
+}
+
+// Close frees Win32 resources associated with the BackupFileReader. It does not close
+// the underlying file.
+func (r *BackupFileReader) Close() error {
+	if r.ctx != 0 {
+		backupRead(syscall.Handle(r.f.Fd()), nil, nil, true, false, &r.ctx)
+		runtime.KeepAlive(r.f)
+		r.ctx = 0
+	}
+	return nil
+}
+
+// BackupFileWriter provides an io.WriteCloser interface on top of the BackupWrite Win32 API.
+type BackupFileWriter struct {
+	f               *os.File
+	includeSecurity bool
+	ctx             uintptr
+}
+
+// NewBackupFileWriter returns a new BackupFileWriter from a file handle. If includeSecurity is true,
+// Write() will attempt to restore the security descriptor from the stream.
+func NewBackupFileWriter(f *os.File, includeSecurity bool) *BackupFileWriter {
+	w := &BackupFileWriter{f, includeSecurity, 0}
+	return w
+}
+
+// Write restores a portion of the file using the provided backup stream.
+func (w *BackupFileWriter) Write(b []byte) (int, error) {
+	var bytesWritten uint32
+	err := backupWrite(syscall.Handle(w.f.Fd()), b, &bytesWritten, false, w.includeSecurity, &w.ctx)
+	if err != nil {
+		return 0, &os.PathError{"BackupWrite", w.f.Name(), err}
+	}
+	runtime.KeepAlive(w.f)
+	if int(bytesWritten) != len(b) {
+		return int(bytesWritten), errors.New("not all bytes could be written")
+	}
+	return len(b), nil
+}
+
+// Close frees Win32 resources associated with the BackupFileWriter. It does not
+// close the underlying file.
+func (w *BackupFileWriter) Close() error {
+	if w.ctx != 0 {
+		backupWrite(syscall.Handle(w.f.Fd()), nil, nil, true, false, &w.ctx)
+		runtime.KeepAlive(w.f)
+		w.ctx = 0
+	}
+	return nil
+}
+
+// OpenForBackup opens a file or directory, potentially skipping access checks if the backup
+// or restore privileges have been acquired.
+//
+// If the file opened was a directory, it cannot be used with Readdir().
+func OpenForBackup(path string, access uint32, share uint32, createmode uint32) (*os.File, error) {
+	winPath, err := syscall.UTF16FromString(path)
+	if err != nil {
+		return nil, err
+	}
+	h, err := syscall.CreateFile(&winPath[0], access, share, nil, createmode, syscall.FILE_FLAG_BACKUP_SEMANTICS|syscall.FILE_FLAG_OPEN_REPARSE_POINT, 0)
+	if err != nil {
+		err = &os.PathError{Op: "open", Path: path, Err: err}
+		return nil, err
+	}
+	return os.NewFile(uintptr(h), path), nil
+}

vendor/github.com/Microsoft/go-winio/privilege.go

@@ -0,0 +1,202 @@
+// +build windows
+
+package winio
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"runtime"
+	"sync"
+	"syscall"
+	"unicode/utf16"
+
+	"golang.org/x/sys/windows"
+)
+
+//sys adjustTokenPrivileges(token windows.Token, releaseAll bool, input *byte, outputSize uint32, output *byte, requiredSize *uint32) (success bool, err error) [true] = advapi32.AdjustTokenPrivileges
+//sys impersonateSelf(level uint32) (err error) = advapi32.ImpersonateSelf
+//sys revertToSelf() (err error) = advapi32.RevertToSelf
+//sys openThreadToken(thread syscall.Handle, accessMask uint32, openAsSelf bool, token *windows.Token) (err error) = advapi32.OpenThreadToken
+//sys getCurrentThread() (h syscall.Handle) = GetCurrentThread
+//sys lookupPrivilegeValue(systemName string, name string, luid *uint64) (err error) = advapi32.LookupPrivilegeValueW
+//sys lookupPrivilegeName(systemName string, luid *uint64, buffer *uint16, size *uint32) (err error) = advapi32.LookupPrivilegeNameW
+//sys lookupPrivilegeDisplayName(systemName string, name *uint16, buffer *uint16, size *uint32, languageId *uint32) (err error) = advapi32.LookupPrivilegeDisplayNameW
+
+const (
+	SE_PRIVILEGE_ENABLED = 2
+
+	ERROR_NOT_ALL_ASSIGNED syscall.Errno = 1300
+
+	SeBackupPrivilege  = "SeBackupPrivilege"
+	SeRestorePrivilege = "SeRestorePrivilege"
+)
+
+const (
+	securityAnonymous = iota
+	securityIdentification
+	securityImpersonation
+	securityDelegation
+)
+
+var (
+	privNames     = make(map[string]uint64)
+	privNameMutex sync.Mutex
+)
+
+// PrivilegeError represents an error enabling privileges.
+type PrivilegeError struct {
+	privileges []uint64
+}
+
+func (e *PrivilegeError) Error() string {
+	s := ""
+	if len(e.privileges) > 1 {
+		s = "Could not enable privileges "
+	} else {
+		s = "Could not enable privilege "
+	}
+	for i, p := range e.privileges {
+		if i != 0 {
+			s += ", "
+		}
+		s += `"`
+		s += getPrivilegeName(p)
+		s += `"`
+	}
+	return s
+}
+
+// RunWithPrivilege enables a single privilege for a function call.
+func RunWithPrivilege(name string, fn func() error) error {
+	return RunWithPrivileges([]string{name}, fn)
+}
+
+// RunWithPrivileges enables privileges for a function call.
+func RunWithPrivileges(names []string, fn func() error) error {
+	privileges, err := mapPrivileges(names)
+	if err != nil {
+		return err
+	}
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+	token, err := newThreadToken()
+	if err != nil {
+		return err
+	}
+	defer releaseThreadToken(token)
+	err = adjustPrivileges(token, privileges, SE_PRIVILEGE_ENABLED)
+	if err != nil {
+		return err
+	}
+	return fn()
+}
+
+func mapPrivileges(names []string) ([]uint64, error) {
+	var privileges []uint64
+	privNameMutex.Lock()
+	defer privNameMutex.Unlock()
+	for _, name := range names {
+		p, ok := privNames[name]
+		if !ok {
+			err := lookupPrivilegeValue("", name, &p)
+			if err != nil {
+				return nil, err
+			}
+			privNames[name] = p
+		}
+		privileges = append(privileges, p)
+	}
+	return privileges, nil
+}
+
+// EnableProcessPrivileges enables privileges globally for the process.
+func EnableProcessPrivileges(names []string) error {
+	return enableDisableProcessPrivilege(names, SE_PRIVILEGE_ENABLED)
+}
+
+// DisableProcessPrivileges disables privileges globally for the process.
+func DisableProcessPrivileges(names []string) error {
+	return enableDisableProcessPrivilege(names, 0)
+}
+
+func enableDisableProcessPrivilege(names []string, action uint32) error {
+	privileges, err := mapPrivileges(names)
+	if err != nil {
+		return err
+	}
+
+	p, _ := windows.GetCurrentProcess()
+	var token windows.Token
+	err = windows.OpenProcessToken(p, windows.TOKEN_ADJUST_PRIVILEGES|windows.TOKEN_QUERY, &token)
+	if err != nil {
+		return err
+	}
+
+	defer token.Close()
+	return adjustPrivileges(token, privileges, action)
+}
+
+func adjustPrivileges(token windows.Token, privileges []uint64, action uint32) error {
+	var b bytes.Buffer
+	binary.Write(&b, binary.LittleEndian, uint32(len(privileges)))
+	for _, p := range privileges {
+		binary.Write(&b, binary.LittleEndian, p)
+		binary.Write(&b, binary.LittleEndian, action)
+	}
+	prevState := make([]byte, b.Len())
+	reqSize := uint32(0)
+	success, err := adjustTokenPrivileges(token, false, &b.Bytes()[0], uint32(len(prevState)), &prevState[0], &reqSize)
+	if !success {
+		return err
+	}
+	if err == ERROR_NOT_ALL_ASSIGNED {
+		return &PrivilegeError{privileges}
+	}
+	return nil
+}
+
+func getPrivilegeName(luid uint64) string {
+	var nameBuffer [256]uint16
+	bufSize := uint32(len(nameBuffer))
+	err := lookupPrivilegeName("", &luid, &nameBuffer[0], &bufSize)
+	if err != nil {
+		return fmt.Sprintf("<unknown privilege %d>", luid)
+	}
+
+	var displayNameBuffer [256]uint16
+	displayBufSize := uint32(len(displayNameBuffer))
+	var langID uint32
+	err = lookupPrivilegeDisplayName("", &nameBuffer[0], &displayNameBuffer[0], &displayBufSize, &langID)
+	if err != nil {
+		return fmt.Sprintf("<unknown privilege %s>", string(utf16.Decode(nameBuffer[:bufSize])))
+	}
+
+	return string(utf16.Decode(displayNameBuffer[:displayBufSize]))
+}
+
+func newThreadToken() (windows.Token, error) {
+	err := impersonateSelf(securityImpersonation)
+	if err != nil {
+		return 0, err
+	}
+
+	var token windows.Token
+	err = openThreadToken(getCurrentThread(), syscall.TOKEN_ADJUST_PRIVILEGES|syscall.TOKEN_QUERY, false, &token)
+	if err != nil {
+		rerr := revertToSelf()
+		if rerr != nil {
+			panic(rerr)
+		}
+		return 0, err
+	}
+	return token, nil
+}
+
+func releaseThreadToken(h windows.Token) {
+	err := revertToSelf()
+	if err != nil {
+		panic(err)
+	}
+	h.Close()
+}

vendor/github.com/Microsoft/go-winio/reparse.go

@@ -0,0 +1,128 @@
+package winio
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"strings"
+	"unicode/utf16"
+	"unsafe"
+)
+
+const (
+	reparseTagMountPoint = 0xA0000003
+	reparseTagSymlink    = 0xA000000C
+)
+
+type reparseDataBuffer struct {
+	ReparseTag           uint32
+	ReparseDataLength    uint16
+	Reserved             uint16
+	SubstituteNameOffset uint16
+	SubstituteNameLength uint16
+	PrintNameOffset      uint16
+	PrintNameLength      uint16
+}
+
+// ReparsePoint describes a Win32 symlink or mount point.
+type ReparsePoint struct {
+	Target       string
+	IsMountPoint bool
+}
+
+// UnsupportedReparsePointError is returned when trying to decode a non-symlink or
+// mount point reparse point.
+type UnsupportedReparsePointError struct {
+	Tag uint32
+}
+
+func (e *UnsupportedReparsePointError) Error() string {
+	return fmt.Sprintf("unsupported reparse point %x", e.Tag)
+}
+
+// DecodeReparsePoint decodes a Win32 REPARSE_DATA_BUFFER structure containing either a symlink
+// or a mount point.
+func DecodeReparsePoint(b []byte) (*ReparsePoint, error) {
+	tag := binary.LittleEndian.Uint32(b[0:4])
+	return DecodeReparsePointData(tag, b[8:])
+}
+
+func DecodeReparsePointData(tag uint32, b []byte) (*ReparsePoint, error) {
+	isMountPoint := false
+	switch tag {
+	case reparseTagMountPoint:
+		isMountPoint = true
+	case reparseTagSymlink:
+	default:
+		return nil, &UnsupportedReparsePointError{tag}
+	}
+	nameOffset := 8 + binary.LittleEndian.Uint16(b[4:6])
+	if !isMountPoint {
+		nameOffset += 4
+	}
+	nameLength := binary.LittleEndian.Uint16(b[6:8])
+	name := make([]uint16, nameLength/2)
+	err := binary.Read(bytes.NewReader(b[nameOffset:nameOffset+nameLength]), binary.LittleEndian, &name)
+	if err != nil {
+		return nil, err
+	}
+	return &ReparsePoint{string(utf16.Decode(name)), isMountPoint}, nil
+}
+
+func isDriveLetter(c byte) bool {
+	return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')
+}
+
+// EncodeReparsePoint encodes a Win32 REPARSE_DATA_BUFFER structure describing a symlink or
+// mount point.
+func EncodeReparsePoint(rp *ReparsePoint) []byte {
+	// Generate an NT path and determine if this is a relative path.
+	var ntTarget string
+	relative := false
+	if strings.HasPrefix(rp.Target, `\\?\`) {
+		ntTarget = `\??\` + rp.Target[4:]
+	} else if strings.HasPrefix(rp.Target, `\\`) {
+		ntTarget = `\??\UNC\` + rp.Target[2:]
+	} else if len(rp.Target) >= 2 && isDriveLetter(rp.Target[0]) && rp.Target[1] == ':' {
+		ntTarget = `\??\` + rp.Target
+	} else {
+		ntTarget = rp.Target
+		relative = true
+	}
+
+	// The paths must be NUL-terminated even though they are counted strings.
+	target16 := utf16.Encode([]rune(rp.Target + "\x00"))
+	ntTarget16 := utf16.Encode([]rune(ntTarget + "\x00"))
+
+	size := int(unsafe.Sizeof(reparseDataBuffer{})) - 8
+	size += len(ntTarget16)*2 + len(target16)*2
+
+	tag := uint32(reparseTagMountPoint)
+	if !rp.IsMountPoint {
+		tag = reparseTagSymlink
+		size += 4 // Add room for symlink flags
+	}
+
+	data := reparseDataBuffer{
+		ReparseTag:           tag,
+		ReparseDataLength:    uint16(size),
+		SubstituteNameOffset: 0,
+		SubstituteNameLength: uint16((len(ntTarget16) - 1) * 2),
+		PrintNameOffset:      uint16(len(ntTarget16) * 2),
+		PrintNameLength:      uint16((len(target16) - 1) * 2),
+	}
+
+	var b bytes.Buffer
+	binary.Write(&b, binary.LittleEndian, &data)
+	if !rp.IsMountPoint {
+		flags := uint32(0)
+		if relative {
+			flags |= 1
+		}
+		binary.Write(&b, binary.LittleEndian, flags)
+	}
+
+	binary.Write(&b, binary.LittleEndian, ntTarget16)
+	binary.Write(&b, binary.LittleEndian, target16)
+	return b.Bytes()
+}

vendor/github.com/Microsoft/go-winio/sd.go

@@ -0,0 +1,98 @@
+// +build windows
+
+package winio
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+//sys lookupAccountName(systemName *uint16, accountName string, sid *byte, sidSize *uint32, refDomain *uint16, refDomainSize *uint32, sidNameUse *uint32) (err error) = advapi32.LookupAccountNameW
+//sys convertSidToStringSid(sid *byte, str **uint16) (err error) = advapi32.ConvertSidToStringSidW
+//sys convertStringSecurityDescriptorToSecurityDescriptor(str string, revision uint32, sd *uintptr, size *uint32) (err error) = advapi32.ConvertStringSecurityDescriptorToSecurityDescriptorW
+//sys convertSecurityDescriptorToStringSecurityDescriptor(sd *byte, revision uint32, secInfo uint32, sddl **uint16, sddlSize *uint32) (err error) = advapi32.ConvertSecurityDescriptorToStringSecurityDescriptorW
+//sys localFree(mem uintptr) = LocalFree
+//sys getSecurityDescriptorLength(sd uintptr) (len uint32) = advapi32.GetSecurityDescriptorLength
+
+const (
+	cERROR_NONE_MAPPED = syscall.Errno(1332)
+)
+
+type AccountLookupError struct {
+	Name string
+	Err  error
+}
+
+func (e *AccountLookupError) Error() string {
+	if e.Name == "" {
+		return "lookup account: empty account name specified"
+	}
+	var s string
+	switch e.Err {
+	case cERROR_NONE_MAPPED:
+		s = "not found"
+	default:
+		s = e.Err.Error()
+	}
+	return "lookup account " + e.Name + ": " + s
+}
+
+type SddlConversionError struct {
+	Sddl string
+	Err  error
+}
+
+func (e *SddlConversionError) Error() string {
+	return "convert " + e.Sddl + ": " + e.Err.Error()
+}
+
+// LookupSidByName looks up the SID of an account by name
+func LookupSidByName(name string) (sid string, err error) {
+	if name == "" {
+		return "", &AccountLookupError{name, cERROR_NONE_MAPPED}
+	}
+
+	var sidSize, sidNameUse, refDomainSize uint32
+	err = lookupAccountName(nil, name, nil, &sidSize, nil, &refDomainSize, &sidNameUse)
+	if err != nil && err != syscall.ERROR_INSUFFICIENT_BUFFER {
+		return "", &AccountLookupError{name, err}
+	}
+	sidBuffer := make([]byte, sidSize)
+	refDomainBuffer := make([]uint16, refDomainSize)
+	err = lookupAccountName(nil, name, &sidBuffer[0], &sidSize, &refDomainBuffer[0], &refDomainSize, &sidNameUse)
+	if err != nil {
+		return "", &AccountLookupError{name, err}
+	}
+	var strBuffer *uint16
+	err = convertSidToStringSid(&sidBuffer[0], &strBuffer)
+	if err != nil {
+		return "", &AccountLookupError{name, err}
+	}
+	sid = syscall.UTF16ToString((*[0xffff]uint16)(unsafe.Pointer(strBuffer))[:])
+	localFree(uintptr(unsafe.Pointer(strBuffer)))
+	return sid, nil
+}
+
+func SddlToSecurityDescriptor(sddl string) ([]byte, error) {
+	var sdBuffer uintptr
+	err := convertStringSecurityDescriptorToSecurityDescriptor(sddl, 1, &sdBuffer, nil)
+	if err != nil {
+		return nil, &SddlConversionError{sddl, err}
+	}
+	defer localFree(sdBuffer)
+	sd := make([]byte, getSecurityDescriptorLength(sdBuffer))
+	copy(sd, (*[0xffff]byte)(unsafe.Pointer(sdBuffer))[:len(sd)])
+	return sd, nil
+}
+
+func SecurityDescriptorToSddl(sd []byte) (string, error) {
+	var sddl *uint16
+	// The returned string length seems to including an aribtrary number of terminating NULs.
+	// Don't use it.
+	err := convertSecurityDescriptorToStringSecurityDescriptor(&sd[0], 1, 0xff, &sddl, nil)
+	if err != nil {
+		return "", err
+	}
+	defer localFree(uintptr(unsafe.Pointer(sddl)))
+	return syscall.UTF16ToString((*[0xffff]uint16)(unsafe.Pointer(sddl))[:]), nil
+}