Add routine for looking up account names

Signed-off-by: John Starks <jostarks@microsoft.com>

pipe.go

@@ -10,11 +10,15 @@ import (
 )
 
 //sys connectNamedPipe(pipe syscall.Handle, o *syscall.Overlapped) (err error) = ConnectNamedPipe
-//sys createNamedPipe(name string, flags uint32, pipeMode uint32, maxInstances uint32, outSize uint32, inSize uint32, defaultTimeout uint32, sa *syscall.SecurityAttributes) (handle syscall.Handle, err error)  [failretval==syscall.InvalidHandle] = CreateNamedPipeW
+//sys createNamedPipe(name string, flags uint32, pipeMode uint32, maxInstances uint32, outSize uint32, inSize uint32, defaultTimeout uint32, sa *securityAttributes) (handle syscall.Handle, err error)  [failretval==syscall.InvalidHandle] = CreateNamedPipeW
-//sys createFile(name string, access uint32, mode uint32, sa *syscall.SecurityAttributes, createmode uint32, attrs uint32, templatefile syscall.Handle) (handle syscall.Handle, err error) [failretval==syscall.InvalidHandle] = CreateFileW
+//sys createFile(name string, access uint32, mode uint32, sa *securityAttributes, createmode uint32, attrs uint32, templatefile syscall.Handle) (handle syscall.Handle, err error) [failretval==syscall.InvalidHandle] = CreateFileW
 //sys waitNamedPipe(name string, timeout uint32) (err error) = WaitNamedPipeW
-//sys convertStringSecurityDescriptorToSecurityDescriptor(str string, revision uint32, sd *uintptr, size *uint32) (err error) = advapi32.ConvertStringSecurityDescriptorToSecurityDescriptorW
+
-//sys localFree(mem uintptr) = LocalFree
+type securityAttributes struct {
+	Length             uint32
+	SecurityDescriptor *byte
+	InheritHandle      uint32
+}
 
 const (
 	cERROR_PIPE_BUSY      = syscall.Errno(231)
@@ -127,31 +131,23 @@ type acceptResponse struct {
 type win32PipeListener struct {
 	firstHandle        syscall.Handle
 	path               string
-	securityDescriptor string
+	securityDescriptor []byte
 	acceptCh           chan (chan acceptResponse)
 	closeCh            chan int
 	doneCh             chan int
 }
 
-func makeServerPipeHandle(path, securityDescriptor string, first bool) (syscall.Handle, error) {
+func makeServerPipeHandle(path string, securityDescriptor []byte, first bool) (syscall.Handle, error) {
 	var flags uint32 = cPIPE_ACCESS_DUPLEX | syscall.FILE_FLAG_OVERLAPPED
 	if first {
 		flags |= cFILE_FLAG_FIRST_PIPE_INSTANCE
 	}
-	var sd uintptr
+	var sa securityAttributes
-	if securityDescriptor != "" {
-		err := convertStringSecurityDescriptorToSecurityDescriptor(securityDescriptor, 1, &sd, nil)
-		if err != nil {
-			return 0, err
-		}
-	}
-	var sa syscall.SecurityAttributes
 	sa.Length = uint32(unsafe.Sizeof(sa))
-	sa.SecurityDescriptor = sd
+	if securityDescriptor != nil {
-	h, err := createNamedPipe(path, flags, cPIPE_REJECT_REMOTE_CLIENTS, cPIPE_UNLIMITED_INSTANCES, 4096, 4096, 0, &sa)
+		sa.SecurityDescriptor = &securityDescriptor[0]
-	if sd != 0 {
-		localFree(sd)
 	}
+	h, err := createNamedPipe(path, flags, cPIPE_REJECT_REMOTE_CLIENTS, cPIPE_UNLIMITED_INSTANCES, 4096, 4096, 0, &sa)
 	if err != nil {
 		return 0, &os.PathError{"open", path, err}
 	}
@@ -211,8 +207,18 @@ func (l *win32PipeListener) listenerRoutine() {
 	close(l.doneCh)
 }
 
-func ListenPipe(path, securityDescriptor string) (net.Listener, error) {
+func ListenPipe(path, sddl string) (net.Listener, error) {
-	h, err := makeServerPipeHandle(path, securityDescriptor, true)
+	var (
+		sd  []byte
+		err error
+	)
+	if sddl != "" {
+		sd, err = sddlToSecurityDescriptor(sddl)
+		if err != nil {
+			return nil, err
+		}
+	}
+	h, err := makeServerPipeHandle(path, sd, true)
 	if err != nil {
 		return nil, err
 	}
@@ -227,7 +233,7 @@ func ListenPipe(path, securityDescriptor string) (net.Listener, error) {
 	l := &win32PipeListener{
 		firstHandle:        h,
 		path:               path,
-		securityDescriptor: securityDescriptor,
+		securityDescriptor: sd,
 		acceptCh:           make(chan (chan acceptResponse)),
 		closeCh:            make(chan int),
 		doneCh:             make(chan int),

sd.go

@@ -0,0 +1,83 @@
+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 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((*[1 << 30]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, (*[1 << 30]byte)(unsafe.Pointer(sdBuffer))[:len(sd)])
+	return sd, nil
+}

sd_test.go

@@ -0,0 +1,26 @@
+package winio
+
+import "testing"
+
+func TestLookupInvalidSid(t *testing.T) {
+	_, err := LookupSidByName(".\\weoifjdsklfj")
+	aerr, ok := err.(*AccountLookupError)
+	if !ok || aerr.Err != cERROR_NONE_MAPPED {
+		t.Fatalf("expected AccountLookupError with ERROR_NONE_MAPPED, got %s", err)
+	}
+}
+
+func TestLookupValidSid(t *testing.T) {
+	sid, err := LookupSidByName("Everyone")
+	if err != nil || sid != "S-1-1-0" {
+		t.Fatal("expected S-1-1-0, got %s, %s", sid, err)
+	}
+}
+
+func TestLookupEmptyNameFails(t *testing.T) {
+	_, err := LookupSidByName(".\\weoifjdsklfj")
+	aerr, ok := err.(*AccountLookupError)
+	if !ok || aerr.Err != cERROR_NONE_MAPPED {
+		t.Fatalf("expected AccountLookupError with ERROR_NONE_MAPPED, got %s", err)
+	}
+}

syscall.go

@@ -1,3 +1,3 @@
 package winio
 
-//go:generate go run mksyscall_windows.go -output zsyscall.go file.go pipe.go
+//go:generate go run mksyscall_windows.go -output zsyscall.go file.go pipe.go sd.go

zsyscall.go

@@ -19,8 +19,11 @@ var (
 	procCreateNamedPipeW                                     = modkernel32.NewProc("CreateNamedPipeW")
 	procCreateFileW                                          = modkernel32.NewProc("CreateFileW")
 	procWaitNamedPipeW                                       = modkernel32.NewProc("WaitNamedPipeW")
+	procLookupAccountNameW                                   = modadvapi32.NewProc("LookupAccountNameW")
+	procConvertSidToStringSidW                               = modadvapi32.NewProc("ConvertSidToStringSidW")
 	procConvertStringSecurityDescriptorToSecurityDescriptorW = modadvapi32.NewProc("ConvertStringSecurityDescriptorToSecurityDescriptorW")
 	procLocalFree                                            = modkernel32.NewProc("LocalFree")
+	procGetSecurityDescriptorLength                          = modadvapi32.NewProc("GetSecurityDescriptorLength")
 )
 
 func cancelIoEx(file syscall.Handle, o *syscall.Overlapped) (err error) {
@@ -84,7 +87,7 @@ func connectNamedPipe(pipe syscall.Handle, o *syscall.Overlapped) (err error) {
 	return
 }
 
-func createNamedPipe(name string, flags uint32, pipeMode uint32, maxInstances uint32, outSize uint32, inSize uint32, defaultTimeout uint32, sa *syscall.SecurityAttributes) (handle syscall.Handle, err error) {
+func createNamedPipe(name string, flags uint32, pipeMode uint32, maxInstances uint32, outSize uint32, inSize uint32, defaultTimeout uint32, sa *securityAttributes) (handle syscall.Handle, err error) {
 	var _p0 *uint16
 	_p0, err = syscall.UTF16PtrFromString(name)
 	if err != nil {
@@ -93,7 +96,7 @@ func createNamedPipe(name string, flags uint32, pipeMode uint32, maxInstances ui
 	return _createNamedPipe(_p0, flags, pipeMode, maxInstances, outSize, inSize, defaultTimeout, sa)
 }
 
-func _createNamedPipe(name *uint16, flags uint32, pipeMode uint32, maxInstances uint32, outSize uint32, inSize uint32, defaultTimeout uint32, sa *syscall.SecurityAttributes) (handle syscall.Handle, err error) {
+func _createNamedPipe(name *uint16, flags uint32, pipeMode uint32, maxInstances uint32, outSize uint32, inSize uint32, defaultTimeout uint32, sa *securityAttributes) (handle syscall.Handle, err error) {
 	r0, _, e1 := syscall.Syscall9(procCreateNamedPipeW.Addr(), 8, uintptr(unsafe.Pointer(name)), uintptr(flags), uintptr(pipeMode), uintptr(maxInstances), uintptr(outSize), uintptr(inSize), uintptr(defaultTimeout), uintptr(unsafe.Pointer(sa)), 0)
 	handle = syscall.Handle(r0)
 	if handle == syscall.InvalidHandle {
@@ -106,7 +109,7 @@ func _createNamedPipe(name *uint16, flags uint32, pipeMode uint32, maxInstances
 	return
 }
 
-func createFile(name string, access uint32, mode uint32, sa *syscall.SecurityAttributes, createmode uint32, attrs uint32, templatefile syscall.Handle) (handle syscall.Handle, err error) {
+func createFile(name string, access uint32, mode uint32, sa *securityAttributes, createmode uint32, attrs uint32, templatefile syscall.Handle) (handle syscall.Handle, err error) {
 	var _p0 *uint16
 	_p0, err = syscall.UTF16PtrFromString(name)
 	if err != nil {
@@ -115,7 +118,7 @@ func createFile(name string, access uint32, mode uint32, sa *syscall.SecurityAtt
 	return _createFile(_p0, access, mode, sa, createmode, attrs, templatefile)
 }
 
-func _createFile(name *uint16, access uint32, mode uint32, sa *syscall.SecurityAttributes, createmode uint32, attrs uint32, templatefile syscall.Handle) (handle syscall.Handle, err error) {
+func _createFile(name *uint16, access uint32, mode uint32, sa *securityAttributes, createmode uint32, attrs uint32, templatefile syscall.Handle) (handle syscall.Handle, err error) {
 	r0, _, e1 := syscall.Syscall9(procCreateFileW.Addr(), 7, uintptr(unsafe.Pointer(name)), uintptr(access), uintptr(mode), uintptr(unsafe.Pointer(sa)), uintptr(createmode), uintptr(attrs), uintptr(templatefile), 0, 0)
 	handle = syscall.Handle(r0)
 	if handle == syscall.InvalidHandle {
@@ -149,6 +152,39 @@ func _waitNamedPipe(name *uint16, timeout uint32) (err error) {
 	return
 }
 
+func lookupAccountName(systemName *uint16, accountName string, sid *byte, sidSize *uint32, refDomain *uint16, refDomainSize *uint32, sidNameUse *uint32) (err error) {
+	var _p0 *uint16
+	_p0, err = syscall.UTF16PtrFromString(accountName)
+	if err != nil {
+		return
+	}
+	return _lookupAccountName(systemName, _p0, sid, sidSize, refDomain, refDomainSize, sidNameUse)
+}
+
+func _lookupAccountName(systemName *uint16, accountName *uint16, sid *byte, sidSize *uint32, refDomain *uint16, refDomainSize *uint32, sidNameUse *uint32) (err error) {
+	r1, _, e1 := syscall.Syscall9(procLookupAccountNameW.Addr(), 7, uintptr(unsafe.Pointer(systemName)), uintptr(unsafe.Pointer(accountName)), uintptr(unsafe.Pointer(sid)), uintptr(unsafe.Pointer(sidSize)), uintptr(unsafe.Pointer(refDomain)), uintptr(unsafe.Pointer(refDomainSize)), uintptr(unsafe.Pointer(sidNameUse)), 0, 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = error(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
+func convertSidToStringSid(sid *byte, str **uint16) (err error) {
+	r1, _, e1 := syscall.Syscall(procConvertSidToStringSidW.Addr(), 2, uintptr(unsafe.Pointer(sid)), uintptr(unsafe.Pointer(str)), 0)
+	if r1 == 0 {
+		if e1 != 0 {
+			err = error(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}
+
 func convertStringSecurityDescriptorToSecurityDescriptor(str string, revision uint32, sd *uintptr, size *uint32) (err error) {
 	var _p0 *uint16
 	_p0, err = syscall.UTF16PtrFromString(str)
@@ -174,3 +210,9 @@ func localFree(mem uintptr) {
 	syscall.Syscall(procLocalFree.Addr(), 1, uintptr(mem), 0, 0)
 	return
 }
+
+func getSecurityDescriptorLength(sd uintptr) (len uint32) {
+	r0, _, _ := syscall.Syscall(procGetSecurityDescriptorLength.Addr(), 1, uintptr(sd), 0, 0)
+	len = uint32(r0)
+	return
+}