windows: add resource extraction functions

These functions make it possible to read executable resource information
at runtime.

Change-Id: I00f260199ecda8daeb3417eaa9c02198663063b7
Reviewed-on: https://go-review.googlesource.com/c/sys/+/298173
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Trust: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>

windows/syscall_windows.go

@@ -9,6 +9,7 @@ package windows
 import (
 	errorspkg "errors"
 	"fmt"
+	"runtime"
 	"sync"
 	"syscall"
 	"time"
@@ -384,6 +385,10 @@ func NewCallbackCDecl(fn interface{}) uintptr {
 //sys	getThreadPreferredUILanguages(flags uint32, numLanguages *uint32, buf *uint16, bufSize *uint32) (err error) = kernel32.GetThreadPreferredUILanguages
 //sys	getUserPreferredUILanguages(flags uint32, numLanguages *uint32, buf *uint16, bufSize *uint32) (err error) = kernel32.GetUserPreferredUILanguages
 //sys	getSystemPreferredUILanguages(flags uint32, numLanguages *uint32, buf *uint16, bufSize *uint32) (err error) = kernel32.GetSystemPreferredUILanguages
+//sys	findResource(module Handle, name uintptr, resType uintptr) (resInfo Handle, err error) = kernel32.FindResourceW
+//sys	SizeofResource(module Handle, resInfo Handle) (size uint32, err error) = kernel32.SizeofResource
+//sys	LoadResource(module Handle, resInfo Handle) (resData Handle, err error) = kernel32.LoadResource
+//sys	LockResource(resData Handle) (addr uintptr, err error) = kernel32.LockResource
 
 // Process Status API (PSAPI)
 //sys	EnumProcesses(processIds []uint32, bytesReturned *uint32) (err error) = psapi.EnumProcesses
@@ -1578,3 +1583,55 @@ func (s *UNICODE_STRING) Slice() []uint16 {
 func (s *UNICODE_STRING) String() string {
 	return UTF16ToString(s.Slice())
 }
+
+// FindResource resolves a resource of the given name and resource type.
+func FindResource(module Handle, name, resType ResourceIDOrString) (Handle, error) {
+	var namePtr, resTypePtr uintptr
+	var name16, resType16 *uint16
+	var err error
+	resolvePtr := func(i interface{}, keep **uint16) (uintptr, error) {
+		switch v := i.(type) {
+		case string:
+			*keep, err = UTF16PtrFromString(v)
+			if err != nil {
+				return 0, err
+			}
+			return uintptr(unsafe.Pointer(*keep)), nil
+		case ResourceID:
+			return uintptr(v), nil
+		}
+		return 0, errorspkg.New("parameter must be a ResourceID or a string")
+	}
+	namePtr, err = resolvePtr(name, &name16)
+	if err != nil {
+		return 0, err
+	}
+	resTypePtr, err = resolvePtr(resType, &resType16)
+	if err != nil {
+		return 0, err
+	}
+	resInfo, err := findResource(module, namePtr, resTypePtr)
+	runtime.KeepAlive(name16)
+	runtime.KeepAlive(resType16)
+	return resInfo, err
+}
+
+func LoadResourceData(module, resInfo Handle) (data []byte, err error) {
+	size, err := SizeofResource(module, resInfo)
+	if err != nil {
+		return
+	}
+	resData, err := LoadResource(module, resInfo)
+	if err != nil {
+		return
+	}
+	ptr, err := LockResource(resData)
+	if err != nil {
+		return
+	}
+	h := (*unsafeheader.Slice)(unsafe.Pointer(&data))
+	h.Data = unsafe.Pointer(ptr)
+	h.Len = int(size)
+	h.Cap = int(size)
+	return
+}

windows/syscall_windows_test.go

@@ -5,6 +5,7 @@
 package windows_test
 
 import (
+	"bytes"
 	"debug/pe"
 	"errors"
 	"fmt"
@@ -562,3 +563,26 @@ func TestPEBFilePath(t *testing.T) {
 		t.Errorf("expected os.Executable() to return same value as peb.Ldr.{entry}.FullDllName - want %#q; got %#q", osPath, pebPath)
 	}
 }
+
+func TestResourceExtraction(t *testing.T) {
+	system32, err := windows.GetSystemDirectory()
+	if err != nil {
+		t.Errorf("unable to find system32 directory: %v", err)
+	}
+	cmd, err := windows.LoadLibrary(filepath.Join(system32, "cmd.exe"))
+	if err != nil {
+		t.Errorf("unable to load cmd.exe: %v", err)
+	}
+	defer windows.FreeLibrary(cmd)
+	rsrc, err := windows.FindResource(cmd, windows.CREATEPROCESS_MANIFEST_RESOURCE_ID, windows.RT_MANIFEST)
+	if err != nil {
+		t.Errorf("unable to find cmd.exe manifest resource: %v", err)
+	}
+	manifest, err := windows.LoadResourceData(cmd, rsrc)
+	if err != nil {
+		t.Errorf("unable to load cmd.exe manifest resource data: %v", err)
+	}
+	if !bytes.Contains(manifest, []byte("</assembly>")) {
+		t.Errorf("did not find </assembly> in manifest")
+	}
+}

windows/types_windows.go

@@ -2600,3 +2600,45 @@ const (
 	SECURITY_SQOS_PRESENT     = 0x100000
 	SECURITY_VALID_SQOS_FLAGS = 0x1f0000
 )
+
+// ResourceID represents a 16-bit resource identifier, traditionally created with the MAKEINTRESOURCE macro.
+type ResourceID uint16
+
+// ResourceIDOrString must be either a ResourceID, to specify a resource or resource type by ID,
+// or a string, to specify a resource or resource type by name.
+type ResourceIDOrString interface{}
+
+// Predefined resource names and types.
+var (
+	// Predefined names.
+	CREATEPROCESS_MANIFEST_RESOURCE_ID                 ResourceID = 1
+	ISOLATIONAWARE_MANIFEST_RESOURCE_ID                ResourceID = 2
+	ISOLATIONAWARE_NOSTATICIMPORT_MANIFEST_RESOURCE_ID ResourceID = 3
+	ISOLATIONPOLICY_MANIFEST_RESOURCE_ID               ResourceID = 4
+	ISOLATIONPOLICY_BROWSER_MANIFEST_RESOURCE_ID       ResourceID = 5
+	MINIMUM_RESERVED_MANIFEST_RESOURCE_ID              ResourceID = 1  // inclusive
+	MAXIMUM_RESERVED_MANIFEST_RESOURCE_ID              ResourceID = 16 // inclusive
+
+	// Predefined types.
+	RT_CURSOR       ResourceID = 1
+	RT_BITMAP       ResourceID = 2
+	RT_ICON         ResourceID = 3
+	RT_MENU         ResourceID = 4
+	RT_DIALOG       ResourceID = 5
+	RT_STRING       ResourceID = 6
+	RT_FONTDIR      ResourceID = 7
+	RT_FONT         ResourceID = 8
+	RT_ACCELERATOR  ResourceID = 9
+	RT_RCDATA       ResourceID = 10
+	RT_MESSAGETABLE ResourceID = 11
+	RT_GROUP_CURSOR ResourceID = 12
+	RT_GROUP_ICON   ResourceID = 14
+	RT_VERSION      ResourceID = 16
+	RT_DLGINCLUDE   ResourceID = 17
+	RT_PLUGPLAY     ResourceID = 19
+	RT_VXD          ResourceID = 20
+	RT_ANICURSOR    ResourceID = 21
+	RT_ANIICON      ResourceID = 22
+	RT_HTML         ResourceID = 23
+	RT_MANIFEST     ResourceID = 24
+)

windows/zsyscall_windows.go

@@ -205,6 +205,7 @@ var (
 	procFindNextFileW                                        = modkernel32.NewProc("FindNextFileW")
 	procFindNextVolumeMountPointW                            = modkernel32.NewProc("FindNextVolumeMountPointW")
 	procFindNextVolumeW                                      = modkernel32.NewProc("FindNextVolumeW")
+	procFindResourceW                                        = modkernel32.NewProc("FindResourceW")
 	procFindVolumeClose                                      = modkernel32.NewProc("FindVolumeClose")
 	procFindVolumeMountPointClose                            = modkernel32.NewProc("FindVolumeMountPointClose")
 	procFlushFileBuffers                                     = modkernel32.NewProc("FlushFileBuffers")
@@ -277,9 +278,11 @@ var (
 	procIsWow64Process2                                      = modkernel32.NewProc("IsWow64Process2")
 	procLoadLibraryExW                                       = modkernel32.NewProc("LoadLibraryExW")
 	procLoadLibraryW                                         = modkernel32.NewProc("LoadLibraryW")
+	procLoadResource                                         = modkernel32.NewProc("LoadResource")
 	procLocalAlloc                                           = modkernel32.NewProc("LocalAlloc")
 	procLocalFree                                            = modkernel32.NewProc("LocalFree")
 	procLockFileEx                                           = modkernel32.NewProc("LockFileEx")
+	procLockResource                                         = modkernel32.NewProc("LockResource")
 	procMapViewOfFile                                        = modkernel32.NewProc("MapViewOfFile")
 	procMoveFileExW                                          = modkernel32.NewProc("MoveFileExW")
 	procMoveFileW                                            = modkernel32.NewProc("MoveFileW")
@@ -326,6 +329,7 @@ var (
 	procSetStdHandle                                         = modkernel32.NewProc("SetStdHandle")
 	procSetVolumeLabelW                                      = modkernel32.NewProc("SetVolumeLabelW")
 	procSetVolumeMountPointW                                 = modkernel32.NewProc("SetVolumeMountPointW")
+	procSizeofResource                                       = modkernel32.NewProc("SizeofResource")
 	procSleepEx                                              = modkernel32.NewProc("SleepEx")
 	procTerminateJobObject                                   = modkernel32.NewProc("TerminateJobObject")
 	procTerminateProcess                                     = modkernel32.NewProc("TerminateProcess")
@@ -1747,6 +1751,15 @@ func FindNextVolume(findVolume Handle, volumeName *uint16, bufferLength uint32)
 	return
 }
 
+func findResource(module Handle, name uintptr, resType uintptr) (resInfo Handle, err error) {
+	r0, _, e1 := syscall.Syscall(procFindResourceW.Addr(), 3, uintptr(module), uintptr(name), uintptr(resType))
+	resInfo = Handle(r0)
+	if resInfo == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
 func FindVolumeClose(findVolume Handle) (err error) {
 	r1, _, e1 := syscall.Syscall(procFindVolumeClose.Addr(), 1, uintptr(findVolume), 0, 0)
 	if r1 == 0 {
@@ -2371,6 +2384,15 @@ func _LoadLibrary(libname *uint16) (handle Handle, err error) {
 	return
 }
 
+func LoadResource(module Handle, resInfo Handle) (resData Handle, err error) {
+	r0, _, e1 := syscall.Syscall(procLoadResource.Addr(), 2, uintptr(module), uintptr(resInfo), 0)
+	resData = Handle(r0)
+	if resData == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
 func LocalAlloc(flags uint32, length uint32) (ptr uintptr, err error) {
 	r0, _, e1 := syscall.Syscall(procLocalAlloc.Addr(), 2, uintptr(flags), uintptr(length), 0)
 	ptr = uintptr(r0)
@@ -2397,6 +2419,15 @@ func LockFileEx(file Handle, flags uint32, reserved uint32, bytesLow uint32, byt
 	return
 }
 
+func LockResource(resData Handle) (addr uintptr, err error) {
+	r0, _, e1 := syscall.Syscall(procLockResource.Addr(), 1, uintptr(resData), 0, 0)
+	addr = uintptr(r0)
+	if addr == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
 func MapViewOfFile(handle Handle, access uint32, offsetHigh uint32, offsetLow uint32, length uintptr) (addr uintptr, err error) {
 	r0, _, e1 := syscall.Syscall6(procMapViewOfFile.Addr(), 5, uintptr(handle), uintptr(access), uintptr(offsetHigh), uintptr(offsetLow), uintptr(length), 0)
 	addr = uintptr(r0)
@@ -2810,6 +2841,15 @@ func SetVolumeMountPoint(volumeMountPoint *uint16, volumeName *uint16) (err erro
 	return
 }
 
+func SizeofResource(module Handle, resInfo Handle) (size uint32, err error) {
+	r0, _, e1 := syscall.Syscall(procSizeofResource.Addr(), 2, uintptr(module), uintptr(resInfo), 0)
+	size = uint32(r0)
+	if size == 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
 func SleepEx(milliseconds uint32, alertable bool) (ret uint32) {
 	var _p0 uint32
 	if alertable {