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gitea/vendor/github.com/mholt/archiver/v3/rar.go

447 lines
12 KiB

package archiver
import (
"bytes"
"fmt"
"io"
"log"
"os"
"path"
"path/filepath"
"strings"
"time"
"github.com/nwaples/rardecode"
)
// Rar provides facilities for reading RAR archives.
// See https://www.rarlab.com/technote.htm.
type Rar struct {
// Whether to overwrite existing files; if false,
// an error is returned if the file exists.
OverwriteExisting bool
// Whether to make all the directories necessary
// to create a rar archive in the desired path.
MkdirAll bool
// A single top-level folder can be implicitly
// created by the Unarchive method if the files
// to be extracted from the archive do not all
// have a common root. This roughly mimics the
// behavior of archival tools integrated into OS
// file browsers which create a subfolder to
// avoid unexpectedly littering the destination
// folder with potentially many files, causing a
// problematic cleanup/organization situation.
// This feature is available for both creation
// and extraction of archives, but may be slightly
// inefficient with lots and lots of files,
// especially on extraction.
ImplicitTopLevelFolder bool
// Strip number of leading paths. This feature is available
// only during unpacking of the entire archive.
StripComponents int
// If true, errors encountered during reading
// or writing a single file will be logged and
// the operation will continue on remaining files.
ContinueOnError bool
// The password to open archives (optional).
Password string
rr *rardecode.Reader // underlying stream reader
rc *rardecode.ReadCloser // supports multi-volume archives (files only)
}
// CheckExt ensures the file extension matches the format.
func (*Rar) CheckExt(filename string) error {
if !strings.HasSuffix(filename, ".rar") {
return fmt.Errorf("filename must have a .rar extension")
}
return nil
}
// CheckPath ensures that the filename has not been crafted to perform path traversal attacks
func (*Rar) CheckPath(to, filename string) error {
to, _ = filepath.Abs(to) //explicit the destination folder to prevent that 'string.HasPrefix' check can be 'bypassed' when no destination folder is supplied in input
dest := filepath.Join(to, filename)
//prevent path traversal attacks
if !strings.HasPrefix(dest, to) {
return &IllegalPathError{AbsolutePath: dest, Filename: filename}
}
return nil
}
// Unarchive unpacks the .rar file at source to destination.
// Destination will be treated as a folder name. It supports
// multi-volume archives.
func (r *Rar) Unarchive(source, destination string) error {
if !fileExists(destination) && r.MkdirAll {
err := mkdir(destination, 0755)
if err != nil {
return fmt.Errorf("preparing destination: %v", err)
}
}
// if the files in the archive do not all share a common
// root, then make sure we extract to a single subfolder
// rather than potentially littering the destination...
if r.ImplicitTopLevelFolder {
var err error
destination, err = r.addTopLevelFolder(source, destination)
if err != nil {
return fmt.Errorf("scanning source archive: %v", err)
}
}
err := r.OpenFile(source)
if err != nil {
return fmt.Errorf("opening rar archive for reading: %v", err)
}
defer r.Close()
for {
err := r.unrarNext(destination)
if err == io.EOF {
break
}
if err != nil {
if r.ContinueOnError || IsIllegalPathError(err) {
log.Printf("[ERROR] Reading file in rar archive: %v", err)
continue
}
return fmt.Errorf("reading file in rar archive: %v", err)
}
}
return nil
}
// addTopLevelFolder scans the files contained inside
// the tarball named sourceArchive and returns a modified
// destination if all the files do not share the same
// top-level folder.
func (r *Rar) addTopLevelFolder(sourceArchive, destination string) (string, error) {
file, err := os.Open(sourceArchive)
if err != nil {
return "", fmt.Errorf("opening source archive: %v", err)
}
defer file.Close()
rc, err := rardecode.NewReader(file, r.Password)
if err != nil {
return "", fmt.Errorf("creating archive reader: %v", err)
}
var files []string
for {
hdr, err := rc.Next()
if err == io.EOF {
break
}
if err != nil {
return "", fmt.Errorf("scanning tarball's file listing: %v", err)
}
files = append(files, hdr.Name)
}
if multipleTopLevels(files) {
destination = filepath.Join(destination, folderNameFromFileName(sourceArchive))
}
return destination, nil
}
func (r *Rar) unrarNext(to string) error {
f, err := r.Read()
if err != nil {
return err // don't wrap error; calling loop must break on io.EOF
}
defer f.Close()
header, ok := f.Header.(*rardecode.FileHeader)
if !ok {
return fmt.Errorf("expected header to be *rardecode.FileHeader but was %T", f.Header)
}
errPath := r.CheckPath(to, header.Name)
if errPath != nil {
return fmt.Errorf("checking path traversal attempt: %v", errPath)
}
if r.StripComponents > 0 {
if strings.Count(header.Name, "/") < r.StripComponents {
return nil // skip path with fewer components
}
for i := 0; i < r.StripComponents; i++ {
slash := strings.Index(header.Name, "/")
header.Name = header.Name[slash+1:]
}
}
return r.unrarFile(f, filepath.Join(to, header.Name))
}
func (r *Rar) unrarFile(f File, to string) error {
// do not overwrite existing files, if configured
if !f.IsDir() && !r.OverwriteExisting && fileExists(to) {
return fmt.Errorf("file already exists: %s", to)
}
hdr, ok := f.Header.(*rardecode.FileHeader)
if !ok {
return fmt.Errorf("expected header to be *rardecode.FileHeader but was %T", f.Header)
}
if f.IsDir() {
if fileExists("testdata") {
err := os.Chmod(to, hdr.Mode())
if err != nil {
return fmt.Errorf("changing dir mode: %v", err)
}
} else {
err := mkdir(to, hdr.Mode())
if err != nil {
return fmt.Errorf("making directories: %v", err)
}
}
return nil
}
// if files come before their containing folders, then we must
// create their folders before writing the file
err := mkdir(filepath.Dir(to), 0755)
if err != nil {
return fmt.Errorf("making parent directories: %v", err)
}
if (hdr.Mode() & os.ModeSymlink) != 0 {
return nil
}
return writeNewFile(to, r.rr, hdr.Mode())
}
// OpenFile opens filename for reading. This method supports
// multi-volume archives, whereas Open does not (but Open
// supports any stream, not just files).
func (r *Rar) OpenFile(filename string) error {
if r.rr != nil {
return fmt.Errorf("rar archive is already open for reading")
}
var err error
r.rc, err = rardecode.OpenReader(filename, r.Password)
if err != nil {
return err
}
r.rr = &r.rc.Reader
return nil
}
// Open opens t for reading an archive from
// in. The size parameter is not used.
func (r *Rar) Open(in io.Reader, size int64) error {
if r.rr != nil {
return fmt.Errorf("rar archive is already open for reading")
}
var err error
r.rr, err = rardecode.NewReader(in, r.Password)
return err
}
// Read reads the next file from t, which must have
// already been opened for reading. If there are no
// more files, the error is io.EOF. The File must
// be closed when finished reading from it.
func (r *Rar) Read() (File, error) {
if r.rr == nil {
return File{}, fmt.Errorf("rar archive is not open")
}
hdr, err := r.rr.Next()
if err != nil {
return File{}, err // don't wrap error; preserve io.EOF
}
file := File{
FileInfo: rarFileInfo{hdr},
Header: hdr,
ReadCloser: ReadFakeCloser{r.rr},
}
return file, nil
}
// Close closes the rar archive(s) opened by Create and Open.
func (r *Rar) Close() error {
var err error
if r.rc != nil {
rc := r.rc
r.rc = nil
err = rc.Close()
}
if r.rr != nil {
r.rr = nil
}
return err
}
// Walk calls walkFn for each visited item in archive.
func (r *Rar) Walk(archive string, walkFn WalkFunc) error {
file, err := os.Open(archive)
if err != nil {
return fmt.Errorf("opening archive file: %v", err)
}
defer file.Close()
err = r.Open(file, 0)
if err != nil {
return fmt.Errorf("opening archive: %v", err)
}
defer r.Close()
for {
f, err := r.Read()
if err == io.EOF {
break
}
if err != nil {
if r.ContinueOnError {
log.Printf("[ERROR] Opening next file: %v", err)
continue
}
return fmt.Errorf("opening next file: %v", err)
}
err = walkFn(f)
if err != nil {
if err == ErrStopWalk {
break
}
if r.ContinueOnError {
log.Printf("[ERROR] Walking %s: %v", f.Name(), err)
continue
}
return fmt.Errorf("walking %s: %v", f.Name(), err)
}
}
return nil
}
// Extract extracts a single file from the rar archive.
// If the target is a directory, the entire folder will
// be extracted into destination.
func (r *Rar) Extract(source, target, destination string) error {
// target refers to a path inside the archive, which should be clean also
target = path.Clean(target)
// if the target ends up being a directory, then
// we will continue walking and extracting files
// until we are no longer within that directory
var targetDirPath string
return r.Walk(source, func(f File) error {
th, ok := f.Header.(*rardecode.FileHeader)
if !ok {
return fmt.Errorf("expected header to be *rardecode.FileHeader but was %T", f.Header)
}
// importantly, cleaning the path strips tailing slash,
// which must be appended to folders within the archive
name := path.Clean(th.Name)
if f.IsDir() && target == name {
targetDirPath = path.Dir(name)
}
if within(target, th.Name) {
// either this is the exact file we want, or is
// in the directory we want to extract
// build the filename we will extract to
end, err := filepath.Rel(targetDirPath, th.Name)
if err != nil {
return fmt.Errorf("relativizing paths: %v", err)
}
joined := filepath.Join(destination, end)
err = r.unrarFile(f, joined)
if err != nil {
return fmt.Errorf("extracting file %s: %v", th.Name, err)
}
// if our target was not a directory, stop walk
if targetDirPath == "" {
return ErrStopWalk
}
} else if targetDirPath != "" {
// finished walking the entire directory
return ErrStopWalk
}
return nil
})
}
// Match returns true if the format of file matches this
// type's format. It should not affect reader position.
func (*Rar) Match(file io.ReadSeeker) (bool, error) {
currentPos, err := file.Seek(0, io.SeekCurrent)
if err != nil {
return false, err
}
_, err = file.Seek(0, 0)
if err != nil {
return false, err
}
defer func() {
_, _ = file.Seek(currentPos, io.SeekStart)
}()
buf := make([]byte, 8)
if n, err := file.Read(buf); err != nil || n < 8 {
return false, nil
}
hasTarHeader := bytes.Equal(buf[:7], []byte("Rar!\x1a\x07\x00")) || // ver 1.5
bytes.Equal(buf, []byte("Rar!\x1a\x07\x01\x00")) // ver 5.0
return hasTarHeader, nil
}
func (r *Rar) String() string { return "rar" }
// NewRar returns a new, default instance ready to be customized and used.
func NewRar() *Rar {
return &Rar{
MkdirAll: true,
}
}
type rarFileInfo struct {
fh *rardecode.FileHeader
}
func (rfi rarFileInfo) Name() string { return rfi.fh.Name }
func (rfi rarFileInfo) Size() int64 { return rfi.fh.UnPackedSize }
func (rfi rarFileInfo) Mode() os.FileMode { return rfi.fh.Mode() }
func (rfi rarFileInfo) ModTime() time.Time { return rfi.fh.ModificationTime }
func (rfi rarFileInfo) IsDir() bool { return rfi.fh.IsDir }
func (rfi rarFileInfo) Sys() interface{} { return nil }
// Compile-time checks to ensure type implements desired interfaces.
var (
_ = Reader(new(Rar))
_ = Unarchiver(new(Rar))
_ = Walker(new(Rar))
_ = Extractor(new(Rar))
_ = Matcher(new(Rar))
_ = ExtensionChecker(new(Rar))
_ = FilenameChecker(new(Rar))
_ = os.FileInfo(rarFileInfo{})
)
// DefaultRar is a default instance that is conveniently ready to use.
var DefaultRar = NewRar()