xtractr

xtractr with zip bombs protection :)

Here you can read a bit about zip bombs:

• Kaspersky IT Encyclopedia
• Some research about non-recursive bombs

Go Library for Queuing and Extracting ZIP, RAR, GZ, BZ2, TAR, TGZ, TBZ2, 7Z, ISO files. Can also be used ad-hoc for direct decompression and extraction. See docs.

• GoDoc
• Works on Linux, Windows, FreeBSD and macOS without Cgo.
• Supports 32 and 64 bit architectures.
• Decrypts RAR and 7-Zip archives with passwords.

Interface

This library provides a queue, and a common interface to extract files. It does not do the heavy lifting, and relies on these libraries to extract files:

• RAR: nwaples/rardecode
• 7-Zip: bodgit/sevenzip
• ISO: kdomanski/iso9660

Zip, Gzip, Tar and Bzip are all handled by the standard Go library.

Examples

Example 1 - Queue

package main

import (
	"log"
	"os"
	"strings"

	"golift.io/xtractr"
)

// Logger satisfies the xtractr.Logger interface.
type Logger struct {
	xtractr *log.Logger
	debug   *log.Logger
	info    *log.Logger
}

// Printf satisfies the xtractr.Logger interface.
func (l *Logger) Printf(msg string, v ...interface{}) {
	l.xtractr.Printf(msg, v...)
}

// Debug satisfies the xtractr.Logger interface.
func (l *Logger) Debugf(msg string, v ...interface{}) {
	l.debug.Printf(msg, v...)
}

// Infof printf an info line.
func (l *Logger) Infof(msg string, v ...interface{}) {
	l.info.Printf(msg, v...)
}

func main() {
	log := &Logger{
		xtractr: log.New(os.Stdout, "[XTRACTR] ", 0),
		debug:   log.New(os.Stdout, "[DEBUG] ", 0),
		info:    log.New(os.Stdout, "[INFO] ", 0),
	}
	q := xtractr.NewQueue(&xtractr.Config{
		Suffix:   "_xtractd",
		Logger:   log,
		Parallel: 1,
		FileMode: 0644, // ignored for tar files.
		DirMode:  0755,
	})
	defer q.Stop() // Stop() waits until all extractions finish.

	response := make(chan *xtractr.Response)
	// This sends an item into the extraction queue (buffered channel).
	q.Extract(&xtractr.Xtract{
		Name:       "my archive",    // name is not import to this library.
		SearchPath: "/tmp/archives", // can also be a direct file.
		CBChannel:  response,        // queue responses are sent here.
	})

	// Queue always sends two responses. 1 on start and again when finished (error or not)
	resp := <-response
	log.Infof("Extraction started: %s", strings.Join(resp.Archives, ", "))

	resp = <-response
	if resp.Error != nil {
		// There is possibly more data in the response that is useful even on error.
		// ie you may want to cleanup any partial extraction.
		log.Printf("Error: %v", resp.Error)
	}

	log.Infof("Extracted Files:\n - %s", strings.Join(resp.NewFiles, "\n - "))
}

Example 2 - Direct

This example shows ExtractFile() with a very simple XFile. You can choose output path, as well as file and dir modes. Failing to provide OutputDir results in unexpected behavior. ExtractFile() attempts to identify the type of file. If you know the file type you may call the direct method instead:

• ExtractZIP(*XFile)
• ExtractRAR(*XFile)
• ExtractTar(*XFile)
• ExtractGzip(*XFile)
• ExtractBzip(*XFile)
• ExtractTarGzip(*XFile)
• ExtractTarBzip(*XFile)
• Extract7z(*XFile)

package main

import (
	"log"
	"strings"

	"golift.io/xtractr"
)

func main() {
	x := &xtractr.XFile{
		FilePath:  "/tmp/myfile.zip",
		OutputDir: "/tmp/myfile", // do not forget this.
	}

	// size is how many bytes were written.
	// files may be nil, but will contain any files written (even with an error).
	size, files, err := xtractr.ExtractFile(x)
	if err != nil || files == nil {
		log.Fatal(size, files, err)
	}

	log.Println("Bytes written:", size, "Files Extracted:\n -", strings.Join(files, "\n -"))
}

This is what XFile looks like (today at least):

// XFile defines the data needed to extract an archive.
type XFile struct {
	FilePath  string      // Path to archive being extracted.
	OutputDir string      // Folder to extract archive into.
	FileMode  os.FileMode // Write files with this mode.
	DirMode   os.FileMode // Write folders with this mode.
	Password  string      // (RAR/7z) Archive password. Blank for none.
}