Sababaraha dinten kapengker, kuring mutuskeun pikeun ngabalikeun insinyur firmware router kuring nganggo binwalk.
Kuring meuli sorangan . Teu router pangalusna, tapi cukup keur kaperluan kuring.
Unggal waktos abdi mésér router anyar, abdi install . Kanggo naon? Sakumaha aturan, produsén henteu paduli pisan ngeunaan ngadukung routerna sareng kana waktos parangkat lunak janten luntur, kerentanan muncul, sareng saterasna, sacara umum, anjeun nampi ideu. Ku alatan éta, kuring resep firmware OpenWRT, anu dirojong ku komunitas open-source.
Saanggeus diundeur OpenWRT, abdi oge handapeun Archer C7 anyar abdi ti ramatloka resmi sarta mutuskeun pikeun nganalisis eta. Murni keur senang jeung ngobrol ngeunaan binwalk.
Naon binwalk?
mangrupa alat open source pikeun analisis, rékayasa balik sarta ékstraksi gambar firmware.
Dijieun dina 2010 ku Craig Heffner, binwalk tiasa nyeken gambar firmware sareng milarian file, ngaidentipikasi sareng ékstrak gambar sistem file, kode anu tiasa dieksekusi, arsip anu dikomprés, bootloader sareng kernels, format file sapertos JPEG sareng PDF, sareng seueur deui.
Anjeun tiasa make binwalk pikeun ngabalikeun insinyur firmware ngartos kumaha gawéna. Pilarian file binér pikeun kerentanan, ekstrak file, sareng milarian backdoors atanapi sertipikat digital. Anjeun oge bisa manggihan opcodes pikeun kebat CPUs béda.
Anjeun tiasa ékstrak gambar filesystem pikeun néangan file sandi husus (passwd, kalangkang, jsb) jeung cobaan pikeun megatkeun hashes sandi. Anjeun tiasa ngalakukeun parsing binér antara dua atanapi langkung file. Anjeun tiasa ngalakukeun analisa éntropi kana data pikeun milarian data anu dikomprés atanapi konci énkripsi anu disandi. Sadaya ieu tanpa kedah ngaksés kode sumber.
Sacara umum, sadaya anu anjeun peryogikeun aya :)
Kumaha binwalk jalan?
Fitur utama binwalk nyaéta scanning signature na. Binwalk tiasa nyeken gambar firmware pikeun milarian rupa-rupa jinis file sareng sistem file anu diwangun.
Naha anjeun terang utilitas garis paréntah file?
file /bin/bash
/bin/bash: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/l, for GNU/Linux 3.2.0, BuildID[sha1]=12f73d7a8e226c663034529c8dd20efec22dde54, strippedregu fileSigana di lulugu file jeung néangan tanda tangan (nomer magic) pikeun nangtukeun jenis file. Contona, upami file dimimitian ku runtuyan bait 0x89 0x50 0x4E 0x47 0x0D 0x0A 0x1A 0x0A, éta terang éta file PNG. Dina Aya daptar tanda tangan file umum.
Binwalk jalan jalan anu sarua. Tapi tinimbang néangan tanda tangan ngan dina awal file, binwalk bakal nyeken sakabéh file. Salaku tambahan, binwalk tiasa nimba file anu aya dina gambar.
instrumen file и binwalk ngagunakeun perpustakaan libmagic pikeun ngaidentipikasi tanda tangan file. Tapi binwalk Sajaba ngarojong daptar tanda tangan magic custom pikeun milarian file dikomprés / zipped, lulugu firmware, kernels Linux Ubuntu, bootloaders, filesystems jeung saterusna.
Hayu urang gaduh sababaraha fun?
Pamasangan Binwalk
Binwalk dirojong dina sababaraha platform kalebet Linux, OSX, FreeBSD sareng Windows.
Pikeun masang versi panganyarna tina binwalk anjeun tiasa jeung nuturkeun atawa , sadia dina ramatloka proyék.
Binwalk gaduh seueur parameter anu béda:
$ binwalk
Binwalk v2.2.0
Craig Heffner, ReFirmLabs
https://github.com/ReFirmLabs/binwalk
Usage: binwalk [OPTIONS] [FILE1] [FILE2] [FILE3] ...
Signature Scan Options:
-B, --signature Scan target file(s) for common file signatures
-R, --raw=<str> Scan target file(s) for the specified sequence of bytes
-A, --opcodes Scan target file(s) for common executable opcode signatures
-m, --magic=<file> Specify a custom magic file to use
-b, --dumb Disable smart signature keywords
-I, --invalid Show results marked as invalid
-x, --exclude=<str> Exclude results that match <str>
-y, --include=<str> Only show results that match <str>
Extraction Options:
-e, --extract Automatically extract known file types
-D, --dd=<type:ext:cmd> Extract <type> signatures, give the files an extension of <ext>, and execute <cmd>
-M, --matryoshka Recursively scan extracted files
-d, --depth=<int> Limit matryoshka recursion depth (default: 8 levels deep)
-C, --directory=<str> Extract files/folders to a custom directory (default: current working directory)
-j, --size=<int> Limit the size of each extracted file
-n, --count=<int> Limit the number of extracted files
-r, --rm Delete carved files after extraction
-z, --carve Carve data from files, but don't execute extraction utilities
-V, --subdirs Extract into sub-directories named by the offset
Entropy Options:
-E, --entropy Calculate file entropy
-F, --fast Use faster, but less detailed, entropy analysis
-J, --save Save plot as a PNG
-Q, --nlegend Omit the legend from the entropy plot graph
-N, --nplot Do not generate an entropy plot graph
-H, --high=<float> Set the rising edge entropy trigger threshold (default: 0.95)
-L, --low=<float> Set the falling edge entropy trigger threshold (default: 0.85)
Binary Diffing Options:
-W, --hexdump Perform a hexdump / diff of a file or files
-G, --green Only show lines containing bytes that are the same among all files
-i, --red Only show lines containing bytes that are different among all files
-U, --blue Only show lines containing bytes that are different among some files
-u, --similar Only display lines that are the same between all files
-w, --terse Diff all files, but only display a hex dump of the first file
Raw Compression Options:
-X, --deflate Scan for raw deflate compression streams
-Z, --lzma Scan for raw LZMA compression streams
-P, --partial Perform a superficial, but faster, scan
-S, --stop Stop after the first result
General Options:
-l, --length=<int> Number of bytes to scan
-o, --offset=<int> Start scan at this file offset
-O, --base=<int> Add a base address to all printed offsets
-K, --block=<int> Set file block size
-g, --swap=<int> Reverse every n bytes before scanning
-f, --log=<file> Log results to file
-c, --csv Log results to file in CSV format
-t, --term Format output to fit the terminal window
-q, --quiet Suppress output to stdout
-v, --verbose Enable verbose output
-h, --help Show help output
-a, --finclude=<str> Only scan files whose names match this regex
-p, --fexclude=<str> Do not scan files whose names match this regex
-s, --status=<int> Enable the status server on the specified portPanyeken gambar
Hayu urang mimitian ku milarian tanda tangan file di jero gambar (gambar tina situs ).
Ngajalankeun binwalk kalayan parameter --signature:
$ binwalk --signature --term archer-c7.bin
DECIMAL HEXADECIMAL DESCRIPTION
------------------------------------------------------------------------------------------
21876 0x5574 U-Boot version string, "U-Boot 1.1.4-g4480d5f9-dirty (May
20 2019 - 18:45:16)"
21940 0x55B4 CRC32 polynomial table, big endian
23232 0x5AC0 uImage header, header size: 64 bytes, header CRC:
0x386C2BD5, created: 2019-05-20 10:45:17, image size:
41162 bytes, Data Address: 0x80010000, Entry Point:
0x80010000, data CRC: 0xC9CD1E38, OS: Linux, CPU: MIPS,
image type: Firmware Image, compression type: lzma, image
name: "u-boot image"
23296 0x5B00 LZMA compressed data, properties: 0x5D, dictionary size:
8388608 bytes, uncompressed size: 97476 bytes
64968 0xFDC8 XML document, version: "1.0"
78448 0x13270 uImage header, header size: 64 bytes, header CRC:
0x78A267FF, created: 2019-07-26 07:46:14, image size:
1088500 bytes, Data Address: 0x80060000, Entry Point:
0x80060000, data CRC: 0xBB9D4F94, OS: Linux, CPU: MIPS,
image type: Multi-File Image, compression type: lzma,
image name: "MIPS OpenWrt Linux-3.3.8"
78520 0x132B8 LZMA compressed data, properties: 0x6D, dictionary size:
8388608 bytes, uncompressed size: 3164228 bytes
1167013 0x11CEA5 Squashfs filesystem, little endian, version 4.0,
compression:xz, size: 14388306 bytes, 2541 inodes,
blocksize: 65536 bytes, created: 2019-07-26 07:51:38
15555328 0xED5B00 gzip compressed data, from Unix, last modified: 2019-07-26
07:51:41Ayeuna urang gaduh seueur inpormasi ngeunaan gambar ieu.
Gambar ngagunakeun salaku bootloader (header gambar di 0x5AC0 jeung gambar bootloader dikomprés di 0x5B00). Dumasar kana lulugu uImage dina 0x13270, urang terang yén arsitéktur prosésor nyaéta MIPS sareng kernel Linux mangrupikeun versi 3.3.8. Sarta dumasar kana gambar kapanggih dina alamat 0x11CEA5, urang tiasa ningali éta rootfs nyaéta sistem file squashfs.
Hayu urang ayeuna nimba bootloader (U-Boot) nganggo paréntah dd:
$ dd if=archer-c7.bin of=u-boot.bin.lzma bs=1 skip=23296 count=41162
41162+0 records in
41162+0 records out
41162 bytes (41 kB, 40 KiB) copied, 0,0939608 s, 438 kB/sKusabab gambar dikomprés nganggo LZMA, urang kedah decompress éta:
$ unlzma u-boot.bin.lzmaAyeuna urang gaduh gambar U-Boot:
$ ls -l u-boot.bin
-rw-rw-r-- 1 sprado sprado 97476 Fev 5 08:48 u-boot.binKumaha ngeunaan manggihan nilai standar pikeun bootargs?
$ strings u-boot.bin | grep bootargs
bootargs
bootargs=console=ttyS0,115200 board=AP152 rootfstype=squashfs init=/etc/preinit mtdparts=spi0.0:128k(factory-uboot),192k(u-boot),64k(ART),1536k(uImage),14464k@0x1e0000(rootfs) mem=128MVariabel Lingkungan U-Boot bootargs dipaké pikeun ngirimkeun parameter ka kernel Linux. Sarta ti luhur, urang boga pamahaman hadé tina mémori flash alat.
Kumaha upami ékstrak gambar kernel Linux?
$ dd if=archer-c7.bin of=uImage bs=1 skip=78448 count=1088572
1088572+0 records in
1088572+0 records out
1088572 bytes (1,1 MB, 1,0 MiB) copied, 1,68628 s, 646 kB/sUrang tiasa pariksa yén gambar éta hasil sasari nganggo paréntah file:
$ file uImage
uImage: u-boot legacy uImage, MIPS OpenWrt Linux-3.3.8, Linux/MIPS, Multi-File Image (lzma), 1088500 bytes, Fri Jul 26 07:46:14 2019, Load Address: 0x80060000, Entry Point: 0x80060000, Header CRC: 0x78A267FF, Data CRC: 0xBB9D4F94Format file uImage dasarna mangrupikeun gambar kernel Linux kalayan lulugu tambahan. Hayu urang hapus lulugu ieu pikeun meunangkeun gambar kernel Linux pamungkas:
$ dd if=uImage of=Image.lzma bs=1 skip=72
1088500+0 records in
1088500+0 records out
1088500 bytes (1,1 MB, 1,0 MiB) copied, 1,65603 s, 657 kB/sGambarna dikomprés, ku kituna hayu urang bongkar:
$ unlzma Image.lzmaAyeuna urang gaduh gambar kernel Linux:
$ ls -la Image
-rw-rw-r-- 1 sprado sprado 3164228 Fev 5 10:51 ImageNaon anu urang tiasa laksanakeun sareng gambar kernel? Urang tiasa, contona, milarian string dina gambar sareng milarian versi kernel Linux sareng diajar ngeunaan lingkungan anu dianggo pikeun ngawangun kernel:
$ strings Image | grep "Linux version"
Linux version 3.3.8 (leo@leo-MS-7529) (gcc version 4.6.3 20120201 (prerelease) (Linaro GCC 4.6-2012.02) ) #1 Mon May 20 18:53:02 CST 2019Sanaos firmware dileupaskeun taun ka tukang (2019), nalika kuring nyerat tulisan ieu, éta ngagunakeun vérsi lami tina kernel Linux (3.3.8) dileupaskeun taun 2012, disusun sareng versi GCC (4.6) anu lami pisan ti taun 2012. !
(approx. transl. Naha anjeun masih percanten ka router anjeun di kantor sareng di bumi?)
Kalawan pilihan --opcodes urang ogé tiasa nganggo binwalk pikeun milarian petunjuk mesin sareng nangtukeun arsitektur prosesor gambar:
$ binwalk --opcodes Image
DECIMAL HEXADECIMAL DESCRIPTION
--------------------------------------------------------------------------------
2400 0x960 MIPS instructions, function epilogue
2572 0xA0C MIPS instructions, function epilogue
2828 0xB0C MIPS instructions, function epilogueKumaha upami sistem file root? Gantina nimba gambar sacara manual, hayu urang nganggo pilihan binwalk --extract:
$ binwalk --extract --quiet archer-c7.binSistem file akar lengkep bakal diekstrak kana subdirektori:
$ cd _archer-c7.bin.extracted/squashfs-root/
$ ls
bin dev etc lib mnt overlay proc rom root sbin sys tmp usr var www
$ cat etc/banner
MM NM MMMMMMM M M
$MMMMM MMMMM MMMMMMMMMMM MMM MMM
MMMMMMMM MM MMMMM. MMMMM:MMMMMM: MMMM MMMMM
MMMM= MMMMMM MMM MMMM MMMMM MMMM MMMMMM MMMM MMMMM'
MMMM= MMMMM MMMM MM MMMMM MMMM MMMM MMMMNMMMMM
MMMM= MMMM MMMMM MMMMM MMMM MMMM MMMMMMMM
MMMM= MMMM MMMMMM MMMMM MMMM MMMM MMMMMMMMM
MMMM= MMMM MMMMM, NMMMMMMMM MMMM MMMM MMMMMMMMMMM
MMMM= MMMM MMMMMM MMMMMMMM MMMM MMMM MMMM MMMMMM
MMMM= MMMM MM MMMM MMMM MMMM MMMM MMMM MMMM
MMMM$ ,MMMMM MMMMM MMMM MMM MMMM MMMMM MMMM MMMM
MMMMMMM: MMMMMMM M MMMMMMMMMMMM MMMMMMM MMMMMMM
MMMMMM MMMMN M MMMMMMMMM MMMM MMMM
MMMM M MMMMMMM M M
M
---------------------------------------------------------------
For those about to rock... (%C, %R)
---------------------------------------------------------------Ayeuna urang tiasa ngalakukeun seueur hal anu béda.
Urang tiasa milarian file konfigurasi, hashes sandi, konci kriptografi sareng sertipikat digital. Urang tiasa nganalisis file binér pikeun jeung vulnerabilities.
jeung и urang malah bisa ngajalankeun (emulate) hiji laksana tina gambar:
$ ls
bin dev etc lib mnt overlay proc rom root sbin sys tmp usr var www
$ cp /usr/bin/qemu-mips-static .
$ sudo chroot . ./qemu-mips-static bin/busybox
BusyBox v1.19.4 (2019-05-20 18:13:49 CST) multi-call binary.
Copyright (C) 1998-2011 Erik Andersen, Rob Landley, Denys Vlasenko
and others. Licensed under GPLv2.
See source distribution for full notice.
Usage: busybox [function] [arguments]...
or: busybox --list[-full]
or: function [arguments]...
BusyBox is a multi-call binary that combines many common Unix
utilities into a single executable. Most people will create a
link to busybox for each function they wish to use and BusyBox
will act like whatever it was invoked as.
Currently defined functions:
[, [[, addgroup, adduser, arping, ash, awk, basename, cat, chgrp, chmod, chown, chroot, clear, cmp, cp, crond, crontab, cut, date, dd, delgroup, deluser, dirname, dmesg, echo, egrep, env, expr, false,
fgrep, find, free, fsync, grep, gunzip, gzip, halt, head, hexdump, hostid, id, ifconfig, init, insmod, kill, killall, klogd, ln, lock, logger, ls, lsmod, mac_addr, md5sum, mkdir, mkfifo, mknod, mktemp,
mount, mv, nice, passwd, pgrep, pidof, ping, ping6, pivot_root, poweroff, printf, ps, pwd, readlink, reboot, reset, rm, rmdir, rmmod, route, sed, seq, sh, sleep, sort, start-stop-daemon, strings,
switch_root, sync, sysctl, tail, tar, tee, telnet, test, tftp, time, top, touch, tr, traceroute, true, udhcpc, umount, uname, uniq, uptime, vconfig, vi, watchdog, wc, wget, which, xargs, yes, zcatHebat! Tapi perhatikeun yén versi BusyBox nyaéta 1.19.4. Ieu mangrupikeun versi BusyBox anu lami pisan, dirilis dina April 2012.
Janten TP-Link ngaluarkeun gambar firmware dina 2019 nganggo parangkat lunak (GCC toolchain, kernel, BusyBox, jsb.) ti 2012!
Ayeuna anjeun ngartos naha kuring sok masang OpenWRT dina router kuring?
Henteu ngan éta
Binwalk ogé tiasa ngalakukeun analisa éntropi, nyitak data éntropi atah, sareng ngahasilkeun grafik éntropi. Ilaharna, éntropi gedé dititénan nalika bait dina gambar acak. Ieu tiasa hartosna yén gambar éta ngandung file anu énkripsi, dikomprés, atanapi obfuscated. Konci énkripsi hardcore? Naha henteu.
Urang ogé tiasa nganggo parameter --raw pikeun manggihan runtuyan bait baku custom dina gambar atawa parameter --hexdump pikeun ngalakukeun dump hex ngabandingkeun dua atawa leuwih file input.
bisa ditambahkeun kana binwalk boh ngaliwatan file signature custom dieusian dina garis paréntah ngagunakeun parameter --magic, atanapi ku cara nambihanana kana diréktori $ HOME / .config / binwalk / magic.
Anjeun tiasa mendakan langkung seueur inpormasi ngeunaan binwalk di .
ekstensi binwalk
di ditu binwalk, dilaksanakeun salaku modul Python nu bisa dipaké ku sagala Aksara Python pikeun programmatically nedunan scan binwalk, sarta utiliti garis paréntah binwalk bisa ampir sakabéhna duplicated kalawan ngan dua garis kode Python!
import binwalk
binwalk.scan()Ngagunakeun Python API Anjeun ogé bisa nyieun pikeun ngonpigurasikeun tur dilegakeun binwalk.
Aya ogé jeung versi awan .
Janten naha anjeun henteu ngaunduh gambar firmware tina Internét sareng cobian binwalk? Kuring janji anjeun bakal boga loba senang :)
sumber: www.habr.com