Bir necha kun oldin men marshrutizatorimning proshivkasini binwalk yordamida teskari muhandislik qilishga qaror qildim.
Men o'zim sotib oldim . Eng yaxshi router emas, lekin mening ehtiyojlarim uchun etarli.
Har safar yangi router sotib olganimda, o'rnataman . Nima uchun? Qoida tariqasida, ishlab chiqaruvchilar o'zlarining marshrutizatorlarini qo'llab-quvvatlashga unchalik ahamiyat bermaydilar va vaqt o'tishi bilan dasturiy ta'minot eskiradi, zaifliklar paydo bo'ladi va hokazo, umuman olganda, siz fikrni olasiz. Shuning uchun men ochiq manbali hamjamiyat tomonidan yaxshi qo'llab-quvvatlanadigan OpenWRT mikrodasturini afzal ko'raman.
OpenWRT ni yuklab olib, men ham rasmiy veb-saytidan yangi Archer C7 ostida va uni tahlil qilishga qaror qildim. Faqat o'yin-kulgi uchun va binwalk haqida gapirish.
Binwalk nima?
tahlil qilish, teskari muhandislik va proshivka tasvirini olish uchun ochiq manbali vositadir.
2010-yilda Kreyg Xeffner tomonidan yaratilgan binwalk proshivka rasmlarini skanerlashi va fayllarni topishi, fayl tizimi tasvirlarini, bajariladigan kodlarni, siqilgan arxivlarni, yuklash moslamalarini va yadrolarni, JPEG va PDF kabi fayl formatlarini va boshqalarni aniqlashi va chiqarib olishi mumkin.
Mikrodastur qanday ishlashini tushunish uchun uni teskari muhandislik qilish uchun binwalk dan foydalanishingiz mumkin. Zaifliklar uchun ikkilik fayllarni qidiring, fayllarni ajratib oling va orqa eshiklar yoki raqamli sertifikatlarni qidiring. Siz ham topishingiz mumkin opcodes turli protsessorlar uchun.
Muayyan parol fayllarini (passwd, soya va boshqalar) qidirish uchun fayl tizimi tasvirlarini ajratib olishingiz va parol xeshlarini buzishga harakat qilishingiz mumkin. Ikki yoki undan ortiq fayllar o'rtasida ikkilik tahlilni amalga oshirishingiz mumkin. Siqilgan ma'lumotlar yoki kodlangan shifrlash kalitlarini qidirish uchun ma'lumotlarda entropiya tahlilini amalga oshirishingiz mumkin. Bularning barchasi manba kodiga kirishni talab qilmasdan.
Umuman olganda, sizga kerak bo'lgan hamma narsa mavjud :)
Binwalk qanday ishlaydi?
Binwalkning asosiy xususiyati uning imzosini skanerlashidir. Binwalk turli xil o'rnatilgan fayl turlari va fayl tizimlarini qidirish uchun proshivka tasvirini skanerlashi mumkin.
Buyruqlar qatori yordam dasturini bilasizmi? 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, strippedkomanda filefayl sarlavhasiga qaraydi va fayl turini aniqlash uchun imzoni (sehrli raqam) qidiradi. Misol uchun, agar fayl baytlar ketma-ketligi bilan boshlansa 0x89 0x50 0x4E 0x47 0x0D 0x0A 0x1A 0x0A, bu PNG fayl ekanligini biladi. Yoniq Umumiy fayl imzolari ro'yxati mavjud.
Binwalk xuddi shunday ishlaydi. Lekin imzolarni faqat fayl boshida qidirish o'rniga, binwalk butun faylni skanerlaydi. Bundan tashqari, binwalk tasvirda topilgan fayllarni chiqarib olishi mumkin.
asboblar file ΠΈ binwalk kutubxonadan foydalaning libmagic fayl imzolarini aniqlash uchun. Lekin binwalk qo'shimcha ravishda siqilgan/ziplangan fayllar, proshivka sarlavhalari, Linux yadrolari, yuklash moslamalari, fayl tizimlari va boshqalarni qidirish uchun maxsus sehrli imzolar ro'yxatini qo'llab-quvvatlaydi.
Keling, dam olaylikmi?
Binwalk o'rnatish
Binwalk Linux, OSX, FreeBSD va Windows kabi bir nechta platformalarda qo'llab-quvvatlanadi.
Binwalkning so'nggi versiyasini o'rnatishingiz mumkin va ergashing yoki , loyiha veb-saytida mavjud.
Binwalk juda ko'p turli xil parametrlarga ega:
$ 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 portTasvirni skanerlash
Tasvir ichidagi fayl imzolarini qidirishdan boshlaylik (saytdagi rasm ).
--signature parametri bilan binwalkni ishga tushirish:
$ 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
07:51:41Endi bu tasvir haqida juda ko'p ma'lumotlarga egamiz.
Rasmdan foydalanish yuklovchi sifatida (tasvir sarlavhasi 0x5AC0 va siqilgan bootloader tasviri 0x5B00). 0x13270 o'lchamdagi uImage sarlavhasiga asoslanib, biz bilamizki, protsessor arxitekturasi MIPS va Linux yadrosi 3.3.8 versiyasidir. Va manzilda topilgan rasmga asoslanib 0x11CEA5, buni ko'rishimiz mumkin rootfs fayl tizimi hisoblanadi squashfs.
Endi buyruq yordamida yuklash moslamasini (U-Boot) chiqaramiz 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/sRasm LZMA yordamida siqilganligi sababli, biz uni ochishimiz kerak:
$ unlzma u-boot.bin.lzmaEndi bizda U-Boot tasviri bor:
$ ls -l u-boot.bin
-rw-rw-r-- 1 sprado sprado 97476 Fev 5 08:48 u-boot.binuchun standart qiymatni topish haqida nima deyish mumkin 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=128MU-Boot muhiti o'zgaruvchisi bootargs Linux yadrosiga parametrlarni uzatish uchun ishlatiladi. Va yuqoridagilardan biz qurilmaning flesh-xotirasini yaxshiroq tushunamiz.
Linux yadrosi tasvirini chiqarish haqida nima deyish mumkin?
$ 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/sBuyruq yordamida tasvir muvaffaqiyatli chiqarilganligini tekshirishimiz mumkin 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: 0xBB9D4F94uImage fayl formati asosan qo'shimcha sarlavhali Linux yadrosi tasviridir. Yakuniy Linux yadrosi tasvirini olish uchun ushbu sarlavhani olib tashlaymiz:
$ 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/sTasvir siqilgan, shuning uchun uni ochamiz:
$ unlzma Image.lzmaEndi bizda Linux yadrosi tasviri bor:
$ ls -la Image
-rw-rw-r-- 1 sprado sprado 3164228 Fev 5 10:51 ImageYadro tasviri bilan nima qilishimiz mumkin? Biz, masalan, rasmda string qidiruvini amalga oshirishimiz va Linux yadrosi versiyasini topishimiz va yadroni yaratish uchun ishlatiladigan muhit haqida bilib olishimiz mumkin:
$ 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 2019Mikrodastur o'tgan yili (2019) chiqarilgan bo'lsa ham, men ushbu maqolani yozayotganimda u Linux yadrosining 3.3.8 yilda chiqarilgan eski versiyasidan (2012) foydalanmoqda va 4.6 yildan beri GCC (2012) ning juda eski versiyasi bilan tuzilgan. !
(taxminan tarjima. Siz hali ham ofis va uyda routerlaringizga ishonasizmi?)
Variant bilan --opcodes mashina ko'rsatmalarini qidirish va tasvirning protsessor arxitekturasini aniqlash uchun binwalk-dan ham foydalanishimiz mumkin:
$ binwalk --opcodes Image
DECIMAL HEXADECIMAL DESCRIPTION
--------------------------------------------------------------------------------
2400 0x960 MIPS instructions, function epilogue
2572 0xA0C MIPS instructions, function epilogue
2828 0xB0C MIPS instructions, function epilogueIldiz fayl tizimi haqida nima deyish mumkin? Tasvirni qo'lda chiqarish o'rniga, variantni ishlataylik binwalk --extract:
$ binwalk --extract --quiet archer-c7.binTo'liq ildiz fayl tizimi quyi katalogga chiqariladi:
$ 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)
---------------------------------------------------------------Endi biz juda ko'p turli xil narsalarni qila olamiz.
Biz konfiguratsiya fayllarini, parol xeshlarini, kriptografik kalitlarni va raqamli sertifikatlarni qidirishimiz mumkin. Biz ikkilik fayllarni tahlil qilishimiz mumkin va zaifliklar.
Yordamida ΠΈ biz hatto tasvirdan bajariladigan faylni ishga tushirishimiz (taqlid qilishimiz) mumkin:
$ 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, zcatAjoyib! BusyBox versiyasi 1.19.4 ekanligini unutmang. Bu BusyBox-ning juda eski versiyasi, 2012 yil aprel oyida chiqarilgan.
Shunday qilib, TP-Link 2019 yildan boshlab dasturiy ta'minot (GCC asboblar zanjiri, yadro, BusyBox va boshqalar) yordamida 2012 yilda proshivka tasvirini chiqaradi!
Endi tushundingizmi, nima uchun men har doim OpenWRT-ni routerlarimga o'rnataman?
Bu hali hammasi emas
Binwalk shuningdek, entropiya tahlilini amalga oshirishi, xom entropiya ma'lumotlarini chop etishi va entropiya grafiklarini yaratishi mumkin. Odatda, rasmdagi baytlar tasodifiy bo'lsa, katta entropiya kuzatiladi. Bu tasvirda shifrlangan, siqilgan yoki noaniq fayl mavjudligini anglatishi mumkin. Hardkor shifrlash kaliti? Nega yo'q.
Biz parametrdan ham foydalanishimiz mumkin --raw rasm yoki parametrda maxsus xom bayt ketma-ketligini topish uchun --hexdump ikki yoki undan ortiq kirish fayllarini taqqoslab, olti burchakli dumpni amalga oshirish uchun.
binwalk-ga parametr yordamida buyruq satrida ko'rsatilgan maxsus imzo fayli orqali qo'shilishi mumkin --magic, yoki ularni katalogga qo'shish orqali $ HOME / .config / binwalk / magic.
Binwalk haqida qo'shimcha ma'lumotni quyidagi manzilda topishingiz mumkin .
binwalk kengaytmasi
U erda binwalk, har qanday Python skripti tomonidan binwalk skanerlashni dasturiy ravishda amalga oshirish uchun ishlatilishi mumkin bo'lgan Python moduli sifatida amalga oshirilgan va binwalk buyruq qatori yordam dasturi Python kodining ikki qatori bilan deyarli to'liq takrorlanishi mumkin!
import binwalk
binwalk.scan()Python API yordamida siz ham yaratishingiz mumkin binwalkni sozlash va kengaytirish uchun.
Bundan tashqari, mavjud va bulutli versiya .
Xo'sh, nega Internetdan proshivka tasvirini yuklab olib, binwalkni sinab ko'rmaysiz? Va'da qilamanki, siz juda qiziqarli bo'lasiz :)
Manba: www.habr.com