O chionn beagan làithean, chuir mi romhpa firmware an router agam a thionndadh air ais le bhith a ’cleachdadh binwalk.
Cheannaich mi mi fhìn
Gach uair a cheannaicheas mi router ùr, bidh mi a’ stàladh
An dèidh OpenWRT a luchdachadh sìos, tha mi cuideachd
Dè th' ann am binwalk?
Air a chruthachadh ann an 2010 le Craig Heffner, faodaidh binwalk ìomhaighean firmware a sganadh agus faidhlichean a lorg, ìomhaighean siostam faidhle aithneachadh agus a thoirt a-mach, còd so-ghnìomhaichte, tasglannan teannachaidh, luchdan boot agus kernels, cruthan faidhle leithid JPEG agus PDF, agus mòran a bharrachd.
Faodaidh tu binwalk a chleachdadh gus am firmware a thionndadh air ais gus tuigsinn mar a tha e ag obair. Rannsaich faidhlichean binary airson so-leòntachd, thoir a-mach faidhlichean, agus coimhead airson backdoors no teisteanasan didseatach. Faodaidh tu cuideachd a lorg opcodes
airson dòrlach de CPUan eadar-dhealaichte.
Faodaidh tu ìomhaighean siostam faidhle a thoirt a-mach gus coimhead airson faidhlichean facal-faire sònraichte (passwd, dubhar, msaa) agus feuchainn ri hashes facal-faire a bhriseadh. Faodaidh tu parsadh binary a dhèanamh eadar dà fhaidhle no barrachd. Faodaidh tu mion-sgrùdadh entropy a dhèanamh air dàta gus coimhead airson dàta teann no iuchraichean crioptachaidh còdaichte. A h-uile càil seo gun fheum air faighinn chun chòd stòr.
San fharsaingeachd, tha a h-uile dad a dh’ fheumas tu ann :)
Ciamar a tha binwalk ag obair?
Is e prìomh fheart binwalk an sganadh ainm-sgrìobhte aige. Faodaidh Binwalk an ìomhaigh firmware a sganadh gus diofar sheòrsaichean faidhle agus siostaman faidhle a lorg.
A bheil thu eòlach air goireas loidhne-àithne 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, stripped
sgioba file
a’ coimhead air bann-cinn an fhaidhle agus a’ coimhead airson ainm-sgrìobhte (àireamh draoidheachd) gus an seòrsa faidhle a dhearbhadh. Mar eisimpleir, ma thòisicheas am faidhle leis an t-sreath de bytes 0x89 0x50 0x4E 0x47 0x0D 0x0A 0x1A 0x0A
, tha fios gur e faidhle PNG a th’ ann. Air adhart
Bidh Binwalk ag obair san aon dòigh. Ach an àite a bhith a’ coimhead airson ainmean-sgrìobhte a-mhàin aig toiseach an fhaidhle, sganaidh binwalk am faidhle gu lèir. A bharrachd air an sin, faodaidh binwalk faidhlichean a lorgar san ìomhaigh a thoirt a-mach.
Innealan file
и binwalk
an leabharlann a chleachdadh libmagic
gus ainmean-sgrìobhte faidhle a chomharrachadh. Ach binwalk
a bharrachd a’ toirt taic do liosta de ainmean-sgrìobhte draoidheachd àbhaisteach gus faidhlichean teannaichte/zipped, cinn firmware, kernels Linux, bootloaders, siostaman fhaidhlichean is mar sin air adhart a lorg.
Am bi beagan spòrs againn?
Stàladh binwalk
Tha Binwalk a’ faighinn taic air iomadh àrd-ùrlar a’ gabhail a-steach Linux, OSX, FreeBSD agus Windows.
Gus an tionndadh as ùire de binwalk a stàladh 's urrainn dhut
Tha mòran pharaimearan eadar-dhealaichte aig Binwalk:
$ 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 port
A 'sganadh dhealbhan
Feuch an tòisich sinn le bhith a’ lorg ainmean-sgrìobhte faidhle taobh a-staigh an ìomhaigh (dealbh bhon làrach
A’ ruith binwalk leis a’ pharameter --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
07:51:41
A-nis tha tòrr fiosrachaidh againn mun ìomhaigh seo.
Cleachdaidhean ìomhaigh 0x5AC0
agus ìomhaigh bootloader teann aig 0x5B00
). Stèidhichte air bann-cinn uImage aig 0x13270, tha fios againn gur e MIPS an ailtireachd pròiseasar agus is e an kernel Linux dreach 3.3.8. Agus stèidhichte air an ìomhaigh a chaidh a lorg aig an t-seòladh 0x11CEA5
, chì sinn sin rootfs
's e siostam faidhle a th' ann squashfs
.
Leig leinn a-nis an bootloader (U-Boot) a thoirt a-mach a ’cleachdadh an àithne 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/s
Leis gu bheil an ìomhaigh air a dhlùthadh le LZMA, feumaidh sinn a dhì-dhùmhlachadh:
$ unlzma u-boot.bin.lzma
A-nis tha ìomhaigh U-Boot againn:
$ ls -l u-boot.bin
-rw-rw-r-- 1 sprado sprado 97476 Fev 5 08:48 u-boot.bin
Dè mu dheidhinn an luach bunaiteach a lorg airson 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=128M
Àrainneachd U-Boot caochlaideach bootargs
air a chleachdadh gus paramadairean a chuir gu kernel Linux. Agus bho na tha gu h-àrd, tha tuigse nas fheàrr againn air cuimhne flash an inneil.
Dè mu dheidhinn a bhith a’ toirt a-mach ìomhaigh 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/s
Faodaidh sinn dèanamh cinnteach gun deach an dealbh a thoirt a-mach gu soirbheachail leis an àithne 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: 0xBB9D4F94
Tha cruth faidhle uImage gu bunaiteach na ìomhaigh kernel Linux le bann-cinn a bharrachd. Bheir sinn air falbh am bann-cinn seo gus an dealbh kernel Linux mu dheireadh fhaighinn:
$ 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/s
Tha an ìomhaigh air a dhlùthadh, mar sin leig leinn a dhì-phapadh:
$ unlzma Image.lzma
A-nis tha ìomhaigh kernel Linux againn:
$ ls -la Image
-rw-rw-r-- 1 sprado sprado 3164228 Fev 5 10:51 Image
Dè as urrainn dhuinn a dhèanamh leis an ìomhaigh kernel? Dh’ fhaodadh sinn, mar eisimpleir, sgrùdadh sreang a dhèanamh san ìomhaigh agus an dreach den kernel Linux a lorg agus ionnsachadh mun àrainneachd a thathas a’ cleachdadh airson an kernel a thogail:
$ 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 2019
Eadhon ged a chaidh am firmware a leigeil ma sgaoil an-uiridh (2019), mar a bhios mi a’ sgrìobhadh an artaigil seo tha e a’ cleachdadh seann dhreach den kernel Linux (3.3.8) a chaidh fhoillseachadh ann an 2012, air a chur ri chèile le dreach fìor sheann de GCC (4.6) cuideachd bho 2012 !
(approx. transl. a bheil earbsa agad fhathast anns na routers agad san oifis agus aig an taigh?)
Le roghainn --opcodes
faodaidh sinn cuideachd binwalk a chleachdadh gus stiùireadh inneal a sgrùdadh agus ailtireachd pròiseasar na h-ìomhaigh a dhearbhadh:
$ binwalk --opcodes Image
DECIMAL HEXADECIMAL DESCRIPTION
--------------------------------------------------------------------------------
2400 0x960 MIPS instructions, function epilogue
2572 0xA0C MIPS instructions, function epilogue
2828 0xB0C MIPS instructions, function epilogue
Dè mu dheidhinn an siostam faidhle root? An àite a bhith a 'toirt a-mach an ìomhaigh le làimh, cleachd sinn an roghainn binwalk --extract
:
$ binwalk --extract --quiet archer-c7.bin
Thèid an siostam faidhle freumh iomlan a thoirt a-mach gu fo-eòlaire:
$ 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)
---------------------------------------------------------------
A-nis is urrainn dhuinn tòrr rudan eadar-dhealaichte a dhèanamh.
Is urrainn dhuinn faidhlichean rèiteachaidh, hashes facal-faire, iuchraichean criptografach agus teisteanasan didseatach a sgrùdadh. Is urrainn dhuinn faidhlichean binary a mhion-sgrùdadh airson
Le cuideachadh bho
$ 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, zcat
Sgoinneil! Ach thoir an aire gur e dreach BusyBox 1.19.4. Is e seo dreach gu math sean de BusyBox, air fhoillseachadh sa Ghiblean 2012.
Mar sin bidh TP-Link a’ leigeil a-mach ìomhaigh firmware ann an 2019 a’ cleachdadh bathar-bog (inneal GCC, kernel, BusyBox, msaa) bho 2012!
A-nis a bheil thu a’ tuigsinn carson a bhios mi an-còmhnaidh a’ stàladh OpenWRT air na routers agam?
Chan e sin uile
Faodaidh Binwalk cuideachd mion-sgrùdadh entropy a dhèanamh, dàta entropy amh a chlò-bhualadh, agus grafaichean entropy a ghineadh. Mar as trice, bidh barrachd entropy air fhaicinn nuair a tha na bytes san ìomhaigh air thuaiream. Dh’ fhaodadh seo a bhith a’ ciallachadh gu bheil faidhle crioptaichte, dùmhlaichte no obfuscated san ìomhaigh. Iuchair crioptachaidh hardcore? Carson nach biodh.
Faodaidh sinn cuideachd am paramadair a chleachdadh --raw
gus sreath àbhaisteach byte amh a lorg ann an ìomhaigh no paramadair --hexdump
gus dump hex a dhèanamh a’ dèanamh coimeas eadar dà fhaidhle cuir a-steach no barrachd.
--magic
, no le bhith gan cur ris an eòlaire $ HOME / .config / binwalk / magic
.
Gheibh thu barrachd fiosrachaidh mu dheidhinn binwalk aig
leudachadh binwalk
Tha
import binwalk
binwalk.scan()
A’ cleachdadh an Python API faodaidh tu cuideachd a chruthachadh
Tha e cuideachd ann
Mar sin carson nach luchdaich thu sìos an ìomhaigh firmware bhon eadar-lìn agus feuch binwalk? Tha mi a' gealltainn gum bi tòrr spòrs agad :)
Source: www.habr.com