Kèk jou de sa, mwen te deside ranvèse mikrolojisyèl routeur mwen an lè l sèvi avèk binwalk.
Mwen te achte tèt mwen . Pa pi bon routeur la, men ase pou bezwen mwen yo.
Chak fwa mwen achte yon nouvo routeur, mwen enstale . Pou kisa? Kòm yon règ, manifaktirè yo pa pran swen anpil sou sipòte routeurs yo ak sou tan lojisyèl an vin demode, frajilite parèt, ak sou sa, an jeneral, ou jwenn lide a. Se poutèt sa, mwen pito OpenWRT firmwèr la, ki se byen sipòte pa kominote a sous louvri.
Èske w gen telechaje OpenWRT, mwen menm tou anba nouvo Archer C7 mwen an soti nan sit entènèt ofisyèl la ak deside analize li. Piman pou plezi ak pale sou binwalk.
Ki sa ki se binwalk?
se yon zouti sous louvri pou analiz, jeni ranvèse ak ekstraksyon imaj firmwèr.
Kreye an 2010 pa Craig Heffner, binwalk ka eskane imaj firmwèr epi jwenn dosye, idantifye ak ekstrè imaj sistèm dosye, kòd ègzèkutabl, achiv konprese, bootloaders ak nwayo, fòma dosye tankou JPEG ak PDF, ak plis ankò.
Ou ka itilize binwalk pou ranvèse enjenyè firmwèr la pou w konprann kijan li fonksyone. Chèche fichye binè pou frajilite, ekstrè fichye, epi chèche pòt dèyè oswa sètifika dijital. Ou ka jwenn tou opcodes pou yon pakèt CPU diferan.
Ou ka ekstrè imaj sistèm fichye pou chèche dosye modpas espesifik (passwd, lonbraj, elatriye) epi eseye kraze hash modpas. Ou ka fè par binè ant de oswa plis dosye. Ou ka fè analiz entropi sou done pou chèche done konprese oswa kle chifreman kode. Tout bagay sa a san yo pa bezwen jwenn aksè nan kòd sous la.
An jeneral, tout sa ou bezwen la :)
Ki jan binwalk travay?
Karakteristik prensipal binwalk se optik siyati li yo. Binwalk ka eskane imaj firmwèr la pou chèche plizyè kalite fichye ak sistèm fichye ki entegre yo.
èske w konnen sèvis piblik liy kòmand lan 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, strippedEkip filegade tèt fichye a epi chèche yon siyati (nimewo majik) pou detèmine kalite fichye a. Pou egzanp, si dosye a kòmanse ak sekans nan bytes 0x89 0x50 0x4E 0x47 0x0D 0x0A 0x1A 0x0A, li konnen se yon dosye PNG. Sou Gen yon lis siyati dosye komen.
Binwalk travay menm jan an. Men, olye pou yo chèche siyati sèlman nan kòmansman fichye a, binwalk pral eskane tout fichye a. Anplis de sa, binwalk ka ekstrè dosye yo jwenn nan imaj la.
Zouti file и binwalk sèvi ak bibliyotèk la libmagic pou idantifye siyati dosye yo. Men binwalk Anplis de sa, sipòte yon lis siyati majik koutim pou fè rechèch pou fichye konprese / konprese, headers firmwèr, nwayo Linux, bootloaders, sistèm fichye ak sou sa.
Ann pran plezi nou?
Enstalasyon Binwalk
Binwalk sipòte sou plizyè tribin tankou Linux, OSX, FreeBSD ak Windows.
Pou enstale dènye vèsyon binwalk ou kapab epi swiv oswa , disponib sou sit entènèt pwojè a.
Binwalk gen anpil paramèt diferan:
$ 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 portImaj optik
Ann kòmanse pa chèche siyati dosye andedan imaj la (imaj ki soti nan sit la ).
Kouri binwalk ak paramèt --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
07:51:41Koulye a, nou gen anpil enfòmasyon sou imaj sa a.
Imaj itilize kòm yon bootloader (header imaj nan 0x5AC0 ak yon imaj bootloader konprese nan 0x5B00). Ki baze sou header uImage nan 0x13270, nou konnen ke achitekti processeur a se MIPS ak nwayo Linux la se vèsyon 3.3.8. Epi ki baze sou imaj yo jwenn nan adrès la 0x11CEA5, nou ka wè sa rootfs se yon sistèm dosye squashfs.
Se pou nou kounye a ekstrè bootloader la (U-Boot) lè l sèvi avèk lòd la 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/sDepi imaj la konprese lè l sèvi avèk LZMA, nou bezwen dekonpresyon li:
$ unlzma u-boot.bin.lzmaKoulye a, nou gen yon imaj U-Boot:
$ ls -l u-boot.bin
-rw-rw-r-- 1 sprado sprado 97476 Fev 5 08:48 u-boot.binKouman sou jwenn valè a default pou 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 Anviwònman Varyab bootargs itilize yo pase paramèt nan nwayo Linux la. Ak soti nan pi wo a, nou gen yon pi bon konpreyansyon sou memwa a flash nan aparèy la.
Kouman sou èkstraksyon imaj nwayo Linux la?
$ 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/sNou ka tcheke ke imaj la te ekstrè avèk siksè lè l sèvi avèk lòd la 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: 0xBB9D4F94Fòma fichye uImage a se fondamantalman yon imaj nwayo Linux ak yon header adisyonèl. Ann retire tèt sa a pou jwenn imaj nwayo Linux final la:
$ 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/sImaj la konprese, kidonk ann depake li:
$ unlzma Image.lzmaKoulye a, nou gen yon imaj nwayo Linux:
$ ls -la Image
-rw-rw-r-- 1 sprado sprado 3164228 Fev 5 10:51 ImageKisa nou ka fè ak imaj nwayo a? Nou ta ka, pou egzanp, fè yon rechèch fisèl nan imaj la epi jwenn vèsyon an nan nwayo a Linux epi aprann sou anviwònman an itilize yo bati nwayo a:
$ 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 2019Menm si firmwèr la te lage ane pase a (2019), pandan m ap ekri atik sa a li ap itilize yon ansyen vèsyon kernel Linux (3.3.8) ki te pibliye an 2012, ki te konpile ak yon vèsyon trè ansyen nan GCC (4.6) tou depi 2012. !
(apeprè trad. èske w toujou fè routè w yo konfyans nan biwo a ak lakay ou?)
Avèk opsyon --opcodes nou ka itilize binwalk tou pou gade enstriksyon machin yo epi detèmine achitekti processeur imaj la:
$ binwalk --opcodes Image
DECIMAL HEXADECIMAL DESCRIPTION
--------------------------------------------------------------------------------
2400 0x960 MIPS instructions, function epilogue
2572 0xA0C MIPS instructions, function epilogue
2828 0xB0C MIPS instructions, function epilogueKi sa ki sou sistèm nan dosye rasin? Olye pou yo ekstrè imaj la manyèlman, ann itilize opsyon an binwalk --extract:
$ binwalk --extract --quiet archer-c7.binSistèm dosye rasin konplè a pral ekstrè nan yon sous-anyè:
$ 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)
---------------------------------------------------------------Koulye a, nou ka fè anpil bagay diferan.
Nou ka fè rechèch pou fichye konfigirasyon, hash modpas, kle kriptografik ak sètifika dijital. Nou ka analize dosye binè pou ak frajilite.
Avèk и nou ka menm kouri (imite) yon ègzèkutabl soti nan imaj la:
$ 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, zcatGwo! Men, tanpri sonje ke vèsyon BusyBox se 1.19.4. Sa a se yon vèsyon trè ansyen nan BusyBox, lage nan mwa avril 2012.
Se konsa, TP-Link lage yon imaj firmwèr nan 2019 lè l sèvi avèk lojisyèl (GCC toolchain, kernel, BusyBox, elatriye) soti nan 2012!
Koulye a, èske w konprann poukisa mwen toujou enstale OpenWRT sou routeurs mwen yo?
Sa se pa tout
Binwalk kapab tou fè analiz entropi, enprime done entropi anvan tout koreksyon, epi jenere graf entropi. Tipikman, yo obsève pi gwo entropi lè bytes yo nan imaj la o aza. Sa a ka vle di ke imaj la gen yon dosye chiffres, konprese, oswa obfuscated. Kle chifreman difisil? Poukisa.
Nou kapab tou itilize paramèt la --raw pou jwenn yon koutim sekans byte anvan tout koreksyon nan yon imaj oswa paramèt --hexdump pou fè yon pil fatra hex konpare de oswa plis dosye antre.
ka ajoute nan binwalk swa atravè yon dosye siyati koutim ki espesifye sou liy lòd la lè l sèvi avèk paramèt la --magic, oswa lè w ajoute yo nan anyè a $ HOME / .config / binwalk / magic.
Ou ka jwenn plis enfòmasyon sou binwalk nan .
ekstansyon binwalk
Gen binwalk, aplike kòm yon modil Python ke nenpòt script Python kapab itilize pou fè yon eskanè binwalk, epi sèvis piblik liy kòmand binwalk la ka prèske konplètman double ak jis de liy kòd Python!
import binwalk
binwalk.scan()Sèvi ak API Python ou ka kreye tou konfigirasyon ak elaji binwalk.
Tou egziste ak vèsyon nwaj .
Se konsa, poukisa ou pa telechaje imaj firmwèr la soti nan entènèt la epi eseye binwalk? Mwen pwomèt ou pral pran anpil plezi :)
Sous: www.habr.com