Lokho i-ProxyChains ekubambayo nokho ekushiyayo

I-ProxyChains-NG ayakhi umhubhe. Ilayisha kusengaphambili ilabhulali eshintsha izingcingo ze-libc ezihlobene nenethiwekhi ngaphakathi kohlelo olulodwa eluyiqalisayo, ngakho umngcele uyingcingo esesimweni, hhayi indlela yedivayisi yonke. Lowo mehluko unquma ukuthi ukuhlolwa okuphumelelayo kufakazela ini ngempela. I-curl esebenzayo ngohlu lwezingxenye iqinisekisa ingcingo eyodwa ebunjiwe, hhayi ukuthi ukuxazululwa kwamagama, i-UDP noma wonke umsua wengane zalandela indlela efanayo. Umhlahlandlela ongezansi uqinisekisa ukusabalala ngezinyathelo ezintathu, bese ubalula lokho iqhwahha engakwazi ukukufinyelela.

Indlela ukulayisha kusengaphambili okufinyelela ngayo kuxhumano

Ekuqaleni umqalisi ufaka i-libproxychains ku-LD_PRELOAD bese esebenzisa uhlelo oluhlosiwe. Ilabhulali ixazulula izimpawu zangempela ze-libc futhi izifaka esikhundleni ngezinguqulo zayo zemisebenzi efana ne-connect ne-getaddrinfo. Izingcingo ezidlula kulezo zimpawu zibhalwa kabusha ziya ku-proxy ye-SOCKS noma ye-HTTP evela kufayela lokumisa. Izingcingo ezithatha enye indlela azikaze zihlangane neqhwahha, yingakho isiqinisekiso sisebenza ngengcingo ngayinye, hhayi ngomshini wonke.

Kuhlanganyela kuphela izinhlelo ezixhunywe ngokuguquguqukayo, futhi amafayela kanambambili e-setuid ngaphansi kokusebenza okuphephile awanaki neze ukulayisha kusengaphambili. Izingane zithola indawo ezungezile njengefa, kodwa kuphela uma umqalisi eyigcina endaweni yayo.

Qinisekisa ukuthi ilabhulali ilayishiwe kuleso simo

Qala isicelo bese uhlola isimo esiphilayo esikhundleni se-shell esiqalile. Ifayela le-maps likhombisa yonke into eyabiwe emiselwe kusimo njengamanje.

proxychains4 -q curl -sS --max-time 8 https://example.com/ -o /dev/null &
pgrep -a curl
grep libproxychains /proc/$(pgrep -n curl)/maps

Ukufanisa kuqinisekisa ukuthi ilabhulali ebunjiwe ikhona, okudingekayo kodwa akwanele. Umphumela ongenalutho ngokuvamile usho ukuthi uhlole esinye isimo, isibonelo isiphequluli esanikeza i-URL kwisimo esaqalwa ngaphambi komqalisi. Ngaphambi kokujaha noma yini enye, hlola nge-ldd ukuthi ifayela kanambambili lixhunyiwe ngokuguquguqukayo, ngoba ukwakhiwa okumile akukwazi neze ukulayisha ukulayisha kusengaphambili. Bese ufunda uhlu lwama-proxy ekumiseni umqalisi awusebenzisile ngempela, ngoba indlela ephelelwe yisikhathi noma imbobo evaliwe iveza iqhwahha elisebenzayo ngaphandle kohlu olusebenzayo.

Landelela ukuxhumana okuphuma kuleso simo

Ukuba khona kwelabhulali akufakazeli ukuthi yonke ingcingo yabhalwa kabusha, ngakho landela izingcingo zesistimu. Gijimisa isicelo esisodwa ngaphansi komlandeli bese ufunda ukuthi amasokhethi aya kuphi ngempela.

strace -f -e trace=connect -o /tmp/pc.trace proxychains4 -q curl -sS https://example.com/ -o /dev/null
grep -o "sin_port=htons([0-9]*)" /tmp/pc.trace | sort -u

Umkhondo kufanele ukhombise kuphela ukuxhumana okuya endaweni yokugcina ye-proxy yakho, futhi imbobo ihambisane nokufakiwe kufayela lokumisa. Uma amakheli okufikela esizeni esihlosiwe evela ngqo kumkhondo, leyo ngcingo yeqa iqhwahha, futhi yilokho kanye okwakuyisitholakele obukufuna. Qhathanisa izinombolo zembobo nohlu lwama-proxy esikhundleni sokuthemba igama lefayela, ngoba ukumisa okusele okuvela kwelinye iphrojekthi kuwumthombo ovamile wokufinyelela okuqondile okuthule. Gcina umkhondo werekhodi lokwamukelwa; uthatha imizuzwana futhi uqeda izingxabano mayelana nokusabalala.

Nquma lokho iqhwahha elingakwazi ukukuhlanganisa

iphrojekthi ye-proxychains-ng ikhawulela ukuqondisa kabusha ku-TCP futhi ixwayisa ukuthi izikripthi, izimo zangemuva namamojula alayishiwe zingaziphatha ngendlela ehlukile kunohlelo oluyinhloko. I-UDP ne-ICMP zingaphandle kwale ndlela, ngakho noma yini ethembele kuzo idinga indlela yayo esekelwayo. I-DNS ilandela isilungiselelo se-proxy_dns nokuziphatha kwesixazululi sohlelo ngokwalo, okusho ukuthi isicelo esisodwa se-HTTPS esiphumelelayo asikutsheli lutho mayelana nokuxazululwa kwamagama. Gcina futhi ukuqinisekiswa kwesitifiketi endaweni efanele: ukufinyelela kuseva nge-proxy akusona isizathu sokucisha ukuhlolwa kobunikazi.

Uma ukubuyela emuva okuqondile kumelwe kube akunakwenzeka, sebenzisa umngcele wokuphoqelela olawula ithrafikhi ngokwayo, njengendawo yamagama yenethiwekhi, imithetho ye-firewall noma i-VPN, futhi uyigcine ihlukile kuqhwahha lelabhulali. Iqhwahha iyithuluzi lokuhambisana nohlelo oluthile, akuyona i-kill switch. Rekhoda uhlelo, umyalo oqondile, imbobo ye-proxy ebonwe kumkhondo nokuthi i-DNS yaxazululwa kude yini; lawo maqiniso amane yiwo mehluko phakathi kobubanzi obuqinisekisiwe nobubanzi bethemba.