Batun intanet wani lamari ne da ke ƙara zama mahimmanci a duniya. Wannan yana haifar da karuwar "kasar makamai" yayin da hukumomin gwamnati da kamfanoni masu zaman kansu a kasashe daban-daban ke neman toshe abubuwan da ke ciki daban-daban da kuma gwagwarmaya tare da hanyoyin da za a bi don kauce wa irin wannan ƙuntatawa, yayin da masu haɓakawa da masu bincike ke ƙoƙarin ƙirƙirar kayan aiki masu inganci don yaƙar sa ido.
Masana kimiyya daga Carnegie Mellon, Jami'ar Stanford da SRI International jami'o'i sun gudanar , a lokacin da suka ɓullo da sabis na musamman don rufe amfani da Tor, daya daga cikin shahararrun kayan aikin da ke kewaye da shinge. Mun gabatar muku da labari game da ayyukan da masu binciken suka yi.
Tor na hana toshewa
Tor yana tabbatar da ɓoye sunayen masu amfani ta hanyar amfani da relays na musamman - wato, sabar tsaka-tsaki tsakanin mai amfani da shafin da yake buƙata. Yawanci, da yawa relays suna samuwa a tsakanin mai amfani da shafin, wanda kowannensu zai iya ɓata ƙananan adadin bayanai a cikin fakitin da aka tura - kawai isa don gano batu na gaba a cikin sarkar kuma aika shi a can. Sakamakon haka, ko da an ƙara relay ɗin da maharan ke sarrafawa a cikin sarkar, ba za su iya gano ma'aikacin adireshin da inda aka nufa ba.
Tor yana aiki yadda ya kamata a matsayin kayan aikin hana cece-kuce, amma masu tace bayanai har yanzu suna da ikon toshe shi gaba daya. Iran da China sun yi nasarar dakile yakin neman zabe. Sun sami damar gano zirga-zirgar zirga-zirgar Tor ta hanyar bincikar musabaha na TLS da sauran fitattun halayen Tor.
Daga baya, masu haɓakawa sun sami damar daidaita tsarin don ƙetare toshewa. Censors sun amsa ta hanyar toshe haɗin HTTPS zuwa shafuka daban-daban, gami da Tor. Masu haɓaka aikin sun ƙirƙiri shirin obfsproxy, wanda kuma yana ɓoye zirga-zirga. Ana ci gaba da wannan gasa a koyaushe.
Bayanan farko na gwajin
Masu binciken sun yanke shawarar samar da wani kayan aiki wanda zai rufe amfani da Tor, wanda zai iya yin amfani da shi har ma a yankunan da tsarin ya toshe gaba daya.
- Kamar yadda zato na farko, masana kimiyya sun gabatar da abubuwa masu zuwa:
- Tace censor tana sarrafa keɓantaccen ɓangaren cibiyar sadarwar, wanda ke haɗa zuwa Intanet na waje, mara ƙima.
- Hukumomin toshewa suna sarrafa duk kayan aikin cibiyar sadarwa a cikin sashin cibiyar sadarwar da aka tantance, amma ba software akan kwamfutocin masu amfani da ƙarshen ba.
- Mai binciken yana neman hana masu amfani damar samun damar abubuwan da ba a so daga ra'ayinsa; ana tsammanin cewa duk irin waɗannan kayan suna cikin sabar a waje da sashin cibiyar sadarwa mai sarrafawa.
- Masu ba da hanya tsakanin hanyoyin sadarwa na wannan yanki suna nazarin bayanan da ba a ɓoye ba na duk fakiti don toshe abubuwan da ba a so da kuma hana fakiti masu dacewa shiga kewayen.
- Duk relays Tor suna waje da kewaye.
Ta yaya wannan aikin
Don ɓoye amfani da Tor, masu bincike sun ƙirƙiri kayan aikin StegoTorus. Babban burinsa shine haɓaka ikon Tor don tsayayya da nazarin yarjejeniya ta atomatik. Kayan aikin yana tsakanin abokin ciniki da na farko a cikin sarkar, yana amfani da ka'idar ɓoyewar kansa da kuma kayan aikin steganography don yin wahalar gano zirga-zirgar Tor.
A mataki na farko, tsarin da ake kira chopper ya zo cikin wasa - yana canza zirga-zirga zuwa jerin tubalan tsayi daban-daban, wanda aka aika ba tare da tsari ba.
An rufaffen bayanai ta amfani da AES a yanayin GCM. Kan katanga ya ƙunshi lambar jeri 32-bit, filaye masu tsayi biyu (d da p) - waɗannan suna nuna adadin bayanai, filin F na musamman da filin dubawa 56-bit, wanda ƙimarsa dole ne ya zama sifili. Matsakaicin tsayin toshe shine 32 bytes, kuma matsakaicin shine 217+32 bytes. Tsawon yana sarrafawa ta hanyar steganography modules.
Lokacin da aka kafa haɗin yanar gizon, ƙananan bayanan farko shine saƙon musafiha, tare da taimakon sa uwar garken ta fahimci ko tana mu'amala da wani haɗin da ke ciki ko kuma sabuwar. Idan haɗin yana cikin sabon hanyar haɗin gwiwa, sabar ɗin tana amsawa tare da musafaha, kuma kowane ɗayan mahalarta musanya yana fitar da makullin zama daga gare ta. Bugu da ƙari, tsarin yana aiwatar da tsarin sake buɗewa - yana kama da rabon maɓallin zama, amma ana amfani da tubalan maimakon saƙon musafaha. Wannan tsarin yana canza lambar jeri, amma baya shafar ID ɗin hanyar haɗin gwiwa.
Da zarar duka mahalarta a cikin sadarwa sun aika kuma sun karɓi shingen fin, hanyar haɗin yana rufe. Don kare kai daga harin sake kunnawa ko toshe jinkirin bayarwa, duka mahalarta dole ne su tuna da ID na tsawon lokacin da aka rufe.
Ginin tsarin steganography yana ɓoye zirga-zirgar Tor a cikin ƙa'idar p2p - kama da yadda Skype ke aiki a cikin amintattun hanyoyin sadarwar VoIP. Tsarin steganography na HTTP yana kwaikwayon zirga-zirgar HTTP mara ɓoyewa. Tsarin yana kwaikwayon mai amfani na gaske tare da mai bincike na yau da kullun.
Juriya ga hare-hare
Domin a gwada nawa hanyar da aka tsara ke inganta haɓakar Tor, masu binciken sun haɓaka nau'ikan hare-hare guda biyu.
Na farko daga cikin wadannan shi ne raba rafukan Tor daga rafukan TCP bisa muhimman halaye na ka'idar Tor - wannan ita ce hanyar da ake amfani da ita wajen toshe tsarin gwamnatin kasar Sin. Harin na biyu ya ƙunshi nazarin sanannun kogin Tor don fitar da bayanai game da wuraren da mai amfani ya ziyarta.
Masu bincike sun tabbatar da tasiri na farkon nau'in harin da "vanilla Tor" - saboda wannan sun tattara alamun ziyartar shafuka daga saman 10 Alexa.com sau ashirin ta hanyar Tor, obfsproxy da StegoTorus na yau da kullum tare da tsarin HTTP steganography. An yi amfani da saitin bayanan CAIDA tare da bayanai akan tashar jiragen ruwa 80 a matsayin ma'ana don kwatanta - kusan dukkanin waɗannan haɗin gwiwar HTTP ne.
Gwajin ya nuna cewa yana da sauƙin ƙididdige Tor na yau da kullun. Ƙa'idar Tor ta yi ƙayyadaddun ƙayyadaddun bayanai kuma tana da halaye masu yawa waɗanda ke da sauƙin ƙididdigewa - alal misali, lokacin amfani da shi, haɗin TCP yana ɗaukar daƙiƙa 20-30. Kayan aikin Obfsproxy shima baya yin kadan don boye wadannan fayyace maki. StegoTorus, bi da bi, yana haifar da zirga-zirgar ababen hawa wanda ya fi kusanci da ambaton CAIDA.
Game da harin da aka kai wa wuraren da aka ziyarta, masu binciken sun kwatanta yiwuwar bayyanar da irin wannan bayanan a cikin yanayin "vanilla Tor" da maganin su na StegoTorus. Anyi amfani da ma'aunin don tantancewa (Yankin Ƙarƙashin Lanƙwasa). Dangane da sakamakon binciken, ya nuna cewa a cikin yanayin Tor na yau da kullun ba tare da ƙarin kariya ba, yuwuwar bayyana bayanai game da wuraren da aka ziyarta yana da girma sosai.
ƙarshe
Tarihin arangama tsakanin mahukuntan kasashen da ke gabatar da bayanan sirri a Intanet da kuma masu kirkiro tsarin hana toshewa ya nuna cewa matakan kariya ne kawai za su iya yin tasiri. Yin amfani da kayan aiki ɗaya kawai ba zai iya ba da garantin samun dama ga mahimman bayanai ba kuma bayanin game da ketare shingen ba zai zama sananne ga masu tace bayanai ba.
Sabili da haka, lokacin amfani da kowane kayan aiki na sirri da abun ciki, yana da mahimmanci kada a manta cewa babu mafita mai kyau, kuma inda zai yiwu, haɗa hanyoyin daban-daban don cimma mafi girman tasiri.
Hanyoyin haɗi masu amfani da kayan aiki daga :
source: www.habr.com