Uma exhashazwa, lawa maphutha angavumela abahlaseli ukuthi bathole ukufinyelela okungagunyaziwe kulwazi olubucayi noma ngokuvamile babangele izinkinga.
Ezinsukwini ezimbalwa ezedlule. Kwamenyezelwa izindaba ukuthi un imishini yabacwaningi we IYunivesithi kusuka eCalifornia eSan Diego ubonise i amandla de dala kabusha Las okhiye Isikhungo se-RSA siyimfihlo of a iseva ssh ngokusebenzisa ukuhlaziywa nje yethrafikhi ye-SSH.
Ucwaningo olushicilelwe umbukiso lokho lapho Kusetshenziswa amasignesha edijithali ngokusekelwe ku i-algorithm I-RSA nge-SSH, iwahlanganisa ndawonyelokhos abasebenzisa indlela ye-Lattice (Fault Attack) ukuze dala kabusha la ukhiye i-RSA yangasese wakhe efanelekayo ukuze amasignesha edijithali ku icala de una ihluleka de isofthiwe noma ihadiwe ngesikhathi senqubo yokubala yesiginesha. I umongo yendlela i lokho al qhathanisa izisiginesha zedijithali ezilungile nezingalungile, unga inqume enkulu kunazo zonke evamile isihlukanisi, ngaleyo ndlela ukukhiqiza uno izinombolo eziyinhloko ezisetshenzisiwe ukuze ukukhiqiza la ukhiye.
Ukubethela kwe-RSA kusekelwe ekusebenzeni kokuchaza inombolo enkulu, kuyilapho ukhiye wasesidlangalaleni uqukethe imodulus nedigri. Imojula yakhiwe ngezinombolo ezimbili eziyinhloko ezingahleliwe, umnikazi wokhiye wangasese kuphela owaziyo. Ukuhlasela kungasetshenziswa ekusetshenzisweni kwe-RSA kusetshenziswa i-theorem yesiShayina esele kanye nezikimu ze-deterministic padding ezifana ne-PKCS#1 v1.5.
Ukuhlasela kungenziwa kumaseva lapho, ngenxa yenhlanganisela yezimo noma izenzo zomhlaseli, Ukwehluleka kungase kwenzeke ngesikhathi sokubala isiginesha yedijithali lapho kusungulwa uxhumano lwe-SSH. Ukwehluleka kungaba isofthiwe (ukwenziwa ngendlela engalungile kwezibalo, ukonakala kwenkumbulo) noma ihadiwe (amaphutha ekusebenzeni kwe-NVRAM ne-DRAM noma ukwehluleka phakathi nokucisha kukagesi).
Enye yezinketho zokugqugquzela ukwehluleka kungaba ukuhlaselwa kwekilasi le-RowHammer, okuyinto phakathi kwezinye izinto, ivumela ukude noma lapho ucubungula ikhodi ye-JavaScript esipheqululini finyelela ukuhlanekezela kokuqukethwe kwezingcezu zememori ngayinye ngesikhathi sokufunda umjikelezo ojulile wedatha evela komakhelwane. amaseli enkumbulo. Enye inketho yokudala ukwehluleka kungaba ukuxhashazwa kobungozi obudala ukuchichima kwebhafa kanye nokonakala kwedatha ngokhiye enkumbulweni.
Ukuze wenze ukuhlasela, kwanele ukuqapha ngokunganaki ukuxhumana okusemthethweni kuseva ye-SSH kuze kube yilapho kukhonjwa isiginesha yedijithali enephutha kuthrafikhi, engasetshenziswa njengomthombo wolwazi ukuze kwakhiwe kabusha ukhiye oyimfihlo we-RSA. Ngemva kokudala kabusha ukhiye we-RSA womsingathi, umhlaseli angasebenzisa ukuhlasela kwe-MITM ukuze aqondise kabusha izicelo buthule kumsingathi mbumbulu ozenza iseva ye-SSH esengozini futhi anqande idatha edluliselwa kule seva.
Ngokuhlola iqoqo ledatha yenethiwekhi ebanjiwe ehlanganisa cishe amarekhodi ayizigidi eziyizinkulungwane ezingu-5200 ahlobene nokusetshenziswa kwephrothokholi ye-SSH, abacwaningi bahlonze cishe okhiye bosokhaya abayizigidi eziyizinkulungwane ezingu-3200 namasiginesha edijithali asetshenziswa phakathi nezingxoxo zamaseshini e-SSH. Kulezi, izigidigidi ezi-1.200 (39,1%) zenziwe kusetshenziswa i-algorithm ye-RSA.
Iqembu labacwaningi lithi:
Ezimweni ezingu-593671 (0,048%) isiginesha ye-RSA yonakaliswa futhi ayikwazanga ukuqinisekiswa, kuyilapho kumasiginesha ahlulekile angu-4962, sakwazi ukusebenzisa indlela ye-Lattice factorization ukuze sinqume ukhiye oyimfihlo kusukela kukhiye womphakathi owaziwayo, okuholele ekwakhiweni kabusha kwe-RSA eyi-189 eyingqayizivele. amapheya okhiye (ezimweni eziningi, okhiye abafanayo abahlulekile namadivayisi asetshenziswa ukuze kukhiqizwe amasiginesha awonakele ahlukene). Kuthathe cishe amahora angu-26 CPU ukudala kabusha okhiye.
Udaba luthinta kuphela ukusetshenziswa okuthile kwephrothokholi ye-SSH, esetshenziswa kakhulu kumadivayisi ashumekiwe. Ngaphezu kwalokho, kuthiwa i-OpenSSH ayithinteki kule nkinga ngoba isebenzisa umtapo wezincwadi we-OpenSSL (noma i-LibreSSL) ukukhiqiza okhiye, obuvikelwe ekuhlaselweni okungalungile kusukela ngo-2001.
Ukwengeza, ku-OpenSSH, uhlelo lwesiginesha yedijithali ye-ssh-rsa (esekelwe ku-sha1) yehlisiwe kusukela ngo-2020 futhi yakhutshazwa kunguqulo 8.8 (ukusekelwa kwezinhlelo ze-rsa-sha2-256 kanye ne-rsa-sha2-512 kusasele). Ukuhlasela kungase kusebenze kuphrothokholi ye-IPsec, kodwa abacwaningi abazange babe nedatha yokuhlola eyanele yokuqinisekisa ukuhlasela okunjalo ngokwenza.
Okokugcina, uma ungathanda ukwazi okwengeziwe ngakho, ungathintana nemininingwane ku isixhumanisi esilandelayo.