CFB1 kuqhathaniswa ne-CFB8 ne-CFB128: usayizi wempendulo, hhayi usayizi wokhiye
Inombolo elandela i-CFB iyisinyathelo sempendulo, hhayi ubude bokhiye: i-CFB1, i-CFB8 ne-CFB128 zisebenzisa ibhloko lamabhithi angu-128. Funda amagama amadala ngaphandle kokusungula okhiye abuthakathaka.
Igama elifana ne-AES-256-CFB1 liphethe izinombolo ezimbili, futhi ziphendula imibuzo ehlukene. U-256 ubude bokhiye we-AES. U-1 yimpendulo ye-CFB, okungukuthi usayizi wengxenye, isimo sendlela imodi eqhubekisela phambili isimo sayo. Uma u-1 efundwa njengobude bokhiye, igama libonakala njengokuhlelwa okungalungile okuyinhlekelele, yingakho lo mbuzo ubuya njalo.
Nquma ukuthi yikuphi kwezilinganiso ezintathu obhekile ngaphambi kokwahlulela igama: usayizi wokhiye, usayizi webhloko noma usayizi wengxenye. Eyokuqala kuphela iyipharamitha yezokuphepha ngomqondo ojwayelekile.
Izinombolo ezintathu, izilinganiso ezintathu
I-AES yamukela okhiye bamabhithi angu-128, 192 noma 256 futhi inebhloko lamabhithi angu-128 noma yikuphi okukhethayo. Usayizi webhloko ungowase-AES, hhayi owemodi. Isijobelelo se-CFB siyingxenye yesithathu: idatha engakanani imodi eyisebenzisayo neyibuyisayo esinyathelweni ngasinye. Idokhumenti ye-AES ye-OpenSSL ibala ngokusobala lokho kusayizi kokushintsha kwezinhlobo ze-CFB.
I-CFB1 ibuyisela ibhithi elilodwa ngesikhathi, i-CFB8 ibhayithi elilodwa, i-CFB128 ibhloko eliphelele. Zontathu zisebenzisa ngaphakathi isifihlo sebhloko esifanayo samabhithi angu-128; okushintshayo inani lamabhithi ebhlokweni ngalinye elibalwe asetshenziswa ngokusebenza ngakunye. Yingakho isijobelelo sishintsha izindleko nokuziphatha kwebhafa, hhayi amandla okhiye.
| Name | Key | AES block | Feedback |
|---|---|---|---|
| AES-256-CFB1 | 256 bits | 128 bits | 1 bit |
| AES-256-CFB8 | 256 bits | 128 bits | 8 bits |
| AES-256-CFB128 | 256 bits | 128 bits | 128 bits |
Kungani usayizi webhloko ungalokothi ushintshe
I-AES iyisifihlo sebhloko elinebhloko eligxilile lamabhithi angu-128, futhi amamodi ayizakhiwo ezakhiwe nxazonke zalo. Alikho nelilodwa elinciphisa ibhloko ukuze lihambisane nosayizi wengxenye. Ukuqaliswa kwe-CFB1 kusabala ibhloko le-AES eliphelele bese kuthatha ibhithi elilodwa kumphumela. Amanye amabhithi ayalahlwa kuleso sinyathelo, futhi yilapho izindleko zokusebenza kahle zikhona.
Ngakho impendulo yebhithi elilodwa ayisho ukhiye webhithi elilodwa, futhi igama alikwazi ukuhlelwa ngesijobelelo salo. I-CFB128 ayinamandla aphindwe kane kune-CFB32; icubungula izingxenye ezinkulu.
Usayizi wengxenye ushintsha ini ngempela
Usayizi wengxenye ushintsha inani lombhalo ofihliwe obuyiselwa esinyathelweni ngasinye kanye nenani lombhalo ocacile umnyakazo ngamunye ongawuthwala. Ushintsha futhi ukusabalala kwamaphutha nokuziphatha kwebhafa, okubalulekile ekusetshenzisweni okufana nokugeleza. Izingxenye eziqondiswe kumabhayithi zihambisana namabhafa, lezo eziqondiswe kumabhithi azihambisani.
Empeleni imodi iyona ekhethwa iphrothokholi, hhayi umqhubi. Isiteshi sedatha se-VPN sisebenzisa isakhiwo esishiwo iphrothokholi yaso, nokuvikelwa kwaso kobuqotho, futhi uhlu lwelabhulali lutshela kuphela ukuthi yimaphi amagama akhona.
Ukufunda ilebuli ye-CFB engenasici
Ilebuli ye-CFB engenasici idinga umongo wokuqaliswa kwayo. Ezihlokweni ze-OpenSSL 1.0.2, i-EVP_aes_128_cfb iyimakro ye-EVP_aes_128_cfb128, namagama amanye ahambisanayo okhiye bamabhithi angu-192 nangu-256. Lokho kuwumkhuba wokuqamba wama-API ovela egatsheni elilodwa, hhayi isimangalo sokuthi yonke ilabhulali, ifomethi yefayela noma i-GUI yandisa leso sifinyezo ngendlela efanayo. Hlola isihloko noma idokhumenti yenguqulo ephambi kwakho.
Uma iphrofayela endala ithi CFB futhi ozakwabo uyayamukela, amapharamitha okuxoxwa ngawo abhalwa endaweni ethile: kuloji, kudumpu lokuhlela, empendulweni ye-API. Funda lokho esikhundleni sokucabangela usayizi wengxenye kusukela kuchungechunge lokubonisa.
Igama lemode elingakutsheli khona
Igama lichaza ukuziphatha kokubethela futhi akukho okunye. I-VPN isadinga ukuvikelwa kobuqotho, ukukhishwa kokhiye nokuqinisekiswa kozakwabo, futhi i-CFB ayikunikezi lokho. Ukushintsha i-CFB8 nge-CFB1 nakho akusona ushintsho lwangaphandle: ukuziphatha ocingweni kuyahluka futhi izinhlangothi zombili kufanele zisekele isakhiwo esifanayo. Futhi igama eliselabhulali alifakazeli ukuthi igethiweyi esetshenzisiwe iyamukela isiteshi saso sedatha.
Kukho konke okugcinwayo, sebenzisa ukuhlelwa okuphelele kokuvikelwa kwephrothokholi kanye nenqubomgomo yomqhubi, futhi bhala izinguqulo zelabhulali negethiweyi, inketho eqondile nomphumela okuxoxwe ngawo. Igama elidala lichaza okufundayo; alithetheleli ukuvuselela lokho kuhlelwa.