I-AES-GCM noma i-ChaCha20-Poly1305: ukukhetha ukubethelwa kwedatha ye-VPN

Womabili amagama ayizakhiwo ze-AEAD, womabili asezingeni, futhi kuseva ye-x86 yamanje noma yikuphi kuzo kuzogcwalisa isixhumanisi se-gigabit ngaphandle komzamo obonakalayo. Ukukhetha kuyeka ukuba ngokunganaki lapho ushiya leyos seva: amarotha ashibhile, amafoni amadala namadivaysi angokoqobo ngokuvamile awanakho ukusheshiswa kwe-AES, futhi lapho umehluko mkhulu. Ngakho ukuqhathanisa akukhona ukuthi iyiphi i-cipher eshesha kakhulu, kodwa ukuthi iyiphi i-cipher esebenza kahle kuleli qoqo lamaphoyinti okugcina, nokuthi ingabe iphrothokholi inikeza ukukhetha nhlobo.

Umsebenzi ofanayo, izingqikithi ezihlukile

Zombili izakhiwo zinikeza imfihlo nokuphelela ngokuhamba okukodwa futhi ziqinisekisa idatha ehlobene, yingakho amaphrothokholi e-VPN eziyisebenzisela umsele wedatha. Umehluko ungaphakathi: i-AES-GCM iyisibethelo samabhulokhi e-AES kumodi yokubala enesiqinisekisi se-polynomial phezu kwe-GF(2^128), kanti i-ChaCha20-Poly1305 iyisibethelo somfudlana esinokhiye wamabhithi angu-256 nesiqinisekisi esisodwa esihlukile.

Okubalulekile ekusebenziseni kuyafana: zombili ziyahluleka kabi lapho i-nonce isetshenziswa kabusha, zombili zidinga ukuphathwa kwendawo ye-nonce kukho konke ukhiye, futhi akukho okulungisa umlingani oqinisekisa into engalungile. Iphrofayela ethi AES-256-GCM ayiphephile ukwedlula leyo ethi CHACHA20-POLY1305; zombili ziqinile lapho ukusetshenziswa kulungile.

Lapho i-AES-GCM inqoba khona

I-AES inemiyalo ekhethekile kuma-CPU amaningi esimanje: i-AES-NI ku-x86, izandiso ze-crypto ku-ARMv8 kanye nokulingana emiklamweni yakamuva ye-POWER ne-RISC-V. Uma zikhona, i-GCM isebenzisa amabhulokhi amaningi ngasikhathi sinye ngekilasi ngalinye lomjikelezo, futhi ukusetshenziswa kwesoftware akusabalulekile. Leli yicala elivamile kumaseva, amakhompyutha asetafuleni namafoni amanje, futhi yingakho iseluleko sokuthi sebenzisa i-AES siyisimo esifanele esizenzakalelayo esikhungweni sedatha.

Inkinga yicala lezinga lesibili. Ngaphandle kwemiyalo ekhethekile i-AES kusoftware iyephuza, futhi ukusetshenziswa kwesoftware okuholwa amathebula yikho okunomlando omude wezinkinga zesikhathi se-cache. Isihlanganisi se-VPN esigijima kumshini ongokoqobo lapho umsingathi wakhe engabonisi izifanekiselo ze-AES kusivakashi yilo kanye leli cala, futhi kulula ukulikhohlwa ngoba i-CPU yomsingathi inalesi sici.

Hlola lokho okubonwa inqubo ngempela, hhayi lokho okusekelwa yi-CPU: grep -o aes /proc/cpuinfo | head -1 ku-Linux, noma isifanekiselo sesici esilinganayo kumodeli ye-CPU ye-hypervisor.

Lapho i-ChaCha20-Poly1305 inqoba khona

I-ChaCha20 iyashesha kusoftware ethwalekayo ngoba isebenzisa kuphela ukuhlanganisa, ukuphenduka ne-XOR, futhi ukusetshenziswa kwayo kugwema ngomklamo ukusesha kwamathebula okuncike emfihlweni. Kudivaysi elingenakho ukusheshiswa kwe-AES lokho kuyinzuzo yangempela, futhi yingakho i-WireGuard iyikhethile: incazelo yephrothokholi ye-WireGuard ibala i-ChaCha20-Poly1305 njengesibethelo sayo sedatha ngaphandle kokunye.

Lokho kukhetha okukodwa kusho into ewusizo: kuhardware lapho i-AES isheshiswa khona, i-WireGuard iyeka ingxenye yokudluliswa uma iqhathaniswa ne-AES-GCM, futhi ababhali bayo bakwamukele lokho njengokushintshana nokuziphatha okulindelekile kumafoni, amarotha asekhaya nakumasingathi kamakhontheyna. Uma iqembu lakho likhulu kumabhokisi amancane e-ARM, lokho kushintshana kusekhona kuwe.

Icala eliphikisayo isihlanganisi se-x86 esimatasa, lapho i-AES-GCM ene-AES-NI iyindlela eshesha futhi esekelwa kangcono, futhi lapho i-ChaCha20 ibiza i-CPU elinganisekayo nge-gigabit ngayinye. Akukho sakhiwo esiwubuthakathaka; umbuzo uwukuthi yikuphi okwenziwa ngokushibhile kuhardware yakho.

Lokho iphrothokholi yakho ekuvumela ngempela ukuthi ukhethe

Qaphela ukwehlukana ku-OpenVPN: umsele wokulawula nomsele wedatha kuxoxwa ngawo ngokwehlukana, ngakho isethi oyibona ku-TLS ayisho lutho ngesibethelo esivikela umthwalo wakho. Isifinyezo sesikhathi sibika kokubili, futhi ukufunda okukodwa kwalokhu okubili kuwumthombo ovamile wokudideka.

Ku-OpenVPN isibethelo somsele wedatha sivela ohlwini lwe-data-ciphers kuzo zombili iziphetho. Uma uhlu lweseva nohlu lwekliyenti lungahlangani, uxhumano lubuyela kulokho okuvunyelwa yi-data-ciphers-fallback noma luhluleke ngokuphelele, futhi lokho kwehluleka kuvame ukubekwa ezingeni elingalungile. Beka uhlu olufanayo kuzo zombili izinhlangothi, bese uqinisekisa umphumela okuxoxwe ngawo kulogi esikhundleni sokucabanga ukuthi ukulandelana kohlu kuhlonishwa.

Nquma kusuka emaqinisweni amathathu mayelana nokusatshalaliswa

Okokuqala, ingabe amaphoyinti okugcina anokusheshiswa kwe-AES? Uma wonke umlingani enakho, i-AES-GCM iyisinqumo eshibhile nesizenzakalelayo kumakhonfigurashini amaningi agcinwayo. Uma ingxenye ebalulekile ingamarotha amancane noma amafoni amadala, i-ChaCha20-Poly1305 ivimbela umsila weqembu ukuba ube umkhawulo womthamo.

Okwesibili, ingabe iphrothokholi inikeza ukukhetha nhlobo? Nge-WireGuard isinqumo sesithathiwe esikhundleni sakho, futhi umsebenzi owusizo ukuqinisekisa ukuthi amathuluzi azungezile awafaki okunye ngokuthula. Nge-OpenVPN ne-IPsec impendulo iwumugqa wokucushwa kanye nomphumela okuxoxwe ngawo okufanele urekhodwe.

Okwesithathu, ingabe iziphetho zombili zingavumelana? Isibethelo umlingani oyedwa angasisebenzisi akusona isinqumo sokwenza kahle, ukuphazamiseka. Yingakho uhlu lwabalingani lubaluleke ukwedlula noma yisiphi isilinganiso: iqembu elixubile lidinga ukuhlangana kwamakhono, hhayi ukuthanda komshini oshesha kakhulu.

Uma ulinganisa, gcina idivaysi, iphoyinti lokugcina nomthwalo kufana futhi ushintshe into eyodwa. Ukuhlolwa okuqhathanisa amaseva amabili ezifundeni ezihlukile kulinganisa umzila, hhayi isibethelo, futhi isilinganiso sekhompyutha ephathwayo asisho lutho ngomsingathi wamakhontheyna ozifanekiselo zawo ze-CPU zifihliwe. Qhathanisa, bese ubhala phansi ukuthi yisiphi isibethelo okuxoxwe ngaso ngempela: lowo mbhalo ubaluleke ukwedlula isilinganiso.