Jason A Donenfeld, munyori weVPN WireGuard akazivisa mazuva mashoma apfuura kushandiswa kutsva yakagadziridzwa kubva kune isina kujairika nhamba jenareta RDRAND, iyo inotarisira iyo /dev/random uye /dev/urandom zvishandiso muLinux kernel.
Pakupera kwaMbudzi, Jason akanyorwa seanongo chengetedza dhizaini uye parizvino akatumira mhinduro dzekutanga dzebasa rake rework.
Zvinotaurwa muchiziviso kuti kushandiswa kutsva kunomira pachena shanduko yekushandisa BLAKE2s hashi basa panzvimbo yeSHA1 ye entropy kusanganisa mabasa.
BLAKE2s pachayo ine yakanaka pfuma yekuve yemukati yakavakirwa pane
ChaCha permutation, iyo RNG yave kutoshandisa pakuwedzera, saka
hapafanirwe kuve nedambudziko nehutsva, mavambo kana CPU inoshamisa
hunhu sezvo hwakavakirwa pane chinhu chiri kutoshandiswa.
Mukuwedzera kune izvi, zvinoratidzwa kuti kuchinja yakavandudzawo kuchengetedzwa kwepseudorandom nhamba jenareta nekubvisa iyo inonetsa SHA1 algorithm uye kudzivirira kunyora iyo RNG yekutanga vector. Sezvo iyo BLAKE2s algorithm iri pamberi peSHA1 mukuita, kushandiswa kwayo kwakavewo nemhedzisiro yakanaka pakuita kwepseudo-random nhamba jenareta (bvunzo pane system ine Intel i7-11850H processor yakaratidza 131% kuwedzera kwekukurumidza).
Imwe mukana unomira pachena ndeye kuendesa iyo entropy musanganiswa kuBLAKE2 ndiko kubatanidzwa kwema algorithms anoshandiswa: BLAKE2 inoshandiswa muChaCha encryption, iyo yakatoshandiswa kuburitsa zvisina kurongeka sequences.
BLAKE2s inowanzo kukurumidza uye yakachengeteka zvakanyanya, yave yakatyoka chaizvo. Uyezve, the Kuvaka kwazvino muRNG hakushandise iyo yakazara SHA1 basa, se inotsanangura, uye inobvumira kunyora pamusoro iyo IV neRDRAND yakabuda so isina kunyorwa, kunyangwe RDRAND isina kuiswa se 'yakavimbika', iyo zvinoreva kuti zvinogoneka zvakashata IV sarudzo.
Uye kureba kwayo kupfupi kunoreva kuchengetedza hafu chete yakavanzika paunenge uchidyisa zvakare kumusanganisi inotipa chete 2 ^ 80 bits ekuvanzika kwemberi. Nemamwe mashoko, kwete chete Sarudzo yebasa rehashi ndeyechinyakare asi kushandiswa kwayo hakuna kunyatso kunaka kana.
Pamusoro pezvo, kukwidziridzwa kwakaitwa kune iyo crypto-yakachengeteka CRNG pseudo-random nhamba jenareta inoshandiswa mukufona getrandom.
Zvinotaurwawo izvozvo kuvandudzwa kunodzika kusvika pakudzikamisa kufona kune jenareta reRDRAND inononoka kana uchibvisa entropy, iyo inogona kuvandudza kushanda nechikamu che3,7. Jason akaratidza kuti kufona kuRDRAND Zvinongonzwisisika mumamiriro ezvinhu apo CRNG haisati yanyatsotangwa, asi kana CRNG kutanga kwapera, kukosha kwayo hakukanganisi kunaka kwerukova rwakagadzirwa uye munyaya iyi zvinokwanisika kuita pasina kudana RDRAND.
Kubvumirana uku kune chinangwa chekugadzirisa matambudziko maviri aya uye, panguva imwe chete, kuchengetedza chimiro chese uye semantics padyo sezvinobvira kune yekutanga.
Kunyanya:a) Panzvimbo pekunyora iyo IV hashi neRDRAND, tinoisa mune BLAKE2 yakanyorwa "munyu" uye "pachedu" minda, iyo iri yakagadzirwa zvakanangana nemhando iyi yekushandisa.
b) Sezvo basa iri rinodzorera mhedzisiro yeheshi yakazara kune iyo entropy muunganidzi, isu tinongodzosera hafu yehurefu hwe hash, sezvazvaiitwa kare. Izvi zvinowedzera kuvaka pamberi chakavanzika kubva 2^80 kusvika 2 ^ 128 zvakanyanya kugadzikana.
c) Panzvimbo pekungoshandisa mbishi "sha1_transform" basa, pachinzvimbo isu tinoshandisa yakazara uye yakakodzera BLAKE2s basa, nekupedzisa.
Shanduko dzakarongerwa kuisirwa mu kernel 5.17 uye vakatoongororwa nevagadziri Ted Ts'o (wechipiri ane basa rekuchengetedza mutungamiriri weasina kurongeka), Greg Kroah-Hartman (ane basa rekuchengetedza Linux kernel yakagadzikana) naJean-Philippe Aumasson (munyori weBLAKE2 algorithms /3).
Chekupedzisira, kana iwe uchida kukwanisa kuziva zvakawanda nezvazvo, unogona kubvunza iwo ruzivo mu inotevera chinongedzo.