{"id":106545,"date":"2023-01-29T12:48:46","date_gmt":"2023-01-29T10:48:46","guid":{"rendered":"https:\/\/prohoster.info\/?p=106545"},"modified":"2023-02-07T12:09:03","modified_gmt":"2023-02-07T10:09:03","slug":"zavisimost-vremeni-vypolneniya-instrukczij-ot-dannyh-na-cpu-arm-i-intel","status":"publish","type":"post","link":"https:\/\/prohoster.info\/ro\/blog\/news\/zavisimost-vremeni-vypolneniya-instrukczij-ot-dannyh-na-cpu-arm-i-intel","title":{"rendered":"Dependenta timpului de execu\u021bie al instruc\u021biunilor de date pe CPU ARM \u0219i Intel","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

Eric Biggers, unul dintre dezvoltatorii algoritmului Adiantum \u0219i men\u021bin\u0103tor al subsistemului fscrypt din kernelul Linux, a propus un set de patch-uri pentru a bloca problemele de securitate care apar din cauza unei caracteristici a procesoarelor Intel, care nu garanteaz\u0103 un timp de execu\u021bie constant pentru diferite date procesate. La procesoarele Intel, problema apare \u00eencep\u00e2nd cu familia Ice Lake. O problem\u0103 similar\u0103 se observ\u0103 \u0219i la procesoarele ARM. <\/p>\n

Prezen\u021ba dependen\u021bei timpului de execu\u021bie al instruc\u021biunilor de datele procesate \u00een aceste instruc\u021biuni este considerat\u0103 de autorul patch-urilor o vulnerabilitate \u00een procesoare, deoarece un astfel de comportament nu poate garanta siguran\u021ba opera\u021biunilor criptografice efectuate \u00een sistem. Multe implement\u0103ri ale algoritmilor criptografici sunt concepute astfel \u00eenc\u00e2t datele s\u0103 nu influen\u021beze timpul de execu\u021bie al instruc\u021biunilor, iar \u00eenc\u0103lcarea acestui comportament poate duce la dezvoltarea atacurilor prin canale laterale, care recupereaz\u0103 date pe baza analizei timpului de procesare. <\/p>\n

\u00cen mod poten\u021bial, dependen\u021ba timpului de execu\u021bie de date poate fi, de asemenea, utilizat\u0103 pentru a organiza atacuri prin definirea datelor nucleului din spa\u021biul utilizatorului. Potrivit lui Eric Biggers, timpul de execu\u021bie constant \u00een mod implicit nu este asigurat nici m\u0103car pentru instruc\u021biunile care efectueaz\u0103 opera\u021bii de adunare \u0219i XOR, precum \u0219i pentru instruc\u021biunile specializate AES-NI (informa\u021bia nu este confirmat\u0103 prin teste, iar conform altor date, la \u00eenmul\u021birea vectorilor \u0219i num\u0103rarea bitilor apare o \u00eent\u00e2rziere de un ciclu). <\/p>\n

Pentru a dezactiva comportamentul discutat, companiile Intel \u0219i ARM au propus noi steaguri: bitul PSTATE DIT (Data Independent Timing) pentru CPU ARM \u0219i bitul MSR DOITM (Data Operand Independent Timing Mode) pentru CPU Intel, care restabilesc vechiul comportament cu timp de execu\u021bie constant. Companiile Intel \u0219i ARM recomand\u0103 activarea protec\u021biei atunci c\u00e2nd este necesar pentru codul critic, dar \u00een realitate, calculele importante pot ap\u0103rea \u00een orice parte a nucleului \u0219i a spa\u021biului utilizatorului, a\u0219a c\u0103 se analizeaz\u0103 posibilitatea activ\u0103rii permanente a modurilor DOITM \u0219i DIT pentru \u00eentregul nucleu. <\/p>\n

Pentru procesoarele ARM, au fost deja acceptate patch-uri \u00een ramura kernel-ului Linux 6.2, care modific\u0103 comportamentul acestuia, dar aceste patch-uri sunt considerate insuficiente, deoarece se concentreaz\u0103 doar pe codul kernel-ului \u0219i nu schimb\u0103 comportamentul pentru spa\u021biul utilizatorului. Pentru procesoarele Intel, activarea protec\u021biei se afl\u0103 doar \u00een stadiul de revizuire. M\u0103surarea impactului patch-ului asupra performan\u021bei nu a avut loc \u00eenc\u0103, dar conform documenta\u021biei Intel, activarea modului DOITM reduce performan\u021ba (de exemplu, din cauza dezactiv\u0103rii unor optimiz\u0103ri, cum ar fi \u00eenc\u0103rcarea anticipat\u0103 specific\u0103 pentru anumite date) \u0219i \u00een modelele viitoare de procesoare, sc\u0103derea performan\u021bei ar putea fi accentuat\u0103.
\n
Sursa: opennet.ro<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"

\u042d\u0440\u0438\u043a \u0411\u0438\u0433\u0433\u0435\u0440\u0441 (Eric Biggers), \u043e\u0434\u0438\u043d \u0438\u0437 \u0440\u0430\u0437\u0440\u0430\u0431\u043e\u0442\u0447\u0438\u043a\u043e\u0432 \u0448\u0438\u0444\u0440\u0430 Adiantum \u0438 \u043c\u044d\u0439\u043d\u0442\u0435\u0439\u043d\u0435\u0440 \u043f\u043e\u0434\u0441\u0438\u0441\u0442\u0435\u043c\u044b \u044f\u0434\u0440\u0430 Linux fscrypt, \u043f\u0440\u0435\u0434\u043b\u043e\u0436\u0438\u043b \u043d\u0430\u0431\u043e\u0440 \u043f\u0430\u0442\u0447\u0435\u0439 \u0434\u043b\u044f \u0431\u043b\u043e\u043a\u0438\u0440\u043e\u0432\u0430\u043d\u0438\u044f \u043f\u0440\u043e\u0431\u043b\u0435\u043c \u0441 \u0431\u0435\u0437\u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u044c\u044e, \u0432\u043e\u0437\u043d\u0438\u043a\u0430\u044e\u0449\u0438\u0445 \u0438\u0437-\u0437\u0430 \u043e\u0441\u043e\u0431\u0435\u043d\u043d\u043e\u0441\u0442\u0438 \u043f\u0440\u043e\u0446\u0435\u0441\u0441\u043e\u0440\u043e\u0432 Intel, \u043d\u0435 \u0433\u0430\u0440\u0430\u043d\u0442\u0438\u0440\u0443\u044e\u0449\u0435\u0439 \u043f\u043e\u0441\u0442\u043e\u044f\u043d\u043d\u043e\u0435 \u0432\u0440\u0435\u043c\u044f \u0432\u044b\u043f\u043e\u043b\u043d\u0435\u043d\u0438\u044f \u0438\u043d\u0441\u0442\u0440\u0443\u043a\u0446\u0438\u0439 \u0434\u043b\u044f \u0440\u0430\u0437\u043d\u044b\u0445 \u043e\u0431\u0440\u0430\u0431\u0430\u0442\u044b\u0432\u0430\u0435\u043c\u044b\u0445 \u0434\u0430\u043d\u043d\u044b\u0445. \u0412 \u043f\u0440\u043e\u0446\u0435\u0441\u0441\u043e\u0440\u0430\u0445 Intel \u043f\u0440\u043e\u0431\u043b\u0435\u043c\u0430 \u043f\u0440\u043e\u044f\u0432\u043b\u044f\u0435\u0442\u0441\u044f \u043d\u0430\u0447\u0438\u043d\u0430\u044f \u0441 \u0441\u0435\u043c\u0435\u0439\u0441\u0442\u0432\u0430 Ice Lake. \u0410\u043d\u0430\u043b\u043e\u0433\u0438\u0447\u043d\u0430\u044f \u043f\u0440\u043e\u0431\u043b\u0435\u043c\u0430 \u043d\u0430\u0431\u043b\u044e\u0434\u0430\u0435\u0442\u0441\u044f \u0438 \u0432 \u043f\u0440\u043e\u0446\u0435\u0441\u0441\u043e\u0440\u0430\u0445 ARM. […]<\/p>\n","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[702],"tags":[],"class_list":["post-106545","post","type-post","status-publish","format-standard","hentry","category-news"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\n","aioseo_head_json":{"title":"\ud83e\udd47Dependen\u021ba timpului de execu\u021bie al instruc\u021biunilor de date pe CPU ARM \u0219i Intel | ProHoster","description":"Eric Biggers, unul dintre dezvoltatorii criptografiei Adiantum \u0219i men\u021bin\u0103tor al subsystemului kernel-ului Linux fscrypt, a propus un set de patch-uri pentru a bloca problemele de securitate care apar din cauza unor caracteristici ale procesoarelor.","canonical_url":"https:\/\/prohoster.info\/ro\/blog\/news\/zavisimost-vremeni-vypolneniya-instrukczij-ot-dannyh-na-cpu-arm-i-intel","robots":"max-image-preview:large","keywords":"","webmasterTools":{"miscellaneous":""},"schema":null,"og:locale":"ro_RO","og:site_name":"ProHoster | \u041a\u0443\u043f\u0438\u0442\u044c \u043d\u0430\u0434\u0435\u0436\u043d\u044b\u0439 \u0445\u043e\u0441\u0442\u0438\u043d\u0433 \u0434\u043b\u044f \u0441\u0430\u0439\u0442\u043e\u0432 \u0441 \u0437\u0430\u0449\u0438\u0442\u043e\u0439 \u043e\u0442 DDoS, VPS VDS \u0441\u0435\u0440\u0432\u0435\u0440\u044b","og:type":"article","og:title":"\ud83e\udd47\u0417\u0430\u0432\u0438\u0441\u0438\u043c\u043e\u0441\u0442\u044c \u0432\u0440\u0435\u043c\u0435\u043d\u0438 \u0432\u044b\u043f\u043e\u043b\u043d\u0435\u043d\u0438\u044f \u0438\u043d\u0441\u0442\u0440\u0443\u043a\u0446\u0438\u0439 \u043e\u0442 \u0434\u0430\u043d\u043d\u044b\u0445 \u043d\u0430 CPU ARM \u0438 Intel | ProHoster","og:description":"\u042d\u0440\u0438\u043a \u0411\u0438\u0433\u0433\u0435\u0440\u0441 (Eric Biggers), \u043e\u0434\u0438\u043d \u0438\u0437 \u0440\u0430\u0437\u0440\u0430\u0431\u043e\u0442\u0447\u0438\u043a\u043e\u0432 \u0448\u0438\u0444\u0440\u0430 Adiantum \u0438 \u043c\u044d\u0439\u043d\u0442\u0435\u0439\u043d\u0435\u0440 \u043f\u043e\u0434\u0441\u0438\u0441\u0442\u0435\u043c\u044b \u044f\u0434\u0440\u0430 Linux fscrypt, \u043f\u0440\u0435\u0434\u043b\u043e\u0436\u0438\u043b \u043d\u0430\u0431\u043e\u0440 \u043f\u0430\u0442\u0447\u0435\u0439 \u0434\u043b\u044f \u0431\u043b\u043e\u043a\u0438\u0440\u043e\u0432\u0430\u043d\u0438\u044f \u043f\u0440\u043e\u0431\u043b\u0435\u043c \u0441 \u0431\u0435\u0437\u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u044c\u044e, \u0432\u043e\u0437\u043d\u0438\u043a\u0430\u044e\u0449\u0438\u0445 \u0438\u0437-\u0437\u0430 \u043e\u0441\u043e\u0431\u0435\u043d\u043d\u043e\u0441\u0442\u0438 \u043f\u0440\u043e\u0446\u0435\u0441\u0441\u043e\u0440\u043e\u0432.","og:url":"https:\/\/prohoster.info\/ro\/blog\/news\/zavisimost-vremeni-vypolneniya-instrukczij-ot-dannyh-na-cpu-arm-i-intel","og:image":"https:\/\/prohoster.info\/wp-content\/uploads\/2021\/11\/logo-350.jpg","og:image:secure_url":"https:\/\/prohoster.info\/wp-content\/uploads\/2021\/11\/logo-350.jpg","og:image:width":350,"og:image:height":350,"article:published_time":"2023-01-29T10:48:46+00:00","article:modified_time":"2023-02-07T10:09:03+00:00","article:publisher":"https:\/\/www.facebook.com\/prohoster","article:author":"https:\/\/www.facebook.com\/prohoster"},"aioseo_meta_data":[],"gt_translate_keys":[{"key":"link","format":"url"}],"_links":{"self":[{"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/posts\/106545","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/comments?post=106545"}],"version-history":[{"count":0,"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/posts\/106545\/revisions"}],"wp:attachment":[{"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/media?parent=106545"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/categories?post=106545"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/prohoster.info\/ro\/wp-json\/wp\/v2\/tags?post=106545"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}