{"id":121189,"date":"2024-12-31T15:46:00","date_gmt":"2024-12-31T13:46:00","guid":{"rendered":"https:\/\/prohoster.info\/blog\/novosti-interneta\/kollizii-v-sokrashhyonnyh-identifikatorah-kommitov-v-yadre-linux"},"modified":"2024-12-31T15:46:00","modified_gmt":"2024-12-31T13:46:00","slug":"kollizii-v-sokrashhyonnyh-identifikatorah-kommitov-v-yadre-linux","status":"publish","type":"post","link":"https:\/\/prohoster.info\/sq\/blog\/news\/kollizii-v-sokrashhyonnyh-identifikatorah-kommitov-v-yadre-linux","title":{"rendered":"Kolizione n\u00eb identifikuesit e shkurtra t\u00eb komiteteve n\u00eb b\u00ebrtham\u00ebn Linux","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"
Kees Cook, ish-udh\u00ebheq\u00ebsi i ekipit t\u00eb siguris\u00eb Ubuntu dhe ish-administrator kryesor i sistemit kernel.org, demonstroi mund\u00ebsin\u00eb e krijimit t\u00eb nj\u00eb komiti, identifikuesi i shkurtuar i t\u00eb cilit p\u00ebrputhet me komitin, q\u00eb ishte shtuar m\u00eb par\u00eb n\u00eb b\u00ebrtham\u00ebn Linux. Eksperimenti u krye si nj\u00eb konfirmim i vlefshm\u00ebris\u00eb s\u00eb kalimit n\u00eb identifikuesit e shkurtuar 16-shifror\u00eb p\u00ebr komitetet n\u00eb b\u00ebrtham\u00ebn Linux, q\u00eb ishte diskutuar m\u00eb par\u00eb n\u00eb list\u00ebn e postimeve t\u00eb zhvilluesve, por nuk ishte miratuar nga Linus Torvalds. <\/p>\n
Identifikuesit e shkurtuar t\u00eb komiteteve formohen duke l\u00ebn\u00eb 12 karakteret e para nga hash-i SHA-1 (48 bit nga 160 bit). Meq\u00eb numri i objekteve n\u00eb b\u00ebrtham\u00eb, q\u00eb identifikohen p\u00ebrmes hash-it SHA-1, ka tejkaluar 13 milion\u00eb, ngjarja e kolizionit gjat\u00eb p\u00ebrdorimit t\u00eb prefiksit 12-shifror ka qen\u00eb \u00e7\u00ebshtje kohe. Si shembuj jan\u00eb treguar objekte tashm\u00eb t\u00eb shtuar n\u00eb b\u00ebrtham\u00eb me identifikues t\u00eb p\u00ebrbashk\u00ebt me 11 karaktere. P\u00ebr m\u00eb tep\u00ebr, u p\u00ebrmend se ishte regjistruar nj\u00eb rimbushje e identifikuesve 12-shifror\u00eb n\u00eb tetor, por gjat\u00eb d\u00ebrgimit t\u00eb patch-it u identifikua nga utilitarja checkpatch. <\/p>\n
Identifikuesit e shkurtuar p\u00ebrdoren kur publikohet lidhje t\u00eb shkurtra p\u00ebr komitetet, si dhe tregohen kur d\u00ebrgohen ndryshime n\u00eb etiket\u00ebn \"Fixes\", si nj\u00eb lidhje me komitin ku problemi \u00ebsht\u00eb zgjidhur n\u00eb patchin e d\u00ebrguar (p.sh., \"Fixes: e21d2170f366\"). Shfaqja e kolizion\u00ebve, kur disa ndryshime t\u00eb ndryshme lidhen me nj\u00eb identifikues t\u00eb shkurtuar, mund t\u00eb \u00e7oj\u00eb n\u00eb funksionimin e pap\u00ebrshtatsh\u00ebm t\u00eb instrumenteve p\u00ebr analiz\u00ebn dhe verifikimin e ndryshimeve q\u00eb marrin parasysh p\u00ebrmbajtjen e etiketave \"Fixes\". P\u00ebr shembull, k\u00ebto etiketa merren parasysh n\u00eb trajtuesin check_fixes, i aplikuar n\u00eb deg\u00ebn linux-next, si dhe n\u00eb skriptet e analiz\u00ebs s\u00eb rregullimeve t\u00eb dob\u00ebsive dhe ndjekjes s\u00eb ciklit t\u00eb jet\u00ebs s\u00eb patch-eve. <\/p>\n
Linus Torvalds was skeptical about the proposal to increase the minimum size of shortened identifiers, as the actual number of commits in the repository is significantly lower than the number of objects (about 1\/8). Most likely, if random collisions occur, they will be between a commit and an object of some other type (for example, a blob or branch). In his opinion, shortened identifiers are shortened for the sake of being clear, readable, and easy to cite, and there are currently no objective reasons to increase their size. <\/p>\n
One of the developers proposed to achieve size reduction by increasing the number of significant bits using a new format based on Base36 encoding (characters 0-9a-z) instead of hexadecimal digits. According to Linus, such a change would create more problems than it solves. For example, it would require adding support for the new format in existing utilities and introducing a format identifier to distinguish between the old and new formats. <\/p>\n
To demonstrate that the issue with shortened identifiers is not theoretical and that its resolution should not be postponed, Kees Cook formed a documentation change for the kernel, whose shortened identifier (1da177e4c3f4) matched the commit ID for creating the kernel branch 2.6.12-rc2. The collision was found in 6 hours of computation on a system with an NVIDIA GeForce RTX 3080 GPU. <\/p>\n
P\u00ebrzgjedhja u krye duke p\u00ebrdorur mjetin lucky-commit \u2014 n\u00eb tekstin e patchit t\u00eb synuar u shtuan hap\u00ebsira t\u00eb rast\u00ebsishme derisa prefixi 12-shifror SHA-1 t\u00eb p\u00ebrputhej me prefix\u00ebt e tash\u00ebm t\u00eb komiteteve n\u00eb b\u00ebrtham\u00eb. Sipas Case-it, problemi p\u00ebrb\u00ebhet m\u00eb shum\u00eb nga nd\u00ebrprerjet e rast\u00ebsishme sesa nga mund\u00ebsia e manipulimit me identifikuesit e shkurtuar p\u00ebr q\u00ebllime t\u00eb d\u00ebmshme, p\u00ebr shembull, p\u00ebr t\u00eb p\u00ebrshkall\u00ebzuar ndonj\u00eb kontroll. \n Burimi: opennet.ru<\/a> <\/p>","protected":false,"gt_translate_keys":[{"key":"rendered","format":"html"}]},"excerpt":{"rendered":"