Re:Linus: Don't bother with grsecurity. Their patches are pu...
by AstralStorm on Monday June 26, 2017 @01:52AM
(#14634407)
Security in git is done by signing tags with GPG. This signs the whole tree state as in all of commit IDs and blobs. To break that, you need to collide a blob hash and commit hash or potentially pack file hash. Much harder than doing it for one file.
(Albeit git used to be lax with its compression allowing garbage at the end.)
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Re:Linus: Don't bother with grsecurity. Their patches are pu...
by geofft on Monday June 26, 2017 @11:17AM
(#14637443)
It signs the whole tree state, which is a collection of SHA-1 hashes. If I'm interested in introducing a backdoor in an application, I'm basically only interested in colliding the hash of one file; colliding a SHA-1 signature on a file is exactly as hard as colliding the SHA-1 hash of a single file inside a git tree inside a git commit signed with a stronger-than-SHA-1 signature. That is, if I've collided the file's SHA-1 hash, the tree that contains the file is going to have the exact same hash because the tree contains the SHA-1 of the file.