Re:SSHD: Random boot time relinking, OpenBSD
by patrakov on Friday January 20, 2023 @09:49PM
(#34463346)
Actually, saving the hashes of the objects into the executable itself, into a new section, would be enough. Then one would need to locate this section, confirm that the hashes there form a permutation of the canonical ones, relink the canonical objects in the same order, and check whether the resulting executable is the same byte-for-byte.
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Re:SSHD: Random boot time relinking, OpenBSD
by vlovich123 on Saturday January 21, 2023 @10:08PM
(#34473820)
If you save the link order, then you’ve provided a map to the stacker of the link order used which defeats the whole point of randomization. No? I must be missing something
Re:SSHD: Random boot time relinking, OpenBSD
by patrakov on Sunday January 22, 2023 @03:10AM
(#34475396)
The section with the link order stays only on disk, i.e. not loaded into RAM, and is therefore useless to the one who tries to exploit sshd. Especially because the sshd binary is readable only by root now.