Linus Torvalds writes: (Summary) wrote:
No, if people use the command line option, *all* pointers - not just the boot-time ones - would get cryptographically bad hashes, since you don't want to change the hash once it's picked (because then you couldn't use the hashing to identify objects).
hashing to identify objects).
So the boot command line wouldn't affect just the bootup hashing, it would be bad at runtime too.
be bad at runtime too.
But at least a person booting with that option would get the same *behavior* as everybody else, and they wouldn't be testing something fundamnetally different (it's still hashing, just not cryptographically strong).
strong).
Although in *practice* we'd have tons of entropy on any modern development CPU too, since any new hardware will have the hardware random number generation.
[...]
that[...]
are missing the good entropy.[...]
happens once during boot.No, if people use the command line option, *all* pointers - not just the boot-time ones - would get cryptographically bad hashes, since you don't want to change the hash once it's picked (because then you couldn't use the hashing to identify objects).
hashing to identify objects).
So the boot command line wouldn't affect just the bootup hashing, it would be bad at runtime too.
be bad at runtime too.
But at least a person booting with that option would get the same *behavior* as everybody else, and they wouldn't be testing something fundamnetally different (it's still hashing, just not cryptographically strong).
strong).
Although in *practice* we'd have tons of entropy on any modern development CPU too, since any new hardware will have the hardware random number generation.