OT: Signed binaries
dgy at DakotaCom.Net
Sun Jun 25 16:27:12 CDT 2006
> Don Y wrote:
>> Are there any OS's that have implemented (non-trivial)
>> signatures on loading executables as a scheme of protecting
>> the operating environment? I.e. something more than
>> verifying the proper COFF/ELF/etc. load format...
Michael B. Brutman wrote:
> IBM System/38 (and later the AS/400 and all of it's renamed versions)
> run a CRC over programs for security reasons, not just for correctness
> checking. It's necessary because everything is in one big address
> space, so an errant program can cause security problems or crash the
> system by corrupting other storage.
Ah, excellent! But, is their intent to catch "incorrectness"
caused by, e.g., hardware failures? I.e., do they assume they
are operating in a HOSTILE environment or just an UNFRIENDLY
For example, most machine's bootstrap code contains checksums.
But, you can usually hack those images if you spend a little
time tweeking the checksum in the process (so the code thinks
everything is fine).
OTOH, cryptographic signatures are *designed* to prevent
(uh, "strongly discourage" :> ) this.
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