On Sat, Jul 10, 2021 at 10:08 PM Maamoun TK <[email protected]> wrote:
> On Sat, Jul 10, 2021 at 9:55 PM David Edelsohn <[email protected]> wrote: > >> On Sat, Jul 10, 2021 at 2:45 PM Maamoun TK <[email protected]> >> wrote: >> > >> > On Fri, Jul 9, 2021 at 10:08 AM Niels Möller <[email protected]> >> wrote: >> > >> > > Maamoun TK <[email protected]> writes: >> > > >> > > > My concern is if the program >> > > > terminates then the operation system will deallocate the program's >> stack >> > > > without clearing its content so that leftover data will remain >> somewhere >> > > at >> > > > the RAM which could be a subject for a memory allocation or dumbing >> by >> > > > other programs. >> > > >> > > I think the kernel is responsible for clearing that memory before >> > > handing it out to a new process. If it didn't, that would be a huge >> > > security problem. I'm fairly sure operating systems do this correctly. >> > > (And I would be a bit curious to know of any exceptions, maybe some >> > > embedded or ancient systems don't do it?) >> > > >> > >> > You are right, modern operating systems are supposed to have this >> > functionality but accessing some program's memory is pretty easy >> nowadays, >> > I think it's a good practice to clean behind the cipher functions for >> what >> > it makes sense and whenever possible. >> > >> > In another topic, I've optimized the SHA-512 algorithm for arm64 >> > architecture but it turned out all CFarm variants don't support SHA-512 >> > crypto extension so I can't do any performance or correctness testing >> for >> > now. Do you know any CFarm alternative that supports SHA-512 and SHA3 >> > extensions for arm64 architectures? >> >> There is a new AArch64 system in the GCC Compile Farm that has not >> been installed yet. That system might provide the SHA-512 support. >> It will have an Ampere eMAG processor supporting ARMv8. >> > > Thanks for the info, I think we have to wait until the new system is set > up. > To clarify, the new Aarch64 machine in GCC Compile Farm doesn't support SHA-512 and SHA3 extensions. Until we figure a way to test the optimized cores of SHA-512 and SHA, we can proceed with the optimized implementation of AES for Arm64 then I'll implement optimizations for Chacha20 and Poly1305 which is planned to be released with corresponding optimizations for S390x architecture by using the supported vector facility. There are also two patches of fat build support and memxor optimization for s390x, it would be great to process them so I can start pushing patches of SHA optimizations for s390x architecture. regards, Mamone _______________________________________________ nettle-bugs mailing list [email protected] http://lists.lysator.liu.se/mailman/listinfo/nettle-bugs
