On Tue, Nov 19, 2024 at 9:45 AM Andrey M. Borodin <x4...@yandex-team.ru> wrote: > > > > > On 19 Nov 2024, at 14:31, Andrey M. Borodin <x4...@yandex-team.ru> wrote: > > > > Done. > > Here's v33 intact + one more patch to add 2 bits of entropy on MacOS (to > compensate lack of nanoseconds). > What do you think? >
Thank you for updating the patch! I've reviewed the v33 patch and made some changes mostly for cosmetic things. Please review it to see if we accept these changes. I have one question about the additional patch: +#if defined(__darwin__) + /* + * On MacOS real time is truncted to microseconds. Thus, 2 least + * significant bits of increased_clock_precision are neither random + * (CSPRNG), nor time-dependent (in a sense - truly random). These 2 bits + * are dependent on other time-specific bits, thus they do not contribute + * to uniqueness. To make these bit random we mix in two bits from CSPRNG. + */ + uuid->data[7] = uuid->data[7] ^ (uuid->data[8] >> 6); +#endif I thought that the whole 12 bits in "rand_a" is actually time-dependent since we store 1/4096 fraction of sub-milliseconds. Am I missing something? Regards, -- Masahiko Sawada Amazon Web Services: https://aws.amazon.com
change_v33.patch
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