Messages in this thread | | | From | Andy Lutomirski <> | Date | Thu, 17 Jul 2014 14:37:34 -0700 | Subject | Re: [PATCH, RFC] random: introduce getrandom(2) system call |
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On Thu, Jul 17, 2014 at 2:28 PM, Theodore Ts'o <tytso@mit.edu> wrote: > On Thu, Jul 17, 2014 at 01:35:15PM -0700, Andy Lutomirski wrote: >> >> Can we please have a mode in which getrandom(2) can neither block nor >> fail? If that gets added, then this can replace things like AT_RANDOM. > > AT_RANDOM has been around for a long time; it's not something we can > remove.
I'm not suggesting removing AT_RANDOM. To the contrary, I'm suggesting that libraries that need to seed some kind of non-cryptographic, non-security-related RNG could use getrandom(2) with appropriate flags rather than screwing around with getpid, clock_gettime, etc.
For example:
unsigned int seed; getrandom(&seed, sizeof(seed), GRND_BEST_EFFORT); /* Never fails on new enough kernels */ srand(seed);
No error checking, no weird cases, and if the RNG isn't well seeded, then I tried my best.
--Andy
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