On Mon, Jan 06, 2014 at 12:12:55AM +0100, Pablo Neira Ayuso wrote: > From: Florian Westphal <fw@xxxxxxxxx> > > All these users need an initial seed value for jhash, prandom is > perfectly fine. This avoids draining the entropy pool where > its not strictly required. Secrets protecting hash tables should be rather strong. prandom_u32() has two seeding points at boot-up. One is at late_initcall. Thanks to parallel boot-up this gets executed fairly early. The other one is when the RNG nonblocking pool is fully initialized. Only after this point we can assume prandom_u32() returns truely random values. In between, only get_random_bytes or net_get_random_once are safe for use. To get the impression when prandom_u32 gets truely seeded, watch out for the message "random: nonblocking pool is initialized" in dmesg. ;) Hmm, some of them look like good candidates for net_get_random_once. I don't see such a problem with draining entropy pool, especially as they don't run that early and they don't request so many random bits. Greetings, Hannes -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
