2015-06-16 0:21 GMT+08:00 Lennart Poettering <lenn...@poettering.net>: > On Mon, 15.06.15 23:33, cee1 (fykc...@gmail.com) wrote: > >> Hi, >> >> I maybe got confused. >> >> First, systemd-random-seed.service will save a "seed" from >> /dev/urandom when shutdown, and load that "seed" to /dev/urandom when >> next boot up. >> >> My questions are: >> 1. Can we not save a seed, but load a seed that is read from ** >> /dev/random ** to ** /dev/urandom **? > > The seed is used for both. Then you'd feed the stuff you got from the > RNG back into the RNG which is a pointless excercise.
systemd-random-seed.service will load the "seed on disk" to /dev/urandom, and save a "seed" to disk when shutdown, right? The article at http://www.2uo.de/myths-about-urandom/ suggests us saving the seed as soon as there is enough entropy(means read from /dev/random? if returns, there's enough entropy), Saving the seed early, make it more tolerant against the case of system crashes - that means not shutdown properly(which maybe the case on some mobile device such as STB. -- Regards, - cee1 _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
