Date: Sun, 2 Nov 2014 13:29:37 +0000 From: Mark R V Murray <mark@grondar.org> To: Ian Lepore <ian@FreeBSD.org> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r273958 - head/sys/dev/random Message-ID: <6FB65828-6A79-4BDE-A9F7-BC472BA538CE@grondar.org> In-Reply-To: <1414934579.17308.248.camel@revolution.hippie.lan> References: <201411020201.sA221unt091493@svn.freebsd.org> <720EB74E-094A-43F3-8B1C-47BC7F6FECC3@grondar.org> <1414934579.17308.248.camel@revolution.hippie.lan>
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> On 2 Nov 2014, at 13:22, Ian Lepore <ian@FreeBSD.org> wrote: >=20 > On Sun, 2014-11-02 at 09:45 +0000, Mark R V Murray wrote: >> Hi DES, >>=20 >> I=C2=B4m scared witless of this being on-by-default, for the reason = given in the removed comment. I=C2=B4d much prefer to see it only turned = on if a kernel option is set, and the embedded folks /et al/ can use = that. >>=20 >> Please reinstate the #ifdef RANDOM_AUTOSEED, and set a kernel option = to turn it on. Please also leave the comment; summarily turning on an = unprepared generator is not going to be obvious to anyone but an = attacker. >>=20 >> Moving the point of the auto-firstseed to where is good, thanks. >>=20 >> M >>=20 >=20 > To give you some idea of how usable this new stuff is on a system that > isn't an x86 server or someone's desktop or laptop... after commenting > out the postrandom so that a board would at least boot (but before = DES' > resend change), I left a board sitting idle at the login prompt. It = was > somewhere between 40 minutes and an hour before I saw this: >=20 > FreeBSD/arm (rpi) (ttyu0) >=20 > login: random: reseed - fast - thresh 96,1 - 0 48 0 0 0 130 0 0 620 0 = 0 0 0 0 0 0 0 0 0 0 > random: reseed - slow - thresh 128,2 - 0 44 0 0 0 130 0 0 619 0 0 0 0 = 0 0 0 0 0 0 0 > random: unblocking device. Thanks for doing this, Ian. This is good information, and tells me a lot about Yarrow on some systems. > Securing a system against some theoretical attack has value only to = the > point where the system is no longer usable at all. At that point you > kind of have to declare the attacker the winner, and he didn't even = have > to actually launch an attack. Point conceded. :-) M --=20 Mark R V Murray
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