From owner-freebsd-security@freebsd.org  Sun Mar 19 14:44:00 2017
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From: =?utf-8?Q?Dag-Erling_Sm=C3=B8rgrav?= <des@des.no>
To: Andrey Chernov <ache@freebsd.org>
Cc: Xin LI <delphij@gmail.com>, Steven Chamberlain <steven@pyro.eu.org>,
 kostikbel@gmail.com,
 "freebsd-security\@freebsd.org" <freebsd-security@freebsd.org>,
 freebsd <freebsd-hackers@freebsd.org>
Subject: Re: arc4random weakness
References: <CAD2Ti28acbW+pGQR5UihECWvg9WduGmVzkVFug_2ZWRF2zyTBw@mail.gmail.com>
 <20170313220639.GB65190@pyro.eu.org>
 <20170315130615.GC25448@pyro.eu.org>
 <5160183b-9778-59aa-6cf9-118014a588eb@freebsd.org>
 <CAGMYy3v4f1y6SwPjj=hqJVLA=ar0aAWsK4mwMGoQV3dEKC7=iA@mail.gmail.com>
 <8677f9d8-b326-2526-47ce-f2e18421c074@freebsd.org>
Date: Sun, 19 Mar 2017 15:43:46 +0100
In-Reply-To: <8677f9d8-b326-2526-47ce-f2e18421c074@freebsd.org> (Andrey
 Chernov's message of "Thu, 16 Mar 2017 22:26:09 +0300")
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Andrey Chernov <ache@freebsd.org> writes:
> Theo kindly explained that zeroing whole page instead of single variable
> suits to his newest arc4random better, since clears two structs at once
> (including ChaCha state), making some form of backward secrecy.

Yes, avoiding leaking key material to child processes would be useful
for more than just arc4random.

DES
--=20
Dag-Erling Sm=C3=B8rgrav - des@des.no