From: Lukasz Stelmach <l.stelmach@samsung.com>
To: Stephan Mueller <smueller@chronox.de>
Cc: Matt Mackall <mpm@selenic.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Ray Jui <rjui@broadcom.com>,
Scott Branden <sbranden@broadcom.com>,
bcm-kernel-feedback-list@broadcom.com,
Kukjin Kim <kgene@kernel.org>,
Krzysztof Kozlowski <krzk@kernel.org>,
Florian Fainelli <f.fainelli@gmail.com>,
Markus Elfring <elfring@users.sourceforge.net>,
Matthias Brugger <mbrugger@suse.com>,
Stefan Wahren <wahrenst@gmx.net>,
linux-crypto@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org,
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Subject: Re: [PATCH 1/2] hwrng: iproc-rng200 - Set the quality value
Date: Fri, 15 May 2020 11:06:46 +0200 [thread overview]
Message-ID: <dleftjblmp8t3t.fsf%l.stelmach@samsung.com> (raw)
In-Reply-To: <2080864.23lDWg4Bvs@tauon.chronox.de> (Stephan Mueller's message of "Fri, 15 May 2020 10:32:22 +0200")
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It was <2020-05-15 pią 10:32>, when Stephan Mueller wrote:
> Am Freitag, 15. Mai 2020, 00:18:41 CEST schrieb Lukasz Stelmach:
>
>> I am running tests using SP800-90B tools and the first issue I can see
>> is the warning that samples contain less than 1e6 bytes of data. I know
>> little about maths behind random number generators, but I have noticed
>> that the bigger chunk of data from an RNG I feed into either ent or ea_iid
>> the higher entropy they report. That is why I divided the data into 1024
>> bit chunks in the first place. To get worse results. With ea_iid they
>> get even worse (128 bytes of random data)
>
> I read that you seem to just take the output data from the RNG. If this is
> correct, I think we can stop right here. The output of an RNG is usually after
> post-processing commonly provided by a cryptographic function.
>
> Thus, when processing the output of the RNG all what we measure here is the
> quality of the cryptographic post-processing and not the entropy that may be
> present in the data.
>
> What we need is to access the noise source and analyze this with the given
> tool set. And yes, the analysis may require adjusting the data to a format
> that can be consumed and analyzed by the statistical tests.
I took data from /dev/hwrng which is directly connected to the
hardware. See rng_dev_read() in drivers/char/hw_random/core.c.
--
Łukasz Stelmach
Samsung R&D Institute Poland
Samsung Electronics
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next prev parent reply other threads:[~2020-05-15 9:06 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20200514190737eucas1p18ccdddb185ea7611683a6859e17bc721@eucas1p1.samsung.com>
2020-05-14 19:07 ` [PATCH 0/2] Set the quality value for two HW RNGs Łukasz Stelmach
[not found] ` <CGME20200514190738eucas1p2695c0d8af064ee702209ca03696ef438@eucas1p2.samsung.com>
2020-05-14 19:07 ` [PATCH 1/2] hwrng: iproc-rng200 - Set the quality value Łukasz Stelmach
2020-05-14 20:20 ` Stephan Mueller
[not found] ` <CGME20200514221852eucas1p2bea169d0b4467b0ec9e195c6ac58a08a@eucas1p2.samsung.com>
2020-05-14 22:18 ` Lukasz Stelmach
2020-05-15 8:32 ` Stephan Mueller
[not found] ` <CGME20200515090647eucas1p21018edfd835730c9a68dcb186349ee74@eucas1p2.samsung.com>
2020-05-15 9:06 ` Lukasz Stelmach [this message]
[not found] ` <CGME20200515090158eucas1p1b653fc50f1ad4f0f6c92525ab3188d45@eucas1p1.samsung.com>
2020-05-15 9:01 ` Lukasz Stelmach
2020-05-15 9:10 ` Stephan Mueller
[not found] ` <CGME20200515110002eucas1p136759396d9b61f214d1f14856c009501@eucas1p1.samsung.com>
2020-05-15 10:59 ` Lukasz Stelmach
[not found] ` <CGME20200514190740eucas1p293129b2ef3ba706652a9327e55db9649@eucas1p2.samsung.com>
2020-05-14 19:07 ` [PATCH 2/2] hwrng: exynos " Łukasz Stelmach
2020-05-14 20:20 ` Stephan Mueller
[not found] ` <CGME20200519212617eucas1p1b6e7af0ecb894896b165601fafd6abe8@eucas1p1.samsung.com>
2020-05-19 21:25 ` [PATCH v2 0/2] Set the quality value for two HW RNGs Łukasz Stelmach
[not found] ` <CGME20200519212619eucas1p22fa5d3db2521096dc4b79f6e53016d17@eucas1p2.samsung.com>
2020-05-19 21:25 ` [PATCH v2 1/2] hwrng: iproc-rng200 - Set the quality value Łukasz Stelmach
2020-05-20 6:23 ` Stephan Mueller
[not found] ` <CGME20200520091043eucas1p15ecae108007382a95b01e42241cc7a26@eucas1p1.samsung.com>
2020-05-20 9:10 ` Lukasz Stelmach
2020-05-20 9:18 ` Stephan Mueller
[not found] ` <CGME20200520104448eucas1p122e9a8ed84d5276a1b796e10ef5e1964@eucas1p1.samsung.com>
2020-05-20 10:44 ` Lukasz Stelmach
2020-05-20 11:53 ` Stephan Mueller
2020-05-20 12:00 ` Krzysztof Kozlowski
2020-05-20 12:11 ` Stephan Mueller
[not found] ` <CGME20200520143211eucas1p21bd93be5c62726aa715db05bb6e7119b@eucas1p2.samsung.com>
2020-05-20 14:31 ` Lukasz Stelmach
2020-05-20 8:18 ` Kamil Konieczny
2020-05-21 11:00 ` Stefan Wahren
[not found] ` <CGME20200521191415eucas1p2d112a86171b23dcf255e7da53a56f4f3@eucas1p2.samsung.com>
2020-05-21 19:14 ` Lukasz Stelmach
2020-05-23 18:46 ` Stephan Müller
[not found] ` <CGME20200519212621eucas1p13279db41d930b69e115972463c994a37@eucas1p1.samsung.com>
2020-05-19 21:25 ` [PATCH v2 2/2] hwrng: exynos " Łukasz Stelmach
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