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From: Stephan Mueller <smueller@chronox.de>
To: "Łukasz Stelmach" <l.stelmach@samsung.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>,
	robh+dt@kernel.org, Herbert Xu <herbert@gondor.apana.org.au>,
	"David S. Miller" <davem@davemloft.net>,
	Kukjin Kim <kgene@kernel.org>,
	linux-crypto@vger.kernel.org, linux-samsung-soc@vger.kernel.org,
	linux-kernel@vger.kernel.org, m.szyprowski@samsung.com,
	b.zolnierkie@samsung.com
Subject: Re: [PATCH 3/3] crypto: exynos - Reseed PRNG after generating 2^16 random bytes
Date: Tue, 05 Dec 2017 14:52:31 +0100	[thread overview]
Message-ID: <6915204.SlqusmoAzB@tauon.chronox.de> (raw)
In-Reply-To: <20171205123558.31087-4-l.stelmach@samsung.com>

Am Dienstag, 5. Dezember 2017, 13:35:58 CET schrieb Łukasz Stelmach:

Hi Łukasz,

> Reseed PRNG after reading 65 kB of randomness. Although this may reduce
> performance, in most casese the loss is not noticable.

Please add to the log that you also increase the timer-based reseed to 1 
second?!

Another suggestion: maybe you want to add a comment to the reseed function to 
indicate it is for enhanced backtracking resistance. Otherwise a lot of folks 
would scratch their head why such code exists in the first place. :-)

Other than that:

Reviewed-by: Stephan Mueller <smueller@chronox.de>

Ciao
Stephan

  reply	other threads:[~2017-12-05 13:52 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20171205123601eucas1p2ef1a2fdce84dce8dc4b54c419ce566a7@eucas1p2.samsung.com>
2017-12-05 12:35 ` [PATCH 0/3] Assorted changes for Exynos PRNG driver Łukasz Stelmach
     [not found]   ` <CGME20171205123602eucas1p2d3ee1e53adc35df7c52917d43bcdebfd@eucas1p2.samsung.com>
2017-12-05 12:35     ` [PATCH 1/3] crypto: exynos - Support Exynos5250+ SoCs Łukasz Stelmach
2017-12-05 13:34       ` Krzysztof Kozlowski
     [not found]         ` <CGME20171206134305eucas1p218c38b977c14cae58763586458c3e78d@eucas1p2.samsung.com>
2017-12-06 13:42           ` Łukasz Stelmach
2017-12-06 14:05             ` Krzysztof Kozlowski
     [not found]               ` <CGME20171206145312eucas1p226d52f60f15e45456aefd6270cc88e07@eucas1p2.samsung.com>
2017-12-06 14:53                 ` Łukasz Stelmach
2017-12-06 15:28                   ` Krzysztof Kozlowski
     [not found]                     ` <CGME20171207092032eucas1p296f7cbc547d159c52561182cc6461504@eucas1p2.samsung.com>
2017-12-07  9:20                       ` Łukasz Stelmach
2017-12-06 17:56               ` Joe Perches
     [not found]   ` <CGME20171205123603eucas1p177cceb022e3a5c0a9d13ca437c05b669@eucas1p1.samsung.com>
2017-12-05 12:35     ` [PATCH 2/3] crypto: exynos - Improve performance of PRNG Łukasz Stelmach
2017-12-05 13:49       ` Krzysztof Kozlowski
2017-12-05 13:54       ` Stephan Mueller
     [not found]         ` <CGME20171205164319eucas1p1e79b9798d655851762cc83a6737b73b4@eucas1p1.samsung.com>
2017-12-05 16:43           ` Łukasz Stelmach
2017-12-05 17:53             ` Krzysztof Kozlowski
2017-12-05 18:06               ` Krzysztof Kozlowski
     [not found]                 ` <CGME20171206113301eucas1p23da9decc34cc646b0bf4eb88953ef94a@eucas1p2.samsung.com>
2017-12-06 11:32                   ` Łukasz Stelmach
2017-12-06 11:37                     ` Krzysztof Kozlowski
     [not found]                       ` <CGME20171206130651eucas1p22b5d0799f2a128d3d9efcc799fc3cfdc@eucas1p2.samsung.com>
2017-12-06 13:06                         ` Łukasz Stelmach
     [not found]   ` <CGME20171205123604eucas1p2a6a2738e3cf1f9c300e8d128362429ed@eucas1p2.samsung.com>
2017-12-05 12:35     ` [PATCH 3/3] crypto: exynos - Reseed PRNG after generating 2^16 random bytes Łukasz Stelmach
2017-12-05 13:52       ` Stephan Mueller [this message]
2017-12-05 13:55       ` Krzysztof Kozlowski
     [not found]   ` <CGME20171211140635eucas1p22ab5dac69623926c583779a6b93872ce@eucas1p2.samsung.com>
2017-12-11 14:06     ` [PATCH v2 0/4] Assorted changes for Exynos PRNG driver Łukasz Stelmach
     [not found]       ` <CGME20171212163609eucas1p2aaee0a21276b66f4cb492a4502f66756@eucas1p2.samsung.com>
2017-12-12 16:36         ` [PATCH v3 " Łukasz Stelmach
2017-12-22  9:09           ` Herbert Xu
2017-12-12 16:36       ` [PATCH v3 1/4] crypto: exynos - Support Exynos5250+ SoCs Łukasz Stelmach
2017-12-13  8:06         ` Krzysztof Kozlowski
2017-12-12 16:36       ` [PATCH v3 2/4] crypto: exynos - Improve performance of PRNG Łukasz Stelmach
2017-12-13  8:07         ` Krzysztof Kozlowski
2017-12-12 16:36       ` [PATCH v3 3/4] crypto: exynos - Reseed PRNG after generating 2^16 random bytes Łukasz Stelmach
2017-12-13  8:12         ` Krzysztof Kozlowski
2017-12-12 16:36       ` [PATCH v3 4/4] crypto: exynos - Introduce mutex to prevent concurrent access to hardware Łukasz Stelmach
2017-12-11 14:06   ` [PATCH v2 1/4] crypto: exynos - Support Exynos5250+ SoCs Łukasz Stelmach
2017-12-11 14:36     ` Krzysztof Kozlowski
2017-12-11 14:06   ` [PATCH v2 2/4] crypto: exynos - Improve performance of PRNG Łukasz Stelmach
2017-12-11 14:54     ` Krzysztof Kozlowski
     [not found]       ` <CGME20171212144953eucas1p2079156cb46dc72e2a73868ca2d88ba05@eucas1p2.samsung.com>
2017-12-12 14:49         ` Łukasz Stelmach
2017-12-11 14:06   ` [PATCH v2 3/4] crypto: exynos - Reseed PRNG after generating 2^16 random bytes Łukasz Stelmach
2017-12-11 14:57     ` Krzysztof Kozlowski
2017-12-11 14:06   ` [PATCH v2 4/4] crypto: exynos - Introduce mutex to prevent concurrent access to hardware Łukasz Stelmach
2017-12-11 15:03     ` Krzysztof Kozlowski
     [not found]       ` <CGME20171212103021eucas1p19a2a24930cadde55eac2f822a6a9f80c@eucas1p1.samsung.com>
2017-12-12 10:30         ` Łukasz Stelmach
2017-12-12 11:09           ` Krzysztof Kozlowski

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