From: Oliver Schinagl <oliver+list@schinagl.nl>
To: Linus Walleij <linus.walleij@linaro.org>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>,
Arnd Bergmann <arnd@ardb.de>,
Greg KH <gregkh@linuxfoundation.org>,
Oliver Schinagl <oliver@schinagl.nl>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH 1/2] Initial support for Allwinner's Security ID fuses
Date: Thu, 23 May 2013 10:10:17 +0200 [thread overview]
Message-ID: <519DCEE9.6070208@schinagl.nl> (raw)
In-Reply-To: <CACRpkdaWADjy1YZXTcRaXU+ZsS6_pG0hojQdnz=qeTgyVY7_Ww@mail.gmail.com>
On 05/23/13 09:56, Linus Walleij wrote:
> On Fri, May 17, 2013 at 3:35 PM, Oliver Schinagl
> <oliver+list@schinagl.nl> wrote:
>
> (...)
>> While initially these fuses are used to somewhat determin the chipID, these
>> appear to be writeable by the user and thus can be used for other purpouses.
>> For example storing a 128 bit root key, a unique serial number, which could
>> then even be used as a MAC address.
> (...)
> Then follows some code to read out the keys from sysfs I guess..
>> +static int __init sid_probe(struct platform_device *pdev)
>
> It's really simple to actually make the kernel use this to seed the
> entropy pool.
>
> #include <linux/random.h>
> add_device_randomness(u8 *, num);
>
> If you know after probe that you can read out a number of bytes
> of device-unique data, I think you should add those bytes to the
> entropy pool like this.
While that is a great idea, we can't guarantee device uniqueness. We've
already seen some chips that where 'forgotten' to program and default
set to all 0. I guess that doesn't have to be a bad thing.
Then, i'm not sure if the driver is the best for this to be loaded?
Maxime, what do you think? Personally I would feel more in having this
in the mach-sunxi/core.c bit, but then again, this is currently a module
and wouldn't be useful to have there. Maxime is far more knowledgeable
to answer that.
It should probably be noted, that the sunxi series have a hardware
crypto engine, with hardware random seed generator, one for a later project.
>
> Yours,
> Linus Walleij
>
next prev parent reply other threads:[~2013-05-23 8:10 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-17 13:35 [PATCH 0/2] Driver for Allwinner sunxi Security ID Oliver Schinagl
2013-05-17 13:35 ` [PATCH 1/2] Initial support for Allwinner's Security ID fuses Oliver Schinagl
2013-05-17 13:45 ` Arnd Bergmann
2013-05-17 18:54 ` Oliver Schinagl
2013-05-17 21:18 ` Maxime Ripard
2013-05-18 17:19 ` Oliver Schinagl
2013-05-19 15:22 ` Maxime Ripard
2013-05-24 21:50 ` Oliver Schinagl
2013-05-25 12:22 ` Maxime Ripard
2013-05-25 19:25 ` Oliver Schinagl
2013-05-26 9:35 ` Maxime Ripard
2013-05-23 7:56 ` Linus Walleij
2013-05-23 8:10 ` Oliver Schinagl [this message]
2013-05-23 8:20 ` Linus Walleij
2013-05-23 14:58 ` Maxime Ripard
2013-05-23 15:05 ` Oliver Schinagl
2013-05-23 15:27 ` Maxime Ripard
2013-05-17 13:35 ` [PATCH 2/2] Add sunxi-sid to dts for sun4i and sun5i Oliver Schinagl
2013-05-17 21:21 ` Maxime Ripard
2013-06-02 14:58 [PATCH 0/2] v2 Driver for Allwinner sunxi Security ID Oliver Schinagl
2013-06-02 14:58 ` [PATCH 1/2] Initial support for Allwinner's Security ID fuses Oliver Schinagl
2013-06-02 15:09 ` Russell King - ARM Linux
2013-06-02 15:21 ` Oliver Schinagl
2013-06-06 19:16 ` Andy Shevchenko
2013-06-10 21:43 ` Oliver Schinagl
2013-06-11 10:51 ` Andy Shevchenko
2013-06-14 23:16 [PATCH 0/2] v3 Driver for Allwinner sunxi Security ID Oliver Schinagl
2013-06-14 23:16 ` [PATCH 1/2] Initial support for Allwinner's Security ID fuses Oliver Schinagl
2013-06-15 2:14 ` Andy Shevchenko
2013-06-15 9:34 ` Oliver Schinagl
2013-06-15 10:28 ` Tomasz Figa
2013-06-17 10:36 ` Oliver Schinagl
2013-06-17 11:25 ` Russell King - ARM Linux
2013-06-17 11:32 ` Oliver Schinagl
2013-06-17 11:51 ` Maxime Ripard
2013-06-17 12:04 ` Oliver Schinagl
2013-06-17 12:51 ` Tomasz Figa
2013-06-17 13:10 ` Oliver Schinagl
2013-06-17 13:23 ` Tomasz Figa
2013-06-17 13:47 ` Oliver Schinagl
2013-06-17 20:59 [PATCH 0/2] v4 Driver for Allwinner sunxi Security ID Oliver Schinagl
2013-06-17 20:59 ` [PATCH 1/2] Initial support for Allwinner's Security ID fuses Oliver Schinagl
2013-06-17 21:06 ` Tomasz Figa
2013-06-17 22:58 ` Greg KH
2013-06-24 9:29 ` Maxime Ripard
2013-06-24 16:04 ` Greg KH
2013-06-24 17:11 ` Oliver Schinagl
2013-06-24 18:15 ` Greg KH
2013-06-24 21:21 ` Oliver Schinagl
2013-06-24 21:46 ` Greg KH
2013-06-26 8:32 ` Oliver Schinagl
2013-06-26 17:51 ` Greg KH
2013-07-05 7:24 ` Oliver Schinagl
2013-07-06 19:36 ` Greg KH
2013-07-07 0:17 ` Greg KH
2013-06-26 9:10 ` Russell King - ARM Linux
2013-06-26 17:51 ` Greg KH
2013-06-24 21:04 ` Maxime Ripard
2013-06-26 9:22 ` Geert Uytterhoeven
2013-06-26 17:49 ` Greg KH
2013-06-18 5:41 ` Andy Shevchenko
2013-08-27 14:13 [PATCHv5 0/2] Driver for Allwinner sunxi Security ID oliver+list
2013-08-27 14:13 ` [PATCH 1/2] Initial support for Allwinner's Security ID fuses oliver+list
2013-08-27 15:42 ` Maxime Ripard
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=519DCEE9.6070208@schinagl.nl \
--to=oliver+list@schinagl.nl \
--cc=arnd@ardb.de \
--cc=gregkh@linuxfoundation.org \
--cc=linus.walleij@linaro.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=maxime.ripard@free-electrons.com \
--cc=oliver@schinagl.nl \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).