[Cerowrt-devel] pcengines apu2c4 hardware random number generation

Dave Taht dave.taht at gmail.com
Fri May 6 16:19:08 EDT 2016

On Thu, May 5, 2016 at 9:10 AM, Josh Datko <jbdatko at gmail.com> wrote:
> On Wed, 2016-05-04 at 16:28 -0700, Dave Taht wrote:
>> so I figure that there might be something even simpler out there from
>> the pi-ish or beaglebone world that could be repurposed to suit?
> I've used Atmel's CryptoAuthentication chips routinely. They are i2c
> based and have a (proprietary) RNG on them. I have a few linux driver
> options for using them.

I forget how fast those chips were (?)

> Presumably, you want this HWRNG thing to be inside the case. Looking at
> that pdf, jumper J4 says it's an I2C connector. Those Atmel chips I was
> playing with are all i2c, so you could try flywiring those to the
> connector.
> I'm not sure what pin is what, but PWR and GND should be easy to find
> and then SDA/SCL I just plug and and try. If it doesn't work, swap the
> pins.
> As long as the CPU has access to that i2c bus, (is there an i2c-tools
> equivalent on cerowrt?), then you should see it.

"cerowrt" as "cerowrt" is dead, I'm doing as much work as possible in
the easier to debug x86 world.

> miniPCIe has I2C as well. I had this idea once to take a miniPCI card
> and solder the atmel chips to the SDA/SCL lines.

Meh. If there is a decent gpio header on j.random x86 board, I'd just
as soon use that.

> 8-pin molex connectors should be easy to find and it probably wouldn't
> be too bad to make it a "proper" expansion board, but ... loose wires
> make life more exciting :)
> Josh
> links:
> Out-of-tree kernel driver for Atmel AT204/108/508 chips with /dev/hwrng
> support: https://github.com/cryptotronix/atsha204-i2c
> CLI application using the AT204: https://github.com/cryptotronix/hashle
> t
> Digikey: https://www.digikey.com/product-detail/en/atmel/ATECC508A-SSHD
> A-B/ATECC508A-SSHDA-B-ND/5213053
> ^ The 204A are cheaper, the 508A have ECDSA/ECDH as well as the RNG and
> my "eclet" driver will support ecdsa signing/ecdh, so might as well get
> those vs. the 204A.

Dave Täht
Let's go make home routers and wifi faster! With better software!

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