.\"	$OpenBSD: urng.4,v 1.5 2018/04/28 15:44:59 jasper Exp $
.\"
.\" Copyright (c) 2015 Sean Levy <attila@stalphonsos.com>
.\" Copyright (c) 2017 Jasper Lievisse Adriaanse <jasper@openbsd.org>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.Dd $Mdocdate: April 28 2018 $
.Dt URNG 4
.Os
.Sh NAME
.Nm urng
.Nd USB Random Number Generator devices
.Sh SYNOPSIS
.Cd "urng* at uhub?"
.Sh DESCRIPTION
The
.Nm
driver provides support for various true random number generator
(TRNG) devices connected via USB.
.Nm
reads raw entropy from the device at a (hardware dependent) interval
and stirs it into the system entropy pool with
.Xr enqueue_randomness 9 .
.Sh HARDWARE
The following devices are supported by this driver:
.Bl -tag -width "Altus Metrum"
.It Araneus Alea I and II
Capable of delivering 100kbit/sec of hardware-generated entropy.
.It Altus Metrum ChaosKey 1.0
This device is capable of providing entropy at 10Mbit/s.
.El
.Sh SEE ALSO
.Xr intro 4 ,
.Xr usb 4 ,
.Xr enqueue_randomness 9
.Sh HISTORY
The
.Nm
driver first appeared in
.Ox 6.2 .
.Sh AUTHORS
The
.Nm
driver was written by
.An Aaron Bieber Aq Mt abieber@openbsd.org ,
.An Jasper Lievisse Adriaanse Aq Mt jasper@openbsd.org ,
and
.An Sean Levy Aq Mt attila@stalphonsos.com .