On 1/15/20 2:34 AM, Stephan Müller wrote: > > CC: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> > CC: "Alexander E. Patrakov" <patrakov@xxxxxxxxx> > CC: "Ahmed S. Darwish" <darwish.07@xxxxxxxxx> > CC: "Theodore Y. Ts'o" <tytso@xxxxxxx> > CC: Willy Tarreau <w@xxxxxx> > CC: Matthew Garrett <mjg59@xxxxxxxxxxxxx> > CC: Vito Caputo <vcaputo@xxxxxxxxxxx> > CC: Andreas Dilger <adilger.kernel@xxxxxxxxx> > CC: Jan Kara <jack@xxxxxxx> > CC: Ray Strode <rstrode@xxxxxxxxxx> > CC: William Jon McCann <mccann@xxxxxxx> > CC: zhangjs <zachary@xxxxxxxxxxxxxxxx> > CC: Andy Lutomirski <luto@xxxxxxxxxx> > CC: Florian Weimer <fweimer@xxxxxxxxxx> > CC: Lennart Poettering <mzxreary@xxxxxxxxxxx> > CC: Nicolai Stange <nstange@xxxxxxx> > Reviewed-by: Marcelo Henrique Cerri <marcelo.cerri@xxxxxxxxxxxxx> > Reviewed-by: Roman Drahtmueller <draht@xxxxxxxxxxxxxx> > Tested-by: Roman Drahtmüller <draht@xxxxxxxxxxxxxx> > Tested-by: Marcelo Henrique Cerri <marcelo.cerri@xxxxxxxxxxxxx> > Tested-by: Neil Horman <nhorman@xxxxxxxxxx> > Signed-off-by: Stephan Mueller <smueller@xxxxxxxxxx> > --- > drivers/char/lrng/Kconfig | 11 +++++ > drivers/char/lrng/Makefile | 1 + > drivers/char/lrng/lrng_jent.c | 89 +++++++++++++++++++++++++++++++++++ > 3 files changed, 101 insertions(+) > create mode 100644 drivers/char/lrng/lrng_jent.c > > diff --git a/drivers/char/lrng/Kconfig b/drivers/char/lrng/Kconfig > index 0d070a3897dd..10b7cbdb8c8e 100644 > --- a/drivers/char/lrng/Kconfig > +++ b/drivers/char/lrng/Kconfig > @@ -92,4 +92,15 @@ config LRNG_KCAPI > provided by the selected kernel crypto API RNG. > endif # LRNG_DRNG_SWITCH > > +config LRNG_JENT > + bool "Enable Jitter RNG as LRNG Seed Source" > + select CRYPTO_JITTERENTROPY Don't select unless CRYPTO is already set/enabled. > + help > + The Linux RNG may use the Jitter RNG as noise source. Enabling > + this option enables the use of the Jitter RNG. Its default > + entropy level is 16 bits of entropy per 256 data bits delivered > + by the Jitter RNG. This entropy level can be changed at boot > + time or at runtime with the lrng_base.jitterrng configuration > + variable. > + > endif # LRNG > diff --git a/drivers/char/lrng/lrng_jent.c b/drivers/char/lrng/lrng_jent.c > new file mode 100644 > index 000000000000..ff0bbe2680c4 > --- /dev/null > +++ b/drivers/char/lrng/lrng_jent.c > @@ -0,0 +1,89 @@ > +// SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause > +/* > + * LRNG Fast Noise Source: Jitter RNG > + * > + * Copyright (C) 2016 - 2020, Stephan Mueller <smueller@xxxxxxxxxx> > + */ > + > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt > + > +#include <linux/types.h> > +#include <crypto/internal/jitterentropy.h> > + > +#include "lrng_internal.h" > + > +/* > + * Estimated entropy of data is a 16th of LRNG_DRNG_SECURITY_STRENGTH_BITS. > + * Albeit a full entropy assessment is provided for the noise source indicating > + * that it provides high entropy rates and considering that it deactivates > + * when it detects insufficient hardware, the chosen under estimation of > + * entropy is considered to be acceptable to all reviewers. > + */ > +static u32 jitterrng = LRNG_DRNG_SECURITY_STRENGTH_BITS>>4; > +module_param(jitterrng, uint, 0644); > +MODULE_PARM_DESC(jitterrng, "Entropy in bits of 256 data bits from Jitter " > + "RNG noise source"); One line for the string, please, not split to 2 lines. -- ~Randy Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
