On 1/15/20 2:33 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: 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_drbg.c | 260 ++++++++++++++++++++++++++++++++++ > 3 files changed, 272 insertions(+) > create mode 100644 drivers/char/lrng/lrng_drbg.c > > diff --git a/drivers/char/lrng/Kconfig b/drivers/char/lrng/Kconfig > index cb701bb0b8b6..15fb623d9d1f 100644 > --- a/drivers/char/lrng/Kconfig > +++ b/drivers/char/lrng/Kconfig > @@ -71,4 +71,15 @@ menuconfig LRNG_DRNG_SWITCH > accessible via the external interfaces. With this configuration > option other DRNGs can be selected and loaded at runtime. > > +if LRNG_DRNG_SWITCH > +config LRNG_DRBG > + tristate "SP800-90A support for the LRNG" > + select CRYPTO_DRBG_MENU > + select CRYPTO_CMAC if CRYPTO_DRBG_CTR Don't select these if CRYPTO is not already set/enabled. It causes Kconfig warnings and possible build errors. > + help > + Enable the SP800-90A DRBG support for the LRNG. Once the > + module is loaded, output from /dev/random, /dev/urandom, > + getrandom(2), or get_random_bytes is provided by a DRBG. > +endif # LRNG_DRNG_SWITCH > + > endif # LRNG > diff --git a/drivers/char/lrng/lrng_drbg.c b/drivers/char/lrng/lrng_drbg.c > new file mode 100644 > index 000000000000..8bf2badb1fe0 > --- /dev/null > +++ b/drivers/char/lrng/lrng_drbg.c > @@ -0,0 +1,260 @@ > +// SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause > +/* > + * Backend for the LRNG providing the cryptographic primitives using the > + * kernel crypto API and its DRBG. > + * > + * Copyright (C) 2016 - 2020, Stephan Mueller <smueller@xxxxxxxxxx> > + */ > + > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt > + > +#include <crypto/drbg.h> > +#include <linux/init.h> > +#include <linux/module.h> > +#include <linux/lrng.h> > + > +/* > + * Define a DRBG plus a hash / MAC used to extract data from the entropy pool. > + * For LRNG_HASH_NAME you can use a hash or a MAC (HMAC or CMAC) of your choice > + * (Note, you should use the suggested selections below -- using SHA-1 or MD5 > + * is not wise). The idea is that the used cipher primitive can be selected to > + * be the same as used for the DRBG. I.e. the LRNG only uses one cipher > + * primitive using the same cipher implementation with the options offered in > + * the following. This means, if the CTR DRBG is selected and AES-NI is present, > + * both the CTR DRBG and the selected cmac(aes) use AES-NI. > + * > + * The security strengths of the DRBGs are all 256 bits according to > + * SP800-57 section 5.6.1. > + * > + * This definition is allowed to be changed. > + */ > +#ifdef CONFIG_CRYPTO_DRBG_CTR > +static unsigned int lrng_drbg_type = 0; > +#elif defined CONFIG_CRYPTO_DRBG_HMAC > +static unsigned int lrng_drbg_type = 1; > +#elif defined CONFIG_CRYPTO_DRBG_HASH > +static unsigned int lrng_drbg_type = 2; > +#else > +#error "Unknown DRBG in use" > +#endif > + > +/* The parameter must be r/o in sysfs as otherwise races appear. */ > +module_param(lrng_drbg_type, uint, 0444); > +MODULE_PARM_DESC(lrng_drbg_type, "DRBG type used for LRNG (0->CTR_DRBG, " > + "1->HMAC_DRBG, 2->Hash_DRBG)"); One line for the string, please, not split. -- ~Randy Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
