| Message ID | 2704719.5neY5jeiZ3@positron.chronox.de (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Herbert Xu |
| Headers | show |
| Series | /dev/random - a new approach with full SP800-90B | expand |
On 1/15/20 2:34 AM, Stephan Müller wrote: > > CC: "Eric W. Biederman" <ebiederm@xmission.com> > CC: "Alexander E. Patrakov" <patrakov@gmail.com> > CC: "Ahmed S. Darwish" <darwish.07@gmail.com> > CC: "Theodore Y. Ts'o" <tytso@mit.edu> > CC: Willy Tarreau <w@1wt.eu> > CC: Matthew Garrett <mjg59@srcf.ucam.org> > CC: Vito Caputo <vcaputo@pengaru.com> > CC: Andreas Dilger <adilger.kernel@dilger.ca> > CC: Jan Kara <jack@suse.cz> > CC: Ray Strode <rstrode@redhat.com> > CC: William Jon McCann <mccann@jhu.edu> > CC: zhangjs <zachary@baishancloud.com> > CC: Andy Lutomirski <luto@kernel.org> > CC: Florian Weimer <fweimer@redhat.com> > CC: Lennart Poettering <mzxreary@0pointer.de> > CC: Nicolai Stange <nstange@suse.de> > Reviewed-by: Marcelo Henrique Cerri <marcelo.cerri@canonical.com> > Reviewed-by: Roman Drahtmueller <draht@schaltsekun.de> > Tested-by: Roman Drahtmüller <draht@schaltsekun.de> > Tested-by: Marcelo Henrique Cerri <marcelo.cerri@canonical.com> > Tested-by: Neil Horman <nhorman@redhat.com> > Signed-off-by: Stephan Mueller <smueller@chronox.de> > --- > 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@chronox.de> > + */ > + > +#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.
Am Donnerstag, 16. Januar 2020, 01:17:05 CET schrieb Randy Dunlap: Hi Randy, > On 1/15/20 2:34 AM, Stephan Müller wrote: > > CC: "Eric W. Biederman" <ebiederm@xmission.com> > > CC: "Alexander E. Patrakov" <patrakov@gmail.com> > > CC: "Ahmed S. Darwish" <darwish.07@gmail.com> > > CC: "Theodore Y. Ts'o" <tytso@mit.edu> > > CC: Willy Tarreau <w@1wt.eu> > > CC: Matthew Garrett <mjg59@srcf.ucam.org> > > CC: Vito Caputo <vcaputo@pengaru.com> > > CC: Andreas Dilger <adilger.kernel@dilger.ca> > > CC: Jan Kara <jack@suse.cz> > > CC: Ray Strode <rstrode@redhat.com> > > CC: William Jon McCann <mccann@jhu.edu> > > CC: zhangjs <zachary@baishancloud.com> > > CC: Andy Lutomirski <luto@kernel.org> > > CC: Florian Weimer <fweimer@redhat.com> > > CC: Lennart Poettering <mzxreary@0pointer.de> > > CC: Nicolai Stange <nstange@suse.de> > > Reviewed-by: Marcelo Henrique Cerri <marcelo.cerri@canonical.com> > > Reviewed-by: Roman Drahtmueller <draht@schaltsekun.de> > > Tested-by: Roman Drahtmüller <draht@schaltsekun.de> > > Tested-by: Marcelo Henrique Cerri <marcelo.cerri@canonical.com> > > Tested-by: Neil Horman <nhorman@redhat.com> > > Signed-off-by: Stephan Mueller <smueller@chronox.de> > > --- > > > > 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. I added "depends on > > > + 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@chronox.de> > > + */ > > + > > +#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. Changed. Thank you. Ciao Stephan
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 + 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/Makefile b/drivers/char/lrng/Makefile index 94b2dfb2dfdb..4f5b6f38f0c4 100644 --- a/drivers/char/lrng/Makefile +++ b/drivers/char/lrng/Makefile @@ -13,3 +13,4 @@ obj-$(CONFIG_SYSCTL) += lrng_proc.o obj-$(CONFIG_LRNG_DRNG_SWITCH) += lrng_switch.o obj-$(CONFIG_LRNG_DRBG) += lrng_drbg.o obj-$(CONFIG_LRNG_KCAPI) += lrng_kcapi.o +obj-$(CONFIG_LRNG_JENT) += lrng_jent.o 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@chronox.de> + */ + +#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"); + +/** + * lrng_get_jent() - Get Jitter RNG entropy + * + * @outbuf: buffer to store entropy + * @outbuflen: length of buffer + * + * Return: + * * > 0 on success where value provides the added entropy in bits + * * 0 if no fast source was available + */ +static struct rand_data *lrng_jent_state; + +u32 lrng_get_jent(u8 *outbuf, unsigned int outbuflen) +{ + int ret; + u32 ent_bits = jitterrng; + unsigned long flags; + static DEFINE_SPINLOCK(lrng_jent_lock); + static int lrng_jent_initialized = 0; + + spin_lock_irqsave(&lrng_jent_lock, flags); + + if (!ent_bits || (lrng_jent_initialized == -1)) { + spin_unlock_irqrestore(&lrng_jent_lock, flags); + return 0; + } + + if (!lrng_jent_initialized) { + lrng_jent_state = jent_lrng_entropy_collector(); + if (!lrng_jent_state) { + jitterrng = 0; + lrng_jent_initialized = -1; + spin_unlock_irqrestore(&lrng_jent_lock, flags); + pr_info("Jitter RNG unusable on current system\n"); + return 0; + } + lrng_jent_initialized = 1; + pr_debug("Jitter RNG working on current system\n"); + } + ret = jent_read_entropy(lrng_jent_state, outbuf, outbuflen); + spin_unlock_irqrestore(&lrng_jent_lock, flags); + + if (ret) { + pr_debug("Jitter RNG failed with %d\n", ret); + return 0; + } + + /* Obtain entropy statement */ + if (outbuflen != LRNG_DRNG_SECURITY_STRENGTH_BYTES) + ent_bits = (ent_bits * outbuflen<<3) / + LRNG_DRNG_SECURITY_STRENGTH_BITS; + /* Cap entropy to buffer size in bits */ + ent_bits = min_t(u32, ent_bits, outbuflen<<3); + pr_debug("obtained %u bits of entropy from Jitter RNG noise source\n", + ent_bits); + + return ent_bits; +} + +u32 lrng_jent_entropylevel(void) +{ + return min_t(u32, jitterrng, LRNG_DRNG_SECURITY_STRENGTH_BITS); +}