crypto: drbg - Remove SHA1 from drbg

SP800-90C 3rd draft states that SHA-1 will be removed from all
specifications, including drbg by end of 2030. Given kernels built
today will be operating past that date, start complying with upcoming
requirements.

No functional change, as SHA-256 / SHA-512 based DRBG have always been
the preferred ones.

Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Reviewed-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - ensure drbg hmac sha512 is used in FIPS selftests

Update code comment, self test & healthcheck to use HMAC SHA512,
instead of HMAC SHA256. These changes are in dead-code, or FIPS
enabled code-paths only and have not effect on usual kernel builds.

On systems booting in FIPS mode that has the effect of switch sanity
selftest to HMAC sha512 based (which has been the default DRBG).

This patch updates code from 9b7b94683a ("crypto: DRBG - switch to
HMAC SHA512 DRBG as default DRBG"), but is not interesting to
cherry-pick for stable updates, because it doesn't affect regular
builds, nor has any tangible effect on FIPS certifcation.

Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Reviewed-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - update FIPS CTR self-checks to aes256

When originally drbg was introduced FIPS self-checks for all types but
CTR were using the most preferred parameters for each type of
DRBG. Update CTR self-check to use aes256.

This patch updates code from 541af946fe ("crypto: drbg - SP800-90A
Deterministic Random Bit Generator"), but is not interesting to
cherry-pick for stable updates, because it doesn't affect regular
builds, nor has any tangible effect on FIPS certifcation.

Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Reviewed-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - ensure most preferred type is FIPS health checked

drbg supports multiple types of drbg, and multiple parameters of
each. Health check sanity only checks one drbg of a single type. One
can enable all three types of drbg. And instead of checking the most
preferred algorithm (last one wins), it is currently checking first
one instead.

Update ifdef to ensure that healthcheck prefers HMAC, over HASH, over
CTR, last one wins, like all other code and functions.

This patch updates code from 541af946fe ("crypto: drbg - SP800-90A
Deterministic Random Bit Generator"), but is not interesting to
cherry-pick for stable updates, because it doesn't affect regular
builds, nor has any tangible effect on FIPS certifcation.

Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Reviewed-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - stop checking crypto_shash_alignmask

Now that the shash algorithm type does not support nonzero alignmasks,
crypto_shash_alignmask() always returns 0 and will be removed. In
preparation for this, stop checking crypto_shash_alignmask() in drbg.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - Only fail when jent is unavailable in FIPS mode

When jent initialisation fails for any reason other than ENOENT,
the entire drbg fails to initialise, even when we're not in FIPS
mode. This is wrong because we can still use the kernel RNG when
we're not in FIPS mode.

Change it so that it only fails when we are in FIPS mode.

Fixes: 57225e679788 ("crypto: drbg - Use callback API for random readiness")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - remove unnecessary (void*) conversions

remove unnecessary void* type casting

v2:
Turn assignments less than 75 characters into one line.

Signed-off-by: Dong Chuanjian <chuanjian@nfschina.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - ignore jitterentropy errors if not in FIPS mode

A subsequent patch will make the jitterentropy RNG to unconditionally
report health test errors back to callers, independent of whether
fips_enabled is set or not. The DRBG needs access to a functional
jitterentropy instance only in FIPS mode (because it's the only SP800-90B
compliant entropy source as it currently stands). Thus, it is perfectly
fine for the DRBGs to obtain entropy from the jitterentropy source only
on a best effort basis if fips_enabled is off.

Make the DRBGs to ignore jitterentropy failures if fips_enabled is not set.

Signed-off-by: Nicolai Stange <nstange@suse.de>
Reviewed-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - reseed 'nopr' drbgs periodically from get_random_bytes()

In contrast to the fully prediction resistant 'pr' DRBGs, the 'nopr'
variants get seeded once at boot and reseeded only rarely thereafter,
namely only after 2^20 requests have been served each. AFAICT, this
reseeding based on the number of requests served is primarily motivated
by information theoretic considerations, c.f. NIST SP800-90Ar1,
sec. 8.6.8 ("Reseeding").

However, given the relatively large seed lifetime of 2^20 requests, the
'nopr' DRBGs can hardly be considered to provide any prediction resistance
whatsoever, i.e. to protect against threats like side channel leaks of the
internal DRBG state (think e.g. leaked VM snapshots). This is expected and
completely in line with the 'nopr' naming, but as e.g. the
"drbg_nopr_hmac_sha512" implementation is potentially being used for
providing the "stdrng" and thus, the crypto_default_rng serving the
in-kernel crypto, it would certainly be desirable to achieve at least the
same level of prediction resistance as get_random_bytes() does.

Note that the chacha20 rngs underlying get_random_bytes() get reseeded
every CRNG_RESEED_INTERVAL == 5min: the secondary, per-NUMA node rngs from
the primary one and the primary rng in turn from the entropy pool, provided
sufficient entropy is available.

The 'nopr' DRBGs do draw randomness from get_random_bytes() for their
initial seed already, so making them to reseed themselves periodically from
get_random_bytes() in order to let them benefit from the latter's
prediction resistance is not such a big change conceptually.

In principle, it would have been also possible to make the 'nopr' DRBGs to
periodically invoke a full reseeding operation, i.e. to also consider the
jitterentropy source (if enabled) in addition to get_random_bytes() for the
seed value. However, get_random_bytes() is relatively lightweight as
compared to the jitterentropy generation process and thus, even though the
'nopr' reseeding is supposed to get invoked infrequently, it's IMO still
worthwhile to avoid occasional latency spikes for drbg_generate() and
stick to get_random_bytes() only. As an additional remark, note that
drawing randomness from the non-SP800-90B-conforming get_random_bytes()
only won't adversely affect SP800-90A conformance either: the very same is
being done during boot via drbg_seed_from_random() already once
rng_is_initialized() flips to true and it follows that if the DRBG
implementation does conform to SP800-90A now, it will continue to do so.

Make the 'nopr' DRBGs to reseed themselves periodically from
get_random_bytes() every CRNG_RESEED_INTERVAL == 5min.

More specifically, introduce a new member ->last_seed_time to struct
drbg_state for recording in units of jiffies when the last seeding
operation had taken place. Make __drbg_seed() maintain it and let
drbg_generate() invoke a reseed from get_random_bytes() via
drbg_seed_from_random() if more than 5min have passed by since the last
seeding operation. Be careful to not to reseed if in testing mode though,
or otherwise the drbg related tests in crypto/testmgr.c would fail to
reproduce the expected output.

In order to keep the formatting clean in drbg_generate() wrap the logic
for deciding whether or not a reseed is due in a new helper,
drbg_nopr_reseed_interval_elapsed().

Signed-off-by: Nicolai Stange <nstange@suse.de>
Reviewed-by: Stephan Müller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - make drbg_prepare_hrng() handle jent instantiation errors

Now that drbg_prepare_hrng() doesn't do anything but to instantiate a
jitterentropy crypto_rng instance, it looks a little odd to have the
related error handling at its only caller, drbg_instantiate().

Move the handling of jitterentropy allocation failures from
drbg_instantiate() close to the allocation itself in drbg_prepare_hrng().

There is no change in behaviour.

Signed-off-by: Nicolai Stange <nstange@suse.de>
Reviewed-by: Stephan Müller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - make reseeding from get_random_bytes() synchronous

get_random_bytes() usually hasn't full entropy available by the time DRBG
instances are first getting seeded from it during boot. Thus, the DRBG
implementation registers random_ready_callbacks which would in turn
schedule some work for reseeding the DRBGs once get_random_bytes() has
sufficient entropy available.

For reference, the relevant history around handling DRBG (re)seeding in
the context of a not yet fully seeded get_random_bytes() is:

commit 16b369a91d0d ("random: Blocking API for accessing
nonblocking_pool")
commit 4c7879907edd ("crypto: drbg - add async seeding operation")

commit 205a525c3342 ("random: Add callback API for random pool
readiness")
commit 57225e679788 ("crypto: drbg - Use callback API for random
readiness")
commit c2719503f5e1 ("random: Remove kernel blocking API")

However, some time later, the initialization state of get_random_bytes()
has been made queryable via rng_is_initialized() introduced with commit
9a47249d444d ("random: Make crng state queryable"). This primitive now
allows for streamlining the DRBG reseeding from get_random_bytes() by
replacing that aforementioned asynchronous work scheduling from
random_ready_callbacks with some simpler, synchronous code in
drbg_generate() next to the related logic already present therein. Apart
from improving overall code readability, this change will also enable DRBG
users to rely on wait_for_random_bytes() for ensuring that the initial
seeding has completed, if desired.

The previous patches already laid the grounds by making drbg_seed() to
record at each DRBG instance whether it was being seeded at a time when
rng_is_initialized() still had been false as indicated by
->seeded == DRBG_SEED_STATE_PARTIAL.

All that remains to be done now is to make drbg_generate() check for this
condition, determine whether rng_is_initialized() has flipped to true in
the meanwhile and invoke a reseed from get_random_bytes() if so.

Make this move:
- rename the former drbg_async_seed() work handler, i.e. the one in charge
of reseeding a DRBG instance from get_random_bytes(), to
"drbg_seed_from_random()",
- change its signature as appropriate, i.e. make it take a struct
drbg_state rather than a work_struct and change its return type from
"void" to "int" in order to allow for passing error information from
e.g. its __drbg_seed() invocation onwards to callers,
- make drbg_generate() invoke this drbg_seed_from_random() once it
encounters a DRBG instance with ->seeded == DRBG_SEED_STATE_PARTIAL by
the time rng_is_initialized() has flipped to true and
- prune everything related to the former, random_ready_callback based
mechanism.

As drbg_seed_from_random() is now getting invoked from drbg_generate() with
the ->drbg_mutex being held, it must not attempt to recursively grab it
once again. Remove the corresponding mutex operations from what is now
drbg_seed_from_random(). Furthermore, as drbg_seed_from_random() can now
report errors directly to its caller, there's no need for it to temporarily
switch the DRBG's ->seeded state to DRBG_SEED_STATE_UNSEEDED so that a
failure of the subsequently invoked __drbg_seed() will get signaled to
drbg_generate(). Don't do it then.

Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - move dynamic ->reseed_threshold adjustments to __drbg_seed()

Since commit 42ea507fae1a ("crypto: drbg - reseed often if seedsource is
degraded"), the maximum seed lifetime represented by ->reseed_threshold
gets temporarily lowered if the get_random_bytes() source cannot provide
sufficient entropy yet, as is common during boot, and restored back to
the original value again once that has changed.

More specifically, if the add_random_ready_callback() invoked from
drbg_prepare_hrng() in the course of DRBG instantiation does not return
-EALREADY, that is, if get_random_bytes() has not been fully initialized
at this point yet, drbg_prepare_hrng() will lower ->reseed_threshold
to a value of 50. The drbg_async_seed() scheduled from said
random_ready_callback will eventually restore the original value.

A future patch will replace the random_ready_callback based notification
mechanism and thus, there will be no add_random_ready_callback() return
value anymore which could get compared to -EALREADY.

However, there's __drbg_seed() which gets invoked in the course of both,
the DRBG instantiation as well as the eventual reseeding from
get_random_bytes() in aforementioned drbg_async_seed(), if any. Moreover,
it knows about the get_random_bytes() initialization state by the time the
seed data had been obtained from it: the new_seed_state argument introduced
with the previous patch would get set to DRBG_SEED_STATE_PARTIAL in case
get_random_bytes() had not been fully initialized yet and to
DRBG_SEED_STATE_FULL otherwise. Thus, __drbg_seed() provides a convenient
alternative for managing that ->reseed_threshold lowering and restoring at
a central place.

Move all ->reseed_threshold adjustment code from drbg_prepare_hrng() and
drbg_async_seed() respectively to __drbg_seed(). Make __drbg_seed()
lower the ->reseed_threshold to 50 in case its new_seed_state argument
equals DRBG_SEED_STATE_PARTIAL and let it restore the original value
otherwise.

There is no change in behaviour.

Signed-off-by: Nicolai Stange <nstange@suse.de>
Reviewed-by: Stephan Müller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - track whether DRBG was seeded with !rng_is_initialized()

Currently, the DRBG implementation schedules asynchronous works from
random_ready_callbacks for reseeding the DRBG instances with output from
get_random_bytes() once the latter has sufficient entropy available.

However, as the get_random_bytes() initialization state can get queried by
means of rng_is_initialized() now, there is no real need for this
asynchronous reseeding logic anymore and it's better to keep things simple
by doing it synchronously when needed instead, i.e. from drbg_generate()
once rng_is_initialized() has flipped to true.

Of course, for this to work, drbg_generate() would need some means by which
it can tell whether or not rng_is_initialized() has flipped to true since
the last seeding from get_random_bytes(). Or equivalently, whether or not
the last seed from get_random_bytes() has happened when
rng_is_initialized() was still evaluating to false.

As it currently stands, enum drbg_seed_state allows for the representation
of two different DRBG seeding states: DRBG_SEED_STATE_UNSEEDED and
DRBG_SEED_STATE_FULL. The former makes drbg_generate() to invoke a full
reseeding operation involving both, the rather expensive jitterentropy as
well as the get_random_bytes() randomness sources. The DRBG_SEED_STATE_FULL
state on the other hand implies that no reseeding at all is required for a
!->pr DRBG variant.

Introduce the new DRBG_SEED_STATE_PARTIAL state to enum drbg_seed_state for
representing the condition that a DRBG was being seeded when
rng_is_initialized() had still been false. In particular, this new state
implies that
- the given DRBG instance has been fully seeded from the jitterentropy
source (if enabled)
- and drbg_generate() is supposed to reseed from get_random_bytes()
*only* once rng_is_initialized() turns to true.

Up to now, the __drbg_seed() helper used to set the given DRBG instance's
->seeded state to constant DRBG_SEED_STATE_FULL. Introduce a new argument
allowing for the specification of the to be written ->seeded value instead.
Make the first of its two callers, drbg_seed(), determine the appropriate
value based on rng_is_initialized(). The remaining caller,
drbg_async_seed(), is known to get invoked only once rng_is_initialized()
is true, hence let it pass constant DRBG_SEED_STATE_FULL for the new
argument to __drbg_seed().

There is no change in behaviour, except for that the pr_devel() in
drbg_generate() would now report "unseeded" for ->pr DRBG instances which
had last been seeded when rng_is_initialized() was still evaluating to
false.

Signed-off-by: Nicolai Stange <nstange@suse.de>
Reviewed-by: Stephan Müller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - prepare for more fine-grained tracking of seeding state

There are two different randomness sources the DRBGs are getting seeded
from, namely the jitterentropy source (if enabled) and get_random_bytes().
At initial DRBG seeding time during boot, the latter might not have
collected sufficient entropy for seeding itself yet and thus, the DRBG
implementation schedules a reseed work from a random_ready_callback once
that has happened. This is particularly important for the !->pr DRBG
instances, for which (almost) no further reseeds are getting triggered
during their lifetime.

Because collecting data from the jitterentropy source is a rather expensive
operation, the aforementioned asynchronously scheduled reseed work
restricts itself to get_random_bytes() only. That is, it in some sense
amends the initial DRBG seed derived from jitterentropy output at full
(estimated) entropy with fresh randomness obtained from get_random_bytes()
once that has been seeded with sufficient entropy itself.

With the advent of rng_is_initialized(), there is no real need for doing
the reseed operation from an asynchronously scheduled work anymore and a
subsequent patch will make it synchronous by moving it next to related
logic already present in drbg_generate().

However, for tracking whether a full reseed including the jitterentropy
source is required or a "partial" reseed involving only get_random_bytes()
would be sufficient already, the boolean struct drbg_state's ->seeded
member must become a tristate value.

Prepare for this by introducing the new enum drbg_seed_state and change
struct drbg_state's ->seeded member's type from bool to that type.

For facilitating review, enum drbg_seed_state is made to only contain
two members corresponding to the former ->seeded values of false and true
resp. at this point: DRBG_SEED_STATE_UNSEEDED and DRBG_SEED_STATE_FULL. A
third one for tracking the intermediate state of "seeded from jitterentropy
only" will be introduced with a subsequent patch.

There is no change in behaviour at this point.

Signed-off-by: Nicolai Stange <nstange@suse.de>
Reviewed-by: Stephan Müller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - Fix unused value warning in drbg_healthcheck_sanity()

Coverity warns uf an unused value:

CID 44865 (#2 of 2): Unused value (UNUSED_VALUE)
assigned_value: Assigning value -14 to ret here, but that stored value is
overwritten before it can be used.
2006 int ret = -EFAULT;
...
value_overwrite: Overwriting previous write to ret with value from drbg_seed(drbg, &addtl, false).
2052 ret = drbg_seed(drbg, &addtl, false);

Fix this by removing the variable initializer.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: DRBG - switch to HMAC SHA512 DRBG as default DRBG

The default DRBG is the one that has the highest priority. The priority
is defined based on the order of the list drbg_cores[] where the highest
priority is given to the last entry by drbg_fill_array.

With this patch the default DRBG is switched from HMAC SHA256 to HMAC
SHA512 to support compliance with SP800-90B and SP800-90C (current
draft).

The user of the crypto API is completely unaffected by the change.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Acked-by: simo Sorce <simo@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: remove cipher routines from public crypto API

The cipher routines in the crypto API are mostly intended for templates
implementing skcipher modes generically in software, and shouldn't be
used outside of the crypto subsystem. So move the prototypes and all
related definitions to a new header file under include/crypto/internal.
Also, let's use the new module namespace feature to move the symbol
exports into a new namespace CRYPTO_INTERNAL.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

mm, treewide: rename kzfree() to kfree_sensitive()

As said by Linus:

A symmetric naming is only helpful if it implies symmetries in use.
Otherwise it's actively misleading.

In "kzalloc()", the z is meaningful and an important part of what the
caller wants.

In "kzfree()", the z is actively detrimental, because maybe in the
future we really _might_ want to use that "memfill(0xdeadbeef)" or
something. The "zero" part of the interface isn't even _relevant_.

The main reason that kzfree() exists is to clear sensitive information
that should not be leaked to other future users of the same memory
objects.

Rename kzfree() to kfree_sensitive() to follow the example of the recently
added kvfree_sensitive() and make the intention of the API more explicit.
In addition, memzero_explicit() is used to clear the memory to make sure
that it won't get optimized away by the compiler.

The renaming is done by using the command sequence:

git grep -w --name-only kzfree |\
xargs sed -i 's/kzfree/kfree_sensitive/'

followed by some editing of the kfree_sensitive() kerneldoc and adding
a kzfree backward compatibility macro in slab.h.

[akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h]
[akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more]

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Joe Perches <joe@perches.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Jason A . Donenfeld" <Jason@zx2c4.com>
Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

crypto: drbg - always try to free Jitter RNG instance

The Jitter RNG is unconditionally allocated as a seed source follwoing
the patch 97f2650e5040. Thus, the instance must always be deallocated.

Reported-by: syzbot+2e635807decef724a1fa@syzkaller.appspotmail.com
Fixes: 97f2650e5040 ("crypto: drbg - always seeded with SP800-90B ...")
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - fix error return code in drbg_alloc_state()

Fix to return negative error code -ENOMEM from the kzalloc error handling
case instead of 0, as done elsewhere in this function.

Reported-by: Xiumei Mu <xmu@redhat.com>
Fixes: db07cd26ac6a ("crypto: drbg - add FIPS 140-2 CTRNG for noise source")
Cc: <stable@vger.kernel.org>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - always seeded with SP800-90B compliant noise source

As the Jitter RNG provides an SP800-90B compliant noise source, use this
noise source always for the (re)seeding of the DRBG.

To make sure the DRBG is always properly seeded, the reseed threshold
is reduced to 1<<20 generate operations.

The Jitter RNG may report health test failures. Such health test
failures are treated as transient as follows. The DRBG will not reseed
from the Jitter RNG (but from get_random_bytes) in case of a health
test failure. Though, it produces the requested random number.

The Jitter RNG has a failure counter where at most 1024 consecutive
resets due to a health test failure are considered as a transient error.
If more consecutive resets are required, the Jitter RNG will return
a permanent error which is returned to the caller by the DRBG. With this
approach, the worst case reseed threshold is significantly lower than
mandated by SP800-90A in order to seed with an SP800-90B noise source:
the DRBG has a reseed threshold of 2^20 * 1024 = 2^30 generate requests.

Yet, in case of a transient Jitter RNG health test failure, the DRBG is
seeded with the data obtained from get_random_bytes.

However, if the Jitter RNG fails during the initial seeding operation
even due to a health test error, the DRBG will send an error to the
caller because at that time, the DRBG has received no seed that is
SP800-90B compliant.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - add FIPS 140-2 CTRNG for noise source

FIPS 140-2 section 4.9.2 requires a continuous self test of the noise
source. Up to kernel 4.8 drivers/char/random.c provided this continuous
self test. Afterwards it was moved to a location that is inconsistent
with the FIPS 140-2 requirements. The relevant patch was
e192be9d9a30555aae2ca1dc3aad37cba484cd4a .

Thus, the FIPS 140-2 CTRNG is added to the DRBG when it obtains the
seed. This patch resurrects the function drbg_fips_continous_test that
existed some time ago and applies it to the noise sources. The patch
that removed the drbg_fips_continous_test was
b3614763059b82c26bdd02ffcb1c016c1132aad0 .

The Jitter RNG implements its own FIPS 140-2 self test and thus does not
need to be subjected to the test in the DRBG.

The patch contains a tiny fix to ensure proper zeroization in case of an
error during the Jitter RNG data gathering.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Reviewed-by: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: shash - remove shash_desc::flags

The flags field in 'struct shash_desc' never actually does anything.
The only ostensibly supported flag is CRYPTO_TFM_REQ_MAY_SLEEP.
However, no shash algorithm ever sleeps, making this flag a no-op.

With this being the case, inevitably some users who can't sleep wrongly
pass MAY_SLEEP. These would all need to be fixed if any shash algorithm
actually started sleeping. For example, the shash_ahash_*() functions,
which wrap a shash algorithm with the ahash API, pass through MAY_SLEEP
from the ahash API to the shash API. However, the shash functions are
called under kmap_atomic(), so actually they're assumed to never sleep.

Even if it turns out that some users do need preemption points while
hashing large buffers, we could easily provide a helper function
crypto_shash_update_large() which divides the data into smaller chunks
and calls crypto_shash_update() and cond_resched() for each chunk. It's
not necessary to have a flag in 'struct shash_desc', nor is it necessary
to make individual shash algorithms aware of this at all.

Therefore, remove shash_desc::flags, and document that the
crypto_shash_*() functions can be called from any context.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: run initcalls for generic implementations earlier

Use subsys_initcall for registration of all templates and generic
algorithm implementations, rather than module_init. Then change
cryptomgr to use arch_initcall, to place it before the subsys_initcalls.

This is needed so that when both a generic and optimized implementation
of an algorithm are built into the kernel (not loadable modules), the
generic implementation is registered before the optimized one.
Otherwise, the self-tests for the optimized implementation are unable to
allocate the generic implementation for the new comparison fuzz tests.

Note that on arm, a side effect of this change is that self-tests for
generic implementations may run before the unaligned access handler has
been installed. So, unaligned accesses will crash the kernel. This is
arguably a good thing as it makes it easier to detect that type of bug.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - in-place cipher operation for CTR

The cipher implementations of the kernel crypto API favor in-place
cipher operations. Thus, switch the CTR cipher operation in the DRBG to
perform in-place operations. This is implemented by using the output
buffer as input buffer and zeroizing it before the cipher operation to
implement a CTR encryption of a NULL buffer.

The speed improvement is quite visibile with the following comparison
using the LRNG implementation.

Without the patch set:

16 bytes| 12.267661 MB/s| 61338304 bytes | 5000000213 ns
32 bytes| 23.603770 MB/s| 118018848 bytes | 5000000073 ns
64 bytes| 46.732262 MB/s| 233661312 bytes | 5000000241 ns
128 bytes| 90.038042 MB/s| 450190208 bytes | 5000000244 ns
256 bytes| 160.399616 MB/s| 801998080 bytes | 5000000393 ns
512 bytes| 259.878400 MB/s| 1299392000 bytes | 5000001675 ns
1024 bytes| 386.050662 MB/s| 1930253312 bytes | 5000001661 ns
2048 bytes| 493.641728 MB/s| 2468208640 bytes | 5000001598 ns
4096 bytes| 581.835981 MB/s| 2909179904 bytes | 5000003426 ns

With the patch set:

16 bytes | 17.051142 MB/s | 85255712 bytes | 5000000854 ns
32 bytes | 32.695898 MB/s | 163479488 bytes | 5000000544 ns
64 bytes | 64.490739 MB/s | 322453696 bytes | 5000000954 ns
128 bytes | 123.285043 MB/s | 616425216 bytes | 5000000201 ns
256 bytes | 233.434573 MB/s | 1167172864 bytes | 5000000573 ns
512 bytes | 384.405197 MB/s | 1922025984 bytes | 5000000671 ns
1024 bytes | 566.313370 MB/s | 2831566848 bytes | 5000001080 ns
2048 bytes | 744.518042 MB/s | 3722590208 bytes | 5000000926 ns
4096 bytes | 867.501670 MB/s | 4337508352 bytes | 5000002181 ns

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - eliminate constant reinitialization of SGL

The CTR DRBG requires two SGLs pointing to input/output buffers for the
CTR AES operation. The used SGLs always have only one entry. Thus, the
SGL can be initialized during allocation time, preventing a
re-initialization of the SGLs during each call.

The performance is increased by about 1 to 3 percent depending on the
size of the requested buffer size.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - set freed buffers to NULL

During freeing of the internal buffers used by the DRBG, set the pointer
to NULL. It is possible that the context with the freed buffers is
reused. In case of an error during initialization where the pointers
do not yet point to allocated memory, the NULL value prevents a double
free.

Cc: stable@vger.kernel.org
Fixes: 3cfc3b9721123 ("crypto: drbg - use aligned buffers")
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Reported-by: syzbot+75397ee3df5c70164154@syzkaller.appspotmail.com
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - move to generic async completion

DRBG is starting an async. crypto op and waiting for it complete.
Move it over to generic code doing the same.

The code now also passes CRYPTO_TFM_REQ_MAY_SLEEP flag indicating
crypto request memory allocation may use GFP_KERNEL which should
be perfectly fine as the code is obviously sleeping for the
completion of the request any way.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - fix freeing of resources

During the change to use aligned buffers, the deallocation code path was
not updated correctly. The current code tries to free the aligned buffer
pointer and not the original buffer pointer as it is supposed to.

Thus, the code is updated to free the original buffer pointer and set
the aligned buffer pointer that is used throughout the code to NULL.

Fixes: 3cfc3b9721123 ("crypto: drbg - use aligned buffers")
CC: <stable@vger.kernel.org>
CC: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - Fixes panic in wait_for_completion call

Initialise ctr_completion variable before use.

Cc: <stable@vger.kernel.org>
Signed-off-by: Harsh Jain <harshjain.prof@gmail.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - Fixes panic in wait_for_completion call

Initialise ctr_completion variable before use.

Signed-off-by: Harsh Jain <harshjain.prof@gmail.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - wait for crypto op not signal safe

drbg_kcapi_sym_ctr() was using wait_for_completion_interruptible() to
wait for completion of async crypto op but if a signal occurs it
may return before DMA ops of HW crypto provider finish, thus
corrupting the output buffer.

Resolve this by using wait_for_completion() instead.

Reported-by: Eric Biggers <ebiggers3@gmail.com>
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
CC: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: DRBG - initialize SGL only once

An SGL to be initialized only once even when its buffers are written
to several times.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - prevent invalid SG mappings

When using SGs, only heap memory (memory that is valid as per
virt_addr_valid) is allowed to be referenced. The CTR DRBG used to
reference the caller-provided memory directly in an SG. In case the
caller provided stack memory pointers, the SG mapping is not considered
to be valid. In some cases, this would even cause a paging fault.

The change adds a new scratch buffer that is used unconditionally to
catch the cases where the caller-provided buffer is not suitable for
use in an SG. The crypto operation of the CTR DRBG produces its output
with that scratch buffer and finally copies the content of the
scratch buffer to the caller's buffer.

The scratch buffer is allocated during allocation time of the CTR DRBG
as its access is protected with the DRBG mutex.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - advance output buffer pointer

The CTR DRBG segments the number of random bytes to be generated into
128 byte blocks. The current code misses the advancement of the output
buffer pointer when the requestor asks for more than 128 bytes of data.
In this case, the next 128 byte block of random numbers is copied to
the beginning of the output buffer again. This implies that only the
first 128 bytes of the output buffer would ever be filled.

The patch adds the advancement of the buffer pointer to fill the entire
buffer.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - fix error return code

Fix to return a negative error code from the error handling
case instead of 0.

Signed-off-by: Wei Yongjun <weiyj.lk@gmail.com>
Acked-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - do not call drbg_instantiate in healt test

When calling the DRBG health test in FIPS mode, the Jitter RNG is not
yet present in the kernel crypto API which will cause the instantiation
to fail and thus the health test to fail.

As the health tests cover the enforcement of various thresholds, invoke
the functions that are supposed to enforce the thresholds directly.

This patch also saves precious seed.

Reported-by: Tapas Sarangi <TSarangi@trustwave.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - fix an error code in drbg_init_sym_kernel()

We accidentally return PTR_ERR(NULL) which is success but we should
return -ENOMEM.

Fixes: 355912852115 ('crypto: drbg - use CTR AES instead of ECB AES')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - fix semicolon.cocci warnings

crypto/drbg.c:1637:39-40: Unneeded semicolon

Remove unneeded semicolon.

Generated by: scripts/coccinelle/misc/semicolon.cocci

CC: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Acked-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - avoid duplicate maintenance of key

The TFM object maintains the key for the CTR DRBG.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - use full CTR AES for update

The CTR DRBG update function performs a full CTR AES operation including
the XOR with "plaintext" data. Hence, remove the XOR from the code and
use the CTR mode to do the XOR.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - use aligned buffers

Hardware cipher implementation may require aligned buffers. All buffers
that potentially are processed with a cipher are now aligned.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - use CTR AES instead of ECB AES

The CTR DRBG derives its random data from the CTR that is encrypted with
AES.

This patch now changes the CTR DRBG implementation such that the
CTR AES mode is employed. This allows the use of steamlined CTR AES
implementation such as ctr-aes-aesni.

Unfortunately there are the following subtile changes we need to apply
when using the CTR AES mode:

- the CTR mode increments the counter after the cipher operation, but
the CTR DRBG requires the increment before the cipher op. Hence, the
crypto_inc is applied to the counter (drbg->V) once it is
recalculated.

- the CTR mode wants to encrypt data, but the CTR DRBG is interested in
the encrypted counter only. The full CTR mode is the XOR of the
encrypted counter with the plaintext data. To access the encrypted
counter, the patch uses a NULL data vector as plaintext to be
"encrypted".

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - reduce number of setkey calls

The CTR DRBG code always set the key for each sym cipher invocation even
though the key has not been changed.

The patch ensures that the setkey is only invoked when a new key is
generated by the DRBG.

With this patch, the CTR DRBG performance increases by more than 150%.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - set HMAC key only when altered

The HMAC implementation allows setting the HMAC key independently from
the hashing operation. Therefore, the key only needs to be set when a
new key is generated.

This patch increases the speed of the HMAC DRBG by at least 35% depending
on the use case.

The patch is fully CAVS tested.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - remove FIPS 140-2 continuous test

The newly released FIPS 140-2 IG 9.8 specifies that for SP800-90A
compliant DRBGs, the FIPS 140-2 continuous random number generator test
is not required any more.

This patch removes the test and all associated data structures.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - constify drbg_state_ops structures

The drbg_state_ops structures are never modified, so declare them as const.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - report backend_cra_name when allocation fails

Be more verbose and also report ->backend_cra_name when
crypto_alloc_shash() or crypto_alloc_cipher() fail in
drbg_init_hash_kernel() or drbg_init_sym_kernel()
correspondingly.

Example
DRBG: could not allocate digest TFM handle: hmac(sha256)

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - reseed often if seedsource is degraded

As required by SP800-90A, the DRBG implements are reseeding threshold.
This threshold is at 2**48 (64 bit) and 2**32 bit (32 bit) as
implemented in drbg_max_requests.

With the recently introduced changes, the DRBG is now always used as a
stdrng which is initialized very early in the boot cycle. To ensure that
sufficient entropy is present, the Jitter RNG is added to even provide
entropy at early boot time.

However, the 2nd seed source, the nonblocking pool, is usually
degraded at that time. Therefore, the DRBG is seeded with the Jitter RNG
(which I believe contains good entropy, which however is questioned by
others) and is seeded with a degradded nonblocking pool. This seed is
now used for quasi the lifetime of the system (2**48 requests is a lot).

The patch now changes the reseed threshold as follows: up until the time
the DRBG obtains a seed from a fully iniitialized nonblocking pool, the
reseeding threshold is lowered such that the DRBG is forced to reseed
itself resonably often. Once it obtains the seed from a fully
initialized nonblocking pool, the reseed threshold is set to the value
required by SP800-90A.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - Use callback API for random readiness

The get_blocking_random_bytes API is broken because the wait can
be arbitrarily long (potentially forever) so there is no safe way
of calling it from within the kernel.

This patch replaces it with the new callback API which does not
have this problem.

The patch also removes the entropy buffer registered with the DRBG
handle in favor of stack variables to hold the seed data.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - Add stdrng alias and increase priority

This patch adds the stdrng module alias and increases the priority
to ensure that it is loaded in preference to other RNGs.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - use Jitter RNG to obtain seed

During initialization, the DRBG now tries to allocate a handle of the
Jitter RNG. If such a Jitter RNG is available during seeding, the DRBG
pulls the required entropy/nonce string from get_random_bytes and
concatenates it with a string of equal size from the Jitter RNG. That
combined string is now the seed for the DRBG.

Written differently, the initial seed of the DRBG is now:

get_random_bytes(entropy/nonce) || jitterentropy (entropy/nonce)

If the Jitter RNG is not available, the DRBG only seeds from
get_random_bytes.

CC: Andreas Steffen <andreas.steffen@strongswan.org>
CC: Theodore Ts'o <tytso@mit.edu>
CC: Sandy Harris <sandyinchina@gmail.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - add async seeding operation

The async seeding operation is triggered during initalization right
after the first non-blocking seeding is completed. As required by the
asynchronous operation of random.c, a callback function is provided that
is triggered by random.c once entropy is available. That callback
function performs the actual seeding of the DRBG.

CC: Andreas Steffen <andreas.steffen@strongswan.org>
CC: Theodore Ts'o <tytso@mit.edu>
CC: Sandy Harris <sandyinchina@gmail.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - prepare for async seeding

In order to prepare for the addition of the asynchronous seeding call,
the invocation of seeding the DRBG is moved out into a helper function.

In addition, a block of memory is allocated during initialization time
that will be used as a scratchpad for obtaining entropy. That scratchpad
is used for the initial seeding operation as well as by the
asynchronous seeding call. The memory must be zeroized every time the
DRBG seeding call succeeds to avoid entropy data lingering in memory.

CC: Andreas Steffen <andreas.steffen@strongswan.org>
CC: Theodore Ts'o <tytso@mit.edu>
CC: Sandy Harris <sandyinchina@gmail.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - Remove FIPS ifdef from drbg_healthcheck_sanity

This patch removes the unnecessary CRYPTO_FIPS ifdef from
drbg_healthcheck_sanity so that the code always gets checked
by the compiler.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Stephan Mueller <smueller@chronox.de>

crypto: drbg - Convert to new rng interface

This patch converts the DRBG implementation to the new low-level
rng interface.

This allows us to get rid of struct drbg_gen by using the new RNG
API instead.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Stephan Mueller <smueller@chronox.de>

crypto: drbg - Do not seed RNG in drbg_kcapi_init

Initialising the RNG in drbg_kcapi_init is a waste of precious
entropy because all users will immediately seed the RNG after
the allocation.

In fact, all users should seed the RNG before using it. So there
is no point in doing the seeding in drbg_kcapi_init.

This patch removes the initial seeding and the user must seed
the RNG explicitly (as they all currently do).

This patch also changes drbg_kcapi_reset to allow reseeding.
That is, if you call it after a successful initial seeding, then
it will not reset the internal state of the DRBG before mixing
the new input and entropy.

If you still wish to reset the internal state, you can always
free the DRBG and allocate a new one.

Finally this patch removes locking from drbg_uninstantiate because
it's now only called from the destruction path which must not be
executed in parallel with normal operations.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Stephan Mueller <smueller@chronox.de>

crypto: drbg - Initialise mutex in drbg_healthcheck_sanity

As we moved the mutex init out of drbg_instantiate and into cra_init
we need to explicitly initialise the mutex in drbg_healthcheck_sanity.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Stephan Mueller <smueller@chronox.de>

crypto: drbg - leave cipher handles operational

As the DRBG does not operate on shadow copies of the DRBG instance
any more, the cipher handles only need to be allocated once during
initalization time and deallocated during uninstantiate time.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - replace spinlock with mutex

The creation of a shadow copy is intended to only hold a short term
lock. But the drawback is that parallel users have a very similar DRBG
state which only differs by a high-resolution time stamp.

The DRBG will now hold a long term lock. Therefore, the lock is changed
to a mutex which implies that the DRBG can only be used in process
context.

The lock now guards the instantiation as well as the entire DRBG
generation operation. Therefore, multiple callers are fully serialized
when generating a random number.

As the locking is changed to use a long-term lock to avoid such similar
DRBG states, the entire creation and maintenance of a shadow copy can be
removed.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - fix drbg_generate return val check

The drbg_generate returns 0 in success case. That means that
drbg_generate_long will always only generate drbg_max_request_bytes at
most. Longer requests will be truncated to drbg_max_request_bytes.

Reported-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

cryoto: drbg - clear all temporary memory

The buffer uses for temporary data must be cleared entirely. In AES192
the used buffer is drbg_statelen(drbg) + drbg_blocklen(drbg) as
documented in the comment above drbg_ctr_df.

This patch ensures that the temp buffer is completely wiped.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: rng - RNGs must return 0 in success case

Change the RNGs to always return 0 in success case.

This patch ensures that seqiv.c works with RNGs other than krng. seqiv
expects that any return code other than 0 is an error. Without the
patch, rfc4106(gcm(aes)) will not work when using a DRBG or an ANSI
X9.31 RNG.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - remove superflowous memsets

The DRBG code contains memset(0) calls to initialize a varaible
that are not necessary as the variable is always overwritten by
the processing.

This patch increases the CTR and Hash DRBGs by about 5%.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - use single block cipher API

The CTR DRBG only encrypts one single block at a time. Thus, use the
single block crypto API to avoid additional overhead from the block
chaining modes.

With the patch, the speed of the DRBG increases between 30% and 40%.

The DRBG still passes the CTR DRBG CAVS test.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Revert "crypto: drbg - use memzero_explicit() for clearing sensitive data"

This reverts commit 421d82f5b3e75f94e31875e37d45cdf6a557c120.

None of the data zeroed are on the stack so the compiler cannot
optimise them away.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - panic on continuous self test error

This patch adds a panic if the FIPS 140-2 self test error failed.
Note, that entire code is only executed with fips_enabled (i.e. when the
kernel is booted with fips=1. It is therefore not executed for 99.9% of
all user base.

As mathematically such failure cannot occur, this panic should never be
triggered. But to comply with NISTs current requirements, an endless
loop must be replaced with the panic.

When the new version of FIPS 140 will be released, this entire
continuous self test function will be ripped out as it will not be
needed any more.

This patch is functionally equivalent as implemented in ansi_cprng.c and drivers/char/random.c.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - use memzero_explicit() for clearing sensitive data

Compiler dead store optimization can sometimes remove final calls
to memset() used to clear sensitive data at the end of a function.
Replace trailing memset() calls with memzero_explicit() to
preclude unwanted removal.

Signed-off-by: Nickolaus Woodruff <nickolauswoodruff@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - use MODULE_ALIAS_CRYPTO

Use the crypto- prefix for the DRBG implementations.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - add MODULE_ALIAS for all DRBG types

The kernel module drbg.ko is currently not loaded automatically when a
DRBG is requested by a consumer. This is due to missing MODULE_ALIAS
flags for each of the implemented DRBG types.

This patch adds aliases for each of the 22 defined DRBGs.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - use crypto_inc

The DRBG internal buffer addition function is replaced with crypto_inc when
a buffer is to be incremented by one.

The function drbg_add_buf is moved to the CONFIG_CRYPTO_DRBG_HASH ifdef
area as it is now only needed for the Hash DRBG.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - remove check for uninitialized DRBG handle

The drbg_healthcheck() contained a test to call the DRBG with an
uninitialized DRBG cipher handle. As this is an inappropriate use of the
kernel crypto API to try to generate random numbers before
initialization, checks verifying for an initialized DRBG have been
removed in previous patches.

Now, the drbg_healthcheck test must also be removed.

Changes V2: Added patch marker to email subject line.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - fix sparse warning for cpu_to_be[32|64]

The sparse tool complained that the cpu_to_be[32|64] functions return
__be[32|64] instead of __u32 or __u64. The patch replaces the __u32 and
__u64 with __be32 and __be64.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - remove unnecessary sanity check for shadow state

During creation of the DRBG shadow state, it is ensured that the DRBG
state structure is already allocated. Thus, a sanity check for verifying
that the structure is allocated is removed.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - remove configuration of fixed values

SP800-90A mandates several hard-coded values. The old drbg_cores allows
the setting of these values per DRBG implementation. However, due to the
hard requirement of SP800-90A, these values are now returned globally
for each DRBG.

The ability to set such values per DRBG is therefore removed.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - remove unnecessary sanity checks

The drbg_make_shadow function contains sanity checks which are not
needed as the function is invoked at times where it is ensured that the
checked-for variables are available.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - use kmalloc instead of kzalloc for V and C

When allocating V, C, the zeroization is only needed when
allocating a new instance of the DRBG, i.e. when performing an
initial seeding. For all other allocations, the memcpy implemented in
drbg_copy_drbg ensures that the memory is filled with the correct
information.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - remove superflowous memset(0)

Remove memset(0) which is not needed due to the kzalloc of the memory.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - remove superflowous checks

The crypto_init and crypto_fini functions are always implemented. Thus,
there is no need for a protecting check.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - kzfree does not need a check for NULL pointer

The kzfree function already performs the NULL pointer check. Therefore,
the DRBG code does not need to implement such check.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - replace int2byte with cpu_to_be

The DRBG requires the conversion of an integer into a string
representation of that integer. The previous implementation converted
the given integer byte-wise. However, the kernel offers the cpu_to_be
function which already re-arranges the memory representation of an
integer such that it applies when interpreting the same memory as
character string.

The change therefore uses an integer-cast / union of the target
character array together with the cpu_to_be function to convert an
integer into its string representation.

Tests show that the Hash and CTR DRBG implementations (the HMAC DRBG
does not require such conversion) is about 10% faster (or requires less
computing power, respectively).

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - fix failure of generating multiple of 2**16 bytes

The function drbg_generate_long slices the request into 2**16 byte
or smaller chunks. However, the loop, however invokes the random number
generation function with zero bytes when the request size is a multiple
of 2**16 bytes. The fix prevents zero bytes requests.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - drbg_exit() can be static

CC: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - HMAC-SHA1 DRBG has crypto strength of 128 bits

The patch corrects the security strength of the HMAC-SHA1 DRBG to 128
bits. This strength defines the size of the seed required for the DRBG.
Thus, the patch lowers the seeding requirement from 256 bits to 128 bits
for HMAC-SHA1.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - Mix a time stamp into DRBG state

The current locking approach of the DRBG tries to keep the protected
code paths very minimal. It is therefore possible that two threads query
one DRBG instance at the same time. When thread A requests random
numbers, a shadow copy of the DRBG state is created upon which the
request for A is processed. After finishing the state for A's request is
merged back into the DRBG state. If now thread B requests random numbers
from the same DRBG after the request for thread A is received, but
before A's shadow state is merged back, the random numbers for B will be
identical to the ones for A. Please note that the time window is very
small for this scenario.

To prevent that there is even a theoretical chance for thread A and B
having the same DRBG state, the current time stamp is provided as
additional information string for each new request.

The addition of the time stamp as additional information string implies
that now all generate functions must be capable to process a linked
list with additional information strings instead of a scalar.

CC: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - Select correct DRBG core for stdrng

When the DRBG is initialized, the core is looked up using the DRBG name.
The name that can be used for the lookup is registered in
cra_driver_name. The cra_name value contains stdrng.

Thus, the lookup code must use crypto_tfm_alg_driver_name to obtain the
precise DRBG name and select the correct DRBG.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - Call CTR DRBG DF function only once

The CTR DRBG requires the update function to be called twice when
generating a random number. In both cases, update function must process
the additional information string by using the DF function. As the DF
produces the same result in both cases, we can save one invocation of
the DF function when the first DF function result is reused.

The result of the DF function is stored in the scratchpad storage. The
patch ensures that the scratchpad is not cleared when we want to reuse
the DF result. For achieving this, the CTR DRBG update function must
know by whom and in which scenario it is called. This information is
provided with the reseed parameter to the update function.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - Fix format string for debugging statements

The initial format strings caused warnings on several architectures. The
updated format strings now match the variable types.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
CC: Joe Perches <joe@perches.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - cleanup of preprocessor macros

The structure used to construct the module description line was marked
problematic by the sparse code analysis tool. The module line
description now does not contain any ifdefs to prevent error reports
from sparse.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - Use Kconfig to ensure at least one RNG option is set

This patch removes the build-time test that ensures at least one RNG
is set. Instead we will simply not build drbg if no options are set
through Kconfig.

This also fixes a typo in the name of the Kconfig option CRYTPO_DRBG
(should be CRYPTO_DRBG).

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - use of kernel linked list

The DRBG-style linked list to manage input data that is fed into the
cipher invocations is replaced with the kernel linked list
implementation.

The change is transparent to users of the interfaces offered by the
DRBG. Therefore, no changes to the testmgr code is needed.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - fix memory corruption for AES192

For the CTR DRBG, the drbg_state->scratchpad temp buffer (i.e. the
memory location immediately before the drbg_state->tfm variable
is the buffer that the BCC function operates on. BCC operates
blockwise. Making the temp buffer drbg_statelen(drbg) in size is
sufficient when the DRBG state length is a multiple of the block
size. For AES192 this is not the case and the length for temp is
insufficient (yes, that also means for such ciphers, the final
output of all BCC rounds are truncated before used to update the
state of the DRBG!!).

The patch enlarges the temp buffer from drbg_statelen to
drbg_statelen + drbg_blocklen to have sufficient space.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - simplify ordering of linked list in drbg_ctr_df

As reported by a static code analyzer, the code for the ordering of
the linked list can be simplified.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: drbg - SP800-90A Deterministic Random Bit Generator

This is a clean-room implementation of the DRBG defined in SP800-90A.
All three viable DRBGs defined in the standard are implemented:

* HMAC: This is the leanest DRBG and compiled per default
* Hash: The more complex DRBG can be enabled at compile time
* CTR: The most complex DRBG can also be enabled at compile time

The DRBG implementation offers the following:

* All three DRBG types are implemented with a derivation function.
* All DRBG types are available with and without prediction resistance.
* All SHA types of SHA-1, SHA-256, SHA-384, SHA-512 are available for
the HMAC and Hash DRBGs.
* All AES types of AES-128, AES-192 and AES-256 are available for the
CTR DRBG.
* A self test is implemented with drbg_healthcheck().
* The FIPS 140-2 continuous self test is implemented.

Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>