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>
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>
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>
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>
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>
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>
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>
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>
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>
This reverts commit 421d82f5b3.
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
