summaryrefslogtreecommitdiff
path: root/crypto/drbg.c
AgeCommit message (Collapse)AuthorFilesLines
2014-08-25crypto: drbg - remove unnecessary sanity checksStephan Mueller1-9/+0
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>
2014-08-25crypto: drbg - use kmalloc instead of kzalloc for V and CStephan Mueller1-3/+8
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>
2014-08-25crypto: drbg - remove superflowous memset(0)Stephan Mueller1-4/+2
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>
2014-08-25crypto: drbg - remove superflowous checksStephan Mueller1-10/+6
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>
2014-08-25crypto: drbg - kzfree does not need a check for NULL pointerStephan Mueller1-12/+6
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>
2014-08-25crypto: drbg - replace int2byte with cpu_to_beStephan Mueller1-16/+18
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>
2014-08-01crypto: drbg - fix failure of generating multiple of 2**16 bytesStephan Mueller1-1/+1
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>
2014-07-10crypto: drbg - drbg_exit() can be staticFengguang Wu1-1/+1
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>
2014-07-08crypto: drbg - HMAC-SHA1 DRBG has crypto strength of 128 bitsStephan Mueller1-1/+1
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>
2014-07-08crypto: drbg - Mix a time stamp into DRBG stateStephan Mueller1-24/+35
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>
2014-07-08crypto: drbg - Select correct DRBG core for stdrngStephan Mueller1-1/+1
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>
2014-07-08crypto: drbg - Call CTR DRBG DF function only onceStephan Mueller1-19/+22
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>
2014-07-08crypto: drbg - Fix format string for debugging statementsStephan Mueller1-2/+2
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>
2014-07-08crypto: drbg - cleanup of preprocessor macrosStephan Mueller1-11/+17
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>
2014-07-04crypto: drbg - Use Kconfig to ensure at least one RNG option is setHerbert Xu1-6/+0
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>
2014-07-04crypto: drbg - use of kernel linked listStephan Mueller1-109/+124
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>
2014-07-04crypto: drbg - fix memory corruption for AES192Stephan Mueller1-3/+11
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>
2014-06-26crypto: drbg - simplify ordering of linked list in drbg_ctr_dfStephan Mueller1-5/+5
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>
2014-06-20crypto: drbg - SP800-90A Deterministic Random Bit GeneratorStephan Mueller1-0/+2007
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>
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-25 19:04:03 +0300