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path: root/include/crypto/drbg.h
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2014-08-26crypto: drbg - fix maximum value checks on 32 bit systemsStephan Mueller
The maximum values for additional input string or generated blocks is larger than 1<<32. To ensure a sensible value on 32 bit systems, return SIZE_MAX on 32 bit systems. This value is lower than the maximum allowed values defined in SP800-90A. The standard allow lower maximum values, but not larger values. SIZE_MAX - 1 is used for drbg_max_addtl to allow drbg_healthcheck_sanity to check the enforcement of the variable without wrapping. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> 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>
2014-08-25crypto: drbg - remove configuration of fixed valuesStephan Mueller
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>
2014-07-08crypto: drbg - Mix a time stamp into DRBG stateStephan Mueller
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>
2014-07-04crypto: drbg - use of kernel linked listStephan Mueller
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>
2014-06-20crypto: drbg - header file for DRBGStephan Mueller
The header file includes the definition of: * DRBG data structures with - struct drbg_state as main structure - struct drbg_core referencing the backend ciphers - struct drbg_state_ops callbach handlers for specific code supporting the Hash, HMAC, CTR DRBG implementations - struct drbg_conc defining a linked list for input data - struct drbg_test_data holding the test "entropy" data for CAVS testing and testmgr.c - struct drbg_gen allowing test data, additional information string and personalization string data to be funneled through the kernel crypto API -- the DRBG requires additional parameters when invoking the reset and random number generation requests than intended by the kernel crypto API * wrapper function to the kernel crypto API functions using struct drbg_gen to pass through all data needed for DRBG * wrapper functions to kernel crypto API functions usable for testing code to inject test_data into the DRBG as needed by CAVS testing and testmgr.c. * DRBG flags required for the operation of the DRBG and for selecting the particular DRBG type and backend cipher * getter functions for data from struct drbg_core Signed-off-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>