Context: The function `mbedtls_mpi_fill_random()` uses a temporary stack
buffer to hold the random data before reading it into the target MPI.
Problem: This is inefficient both computationally and memory-wise.
Memory-wise, it may lead to a stack overflow on constrained devices with
limited stack.
Fix: This commit introduces the following changes to get rid of the
temporary stack buffer entirely:
1. It modifies the call to the PRNG to output the random data directly
into the target MPI's data buffer.
This alone, however, constitutes a change of observable behaviour:
The previous implementation guaranteed to interpret the bytes emitted by
the PRNG in a big-endian fashion, while rerouting the PRNG output into the
target MPI's limb array leads to an interpretation that depends on the
endianness of the host machine.
As a remedy, the following change is applied, too:
2. Reorder the bytes emitted from the PRNG within the target MPI's
data buffer to ensure big-endian semantics.
Luckily, the byte reordering was already implemented as part of
`mbedtls_mpi_read_binary()`, so:
3. Extract bigendian-to-host byte reordering from
`mbedtls_mpi_read_binary()` to a separate internal function
`mpi_bigendian_to_host()` to be used by `mbedtls_mpi_read_binary()`
and `mbedtls_mpi_fill_random()`.
Split crypto_driver.h into 4:
* crypto_driver_common.h for common definitions, not meant to be
included directly by driver code.
* crypto_accel_driver.h for drivers that work with transparent
key material.
* crypto_se_driver.h for drivers that work with opaque key
material.
* crypto_entropy_driver.h for drivers of entropy sources.
There is no code change in this commit, I only moved some code around.
Now that the type definitions that are useful for driver are in a
separate header file from the application interface function
declarations, include that header file in crypto_driver.h.
Some parts of the library, and crypto drivers, need to see key types,
algorithms, policies, etc. but not API functions. Move portable
integral types and macros to build and analyze values of these types
to a separate headers crypto_types.h and crypto_values.h.
No functional changes, code was only moved from crypto.h to the new headers.
GCC 4.8 warns that some variables may be used without having been
initialized. They aren't, but determining that takes nontrivial
analysis, so initialize them at the point of definition.
Define psa_status_t to int32_t unconditionally. There's no reason to
refer to psa_error_t here: psa_error_t is int32_t if it's present. We
would only need a conditional definition if psa_defs.h and
psa_crypto.h used the same type name.
Keep the conditional definition of PSA_SUCCESS. Although the C
preprocessor allows a duplicate definition for a macro, it has to be
the exact same token sequence, not merely an equivalent way to build
the same value.
Change the way some lines are wrapped to cut at a more logical place.
This commit mainly rewrites multi-line calls to TEST_EQUAL, and also a
few calls to PSA_ASSERT.
This commit is the result of the following command, followed by
reindenting (but not wrapping lines):
perl -00 -i -pe 's/^( *)TEST_ASSERT\(([^;=]*)(?: |\n *)==([^;=]*)\);$/${1}TEST_EQUAL($2,$3);/gm' tests/suites/test_suite_psa_*.function
This commit is the result of the following command, followed by
reindenting (but not wrapping lines):
perl -00 -i -pe 's/^( *)TEST_ASSERT\(([^;=]*)(?: |\n *)==\s*PSA_SUCCESS\s*\);$/${1}PSA_ASSERT($2 );/gm' tests/suites/test_suite_psa_*.function
Cause a compilation error on ARRAY_LENGTH(p) where p is a pointer as
opposed to an array. This only works under GCC and compatible
compilers such as Clang. On other compilers, ARRAY_LENGTH works but
doesn't check the type of its argument.
Clarified and made more coherent the parameter validation feature, it's scope
and what has changed. Added version 2.14.1 to the history which was released on
a branch.
