This commit marks the beginning of the removal of support for direct
access to key slots. From this commit on, programs that use
psa_key_slot_t will no longer compile.
Subsequent commits will remove the now-unused legacy support in
psa_crypto.c.
Switch from the direct use of slot numbers to handles allocated by
psa_allocate_key.
The general principle for each function is:
* Change `psa_key_slot_t slot` to `psa_key_handle_t handle` or
`psa_key_id_t key_id` depending on whether it's used as a handle to
an open slot or as a persistent name for a key.
* Call psa_create_key() before using a slot, instead of calling
psa_set_key_lifetime to make a slot persistent.
Remove the unit test persistent_key_is_configurable which is no longer
relevant.
The code only worked if psa_key_id_t (formerly psa_key_slot_t)
promoted to int and every value fit in int. Now the code only assumes
that psa_key_id_t is less wide than unsigned long, which is the case
since psa_key_id_t is a 32-bit type in our implementation.
Move the persistent storage implementation from psa_key_slot_t to
psa_key_id_t. For the most part, this just means changing the types of
function arguments.
Update the documentation of some functions to reflect the fact that
the slot identifier is purely a storage identifier and is not related
to how the slot is designated in memory.
Switch from the direct use of slot numbers to handles allocated by
psa_allocate_key.
This commit does not affect persistent key tests except for the one
test function in test_suite_psa_crypto that uses persistent keys
(persistent_key_load_key_from_storage).
The general principle for each function is:
* Change `psa_key_slot_t slot` to `psa_key_handle_t handle`.
* Call psa_allocate_key() before setting the policy of the slot,
or before creating key material in functions that don't set a policy.
* Some PSA_ERROR_EMPTY_SLOT errors become PSA_ERROR_INVALID_HANDLE
because there is now a distinction between not having a valid
handle, and having a valid handle to a slot that doesn't contain key
material.
* In tests that use symmetric keys, calculate the max_bits parameters
of psa_allocate_key() from the key data size. In tests where the key
may be asymmetric, call an auxiliary macro KEY_BITS_FROM_DATA which
returns an overapproximation. There's no good way to find a good
value for max_bits with the API, I think the API should be tweaked.
Many places in the code called psa_remove_key_data_from_memory (which
preserves metadata for the sake of failues in psa_import_key) followed
by clearing the slot data. Use an auxiliary function for this.
Access the slot directly rather than going through psa_get_key_slot.
Unlike other places where key slots are accessed through
psa_get_key_slot, here, we know where all the slots are and there are
no policy or permission considerations.
This resolves a memory leak: allocated slots were not getting freed
because psa_get_key_slot rejected the attempt of accessing them
directly rather than via a handle.
Implement psa_allocate_key, psa_open_key, psa_create_key,
psa_close_key.
Add support for keys designated to handles to psa_get_key_slot, and
thereby to the whole API.
Allocated and non-allocated keys can coexist. This is a temporary
stage in order to transition from the use of direct slot numbers to
allocated handles only. Once all the tests and sample programs have
been migrated to use handles, the implementation will be simplified
and made more robust with support for handles only.
At the moment, the in-storage slot identifier is the in-memory slot
number. But track them separately, to prepare for API changes that
will let them be different (psa_open_key, psa_create_key).
Replace `psa_key_slot_t key` by `psa_key_handle_t` in function
declarations.
This is a transition period during which handles are key slot numbers
and the whole library can still be used by accessing a key slot number
without allocating a handle.
Programs must not include mbedtls/platform.h if MBEDTLS_PLATFORM_C is
not defined. Test suites don't need to include mbedtls/platform.h
because helpers.function takes care of it.
This commit also removes a stray `;` which is technically not standard C.
Add missing compilation guards that broke the build if either GCM or
CCM was not defined.
Add missing guards on test cases that require GCM or CBC.
The build and tests now pass for any subset of {MBEDTLS_CCM_C,
MBEDTLS_GCM_C}. There are still unused variables warnings if neither
is defined.
Write an all-bits-zero NV seed file for the tests. Without this, if
the seed file is not present when this test suite is executed, the
PSA module initialization will fail, causing most test cases to fail.
Also write an all-bits-zero NV seed file at the end. The test cases in
this test suite mess with the file, but subsequent test suites may
need it.
When testing with custom entropy sources, if MBEDTLS_ENTROPY_NV_SEED
is enabled at compile time but the NV seed source is not used at
runtime, mbedtls_entropy_func makes a second pass anyway. Cope with
this in the test code by telling the entropy module not to make this
second pass.
Add a function to configure entropy sources. For testing only.
Use it to test that the library initialization fails properly if there is no
entropy source.
