When MBEDTLS_PSA_KEY_STORE_DYNAMIC is enabled, key slots are now organized in
multiple slices. The slices are allocated on demand, which allows the key
store to grow. The size of slices grows exponentially, which allows reaching
a large number of slots with a small (static) number of slices without too
much overhead.
Maintain a linked list of free slots in each slice. This way, allocating a
slot takes O(1) time unless a slice needs to be allocated.
In this commit, slices are only ever freed when deinitializing the key
store. This should be improved in the future to free empty slices.
To avoid growing the persistent key cache without control, the persistent
key cache has a fixed size (reusing MBEDTLS_PSA_KEY_SLOT_COUNT to avoid
creating yet another option).
When MBEDTLS_PSA_KEY_STORE_DYNAMIC is disabled. no semantic change and
minimal changes to the code.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Place some fields of psa_key_slot_t in a union, to prepare for a new field
in free slots that should not require extra memory.
For occupied slots, place only the registered_readers field in the union,
not other fields, to minimize textual changes. All fields could move to the
union except state (also needed in free slots) and attr (which must stay
first to reduce the code size, because it is accessed at many call sites).
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Implement `psa_generate_key_custom()` and
`psa_key_derivation_output_key_custom()`. These functions replace
`psa_generate_key_ext()` and `psa_key_derivation_output_key_ext()`.
They have the same functionality, but a slightly different interface:
the `ext` functions use a structure with a flexible array member to pass
variable-length data, while the `custom` functions use a separate parameter.
Keep the `ext` functions for backward compatibility with Mbed TLS 3.6.0.
But make them a thin wrapper around the new `custom` functions.
Duplicate the test code and data. The test cases have to be duplicated
anyway, and the test functions are individually more readable this way.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
The `flags` field in `psa_key_attributes_t` was a general mechanism that
only ever got used for a single flag: to indicate that the `slot_number`
field has been set. We have switched to a dedicated indicator for that, so
we can now remove `flags`.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Switch `psa_key_slot_t` to the full `psa_key_attributes_t`, now that this
structure only has psa_core_key_attributes_t`.
To minimize the diff without breaking the build much, temporarily make
`psa_key_attributes_t` contain either the `core` field or all the fields.
This allows both things like `slot->attr.core.type` and `slot->attr.type`
to exist. The build breaks with compilers that don't support anonymous
unions and structs, which are only standard C since C11.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
"Key generation method" was misleading since it also applies to key
derivation. Change "key generation" to "key production", which we aren't
using yet and has roughly the right intuition. Change "method" to
"parameters" which there seems to be a slight preference for. Discussion
thread: https://github.com/Mbed-TLS/mbedtls/pull/8815#discussion_r1486524295
Identifiers renamed:
psa_key_generation_method_t → psa_key_production_parameters_t
psa_key_generation_method_s → psa_key_production_parameters_s
PSA_KEY_GENERATION_METHOD_INIT → PSA_KEY_PRODUCTION_PARAMETERS_INIT
method → params
method_data_length → params_data_length
default_method → default_production_parameters
psa_key_generation_method_is_default → psa_key_production_parameters_are_default
setup_key_generation_method → setup_key_production_parameters
key_generation_method_init → key_production_parameters_init
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
In the driver wrapper for psa_generate_key() and psa_generate_key_ext():
* Invoke the built-in code if using a non-default method, even if there
might be an accelerator. This is ok because we only support non-default
methods for RSA and we don't support driver-only RSA, therefore a
non-default method will always have built-in code behind it.
* Return NOT_SUPPORTED if trying to use a non-default method with an opaque
driver.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Instead of passing the size of the whole structure, just pass the data
length and let the implementation worry about adding the size of the
structure. The intent with passing the structure size was to allow
the client code in a client-server implementation to know nothing
about the structure and just copy the bytes to the server. But that was not
really a useful consideration since the application has to know the
structure layout, so it has to be available in the client implementation's
headers. Passing the method data length makes life simpler for everyone by
not having to worry about possible padding at the end of the structure, and
removes a potential error condition
(method_length < sizeof(psa_key_generation_method_t)).
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
Add a new macro `LOCAL_OUTPUT_ALLOC_WITH_COPY` to support the output buffer
handling of the multipart operations like `psa_cipher_update`. This will
allocate a local buffer and copy the content of the original buffer.
Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
These error codes are only returned if the program has been tampered with,
so they should be CORRUPTION_DETECTED.
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
psa_wipe_key_slot can now be called on a slot in any state, if the slot's state
is PSA_SLOT_FULL or PSA_SLOT_PENDING_DELETION then there must be exactly 1 registered
reader.
Remove the state changing calls that are no longer necessary.
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
Remove psa_is_key_slot_occupied, any function which calls this can just check
the state variable instead.
Replace psa_is_key_slot_locked with psa_key_slot_has_readers.
References to the now removed functions are changed in future commits.
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
Remove the `status` field and replace with the `state` field.
Remove the `lock_count` field and replace with the `registered_readers` field.
Add documentation which describes how and why these fields are to be used.
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
This helps to prevent confusion as it avoids overloading the word
"copy" as both an action and an object.
Signed-off-by: David Horstmann <david.horstmann@arm.com>
This helps to prevent confusion as it avoids overloading the word
"copy" as both an action and an object.
Signed-off-by: David Horstmann <david.horstmann@arm.com>
This includes:
* The psa_crypto_input_copy_t struct
* psa_crypto_input_copy_alloc()
* psa_crypto_input_copy_free()
Signed-off-by: David Horstmann <david.horstmann@arm.com>
This tied input and output buffers together in
awkward pairs, which made the API more difficult
to use.
Signed-off-by: David Horstmann <david.horstmann@arm.com>
Since we are internal rather than user-facing,
PSA_ERROR_CORRUPTION_DETECTED makes more sense than
PSA_ERROR_BUFFER_TOO_SMALL. Whilst it really is a buffer that is too
small, this error code is intended to indicate that a user-supplied
buffer is too small, not an internal one.
Signed-off-by: David Horstmann <david.horstmann@arm.com>
