Within setup we create a copy of the key and put it in the operation field.
After setup, we only ever use the new copy,
and do not interact with any key slots.
Therefore we need only register as a reader of the key during setup,
then unregister after we stop accessing the key.
Simultaneous API calls on the same operation object are not thread-safe.
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
We copy the key from a slot to the operation object in _start.
_complete and _abort do not access any key slots, instead using
the local copy.
Concurrently using the same operation object is not thread-safe.
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
We copy the key from a slot to the operation object in _start.
_complete and _abort do not access any key slots, instead using
the local copy.
Concurrently using the same operation object is not thread-safe.
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
Within setup we create a copy of the key and put it in the operation field.
After setup, we only ever use the new copy - and do not interact with any key slots.
Therefore we need only register as a reader of the key during setup,
then unregister after we stop accessing the key.
Simultaneous API calls on the same operation object are not thread-safe.
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
This means we can hold the mutex around the call to reserve_free_key_slot
in get_and_lock_key_slot, avoiding inefficient rework.
(Changes to get_and_lock_key_slot are not in scope in this PR)
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
Hold the mutex for the entirety of the call.
We need the mutex for the wipe, also hold it for aborting driver transactions as this
may have side effects.
We can't use the macros here as this function returns void.
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
Hold mutex for the entirety of the call.
We are writing to storage and writing to the slot state here.
If we didn't keep the mutex for the whole duration then we may end up with
another thread seeing that a persistent key is in storage before
our slot is set to FULL; this would be unlinearizable behaviour.
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
These all follow a pattern of locking some key slot,
reading its contents, and then unregistering from reading the slot.
psa_copy_key also writes to another slot,
but calls the functions needed to be threadsafe.
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
Between the call to psa_get_and_lock_key_slot and psa_unregister_read
we only read the contents of a slot which we are registered to read,
so no extra mutex taking is needed.
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
We do not require linearizability in the case of destroying a key in use.
Using a key and destroying it simultaneously will not cause any issues
as the user will only use the copy of the key in the slot.
Two simulatenous deletion calls to one key cannot interfere, the first caller
sets the slot's state to PENDING_DELETION, the second caller will back off.
Remove outdated comment about one key being in multiple slots, psa_open_key
does not put the key into a new slot.
Signed-off-by: Ryan Everett <ryan.everett@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>
Replaces calls to psa_unlock_key_slot with calls to psa_unregister_read.
All instances follow a pattern of a call to psa_get_and_lock_key_slot_X,
followed by some code which reads from a slot, followed by a call to psa_unregister_read.
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
This does not yet implement destruction while a key is in use for psa_destroy_key;
that will be implemented in a separate pr.
(I am not sure if I am allowed to change the documentation in the include files.)
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
Move the mbedtls_ecc helper functions from psa_core to psa_util.
These files are not implemented as part of the PSA API and should not
be part of the PSA crypto implementation.
Signed-off-by: Joakim Andersson <joakim.andersson@nordicsemi.no>
