Update psa_get_and_lock_key_slot_in_memory
Document that callers must hold the key slot mutex.
Change the volatile key checking behaviour so that it
doesn't read the contents of non-FULL slots.
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
diff --git a/library/psa_crypto_slot_management.c b/library/psa_crypto_slot_management.c
index 9358619..2a73c0a 100644
--- a/library/psa_crypto_slot_management.c
+++ b/library/psa_crypto_slot_management.c
@@ -70,6 +70,9 @@
* On success, the function locks the key slot. It is the responsibility of
* the caller to unlock the key slot when it does not access it anymore.
*
+ * If multi-threading is enabled, the caller must hold the
+ * global key slot mutex.
+ *
* \param key Key identifier to query.
* \param[out] p_slot On success, `*p_slot` contains a pointer to the
* key slot containing the description of the key
@@ -94,16 +97,14 @@
if (psa_key_id_is_volatile(key_id)) {
slot = &global_data.key_slots[key_id - PSA_KEY_ID_VOLATILE_MIN];
- /*
- * Check if both the PSA key identifier key_id and the owner
- * identifier of key match those of the key slot.
- *
- * Note that, if the key slot is not occupied, its PSA key identifier
- * is equal to zero. This is an invalid value for a PSA key identifier
- * and thus cannot be equal to the valid PSA key identifier key_id.
- */
- status = mbedtls_svc_key_id_equal(key, slot->attr.id) ?
- PSA_SUCCESS : PSA_ERROR_DOES_NOT_EXIST;
+ /* Check if both the PSA key identifier key_id and the owner
+ * identifier of key match those of the key slot. */
+ if ((slot->state == PSA_SLOT_FULL) &&
+ (mbedtls_svc_key_id_equal(key, slot->attr.id))) {
+ status = PSA_SUCCESS;
+ } else {
+ status = PSA_ERROR_DOES_NOT_EXIST;
+ }
} else {
if (!psa_is_valid_key_id(key, 1)) {
return PSA_ERROR_INVALID_HANDLE;