nrf_security: cracen_kmu: small KMU DEST and METADATA improvement

Define the KMU DEST field as uint32_t, and use UINT32_MAX everywhere for to refer to the metadata of secondary slots. Signed-off-by: Tomi Fontanilles <tomi.fontanilles@nordicsemi.no>
nrfconnect · Oct 8, 2024 · 4639a26 · 4639a26
1 parent 933a189
commit 4639a26
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Showing 2 changed files with 6 additions and 5 deletions.
diff --git a/subsys/nrf_security/src/drivers/cracen/common/include/cracen/lib_kmu.h b/subsys/nrf_security/src/drivers/cracen/common/include/cracen/lib_kmu.h
@@ -66,7 +66,7 @@ struct kmu_src_t {
  /** 32-bit destination address. Cannot point to SICR and must be on a
  * 128-bit boundary.
  */
- uint8_t *dest;
+ uint32_t dest;
  /** 32 bits of any clear-text metadata that belongs with the key slot.
  */
  uint32_t metadata;

diff --git a/subsys/nrf_security/src/drivers/cracen/cracenpsa/src/kmu.c b/subsys/nrf_security/src/drivers/cracen/cracenpsa/src/kmu.c
@@ -238,7 +238,7 @@ int cracen_kmu_clean_key(const uint8_t *user_data)
  */
 bool is_secondary_slot(kmu_metadata *metadata)
 {
- uint32_t value = 0xffffffff;
+ uint32_t value = UINT32_MAX;
 
  return memcmp(&value, metadata, sizeof(value)) == 0;
 }
@@ -759,10 +759,11 @@ psa_status_t cracen_kmu_provision(const psa_key_attributes_t *key_attr, int slot
  struct kmu_src_t kmu_desc = {};
 
  for (size_t i = 0; i < num_slots; i++) {
- kmu_desc.dest = push_address + (CRACEN_KMU_SLOT_KEY_SIZE * i);
- kmu_desc.metadata = UINT32_MAX;
+ kmu_desc.dest = (uint32_t)push_address + (CRACEN_KMU_SLOT_KEY_SIZE * i);
  if (i == 0) {
- memcpy(&kmu_desc.metadata, &metadata, sizeof(metadata));
+ memcpy(&kmu_desc.metadata, &metadata, sizeof(kmu_desc.metadata));
+ } else {
+ kmu_desc.metadata = UINT32_MAX;
  }
  kmu_desc.rpolicy = metadata.rpolicy;
  memcpy(kmu_desc.value, key_buffer + CRACEN_KMU_SLOT_KEY_SIZE * i,