nrf_security: Avoid psa_generate_random inside CRACEN driver

Change all the psa_generate_random calls to call the driver
directly (cracen_get_random). This makes it more consistent
with the rest of the driver. It is also a better practice
to stay on the same levels of APIs and avoid calling APIs
in higher levels.

Signed-off-by: Georgios Vasilakis <[email protected]>

Author: Vge0rge

subsys/nrf_security/src/drivers/cracen/cracenpsa/src/common.c

@@ -395,7 +395,7 @@ psa_status_t rnd_in_range(uint8_t *n, size_t sz, const uint8_t *upperlimit, size
 	msb_mask = ~msb_mask;
 
 	while (retries++ < retry_limit) {
-		psa_status_t status = psa_generate_random(n, sz);
+		psa_status_t status = cracen_get_random(NULL, n, sz);
 
 		if (status) {
 			return status;

subsys/nrf_security/src/drivers/cracen/cracenpsa/src/common.h

@@ -150,7 +150,7 @@ int cracen_signature_get_rsa_key(struct cracen_rsa_key *rsa, bool extract_pubkey
 int cracen_signature_asn1_get_operand(uint8_t **p, const uint8_t *end, struct sx_buf *op);
 
 /**
- * @brief Use psa_generate_random up to generate a random number in the range [1, upperlimit).
+ * @brief Use cracen_get_random up to generate a random number in the range [1, upperlimit).
  *
  * @param[out] n           Output number.
  * @param[in]  sz          Size of number in bytes.

subsys/nrf_security/src/drivers/cracen/cracenpsa/src/key_management.c

@@ -1167,7 +1167,8 @@ psa_status_t generate_key_for_kmu(const psa_key_attributes_t *attributes, uint8_
 		}
 	} else if (key_type == PSA_KEY_TYPE_AES || key_type == PSA_KEY_TYPE_HMAC ||
 		   key_type == PSA_KEY_TYPE_CHACHA20) {
-		status = psa_generate_random(key, PSA_BITS_TO_BYTES(psa_get_key_bits(attributes)));
+		status = cracen_get_random(NULL, key,
+					   PSA_BITS_TO_BYTES(psa_get_key_bits(attributes)));
 		if (status != PSA_SUCCESS) {
 			return status;
 		}

subsys/nrf_security/src/drivers/cracen/cracenpsa/src/kmu.c

@@ -159,7 +159,7 @@ static psa_status_t cracen_kmu_encrypt(const uint8_t *key, size_t key_length,
 	psa_set_key_usage_flags(&attr, PSA_KEY_USAGE_ENCRYPT);
 
 	if (encrypted_buffer_size > CRACEN_KMU_SLOT_KEY_SIZE) {
-		psa_status = psa_generate_random(encrypted_buffer, CRACEN_KMU_SLOT_KEY_SIZE);
+		psa_status = cracen_get_random(NULL, encrypted_buffer, CRACEN_KMU_SLOT_KEY_SIZE);
 	} else {
 		return PSA_ERROR_GENERIC_ERROR;
 	}

subsys/nrf_security/src/drivers/cracen/cracenpsa/src/spake2p.c

@@ -443,7 +443,7 @@ static psa_status_t cracen_write_key_share(cracen_spake2p_operation_t *operation
 		}
 	}
 
-	status = psa_generate_random(xs, sizeof(xs));
+	status = cracen_get_random(NULL, xs, sizeof(xs));
 	if (status != PSA_SUCCESS) {
 		return status;
 	}