Revert "nrf_security: Enable NRF_RNG_ENTROPY_DRIVER for fake entropy"

This reverts commit ed84479.

Signed-off-by: Sergey Korotkov <[email protected]>

Author: seko-nordic

subsys/nrf_security/src/drivers/zephyr/Kconfig

@@ -10,6 +10,6 @@ config PSA_NEED_NRF_RNG_ENTROPY_DRIVER
 	# Cannot select entropy-generator without creating a loop to ENTROPY_PSA_CRYPTO_RNG
 	depends on ENTROPY_GENERATOR
 	select PSA_ACCEL_GET_ENTROPY
-	depends on HAS_HW_NRF_RNG || FAKE_ENTROPY_NRF_PRNG
+	depends on HAS_HW_NRF_RNG
 	depends on (!PSA_USE_CC3XX_CTR_DRBG_DRIVER && !PSA_USE_CC3XX_HMAC_DRBG_DRIVER) && \
 		   (PSA_USE_CTR_DRBG_DRIVER || PSA_USE_HMAC_DRBG_DRIVER)

subsys/nrf_security/src/drivers/zephyr/nrf_rng_entropy.c

@@ -17,29 +17,19 @@
  * It uses a "Zephyr entropy driver" and can therefore only be used in
  * Zephyr images.
  *
- * This is used for two uses cases, the first use case is when hardware
- * crypto/entropy is not yet supported. This enables running software crypto
- * with a non cryptographically secure random generator to unblock development
- * when the device tree node with the DT label 'prng' is enabled.
+ * Note that it is only the device driver with the DT label 'rng' that
+ * is supported and that this rng label is only applied for the Zephyr
+ * driver that uses the HW peripheral NRF_RNG (entropy_nrf5.c).
  *
- * The second use case is for instance nrf52820 which has an NRF_RNG
+ * An intended use-case is for instance nrf52820 which has an NRF_RNG
  * peripheral, but does not have a HW crypto trng like cryptocell.
- * In this use case the device driver with the DT label 'rng'
- * is supported and this rng label is only applied for the Zephyr
- * driver that uses the HW peripheral NRF_RNG (entropy_nrf5.c).
  *
  * Note that NRF_RNG produces TRNG, not CSPRNG.
  */
-#ifdef CONFIG_FAKE_ENTROPY_NRF_PRNG
-#define DTS_RNG_NODE_LABEL prng
-#else
-#define DTS_RNG_NODE_LABEL rng
-#endif
-
 psa_status_t nrf_rng_get_entropy(uint32_t flags, size_t *estimate_bits, uint8_t *output,
 				 size_t output_size)
 {
-	const struct device *dev = DEVICE_DT_GET(DT_NODELABEL(DTS_RNG_NODE_LABEL));
+	const struct device *dev = DEVICE_DT_GET(DT_NODELABEL(rng));
 	uint16_t request_len = MIN(UINT16_MAX, output_size);
 	int err;