tests: crypto: Remove unused random configurations

The crypto tests only use the external_rng function
and they only test for one configuration where
MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG is enabled.
This removes the unused code and configurations.

Signed-off-by: Georgios Vasilakis <georgios.vasilakis@nordicsemi.no>

tests/crypto/src/common_test.c

@@ -39,104 +39,20 @@ const size_t test_vector_name_offset[] = {
 	offsetof(test_vector_ecjpake_t, p_test_vector_name),
 };
 
-#if !defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
-static int entropy_func(void *ctx, unsigned char *buf, size_t len)
-{
-	return entropy_get_entropy(ctx, buf, len);
-}
-#endif
-
-#if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
-
 /* Dummy context since we don't use it in the external_rng function */
 char drbg_ctx;
 
-int init_drbg(const unsigned char *p_optional_seed, size_t len)
-{
-	if (p_optional_seed != NULL) {
-		return -EINVAL;
-	}
-
-	return 0;
-}
-
 int external_rng(void *ctx, unsigned char *output, size_t len)
 {
+	/* No context is required for the nrf_cc3xx_platform library */
+	(void) ctx;
 	int out_len;
 	int ret = nrf_cc3xx_platform_ctr_drbg_get(NULL, output, len, &out_len);
 	return ret;
 }
 
 int (*drbg_random)(void *, unsigned char *, size_t) = &external_rng;
 
-#elif defined(MBEDTLS_CTR_DRBG_C)
-mbedtls_ctr_drbg_context drbg_ctx;
-int (*drbg_random)(void *, unsigned char *, size_t) = &mbedtls_ctr_drbg_random;
-
-int init_drbg(const unsigned char *p_optional_seed, size_t len)
-{
-	static const unsigned char ncs_seed[] = "ncs_drbg_seed";
-
-	const unsigned char *p_seed;
-
-	if (p_optional_seed == NULL) {
-		p_seed = ncs_seed;
-		len = sizeof(ncs_seed);
-	} else {
-		p_seed = p_optional_seed;
-	}
-
-	const struct device *p_device = DEVICE_DT_GET(DT_CHOSEN(zephyr_entropy));
-
-	if (!device_is_ready(p_device)) {
-		return -ENODEV;
-	}
-
-	// Ensure previously run test is properly deallocated
-	// (This frees the mutex inside ctr_drbg context)
-	mbedtls_ctr_drbg_free(&drbg_ctx);
-	mbedtls_ctr_drbg_init(&drbg_ctx);
-	return mbedtls_ctr_drbg_seed(&drbg_ctx, entropy_func, (void *)p_device,
-				     p_seed, len);
-}
-#elif defined(MBEDTLS_HMAC_DRBG_C)
-
-mbedtls_hmac_drbg_context drbg_ctx;
-int (*drbg_random)(void *, unsigned char *, size_t) = &mbedtls_hmac_drbg_random;
-
-int init_drbg(const unsigned char *p_optional_seed, size_t len)
-{
-	static const unsigned char ncs_seed[] = "ncs_drbg_seed";
-
-	const unsigned char *p_seed;
-
-	if (p_optional_seed == NULL) {
-		p_seed = ncs_seed;
-		len = sizeof(ncs_seed);
-	} else {
-		p_seed = p_optional_seed;
-	}
-
-	// Ensure previously run test is properly deallocated
-	// (This frees the mutex inside hmac_drbg context)
-	mbedtls_hmac_drbg_free(&drbg_ctx);
-	mbedtls_hmac_drbg_init(&drbg_ctx);
-
-	const struct device *p_device = DEVICE_DT_GET(DT_CHOSEN(zephyr_entropy));
-
-	if (!device_is_ready(p_device)) {
-		return -ENODEV;
-	}
-
-	const mbedtls_md_info_t *p_info =
-		mbedtls_md_info_from_type(MBEDTLS_MD_SHA256);
-
-	return mbedtls_hmac_drbg_seed(&drbg_ctx, p_info, entropy_func,
-		(void *)p_device, p_seed, len);
-}
-
-#endif
-
 const char *get_vector_name(const test_case_t *tc, uint32_t v)
 {
 	uint32_t tv_offset = test_vector_sizes[tc->vector_type] * v;

tests/crypto/src/common_test.h

@@ -52,26 +52,12 @@ int init_drbg(const unsigned char *p_optional_seed, size_t len);
 size_t hex2bin_safe(const char *hex, uint8_t *buf, size_t buflen);
 
 #if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
-
 #include "psa/crypto.h"
 #include "nrf_cc3xx_platform_ctr_drbg.h"
-
 extern char drbg_ctx;
 
-#elif defined(MBEDTLS_CTR_DRBG_C)
-
-#include <mbedtls/ctr_drbg.h>
-
-/* This context will be populated by init_drbg.
- * If the initialization is successful it can be used in subsequent calls to
- * mbedtls drbg APIs.
- */
-extern mbedtls_ctr_drbg_context drbg_ctx;
-
-#elif defined(MBEDTLS_HMAC_DRBG_C)
-
-#include <mbedtls/hmac_drbg.h>
-extern mbedtls_hmac_drbg_context drbg_ctx;
+#else
+#error "No RNG is enabled, MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG needs to be defined in nrf-config.h"
 
 #endif