mbedtls/tests/suites/test_suite_psa_crypto_entropy.function

/* BEGIN_HEADER */
#include <stdint.h>
#include <string.h>

#include <psa/crypto.h>

#include "mbedtls/entropy.h"
#include "entropy_poll.h"

/* Calculating the minimum allowed entropy size in bytes */
#define MBEDTLS_PSA_INJECT_ENTROPY_MIN_SIZE MAX(MBEDTLS_ENTROPY_MIN_PLATFORM, \
                                                MBEDTLS_ENTROPY_BLOCK_SIZE)

#if defined(MBEDTLS_PSA_INJECT_ENTROPY)
#include <psa_crypto_its.h>

/* Check the entropy seed file.
 *
 * \param expected_size     Expected size in bytes.
 *                          If 0, the file must not exist.
 *
 * \retval 1    Either \p expected_size is nonzero and
 *              the entropy seed file exists and has exactly this size,
 *              or \p expected_size is zero and the file does not exist.
 * \retval 0    Either \p expected_size is nonzero but
 *              the entropy seed file does not exist or has a different size,
 *              or \p expected_size is zero but the file exists.
 *              In this case, the test case is marked as failed.
 *
 * \note We enforce that the seed is in a specific ITS file.
 *       This must not change, otherwise we break backward compatibility if
 *       the library is upgraded on a device with an existing seed.
 */
int check_random_seed_file(size_t expected_size)
{
    /* The value of the random seed UID must not change. Otherwise that would
     * break upgrades of the library on devices that already contain a seed
     * file. If this test assertion fails, you've presumably broken backward
     * compatibility! */
    TEST_EQUAL(PSA_CRYPTO_ITS_RANDOM_SEED_UID, 0xFFFFFF52);

    struct psa_storage_info_t info = { 0, 0 };
    psa_status_t status = psa_its_get_info(PSA_CRYPTO_ITS_RANDOM_SEED_UID,
                                           &info);

    if (expected_size == 0) {
        TEST_EQUAL(status, PSA_ERROR_DOES_NOT_EXIST);
    } else {
        TEST_EQUAL(status, PSA_SUCCESS);
        TEST_EQUAL(info.size, expected_size);
    }
    return 1;

exit:
    return 0;
}

/* Remove the entropy seed file.
 *
 * See check_random_seed_file() regarding abstraction boundaries.
 */
psa_status_t remove_seed_file(void)
{
    return psa_its_remove(PSA_CRYPTO_ITS_RANDOM_SEED_UID);
}

#endif /* MBEDTLS_PSA_INJECT_ENTROPY */

/* END_HEADER */

/* BEGIN_CASE depends_on:MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
void external_rng_failure_generate()
{
    psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
    psa_set_key_type(&attributes, PSA_KEY_TYPE_DERIVE);
    psa_set_key_bits(&attributes, 128);
    mbedtls_svc_key_id_t key = MBEDTLS_SVC_KEY_ID_INIT;
    uint8_t output[1];

    PSA_ASSERT(psa_crypto_init());

    PSA_ASSERT(psa_generate_random(output, sizeof(output)));
    PSA_ASSERT(psa_generate_key(&attributes, &key));
    PSA_ASSERT(psa_destroy_key(key));

    mbedtls_test_disable_insecure_external_rng();
    TEST_EQUAL(PSA_ERROR_INSUFFICIENT_ENTROPY,
               psa_generate_random(output, sizeof(output)));
    TEST_EQUAL(PSA_ERROR_INSUFFICIENT_ENTROPY,
               psa_generate_key(&attributes, &key));

exit:
    psa_destroy_key(key);
    PSA_DONE();
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
void external_rng_failure_sign(int key_type, data_t *key_data, int alg,
                               int input_size_arg)
{
    /* This test case is only expected to pass if the signature mechanism
     * requires randomness, either because it is a randomized signature
     * or because the implementation uses blinding. */

    psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
    psa_set_key_type(&attributes, key_type);
    psa_set_key_usage_flags(&attributes, PSA_KEY_USAGE_SIGN_HASH);
    psa_set_key_algorithm(&attributes, alg);
    mbedtls_svc_key_id_t key = MBEDTLS_SVC_KEY_ID_INIT;
    size_t input_size = input_size_arg;
    uint8_t *input = NULL;
    uint8_t *signature = NULL;
    size_t signature_size = PSA_SIGNATURE_MAX_SIZE;
    size_t signature_length;

    ASSERT_ALLOC(input, input_size);
    ASSERT_ALLOC(signature, signature_size);

    PSA_ASSERT(psa_crypto_init());
    PSA_ASSERT(psa_import_key(&attributes, key_data->x, key_data->len,
                              &key));
    PSA_ASSERT(psa_sign_hash(key, alg,
                             input, input_size,
                             signature, signature_size,
                             &signature_length));
    PSA_ASSERT(psa_destroy_key(key));

    mbedtls_test_disable_insecure_external_rng();
    /* Import the key again, because for RSA Mbed TLS caches blinding values
     * in the key object and this could perturb the test. */
    PSA_ASSERT(psa_import_key(&attributes, key_data->x, key_data->len,
                              &key));
    TEST_EQUAL(PSA_ERROR_INSUFFICIENT_ENTROPY,
               psa_sign_hash(key, alg,
                             input, input_size,
                             signature, signature_size,
                             &signature_length));
    PSA_ASSERT(psa_destroy_key(key));

exit:
    psa_destroy_key(key);
    PSA_DONE();
    mbedtls_free(input);
    mbedtls_free(signature);
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_PSA_INJECT_ENTROPY */
void validate_entropy_seed_injection(int seed_length_a,
                                     int expected_status_a,
                                     int seed_length_b,
                                     int expected_status_b)
{
    psa_status_t status;
    uint8_t output[32] = { 0 };
    uint8_t zeros[32] = { 0 };
    uint8_t *seed = NULL;
    int i;
    int seed_size;
    if (seed_length_a > seed_length_b) {
        seed_size = seed_length_a;
    } else {
        seed_size = seed_length_b;
    }
    ASSERT_ALLOC(seed, seed_size);
    /* fill seed with some data */
    for (i = 0; i < seed_size; ++i) {
        seed[i] = i;
    }
    status =  remove_seed_file();
    TEST_ASSERT((status == PSA_SUCCESS) ||
                (status == PSA_ERROR_DOES_NOT_EXIST));
    if (!check_random_seed_file(0)) {
        goto exit;
    }

    status = mbedtls_psa_inject_entropy(seed, seed_length_a);
    TEST_EQUAL(status, expected_status_a);
    if (!check_random_seed_file(expected_status_a == PSA_SUCCESS ? seed_length_a :
                                0)) {
        goto exit;
    }

    status = mbedtls_psa_inject_entropy(seed, seed_length_b);
    TEST_EQUAL(status, expected_status_b);
    if (!check_random_seed_file(expected_status_a == PSA_SUCCESS ? seed_length_a :
                                expected_status_b == PSA_SUCCESS ? seed_length_b :
                                0)) {
        goto exit;
    }

    PSA_ASSERT(psa_crypto_init());
    PSA_ASSERT(psa_generate_random(output,
                                   sizeof(output)));
    TEST_ASSERT(memcmp(output, zeros, sizeof(output)) != 0);

exit:
    mbedtls_free(seed);
    PSA_DONE();
    mbedtls_test_inject_entropy_restore();
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_PSA_INJECT_ENTROPY */
void run_entropy_inject_with_crypto_init()
{
    psa_status_t status;
    size_t i;
    uint8_t seed[MBEDTLS_PSA_INJECT_ENTROPY_MIN_SIZE] = { 0 };
    /* fill seed with some data */
    for (i = 0; i < sizeof(seed); ++i) {
        seed[i] = i;
    }

    status =  remove_seed_file();
    TEST_ASSERT((status == PSA_SUCCESS) ||
                (status == PSA_ERROR_DOES_NOT_EXIST));
    if (!check_random_seed_file(0)) {
        goto exit;
    }
    status = mbedtls_psa_inject_entropy(seed, sizeof(seed));
    PSA_ASSERT(status);
    TEST_ASSERT(check_random_seed_file(sizeof(seed)));
    status =  remove_seed_file();
    TEST_EQUAL(status, PSA_SUCCESS);
    if (!check_random_seed_file(0)) {
        goto exit;
    }

    status = psa_crypto_init();
    TEST_EQUAL(status, PSA_ERROR_INSUFFICIENT_ENTROPY);
    status = mbedtls_psa_inject_entropy(seed, sizeof(seed));
    PSA_ASSERT(status);
    if (!check_random_seed_file(sizeof(seed))) {
        goto exit;
    }

    status = psa_crypto_init();
    PSA_ASSERT(status);
    PSA_DONE();

    /* The seed is written by nv_seed callback functions therefore the injection will fail */
    status = mbedtls_psa_inject_entropy(seed, sizeof(seed));
    TEST_EQUAL(status, PSA_ERROR_NOT_PERMITTED);

exit:
    PSA_DONE();
    mbedtls_test_inject_entropy_restore();
}
/* END_CASE */