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

/* Some tests in this module configure entropy sources. */
#include "psa_crypto_invasive.h"

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

#define ENTROPY_MIN_NV_SEED_SIZE                                        \
    MAX(MBEDTLS_ENTROPY_MIN_PLATFORM, MBEDTLS_ENTROPY_BLOCK_SIZE)

#include "psa_crypto_random_impl.h"
#if defined(MBEDTLS_PSA_HMAC_DRBG_MD_TYPE)
/* PSA crypto uses the HMAC_DRBG module. It reads from the entropy source twice:
 * once for the initial entropy and once for a nonce. The nonce length is
 * half the entropy length. For SHA-256, SHA-384 or SHA-512, the
 * entropy length is 256 per the documentation of mbedtls_hmac_drbg_seed(),
 * and PSA crypto doesn't support other hashes for HMAC_DRBG. */
#define ENTROPY_NONCE_LEN (256 / 2)
#else
/* PSA crypto uses the CTR_DRBG module. In some configurations, it needs
 * to read from the entropy source twice: once for the initial entropy
 * and once for a nonce. */
#include "mbedtls/ctr_drbg.h"
#define ENTROPY_NONCE_LEN MBEDTLS_CTR_DRBG_ENTROPY_NONCE_LEN
#endif

#if !defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)

typedef struct {
    size_t threshold; /* Minimum bytes to make mbedtls_entropy_func happy */
    size_t max_steps;
    size_t *length_sequence;
    size_t step;
} fake_entropy_state_t;
static int fake_entropy_source(void *state_arg,
                               unsigned char *output, size_t len,
                               size_t *olen)
{
    fake_entropy_state_t *state = state_arg;
    size_t i;

    if (state->step >= state->max_steps) {
        return MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
    }

    *olen = MIN(len, state->length_sequence[state->step]);
    for (i = 0; i < *olen; i++) {
        output[i] = i;
    }
    ++state->step;
    return 0;
}

#define ENTROPY_SOURCE_PLATFORM                 0x00000001
#define ENTROPY_SOURCE_TIMING                   0x00000002
#define ENTROPY_SOURCE_HARDWARE                 0x00000004
#define ENTROPY_SOURCE_NV_SEED                  0x00000008
#define ENTROPY_SOURCE_FAKE                     0x40000000

static uint32_t custom_entropy_sources_mask;
static fake_entropy_state_t fake_entropy_state;

/* This is a modified version of mbedtls_entropy_init() from entropy.c
 * which chooses entropy sources dynamically. */
static void custom_entropy_init(mbedtls_entropy_context *ctx)
{
    ctx->source_count = 0;
    memset(ctx->source, 0, sizeof(ctx->source));

#if defined(MBEDTLS_THREADING_C)
    mbedtls_mutex_init(&ctx->mutex);
#endif

    ctx->accumulator_started = 0;
    mbedtls_md_init(&ctx->accumulator);

#if !defined(MBEDTLS_NO_PLATFORM_ENTROPY)
    if (custom_entropy_sources_mask & ENTROPY_SOURCE_PLATFORM) {
        mbedtls_entropy_add_source(ctx, mbedtls_platform_entropy_poll, NULL,
                                   MBEDTLS_ENTROPY_MIN_PLATFORM,
                                   MBEDTLS_ENTROPY_SOURCE_STRONG);
    }
#endif
#if defined(MBEDTLS_ENTROPY_HARDWARE_ALT)
    if (custom_entropy_sources_mask & ENTROPY_SOURCE_HARDWARE) {
        mbedtls_entropy_add_source(ctx, mbedtls_hardware_poll, NULL,
                                   MBEDTLS_ENTROPY_MIN_HARDWARE,
                                   MBEDTLS_ENTROPY_SOURCE_STRONG);
    }
#endif
#if defined(MBEDTLS_ENTROPY_NV_SEED)
    if (custom_entropy_sources_mask & ENTROPY_SOURCE_NV_SEED) {
        mbedtls_entropy_add_source(ctx, mbedtls_nv_seed_poll, NULL,
                                   MBEDTLS_ENTROPY_BLOCK_SIZE,
                                   MBEDTLS_ENTROPY_SOURCE_STRONG);
        ctx->initial_entropy_run = 0;
    } else {
        /* Skip the NV seed even though it's compiled in. */
        ctx->initial_entropy_run = 1;
    }
#endif

    if (custom_entropy_sources_mask & ENTROPY_SOURCE_FAKE) {
        mbedtls_entropy_add_source(ctx,
                                   fake_entropy_source, &fake_entropy_state,
                                   fake_entropy_state.threshold,
                                   MBEDTLS_ENTROPY_SOURCE_STRONG);
    }
}

#endif /* !defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG) */

/* END_HEADER */

/* BEGIN_DEPENDENCIES
 * depends_on:MBEDTLS_PSA_CRYPTO_C
 * END_DEPENDENCIES
 */

/* BEGIN_CASE depends_on:MBEDTLS_ENTROPY_NV_SEED:!MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
void create_nv_seed()
{
    static unsigned char seed[ENTROPY_MIN_NV_SEED_SIZE];
    TEST_ASSERT(mbedtls_nv_seed_write(seed, sizeof(seed)) >= 0);
}
/* END_CASE */

/* BEGIN_CASE */
void init_deinit(int count)
{
    psa_status_t status;
    int i;
    for (i = 0; i < count; i++) {
        status = psa_crypto_init();
        PSA_ASSERT(status);
        status = psa_crypto_init();
        PSA_ASSERT(status);
        PSA_DONE();
    }
}
/* END_CASE */

/* BEGIN_CASE */
void deinit_without_init(int count)
{
    int i;
    for (i = 0; i < count; i++) {
        PSA_ASSERT(psa_crypto_init());
        PSA_DONE();
    }
    PSA_DONE();
}
/* END_CASE */

/* BEGIN_CASE */
void validate_module_init_generate_random(int count)
{
    psa_status_t status;
    uint8_t random[10] = { 0 };
    int i;
    for (i = 0; i < count; i++) {
        status = psa_crypto_init();
        PSA_ASSERT(status);
        PSA_DONE();
    }
    status = psa_generate_random(random, sizeof(random));
    TEST_EQUAL(status, PSA_ERROR_BAD_STATE);
}
/* END_CASE */

/* BEGIN_CASE */
void validate_module_init_key_based(int count)
{
    psa_status_t status;
    uint8_t data[10] = { 0 };
    psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
    mbedtls_svc_key_id_t key = mbedtls_svc_key_id_make(0xdead, 0xdead);
    int i;

    for (i = 0; i < count; i++) {
        status = psa_crypto_init();
        PSA_ASSERT(status);
        PSA_DONE();
    }
    psa_set_key_type(&attributes, PSA_KEY_TYPE_RAW_DATA);
    status = psa_import_key(&attributes, data, sizeof(data), &key);
    TEST_EQUAL(status, PSA_ERROR_BAD_STATE);
    TEST_ASSERT(mbedtls_svc_key_id_is_null(key));
}
/* END_CASE */

/* BEGIN_CASE depends_on:!MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
void custom_entropy_sources(int sources_arg, int expected_init_status_arg)
{
    psa_status_t expected_init_status = expected_init_status_arg;
    uint8_t random[10] = { 0 };

    custom_entropy_sources_mask = sources_arg;
    PSA_ASSERT(mbedtls_psa_crypto_configure_entropy_sources(
                   custom_entropy_init, mbedtls_entropy_free));

    TEST_EQUAL(psa_crypto_init(), expected_init_status);
    if (expected_init_status != PSA_SUCCESS) {
        goto exit;
    }

    PSA_ASSERT(psa_generate_random(random, sizeof(random)));

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

/* BEGIN_CASE depends_on:!MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
void fake_entropy_source(int threshold,
                         int amount1,
                         int amount2,
                         int amount3,
                         int amount4,
                         int expected_init_status_arg)
{
    psa_status_t expected_init_status = expected_init_status_arg;
    uint8_t random[10] = { 0 };
    size_t lengths[4];

    fake_entropy_state.threshold = threshold;
    fake_entropy_state.step = 0;
    fake_entropy_state.max_steps = 0;
    if (amount1 >= 0) {
        lengths[fake_entropy_state.max_steps++] = amount1;
    }
    if (amount2 >= 0) {
        lengths[fake_entropy_state.max_steps++] = amount2;
    }
    if (amount3 >= 0) {
        lengths[fake_entropy_state.max_steps++] = amount3;
    }
    if (amount4 >= 0) {
        lengths[fake_entropy_state.max_steps++] = amount4;
    }
    fake_entropy_state.length_sequence = lengths;

    custom_entropy_sources_mask = ENTROPY_SOURCE_FAKE;
    PSA_ASSERT(mbedtls_psa_crypto_configure_entropy_sources(
                   custom_entropy_init, mbedtls_entropy_free));

    TEST_EQUAL(psa_crypto_init(), expected_init_status);
    if (expected_init_status != PSA_SUCCESS) {
        goto exit;
    }

    PSA_ASSERT(psa_generate_random(random, sizeof(random)));

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

/* BEGIN_CASE depends_on:MBEDTLS_ENTROPY_NV_SEED:!MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
void entropy_from_nv_seed(int seed_size_arg,
                          int expected_init_status_arg)
{
    psa_status_t expected_init_status = expected_init_status_arg;
    uint8_t random[10] = { 0 };
    uint8_t *seed = NULL;
    size_t seed_size = seed_size_arg;

    TEST_CALLOC(seed, seed_size);
    TEST_ASSERT(mbedtls_nv_seed_write(seed, seed_size) >= 0);

    custom_entropy_sources_mask = ENTROPY_SOURCE_NV_SEED;
    PSA_ASSERT(mbedtls_psa_crypto_configure_entropy_sources(
                   custom_entropy_init, mbedtls_entropy_free));

    TEST_EQUAL(psa_crypto_init(), expected_init_status);
    if (expected_init_status != PSA_SUCCESS) {
        goto exit;
    }

    PSA_ASSERT(psa_generate_random(random, sizeof(random)));

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