tests/suites/test_suite_ecdh.function

/* BEGIN_HEADER */
#include "mbedtls/ecdh.h"

static int load_public_key(int grp_id, data_t *point,
                           mbedtls_ecp_keypair *ecp)
{
    int ok = 0;
    TEST_ASSERT(mbedtls_ecp_group_load(&ecp->grp, grp_id) == 0);
    TEST_ASSERT(mbedtls_ecp_point_read_binary(&ecp->grp,
                                              &ecp->Q,
                                              point->x,
                                              point->len) == 0);
    TEST_ASSERT(mbedtls_ecp_check_pubkey(&ecp->grp,
                                         &ecp->Q) == 0);
    ok = 1;
exit:
    return ok;
}

static int load_private_key(int grp_id, data_t *private_key,
                            mbedtls_ecp_keypair *ecp,
                            mbedtls_test_rnd_pseudo_info *rnd_info)
{
    int ok = 0;
    TEST_ASSERT(mbedtls_ecp_read_key(grp_id, ecp,
                                     private_key->x,
                                     private_key->len) == 0);
    TEST_ASSERT(mbedtls_ecp_check_privkey(&ecp->grp, &ecp->d) == 0);
    /* Calculate the public key from the private key. */
    TEST_ASSERT(mbedtls_ecp_mul(&ecp->grp, &ecp->Q, &ecp->d,
                                &ecp->grp.G,
                                &mbedtls_test_rnd_pseudo_rand,
                                rnd_info) == 0);
    ok = 1;
exit:
    return ok;
}

/* END_HEADER */

/* BEGIN_DEPENDENCIES
 * depends_on:MBEDTLS_ECDH_C
 * END_DEPENDENCIES
 */

/* BEGIN_CASE */
void ecdh_valid_param()
{
    TEST_VALID_PARAM(mbedtls_ecdh_free(NULL));
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_CHECK_PARAMS:!MBEDTLS_PARAM_FAILED_ALT */
void ecdh_invalid_param()
{
    mbedtls_ecp_group grp;
    mbedtls_ecdh_context ctx;
    mbedtls_mpi m;
    mbedtls_ecp_point P;
    mbedtls_ecp_keypair kp;
    size_t olen;
    unsigned char buf[42] = { 0 };
    const unsigned char *buf_null = NULL;
    size_t const buflen = sizeof(buf);
    int invalid_side = 42;
    mbedtls_ecp_group_id valid_grp = MBEDTLS_ECP_DP_SECP192R1;

    mbedtls_ecp_keypair_init(&kp);
    mbedtls_ecdh_init(&ctx);
    TEST_INVALID_PARAM(mbedtls_ecdh_init(NULL));

#if defined(MBEDTLS_ECP_RESTARTABLE)
    TEST_INVALID_PARAM(mbedtls_ecdh_enable_restart(NULL));
#endif /* MBEDTLS_ECP_RESTARTABLE */

    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_gen_public(NULL, &m, &P,
                                                   mbedtls_test_rnd_std_rand,
                                                   NULL));
    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_gen_public(&grp, NULL, &P,
                                                   mbedtls_test_rnd_std_rand,
                                                   NULL));
    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_gen_public(&grp, &m, NULL,
                                                   mbedtls_test_rnd_std_rand,
                                                   NULL));
    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_gen_public(&grp, &m, &P,
                                                   NULL, NULL));

    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_compute_shared(NULL, &m, &P, &m,
                                                       mbedtls_test_rnd_std_rand,
                                                       NULL));
    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_compute_shared(&grp, NULL, &P, &m,
                                                       mbedtls_test_rnd_std_rand,
                                                       NULL));
    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_compute_shared(&grp, &m, NULL, &m,
                                                       mbedtls_test_rnd_std_rand,
                                                       NULL));
    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_compute_shared(&grp, &m, &P, NULL,
                                                       mbedtls_test_rnd_std_rand,
                                                       NULL));

    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_setup(NULL, valid_grp));

    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_make_params(NULL, &olen, buf, buflen,
                                                    mbedtls_test_rnd_std_rand, NULL));

    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_make_params(&ctx, NULL, buf, buflen,
                                                    mbedtls_test_rnd_std_rand, NULL));

    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_make_params(&ctx, &olen, NULL, buflen,
                                                    mbedtls_test_rnd_std_rand, NULL));

    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_make_params(&ctx, &olen, buf, buflen, NULL, NULL));

    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_read_params(NULL,
                                                    (const unsigned char **) &buf,
                                                    buf));
    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_read_params(&ctx, &buf_null,
                                                    buf));
    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_read_params(&ctx, NULL, buf));
    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_read_params(&ctx,
                                                    (const unsigned char **) &buf,
                                                    NULL));

    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_get_params(NULL, &kp,
                                                   MBEDTLS_ECDH_OURS));
    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_get_params(&ctx, NULL,
                                                   MBEDTLS_ECDH_OURS));
    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_get_params(&ctx, &kp,
                                                   invalid_side));

    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_make_public(NULL, &olen, buf, buflen,
                                                    mbedtls_test_rnd_std_rand, NULL));

    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_make_public(&ctx, NULL, buf, buflen,
                                                    mbedtls_test_rnd_std_rand, NULL));

    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_make_public(&ctx, &olen, NULL, buflen,
                                                    mbedtls_test_rnd_std_rand, NULL));

    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_make_public(&ctx, &olen, buf, buflen, NULL, NULL));

    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_read_public(NULL, buf, buflen));
    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_read_public(&ctx, NULL, buflen));

    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_calc_secret(NULL, &olen, buf, buflen,
                                                    mbedtls_test_rnd_std_rand, NULL));

    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_calc_secret(&ctx, NULL, buf, buflen,
                                                    mbedtls_test_rnd_std_rand, NULL));

    TEST_INVALID_PARAM_RET(MBEDTLS_ERR_ECP_BAD_INPUT_DATA,
                           mbedtls_ecdh_calc_secret(&ctx, &olen, NULL, buflen,
                                                    mbedtls_test_rnd_std_rand, NULL));

exit:
    return;
}
/* END_CASE */

/* BEGIN_CASE */
void ecdh_primitive_random(int id)
{
    mbedtls_ecp_group grp;
    mbedtls_ecp_point qA, qB;
    mbedtls_mpi dA, dB, zA, zB;
    mbedtls_test_rnd_pseudo_info rnd_info;

    mbedtls_ecp_group_init(&grp);
    mbedtls_ecp_point_init(&qA); mbedtls_ecp_point_init(&qB);
    mbedtls_mpi_init(&dA); mbedtls_mpi_init(&dB);
    mbedtls_mpi_init(&zA); mbedtls_mpi_init(&zB);
    memset(&rnd_info, 0x00, sizeof(mbedtls_test_rnd_pseudo_info));

    TEST_ASSERT(mbedtls_ecp_group_load(&grp, id) == 0);

    TEST_ASSERT(mbedtls_ecdh_gen_public(&grp, &dA, &qA,
                                        &mbedtls_test_rnd_pseudo_rand,
                                        &rnd_info) == 0);
    TEST_ASSERT(mbedtls_ecdh_gen_public(&grp, &dB, &qB,
                                        &mbedtls_test_rnd_pseudo_rand,
                                        &rnd_info) == 0);
    TEST_ASSERT(mbedtls_ecdh_compute_shared(&grp, &zA, &qB, &dA,
                                            &mbedtls_test_rnd_pseudo_rand,
                                            &rnd_info) == 0);
    TEST_ASSERT(mbedtls_ecdh_compute_shared(&grp, &zB, &qA, &dB,
                                            NULL, NULL) == 0);

    TEST_ASSERT(mbedtls_mpi_cmp_mpi(&zA, &zB) == 0);

exit:
    mbedtls_ecp_group_free(&grp);
    mbedtls_ecp_point_free(&qA); mbedtls_ecp_point_free(&qB);
    mbedtls_mpi_free(&dA); mbedtls_mpi_free(&dB);
    mbedtls_mpi_free(&zA); mbedtls_mpi_free(&zB);
}
/* END_CASE */

/* BEGIN_CASE */
void ecdh_primitive_testvec(int id, data_t *rnd_buf_A, char *xA_str,
                            char *yA_str, data_t *rnd_buf_B,
                            char *xB_str, char *yB_str, char *z_str)
{
    mbedtls_ecp_group grp;
    mbedtls_ecp_point qA, qB;
    mbedtls_mpi dA, dB, zA, zB, check;
    mbedtls_test_rnd_buf_info rnd_info_A, rnd_info_B;

    mbedtls_ecp_group_init(&grp);
    mbedtls_ecp_point_init(&qA); mbedtls_ecp_point_init(&qB);
    mbedtls_mpi_init(&dA); mbedtls_mpi_init(&dB);
    mbedtls_mpi_init(&zA); mbedtls_mpi_init(&zB); mbedtls_mpi_init(&check);

    TEST_ASSERT(mbedtls_ecp_group_load(&grp, id) == 0);

    rnd_info_A.buf = rnd_buf_A->x;
    rnd_info_A.length = rnd_buf_A->len;
    rnd_info_A.fallback_f_rng = mbedtls_test_rnd_std_rand;
    rnd_info_A.fallback_p_rng = NULL;

    /* Fix rnd_buf_A->x by shifting it left if necessary */
    if (grp.nbits % 8 != 0) {
        unsigned char shift = 8 - (grp.nbits % 8);
        size_t i;

        for (i = 0; i < rnd_info_A.length - 1; i++) {
            rnd_buf_A->x[i] = rnd_buf_A->x[i] << shift
                              | rnd_buf_A->x[i+1] >> (8 - shift);
        }

        rnd_buf_A->x[rnd_info_A.length-1] <<= shift;
    }

    rnd_info_B.buf = rnd_buf_B->x;
    rnd_info_B.length = rnd_buf_B->len;
    rnd_info_B.fallback_f_rng = mbedtls_test_rnd_std_rand;
    rnd_info_B.fallback_p_rng = NULL;

    /* Fix rnd_buf_B->x by shifting it left if necessary */
    if (grp.nbits % 8 != 0) {
        unsigned char shift = 8 - (grp.nbits % 8);
        size_t i;

        for (i = 0; i < rnd_info_B.length - 1; i++) {
            rnd_buf_B->x[i] = rnd_buf_B->x[i] << shift
                              | rnd_buf_B->x[i+1] >> (8 - shift);
        }

        rnd_buf_B->x[rnd_info_B.length-1] <<= shift;
    }

    TEST_ASSERT(mbedtls_ecdh_gen_public(&grp, &dA, &qA,
                                        mbedtls_test_rnd_buffer_rand,
                                        &rnd_info_A) == 0);
    TEST_ASSERT(!mbedtls_ecp_is_zero(&qA));
    TEST_ASSERT(mbedtls_test_read_mpi(&check, xA_str) == 0);
    TEST_ASSERT(mbedtls_mpi_cmp_mpi(&qA.X, &check) == 0);
    TEST_ASSERT(mbedtls_test_read_mpi(&check, yA_str) == 0);
    TEST_ASSERT(mbedtls_mpi_cmp_mpi(&qA.Y, &check) == 0);

    TEST_ASSERT(mbedtls_ecdh_gen_public(&grp, &dB, &qB,
                                        mbedtls_test_rnd_buffer_rand,
                                        &rnd_info_B) == 0);
    TEST_ASSERT(!mbedtls_ecp_is_zero(&qB));
    TEST_ASSERT(mbedtls_test_read_mpi(&check, xB_str) == 0);
    TEST_ASSERT(mbedtls_mpi_cmp_mpi(&qB.X, &check) == 0);
    TEST_ASSERT(mbedtls_test_read_mpi(&check, yB_str) == 0);
    TEST_ASSERT(mbedtls_mpi_cmp_mpi(&qB.Y, &check) == 0);

    TEST_ASSERT(mbedtls_test_read_mpi(&check, z_str) == 0);
    TEST_ASSERT(mbedtls_ecdh_compute_shared(&grp, &zA, &qB, &dA, NULL, NULL) == 0);
    TEST_ASSERT(mbedtls_mpi_cmp_mpi(&zA, &check) == 0);
    TEST_ASSERT(mbedtls_ecdh_compute_shared(&grp, &zB, &qA, &dB, NULL, NULL) == 0);
    TEST_ASSERT(mbedtls_mpi_cmp_mpi(&zB, &check) == 0);

exit:
    mbedtls_ecp_group_free(&grp);
    mbedtls_ecp_point_free(&qA); mbedtls_ecp_point_free(&qB);
    mbedtls_mpi_free(&dA); mbedtls_mpi_free(&dB);
    mbedtls_mpi_free(&zA); mbedtls_mpi_free(&zB); mbedtls_mpi_free(&check);
}
/* END_CASE */

/* BEGIN_CASE */
void ecdh_exchange(int id)
{
    mbedtls_ecdh_context srv, cli;
    unsigned char buf[1000];
    const unsigned char *vbuf;
    size_t len;
    mbedtls_test_rnd_pseudo_info rnd_info;
    unsigned char res_buf[1000];
    size_t res_len;

    mbedtls_ecdh_init(&srv);
    mbedtls_ecdh_init(&cli);
    memset(&rnd_info, 0x00, sizeof(mbedtls_test_rnd_pseudo_info));

    TEST_ASSERT(mbedtls_ecdh_setup(&srv, id) == 0);

    memset(buf, 0x00, sizeof(buf)); vbuf = buf;
    TEST_ASSERT(mbedtls_ecdh_make_params(&srv, &len, buf, 1000,
                                         &mbedtls_test_rnd_pseudo_rand,
                                         &rnd_info) == 0);
    TEST_ASSERT(mbedtls_ecdh_read_params(&cli, &vbuf, buf + len) == 0);

    memset(buf, 0x00, sizeof(buf));
    TEST_ASSERT(mbedtls_ecdh_make_public(&cli, &len, buf, 1000,
                                         &mbedtls_test_rnd_pseudo_rand,
                                         &rnd_info) == 0);
    TEST_ASSERT(mbedtls_ecdh_read_public(&srv, buf, len) == 0);

    TEST_ASSERT(mbedtls_ecdh_calc_secret(&srv, &len, buf, 1000,
                                         &mbedtls_test_rnd_pseudo_rand,
                                         &rnd_info) == 0);
    TEST_ASSERT(mbedtls_ecdh_calc_secret(&cli, &res_len, res_buf, 1000,
                                         NULL, NULL) == 0);
    TEST_ASSERT(len == res_len);
    TEST_ASSERT(memcmp(buf, res_buf, len) == 0);

exit:
    mbedtls_ecdh_free(&srv);
    mbedtls_ecdh_free(&cli);
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_ECP_RESTARTABLE */
void ecdh_restart(int id, data_t *dA, data_t *dB, data_t *z,
                  int enable, int max_ops, int min_restart, int max_restart)
{
    int ret;
    mbedtls_ecdh_context srv, cli;
    unsigned char buf[1000];
    const unsigned char *vbuf;
    size_t len;
    mbedtls_test_rnd_buf_info rnd_info_A, rnd_info_B;
    int cnt_restart;
    mbedtls_ecp_group grp;

    mbedtls_ecp_group_init(&grp);
    mbedtls_ecdh_init(&srv);
    mbedtls_ecdh_init(&cli);

    rnd_info_A.fallback_f_rng = mbedtls_test_rnd_std_rand;
    rnd_info_A.fallback_p_rng = NULL;
    rnd_info_A.buf = dA->x;
    rnd_info_A.length = dA->len;

    rnd_info_B.fallback_f_rng = mbedtls_test_rnd_std_rand;
    rnd_info_B.fallback_p_rng = NULL;
    rnd_info_B.buf = dB->x;
    rnd_info_B.length = dB->len;

    /* The ECDH context is not guaranteed to have an mbedtls_ecp_group structure
     * in every configuration, therefore we load it separately. */
    TEST_ASSERT(mbedtls_ecp_group_load(&grp, id) == 0);

    /* Otherwise we would have to fix the random buffer,
     * as in ecdh_primitive_testvec. */
    TEST_ASSERT(grp.nbits % 8 == 0);

    TEST_ASSERT(mbedtls_ecdh_setup(&srv, id) == 0);

    /* set up restart parameters */
    mbedtls_ecp_set_max_ops(max_ops);

    if (enable) {
        mbedtls_ecdh_enable_restart(&srv);
        mbedtls_ecdh_enable_restart(&cli);
    }

    /* server writes its parameters */
    memset(buf, 0x00, sizeof(buf));
    len = 0;

    cnt_restart = 0;
    do {
        ret = mbedtls_ecdh_make_params(&srv, &len, buf, sizeof(buf),
                                       mbedtls_test_rnd_buffer_rand,
                                       &rnd_info_A);
    } while (ret == MBEDTLS_ERR_ECP_IN_PROGRESS && ++cnt_restart);

    TEST_ASSERT(ret == 0);
    TEST_ASSERT(cnt_restart >= min_restart);
    TEST_ASSERT(cnt_restart <= max_restart);

    /* client read server params */
    vbuf = buf;
    TEST_ASSERT(mbedtls_ecdh_read_params(&cli, &vbuf, buf + len) == 0);

    /* client writes its key share */
    memset(buf, 0x00, sizeof(buf));
    len = 0;

    cnt_restart = 0;
    do {
        ret = mbedtls_ecdh_make_public(&cli, &len, buf, sizeof(buf),
                                       mbedtls_test_rnd_buffer_rand,
                                       &rnd_info_B);
    } while (ret == MBEDTLS_ERR_ECP_IN_PROGRESS && ++cnt_restart);

    TEST_ASSERT(ret == 0);
    TEST_ASSERT(cnt_restart >= min_restart);
    TEST_ASSERT(cnt_restart <= max_restart);

    /* server reads client key share */
    TEST_ASSERT(mbedtls_ecdh_read_public(&srv, buf, len) == 0);

    /* server computes shared secret */
    memset(buf, 0, sizeof(buf));
    len = 0;

    cnt_restart = 0;
    do {
        ret = mbedtls_ecdh_calc_secret(&srv, &len, buf, sizeof(buf),
                                       NULL, NULL);
    } while (ret == MBEDTLS_ERR_ECP_IN_PROGRESS && ++cnt_restart);

    TEST_ASSERT(ret == 0);
    TEST_ASSERT(cnt_restart >= min_restart);
    TEST_ASSERT(cnt_restart <= max_restart);

    TEST_ASSERT(len == z->len);
    TEST_ASSERT(memcmp(buf, z->x, len) == 0);

    /* client computes shared secret */
    memset(buf, 0, sizeof(buf));
    len = 0;

    cnt_restart = 0;
    do {
        ret = mbedtls_ecdh_calc_secret(&cli, &len, buf, sizeof(buf),
                                       NULL, NULL);
    } while (ret == MBEDTLS_ERR_ECP_IN_PROGRESS && ++cnt_restart);

    TEST_ASSERT(ret == 0);
    TEST_ASSERT(cnt_restart >= min_restart);
    TEST_ASSERT(cnt_restart <= max_restart);

    TEST_ASSERT(len == z->len);
    TEST_ASSERT(memcmp(buf, z->x, len) == 0);

exit:
    mbedtls_ecp_group_free(&grp);
    mbedtls_ecdh_free(&srv);
    mbedtls_ecdh_free(&cli);
}
/* END_CASE */

/* BEGIN_CASE depends_on:MBEDTLS_ECDH_LEGACY_CONTEXT */
void ecdh_exchange_legacy(int id)
{
    mbedtls_ecdh_context srv, cli;
    unsigned char buf[1000];
    const unsigned char *vbuf;
    size_t len;

    mbedtls_test_rnd_pseudo_info rnd_info;

    mbedtls_ecdh_init(&srv);
    mbedtls_ecdh_init(&cli);
    memset(&rnd_info, 0x00, sizeof(mbedtls_test_rnd_pseudo_info));

    TEST_ASSERT(mbedtls_ecp_group_load(&srv.grp, id) == 0);

    memset(buf, 0x00, sizeof(buf)); vbuf = buf;
    TEST_ASSERT(mbedtls_ecdh_make_params(&srv, &len, buf, 1000,
                                         &mbedtls_test_rnd_pseudo_rand,
                                         &rnd_info) == 0);
    TEST_ASSERT(mbedtls_ecdh_read_params(&cli, &vbuf, buf + len) == 0);

    memset(buf, 0x00, sizeof(buf));
    TEST_ASSERT(mbedtls_ecdh_make_public(&cli, &len, buf, 1000,
                                         &mbedtls_test_rnd_pseudo_rand,
                                         &rnd_info) == 0);
    TEST_ASSERT(mbedtls_ecdh_read_public(&srv, buf, len) == 0);

    TEST_ASSERT(mbedtls_ecdh_calc_secret(&srv, &len, buf, 1000,
                                         &mbedtls_test_rnd_pseudo_rand,
                                         &rnd_info) == 0);
    TEST_ASSERT(mbedtls_ecdh_calc_secret(&cli, &len, buf, 1000, NULL,
                                         NULL) == 0);
    TEST_ASSERT(mbedtls_mpi_cmp_mpi(&srv.z, &cli.z) == 0);

exit:
    mbedtls_ecdh_free(&srv);
    mbedtls_ecdh_free(&cli);
}
/* END_CASE */

/* BEGIN_CASE */
void ecdh_exchange_calc_secret(int grp_id,
                               data_t *our_private_key,
                               data_t *their_point,
                               int ours_first,
                               data_t *expected)
{
    mbedtls_test_rnd_pseudo_info rnd_info;
    mbedtls_ecp_keypair our_key;
    mbedtls_ecp_keypair their_key;
    mbedtls_ecdh_context ecdh;
    unsigned char shared_secret[MBEDTLS_ECP_MAX_BYTES];
    size_t shared_secret_length = 0;

    memset(&rnd_info, 0x00, sizeof(mbedtls_test_rnd_pseudo_info));
    mbedtls_ecdh_init(&ecdh);
    mbedtls_ecp_keypair_init(&our_key);
    mbedtls_ecp_keypair_init(&their_key);

    if (!load_private_key(grp_id, our_private_key, &our_key, &rnd_info)) {
        goto exit;
    }
    if (!load_public_key(grp_id, their_point, &their_key)) {
        goto exit;
    }

    /* Import the keys to the ECDH calculation. */
    if (ours_first) {
        TEST_ASSERT(mbedtls_ecdh_get_params(
                        &ecdh, &our_key, MBEDTLS_ECDH_OURS) == 0);
        TEST_ASSERT(mbedtls_ecdh_get_params(
                        &ecdh, &their_key, MBEDTLS_ECDH_THEIRS) == 0);
    } else {
        TEST_ASSERT(mbedtls_ecdh_get_params(
                        &ecdh, &their_key, MBEDTLS_ECDH_THEIRS) == 0);
        TEST_ASSERT(mbedtls_ecdh_get_params(
                        &ecdh, &our_key, MBEDTLS_ECDH_OURS) == 0);
    }

    /* Perform the ECDH calculation. */
    TEST_ASSERT(mbedtls_ecdh_calc_secret(
                    &ecdh,
                    &shared_secret_length,
                    shared_secret, sizeof(shared_secret),
                    &mbedtls_test_rnd_pseudo_rand, &rnd_info) == 0);
    TEST_ASSERT(shared_secret_length == expected->len);
    TEST_ASSERT(memcmp(expected->x, shared_secret,
                       shared_secret_length) == 0);

exit:
    mbedtls_ecdh_free(&ecdh);
    mbedtls_ecp_keypair_free(&our_key);
    mbedtls_ecp_keypair_free(&their_key);
}
/* END_CASE */

/* BEGIN_CASE */
void ecdh_exchange_get_params_fail(int our_grp_id,
                                   data_t *our_private_key,
                                   int their_grp_id,
                                   data_t *their_point,
                                   int ours_first,
                                   int expected_ret)
{
    mbedtls_test_rnd_pseudo_info rnd_info;
    mbedtls_ecp_keypair our_key;
    mbedtls_ecp_keypair their_key;
    mbedtls_ecdh_context ecdh;

    memset(&rnd_info, 0x00, sizeof(mbedtls_test_rnd_pseudo_info));
    mbedtls_ecdh_init(&ecdh);
    mbedtls_ecp_keypair_init(&our_key);
    mbedtls_ecp_keypair_init(&their_key);

    if (!load_private_key(our_grp_id, our_private_key, &our_key, &rnd_info)) {
        goto exit;
    }
    if (!load_public_key(their_grp_id, their_point, &their_key)) {
        goto exit;
    }

    if (ours_first) {
        TEST_ASSERT(mbedtls_ecdh_get_params(
                        &ecdh, &our_key, MBEDTLS_ECDH_OURS) == 0);
        TEST_ASSERT(mbedtls_ecdh_get_params(
                        &ecdh, &their_key, MBEDTLS_ECDH_THEIRS) ==
                    expected_ret);
    } else {
        TEST_ASSERT(mbedtls_ecdh_get_params(
                        &ecdh, &their_key, MBEDTLS_ECDH_THEIRS) == 0);
        TEST_ASSERT(mbedtls_ecdh_get_params(
                        &ecdh, &our_key, MBEDTLS_ECDH_OURS) ==
                    expected_ret);
    }

exit:
    mbedtls_ecdh_free(&ecdh);
    mbedtls_ecp_keypair_free(&our_key);
    mbedtls_ecp_keypair_free(&their_key);
}
/* END_CASE */