/*      $OpenBSD: sm2crypttest.c,v 1.2 2022/11/26 16:08:56 tb Exp $ */
/*
 * Copyright (c) 2017, 2019 Ribose Inc
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <openssl/bio.h>
#include <openssl/evp.h>
#include <openssl/bn.h>
#include <openssl/crypto.h>
#include <openssl/err.h>
#include <openssl/rand.h>

#ifdef OPENSSL_NO_SM2
int main(int argc, char *argv[])
{
    printf("No SM2 support\n");
    return (0);
}
#else
#include <openssl/sm2.h>
#include "sm2_local.h"

static EC_GROUP *
create_EC_group(const char *p_hex, const char *a_hex, const char *b_hex,
    const char *x_hex, const char *y_hex, const char *order_hex,
    const char *cof_hex)
{
        BIGNUM *p = NULL;
        BIGNUM *a = NULL;
        BIGNUM *b = NULL;
        BIGNUM *g_x = NULL;
        BIGNUM *g_y = NULL;
        BIGNUM *order = NULL;
        BIGNUM *cof = NULL;
        EC_POINT *generator = NULL;
        EC_GROUP *group = NULL;

        BN_hex2bn(&p, p_hex);
        BN_hex2bn(&a, a_hex);
        BN_hex2bn(&b, b_hex);

        group = EC_GROUP_new_curve_GFp(p, a, b, NULL);
        BN_free(p);
        BN_free(a);
        BN_free(b);

        if (group == NULL)
                return NULL;

        generator = EC_POINT_new(group);
        if (generator == NULL)
                return NULL;

        BN_hex2bn(&g_x, x_hex);
        BN_hex2bn(&g_y, y_hex);

        if (EC_POINT_set_affine_coordinates(group, generator, g_x, g_y,
            NULL) == 0)
                return NULL;

        BN_free(g_x);
        BN_free(g_y);

        BN_hex2bn(&order, order_hex);
        BN_hex2bn(&cof, cof_hex);

        if (EC_GROUP_set_generator(group, generator, order, cof) == 0)
                return NULL;

        EC_POINT_free(generator);
        BN_free(order);
        BN_free(cof);

        return group;
}

static int
test_sm2(const EC_GROUP *group, const EVP_MD *digest, const char *privkey_hex,
    const char *message)
{
        const size_t msg_len = strlen(message);

        BIGNUM *priv = NULL;
        EC_KEY *key = NULL;
        EC_POINT *pt = NULL;
        size_t ctext_len = 0;
        uint8_t *ctext = NULL;
        uint8_t *recovered = NULL;
        size_t recovered_len = msg_len;
        int rc = 0;

        BN_hex2bn(&priv, privkey_hex);

        key = EC_KEY_new();
        EC_KEY_set_group(key, group);
        EC_KEY_set_private_key(key, priv);

        pt = EC_POINT_new(group);
        EC_POINT_mul(group, pt, priv, NULL, NULL, NULL);

        EC_KEY_set_public_key(key, pt);
        BN_free(priv);
        EC_POINT_free(pt);

        if (!SM2_ciphertext_size(key, digest, msg_len, &ctext_len))
                goto done;
        ctext = calloc(1, ctext_len);
        if (ctext == NULL)
                goto done;

        rc = SM2_encrypt(key, digest, (const uint8_t *)message, msg_len, ctext, &ctext_len);

        if (rc == 0)
                goto done;

        recovered = calloc(1, msg_len);
        if (recovered == NULL)
                goto done;
        rc = SM2_decrypt(key, digest, ctext, ctext_len, recovered, &recovered_len);

        if (rc == 0)
                goto done;
        if (recovered_len != msg_len)
                goto done;
        if (memcmp(recovered, message, msg_len) != 0)
                goto done;

        rc = 1;
 done:

        free(ctext);
        free(recovered);
        EC_KEY_free(key);
        return rc;
}

int
main(int argc, char **argv)
{
        int rc;
        EC_GROUP *test_group =
                create_EC_group
                ("8542D69E4C044F18E8B92435BF6FF7DE457283915C45517D722EDB8B08F1DFC3",
                 "787968B4FA32C3FD2417842E73BBFEFF2F3C848B6831D7E0EC65228B3937E498",
                 "63E4C6D3B23B0C849CF84241484BFE48F61D59A5B16BA06E6E12D1DA27C5249A",
                 "421DEBD61B62EAB6746434EBC3CC315E32220B3BADD50BDC4C4E6C147FEDD43D",
                 "0680512BCBB42C07D47349D2153B70C4E5D7FDFCBFA36EA1A85841B9E46E09A2",
                 "8542D69E4C044F18E8B92435BF6FF7DD297720630485628D5AE74EE7C32E79B7",
                 "1");

        if (test_group == NULL)
                return 1;

        rc = test_sm2(test_group, EVP_sm3(),
            "1649AB77A00637BD5E2EFE283FBF353534AA7F7CB89463F208DDBC2920BB0DA0",
            "encryption standard");

        if (rc == 0)
                return 1;

        /* Same test as above except using SHA-256 instead of SM3 */
        rc = test_sm2(test_group, EVP_sha256(),
            "1649AB77A00637BD5E2EFE283FBF353534AA7F7CB89463F208DDBC2920BB0DA0",
            "encryption standard");
        if (rc == 0)
                return 1;

        EC_GROUP_free(test_group);

        printf("SUCCESS\n");

        return 0;
}

#endif