/*      $OpenBSD: ecdsatest.c,v 1.18 2023/11/19 13:11:06 tb Exp $       */
/*
 * Written by Nils Larsch for the OpenSSL project.
 */
/* ====================================================================
 * Copyright (c) 2000-2005 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    licensing@OpenSSL.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */
/* ====================================================================
 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
 *
 * Portions of the attached software ("Contribution") are developed by
 * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project.
 *
 * The Contribution is licensed pursuant to the OpenSSL open source
 * license provided above.
 *
 * The elliptic curve binary polynomial software is originally written by
 * Sheueling Chang Shantz and Douglas Stebila of Sun Microsystems Laboratories.
 *
 */

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

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

int test_builtin(void);

int
test_builtin(void)
{
        unsigned char digest[20], wrong_digest[20];
        EC_builtin_curve *curves = NULL;
        size_t num_curves = 0, n = 0;
        EC_KEY *eckey = NULL, *wrong_eckey = NULL;
        EC_GROUP *group;
        ECDSA_SIG *ecdsa_sig = NULL;
        BIGNUM *r = NULL, *s = NULL;
        unsigned char *signature = NULL;
        const unsigned char *sig_ptr;
        unsigned char *sig_ptr2;
        unsigned char *raw_buf = NULL;
        unsigned int sig_len, degree, r_len, s_len, bn_len, buf_len;
        int nid;
        int failed = 1;

        /* fill digest values with some random data */
        arc4random_buf(digest, 20);
        arc4random_buf(wrong_digest, 20);

        /* create and verify a ecdsa signature with every available curve */
        printf("\ntesting ECDSA_sign() and ECDSA_verify() "
            "with some internal curves:\n");

        /* get a list of all internal curves */
        num_curves = EC_get_builtin_curves(NULL, 0);

        curves = reallocarray(NULL, sizeof(EC_builtin_curve), num_curves);
        if (curves == NULL) {
                printf("reallocarray error\n");
                goto err;
        }

        if (!EC_get_builtin_curves(curves, num_curves)) {
                printf("unable to get internal curves\n");
                goto err;
        }

        /* now create and verify a signature for every curve */
        for (n = 0; n < num_curves; n++) {
                unsigned char dirt, offset;

                nid = curves[n].nid;
                if (nid == NID_ipsec4)
                        continue;

                if ((eckey = EC_KEY_new()) == NULL)
                        goto err;
                group = EC_GROUP_new_by_curve_name(nid);
                if (group == NULL)
                        goto err;
                if (EC_KEY_set_group(eckey, group) == 0)
                        goto err;
                degree = EC_GROUP_get_degree(group);
                EC_GROUP_free(group);
                if (degree < 160) {
                        /* drop the curve */
                        EC_KEY_free(eckey);
                        eckey = NULL;
                        continue;
                }
                printf("%s: ", OBJ_nid2sn(nid));

                if (!EC_KEY_generate_key(eckey)) {
                        goto err;
                }

                /* Exercise ECParameters_dup() and let ASAN test for leaks. */
                if ((wrong_eckey = ECParameters_dup(eckey)) == NULL)
                        goto err;
                group = EC_GROUP_new_by_curve_name(nid);
                if (group == NULL)
                        goto err;
                if (EC_KEY_set_group(wrong_eckey, group) == 0)
                        goto err;
                EC_GROUP_free(group);
                if (!EC_KEY_generate_key(wrong_eckey))
                        goto err;

                printf(".");
                fflush(stdout);

                if (!EC_KEY_check_key(eckey))
                        goto err;

                printf(".");
                fflush(stdout);

                if ((sig_len = ECDSA_size(eckey)) == 0)
                        goto err;
                if ((signature = malloc(sig_len)) == NULL)
                        goto err;
                if (!ECDSA_sign(0, digest, 20, signature, &sig_len, eckey))
                        goto err;

                printf(".");
                fflush(stdout);

                if (ECDSA_verify(0, digest, 20, signature, sig_len, eckey) != 1)
                        goto err;

                printf(".");
                fflush(stdout);

                /* verify signature with the wrong key */
                if (ECDSA_verify(0, digest, 20, signature, sig_len,
                    wrong_eckey) == 1)
                        goto err;

                printf(".");
                fflush(stdout);

                if (ECDSA_verify(0, wrong_digest, 20, signature, sig_len,
                    eckey) == 1)
                        goto err;

                printf(".");
                fflush(stdout);

                if (ECDSA_verify(0, digest, 20, signature, sig_len - 1,
                    eckey) == 1)
                        goto err;

                printf(".");
                fflush(stdout);

                /*
                 * Modify a single byte of the signature: to ensure we don't
                 * garble the ASN1 structure, we read the raw signature and
                 * modify a byte in one of the bignums directly.
                 */
                sig_ptr = signature;
                if ((ecdsa_sig = d2i_ECDSA_SIG(NULL, &sig_ptr,
                    sig_len)) == NULL)
                        goto err;

                /* Store the two BIGNUMs in raw_buf. */
                r_len = BN_num_bytes(ECDSA_SIG_get0_r(ecdsa_sig));
                s_len = BN_num_bytes(ECDSA_SIG_get0_s(ecdsa_sig));
                bn_len = (degree + 7) / 8;
                if ((r_len > bn_len) || (s_len > bn_len))
                        goto err;

                buf_len = 2 * bn_len;
                if ((raw_buf = calloc(1, buf_len)) == NULL)
                        goto err;
                BN_bn2bin(ECDSA_SIG_get0_r(ecdsa_sig),
                    raw_buf + bn_len - r_len);
                BN_bn2bin(ECDSA_SIG_get0_s(ecdsa_sig),
                    raw_buf + buf_len - s_len);

                /* Modify a single byte in the buffer. */
                offset = raw_buf[10] % buf_len;
                dirt = raw_buf[11] ? raw_buf[11] : 1;
                raw_buf[offset] ^= dirt;
                /* Now read the BIGNUMs back in from raw_buf. */
                if ((r = BN_bin2bn(raw_buf, bn_len, NULL)) == NULL ||
                    (s = BN_bin2bn(raw_buf + bn_len, bn_len, NULL)) == NULL)
                        goto err;
                if (!ECDSA_SIG_set0(ecdsa_sig, r, s))
                        goto err;
                r = NULL;
                s = NULL;

                if ((sig_len = i2d_ECDSA_SIG(ecdsa_sig, NULL)) <= 0)
                        goto err;
                free(signature);
                if ((signature = calloc(1, sig_len)) == NULL)
                        goto err;

                sig_ptr2 = signature;
                if ((sig_len = i2d_ECDSA_SIG(ecdsa_sig, &sig_ptr2)) <= 0)
                        goto err;
                if (ECDSA_verify(0, digest, 20, signature, sig_len, eckey) == 1)
                        goto err;

                /* Sanity check: undo the modification and verify signature. */
                raw_buf[offset] ^= dirt;
                if ((r = BN_bin2bn(raw_buf, bn_len, NULL)) == NULL ||
                    (s = BN_bin2bn(raw_buf + bn_len, bn_len, NULL)) == NULL)
                        goto err;
                if (!ECDSA_SIG_set0(ecdsa_sig, r, s))
                        goto err;
                r = NULL;
                s = NULL;

                if ((sig_len = i2d_ECDSA_SIG(ecdsa_sig, NULL)) <= 0)
                        goto err;
                free(signature);
                if ((signature = calloc(1, sig_len)) == NULL)
                        goto err;

                sig_ptr2 = signature;
                if ((sig_len = i2d_ECDSA_SIG(ecdsa_sig, &sig_ptr2)) <= 0)
                        goto err;
                if (ECDSA_verify(0, digest, 20, signature, sig_len,
                    eckey) != 1)
                        goto err;

                printf(".");
                fflush(stdout);

                printf(" ok\n");

                ERR_clear_error();
                free(signature);
                signature = NULL;
                EC_KEY_free(eckey);
                eckey = NULL;
                EC_KEY_free(wrong_eckey);
                wrong_eckey = NULL;
                ECDSA_SIG_free(ecdsa_sig);
                ecdsa_sig = NULL;
                free(raw_buf);
                raw_buf = NULL;
        }

        failed = 0;

 err:
        if (failed)
                printf(" failed\n");

        BN_free(r);
        BN_free(s);
        EC_KEY_free(eckey);
        EC_KEY_free(wrong_eckey);
        ECDSA_SIG_free(ecdsa_sig);
        free(signature);
        free(raw_buf);
        free(curves);

        return failed;
}

int
main(void)
{
        int failed = 1;

        /* the tests */
        if (test_builtin())
                goto err;

        printf("\nECDSA test passed\n");
        failed = 0;

 err:
        if (failed) {
                printf("\nECDSA test failed\n");
                ERR_print_errors_fp(stdout);
        }

        CRYPTO_cleanup_all_ex_data();
        ERR_remove_thread_state(NULL);
        ERR_free_strings();

        return failed;
}