/* ====================================================================
 * Copyright (c) 2016 - 2018 The GmSSL 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 GmSSL Project.
 *    (http://gmssl.org/)"
 *
 * 4. The name "GmSSL Project" must not be used to endorse or promote
 *    products derived from this software without prior written
 *    permission. For written permission, please contact
 *    guanzhi1980@gmail.com.
 *
 * 5. Products derived from this software may not be called "GmSSL"
 *    nor may "GmSSL" appear in their names without prior written
 *    permission of the GmSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the GmSSL Project
 *    (http://gmssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE GmSSL 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 GmSSL 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.
 * ====================================================================
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <libgen.h>
#include <openssl/sm9.h>
#include <openssl/err.h>
#include <openssl/objects.h>

int main(int argc, char **argv)
{
	int ret = -1;
	char *prog = basename(argv[0]);
	EVP_MD_CTX *ctx = NULL;
	FILE *msg_fp = NULL;
	FILE *sk_fp = NULL;
	FILE *sig_fp = NULL;
	SM9PrivateKey *sk = NULL;
	SM9Signature *sig = NULL;
	unsigned char buf[2048];
	int len;

	if (argc != 4) {
		printf("usage: %s <msg-file> <sk-file> <sig-file>\n", prog);
		return 0;
	}

	if (!(ctx = EVP_MD_CTX_new())) {
		ERR_print_errors_fp(stderr);
		goto end;
	}
	if (!SM9_SignInit(ctx, EVP_sm3(), NULL)) {
		ERR_print_errors_fp(stderr);
		goto end;
	}

	if (!(msg_fp = fopen(argv[1], "r"))) {
		fprintf(stderr, "%s: can not open file '%s'\n", prog, argv[1]);
		goto end;
	}
	while ((len = fread(buf, 1, sizeof(buf), msg_fp)) > 0) {
		if (!SM9_SignUpdate(ctx, buf, len)) {
			ERR_print_errors_fp(stderr);
			goto end;
		}
	}

	if (!(sk_fp = fopen(argv[2], "r"))) {
		fprintf(stderr, "%s: can not open file '%s'\n", prog, argv[2]);
		goto end;
	}
	if (!(sk = d2i_SM9PrivateKey_fp(sk_fp, NULL))) {
		ERR_print_errors_fp(stderr);
		fprintf(stderr, "%s: parse private key failed\n", prog);
		goto end;
	}

	if (!(sig = SM9_SignFinal(ctx, sk))) {
		ERR_print_errors_fp(stderr);
		fprintf(stderr, "%s: failed to generate siganture\n", prog);
		goto end;
	}
	if (!(sig_fp = fopen(argv[3], "w"))) {
		fprintf(stderr, "%s: can not open file '%s'\n", prog, argv[3]);
		goto end;
	}
	if (!i2d_SM9Signature_fp(sig_fp, sig)) {
		ERR_print_errors_fp(stderr);
		goto end;
	}

	ret = 0;

end:
	EVP_MD_CTX_free(ctx);
	fclose(msg_fp);
	fclose(sk_fp);
	fclose(sig_fp);
	SM9PrivateKey_free(sk);
	SM9Signature_free(sig);
	return ret;
}