xref: /freebsd/usr.sbin/pkg/hash.c (revision b2654064c2d11a1ee36667b3ff8b0f4d2536af74)

/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 *
 * Copyright (c) 2012-2014 Baptiste Daroussin <bapt@FreeBSD.org>
 * Copyright (c) 2013 Bryan Drewery <bdrewery@FreeBSD.org>
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS 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 AUTHOR OR 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 <err.h>
#include <sha256.h>
#include <stdio.h>
#include <unistd.h>

#include "hash.h"

static void
sha256_hash(unsigned char hash[SHA256_DIGEST_LENGTH],
    char out[SHA256_DIGEST_LENGTH * 2 + 1])
{
	int i;

	for (i = 0; i < SHA256_DIGEST_LENGTH; i++)
		sprintf(out + (i * 2), "%02x", hash[i]);

	out[SHA256_DIGEST_LENGTH * 2] = '\0';
}

void
sha256_buf(char *buf, size_t len, char out[SHA256_DIGEST_LENGTH * 2 + 1])
{
	unsigned char hash[SHA256_DIGEST_LENGTH];
	SHA256_CTX sha256;

	out[0] = '\0';

	SHA256_Init(&sha256);
	SHA256_Update(&sha256, buf, len);
	SHA256_Final(hash, &sha256);
	sha256_hash(hash, out);
}

int
sha256_fd(int fd, char out[SHA256_DIGEST_LENGTH * 2 + 1])
{
	int my_fd;
	FILE *fp;
	char buffer[BUFSIZ];
	unsigned char hash[SHA256_DIGEST_LENGTH];
	size_t r;
	int ret;
	SHA256_CTX sha256;

	fp = NULL;
	ret = 1;

	out[0] = '\0';

	/* Duplicate the fd so that fclose(3) does not close it. */
	if ((my_fd = dup(fd)) == -1) {
		warnx("dup");
		goto cleanup;
	}

	if ((fp = fdopen(my_fd, "rb")) == NULL) {
		warnx("fdopen");
		goto cleanup;
	}

	SHA256_Init(&sha256);

	while ((r = fread(buffer, 1, BUFSIZ, fp)) > 0)
		SHA256_Update(&sha256, buffer, r);

	if (ferror(fp) != 0) {
		warnx("fread");
		goto cleanup;
	}

	SHA256_Final(hash, &sha256);
	sha256_hash(hash, out);
	ret = 0;

cleanup:
	if (fp != NULL)
		fclose(fp);
	else if (my_fd != -1)
		close(my_fd);
	(void)lseek(fd, 0, SEEK_SET);

	return (ret);
}