freebsd-dev/sbin/hastd/hast_checksum.c

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/*-
* Copyright (c) 2011 Pawel Jakub Dawidek <pawel@dawidek.net>
* 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 AUTHORS 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 AUTHORS 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <errno.h>
#include <string.h>
#include <strings.h>
#ifdef HAVE_CRYPTO
#include <openssl/sha.h>
#endif
#include <crc32.h>
#include <hast.h>
#include <nv.h>
#include <pjdlog.h>
#include "hast_checksum.h"
#ifdef HAVE_CRYPTO
#define MAX_HASH_SIZE SHA256_DIGEST_LENGTH
#else
#define MAX_HASH_SIZE 4
#endif
static void
hast_crc32_checksum(const unsigned char *data, size_t size,
unsigned char *hash, size_t *hsizep)
{
uint32_t crc;
crc = crc32(data, size);
/* XXXPJD: Do we have to use htole32() on crc first? */
bcopy(&crc, hash, sizeof(crc));
*hsizep = sizeof(crc);
}
#ifdef HAVE_CRYPTO
static void
hast_sha256_checksum(const unsigned char *data, size_t size,
unsigned char *hash, size_t *hsizep)
{
SHA256_CTX ctx;
SHA256_Init(&ctx);
SHA256_Update(&ctx, data, size);
SHA256_Final(hash, &ctx);
*hsizep = SHA256_DIGEST_LENGTH;
}
#endif /* HAVE_CRYPTO */
const char *
checksum_name(int num)
{
switch (num) {
case HAST_CHECKSUM_NONE:
return ("none");
case HAST_CHECKSUM_CRC32:
return ("crc32");
case HAST_CHECKSUM_SHA256:
return ("sha256");
}
return ("unknown");
}
int
checksum_send(const struct hast_resource *res, struct nv *nv, void **datap,
size_t *sizep, bool *freedatap __unused)
{
unsigned char hash[MAX_HASH_SIZE];
size_t hsize;
switch (res->hr_checksum) {
case HAST_CHECKSUM_NONE:
return (0);
case HAST_CHECKSUM_CRC32:
hast_crc32_checksum(*datap, *sizep, hash, &hsize);
break;
#ifdef HAVE_CRYPTO
case HAST_CHECKSUM_SHA256:
hast_sha256_checksum(*datap, *sizep, hash, &hsize);
break;
#endif
default:
PJDLOG_ABORT("Invalid checksum: %d.", res->hr_checksum);
}
nv_add_string(nv, checksum_name(res->hr_checksum), "checksum");
nv_add_uint8_array(nv, hash, hsize, "hash");
if (nv_error(nv) != 0) {
errno = nv_error(nv);
return (-1);
}
return (0);
}
int
checksum_recv(const struct hast_resource *res __unused, struct nv *nv,
void **datap, size_t *sizep, bool *freedatap __unused)
{
unsigned char chash[MAX_HASH_SIZE];
const unsigned char *rhash;
size_t chsize, rhsize;
const char *algo;
algo = nv_get_string(nv, "checksum");
if (algo == NULL)
return (0); /* No checksum. */
rhash = nv_get_uint8_array(nv, &rhsize, "hash");
if (rhash == NULL) {
pjdlog_error("Hash is missing.");
return (-1); /* Hash not found. */
}
if (strcmp(algo, "crc32") == 0)
hast_crc32_checksum(*datap, *sizep, chash, &chsize);
#ifdef HAVE_CRYPTO
else if (strcmp(algo, "sha256") == 0)
hast_sha256_checksum(*datap, *sizep, chash, &chsize);
#endif
else {
pjdlog_error("Unknown checksum algorithm '%s'.", algo);
return (-1); /* Unknown checksum algorithm. */
}
if (rhsize != chsize) {
pjdlog_error("Invalid hash size (%zu) for %s, should be %zu.",
rhsize, algo, chsize);
return (-1); /* Different hash size. */
}
if (bcmp(rhash, chash, chsize) != 0) {
pjdlog_error("Hash mismatch.");
return (-1); /* Hash mismatch. */
}
return (0);
}