hast_checksum.c revision 219351 
1/*-
2 * Copyright (c) 2011 Pawel Jakub Dawidek <pawel@dawidek.net>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD: head/sbin/hastd/hast_checksum.c 219351 2011-03-06 22:56:14Z pjd $");
29
30#include <errno.h>
31#include <string.h>
32#include <strings.h>
33
34#ifdef HAVE_CRYPTO
35#include <openssl/sha.h>
36#endif
37
38#include <crc32.h>
39#include <hast.h>
40#include <nv.h>
41#include <pjdlog.h>
42
43#include "hast_checksum.h"
44
45#ifdef HAVE_CRYPTO
46#define	MAX_HASH_SIZE	SHA256_DIGEST_LENGTH
47#else
48#define	MAX_HASH_SIZE	4
49#endif
50
51static int
52hast_crc32_checksum(const unsigned char *data, size_t size,
53    unsigned char *hash, size_t *hsizep)
54{
55	uint32_t crc;
56
57	crc = crc32(data, size);
58	/* XXXPJD: Do we have to use htole32() on crc first? */
59	bcopy(&crc, hash, sizeof(crc));
60	*hsizep = sizeof(crc);
61
62	return (0);
63}
64
65#ifdef HAVE_CRYPTO
66static int
67hast_sha256_checksum(const unsigned char *data, size_t size,
68    unsigned char *hash, size_t *hsizep)
69{
70	SHA256_CTX ctx;
71
72	SHA256_Init(&ctx);
73	SHA256_Update(&ctx, data, size);
74	SHA256_Final(hash, &ctx);
75	*hsizep = SHA256_DIGEST_LENGTH;
76
77	return (0);
78}
79#endif	/* HAVE_CRYPTO */
80
81const char *
82checksum_name(int num)
83{
84
85	switch (num) {
86	case HAST_CHECKSUM_NONE:
87		return ("none");
88	case HAST_CHECKSUM_CRC32:
89		return ("crc32");
90	case HAST_CHECKSUM_SHA256:
91		return ("sha256");
92	}
93	return ("unknown");
94}
95
96int
97checksum_send(const struct hast_resource *res, struct nv *nv, void **datap,
98    size_t *sizep, bool *freedatap __unused)
99{
100	unsigned char hash[MAX_HASH_SIZE];
101	size_t hsize;
102	int ret;
103
104	switch (res->hr_checksum) {
105	case HAST_CHECKSUM_NONE:
106		return (0);
107	case HAST_CHECKSUM_CRC32:
108		ret = hast_crc32_checksum(*datap, *sizep, hash, &hsize);
109		break;
110#ifdef HAVE_CRYPTO
111	case HAST_CHECKSUM_SHA256:
112		ret = hast_sha256_checksum(*datap, *sizep, hash, &hsize);
113		break;
114#endif
115	default:
116		PJDLOG_ABORT("Invalid checksum: %d.", res->hr_checksum);
117	}
118
119	if (ret != 0)
120		return (ret);
121	nv_add_string(nv, checksum_name(res->hr_checksum), "checksum");
122	nv_add_uint8_array(nv, hash, hsize, "hash");
123	if (nv_error(nv) != 0) {
124		errno = nv_error(nv);
125		return (-1);
126	}
127	return (0);
128}
129
130int
131checksum_recv(const struct hast_resource *res __unused, struct nv *nv,
132    void **datap, size_t *sizep, bool *freedatap __unused)
133{
134	unsigned char chash[MAX_HASH_SIZE];
135	const unsigned char *rhash;
136	size_t chsize, rhsize;
137	const char *algo;
138	int ret;
139
140	algo = nv_get_string(nv, "checksum");
141	if (algo == NULL)
142		return (0);	/* No checksum. */
143	rhash = nv_get_uint8_array(nv, &rhsize, "hash");
144	if (rhash == NULL) {
145		pjdlog_error("Hash is missing.");
146		return (-1);	/* Hash not found. */
147	}
148	if (strcmp(algo, "crc32") == 0)
149		ret = hast_crc32_checksum(*datap, *sizep, chash, &chsize);
150#ifdef HAVE_CRYPTO
151	else if (strcmp(algo, "sha256") == 0)
152		ret = hast_sha256_checksum(*datap, *sizep, chash, &chsize);
153#endif
154	else {
155		pjdlog_error("Unknown checksum algorithm '%s'.", algo);
156		return (-1);	/* Unknown checksum algorithm. */
157	}
158	if (rhsize != chsize) {
159		pjdlog_error("Invalid hash size (%zu) for %s, should be %zu.",
160		    rhsize, algo, chsize);
161		return (-1);	/* Different hash size. */
162	}
163	if (bcmp(rhash, chash, chsize) != 0) {
164		pjdlog_error("Hash mismatch.");
165		return (-1);	/* Hash mismatch. */
166	}
167
168	return (0);
169}
170