hast_checksum.c revision 229509 
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: stable/9/sbin/hastd/hast_checksum.c 229509 2012-01-04 17:22:10Z trociny $");
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 void
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
63#ifdef HAVE_CRYPTO
64static void
65hast_sha256_checksum(const unsigned char *data, size_t size,
66    unsigned char *hash, size_t *hsizep)
67{
68	SHA256_CTX ctx;
69
70	SHA256_Init(&ctx);
71	SHA256_Update(&ctx, data, size);
72	SHA256_Final(hash, &ctx);
73	*hsizep = SHA256_DIGEST_LENGTH;
74}
75#endif	/* HAVE_CRYPTO */
76
77const char *
78checksum_name(int num)
79{
80
81	switch (num) {
82	case HAST_CHECKSUM_NONE:
83		return ("none");
84	case HAST_CHECKSUM_CRC32:
85		return ("crc32");
86	case HAST_CHECKSUM_SHA256:
87		return ("sha256");
88	}
89	return ("unknown");
90}
91
92int
93checksum_send(const struct hast_resource *res, struct nv *nv, void **datap,
94    size_t *sizep, bool *freedatap __unused)
95{
96	unsigned char hash[MAX_HASH_SIZE];
97	size_t hsize;
98
99	switch (res->hr_checksum) {
100	case HAST_CHECKSUM_NONE:
101		return (0);
102	case HAST_CHECKSUM_CRC32:
103		hast_crc32_checksum(*datap, *sizep, hash, &hsize);
104		break;
105#ifdef HAVE_CRYPTO
106	case HAST_CHECKSUM_SHA256:
107		hast_sha256_checksum(*datap, *sizep, hash, &hsize);
108		break;
109#endif
110	default:
111		PJDLOG_ABORT("Invalid checksum: %d.", res->hr_checksum);
112	}
113	nv_add_string(nv, checksum_name(res->hr_checksum), "checksum");
114	nv_add_uint8_array(nv, hash, hsize, "hash");
115	if (nv_error(nv) != 0) {
116		errno = nv_error(nv);
117		return (-1);
118	}
119	return (0);
120}
121
122int
123checksum_recv(const struct hast_resource *res __unused, struct nv *nv,
124    void **datap, size_t *sizep, bool *freedatap __unused)
125{
126	unsigned char chash[MAX_HASH_SIZE];
127	const unsigned char *rhash;
128	size_t chsize, rhsize;
129	const char *algo;
130
131	algo = nv_get_string(nv, "checksum");
132	if (algo == NULL)
133		return (0);	/* No checksum. */
134	rhash = nv_get_uint8_array(nv, &rhsize, "hash");
135	if (rhash == NULL) {
136		pjdlog_error("Hash is missing.");
137		return (-1);	/* Hash not found. */
138	}
139	if (strcmp(algo, "crc32") == 0)
140		hast_crc32_checksum(*datap, *sizep, chash, &chsize);
141#ifdef HAVE_CRYPTO
142	else if (strcmp(algo, "sha256") == 0)
143		hast_sha256_checksum(*datap, *sizep, chash, &chsize);
144#endif
145	else {
146		pjdlog_error("Unknown checksum algorithm '%s'.", algo);
147		return (-1);	/* Unknown checksum algorithm. */
148	}
149	if (rhsize != chsize) {
150		pjdlog_error("Invalid hash size (%zu) for %s, should be %zu.",
151		    rhsize, algo, chsize);
152		return (-1);	/* Different hash size. */
153	}
154	if (bcmp(rhash, chash, chsize) != 0) {
155		pjdlog_error("Hash mismatch.");
156		return (-1);	/* Hash mismatch. */
157	}
158
159	return (0);
160}
161