xref: /freebsd/sbin/hastd/hast_checksum.c (revision 13464e4a44fc58490a03bb8bfc7e3c972e9c30b2)
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("$FreeBSD$");
29 
30 #include <errno.h>
31 #include <string.h>
32 #include <strings.h>
33 
34 #include <crc32.h>
35 #include <hast.h>
36 #include <nv.h>
37 #include <sha256.h>
38 #include <pjdlog.h>
39 
40 #include "hast_checksum.h"
41 
42 #define	MAX_HASH_SIZE	SHA256_DIGEST_LENGTH
43 
44 static void
45 hast_crc32_checksum(const unsigned char *data, size_t size,
46     unsigned char *hash, size_t *hsizep)
47 {
48 	uint32_t crc;
49 
50 	crc = crc32(data, size);
51 	/* XXXPJD: Do we have to use htole32() on crc first? */
52 	bcopy(&crc, hash, sizeof(crc));
53 	*hsizep = sizeof(crc);
54 }
55 
56 static void
57 hast_sha256_checksum(const unsigned char *data, size_t size,
58     unsigned char *hash, size_t *hsizep)
59 {
60 	SHA256_CTX ctx;
61 
62 	SHA256_Init(&ctx);
63 	SHA256_Update(&ctx, data, size);
64 	SHA256_Final(hash, &ctx);
65 	*hsizep = SHA256_DIGEST_LENGTH;
66 }
67 
68 const char *
69 checksum_name(int num)
70 {
71 
72 	switch (num) {
73 	case HAST_CHECKSUM_NONE:
74 		return ("none");
75 	case HAST_CHECKSUM_CRC32:
76 		return ("crc32");
77 	case HAST_CHECKSUM_SHA256:
78 		return ("sha256");
79 	}
80 	return ("unknown");
81 }
82 
83 int
84 checksum_send(const struct hast_resource *res, struct nv *nv, void **datap,
85     size_t *sizep, bool *freedatap __unused)
86 {
87 	unsigned char hash[MAX_HASH_SIZE];
88 	size_t hsize;
89 
90 	switch (res->hr_checksum) {
91 	case HAST_CHECKSUM_NONE:
92 		return (0);
93 	case HAST_CHECKSUM_CRC32:
94 		hast_crc32_checksum(*datap, *sizep, hash, &hsize);
95 		break;
96 	case HAST_CHECKSUM_SHA256:
97 		hast_sha256_checksum(*datap, *sizep, hash, &hsize);
98 		break;
99 	default:
100 		PJDLOG_ABORT("Invalid checksum: %d.", res->hr_checksum);
101 	}
102 	nv_add_string(nv, checksum_name(res->hr_checksum), "checksum");
103 	nv_add_uint8_array(nv, hash, hsize, "hash");
104 	if (nv_error(nv) != 0) {
105 		errno = nv_error(nv);
106 		return (-1);
107 	}
108 	return (0);
109 }
110 
111 int
112 checksum_recv(const struct hast_resource *res __unused, struct nv *nv,
113     void **datap, size_t *sizep, bool *freedatap __unused)
114 {
115 	unsigned char chash[MAX_HASH_SIZE];
116 	const unsigned char *rhash;
117 	size_t chsize, rhsize;
118 	const char *algo;
119 
120 	algo = nv_get_string(nv, "checksum");
121 	if (algo == NULL)
122 		return (0);	/* No checksum. */
123 	rhash = nv_get_uint8_array(nv, &rhsize, "hash");
124 	if (rhash == NULL) {
125 		pjdlog_error("Hash is missing.");
126 		return (-1);	/* Hash not found. */
127 	}
128 	if (strcmp(algo, "crc32") == 0)
129 		hast_crc32_checksum(*datap, *sizep, chash, &chsize);
130 	else if (strcmp(algo, "sha256") == 0)
131 		hast_sha256_checksum(*datap, *sizep, chash, &chsize);
132 	else {
133 		pjdlog_error("Unknown checksum algorithm '%s'.", algo);
134 		return (-1);	/* Unknown checksum algorithm. */
135 	}
136 	if (rhsize != chsize) {
137 		pjdlog_error("Invalid hash size (%zu) for %s, should be %zu.",
138 		    rhsize, algo, chsize);
139 		return (-1);	/* Different hash size. */
140 	}
141 	if (bcmp(rhash, chash, chsize) != 0) {
142 		pjdlog_error("Hash mismatch.");
143 		return (-1);	/* Hash mismatch. */
144 	}
145 
146 	return (0);
147 }
148