xref: /freebsd/sbin/hastd/hast_checksum.c (revision f7c32ed617858bcd22f8d1b03199099d50125721)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2011 Pawel Jakub Dawidek <pawel@dawidek.net>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <errno.h>
33 #include <string.h>
34 #include <strings.h>
35 
36 #include <crc32.h>
37 #include <hast.h>
38 #include <nv.h>
39 #include <sha256.h>
40 #include <pjdlog.h>
41 
42 #include "hast_checksum.h"
43 
44 #define	MAX_HASH_SIZE	SHA256_DIGEST_LENGTH
45 
46 static void
47 hast_crc32_checksum(const unsigned char *data, size_t size,
48     unsigned char *hash, size_t *hsizep)
49 {
50 	uint32_t crc;
51 
52 	crc = crc32(data, size);
53 	/* XXXPJD: Do we have to use htole32() on crc first? */
54 	bcopy(&crc, hash, sizeof(crc));
55 	*hsizep = sizeof(crc);
56 }
57 
58 static void
59 hast_sha256_checksum(const unsigned char *data, size_t size,
60     unsigned char *hash, size_t *hsizep)
61 {
62 	SHA256_CTX ctx;
63 
64 	SHA256_Init(&ctx);
65 	SHA256_Update(&ctx, data, size);
66 	SHA256_Final(hash, &ctx);
67 	*hsizep = SHA256_DIGEST_LENGTH;
68 }
69 
70 const char *
71 checksum_name(int num)
72 {
73 
74 	switch (num) {
75 	case HAST_CHECKSUM_NONE:
76 		return ("none");
77 	case HAST_CHECKSUM_CRC32:
78 		return ("crc32");
79 	case HAST_CHECKSUM_SHA256:
80 		return ("sha256");
81 	}
82 	return ("unknown");
83 }
84 
85 int
86 checksum_send(const struct hast_resource *res, struct nv *nv, void **datap,
87     size_t *sizep, bool *freedatap __unused)
88 {
89 	unsigned char hash[MAX_HASH_SIZE];
90 	size_t hsize;
91 
92 	switch (res->hr_checksum) {
93 	case HAST_CHECKSUM_NONE:
94 		return (0);
95 	case HAST_CHECKSUM_CRC32:
96 		hast_crc32_checksum(*datap, *sizep, hash, &hsize);
97 		break;
98 	case HAST_CHECKSUM_SHA256:
99 		hast_sha256_checksum(*datap, *sizep, hash, &hsize);
100 		break;
101 	default:
102 		PJDLOG_ABORT("Invalid checksum: %d.", res->hr_checksum);
103 	}
104 	nv_add_string(nv, checksum_name(res->hr_checksum), "checksum");
105 	nv_add_uint8_array(nv, hash, hsize, "hash");
106 	if (nv_error(nv) != 0) {
107 		errno = nv_error(nv);
108 		return (-1);
109 	}
110 	return (0);
111 }
112 
113 int
114 checksum_recv(const struct hast_resource *res __unused, struct nv *nv,
115     void **datap, size_t *sizep, bool *freedatap __unused)
116 {
117 	unsigned char chash[MAX_HASH_SIZE];
118 	const unsigned char *rhash;
119 	size_t chsize, rhsize;
120 	const char *algo;
121 
122 	algo = nv_get_string(nv, "checksum");
123 	if (algo == NULL)
124 		return (0);	/* No checksum. */
125 	rhash = nv_get_uint8_array(nv, &rhsize, "hash");
126 	if (rhash == NULL) {
127 		pjdlog_error("Hash is missing.");
128 		return (-1);	/* Hash not found. */
129 	}
130 	if (strcmp(algo, "crc32") == 0)
131 		hast_crc32_checksum(*datap, *sizep, chash, &chsize);
132 	else if (strcmp(algo, "sha256") == 0)
133 		hast_sha256_checksum(*datap, *sizep, chash, &chsize);
134 	else {
135 		pjdlog_error("Unknown checksum algorithm '%s'.", algo);
136 		return (-1);	/* Unknown checksum algorithm. */
137 	}
138 	if (rhsize != chsize) {
139 		pjdlog_error("Invalid hash size (%zu) for %s, should be %zu.",
140 		    rhsize, algo, chsize);
141 		return (-1);	/* Different hash size. */
142 	}
143 	if (bcmp(rhash, chash, chsize) != 0) {
144 		pjdlog_error("Hash mismatch.");
145 		return (-1);	/* Hash mismatch. */
146 	}
147 
148 	return (0);
149 }
150