xref: /freebsd/sbin/hastd/hast_checksum.c (revision d91f8db5f1822c43cd256f19aae1d059e4b25a26)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 <hast.h>
37 #include <nv.h>
38 #include <sha256.h>
39 #include <zlib.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(0L, Z_NULL, 0);
53 	crc = crc32(crc, data, size);
54 
55 	/* XXXPJD: Do we have to use htole32() on crc first? */
56 	bcopy(&crc, hash, sizeof(crc));
57 	*hsizep = sizeof(crc);
58 }
59 
60 static void
61 hast_sha256_checksum(const unsigned char *data, size_t size,
62     unsigned char *hash, size_t *hsizep)
63 {
64 	SHA256_CTX ctx;
65 
66 	SHA256_Init(&ctx);
67 	SHA256_Update(&ctx, data, size);
68 	SHA256_Final(hash, &ctx);
69 	*hsizep = SHA256_DIGEST_LENGTH;
70 }
71 
72 const char *
73 checksum_name(int num)
74 {
75 
76 	switch (num) {
77 	case HAST_CHECKSUM_NONE:
78 		return ("none");
79 	case HAST_CHECKSUM_CRC32:
80 		return ("crc32");
81 	case HAST_CHECKSUM_SHA256:
82 		return ("sha256");
83 	}
84 	return ("unknown");
85 }
86 
87 int
88 checksum_send(const struct hast_resource *res, struct nv *nv, void **datap,
89     size_t *sizep, bool *freedatap __unused)
90 {
91 	unsigned char hash[MAX_HASH_SIZE];
92 	size_t hsize;
93 
94 	switch (res->hr_checksum) {
95 	case HAST_CHECKSUM_NONE:
96 		return (0);
97 	case HAST_CHECKSUM_CRC32:
98 		hast_crc32_checksum(*datap, *sizep, hash, &hsize);
99 		break;
100 	case HAST_CHECKSUM_SHA256:
101 		hast_sha256_checksum(*datap, *sizep, hash, &hsize);
102 		break;
103 	default:
104 		PJDLOG_ABORT("Invalid checksum: %d.", res->hr_checksum);
105 	}
106 	nv_add_string(nv, checksum_name(res->hr_checksum), "checksum");
107 	nv_add_uint8_array(nv, hash, hsize, "hash");
108 	if (nv_error(nv) != 0) {
109 		errno = nv_error(nv);
110 		return (-1);
111 	}
112 	return (0);
113 }
114 
115 int
116 checksum_recv(const struct hast_resource *res __unused, struct nv *nv,
117     void **datap, size_t *sizep, bool *freedatap __unused)
118 {
119 	unsigned char chash[MAX_HASH_SIZE];
120 	const unsigned char *rhash;
121 	size_t chsize, rhsize;
122 	const char *algo;
123 
124 	algo = nv_get_string(nv, "checksum");
125 	if (algo == NULL)
126 		return (0);	/* No checksum. */
127 	rhash = nv_get_uint8_array(nv, &rhsize, "hash");
128 	if (rhash == NULL) {
129 		pjdlog_error("Hash is missing.");
130 		return (-1);	/* Hash not found. */
131 	}
132 	if (strcmp(algo, "crc32") == 0)
133 		hast_crc32_checksum(*datap, *sizep, chash, &chsize);
134 	else if (strcmp(algo, "sha256") == 0)
135 		hast_sha256_checksum(*datap, *sizep, chash, &chsize);
136 	else {
137 		pjdlog_error("Unknown checksum algorithm '%s'.", algo);
138 		return (-1);	/* Unknown checksum algorithm. */
139 	}
140 	if (rhsize != chsize) {
141 		pjdlog_error("Invalid hash size (%zu) for %s, should be %zu.",
142 		    rhsize, algo, chsize);
143 		return (-1);	/* Different hash size. */
144 	}
145 	if (bcmp(rhash, chash, chsize) != 0) {
146 		pjdlog_error("Hash mismatch.");
147 		return (-1);	/* Hash mismatch. */
148 	}
149 
150 	return (0);
151 }
152