xref: /freebsd/sbin/hastd/hast_checksum.c (revision 7a1c0d963366a31363d3705697a083dd8efee077)
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 #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 
51 static int
52 hast_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
66 static int
67 hast_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 
81 const char *
82 checksum_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 
96 int
97 checksum_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 
130 int
131 checksum_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