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78c37d19 AB |
1 | /* GPL HEADER START |
2 | * | |
3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License version 2 only, | |
7 | * as published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, but | |
10 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | * General Public License version 2 for more details (a copy is included | |
13 | * in the LICENSE file that accompanied this code). | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * version 2 along with this program; If not, see http://www.gnu.org/licenses | |
17 | * | |
18 | * Please visit http://www.xyratex.com/contact if you need additional | |
19 | * information or have any questions. | |
20 | * | |
21 | * GPL HEADER END | |
22 | */ | |
23 | ||
24 | /* | |
25 | * Copyright 2012 Xyratex Technology Limited | |
26 | */ | |
27 | ||
28 | /* | |
29 | * This is crypto api shash wrappers to crc32_le. | |
30 | */ | |
31 | ||
fffe7d92 | 32 | #include <asm/unaligned.h> |
78c37d19 AB |
33 | #include <linux/crc32.h> |
34 | #include <crypto/internal/hash.h> | |
35 | #include <linux/init.h> | |
36 | #include <linux/module.h> | |
37 | #include <linux/string.h> | |
38 | #include <linux/kernel.h> | |
39 | ||
40 | #define CHKSUM_BLOCK_SIZE 1 | |
41 | #define CHKSUM_DIGEST_SIZE 4 | |
42 | ||
78c37d19 AB |
43 | /** No default init with ~0 */ |
44 | static int crc32_cra_init(struct crypto_tfm *tfm) | |
45 | { | |
46 | u32 *key = crypto_tfm_ctx(tfm); | |
47 | ||
48 | *key = 0; | |
49 | ||
50 | return 0; | |
51 | } | |
52 | ||
78c37d19 AB |
53 | /* |
54 | * Setting the seed allows arbitrary accumulators and flexible XOR policy | |
55 | * If your algorithm starts with ~0, then XOR with ~0 before you set | |
56 | * the seed. | |
57 | */ | |
58 | static int crc32_setkey(struct crypto_shash *hash, const u8 *key, | |
59 | unsigned int keylen) | |
60 | { | |
61 | u32 *mctx = crypto_shash_ctx(hash); | |
62 | ||
674f368a | 63 | if (keylen != sizeof(u32)) |
78c37d19 | 64 | return -EINVAL; |
fffe7d92 | 65 | *mctx = get_unaligned_le32(key); |
78c37d19 AB |
66 | return 0; |
67 | } | |
68 | ||
69 | static int crc32_init(struct shash_desc *desc) | |
70 | { | |
71 | u32 *mctx = crypto_shash_ctx(desc->tfm); | |
72 | u32 *crcp = shash_desc_ctx(desc); | |
73 | ||
74 | *crcp = *mctx; | |
75 | ||
76 | return 0; | |
77 | } | |
78 | ||
79 | static int crc32_update(struct shash_desc *desc, const u8 *data, | |
80 | unsigned int len) | |
81 | { | |
82 | u32 *crcp = shash_desc_ctx(desc); | |
83 | ||
6943546c | 84 | *crcp = crc32_le(*crcp, data, len); |
78c37d19 AB |
85 | return 0; |
86 | } | |
87 | ||
88 | /* No final XOR 0xFFFFFFFF, like crc32_le */ | |
89 | static int __crc32_finup(u32 *crcp, const u8 *data, unsigned int len, | |
90 | u8 *out) | |
91 | { | |
6943546c | 92 | put_unaligned_le32(crc32_le(*crcp, data, len), out); |
78c37d19 AB |
93 | return 0; |
94 | } | |
95 | ||
96 | static int crc32_finup(struct shash_desc *desc, const u8 *data, | |
97 | unsigned int len, u8 *out) | |
98 | { | |
99 | return __crc32_finup(shash_desc_ctx(desc), data, len, out); | |
100 | } | |
101 | ||
102 | static int crc32_final(struct shash_desc *desc, u8 *out) | |
103 | { | |
104 | u32 *crcp = shash_desc_ctx(desc); | |
105 | ||
fffe7d92 | 106 | put_unaligned_le32(*crcp, out); |
78c37d19 AB |
107 | return 0; |
108 | } | |
109 | ||
110 | static int crc32_digest(struct shash_desc *desc, const u8 *data, | |
111 | unsigned int len, u8 *out) | |
112 | { | |
113 | return __crc32_finup(crypto_shash_ctx(desc->tfm), data, len, | |
114 | out); | |
115 | } | |
116 | static struct shash_alg alg = { | |
117 | .setkey = crc32_setkey, | |
118 | .init = crc32_init, | |
119 | .update = crc32_update, | |
120 | .final = crc32_final, | |
121 | .finup = crc32_finup, | |
122 | .digest = crc32_digest, | |
123 | .descsize = sizeof(u32), | |
124 | .digestsize = CHKSUM_DIGEST_SIZE, | |
125 | .base = { | |
126 | .cra_name = "crc32", | |
a7c58ac0 | 127 | .cra_driver_name = "crc32-generic", |
78c37d19 | 128 | .cra_priority = 100, |
a208fa8f | 129 | .cra_flags = CRYPTO_ALG_OPTIONAL_KEY, |
78c37d19 AB |
130 | .cra_blocksize = CHKSUM_BLOCK_SIZE, |
131 | .cra_ctxsize = sizeof(u32), | |
132 | .cra_module = THIS_MODULE, | |
133 | .cra_init = crc32_cra_init, | |
134 | } | |
135 | }; | |
136 | ||
137 | static int __init crc32_mod_init(void) | |
138 | { | |
139 | return crypto_register_shash(&alg); | |
140 | } | |
141 | ||
142 | static void __exit crc32_mod_fini(void) | |
143 | { | |
144 | crypto_unregister_shash(&alg); | |
145 | } | |
146 | ||
c4741b23 | 147 | subsys_initcall(crc32_mod_init); |
78c37d19 AB |
148 | module_exit(crc32_mod_fini); |
149 | ||
150 | MODULE_AUTHOR("Alexander Boyko <alexander_boyko@xyratex.com>"); | |
151 | MODULE_DESCRIPTION("CRC32 calculations wrapper for lib/crc32"); | |
152 | MODULE_LICENSE("GPL"); | |
5d26a105 | 153 | MODULE_ALIAS_CRYPTO("crc32"); |
a7c58ac0 | 154 | MODULE_ALIAS_CRYPTO("crc32-generic"); |