1 /*
2 * Cryptographic API.
3 *
4 * T10 Data Integrity Field CRC16 Crypto Transform
5 *
6 * Copyright (c) 2007 Oracle Corporation. All rights reserved.
7 * Written by Martin K. Petersen <martin.petersen@oracle.com>
8 * Copyright (C) 2013 Intel Corporation
9 * Author: Tim Chen <tim.c.chen@linux.intel.com>
10 *
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by the Free
13 * Software Foundation; either version 2 of the License, or (at your option)
14 * any later version.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
17 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
19 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
20 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
21 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 * SOFTWARE.
24 *
25 */
26
27 #include <linux/module.h>
28 #include <linux/crc-t10dif.h>
29 #include <crypto/internal/hash.h>
30 #include <linux/init.h>
31 #include <linux/kernel.h>
32
33 struct chksum_desc_ctx {
34 __u16 crc;
35 };
36
37 /*
38 * Steps through buffer one byte at a time, calculates reflected
39 * crc using table.
40 */
41
42 static int chksum_init(struct shash_desc *desc)
43 {
44 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
45
46 ctx->crc = 0;
47
48 return 0;
49 }
50
51 static int chksum_update(struct shash_desc *desc, const u8 *data,
52 unsigned int length)
53 {
54 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
55
56 ctx->crc = crc_t10dif_generic(ctx->crc, data, length);
57 return 0;
58 }
59
60 static int chksum_final(struct shash_desc *desc, u8 *out)
61 {
62 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
63
64 *(__u16 *)out = ctx->crc;
65 return 0;
66 }
67
68 static int __chksum_finup(__u16 crc, const u8 *data, unsigned int len, u8 *out)
69 {
70 *(__u16 *)out = crc_t10dif_generic(crc, data, len);
71 return 0;
72 }
73
74 static int chksum_finup(struct shash_desc *desc, const u8 *data,
75 unsigned int len, u8 *out)
76 {
77 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
78
79 return __chksum_finup(ctx->crc, data, len, out);
80 }
81
82 static int chksum_digest(struct shash_desc *desc, const u8 *data,
83 unsigned int length, u8 *out)
84 {
85 return __chksum_finup(0, data, length, out);
86 }
87
88 static struct shash_alg alg = {
89 .digestsize = CRC_T10DIF_DIGEST_SIZE,
90 .init = chksum_init,
91 .update = chksum_update,
92 .final = chksum_final,
93 .finup = chksum_finup,
94 .digest = chksum_digest,
95 .descsize = sizeof(struct chksum_desc_ctx),
96 .base = {
97 .cra_name = "crct10dif",
98 .cra_driver_name = "crct10dif-generic",
99 .cra_priority = 100,
100 .cra_blocksize = CRC_T10DIF_BLOCK_SIZE,
101 .cra_module = THIS_MODULE,
102 }
103 };
104
105 static int __init crct10dif_mod_init(void)
106 {
107 return crypto_register_shash(&alg);
108 }
109
110 static void __exit crct10dif_mod_fini(void)
111 {
112 crypto_unregister_shash(&alg);
113 }
114
115 subsys_initcall(crct10dif_mod_init);
116 module_exit(crct10dif_mod_fini);
117
118 MODULE_AUTHOR("Tim Chen <tim.c.chen@linux.intel.com>");
119 MODULE_DESCRIPTION("T10 DIF CRC calculation.");
120 MODULE_LICENSE("GPL");
121 MODULE_ALIAS_CRYPTO("crct10dif");
122 MODULE_ALIAS_CRYPTO("crct10dif-generic");
123
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