1 // SPDX-License-Identifier: GPL-2.0-or-later <<
2 /* 1 /*
3 * Cryptographic API. 2 * Cryptographic API.
4 * 3 *
5 * CRC32C chksum 4 * CRC32C chksum
6 * 5 *
7 *@Article{castagnoli-crc, 6 *@Article{castagnoli-crc,
8 * author = { Guy Castagnoli and Stefan 7 * author = { Guy Castagnoli and Stefan Braeuer and Martin Herrman},
9 * title = {{Optimization of Cyclic Red 8 * title = {{Optimization of Cyclic Redundancy-Check Codes with 24
10 * and 32 Parity Bits}}, 9 * and 32 Parity Bits}},
11 * journal = IEEE Transactions on Communi 10 * journal = IEEE Transactions on Communication,
12 * year = {1993}, 11 * year = {1993},
13 * volume = {41}, 12 * volume = {41},
14 * number = {6}, 13 * number = {6},
15 * pages = {}, 14 * pages = {},
16 * month = {June}, 15 * month = {June},
17 *} 16 *}
18 * Used by the iSCSI driver, possibly others, !! 17 * Used by the iSCSI driver, possibly others, and derived from the
19 * the iscsi-crc.c module of the linux-iscsi d 18 * the iscsi-crc.c module of the linux-iscsi driver at
20 * http://linux-iscsi.sourceforge.net. 19 * http://linux-iscsi.sourceforge.net.
21 * 20 *
22 * Following the example of lib/crc32, this fu 21 * Following the example of lib/crc32, this function is intended to be
23 * flexible and useful for all users. Modules 22 * flexible and useful for all users. Modules that currently have their
24 * own crc32c, but hopefully may be able to us 23 * own crc32c, but hopefully may be able to use this one are:
25 * net/sctp (please add all your doco to here 24 * net/sctp (please add all your doco to here if you change to
26 * use this one!) 25 * use this one!)
27 * <endoflist> 26 * <endoflist>
28 * 27 *
29 * Copyright (c) 2004 Cisco Systems, Inc. 28 * Copyright (c) 2004 Cisco Systems, Inc.
30 * Copyright (c) 2008 Herbert Xu <herbert@gond 29 * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
>> 30 *
>> 31 * This program is free software; you can redistribute it and/or modify it
>> 32 * under the terms of the GNU General Public License as published by the Free
>> 33 * Software Foundation; either version 2 of the License, or (at your option)
>> 34 * any later version.
>> 35 *
31 */ 36 */
32 37
33 #include <linux/unaligned.h> <<
34 #include <crypto/internal/hash.h> 38 #include <crypto/internal/hash.h>
35 #include <linux/init.h> 39 #include <linux/init.h>
36 #include <linux/module.h> 40 #include <linux/module.h>
37 #include <linux/string.h> 41 #include <linux/string.h>
38 #include <linux/kernel.h> 42 #include <linux/kernel.h>
39 #include <linux/crc32.h> 43 #include <linux/crc32.h>
40 44
41 #define CHKSUM_BLOCK_SIZE 1 45 #define CHKSUM_BLOCK_SIZE 1
42 #define CHKSUM_DIGEST_SIZE 4 46 #define CHKSUM_DIGEST_SIZE 4
43 47
44 struct chksum_ctx { 48 struct chksum_ctx {
45 u32 key; 49 u32 key;
46 }; 50 };
47 51
48 struct chksum_desc_ctx { 52 struct chksum_desc_ctx {
49 u32 crc; 53 u32 crc;
50 }; 54 };
51 55
52 /* 56 /*
53 * Steps through buffer one byte at a time, ca !! 57 * Steps through buffer one byte at at time, calculates reflected
54 * crc using table. 58 * crc using table.
55 */ 59 */
56 60
57 static int chksum_init(struct shash_desc *desc 61 static int chksum_init(struct shash_desc *desc)
58 { 62 {
59 struct chksum_ctx *mctx = crypto_shash 63 struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
60 struct chksum_desc_ctx *ctx = shash_de 64 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
61 65
62 ctx->crc = mctx->key; 66 ctx->crc = mctx->key;
63 67
64 return 0; 68 return 0;
65 } 69 }
66 70
67 /* 71 /*
68 * Setting the seed allows arbitrary accumulat 72 * Setting the seed allows arbitrary accumulators and flexible XOR policy
69 * If your algorithm starts with ~0, then XOR 73 * If your algorithm starts with ~0, then XOR with ~0 before you set
70 * the seed. 74 * the seed.
71 */ 75 */
72 static int chksum_setkey(struct crypto_shash * 76 static int chksum_setkey(struct crypto_shash *tfm, const u8 *key,
73 unsigned int keylen) 77 unsigned int keylen)
74 { 78 {
75 struct chksum_ctx *mctx = crypto_shash 79 struct chksum_ctx *mctx = crypto_shash_ctx(tfm);
76 80
77 if (keylen != sizeof(mctx->key)) !! 81 if (keylen != sizeof(mctx->key)) {
>> 82 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
78 return -EINVAL; 83 return -EINVAL;
79 mctx->key = get_unaligned_le32(key); !! 84 }
>> 85 mctx->key = le32_to_cpu(*(__le32 *)key);
80 return 0; 86 return 0;
81 } 87 }
82 88
83 static int chksum_update(struct shash_desc *de 89 static int chksum_update(struct shash_desc *desc, const u8 *data,
84 unsigned int length) 90 unsigned int length)
85 { 91 {
86 struct chksum_desc_ctx *ctx = shash_de 92 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
87 93
88 ctx->crc = __crc32c_le(ctx->crc, data, 94 ctx->crc = __crc32c_le(ctx->crc, data, length);
89 return 0; 95 return 0;
90 } 96 }
91 97
92 static int chksum_final(struct shash_desc *des 98 static int chksum_final(struct shash_desc *desc, u8 *out)
93 { 99 {
94 struct chksum_desc_ctx *ctx = shash_de 100 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
95 101
96 put_unaligned_le32(~ctx->crc, out); !! 102 *(__le32 *)out = ~cpu_to_le32p(&ctx->crc);
97 return 0; 103 return 0;
98 } 104 }
99 105
100 static int __chksum_finup(u32 *crcp, const u8 106 static int __chksum_finup(u32 *crcp, const u8 *data, unsigned int len, u8 *out)
101 { 107 {
102 put_unaligned_le32(~__crc32c_le(*crcp, !! 108 *(__le32 *)out = ~cpu_to_le32(__crc32c_le(*crcp, data, len));
103 return 0; 109 return 0;
104 } 110 }
105 111
106 static int chksum_finup(struct shash_desc *des 112 static int chksum_finup(struct shash_desc *desc, const u8 *data,
107 unsigned int len, u8 * 113 unsigned int len, u8 *out)
108 { 114 {
109 struct chksum_desc_ctx *ctx = shash_de 115 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
110 116
111 return __chksum_finup(&ctx->crc, data, 117 return __chksum_finup(&ctx->crc, data, len, out);
112 } 118 }
113 119
114 static int chksum_digest(struct shash_desc *de 120 static int chksum_digest(struct shash_desc *desc, const u8 *data,
115 unsigned int length, 121 unsigned int length, u8 *out)
116 { 122 {
117 struct chksum_ctx *mctx = crypto_shash 123 struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
118 124
119 return __chksum_finup(&mctx->key, data 125 return __chksum_finup(&mctx->key, data, length, out);
120 } 126 }
121 127
122 static int crc32c_cra_init(struct crypto_tfm * 128 static int crc32c_cra_init(struct crypto_tfm *tfm)
123 { 129 {
124 struct chksum_ctx *mctx = crypto_tfm_c 130 struct chksum_ctx *mctx = crypto_tfm_ctx(tfm);
125 131
126 mctx->key = ~0; 132 mctx->key = ~0;
127 return 0; 133 return 0;
128 } 134 }
129 135
130 static struct shash_alg alg = { 136 static struct shash_alg alg = {
131 .digestsize = CHKSUM 137 .digestsize = CHKSUM_DIGEST_SIZE,
132 .setkey = chksum 138 .setkey = chksum_setkey,
133 .init = chksum_init, 139 .init = chksum_init,
134 .update = chksum_update, 140 .update = chksum_update,
135 .final = chksum_final, 141 .final = chksum_final,
136 .finup = chksum_finup, 142 .finup = chksum_finup,
137 .digest = chksum_digest, 143 .digest = chksum_digest,
138 .descsize = sizeof 144 .descsize = sizeof(struct chksum_desc_ctx),
139 .base = { 145 .base = {
140 .cra_name = 146 .cra_name = "crc32c",
141 .cra_driver_name = 147 .cra_driver_name = "crc32c-generic",
142 .cra_priority = 148 .cra_priority = 100,
143 .cra_flags = <<
144 .cra_blocksize = 149 .cra_blocksize = CHKSUM_BLOCK_SIZE,
>> 150 .cra_alignmask = 3,
145 .cra_ctxsize = 151 .cra_ctxsize = sizeof(struct chksum_ctx),
146 .cra_module = 152 .cra_module = THIS_MODULE,
147 .cra_init = 153 .cra_init = crc32c_cra_init,
148 } 154 }
149 }; 155 };
150 156
151 static int __init crc32c_mod_init(void) 157 static int __init crc32c_mod_init(void)
152 { 158 {
153 return crypto_register_shash(&alg); 159 return crypto_register_shash(&alg);
154 } 160 }
155 161
156 static void __exit crc32c_mod_fini(void) 162 static void __exit crc32c_mod_fini(void)
157 { 163 {
158 crypto_unregister_shash(&alg); 164 crypto_unregister_shash(&alg);
159 } 165 }
160 166
161 subsys_initcall(crc32c_mod_init); !! 167 module_init(crc32c_mod_init);
162 module_exit(crc32c_mod_fini); 168 module_exit(crc32c_mod_fini);
163 169
164 MODULE_AUTHOR("Clay Haapala <chaapala@cisco.co 170 MODULE_AUTHOR("Clay Haapala <chaapala@cisco.com>");
165 MODULE_DESCRIPTION("CRC32c (Castagnoli) calcul 171 MODULE_DESCRIPTION("CRC32c (Castagnoli) calculations wrapper for lib/crc32c");
166 MODULE_LICENSE("GPL"); 172 MODULE_LICENSE("GPL");
167 MODULE_ALIAS_CRYPTO("crc32c"); 173 MODULE_ALIAS_CRYPTO("crc32c");
168 MODULE_ALIAS_CRYPTO("crc32c-generic"); 174 MODULE_ALIAS_CRYPTO("crc32c-generic");
169 175
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