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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Cryptographic API.
4 *
5 * CRC32C chksum
6 *
7 *@Article{castagnoli-crc,
8 * author = { Guy Castagnoli and Stefan Braeuer and Martin Herrman},
9 * title = {{Optimization of Cyclic Redundancy-Check Codes with 24
10 * and 32 Parity Bits}},
11 * journal = IEEE Transactions on Communication,
12 * year = {1993},
13 * volume = {41},
14 * number = {6},
15 * pages = {},
16 * month = {June},
17 *}
18 * Used by the iSCSI driver, possibly others, and derived from
19 * the iscsi-crc.c module of the linux-iscsi driver at
20 * http://linux-iscsi.sourceforge.net.
21 *
22 * Following the example of lib/crc32, this function is intended to be
23 * flexible and useful for all users. Modules that currently have their
24 * own crc32c, but hopefully may be able to use this one are:
25 * net/sctp (please add all your doco to here if you change to
26 * use this one!)
27 * <endoflist>
28 *
29 * Copyright (c) 2004 Cisco Systems, Inc.
30 * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
31 */
32
33#include <linux/unaligned.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#include <linux/crc32.h>
40
41#define CHKSUM_BLOCK_SIZE 1
42#define CHKSUM_DIGEST_SIZE 4
43
44struct chksum_ctx {
45 u32 key;
46};
47
48struct chksum_desc_ctx {
49 u32 crc;
50};
51
52/*
53 * Steps through buffer one byte at a time, calculates reflected
54 * crc using table.
55 */
56
57static int chksum_init(struct shash_desc *desc)
58{
59 struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
60 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
61
62 ctx->crc = mctx->key;
63
64 return 0;
65}
66
67/*
68 * Setting the seed allows arbitrary accumulators and flexible XOR policy
69 * If your algorithm starts with ~0, then XOR with ~0 before you set
70 * the seed.
71 */
72static int chksum_setkey(struct crypto_shash *tfm, const u8 *key,
73 unsigned int keylen)
74{
75 struct chksum_ctx *mctx = crypto_shash_ctx(tfm);
76
77 if (keylen != sizeof(mctx->key))
78 return -EINVAL;
79 mctx->key = get_unaligned_le32(key);
80 return 0;
81}
82
83static int chksum_update(struct shash_desc *desc, const u8 *data,
84 unsigned int length)
85{
86 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
87
88 ctx->crc = __crc32c_le_base(ctx->crc, data, length);
89 return 0;
90}
91
92static int chksum_update_arch(struct shash_desc *desc, const u8 *data,
93 unsigned int length)
94{
95 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
96
97 ctx->crc = __crc32c_le(ctx->crc, data, length);
98 return 0;
99}
100
101static int chksum_final(struct shash_desc *desc, u8 *out)
102{
103 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
104
105 put_unaligned_le32(~ctx->crc, out);
106 return 0;
107}
108
109static int __chksum_finup(u32 *crcp, const u8 *data, unsigned int len, u8 *out)
110{
111 put_unaligned_le32(~__crc32c_le_base(*crcp, data, len), out);
112 return 0;
113}
114
115static int __chksum_finup_arch(u32 *crcp, const u8 *data, unsigned int len,
116 u8 *out)
117{
118 put_unaligned_le32(~__crc32c_le(*crcp, data, len), out);
119 return 0;
120}
121
122static int chksum_finup(struct shash_desc *desc, const u8 *data,
123 unsigned int len, u8 *out)
124{
125 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
126
127 return __chksum_finup(&ctx->crc, data, len, out);
128}
129
130static int chksum_finup_arch(struct shash_desc *desc, const u8 *data,
131 unsigned int len, u8 *out)
132{
133 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
134
135 return __chksum_finup_arch(&ctx->crc, data, len, out);
136}
137
138static int chksum_digest(struct shash_desc *desc, const u8 *data,
139 unsigned int length, u8 *out)
140{
141 struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
142
143 return __chksum_finup(&mctx->key, data, length, out);
144}
145
146static int chksum_digest_arch(struct shash_desc *desc, const u8 *data,
147 unsigned int length, u8 *out)
148{
149 struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
150
151 return __chksum_finup_arch(&mctx->key, data, length, out);
152}
153
154static int crc32c_cra_init(struct crypto_tfm *tfm)
155{
156 struct chksum_ctx *mctx = crypto_tfm_ctx(tfm);
157
158 mctx->key = ~0;
159 return 0;
160}
161
162static struct shash_alg algs[] = {{
163 .digestsize = CHKSUM_DIGEST_SIZE,
164 .setkey = chksum_setkey,
165 .init = chksum_init,
166 .update = chksum_update,
167 .final = chksum_final,
168 .finup = chksum_finup,
169 .digest = chksum_digest,
170 .descsize = sizeof(struct chksum_desc_ctx),
171
172 .base.cra_name = "crc32c",
173 .base.cra_driver_name = "crc32c-generic",
174 .base.cra_priority = 100,
175 .base.cra_flags = CRYPTO_ALG_OPTIONAL_KEY,
176 .base.cra_blocksize = CHKSUM_BLOCK_SIZE,
177 .base.cra_ctxsize = sizeof(struct chksum_ctx),
178 .base.cra_module = THIS_MODULE,
179 .base.cra_init = crc32c_cra_init,
180}, {
181 .digestsize = CHKSUM_DIGEST_SIZE,
182 .setkey = chksum_setkey,
183 .init = chksum_init,
184 .update = chksum_update_arch,
185 .final = chksum_final,
186 .finup = chksum_finup_arch,
187 .digest = chksum_digest_arch,
188 .descsize = sizeof(struct chksum_desc_ctx),
189
190 .base.cra_name = "crc32c",
191 .base.cra_driver_name = "crc32c-" __stringify(ARCH),
192 .base.cra_priority = 150,
193 .base.cra_flags = CRYPTO_ALG_OPTIONAL_KEY,
194 .base.cra_blocksize = CHKSUM_BLOCK_SIZE,
195 .base.cra_ctxsize = sizeof(struct chksum_ctx),
196 .base.cra_module = THIS_MODULE,
197 .base.cra_init = crc32c_cra_init,
198}};
199
200static int __init crc32c_mod_init(void)
201{
202 /* register the arch flavor only if it differs from the generic one */
203 return crypto_register_shashes(algs, 1 + (&__crc32c_le != &__crc32c_le_base));
204}
205
206static void __exit crc32c_mod_fini(void)
207{
208 crypto_unregister_shashes(algs, 1 + (&__crc32c_le != &__crc32c_le_base));
209}
210
211subsys_initcall(crc32c_mod_init);
212module_exit(crc32c_mod_fini);
213
214MODULE_AUTHOR("Clay Haapala <chaapala@cisco.com>");
215MODULE_DESCRIPTION("CRC32c (Castagnoli) calculations wrapper for lib/crc32c");
216MODULE_LICENSE("GPL");
217MODULE_ALIAS_CRYPTO("crc32c");
218MODULE_ALIAS_CRYPTO("crc32c-generic");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Cryptographic API.
4 *
5 * CRC32C chksum
6 *
7 *@Article{castagnoli-crc,
8 * author = { Guy Castagnoli and Stefan Braeuer and Martin Herrman},
9 * title = {{Optimization of Cyclic Redundancy-Check Codes with 24
10 * and 32 Parity Bits}},
11 * journal = IEEE Transactions on Communication,
12 * year = {1993},
13 * volume = {41},
14 * number = {6},
15 * pages = {},
16 * month = {June},
17 *}
18 * Used by the iSCSI driver, possibly others, and derived from
19 * the iscsi-crc.c module of the linux-iscsi driver at
20 * http://linux-iscsi.sourceforge.net.
21 *
22 * Following the example of lib/crc32, this function is intended to be
23 * flexible and useful for all users. Modules that currently have their
24 * own crc32c, but hopefully may be able to use this one are:
25 * net/sctp (please add all your doco to here if you change to
26 * use this one!)
27 * <endoflist>
28 *
29 * Copyright (c) 2004 Cisco Systems, Inc.
30 * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
31 */
32
33#include <asm/unaligned.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#include <linux/crc32.h>
40
41#define CHKSUM_BLOCK_SIZE 1
42#define CHKSUM_DIGEST_SIZE 4
43
44struct chksum_ctx {
45 u32 key;
46};
47
48struct chksum_desc_ctx {
49 u32 crc;
50};
51
52/*
53 * Steps through buffer one byte at a time, calculates reflected
54 * crc using table.
55 */
56
57static int chksum_init(struct shash_desc *desc)
58{
59 struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
60 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
61
62 ctx->crc = mctx->key;
63
64 return 0;
65}
66
67/*
68 * Setting the seed allows arbitrary accumulators and flexible XOR policy
69 * If your algorithm starts with ~0, then XOR with ~0 before you set
70 * the seed.
71 */
72static int chksum_setkey(struct crypto_shash *tfm, const u8 *key,
73 unsigned int keylen)
74{
75 struct chksum_ctx *mctx = crypto_shash_ctx(tfm);
76
77 if (keylen != sizeof(mctx->key))
78 return -EINVAL;
79 mctx->key = get_unaligned_le32(key);
80 return 0;
81}
82
83static int chksum_update(struct shash_desc *desc, const u8 *data,
84 unsigned int length)
85{
86 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
87
88 ctx->crc = __crc32c_le(ctx->crc, data, length);
89 return 0;
90}
91
92static int chksum_final(struct shash_desc *desc, u8 *out)
93{
94 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
95
96 put_unaligned_le32(~ctx->crc, out);
97 return 0;
98}
99
100static int __chksum_finup(u32 *crcp, const u8 *data, unsigned int len, u8 *out)
101{
102 put_unaligned_le32(~__crc32c_le(*crcp, data, len), out);
103 return 0;
104}
105
106static int chksum_finup(struct shash_desc *desc, const u8 *data,
107 unsigned int len, u8 *out)
108{
109 struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
110
111 return __chksum_finup(&ctx->crc, data, len, out);
112}
113
114static int chksum_digest(struct shash_desc *desc, const u8 *data,
115 unsigned int length, u8 *out)
116{
117 struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
118
119 return __chksum_finup(&mctx->key, data, length, out);
120}
121
122static int crc32c_cra_init(struct crypto_tfm *tfm)
123{
124 struct chksum_ctx *mctx = crypto_tfm_ctx(tfm);
125
126 mctx->key = ~0;
127 return 0;
128}
129
130static struct shash_alg alg = {
131 .digestsize = CHKSUM_DIGEST_SIZE,
132 .setkey = chksum_setkey,
133 .init = chksum_init,
134 .update = chksum_update,
135 .final = chksum_final,
136 .finup = chksum_finup,
137 .digest = chksum_digest,
138 .descsize = sizeof(struct chksum_desc_ctx),
139 .base = {
140 .cra_name = "crc32c",
141 .cra_driver_name = "crc32c-generic",
142 .cra_priority = 100,
143 .cra_flags = CRYPTO_ALG_OPTIONAL_KEY,
144 .cra_blocksize = CHKSUM_BLOCK_SIZE,
145 .cra_ctxsize = sizeof(struct chksum_ctx),
146 .cra_module = THIS_MODULE,
147 .cra_init = crc32c_cra_init,
148 }
149};
150
151static int __init crc32c_mod_init(void)
152{
153 return crypto_register_shash(&alg);
154}
155
156static void __exit crc32c_mod_fini(void)
157{
158 crypto_unregister_shash(&alg);
159}
160
161subsys_initcall(crc32c_mod_init);
162module_exit(crc32c_mod_fini);
163
164MODULE_AUTHOR("Clay Haapala <chaapala@cisco.com>");
165MODULE_DESCRIPTION("CRC32c (Castagnoli) calculations wrapper for lib/crc32c");
166MODULE_LICENSE("GPL");
167MODULE_ALIAS_CRYPTO("crc32c");
168MODULE_ALIAS_CRYPTO("crc32c-generic");