1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Copyright 2012 Xyratex Technology Limited |
4 | */ |
5 | |
6 | /* |
7 | * This is crypto api shash wrappers to crc32_le. |
8 | */ |
9 | |
10 | #include <asm/unaligned.h> |
11 | #include <linux/crc32.h> |
12 | #include <crypto/internal/hash.h> |
13 | #include <linux/init.h> |
14 | #include <linux/module.h> |
15 | #include <linux/string.h> |
16 | #include <linux/kernel.h> |
17 | |
18 | #define CHKSUM_BLOCK_SIZE 1 |
19 | #define CHKSUM_DIGEST_SIZE 4 |
20 | |
21 | /** No default init with ~0 */ |
22 | static int crc32_cra_init(struct crypto_tfm *tfm) |
23 | { |
24 | u32 *key = crypto_tfm_ctx(tfm); |
25 | |
26 | *key = 0; |
27 | |
28 | return 0; |
29 | } |
30 | |
31 | /* |
32 | * Setting the seed allows arbitrary accumulators and flexible XOR policy |
33 | * If your algorithm starts with ~0, then XOR with ~0 before you set |
34 | * the seed. |
35 | */ |
36 | static int crc32_setkey(struct crypto_shash *hash, const u8 *key, |
37 | unsigned int keylen) |
38 | { |
39 | u32 *mctx = crypto_shash_ctx(tfm: hash); |
40 | |
41 | if (keylen != sizeof(u32)) |
42 | return -EINVAL; |
43 | *mctx = get_unaligned_le32(p: key); |
44 | return 0; |
45 | } |
46 | |
47 | static int crc32_init(struct shash_desc *desc) |
48 | { |
49 | u32 *mctx = crypto_shash_ctx(tfm: desc->tfm); |
50 | u32 *crcp = shash_desc_ctx(desc); |
51 | |
52 | *crcp = *mctx; |
53 | |
54 | return 0; |
55 | } |
56 | |
57 | static int crc32_update(struct shash_desc *desc, const u8 *data, |
58 | unsigned int len) |
59 | { |
60 | u32 *crcp = shash_desc_ctx(desc); |
61 | |
62 | *crcp = crc32_le(crc: *crcp, p: data, len); |
63 | return 0; |
64 | } |
65 | |
66 | /* No final XOR 0xFFFFFFFF, like crc32_le */ |
67 | static int __crc32_finup(u32 *crcp, const u8 *data, unsigned int len, |
68 | u8 *out) |
69 | { |
70 | put_unaligned_le32(val: crc32_le(crc: *crcp, p: data, len), p: out); |
71 | return 0; |
72 | } |
73 | |
74 | static int crc32_finup(struct shash_desc *desc, const u8 *data, |
75 | unsigned int len, u8 *out) |
76 | { |
77 | return __crc32_finup(crcp: shash_desc_ctx(desc), data, len, out); |
78 | } |
79 | |
80 | static int crc32_final(struct shash_desc *desc, u8 *out) |
81 | { |
82 | u32 *crcp = shash_desc_ctx(desc); |
83 | |
84 | put_unaligned_le32(val: *crcp, p: out); |
85 | return 0; |
86 | } |
87 | |
88 | static int crc32_digest(struct shash_desc *desc, const u8 *data, |
89 | unsigned int len, u8 *out) |
90 | { |
91 | return __crc32_finup(crcp: crypto_shash_ctx(tfm: desc->tfm), data, len, |
92 | out); |
93 | } |
94 | static struct shash_alg alg = { |
95 | .setkey = crc32_setkey, |
96 | .init = crc32_init, |
97 | .update = crc32_update, |
98 | .final = crc32_final, |
99 | .finup = crc32_finup, |
100 | .digest = crc32_digest, |
101 | .descsize = sizeof(u32), |
102 | .digestsize = CHKSUM_DIGEST_SIZE, |
103 | .base = { |
104 | .cra_name = "crc32" , |
105 | .cra_driver_name = "crc32-generic" , |
106 | .cra_priority = 100, |
107 | .cra_flags = CRYPTO_ALG_OPTIONAL_KEY, |
108 | .cra_blocksize = CHKSUM_BLOCK_SIZE, |
109 | .cra_ctxsize = sizeof(u32), |
110 | .cra_module = THIS_MODULE, |
111 | .cra_init = crc32_cra_init, |
112 | } |
113 | }; |
114 | |
115 | static int __init crc32_mod_init(void) |
116 | { |
117 | return crypto_register_shash(alg: &alg); |
118 | } |
119 | |
120 | static void __exit crc32_mod_fini(void) |
121 | { |
122 | crypto_unregister_shash(alg: &alg); |
123 | } |
124 | |
125 | subsys_initcall(crc32_mod_init); |
126 | module_exit(crc32_mod_fini); |
127 | |
128 | MODULE_AUTHOR("Alexander Boyko <alexander_boyko@xyratex.com>" ); |
129 | MODULE_DESCRIPTION("CRC32 calculations wrapper for lib/crc32" ); |
130 | MODULE_LICENSE("GPL" ); |
131 | MODULE_ALIAS_CRYPTO("crc32" ); |
132 | MODULE_ALIAS_CRYPTO("crc32-generic" ); |
133 | |