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32#include <asm/unaligned.h>
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
43
44static 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
53
54
55
56
57
58static int crc32_setkey(struct crypto_shash *hash, const u8 *key,
59 unsigned int keylen)
60{
61 u32 *mctx = crypto_shash_ctx(hash);
62
63 if (keylen != sizeof(u32))
64 return -EINVAL;
65 *mctx = get_unaligned_le32(key);
66 return 0;
67}
68
69static 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
79static int crc32_update(struct shash_desc *desc, const u8 *data,
80 unsigned int len)
81{
82 u32 *crcp = shash_desc_ctx(desc);
83
84 *crcp = crc32_le(*crcp, data, len);
85 return 0;
86}
87
88
89static int __crc32_finup(u32 *crcp, const u8 *data, unsigned int len,
90 u8 *out)
91{
92 put_unaligned_le32(crc32_le(*crcp, data, len), out);
93 return 0;
94}
95
96static 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
102static int crc32_final(struct shash_desc *desc, u8 *out)
103{
104 u32 *crcp = shash_desc_ctx(desc);
105
106 put_unaligned_le32(*crcp, out);
107 return 0;
108}
109
110static 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}
116static 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",
127 .cra_driver_name = "crc32-generic",
128 .cra_priority = 100,
129 .cra_flags = CRYPTO_ALG_OPTIONAL_KEY,
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
137static int __init crc32_mod_init(void)
138{
139 return crypto_register_shash(&alg);
140}
141
142static void __exit crc32_mod_fini(void)
143{
144 crypto_unregister_shash(&alg);
145}
146
147subsys_initcall(crc32_mod_init);
148module_exit(crc32_mod_fini);
149
150MODULE_AUTHOR("Alexander Boyko <alexander_boyko@xyratex.com>");
151MODULE_DESCRIPTION("CRC32 calculations wrapper for lib/crc32");
152MODULE_LICENSE("GPL");
153MODULE_ALIAS_CRYPTO("crc32");
154MODULE_ALIAS_CRYPTO("crc32-generic");
155