diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /crypto/crc32c.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'crypto/crc32c.c')
-rw-r--r-- | crypto/crc32c.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/crypto/crc32c.c b/crypto/crc32c.c new file mode 100644 index 000000000000..256956cd9377 --- /dev/null +++ b/crypto/crc32c.c | |||
@@ -0,0 +1,110 @@ | |||
1 | /* | ||
2 | * Cryptographic API. | ||
3 | * | ||
4 | * CRC32C chksum | ||
5 | * | ||
6 | * This module file is a wrapper to invoke the lib/crc32c routines. | ||
7 | * | ||
8 | * This program is free software; you can redistribute it and/or modify it | ||
9 | * under the terms of the GNU General Public License as published by the Free | ||
10 | * Software Foundation; either version 2 of the License, or (at your option) | ||
11 | * any later version. | ||
12 | * | ||
13 | */ | ||
14 | #include <linux/init.h> | ||
15 | #include <linux/module.h> | ||
16 | #include <linux/string.h> | ||
17 | #include <linux/crypto.h> | ||
18 | #include <linux/crc32c.h> | ||
19 | #include <asm/byteorder.h> | ||
20 | |||
21 | #define CHKSUM_BLOCK_SIZE 32 | ||
22 | #define CHKSUM_DIGEST_SIZE 4 | ||
23 | |||
24 | struct chksum_ctx { | ||
25 | u32 crc; | ||
26 | }; | ||
27 | |||
28 | /* | ||
29 | * Steps through buffer one byte at at time, calculates reflected | ||
30 | * crc using table. | ||
31 | */ | ||
32 | |||
33 | static void chksum_init(void *ctx) | ||
34 | { | ||
35 | struct chksum_ctx *mctx = ctx; | ||
36 | |||
37 | mctx->crc = ~(u32)0; /* common usage */ | ||
38 | } | ||
39 | |||
40 | /* | ||
41 | * Setting the seed allows arbitrary accumulators and flexible XOR policy | ||
42 | * If your algorithm starts with ~0, then XOR with ~0 before you set | ||
43 | * the seed. | ||
44 | */ | ||
45 | static int chksum_setkey(void *ctx, const u8 *key, unsigned int keylen, | ||
46 | u32 *flags) | ||
47 | { | ||
48 | struct chksum_ctx *mctx = ctx; | ||
49 | |||
50 | if (keylen != sizeof(mctx->crc)) { | ||
51 | if (flags) | ||
52 | *flags = CRYPTO_TFM_RES_BAD_KEY_LEN; | ||
53 | return -EINVAL; | ||
54 | } | ||
55 | mctx->crc = __cpu_to_le32(*(u32 *)key); | ||
56 | return 0; | ||
57 | } | ||
58 | |||
59 | static void chksum_update(void *ctx, const u8 *data, unsigned int length) | ||
60 | { | ||
61 | struct chksum_ctx *mctx = ctx; | ||
62 | u32 mcrc; | ||
63 | |||
64 | mcrc = crc32c(mctx->crc, data, (size_t)length); | ||
65 | |||
66 | mctx->crc = mcrc; | ||
67 | } | ||
68 | |||
69 | static void chksum_final(void *ctx, u8 *out) | ||
70 | { | ||
71 | struct chksum_ctx *mctx = ctx; | ||
72 | u32 mcrc = (mctx->crc ^ ~(u32)0); | ||
73 | |||
74 | *(u32 *)out = __le32_to_cpu(mcrc); | ||
75 | } | ||
76 | |||
77 | static struct crypto_alg alg = { | ||
78 | .cra_name = "crc32c", | ||
79 | .cra_flags = CRYPTO_ALG_TYPE_DIGEST, | ||
80 | .cra_blocksize = CHKSUM_BLOCK_SIZE, | ||
81 | .cra_ctxsize = sizeof(struct chksum_ctx), | ||
82 | .cra_module = THIS_MODULE, | ||
83 | .cra_list = LIST_HEAD_INIT(alg.cra_list), | ||
84 | .cra_u = { | ||
85 | .digest = { | ||
86 | .dia_digestsize= CHKSUM_DIGEST_SIZE, | ||
87 | .dia_setkey = chksum_setkey, | ||
88 | .dia_init = chksum_init, | ||
89 | .dia_update = chksum_update, | ||
90 | .dia_final = chksum_final | ||
91 | } | ||
92 | } | ||
93 | }; | ||
94 | |||
95 | static int __init init(void) | ||
96 | { | ||
97 | return crypto_register_alg(&alg); | ||
98 | } | ||
99 | |||
100 | static void __exit fini(void) | ||
101 | { | ||
102 | crypto_unregister_alg(&alg); | ||
103 | } | ||
104 | |||
105 | module_init(init); | ||
106 | module_exit(fini); | ||
107 | |||
108 | MODULE_AUTHOR("Clay Haapala <chaapala@cisco.com>"); | ||
109 | MODULE_DESCRIPTION("CRC32c (Castagnoli) calculations wrapper for lib/crc32c"); | ||
110 | MODULE_LICENSE("GPL"); | ||