Contents of /alx-src/tags/kernel26-2.6.12-alx-r9/crypto/hmac.c
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Wed Mar 4 11:03:09 2009 UTC (15 years, 6 months ago) by niro
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Wed Mar 4 11:03:09 2009 UTC (15 years, 6 months ago) by niro
File MIME type: text/plain
File size: 3465 byte(s)
Tag kernel26-2.6.12-alx-r9
1 | /* |
2 | * Cryptographic API. |
3 | * |
4 | * HMAC: Keyed-Hashing for Message Authentication (RFC2104). |
5 | * |
6 | * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> |
7 | * |
8 | * The HMAC implementation is derived from USAGI. |
9 | * Copyright (c) 2002 Kazunori Miyazawa <miyazawa@linux-ipv6.org> / USAGI |
10 | * |
11 | * This program is free software; you can redistribute it and/or modify it |
12 | * under the terms of the GNU General Public License as published by the Free |
13 | * Software Foundation; either version 2 of the License, or (at your option) |
14 | * any later version. |
15 | * |
16 | */ |
17 | #include <linux/crypto.h> |
18 | #include <linux/mm.h> |
19 | #include <linux/highmem.h> |
20 | #include <linux/slab.h> |
21 | #include <asm/scatterlist.h> |
22 | #include "internal.h" |
23 | |
24 | static void hash_key(struct crypto_tfm *tfm, u8 *key, unsigned int keylen) |
25 | { |
26 | struct scatterlist tmp; |
27 | |
28 | tmp.page = virt_to_page(key); |
29 | tmp.offset = offset_in_page(key); |
30 | tmp.length = keylen; |
31 | crypto_digest_digest(tfm, &tmp, 1, key); |
32 | |
33 | } |
34 | |
35 | int crypto_alloc_hmac_block(struct crypto_tfm *tfm) |
36 | { |
37 | int ret = 0; |
38 | |
39 | BUG_ON(!crypto_tfm_alg_blocksize(tfm)); |
40 | |
41 | tfm->crt_digest.dit_hmac_block = kmalloc(crypto_tfm_alg_blocksize(tfm), |
42 | GFP_KERNEL); |
43 | if (tfm->crt_digest.dit_hmac_block == NULL) |
44 | ret = -ENOMEM; |
45 | |
46 | return ret; |
47 | |
48 | } |
49 | |
50 | void crypto_free_hmac_block(struct crypto_tfm *tfm) |
51 | { |
52 | if (tfm->crt_digest.dit_hmac_block) |
53 | kfree(tfm->crt_digest.dit_hmac_block); |
54 | } |
55 | |
56 | void crypto_hmac_init(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen) |
57 | { |
58 | unsigned int i; |
59 | struct scatterlist tmp; |
60 | char *ipad = tfm->crt_digest.dit_hmac_block; |
61 | |
62 | if (*keylen > crypto_tfm_alg_blocksize(tfm)) { |
63 | hash_key(tfm, key, *keylen); |
64 | *keylen = crypto_tfm_alg_digestsize(tfm); |
65 | } |
66 | |
67 | memset(ipad, 0, crypto_tfm_alg_blocksize(tfm)); |
68 | memcpy(ipad, key, *keylen); |
69 | |
70 | for (i = 0; i < crypto_tfm_alg_blocksize(tfm); i++) |
71 | ipad[i] ^= 0x36; |
72 | |
73 | tmp.page = virt_to_page(ipad); |
74 | tmp.offset = offset_in_page(ipad); |
75 | tmp.length = crypto_tfm_alg_blocksize(tfm); |
76 | |
77 | crypto_digest_init(tfm); |
78 | crypto_digest_update(tfm, &tmp, 1); |
79 | } |
80 | |
81 | void crypto_hmac_update(struct crypto_tfm *tfm, |
82 | struct scatterlist *sg, unsigned int nsg) |
83 | { |
84 | crypto_digest_update(tfm, sg, nsg); |
85 | } |
86 | |
87 | void crypto_hmac_final(struct crypto_tfm *tfm, u8 *key, |
88 | unsigned int *keylen, u8 *out) |
89 | { |
90 | unsigned int i; |
91 | struct scatterlist tmp; |
92 | char *opad = tfm->crt_digest.dit_hmac_block; |
93 | |
94 | if (*keylen > crypto_tfm_alg_blocksize(tfm)) { |
95 | hash_key(tfm, key, *keylen); |
96 | *keylen = crypto_tfm_alg_digestsize(tfm); |
97 | } |
98 | |
99 | crypto_digest_final(tfm, out); |
100 | |
101 | memset(opad, 0, crypto_tfm_alg_blocksize(tfm)); |
102 | memcpy(opad, key, *keylen); |
103 | |
104 | for (i = 0; i < crypto_tfm_alg_blocksize(tfm); i++) |
105 | opad[i] ^= 0x5c; |
106 | |
107 | tmp.page = virt_to_page(opad); |
108 | tmp.offset = offset_in_page(opad); |
109 | tmp.length = crypto_tfm_alg_blocksize(tfm); |
110 | |
111 | crypto_digest_init(tfm); |
112 | crypto_digest_update(tfm, &tmp, 1); |
113 | |
114 | tmp.page = virt_to_page(out); |
115 | tmp.offset = offset_in_page(out); |
116 | tmp.length = crypto_tfm_alg_digestsize(tfm); |
117 | |
118 | crypto_digest_update(tfm, &tmp, 1); |
119 | crypto_digest_final(tfm, out); |
120 | } |
121 | |
122 | void crypto_hmac(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen, |
123 | struct scatterlist *sg, unsigned int nsg, u8 *out) |
124 | { |
125 | crypto_hmac_init(tfm, key, keylen); |
126 | crypto_hmac_update(tfm, sg, nsg); |
127 | crypto_hmac_final(tfm, key, keylen, out); |
128 | } |
129 | |
130 | EXPORT_SYMBOL_GPL(crypto_hmac_init); |
131 | EXPORT_SYMBOL_GPL(crypto_hmac_update); |
132 | EXPORT_SYMBOL_GPL(crypto_hmac_final); |
133 | EXPORT_SYMBOL_GPL(crypto_hmac); |
134 |