Commit | Line | Data |
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1da177e4 LT |
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 |