4 * HMAC: Keyed-Hashing for Message Authentication (RFC2104).
6 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
8 * The HMAC implementation is derived from USAGI.
9 * Copyright (c) 2002 Kazunori Miyazawa <miyazawa@linux-ipv6.org> / USAGI
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)
17 #include <linux/crypto.h>
19 #include <linux/highmem.h>
20 #include <linux/slab.h>
21 #include <linux/scatterlist.h>
24 static void hash_key(struct crypto_tfm *tfm, u8 *key, unsigned int keylen)
26 struct scatterlist tmp;
28 sg_set_buf(&tmp, key, keylen);
29 crypto_digest_digest(tfm, &tmp, 1, key);
32 int crypto_alloc_hmac_block(struct crypto_tfm *tfm)
36 BUG_ON(!crypto_tfm_alg_blocksize(tfm));
38 tfm->crt_digest.dit_hmac_block = kmalloc(crypto_tfm_alg_blocksize(tfm),
40 if (tfm->crt_digest.dit_hmac_block == NULL)
47 void crypto_free_hmac_block(struct crypto_tfm *tfm)
49 kfree(tfm->crt_digest.dit_hmac_block);
52 void crypto_hmac_init(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen)
55 struct scatterlist tmp;
56 char *ipad = tfm->crt_digest.dit_hmac_block;
58 if (*keylen > crypto_tfm_alg_blocksize(tfm)) {
59 hash_key(tfm, key, *keylen);
60 *keylen = crypto_tfm_alg_digestsize(tfm);
63 memset(ipad, 0, crypto_tfm_alg_blocksize(tfm));
64 memcpy(ipad, key, *keylen);
66 for (i = 0; i < crypto_tfm_alg_blocksize(tfm); i++)
69 sg_set_buf(&tmp, ipad, crypto_tfm_alg_blocksize(tfm));
71 crypto_digest_init(tfm);
72 crypto_digest_update(tfm, &tmp, 1);
75 void crypto_hmac_update(struct crypto_tfm *tfm,
76 struct scatterlist *sg, unsigned int nsg)
78 crypto_digest_update(tfm, sg, nsg);
81 void crypto_hmac_final(struct crypto_tfm *tfm, u8 *key,
82 unsigned int *keylen, u8 *out)
85 struct scatterlist tmp;
86 char *opad = tfm->crt_digest.dit_hmac_block;
88 if (*keylen > crypto_tfm_alg_blocksize(tfm)) {
89 hash_key(tfm, key, *keylen);
90 *keylen = crypto_tfm_alg_digestsize(tfm);
93 crypto_digest_final(tfm, out);
95 memset(opad, 0, crypto_tfm_alg_blocksize(tfm));
96 memcpy(opad, key, *keylen);
98 for (i = 0; i < crypto_tfm_alg_blocksize(tfm); i++)
101 sg_set_buf(&tmp, opad, crypto_tfm_alg_blocksize(tfm));
103 crypto_digest_init(tfm);
104 crypto_digest_update(tfm, &tmp, 1);
106 sg_set_buf(&tmp, out, crypto_tfm_alg_digestsize(tfm));
108 crypto_digest_update(tfm, &tmp, 1);
109 crypto_digest_final(tfm, out);
112 void crypto_hmac(struct crypto_tfm *tfm, u8 *key, unsigned int *keylen,
113 struct scatterlist *sg, unsigned int nsg, u8 *out)
115 crypto_hmac_init(tfm, key, keylen);
116 crypto_hmac_update(tfm, sg, nsg);
117 crypto_hmac_final(tfm, key, keylen, out);
120 EXPORT_SYMBOL_GPL(crypto_hmac_init);
121 EXPORT_SYMBOL_GPL(crypto_hmac_update);
122 EXPORT_SYMBOL_GPL(crypto_hmac_final);
123 EXPORT_SYMBOL_GPL(crypto_hmac);