root/crypto/digest.c

Revision 1, 2.5 kB (checked in by dkaplan1, 7 years ago)

Initial import

Line 
1 /*
2  * Cryptographic API.
3  *
4  * Digest operations.
5  *
6  * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
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/crypto.h>
15 #include <linux/mm.h>
16 #include <linux/errno.h>
17 #include <linux/highmem.h>
18 #include <asm/scatterlist.h>
19 #include "internal.h"
20
21 static void init(struct crypto_tfm *tfm)
22 {
23         tfm->__crt_alg->cra_digest.dia_init(crypto_tfm_ctx(tfm));
24 }
25
26 static void update(struct crypto_tfm *tfm,
27                    struct scatterlist *sg, unsigned int nsg)
28 {
29         unsigned int i;
30
31         for (i = 0; i < nsg; i++) {
32
33                 struct page *pg = sg[i].page;
34                 unsigned int offset = sg[i].offset;
35                 unsigned int l = sg[i].length;
36
37                 do {
38                         unsigned int bytes_from_page = min(l, ((unsigned int)
39                                                            (PAGE_SIZE)) -
40                                                            offset);
41                         char *p = crypto_kmap(pg, 0) + offset;
42
43                         tfm->__crt_alg->cra_digest.dia_update
44                                         (crypto_tfm_ctx(tfm), p,
45                                          bytes_from_page);
46                         crypto_kunmap(p, 0);
47                         crypto_yield(tfm);
48                         offset = 0;
49                         pg++;
50                         l -= bytes_from_page;
51                 } while (l > 0);
52         }
53 }
54
55 static void final(struct crypto_tfm *tfm, u8 *out)
56 {
57         tfm->__crt_alg->cra_digest.dia_final(crypto_tfm_ctx(tfm), out);
58 }
59
60 static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
61 {
62         u32 flags;
63         if (tfm->__crt_alg->cra_digest.dia_setkey == NULL)
64                 return -ENOSYS;
65         return tfm->__crt_alg->cra_digest.dia_setkey(crypto_tfm_ctx(tfm),
66                                                      key, keylen, &flags);
67 }
68
69 static void digest(struct crypto_tfm *tfm,
70                    struct scatterlist *sg, unsigned int nsg, u8 *out)
71 {
72         unsigned int i;
73
74         tfm->crt_digest.dit_init(tfm);
75                
76         for (i = 0; i < nsg; i++) {
77                 char *p = crypto_kmap(sg[i].page, 0) + sg[i].offset;
78                 tfm->__crt_alg->cra_digest.dia_update(crypto_tfm_ctx(tfm),
79                                                       p, sg[i].length);
80                 crypto_kunmap(p, 0);
81                 crypto_yield(tfm);
82         }
83         crypto_digest_final(tfm, out);
84 }
85
86 int crypto_init_digest_flags(struct crypto_tfm *tfm, u32 flags)
87 {
88         return flags ? -EINVAL : 0;
89 }
90
91 int crypto_init_digest_ops(struct crypto_tfm *tfm)
92 {
93         struct digest_tfm *ops = &tfm->crt_digest;
94        
95         ops->dit_init   = init;
96         ops->dit_update = update;
97         ops->dit_final  = final;
98         ops->dit_digest = digest;
99         ops->dit_setkey = setkey;
100        
101         return crypto_alloc_hmac_block(tfm);
102 }
103
104 void crypto_exit_digest_ops(struct crypto_tfm *tfm)
105 {
106         crypto_free_hmac_block(tfm);
107 }
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