Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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
15#include <crypto/scatterwalk.h>
16#include <linux/mm.h>
17#include <linux/errno.h>
18#include <linux/hardirq.h>
19#include <linux/highmem.h>
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/scatterlist.h>
23
24static int init(struct hash_desc *desc)
25{
26 struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
27
28 tfm->__crt_alg->cra_digest.dia_init(tfm);
29 return 0;
30}
31
32static int update2(struct hash_desc *desc,
33 struct scatterlist *sg, unsigned int nbytes)
34{
35 struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
36 unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);
37
38 if (!nbytes)
39 return 0;
40
41 for (;;) {
42 struct page *pg = sg_page(sg);
43 unsigned int offset = sg->offset;
44 unsigned int l = sg->length;
45
46 if (unlikely(l > nbytes))
47 l = nbytes;
48 nbytes -= l;
49
50 do {
51 unsigned int bytes_from_page = min(l, ((unsigned int)
52 (PAGE_SIZE)) -
53 offset);
54 char *src = crypto_kmap(pg, 0);
55 char *p = src + offset;
56
57 if (unlikely(offset & alignmask)) {
58 unsigned int bytes =
59 alignmask + 1 - (offset & alignmask);
60 bytes = min(bytes, bytes_from_page);
61 tfm->__crt_alg->cra_digest.dia_update(tfm, p,
62 bytes);
63 p += bytes;
64 bytes_from_page -= bytes;
65 l -= bytes;
66 }
67 tfm->__crt_alg->cra_digest.dia_update(tfm, p,
68 bytes_from_page);
69 crypto_kunmap(src, 0);
70 crypto_yield(desc->flags);
71 offset = 0;
72 pg++;
73 l -= bytes_from_page;
74 } while (l > 0);
75
76 if (!nbytes)
77 break;
78 sg = scatterwalk_sg_next(sg);
79 }
80
81 return 0;
82}
83
84static int update(struct hash_desc *desc,
85 struct scatterlist *sg, unsigned int nbytes)
86{
87 if (WARN_ON_ONCE(in_irq()))
88 return -EDEADLK;
89 return update2(desc, sg, nbytes);
90}
91
92static int final(struct hash_desc *desc, u8 *out)
93{
94 struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
95 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
96 struct digest_alg *digest = &tfm->__crt_alg->cra_digest;
97
98 if (unlikely((unsigned long)out & alignmask)) {
99 unsigned long align = alignmask + 1;
100 unsigned long addr = (unsigned long)crypto_tfm_ctx(tfm);
101 u8 *dst = (u8 *)ALIGN(addr, align) +
102 ALIGN(tfm->__crt_alg->cra_ctxsize, align);
103
104 digest->dia_final(tfm, dst);
105 memcpy(out, dst, digest->dia_digestsize);
106 } else
107 digest->dia_final(tfm, out);
108
109 return 0;
110}
111
112static int nosetkey(struct crypto_hash *tfm, const u8 *key, unsigned int keylen)
113{
114 crypto_hash_clear_flags(tfm, CRYPTO_TFM_RES_MASK);
115 return -ENOSYS;
116}
117
118static int setkey(struct crypto_hash *hash, const u8 *key, unsigned int keylen)
119{
120 struct crypto_tfm *tfm = crypto_hash_tfm(hash);
121
122 crypto_hash_clear_flags(hash, CRYPTO_TFM_RES_MASK);
123 return tfm->__crt_alg->cra_digest.dia_setkey(tfm, key, keylen);
124}
125
126static int digest(struct hash_desc *desc,
127 struct scatterlist *sg, unsigned int nbytes, u8 *out)
128{
129 if (WARN_ON_ONCE(in_irq()))
130 return -EDEADLK;
131
132 init(desc);
133 update2(desc, sg, nbytes);
134 return final(desc, out);
135}
136
137int crypto_init_digest_ops(struct crypto_tfm *tfm)
138{
139 struct hash_tfm *ops = &tfm->crt_hash;
140 struct digest_alg *dalg = &tfm->__crt_alg->cra_digest;
141
142 if (dalg->dia_digestsize > crypto_tfm_alg_blocksize(tfm))
143 return -EINVAL;
144
145 ops->init = init;
146 ops->update = update;
147 ops->final = final;
148 ops->digest = digest;
149 ops->setkey = dalg->dia_setkey ? setkey : nosetkey;
150 ops->digestsize = dalg->dia_digestsize;
151
152 return 0;
153}
154
155void crypto_exit_digest_ops(struct crypto_tfm *tfm)
156{
157}