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 <linux/mm.h>
16#include <linux/errno.h>
17#include <linux/highmem.h>
18#include <linux/module.h>
19#include <linux/scatterlist.h>
20
21#include "internal.h"
22#include "scatterwalk.h"
23
24void crypto_digest_init(struct crypto_tfm *tfm)
25{
26 struct crypto_hash *hash = crypto_hash_cast(tfm);
27 struct hash_desc desc = { .tfm = hash, .flags = tfm->crt_flags };
28
29 crypto_hash_init(&desc);
30}
31EXPORT_SYMBOL_GPL(crypto_digest_init);
32
33void crypto_digest_update(struct crypto_tfm *tfm,
34 struct scatterlist *sg, unsigned int nsg)
35{
36 struct crypto_hash *hash = crypto_hash_cast(tfm);
37 struct hash_desc desc = { .tfm = hash, .flags = tfm->crt_flags };
38 unsigned int nbytes = 0;
39 unsigned int i;
40
41 for (i = 0; i < nsg; i++)
42 nbytes += sg[i].length;
43
44 crypto_hash_update(&desc, sg, nbytes);
45}
46EXPORT_SYMBOL_GPL(crypto_digest_update);
47
48void crypto_digest_final(struct crypto_tfm *tfm, u8 *out)
49{
50 struct crypto_hash *hash = crypto_hash_cast(tfm);
51 struct hash_desc desc = { .tfm = hash, .flags = tfm->crt_flags };
52
53 crypto_hash_final(&desc, out);
54}
55EXPORT_SYMBOL_GPL(crypto_digest_final);
56
57void crypto_digest_digest(struct crypto_tfm *tfm,
58 struct scatterlist *sg, unsigned int nsg, u8 *out)
59{
60 struct crypto_hash *hash = crypto_hash_cast(tfm);
61 struct hash_desc desc = { .tfm = hash, .flags = tfm->crt_flags };
62 unsigned int nbytes = 0;
63 unsigned int i;
64
65 for (i = 0; i < nsg; i++)
66 nbytes += sg[i].length;
67
68 crypto_hash_digest(&desc, sg, nbytes, out);
69}
70EXPORT_SYMBOL_GPL(crypto_digest_digest);
71
72static int init(struct hash_desc *desc)
73{
74 struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
75
76 tfm->__crt_alg->cra_digest.dia_init(tfm);
77 return 0;
78}
79
80static int update(struct hash_desc *desc,
81 struct scatterlist *sg, unsigned int nbytes)
82{
83 struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
84 unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);
85
86 if (!nbytes)
87 return 0;
88
89 for (;;) {
90 struct page *pg = sg->page;
91 unsigned int offset = sg->offset;
92 unsigned int l = sg->length;
93
94 if (unlikely(l > nbytes))
95 l = nbytes;
96 nbytes -= l;
97
98 do {
99 unsigned int bytes_from_page = min(l, ((unsigned int)
100 (PAGE_SIZE)) -
101 offset);
102 char *src = crypto_kmap(pg, 0);
103 char *p = src + offset;
104
105 if (unlikely(offset & alignmask)) {
106 unsigned int bytes =
107 alignmask + 1 - (offset & alignmask);
108 bytes = min(bytes, bytes_from_page);
109 tfm->__crt_alg->cra_digest.dia_update(tfm, p,
110 bytes);
111 p += bytes;
112 bytes_from_page -= bytes;
113 l -= bytes;
114 }
115 tfm->__crt_alg->cra_digest.dia_update(tfm, p,
116 bytes_from_page);
117 crypto_kunmap(src, 0);
118 crypto_yield(desc->flags);
119 offset = 0;
120 pg++;
121 l -= bytes_from_page;
122 } while (l > 0);
123
124 if (!nbytes)
125 break;
126 sg = sg_next(sg);
127 }
128
129 return 0;
130}
131
132static int final(struct hash_desc *desc, u8 *out)
133{
134 struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
135 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
136 struct digest_alg *digest = &tfm->__crt_alg->cra_digest;
137
138 if (unlikely((unsigned long)out & alignmask)) {
139 unsigned long align = alignmask + 1;
140 unsigned long addr = (unsigned long)crypto_tfm_ctx(tfm);
141 u8 *dst = (u8 *)ALIGN(addr, align) +
142 ALIGN(tfm->__crt_alg->cra_ctxsize, align);
143
144 digest->dia_final(tfm, dst);
145 memcpy(out, dst, digest->dia_digestsize);
146 } else
147 digest->dia_final(tfm, out);
148
149 return 0;
150}
151
152static int nosetkey(struct crypto_hash *tfm, const u8 *key, unsigned int keylen)
153{
154 crypto_hash_clear_flags(tfm, CRYPTO_TFM_RES_MASK);
155 return -ENOSYS;
156}
157
158static int setkey(struct crypto_hash *hash, const u8 *key, unsigned int keylen)
159{
160 struct crypto_tfm *tfm = crypto_hash_tfm(hash);
161
162 crypto_hash_clear_flags(hash, CRYPTO_TFM_RES_MASK);
163 return tfm->__crt_alg->cra_digest.dia_setkey(tfm, key, keylen);
164}
165
166static int digest(struct hash_desc *desc,
167 struct scatterlist *sg, unsigned int nbytes, u8 *out)
168{
169 init(desc);
170 update(desc, sg, nbytes);
171 return final(desc, out);
172}
173
174int crypto_init_digest_flags(struct crypto_tfm *tfm, u32 flags)
175{
176 return flags ? -EINVAL : 0;
177}
178
179int crypto_init_digest_ops(struct crypto_tfm *tfm)
180{
181 struct hash_tfm *ops = &tfm->crt_hash;
182 struct digest_alg *dalg = &tfm->__crt_alg->cra_digest;
183
184 if (dalg->dia_digestsize > crypto_tfm_alg_blocksize(tfm))
185 return -EINVAL;
186
187 ops->init = init;
188 ops->update = update;
189 ops->final = final;
190 ops->digest = digest;
191 ops->setkey = dalg->dia_setkey ? setkey : nosetkey;
192 ops->digestsize = dalg->dia_digestsize;
193
194 return 0;
195}
196
197void crypto_exit_digest_ops(struct crypto_tfm *tfm)
198{
199}