aboutsummaryrefslogtreecommitdiff
path: root/crypto/digest.c
blob: d63d5d96feecc4e7e040765d4719992737b0c345 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
/*
 * Cryptographic API.
 *
 * Digest operations.
 *
 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option) 
 * any later version.
 *
 */

#include <crypto/scatterwalk.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/hardirq.h>
#include <linux/highmem.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/scatterlist.h>

#include "internal.h"

static int init(struct hash_desc *desc)
{
	struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);

	tfm->__crt_alg->cra_digest.dia_init(tfm);
	return 0;
}

static int update2(struct hash_desc *desc,
		   struct scatterlist *sg, unsigned int nbytes)
{
	struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
	unsigned int alignmask = crypto_tfm_alg_alignmask(tfm);

	if (!nbytes)
		return 0;

	for (;;) {
		struct page *pg = sg_page(sg);
		unsigned int offset = sg->offset;
		unsigned int l = sg->length;

		if (unlikely(l > nbytes))
			l = nbytes;
		nbytes -= l;

		do {
			unsigned int bytes_from_page = min(l, ((unsigned int)
							   (PAGE_SIZE)) - 
							   offset);
			char *src = crypto_kmap(pg, 0);
			char *p = src + offset;

			if (unlikely(offset & alignmask)) {
				unsigned int bytes =
					alignmask + 1 - (offset & alignmask);
				bytes = min(bytes, bytes_from_page);
				tfm->__crt_alg->cra_digest.dia_update(tfm, p,
								      bytes);
				p += bytes;
				bytes_from_page -= bytes;
				l -= bytes;
			}
			tfm->__crt_alg->cra_digest.dia_update(tfm, p,
							      bytes_from_page);
			crypto_kunmap(src, 0);
			crypto_yield(desc->flags);
			offset = 0;
			pg++;
			l -= bytes_from_page;
		} while (l > 0);

		if (!nbytes)
			break;
		sg = scatterwalk_sg_next(sg);
	}

	return 0;
}

static int update(struct hash_desc *desc,
		  struct scatterlist *sg, unsigned int nbytes)
{
	if (WARN_ON_ONCE(in_irq()))
		return -EDEADLK;
	return update2(desc, sg, nbytes);
}

static int final(struct hash_desc *desc, u8 *out)
{
	struct crypto_tfm *tfm = crypto_hash_tfm(desc->tfm);
	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
	struct digest_alg *digest = &tfm->__crt_alg->cra_digest;

	if (unlikely((unsigned long)out & alignmask)) {
		unsigned long align = alignmask + 1;
		unsigned long addr = (unsigned long)crypto_tfm_ctx(tfm);
		u8 *dst = (u8 *)ALIGN(addr, align) +
			  ALIGN(tfm->__crt_alg->cra_ctxsize, align);

		digest->dia_final(tfm, dst);
		memcpy(out, dst, digest->dia_digestsize);
	} else
		digest->dia_final(tfm, out);

	return 0;
}

static int nosetkey(struct crypto_hash *tfm, const u8 *key, unsigned int keylen)
{
	crypto_hash_clear_flags(tfm, CRYPTO_TFM_RES_MASK);
	return -ENOSYS;
}

static int setkey(struct crypto_hash *hash, const u8 *key, unsigned int keylen)
{
	struct crypto_tfm *tfm = crypto_hash_tfm(hash);

	crypto_hash_clear_flags(hash, CRYPTO_TFM_RES_MASK);
	return tfm->__crt_alg->cra_digest.dia_setkey(tfm, key, keylen);
}

static int digest(struct hash_desc *desc,
		  struct scatterlist *sg, unsigned int nbytes, u8 *out)
{
	if (WARN_ON_ONCE(in_irq()))
		return -EDEADLK;

	init(desc);
	update2(desc, sg, nbytes);
	return final(desc, out);
}

int crypto_init_digest_ops(struct crypto_tfm *tfm)
{
	struct hash_tfm *ops = &tfm->crt_hash;
	struct digest_alg *dalg = &tfm->__crt_alg->cra_digest;

	if (dalg->dia_digestsize > PAGE_SIZE / 8)
		return -EINVAL;
	
	ops->init	= init;
	ops->update	= update;
	ops->final	= final;
	ops->digest	= digest;
	ops->setkey	= dalg->dia_setkey ? setkey : nosetkey;
	ops->digestsize	= dalg->dia_digestsize;
	
	return 0;
}

void crypto_exit_digest_ops(struct crypto_tfm *tfm)
{
}

static int digest_async_nosetkey(struct crypto_ahash *tfm_async, const u8 *key,
			unsigned int keylen)
{
	crypto_ahash_clear_flags(tfm_async, CRYPTO_TFM_RES_MASK);
	return -ENOSYS;
}

static int digest_async_setkey(struct crypto_ahash *tfm_async, const u8 *key,
			unsigned int keylen)
{
	struct crypto_tfm    *tfm        = crypto_ahash_tfm(tfm_async);
	struct digest_alg    *dalg       = &tfm->__crt_alg->cra_digest;

	crypto_ahash_clear_flags(tfm_async, CRYPTO_TFM_RES_MASK);
	return dalg->dia_setkey(tfm, key, keylen);
}

static int digest_async_init(struct ahash_request *req)
{
	struct crypto_tfm *tfm  = req->base.tfm;
	struct digest_alg *dalg = &tfm->__crt_alg->cra_digest;

	dalg->dia_init(tfm);
	return 0;
}

static int digest_async_update(struct ahash_request *req)
{
	struct crypto_tfm *tfm = req->base.tfm;
	struct hash_desc  desc = {
		.tfm   = __crypto_hash_cast(tfm),
		.flags = req->base.flags,
	};

	update(&desc, req->src, req->nbytes);
	return 0;
}

static int digest_async_final(struct ahash_request *req)
{
	struct crypto_tfm *tfm  = req->base.tfm;
	struct hash_desc  desc = {
		.tfm   = __crypto_hash_cast(tfm),
		.flags = req->base.flags,
	};

	final(&desc, req->result);
	return 0;
}

static int digest_async_digest(struct ahash_request *req)
{
	struct crypto_tfm *tfm  = req->base.tfm;
	struct hash_desc  desc = {
		.tfm   = __crypto_hash_cast(tfm),
		.flags = req->base.flags,
	};

	return digest(&desc, req->src, req->nbytes, req->result);
}

int crypto_init_digest_ops_async(struct crypto_tfm *tfm)
{
	struct ahash_tfm  *crt  = &tfm->crt_ahash;
	struct digest_alg *dalg = &tfm->__crt_alg->cra_digest;

	if (dalg->dia_digestsize > crypto_tfm_alg_blocksize(tfm))
		return -EINVAL;

	crt->init       = digest_async_init;
	crt->update     = digest_async_update;
	crt->final      = digest_async_final;
	crt->digest     = digest_async_digest;
	crt->setkey     = dalg->dia_setkey ? digest_async_setkey :
						digest_async_nosetkey;
	crt->digestsize = dalg->dia_digestsize;
	crt->base       = __crypto_ahash_cast(tfm);

	return 0;
}