aboutsummaryrefslogtreecommitdiff
path: root/crypto/algapi.c
blob: acea250677c0285266adbd877710c2e5873bd26f (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
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
/*
 * Cryptographic API for algorithms (i.e., low-level API).
 *
 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.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 <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/string.h>

#include "internal.h"

static LIST_HEAD(crypto_template_list);

void crypto_larval_error(const char *name, u32 type, u32 mask)
{
	struct crypto_alg *alg;

	down_read(&crypto_alg_sem);
	alg = __crypto_alg_lookup(name, type, mask);
	up_read(&crypto_alg_sem);

	if (alg) {
		if (crypto_is_larval(alg)) {
			struct crypto_larval *larval = (void *)alg;
			complete(&larval->completion);
		}
		crypto_mod_put(alg);
	}
}
EXPORT_SYMBOL_GPL(crypto_larval_error);

static inline int crypto_set_driver_name(struct crypto_alg *alg)
{
	static const char suffix[] = "-generic";
	char *driver_name = alg->cra_driver_name;
	int len;

	if (*driver_name)
		return 0;

	len = strlcpy(driver_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
	if (len + sizeof(suffix) > CRYPTO_MAX_ALG_NAME)
		return -ENAMETOOLONG;

	memcpy(driver_name + len, suffix, sizeof(suffix));
	return 0;
}

static int crypto_check_alg(struct crypto_alg *alg)
{
	if (alg->cra_alignmask & (alg->cra_alignmask + 1))
		return -EINVAL;

	if (alg->cra_alignmask & alg->cra_blocksize)
		return -EINVAL;

	if (alg->cra_blocksize > PAGE_SIZE / 8)
		return -EINVAL;

	if (alg->cra_priority < 0)
		return -EINVAL;

	return crypto_set_driver_name(alg);
}

static int __crypto_register_alg(struct crypto_alg *alg)
{
	struct crypto_alg *q;
	int ret = -EEXIST;

	atomic_set(&alg->cra_refcnt, 1);
	list_for_each_entry(q, &crypto_alg_list, cra_list) {
		if (q == alg)
			goto out;
		if (crypto_is_larval(q) &&
		    (!strcmp(alg->cra_name, q->cra_name) ||
		     !strcmp(alg->cra_driver_name, q->cra_name))) {
			struct crypto_larval *larval = (void *)q;

			if ((q->cra_flags ^ alg->cra_flags) & larval->mask)
				continue;
			if (!crypto_mod_get(alg))
				continue;
			larval->adult = alg;
			complete(&larval->completion);
		}
	}
	
	list_add(&alg->cra_list, &crypto_alg_list);

	crypto_notify(CRYPTO_MSG_ALG_REGISTER, alg);
	ret = 0;

out:	
	return ret;
}

int crypto_register_alg(struct crypto_alg *alg)
{
	int err;

	err = crypto_check_alg(alg);
	if (err)
		return err;

	down_write(&crypto_alg_sem);
	err = __crypto_register_alg(alg);
	up_write(&crypto_alg_sem);

	return err;
}
EXPORT_SYMBOL_GPL(crypto_register_alg);

int crypto_unregister_alg(struct crypto_alg *alg)
{
	int ret = -ENOENT;
	
	down_write(&crypto_alg_sem);
	if (likely(!list_empty(&alg->cra_list))) {
		list_del_init(&alg->cra_list);
		ret = 0;
	}
	crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);
	up_write(&crypto_alg_sem);

	if (ret)
		return ret;

	BUG_ON(atomic_read(&alg->cra_refcnt) != 1);
	if (alg->cra_destroy)
		alg->cra_destroy(alg);

	return 0;
}
EXPORT_SYMBOL_GPL(crypto_unregister_alg);

int crypto_register_template(struct crypto_template *tmpl)
{
	struct crypto_template *q;
	int err = -EEXIST;

	down_write(&crypto_alg_sem);

	list_for_each_entry(q, &crypto_template_list, list) {
		if (q == tmpl)
			goto out;
	}

	list_add(&tmpl->list, &crypto_template_list);
	crypto_notify(CRYPTO_MSG_TMPL_REGISTER, tmpl);
	err = 0;
out:
	up_write(&crypto_alg_sem);
	return err;
}
EXPORT_SYMBOL_GPL(crypto_register_template);

void crypto_unregister_template(struct crypto_template *tmpl)
{
	struct crypto_instance *inst;
	struct hlist_node *p, *n;
	struct hlist_head *list;

	down_write(&crypto_alg_sem);

	BUG_ON(list_empty(&tmpl->list));
	list_del_init(&tmpl->list);

	list = &tmpl->instances;
	hlist_for_each_entry(inst, p, list, list) {
		BUG_ON(list_empty(&inst->alg.cra_list));
		list_del_init(&inst->alg.cra_list);
		crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, &inst->alg);
	}

	crypto_notify(CRYPTO_MSG_TMPL_UNREGISTER, tmpl);

	up_write(&crypto_alg_sem);

	hlist_for_each_entry_safe(inst, p, n, list, list) {
		BUG_ON(atomic_read(&inst->alg.cra_refcnt) != 1);
		tmpl->free(inst);
	}
}
EXPORT_SYMBOL_GPL(crypto_unregister_template);

static struct crypto_template *__crypto_lookup_template(const char *name)
{
	struct crypto_template *q, *tmpl = NULL;

	down_read(&crypto_alg_sem);
	list_for_each_entry(q, &crypto_template_list, list) {
		if (strcmp(q->name, name))
			continue;
		if (unlikely(!crypto_tmpl_get(q)))
			continue;

		tmpl = q;
		break;
	}
	up_read(&crypto_alg_sem);

	return tmpl;
}

struct crypto_template *crypto_lookup_template(const char *name)
{
	return try_then_request_module(__crypto_lookup_template(name), name);
}
EXPORT_SYMBOL_GPL(crypto_lookup_template);

int crypto_register_instance(struct crypto_template *tmpl,
			     struct crypto_instance *inst)
{
	int err = -EINVAL;

	if (inst->alg.cra_destroy)
		goto err;

	err = crypto_check_alg(&inst->alg);
	if (err)
		goto err;

	inst->alg.cra_module = tmpl->module;

	down_write(&crypto_alg_sem);

	err = __crypto_register_alg(&inst->alg);
	if (err)
		goto unlock;

	hlist_add_head(&inst->list, &tmpl->instances);
	inst->tmpl = tmpl;

unlock:
	up_write(&crypto_alg_sem);

err:
	return err;
}
EXPORT_SYMBOL_GPL(crypto_register_instance);

int crypto_register_notifier(struct notifier_block *nb)
{
	return blocking_notifier_chain_register(&crypto_chain, nb);
}
EXPORT_SYMBOL_GPL(crypto_register_notifier);

int crypto_unregister_notifier(struct notifier_block *nb)
{
	return blocking_notifier_chain_unregister(&crypto_chain, nb);
}
EXPORT_SYMBOL_GPL(crypto_unregister_notifier);

static int __init crypto_algapi_init(void)
{
	crypto_init_proc();
	return 0;
}

static void __exit crypto_algapi_exit(void)
{
	crypto_exit_proc();
}

module_init(crypto_algapi_init);
module_exit(crypto_algapi_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Cryptographic algorithms API");