summaryrefslogtreecommitdiff
path: root/arch/x86/crypto/fpu.c
blob: 406680476c529a3bfc7dbae317d8fcf5e0a7aed5 (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
/*
 * FPU: Wrapper for blkcipher touching fpu
 *
 * Copyright (c) Intel Corp.
 *   Author: Huang Ying <ying.huang@intel.com>
 *
 * 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/internal/skcipher.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <asm/fpu/api.h>

struct crypto_fpu_ctx {
	struct crypto_skcipher *child;
};

static int crypto_fpu_setkey(struct crypto_skcipher *parent, const u8 *key,
			     unsigned int keylen)
{
	struct crypto_fpu_ctx *ctx = crypto_skcipher_ctx(parent);
	struct crypto_skcipher *child = ctx->child;
	int err;

	crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
					 CRYPTO_TFM_REQ_MASK);
	err = crypto_skcipher_setkey(child, key, keylen);
	crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) &
					  CRYPTO_TFM_RES_MASK);
	return err;
}

static int crypto_fpu_encrypt(struct skcipher_request *req)
{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	struct crypto_fpu_ctx *ctx = crypto_skcipher_ctx(tfm);
	struct crypto_skcipher *child = ctx->child;
	SKCIPHER_REQUEST_ON_STACK(subreq, child);
	int err;

	skcipher_request_set_tfm(subreq, child);
	skcipher_request_set_callback(subreq, 0, NULL, NULL);
	skcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
				   req->iv);

	kernel_fpu_begin();
	err = crypto_skcipher_encrypt(subreq);
	kernel_fpu_end();

	skcipher_request_zero(subreq);
	return err;
}

static int crypto_fpu_decrypt(struct skcipher_request *req)
{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	struct crypto_fpu_ctx *ctx = crypto_skcipher_ctx(tfm);
	struct crypto_skcipher *child = ctx->child;
	SKCIPHER_REQUEST_ON_STACK(subreq, child);
	int err;

	skcipher_request_set_tfm(subreq, child);
	skcipher_request_set_callback(subreq, 0, NULL, NULL);
	skcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
				   req->iv);

	kernel_fpu_begin();
	err = crypto_skcipher_decrypt(subreq);
	kernel_fpu_end();

	skcipher_request_zero(subreq);
	return err;
}

static int crypto_fpu_init_tfm(struct crypto_skcipher *tfm)
{
	struct skcipher_instance *inst = skcipher_alg_instance(tfm);
	struct crypto_fpu_ctx *ctx = crypto_skcipher_ctx(tfm);
	struct crypto_skcipher_spawn *spawn;
	struct crypto_skcipher *cipher;

	spawn = skcipher_instance_ctx(inst);
	cipher = crypto_spawn_skcipher(spawn);
	if (IS_ERR(cipher))
		return PTR_ERR(cipher);

	ctx->child = cipher;

	return 0;
}

static void crypto_fpu_exit_tfm(struct crypto_skcipher *tfm)
{
	struct crypto_fpu_ctx *ctx = crypto_skcipher_ctx(tfm);

	crypto_free_skcipher(ctx->child);
}

static void crypto_fpu_free(struct skcipher_instance *inst)
{
	crypto_drop_skcipher(skcipher_instance_ctx(inst));
	kfree(inst);
}

static int crypto_fpu_create(struct crypto_template *tmpl, struct rtattr **tb)
{
	struct crypto_skcipher_spawn *spawn;
	struct skcipher_instance *inst;
	struct crypto_attr_type *algt;
	struct skcipher_alg *alg;
	const char *cipher_name;
	int err;

	algt = crypto_get_attr_type(tb);
	if (IS_ERR(algt))
		return PTR_ERR(algt);

	if ((algt->type ^ (CRYPTO_ALG_INTERNAL | CRYPTO_ALG_TYPE_SKCIPHER)) &
	    algt->mask)
		return -EINVAL;

	if (!(algt->mask & CRYPTO_ALG_INTERNAL))
		return -EINVAL;

	cipher_name = crypto_attr_alg_name(tb[1]);
	if (IS_ERR(cipher_name))
		return PTR_ERR(cipher_name);

	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
	if (!inst)
		return -ENOMEM;

	spawn = skcipher_instance_ctx(inst);

	crypto_set_skcipher_spawn(spawn, skcipher_crypto_instance(inst));
	err = crypto_grab_skcipher(spawn, cipher_name, CRYPTO_ALG_INTERNAL,
				   CRYPTO_ALG_INTERNAL | CRYPTO_ALG_ASYNC);
	if (err)
		goto out_free_inst;

	alg = crypto_skcipher_spawn_alg(spawn);

	err = crypto_inst_setname(skcipher_crypto_instance(inst), "fpu",
				  &alg->base);
	if (err)
		goto out_drop_skcipher;

	inst->alg.base.cra_flags = CRYPTO_ALG_INTERNAL;
	inst->alg.base.cra_priority = alg->base.cra_priority;
	inst->alg.base.cra_blocksize = alg->base.cra_blocksize;
	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;

	inst->alg.ivsize = crypto_skcipher_alg_ivsize(alg);
	inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg);
	inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg);

	inst->alg.base.cra_ctxsize = sizeof(struct crypto_fpu_ctx);

	inst->alg.init = crypto_fpu_init_tfm;
	inst->alg.exit = crypto_fpu_exit_tfm;

	inst->alg.setkey = crypto_fpu_setkey;
	inst->alg.encrypt = crypto_fpu_encrypt;
	inst->alg.decrypt = crypto_fpu_decrypt;

	inst->free = crypto_fpu_free;

	err = skcipher_register_instance(tmpl, inst);
	if (err)
		goto out_drop_skcipher;

out:
	return err;

out_drop_skcipher:
	crypto_drop_skcipher(spawn);
out_free_inst:
	kfree(inst);
	goto out;
}

static struct crypto_template crypto_fpu_tmpl = {
	.name = "fpu",
	.create = crypto_fpu_create,
	.module = THIS_MODULE,
};

int __init crypto_fpu_init(void)
{
	return crypto_register_template(&crypto_fpu_tmpl);
}

void crypto_fpu_exit(void)
{
	crypto_unregister_template(&crypto_fpu_tmpl);
}

MODULE_ALIAS_CRYPTO("fpu");