summaryrefslogtreecommitdiff
path: root/arch/x86/crypto/fpu.c
blob: 5a2f30f9f52dca78820b67cef7c025c53aa0b735 (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
/*
 * 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/algapi.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/crypto.h>
#include <asm/fpu/api.h>

struct crypto_fpu_ctx {
	struct crypto_blkcipher *child;
};

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

	crypto_blkcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	crypto_blkcipher_set_flags(child, crypto_tfm_get_flags(parent) &
				   CRYPTO_TFM_REQ_MASK);
	err = crypto_blkcipher_setkey(child, key, keylen);
	crypto_tfm_set_flags(parent, crypto_blkcipher_get_flags(child) &
				     CRYPTO_TFM_RES_MASK);
	return err;
}

static int crypto_fpu_encrypt(struct blkcipher_desc *desc_in,
			      struct scatterlist *dst, struct scatterlist *src,
			      unsigned int nbytes)
{
	int err;
	struct crypto_fpu_ctx *ctx = crypto_blkcipher_ctx(desc_in->tfm);
	struct crypto_blkcipher *child = ctx->child;
	struct blkcipher_desc desc = {
		.tfm = child,
		.info = desc_in->info,
		.flags = desc_in->flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
	};

	kernel_fpu_begin();
	err = crypto_blkcipher_crt(desc.tfm)->encrypt(&desc, dst, src, nbytes);
	kernel_fpu_end();
	return err;
}

static int crypto_fpu_decrypt(struct blkcipher_desc *desc_in,
			      struct scatterlist *dst, struct scatterlist *src,
			      unsigned int nbytes)
{
	int err;
	struct crypto_fpu_ctx *ctx = crypto_blkcipher_ctx(desc_in->tfm);
	struct crypto_blkcipher *child = ctx->child;
	struct blkcipher_desc desc = {
		.tfm = child,
		.info = desc_in->info,
		.flags = desc_in->flags & ~CRYPTO_TFM_REQ_MAY_SLEEP,
	};

	kernel_fpu_begin();
	err = crypto_blkcipher_crt(desc.tfm)->decrypt(&desc, dst, src, nbytes);
	kernel_fpu_end();
	return err;
}

static int crypto_fpu_init_tfm(struct crypto_tfm *tfm)
{
	struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
	struct crypto_fpu_ctx *ctx = crypto_tfm_ctx(tfm);
	struct crypto_blkcipher *cipher;

	cipher = crypto_spawn_blkcipher(spawn);
	if (IS_ERR(cipher))
		return PTR_ERR(cipher);

	ctx->child = cipher;
	return 0;
}

static void crypto_fpu_exit_tfm(struct crypto_tfm *tfm)
{
	struct crypto_fpu_ctx *ctx = crypto_tfm_ctx(tfm);
	crypto_free_blkcipher(ctx->child);
}

static struct crypto_instance *crypto_fpu_alloc(struct rtattr **tb)
{
	struct crypto_instance *inst;
	struct crypto_alg *alg;
	int err;

	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
	if (err)
		return ERR_PTR(err);

	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_BLKCIPHER,
				  CRYPTO_ALG_TYPE_MASK);
	if (IS_ERR(alg))
		return ERR_CAST(alg);

	inst = crypto_alloc_instance("fpu", alg);
	if (IS_ERR(inst))
		goto out_put_alg;

	inst->alg.cra_flags = alg->cra_flags;
	inst->alg.cra_priority = alg->cra_priority;
	inst->alg.cra_blocksize = alg->cra_blocksize;
	inst->alg.cra_alignmask = alg->cra_alignmask;
	inst->alg.cra_type = alg->cra_type;
	inst->alg.cra_blkcipher.ivsize = alg->cra_blkcipher.ivsize;
	inst->alg.cra_blkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
	inst->alg.cra_blkcipher.max_keysize = alg->cra_blkcipher.max_keysize;
	inst->alg.cra_ctxsize = sizeof(struct crypto_fpu_ctx);
	inst->alg.cra_init = crypto_fpu_init_tfm;
	inst->alg.cra_exit = crypto_fpu_exit_tfm;
	inst->alg.cra_blkcipher.setkey = crypto_fpu_setkey;
	inst->alg.cra_blkcipher.encrypt = crypto_fpu_encrypt;
	inst->alg.cra_blkcipher.decrypt = crypto_fpu_decrypt;

out_put_alg:
	crypto_mod_put(alg);
	return inst;
}

static void crypto_fpu_free(struct crypto_instance *inst)
{
	crypto_drop_spawn(crypto_instance_ctx(inst));
	kfree(inst);
}

static struct crypto_template crypto_fpu_tmpl = {
	.name = "fpu",
	.alloc = crypto_fpu_alloc,
	.free = crypto_fpu_free,
	.module = THIS_MODULE,
};

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

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

MODULE_ALIAS_CRYPTO("fpu");