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
|
/**
* AES XTS routines supporting VMX In-core instructions on Power 8
*
* Copyright (C) 2015 International Business Machines Inc.
*
* 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 Foundations; version 2 only.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY of FITNESS FOR A PARTICUPAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Author: Leonidas S. Barbosa <leosilva@linux.vnet.ibm.com>
*/
#include <linux/types.h>
#include <linux/err.h>
#include <linux/crypto.h>
#include <linux/delay.h>
#include <linux/hardirq.h>
#include <asm/switch_to.h>
#include <crypto/aes.h>
#include <crypto/scatterwalk.h>
#include <crypto/xts.h>
#include "aesp8-ppc.h"
struct p8_aes_xts_ctx {
struct crypto_blkcipher *fallback;
struct aes_key enc_key;
struct aes_key dec_key;
struct aes_key tweak_key;
};
static int p8_aes_xts_init(struct crypto_tfm *tfm)
{
const char *alg;
struct crypto_blkcipher *fallback;
struct p8_aes_xts_ctx *ctx = crypto_tfm_ctx(tfm);
if (!(alg = crypto_tfm_alg_name(tfm))) {
printk(KERN_ERR "Failed to get algorithm name.\n");
return -ENOENT;
}
fallback =
crypto_alloc_blkcipher(alg, 0, CRYPTO_ALG_NEED_FALLBACK);
if (IS_ERR(fallback)) {
printk(KERN_ERR
"Failed to allocate transformation for '%s': %ld\n",
alg, PTR_ERR(fallback));
return PTR_ERR(fallback);
}
printk(KERN_INFO "Using '%s' as fallback implementation.\n",
crypto_tfm_alg_driver_name((struct crypto_tfm *) fallback));
crypto_blkcipher_set_flags(
fallback,
crypto_blkcipher_get_flags((struct crypto_blkcipher *)tfm));
ctx->fallback = fallback;
return 0;
}
static void p8_aes_xts_exit(struct crypto_tfm *tfm)
{
struct p8_aes_xts_ctx *ctx = crypto_tfm_ctx(tfm);
if (ctx->fallback) {
crypto_free_blkcipher(ctx->fallback);
ctx->fallback = NULL;
}
}
static int p8_aes_xts_setkey(struct crypto_tfm *tfm, const u8 *key,
unsigned int keylen)
{
int ret;
struct p8_aes_xts_ctx *ctx = crypto_tfm_ctx(tfm);
ret = xts_check_key(tfm, key, keylen);
if (ret)
return ret;
preempt_disable();
pagefault_disable();
enable_kernel_vsx();
ret = aes_p8_set_encrypt_key(key + keylen/2, (keylen/2) * 8, &ctx->tweak_key);
ret += aes_p8_set_encrypt_key(key, (keylen/2) * 8, &ctx->enc_key);
ret += aes_p8_set_decrypt_key(key, (keylen/2) * 8, &ctx->dec_key);
disable_kernel_vsx();
pagefault_enable();
preempt_enable();
ret += crypto_blkcipher_setkey(ctx->fallback, key, keylen);
return ret;
}
static int p8_aes_xts_crypt(struct blkcipher_desc *desc,
struct scatterlist *dst,
struct scatterlist *src,
unsigned int nbytes, int enc)
{
int ret;
u8 tweak[AES_BLOCK_SIZE];
u8 *iv;
struct blkcipher_walk walk;
struct p8_aes_xts_ctx *ctx =
crypto_tfm_ctx(crypto_blkcipher_tfm(desc->tfm));
struct blkcipher_desc fallback_desc = {
.tfm = ctx->fallback,
.info = desc->info,
.flags = desc->flags
};
if (in_interrupt()) {
ret = enc ? crypto_blkcipher_encrypt(&fallback_desc, dst, src, nbytes) :
crypto_blkcipher_decrypt(&fallback_desc, dst, src, nbytes);
} else {
preempt_disable();
pagefault_disable();
enable_kernel_vsx();
blkcipher_walk_init(&walk, dst, src, nbytes);
ret = blkcipher_walk_virt(desc, &walk);
iv = walk.iv;
memset(tweak, 0, AES_BLOCK_SIZE);
aes_p8_encrypt(iv, tweak, &ctx->tweak_key);
while ((nbytes = walk.nbytes)) {
if (enc)
aes_p8_xts_encrypt(walk.src.virt.addr, walk.dst.virt.addr,
nbytes & AES_BLOCK_MASK, &ctx->enc_key, NULL, tweak);
else
aes_p8_xts_decrypt(walk.src.virt.addr, walk.dst.virt.addr,
nbytes & AES_BLOCK_MASK, &ctx->dec_key, NULL, tweak);
nbytes &= AES_BLOCK_SIZE - 1;
ret = blkcipher_walk_done(desc, &walk, nbytes);
}
disable_kernel_vsx();
pagefault_enable();
preempt_enable();
}
return ret;
}
static int p8_aes_xts_encrypt(struct blkcipher_desc *desc,
struct scatterlist *dst,
struct scatterlist *src, unsigned int nbytes)
{
return p8_aes_xts_crypt(desc, dst, src, nbytes, 1);
}
static int p8_aes_xts_decrypt(struct blkcipher_desc *desc,
struct scatterlist *dst,
struct scatterlist *src, unsigned int nbytes)
{
return p8_aes_xts_crypt(desc, dst, src, nbytes, 0);
}
struct crypto_alg p8_aes_xts_alg = {
.cra_name = "xts(aes)",
.cra_driver_name = "p8_aes_xts",
.cra_module = THIS_MODULE,
.cra_priority = 2000,
.cra_type = &crypto_blkcipher_type,
.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | CRYPTO_ALG_NEED_FALLBACK,
.cra_alignmask = 0,
.cra_blocksize = AES_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct p8_aes_xts_ctx),
.cra_init = p8_aes_xts_init,
.cra_exit = p8_aes_xts_exit,
.cra_blkcipher = {
.ivsize = AES_BLOCK_SIZE,
.min_keysize = 2 * AES_MIN_KEY_SIZE,
.max_keysize = 2 * AES_MAX_KEY_SIZE,
.setkey = p8_aes_xts_setkey,
.encrypt = p8_aes_xts_encrypt,
.decrypt = p8_aes_xts_decrypt,
}
};
|
