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
|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Glue code for SHA-256 implementation for SPE instructions (PPC)
*
* Based on generic implementation. The assembler module takes care
* about the SPE registers so it can run from interrupt context.
*
* Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de>
*/
#include <crypto/internal/hash.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/types.h>
#include <crypto/sha2.h>
#include <crypto/sha256_base.h>
#include <asm/byteorder.h>
#include <asm/switch_to.h>
#include <linux/hardirq.h>
/*
* MAX_BYTES defines the number of bytes that are allowed to be processed
* between preempt_disable() and preempt_enable(). SHA256 takes ~2,000
* operations per 64 bytes. e500 cores can issue two arithmetic instructions
* per clock cycle using one 32/64 bit unit (SU1) and one 32 bit unit (SU2).
* Thus 1KB of input data will need an estimated maximum of 18,000 cycles.
* Headroom for cache misses included. Even with the low end model clocked
* at 667 MHz this equals to a critical time window of less than 27us.
*
*/
#define MAX_BYTES 1024
extern void ppc_spe_sha256_transform(u32 *state, const u8 *src, u32 blocks);
static void spe_begin(void)
{
/* We just start SPE operations and will save SPE registers later. */
preempt_disable();
enable_kernel_spe();
}
static void spe_end(void)
{
disable_kernel_spe();
/* reenable preemption */
preempt_enable();
}
static inline void ppc_sha256_clear_context(struct sha256_state *sctx)
{
int count = sizeof(struct sha256_state) >> 2;
u32 *ptr = (u32 *)sctx;
/* make sure we can clear the fast way */
BUILD_BUG_ON(sizeof(struct sha256_state) % 4);
do { *ptr++ = 0; } while (--count);
}
static int ppc_spe_sha256_update(struct shash_desc *desc, const u8 *data,
unsigned int len)
{
struct sha256_state *sctx = shash_desc_ctx(desc);
const unsigned int offset = sctx->count & 0x3f;
const unsigned int avail = 64 - offset;
unsigned int bytes;
const u8 *src = data;
if (avail > len) {
sctx->count += len;
memcpy((char *)sctx->buf + offset, src, len);
return 0;
}
sctx->count += len;
if (offset) {
memcpy((char *)sctx->buf + offset, src, avail);
spe_begin();
ppc_spe_sha256_transform(sctx->state, (const u8 *)sctx->buf, 1);
spe_end();
len -= avail;
src += avail;
}
while (len > 63) {
/* cut input data into smaller blocks */
bytes = (len > MAX_BYTES) ? MAX_BYTES : len;
bytes = bytes & ~0x3f;
spe_begin();
ppc_spe_sha256_transform(sctx->state, src, bytes >> 6);
spe_end();
src += bytes;
len -= bytes;
}
memcpy((char *)sctx->buf, src, len);
return 0;
}
static int ppc_spe_sha256_final(struct shash_desc *desc, u8 *out)
{
struct sha256_state *sctx = shash_desc_ctx(desc);
const unsigned int offset = sctx->count & 0x3f;
char *p = (char *)sctx->buf + offset;
int padlen;
__be64 *pbits = (__be64 *)(((char *)&sctx->buf) + 56);
__be32 *dst = (__be32 *)out;
padlen = 55 - offset;
*p++ = 0x80;
spe_begin();
if (padlen < 0) {
memset(p, 0x00, padlen + sizeof (u64));
ppc_spe_sha256_transform(sctx->state, sctx->buf, 1);
p = (char *)sctx->buf;
padlen = 56;
}
memset(p, 0, padlen);
*pbits = cpu_to_be64(sctx->count << 3);
ppc_spe_sha256_transform(sctx->state, sctx->buf, 1);
spe_end();
dst[0] = cpu_to_be32(sctx->state[0]);
dst[1] = cpu_to_be32(sctx->state[1]);
dst[2] = cpu_to_be32(sctx->state[2]);
dst[3] = cpu_to_be32(sctx->state[3]);
dst[4] = cpu_to_be32(sctx->state[4]);
dst[5] = cpu_to_be32(sctx->state[5]);
dst[6] = cpu_to_be32(sctx->state[6]);
dst[7] = cpu_to_be32(sctx->state[7]);
ppc_sha256_clear_context(sctx);
return 0;
}
static int ppc_spe_sha224_final(struct shash_desc *desc, u8 *out)
{
__be32 D[SHA256_DIGEST_SIZE >> 2];
__be32 *dst = (__be32 *)out;
ppc_spe_sha256_final(desc, (u8 *)D);
/* avoid bytewise memcpy */
dst[0] = D[0];
dst[1] = D[1];
dst[2] = D[2];
dst[3] = D[3];
dst[4] = D[4];
dst[5] = D[5];
dst[6] = D[6];
/* clear sensitive data */
memzero_explicit(D, SHA256_DIGEST_SIZE);
return 0;
}
static int ppc_spe_sha256_export(struct shash_desc *desc, void *out)
{
struct sha256_state *sctx = shash_desc_ctx(desc);
memcpy(out, sctx, sizeof(*sctx));
return 0;
}
static int ppc_spe_sha256_import(struct shash_desc *desc, const void *in)
{
struct sha256_state *sctx = shash_desc_ctx(desc);
memcpy(sctx, in, sizeof(*sctx));
return 0;
}
static struct shash_alg algs[2] = { {
.digestsize = SHA256_DIGEST_SIZE,
.init = sha256_base_init,
.update = ppc_spe_sha256_update,
.final = ppc_spe_sha256_final,
.export = ppc_spe_sha256_export,
.import = ppc_spe_sha256_import,
.descsize = sizeof(struct sha256_state),
.statesize = sizeof(struct sha256_state),
.base = {
.cra_name = "sha256",
.cra_driver_name= "sha256-ppc-spe",
.cra_priority = 300,
.cra_blocksize = SHA256_BLOCK_SIZE,
.cra_module = THIS_MODULE,
}
}, {
.digestsize = SHA224_DIGEST_SIZE,
.init = sha224_base_init,
.update = ppc_spe_sha256_update,
.final = ppc_spe_sha224_final,
.export = ppc_spe_sha256_export,
.import = ppc_spe_sha256_import,
.descsize = sizeof(struct sha256_state),
.statesize = sizeof(struct sha256_state),
.base = {
.cra_name = "sha224",
.cra_driver_name= "sha224-ppc-spe",
.cra_priority = 300,
.cra_blocksize = SHA224_BLOCK_SIZE,
.cra_module = THIS_MODULE,
}
} };
static int __init ppc_spe_sha256_mod_init(void)
{
return crypto_register_shashes(algs, ARRAY_SIZE(algs));
}
static void __exit ppc_spe_sha256_mod_fini(void)
{
crypto_unregister_shashes(algs, ARRAY_SIZE(algs));
}
module_init(ppc_spe_sha256_mod_init);
module_exit(ppc_spe_sha256_mod_fini);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("SHA-224 and SHA-256 Secure Hash Algorithm, SPE optimized");
MODULE_ALIAS_CRYPTO("sha224");
MODULE_ALIAS_CRYPTO("sha224-ppc-spe");
MODULE_ALIAS_CRYPTO("sha256");
MODULE_ALIAS_CRYPTO("sha256-ppc-spe");
|
