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
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
|
// SPDX-License-Identifier: GPL-2.0
/*
* ARM NEON accelerated ChaCha and XChaCha stream ciphers,
* including ChaCha20 (RFC7539)
*
* Copyright (C) 2016-2019 Linaro, Ltd. <ard.biesheuvel@linaro.org>
* Copyright (C) 2015 Martin Willi
*/
#include <crypto/algapi.h>
#include <crypto/internal/chacha.h>
#include <crypto/internal/simd.h>
#include <crypto/internal/skcipher.h>
#include <linux/jump_label.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <asm/cputype.h>
#include <asm/hwcap.h>
#include <asm/neon.h>
#include <asm/simd.h>
asmlinkage void chacha_block_xor_neon(const u32 *state, u8 *dst, const u8 *src,
int nrounds);
asmlinkage void chacha_4block_xor_neon(const u32 *state, u8 *dst, const u8 *src,
int nrounds);
asmlinkage void hchacha_block_arm(const u32 *state, u32 *out, int nrounds);
asmlinkage void hchacha_block_neon(const u32 *state, u32 *out, int nrounds);
asmlinkage void chacha_doarm(u8 *dst, const u8 *src, unsigned int bytes,
const u32 *state, int nrounds);
static __ro_after_init DEFINE_STATIC_KEY_FALSE(use_neon);
static inline bool neon_usable(void)
{
return static_branch_likely(&use_neon) && crypto_simd_usable();
}
static void chacha_doneon(u32 *state, u8 *dst, const u8 *src,
unsigned int bytes, int nrounds)
{
u8 buf[CHACHA_BLOCK_SIZE];
while (bytes >= CHACHA_BLOCK_SIZE * 4) {
chacha_4block_xor_neon(state, dst, src, nrounds);
bytes -= CHACHA_BLOCK_SIZE * 4;
src += CHACHA_BLOCK_SIZE * 4;
dst += CHACHA_BLOCK_SIZE * 4;
state[12] += 4;
}
while (bytes >= CHACHA_BLOCK_SIZE) {
chacha_block_xor_neon(state, dst, src, nrounds);
bytes -= CHACHA_BLOCK_SIZE;
src += CHACHA_BLOCK_SIZE;
dst += CHACHA_BLOCK_SIZE;
state[12]++;
}
if (bytes) {
memcpy(buf, src, bytes);
chacha_block_xor_neon(state, buf, buf, nrounds);
memcpy(dst, buf, bytes);
}
}
void hchacha_block_arch(const u32 *state, u32 *stream, int nrounds)
{
if (!IS_ENABLED(CONFIG_KERNEL_MODE_NEON) || !neon_usable()) {
hchacha_block_arm(state, stream, nrounds);
} else {
kernel_neon_begin();
hchacha_block_neon(state, stream, nrounds);
kernel_neon_end();
}
}
EXPORT_SYMBOL(hchacha_block_arch);
void chacha_init_arch(u32 *state, const u32 *key, const u8 *iv)
{
chacha_init_generic(state, key, iv);
}
EXPORT_SYMBOL(chacha_init_arch);
void chacha_crypt_arch(u32 *state, u8 *dst, const u8 *src, unsigned int bytes,
int nrounds)
{
if (!IS_ENABLED(CONFIG_KERNEL_MODE_NEON) || !neon_usable() ||
bytes <= CHACHA_BLOCK_SIZE) {
chacha_doarm(dst, src, bytes, state, nrounds);
state[12] += DIV_ROUND_UP(bytes, CHACHA_BLOCK_SIZE);
return;
}
kernel_neon_begin();
chacha_doneon(state, dst, src, bytes, nrounds);
kernel_neon_end();
}
EXPORT_SYMBOL(chacha_crypt_arch);
static int chacha_stream_xor(struct skcipher_request *req,
const struct chacha_ctx *ctx, const u8 *iv,
bool neon)
{
struct skcipher_walk walk;
u32 state[16];
int err;
err = skcipher_walk_virt(&walk, req, false);
chacha_init_generic(state, ctx->key, iv);
while (walk.nbytes > 0) {
unsigned int nbytes = walk.nbytes;
if (nbytes < walk.total)
nbytes = round_down(nbytes, walk.stride);
if (!neon) {
chacha_doarm(walk.dst.virt.addr, walk.src.virt.addr,
nbytes, state, ctx->nrounds);
state[12] += DIV_ROUND_UP(nbytes, CHACHA_BLOCK_SIZE);
} else {
kernel_neon_begin();
chacha_doneon(state, walk.dst.virt.addr,
walk.src.virt.addr, nbytes, ctx->nrounds);
kernel_neon_end();
}
err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
}
return err;
}
static int do_chacha(struct skcipher_request *req, bool neon)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
return chacha_stream_xor(req, ctx, req->iv, neon);
}
static int chacha_arm(struct skcipher_request *req)
{
return do_chacha(req, false);
}
static int chacha_neon(struct skcipher_request *req)
{
return do_chacha(req, neon_usable());
}
static int do_xchacha(struct skcipher_request *req, bool neon)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
struct chacha_ctx subctx;
u32 state[16];
u8 real_iv[16];
chacha_init_generic(state, ctx->key, req->iv);
if (!neon) {
hchacha_block_arm(state, subctx.key, ctx->nrounds);
} else {
kernel_neon_begin();
hchacha_block_neon(state, subctx.key, ctx->nrounds);
kernel_neon_end();
}
subctx.nrounds = ctx->nrounds;
memcpy(&real_iv[0], req->iv + 24, 8);
memcpy(&real_iv[8], req->iv + 16, 8);
return chacha_stream_xor(req, &subctx, real_iv, neon);
}
static int xchacha_arm(struct skcipher_request *req)
{
return do_xchacha(req, false);
}
static int xchacha_neon(struct skcipher_request *req)
{
return do_xchacha(req, neon_usable());
}
static struct skcipher_alg arm_algs[] = {
{
.base.cra_name = "chacha20",
.base.cra_driver_name = "chacha20-arm",
.base.cra_priority = 200,
.base.cra_blocksize = 1,
.base.cra_ctxsize = sizeof(struct chacha_ctx),
.base.cra_module = THIS_MODULE,
.min_keysize = CHACHA_KEY_SIZE,
.max_keysize = CHACHA_KEY_SIZE,
.ivsize = CHACHA_IV_SIZE,
.chunksize = CHACHA_BLOCK_SIZE,
.setkey = chacha20_setkey,
.encrypt = chacha_arm,
.decrypt = chacha_arm,
}, {
.base.cra_name = "xchacha20",
.base.cra_driver_name = "xchacha20-arm",
.base.cra_priority = 200,
.base.cra_blocksize = 1,
.base.cra_ctxsize = sizeof(struct chacha_ctx),
.base.cra_module = THIS_MODULE,
.min_keysize = CHACHA_KEY_SIZE,
.max_keysize = CHACHA_KEY_SIZE,
.ivsize = XCHACHA_IV_SIZE,
.chunksize = CHACHA_BLOCK_SIZE,
.setkey = chacha20_setkey,
.encrypt = xchacha_arm,
.decrypt = xchacha_arm,
}, {
.base.cra_name = "xchacha12",
.base.cra_driver_name = "xchacha12-arm",
.base.cra_priority = 200,
.base.cra_blocksize = 1,
.base.cra_ctxsize = sizeof(struct chacha_ctx),
.base.cra_module = THIS_MODULE,
.min_keysize = CHACHA_KEY_SIZE,
.max_keysize = CHACHA_KEY_SIZE,
.ivsize = XCHACHA_IV_SIZE,
.chunksize = CHACHA_BLOCK_SIZE,
.setkey = chacha12_setkey,
.encrypt = xchacha_arm,
.decrypt = xchacha_arm,
},
};
static struct skcipher_alg neon_algs[] = {
{
.base.cra_name = "chacha20",
.base.cra_driver_name = "chacha20-neon",
.base.cra_priority = 300,
.base.cra_blocksize = 1,
.base.cra_ctxsize = sizeof(struct chacha_ctx),
.base.cra_module = THIS_MODULE,
.min_keysize = CHACHA_KEY_SIZE,
.max_keysize = CHACHA_KEY_SIZE,
.ivsize = CHACHA_IV_SIZE,
.chunksize = CHACHA_BLOCK_SIZE,
.walksize = 4 * CHACHA_BLOCK_SIZE,
.setkey = chacha20_setkey,
.encrypt = chacha_neon,
.decrypt = chacha_neon,
}, {
.base.cra_name = "xchacha20",
.base.cra_driver_name = "xchacha20-neon",
.base.cra_priority = 300,
.base.cra_blocksize = 1,
.base.cra_ctxsize = sizeof(struct chacha_ctx),
.base.cra_module = THIS_MODULE,
.min_keysize = CHACHA_KEY_SIZE,
.max_keysize = CHACHA_KEY_SIZE,
.ivsize = XCHACHA_IV_SIZE,
.chunksize = CHACHA_BLOCK_SIZE,
.walksize = 4 * CHACHA_BLOCK_SIZE,
.setkey = chacha20_setkey,
.encrypt = xchacha_neon,
.decrypt = xchacha_neon,
}, {
.base.cra_name = "xchacha12",
.base.cra_driver_name = "xchacha12-neon",
.base.cra_priority = 300,
.base.cra_blocksize = 1,
.base.cra_ctxsize = sizeof(struct chacha_ctx),
.base.cra_module = THIS_MODULE,
.min_keysize = CHACHA_KEY_SIZE,
.max_keysize = CHACHA_KEY_SIZE,
.ivsize = XCHACHA_IV_SIZE,
.chunksize = CHACHA_BLOCK_SIZE,
.walksize = 4 * CHACHA_BLOCK_SIZE,
.setkey = chacha12_setkey,
.encrypt = xchacha_neon,
.decrypt = xchacha_neon,
}
};
static int __init chacha_simd_mod_init(void)
{
int err;
err = crypto_register_skciphers(arm_algs, ARRAY_SIZE(arm_algs));
if (err)
return err;
if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && (elf_hwcap & HWCAP_NEON)) {
int i;
switch (read_cpuid_part()) {
case ARM_CPU_PART_CORTEX_A7:
case ARM_CPU_PART_CORTEX_A5:
/*
* The Cortex-A7 and Cortex-A5 do not perform well with
* the NEON implementation but do incredibly with the
* scalar one and use less power.
*/
for (i = 0; i < ARRAY_SIZE(neon_algs); i++)
neon_algs[i].base.cra_priority = 0;
break;
default:
static_branch_enable(&use_neon);
}
err = crypto_register_skciphers(neon_algs, ARRAY_SIZE(neon_algs));
if (err)
crypto_unregister_skciphers(arm_algs, ARRAY_SIZE(arm_algs));
}
return err;
}
static void __exit chacha_simd_mod_fini(void)
{
crypto_unregister_skciphers(arm_algs, ARRAY_SIZE(arm_algs));
if (IS_ENABLED(CONFIG_KERNEL_MODE_NEON) && (elf_hwcap & HWCAP_NEON))
crypto_unregister_skciphers(neon_algs, ARRAY_SIZE(neon_algs));
}
module_init(chacha_simd_mod_init);
module_exit(chacha_simd_mod_fini);
MODULE_DESCRIPTION("ChaCha and XChaCha stream ciphers (scalar and NEON accelerated)");
MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS_CRYPTO("chacha20");
MODULE_ALIAS_CRYPTO("chacha20-arm");
MODULE_ALIAS_CRYPTO("xchacha20");
MODULE_ALIAS_CRYPTO("xchacha20-arm");
MODULE_ALIAS_CRYPTO("xchacha12");
MODULE_ALIAS_CRYPTO("xchacha12-arm");
#ifdef CONFIG_KERNEL_MODE_NEON
MODULE_ALIAS_CRYPTO("chacha20-neon");
MODULE_ALIAS_CRYPTO("xchacha20-neon");
MODULE_ALIAS_CRYPTO("xchacha12-neon");
#endif
|
