aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/crypto/chacha_glue.c
blob: 45c1c41431766dc397a9f8591f6785d0ca013cb5 (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
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
/*
 * x64 SIMD accelerated ChaCha and XChaCha stream ciphers,
 * including ChaCha20 (RFC7539)
 *
 * Copyright (C) 2015 Martin Willi
 *
 * 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 <crypto/chacha.h>
#include <crypto/internal/skcipher.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <asm/fpu/api.h>
#include <asm/simd.h>

#define CHACHA_STATE_ALIGN 16

asmlinkage void chacha_block_xor_ssse3(u32 *state, u8 *dst, const u8 *src,
				       unsigned int len, int nrounds);
asmlinkage void chacha_4block_xor_ssse3(u32 *state, u8 *dst, const u8 *src,
					unsigned int len, int nrounds);
asmlinkage void hchacha_block_ssse3(const u32 *state, u32 *out, int nrounds);
#ifdef CONFIG_AS_AVX2
asmlinkage void chacha_2block_xor_avx2(u32 *state, u8 *dst, const u8 *src,
				       unsigned int len, int nrounds);
asmlinkage void chacha_4block_xor_avx2(u32 *state, u8 *dst, const u8 *src,
				       unsigned int len, int nrounds);
asmlinkage void chacha_8block_xor_avx2(u32 *state, u8 *dst, const u8 *src,
				       unsigned int len, int nrounds);
static bool chacha_use_avx2;
#ifdef CONFIG_AS_AVX512
asmlinkage void chacha_2block_xor_avx512vl(u32 *state, u8 *dst, const u8 *src,
					   unsigned int len, int nrounds);
asmlinkage void chacha_4block_xor_avx512vl(u32 *state, u8 *dst, const u8 *src,
					   unsigned int len, int nrounds);
asmlinkage void chacha_8block_xor_avx512vl(u32 *state, u8 *dst, const u8 *src,
					   unsigned int len, int nrounds);
static bool chacha_use_avx512vl;
#endif
#endif

static unsigned int chacha_advance(unsigned int len, unsigned int maxblocks)
{
	len = min(len, maxblocks * CHACHA_BLOCK_SIZE);
	return round_up(len, CHACHA_BLOCK_SIZE) / CHACHA_BLOCK_SIZE;
}

static void chacha_dosimd(u32 *state, u8 *dst, const u8 *src,
			  unsigned int bytes, int nrounds)
{
#ifdef CONFIG_AS_AVX2
#ifdef CONFIG_AS_AVX512
	if (chacha_use_avx512vl) {
		while (bytes >= CHACHA_BLOCK_SIZE * 8) {
			chacha_8block_xor_avx512vl(state, dst, src, bytes,
						   nrounds);
			bytes -= CHACHA_BLOCK_SIZE * 8;
			src += CHACHA_BLOCK_SIZE * 8;
			dst += CHACHA_BLOCK_SIZE * 8;
			state[12] += 8;
		}
		if (bytes > CHACHA_BLOCK_SIZE * 4) {
			chacha_8block_xor_avx512vl(state, dst, src, bytes,
						   nrounds);
			state[12] += chacha_advance(bytes, 8);
			return;
		}
		if (bytes > CHACHA_BLOCK_SIZE * 2) {
			chacha_4block_xor_avx512vl(state, dst, src, bytes,
						   nrounds);
			state[12] += chacha_advance(bytes, 4);
			return;
		}
		if (bytes) {
			chacha_2block_xor_avx512vl(state, dst, src, bytes,
						   nrounds);
			state[12] += chacha_advance(bytes, 2);
			return;
		}
	}
#endif
	if (chacha_use_avx2) {
		while (bytes >= CHACHA_BLOCK_SIZE * 8) {
			chacha_8block_xor_avx2(state, dst, src, bytes, nrounds);
			bytes -= CHACHA_BLOCK_SIZE * 8;
			src += CHACHA_BLOCK_SIZE * 8;
			dst += CHACHA_BLOCK_SIZE * 8;
			state[12] += 8;
		}
		if (bytes > CHACHA_BLOCK_SIZE * 4) {
			chacha_8block_xor_avx2(state, dst, src, bytes, nrounds);
			state[12] += chacha_advance(bytes, 8);
			return;
		}
		if (bytes > CHACHA_BLOCK_SIZE * 2) {
			chacha_4block_xor_avx2(state, dst, src, bytes, nrounds);
			state[12] += chacha_advance(bytes, 4);
			return;
		}
		if (bytes > CHACHA_BLOCK_SIZE) {
			chacha_2block_xor_avx2(state, dst, src, bytes, nrounds);
			state[12] += chacha_advance(bytes, 2);
			return;
		}
	}
#endif
	while (bytes >= CHACHA_BLOCK_SIZE * 4) {
		chacha_4block_xor_ssse3(state, dst, src, bytes, nrounds);
		bytes -= CHACHA_BLOCK_SIZE * 4;
		src += CHACHA_BLOCK_SIZE * 4;
		dst += CHACHA_BLOCK_SIZE * 4;
		state[12] += 4;
	}
	if (bytes > CHACHA_BLOCK_SIZE) {
		chacha_4block_xor_ssse3(state, dst, src, bytes, nrounds);
		state[12] += chacha_advance(bytes, 4);
		return;
	}
	if (bytes) {
		chacha_block_xor_ssse3(state, dst, src, bytes, nrounds);
		state[12]++;
	}
}

static int chacha_simd_stream_xor(struct skcipher_walk *walk,
				  struct chacha_ctx *ctx, u8 *iv)
{
	u32 *state, state_buf[16 + 2] __aligned(8);
	int next_yield = 4096; /* bytes until next FPU yield */
	int err = 0;

	BUILD_BUG_ON(CHACHA_STATE_ALIGN != 16);
	state = PTR_ALIGN(state_buf + 0, CHACHA_STATE_ALIGN);

	crypto_chacha_init(state, ctx, iv);

	while (walk->nbytes > 0) {
		unsigned int nbytes = walk->nbytes;

		if (nbytes < walk->total) {
			nbytes = round_down(nbytes, walk->stride);
			next_yield -= nbytes;
		}

		chacha_dosimd(state, walk->dst.virt.addr, walk->src.virt.addr,
			      nbytes, ctx->nrounds);

		if (next_yield <= 0) {
			/* temporarily allow preemption */
			kernel_fpu_end();
			kernel_fpu_begin();
			next_yield = 4096;
		}

		err = skcipher_walk_done(walk, walk->nbytes - nbytes);
	}

	return err;
}

static int chacha_simd(struct skcipher_request *req)
{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
	struct skcipher_walk walk;
	int err;

	if (req->cryptlen <= CHACHA_BLOCK_SIZE || !irq_fpu_usable())
		return crypto_chacha_crypt(req);

	err = skcipher_walk_virt(&walk, req, true);
	if (err)
		return err;

	kernel_fpu_begin();
	err = chacha_simd_stream_xor(&walk, ctx, req->iv);
	kernel_fpu_end();
	return err;
}

static int xchacha_simd(struct skcipher_request *req)
{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
	struct skcipher_walk walk;
	struct chacha_ctx subctx;
	u32 *state, state_buf[16 + 2] __aligned(8);
	u8 real_iv[16];
	int err;

	if (req->cryptlen <= CHACHA_BLOCK_SIZE || !irq_fpu_usable())
		return crypto_xchacha_crypt(req);

	err = skcipher_walk_virt(&walk, req, true);
	if (err)
		return err;

	BUILD_BUG_ON(CHACHA_STATE_ALIGN != 16);
	state = PTR_ALIGN(state_buf + 0, CHACHA_STATE_ALIGN);
	crypto_chacha_init(state, ctx, req->iv);

	kernel_fpu_begin();

	hchacha_block_ssse3(state, subctx.key, ctx->nrounds);
	subctx.nrounds = ctx->nrounds;

	memcpy(&real_iv[0], req->iv + 24, 8);
	memcpy(&real_iv[8], req->iv + 16, 8);
	err = chacha_simd_stream_xor(&walk, &subctx, real_iv);

	kernel_fpu_end();

	return err;
}

static struct skcipher_alg algs[] = {
	{
		.base.cra_name		= "chacha20",
		.base.cra_driver_name	= "chacha20-simd",
		.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,
		.setkey			= crypto_chacha20_setkey,
		.encrypt		= chacha_simd,
		.decrypt		= chacha_simd,
	}, {
		.base.cra_name		= "xchacha20",
		.base.cra_driver_name	= "xchacha20-simd",
		.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,
		.setkey			= crypto_chacha20_setkey,
		.encrypt		= xchacha_simd,
		.decrypt		= xchacha_simd,
	}, {
		.base.cra_name		= "xchacha12",
		.base.cra_driver_name	= "xchacha12-simd",
		.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,
		.setkey			= crypto_chacha12_setkey,
		.encrypt		= xchacha_simd,
		.decrypt		= xchacha_simd,
	},
};

static int __init chacha_simd_mod_init(void)
{
	if (!boot_cpu_has(X86_FEATURE_SSSE3))
		return -ENODEV;

#ifdef CONFIG_AS_AVX2
	chacha_use_avx2 = boot_cpu_has(X86_FEATURE_AVX) &&
			  boot_cpu_has(X86_FEATURE_AVX2) &&
			  cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL);
#ifdef CONFIG_AS_AVX512
	chacha_use_avx512vl = chacha_use_avx2 &&
			      boot_cpu_has(X86_FEATURE_AVX512VL) &&
			      boot_cpu_has(X86_FEATURE_AVX512BW); /* kmovq */
#endif
#endif
	return crypto_register_skciphers(algs, ARRAY_SIZE(algs));
}

static void __exit chacha_simd_mod_fini(void)
{
	crypto_unregister_skciphers(algs, ARRAY_SIZE(algs));
}

module_init(chacha_simd_mod_init);
module_exit(chacha_simd_mod_fini);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Martin Willi <martin@strongswan.org>");
MODULE_DESCRIPTION("ChaCha and XChaCha stream ciphers (x64 SIMD accelerated)");
MODULE_ALIAS_CRYPTO("chacha20");
MODULE_ALIAS_CRYPTO("chacha20-simd");
MODULE_ALIAS_CRYPTO("xchacha20");
MODULE_ALIAS_CRYPTO("xchacha20-simd");
MODULE_ALIAS_CRYPTO("xchacha12");
MODULE_ALIAS_CRYPTO("xchacha12-simd");