aboutsummaryrefslogtreecommitdiff
path: root/arch/arm64/crypto/poly1305-glue.c
blob: 9c3d86e397bf3a1fd9302c0a3057913f9a6ed9ca (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
// SPDX-License-Identifier: GPL-2.0
/*
 * OpenSSL/Cryptogams accelerated Poly1305 transform for arm64
 *
 * Copyright (C) 2019 Linaro Ltd. <ard.biesheuvel@linaro.org>
 */

#include <asm/hwcap.h>
#include <asm/neon.h>
#include <asm/simd.h>
#include <asm/unaligned.h>
#include <crypto/algapi.h>
#include <crypto/internal/hash.h>
#include <crypto/internal/poly1305.h>
#include <crypto/internal/simd.h>
#include <linux/cpufeature.h>
#include <linux/crypto.h>
#include <linux/jump_label.h>
#include <linux/module.h>

asmlinkage void poly1305_init_arm64(void *state, const u8 *key);
asmlinkage void poly1305_blocks(void *state, const u8 *src, u32 len, u32 hibit);
asmlinkage void poly1305_blocks_neon(void *state, const u8 *src, u32 len, u32 hibit);
asmlinkage void poly1305_emit(void *state, u8 *digest, const u32 *nonce);

static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon);

void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 key[POLY1305_KEY_SIZE])
{
	poly1305_init_arm64(&dctx->h, key);
	dctx->s[0] = get_unaligned_le32(key + 16);
	dctx->s[1] = get_unaligned_le32(key + 20);
	dctx->s[2] = get_unaligned_le32(key + 24);
	dctx->s[3] = get_unaligned_le32(key + 28);
	dctx->buflen = 0;
}
EXPORT_SYMBOL(poly1305_init_arch);

static int neon_poly1305_init(struct shash_desc *desc)
{
	struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);

	dctx->buflen = 0;
	dctx->rset = 0;
	dctx->sset = false;

	return 0;
}

static void neon_poly1305_blocks(struct poly1305_desc_ctx *dctx, const u8 *src,
				 u32 len, u32 hibit, bool do_neon)
{
	if (unlikely(!dctx->sset)) {
		if (!dctx->rset) {
			poly1305_init_arch(dctx, src);
			src += POLY1305_BLOCK_SIZE;
			len -= POLY1305_BLOCK_SIZE;
			dctx->rset = 1;
		}
		if (len >= POLY1305_BLOCK_SIZE) {
			dctx->s[0] = get_unaligned_le32(src +  0);
			dctx->s[1] = get_unaligned_le32(src +  4);
			dctx->s[2] = get_unaligned_le32(src +  8);
			dctx->s[3] = get_unaligned_le32(src + 12);
			src += POLY1305_BLOCK_SIZE;
			len -= POLY1305_BLOCK_SIZE;
			dctx->sset = true;
		}
		if (len < POLY1305_BLOCK_SIZE)
			return;
	}

	len &= ~(POLY1305_BLOCK_SIZE - 1);

	if (static_branch_likely(&have_neon) && likely(do_neon))
		poly1305_blocks_neon(&dctx->h, src, len, hibit);
	else
		poly1305_blocks(&dctx->h, src, len, hibit);
}

static void neon_poly1305_do_update(struct poly1305_desc_ctx *dctx,
				    const u8 *src, u32 len, bool do_neon)
{
	if (unlikely(dctx->buflen)) {
		u32 bytes = min(len, POLY1305_BLOCK_SIZE - dctx->buflen);

		memcpy(dctx->buf + dctx->buflen, src, bytes);
		src += bytes;
		len -= bytes;
		dctx->buflen += bytes;

		if (dctx->buflen == POLY1305_BLOCK_SIZE) {
			neon_poly1305_blocks(dctx, dctx->buf,
					     POLY1305_BLOCK_SIZE, 1, false);
			dctx->buflen = 0;
		}
	}

	if (likely(len >= POLY1305_BLOCK_SIZE)) {
		neon_poly1305_blocks(dctx, src, len, 1, do_neon);
		src += round_down(len, POLY1305_BLOCK_SIZE);
		len %= POLY1305_BLOCK_SIZE;
	}

	if (unlikely(len)) {
		dctx->buflen = len;
		memcpy(dctx->buf, src, len);
	}
}

static int neon_poly1305_update(struct shash_desc *desc,
				const u8 *src, unsigned int srclen)
{
	bool do_neon = crypto_simd_usable() && srclen > 128;
	struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);

	if (static_branch_likely(&have_neon) && do_neon)
		kernel_neon_begin();
	neon_poly1305_do_update(dctx, src, srclen, do_neon);
	if (static_branch_likely(&have_neon) && do_neon)
		kernel_neon_end();
	return 0;
}

void poly1305_update_arch(struct poly1305_desc_ctx *dctx, const u8 *src,
			  unsigned int nbytes)
{
	if (unlikely(dctx->buflen)) {
		u32 bytes = min(nbytes, POLY1305_BLOCK_SIZE - dctx->buflen);

		memcpy(dctx->buf + dctx->buflen, src, bytes);
		src += bytes;
		nbytes -= bytes;
		dctx->buflen += bytes;

		if (dctx->buflen == POLY1305_BLOCK_SIZE) {
			poly1305_blocks(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 1);
			dctx->buflen = 0;
		}
	}

	if (likely(nbytes >= POLY1305_BLOCK_SIZE)) {
		unsigned int len = round_down(nbytes, POLY1305_BLOCK_SIZE);

		if (static_branch_likely(&have_neon) && crypto_simd_usable()) {
			do {
				unsigned int todo = min_t(unsigned int, len, SZ_4K);

				kernel_neon_begin();
				poly1305_blocks_neon(&dctx->h, src, todo, 1);
				kernel_neon_end();

				len -= todo;
				src += todo;
			} while (len);
		} else {
			poly1305_blocks(&dctx->h, src, len, 1);
			src += len;
		}
		nbytes %= POLY1305_BLOCK_SIZE;
	}

	if (unlikely(nbytes)) {
		dctx->buflen = nbytes;
		memcpy(dctx->buf, src, nbytes);
	}
}
EXPORT_SYMBOL(poly1305_update_arch);

void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8 *dst)
{
	if (unlikely(dctx->buflen)) {
		dctx->buf[dctx->buflen++] = 1;
		memset(dctx->buf + dctx->buflen, 0,
		       POLY1305_BLOCK_SIZE - dctx->buflen);
		poly1305_blocks(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 0);
	}

	poly1305_emit(&dctx->h, dst, dctx->s);
	memzero_explicit(dctx, sizeof(*dctx));
}
EXPORT_SYMBOL(poly1305_final_arch);

static int neon_poly1305_final(struct shash_desc *desc, u8 *dst)
{
	struct poly1305_desc_ctx *dctx = shash_desc_ctx(desc);

	if (unlikely(!dctx->sset))
		return -ENOKEY;

	poly1305_final_arch(dctx, dst);
	return 0;
}

static struct shash_alg neon_poly1305_alg = {
	.init			= neon_poly1305_init,
	.update			= neon_poly1305_update,
	.final			= neon_poly1305_final,
	.digestsize		= POLY1305_DIGEST_SIZE,
	.descsize		= sizeof(struct poly1305_desc_ctx),

	.base.cra_name		= "poly1305",
	.base.cra_driver_name	= "poly1305-neon",
	.base.cra_priority	= 200,
	.base.cra_blocksize	= POLY1305_BLOCK_SIZE,
	.base.cra_module	= THIS_MODULE,
};

static int __init neon_poly1305_mod_init(void)
{
	if (!cpu_have_named_feature(ASIMD))
		return 0;

	static_branch_enable(&have_neon);

	return IS_REACHABLE(CONFIG_CRYPTO_HASH) ?
		crypto_register_shash(&neon_poly1305_alg) : 0;
}

static void __exit neon_poly1305_mod_exit(void)
{
	if (IS_REACHABLE(CONFIG_CRYPTO_HASH) && cpu_have_named_feature(ASIMD))
		crypto_unregister_shash(&neon_poly1305_alg);
}

module_init(neon_poly1305_mod_init);
module_exit(neon_poly1305_mod_exit);

MODULE_LICENSE("GPL v2");
MODULE_ALIAS_CRYPTO("poly1305");
MODULE_ALIAS_CRYPTO("poly1305-neon");