aboutsummaryrefslogtreecommitdiffstats
path: root/arch/mips/crypto/chacha-glue.c
blob: d1fd23e6ef844d13282af3f5731366642bd4a456 (plain) (blame)
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
// SPDX-License-Identifier: GPL-2.0
/*
 * MIPS accelerated ChaCha and XChaCha stream ciphers,
 * including ChaCha20 (RFC7539)
 *
 * Copyright (C) 2019 Linaro, Ltd. <ard.biesheuvel@linaro.org>
 */

#include <asm/byteorder.h>
#include <crypto/algapi.h>
#include <crypto/internal/chacha.h>
#include <crypto/internal/skcipher.h>
#include <linux/kernel.h>
#include <linux/module.h>

asmlinkage void chacha_crypt_arch(u32 *state, u8 *dst, const u8 *src,
				  unsigned int bytes, int nrounds);
EXPORT_SYMBOL(chacha_crypt_arch);

asmlinkage void hchacha_block_arch(const u32 *state, u32 *stream, int nrounds);
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);

static int chacha_mips_stream_xor(struct skcipher_request *req,
				  const struct chacha_ctx *ctx, const u8 *iv)
{
	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);

		chacha_crypt(state, walk.dst.virt.addr, walk.src.virt.addr,
			     nbytes, ctx->nrounds);
		err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
	}

	return err;
}

static int chacha_mips(struct skcipher_request *req)
{
	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
	struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);

	return chacha_mips_stream_xor(req, ctx, req->iv);
}

static int xchacha_mips(struct skcipher_request *req)
{
	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);

	hchacha_block(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);
	return chacha_mips_stream_xor(req, &subctx, real_iv);
}

static struct skcipher_alg algs[] = {
	{
		.base.cra_name		= "chacha20",
		.base.cra_driver_name	= "chacha20-mips",
		.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_mips,
		.decrypt		= chacha_mips,
	}, {
		.base.cra_name		= "xchacha20",
		.base.cra_driver_name	= "xchacha20-mips",
		.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_mips,
		.decrypt		= xchacha_mips,
	}, {
		.base.cra_name		= "xchacha12",
		.base.cra_driver_name	= "xchacha12-mips",
		.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_mips,
		.decrypt		= xchacha_mips,
	}
};

static int __init chacha_simd_mod_init(void)
{
	return IS_REACHABLE(CONFIG_CRYPTO_SKCIPHER) ?
		crypto_register_skciphers(algs, ARRAY_SIZE(algs)) : 0;
}

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

module_init(chacha_simd_mod_init);
module_exit(chacha_simd_mod_fini);

MODULE_DESCRIPTION("ChaCha and XChaCha stream ciphers (MIPS accelerated)");
MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS_CRYPTO("chacha20");
MODULE_ALIAS_CRYPTO("chacha20-mips");
MODULE_ALIAS_CRYPTO("xchacha20");
MODULE_ALIAS_CRYPTO("xchacha20-mips");
MODULE_ALIAS_CRYPTO("xchacha12");
MODULE_ALIAS_CRYPTO("xchacha12-mips");