aboutsummaryrefslogtreecommitdiff
path: root/sys/opencrypto/xform_chacha20_poly1305.c
blob: 3a72c06f931baa1198f2a4138e2ee5e511bb667d (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
153
154
155
156
157
158
159
160
161
162
163
/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 *
 * Copyright (c) 2020 Netflix Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <opencrypto/xform_auth.h>
#include <opencrypto/xform_enc.h>

#include <sodium/crypto_onetimeauth_poly1305.h>
#include <sodium/crypto_stream_chacha20.h>

struct chacha20_poly1305_cipher_ctx {
	const void *key;
	uint32_t ic;
	char nonce[CHACHA20_POLY1305_IV_LEN];
};

static int
chacha20_poly1305_setkey(void *vctx, const uint8_t *key, int len)
{
	struct chacha20_poly1305_cipher_ctx *ctx = vctx;

	if (len != CHACHA20_POLY1305_KEY)
		return (EINVAL);

	ctx->key = key;
	return (0);
}

static void
chacha20_poly1305_reinit(void *vctx, const uint8_t *iv)
{
	struct chacha20_poly1305_cipher_ctx *ctx = vctx;

	/* Block 0 is used for the poly1305 key. */
	memcpy(ctx->nonce, iv, sizeof(ctx->nonce));
	ctx->ic = 1;
}

static void
chacha20_poly1305_crypt(void *vctx, const uint8_t *in, uint8_t *out)
{
	struct chacha20_poly1305_cipher_ctx *ctx = vctx;
	int error;

	error = crypto_stream_chacha20_ietf_xor_ic(out, in,
	    CHACHA20_NATIVE_BLOCK_LEN, ctx->nonce, ctx->ic, ctx->key);
	KASSERT(error == 0, ("%s failed: %d", __func__, error));
	ctx->ic++;
}

static void
chacha20_poly1305_crypt_last(void *vctx, const uint8_t *in, uint8_t *out,
    size_t len)
{
	struct chacha20_poly1305_cipher_ctx *ctx = vctx;

	int error;

	error = crypto_stream_chacha20_ietf_xor_ic(out, in, len, ctx->nonce,
	    ctx->ic, ctx->key);
	KASSERT(error == 0, ("%s failed: %d", __func__, error));
}

struct enc_xform enc_xform_chacha20_poly1305 = {
	.type = CRYPTO_CHACHA20_POLY1305,
	.name = "ChaCha20-Poly1305",
	.ctxsize = sizeof(struct chacha20_poly1305_cipher_ctx),
	.blocksize = 1,
	.native_blocksize = CHACHA20_NATIVE_BLOCK_LEN,
	.ivsize = CHACHA20_POLY1305_IV_LEN,
	.minkey = CHACHA20_POLY1305_KEY,
	.maxkey = CHACHA20_POLY1305_KEY,
	.encrypt = chacha20_poly1305_crypt,
	.decrypt = chacha20_poly1305_crypt,
	.setkey = chacha20_poly1305_setkey,
	.reinit = chacha20_poly1305_reinit,
	.encrypt_last = chacha20_poly1305_crypt_last,
	.decrypt_last = chacha20_poly1305_crypt_last,
};

struct chacha20_poly1305_auth_ctx {
	struct crypto_onetimeauth_poly1305_state state;
	const void *key;
};
CTASSERT(sizeof(union authctx) >= sizeof(struct chacha20_poly1305_auth_ctx));

static void
chacha20_poly1305_Init(void *vctx)
{
}

static void
chacha20_poly1305_Setkey(void *vctx, const uint8_t *key, u_int klen)
{
	struct chacha20_poly1305_auth_ctx *ctx = vctx;

	ctx->key = key;
}

static void
chacha20_poly1305_Reinit(void *vctx, const uint8_t *nonce, u_int noncelen)
{
	struct chacha20_poly1305_auth_ctx *ctx = vctx;
	char block[CHACHA20_NATIVE_BLOCK_LEN];

	crypto_stream_chacha20_ietf(block, sizeof(block), nonce, ctx->key);
	crypto_onetimeauth_poly1305_init(&ctx->state, block);
	explicit_bzero(block, sizeof(block));
}

static int
chacha20_poly1305_Update(void *vctx, const void *data, u_int len)
{
	struct chacha20_poly1305_auth_ctx *ctx = vctx;

	crypto_onetimeauth_poly1305_update(&ctx->state, data, len);
	return (0);
}

static void
chacha20_poly1305_Final(uint8_t *digest, void *vctx)
{
	struct chacha20_poly1305_auth_ctx *ctx = vctx;

	crypto_onetimeauth_poly1305_final(&ctx->state, digest);
}

struct auth_hash auth_hash_chacha20_poly1305 = {
	.type = CRYPTO_POLY1305,
	.name = "ChaCha20-Poly1305",
	.keysize = POLY1305_KEY_LEN,
	.hashsize = POLY1305_HASH_LEN,
	.ctxsize = sizeof(struct chacha20_poly1305_auth_ctx),
	.blocksize = crypto_onetimeauth_poly1305_BYTES,
	.Init = chacha20_poly1305_Init,
	.Setkey = chacha20_poly1305_Setkey,
	.Reinit = chacha20_poly1305_Reinit,
	.Update = chacha20_poly1305_Update,
	.Final = chacha20_poly1305_Final,
};