1/*-
2 * Copyright (c) 2014 The FreeBSD Foundation
3 *
4 * This software was developed by John-Mark Gurney under
5 * the sponsorship of the FreeBSD Foundation and
6 * Rubicon Communications, LLC (Netgate).
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1.  Redistributions of source code must retain the above copyright
11 *     notice, this list of conditions and the following disclaimer.
12 * 2.  Redistributions in binary form must reproduce the above copyright
13 *     notice, this list of conditions and the following disclaimer in the
14 *     documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 */
29
30#include <sys/types.h>
31#include <sys/systm.h>
32#include <opencrypto/gfmult.h>
33#include <opencrypto/gmac.h>
34
35void
36AES_GMAC_Init(void *ctx)
37{
38	struct aes_gmac_ctx *agc;
39
40	agc = ctx;
41	bzero(agc, sizeof *agc);
42}
43
44void
45AES_GMAC_Setkey(void *ctx, const uint8_t *key, u_int klen)
46{
47	struct aes_gmac_ctx *agc;
48	const uint8_t zeros[GMAC_BLOCK_LEN] = {};
49	struct gf128 h;
50	uint8_t hbuf[GMAC_BLOCK_LEN];
51
52	agc = ctx;
53	agc->rounds = rijndaelKeySetupEnc(agc->keysched, key, klen * 8);
54
55	rijndaelEncrypt(agc->keysched, agc->rounds, zeros, hbuf);
56
57	h = gf128_read(hbuf);
58	gf128_genmultable4(h, &agc->ghashtbl);
59
60	explicit_bzero(&h, sizeof h);
61	explicit_bzero(hbuf, sizeof hbuf);
62}
63
64void
65AES_GMAC_Reinit(void *ctx, const uint8_t *iv, u_int ivlen)
66{
67	struct aes_gmac_ctx *agc;
68
69	agc = ctx;
70	KASSERT(ivlen <= sizeof agc->counter, ("passed ivlen too large!"));
71	memset(agc->counter, 0, sizeof(agc->counter));
72	bcopy(iv, agc->counter, ivlen);
73	agc->counter[GMAC_BLOCK_LEN - 1] = 1;
74
75	memset(&agc->hash, 0, sizeof(agc->hash));
76}
77
78int
79AES_GMAC_Update(void *ctx, const void *vdata, u_int len)
80{
81	struct aes_gmac_ctx *agc;
82	const uint8_t *data;
83	struct gf128 v;
84	uint8_t buf[GMAC_BLOCK_LEN] = {};
85	int i;
86
87	agc = ctx;
88	data = vdata;
89	v = agc->hash;
90
91	while (len > 0) {
92		if (len >= 4*GMAC_BLOCK_LEN) {
93			i = 4*GMAC_BLOCK_LEN;
94			v = gf128_mul4b(v, data, &agc->ghashtbl);
95		} else if (len >= GMAC_BLOCK_LEN) {
96			i = GMAC_BLOCK_LEN;
97			v = gf128_add(v, gf128_read(data));
98			v = gf128_mul(v, &agc->ghashtbl.tbls[0]);
99		} else {
100			i = len;
101			bcopy(data, buf, i);
102			v = gf128_add(v, gf128_read(&buf[0]));
103			v = gf128_mul(v, &agc->ghashtbl.tbls[0]);
104			explicit_bzero(buf, sizeof buf);
105		}
106		len -= i;
107		data += i;
108	}
109
110	agc->hash = v;
111	explicit_bzero(&v, sizeof v);
112
113	return (0);
114}
115
116void
117AES_GMAC_Final(uint8_t *digest, void *ctx)
118{
119	struct aes_gmac_ctx *agc;
120	uint8_t enccntr[GMAC_BLOCK_LEN];
121	struct gf128 a;
122
123	agc = ctx;
124
125	rijndaelEncrypt(agc->keysched, agc->rounds, agc->counter, enccntr);
126	a = gf128_add(agc->hash, gf128_read(enccntr));
127	gf128_write(a, digest);
128
129	explicit_bzero(enccntr, sizeof enccntr);
130}
131