1/*-
2 * Copyright (c) 2014 The FreeBSD Foundation
3 * All rights reserved.
4 *
5 * This software was developed by John-Mark Gurney under
6 * the sponsorship of the FreeBSD Foundation and
7 * Rubicon Communications, LLC (Netgate).
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1.  Redistributions of source code must retain the above copyright
12 *     notice, this list of conditions and the following disclaimer.
13 * 2.  Redistributions in binary form must reproduce the above copyright
14 *     notice, this list of conditions and the following disclaimer in the
15 *     documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 *	$FreeBSD$
30 *
31 */
32
33#include <sys/types.h>
34#include <sys/systm.h>
35#include <opencrypto/gfmult.h>
36#include <opencrypto/gmac.h>
37
38void
39AES_GMAC_Init(void *ctx)
40{
41	struct aes_gmac_ctx *agc;
42
43	agc = ctx;
44	bzero(agc, sizeof *agc);
45}
46
47void
48AES_GMAC_Setkey(void *ctx, const uint8_t *key, u_int klen)
49{
50	struct aes_gmac_ctx *agc;
51	const uint8_t zeros[GMAC_BLOCK_LEN] = {};
52	struct gf128 h;
53	uint8_t hbuf[GMAC_BLOCK_LEN];
54
55	agc = ctx;
56	agc->rounds = rijndaelKeySetupEnc(agc->keysched, key, klen * 8);
57
58	rijndaelEncrypt(agc->keysched, agc->rounds, zeros, hbuf);
59
60	h = gf128_read(hbuf);
61	gf128_genmultable4(h, &agc->ghashtbl);
62
63	explicit_bzero(&h, sizeof h);
64	explicit_bzero(hbuf, sizeof hbuf);
65}
66
67void
68AES_GMAC_Reinit(void *ctx, const uint8_t *iv, u_int ivlen)
69{
70	struct aes_gmac_ctx *agc;
71
72	agc = ctx;
73	KASSERT(ivlen <= sizeof agc->counter, ("passed ivlen too large!"));
74	bcopy(iv, agc->counter, ivlen);
75}
76
77int
78AES_GMAC_Update(void *ctx, const void *vdata, u_int len)
79{
80	struct aes_gmac_ctx *agc;
81	const uint8_t *data;
82	struct gf128 v;
83	uint8_t buf[GMAC_BLOCK_LEN] = {};
84	int i;
85
86	agc = ctx;
87	data = vdata;
88	v = agc->hash;
89
90	while (len > 0) {
91		if (len >= 4*GMAC_BLOCK_LEN) {
92			i = 4*GMAC_BLOCK_LEN;
93			v = gf128_mul4b(v, data, &agc->ghashtbl);
94		} else if (len >= GMAC_BLOCK_LEN) {
95			i = GMAC_BLOCK_LEN;
96			v = gf128_add(v, gf128_read(data));
97			v = gf128_mul(v, &agc->ghashtbl.tbls[0]);
98		} else {
99			i = len;
100			bcopy(data, buf, i);
101			v = gf128_add(v, gf128_read(&buf[0]));
102			v = gf128_mul(v, &agc->ghashtbl.tbls[0]);
103			explicit_bzero(buf, sizeof buf);
104		}
105		len -= i;
106		data += i;
107	}
108
109	agc->hash = v;
110	explicit_bzero(&v, sizeof v);
111
112	return (0);
113}
114
115void
116AES_GMAC_Final(uint8_t *digest, void *ctx)
117{
118	struct aes_gmac_ctx *agc;
119	uint8_t enccntr[GMAC_BLOCK_LEN];
120	struct gf128 a;
121
122	/* XXX - zero additional bytes? */
123	agc = ctx;
124	agc->counter[GMAC_BLOCK_LEN - 1] = 1;
125
126	rijndaelEncrypt(agc->keysched, agc->rounds, agc->counter, enccntr);
127	a = gf128_add(agc->hash, gf128_read(enccntr));
128	gf128_write(a, digest);
129
130	explicit_bzero(enccntr, sizeof enccntr);
131}
132