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 * $FreeBSD$
29 *
30 */
31
32 #include <sys/types.h>
33 #include <sys/systm.h>
34 #include <opencrypto/gfmult.h>
35 #include <opencrypto/gmac.h>
36
37 void
AES_GMAC_Init(void * ctx)38 AES_GMAC_Init(void *ctx)
39 {
40 struct aes_gmac_ctx *agc;
41
42 agc = ctx;
43 bzero(agc, sizeof *agc);
44 }
45
46 void
AES_GMAC_Setkey(void * ctx,const uint8_t * key,u_int klen)47 AES_GMAC_Setkey(void *ctx, const uint8_t *key, u_int klen)
48 {
49 struct aes_gmac_ctx *agc;
50 const uint8_t zeros[GMAC_BLOCK_LEN] = {};
51 struct gf128 h;
52 uint8_t hbuf[GMAC_BLOCK_LEN];
53
54 agc = ctx;
55 agc->rounds = rijndaelKeySetupEnc(agc->keysched, key, klen * 8);
56
57 rijndaelEncrypt(agc->keysched, agc->rounds, zeros, hbuf);
58
59 h = gf128_read(hbuf);
60 gf128_genmultable4(h, &agc->ghashtbl);
61
62 explicit_bzero(&h, sizeof h);
63 explicit_bzero(hbuf, sizeof hbuf);
64 }
65
66 void
AES_GMAC_Reinit(void * ctx,const uint8_t * iv,u_int ivlen)67 AES_GMAC_Reinit(void *ctx, const uint8_t *iv, u_int ivlen)
68 {
69 struct aes_gmac_ctx *agc;
70
71 agc = ctx;
72 KASSERT(ivlen <= sizeof agc->counter, ("passed ivlen too large!"));
73 bcopy(iv, agc->counter, ivlen);
74 }
75
76 int
AES_GMAC_Update(void * ctx,const void * vdata,u_int len)77 AES_GMAC_Update(void *ctx, const void *vdata, u_int len)
78 {
79 struct aes_gmac_ctx *agc;
80 const uint8_t *data;
81 struct gf128 v;
82 uint8_t buf[GMAC_BLOCK_LEN] = {};
83 int i;
84
85 agc = ctx;
86 data = vdata;
87 v = agc->hash;
88
89 while (len > 0) {
90 if (len >= 4*GMAC_BLOCK_LEN) {
91 i = 4*GMAC_BLOCK_LEN;
92 v = gf128_mul4b(v, data, &agc->ghashtbl);
93 } else if (len >= GMAC_BLOCK_LEN) {
94 i = GMAC_BLOCK_LEN;
95 v = gf128_add(v, gf128_read(data));
96 v = gf128_mul(v, &agc->ghashtbl.tbls[0]);
97 } else {
98 i = len;
99 bcopy(data, buf, i);
100 v = gf128_add(v, gf128_read(&buf[0]));
101 v = gf128_mul(v, &agc->ghashtbl.tbls[0]);
102 explicit_bzero(buf, sizeof buf);
103 }
104 len -= i;
105 data += i;
106 }
107
108 agc->hash = v;
109 explicit_bzero(&v, sizeof v);
110
111 return (0);
112 }
113
114 void
AES_GMAC_Final(uint8_t * digest,void * ctx)115 AES_GMAC_Final(uint8_t *digest, void *ctx)
116 {
117 struct aes_gmac_ctx *agc;
118 uint8_t enccntr[GMAC_BLOCK_LEN];
119 struct gf128 a;
120
121 /* XXX - zero additional bytes? */
122 agc = ctx;
123 agc->counter[GMAC_BLOCK_LEN - 1] = 1;
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