/*-
* Copyright (c) 2014 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by John-Mark Gurney under
* the sponsorship of the FreeBSD Foundation and
* Rubicon Communications, LLC (Netgate).
* 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 AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*
*/
#include <sys/types.h>
#include <sys/systm.h>
#include <opencrypto/gfmult.h>
#include <opencrypto/gmac.h>
void
AES_GMAC_Init(struct aes_gmac_ctx *agc)
{
bzero(agc, sizeof *agc);
}
void
AES_GMAC_Setkey(struct aes_gmac_ctx *agc, const uint8_t *key, uint16_t klen)
{
const uint8_t zeros[GMAC_BLOCK_LEN] = {};
struct gf128 h;
uint8_t hbuf[GMAC_BLOCK_LEN];
agc->rounds = rijndaelKeySetupEnc(agc->keysched, key, klen * 8);
rijndaelEncrypt(agc->keysched, agc->rounds, zeros, hbuf);
h = gf128_read(hbuf);
gf128_genmultable4(h, &agc->ghashtbl);
explicit_bzero(&h, sizeof h);
explicit_bzero(hbuf, sizeof hbuf);
}
void
AES_GMAC_Reinit(struct aes_gmac_ctx *agc, const uint8_t *iv, uint16_t ivlen)
{
KASSERT(ivlen <= sizeof agc->counter, ("passed ivlen too large!"));
bcopy(iv, agc->counter, ivlen);
}
int
AES_GMAC_Update(struct aes_gmac_ctx *agc, const uint8_t *data, uint16_t len)
{
struct gf128 v;
uint8_t buf[GMAC_BLOCK_LEN] = {};
int i;
v = agc->hash;
while (len > 0) {
if (len >= 4*GMAC_BLOCK_LEN) {
i = 4*GMAC_BLOCK_LEN;
v = gf128_mul4b(v, data, &agc->ghashtbl);
} else if (len >= GMAC_BLOCK_LEN) {
i = GMAC_BLOCK_LEN;
v = gf128_add(v, gf128_read(data));
v = gf128_mul(v, &agc->ghashtbl.tbls[0]);
} else {
i = len;
bcopy(data, buf, i);
v = gf128_add(v, gf128_read(&buf[0]));
v = gf128_mul(v, &agc->ghashtbl.tbls[0]);
explicit_bzero(buf, sizeof buf);
}
len -= i;
data += i;
}
agc->hash = v;
explicit_bzero(&v, sizeof v);
return (0);
}
void
AES_GMAC_Final(uint8_t digest[GMAC_DIGEST_LEN], struct aes_gmac_ctx *agc)
{
uint8_t enccntr[GMAC_BLOCK_LEN];
struct gf128 a;
/* XXX - zero additional bytes? */
agc->counter[GMAC_BLOCK_LEN - 1] = 1;
rijndaelEncrypt(agc->keysched, agc->rounds, agc->counter, enccntr);
a = gf128_add(agc->hash, gf128_read(enccntr));
gf128_write(a, digest);
explicit_bzero(enccntr, sizeof enccntr);
}
