freebsd-dev/sys/opencrypto/gmac.c
John Baldwin 356c922f74 GMAC: Reset initial hash value and counter in AES_GMAC_Reinit().
Previously, these values were only cleared in AES_GMAC_Init(), so a
second set of operations could reuse the final hash as the initial
hash.  Currently this bug does not trigger in cryptosoft as existing
GMAC and GCM operations always use an on-stack auth context
initialized from a template context.

Reviewed by:	markj
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D33315
2021-12-09 11:52:42 -08:00

133 lines
3.5 KiB
C

/*-
* Copyright (c) 2014 The FreeBSD Foundation
*
* 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(void *ctx)
{
struct aes_gmac_ctx *agc;
agc = ctx;
bzero(agc, sizeof *agc);
}
void
AES_GMAC_Setkey(void *ctx, const uint8_t *key, u_int klen)
{
struct aes_gmac_ctx *agc;
const uint8_t zeros[GMAC_BLOCK_LEN] = {};
struct gf128 h;
uint8_t hbuf[GMAC_BLOCK_LEN];
agc = ctx;
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(void *ctx, const uint8_t *iv, u_int ivlen)
{
struct aes_gmac_ctx *agc;
agc = ctx;
KASSERT(ivlen <= sizeof agc->counter, ("passed ivlen too large!"));
memset(agc->counter, 0, sizeof(agc->counter));
bcopy(iv, agc->counter, ivlen);
agc->counter[GMAC_BLOCK_LEN - 1] = 1;
memset(&agc->hash, 0, sizeof(agc->hash));
}
int
AES_GMAC_Update(void *ctx, const void *vdata, u_int len)
{
struct aes_gmac_ctx *agc;
const uint8_t *data;
struct gf128 v;
uint8_t buf[GMAC_BLOCK_LEN] = {};
int i;
agc = ctx;
data = vdata;
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, void *ctx)
{
struct aes_gmac_ctx *agc;
uint8_t enccntr[GMAC_BLOCK_LEN];
struct gf128 a;
agc = ctx;
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);
}