freebsd-dev/sys/opencrypto/gfmult.h

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2014-12-12 19:56:36 +00:00
/*-
* 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.
*
* $FreeBSD$
*
*/
#ifndef _GFMULT_H_
#define _GFMULT_H_
#ifdef __APPLE__
#define __aligned(x) __attribute__((__aligned__(x)))
#define be64dec(buf) __builtin_bswap64(*(uint64_t *)buf)
#define be64enc(buf, x) (*(uint64_t *)buf = __builtin_bswap64(x))
#else
#include <sys/endian.h>
#endif
#ifdef _KERNEL
#include <sys/types.h>
#else
#include <stdint.h>
#include <strings.h>
#endif
#define REQ_ALIGN (16 * 4)
/*
* The rows are striped across cache lines. Note that the indexes
* are bit reversed to make accesses quicker.
*/
struct gf128table {
uint32_t a[16] __aligned(REQ_ALIGN); /* bits 0 - 31 */
uint32_t b[16] __aligned(REQ_ALIGN); /* bits 63 - 32 */
uint32_t c[16] __aligned(REQ_ALIGN); /* bits 95 - 64 */
uint32_t d[16] __aligned(REQ_ALIGN); /* bits 127 - 96 */
} __aligned(REQ_ALIGN);
/*
* A set of tables that contain h, h^2, h^3, h^4. To be used w/ gf128_mul4.
*/
struct gf128table4 {
struct gf128table tbls[4];
};
/*
* GCM per spec is bit reversed in memory. So byte 0 is really bit reversed
* and contains bits 0-7. We can deal w/ this by using right shifts and
* related math instead of having to bit reverse everything. This means that
* the low bits are in v[0] (bits 0-63) and reverse order, while the high
* bits are in v[1] (bits 64-127) and reverse order. The high bit of v[0] is
* bit 0, and the low bit of v[1] is bit 127.
*/
struct gf128 {
uint64_t v[2];
};
/* Note that we don't bit reverse in MAKE_GF128. */
#define MAKE_GF128(a, b) ((struct gf128){.v = { (a), (b) } })
#define GF128_EQ(a, b) ((((a).v[0] ^ (b).v[0]) | \
((a).v[1] ^ (b).v[1])) == 0)
static inline struct gf128
gf128_read(const uint8_t *buf)
{
struct gf128 r;
r.v[0] = be64dec(buf);
buf += sizeof(uint64_t);
r.v[1] = be64dec(buf);
return r;
}
static inline void
gf128_write(struct gf128 v, uint8_t *buf)
{
uint64_t tmp;
be64enc(buf, v.v[0]);
buf += sizeof tmp;
be64enc(buf, v.v[1]);
}
static inline struct gf128 __pure /* XXX - __pure2 instead */
gf128_add(struct gf128 a, struct gf128 b)
{
a.v[0] ^= b.v[0];
a.v[1] ^= b.v[1];
return a;
}
void gf128_genmultable(struct gf128 h, struct gf128table *t);
void gf128_genmultable4(struct gf128 h, struct gf128table4 *t);
struct gf128 gf128_mul(struct gf128 v, struct gf128table *tbl);
struct gf128 gf128_mul4(struct gf128 a, struct gf128 b, struct gf128 c,
struct gf128 d, struct gf128table4 *tbl);
struct gf128 gf128_mul4b(struct gf128 r, const uint8_t *v,
struct gf128table4 *tbl);
#endif /* _GFMULT_H_ */