zfs-builds-mm/zfs-2.0.0-rc6/module/icp/algs/modes/gcm_generic.c
2020-11-15 11:35:49 +01:00

83 lines
2.1 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
*/
#include <modes/gcm_impl.h>
struct aes_block {
uint64_t a;
uint64_t b;
};
/*
* Perform a carry-less multiplication (that is, use XOR instead of the
* multiply operator) on *x_in and *y and place the result in *res.
*
* Byte swap the input (*x_in and *y) and the output (*res).
*
* Note: x_in, y, and res all point to 16-byte numbers (an array of two
* 64-bit integers).
*/
static void
gcm_generic_mul(uint64_t *x_in, uint64_t *y, uint64_t *res)
{
static const uint64_t R = 0xe100000000000000ULL;
struct aes_block z = {0, 0};
struct aes_block v;
uint64_t x;
int i, j;
v.a = ntohll(y[0]);
v.b = ntohll(y[1]);
for (j = 0; j < 2; j++) {
x = ntohll(x_in[j]);
for (i = 0; i < 64; i++, x <<= 1) {
if (x & 0x8000000000000000ULL) {
z.a ^= v.a;
z.b ^= v.b;
}
if (v.b & 1ULL) {
v.b = (v.a << 63)|(v.b >> 1);
v.a = (v.a >> 1) ^ R;
} else {
v.b = (v.a << 63)|(v.b >> 1);
v.a = v.a >> 1;
}
}
}
res[0] = htonll(z.a);
res[1] = htonll(z.b);
}
static boolean_t
gcm_generic_will_work(void)
{
return (B_TRUE);
}
const gcm_impl_ops_t gcm_generic_impl = {
.mul = &gcm_generic_mul,
.is_supported = &gcm_generic_will_work,
.name = "generic"
};