1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3 * CDDL HEADER START
4 *
5 * The contents of this file are subject to the terms of the
6 * Common Development and Distribution License (the "License").
7 * You may not use this file except in compliance with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or https://opensource.org/licenses/CDDL-1.0.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /*
23 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
24 */
25
26 #include <modes/gcm_impl.h>
27
28 struct aes_block {
29 uint64_t a;
30 uint64_t b;
31 };
32
33 /*
34 * Perform a carry-less multiplication (that is, use XOR instead of the
35 * multiply operator) on *x_in and *y and place the result in *res.
36 *
37 * Byte swap the input (*x_in and *y) and the output (*res).
38 *
39 * Note: x_in, y, and res all point to 16-byte numbers (an array of two
40 * 64-bit integers).
41 */
42 static void
gcm_generic_mul(uint64_t * x_in,uint64_t * y,uint64_t * res)43 gcm_generic_mul(uint64_t *x_in, uint64_t *y, uint64_t *res)
44 {
45 static const uint64_t R = 0xe100000000000000ULL;
46 struct aes_block z = {0, 0};
47 struct aes_block v;
48 uint64_t x;
49 int i, j;
50
51 v.a = ntohll(y[0]);
52 v.b = ntohll(y[1]);
53
54 for (j = 0; j < 2; j++) {
55 x = ntohll(x_in[j]);
56 for (i = 0; i < 64; i++, x <<= 1) {
57 if (x & 0x8000000000000000ULL) {
58 z.a ^= v.a;
59 z.b ^= v.b;
60 }
61 if (v.b & 1ULL) {
62 v.b = (v.a << 63)|(v.b >> 1);
63 v.a = (v.a >> 1) ^ R;
64 } else {
65 v.b = (v.a << 63)|(v.b >> 1);
66 v.a = v.a >> 1;
67 }
68 }
69 }
70 res[0] = htonll(z.a);
71 res[1] = htonll(z.b);
72 }
73
74 static boolean_t
gcm_generic_will_work(void)75 gcm_generic_will_work(void)
76 {
77 return (B_TRUE);
78 }
79
80 const gcm_impl_ops_t gcm_generic_impl = {
81 .mul = &gcm_generic_mul,
82 .is_supported = &gcm_generic_will_work,
83 .name = "generic"
84 };
85