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