1 /* $NetBSD: aes_ct_enc.c,v 1.1 2020/06/29 23:27:52 riastradh Exp $ */
2
3 /*
4 * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining
7 * a copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sublicense, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be
15 * included in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
20 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
21 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
22 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
23 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
24 * SOFTWARE.
25 */
26
27 #include <sys/cdefs.h>
28 __KERNEL_RCSID(1, "$NetBSD: aes_ct_enc.c,v 1.1 2020/06/29 23:27:52 riastradh Exp $");
29
30 #include <sys/types.h>
31
32 #include <crypto/aes/aes_bear.h>
33
34 static inline void
add_round_key(uint32_t * q,const uint32_t * sk)35 add_round_key(uint32_t *q, const uint32_t *sk)
36 {
37 q[0] ^= sk[0];
38 q[1] ^= sk[1];
39 q[2] ^= sk[2];
40 q[3] ^= sk[3];
41 q[4] ^= sk[4];
42 q[5] ^= sk[5];
43 q[6] ^= sk[6];
44 q[7] ^= sk[7];
45 }
46
47 static inline void
shift_rows(uint32_t * q)48 shift_rows(uint32_t *q)
49 {
50 int i;
51
52 for (i = 0; i < 8; i ++) {
53 uint32_t x;
54
55 x = q[i];
56 q[i] = (x & 0x000000FF)
57 | ((x & 0x0000FC00) >> 2) | ((x & 0x00000300) << 6)
58 | ((x & 0x00F00000) >> 4) | ((x & 0x000F0000) << 4)
59 | ((x & 0xC0000000) >> 6) | ((x & 0x3F000000) << 2);
60 }
61 }
62
63 static inline uint32_t
rotr16(uint32_t x)64 rotr16(uint32_t x)
65 {
66 return (x << 16) | (x >> 16);
67 }
68
69 static inline void
mix_columns(uint32_t * q)70 mix_columns(uint32_t *q)
71 {
72 uint32_t q0, q1, q2, q3, q4, q5, q6, q7;
73 uint32_t r0, r1, r2, r3, r4, r5, r6, r7;
74
75 q0 = q[0];
76 q1 = q[1];
77 q2 = q[2];
78 q3 = q[3];
79 q4 = q[4];
80 q5 = q[5];
81 q6 = q[6];
82 q7 = q[7];
83 r0 = (q0 >> 8) | (q0 << 24);
84 r1 = (q1 >> 8) | (q1 << 24);
85 r2 = (q2 >> 8) | (q2 << 24);
86 r3 = (q3 >> 8) | (q3 << 24);
87 r4 = (q4 >> 8) | (q4 << 24);
88 r5 = (q5 >> 8) | (q5 << 24);
89 r6 = (q6 >> 8) | (q6 << 24);
90 r7 = (q7 >> 8) | (q7 << 24);
91
92 q[0] = q7 ^ r7 ^ r0 ^ rotr16(q0 ^ r0);
93 q[1] = q0 ^ r0 ^ q7 ^ r7 ^ r1 ^ rotr16(q1 ^ r1);
94 q[2] = q1 ^ r1 ^ r2 ^ rotr16(q2 ^ r2);
95 q[3] = q2 ^ r2 ^ q7 ^ r7 ^ r3 ^ rotr16(q3 ^ r3);
96 q[4] = q3 ^ r3 ^ q7 ^ r7 ^ r4 ^ rotr16(q4 ^ r4);
97 q[5] = q4 ^ r4 ^ r5 ^ rotr16(q5 ^ r5);
98 q[6] = q5 ^ r5 ^ r6 ^ rotr16(q6 ^ r6);
99 q[7] = q6 ^ r6 ^ r7 ^ rotr16(q7 ^ r7);
100 }
101
102 /* see inner.h */
103 void
br_aes_ct_bitslice_encrypt(unsigned num_rounds,const uint32_t * skey,uint32_t * q)104 br_aes_ct_bitslice_encrypt(unsigned num_rounds,
105 const uint32_t *skey, uint32_t *q)
106 {
107 unsigned u;
108
109 add_round_key(q, skey);
110 for (u = 1; u < num_rounds; u ++) {
111 br_aes_ct_bitslice_Sbox(q);
112 shift_rows(q);
113 mix_columns(q);
114 add_round_key(q, skey + (u << 3));
115 }
116 br_aes_ct_bitslice_Sbox(q);
117 shift_rows(q);
118 add_round_key(q, skey + (num_rounds << 3));
119 }
120