xref: /netbsd-src/sys/crypto/aes/arch/x86/aes_sse2_dec.c (revision 336b5650c616345272bc32eac80cd5c63757e79f)
1 /*
2  * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining
5  * a copy of this software and associated documentation files (the
6  * "Software"), to deal in the Software without restriction, including
7  * without limitation the rights to use, copy, modify, merge, publish,
8  * distribute, sublicense, and/or sell copies of the Software, and to
9  * permit persons to whom the Software is furnished to do so, subject to
10  * the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be
13  * included in all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22  * SOFTWARE.
23  */
24 
25 #include <sys/cdefs.h>
26 __KERNEL_RCSID(1, "$NetBSD: aes_sse2_dec.c,v 1.1 2020/06/29 23:47:54 riastradh Exp $");
27 
28 #include <sys/types.h>
29 
30 #include "aes_sse2_impl.h"
31 
32 /* see inner.h */
33 void
aes_sse2_bitslice_invSbox(__m128i q[static4])34 aes_sse2_bitslice_invSbox(__m128i q[static 4])
35 {
36 	/*
37 	 * See br_aes_ct_bitslice_invSbox(). This is the natural extension
38 	 * to 64-bit registers.
39 	 */
40 	__m128i q0, q1, q2, q3, q4, q5, q6, q7;
41 
42 	q0 = ~q[0];
43 	q1 = ~q[1];
44 	q2 = q[2];
45 	q3 = q[3];
46 	q4 = _mm_shuffle_epi32(q[0], 0x0e);
47 	q5 = _mm_shuffle_epi32(~q[1], 0x0e);
48 	q6 = _mm_shuffle_epi32(~q[2], 0x0e);
49 	q7 = _mm_shuffle_epi32(q[3], 0x0e);
50 
51 	q[3] = _mm_unpacklo_epi64(q5 ^ q0 ^ q2, q1 ^ q4 ^ q6);
52 	q[2] = _mm_unpacklo_epi64(q4 ^ q7 ^ q1, q0 ^ q3 ^ q5);
53 	q[1] = _mm_unpacklo_epi64(q3 ^ q6 ^ q0, q7 ^ q2 ^ q4);
54 	q[0] = _mm_unpacklo_epi64(q2 ^ q5 ^ q7, q6 ^ q1 ^ q3);
55 
56 	aes_sse2_bitslice_Sbox(q);
57 
58 	q0 = ~q[0];
59 	q1 = ~q[1];
60 	q2 = q[2];
61 	q3 = q[3];
62 	q4 = _mm_shuffle_epi32(q[0], 0x0e);
63 	q5 = _mm_shuffle_epi32(~q[1], 0x0e);
64 	q6 = _mm_shuffle_epi32(~q[2], 0x0e);
65 	q7 = _mm_shuffle_epi32(q[3], 0x0e);
66 
67 	q[3] = _mm_unpacklo_epi64(q5 ^ q0 ^ q2, q1 ^ q4 ^ q6);
68 	q[2] = _mm_unpacklo_epi64(q4 ^ q7 ^ q1, q0 ^ q3 ^ q5);
69 	q[1] = _mm_unpacklo_epi64(q3 ^ q6 ^ q0, q7 ^ q2 ^ q4);
70 	q[0] = _mm_unpacklo_epi64(q2 ^ q5 ^ q7, q6 ^ q1 ^ q3);
71 }
72 
73 static inline void
add_round_key(__m128i q[static4],const uint64_t sk[static8])74 add_round_key(__m128i q[static 4], const uint64_t sk[static 8])
75 {
76 	q[0] ^= _mm_set_epi64x(sk[4], sk[0]);
77 	q[1] ^= _mm_set_epi64x(sk[5], sk[1]);
78 	q[2] ^= _mm_set_epi64x(sk[6], sk[2]);
79 	q[3] ^= _mm_set_epi64x(sk[7], sk[3]);
80 }
81 
82 static inline __m128i
inv_shift_row(__m128i q)83 inv_shift_row(__m128i q)
84 {
85 	__m128i x, y0, y1, y2, y3, y4, y5, y6;
86 
87 	x = q;
88 	y0 = x & _mm_set1_epi64x(0x000000000000FFFF);
89 	y1 = x & _mm_set1_epi64x(0x000000000FFF0000);
90 	y2 = x & _mm_set1_epi64x(0x00000000F0000000);
91 	y3 = x & _mm_set1_epi64x(0x000000FF00000000);
92 	y4 = x & _mm_set1_epi64x(0x0000FF0000000000);
93 	y5 = x & _mm_set1_epi64x(0x000F000000000000);
94 	y6 = x & _mm_set1_epi64x(0xFFF0000000000000);
95 	y1 = _mm_slli_epi64(y1, 4);
96 	y2 = _mm_srli_epi64(y2, 12);
97 	y3 = _mm_slli_epi64(y3, 8);
98 	y4 = _mm_srli_epi64(y4, 8);
99 	y5 = _mm_slli_epi64(y5, 12);
100 	y6 = _mm_srli_epi64(y6, 4);
101 	return y0 | y1 | y2 | y3 | y4 | y5 | y6;
102 }
103 
104 static inline void
inv_shift_rows(__m128i q[static4])105 inv_shift_rows(__m128i q[static 4])
106 {
107 
108 	q[0] = inv_shift_row(q[0]);
109 	q[1] = inv_shift_row(q[1]);
110 	q[2] = inv_shift_row(q[2]);
111 	q[3] = inv_shift_row(q[3]);
112 }
113 
114 static inline __m128i
rotr32(__m128i x)115 rotr32(__m128i x)
116 {
117 	return _mm_slli_epi64(x, 32) | _mm_srli_epi64(x, 32);
118 }
119 
120 static inline void
inv_mix_columns(__m128i q[4])121 inv_mix_columns(__m128i q[4])
122 {
123 	__m128i q0, q1, q2, q3, q4, q5, q6, q7;
124 	__m128i r0, r1, r2, r3, r4, r5, r6, r7;
125 	__m128i s0, s1, s2, s3, s4, s5, s6, s7;
126 
127 	q0 = q[0];
128 	q1 = q[1];
129 	q2 = q[2];
130 	q3 = q[3];
131 	r0 = _mm_srli_epi64(q0, 16) | _mm_slli_epi64(q0, 48);
132 	r1 = _mm_srli_epi64(q1, 16) | _mm_slli_epi64(q1, 48);
133 	r2 = _mm_srli_epi64(q2, 16) | _mm_slli_epi64(q2, 48);
134 	r3 = _mm_srli_epi64(q3, 16) | _mm_slli_epi64(q3, 48);
135 
136 	q7 = _mm_shuffle_epi32(q3, 0x0e);
137 	q6 = _mm_shuffle_epi32(q2, 0x0e);
138 	q5 = _mm_shuffle_epi32(q1, 0x0e);
139 	q4 = _mm_shuffle_epi32(q0, 0x0e);
140 
141 	r7 = _mm_shuffle_epi32(r3, 0x0e);
142 	r6 = _mm_shuffle_epi32(r2, 0x0e);
143 	r5 = _mm_shuffle_epi32(r1, 0x0e);
144 	r4 = _mm_shuffle_epi32(r0, 0x0e);
145 
146 	s0 = q5 ^ q6 ^ q7 ^ r0 ^ r5 ^ r7 ^ rotr32(q0 ^ q5 ^ q6 ^ r0 ^ r5);
147 	s1 = q0 ^ q5 ^ r0 ^ r1 ^ r5 ^ r6 ^ r7 ^ rotr32(q1 ^ q5 ^ q7 ^ r1 ^ r5 ^ r6);
148 	s2 = q0 ^ q1 ^ q6 ^ r1 ^ r2 ^ r6 ^ r7 ^ rotr32(q0 ^ q2 ^ q6 ^ r2 ^ r6 ^ r7);
149 	s3 = q0 ^ q1 ^ q2 ^ q5 ^ q6 ^ r0 ^ r2 ^ r3 ^ r5 ^ rotr32(q0 ^ q1 ^ q3 ^ q5 ^ q6 ^ q7 ^ r0 ^ r3 ^ r5 ^ r7);
150 	s4 = q1 ^ q2 ^ q3 ^ q5 ^ r1 ^ r3 ^ r4 ^ r5 ^ r6 ^ r7 ^ rotr32(q1 ^ q2 ^ q4 ^ q5 ^ q7 ^ r1 ^ r4 ^ r5 ^ r6);
151 	s5 = q2 ^ q3 ^ q4 ^ q6 ^ r2 ^ r4 ^ r5 ^ r6 ^ r7 ^ rotr32(q2 ^ q3 ^ q5 ^ q6 ^ r2 ^ r5 ^ r6 ^ r7);
152 	s6 = q3 ^ q4 ^ q5 ^ q7 ^ r3 ^ r5 ^ r6 ^ r7 ^ rotr32(q3 ^ q4 ^ q6 ^ q7 ^ r3 ^ r6 ^ r7);
153 	s7 = q4 ^ q5 ^ q6 ^ r4 ^ r6 ^ r7 ^ rotr32(q4 ^ q5 ^ q7 ^ r4 ^ r7);
154 
155 	q[0] = _mm_unpacklo_epi64(s0, s4);
156 	q[1] = _mm_unpacklo_epi64(s1, s5);
157 	q[2] = _mm_unpacklo_epi64(s2, s6);
158 	q[3] = _mm_unpacklo_epi64(s3, s7);
159 }
160 
161 /* see inner.h */
162 void
aes_sse2_bitslice_decrypt(unsigned num_rounds,const uint64_t * skey,__m128i q[static4])163 aes_sse2_bitslice_decrypt(unsigned num_rounds,
164 	const uint64_t *skey, __m128i q[static 4])
165 {
166 	unsigned u;
167 
168 	add_round_key(q, skey + (num_rounds << 3));
169 	for (u = num_rounds - 1; u > 0; u --) {
170 		inv_shift_rows(q);
171 		aes_sse2_bitslice_invSbox(q);
172 		add_round_key(q, skey + (u << 3));
173 		inv_mix_columns(q);
174 	}
175 	inv_shift_rows(q);
176 	aes_sse2_bitslice_invSbox(q);
177 	add_round_key(q, skey);
178 }
179