1 /*
2 * Copyright 2013-2016 The OpenSSL Project Authors. All Rights Reserved.
3 * Copyright (c) 2012, Intel Corporation. All Rights Reserved.
4 *
5 * Licensed under the OpenSSL license (the "License"). You may not use
6 * this file except in compliance with the License. You can obtain a copy
7 * in the file LICENSE in the source distribution or at
8 * https://www.openssl.org/source/license.html
9 *
10 * Originally written by Shay Gueron (1, 2), and Vlad Krasnov (1)
11 * (1) Intel Corporation, Israel Development Center, Haifa, Israel
12 * (2) University of Haifa, Israel
13 */
14
15 #include "rsaz_exp.h"
16
17 #if defined(RSAZ_ENABLED)
18
19 #include <openssl/mem.h>
20
21 #include <assert.h>
22
23 #include "internal.h"
24 #include "../../internal.h"
25
26
27 // rsaz_one is 1 in RSAZ's representation.
28 alignas(64) static const BN_ULONG rsaz_one[40] = {
29 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
30 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
31 // rsaz_two80 is 2^80 in RSAZ's representation. Note RSAZ uses base 2^29, so this is
32 // 2^(29*2 + 22) = 2^80, not 2^(64*2 + 22).
33 alignas(64) static const BN_ULONG rsaz_two80[40] = {
34 0, 0, 1 << 22, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
35 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
36
RSAZ_1024_mod_exp_avx2(BN_ULONG result_norm[16],const BN_ULONG base_norm[16],const BN_ULONG exponent[16],const BN_ULONG m_norm[16],const BN_ULONG RR[16],BN_ULONG k0,BN_ULONG storage[MOD_EXP_CTIME_STORAGE_LEN])37 void RSAZ_1024_mod_exp_avx2(BN_ULONG result_norm[16],
38 const BN_ULONG base_norm[16],
39 const BN_ULONG exponent[16],
40 const BN_ULONG m_norm[16], const BN_ULONG RR[16],
41 BN_ULONG k0,
42 BN_ULONG storage[MOD_EXP_CTIME_STORAGE_LEN]) {
43 static_assert(MOD_EXP_CTIME_ALIGN % 64 == 0,
44 "MOD_EXP_CTIME_ALIGN is too small");
45 assert((uintptr_t)storage % 64 == 0);
46
47 BN_ULONG *a_inv, *m, *result, *table_s = storage + 40 * 3, *R2 = table_s;
48 // Note |R2| aliases |table_s|.
49 if (((((uintptr_t)storage & 4095) + 320) >> 12) != 0) {
50 result = storage;
51 a_inv = storage + 40;
52 m = storage + 40 * 2; // should not cross page
53 } else {
54 m = storage; // should not cross page
55 result = storage + 40;
56 a_inv = storage + 40 * 2;
57 }
58
59 rsaz_1024_norm2red_avx2(m, m_norm);
60 rsaz_1024_norm2red_avx2(a_inv, base_norm);
61 rsaz_1024_norm2red_avx2(R2, RR);
62
63 // Convert |R2| from the usual radix, giving R = 2^1024, to RSAZ's radix,
64 // giving R = 2^(36*29) = 2^1044.
65 rsaz_1024_mul_avx2(R2, R2, R2, m, k0);
66 // R2 = 2^2048 * 2^2048 / 2^1044 = 2^3052
67 rsaz_1024_mul_avx2(R2, R2, rsaz_two80, m, k0);
68 // R2 = 2^3052 * 2^80 / 2^1044 = 2^2088 = (2^1044)^2
69
70 // table[0] = 1
71 // table[1] = a_inv^1
72 rsaz_1024_mul_avx2(result, R2, rsaz_one, m, k0);
73 rsaz_1024_mul_avx2(a_inv, a_inv, R2, m, k0);
74 rsaz_1024_scatter5_avx2(table_s, result, 0);
75 rsaz_1024_scatter5_avx2(table_s, a_inv, 1);
76 // table[2] = a_inv^2
77 rsaz_1024_sqr_avx2(result, a_inv, m, k0, 1);
78 rsaz_1024_scatter5_avx2(table_s, result, 2);
79 // table[4] = a_inv^4
80 rsaz_1024_sqr_avx2(result, result, m, k0, 1);
81 rsaz_1024_scatter5_avx2(table_s, result, 4);
82 // table[8] = a_inv^8
83 rsaz_1024_sqr_avx2(result, result, m, k0, 1);
84 rsaz_1024_scatter5_avx2(table_s, result, 8);
85 // table[16] = a_inv^16
86 rsaz_1024_sqr_avx2(result, result, m, k0, 1);
87 rsaz_1024_scatter5_avx2(table_s, result, 16);
88 for (int i = 3; i < 32; i += 2) {
89 // table[i] = table[i-1] * a_inv = a_inv^i
90 rsaz_1024_gather5_avx2(result, table_s, i - 1);
91 rsaz_1024_mul_avx2(result, result, a_inv, m, k0);
92 rsaz_1024_scatter5_avx2(table_s, result, i);
93 for (int j = 2 * i; j < 32; j *= 2) {
94 // table[j] = table[j/2]^2 = a_inv^j
95 rsaz_1024_sqr_avx2(result, result, m, k0, 1);
96 rsaz_1024_scatter5_avx2(table_s, result, j);
97 }
98 }
99
100 // Load the first window.
101 const uint8_t *p_str = (const uint8_t *)exponent;
102 int wvalue = p_str[127] >> 3;
103 rsaz_1024_gather5_avx2(result, table_s, wvalue);
104
105 int index = 1014;
106 while (index > -1) { // Loop for the remaining 127 windows.
107 rsaz_1024_sqr_avx2(result, result, m, k0, 5);
108
109 uint16_t wvalue_16;
110 memcpy(&wvalue_16, &p_str[index / 8], sizeof(wvalue_16));
111 wvalue = wvalue_16;
112 wvalue = (wvalue >> (index % 8)) & 31;
113 index -= 5;
114
115 rsaz_1024_gather5_avx2(a_inv, table_s, wvalue); // Borrow |a_inv|.
116 rsaz_1024_mul_avx2(result, result, a_inv, m, k0);
117 }
118
119 // Square four times.
120 rsaz_1024_sqr_avx2(result, result, m, k0, 4);
121
122 wvalue = p_str[0] & 15;
123
124 rsaz_1024_gather5_avx2(a_inv, table_s, wvalue); // Borrow |a_inv|.
125 rsaz_1024_mul_avx2(result, result, a_inv, m, k0);
126
127 // Convert from Montgomery.
128 rsaz_1024_mul_avx2(result, result, rsaz_one, m, k0);
129
130 rsaz_1024_red2norm_avx2(result_norm, result);
131 BN_ULONG scratch[16];
132 bn_reduce_once_in_place(result_norm, /*carry=*/0, m_norm, scratch, 16);
133
134 OPENSSL_cleanse(storage, MOD_EXP_CTIME_STORAGE_LEN * sizeof(BN_ULONG));
135 }
136
137 #endif // RSAZ_ENABLED
138