1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
|
// SPDX-License-Identifier: GPL-2.0 OR MIT
/*
* Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*
* This is based in part on Andrew Moon's poly1305-donna, which is in the
* public domain.
*/
#include <linux/kernel.h>
#include <linux/unaligned.h>
#include <crypto/internal/poly1305.h>
void poly1305_core_setkey(struct poly1305_core_key *key,
const u8 raw_key[POLY1305_BLOCK_SIZE])
{
/* r &= 0xffffffc0ffffffc0ffffffc0fffffff */
key->key.r[0] = (get_unaligned_le32(&raw_key[0])) & 0x3ffffff;
key->key.r[1] = (get_unaligned_le32(&raw_key[3]) >> 2) & 0x3ffff03;
key->key.r[2] = (get_unaligned_le32(&raw_key[6]) >> 4) & 0x3ffc0ff;
key->key.r[3] = (get_unaligned_le32(&raw_key[9]) >> 6) & 0x3f03fff;
key->key.r[4] = (get_unaligned_le32(&raw_key[12]) >> 8) & 0x00fffff;
/* s = 5*r */
key->precomputed_s.r[0] = key->key.r[1] * 5;
key->precomputed_s.r[1] = key->key.r[2] * 5;
key->precomputed_s.r[2] = key->key.r[3] * 5;
key->precomputed_s.r[3] = key->key.r[4] * 5;
}
EXPORT_SYMBOL(poly1305_core_setkey);
void poly1305_core_blocks(struct poly1305_state *state,
const struct poly1305_core_key *key, const void *src,
unsigned int nblocks, u32 hibit)
{
const u8 *input = src;
u32 r0, r1, r2, r3, r4;
u32 s1, s2, s3, s4;
u32 h0, h1, h2, h3, h4;
u64 d0, d1, d2, d3, d4;
u32 c;
if (!nblocks)
return;
hibit <<= 24;
r0 = key->key.r[0];
r1 = key->key.r[1];
r2 = key->key.r[2];
r3 = key->key.r[3];
r4 = key->key.r[4];
s1 = key->precomputed_s.r[0];
s2 = key->precomputed_s.r[1];
s3 = key->precomputed_s.r[2];
s4 = key->precomputed_s.r[3];
h0 = state->h[0];
h1 = state->h[1];
h2 = state->h[2];
h3 = state->h[3];
h4 = state->h[4];
do {
/* h += m[i] */
h0 += (get_unaligned_le32(&input[0])) & 0x3ffffff;
h1 += (get_unaligned_le32(&input[3]) >> 2) & 0x3ffffff;
h2 += (get_unaligned_le32(&input[6]) >> 4) & 0x3ffffff;
h3 += (get_unaligned_le32(&input[9]) >> 6) & 0x3ffffff;
h4 += (get_unaligned_le32(&input[12]) >> 8) | hibit;
/* h *= r */
d0 = ((u64)h0 * r0) + ((u64)h1 * s4) +
((u64)h2 * s3) + ((u64)h3 * s2) +
((u64)h4 * s1);
d1 = ((u64)h0 * r1) + ((u64)h1 * r0) +
((u64)h2 * s4) + ((u64)h3 * s3) +
((u64)h4 * s2);
d2 = ((u64)h0 * r2) + ((u64)h1 * r1) +
((u64)h2 * r0) + ((u64)h3 * s4) +
((u64)h4 * s3);
d3 = ((u64)h0 * r3) + ((u64)h1 * r2) +
((u64)h2 * r1) + ((u64)h3 * r0) +
((u64)h4 * s4);
d4 = ((u64)h0 * r4) + ((u64)h1 * r3) +
((u64)h2 * r2) + ((u64)h3 * r1) +
((u64)h4 * r0);
/* (partial) h %= p */
c = (u32)(d0 >> 26);
h0 = (u32)d0 & 0x3ffffff;
d1 += c;
c = (u32)(d1 >> 26);
h1 = (u32)d1 & 0x3ffffff;
d2 += c;
c = (u32)(d2 >> 26);
h2 = (u32)d2 & 0x3ffffff;
d3 += c;
c = (u32)(d3 >> 26);
h3 = (u32)d3 & 0x3ffffff;
d4 += c;
c = (u32)(d4 >> 26);
h4 = (u32)d4 & 0x3ffffff;
h0 += c * 5;
c = (h0 >> 26);
h0 = h0 & 0x3ffffff;
h1 += c;
input += POLY1305_BLOCK_SIZE;
} while (--nblocks);
state->h[0] = h0;
state->h[1] = h1;
state->h[2] = h2;
state->h[3] = h3;
state->h[4] = h4;
}
EXPORT_SYMBOL(poly1305_core_blocks);
void poly1305_core_emit(const struct poly1305_state *state, const u32 nonce[4],
void *dst)
{
u8 *mac = dst;
u32 h0, h1, h2, h3, h4, c;
u32 g0, g1, g2, g3, g4;
u64 f;
u32 mask;
/* fully carry h */
h0 = state->h[0];
h1 = state->h[1];
h2 = state->h[2];
h3 = state->h[3];
h4 = state->h[4];
c = h1 >> 26;
h1 = h1 & 0x3ffffff;
h2 += c;
c = h2 >> 26;
h2 = h2 & 0x3ffffff;
h3 += c;
c = h3 >> 26;
h3 = h3 & 0x3ffffff;
h4 += c;
c = h4 >> 26;
h4 = h4 & 0x3ffffff;
h0 += c * 5;
c = h0 >> 26;
h0 = h0 & 0x3ffffff;
h1 += c;
/* compute h + -p */
g0 = h0 + 5;
c = g0 >> 26;
g0 &= 0x3ffffff;
g1 = h1 + c;
c = g1 >> 26;
g1 &= 0x3ffffff;
g2 = h2 + c;
c = g2 >> 26;
g2 &= 0x3ffffff;
g3 = h3 + c;
c = g3 >> 26;
g3 &= 0x3ffffff;
g4 = h4 + c - (1UL << 26);
/* select h if h < p, or h + -p if h >= p */
mask = (g4 >> ((sizeof(u32) * 8) - 1)) - 1;
g0 &= mask;
g1 &= mask;
g2 &= mask;
g3 &= mask;
g4 &= mask;
mask = ~mask;
h0 = (h0 & mask) | g0;
h1 = (h1 & mask) | g1;
h2 = (h2 & mask) | g2;
h3 = (h3 & mask) | g3;
h4 = (h4 & mask) | g4;
/* h = h % (2^128) */
h0 = ((h0) | (h1 << 26)) & 0xffffffff;
h1 = ((h1 >> 6) | (h2 << 20)) & 0xffffffff;
h2 = ((h2 >> 12) | (h3 << 14)) & 0xffffffff;
h3 = ((h3 >> 18) | (h4 << 8)) & 0xffffffff;
if (likely(nonce)) {
/* mac = (h + nonce) % (2^128) */
f = (u64)h0 + nonce[0];
h0 = (u32)f;
f = (u64)h1 + nonce[1] + (f >> 32);
h1 = (u32)f;
f = (u64)h2 + nonce[2] + (f >> 32);
h2 = (u32)f;
f = (u64)h3 + nonce[3] + (f >> 32);
h3 = (u32)f;
}
put_unaligned_le32(h0, &mac[0]);
put_unaligned_le32(h1, &mac[4]);
put_unaligned_le32(h2, &mac[8]);
put_unaligned_le32(h3, &mac[12]);
}
EXPORT_SYMBOL(poly1305_core_emit);
|
