forked from ElementsProject/elements
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathpoly1305.cpp
141 lines (115 loc) · 4.59 KB
/
poly1305.cpp
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
// Copyright (c) 2019 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
// Based on the public domain implementation by Andrew Moon
// poly1305-donna-unrolled.c from https://github.com/floodyberry/poly1305-donna
#include <crypto/common.h>
#include <crypto/poly1305.h>
#include <string.h>
#define mul32x32_64(a,b) ((uint64_t)(a) * (b))
void poly1305_auth(unsigned char out[POLY1305_TAGLEN], const unsigned char *m, size_t inlen, const unsigned char key[POLY1305_KEYLEN]) {
uint32_t t0,t1,t2,t3;
uint32_t h0,h1,h2,h3,h4;
uint32_t r0,r1,r2,r3,r4;
uint32_t s1,s2,s3,s4;
uint32_t b, nb;
size_t j;
uint64_t t[5];
uint64_t f0,f1,f2,f3;
uint64_t g0,g1,g2,g3,g4;
uint64_t c;
unsigned char mp[16];
/* clamp key */
t0 = ReadLE32(key+0);
t1 = ReadLE32(key+4);
t2 = ReadLE32(key+8);
t3 = ReadLE32(key+12);
/* precompute multipliers */
r0 = t0 & 0x3ffffff; t0 >>= 26; t0 |= t1 << 6;
r1 = t0 & 0x3ffff03; t1 >>= 20; t1 |= t2 << 12;
r2 = t1 & 0x3ffc0ff; t2 >>= 14; t2 |= t3 << 18;
r3 = t2 & 0x3f03fff; t3 >>= 8;
r4 = t3 & 0x00fffff;
s1 = r1 * 5;
s2 = r2 * 5;
s3 = r3 * 5;
s4 = r4 * 5;
/* init state */
h0 = 0;
h1 = 0;
h2 = 0;
h3 = 0;
h4 = 0;
/* full blocks */
if (inlen < 16) goto poly1305_donna_atmost15bytes;
poly1305_donna_16bytes:
m += 16;
inlen -= 16;
t0 = ReadLE32(m-16);
t1 = ReadLE32(m-12);
t2 = ReadLE32(m-8);
t3 = ReadLE32(m-4);
h0 += t0 & 0x3ffffff;
h1 += ((((uint64_t)t1 << 32) | t0) >> 26) & 0x3ffffff;
h2 += ((((uint64_t)t2 << 32) | t1) >> 20) & 0x3ffffff;
h3 += ((((uint64_t)t3 << 32) | t2) >> 14) & 0x3ffffff;
h4 += (t3 >> 8) | (1 << 24);
poly1305_donna_mul:
t[0] = mul32x32_64(h0,r0) + mul32x32_64(h1,s4) + mul32x32_64(h2,s3) + mul32x32_64(h3,s2) + mul32x32_64(h4,s1);
t[1] = mul32x32_64(h0,r1) + mul32x32_64(h1,r0) + mul32x32_64(h2,s4) + mul32x32_64(h3,s3) + mul32x32_64(h4,s2);
t[2] = mul32x32_64(h0,r2) + mul32x32_64(h1,r1) + mul32x32_64(h2,r0) + mul32x32_64(h3,s4) + mul32x32_64(h4,s3);
t[3] = mul32x32_64(h0,r3) + mul32x32_64(h1,r2) + mul32x32_64(h2,r1) + mul32x32_64(h3,r0) + mul32x32_64(h4,s4);
t[4] = mul32x32_64(h0,r4) + mul32x32_64(h1,r3) + mul32x32_64(h2,r2) + mul32x32_64(h3,r1) + mul32x32_64(h4,r0);
h0 = (uint32_t)t[0] & 0x3ffffff; c = (t[0] >> 26);
t[1] += c; h1 = (uint32_t)t[1] & 0x3ffffff; b = (uint32_t)(t[1] >> 26);
t[2] += b; h2 = (uint32_t)t[2] & 0x3ffffff; b = (uint32_t)(t[2] >> 26);
t[3] += b; h3 = (uint32_t)t[3] & 0x3ffffff; b = (uint32_t)(t[3] >> 26);
t[4] += b; h4 = (uint32_t)t[4] & 0x3ffffff; b = (uint32_t)(t[4] >> 26);
h0 += b * 5;
if (inlen >= 16) goto poly1305_donna_16bytes;
/* final bytes */
poly1305_donna_atmost15bytes:
if (!inlen) goto poly1305_donna_finish;
for (j = 0; j < inlen; j++) mp[j] = m[j];
mp[j++] = 1;
for (; j < 16; j++) mp[j] = 0;
inlen = 0;
t0 = ReadLE32(mp+0);
t1 = ReadLE32(mp+4);
t2 = ReadLE32(mp+8);
t3 = ReadLE32(mp+12);
h0 += t0 & 0x3ffffff;
h1 += ((((uint64_t)t1 << 32) | t0) >> 26) & 0x3ffffff;
h2 += ((((uint64_t)t2 << 32) | t1) >> 20) & 0x3ffffff;
h3 += ((((uint64_t)t3 << 32) | t2) >> 14) & 0x3ffffff;
h4 += (t3 >> 8);
goto poly1305_donna_mul;
poly1305_donna_finish:
b = h0 >> 26; h0 = h0 & 0x3ffffff;
h1 += b; b = h1 >> 26; h1 = h1 & 0x3ffffff;
h2 += b; b = h2 >> 26; h2 = h2 & 0x3ffffff;
h3 += b; b = h3 >> 26; h3 = h3 & 0x3ffffff;
h4 += b; b = h4 >> 26; h4 = h4 & 0x3ffffff;
h0 += b * 5; b = h0 >> 26; h0 = h0 & 0x3ffffff;
h1 += b;
g0 = h0 + 5; b = g0 >> 26; g0 &= 0x3ffffff;
g1 = h1 + b; b = g1 >> 26; g1 &= 0x3ffffff;
g2 = h2 + b; b = g2 >> 26; g2 &= 0x3ffffff;
g3 = h3 + b; b = g3 >> 26; g3 &= 0x3ffffff;
g4 = h4 + b - (1 << 26);
b = (g4 >> 31) - 1;
nb = ~b;
h0 = (h0 & nb) | (g0 & b);
h1 = (h1 & nb) | (g1 & b);
h2 = (h2 & nb) | (g2 & b);
h3 = (h3 & nb) | (g3 & b);
h4 = (h4 & nb) | (g4 & b);
f0 = ((h0 ) | (h1 << 26)) + (uint64_t)ReadLE32(&key[16]);
f1 = ((h1 >> 6) | (h2 << 20)) + (uint64_t)ReadLE32(&key[20]);
f2 = ((h2 >> 12) | (h3 << 14)) + (uint64_t)ReadLE32(&key[24]);
f3 = ((h3 >> 18) | (h4 << 8)) + (uint64_t)ReadLE32(&key[28]);
WriteLE32(&out[ 0], f0); f1 += (f0 >> 32);
WriteLE32(&out[ 4], f1); f2 += (f1 >> 32);
WriteLE32(&out[ 8], f2); f3 += (f2 >> 32);
WriteLE32(&out[12], f3);
}