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
206
|
/* sha256-compress-n.c
The compression function of the sha256 hash function.
Copyright (C) 2001, 2010, 2022 Niels Möller
This file is part of GNU Nettle.
GNU Nettle is free software: you can redistribute it and/or
modify it under the terms of either:
* the GNU Lesser General Public License as published by the Free
Software Foundation; either version 3 of the License, or (at your
option) any later version.
or
* the GNU General Public License as published by the Free
Software Foundation; either version 2 of the License, or (at your
option) any later version.
or both in parallel, as here.
GNU Nettle is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received copies of the GNU General Public License and
the GNU Lesser General Public License along with this program. If
not, see http://www.gnu.org/licenses/.
*/
#if HAVE_CONFIG_H
# include "config.h"
#endif
#ifndef SHA256_DEBUG
# define SHA256_DEBUG 0
#endif
#if SHA256_DEBUG
# include <stdio.h>
# define DEBUG(i) \
fprintf(stderr, "%2d: %8x %8x %8x %8x %8x %8x %8x %8x\n", \
i, A, B, C, D ,E, F, G, H)
#else
# define DEBUG(i)
#endif
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include "sha2.h"
#include "sha2-internal.h"
#include "macros.h"
/* A block, treated as a sequence of 32-bit words. */
#define SHA256_DATA_LENGTH 16
/* The SHA256 functions. The Choice function is the same as the SHA1
function f1, and the majority function is the same as the SHA1 f3
function. They can be optimized to save one boolean operation each
- thanks to Rich Schroeppel, rcs@cs.arizona.edu for discovering
this */
/* #define Choice(x,y,z) ( ( (x) & (y) ) | ( ~(x) & (z) ) ) */
#define Choice(x,y,z) ( (z) ^ ( (x) & ( (y) ^ (z) ) ) )
/* #define Majority(x,y,z) ( ((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)) ) */
#define Majority(x,y,z) ( ((x) & (y)) ^ ((z) & ((x) ^ (y))) )
#define S0(x) (ROTL32(30,(x)) ^ ROTL32(19,(x)) ^ ROTL32(10,(x)))
#define S1(x) (ROTL32(26,(x)) ^ ROTL32(21,(x)) ^ ROTL32(7,(x)))
#define s0(x) (ROTL32(25,(x)) ^ ROTL32(14,(x)) ^ ((x) >> 3))
#define s1(x) (ROTL32(15,(x)) ^ ROTL32(13,(x)) ^ ((x) >> 10))
/* The initial expanding function. The hash function is defined over an
64-word expanded input array W, where the first 16 are copies of the input
data, and the remaining 64 are defined by
W[ t ] = s1(W[t-2]) + W[t-7] + s0(W[i-15]) + W[i-16]
This implementation generates these values on the fly in a circular
buffer - thanks to Colin Plumb, colin@nyx10.cs.du.edu for this
optimization.
*/
#define EXPAND(W,i) \
( W[(i) & 15 ] += (s1(W[((i)-2) & 15]) + W[((i)-7) & 15] + s0(W[((i)-15) & 15])) )
/* The prototype SHA sub-round. The fundamental sub-round is:
T1 = h + S1(e) + Choice(e,f,g) + K[t] + W[t]
T2 = S0(a) + Majority(a,b,c)
a' = T1+T2
b' = a
c' = b
d' = c
e' = d + T1
f' = e
g' = f
h' = g
but this is implemented by unrolling the loop 8 times and renaming
the variables
( h, a, b, c, d, e, f, g ) = ( a, b, c, d, e, f, g, h ) each
iteration. */
/* It's crucial that DATA is only used once, as that argument will
* have side effects. */
#define ROUND(a,b,c,d,e,f,g,h,k,data) do { \
h += S1(e) + Choice(e,f,g) + k + data; \
d += h; \
h += S0(a) + Majority(a,b,c); \
} while (0)
/* For fat builds */
#if HAVE_NATIVE_sha256_compress_n
const uint8_t *
_nettle_sha256_compress_n_c(uint32_t *state, const uint32_t *table,
size_t blocks, const uint8_t *input);
#define _nettle_sha256_compress_n _nettle_sha256_compress_n_c
#endif
const uint8_t *
_nettle_sha256_compress_n(uint32_t *state, const uint32_t *table,
size_t blocks, const uint8_t *input)
{
uint32_t A, B, C, D, E, F, G, H; /* Local vars */
A = state[0];
B = state[1];
C = state[2];
D = state[3];
E = state[4];
F = state[5];
G = state[6];
H = state[7];
for (; blocks > 0; blocks--)
{
uint32_t data[SHA256_DATA_LENGTH];
unsigned i;
const uint32_t *k;
uint32_t *d;
for (i = 0; i < SHA256_DATA_LENGTH; i++, input+= 4)
{
data[i] = READ_UINT32(input);
}
/* Heavy mangling */
/* First 16 subrounds that act on the original data */
DEBUG(-1);
for (i = 0, d = data, k = table; i<16; i+=8, k += 8, d+= 8)
{
ROUND(A, B, C, D, E, F, G, H, k[0], d[0]); DEBUG(i);
ROUND(H, A, B, C, D, E, F, G, k[1], d[1]); DEBUG(i+1);
ROUND(G, H, A, B, C, D, E, F, k[2], d[2]);
ROUND(F, G, H, A, B, C, D, E, k[3], d[3]);
ROUND(E, F, G, H, A, B, C, D, k[4], d[4]);
ROUND(D, E, F, G, H, A, B, C, k[5], d[5]);
ROUND(C, D, E, F, G, H, A, B, k[6], d[6]); DEBUG(i+6);
ROUND(B, C, D, E, F, G, H, A, k[7], d[7]); DEBUG(i+7);
}
for (; i<64; i += 16, k+= 16)
{
ROUND(A, B, C, D, E, F, G, H, k[ 0], EXPAND(data, 0)); DEBUG(i);
ROUND(H, A, B, C, D, E, F, G, k[ 1], EXPAND(data, 1)); DEBUG(i+1);
ROUND(G, H, A, B, C, D, E, F, k[ 2], EXPAND(data, 2)); DEBUG(i+2);
ROUND(F, G, H, A, B, C, D, E, k[ 3], EXPAND(data, 3)); DEBUG(i+3);
ROUND(E, F, G, H, A, B, C, D, k[ 4], EXPAND(data, 4)); DEBUG(i+4);
ROUND(D, E, F, G, H, A, B, C, k[ 5], EXPAND(data, 5)); DEBUG(i+5);
ROUND(C, D, E, F, G, H, A, B, k[ 6], EXPAND(data, 6)); DEBUG(i+6);
ROUND(B, C, D, E, F, G, H, A, k[ 7], EXPAND(data, 7)); DEBUG(i+7);
ROUND(A, B, C, D, E, F, G, H, k[ 8], EXPAND(data, 8)); DEBUG(i+8);
ROUND(H, A, B, C, D, E, F, G, k[ 9], EXPAND(data, 9)); DEBUG(i+9);
ROUND(G, H, A, B, C, D, E, F, k[10], EXPAND(data, 10)); DEBUG(i+10);
ROUND(F, G, H, A, B, C, D, E, k[11], EXPAND(data, 11)); DEBUG(i+11);
ROUND(E, F, G, H, A, B, C, D, k[12], EXPAND(data, 12)); DEBUG(i+12);
ROUND(D, E, F, G, H, A, B, C, k[13], EXPAND(data, 13)); DEBUG(i+13);
ROUND(C, D, E, F, G, H, A, B, k[14], EXPAND(data, 14)); DEBUG(i+14);
ROUND(B, C, D, E, F, G, H, A, k[15], EXPAND(data, 15)); DEBUG(i+15);
}
/* Update state */
state[0] = A = state[0] + A;
state[1] = B = state[1] + B;
state[2] = C = state[2] + C;
state[3] = D = state[3] + D;
state[4] = E = state[4] + E;
state[5] = F = state[5] + F;
state[6] = G = state[6] + G;
state[7] = H = state[7] + H;
#if SHA256_DEBUG
fprintf(stderr, "99: %8x %8x %8x %8x %8x %8x %8x %8x\n",
state[0], state[1], state[2], state[3],
state[4], state[5], state[6], state[7]);
#endif
}
return input;
}
|
