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
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
|
/*
* Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program 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 a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*/
FILE_LICENCE ( GPL2_OR_LATER );
/** @file
*
* SHA-256 algorithm
*
*/
#include <stdint.h>
#include <string.h>
#include <byteswap.h>
#include <assert.h>
#include <ipxe/rotate.h>
#include <ipxe/crypto.h>
#include <ipxe/asn1.h>
#include <ipxe/sha256.h>
/** SHA-256 variables */
struct sha256_variables {
/* This layout matches that of struct sha256_digest_data,
* allowing for efficient endianness-conversion,
*/
uint32_t a;
uint32_t b;
uint32_t c;
uint32_t d;
uint32_t e;
uint32_t f;
uint32_t g;
uint32_t h;
uint32_t w[64];
} __attribute__ (( packed ));
/** SHA-256 constants */
static const uint32_t k[64] = {
0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1,
0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786,
0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147,
0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b,
0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a,
0x5b9cca4f, 0x682e6ff3, 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
};
/**
* Initialise SHA-256 algorithm
*
* @v ctx SHA-256 context
*/
static void sha256_init ( void *ctx ) {
struct sha256_context *context = ctx;
context->ddd.dd.digest.h[0] = cpu_to_be32 ( 0x6a09e667 );
context->ddd.dd.digest.h[1] = cpu_to_be32 ( 0xbb67ae85 );
context->ddd.dd.digest.h[2] = cpu_to_be32 ( 0x3c6ef372 );
context->ddd.dd.digest.h[3] = cpu_to_be32 ( 0xa54ff53a );
context->ddd.dd.digest.h[4] = cpu_to_be32 ( 0x510e527f );
context->ddd.dd.digest.h[5] = cpu_to_be32 ( 0x9b05688c );
context->ddd.dd.digest.h[6] = cpu_to_be32 ( 0x1f83d9ab );
context->ddd.dd.digest.h[7] = cpu_to_be32 ( 0x5be0cd19 );
context->len = 0;
}
/**
* Calculate SHA-256 digest of accumulated data
*
* @v context SHA-256 context
*/
static void sha256_digest ( struct sha256_context *context ) {
union {
union sha256_digest_data_dwords ddd;
struct sha256_variables v;
} u;
uint32_t *a = &u.v.a;
uint32_t *b = &u.v.b;
uint32_t *c = &u.v.c;
uint32_t *d = &u.v.d;
uint32_t *e = &u.v.e;
uint32_t *f = &u.v.f;
uint32_t *g = &u.v.g;
uint32_t *h = &u.v.h;
uint32_t *w = u.v.w;
uint32_t s0;
uint32_t s1;
uint32_t maj;
uint32_t t1;
uint32_t t2;
uint32_t ch;
unsigned int i;
/* Sanity checks */
assert ( ( context->len % sizeof ( context->ddd.dd.data ) ) == 0 );
linker_assert ( &u.ddd.dd.digest.h[0] == a, sha256_bad_layout );
linker_assert ( &u.ddd.dd.digest.h[1] == b, sha256_bad_layout );
linker_assert ( &u.ddd.dd.digest.h[2] == c, sha256_bad_layout );
linker_assert ( &u.ddd.dd.digest.h[3] == d, sha256_bad_layout );
linker_assert ( &u.ddd.dd.digest.h[4] == e, sha256_bad_layout );
linker_assert ( &u.ddd.dd.digest.h[5] == f, sha256_bad_layout );
linker_assert ( &u.ddd.dd.digest.h[6] == g, sha256_bad_layout );
linker_assert ( &u.ddd.dd.digest.h[7] == h, sha256_bad_layout );
linker_assert ( &u.ddd.dd.data.dword[0] == w, sha256_bad_layout );
DBGC ( context, "SHA256 digesting:\n" );
DBGC_HDA ( context, 0, &context->ddd.dd.digest,
sizeof ( context->ddd.dd.digest ) );
DBGC_HDA ( context, context->len, &context->ddd.dd.data,
sizeof ( context->ddd.dd.data ) );
/* Convert h[0..7] to host-endian, and initialise a, b, c, d,
* e, f, g, h, and w[0..15]
*/
for ( i = 0 ; i < ( sizeof ( u.ddd.dword ) /
sizeof ( u.ddd.dword[0] ) ) ; i++ ) {
be32_to_cpus ( &context->ddd.dword[i] );
u.ddd.dword[i] = context->ddd.dword[i];
}
/* Initialise w[16..63] */
for ( i = 16 ; i < 64 ; i++ ) {
s0 = ( ror32 ( w[i-15], 7 ) ^ ror32 ( w[i-15], 18 ) ^
( w[i-15] >> 3 ) );
s1 = ( ror32 ( w[i-2], 17 ) ^ ror32 ( w[i-2], 19 ) ^
( w[i-2] >> 10 ) );
w[i] = ( w[i-16] + s0 + w[i-7] + s1 );
}
/* Main loop */
for ( i = 0 ; i < 64 ; i++ ) {
s0 = ( ror32 ( *a, 2 ) ^ ror32 ( *a, 13 ) ^ ror32 ( *a, 22 ) );
maj = ( ( *a & *b ) ^ ( *a & *c ) ^ ( *b & *c ) );
t2 = ( s0 + maj );
s1 = ( ror32 ( *e, 6 ) ^ ror32 ( *e, 11 ) ^ ror32 ( *e, 25 ) );
ch = ( ( *e & *f ) ^ ( (~*e) & *g ) );
t1 = ( *h + s1 + ch + k[i] + w[i] );
*h = *g;
*g = *f;
*f = *e;
*e = ( *d + t1 );
*d = *c;
*c = *b;
*b = *a;
*a = ( t1 + t2 );
DBGC2 ( context, "%2d : %08x %08x %08x %08x %08x %08x %08x "
"%08x\n", i, *a, *b, *c, *d, *e, *f, *g, *h );
}
/* Add chunk to hash and convert back to big-endian */
for ( i = 0 ; i < 8 ; i++ ) {
context->ddd.dd.digest.h[i] =
cpu_to_be32 ( context->ddd.dd.digest.h[i] +
u.ddd.dd.digest.h[i] );
}
DBGC ( context, "SHA256 digested:\n" );
DBGC_HDA ( context, 0, &context->ddd.dd.digest,
sizeof ( context->ddd.dd.digest ) );
}
/**
* Accumulate data with SHA-256 algorithm
*
* @v ctx SHA-256 context
* @v data Data
* @v len Length of data
*/
static void sha256_update ( void *ctx, const void *data, size_t len ) {
struct sha256_context *context = ctx;
const uint8_t *byte = data;
size_t offset;
/* Accumulate data a byte at a time, performing the digest
* whenever we fill the data buffer
*/
while ( len-- ) {
offset = ( context->len % sizeof ( context->ddd.dd.data ) );
context->ddd.dd.data.byte[offset] = *(byte++);
context->len++;
if ( ( context->len % sizeof ( context->ddd.dd.data ) ) == 0 )
sha256_digest ( context );
}
}
/**
* Generate SHA-256 digest
*
* @v ctx SHA-256 context
* @v out Output buffer
*/
static void sha256_final ( void *ctx, void *out ) {
struct sha256_context *context = ctx;
uint64_t len_bits;
uint8_t pad;
/* Record length before pre-processing */
len_bits = cpu_to_be64 ( ( ( uint64_t ) context->len ) * 8 );
/* Pad with a single "1" bit followed by as many "0" bits as required */
pad = 0x80;
do {
sha256_update ( ctx, &pad, sizeof ( pad ) );
pad = 0x00;
} while ( ( context->len % sizeof ( context->ddd.dd.data ) ) !=
offsetof ( typeof ( context->ddd.dd.data ), final.len ) );
/* Append length (in bits) */
sha256_update ( ctx, &len_bits, sizeof ( len_bits ) );
assert ( ( context->len % sizeof ( context->ddd.dd.data ) ) == 0 );
/* Copy out final digest */
memcpy ( out, &context->ddd.dd.digest,
sizeof ( context->ddd.dd.digest ) );
}
/** SHA-256 algorithm */
struct digest_algorithm sha256_algorithm = {
.name = "sha256",
.ctxsize = sizeof ( struct sha256_context ),
.blocksize = sizeof ( union sha256_block ),
.digestsize = sizeof ( struct sha256_digest ),
.init = sha256_init,
.update = sha256_update,
.final = sha256_final,
};
/** "sha256" object identifier */
static uint8_t oid_sha256[] = { ASN1_OID_SHA256 };
/** "sha256" OID-identified algorithm */
struct asn1_algorithm oid_sha256_algorithm __asn1_algorithm = {
.name = "sha256",
.digest = &sha256_algorithm,
.oid = ASN1_OID_CURSOR ( oid_sha256 ),
};
|
