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
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
|
/*
* 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.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
/** @file
*
* SHA-1 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/sha1.h>
/** SHA-1 variables */
struct sha1_variables {
/* This layout matches that of struct sha1_digest_data,
* allowing for efficient endianness-conversion,
*/
uint32_t a;
uint32_t b;
uint32_t c;
uint32_t d;
uint32_t e;
uint32_t w[80];
} __attribute__ (( packed ));
/**
* f(a,b,c,d) for steps 0 to 19
*
* @v v SHA-1 variables
* @ret f f(a,b,c,d)
*/
static uint32_t sha1_f_0_19 ( struct sha1_variables *v ) {
return ( ( v->b & v->c ) | ( (~v->b) & v->d ) );
}
/**
* f(a,b,c,d) for steps 20 to 39 and 60 to 79
*
* @v v SHA-1 variables
* @ret f f(a,b,c,d)
*/
static uint32_t sha1_f_20_39_60_79 ( struct sha1_variables *v ) {
return ( v->b ^ v->c ^ v->d );
}
/**
* f(a,b,c,d) for steps 40 to 59
*
* @v v SHA-1 variables
* @ret f f(a,b,c,d)
*/
static uint32_t sha1_f_40_59 ( struct sha1_variables *v ) {
return ( ( v->b & v->c ) | ( v->b & v->d ) | ( v->c & v->d ) );
}
/** An SHA-1 step function */
struct sha1_step {
/**
* Calculate f(a,b,c,d)
*
* @v v SHA-1 variables
* @ret f f(a,b,c,d)
*/
uint32_t ( * f ) ( struct sha1_variables *v );
/** Constant k */
uint32_t k;
};
/** SHA-1 steps */
static struct sha1_step sha1_steps[4] = {
/** 0 to 19 */
{ .f = sha1_f_0_19, .k = 0x5a827999 },
/** 20 to 39 */
{ .f = sha1_f_20_39_60_79, .k = 0x6ed9eba1 },
/** 40 to 59 */
{ .f = sha1_f_40_59, .k = 0x8f1bbcdc },
/** 60 to 79 */
{ .f = sha1_f_20_39_60_79, .k = 0xca62c1d6 },
};
/**
* Initialise SHA-1 algorithm
*
* @v ctx SHA-1 context
*/
static void sha1_init ( void *ctx ) {
struct sha1_context *context = ctx;
context->ddd.dd.digest.h[0] = cpu_to_be32 ( 0x67452301 );
context->ddd.dd.digest.h[1] = cpu_to_be32 ( 0xefcdab89 );
context->ddd.dd.digest.h[2] = cpu_to_be32 ( 0x98badcfe );
context->ddd.dd.digest.h[3] = cpu_to_be32 ( 0x10325476 );
context->ddd.dd.digest.h[4] = cpu_to_be32 ( 0xc3d2e1f0 );
context->len = 0;
}
/**
* Calculate SHA-1 digest of accumulated data
*
* @v context SHA-1 context
*/
static void sha1_digest ( struct sha1_context *context ) {
union {
union sha1_digest_data_dwords ddd;
struct sha1_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 *w = u.v.w;
uint32_t f;
uint32_t k;
uint32_t temp;
struct sha1_step *step;
unsigned int i;
/* Sanity checks */
assert ( ( context->len % sizeof ( context->ddd.dd.data ) ) == 0 );
linker_assert ( &u.ddd.dd.digest.h[0] == a, sha1_bad_layout );
linker_assert ( &u.ddd.dd.digest.h[1] == b, sha1_bad_layout );
linker_assert ( &u.ddd.dd.digest.h[2] == c, sha1_bad_layout );
linker_assert ( &u.ddd.dd.digest.h[3] == d, sha1_bad_layout );
linker_assert ( &u.ddd.dd.digest.h[4] == e, sha1_bad_layout );
linker_assert ( &u.ddd.dd.data.dword[0] == w, sha1_bad_layout );
DBGC ( context, "SHA1 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..4] to host-endian, and initialise a, b, c, d,
* e, 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..79] */
for ( i = 16 ; i < 80 ; i++ )
w[i] = rol32 ( ( w[i-3] ^ w[i-8] ^ w[i-14] ^ w[i-16] ), 1 );
/* Main loop */
for ( i = 0 ; i < 80 ; i++ ) {
step = &sha1_steps[ i / 20 ];
f = step->f ( &u.v );
k = step->k;
temp = ( rol32 ( *a, 5 ) + f + *e + k + w[i] );
*e = *d;
*d = *c;
*c = rol32 ( *b, 30 );
*b = *a;
*a = temp;
DBGC2 ( context, "%2d : %08x %08x %08x %08x %08x\n",
i, *a, *b, *c, *d, *e );
}
/* Add chunk to hash and convert back to big-endian */
for ( i = 0 ; i < 5 ; i++ ) {
context->ddd.dd.digest.h[i] =
cpu_to_be32 ( context->ddd.dd.digest.h[i] +
u.ddd.dd.digest.h[i] );
}
DBGC ( context, "SHA1 digested:\n" );
DBGC_HDA ( context, 0, &context->ddd.dd.digest,
sizeof ( context->ddd.dd.digest ) );
}
/**
* Accumulate data with SHA-1 algorithm
*
* @v ctx SHA-1 context
* @v data Data
* @v len Length of data
*/
static void sha1_update ( void *ctx, const void *data, size_t len ) {
struct sha1_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 )
sha1_digest ( context );
}
}
/**
* Generate SHA-1 digest
*
* @v ctx SHA-1 context
* @v out Output buffer
*/
static void sha1_final ( void *ctx, void *out ) {
struct sha1_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 {
sha1_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) */
sha1_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-1 algorithm */
struct digest_algorithm sha1_algorithm = {
.name = "sha1",
.ctxsize = sizeof ( struct sha1_context ),
.blocksize = sizeof ( union sha1_block ),
.digestsize = sizeof ( struct sha1_digest ),
.init = sha1_init,
.update = sha1_update,
.final = sha1_final,
};
/** "sha1" object identifier */
static uint8_t oid_sha1[] = { ASN1_OID_SHA1 };
/** "sha1" OID-identified algorithm */
struct asn1_algorithm oid_sha1_algorithm __asn1_algorithm = {
.name = "sha1",
.digest = &sha1_algorithm,
.oid = ASN1_OID_CURSOR ( oid_sha1 ),
};
|
