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
|
/*
* Copyright (C) 2017 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
*
* MD4 algorithm
*
*/
#include <stdint.h>
#include <string.h>
#include <byteswap.h>
#include <assert.h>
#include <ipxe/rotate.h>
#include <ipxe/crypto.h>
#include <ipxe/md4.h>
/** MD4 variables */
struct md4_variables {
/* This layout matches that of struct md4_digest_data,
* allowing for efficient endianness-conversion,
*/
uint32_t a;
uint32_t b;
uint32_t c;
uint32_t d;
uint32_t w[16];
} __attribute__ (( packed ));
/** MD4 shift amounts */
static const uint8_t r[3][4] = {
{ 3, 7, 11, 19 },
{ 3, 5, 9, 13 },
{ 3, 9, 11, 15 },
};
/**
* f(b,c,d,w) for steps 0 to 15
*
* @v v MD4 variables
* @v i Index within round
* @ret f f(b,c,d,w)
*/
static uint32_t md4_f_0_15 ( struct md4_variables *v, unsigned int i ) {
return ( ( ( v->b & v->c ) | ( ~v->b & v->d ) ) + v->w[i] );
}
/**
* f(b,c,d,w) for steps 16 to 31
*
* @v v MD4 variables
* @v i Index within round
* @ret f f(b,c,d,w)
*/
static uint32_t md4_f_16_31 ( struct md4_variables *v, unsigned int i ) {
return ( ( ( v->b & v->c ) | ( v->b & v->d ) | ( v->c & v->d ) ) +
v->w[ ( ( i << 2 ) | ( i >> 2 ) ) % 16 ] );
}
/**
* f(b,c,d,w) for steps 32 to 47
*
* @v v MD4 variables
* @v i Index within round
* @ret f f(b,c,d,w)
*/
static uint32_t md4_f_32_47 ( struct md4_variables *v, unsigned int i ) {
static const uint8_t reverse[16] = {
0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15
};
return ( ( v->b ^ v->c ^ v->d ) + v->w[reverse[i]] );
}
/** An MD4 step function */
struct md4_step {
/**
* Calculate f(b,c,d,w)
*
* @v v MD4 variables
* @v i Index within round
* @ret f f(b,c,d,w)
*/
uint32_t ( * f ) ( struct md4_variables *v, unsigned int i );
/** Constant */
uint32_t constant;
};
/** MD4 steps */
static struct md4_step md4_steps[4] = {
/** 0 to 15 */
{ .f = md4_f_0_15, .constant = 0x00000000UL },
/** 16 to 31 */
{ .f = md4_f_16_31, .constant = 0x5a827999UL },
/** 32 to 47 */
{ .f = md4_f_32_47, .constant = 0x6ed9eba1UL },
};
/**
* Initialise MD4 algorithm
*
* @v ctx MD4 context
*/
static void md4_init ( void *ctx ) {
struct md4_context *context = ctx;
context->ddd.dd.digest.h[0] = cpu_to_le32 ( 0x67452301 );
context->ddd.dd.digest.h[1] = cpu_to_le32 ( 0xefcdab89 );
context->ddd.dd.digest.h[2] = cpu_to_le32 ( 0x98badcfe );
context->ddd.dd.digest.h[3] = cpu_to_le32 ( 0x10325476 );
context->len = 0;
}
/**
* Calculate MD4 digest of accumulated data
*
* @v context MD4 context
*/
static void md4_digest ( struct md4_context *context ) {
union {
union md4_digest_data_dwords ddd;
struct md4_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 *w = u.v.w;
uint32_t f;
uint32_t temp;
struct md4_step *step;
unsigned int round;
unsigned int i;
/* Sanity checks */
assert ( ( context->len % sizeof ( context->ddd.dd.data ) ) == 0 );
linker_assert ( &u.ddd.dd.digest.h[0] == a, md4_bad_layout );
linker_assert ( &u.ddd.dd.digest.h[1] == b, md4_bad_layout );
linker_assert ( &u.ddd.dd.digest.h[2] == c, md4_bad_layout );
linker_assert ( &u.ddd.dd.digest.h[3] == d, md4_bad_layout );
linker_assert ( &u.ddd.dd.data.dword[0] == w, md4_bad_layout );
DBGC ( context, "MD4 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..3] to host-endian, and initialise a, b, c, d,
* and x[0..15]
*/
for ( i = 0 ; i < ( sizeof ( u.ddd.dword ) /
sizeof ( u.ddd.dword[0] ) ) ; i++ ) {
le32_to_cpus ( &context->ddd.dword[i] );
u.ddd.dword[i] = context->ddd.dword[i];
}
/* Main loop */
for ( i = 0 ; i < 48 ; i++ ) {
round = ( i / 16 );
step = &md4_steps[round];
f = step->f ( &u.v, ( i % 16 ) );
temp = *d;
*d = *c;
*c = *b;
*b = rol32 ( ( *a + f + step->constant ), r[round][ i % 4 ] );
*a = temp;
DBGC2 ( context, "%2d : %08x %08x %08x %08x\n",
i, *a, *b, *c, *d );
}
/* Add chunk to hash and convert back to little-endian */
for ( i = 0 ; i < 4 ; i++ ) {
context->ddd.dd.digest.h[i] =
cpu_to_le32 ( context->ddd.dd.digest.h[i] +
u.ddd.dd.digest.h[i] );
}
DBGC ( context, "MD4 digested:\n" );
DBGC_HDA ( context, 0, &context->ddd.dd.digest,
sizeof ( context->ddd.dd.digest ) );
}
/**
* Accumulate data with MD4 algorithm
*
* @v ctx MD4 context
* @v data Data
* @v len Length of data
*/
static void md4_update ( void *ctx, const void *data, size_t len ) {
struct md4_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 )
md4_digest ( context );
}
}
/**
* Generate MD4 digest
*
* @v ctx MD4 context
* @v out Output buffer
*/
static void md4_final ( void *ctx, void *out ) {
struct md4_context *context = ctx;
uint64_t len_bits;
uint8_t pad;
/* Record length before pre-processing */
len_bits = cpu_to_le64 ( ( ( uint64_t ) context->len ) * 8 );
/* Pad with a single "1" bit followed by as many "0" bits as required */
pad = 0x80;
do {
md4_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) */
md4_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 ) );
}
/** MD4 algorithm */
struct digest_algorithm md4_algorithm = {
.name = "md4",
.ctxsize = sizeof ( struct md4_context ),
.blocksize = sizeof ( union md4_block ),
.digestsize = sizeof ( struct md4_digest ),
.init = md4_init,
.update = md4_update,
.final = md4_final,
};
|
