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
|
/*
* 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.
*
* Alternatively, you may distribute this code in source or binary
* form, with or without modification, provided that the following
* conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the above disclaimer.
*
* 2. Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the above
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
/** @file
*
* RBG mechanism
*
* This mechanism is designed to comply with ANS X9.82 Part 4 (April
* 2011 Draft) Section 10. This standard is unfortunately not freely
* available.
*
* The chosen RBG design is that of a DRBG with a live entropy source
* with no conditioning function. Only a single security strength is
* supported. No seedfile is used since there may be no non-volatile
* storage available. The system UUID is used as the personalisation
* string.
*/
#include <stdint.h>
#include <string.h>
#include <ipxe/init.h>
#include <ipxe/settings.h>
#include <ipxe/uuid.h>
#include <ipxe/crypto.h>
#include <ipxe/drbg.h>
#include <ipxe/rbg.h>
/** The RBG */
struct random_bit_generator rbg;
/**
* Start up RBG
*
* @ret rc Return status code
*
* This is the RBG_Startup function defined in ANS X9.82 Part 4 (April
* 2011 Draft) Section 9.1.2.2.
*/
static int rbg_startup ( void ) {
union uuid uuid;
int len;
int rc;
/* Try to obtain system UUID for use as personalisation
* string, in accordance with ANS X9.82 Part 3-2007 Section
* 8.5.2. If no UUID is available, proceed without a
* personalisation string.
*/
if ( ( len = fetch_uuid_setting ( NULL, &uuid_setting, &uuid ) ) < 0 ) {
rc = len;
DBGC ( &rbg, "RBG could not fetch personalisation string: "
"%s\n", strerror ( rc ) );
len = 0;
}
/* Instantiate DRBG */
if ( ( rc = drbg_instantiate ( &rbg.state, &uuid, len ) ) != 0 ) {
DBGC ( &rbg, "RBG could not instantiate DRBG: %s\n",
strerror ( rc ) );
return rc;
}
return 0;
}
/**
* Shut down RBG
*
*/
static void rbg_shutdown ( void ) {
/* Uninstantiate DRBG */
drbg_uninstantiate ( &rbg.state );
}
/** RBG startup function */
static void rbg_startup_fn ( void ) {
/* Start up RBG. There is no way to report an error at this
* stage, but a failed startup will result in an invalid DRBG
* that refuses to generate bits.
*/
rbg_startup();
}
/** RBG shutdown function */
static void rbg_shutdown_fn ( int booting __unused ) {
/* Shut down RBG */
rbg_shutdown();
}
/** RBG startup table entry */
struct startup_fn startup_rbg __startup_fn ( STARTUP_NORMAL ) = {
.name = "rbg",
.startup = rbg_startup_fn,
.shutdown = rbg_shutdown_fn,
};
|
