[pci] Add support for PCI MSI-X interrupts
[ipxe.git] / src / crypto / rbg.c
1 /*
2 * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17 * 02110-1301, USA.
18 *
19 * You can also choose to distribute this program under the terms of
20 * the Unmodified Binary Distribution Licence (as given in the file
21 * COPYING.UBDL), provided that you have satisfied its requirements.
22 *
23 * Alternatively, you may distribute this code in source or binary
24 * form, with or without modification, provided that the following
25 * conditions are met:
26 *
27 * 1. Redistributions of source code must retain the above copyright
28 * notice, this list of conditions and the above disclaimer.
29 *
30 * 2. Redistributions in binary form must reproduce the above
31 * copyright notice, this list of conditions and the above
32 * disclaimer in the documentation and/or other materials provided
33 * with the distribution.
34 */
35
36 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
37
38 /** @file
39 *
40 * RBG mechanism
41 *
42 * This mechanism is designed to comply with ANS X9.82 Part 4 (April
43 * 2011 Draft) Section 10. This standard is unfortunately not freely
44 * available.
45 *
46 * The chosen RBG design is that of a DRBG with a live entropy source
47 * with no conditioning function. Only a single security strength is
48 * supported. No seedfile is used since there may be no non-volatile
49 * storage available. The system UUID is used as the personalisation
50 * string.
51 */
52
53 #include <stdint.h>
54 #include <string.h>
55 #include <ipxe/init.h>
56 #include <ipxe/settings.h>
57 #include <ipxe/uuid.h>
58 #include <ipxe/crypto.h>
59 #include <ipxe/drbg.h>
60 #include <ipxe/rbg.h>
61
62 /** The RBG */
63 struct random_bit_generator rbg;
64
65 /**
66 * Start up RBG
67 *
68 * @ret rc Return status code
69 *
70 * This is the RBG_Startup function defined in ANS X9.82 Part 4 (April
71 * 2011 Draft) Section 9.1.2.2.
72 */
73 static int rbg_startup ( void ) {
74 union uuid uuid;
75 int len;
76 int rc;
77
78 /* Try to obtain system UUID for use as personalisation
79 * string, in accordance with ANS X9.82 Part 3-2007 Section
80 * 8.5.2. If no UUID is available, proceed without a
81 * personalisation string.
82 */
83 if ( ( len = fetch_uuid_setting ( NULL, &uuid_setting, &uuid ) ) < 0 ) {
84 rc = len;
85 DBGC ( &rbg, "RBG could not fetch personalisation string: "
86 "%s\n", strerror ( rc ) );
87 len = 0;
88 }
89
90 /* Instantiate DRBG */
91 if ( ( rc = drbg_instantiate ( &rbg.state, &uuid, len ) ) != 0 ) {
92 DBGC ( &rbg, "RBG could not instantiate DRBG: %s\n",
93 strerror ( rc ) );
94 return rc;
95 }
96
97 return 0;
98 }
99
100 /**
101 * Shut down RBG
102 *
103 */
104 static void rbg_shutdown ( void ) {
105
106 /* Uninstantiate DRBG */
107 drbg_uninstantiate ( &rbg.state );
108 }
109
110 /** RBG startup function */
111 static void rbg_startup_fn ( void ) {
112
113 /* Start up RBG. There is no way to report an error at this
114 * stage, but a failed startup will result in an invalid DRBG
115 * that refuses to generate bits.
116 */
117 rbg_startup();
118 }
119
120 /** RBG shutdown function */
121 static void rbg_shutdown_fn ( int booting __unused ) {
122
123 /* Shut down RBG */
124 rbg_shutdown();
125 }
126
127 /** RBG startup table entry */
128 struct startup_fn startup_rbg __startup_fn ( STARTUP_NORMAL ) = {
129 .name = "rbg",
130 .startup = rbg_startup_fn,
131 .shutdown = rbg_shutdown_fn,
132 };