[fdt] Add ability to parse a MAC address from a flattened device tree
[ipxe.git] / src / crypto / certstore.c
1 /*
2 * Copyright (C) 2014 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
24 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
25
26 #include <string.h>
27 #include <stdlib.h>
28 #include <ipxe/init.h>
29 #include <ipxe/dhcp.h>
30 #include <ipxe/settings.h>
31 #include <ipxe/malloc.h>
32 #include <ipxe/crypto.h>
33 #include <ipxe/asn1.h>
34 #include <ipxe/x509.h>
35 #include <ipxe/certstore.h>
36
37 /** @file
38 *
39 * Certificate store
40 *
41 */
42
43 /** Raw certificate data for all permanent stored certificates */
44 #undef CERT
45 #define CERT( _index, _path ) \
46 extern char stored_cert_ ## _index ## _data[]; \
47 extern char stored_cert_ ## _index ## _len[]; \
48 __asm__ ( ".section \".rodata\", \"a\", " PROGBITS "\n\t" \
49 "\nstored_cert_" #_index "_data:\n\t" \
50 ".incbin \"" _path "\"\n\t" \
51 "\nstored_cert_" #_index "_end:\n\t" \
52 ".equ stored_cert_" #_index "_len, " \
53 "( stored_cert_" #_index "_end - " \
54 " stored_cert_" #_index "_data )\n\t" \
55 ".previous\n\t" );
56 CERT_ALL
57
58 /** Raw certificate cursors for all permanent stored certificates */
59 #undef CERT
60 #define CERT( _index, _path ) { \
61 .data = stored_cert_ ## _index ## _data, \
62 .len = ( size_t ) stored_cert_ ## _index ## _len, \
63 },
64 static struct asn1_cursor certstore_raw[] = {
65 CERT_ALL
66 };
67
68 /** X.509 certificate structures for all permanent stored certificates */
69 static struct x509_certificate certstore_certs[ sizeof ( certstore_raw ) /
70 sizeof ( certstore_raw[0] ) ];
71
72 /** Certificate store */
73 struct x509_chain certstore = {
74 .refcnt = REF_INIT ( ref_no_free ),
75 .links = LIST_HEAD_INIT ( certstore.links ),
76 };
77
78 /**
79 * Mark stored certificate as most recently used
80 *
81 * @v cert X.509 certificate
82 * @ret cert X.509 certificate
83 */
84 static struct x509_certificate *
85 certstore_found ( struct x509_certificate *cert ) {
86
87 /* Mark as most recently used */
88 list_del ( &cert->store.list );
89 list_add ( &cert->store.list, &certstore.links );
90 DBGC2 ( &certstore, "CERTSTORE found certificate %s\n",
91 x509_name ( cert ) );
92
93 return cert;
94 }
95
96 /**
97 * Find certificate in store
98 *
99 * @v raw Raw certificate data
100 * @ret cert X.509 certificate, or NULL if not found
101 */
102 struct x509_certificate * certstore_find ( struct asn1_cursor *raw ) {
103 struct x509_certificate *cert;
104
105 /* Search for certificate within store */
106 list_for_each_entry ( cert, &certstore.links, store.list ) {
107 if ( asn1_compare ( raw, &cert->raw ) == 0 )
108 return certstore_found ( cert );
109 }
110 return NULL;
111 }
112
113 /**
114 * Find certificate in store corresponding to a private key
115 *
116 * @v key Private key
117 * @ret cert X.509 certificate, or NULL if not found
118 */
119 struct x509_certificate * certstore_find_key ( struct asn1_cursor *key ) {
120 struct x509_certificate *cert;
121
122 /* Search for certificate within store */
123 list_for_each_entry ( cert, &certstore.links, store.list ) {
124 if ( pubkey_match ( cert->signature_algorithm->pubkey,
125 key->data, key->len,
126 cert->subject.public_key.raw.data,
127 cert->subject.public_key.raw.len ) == 0 )
128 return certstore_found ( cert );
129 }
130 return NULL;
131 }
132
133 /**
134 * Add certificate to store
135 *
136 * @v cert X.509 certificate
137 */
138 void certstore_add ( struct x509_certificate *cert ) {
139
140 /* Add certificate to store */
141 cert->store.cert = cert;
142 x509_get ( cert );
143 list_add ( &cert->store.list, &certstore.links );
144 DBGC ( &certstore, "CERTSTORE added certificate %s\n",
145 x509_name ( cert ) );
146 }
147
148 /**
149 * Remove certificate from store
150 *
151 * @v cert X.509 certificate
152 */
153 void certstore_del ( struct x509_certificate *cert ) {
154
155 /* Ignore attempts to remove permanent certificates */
156 if ( cert->flags & X509_FL_PERMANENT )
157 return;
158
159 /* Remove certificate from store */
160 DBGC ( &certstore, "CERTSTORE removed certificate %s\n",
161 x509_name ( cert ) );
162 list_del ( &cert->store.list );
163 x509_put ( cert );
164 }
165
166 /**
167 * Discard a stored certificate
168 *
169 * @ret discarded Number of cached items discarded
170 */
171 static unsigned int certstore_discard ( void ) {
172 struct x509_certificate *cert;
173
174 /* Discard the least recently used certificate for which the
175 * only reference is held by the store itself.
176 */
177 list_for_each_entry_reverse ( cert, &certstore.links, store.list ) {
178
179 /* Skip certificates for which another reference is held */
180 if ( cert->refcnt.count > 0 )
181 continue;
182
183 /* Skip certificates that were added at build time or
184 * added explicitly at run time.
185 */
186 if ( cert->flags & ( X509_FL_PERMANENT | X509_FL_EXPLICIT ) )
187 continue;
188
189 /* Discard certificate */
190 certstore_del ( cert );
191 return 1;
192 }
193
194 return 0;
195 }
196
197 /** Certificate store cache discarder */
198 struct cache_discarder certstore_discarder __cache_discarder ( CACHE_NORMAL ) ={
199 .discard = certstore_discard,
200 };
201
202 /**
203 * Construct permanent certificate store
204 *
205 */
206 static void certstore_init ( void ) {
207 struct asn1_cursor *raw;
208 struct x509_certificate *cert;
209 int i;
210 int rc;
211
212 /* Skip if we have no permanent stored certificates */
213 if ( ! sizeof ( certstore_raw ) )
214 return;
215
216 /* Add certificates */
217 for ( i = 0 ; i < ( int ) ( sizeof ( certstore_raw ) /
218 sizeof ( certstore_raw[0] ) ) ; i++ ) {
219
220 /* Skip if certificate already present in store */
221 raw = &certstore_raw[i];
222 if ( ( cert = certstore_find ( raw ) ) != NULL ) {
223 DBGC ( &certstore, "CERTSTORE permanent certificate %d "
224 "is a duplicate of %s\n", i, x509_name ( cert ));
225 continue;
226 }
227
228 /* Parse certificate */
229 cert = &certstore_certs[i];
230 ref_init ( &cert->refcnt, ref_no_free );
231 if ( ( rc = x509_parse ( cert, raw ) ) != 0 ) {
232 DBGC ( &certstore, "CERTSTORE could not parse "
233 "permanent certificate %d: %s\n",
234 i, strerror ( rc ) );
235 continue;
236 }
237
238 /* Add certificate to store. Certificate will never
239 * be discarded from the store, since we retain a
240 * permanent reference to it.
241 */
242 certstore_add ( cert );
243 cert->flags |= X509_FL_PERMANENT;
244 DBGC ( &certstore, "CERTSTORE permanent certificate %d is %s\n",
245 i, x509_name ( cert ) );
246 }
247 }
248
249 /** Certificate store initialisation function */
250 struct init_fn certstore_init_fn __init_fn ( INIT_LATE ) = {
251 .initialise = certstore_init,
252 };
253
254 /** Additional certificate setting */
255 static struct setting cert_setting __setting ( SETTING_CRYPTO, cert ) = {
256 .name = "cert",
257 .description = "Certificate",
258 .tag = DHCP_EB_CERT,
259 .type = &setting_type_hex,
260 };
261
262 /**
263 * Apply certificate store configuration settings
264 *
265 * @ret rc Return status code
266 */
267 static int certstore_apply_settings ( void ) {
268 static struct x509_certificate *cert = NULL;
269 struct x509_certificate *old_cert;
270 void *cert_data;
271 int len;
272 int rc;
273
274 /* Record any existing additional certificate */
275 old_cert = cert;
276 cert = NULL;
277
278 /* Add additional certificate, if any */
279 if ( ( len = fetch_raw_setting_copy ( NULL, &cert_setting,
280 &cert_data ) ) >= 0 ) {
281 if ( ( rc = x509_certificate ( cert_data, len, &cert ) ) == 0 ){
282 DBGC ( &certstore, "CERTSTORE added additional "
283 "certificate %s\n", x509_name ( cert ) );
284 } else {
285 DBGC ( &certstore, "CERTSTORE could not parse "
286 "additional certificate: %s\n",
287 strerror ( rc ) );
288 /* Do not fail; leave as an unusable certificate */
289 }
290 free ( cert_data );
291 }
292
293 /* Free old additional certificiate. Do this after reparsing
294 * the additional certificate; in the common case that the
295 * certificate has not changed, this will allow the stored
296 * certificate to be reused.
297 */
298 x509_put ( old_cert );
299
300 return 0;
301 }
302
303 /** Certificate store settings applicator */
304 struct settings_applicator certstore_applicator __settings_applicator = {
305 .apply = certstore_apply_settings,
306 };