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
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
|
// SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
/* Copyright 2020 IBM Corp. */
#ifndef pr_fmt
#define pr_fmt(fmt) "EDK2_COMPAT: " fmt
#endif
#include <opal.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <stdint.h>
#include <ccan/endian/endian.h>
#include <mbedtls/error.h>
#include <device.h>
#include <assert.h>
#include "libstb/crypto/pkcs7/pkcs7.h"
#include "edk2.h"
#include "../secvar.h"
#include "edk2-compat-process.h"
bool setup_mode;
int update_variable_in_bank(struct secvar *update_var, const char *data,
const uint64_t dsize, struct list_head *bank)
{
struct secvar *var;
var = find_secvar(update_var->key, update_var->key_len, bank);
if (!var)
return OPAL_EMPTY;
/* Reallocate the data memory, if there is change in data size */
if (var->data_size < dsize)
if (realloc_secvar(var, dsize))
return OPAL_NO_MEM;
if (dsize && data)
memcpy(var->data, data, dsize);
var->data_size = dsize;
/* Clear the volatile bit only if updated with positive data size */
if (dsize)
var->flags &= ~SECVAR_FLAG_VOLATILE;
else
var->flags |= SECVAR_FLAG_VOLATILE;
if (key_equals(update_var->key, "PK") || key_equals(update_var->key, "HWKH"))
var->flags |= SECVAR_FLAG_PROTECTED;
return 0;
}
/* Expand char to wide character size */
static char *char_to_wchar(const char *key, const size_t keylen)
{
int i;
char *str;
str = zalloc(keylen * 2);
if (!str)
return NULL;
for (i = 0; i < keylen*2; key++) {
str[i++] = *key;
str[i++] = '\0';
}
return str;
}
/* Returns the authority that can sign the given key update */
static void get_key_authority(const char *ret[3], const char *key)
{
int i = 0;
if (key_equals(key, "PK")) {
ret[i++] = "PK";
} else if (key_equals(key, "KEK")) {
ret[i++] = "PK";
} else if (key_equals(key, "db") || key_equals(key, "dbx")) {
ret[i++] = "KEK";
ret[i++] = "PK";
}
ret[i] = NULL;
}
static EFI_SIGNATURE_LIST* get_esl_signature_list(const char *buf, size_t buflen)
{
EFI_SIGNATURE_LIST *list = NULL;
if (buflen < sizeof(EFI_SIGNATURE_LIST) || !buf)
return NULL;
list = (EFI_SIGNATURE_LIST *)buf;
return list;
}
/* Returns the size of the complete ESL. */
static int32_t get_esl_signature_list_size(const char *buf, const size_t buflen)
{
EFI_SIGNATURE_LIST *list = get_esl_signature_list(buf, buflen);
if (!list)
return OPAL_PARAMETER;
return le32_to_cpu(list->SignatureListSize);
}
/*
* Copies the certificate from the ESL into cert buffer and returns the size
* of the certificate
*/
static int get_esl_cert(const char *buf, const size_t buflen, char **cert)
{
size_t sig_data_offset;
size_t size;
EFI_SIGNATURE_LIST *list = get_esl_signature_list(buf, buflen);
if (!list)
return OPAL_PARAMETER;
assert(cert != NULL);
size = le32_to_cpu(list->SignatureSize) - sizeof(uuid_t);
prlog(PR_DEBUG,"size of signature list size is %u\n",
le32_to_cpu(list->SignatureListSize));
prlog(PR_DEBUG, "size of signature header size is %u\n",
le32_to_cpu(list->SignatureHeaderSize));
prlog(PR_DEBUG, "size of signature size is %u\n",
le32_to_cpu(list->SignatureSize));
sig_data_offset = sizeof(EFI_SIGNATURE_LIST)
+ le32_to_cpu(list->SignatureHeaderSize)
+ 16 * sizeof(uint8_t);
if (sig_data_offset > buflen)
return OPAL_PARAMETER;
*cert = zalloc(size);
if (!(*cert))
return OPAL_NO_MEM;
/* Since buf can have more than one ESL, copy only the size calculated
* to return single ESL */
memcpy(*cert, buf + sig_data_offset, size);
return size;
}
/*
* Extracts size of the PKCS7 signed data embedded in the
* struct Authentication 2 Descriptor Header.
*/
static size_t get_pkcs7_len(const struct efi_variable_authentication_2 *auth)
{
uint32_t dw_length;
size_t size;
assert(auth != NULL);
dw_length = le32_to_cpu(auth->auth_info.hdr.dw_length);
size = dw_length - (sizeof(auth->auth_info.hdr.dw_length)
+ sizeof(auth->auth_info.hdr.w_revision)
+ sizeof(auth->auth_info.hdr.w_certificate_type)
+ sizeof(auth->auth_info.cert_type));
return size;
}
int get_auth_descriptor2(const void *buf, const size_t buflen, void **auth_buffer)
{
const struct efi_variable_authentication_2 *auth = buf;
int auth_buffer_size;
size_t len;
assert(auth_buffer != NULL);
if (buflen < sizeof(struct efi_variable_authentication_2)
|| !buf)
return OPAL_PARAMETER;
len = get_pkcs7_len(auth);
/* pkcs7 content length cannot be greater than buflen */
if (len > buflen)
return OPAL_PARAMETER;
auth_buffer_size = sizeof(auth->timestamp) + sizeof(auth->auth_info.hdr)
+ sizeof(auth->auth_info.cert_type) + len;
*auth_buffer = zalloc(auth_buffer_size);
if (!(*auth_buffer))
return OPAL_NO_MEM;
/*
* Data = auth descriptor + new ESL data.
* Extracts only the auth descriptor from data.
*/
memcpy(*auth_buffer, buf, auth_buffer_size);
return auth_buffer_size;
}
static bool validate_cert(char *signing_cert, int signing_cert_size)
{
mbedtls_x509_crt x509;
char *x509_buf = NULL;
int rc;
mbedtls_x509_crt_init(&x509);
rc = mbedtls_x509_crt_parse(&x509, signing_cert, signing_cert_size);
/* If failure in parsing the certificate, exit */
if(rc) {
prlog(PR_ERR, "X509 certificate parsing failed %04x\n", rc);
return false;
}
x509_buf = zalloc(CERT_BUFFER_SIZE);
rc = mbedtls_x509_crt_info(x509_buf, CERT_BUFFER_SIZE, "CRT:", &x509);
mbedtls_x509_crt_free(&x509);
free(x509_buf);
x509_buf = NULL;
/* If failure in reading the certificate, exit */
if (rc < 0)
return false;
return true;
}
static bool validate_hash(uuid_t type, int size)
{
if (uuid_equals(&type, &EFI_CERT_SHA1_GUID) && (size == 20))
return true;
if (uuid_equals(&type, &EFI_CERT_SHA224_GUID) && (size == 28))
return true;
if (uuid_equals(&type, &EFI_CERT_SHA256_GUID) && (size == 32))
return true;
if (uuid_equals(&type, &EFI_CERT_SHA384_GUID) && (size == 48))
return true;
if (uuid_equals(&type, &EFI_CERT_SHA512_GUID) && (size == 64))
return true;
return false;
}
int validate_esl_list(const char *key, const char *esl, const size_t size)
{
int count = 0;
int dsize;
char *data = NULL;
int eslvarsize = size;
int eslsize;
int rc = OPAL_SUCCESS;
int offset = 0;
EFI_SIGNATURE_LIST *list = NULL;
while (eslvarsize > 0) {
prlog(PR_DEBUG, "esl var size size is %d offset is %d\n", eslvarsize, offset);
if (eslvarsize < sizeof(EFI_SIGNATURE_LIST))
break;
/* Check Supported ESL Type */
list = get_esl_signature_list(esl, eslvarsize);
if (!list)
return OPAL_PARAMETER;
/* Calculate the size of the ESL */
eslsize = le32_to_cpu(list->SignatureListSize);
/* If could not extract the size */
if (eslsize <= 0) {
prlog(PR_ERR, "Invalid size of the ESL: %u\n",
le32_to_cpu(list->SignatureListSize));
rc = OPAL_PARAMETER;
break;
}
/* Extract the certificate from the ESL */
dsize = get_esl_cert(esl, eslvarsize, &data);
if (dsize < 0) {
rc = dsize;
break;
}
if (key_equals(key, "dbx")) {
if (!validate_hash(list->SignatureType, dsize)) {
prlog(PR_ERR, "No valid hash is found\n");
rc = OPAL_PARAMETER;
break;
}
} else {
if (!uuid_equals(&list->SignatureType, &EFI_CERT_X509_GUID)
|| !validate_cert(data, dsize)) {
prlog(PR_ERR, "No valid cert is found\n");
rc = OPAL_PARAMETER;
break;
}
}
count++;
/* Look for the next ESL */
offset = offset + eslsize;
eslvarsize = eslvarsize - eslsize;
free(data);
/* Since we are going to allocate again in the next iteration */
data = NULL;
}
if (rc == OPAL_SUCCESS) {
if (key_equals(key, "PK") && (count > 1)) {
prlog(PR_ERR, "PK can only be one\n");
rc = OPAL_PARAMETER;
} else {
rc = count;
}
}
free(data);
prlog(PR_INFO, "Total ESLs are %d\n", rc);
return rc;
}
/* Get the timestamp for the last update of the give key */
static struct efi_time *get_last_timestamp(const char *key, char *last_timestamp)
{
struct efi_time *timestamp = (struct efi_time*)last_timestamp;
if (!last_timestamp)
return NULL;
if (key_equals(key, "PK"))
return ×tamp[0];
else if (key_equals(key, "KEK"))
return ×tamp[1];
else if (key_equals(key, "db"))
return ×tamp[2];
else if (key_equals(key, "dbx"))
return ×tamp[3];
else
return NULL;
}
int update_timestamp(const char *key, const struct efi_time *timestamp, char *last_timestamp)
{
struct efi_time *prev;
prev = get_last_timestamp(key, last_timestamp);
if (prev == NULL)
return OPAL_INTERNAL_ERROR;
/* Update with new timestamp */
memcpy(prev, timestamp, sizeof(struct efi_time));
prlog(PR_DEBUG, "updated prev year is %d month %d day %d\n",
le16_to_cpu(prev->year), prev->month, prev->day);
return OPAL_SUCCESS;
}
static uint64_t unpack_timestamp(const struct efi_time *timestamp)
{
uint64_t val = 0;
uint16_t year = le32_to_cpu(timestamp->year);
/* pad1, nanosecond, timezone, daylight and pad2 are meant to be zero */
val |= ((uint64_t) timestamp->pad1 & 0xFF) << 0;
val |= ((uint64_t) timestamp->second & 0xFF) << (1*8);
val |= ((uint64_t) timestamp->minute & 0xFF) << (2*8);
val |= ((uint64_t) timestamp->hour & 0xFF) << (3*8);
val |= ((uint64_t) timestamp->day & 0xFF) << (4*8);
val |= ((uint64_t) timestamp->month & 0xFF) << (5*8);
val |= ((uint64_t) year) << (6*8);
return val;
}
int check_timestamp(const char *key, const struct efi_time *timestamp,
char *last_timestamp)
{
struct efi_time *prev;
uint64_t new;
uint64_t last;
prev = get_last_timestamp(key, last_timestamp);
if (prev == NULL)
return OPAL_INTERNAL_ERROR;
prlog(PR_DEBUG, "timestamp year is %d month %d day %d\n",
le16_to_cpu(timestamp->year), timestamp->month,
timestamp->day);
prlog(PR_DEBUG, "prev year is %d month %d day %d\n",
le16_to_cpu(prev->year), prev->month, prev->day);
new = unpack_timestamp(timestamp);
last = unpack_timestamp(prev);
if (new > last)
return OPAL_SUCCESS;
return OPAL_PERMISSION;
}
/* Extract PKCS7 from the authentication header */
static mbedtls_pkcs7* get_pkcs7(const struct efi_variable_authentication_2 *auth)
{
char *checkpkcs7cert = NULL;
size_t len;
mbedtls_pkcs7 *pkcs7 = NULL;
int rc;
len = get_pkcs7_len(auth);
pkcs7 = malloc(sizeof(struct mbedtls_pkcs7));
if (!pkcs7)
return NULL;
mbedtls_pkcs7_init(pkcs7);
rc = mbedtls_pkcs7_parse_der( auth->auth_info.cert_data, len, pkcs7);
if (rc <= 0) {
prlog(PR_ERR, "Parsing pkcs7 failed %04x\n", rc);
goto out;
}
checkpkcs7cert = zalloc(CERT_BUFFER_SIZE);
if (!checkpkcs7cert)
goto out;
rc = mbedtls_x509_crt_info(checkpkcs7cert, CERT_BUFFER_SIZE, "CRT:",
&(pkcs7->signed_data.certs));
if (rc < 0) {
prlog(PR_ERR, "Failed to parse the certificate in PKCS7 structure\n");
free(checkpkcs7cert);
goto out;
}
prlog(PR_DEBUG, "%s \n", checkpkcs7cert);
free(checkpkcs7cert);
return pkcs7;
out:
mbedtls_pkcs7_free(pkcs7);
pkcs7 = NULL;
return pkcs7;
}
/* Verify the PKCS7 signature on the signed data. */
static int verify_signature(const struct efi_variable_authentication_2 *auth,
const char *newcert, const size_t new_data_size,
const struct secvar *avar)
{
mbedtls_pkcs7 *pkcs7 = NULL;
mbedtls_x509_crt x509;
char *signing_cert = NULL;
char *x509_buf = NULL;
int signing_cert_size;
int rc = 0;
char *errbuf;
int eslvarsize;
int eslsize;
int offset = 0;
if (!auth)
return OPAL_PARAMETER;
/* Extract the pkcs7 from the auth structure */
pkcs7 = get_pkcs7(auth);
/* Failure to parse pkcs7 implies bad input. */
if (!pkcs7)
return OPAL_PARAMETER;
prlog(PR_INFO, "Load the signing certificate from the keystore");
eslvarsize = avar->data_size;
/* Variable is not empty */
while (eslvarsize > 0) {
prlog(PR_DEBUG, "esl var size size is %d offset is %d\n", eslvarsize, offset);
if (eslvarsize < sizeof(EFI_SIGNATURE_LIST))
break;
/* Calculate the size of the ESL */
eslsize = get_esl_signature_list_size(avar->data + offset,
eslvarsize);
/* If could not extract the size */
if (eslsize <= 0) {
rc = OPAL_PARAMETER;
break;
}
/* Extract the certificate from the ESL */
signing_cert_size = get_esl_cert(avar->data + offset,
eslvarsize, &signing_cert);
if (signing_cert_size < 0) {
rc = signing_cert_size;
break;
}
mbedtls_x509_crt_init(&x509);
rc = mbedtls_x509_crt_parse(&x509,
signing_cert,
signing_cert_size);
/* This should not happen, unless something corrupted in PNOR */
if(rc) {
prlog(PR_ERR, "X509 certificate parsing failed %04x\n", rc);
rc = OPAL_INTERNAL_ERROR;
break;
}
x509_buf = zalloc(CERT_BUFFER_SIZE);
rc = mbedtls_x509_crt_info(x509_buf,
CERT_BUFFER_SIZE,
"CRT:",
&x509);
/* This should not happen, unless something corrupted in PNOR */
if (rc < 0) {
free(x509_buf);
rc = OPAL_INTERNAL_ERROR;
break;
}
prlog(PR_INFO, "%s \n", x509_buf);
free(x509_buf);
x509_buf = NULL;
rc = mbedtls_pkcs7_signed_hash_verify(pkcs7, &x509, newcert, new_data_size);
/* If you find a signing certificate, you are done */
if (rc == 0) {
prlog(PR_INFO, "Signature Verification passed\n");
mbedtls_x509_crt_free(&x509);
break;
} else {
errbuf = zalloc(MBEDTLS_ERR_BUFFER_SIZE);
mbedtls_strerror(rc, errbuf, MBEDTLS_ERR_BUFFER_SIZE);
prlog(PR_ERR, "Signature Verification failed %02x %s\n",
rc, errbuf);
free(errbuf);
rc = OPAL_PERMISSION;
}
/* Look for the next ESL */
offset = offset + eslsize;
eslvarsize = eslvarsize - eslsize;
mbedtls_x509_crt_free(&x509);
free(signing_cert);
/* Since we are going to allocate again in the next iteration */
signing_cert = NULL;
}
free(signing_cert);
mbedtls_pkcs7_free(pkcs7);
free(pkcs7);
return rc;
}
/*
* Create the hash of the buffer
* name || vendor guid || attributes || timestamp || newcontent
* which is submitted as signed by the user.
* Returns the sha256 hash, else negative error code.
*/
static char *get_hash_to_verify(const char *key, const char *new_data,
const size_t new_data_size,
const struct efi_time *timestamp)
{
le32 attr = cpu_to_le32(SECVAR_ATTRIBUTES);
size_t varlen;
char *wkey;
uuid_t guid;
unsigned char *hash = NULL;
const mbedtls_md_info_t *md_info;
mbedtls_md_context_t ctx;
int rc;
md_info = mbedtls_md_info_from_type( MBEDTLS_MD_SHA256 );
mbedtls_md_init(&ctx);
rc = mbedtls_md_setup(&ctx, md_info, 0);
if (rc)
goto out;
rc = mbedtls_md_starts(&ctx);
if (rc)
goto out;
if (key_equals(key, "PK")
|| key_equals(key, "KEK"))
guid = EFI_GLOBAL_VARIABLE_GUID;
else if (key_equals(key, "db")
|| key_equals(key, "dbx"))
guid = EFI_IMAGE_SECURITY_DATABASE_GUID;
else
return NULL;
/* Expand char name to wide character width */
varlen = strlen(key) * 2;
wkey = char_to_wchar(key, strlen(key));
rc = mbedtls_md_update(&ctx, wkey, varlen);
free(wkey);
if (rc)
goto out;
rc = mbedtls_md_update(&ctx, (const unsigned char *)&guid, sizeof(guid));
if (rc)
goto out;
rc = mbedtls_md_update(&ctx, (const unsigned char *)&attr, sizeof(attr));
if (rc)
goto out;
rc = mbedtls_md_update(&ctx, (const unsigned char *)timestamp,
sizeof(struct efi_time));
if (rc)
goto out;
rc = mbedtls_md_update(&ctx, new_data, new_data_size);
if (rc)
goto out;
hash = zalloc(32);
if (!hash)
return NULL;
rc = mbedtls_md_finish(&ctx, hash);
if (rc) {
free(hash);
hash = NULL;
}
out:
mbedtls_md_free(&ctx);
return hash;
}
bool is_pkcs7_sig_format(const void *data)
{
const struct efi_variable_authentication_2 *auth = data;
uuid_t pkcs7_guid = EFI_CERT_TYPE_PKCS7_GUID;
return !memcmp(&auth->auth_info.cert_type, &pkcs7_guid, 16);
}
int process_update(const struct secvar *update, char **newesl,
int *new_data_size, struct efi_time *timestamp,
struct list_head *bank, char *last_timestamp)
{
struct efi_variable_authentication_2 *auth = NULL;
void *auth_buffer = NULL;
int auth_buffer_size = 0;
const char *key_authority[3];
char *tbhbuffer = NULL;
size_t tbhbuffersize = 0;
struct secvar *avar = NULL;
int rc = 0;
int i;
/* We need to split data into authentication descriptor and new ESL */
auth_buffer_size = get_auth_descriptor2(update->data,
update->data_size,
&auth_buffer);
if ((auth_buffer_size < 0)
|| (update->data_size < auth_buffer_size)) {
prlog(PR_ERR, "Invalid auth buffer size\n");
rc = auth_buffer_size;
goto out;
}
auth = auth_buffer;
if (!timestamp) {
rc = OPAL_INTERNAL_ERROR;
goto out;
}
memcpy(timestamp, auth_buffer, sizeof(struct efi_time));
rc = check_timestamp(update->key, timestamp, last_timestamp);
/* Failure implies probably an older command being resubmitted */
if (rc != OPAL_SUCCESS) {
prlog(PR_ERR, "Timestamp verification failed for key %s\n", update->key);
goto out;
}
/* Calculate the size of new ESL data */
*new_data_size = update->data_size - auth_buffer_size;
if (*new_data_size < 0) {
prlog(PR_ERR, "Invalid new ESL (new data content) size\n");
rc = OPAL_PARAMETER;
goto out;
}
*newesl = zalloc(*new_data_size);
if (!(*newesl)) {
rc = OPAL_NO_MEM;
goto out;
}
memcpy(*newesl, update->data + auth_buffer_size, *new_data_size);
/* Validate the new ESL is in right format */
rc = validate_esl_list(update->key, *newesl, *new_data_size);
if (rc < 0) {
prlog(PR_ERR, "ESL validation failed for key %s with error %04x\n",
update->key, rc);
goto out;
}
if (setup_mode) {
rc = OPAL_SUCCESS;
goto out;
}
/* Prepare the data to be verified */
tbhbuffer = get_hash_to_verify(update->key, *newesl, *new_data_size,
timestamp);
if (!tbhbuffer) {
rc = OPAL_INTERNAL_ERROR;
goto out;
}
/* Get the authority to verify the signature */
get_key_authority(key_authority, update->key);
/*
* Try for all the authorities that are allowed to sign.
* For eg. db/dbx can be signed by both PK or KEK
*/
for (i = 0; key_authority[i] != NULL; i++) {
prlog(PR_DEBUG, "key is %s\n", update->key);
prlog(PR_DEBUG, "key authority is %s\n", key_authority[i]);
avar = find_secvar(key_authority[i],
strlen(key_authority[i]) + 1,
bank);
if (!avar || !avar->data_size)
continue;
/* Verify the signature */
rc = verify_signature(auth, tbhbuffer, tbhbuffersize,
avar);
/* Break if signature verification is successful */
if (rc == OPAL_SUCCESS) {
prlog(PR_INFO, "Key %s successfully verified by authority %s\n", update->key, key_authority[i]);
break;
}
}
out:
free(auth_buffer);
free(tbhbuffer);
return rc;
}
|