/
trusted.c
1180 lines (1064 loc) · 27.8 KB
/
trusted.c
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
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* Copyright (C) 2010 IBM Corporation
*
* Author:
* David Safford <safford@us.ibm.com>
*
* 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, version 2 of the License.
*
* See Documentation/security/keys-trusted-encrypted.txt
*/
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/parser.h>
#include <linux/string.h>
#include <linux/err.h>
#include <keys/user-type.h>
#include <keys/trusted-type.h>
#include <linux/key-type.h>
#include <linux/rcupdate.h>
#include <linux/crypto.h>
#include <crypto/hash.h>
#include <crypto/sha.h>
#include <linux/capability.h>
#include <linux/tpm.h>
#include <linux/tpm_command.h>
#include "trusted.h"
static const char hmac_alg[] = "hmac(sha1)";
static const char hash_alg[] = "sha1";
struct sdesc {
struct shash_desc shash;
char ctx[];
};
static struct crypto_shash *hashalg;
static struct crypto_shash *hmacalg;
static struct sdesc *init_sdesc(struct crypto_shash *alg)
{
struct sdesc *sdesc;
int size;
size = sizeof(struct shash_desc) + crypto_shash_descsize(alg);
sdesc = kmalloc(size, GFP_KERNEL);
if (!sdesc)
return ERR_PTR(-ENOMEM);
sdesc->shash.tfm = alg;
sdesc->shash.flags = 0x0;
return sdesc;
}
static int TSS_sha1(const unsigned char *data, unsigned int datalen,
unsigned char *digest)
{
struct sdesc *sdesc;
int ret;
sdesc = init_sdesc(hashalg);
if (IS_ERR(sdesc)) {
pr_info("trusted_key: can't alloc %s\n", hash_alg);
return PTR_ERR(sdesc);
}
ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest);
kfree(sdesc);
return ret;
}
static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
unsigned int keylen, ...)
{
struct sdesc *sdesc;
va_list argp;
unsigned int dlen;
unsigned char *data;
int ret;
sdesc = init_sdesc(hmacalg);
if (IS_ERR(sdesc)) {
pr_info("trusted_key: can't alloc %s\n", hmac_alg);
return PTR_ERR(sdesc);
}
ret = crypto_shash_setkey(hmacalg, key, keylen);
if (ret < 0)
goto out;
ret = crypto_shash_init(&sdesc->shash);
if (ret < 0)
goto out;
va_start(argp, keylen);
for (;;) {
dlen = va_arg(argp, unsigned int);
if (dlen == 0)
break;
data = va_arg(argp, unsigned char *);
if (data == NULL) {
ret = -EINVAL;
break;
}
ret = crypto_shash_update(&sdesc->shash, data, dlen);
if (ret < 0)
break;
}
va_end(argp);
if (!ret)
ret = crypto_shash_final(&sdesc->shash, digest);
out:
kfree(sdesc);
return ret;
}
/*
* calculate authorization info fields to send to TPM
*/
static int TSS_authhmac(unsigned char *digest, const unsigned char *key,
unsigned int keylen, unsigned char *h1,
unsigned char *h2, unsigned char h3, ...)
{
unsigned char paramdigest[SHA1_DIGEST_SIZE];
struct sdesc *sdesc;
unsigned int dlen;
unsigned char *data;
unsigned char c;
int ret;
va_list argp;
sdesc = init_sdesc(hashalg);
if (IS_ERR(sdesc)) {
pr_info("trusted_key: can't alloc %s\n", hash_alg);
return PTR_ERR(sdesc);
}
c = h3;
ret = crypto_shash_init(&sdesc->shash);
if (ret < 0)
goto out;
va_start(argp, h3);
for (;;) {
dlen = va_arg(argp, unsigned int);
if (dlen == 0)
break;
data = va_arg(argp, unsigned char *);
if (!data) {
ret = -EINVAL;
break;
}
ret = crypto_shash_update(&sdesc->shash, data, dlen);
if (ret < 0)
break;
}
va_end(argp);
if (!ret)
ret = crypto_shash_final(&sdesc->shash, paramdigest);
if (!ret)
ret = TSS_rawhmac(digest, key, keylen, SHA1_DIGEST_SIZE,
paramdigest, TPM_NONCE_SIZE, h1,
TPM_NONCE_SIZE, h2, 1, &c, 0, 0);
out:
kfree(sdesc);
return ret;
}
/*
* verify the AUTH1_COMMAND (Seal) result from TPM
*/
static int TSS_checkhmac1(unsigned char *buffer,
const uint32_t command,
const unsigned char *ononce,
const unsigned char *key,
unsigned int keylen, ...)
{
uint32_t bufsize;
uint16_t tag;
uint32_t ordinal;
uint32_t result;
unsigned char *enonce;
unsigned char *continueflag;
unsigned char *authdata;
unsigned char testhmac[SHA1_DIGEST_SIZE];
unsigned char paramdigest[SHA1_DIGEST_SIZE];
struct sdesc *sdesc;
unsigned int dlen;
unsigned int dpos;
va_list argp;
int ret;
bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
tag = LOAD16(buffer, 0);
ordinal = command;
result = LOAD32N(buffer, TPM_RETURN_OFFSET);
if (tag == TPM_TAG_RSP_COMMAND)
return 0;
if (tag != TPM_TAG_RSP_AUTH1_COMMAND)
return -EINVAL;
authdata = buffer + bufsize - SHA1_DIGEST_SIZE;
continueflag = authdata - 1;
enonce = continueflag - TPM_NONCE_SIZE;
sdesc = init_sdesc(hashalg);
if (IS_ERR(sdesc)) {
pr_info("trusted_key: can't alloc %s\n", hash_alg);
return PTR_ERR(sdesc);
}
ret = crypto_shash_init(&sdesc->shash);
if (ret < 0)
goto out;
ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
sizeof result);
if (ret < 0)
goto out;
ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
sizeof ordinal);
if (ret < 0)
goto out;
va_start(argp, keylen);
for (;;) {
dlen = va_arg(argp, unsigned int);
if (dlen == 0)
break;
dpos = va_arg(argp, unsigned int);
ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
if (ret < 0)
break;
}
va_end(argp);
if (!ret)
ret = crypto_shash_final(&sdesc->shash, paramdigest);
if (ret < 0)
goto out;
ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest,
TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce,
1, continueflag, 0, 0);
if (ret < 0)
goto out;
if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE))
ret = -EINVAL;
out:
kfree(sdesc);
return ret;
}
/*
* verify the AUTH2_COMMAND (unseal) result from TPM
*/
static int TSS_checkhmac2(unsigned char *buffer,
const uint32_t command,
const unsigned char *ononce,
const unsigned char *key1,
unsigned int keylen1,
const unsigned char *key2,
unsigned int keylen2, ...)
{
uint32_t bufsize;
uint16_t tag;
uint32_t ordinal;
uint32_t result;
unsigned char *enonce1;
unsigned char *continueflag1;
unsigned char *authdata1;
unsigned char *enonce2;
unsigned char *continueflag2;
unsigned char *authdata2;
unsigned char testhmac1[SHA1_DIGEST_SIZE];
unsigned char testhmac2[SHA1_DIGEST_SIZE];
unsigned char paramdigest[SHA1_DIGEST_SIZE];
struct sdesc *sdesc;
unsigned int dlen;
unsigned int dpos;
va_list argp;
int ret;
bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
tag = LOAD16(buffer, 0);
ordinal = command;
result = LOAD32N(buffer, TPM_RETURN_OFFSET);
if (tag == TPM_TAG_RSP_COMMAND)
return 0;
if (tag != TPM_TAG_RSP_AUTH2_COMMAND)
return -EINVAL;
authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1
+ SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE);
authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE);
continueflag1 = authdata1 - 1;
continueflag2 = authdata2 - 1;
enonce1 = continueflag1 - TPM_NONCE_SIZE;
enonce2 = continueflag2 - TPM_NONCE_SIZE;
sdesc = init_sdesc(hashalg);
if (IS_ERR(sdesc)) {
pr_info("trusted_key: can't alloc %s\n", hash_alg);
return PTR_ERR(sdesc);
}
ret = crypto_shash_init(&sdesc->shash);
if (ret < 0)
goto out;
ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
sizeof result);
if (ret < 0)
goto out;
ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
sizeof ordinal);
if (ret < 0)
goto out;
va_start(argp, keylen2);
for (;;) {
dlen = va_arg(argp, unsigned int);
if (dlen == 0)
break;
dpos = va_arg(argp, unsigned int);
ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
if (ret < 0)
break;
}
va_end(argp);
if (!ret)
ret = crypto_shash_final(&sdesc->shash, paramdigest);
if (ret < 0)
goto out;
ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE,
paramdigest, TPM_NONCE_SIZE, enonce1,
TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0);
if (ret < 0)
goto out;
if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) {
ret = -EINVAL;
goto out;
}
ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE,
paramdigest, TPM_NONCE_SIZE, enonce2,
TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0);
if (ret < 0)
goto out;
if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE))
ret = -EINVAL;
out:
kfree(sdesc);
return ret;
}
/*
* For key specific tpm requests, we will generate and send our
* own TPM command packets using the drivers send function.
*/
static int trusted_tpm_send(const u32 chip_num, unsigned char *cmd,
size_t buflen)
{
int rc;
dump_tpm_buf(cmd);
rc = tpm_send(chip_num, cmd, buflen);
dump_tpm_buf(cmd);
if (rc > 0)
/* Can't return positive return codes values to keyctl */
rc = -EPERM;
return rc;
}
/*
* get a random value from TPM
*/
static int tpm_get_random(struct tpm_buf *tb, unsigned char *buf, uint32_t len)
{
int ret;
INIT_BUF(tb);
store16(tb, TPM_TAG_RQU_COMMAND);
store32(tb, TPM_GETRANDOM_SIZE);
store32(tb, TPM_ORD_GETRANDOM);
store32(tb, len);
ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, sizeof tb->data);
if (!ret)
memcpy(buf, tb->data + TPM_GETRANDOM_SIZE, len);
return ret;
}
static int my_get_random(unsigned char *buf, int len)
{
struct tpm_buf *tb;
int ret;
tb = kmalloc(sizeof *tb, GFP_KERNEL);
if (!tb)
return -ENOMEM;
ret = tpm_get_random(tb, buf, len);
kfree(tb);
return ret;
}
/*
* Lock a trusted key, by extending a selected PCR.
*
* Prevents a trusted key that is sealed to PCRs from being accessed.
* This uses the tpm driver's extend function.
*/
static int pcrlock(const int pcrnum)
{
unsigned char hash[SHA1_DIGEST_SIZE];
int ret;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
ret = my_get_random(hash, SHA1_DIGEST_SIZE);
if (ret < 0)
return ret;
return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0;
}
/*
* Create an object specific authorisation protocol (OSAP) session
*/
static int osap(struct tpm_buf *tb, struct osapsess *s,
const unsigned char *key, uint16_t type, uint32_t handle)
{
unsigned char enonce[TPM_NONCE_SIZE];
unsigned char ononce[TPM_NONCE_SIZE];
int ret;
ret = tpm_get_random(tb, ononce, TPM_NONCE_SIZE);
if (ret < 0)
return ret;
INIT_BUF(tb);
store16(tb, TPM_TAG_RQU_COMMAND);
store32(tb, TPM_OSAP_SIZE);
store32(tb, TPM_ORD_OSAP);
store16(tb, type);
store32(tb, handle);
storebytes(tb, ononce, TPM_NONCE_SIZE);
ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
if (ret < 0)
return ret;
s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
TPM_NONCE_SIZE);
memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
enonce, TPM_NONCE_SIZE, ononce, 0, 0);
}
/*
* Create an object independent authorisation protocol (oiap) session
*/
static int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
{
int ret;
INIT_BUF(tb);
store16(tb, TPM_TAG_RQU_COMMAND);
store32(tb, TPM_OIAP_SIZE);
store32(tb, TPM_ORD_OIAP);
ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
if (ret < 0)
return ret;
*handle = LOAD32(tb->data, TPM_DATA_OFFSET);
memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
TPM_NONCE_SIZE);
return 0;
}
struct tpm_digests {
unsigned char encauth[SHA1_DIGEST_SIZE];
unsigned char pubauth[SHA1_DIGEST_SIZE];
unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
unsigned char xorhash[SHA1_DIGEST_SIZE];
unsigned char nonceodd[TPM_NONCE_SIZE];
};
/*
* Have the TPM seal(encrypt) the trusted key, possibly based on
* Platform Configuration Registers (PCRs). AUTH1 for sealing key.
*/
static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
uint32_t keyhandle, const unsigned char *keyauth,
const unsigned char *data, uint32_t datalen,
unsigned char *blob, uint32_t *bloblen,
const unsigned char *blobauth,
const unsigned char *pcrinfo, uint32_t pcrinfosize)
{
struct osapsess sess;
struct tpm_digests *td;
unsigned char cont;
uint32_t ordinal;
uint32_t pcrsize;
uint32_t datsize;
int sealinfosize;
int encdatasize;
int storedsize;
int ret;
int i;
/* alloc some work space for all the hashes */
td = kmalloc(sizeof *td, GFP_KERNEL);
if (!td)
return -ENOMEM;
/* get session for sealing key */
ret = osap(tb, &sess, keyauth, keytype, keyhandle);
if (ret < 0)
goto out;
dump_sess(&sess);
/* calculate encrypted authorization value */
memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
if (ret < 0)
goto out;
ret = tpm_get_random(tb, td->nonceodd, TPM_NONCE_SIZE);
if (ret < 0)
goto out;
ordinal = htonl(TPM_ORD_SEAL);
datsize = htonl(datalen);
pcrsize = htonl(pcrinfosize);
cont = 0;
/* encrypt data authorization key */
for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
td->encauth[i] = td->xorhash[i] ^ blobauth[i];
/* calculate authorization HMAC value */
if (pcrinfosize == 0) {
/* no pcr info specified */
ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
sess.enonce, td->nonceodd, cont,
sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
td->encauth, sizeof(uint32_t), &pcrsize,
sizeof(uint32_t), &datsize, datalen, data, 0,
0);
} else {
/* pcr info specified */
ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
sess.enonce, td->nonceodd, cont,
sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
td->encauth, sizeof(uint32_t), &pcrsize,
pcrinfosize, pcrinfo, sizeof(uint32_t),
&datsize, datalen, data, 0, 0);
}
if (ret < 0)
goto out;
/* build and send the TPM request packet */
INIT_BUF(tb);
store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
store32(tb, TPM_SEAL_SIZE + pcrinfosize + datalen);
store32(tb, TPM_ORD_SEAL);
store32(tb, keyhandle);
storebytes(tb, td->encauth, SHA1_DIGEST_SIZE);
store32(tb, pcrinfosize);
storebytes(tb, pcrinfo, pcrinfosize);
store32(tb, datalen);
storebytes(tb, data, datalen);
store32(tb, sess.handle);
storebytes(tb, td->nonceodd, TPM_NONCE_SIZE);
store8(tb, cont);
storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE);
ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
if (ret < 0)
goto out;
/* calculate the size of the returned Blob */
sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
sizeof(uint32_t) + sealinfosize);
storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
sizeof(uint32_t) + encdatasize;
/* check the HMAC in the response */
ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
0);
/* copy the returned blob to caller */
if (!ret) {
memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
*bloblen = storedsize;
}
out:
kfree(td);
return ret;
}
/*
* use the AUTH2_COMMAND form of unseal, to authorize both key and blob
*/
static int tpm_unseal(struct tpm_buf *tb,
uint32_t keyhandle, const unsigned char *keyauth,
const unsigned char *blob, int bloblen,
const unsigned char *blobauth,
unsigned char *data, unsigned int *datalen)
{
unsigned char nonceodd[TPM_NONCE_SIZE];
unsigned char enonce1[TPM_NONCE_SIZE];
unsigned char enonce2[TPM_NONCE_SIZE];
unsigned char authdata1[SHA1_DIGEST_SIZE];
unsigned char authdata2[SHA1_DIGEST_SIZE];
uint32_t authhandle1 = 0;
uint32_t authhandle2 = 0;
unsigned char cont = 0;
uint32_t ordinal;
uint32_t keyhndl;
int ret;
/* sessions for unsealing key and data */
ret = oiap(tb, &authhandle1, enonce1);
if (ret < 0) {
pr_info("trusted_key: oiap failed (%d)\n", ret);
return ret;
}
ret = oiap(tb, &authhandle2, enonce2);
if (ret < 0) {
pr_info("trusted_key: oiap failed (%d)\n", ret);
return ret;
}
ordinal = htonl(TPM_ORD_UNSEAL);
keyhndl = htonl(SRKHANDLE);
ret = tpm_get_random(tb, nonceodd, TPM_NONCE_SIZE);
if (ret < 0) {
pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
return ret;
}
ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
enonce1, nonceodd, cont, sizeof(uint32_t),
&ordinal, bloblen, blob, 0, 0);
if (ret < 0)
return ret;
ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
enonce2, nonceodd, cont, sizeof(uint32_t),
&ordinal, bloblen, blob, 0, 0);
if (ret < 0)
return ret;
/* build and send TPM request packet */
INIT_BUF(tb);
store16(tb, TPM_TAG_RQU_AUTH2_COMMAND);
store32(tb, TPM_UNSEAL_SIZE + bloblen);
store32(tb, TPM_ORD_UNSEAL);
store32(tb, keyhandle);
storebytes(tb, blob, bloblen);
store32(tb, authhandle1);
storebytes(tb, nonceodd, TPM_NONCE_SIZE);
store8(tb, cont);
storebytes(tb, authdata1, SHA1_DIGEST_SIZE);
store32(tb, authhandle2);
storebytes(tb, nonceodd, TPM_NONCE_SIZE);
store8(tb, cont);
storebytes(tb, authdata2, SHA1_DIGEST_SIZE);
ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
if (ret < 0) {
pr_info("trusted_key: authhmac failed (%d)\n", ret);
return ret;
}
*datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
keyauth, SHA1_DIGEST_SIZE,
blobauth, SHA1_DIGEST_SIZE,
sizeof(uint32_t), TPM_DATA_OFFSET,
*datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
0);
if (ret < 0) {
pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret);
return ret;
}
memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
return 0;
}
/*
* Have the TPM seal(encrypt) the symmetric key
*/
static int key_seal(struct trusted_key_payload *p,
struct trusted_key_options *o)
{
struct tpm_buf *tb;
int ret;
tb = kzalloc(sizeof *tb, GFP_KERNEL);
if (!tb)
return -ENOMEM;
/* include migratable flag at end of sealed key */
p->key[p->key_len] = p->migratable;
ret = tpm_seal(tb, o->keytype, o->keyhandle, o->keyauth,
p->key, p->key_len + 1, p->blob, &p->blob_len,
o->blobauth, o->pcrinfo, o->pcrinfo_len);
if (ret < 0)
pr_info("trusted_key: srkseal failed (%d)\n", ret);
kfree(tb);
return ret;
}
/*
* Have the TPM unseal(decrypt) the symmetric key
*/
static int key_unseal(struct trusted_key_payload *p,
struct trusted_key_options *o)
{
struct tpm_buf *tb;
int ret;
tb = kzalloc(sizeof *tb, GFP_KERNEL);
if (!tb)
return -ENOMEM;
ret = tpm_unseal(tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
o->blobauth, p->key, &p->key_len);
if (ret < 0)
pr_info("trusted_key: srkunseal failed (%d)\n", ret);
else
/* pull migratable flag out of sealed key */
p->migratable = p->key[--p->key_len];
kfree(tb);
return ret;
}
enum {
Opt_err = -1,
Opt_new, Opt_load, Opt_update,
Opt_keyhandle, Opt_keyauth, Opt_blobauth,
Opt_pcrinfo, Opt_pcrlock, Opt_migratable
};
static const match_table_t key_tokens = {
{Opt_new, "new"},
{Opt_load, "load"},
{Opt_update, "update"},
{Opt_keyhandle, "keyhandle=%s"},
{Opt_keyauth, "keyauth=%s"},
{Opt_blobauth, "blobauth=%s"},
{Opt_pcrinfo, "pcrinfo=%s"},
{Opt_pcrlock, "pcrlock=%s"},
{Opt_migratable, "migratable=%s"},
{Opt_err, NULL}
};
/* can have zero or more token= options */
static int getoptions(char *c, struct trusted_key_payload *pay,
struct trusted_key_options *opt)
{
substring_t args[MAX_OPT_ARGS];
char *p = c;
int token;
int res;
unsigned long handle;
unsigned long lock;
while ((p = strsep(&c, " \t"))) {
if (*p == '\0' || *p == ' ' || *p == '\t')
continue;
token = match_token(p, key_tokens, args);
switch (token) {
case Opt_pcrinfo:
opt->pcrinfo_len = strlen(args[0].from) / 2;
if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
return -EINVAL;
hex2bin(opt->pcrinfo, args[0].from, opt->pcrinfo_len);
break;
case Opt_keyhandle:
res = strict_strtoul(args[0].from, 16, &handle);
if (res < 0)
return -EINVAL;
opt->keytype = SEAL_keytype;
opt->keyhandle = handle;
break;
case Opt_keyauth:
if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
return -EINVAL;
hex2bin(opt->keyauth, args[0].from, SHA1_DIGEST_SIZE);
break;
case Opt_blobauth:
if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
return -EINVAL;
hex2bin(opt->blobauth, args[0].from, SHA1_DIGEST_SIZE);
break;
case Opt_migratable:
if (*args[0].from == '0')
pay->migratable = 0;
else
return -EINVAL;
break;
case Opt_pcrlock:
res = strict_strtoul(args[0].from, 10, &lock);
if (res < 0)
return -EINVAL;
opt->pcrlock = lock;
break;
default:
return -EINVAL;
}
}
return 0;
}
/*
* datablob_parse - parse the keyctl data and fill in the
* payload and options structures
*
* On success returns 0, otherwise -EINVAL.
*/
static int datablob_parse(char *datablob, struct trusted_key_payload *p,
struct trusted_key_options *o)
{
substring_t args[MAX_OPT_ARGS];
long keylen;
int ret = -EINVAL;
int key_cmd;
char *c;
/* main command */
c = strsep(&datablob, " \t");
if (!c)
return -EINVAL;
key_cmd = match_token(c, key_tokens, args);
switch (key_cmd) {
case Opt_new:
/* first argument is key size */
c = strsep(&datablob, " \t");
if (!c)
return -EINVAL;
ret = strict_strtol(c, 10, &keylen);
if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
return -EINVAL;
p->key_len = keylen;
ret = getoptions(datablob, p, o);
if (ret < 0)
return ret;
ret = Opt_new;
break;
case Opt_load:
/* first argument is sealed blob */
c = strsep(&datablob, " \t");
if (!c)
return -EINVAL;
p->blob_len = strlen(c) / 2;
if (p->blob_len > MAX_BLOB_SIZE)
return -EINVAL;
hex2bin(p->blob, c, p->blob_len);
ret = getoptions(datablob, p, o);
if (ret < 0)
return ret;
ret = Opt_load;
break;
case Opt_update:
/* all arguments are options */
ret = getoptions(datablob, p, o);
if (ret < 0)
return ret;
ret = Opt_update;
break;
case Opt_err:
return -EINVAL;
break;
}
return ret;
}
static struct trusted_key_options *trusted_options_alloc(void)
{
struct trusted_key_options *options;
options = kzalloc(sizeof *options, GFP_KERNEL);
if (options) {
/* set any non-zero defaults */
options->keytype = SRK_keytype;
options->keyhandle = SRKHANDLE;
}
return options;
}
static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
{
struct trusted_key_payload *p = NULL;
int ret;
ret = key_payload_reserve(key, sizeof *p);
if (ret < 0)
return p;
p = kzalloc(sizeof *p, GFP_KERNEL);
if (p)
p->migratable = 1; /* migratable by default */
return p;
}
/*
* trusted_instantiate - create a new trusted key
*
* Unseal an existing trusted blob or, for a new key, get a
* random key, then seal and create a trusted key-type key,
* adding it to the specified keyring.
*
* On success, return 0. Otherwise return errno.
*/
static int trusted_instantiate(struct key *key, const void *data,
size_t datalen)
{
struct trusted_key_payload *payload = NULL;
struct trusted_key_options *options = NULL;
char *datablob;
int ret = 0;
int key_cmd;
if (datalen <= 0 || datalen > 32767 || !data)
return -EINVAL;
datablob = kmalloc(datalen + 1, GFP_KERNEL);
if (!datablob)
return -ENOMEM;
memcpy(datablob, data, datalen);
datablob[datalen] = '\0';
options = trusted_options_alloc();
if (!options) {
ret = -ENOMEM;
goto out;
}
payload = trusted_payload_alloc(key);
if (!payload) {
ret = -ENOMEM;
goto out;
}
key_cmd = datablob_parse(datablob, payload, options);
if (key_cmd < 0) {
ret = key_cmd;
goto out;
}
dump_payload(payload);
dump_options(options);
switch (key_cmd) {
case Opt_load:
ret = key_unseal(payload, options);
dump_payload(payload);
dump_options(options);
if (ret < 0)
pr_info("trusted_key: key_unseal failed (%d)\n", ret);
break;
case Opt_new:
ret = my_get_random(payload->key, payload->key_len);
if (ret < 0) {
pr_info("trusted_key: key_create failed (%d)\n", ret);
goto out;
}
ret = key_seal(payload, options);
if (ret < 0)
pr_info("trusted_key: key_seal failed (%d)\n", ret);
break;
default:
ret = -EINVAL;
goto out;
}
if (!ret && options->pcrlock)
ret = pcrlock(options->pcrlock);
out:
kfree(datablob);
kfree(options);
if (!ret)
rcu_assign_pointer(key->payload.data, payload);
else
kfree(payload);
return ret;
}
static void trusted_rcu_free(struct rcu_head *rcu)
{
struct trusted_key_payload *p;
p = container_of(rcu, struct trusted_key_payload, rcu);
memset(p->key, 0, p->key_len);
kfree(p);
}
/*