aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/char/tpm/tpm2-cmd.c
blob: d103545e40550bd6b1f71048400db8b217b2cd29 (plain)
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
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2014, 2015 Intel Corporation
 *
 * Authors:
 * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
 *
 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
 *
 * This file contains TPM2 protocol implementations of the commands
 * used by the kernel internally.
 */

#include "tpm.h"
#include <crypto/hash_info.h>
#include <keys/trusted-type.h>

enum tpm2_object_attributes {
	TPM2_OA_USER_WITH_AUTH		= BIT(6),
};

enum tpm2_session_attributes {
	TPM2_SA_CONTINUE_SESSION	= BIT(0),
};

struct tpm2_hash {
	unsigned int crypto_id;
	unsigned int tpm_id;
};

static struct tpm2_hash tpm2_hash_map[] = {
	{HASH_ALGO_SHA1, TPM_ALG_SHA1},
	{HASH_ALGO_SHA256, TPM_ALG_SHA256},
	{HASH_ALGO_SHA384, TPM_ALG_SHA384},
	{HASH_ALGO_SHA512, TPM_ALG_SHA512},
	{HASH_ALGO_SM3_256, TPM_ALG_SM3_256},
};

int tpm2_get_timeouts(struct tpm_chip *chip)
{
	/* Fixed timeouts for TPM2 */
	chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
	chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
	chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
	chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);

	/* PTP spec timeouts */
	chip->duration[TPM_SHORT] = msecs_to_jiffies(TPM2_DURATION_SHORT);
	chip->duration[TPM_MEDIUM] = msecs_to_jiffies(TPM2_DURATION_MEDIUM);
	chip->duration[TPM_LONG] = msecs_to_jiffies(TPM2_DURATION_LONG);

	/* Key creation commands long timeouts */
	chip->duration[TPM_LONG_LONG] =
		msecs_to_jiffies(TPM2_DURATION_LONG_LONG);

	chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;

	return 0;
}

/**
 * tpm2_ordinal_duration_index() - returns an index to the chip duration table
 * @ordinal: TPM command ordinal.
 *
 * The function returns an index to the chip duration table
 * (enum tpm_duration), that describes the maximum amount of
 * time the chip could take to return the result for a  particular ordinal.
 *
 * The values of the MEDIUM, and LONG durations are taken
 * from the PC Client Profile (PTP) specification (750, 2000 msec)
 *
 * LONG_LONG is for commands that generates keys which empirically takes
 * a longer time on some systems.
 *
 * Return:
 * * TPM_MEDIUM
 * * TPM_LONG
 * * TPM_LONG_LONG
 * * TPM_UNDEFINED
 */
static u8 tpm2_ordinal_duration_index(u32 ordinal)
{
	switch (ordinal) {
	/* Startup */
	case TPM2_CC_STARTUP:                 /* 144 */
		return TPM_MEDIUM;

	case TPM2_CC_SELF_TEST:               /* 143 */
		return TPM_LONG;

	case TPM2_CC_GET_RANDOM:              /* 17B */
		return TPM_LONG;

	case TPM2_CC_SEQUENCE_UPDATE:         /* 15C */
		return TPM_MEDIUM;
	case TPM2_CC_SEQUENCE_COMPLETE:       /* 13E */
		return TPM_MEDIUM;
	case TPM2_CC_EVENT_SEQUENCE_COMPLETE: /* 185 */
		return TPM_MEDIUM;
	case TPM2_CC_HASH_SEQUENCE_START:     /* 186 */
		return TPM_MEDIUM;

	case TPM2_CC_VERIFY_SIGNATURE:        /* 177 */
		return TPM_LONG;

	case TPM2_CC_PCR_EXTEND:              /* 182 */
		return TPM_MEDIUM;

	case TPM2_CC_HIERARCHY_CONTROL:       /* 121 */
		return TPM_LONG;
	case TPM2_CC_HIERARCHY_CHANGE_AUTH:   /* 129 */
		return TPM_LONG;

	case TPM2_CC_GET_CAPABILITY:          /* 17A */
		return TPM_MEDIUM;

	case TPM2_CC_NV_READ:                 /* 14E */
		return TPM_LONG;

	case TPM2_CC_CREATE_PRIMARY:          /* 131 */
		return TPM_LONG_LONG;
	case TPM2_CC_CREATE:                  /* 153 */
		return TPM_LONG_LONG;
	case TPM2_CC_CREATE_LOADED:           /* 191 */
		return TPM_LONG_LONG;

	default:
		return TPM_UNDEFINED;
	}
}

/**
 * tpm2_calc_ordinal_duration() - calculate the maximum command duration
 * @chip:    TPM chip to use.
 * @ordinal: TPM command ordinal.
 *
 * The function returns the maximum amount of time the chip could take
 * to return the result for a particular ordinal in jiffies.
 *
 * Return: A maximal duration time for an ordinal in jiffies.
 */
unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
{
	unsigned int index;

	index = tpm2_ordinal_duration_index(ordinal);

	if (index != TPM_UNDEFINED)
		return chip->duration[index];
	else
		return msecs_to_jiffies(TPM2_DURATION_DEFAULT);
}


struct tpm2_pcr_read_out {
	__be32	update_cnt;
	__be32	pcr_selects_cnt;
	__be16	hash_alg;
	u8	pcr_select_size;
	u8	pcr_select[TPM2_PCR_SELECT_MIN];
	__be32	digests_cnt;
	__be16	digest_size;
	u8	digest[];
} __packed;

/**
 * tpm2_pcr_read() - read a PCR value
 * @chip:	TPM chip to use.
 * @pcr_idx:	index of the PCR to read.
 * @digest:	PCR bank and buffer current PCR value is written to.
 * @digest_size_ptr:	pointer to variable that stores the digest size.
 *
 * Return: Same as with tpm_transmit_cmd.
 */
int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
		  struct tpm_digest *digest, u16 *digest_size_ptr)
{
	int i;
	int rc;
	struct tpm_buf buf;
	struct tpm2_pcr_read_out *out;
	u8 pcr_select[TPM2_PCR_SELECT_MIN] = {0};
	u16 digest_size;
	u16 expected_digest_size = 0;

	if (pcr_idx >= TPM2_PLATFORM_PCR)
		return -EINVAL;

	if (!digest_size_ptr) {
		for (i = 0; i < chip->nr_allocated_banks &&
		     chip->allocated_banks[i].alg_id != digest->alg_id; i++)
			;

		if (i == chip->nr_allocated_banks)
			return -EINVAL;

		expected_digest_size = chip->allocated_banks[i].digest_size;
	}

	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_PCR_READ);
	if (rc)
		return rc;

	pcr_select[pcr_idx >> 3] = 1 << (pcr_idx & 0x7);

	tpm_buf_append_u32(&buf, 1);
	tpm_buf_append_u16(&buf, digest->alg_id);
	tpm_buf_append_u8(&buf, TPM2_PCR_SELECT_MIN);
	tpm_buf_append(&buf, (const unsigned char *)pcr_select,
		       sizeof(pcr_select));

	rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to read a pcr value");
	if (rc)
		goto out;

	out = (struct tpm2_pcr_read_out *)&buf.data[TPM_HEADER_SIZE];
	digest_size = be16_to_cpu(out->digest_size);
	if (digest_size > sizeof(digest->digest) ||
	    (!digest_size_ptr && digest_size != expected_digest_size)) {
		rc = -EINVAL;
		goto out;
	}

	if (digest_size_ptr)
		*digest_size_ptr = digest_size;

	memcpy(digest->digest, out->digest, digest_size);
out:
	tpm_buf_destroy(&buf);
	return rc;
}

struct tpm2_null_auth_area {
	__be32  handle;
	__be16  nonce_size;
	u8  attributes;
	__be16  auth_size;
} __packed;

/**
 * tpm2_pcr_extend() - extend a PCR value
 *
 * @chip:	TPM chip to use.
 * @pcr_idx:	index of the PCR.
 * @digests:	list of pcr banks and corresponding digest values to extend.
 *
 * Return: Same as with tpm_transmit_cmd.
 */
int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
		    struct tpm_digest *digests)
{
	struct tpm_buf buf;
	struct tpm2_null_auth_area auth_area;
	int rc;
	int i;

	rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND);
	if (rc)
		return rc;

	tpm_buf_append_u32(&buf, pcr_idx);

	auth_area.handle = cpu_to_be32(TPM2_RS_PW);
	auth_area.nonce_size = 0;
	auth_area.attributes = 0;
	auth_area.auth_size = 0;

	tpm_buf_append_u32(&buf, sizeof(struct tpm2_null_auth_area));
	tpm_buf_append(&buf, (const unsigned char *)&auth_area,
		       sizeof(auth_area));
	tpm_buf_append_u32(&buf, chip->nr_allocated_banks);

	for (i = 0; i < chip->nr_allocated_banks; i++) {
		tpm_buf_append_u16(&buf, digests[i].alg_id);
		tpm_buf_append(&buf, (const unsigned char *)&digests[i].digest,
			       chip->allocated_banks[i].digest_size);
	}

	rc = tpm_transmit_cmd(chip, &buf, 0, "attempting extend a PCR value");

	tpm_buf_destroy(&buf);

	return rc;
}

struct tpm2_get_random_out {
	__be16 size;
	u8 buffer[TPM_MAX_RNG_DATA];
} __packed;

/**
 * tpm2_get_random() - get random bytes from the TPM RNG
 *
 * @chip:	a &tpm_chip instance
 * @dest:	destination buffer
 * @max:	the max number of random bytes to pull
 *
 * Return:
 *   size of the buffer on success,
 *   -errno otherwise (positive TPM return codes are masked to -EIO)
 */
int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
{
	struct tpm2_get_random_out *out;
	struct tpm_buf buf;
	u32 recd;
	u32 num_bytes = max;
	int err;
	int total = 0;
	int retries = 5;
	u8 *dest_ptr = dest;

	if (!num_bytes || max > TPM_MAX_RNG_DATA)
		return -EINVAL;

	err = tpm_buf_init(&buf, 0, 0);
	if (err)
		return err;

	do {
		tpm_buf_reset(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_RANDOM);
		tpm_buf_append_u16(&buf, num_bytes);
		err = tpm_transmit_cmd(chip, &buf,
				       offsetof(struct tpm2_get_random_out,
						buffer),
				       "attempting get random");
		if (err) {
			if (err > 0)
				err = -EIO;
			goto out;
		}

		out = (struct tpm2_get_random_out *)
			&buf.data[TPM_HEADER_SIZE];
		recd = min_t(u32, be16_to_cpu(out->size), num_bytes);
		if (tpm_buf_length(&buf) <
		    TPM_HEADER_SIZE +
		    offsetof(struct tpm2_get_random_out, buffer) +
		    recd) {
			err = -EFAULT;
			goto out;
		}
		memcpy(dest_ptr, out->buffer, recd);

		dest_ptr += recd;
		total += recd;
		num_bytes -= recd;
	} while (retries-- && total < max);

	tpm_buf_destroy(&buf);
	return total ? total : -EIO;
out:
	tpm_buf_destroy(&buf);
	return err;
}

/**
 * tpm2_flush_context() - execute a TPM2_FlushContext command
 * @chip:	TPM chip to use
 * @handle:	context handle
 */
void tpm2_flush_context(struct tpm_chip *chip, u32 handle)
{
	struct tpm_buf buf;
	int rc;

	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_FLUSH_CONTEXT);
	if (rc) {
		dev_warn(&chip->dev, "0x%08x was not flushed, out of memory\n",
			 handle);
		return;
	}

	tpm_buf_append_u32(&buf, handle);

	tpm_transmit_cmd(chip, &buf, 0, "flushing context");
	tpm_buf_destroy(&buf);
}

/**
 * tpm_buf_append_auth() - append TPMS_AUTH_COMMAND to the buffer.
 *
 * @buf: an allocated tpm_buf instance
 * @session_handle: session handle
 * @nonce: the session nonce, may be NULL if not used
 * @nonce_len: the session nonce length, may be 0 if not used
 * @attributes: the session attributes
 * @hmac: the session HMAC or password, may be NULL if not used
 * @hmac_len: the session HMAC or password length, maybe 0 if not used
 */
static void tpm2_buf_append_auth(struct tpm_buf *buf, u32 session_handle,
				 const u8 *nonce, u16 nonce_len,
				 u8 attributes,
				 const u8 *hmac, u16 hmac_len)
{
	tpm_buf_append_u32(buf, 9 + nonce_len + hmac_len);
	tpm_buf_append_u32(buf, session_handle);
	tpm_buf_append_u16(buf, nonce_len);

	if (nonce && nonce_len)
		tpm_buf_append(buf, nonce, nonce_len);

	tpm_buf_append_u8(buf, attributes);
	tpm_buf_append_u16(buf, hmac_len);

	if (hmac && hmac_len)
		tpm_buf_append(buf, hmac, hmac_len);
}

/**
 * tpm2_seal_trusted() - seal the payload of a trusted key
 *
 * @chip: TPM chip to use
 * @payload: the key data in clear and encrypted form
 * @options: authentication values and other options
 *
 * Return: < 0 on error and 0 on success.
 */
int tpm2_seal_trusted(struct tpm_chip *chip,
		      struct trusted_key_payload *payload,
		      struct trusted_key_options *options)
{
	unsigned int blob_len;
	struct tpm_buf buf;
	u32 hash;
	int i;
	int rc;

	for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
		if (options->hash == tpm2_hash_map[i].crypto_id) {
			hash = tpm2_hash_map[i].tpm_id;
			break;
		}
	}

	if (i == ARRAY_SIZE(tpm2_hash_map))
		return -EINVAL;

	rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE);
	if (rc)
		return rc;

	tpm_buf_append_u32(&buf, options->keyhandle);
	tpm2_buf_append_auth(&buf, TPM2_RS_PW,
			     NULL /* nonce */, 0,
			     0 /* session_attributes */,
			     options->keyauth /* hmac */,
			     TPM_DIGEST_SIZE);

	/* sensitive */
	tpm_buf_append_u16(&buf, 4 + TPM_DIGEST_SIZE + payload->key_len + 1);

	tpm_buf_append_u16(&buf, TPM_DIGEST_SIZE);
	tpm_buf_append(&buf, options->blobauth, TPM_DIGEST_SIZE);
	tpm_buf_append_u16(&buf, payload->key_len + 1);
	tpm_buf_append(&buf, payload->key, payload->key_len);
	tpm_buf_append_u8(&buf, payload->migratable);

	/* public */
	tpm_buf_append_u16(&buf, 14 + options->policydigest_len);
	tpm_buf_append_u16(&buf, TPM_ALG_KEYEDHASH);
	tpm_buf_append_u16(&buf, hash);

	/* policy */
	if (options->policydigest_len) {
		tpm_buf_append_u32(&buf, 0);
		tpm_buf_append_u16(&buf, options->policydigest_len);
		tpm_buf_append(&buf, options->policydigest,
			       options->policydigest_len);
	} else {
		tpm_buf_append_u32(&buf, TPM2_OA_USER_WITH_AUTH);
		tpm_buf_append_u16(&buf, 0);
	}

	/* public parameters */
	tpm_buf_append_u16(&buf, TPM_ALG_NULL);
	tpm_buf_append_u16(&buf, 0);

	/* outside info */
	tpm_buf_append_u16(&buf, 0);

	/* creation PCR */
	tpm_buf_append_u32(&buf, 0);

	if (buf.flags & TPM_BUF_OVERFLOW) {
		rc = -E2BIG;
		goto out;
	}

	rc = tpm_transmit_cmd(chip, &buf, 4, "sealing data");
	if (rc)
		goto out;

	blob_len = be32_to_cpup((__be32 *) &buf.data[TPM_HEADER_SIZE]);
	if (blob_len > MAX_BLOB_SIZE) {
		rc = -E2BIG;
		goto out;
	}
	if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 4 + blob_len) {
		rc = -EFAULT;
		goto out;
	}

	memcpy(payload->blob, &buf.data[TPM_HEADER_SIZE + 4], blob_len);
	payload->blob_len = blob_len;

out:
	tpm_buf_destroy(&buf);

	if (rc > 0) {
		if (tpm2_rc_value(rc) == TPM2_RC_HASH)
			rc = -EINVAL;
		else
			rc = -EPERM;
	}

	return rc;
}

/**
 * tpm2_load_cmd() - execute a TPM2_Load command
 *
 * @chip: TPM chip to use
 * @payload: the key data in clear and encrypted form
 * @options: authentication values and other options
 * @blob_handle: returned blob handle
 *
 * Return: 0 on success.
 *        -E2BIG on wrong payload size.
 *        -EPERM on tpm error status.
 *        < 0 error from tpm_transmit_cmd.
 */
static int tpm2_load_cmd(struct tpm_chip *chip,
			 struct trusted_key_payload *payload,
			 struct trusted_key_options *options,
			 u32 *blob_handle)
{
	struct tpm_buf buf;
	unsigned int private_len;
	unsigned int public_len;
	unsigned int blob_len;
	int rc;

	private_len = be16_to_cpup((__be16 *) &payload->blob[0]);
	if (private_len > (payload->blob_len - 2))
		return -E2BIG;

	public_len = be16_to_cpup((__be16 *) &payload->blob[2 + private_len]);
	blob_len = private_len + public_len + 4;
	if (blob_len > payload->blob_len)
		return -E2BIG;

	rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD);
	if (rc)
		return rc;

	tpm_buf_append_u32(&buf, options->keyhandle);
	tpm2_buf_append_auth(&buf, TPM2_RS_PW,
			     NULL /* nonce */, 0,
			     0 /* session_attributes */,
			     options->keyauth /* hmac */,
			     TPM_DIGEST_SIZE);

	tpm_buf_append(&buf, payload->blob, blob_len);

	if (buf.flags & TPM_BUF_OVERFLOW) {
		rc = -E2BIG;
		goto out;
	}

	rc = tpm_transmit_cmd(chip, &buf, 4, "loading blob");
	if (!rc)
		*blob_handle = be32_to_cpup(
			(__be32 *) &buf.data[TPM_HEADER_SIZE]);

out:
	tpm_buf_destroy(&buf);

	if (rc > 0)
		rc = -EPERM;

	return rc;
}

/**
 * tpm2_unseal_cmd() - execute a TPM2_Unload command
 *
 * @chip: TPM chip to use
 * @payload: the key data in clear and encrypted form
 * @options: authentication values and other options
 * @blob_handle: blob handle
 *
 * Return: 0 on success
 *         -EPERM on tpm error status
 *         < 0 error from tpm_transmit_cmd
 */
static int tpm2_unseal_cmd(struct tpm_chip *chip,
			   struct trusted_key_payload *payload,
			   struct trusted_key_options *options,
			   u32 blob_handle)
{
	struct tpm_buf buf;
	u16 data_len;
	u8 *data;
	int rc;

	rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL);
	if (rc)
		return rc;

	tpm_buf_append_u32(&buf, blob_handle);
	tpm2_buf_append_auth(&buf,
			     options->policyhandle ?
			     options->policyhandle : TPM2_RS_PW,
			     NULL /* nonce */, 0,
			     TPM2_SA_CONTINUE_SESSION,
			     options->blobauth /* hmac */,
			     TPM_DIGEST_SIZE);

	rc = tpm_transmit_cmd(chip, &buf, 6, "unsealing");
	if (rc > 0)
		rc = -EPERM;

	if (!rc) {
		data_len = be16_to_cpup(
			(__be16 *) &buf.data[TPM_HEADER_SIZE + 4]);
		if (data_len < MIN_KEY_SIZE ||  data_len > MAX_KEY_SIZE + 1) {
			rc = -EFAULT;
			goto out;
		}

		if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 6 + data_len) {
			rc = -EFAULT;
			goto out;
		}
		data = &buf.data[TPM_HEADER_SIZE + 6];

		memcpy(payload->key, data, data_len - 1);
		payload->key_len = data_len - 1;
		payload->migratable = data[data_len - 1];
	}

out:
	tpm_buf_destroy(&buf);
	return rc;
}

/**
 * tpm2_unseal_trusted() - unseal the payload of a trusted key
 *
 * @chip: TPM chip to use
 * @payload: the key data in clear and encrypted form
 * @options: authentication values and other options
 *
 * Return: Same as with tpm_transmit_cmd.
 */
int tpm2_unseal_trusted(struct tpm_chip *chip,
			struct trusted_key_payload *payload,
			struct trusted_key_options *options)
{
	u32 blob_handle;
	int rc;

	rc = tpm2_load_cmd(chip, payload, options, &blob_handle);
	if (rc)
		return rc;

	rc = tpm2_unseal_cmd(chip, payload, options, blob_handle);
	tpm2_flush_context(chip, blob_handle);
	return rc;
}

struct tpm2_get_cap_out {
	u8 more_data;
	__be32 subcap_id;
	__be32 property_cnt;
	__be32 property_id;
	__be32 value;
} __packed;

/**
 * tpm2_get_tpm_pt() - get value of a TPM_CAP_TPM_PROPERTIES type property
 * @chip:		a &tpm_chip instance
 * @property_id:	property ID.
 * @value:		output variable.
 * @desc:		passed to tpm_transmit_cmd()
 *
 * Return:
 *   0 on success,
 *   -errno or a TPM return code otherwise
 */
ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id,  u32 *value,
			const char *desc)
{
	struct tpm2_get_cap_out *out;
	struct tpm_buf buf;
	int rc;

	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
	if (rc)
		return rc;
	tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
	tpm_buf_append_u32(&buf, property_id);
	tpm_buf_append_u32(&buf, 1);
	rc = tpm_transmit_cmd(chip, &buf, 0, NULL);
	if (!rc) {
		out = (struct tpm2_get_cap_out *)
			&buf.data[TPM_HEADER_SIZE];
		*value = be32_to_cpu(out->value);
	}
	tpm_buf_destroy(&buf);
	return rc;
}
EXPORT_SYMBOL_GPL(tpm2_get_tpm_pt);

/**
 * tpm2_shutdown() - send a TPM shutdown command
 *
 * Sends a TPM shutdown command. The shutdown command is used in call
 * sites where the system is going down. If it fails, there is not much
 * that can be done except print an error message.
 *
 * @chip:		a &tpm_chip instance
 * @shutdown_type:	TPM_SU_CLEAR or TPM_SU_STATE.
 */
void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
{
	struct tpm_buf buf;
	int rc;

	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SHUTDOWN);
	if (rc)
		return;
	tpm_buf_append_u16(&buf, shutdown_type);
	tpm_transmit_cmd(chip, &buf, 0, "stopping the TPM");
	tpm_buf_destroy(&buf);
}

/**
 * tpm2_do_selftest() - ensure that all self tests have passed
 *
 * @chip: TPM chip to use
 *
 * Return: Same as with tpm_transmit_cmd.
 *
 * The TPM can either run all self tests synchronously and then return
 * RC_SUCCESS once all tests were successful. Or it can choose to run the tests
 * asynchronously and return RC_TESTING immediately while the self tests still
 * execute in the background. This function handles both cases and waits until
 * all tests have completed.
 */
static int tpm2_do_selftest(struct tpm_chip *chip)
{
	struct tpm_buf buf;
	int full;
	int rc;

	for (full = 0; full < 2; full++) {
		rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SELF_TEST);
		if (rc)
			return rc;

		tpm_buf_append_u8(&buf, full);
		rc = tpm_transmit_cmd(chip, &buf, 0,
				      "attempting the self test");
		tpm_buf_destroy(&buf);

		if (rc == TPM2_RC_TESTING)
			rc = TPM2_RC_SUCCESS;
		if (rc == TPM2_RC_INITIALIZE || rc == TPM2_RC_SUCCESS)
			return rc;
	}

	return rc;
}

/**
 * tpm2_probe() - probe for the TPM 2.0 protocol
 * @chip:	a &tpm_chip instance
 *
 * Send an idempotent TPM 2.0 command and see whether there is TPM2 chip in the
 * other end based on the response tag. The flag TPM_CHIP_FLAG_TPM2 is set by
 * this function if this is the case.
 *
 * Return:
 *   0 on success,
 *   -errno otherwise
 */
int tpm2_probe(struct tpm_chip *chip)
{
	struct tpm_header *out;
	struct tpm_buf buf;
	int rc;

	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
	if (rc)
		return rc;
	tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
	tpm_buf_append_u32(&buf, TPM_PT_TOTAL_COMMANDS);
	tpm_buf_append_u32(&buf, 1);
	rc = tpm_transmit_cmd(chip, &buf, 0, NULL);
	/* We ignore TPM return codes on purpose. */
	if (rc >=  0) {
		out = (struct tpm_header *)buf.data;
		if (be16_to_cpu(out->tag) == TPM2_ST_NO_SESSIONS)
			chip->flags |= TPM_CHIP_FLAG_TPM2;
	}
	tpm_buf_destroy(&buf);
	return 0;
}
EXPORT_SYMBOL_GPL(tpm2_probe);

static int tpm2_init_bank_info(struct tpm_chip *chip, u32 bank_index)
{
	struct tpm_bank_info *bank = chip->allocated_banks + bank_index;
	struct tpm_digest digest = { .alg_id = bank->alg_id };
	int i;

	/*
	 * Avoid unnecessary PCR read operations to reduce overhead
	 * and obtain identifiers of the crypto subsystem.
	 */
	for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
		enum hash_algo crypto_algo = tpm2_hash_map[i].crypto_id;

		if (bank->alg_id != tpm2_hash_map[i].tpm_id)
			continue;

		bank->digest_size = hash_digest_size[crypto_algo];
		bank->crypto_id = crypto_algo;
		return 0;
	}

	return tpm2_pcr_read(chip, 0, &digest, &bank->digest_size);
}

struct tpm2_pcr_selection {
	__be16  hash_alg;
	u8  size_of_select;
	u8  pcr_select[3];
} __packed;

static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
{
	struct tpm2_pcr_selection pcr_selection;
	struct tpm_buf buf;
	void *marker;
	void *end;
	void *pcr_select_offset;
	u32 sizeof_pcr_selection;
	u32 nr_possible_banks;
	u32 nr_alloc_banks = 0;
	u16 hash_alg;
	u32 rsp_len;
	int rc;
	int i = 0;

	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
	if (rc)
		return rc;

	tpm_buf_append_u32(&buf, TPM2_CAP_PCRS);
	tpm_buf_append_u32(&buf, 0);
	tpm_buf_append_u32(&buf, 1);

	rc = tpm_transmit_cmd(chip, &buf, 9, "get tpm pcr allocation");
	if (rc)
		goto out;

	nr_possible_banks = be32_to_cpup(
		(__be32 *)&buf.data[TPM_HEADER_SIZE + 5]);

	chip->allocated_banks = kcalloc(nr_possible_banks,
					sizeof(*chip->allocated_banks),
					GFP_KERNEL);
	if (!chip->allocated_banks) {
		rc = -ENOMEM;
		goto out;
	}

	marker = &buf.data[TPM_HEADER_SIZE + 9];

	rsp_len = be32_to_cpup((__be32 *)&buf.data[2]);
	end = &buf.data[rsp_len];

	for (i = 0; i < nr_possible_banks; i++) {
		pcr_select_offset = marker +
			offsetof(struct tpm2_pcr_selection, size_of_select);
		if (pcr_select_offset >= end) {
			rc = -EFAULT;
			break;
		}

		memcpy(&pcr_selection, marker, sizeof(pcr_selection));
		hash_alg = be16_to_cpu(pcr_selection.hash_alg);

		pcr_select_offset = memchr_inv(pcr_selection.pcr_select, 0,
					       pcr_selection.size_of_select);
		if (pcr_select_offset) {
			chip->allocated_banks[nr_alloc_banks].alg_id = hash_alg;

			rc = tpm2_init_bank_info(chip, nr_alloc_banks);
			if (rc < 0)
				break;

			nr_alloc_banks++;
		}

		sizeof_pcr_selection = sizeof(pcr_selection.hash_alg) +
			sizeof(pcr_selection.size_of_select) +
			pcr_selection.size_of_select;
		marker = marker + sizeof_pcr_selection;
	}

	chip->nr_allocated_banks = nr_alloc_banks;
out:
	tpm_buf_destroy(&buf);

	return rc;
}

static int tpm2_get_cc_attrs_tbl(struct tpm_chip *chip)
{
	struct tpm_buf buf;
	u32 nr_commands;
	__be32 *attrs;
	u32 cc;
	int i;
	int rc;

	rc = tpm2_get_tpm_pt(chip, TPM_PT_TOTAL_COMMANDS, &nr_commands, NULL);
	if (rc)
		goto out;

	if (nr_commands > 0xFFFFF) {
		rc = -EFAULT;
		goto out;
	}

	chip->cc_attrs_tbl = devm_kcalloc(&chip->dev, 4, nr_commands,
					  GFP_KERNEL);

	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
	if (rc)
		goto out;

	tpm_buf_append_u32(&buf, TPM2_CAP_COMMANDS);
	tpm_buf_append_u32(&buf, TPM2_CC_FIRST);
	tpm_buf_append_u32(&buf, nr_commands);

	rc = tpm_transmit_cmd(chip, &buf, 9 + 4 * nr_commands, NULL);
	if (rc) {
		tpm_buf_destroy(&buf);
		goto out;
	}

	if (nr_commands !=
	    be32_to_cpup((__be32 *)&buf.data[TPM_HEADER_SIZE + 5])) {
		tpm_buf_destroy(&buf);
		goto out;
	}

	chip->nr_commands = nr_commands;

	attrs = (__be32 *)&buf.data[TPM_HEADER_SIZE + 9];
	for (i = 0; i < nr_commands; i++, attrs++) {
		chip->cc_attrs_tbl[i] = be32_to_cpup(attrs);
		cc = chip->cc_attrs_tbl[i] & 0xFFFF;

		if (cc == TPM2_CC_CONTEXT_SAVE || cc == TPM2_CC_FLUSH_CONTEXT) {
			chip->cc_attrs_tbl[i] &=
				~(GENMASK(2, 0) << TPM2_CC_ATTR_CHANDLES);
			chip->cc_attrs_tbl[i] |= 1 << TPM2_CC_ATTR_CHANDLES;
		}
	}

	tpm_buf_destroy(&buf);

out:
	if (rc > 0)
		rc = -ENODEV;
	return rc;
}

/**
 * tpm2_startup - turn on the TPM
 * @chip: TPM chip to use
 *
 * Normally the firmware should start the TPM. This function is provided as a
 * workaround if this does not happen. A legal case for this could be for
 * example when a TPM emulator is used.
 *
 * Return: same as tpm_transmit_cmd()
 */

static int tpm2_startup(struct tpm_chip *chip)
{
	struct tpm_buf buf;
	int rc;

	dev_info(&chip->dev, "starting up the TPM manually\n");

	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_STARTUP);
	if (rc < 0)
		return rc;

	tpm_buf_append_u16(&buf, TPM2_SU_CLEAR);
	rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to start the TPM");
	tpm_buf_destroy(&buf);

	return rc;
}

/**
 * tpm2_auto_startup - Perform the standard automatic TPM initialization
 *                     sequence
 * @chip: TPM chip to use
 *
 * Returns 0 on success, < 0 in case of fatal error.
 */
int tpm2_auto_startup(struct tpm_chip *chip)
{
	int rc;

	rc = tpm2_get_timeouts(chip);
	if (rc)
		goto out;

	rc = tpm2_do_selftest(chip);
	if (rc && rc != TPM2_RC_INITIALIZE)
		goto out;

	if (rc == TPM2_RC_INITIALIZE) {
		rc = tpm2_startup(chip);
		if (rc)
			goto out;

		rc = tpm2_do_selftest(chip);
		if (rc)
			goto out;
	}

	rc = tpm2_get_pcr_allocation(chip);
	if (rc)
		goto out;

	rc = tpm2_get_cc_attrs_tbl(chip);

out:
	if (rc > 0)
		rc = -ENODEV;
	return rc;
}

int tpm2_find_cc(struct tpm_chip *chip, u32 cc)
{
	int i;

	for (i = 0; i < chip->nr_commands; i++)
		if (cc == (chip->cc_attrs_tbl[i] & GENMASK(15, 0)))
			return i;

	return -1;
}

Privacy Policy