1
// SPDX-License-Identifier: GPL-2.0-only
2
/*
3
 * Copyright (C) 2010 IBM Corporation
4
 * Copyright (c) 2019-2021, Linaro Limited
5
 *
6
 * See Documentation/security/keys/trusted-encrypted.rst
7
 */
8

9
#include <crypto/hash_info.h>
10
#include <crypto/sha1.h>
11
#include <crypto/utils.h>
12
#include <linux/init.h>
13
#include <linux/slab.h>
14
#include <linux/parser.h>
15
#include <linux/string.h>
16
#include <linux/err.h>
17
#include <keys/trusted-type.h>
18
#include <linux/key-type.h>
19
#include <linux/tpm.h>
20
#include <linux/tpm_command.h>
21

22
#include <keys/trusted_tpm.h>
23

24
static struct tpm_chip *chip;
25
static struct tpm_digest *digests;
26

27
/* implementation specific TPM constants */
28
#define TPM_SIZE_OFFSET			2
29
#define TPM_RETURN_OFFSET		6
30
#define TPM_DATA_OFFSET			10
31

32
#define LOAD32(buffer, offset)	(ntohl(*(uint32_t *)&buffer[offset]))
33
#define LOAD32N(buffer, offset)	(*(uint32_t *)&buffer[offset])
34
#define LOAD16(buffer, offset)	(ntohs(*(uint16_t *)&buffer[offset]))
35

36
struct osapsess {
37
	uint32_t handle;
38
	unsigned char secret[SHA1_DIGEST_SIZE];
39
	unsigned char enonce[TPM_NONCE_SIZE];
40
};
41

42
/* discrete values, but have to store in uint16_t for TPM use */
43
enum {
44
	SEAL_keytype = 1,
45
	SRK_keytype = 4
46
};
47

48
#define TPM_DEBUG 0
49

50
#if TPM_DEBUG
51
static inline void dump_options(struct trusted_key_options *o)
52
{
53
	pr_info("sealing key type %d\n", o->keytype);
54
	pr_info("sealing key handle %0X\n", o->keyhandle);
55
	pr_info("pcrlock %d\n", o->pcrlock);
56
	pr_info("pcrinfo %d\n", o->pcrinfo_len);
57
	print_hex_dump(KERN_INFO, "pcrinfo ", DUMP_PREFIX_NONE,
58
		       16, 1, o->pcrinfo, o->pcrinfo_len, 0);
59
}
60

61
static inline void dump_sess(struct osapsess *s)
62
{
63
	print_hex_dump(KERN_INFO, "trusted-key: handle ", DUMP_PREFIX_NONE,
64
		       16, 1, &s->handle, 4, 0);
65
	pr_info("secret:\n");
66
	print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE,
67
		       16, 1, &s->secret, SHA1_DIGEST_SIZE, 0);
68
	pr_info("trusted-key: enonce:\n");
69
	print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE,
70
		       16, 1, &s->enonce, SHA1_DIGEST_SIZE, 0);
71
}
72

73
static inline void dump_tpm_buf(unsigned char *buf)
74
{
75
	int len;
76

77
	pr_info("\ntpm buffer\n");
78
	len = LOAD32(buf, TPM_SIZE_OFFSET);
79
	print_hex_dump(KERN_INFO, "", DUMP_PREFIX_NONE, 16, 1, buf, len, 0);
80
}
81
#else
82
static inline void dump_options(struct trusted_key_options *o)
83
{
84
}
85

86
static inline void dump_sess(struct osapsess *s)
87
{
88
}
89

90
static inline void dump_tpm_buf(unsigned char *buf)
91
{
92
}
93
#endif
94

95
static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
96
		       unsigned int keylen, ...)
97
{
98
	struct hmac_sha1_ctx hmac_ctx;
99
	va_list argp;
100
	unsigned int dlen;
101
	unsigned char *data;
102
	int ret = 0;
103

104
	hmac_sha1_init_usingrawkey(&hmac_ctx, key, keylen);
105

106
	va_start(argp, keylen);
107
	for (;;) {
108
		dlen = va_arg(argp, unsigned int);
109
		if (dlen == 0)
110
			break;
111
		data = va_arg(argp, unsigned char *);
112
		if (data == NULL) {
113
			ret = -EINVAL;
114
			break;
115
		}
116
		hmac_sha1_update(&hmac_ctx, data, dlen);
117
	}
118
	va_end(argp);
119
	if (!ret)
120
		hmac_sha1_final(&hmac_ctx, digest);
121
	return ret;
122
}
123

124
/*
125
 * calculate authorization info fields to send to TPM
126
 */
127
static int TSS_authhmac(unsigned char *digest, const unsigned char *key,
128
			unsigned int keylen, unsigned char *h1,
129
			unsigned char *h2, unsigned int h3, ...)
130
{
131
	unsigned char paramdigest[SHA1_DIGEST_SIZE];
132
	struct sha1_ctx sha_ctx;
133
	unsigned int dlen;
134
	unsigned char *data;
135
	unsigned char c;
136
	int ret = 0;
137
	va_list argp;
138

139
	if (!chip)
140
		return -ENODEV;
141

142
	c = !!h3;
143
	sha1_init(&sha_ctx);
144
	va_start(argp, h3);
145
	for (;;) {
146
		dlen = va_arg(argp, unsigned int);
147
		if (dlen == 0)
148
			break;
149
		data = va_arg(argp, unsigned char *);
150
		if (!data) {
151
			ret = -EINVAL;
152
			break;
153
		}
154
		sha1_update(&sha_ctx, data, dlen);
155
	}
156
	va_end(argp);
157
	if (!ret)
158
		sha1_final(&sha_ctx, paramdigest);
159
	if (!ret)
160
		ret = TSS_rawhmac(digest, key, keylen, SHA1_DIGEST_SIZE,
161
				  paramdigest, TPM_NONCE_SIZE, h1,
162
				  TPM_NONCE_SIZE, h2, 1, &c, 0, 0);
163
	return ret;
164
}
165

166
/*
167
 * verify the AUTH1_COMMAND (Seal) result from TPM
168
 */
169
static int TSS_checkhmac1(unsigned char *buffer,
170
			  const uint32_t command,
171
			  const unsigned char *ononce,
172
			  const unsigned char *key,
173
			  unsigned int keylen, ...)
174
{
175
	uint32_t bufsize;
176
	uint16_t tag;
177
	uint32_t ordinal;
178
	uint32_t result;
179
	unsigned char *enonce;
180
	unsigned char *continueflag;
181
	unsigned char *authdata;
182
	unsigned char testhmac[SHA1_DIGEST_SIZE];
183
	unsigned char paramdigest[SHA1_DIGEST_SIZE];
184
	struct sha1_ctx sha_ctx;
185
	unsigned int dlen;
186
	unsigned int dpos;
187
	va_list argp;
188
	int ret;
189

190
	if (!chip)
191
		return -ENODEV;
192

193
	bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
194
	tag = LOAD16(buffer, 0);
195
	ordinal = command;
196
	result = LOAD32N(buffer, TPM_RETURN_OFFSET);
197
	if (tag == TPM_TAG_RSP_COMMAND)
198
		return 0;
199
	if (tag != TPM_TAG_RSP_AUTH1_COMMAND)
200
		return -EINVAL;
201
	authdata = buffer + bufsize - SHA1_DIGEST_SIZE;
202
	continueflag = authdata - 1;
203
	enonce = continueflag - TPM_NONCE_SIZE;
204

205
	sha1_init(&sha_ctx);
206
	sha1_update(&sha_ctx, (const u8 *)&result, sizeof(result));
207
	sha1_update(&sha_ctx, (const u8 *)&ordinal, sizeof(ordinal));
208
	va_start(argp, keylen);
209
	for (;;) {
210
		dlen = va_arg(argp, unsigned int);
211
		if (dlen == 0)
212
			break;
213
		dpos = va_arg(argp, unsigned int);
214
		sha1_update(&sha_ctx, buffer + dpos, dlen);
215
	}
216
	va_end(argp);
217
	sha1_final(&sha_ctx, paramdigest);
218

219
	ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest,
220
			  TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce,
221
			  1, continueflag, 0, 0);
222
	if (ret < 0)
223
		return ret;
224

225
	if (crypto_memneq(testhmac, authdata, SHA1_DIGEST_SIZE))
226
		return -EINVAL;
227
	return 0;
228
}
229

230
/*
231
 * verify the AUTH2_COMMAND (unseal) result from TPM
232
 */
233
static int TSS_checkhmac2(unsigned char *buffer,
234
			  const uint32_t command,
235
			  const unsigned char *ononce,
236
			  const unsigned char *key1,
237
			  unsigned int keylen1,
238
			  const unsigned char *key2,
239
			  unsigned int keylen2, ...)
240
{
241
	uint32_t bufsize;
242
	uint16_t tag;
243
	uint32_t ordinal;
244
	uint32_t result;
245
	unsigned char *enonce1;
246
	unsigned char *continueflag1;
247
	unsigned char *authdata1;
248
	unsigned char *enonce2;
249
	unsigned char *continueflag2;
250
	unsigned char *authdata2;
251
	unsigned char testhmac1[SHA1_DIGEST_SIZE];
252
	unsigned char testhmac2[SHA1_DIGEST_SIZE];
253
	unsigned char paramdigest[SHA1_DIGEST_SIZE];
254
	struct sha1_ctx sha_ctx;
255
	unsigned int dlen;
256
	unsigned int dpos;
257
	va_list argp;
258
	int ret;
259

260
	bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
261
	tag = LOAD16(buffer, 0);
262
	ordinal = command;
263
	result = LOAD32N(buffer, TPM_RETURN_OFFSET);
264

265
	if (tag == TPM_TAG_RSP_COMMAND)
266
		return 0;
267
	if (tag != TPM_TAG_RSP_AUTH2_COMMAND)
268
		return -EINVAL;
269
	authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1
270
			+ SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE);
271
	authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE);
272
	continueflag1 = authdata1 - 1;
273
	continueflag2 = authdata2 - 1;
274
	enonce1 = continueflag1 - TPM_NONCE_SIZE;
275
	enonce2 = continueflag2 - TPM_NONCE_SIZE;
276

277
	sha1_init(&sha_ctx);
278
	sha1_update(&sha_ctx, (const u8 *)&result, sizeof(result));
279
	sha1_update(&sha_ctx, (const u8 *)&ordinal, sizeof(ordinal));
280

281
	va_start(argp, keylen2);
282
	for (;;) {
283
		dlen = va_arg(argp, unsigned int);
284
		if (dlen == 0)
285
			break;
286
		dpos = va_arg(argp, unsigned int);
287
		sha1_update(&sha_ctx, buffer + dpos, dlen);
288
	}
289
	va_end(argp);
290
	sha1_final(&sha_ctx, paramdigest);
291

292
	ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE,
293
			  paramdigest, TPM_NONCE_SIZE, enonce1,
294
			  TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0);
295
	if (ret < 0)
296
		return ret;
297
	if (crypto_memneq(testhmac1, authdata1, SHA1_DIGEST_SIZE))
298
		return -EINVAL;
299
	ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE,
300
			  paramdigest, TPM_NONCE_SIZE, enonce2,
301
			  TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0);
302
	if (ret < 0)
303
		return ret;
304
	if (crypto_memneq(testhmac2, authdata2, SHA1_DIGEST_SIZE))
305
		return -EINVAL;
306
	return 0;
307
}
308

309
/*
310
 * For key specific tpm requests, we will generate and send our
311
 * own TPM command packets using the drivers send function.
312
 */
313
static int trusted_tpm_send(unsigned char *cmd, size_t buflen)
314
{
315
	struct tpm_buf buf;
316
	int rc;
317

318
	if (!chip)
319
		return -ENODEV;
320

321
	rc = tpm_try_get_ops(chip);
322
	if (rc)
323
		return rc;
324

325
	buf.flags = 0;
326
	buf.length = buflen;
327
	buf.data = cmd;
328
	dump_tpm_buf(cmd);
329
	rc = tpm_transmit_cmd(chip, &buf, 4, "sending data");
330
	dump_tpm_buf(cmd);
331

332
	if (rc > 0)
333
		/* TPM error */
334
		rc = -EPERM;
335

336
	tpm_put_ops(chip);
337
	return rc;
338
}
339

340
/*
341
 * Lock a trusted key, by extending a selected PCR.
342
 *
343
 * Prevents a trusted key that is sealed to PCRs from being accessed.
344
 * This uses the tpm driver's extend function.
345
 */
346
static int pcrlock(const int pcrnum)
347
{
348
	if (!capable(CAP_SYS_ADMIN))
349
		return -EPERM;
350

351
	return tpm_pcr_extend(chip, pcrnum, digests) ? -EINVAL : 0;
352
}
353

354
/*
355
 * Create an object specific authorisation protocol (OSAP) session
356
 */
357
static int osap(struct tpm_buf *tb, struct osapsess *s,
358
		const unsigned char *key, uint16_t type, uint32_t handle)
359
{
360
	unsigned char enonce[TPM_NONCE_SIZE];
361
	unsigned char ononce[TPM_NONCE_SIZE];
362
	int ret;
363

364
	ret = tpm_get_random(chip, ononce, TPM_NONCE_SIZE);
365
	if (ret < 0)
366
		return ret;
367

368
	if (ret != TPM_NONCE_SIZE)
369
		return -EIO;
370

371
	tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OSAP);
372
	tpm_buf_append_u16(tb, type);
373
	tpm_buf_append_u32(tb, handle);
374
	tpm_buf_append(tb, ononce, TPM_NONCE_SIZE);
375

376
	ret = trusted_tpm_send(tb->data, tb->length);
377
	if (ret < 0)
378
		return ret;
379

380
	s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
381
	memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
382
	       TPM_NONCE_SIZE);
383
	memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
384
				  TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
385
	return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
386
			   enonce, TPM_NONCE_SIZE, ononce, 0, 0);
387
}
388

389
/*
390
 * Create an object independent authorisation protocol (oiap) session
391
 */
392
static int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
393
{
394
	int ret;
395

396
	if (!chip)
397
		return -ENODEV;
398

399
	tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OIAP);
400
	ret = trusted_tpm_send(tb->data, tb->length);
401
	if (ret < 0)
402
		return ret;
403

404
	*handle = LOAD32(tb->data, TPM_DATA_OFFSET);
405
	memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
406
	       TPM_NONCE_SIZE);
407
	return 0;
408
}
409

410
struct tpm_digests {
411
	unsigned char encauth[SHA1_DIGEST_SIZE];
412
	unsigned char pubauth[SHA1_DIGEST_SIZE];
413
	unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
414
	unsigned char xorhash[SHA1_DIGEST_SIZE];
415
	unsigned char nonceodd[TPM_NONCE_SIZE];
416
};
417

418
/*
419
 * Have the TPM seal(encrypt) the trusted key, possibly based on
420
 * Platform Configuration Registers (PCRs). AUTH1 for sealing key.
421
 */
422
static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
423
		    uint32_t keyhandle, const unsigned char *keyauth,
424
		    const unsigned char *data, uint32_t datalen,
425
		    unsigned char *blob, uint32_t *bloblen,
426
		    const unsigned char *blobauth,
427
		    const unsigned char *pcrinfo, uint32_t pcrinfosize)
428
{
429
	struct osapsess sess;
430
	struct tpm_digests *td;
431
	unsigned char cont;
432
	uint32_t ordinal;
433
	uint32_t pcrsize;
434
	uint32_t datsize;
435
	int sealinfosize;
436
	int encdatasize;
437
	int storedsize;
438
	int ret;
439
	int i;
440

441
	/* alloc some work space for all the hashes */
442
	td = kmalloc(sizeof *td, GFP_KERNEL);
443
	if (!td)
444
		return -ENOMEM;
445

446
	/* get session for sealing key */
447
	ret = osap(tb, &sess, keyauth, keytype, keyhandle);
448
	if (ret < 0)
449
		goto out;
450
	dump_sess(&sess);
451

452
	/* calculate encrypted authorization value */
453
	memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
454
	memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
455
	sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
456

457
	ret = tpm_get_random(chip, td->nonceodd, TPM_NONCE_SIZE);
458
	if (ret < 0)
459
		goto out;
460

461
	if (ret != TPM_NONCE_SIZE) {
462
		ret = -EIO;
463
		goto out;
464
	}
465

466
	ordinal = htonl(TPM_ORD_SEAL);
467
	datsize = htonl(datalen);
468
	pcrsize = htonl(pcrinfosize);
469
	cont = 0;
470

471
	/* encrypt data authorization key */
472
	for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
473
		td->encauth[i] = td->xorhash[i] ^ blobauth[i];
474

475
	/* calculate authorization HMAC value */
476
	if (pcrinfosize == 0) {
477
		/* no pcr info specified */
478
		ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
479
				   sess.enonce, td->nonceodd, cont,
480
				   sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
481
				   td->encauth, sizeof(uint32_t), &pcrsize,
482
				   sizeof(uint32_t), &datsize, datalen, data, 0,
483
				   0);
484
	} else {
485
		/* pcr info specified */
486
		ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
487
				   sess.enonce, td->nonceodd, cont,
488
				   sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
489
				   td->encauth, sizeof(uint32_t), &pcrsize,
490
				   pcrinfosize, pcrinfo, sizeof(uint32_t),
491
				   &datsize, datalen, data, 0, 0);
492
	}
493
	if (ret < 0)
494
		goto out;
495

496
	/* build and send the TPM request packet */
497
	tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_SEAL);
498
	tpm_buf_append_u32(tb, keyhandle);
499
	tpm_buf_append(tb, td->encauth, SHA1_DIGEST_SIZE);
500
	tpm_buf_append_u32(tb, pcrinfosize);
501
	tpm_buf_append(tb, pcrinfo, pcrinfosize);
502
	tpm_buf_append_u32(tb, datalen);
503
	tpm_buf_append(tb, data, datalen);
504
	tpm_buf_append_u32(tb, sess.handle);
505
	tpm_buf_append(tb, td->nonceodd, TPM_NONCE_SIZE);
506
	tpm_buf_append_u8(tb, cont);
507
	tpm_buf_append(tb, td->pubauth, SHA1_DIGEST_SIZE);
508

509
	ret = trusted_tpm_send(tb->data, tb->length);
510
	if (ret < 0)
511
		goto out;
512

513
	/* calculate the size of the returned Blob */
514
	sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
515
	encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
516
			     sizeof(uint32_t) + sealinfosize);
517
	storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
518
	    sizeof(uint32_t) + encdatasize;
519

520
	/* check the HMAC in the response */
521
	ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
522
			     SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
523
			     0);
524

525
	/* copy the returned blob to caller */
526
	if (!ret) {
527
		memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
528
		*bloblen = storedsize;
529
	}
530
out:
531
	kfree_sensitive(td);
532
	return ret;
533
}
534

535
/*
536
 * use the AUTH2_COMMAND form of unseal, to authorize both key and blob
537
 */
538
static int tpm_unseal(struct tpm_buf *tb,
539
		      uint32_t keyhandle, const unsigned char *keyauth,
540
		      const unsigned char *blob, int bloblen,
541
		      const unsigned char *blobauth,
542
		      unsigned char *data, unsigned int *datalen)
543
{
544
	unsigned char nonceodd[TPM_NONCE_SIZE];
545
	unsigned char enonce1[TPM_NONCE_SIZE];
546
	unsigned char enonce2[TPM_NONCE_SIZE];
547
	unsigned char authdata1[SHA1_DIGEST_SIZE];
548
	unsigned char authdata2[SHA1_DIGEST_SIZE];
549
	uint32_t authhandle1 = 0;
550
	uint32_t authhandle2 = 0;
551
	unsigned char cont = 0;
552
	uint32_t ordinal;
553
	int ret;
554

555
	/* sessions for unsealing key and data */
556
	ret = oiap(tb, &authhandle1, enonce1);
557
	if (ret < 0) {
558
		pr_info("oiap failed (%d)\n", ret);
559
		return ret;
560
	}
561
	ret = oiap(tb, &authhandle2, enonce2);
562
	if (ret < 0) {
563
		pr_info("oiap failed (%d)\n", ret);
564
		return ret;
565
	}
566

567
	ordinal = htonl(TPM_ORD_UNSEAL);
568
	ret = tpm_get_random(chip, nonceodd, TPM_NONCE_SIZE);
569
	if (ret < 0)
570
		return ret;
571

572
	if (ret != TPM_NONCE_SIZE) {
573
		pr_info("tpm_get_random failed (%d)\n", ret);
574
		return -EIO;
575
	}
576
	ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
577
			   enonce1, nonceodd, cont, sizeof(uint32_t),
578
			   &ordinal, bloblen, blob, 0, 0);
579
	if (ret < 0)
580
		return ret;
581
	ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
582
			   enonce2, nonceodd, cont, sizeof(uint32_t),
583
			   &ordinal, bloblen, blob, 0, 0);
584
	if (ret < 0)
585
		return ret;
586

587
	/* build and send TPM request packet */
588
	tpm_buf_reset(tb, TPM_TAG_RQU_AUTH2_COMMAND, TPM_ORD_UNSEAL);
589
	tpm_buf_append_u32(tb, keyhandle);
590
	tpm_buf_append(tb, blob, bloblen);
591
	tpm_buf_append_u32(tb, authhandle1);
592
	tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
593
	tpm_buf_append_u8(tb, cont);
594
	tpm_buf_append(tb, authdata1, SHA1_DIGEST_SIZE);
595
	tpm_buf_append_u32(tb, authhandle2);
596
	tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
597
	tpm_buf_append_u8(tb, cont);
598
	tpm_buf_append(tb, authdata2, SHA1_DIGEST_SIZE);
599

600
	ret = trusted_tpm_send(tb->data, tb->length);
601
	if (ret < 0) {
602
		pr_info("authhmac failed (%d)\n", ret);
603
		return ret;
604
	}
605

606
	*datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
607
	ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
608
			     keyauth, SHA1_DIGEST_SIZE,
609
			     blobauth, SHA1_DIGEST_SIZE,
610
			     sizeof(uint32_t), TPM_DATA_OFFSET,
611
			     *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
612
			     0);
613
	if (ret < 0) {
614
		pr_info("TSS_checkhmac2 failed (%d)\n", ret);
615
		return ret;
616
	}
617
	memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
618
	return 0;
619
}
620

621
/*
622
 * Have the TPM seal(encrypt) the symmetric key
623
 */
624
static int key_seal(struct trusted_key_payload *p,
625
		    struct trusted_key_options *o)
626
{
627
	struct tpm_buf tb;
628
	int ret;
629

630
	ret = tpm_buf_init(&tb, 0, 0);
631
	if (ret)
632
		return ret;
633

634
	/* include migratable flag at end of sealed key */
635
	p->key[p->key_len] = p->migratable;
636

637
	ret = tpm_seal(&tb, o->keytype, o->keyhandle, o->keyauth,
638
		       p->key, p->key_len + 1, p->blob, &p->blob_len,
639
		       o->blobauth, o->pcrinfo, o->pcrinfo_len);
640
	if (ret < 0)
641
		pr_info("srkseal failed (%d)\n", ret);
642

643
	tpm_buf_destroy(&tb);
644
	return ret;
645
}
646

647
/*
648
 * Have the TPM unseal(decrypt) the symmetric key
649
 */
650
static int key_unseal(struct trusted_key_payload *p,
651
		      struct trusted_key_options *o)
652
{
653
	struct tpm_buf tb;
654
	int ret;
655

656
	ret = tpm_buf_init(&tb, 0, 0);
657
	if (ret)
658
		return ret;
659

660
	ret = tpm_unseal(&tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
661
			 o->blobauth, p->key, &p->key_len);
662
	if (ret < 0)
663
		pr_info("srkunseal failed (%d)\n", ret);
664
	else
665
		/* pull migratable flag out of sealed key */
666
		p->migratable = p->key[--p->key_len];
667

668
	tpm_buf_destroy(&tb);
669
	return ret;
670
}
671

672
enum {
673
	Opt_err,
674
	Opt_keyhandle, Opt_keyauth, Opt_blobauth,
675
	Opt_pcrinfo, Opt_pcrlock, Opt_migratable,
676
	Opt_hash,
677
	Opt_policydigest,
678
	Opt_policyhandle,
679
};
680

681
static const match_table_t key_tokens = {
682
	{Opt_keyhandle, "keyhandle=%s"},
683
	{Opt_keyauth, "keyauth=%s"},
684
	{Opt_blobauth, "blobauth=%s"},
685
	{Opt_pcrinfo, "pcrinfo=%s"},
686
	{Opt_pcrlock, "pcrlock=%s"},
687
	{Opt_migratable, "migratable=%s"},
688
	{Opt_hash, "hash=%s"},
689
	{Opt_policydigest, "policydigest=%s"},
690
	{Opt_policyhandle, "policyhandle=%s"},
691
	{Opt_err, NULL}
692
};
693

694
/* can have zero or more token= options */
695
static int getoptions(char *c, struct trusted_key_payload *pay,
696
		      struct trusted_key_options *opt)
697
{
698
	substring_t args[MAX_OPT_ARGS];
699
	char *p = c;
700
	int token;
701
	int res;
702
	unsigned long handle;
703
	unsigned long lock;
704
	unsigned long token_mask = 0;
705
	unsigned int digest_len;
706
	int i;
707
	int tpm2;
708

709
	tpm2 = tpm_is_tpm2(chip);
710
	if (tpm2 < 0)
711
		return tpm2;
712

713
	opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1;
714

715
	if (!c)
716
		return 0;
717

718
	while ((p = strsep(&c, " \t"))) {
719
		if (*p == '\0' || *p == ' ' || *p == '\t')
720
			continue;
721
		token = match_token(p, key_tokens, args);
722
		if (test_and_set_bit(token, &token_mask))
723
			return -EINVAL;
724

725
		switch (token) {
726
		case Opt_pcrinfo:
727
			opt->pcrinfo_len = strlen(args[0].from) / 2;
728
			if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
729
				return -EINVAL;
730
			res = hex2bin(opt->pcrinfo, args[0].from,
731
				      opt->pcrinfo_len);
732
			if (res < 0)
733
				return -EINVAL;
734
			break;
735
		case Opt_keyhandle:
736
			res = kstrtoul(args[0].from, 16, &handle);
737
			if (res < 0)
738
				return -EINVAL;
739
			opt->keytype = SEAL_keytype;
740
			opt->keyhandle = handle;
741
			break;
742
		case Opt_keyauth:
743
			if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
744
				return -EINVAL;
745
			res = hex2bin(opt->keyauth, args[0].from,
746
				      SHA1_DIGEST_SIZE);
747
			if (res < 0)
748
				return -EINVAL;
749
			break;
750
		case Opt_blobauth:
751
			/*
752
			 * TPM 1.2 authorizations are sha1 hashes passed in as
753
			 * hex strings.  TPM 2.0 authorizations are simple
754
			 * passwords (although it can take a hash as well)
755
			 */
756
			opt->blobauth_len = strlen(args[0].from);
757

758
			if (opt->blobauth_len == 2 * TPM_DIGEST_SIZE) {
759
				res = hex2bin(opt->blobauth, args[0].from,
760
					      TPM_DIGEST_SIZE);
761
				if (res < 0)
762
					return -EINVAL;
763

764
				opt->blobauth_len = TPM_DIGEST_SIZE;
765
				break;
766
			}
767

768
			if (tpm2 && opt->blobauth_len <= sizeof(opt->blobauth)) {
769
				memcpy(opt->blobauth, args[0].from,
770
				       opt->blobauth_len);
771
				break;
772
			}
773

774
			return -EINVAL;
775

776
			break;
777

778
		case Opt_migratable:
779
			if (*args[0].from == '0')
780
				pay->migratable = 0;
781
			else if (*args[0].from != '1')
782
				return -EINVAL;
783
			break;
784
		case Opt_pcrlock:
785
			res = kstrtoul(args[0].from, 10, &lock);
786
			if (res < 0)
787
				return -EINVAL;
788
			opt->pcrlock = lock;
789
			break;
790
		case Opt_hash:
791
			if (test_bit(Opt_policydigest, &token_mask))
792
				return -EINVAL;
793
			for (i = 0; i < HASH_ALGO__LAST; i++) {
794
				if (!strcmp(args[0].from, hash_algo_name[i])) {
795
					opt->hash = i;
796
					break;
797
				}
798
			}
799
			if (i == HASH_ALGO__LAST)
800
				return -EINVAL;
801
			if  (!tpm2 && i != HASH_ALGO_SHA1) {
802
				pr_info("TPM 1.x only supports SHA-1.\n");
803
				return -EINVAL;
804
			}
805
			break;
806
		case Opt_policydigest:
807
			digest_len = hash_digest_size[opt->hash];
808
			if (!tpm2 || strlen(args[0].from) != (2 * digest_len))
809
				return -EINVAL;
810
			res = hex2bin(opt->policydigest, args[0].from,
811
				      digest_len);
812
			if (res < 0)
813
				return -EINVAL;
814
			opt->policydigest_len = digest_len;
815
			break;
816
		case Opt_policyhandle:
817
			if (!tpm2)
818
				return -EINVAL;
819
			res = kstrtoul(args[0].from, 16, &handle);
820
			if (res < 0)
821
				return -EINVAL;
822
			opt->policyhandle = handle;
823
			break;
824
		default:
825
			return -EINVAL;
826
		}
827
	}
828
	return 0;
829
}
830

831
static struct trusted_key_options *trusted_options_alloc(void)
832
{
833
	struct trusted_key_options *options;
834
	int tpm2;
835

836
	tpm2 = tpm_is_tpm2(chip);
837
	if (tpm2 < 0)
838
		return NULL;
839

840
	options = kzalloc(sizeof *options, GFP_KERNEL);
841
	if (options) {
842
		/* set any non-zero defaults */
843
		options->keytype = SRK_keytype;
844

845
		if (!tpm2)
846
			options->keyhandle = SRKHANDLE;
847
	}
848
	return options;
849
}
850

851
static int trusted_tpm_seal(struct trusted_key_payload *p, char *datablob)
852
{
853
	struct trusted_key_options *options = NULL;
854
	int ret = 0;
855
	int tpm2;
856

857
	tpm2 = tpm_is_tpm2(chip);
858
	if (tpm2 < 0)
859
		return tpm2;
860

861
	options = trusted_options_alloc();
862
	if (!options)
863
		return -ENOMEM;
864

865
	ret = getoptions(datablob, p, options);
866
	if (ret < 0)
867
		goto out;
868
	dump_options(options);
869

870
	if (!options->keyhandle && !tpm2) {
871
		ret = -EINVAL;
872
		goto out;
873
	}
874

875
	if (tpm2)
876
		ret = tpm2_seal_trusted(chip, p, options);
877
	else
878
		ret = key_seal(p, options);
879
	if (ret < 0) {
880
		pr_info("key_seal failed (%d)\n", ret);
881
		goto out;
882
	}
883

884
	if (options->pcrlock) {
885
		ret = pcrlock(options->pcrlock);
886
		if (ret < 0) {
887
			pr_info("pcrlock failed (%d)\n", ret);
888
			goto out;
889
		}
890
	}
891
out:
892
	kfree_sensitive(options);
893
	return ret;
894
}
895

896
static int trusted_tpm_unseal(struct trusted_key_payload *p, char *datablob)
897
{
898
	struct trusted_key_options *options = NULL;
899
	int ret = 0;
900
	int tpm2;
901

902
	tpm2 = tpm_is_tpm2(chip);
903
	if (tpm2 < 0)
904
		return tpm2;
905

906
	options = trusted_options_alloc();
907
	if (!options)
908
		return -ENOMEM;
909

910
	ret = getoptions(datablob, p, options);
911
	if (ret < 0)
912
		goto out;
913
	dump_options(options);
914

915
	if (!options->keyhandle && !tpm2) {
916
		ret = -EINVAL;
917
		goto out;
918
	}
919

920
	if (tpm2)
921
		ret = tpm2_unseal_trusted(chip, p, options);
922
	else
923
		ret = key_unseal(p, options);
924
	if (ret < 0)
925
		pr_info("key_unseal failed (%d)\n", ret);
926

927
	if (options->pcrlock) {
928
		ret = pcrlock(options->pcrlock);
929
		if (ret < 0) {
930
			pr_info("pcrlock failed (%d)\n", ret);
931
			goto out;
932
		}
933
	}
934
out:
935
	kfree_sensitive(options);
936
	return ret;
937
}
938

939
static int trusted_tpm_get_random(unsigned char *key, size_t key_len)
940
{
941
	return tpm_get_random(chip, key, key_len);
942
}
943

944
static int __init init_digests(void)
945
{
946
	int i;
947

948
	digests = kcalloc(chip->nr_allocated_banks, sizeof(*digests),
949
			  GFP_KERNEL);
950
	if (!digests)
951
		return -ENOMEM;
952

953
	for (i = 0; i < chip->nr_allocated_banks; i++)
954
		digests[i].alg_id = chip->allocated_banks[i].alg_id;
955

956
	return 0;
957
}
958

959
static int __init trusted_tpm_init(void)
960
{
961
	int ret;
962

963
	chip = tpm_default_chip();
964
	if (!chip)
965
		return -ENODEV;
966

967
	ret = init_digests();
968
	if (ret < 0)
969
		goto err_put;
970
	ret = register_key_type(&key_type_trusted);
971
	if (ret < 0)
972
		goto err_free;
973
	return 0;
974
err_free:
975
	kfree(digests);
976
err_put:
977
	put_device(&chip->dev);
978
	return ret;
979
}
980

981
static void trusted_tpm_exit(void)
982
{
983
	if (chip) {
984
		put_device(&chip->dev);
985
		kfree(digests);
986
		unregister_key_type(&key_type_trusted);
987
	}
988
}
989

990
struct trusted_key_ops trusted_key_tpm_ops = {
991
	.migratable = 1, /* migratable by default */
992
	.init = trusted_tpm_init,
993
	.seal = trusted_tpm_seal,
994
	.unseal = trusted_tpm_unseal,
995
	.get_random = trusted_tpm_get_random,
996
	.exit = trusted_tpm_exit,
997
};
998

999