xref: /linux/drivers/char/tpm/tpm2-cmd.c (revision 4ba05b0e857d1f78f92084a15e618ea89a318089)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2014, 2015 Intel Corporation
4  *
5  * Authors:
6  * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
7  *
8  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
9  *
10  * This file contains TPM2 protocol implementations of the commands
11  * used by the kernel internally.
12  */
13 
14 #include "tpm.h"
15 #include <crypto/hash_info.h>
16 
17 static bool disable_pcr_integrity;
18 module_param(disable_pcr_integrity, bool, 0444);
19 MODULE_PARM_DESC(disable_pcr_integrity, "Disable integrity protection of TPM2_PCR_Extend");
20 
21 static struct tpm2_hash tpm2_hash_map[] = {
22 	{HASH_ALGO_SHA1, TPM_ALG_SHA1},
23 	{HASH_ALGO_SHA256, TPM_ALG_SHA256},
24 	{HASH_ALGO_SHA384, TPM_ALG_SHA384},
25 	{HASH_ALGO_SHA512, TPM_ALG_SHA512},
26 	{HASH_ALGO_SM3_256, TPM_ALG_SM3_256},
27 };
28 
tpm2_get_timeouts(struct tpm_chip * chip)29 int tpm2_get_timeouts(struct tpm_chip *chip)
30 {
31 	/* Fixed timeouts for TPM2 */
32 	chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
33 	chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
34 	chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
35 	chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
36 
37 	/* PTP spec timeouts */
38 	chip->duration[TPM_SHORT] = msecs_to_jiffies(TPM2_DURATION_SHORT);
39 	chip->duration[TPM_MEDIUM] = msecs_to_jiffies(TPM2_DURATION_MEDIUM);
40 	chip->duration[TPM_LONG] = msecs_to_jiffies(TPM2_DURATION_LONG);
41 
42 	/* Key creation commands long timeouts */
43 	chip->duration[TPM_LONG_LONG] =
44 		msecs_to_jiffies(TPM2_DURATION_LONG_LONG);
45 
46 	chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
47 
48 	return 0;
49 }
50 
51 /**
52  * tpm2_ordinal_duration_index() - returns an index to the chip duration table
53  * @ordinal: TPM command ordinal.
54  *
55  * The function returns an index to the chip duration table
56  * (enum tpm_duration), that describes the maximum amount of
57  * time the chip could take to return the result for a  particular ordinal.
58  *
59  * The values of the MEDIUM, and LONG durations are taken
60  * from the PC Client Profile (PTP) specification (750, 2000 msec)
61  *
62  * LONG_LONG is for commands that generates keys which empirically takes
63  * a longer time on some systems.
64  *
65  * Return:
66  * * TPM_MEDIUM
67  * * TPM_LONG
68  * * TPM_LONG_LONG
69  * * TPM_UNDEFINED
70  */
tpm2_ordinal_duration_index(u32 ordinal)71 static u8 tpm2_ordinal_duration_index(u32 ordinal)
72 {
73 	switch (ordinal) {
74 	/* Startup */
75 	case TPM2_CC_STARTUP:                 /* 144 */
76 		return TPM_MEDIUM;
77 
78 	case TPM2_CC_SELF_TEST:               /* 143 */
79 		return TPM_LONG;
80 
81 	case TPM2_CC_GET_RANDOM:              /* 17B */
82 		return TPM_LONG;
83 
84 	case TPM2_CC_SEQUENCE_UPDATE:         /* 15C */
85 		return TPM_MEDIUM;
86 	case TPM2_CC_SEQUENCE_COMPLETE:       /* 13E */
87 		return TPM_MEDIUM;
88 	case TPM2_CC_EVENT_SEQUENCE_COMPLETE: /* 185 */
89 		return TPM_MEDIUM;
90 	case TPM2_CC_HASH_SEQUENCE_START:     /* 186 */
91 		return TPM_MEDIUM;
92 
93 	case TPM2_CC_VERIFY_SIGNATURE:        /* 177 */
94 		return TPM_LONG_LONG;
95 
96 	case TPM2_CC_PCR_EXTEND:              /* 182 */
97 		return TPM_MEDIUM;
98 
99 	case TPM2_CC_HIERARCHY_CONTROL:       /* 121 */
100 		return TPM_LONG;
101 	case TPM2_CC_HIERARCHY_CHANGE_AUTH:   /* 129 */
102 		return TPM_LONG;
103 
104 	case TPM2_CC_GET_CAPABILITY:          /* 17A */
105 		return TPM_MEDIUM;
106 
107 	case TPM2_CC_NV_READ:                 /* 14E */
108 		return TPM_LONG;
109 
110 	case TPM2_CC_CREATE_PRIMARY:          /* 131 */
111 		return TPM_LONG_LONG;
112 	case TPM2_CC_CREATE:                  /* 153 */
113 		return TPM_LONG_LONG;
114 	case TPM2_CC_CREATE_LOADED:           /* 191 */
115 		return TPM_LONG_LONG;
116 
117 	default:
118 		return TPM_UNDEFINED;
119 	}
120 }
121 
122 /**
123  * tpm2_calc_ordinal_duration() - calculate the maximum command duration
124  * @chip:    TPM chip to use.
125  * @ordinal: TPM command ordinal.
126  *
127  * The function returns the maximum amount of time the chip could take
128  * to return the result for a particular ordinal in jiffies.
129  *
130  * Return: A maximal duration time for an ordinal in jiffies.
131  */
tpm2_calc_ordinal_duration(struct tpm_chip * chip,u32 ordinal)132 unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
133 {
134 	unsigned int index;
135 
136 	index = tpm2_ordinal_duration_index(ordinal);
137 
138 	if (index != TPM_UNDEFINED)
139 		return chip->duration[index];
140 	else
141 		return msecs_to_jiffies(TPM2_DURATION_DEFAULT);
142 }
143 
144 
145 struct tpm2_pcr_read_out {
146 	__be32	update_cnt;
147 	__be32	pcr_selects_cnt;
148 	__be16	hash_alg;
149 	u8	pcr_select_size;
150 	u8	pcr_select[TPM2_PCR_SELECT_MIN];
151 	__be32	digests_cnt;
152 	__be16	digest_size;
153 	u8	digest[];
154 } __packed;
155 
156 /**
157  * tpm2_pcr_read() - read a PCR value
158  * @chip:	TPM chip to use.
159  * @pcr_idx:	index of the PCR to read.
160  * @digest:	PCR bank and buffer current PCR value is written to.
161  * @digest_size_ptr:	pointer to variable that stores the digest size.
162  *
163  * Return: Same as with tpm_transmit_cmd.
164  */
tpm2_pcr_read(struct tpm_chip * chip,u32 pcr_idx,struct tpm_digest * digest,u16 * digest_size_ptr)165 int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
166 		  struct tpm_digest *digest, u16 *digest_size_ptr)
167 {
168 	int i;
169 	int rc;
170 	struct tpm_buf buf;
171 	struct tpm2_pcr_read_out *out;
172 	u8 pcr_select[TPM2_PCR_SELECT_MIN] = {0};
173 	u16 digest_size;
174 	u16 expected_digest_size = 0;
175 
176 	if (pcr_idx >= TPM2_PLATFORM_PCR)
177 		return -EINVAL;
178 
179 	if (!digest_size_ptr) {
180 		for (i = 0; i < chip->nr_allocated_banks &&
181 		     chip->allocated_banks[i].alg_id != digest->alg_id; i++)
182 			;
183 
184 		if (i == chip->nr_allocated_banks)
185 			return -EINVAL;
186 
187 		expected_digest_size = chip->allocated_banks[i].digest_size;
188 	}
189 
190 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_PCR_READ);
191 	if (rc)
192 		return rc;
193 
194 	pcr_select[pcr_idx >> 3] = 1 << (pcr_idx & 0x7);
195 
196 	tpm_buf_append_u32(&buf, 1);
197 	tpm_buf_append_u16(&buf, digest->alg_id);
198 	tpm_buf_append_u8(&buf, TPM2_PCR_SELECT_MIN);
199 	tpm_buf_append(&buf, (const unsigned char *)pcr_select,
200 		       sizeof(pcr_select));
201 
202 	rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to read a pcr value");
203 	if (rc)
204 		goto out;
205 
206 	out = (struct tpm2_pcr_read_out *)&buf.data[TPM_HEADER_SIZE];
207 	digest_size = be16_to_cpu(out->digest_size);
208 	if (digest_size > sizeof(digest->digest) ||
209 	    (!digest_size_ptr && digest_size != expected_digest_size)) {
210 		rc = -EINVAL;
211 		goto out;
212 	}
213 
214 	if (digest_size_ptr)
215 		*digest_size_ptr = digest_size;
216 
217 	memcpy(digest->digest, out->digest, digest_size);
218 out:
219 	tpm_buf_destroy(&buf);
220 	return rc;
221 }
222 
223 /**
224  * tpm2_pcr_extend() - extend a PCR value
225  *
226  * @chip:	TPM chip to use.
227  * @pcr_idx:	index of the PCR.
228  * @digests:	list of pcr banks and corresponding digest values to extend.
229  *
230  * Return: Same as with tpm_transmit_cmd.
231  */
tpm2_pcr_extend(struct tpm_chip * chip,u32 pcr_idx,struct tpm_digest * digests)232 int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
233 		    struct tpm_digest *digests)
234 {
235 	struct tpm_buf buf;
236 	int rc;
237 	int i;
238 
239 	if (!disable_pcr_integrity) {
240 		rc = tpm2_start_auth_session(chip);
241 		if (rc)
242 			return rc;
243 	}
244 
245 	rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND);
246 	if (rc) {
247 		if (!disable_pcr_integrity)
248 			tpm2_end_auth_session(chip);
249 		return rc;
250 	}
251 
252 	if (!disable_pcr_integrity) {
253 		tpm_buf_append_name(chip, &buf, pcr_idx, NULL);
254 		tpm_buf_append_hmac_session(chip, &buf, 0, NULL, 0);
255 	} else {
256 		tpm_buf_append_handle(chip, &buf, pcr_idx);
257 		tpm_buf_append_auth(chip, &buf, 0, NULL, 0);
258 	}
259 
260 	tpm_buf_append_u32(&buf, chip->nr_allocated_banks);
261 
262 	for (i = 0; i < chip->nr_allocated_banks; i++) {
263 		tpm_buf_append_u16(&buf, digests[i].alg_id);
264 		tpm_buf_append(&buf, (const unsigned char *)&digests[i].digest,
265 			       chip->allocated_banks[i].digest_size);
266 	}
267 
268 	if (!disable_pcr_integrity)
269 		tpm_buf_fill_hmac_session(chip, &buf);
270 	rc = tpm_transmit_cmd(chip, &buf, 0, "attempting extend a PCR value");
271 	if (!disable_pcr_integrity)
272 		rc = tpm_buf_check_hmac_response(chip, &buf, rc);
273 
274 	tpm_buf_destroy(&buf);
275 
276 	return rc;
277 }
278 
279 struct tpm2_get_random_out {
280 	__be16 size;
281 	u8 buffer[TPM_MAX_RNG_DATA];
282 } __packed;
283 
284 /**
285  * tpm2_get_random() - get random bytes from the TPM RNG
286  *
287  * @chip:	a &tpm_chip instance
288  * @dest:	destination buffer
289  * @max:	the max number of random bytes to pull
290  *
291  * Return:
292  *   size of the buffer on success,
293  *   -errno otherwise (positive TPM return codes are masked to -EIO)
294  */
tpm2_get_random(struct tpm_chip * chip,u8 * dest,size_t max)295 int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
296 {
297 	struct tpm2_get_random_out *out;
298 	struct tpm_header *head;
299 	struct tpm_buf buf;
300 	u32 recd;
301 	u32 num_bytes = max;
302 	int err;
303 	int total = 0;
304 	int retries = 5;
305 	u8 *dest_ptr = dest;
306 	off_t offset;
307 
308 	if (!num_bytes || max > TPM_MAX_RNG_DATA)
309 		return -EINVAL;
310 
311 	err = tpm2_start_auth_session(chip);
312 	if (err)
313 		return err;
314 
315 	err = tpm_buf_init(&buf, 0, 0);
316 	if (err) {
317 		tpm2_end_auth_session(chip);
318 		return err;
319 	}
320 
321 	do {
322 		tpm_buf_reset(&buf, TPM2_ST_SESSIONS, TPM2_CC_GET_RANDOM);
323 		tpm_buf_append_hmac_session_opt(chip, &buf, TPM2_SA_ENCRYPT
324 						| TPM2_SA_CONTINUE_SESSION,
325 						NULL, 0);
326 		tpm_buf_append_u16(&buf, num_bytes);
327 		tpm_buf_fill_hmac_session(chip, &buf);
328 		err = tpm_transmit_cmd(chip, &buf,
329 				       offsetof(struct tpm2_get_random_out,
330 						buffer),
331 				       "attempting get random");
332 		err = tpm_buf_check_hmac_response(chip, &buf, err);
333 		if (err) {
334 			if (err > 0)
335 				err = -EIO;
336 			goto out;
337 		}
338 
339 		head = (struct tpm_header *)buf.data;
340 		offset = TPM_HEADER_SIZE;
341 		/* Skip the parameter size field: */
342 		if (be16_to_cpu(head->tag) == TPM2_ST_SESSIONS)
343 			offset += 4;
344 
345 		out = (struct tpm2_get_random_out *)&buf.data[offset];
346 		recd = min_t(u32, be16_to_cpu(out->size), num_bytes);
347 		if (tpm_buf_length(&buf) <
348 		    TPM_HEADER_SIZE +
349 		    offsetof(struct tpm2_get_random_out, buffer) +
350 		    recd) {
351 			err = -EFAULT;
352 			goto out;
353 		}
354 		memcpy(dest_ptr, out->buffer, recd);
355 
356 		dest_ptr += recd;
357 		total += recd;
358 		num_bytes -= recd;
359 	} while (retries-- && total < max);
360 
361 	tpm_buf_destroy(&buf);
362 	tpm2_end_auth_session(chip);
363 
364 	return total ? total : -EIO;
365 out:
366 	tpm_buf_destroy(&buf);
367 	tpm2_end_auth_session(chip);
368 	return err;
369 }
370 
371 /**
372  * tpm2_flush_context() - execute a TPM2_FlushContext command
373  * @chip:	TPM chip to use
374  * @handle:	context handle
375  */
tpm2_flush_context(struct tpm_chip * chip,u32 handle)376 void tpm2_flush_context(struct tpm_chip *chip, u32 handle)
377 {
378 	struct tpm_buf buf;
379 	int rc;
380 
381 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_FLUSH_CONTEXT);
382 	if (rc) {
383 		dev_warn(&chip->dev, "0x%08x was not flushed, out of memory\n",
384 			 handle);
385 		return;
386 	}
387 
388 	tpm_buf_append_u32(&buf, handle);
389 
390 	tpm_transmit_cmd(chip, &buf, 0, "flushing context");
391 	tpm_buf_destroy(&buf);
392 }
393 EXPORT_SYMBOL_GPL(tpm2_flush_context);
394 
395 struct tpm2_get_cap_out {
396 	u8 more_data;
397 	__be32 subcap_id;
398 	__be32 property_cnt;
399 	__be32 property_id;
400 	__be32 value;
401 } __packed;
402 
403 /**
404  * tpm2_get_tpm_pt() - get value of a TPM_CAP_TPM_PROPERTIES type property
405  * @chip:		a &tpm_chip instance
406  * @property_id:	property ID.
407  * @value:		output variable.
408  * @desc:		passed to tpm_transmit_cmd()
409  *
410  * Return:
411  *   0 on success,
412  *   -errno or a TPM return code otherwise
413  */
tpm2_get_tpm_pt(struct tpm_chip * chip,u32 property_id,u32 * value,const char * desc)414 ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id,  u32 *value,
415 			const char *desc)
416 {
417 	struct tpm2_get_cap_out *out;
418 	struct tpm_buf buf;
419 	int rc;
420 
421 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
422 	if (rc)
423 		return rc;
424 	tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
425 	tpm_buf_append_u32(&buf, property_id);
426 	tpm_buf_append_u32(&buf, 1);
427 	rc = tpm_transmit_cmd(chip, &buf, 0, NULL);
428 	if (!rc) {
429 		out = (struct tpm2_get_cap_out *)
430 			&buf.data[TPM_HEADER_SIZE];
431 		/*
432 		 * To prevent failing boot up of some systems, Infineon TPM2.0
433 		 * returns SUCCESS on TPM2_Startup in field upgrade mode. Also
434 		 * the TPM2_Getcapability command returns a zero length list
435 		 * in field upgrade mode.
436 		 */
437 		if (be32_to_cpu(out->property_cnt) > 0)
438 			*value = be32_to_cpu(out->value);
439 		else
440 			rc = -ENODATA;
441 	}
442 	tpm_buf_destroy(&buf);
443 	return rc;
444 }
445 EXPORT_SYMBOL_GPL(tpm2_get_tpm_pt);
446 
447 /**
448  * tpm2_shutdown() - send a TPM shutdown command
449  *
450  * Sends a TPM shutdown command. The shutdown command is used in call
451  * sites where the system is going down. If it fails, there is not much
452  * that can be done except print an error message.
453  *
454  * @chip:		a &tpm_chip instance
455  * @shutdown_type:	TPM_SU_CLEAR or TPM_SU_STATE.
456  */
tpm2_shutdown(struct tpm_chip * chip,u16 shutdown_type)457 void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
458 {
459 	struct tpm_buf buf;
460 	int rc;
461 
462 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SHUTDOWN);
463 	if (rc)
464 		return;
465 	tpm_buf_append_u16(&buf, shutdown_type);
466 	tpm_transmit_cmd(chip, &buf, 0, "stopping the TPM");
467 	tpm_buf_destroy(&buf);
468 }
469 
470 /**
471  * tpm2_do_selftest() - ensure that all self tests have passed
472  *
473  * @chip: TPM chip to use
474  *
475  * Return: Same as with tpm_transmit_cmd.
476  *
477  * The TPM can either run all self tests synchronously and then return
478  * RC_SUCCESS once all tests were successful. Or it can choose to run the tests
479  * asynchronously and return RC_TESTING immediately while the self tests still
480  * execute in the background. This function handles both cases and waits until
481  * all tests have completed.
482  */
tpm2_do_selftest(struct tpm_chip * chip)483 static int tpm2_do_selftest(struct tpm_chip *chip)
484 {
485 	struct tpm_buf buf;
486 	int full;
487 	int rc;
488 
489 	for (full = 0; full < 2; full++) {
490 		rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SELF_TEST);
491 		if (rc)
492 			return rc;
493 
494 		tpm_buf_append_u8(&buf, full);
495 		rc = tpm_transmit_cmd(chip, &buf, 0,
496 				      "attempting the self test");
497 		tpm_buf_destroy(&buf);
498 
499 		if (rc == TPM2_RC_TESTING)
500 			rc = TPM2_RC_SUCCESS;
501 		if (rc == TPM2_RC_INITIALIZE || rc == TPM2_RC_SUCCESS)
502 			return rc;
503 	}
504 
505 	return rc;
506 }
507 
508 /**
509  * tpm2_probe() - probe for the TPM 2.0 protocol
510  * @chip:	a &tpm_chip instance
511  *
512  * Send an idempotent TPM 2.0 command and see whether there is TPM2 chip in the
513  * other end based on the response tag. The flag TPM_CHIP_FLAG_TPM2 is set by
514  * this function if this is the case.
515  *
516  * Return:
517  *   0 on success,
518  *   -errno otherwise
519  */
tpm2_probe(struct tpm_chip * chip)520 int tpm2_probe(struct tpm_chip *chip)
521 {
522 	struct tpm_header *out;
523 	struct tpm_buf buf;
524 	int rc;
525 
526 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
527 	if (rc)
528 		return rc;
529 	tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
530 	tpm_buf_append_u32(&buf, TPM_PT_TOTAL_COMMANDS);
531 	tpm_buf_append_u32(&buf, 1);
532 	rc = tpm_transmit_cmd(chip, &buf, 0, NULL);
533 	/* We ignore TPM return codes on purpose. */
534 	if (rc >=  0) {
535 		out = (struct tpm_header *)buf.data;
536 		if (be16_to_cpu(out->tag) == TPM2_ST_NO_SESSIONS)
537 			chip->flags |= TPM_CHIP_FLAG_TPM2;
538 	}
539 	tpm_buf_destroy(&buf);
540 	return 0;
541 }
542 EXPORT_SYMBOL_GPL(tpm2_probe);
543 
tpm2_init_bank_info(struct tpm_chip * chip,u32 bank_index)544 static int tpm2_init_bank_info(struct tpm_chip *chip, u32 bank_index)
545 {
546 	struct tpm_bank_info *bank = chip->allocated_banks + bank_index;
547 	struct tpm_digest digest = { .alg_id = bank->alg_id };
548 	int i;
549 
550 	/*
551 	 * Avoid unnecessary PCR read operations to reduce overhead
552 	 * and obtain identifiers of the crypto subsystem.
553 	 */
554 	for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
555 		enum hash_algo crypto_algo = tpm2_hash_map[i].crypto_id;
556 
557 		if (bank->alg_id != tpm2_hash_map[i].tpm_id)
558 			continue;
559 
560 		bank->digest_size = hash_digest_size[crypto_algo];
561 		bank->crypto_id = crypto_algo;
562 		return 0;
563 	}
564 
565 	bank->crypto_id = HASH_ALGO__LAST;
566 
567 	return tpm2_pcr_read(chip, 0, &digest, &bank->digest_size);
568 }
569 
570 struct tpm2_pcr_selection {
571 	__be16  hash_alg;
572 	u8  size_of_select;
573 	u8  pcr_select[3];
574 } __packed;
575 
tpm2_get_pcr_allocation(struct tpm_chip * chip)576 ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
577 {
578 	struct tpm2_pcr_selection pcr_selection;
579 	struct tpm_buf buf;
580 	void *marker;
581 	void *end;
582 	void *pcr_select_offset;
583 	u32 sizeof_pcr_selection;
584 	u32 nr_possible_banks;
585 	u32 nr_alloc_banks = 0;
586 	u16 hash_alg;
587 	u32 rsp_len;
588 	int rc;
589 	int i = 0;
590 
591 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
592 	if (rc)
593 		return rc;
594 
595 	tpm_buf_append_u32(&buf, TPM2_CAP_PCRS);
596 	tpm_buf_append_u32(&buf, 0);
597 	tpm_buf_append_u32(&buf, 1);
598 
599 	rc = tpm_transmit_cmd(chip, &buf, 9, "get tpm pcr allocation");
600 	if (rc)
601 		goto out;
602 
603 	nr_possible_banks = be32_to_cpup(
604 		(__be32 *)&buf.data[TPM_HEADER_SIZE + 5]);
605 
606 	chip->allocated_banks = kcalloc(nr_possible_banks,
607 					sizeof(*chip->allocated_banks),
608 					GFP_KERNEL);
609 	if (!chip->allocated_banks) {
610 		rc = -ENOMEM;
611 		goto out;
612 	}
613 
614 	marker = &buf.data[TPM_HEADER_SIZE + 9];
615 
616 	rsp_len = be32_to_cpup((__be32 *)&buf.data[2]);
617 	end = &buf.data[rsp_len];
618 
619 	for (i = 0; i < nr_possible_banks; i++) {
620 		pcr_select_offset = marker +
621 			offsetof(struct tpm2_pcr_selection, size_of_select);
622 		if (pcr_select_offset >= end) {
623 			rc = -EFAULT;
624 			break;
625 		}
626 
627 		memcpy(&pcr_selection, marker, sizeof(pcr_selection));
628 		hash_alg = be16_to_cpu(pcr_selection.hash_alg);
629 
630 		pcr_select_offset = memchr_inv(pcr_selection.pcr_select, 0,
631 					       pcr_selection.size_of_select);
632 		if (pcr_select_offset) {
633 			chip->allocated_banks[nr_alloc_banks].alg_id = hash_alg;
634 
635 			rc = tpm2_init_bank_info(chip, nr_alloc_banks);
636 			if (rc < 0)
637 				break;
638 
639 			nr_alloc_banks++;
640 		}
641 
642 		sizeof_pcr_selection = sizeof(pcr_selection.hash_alg) +
643 			sizeof(pcr_selection.size_of_select) +
644 			pcr_selection.size_of_select;
645 		marker = marker + sizeof_pcr_selection;
646 	}
647 
648 	chip->nr_allocated_banks = nr_alloc_banks;
649 out:
650 	tpm_buf_destroy(&buf);
651 
652 	return rc;
653 }
654 
tpm2_get_cc_attrs_tbl(struct tpm_chip * chip)655 int tpm2_get_cc_attrs_tbl(struct tpm_chip *chip)
656 {
657 	struct tpm_buf buf;
658 	u32 nr_commands;
659 	__be32 *attrs;
660 	u32 cc;
661 	int i;
662 	int rc;
663 
664 	rc = tpm2_get_tpm_pt(chip, TPM_PT_TOTAL_COMMANDS, &nr_commands, NULL);
665 	if (rc)
666 		goto out;
667 
668 	if (nr_commands > 0xFFFFF) {
669 		rc = -EFAULT;
670 		goto out;
671 	}
672 
673 	chip->cc_attrs_tbl = devm_kcalloc(&chip->dev, 4, nr_commands,
674 					  GFP_KERNEL);
675 	if (!chip->cc_attrs_tbl) {
676 		rc = -ENOMEM;
677 		goto out;
678 	}
679 
680 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
681 	if (rc)
682 		goto out;
683 
684 	tpm_buf_append_u32(&buf, TPM2_CAP_COMMANDS);
685 	tpm_buf_append_u32(&buf, TPM2_CC_FIRST);
686 	tpm_buf_append_u32(&buf, nr_commands);
687 
688 	rc = tpm_transmit_cmd(chip, &buf, 9 + 4 * nr_commands, NULL);
689 	if (rc) {
690 		tpm_buf_destroy(&buf);
691 		goto out;
692 	}
693 
694 	if (nr_commands !=
695 	    be32_to_cpup((__be32 *)&buf.data[TPM_HEADER_SIZE + 5])) {
696 		rc = -EFAULT;
697 		tpm_buf_destroy(&buf);
698 		goto out;
699 	}
700 
701 	chip->nr_commands = nr_commands;
702 
703 	attrs = (__be32 *)&buf.data[TPM_HEADER_SIZE + 9];
704 	for (i = 0; i < nr_commands; i++, attrs++) {
705 		chip->cc_attrs_tbl[i] = be32_to_cpup(attrs);
706 		cc = chip->cc_attrs_tbl[i] & 0xFFFF;
707 
708 		if (cc == TPM2_CC_CONTEXT_SAVE || cc == TPM2_CC_FLUSH_CONTEXT) {
709 			chip->cc_attrs_tbl[i] &=
710 				~(GENMASK(2, 0) << TPM2_CC_ATTR_CHANDLES);
711 			chip->cc_attrs_tbl[i] |= 1 << TPM2_CC_ATTR_CHANDLES;
712 		}
713 	}
714 
715 	tpm_buf_destroy(&buf);
716 
717 out:
718 	if (rc > 0)
719 		rc = -ENODEV;
720 	return rc;
721 }
722 EXPORT_SYMBOL_GPL(tpm2_get_cc_attrs_tbl);
723 
724 /**
725  * tpm2_startup - turn on the TPM
726  * @chip: TPM chip to use
727  *
728  * Normally the firmware should start the TPM. This function is provided as a
729  * workaround if this does not happen. A legal case for this could be for
730  * example when a TPM emulator is used.
731  *
732  * Return: same as tpm_transmit_cmd()
733  */
734 
tpm2_startup(struct tpm_chip * chip)735 static int tpm2_startup(struct tpm_chip *chip)
736 {
737 	struct tpm_buf buf;
738 	int rc;
739 
740 	dev_info(&chip->dev, "starting up the TPM manually\n");
741 
742 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_STARTUP);
743 	if (rc < 0)
744 		return rc;
745 
746 	tpm_buf_append_u16(&buf, TPM2_SU_CLEAR);
747 	rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to start the TPM");
748 	tpm_buf_destroy(&buf);
749 
750 	return rc;
751 }
752 
753 /**
754  * tpm2_auto_startup - Perform the standard automatic TPM initialization
755  *                     sequence
756  * @chip: TPM chip to use
757  *
758  * Returns 0 on success, < 0 in case of fatal error.
759  */
tpm2_auto_startup(struct tpm_chip * chip)760 int tpm2_auto_startup(struct tpm_chip *chip)
761 {
762 	int rc;
763 
764 	rc = tpm2_get_timeouts(chip);
765 	if (rc)
766 		goto out;
767 
768 	rc = tpm2_do_selftest(chip);
769 	if (rc && rc != TPM2_RC_INITIALIZE)
770 		goto out;
771 
772 	if (rc == TPM2_RC_INITIALIZE) {
773 		rc = tpm2_startup(chip);
774 		if (rc)
775 			goto out;
776 
777 		rc = tpm2_do_selftest(chip);
778 		if (rc)
779 			goto out;
780 	}
781 
782 	rc = tpm2_get_cc_attrs_tbl(chip);
783 	if (rc == TPM2_RC_FAILURE || (rc < 0 && rc != -ENOMEM)) {
784 		dev_info(&chip->dev,
785 			 "TPM in field failure mode, requires firmware upgrade\n");
786 		chip->flags |= TPM_CHIP_FLAG_FIRMWARE_UPGRADE;
787 		rc = 0;
788 	}
789 
790 	if (rc)
791 		goto out;
792 
793 	rc = tpm2_sessions_init(chip);
794 
795 out:
796 	/*
797 	 * Infineon TPM in field upgrade mode will return no data for the number
798 	 * of supported commands.
799 	 */
800 	if (rc == TPM2_RC_UPGRADE || rc == -ENODATA) {
801 		dev_info(&chip->dev, "TPM in field upgrade mode, requires firmware upgrade\n");
802 		chip->flags |= TPM_CHIP_FLAG_FIRMWARE_UPGRADE;
803 		rc = 0;
804 	}
805 
806 	if (rc > 0)
807 		rc = -ENODEV;
808 	return rc;
809 }
810 
tpm2_find_cc(struct tpm_chip * chip,u32 cc)811 int tpm2_find_cc(struct tpm_chip *chip, u32 cc)
812 {
813 	u32 cc_mask;
814 	int i;
815 
816 	cc_mask = 1 << TPM2_CC_ATTR_VENDOR | GENMASK(15, 0);
817 	for (i = 0; i < chip->nr_commands; i++)
818 		if (cc == (chip->cc_attrs_tbl[i] & cc_mask))
819 			return i;
820 
821 	return -1;
822 }
823