xref: /openbmc/linux/drivers/char/tpm/tpm2-cmd.c (revision f220d3eb)
1 /*
2  * Copyright (C) 2014, 2015 Intel Corporation
3  *
4  * Authors:
5  * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
6  *
7  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
8  *
9  * This file contains TPM2 protocol implementations of the commands
10  * used by the kernel internally.
11  *
12  * This program is free software; you can redistribute it and/or
13  * modify it under the terms of the GNU General Public License
14  * as published by the Free Software Foundation; version 2
15  * of the License.
16  */
17 
18 #include "tpm.h"
19 #include <crypto/hash_info.h>
20 #include <keys/trusted-type.h>
21 
22 enum tpm2_object_attributes {
23 	TPM2_OA_USER_WITH_AUTH		= BIT(6),
24 };
25 
26 enum tpm2_session_attributes {
27 	TPM2_SA_CONTINUE_SESSION	= BIT(0),
28 };
29 
30 struct tpm2_hash {
31 	unsigned int crypto_id;
32 	unsigned int tpm_id;
33 };
34 
35 static struct tpm2_hash tpm2_hash_map[] = {
36 	{HASH_ALGO_SHA1, TPM2_ALG_SHA1},
37 	{HASH_ALGO_SHA256, TPM2_ALG_SHA256},
38 	{HASH_ALGO_SHA384, TPM2_ALG_SHA384},
39 	{HASH_ALGO_SHA512, TPM2_ALG_SHA512},
40 	{HASH_ALGO_SM3_256, TPM2_ALG_SM3_256},
41 };
42 
43 /*
44  * Array with one entry per ordinal defining the maximum amount
45  * of time the chip could take to return the result. The values
46  * of the SHORT, MEDIUM, and LONG durations are taken from the
47  * PC Client Profile (PTP) specification.
48  * LONG_LONG is for commands that generates keys which empirically
49  * takes longer time on some systems.
50  */
51 static const u8 tpm2_ordinal_duration[TPM2_CC_LAST - TPM2_CC_FIRST + 1] = {
52 	TPM_UNDEFINED,		/* 11F */
53 	TPM_UNDEFINED,		/* 120 */
54 	TPM_LONG,		/* 121 */
55 	TPM_UNDEFINED,		/* 122 */
56 	TPM_UNDEFINED,		/* 123 */
57 	TPM_UNDEFINED,		/* 124 */
58 	TPM_UNDEFINED,		/* 125 */
59 	TPM_UNDEFINED,		/* 126 */
60 	TPM_UNDEFINED,		/* 127 */
61 	TPM_UNDEFINED,		/* 128 */
62 	TPM_LONG,		/* 129 */
63 	TPM_UNDEFINED,		/* 12a */
64 	TPM_UNDEFINED,		/* 12b */
65 	TPM_UNDEFINED,		/* 12c */
66 	TPM_UNDEFINED,		/* 12d */
67 	TPM_UNDEFINED,		/* 12e */
68 	TPM_UNDEFINED,		/* 12f */
69 	TPM_UNDEFINED,		/* 130 */
70 	TPM_LONG_LONG,		/* 131 */
71 	TPM_UNDEFINED,		/* 132 */
72 	TPM_UNDEFINED,		/* 133 */
73 	TPM_UNDEFINED,		/* 134 */
74 	TPM_UNDEFINED,		/* 135 */
75 	TPM_UNDEFINED,		/* 136 */
76 	TPM_UNDEFINED,		/* 137 */
77 	TPM_UNDEFINED,		/* 138 */
78 	TPM_UNDEFINED,		/* 139 */
79 	TPM_UNDEFINED,		/* 13a */
80 	TPM_UNDEFINED,		/* 13b */
81 	TPM_UNDEFINED,		/* 13c */
82 	TPM_UNDEFINED,		/* 13d */
83 	TPM_MEDIUM,		/* 13e */
84 	TPM_UNDEFINED,		/* 13f */
85 	TPM_UNDEFINED,		/* 140 */
86 	TPM_UNDEFINED,		/* 141 */
87 	TPM_UNDEFINED,		/* 142 */
88 	TPM_LONG,		/* 143 */
89 	TPM_MEDIUM,		/* 144 */
90 	TPM_UNDEFINED,		/* 145 */
91 	TPM_UNDEFINED,		/* 146 */
92 	TPM_UNDEFINED,		/* 147 */
93 	TPM_UNDEFINED,		/* 148 */
94 	TPM_UNDEFINED,		/* 149 */
95 	TPM_UNDEFINED,		/* 14a */
96 	TPM_UNDEFINED,		/* 14b */
97 	TPM_UNDEFINED,		/* 14c */
98 	TPM_UNDEFINED,		/* 14d */
99 	TPM_LONG,		/* 14e */
100 	TPM_UNDEFINED,		/* 14f */
101 	TPM_UNDEFINED,		/* 150 */
102 	TPM_UNDEFINED,		/* 151 */
103 	TPM_UNDEFINED,		/* 152 */
104 	TPM_LONG_LONG,		/* 153 */
105 	TPM_UNDEFINED,		/* 154 */
106 	TPM_UNDEFINED,		/* 155 */
107 	TPM_UNDEFINED,		/* 156 */
108 	TPM_UNDEFINED,		/* 157 */
109 	TPM_UNDEFINED,		/* 158 */
110 	TPM_UNDEFINED,		/* 159 */
111 	TPM_UNDEFINED,		/* 15a */
112 	TPM_UNDEFINED,		/* 15b */
113 	TPM_MEDIUM,		/* 15c */
114 	TPM_UNDEFINED,		/* 15d */
115 	TPM_UNDEFINED,		/* 15e */
116 	TPM_UNDEFINED,		/* 15f */
117 	TPM_UNDEFINED,		/* 160 */
118 	TPM_UNDEFINED,		/* 161 */
119 	TPM_UNDEFINED,		/* 162 */
120 	TPM_UNDEFINED,		/* 163 */
121 	TPM_UNDEFINED,		/* 164 */
122 	TPM_UNDEFINED,		/* 165 */
123 	TPM_UNDEFINED,		/* 166 */
124 	TPM_UNDEFINED,		/* 167 */
125 	TPM_UNDEFINED,		/* 168 */
126 	TPM_UNDEFINED,		/* 169 */
127 	TPM_UNDEFINED,		/* 16a */
128 	TPM_UNDEFINED,		/* 16b */
129 	TPM_UNDEFINED,		/* 16c */
130 	TPM_UNDEFINED,		/* 16d */
131 	TPM_UNDEFINED,		/* 16e */
132 	TPM_UNDEFINED,		/* 16f */
133 	TPM_UNDEFINED,		/* 170 */
134 	TPM_UNDEFINED,		/* 171 */
135 	TPM_UNDEFINED,		/* 172 */
136 	TPM_UNDEFINED,		/* 173 */
137 	TPM_UNDEFINED,		/* 174 */
138 	TPM_UNDEFINED,		/* 175 */
139 	TPM_UNDEFINED,		/* 176 */
140 	TPM_LONG,		/* 177 */
141 	TPM_UNDEFINED,		/* 178 */
142 	TPM_UNDEFINED,		/* 179 */
143 	TPM_MEDIUM,		/* 17a */
144 	TPM_LONG,		/* 17b */
145 	TPM_UNDEFINED,		/* 17c */
146 	TPM_UNDEFINED,		/* 17d */
147 	TPM_UNDEFINED,		/* 17e */
148 	TPM_UNDEFINED,		/* 17f */
149 	TPM_UNDEFINED,		/* 180 */
150 	TPM_UNDEFINED,		/* 181 */
151 	TPM_MEDIUM,		/* 182 */
152 	TPM_UNDEFINED,		/* 183 */
153 	TPM_UNDEFINED,		/* 184 */
154 	TPM_MEDIUM,		/* 185 */
155 	TPM_MEDIUM,		/* 186 */
156 	TPM_UNDEFINED,		/* 187 */
157 	TPM_UNDEFINED,		/* 188 */
158 	TPM_UNDEFINED,		/* 189 */
159 	TPM_UNDEFINED,		/* 18a */
160 	TPM_UNDEFINED,		/* 18b */
161 	TPM_UNDEFINED,		/* 18c */
162 	TPM_UNDEFINED,		/* 18d */
163 	TPM_UNDEFINED,		/* 18e */
164 	TPM_UNDEFINED		/* 18f */
165 };
166 
167 struct tpm2_pcr_read_out {
168 	__be32	update_cnt;
169 	__be32	pcr_selects_cnt;
170 	__be16	hash_alg;
171 	u8	pcr_select_size;
172 	u8	pcr_select[TPM2_PCR_SELECT_MIN];
173 	__be32	digests_cnt;
174 	__be16	digest_size;
175 	u8	digest[];
176 } __packed;
177 
178 /**
179  * tpm2_pcr_read() - read a PCR value
180  * @chip:	TPM chip to use.
181  * @pcr_idx:	index of the PCR to read.
182  * @res_buf:	buffer to store the resulting hash.
183  *
184  * Return: Same as with tpm_transmit_cmd.
185  */
186 int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
187 {
188 	int rc;
189 	struct tpm_buf buf;
190 	struct tpm2_pcr_read_out *out;
191 	u8 pcr_select[TPM2_PCR_SELECT_MIN] = {0};
192 
193 	if (pcr_idx >= TPM2_PLATFORM_PCR)
194 		return -EINVAL;
195 
196 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_PCR_READ);
197 	if (rc)
198 		return rc;
199 
200 	pcr_select[pcr_idx >> 3] = 1 << (pcr_idx & 0x7);
201 
202 	tpm_buf_append_u32(&buf, 1);
203 	tpm_buf_append_u16(&buf, TPM2_ALG_SHA1);
204 	tpm_buf_append_u8(&buf, TPM2_PCR_SELECT_MIN);
205 	tpm_buf_append(&buf, (const unsigned char *)pcr_select,
206 		       sizeof(pcr_select));
207 
208 	rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
209 			res_buf ? "attempting to read a pcr value" : NULL);
210 	if (rc == 0 && res_buf) {
211 		out = (struct tpm2_pcr_read_out *)&buf.data[TPM_HEADER_SIZE];
212 		memcpy(res_buf, out->digest, SHA1_DIGEST_SIZE);
213 	}
214 
215 	tpm_buf_destroy(&buf);
216 	return rc;
217 }
218 
219 struct tpm2_null_auth_area {
220 	__be32  handle;
221 	__be16  nonce_size;
222 	u8  attributes;
223 	__be16  auth_size;
224 } __packed;
225 
226 /**
227  * tpm2_pcr_extend() - extend a PCR value
228  *
229  * @chip:	TPM chip to use.
230  * @pcr_idx:	index of the PCR.
231  * @count:	number of digests passed.
232  * @digests:	list of pcr banks and corresponding digest values to extend.
233  *
234  * Return: Same as with tpm_transmit_cmd.
235  */
236 int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, u32 count,
237 		    struct tpm2_digest *digests)
238 {
239 	struct tpm_buf buf;
240 	struct tpm2_null_auth_area auth_area;
241 	int rc;
242 	int i;
243 	int j;
244 
245 	if (count > ARRAY_SIZE(chip->active_banks))
246 		return -EINVAL;
247 
248 	rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND);
249 	if (rc)
250 		return rc;
251 
252 	tpm_buf_append_u32(&buf, pcr_idx);
253 
254 	auth_area.handle = cpu_to_be32(TPM2_RS_PW);
255 	auth_area.nonce_size = 0;
256 	auth_area.attributes = 0;
257 	auth_area.auth_size = 0;
258 
259 	tpm_buf_append_u32(&buf, sizeof(struct tpm2_null_auth_area));
260 	tpm_buf_append(&buf, (const unsigned char *)&auth_area,
261 		       sizeof(auth_area));
262 	tpm_buf_append_u32(&buf, count);
263 
264 	for (i = 0; i < count; i++) {
265 		for (j = 0; j < ARRAY_SIZE(tpm2_hash_map); j++) {
266 			if (digests[i].alg_id != tpm2_hash_map[j].tpm_id)
267 				continue;
268 			tpm_buf_append_u16(&buf, digests[i].alg_id);
269 			tpm_buf_append(&buf, (const unsigned char
270 					      *)&digests[i].digest,
271 			       hash_digest_size[tpm2_hash_map[j].crypto_id]);
272 		}
273 	}
274 
275 	rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
276 			      "attempting extend a PCR value");
277 
278 	tpm_buf_destroy(&buf);
279 
280 	return rc;
281 }
282 
283 
284 struct tpm2_get_random_out {
285 	__be16 size;
286 	u8 buffer[TPM_MAX_RNG_DATA];
287 } __packed;
288 
289 /**
290  * tpm2_get_random() - get random bytes from the TPM RNG
291  *
292  * @chip:	a &tpm_chip instance
293  * @dest:	destination buffer
294  * @max:	the max number of random bytes to pull
295  *
296  * Return:
297  *   size of the buffer on success,
298  *   -errno otherwise
299  */
300 int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
301 {
302 	struct tpm2_get_random_out *out;
303 	struct tpm_buf buf;
304 	u32 recd;
305 	u32 num_bytes = max;
306 	int err;
307 	int total = 0;
308 	int retries = 5;
309 	u8 *dest_ptr = dest;
310 
311 	if (!num_bytes || max > TPM_MAX_RNG_DATA)
312 		return -EINVAL;
313 
314 	err = tpm_buf_init(&buf, 0, 0);
315 	if (err)
316 		return err;
317 
318 	do {
319 		tpm_buf_reset(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_RANDOM);
320 		tpm_buf_append_u16(&buf, num_bytes);
321 		err = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
322 				       offsetof(struct tpm2_get_random_out,
323 						buffer),
324 				       0, "attempting get random");
325 		if (err)
326 			goto out;
327 
328 		out = (struct tpm2_get_random_out *)
329 			&buf.data[TPM_HEADER_SIZE];
330 		recd = min_t(u32, be16_to_cpu(out->size), num_bytes);
331 		if (tpm_buf_length(&buf) <
332 		    offsetof(struct tpm2_get_random_out, buffer) + recd) {
333 			err = -EFAULT;
334 			goto out;
335 		}
336 		memcpy(dest_ptr, out->buffer, recd);
337 
338 		dest_ptr += recd;
339 		total += recd;
340 		num_bytes -= recd;
341 	} while (retries-- && total < max);
342 
343 	tpm_buf_destroy(&buf);
344 	return total ? total : -EIO;
345 out:
346 	tpm_buf_destroy(&buf);
347 	return err;
348 }
349 
350 /**
351  * tpm2_flush_context_cmd() - execute a TPM2_FlushContext command
352  * @chip: TPM chip to use
353  * @payload: the key data in clear and encrypted form
354  * @options: authentication values and other options
355  *
356  * Return: same as with tpm_transmit_cmd
357  */
358 void tpm2_flush_context_cmd(struct tpm_chip *chip, u32 handle,
359 			    unsigned int flags)
360 {
361 	struct tpm_buf buf;
362 	int rc;
363 
364 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_FLUSH_CONTEXT);
365 	if (rc) {
366 		dev_warn(&chip->dev, "0x%08x was not flushed, out of memory\n",
367 			 handle);
368 		return;
369 	}
370 
371 	tpm_buf_append_u32(&buf, handle);
372 
373 	(void) tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, flags,
374 				"flushing context");
375 
376 	tpm_buf_destroy(&buf);
377 }
378 
379 /**
380  * tpm_buf_append_auth() - append TPMS_AUTH_COMMAND to the buffer.
381  *
382  * @buf: an allocated tpm_buf instance
383  * @session_handle: session handle
384  * @nonce: the session nonce, may be NULL if not used
385  * @nonce_len: the session nonce length, may be 0 if not used
386  * @attributes: the session attributes
387  * @hmac: the session HMAC or password, may be NULL if not used
388  * @hmac_len: the session HMAC or password length, maybe 0 if not used
389  */
390 static void tpm2_buf_append_auth(struct tpm_buf *buf, u32 session_handle,
391 				 const u8 *nonce, u16 nonce_len,
392 				 u8 attributes,
393 				 const u8 *hmac, u16 hmac_len)
394 {
395 	tpm_buf_append_u32(buf, 9 + nonce_len + hmac_len);
396 	tpm_buf_append_u32(buf, session_handle);
397 	tpm_buf_append_u16(buf, nonce_len);
398 
399 	if (nonce && nonce_len)
400 		tpm_buf_append(buf, nonce, nonce_len);
401 
402 	tpm_buf_append_u8(buf, attributes);
403 	tpm_buf_append_u16(buf, hmac_len);
404 
405 	if (hmac && hmac_len)
406 		tpm_buf_append(buf, hmac, hmac_len);
407 }
408 
409 /**
410  * tpm2_seal_trusted() - seal the payload of a trusted key
411  *
412  * @chip: TPM chip to use
413  * @payload: the key data in clear and encrypted form
414  * @options: authentication values and other options
415  *
416  * Return: < 0 on error and 0 on success.
417  */
418 int tpm2_seal_trusted(struct tpm_chip *chip,
419 		      struct trusted_key_payload *payload,
420 		      struct trusted_key_options *options)
421 {
422 	unsigned int blob_len;
423 	struct tpm_buf buf;
424 	u32 hash;
425 	int i;
426 	int rc;
427 
428 	for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
429 		if (options->hash == tpm2_hash_map[i].crypto_id) {
430 			hash = tpm2_hash_map[i].tpm_id;
431 			break;
432 		}
433 	}
434 
435 	if (i == ARRAY_SIZE(tpm2_hash_map))
436 		return -EINVAL;
437 
438 	rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE);
439 	if (rc)
440 		return rc;
441 
442 	tpm_buf_append_u32(&buf, options->keyhandle);
443 	tpm2_buf_append_auth(&buf, TPM2_RS_PW,
444 			     NULL /* nonce */, 0,
445 			     0 /* session_attributes */,
446 			     options->keyauth /* hmac */,
447 			     TPM_DIGEST_SIZE);
448 
449 	/* sensitive */
450 	tpm_buf_append_u16(&buf, 4 + TPM_DIGEST_SIZE + payload->key_len + 1);
451 
452 	tpm_buf_append_u16(&buf, TPM_DIGEST_SIZE);
453 	tpm_buf_append(&buf, options->blobauth, TPM_DIGEST_SIZE);
454 	tpm_buf_append_u16(&buf, payload->key_len + 1);
455 	tpm_buf_append(&buf, payload->key, payload->key_len);
456 	tpm_buf_append_u8(&buf, payload->migratable);
457 
458 	/* public */
459 	tpm_buf_append_u16(&buf, 14 + options->policydigest_len);
460 	tpm_buf_append_u16(&buf, TPM2_ALG_KEYEDHASH);
461 	tpm_buf_append_u16(&buf, hash);
462 
463 	/* policy */
464 	if (options->policydigest_len) {
465 		tpm_buf_append_u32(&buf, 0);
466 		tpm_buf_append_u16(&buf, options->policydigest_len);
467 		tpm_buf_append(&buf, options->policydigest,
468 			       options->policydigest_len);
469 	} else {
470 		tpm_buf_append_u32(&buf, TPM2_OA_USER_WITH_AUTH);
471 		tpm_buf_append_u16(&buf, 0);
472 	}
473 
474 	/* public parameters */
475 	tpm_buf_append_u16(&buf, TPM2_ALG_NULL);
476 	tpm_buf_append_u16(&buf, 0);
477 
478 	/* outside info */
479 	tpm_buf_append_u16(&buf, 0);
480 
481 	/* creation PCR */
482 	tpm_buf_append_u32(&buf, 0);
483 
484 	if (buf.flags & TPM_BUF_OVERFLOW) {
485 		rc = -E2BIG;
486 		goto out;
487 	}
488 
489 	rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 4, 0,
490 			      "sealing data");
491 	if (rc)
492 		goto out;
493 
494 	blob_len = be32_to_cpup((__be32 *) &buf.data[TPM_HEADER_SIZE]);
495 	if (blob_len > MAX_BLOB_SIZE) {
496 		rc = -E2BIG;
497 		goto out;
498 	}
499 	if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 4 + blob_len) {
500 		rc = -EFAULT;
501 		goto out;
502 	}
503 
504 	memcpy(payload->blob, &buf.data[TPM_HEADER_SIZE + 4], blob_len);
505 	payload->blob_len = blob_len;
506 
507 out:
508 	tpm_buf_destroy(&buf);
509 
510 	if (rc > 0) {
511 		if (tpm2_rc_value(rc) == TPM2_RC_HASH)
512 			rc = -EINVAL;
513 		else
514 			rc = -EPERM;
515 	}
516 
517 	return rc;
518 }
519 
520 /**
521  * tpm2_load_cmd() - execute a TPM2_Load command
522  *
523  * @chip: TPM chip to use
524  * @payload: the key data in clear and encrypted form
525  * @options: authentication values and other options
526  * @blob_handle: returned blob handle
527  * @flags: tpm transmit flags
528  *
529  * Return: 0 on success.
530  *        -E2BIG on wrong payload size.
531  *        -EPERM on tpm error status.
532  *        < 0 error from tpm_transmit_cmd.
533  */
534 static int tpm2_load_cmd(struct tpm_chip *chip,
535 			 struct trusted_key_payload *payload,
536 			 struct trusted_key_options *options,
537 			 u32 *blob_handle, unsigned int flags)
538 {
539 	struct tpm_buf buf;
540 	unsigned int private_len;
541 	unsigned int public_len;
542 	unsigned int blob_len;
543 	int rc;
544 
545 	private_len = be16_to_cpup((__be16 *) &payload->blob[0]);
546 	if (private_len > (payload->blob_len - 2))
547 		return -E2BIG;
548 
549 	public_len = be16_to_cpup((__be16 *) &payload->blob[2 + private_len]);
550 	blob_len = private_len + public_len + 4;
551 	if (blob_len > payload->blob_len)
552 		return -E2BIG;
553 
554 	rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD);
555 	if (rc)
556 		return rc;
557 
558 	tpm_buf_append_u32(&buf, options->keyhandle);
559 	tpm2_buf_append_auth(&buf, TPM2_RS_PW,
560 			     NULL /* nonce */, 0,
561 			     0 /* session_attributes */,
562 			     options->keyauth /* hmac */,
563 			     TPM_DIGEST_SIZE);
564 
565 	tpm_buf_append(&buf, payload->blob, blob_len);
566 
567 	if (buf.flags & TPM_BUF_OVERFLOW) {
568 		rc = -E2BIG;
569 		goto out;
570 	}
571 
572 	rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 4, flags,
573 			      "loading blob");
574 	if (!rc)
575 		*blob_handle = be32_to_cpup(
576 			(__be32 *) &buf.data[TPM_HEADER_SIZE]);
577 
578 out:
579 	tpm_buf_destroy(&buf);
580 
581 	if (rc > 0)
582 		rc = -EPERM;
583 
584 	return rc;
585 }
586 
587 /**
588  * tpm2_unseal_cmd() - execute a TPM2_Unload command
589  *
590  * @chip: TPM chip to use
591  * @payload: the key data in clear and encrypted form
592  * @options: authentication values and other options
593  * @blob_handle: blob handle
594  * @flags: tpm_transmit_cmd flags
595  *
596  * Return: 0 on success
597  *         -EPERM on tpm error status
598  *         < 0 error from tpm_transmit_cmd
599  */
600 static int tpm2_unseal_cmd(struct tpm_chip *chip,
601 			   struct trusted_key_payload *payload,
602 			   struct trusted_key_options *options,
603 			   u32 blob_handle, unsigned int flags)
604 {
605 	struct tpm_buf buf;
606 	u16 data_len;
607 	u8 *data;
608 	int rc;
609 
610 	rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL);
611 	if (rc)
612 		return rc;
613 
614 	tpm_buf_append_u32(&buf, blob_handle);
615 	tpm2_buf_append_auth(&buf,
616 			     options->policyhandle ?
617 			     options->policyhandle : TPM2_RS_PW,
618 			     NULL /* nonce */, 0,
619 			     TPM2_SA_CONTINUE_SESSION,
620 			     options->blobauth /* hmac */,
621 			     TPM_DIGEST_SIZE);
622 
623 	rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 6, flags,
624 			      "unsealing");
625 	if (rc > 0)
626 		rc = -EPERM;
627 
628 	if (!rc) {
629 		data_len = be16_to_cpup(
630 			(__be16 *) &buf.data[TPM_HEADER_SIZE + 4]);
631 		if (data_len < MIN_KEY_SIZE ||  data_len > MAX_KEY_SIZE + 1) {
632 			rc = -EFAULT;
633 			goto out;
634 		}
635 
636 		if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 6 + data_len) {
637 			rc = -EFAULT;
638 			goto out;
639 		}
640 		data = &buf.data[TPM_HEADER_SIZE + 6];
641 
642 		memcpy(payload->key, data, data_len - 1);
643 		payload->key_len = data_len - 1;
644 		payload->migratable = data[data_len - 1];
645 	}
646 
647 out:
648 	tpm_buf_destroy(&buf);
649 	return rc;
650 }
651 
652 /**
653  * tpm2_unseal_trusted() - unseal the payload of a trusted key
654  *
655  * @chip: TPM chip to use
656  * @payload: the key data in clear and encrypted form
657  * @options: authentication values and other options
658  *
659  * Return: Same as with tpm_transmit_cmd.
660  */
661 int tpm2_unseal_trusted(struct tpm_chip *chip,
662 			struct trusted_key_payload *payload,
663 			struct trusted_key_options *options)
664 {
665 	u32 blob_handle;
666 	int rc;
667 
668 	mutex_lock(&chip->tpm_mutex);
669 	rc = tpm2_load_cmd(chip, payload, options, &blob_handle,
670 			   TPM_TRANSMIT_UNLOCKED);
671 	if (rc)
672 		goto out;
673 
674 	rc = tpm2_unseal_cmd(chip, payload, options, blob_handle,
675 			     TPM_TRANSMIT_UNLOCKED);
676 	tpm2_flush_context_cmd(chip, blob_handle, TPM_TRANSMIT_UNLOCKED);
677 out:
678 	mutex_unlock(&chip->tpm_mutex);
679 	return rc;
680 }
681 
682 struct tpm2_get_cap_out {
683 	u8 more_data;
684 	__be32 subcap_id;
685 	__be32 property_cnt;
686 	__be32 property_id;
687 	__be32 value;
688 } __packed;
689 
690 /**
691  * tpm2_get_tpm_pt() - get value of a TPM_CAP_TPM_PROPERTIES type property
692  * @chip:		a &tpm_chip instance
693  * @property_id:	property ID.
694  * @value:		output variable.
695  * @desc:		passed to tpm_transmit_cmd()
696  *
697  * Return:
698  *   0 on success,
699  *   -errno or a TPM return code otherwise
700  */
701 ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id,  u32 *value,
702 			const char *desc)
703 {
704 	struct tpm2_get_cap_out *out;
705 	struct tpm_buf buf;
706 	int rc;
707 
708 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
709 	if (rc)
710 		return rc;
711 	tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
712 	tpm_buf_append_u32(&buf, property_id);
713 	tpm_buf_append_u32(&buf, 1);
714 	rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0, NULL);
715 	if (!rc) {
716 		out = (struct tpm2_get_cap_out *)
717 			&buf.data[TPM_HEADER_SIZE];
718 		*value = be32_to_cpu(out->value);
719 	}
720 	tpm_buf_destroy(&buf);
721 	return rc;
722 }
723 EXPORT_SYMBOL_GPL(tpm2_get_tpm_pt);
724 
725 /**
726  * tpm2_shutdown() - send a TPM shutdown command
727  *
728  * Sends a TPM shutdown command. The shutdown command is used in call
729  * sites where the system is going down. If it fails, there is not much
730  * that can be done except print an error message.
731  *
732  * @chip:		a &tpm_chip instance
733  * @shutdown_type:	TPM_SU_CLEAR or TPM_SU_STATE.
734  */
735 void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
736 {
737 	struct tpm_buf buf;
738 	int rc;
739 
740 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SHUTDOWN);
741 	if (rc)
742 		return;
743 	tpm_buf_append_u16(&buf, shutdown_type);
744 	tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
745 			 "stopping the TPM");
746 	tpm_buf_destroy(&buf);
747 }
748 
749 /*
750  * tpm2_calc_ordinal_duration() - maximum duration for a command
751  *
752  * @chip:	TPM chip to use.
753  * @ordinal:	command code number.
754  *
755  * Return: maximum duration for a command
756  */
757 unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
758 {
759 	int index = TPM_UNDEFINED;
760 	int duration = 0;
761 
762 	if (ordinal >= TPM2_CC_FIRST && ordinal <= TPM2_CC_LAST)
763 		index = tpm2_ordinal_duration[ordinal - TPM2_CC_FIRST];
764 
765 	if (index != TPM_UNDEFINED)
766 		duration = chip->duration[index];
767 
768 	if (duration <= 0)
769 		duration = msecs_to_jiffies(TPM2_DURATION_DEFAULT);
770 
771 	return duration;
772 }
773 EXPORT_SYMBOL_GPL(tpm2_calc_ordinal_duration);
774 
775 /**
776  * tpm2_do_selftest() - ensure that all self tests have passed
777  *
778  * @chip: TPM chip to use
779  *
780  * Return: Same as with tpm_transmit_cmd.
781  *
782  * The TPM can either run all self tests synchronously and then return
783  * RC_SUCCESS once all tests were successful. Or it can choose to run the tests
784  * asynchronously and return RC_TESTING immediately while the self tests still
785  * execute in the background. This function handles both cases and waits until
786  * all tests have completed.
787  */
788 static int tpm2_do_selftest(struct tpm_chip *chip)
789 {
790 	struct tpm_buf buf;
791 	int full;
792 	int rc;
793 
794 	for (full = 0; full < 2; full++) {
795 		rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SELF_TEST);
796 		if (rc)
797 			return rc;
798 
799 		tpm_buf_append_u8(&buf, full);
800 		rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
801 				      "attempting the self test");
802 		tpm_buf_destroy(&buf);
803 
804 		if (rc == TPM2_RC_TESTING)
805 			rc = TPM2_RC_SUCCESS;
806 		if (rc == TPM2_RC_INITIALIZE || rc == TPM2_RC_SUCCESS)
807 			return rc;
808 	}
809 
810 	return rc;
811 }
812 
813 /**
814  * tpm2_probe() - probe for the TPM 2.0 protocol
815  * @chip:	a &tpm_chip instance
816  *
817  * Send an idempotent TPM 2.0 command and see whether there is TPM2 chip in the
818  * other end based on the response tag. The flag TPM_CHIP_FLAG_TPM2 is set by
819  * this function if this is the case.
820  *
821  * Return:
822  *   0 on success,
823  *   -errno otherwise
824  */
825 int tpm2_probe(struct tpm_chip *chip)
826 {
827 	struct tpm_output_header *out;
828 	struct tpm_buf buf;
829 	int rc;
830 
831 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
832 	if (rc)
833 		return rc;
834 	tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
835 	tpm_buf_append_u32(&buf, TPM_PT_TOTAL_COMMANDS);
836 	tpm_buf_append_u32(&buf, 1);
837 	rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0, NULL);
838 	/* We ignore TPM return codes on purpose. */
839 	if (rc >=  0) {
840 		out = (struct tpm_output_header *)buf.data;
841 		if (be16_to_cpu(out->tag) == TPM2_ST_NO_SESSIONS)
842 			chip->flags |= TPM_CHIP_FLAG_TPM2;
843 	}
844 	tpm_buf_destroy(&buf);
845 	return 0;
846 }
847 EXPORT_SYMBOL_GPL(tpm2_probe);
848 
849 struct tpm2_pcr_selection {
850 	__be16  hash_alg;
851 	u8  size_of_select;
852 	u8  pcr_select[3];
853 } __packed;
854 
855 static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
856 {
857 	struct tpm2_pcr_selection pcr_selection;
858 	struct tpm_buf buf;
859 	void *marker;
860 	void *end;
861 	void *pcr_select_offset;
862 	unsigned int count;
863 	u32 sizeof_pcr_selection;
864 	u32 rsp_len;
865 	int rc;
866 	int i = 0;
867 
868 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
869 	if (rc)
870 		return rc;
871 
872 	tpm_buf_append_u32(&buf, TPM2_CAP_PCRS);
873 	tpm_buf_append_u32(&buf, 0);
874 	tpm_buf_append_u32(&buf, 1);
875 
876 	rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 9, 0,
877 			      "get tpm pcr allocation");
878 	if (rc)
879 		goto out;
880 
881 	count = be32_to_cpup(
882 		(__be32 *)&buf.data[TPM_HEADER_SIZE + 5]);
883 
884 	if (count > ARRAY_SIZE(chip->active_banks)) {
885 		rc = -ENODEV;
886 		goto out;
887 	}
888 
889 	marker = &buf.data[TPM_HEADER_SIZE + 9];
890 
891 	rsp_len = be32_to_cpup((__be32 *)&buf.data[2]);
892 	end = &buf.data[rsp_len];
893 
894 	for (i = 0; i < count; i++) {
895 		pcr_select_offset = marker +
896 			offsetof(struct tpm2_pcr_selection, size_of_select);
897 		if (pcr_select_offset >= end) {
898 			rc = -EFAULT;
899 			break;
900 		}
901 
902 		memcpy(&pcr_selection, marker, sizeof(pcr_selection));
903 		chip->active_banks[i] = be16_to_cpu(pcr_selection.hash_alg);
904 		sizeof_pcr_selection = sizeof(pcr_selection.hash_alg) +
905 			sizeof(pcr_selection.size_of_select) +
906 			pcr_selection.size_of_select;
907 		marker = marker + sizeof_pcr_selection;
908 	}
909 
910 out:
911 	if (i < ARRAY_SIZE(chip->active_banks))
912 		chip->active_banks[i] = TPM2_ALG_ERROR;
913 
914 	tpm_buf_destroy(&buf);
915 
916 	return rc;
917 }
918 
919 static int tpm2_get_cc_attrs_tbl(struct tpm_chip *chip)
920 {
921 	struct tpm_buf buf;
922 	u32 nr_commands;
923 	__be32 *attrs;
924 	u32 cc;
925 	int i;
926 	int rc;
927 
928 	rc = tpm2_get_tpm_pt(chip, TPM_PT_TOTAL_COMMANDS, &nr_commands, NULL);
929 	if (rc)
930 		goto out;
931 
932 	if (nr_commands > 0xFFFFF) {
933 		rc = -EFAULT;
934 		goto out;
935 	}
936 
937 	chip->cc_attrs_tbl = devm_kcalloc(&chip->dev, 4, nr_commands,
938 					  GFP_KERNEL);
939 
940 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
941 	if (rc)
942 		goto out;
943 
944 	tpm_buf_append_u32(&buf, TPM2_CAP_COMMANDS);
945 	tpm_buf_append_u32(&buf, TPM2_CC_FIRST);
946 	tpm_buf_append_u32(&buf, nr_commands);
947 
948 	rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
949 			      9 + 4 * nr_commands, 0, NULL);
950 	if (rc) {
951 		tpm_buf_destroy(&buf);
952 		goto out;
953 	}
954 
955 	if (nr_commands !=
956 	    be32_to_cpup((__be32 *)&buf.data[TPM_HEADER_SIZE + 5])) {
957 		tpm_buf_destroy(&buf);
958 		goto out;
959 	}
960 
961 	chip->nr_commands = nr_commands;
962 
963 	attrs = (__be32 *)&buf.data[TPM_HEADER_SIZE + 9];
964 	for (i = 0; i < nr_commands; i++, attrs++) {
965 		chip->cc_attrs_tbl[i] = be32_to_cpup(attrs);
966 		cc = chip->cc_attrs_tbl[i] & 0xFFFF;
967 
968 		if (cc == TPM2_CC_CONTEXT_SAVE || cc == TPM2_CC_FLUSH_CONTEXT) {
969 			chip->cc_attrs_tbl[i] &=
970 				~(GENMASK(2, 0) << TPM2_CC_ATTR_CHANDLES);
971 			chip->cc_attrs_tbl[i] |= 1 << TPM2_CC_ATTR_CHANDLES;
972 		}
973 	}
974 
975 	tpm_buf_destroy(&buf);
976 
977 out:
978 	if (rc > 0)
979 		rc = -ENODEV;
980 	return rc;
981 }
982 
983 /**
984  * tpm2_auto_startup - Perform the standard automatic TPM initialization
985  *                     sequence
986  * @chip: TPM chip to use
987  *
988  * Returns 0 on success, < 0 in case of fatal error.
989  */
990 int tpm2_auto_startup(struct tpm_chip *chip)
991 {
992 	int rc;
993 
994 	rc = tpm_get_timeouts(chip);
995 	if (rc)
996 		goto out;
997 
998 	rc = tpm2_do_selftest(chip);
999 	if (rc && rc != TPM2_RC_INITIALIZE)
1000 		goto out;
1001 
1002 	if (rc == TPM2_RC_INITIALIZE) {
1003 		rc = tpm_startup(chip);
1004 		if (rc)
1005 			goto out;
1006 
1007 		rc = tpm2_do_selftest(chip);
1008 		if (rc)
1009 			goto out;
1010 	}
1011 
1012 	rc = tpm2_get_pcr_allocation(chip);
1013 	if (rc)
1014 		goto out;
1015 
1016 	rc = tpm2_get_cc_attrs_tbl(chip);
1017 
1018 out:
1019 	if (rc > 0)
1020 		rc = -ENODEV;
1021 	return rc;
1022 }
1023 
1024 int tpm2_find_cc(struct tpm_chip *chip, u32 cc)
1025 {
1026 	int i;
1027 
1028 	for (i = 0; i < chip->nr_commands; i++)
1029 		if (cc == (chip->cc_attrs_tbl[i] & GENMASK(15, 0)))
1030 			return i;
1031 
1032 	return -1;
1033 }
1034