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 #include <keys/trusted-type.h>
17
18 enum tpm2_object_attributes {
19 TPM2_OA_USER_WITH_AUTH = BIT(6),
20 };
21
22 enum tpm2_session_attributes {
23 TPM2_SA_CONTINUE_SESSION = BIT(0),
24 };
25
26 struct tpm2_hash {
27 unsigned int crypto_id;
28 unsigned int tpm_id;
29 };
30
31 static struct tpm2_hash tpm2_hash_map[] = {
32 {HASH_ALGO_SHA1, TPM_ALG_SHA1},
33 {HASH_ALGO_SHA256, TPM_ALG_SHA256},
34 {HASH_ALGO_SHA384, TPM_ALG_SHA384},
35 {HASH_ALGO_SHA512, TPM_ALG_SHA512},
36 {HASH_ALGO_SM3_256, TPM_ALG_SM3_256},
37 };
38
tpm2_get_timeouts(struct tpm_chip * chip)39 int tpm2_get_timeouts(struct tpm_chip *chip)
40 {
41 /* Fixed timeouts for TPM2 */
42 chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
43 chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
44 chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
45 chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
46
47 /* PTP spec timeouts */
48 chip->duration[TPM_SHORT] = msecs_to_jiffies(TPM2_DURATION_SHORT);
49 chip->duration[TPM_MEDIUM] = msecs_to_jiffies(TPM2_DURATION_MEDIUM);
50 chip->duration[TPM_LONG] = msecs_to_jiffies(TPM2_DURATION_LONG);
51
52 /* Key creation commands long timeouts */
53 chip->duration[TPM_LONG_LONG] =
54 msecs_to_jiffies(TPM2_DURATION_LONG_LONG);
55
56 chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
57
58 return 0;
59 }
60
61 /**
62 * tpm2_ordinal_duration_index() - returns an index to the chip duration table
63 * @ordinal: TPM command ordinal.
64 *
65 * The function returns an index to the chip duration table
66 * (enum tpm_duration), that describes the maximum amount of
67 * time the chip could take to return the result for a particular ordinal.
68 *
69 * The values of the MEDIUM, and LONG durations are taken
70 * from the PC Client Profile (PTP) specification (750, 2000 msec)
71 *
72 * LONG_LONG is for commands that generates keys which empirically takes
73 * a longer time on some systems.
74 *
75 * Return:
76 * * TPM_MEDIUM
77 * * TPM_LONG
78 * * TPM_LONG_LONG
79 * * TPM_UNDEFINED
80 */
tpm2_ordinal_duration_index(u32 ordinal)81 static u8 tpm2_ordinal_duration_index(u32 ordinal)
82 {
83 switch (ordinal) {
84 /* Startup */
85 case TPM2_CC_STARTUP: /* 144 */
86 return TPM_MEDIUM;
87
88 case TPM2_CC_SELF_TEST: /* 143 */
89 return TPM_LONG;
90
91 case TPM2_CC_GET_RANDOM: /* 17B */
92 return TPM_LONG;
93
94 case TPM2_CC_SEQUENCE_UPDATE: /* 15C */
95 return TPM_MEDIUM;
96 case TPM2_CC_SEQUENCE_COMPLETE: /* 13E */
97 return TPM_MEDIUM;
98 case TPM2_CC_EVENT_SEQUENCE_COMPLETE: /* 185 */
99 return TPM_MEDIUM;
100 case TPM2_CC_HASH_SEQUENCE_START: /* 186 */
101 return TPM_MEDIUM;
102
103 case TPM2_CC_VERIFY_SIGNATURE: /* 177 */
104 return TPM_LONG;
105
106 case TPM2_CC_PCR_EXTEND: /* 182 */
107 return TPM_MEDIUM;
108
109 case TPM2_CC_HIERARCHY_CONTROL: /* 121 */
110 return TPM_LONG;
111 case TPM2_CC_HIERARCHY_CHANGE_AUTH: /* 129 */
112 return TPM_LONG;
113
114 case TPM2_CC_GET_CAPABILITY: /* 17A */
115 return TPM_MEDIUM;
116
117 case TPM2_CC_NV_READ: /* 14E */
118 return TPM_LONG;
119
120 case TPM2_CC_CREATE_PRIMARY: /* 131 */
121 return TPM_LONG_LONG;
122 case TPM2_CC_CREATE: /* 153 */
123 return TPM_LONG_LONG;
124 case TPM2_CC_CREATE_LOADED: /* 191 */
125 return TPM_LONG_LONG;
126
127 default:
128 return TPM_UNDEFINED;
129 }
130 }
131
132 /**
133 * tpm2_calc_ordinal_duration() - calculate the maximum command duration
134 * @chip: TPM chip to use.
135 * @ordinal: TPM command ordinal.
136 *
137 * The function returns the maximum amount of time the chip could take
138 * to return the result for a particular ordinal in jiffies.
139 *
140 * Return: A maximal duration time for an ordinal in jiffies.
141 */
tpm2_calc_ordinal_duration(struct tpm_chip * chip,u32 ordinal)142 unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
143 {
144 unsigned int index;
145
146 index = tpm2_ordinal_duration_index(ordinal);
147
148 if (index != TPM_UNDEFINED)
149 return chip->duration[index];
150 else
151 return msecs_to_jiffies(TPM2_DURATION_DEFAULT);
152 }
153
154
155 struct tpm2_pcr_read_out {
156 __be32 update_cnt;
157 __be32 pcr_selects_cnt;
158 __be16 hash_alg;
159 u8 pcr_select_size;
160 u8 pcr_select[TPM2_PCR_SELECT_MIN];
161 __be32 digests_cnt;
162 __be16 digest_size;
163 u8 digest[];
164 } __packed;
165
166 /**
167 * tpm2_pcr_read() - read a PCR value
168 * @chip: TPM chip to use.
169 * @pcr_idx: index of the PCR to read.
170 * @digest: PCR bank and buffer current PCR value is written to.
171 * @digest_size_ptr: pointer to variable that stores the digest size.
172 *
173 * Return: Same as with tpm_transmit_cmd.
174 */
tpm2_pcr_read(struct tpm_chip * chip,u32 pcr_idx,struct tpm_digest * digest,u16 * digest_size_ptr)175 int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
176 struct tpm_digest *digest, u16 *digest_size_ptr)
177 {
178 int i;
179 int rc;
180 struct tpm_buf buf;
181 struct tpm2_pcr_read_out *out;
182 u8 pcr_select[TPM2_PCR_SELECT_MIN] = {0};
183 u16 digest_size;
184 u16 expected_digest_size = 0;
185
186 if (pcr_idx >= TPM2_PLATFORM_PCR)
187 return -EINVAL;
188
189 if (!digest_size_ptr) {
190 for (i = 0; i < chip->nr_allocated_banks &&
191 chip->allocated_banks[i].alg_id != digest->alg_id; i++)
192 ;
193
194 if (i == chip->nr_allocated_banks)
195 return -EINVAL;
196
197 expected_digest_size = chip->allocated_banks[i].digest_size;
198 }
199
200 rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_PCR_READ);
201 if (rc)
202 return rc;
203
204 pcr_select[pcr_idx >> 3] = 1 << (pcr_idx & 0x7);
205
206 tpm_buf_append_u32(&buf, 1);
207 tpm_buf_append_u16(&buf, digest->alg_id);
208 tpm_buf_append_u8(&buf, TPM2_PCR_SELECT_MIN);
209 tpm_buf_append(&buf, (const unsigned char *)pcr_select,
210 sizeof(pcr_select));
211
212 rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to read a pcr value");
213 if (rc)
214 goto out;
215
216 out = (struct tpm2_pcr_read_out *)&buf.data[TPM_HEADER_SIZE];
217 digest_size = be16_to_cpu(out->digest_size);
218 if (digest_size > sizeof(digest->digest) ||
219 (!digest_size_ptr && digest_size != expected_digest_size)) {
220 rc = -EINVAL;
221 goto out;
222 }
223
224 if (digest_size_ptr)
225 *digest_size_ptr = digest_size;
226
227 memcpy(digest->digest, out->digest, digest_size);
228 out:
229 tpm_buf_destroy(&buf);
230 return rc;
231 }
232
233 struct tpm2_null_auth_area {
234 __be32 handle;
235 __be16 nonce_size;
236 u8 attributes;
237 __be16 auth_size;
238 } __packed;
239
240 /**
241 * tpm2_pcr_extend() - extend a PCR value
242 *
243 * @chip: TPM chip to use.
244 * @pcr_idx: index of the PCR.
245 * @digests: list of pcr banks and corresponding digest values to extend.
246 *
247 * Return: Same as with tpm_transmit_cmd.
248 */
tpm2_pcr_extend(struct tpm_chip * chip,u32 pcr_idx,struct tpm_digest * digests)249 int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
250 struct tpm_digest *digests)
251 {
252 struct tpm_buf buf;
253 struct tpm2_null_auth_area auth_area;
254 int rc;
255 int i;
256
257 rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND);
258 if (rc)
259 return rc;
260
261 tpm_buf_append_u32(&buf, pcr_idx);
262
263 auth_area.handle = cpu_to_be32(TPM2_RS_PW);
264 auth_area.nonce_size = 0;
265 auth_area.attributes = 0;
266 auth_area.auth_size = 0;
267
268 tpm_buf_append_u32(&buf, sizeof(struct tpm2_null_auth_area));
269 tpm_buf_append(&buf, (const unsigned char *)&auth_area,
270 sizeof(auth_area));
271 tpm_buf_append_u32(&buf, chip->nr_allocated_banks);
272
273 for (i = 0; i < chip->nr_allocated_banks; i++) {
274 tpm_buf_append_u16(&buf, digests[i].alg_id);
275 tpm_buf_append(&buf, (const unsigned char *)&digests[i].digest,
276 chip->allocated_banks[i].digest_size);
277 }
278
279 rc = tpm_transmit_cmd(chip, &buf, 0, "attempting extend a PCR value");
280
281 tpm_buf_destroy(&buf);
282
283 return rc;
284 }
285
286 struct tpm2_get_random_out {
287 __be16 size;
288 u8 buffer[TPM_MAX_RNG_DATA];
289 } __packed;
290
291 /**
292 * tpm2_get_random() - get random bytes from the TPM RNG
293 *
294 * @chip: a &tpm_chip instance
295 * @dest: destination buffer
296 * @max: the max number of random bytes to pull
297 *
298 * Return:
299 * size of the buffer on success,
300 * -errno otherwise (positive TPM return codes are masked to -EIO)
301 */
tpm2_get_random(struct tpm_chip * chip,u8 * dest,size_t max)302 int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
303 {
304 struct tpm2_get_random_out *out;
305 struct tpm_buf buf;
306 u32 recd;
307 u32 num_bytes = max;
308 int err;
309 int total = 0;
310 int retries = 5;
311 u8 *dest_ptr = dest;
312
313 if (!num_bytes || max > TPM_MAX_RNG_DATA)
314 return -EINVAL;
315
316 err = tpm_buf_init(&buf, 0, 0);
317 if (err)
318 return err;
319
320 do {
321 tpm_buf_reset(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_RANDOM);
322 tpm_buf_append_u16(&buf, num_bytes);
323 err = tpm_transmit_cmd(chip, &buf,
324 offsetof(struct tpm2_get_random_out,
325 buffer),
326 "attempting get random");
327 if (err) {
328 if (err > 0)
329 err = -EIO;
330 goto out;
331 }
332
333 out = (struct tpm2_get_random_out *)
334 &buf.data[TPM_HEADER_SIZE];
335 recd = min_t(u32, be16_to_cpu(out->size), num_bytes);
336 if (tpm_buf_length(&buf) <
337 TPM_HEADER_SIZE +
338 offsetof(struct tpm2_get_random_out, buffer) +
339 recd) {
340 err = -EFAULT;
341 goto out;
342 }
343 memcpy(dest_ptr, out->buffer, recd);
344
345 dest_ptr += recd;
346 total += recd;
347 num_bytes -= recd;
348 } while (retries-- && total < max);
349
350 tpm_buf_destroy(&buf);
351 return total ? total : -EIO;
352 out:
353 tpm_buf_destroy(&buf);
354 return err;
355 }
356
357 /**
358 * tpm2_flush_context() - execute a TPM2_FlushContext command
359 * @chip: TPM chip to use
360 * @handle: context handle
361 */
tpm2_flush_context(struct tpm_chip * chip,u32 handle)362 void tpm2_flush_context(struct tpm_chip *chip, u32 handle)
363 {
364 struct tpm_buf buf;
365 int rc;
366
367 rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_FLUSH_CONTEXT);
368 if (rc) {
369 dev_warn(&chip->dev, "0x%08x was not flushed, out of memory\n",
370 handle);
371 return;
372 }
373
374 tpm_buf_append_u32(&buf, handle);
375
376 tpm_transmit_cmd(chip, &buf, 0, "flushing context");
377 tpm_buf_destroy(&buf);
378 }
379
380 /**
381 * tpm_buf_append_auth() - append TPMS_AUTH_COMMAND to the buffer.
382 *
383 * @buf: an allocated tpm_buf instance
384 * @session_handle: session handle
385 * @nonce: the session nonce, may be NULL if not used
386 * @nonce_len: the session nonce length, may be 0 if not used
387 * @attributes: the session attributes
388 * @hmac: the session HMAC or password, may be NULL if not used
389 * @hmac_len: the session HMAC or password length, maybe 0 if not used
390 */
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)391 static void tpm2_buf_append_auth(struct tpm_buf *buf, u32 session_handle,
392 const u8 *nonce, u16 nonce_len,
393 u8 attributes,
394 const u8 *hmac, u16 hmac_len)
395 {
396 tpm_buf_append_u32(buf, 9 + nonce_len + hmac_len);
397 tpm_buf_append_u32(buf, session_handle);
398 tpm_buf_append_u16(buf, nonce_len);
399
400 if (nonce && nonce_len)
401 tpm_buf_append(buf, nonce, nonce_len);
402
403 tpm_buf_append_u8(buf, attributes);
404 tpm_buf_append_u16(buf, hmac_len);
405
406 if (hmac && hmac_len)
407 tpm_buf_append(buf, hmac, hmac_len);
408 }
409
410 /**
411 * tpm2_seal_trusted() - seal the payload of a trusted key
412 *
413 * @chip: TPM chip to use
414 * @payload: the key data in clear and encrypted form
415 * @options: authentication values and other options
416 *
417 * Return: < 0 on error and 0 on success.
418 */
tpm2_seal_trusted(struct tpm_chip * chip,struct trusted_key_payload * payload,struct trusted_key_options * options)419 int tpm2_seal_trusted(struct tpm_chip *chip,
420 struct trusted_key_payload *payload,
421 struct trusted_key_options *options)
422 {
423 unsigned int blob_len;
424 struct tpm_buf buf;
425 u32 hash;
426 int i;
427 int rc;
428
429 for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
430 if (options->hash == tpm2_hash_map[i].crypto_id) {
431 hash = tpm2_hash_map[i].tpm_id;
432 break;
433 }
434 }
435
436 if (i == ARRAY_SIZE(tpm2_hash_map))
437 return -EINVAL;
438
439 rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE);
440 if (rc)
441 return rc;
442
443 tpm_buf_append_u32(&buf, options->keyhandle);
444 tpm2_buf_append_auth(&buf, TPM2_RS_PW,
445 NULL /* nonce */, 0,
446 0 /* session_attributes */,
447 options->keyauth /* hmac */,
448 TPM_DIGEST_SIZE);
449
450 /* sensitive */
451 tpm_buf_append_u16(&buf, 4 + TPM_DIGEST_SIZE + payload->key_len + 1);
452
453 tpm_buf_append_u16(&buf, TPM_DIGEST_SIZE);
454 tpm_buf_append(&buf, options->blobauth, TPM_DIGEST_SIZE);
455 tpm_buf_append_u16(&buf, payload->key_len + 1);
456 tpm_buf_append(&buf, payload->key, payload->key_len);
457 tpm_buf_append_u8(&buf, payload->migratable);
458
459 /* public */
460 tpm_buf_append_u16(&buf, 14 + options->policydigest_len);
461 tpm_buf_append_u16(&buf, TPM_ALG_KEYEDHASH);
462 tpm_buf_append_u16(&buf, hash);
463
464 /* policy */
465 if (options->policydigest_len) {
466 tpm_buf_append_u32(&buf, 0);
467 tpm_buf_append_u16(&buf, options->policydigest_len);
468 tpm_buf_append(&buf, options->policydigest,
469 options->policydigest_len);
470 } else {
471 tpm_buf_append_u32(&buf, TPM2_OA_USER_WITH_AUTH);
472 tpm_buf_append_u16(&buf, 0);
473 }
474
475 /* public parameters */
476 tpm_buf_append_u16(&buf, TPM_ALG_NULL);
477 tpm_buf_append_u16(&buf, 0);
478
479 /* outside info */
480 tpm_buf_append_u16(&buf, 0);
481
482 /* creation PCR */
483 tpm_buf_append_u32(&buf, 0);
484
485 if (buf.flags & TPM_BUF_OVERFLOW) {
486 rc = -E2BIG;
487 goto out;
488 }
489
490 rc = tpm_transmit_cmd(chip, &buf, 4, "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 *
528 * Return: 0 on success.
529 * -E2BIG on wrong payload size.
530 * -EPERM on tpm error status.
531 * < 0 error from tpm_transmit_cmd.
532 */
tpm2_load_cmd(struct tpm_chip * chip,struct trusted_key_payload * payload,struct trusted_key_options * options,u32 * blob_handle)533 static int tpm2_load_cmd(struct tpm_chip *chip,
534 struct trusted_key_payload *payload,
535 struct trusted_key_options *options,
536 u32 *blob_handle)
537 {
538 struct tpm_buf buf;
539 unsigned int private_len;
540 unsigned int public_len;
541 unsigned int blob_len;
542 int rc;
543
544 private_len = be16_to_cpup((__be16 *) &payload->blob[0]);
545 if (private_len > (payload->blob_len - 2))
546 return -E2BIG;
547
548 public_len = be16_to_cpup((__be16 *) &payload->blob[2 + private_len]);
549 blob_len = private_len + public_len + 4;
550 if (blob_len > payload->blob_len)
551 return -E2BIG;
552
553 rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD);
554 if (rc)
555 return rc;
556
557 tpm_buf_append_u32(&buf, options->keyhandle);
558 tpm2_buf_append_auth(&buf, TPM2_RS_PW,
559 NULL /* nonce */, 0,
560 0 /* session_attributes */,
561 options->keyauth /* hmac */,
562 TPM_DIGEST_SIZE);
563
564 tpm_buf_append(&buf, payload->blob, blob_len);
565
566 if (buf.flags & TPM_BUF_OVERFLOW) {
567 rc = -E2BIG;
568 goto out;
569 }
570
571 rc = tpm_transmit_cmd(chip, &buf, 4, "loading blob");
572 if (!rc)
573 *blob_handle = be32_to_cpup(
574 (__be32 *) &buf.data[TPM_HEADER_SIZE]);
575
576 out:
577 tpm_buf_destroy(&buf);
578
579 if (rc > 0)
580 rc = -EPERM;
581
582 return rc;
583 }
584
585 /**
586 * tpm2_unseal_cmd() - execute a TPM2_Unload command
587 *
588 * @chip: TPM chip to use
589 * @payload: the key data in clear and encrypted form
590 * @options: authentication values and other options
591 * @blob_handle: blob handle
592 *
593 * Return: 0 on success
594 * -EPERM on tpm error status
595 * < 0 error from tpm_transmit_cmd
596 */
tpm2_unseal_cmd(struct tpm_chip * chip,struct trusted_key_payload * payload,struct trusted_key_options * options,u32 blob_handle)597 static int tpm2_unseal_cmd(struct tpm_chip *chip,
598 struct trusted_key_payload *payload,
599 struct trusted_key_options *options,
600 u32 blob_handle)
601 {
602 struct tpm_buf buf;
603 u16 data_len;
604 u8 *data;
605 int rc;
606
607 rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL);
608 if (rc)
609 return rc;
610
611 tpm_buf_append_u32(&buf, blob_handle);
612 tpm2_buf_append_auth(&buf,
613 options->policyhandle ?
614 options->policyhandle : TPM2_RS_PW,
615 NULL /* nonce */, 0,
616 TPM2_SA_CONTINUE_SESSION,
617 options->blobauth /* hmac */,
618 TPM_DIGEST_SIZE);
619
620 rc = tpm_transmit_cmd(chip, &buf, 6, "unsealing");
621 if (rc > 0)
622 rc = -EPERM;
623
624 if (!rc) {
625 data_len = be16_to_cpup(
626 (__be16 *) &buf.data[TPM_HEADER_SIZE + 4]);
627 if (data_len < MIN_KEY_SIZE || data_len > MAX_KEY_SIZE + 1) {
628 rc = -EFAULT;
629 goto out;
630 }
631
632 if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 6 + data_len) {
633 rc = -EFAULT;
634 goto out;
635 }
636 data = &buf.data[TPM_HEADER_SIZE + 6];
637
638 memcpy(payload->key, data, data_len - 1);
639 payload->key_len = data_len - 1;
640 payload->migratable = data[data_len - 1];
641 }
642
643 out:
644 tpm_buf_destroy(&buf);
645 return rc;
646 }
647
648 /**
649 * tpm2_unseal_trusted() - unseal the payload of a trusted key
650 *
651 * @chip: TPM chip to use
652 * @payload: the key data in clear and encrypted form
653 * @options: authentication values and other options
654 *
655 * Return: Same as with tpm_transmit_cmd.
656 */
tpm2_unseal_trusted(struct tpm_chip * chip,struct trusted_key_payload * payload,struct trusted_key_options * options)657 int tpm2_unseal_trusted(struct tpm_chip *chip,
658 struct trusted_key_payload *payload,
659 struct trusted_key_options *options)
660 {
661 u32 blob_handle;
662 int rc;
663
664 rc = tpm2_load_cmd(chip, payload, options, &blob_handle);
665 if (rc)
666 return rc;
667
668 rc = tpm2_unseal_cmd(chip, payload, options, blob_handle);
669 tpm2_flush_context(chip, blob_handle);
670 return rc;
671 }
672
673 struct tpm2_get_cap_out {
674 u8 more_data;
675 __be32 subcap_id;
676 __be32 property_cnt;
677 __be32 property_id;
678 __be32 value;
679 } __packed;
680
681 /**
682 * tpm2_get_tpm_pt() - get value of a TPM_CAP_TPM_PROPERTIES type property
683 * @chip: a &tpm_chip instance
684 * @property_id: property ID.
685 * @value: output variable.
686 * @desc: passed to tpm_transmit_cmd()
687 *
688 * Return:
689 * 0 on success,
690 * -errno or a TPM return code otherwise
691 */
tpm2_get_tpm_pt(struct tpm_chip * chip,u32 property_id,u32 * value,const char * desc)692 ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id, u32 *value,
693 const char *desc)
694 {
695 struct tpm2_get_cap_out *out;
696 struct tpm_buf buf;
697 int rc;
698
699 rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
700 if (rc)
701 return rc;
702 tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
703 tpm_buf_append_u32(&buf, property_id);
704 tpm_buf_append_u32(&buf, 1);
705 rc = tpm_transmit_cmd(chip, &buf, 0, NULL);
706 if (!rc) {
707 out = (struct tpm2_get_cap_out *)
708 &buf.data[TPM_HEADER_SIZE];
709 *value = be32_to_cpu(out->value);
710 }
711 tpm_buf_destroy(&buf);
712 return rc;
713 }
714 EXPORT_SYMBOL_GPL(tpm2_get_tpm_pt);
715
716 /**
717 * tpm2_shutdown() - send a TPM shutdown command
718 *
719 * Sends a TPM shutdown command. The shutdown command is used in call
720 * sites where the system is going down. If it fails, there is not much
721 * that can be done except print an error message.
722 *
723 * @chip: a &tpm_chip instance
724 * @shutdown_type: TPM_SU_CLEAR or TPM_SU_STATE.
725 */
tpm2_shutdown(struct tpm_chip * chip,u16 shutdown_type)726 void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
727 {
728 struct tpm_buf buf;
729 int rc;
730
731 rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SHUTDOWN);
732 if (rc)
733 return;
734 tpm_buf_append_u16(&buf, shutdown_type);
735 tpm_transmit_cmd(chip, &buf, 0, "stopping the TPM");
736 tpm_buf_destroy(&buf);
737 }
738
739 /**
740 * tpm2_do_selftest() - ensure that all self tests have passed
741 *
742 * @chip: TPM chip to use
743 *
744 * Return: Same as with tpm_transmit_cmd.
745 *
746 * The TPM can either run all self tests synchronously and then return
747 * RC_SUCCESS once all tests were successful. Or it can choose to run the tests
748 * asynchronously and return RC_TESTING immediately while the self tests still
749 * execute in the background. This function handles both cases and waits until
750 * all tests have completed.
751 */
tpm2_do_selftest(struct tpm_chip * chip)752 static int tpm2_do_selftest(struct tpm_chip *chip)
753 {
754 struct tpm_buf buf;
755 int full;
756 int rc;
757
758 for (full = 0; full < 2; full++) {
759 rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SELF_TEST);
760 if (rc)
761 return rc;
762
763 tpm_buf_append_u8(&buf, full);
764 rc = tpm_transmit_cmd(chip, &buf, 0,
765 "attempting the self test");
766 tpm_buf_destroy(&buf);
767
768 if (rc == TPM2_RC_TESTING)
769 rc = TPM2_RC_SUCCESS;
770 if (rc == TPM2_RC_INITIALIZE || rc == TPM2_RC_SUCCESS)
771 return rc;
772 }
773
774 return rc;
775 }
776
777 /**
778 * tpm2_probe() - probe for the TPM 2.0 protocol
779 * @chip: a &tpm_chip instance
780 *
781 * Send an idempotent TPM 2.0 command and see whether there is TPM2 chip in the
782 * other end based on the response tag. The flag TPM_CHIP_FLAG_TPM2 is set by
783 * this function if this is the case.
784 *
785 * Return:
786 * 0 on success,
787 * -errno otherwise
788 */
tpm2_probe(struct tpm_chip * chip)789 int tpm2_probe(struct tpm_chip *chip)
790 {
791 struct tpm_header *out;
792 struct tpm_buf buf;
793 int rc;
794
795 rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
796 if (rc)
797 return rc;
798 tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
799 tpm_buf_append_u32(&buf, TPM_PT_TOTAL_COMMANDS);
800 tpm_buf_append_u32(&buf, 1);
801 rc = tpm_transmit_cmd(chip, &buf, 0, NULL);
802 /* We ignore TPM return codes on purpose. */
803 if (rc >= 0) {
804 out = (struct tpm_header *)buf.data;
805 if (be16_to_cpu(out->tag) == TPM2_ST_NO_SESSIONS)
806 chip->flags |= TPM_CHIP_FLAG_TPM2;
807 }
808 tpm_buf_destroy(&buf);
809 return 0;
810 }
811 EXPORT_SYMBOL_GPL(tpm2_probe);
812
tpm2_init_bank_info(struct tpm_chip * chip,u32 bank_index)813 static int tpm2_init_bank_info(struct tpm_chip *chip, u32 bank_index)
814 {
815 struct tpm_bank_info *bank = chip->allocated_banks + bank_index;
816 struct tpm_digest digest = { .alg_id = bank->alg_id };
817 int i;
818
819 /*
820 * Avoid unnecessary PCR read operations to reduce overhead
821 * and obtain identifiers of the crypto subsystem.
822 */
823 for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
824 enum hash_algo crypto_algo = tpm2_hash_map[i].crypto_id;
825
826 if (bank->alg_id != tpm2_hash_map[i].tpm_id)
827 continue;
828
829 bank->digest_size = hash_digest_size[crypto_algo];
830 bank->crypto_id = crypto_algo;
831 return 0;
832 }
833
834 return tpm2_pcr_read(chip, 0, &digest, &bank->digest_size);
835 }
836
837 struct tpm2_pcr_selection {
838 __be16 hash_alg;
839 u8 size_of_select;
840 u8 pcr_select[3];
841 } __packed;
842
tpm2_get_pcr_allocation(struct tpm_chip * chip)843 ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
844 {
845 struct tpm2_pcr_selection pcr_selection;
846 struct tpm_buf buf;
847 void *marker;
848 void *end;
849 void *pcr_select_offset;
850 u32 sizeof_pcr_selection;
851 u32 nr_possible_banks;
852 u32 nr_alloc_banks = 0;
853 u16 hash_alg;
854 u32 rsp_len;
855 int rc;
856 int i = 0;
857
858 rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
859 if (rc)
860 return rc;
861
862 tpm_buf_append_u32(&buf, TPM2_CAP_PCRS);
863 tpm_buf_append_u32(&buf, 0);
864 tpm_buf_append_u32(&buf, 1);
865
866 rc = tpm_transmit_cmd(chip, &buf, 9, "get tpm pcr allocation");
867 if (rc)
868 goto out;
869
870 nr_possible_banks = be32_to_cpup(
871 (__be32 *)&buf.data[TPM_HEADER_SIZE + 5]);
872
873 chip->allocated_banks = kcalloc(nr_possible_banks,
874 sizeof(*chip->allocated_banks),
875 GFP_KERNEL);
876 if (!chip->allocated_banks) {
877 rc = -ENOMEM;
878 goto out;
879 }
880
881 marker = &buf.data[TPM_HEADER_SIZE + 9];
882
883 rsp_len = be32_to_cpup((__be32 *)&buf.data[2]);
884 end = &buf.data[rsp_len];
885
886 for (i = 0; i < nr_possible_banks; i++) {
887 pcr_select_offset = marker +
888 offsetof(struct tpm2_pcr_selection, size_of_select);
889 if (pcr_select_offset >= end) {
890 rc = -EFAULT;
891 break;
892 }
893
894 memcpy(&pcr_selection, marker, sizeof(pcr_selection));
895 hash_alg = be16_to_cpu(pcr_selection.hash_alg);
896
897 pcr_select_offset = memchr_inv(pcr_selection.pcr_select, 0,
898 pcr_selection.size_of_select);
899 if (pcr_select_offset) {
900 chip->allocated_banks[nr_alloc_banks].alg_id = hash_alg;
901
902 rc = tpm2_init_bank_info(chip, nr_alloc_banks);
903 if (rc < 0)
904 break;
905
906 nr_alloc_banks++;
907 }
908
909 sizeof_pcr_selection = sizeof(pcr_selection.hash_alg) +
910 sizeof(pcr_selection.size_of_select) +
911 pcr_selection.size_of_select;
912 marker = marker + sizeof_pcr_selection;
913 }
914
915 chip->nr_allocated_banks = nr_alloc_banks;
916 out:
917 tpm_buf_destroy(&buf);
918
919 return rc;
920 }
921
tpm2_get_cc_attrs_tbl(struct tpm_chip * chip)922 static int tpm2_get_cc_attrs_tbl(struct tpm_chip *chip)
923 {
924 struct tpm_buf buf;
925 u32 nr_commands;
926 __be32 *attrs;
927 u32 cc;
928 int i;
929 int rc;
930
931 rc = tpm2_get_tpm_pt(chip, TPM_PT_TOTAL_COMMANDS, &nr_commands, NULL);
932 if (rc)
933 goto out;
934
935 if (nr_commands > 0xFFFFF) {
936 rc = -EFAULT;
937 goto out;
938 }
939
940 chip->cc_attrs_tbl = devm_kcalloc(&chip->dev, 4, nr_commands,
941 GFP_KERNEL);
942
943 rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
944 if (rc)
945 goto out;
946
947 tpm_buf_append_u32(&buf, TPM2_CAP_COMMANDS);
948 tpm_buf_append_u32(&buf, TPM2_CC_FIRST);
949 tpm_buf_append_u32(&buf, nr_commands);
950
951 rc = tpm_transmit_cmd(chip, &buf, 9 + 4 * nr_commands, NULL);
952 if (rc) {
953 tpm_buf_destroy(&buf);
954 goto out;
955 }
956
957 if (nr_commands !=
958 be32_to_cpup((__be32 *)&buf.data[TPM_HEADER_SIZE + 5])) {
959 tpm_buf_destroy(&buf);
960 goto out;
961 }
962
963 chip->nr_commands = nr_commands;
964
965 attrs = (__be32 *)&buf.data[TPM_HEADER_SIZE + 9];
966 for (i = 0; i < nr_commands; i++, attrs++) {
967 chip->cc_attrs_tbl[i] = be32_to_cpup(attrs);
968 cc = chip->cc_attrs_tbl[i] & 0xFFFF;
969
970 if (cc == TPM2_CC_CONTEXT_SAVE || cc == TPM2_CC_FLUSH_CONTEXT) {
971 chip->cc_attrs_tbl[i] &=
972 ~(GENMASK(2, 0) << TPM2_CC_ATTR_CHANDLES);
973 chip->cc_attrs_tbl[i] |= 1 << TPM2_CC_ATTR_CHANDLES;
974 }
975 }
976
977 tpm_buf_destroy(&buf);
978
979 out:
980 if (rc > 0)
981 rc = -ENODEV;
982 return rc;
983 }
984
985 /**
986 * tpm2_startup - turn on the TPM
987 * @chip: TPM chip to use
988 *
989 * Normally the firmware should start the TPM. This function is provided as a
990 * workaround if this does not happen. A legal case for this could be for
991 * example when a TPM emulator is used.
992 *
993 * Return: same as tpm_transmit_cmd()
994 */
995
tpm2_startup(struct tpm_chip * chip)996 static int tpm2_startup(struct tpm_chip *chip)
997 {
998 struct tpm_buf buf;
999 int rc;
1000
1001 dev_info(&chip->dev, "starting up the TPM manually\n");
1002
1003 rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_STARTUP);
1004 if (rc < 0)
1005 return rc;
1006
1007 tpm_buf_append_u16(&buf, TPM2_SU_CLEAR);
1008 rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to start the TPM");
1009 tpm_buf_destroy(&buf);
1010
1011 return rc;
1012 }
1013
1014 /**
1015 * tpm2_auto_startup - Perform the standard automatic TPM initialization
1016 * sequence
1017 * @chip: TPM chip to use
1018 *
1019 * Returns 0 on success, < 0 in case of fatal error.
1020 */
tpm2_auto_startup(struct tpm_chip * chip)1021 int tpm2_auto_startup(struct tpm_chip *chip)
1022 {
1023 int rc;
1024
1025 rc = tpm2_get_timeouts(chip);
1026 if (rc)
1027 goto out;
1028
1029 rc = tpm2_do_selftest(chip);
1030 if (rc && rc != TPM2_RC_INITIALIZE)
1031 goto out;
1032
1033 if (rc == TPM2_RC_INITIALIZE) {
1034 rc = tpm2_startup(chip);
1035 if (rc)
1036 goto out;
1037
1038 rc = tpm2_do_selftest(chip);
1039 if (rc)
1040 goto out;
1041 }
1042
1043 rc = tpm2_get_cc_attrs_tbl(chip);
1044
1045 out:
1046 if (rc > 0)
1047 rc = -ENODEV;
1048 return rc;
1049 }
1050
tpm2_find_cc(struct tpm_chip * chip,u32 cc)1051 int tpm2_find_cc(struct tpm_chip *chip, u32 cc)
1052 {
1053 int i;
1054
1055 for (i = 0; i < chip->nr_commands; i++)
1056 if (cc == (chip->cc_attrs_tbl[i] & GENMASK(15, 0)))
1057 return i;
1058
1059 return -1;
1060 }
1061
