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 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 */ 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 */ 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 */ 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 */ 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 301 */ 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 goto out; 329 330 out = (struct tpm2_get_random_out *) 331 &buf.data[TPM_HEADER_SIZE]; 332 recd = min_t(u32, be16_to_cpu(out->size), num_bytes); 333 if (tpm_buf_length(&buf) < 334 TPM_HEADER_SIZE + 335 offsetof(struct tpm2_get_random_out, buffer) + 336 recd) { 337 err = -EFAULT; 338 goto out; 339 } 340 memcpy(dest_ptr, out->buffer, recd); 341 342 dest_ptr += recd; 343 total += recd; 344 num_bytes -= recd; 345 } while (retries-- && total < max); 346 347 tpm_buf_destroy(&buf); 348 return total ? total : -EIO; 349 out: 350 tpm_buf_destroy(&buf); 351 return err; 352 } 353 354 /** 355 * tpm2_flush_context() - execute a TPM2_FlushContext command 356 * @chip: TPM chip to use 357 * @handle: context handle 358 */ 359 void tpm2_flush_context(struct tpm_chip *chip, u32 handle) 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 tpm_transmit_cmd(chip, &buf, 0, "flushing context"); 374 tpm_buf_destroy(&buf); 375 } 376 377 /** 378 * tpm_buf_append_auth() - append TPMS_AUTH_COMMAND to the buffer. 379 * 380 * @buf: an allocated tpm_buf instance 381 * @session_handle: session handle 382 * @nonce: the session nonce, may be NULL if not used 383 * @nonce_len: the session nonce length, may be 0 if not used 384 * @attributes: the session attributes 385 * @hmac: the session HMAC or password, may be NULL if not used 386 * @hmac_len: the session HMAC or password length, maybe 0 if not used 387 */ 388 static void tpm2_buf_append_auth(struct tpm_buf *buf, u32 session_handle, 389 const u8 *nonce, u16 nonce_len, 390 u8 attributes, 391 const u8 *hmac, u16 hmac_len) 392 { 393 tpm_buf_append_u32(buf, 9 + nonce_len + hmac_len); 394 tpm_buf_append_u32(buf, session_handle); 395 tpm_buf_append_u16(buf, nonce_len); 396 397 if (nonce && nonce_len) 398 tpm_buf_append(buf, nonce, nonce_len); 399 400 tpm_buf_append_u8(buf, attributes); 401 tpm_buf_append_u16(buf, hmac_len); 402 403 if (hmac && hmac_len) 404 tpm_buf_append(buf, hmac, hmac_len); 405 } 406 407 /** 408 * tpm2_seal_trusted() - seal the payload of a trusted key 409 * 410 * @chip: TPM chip to use 411 * @payload: the key data in clear and encrypted form 412 * @options: authentication values and other options 413 * 414 * Return: < 0 on error and 0 on success. 415 */ 416 int tpm2_seal_trusted(struct tpm_chip *chip, 417 struct trusted_key_payload *payload, 418 struct trusted_key_options *options) 419 { 420 unsigned int blob_len; 421 struct tpm_buf buf; 422 u32 hash; 423 int i; 424 int rc; 425 426 for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) { 427 if (options->hash == tpm2_hash_map[i].crypto_id) { 428 hash = tpm2_hash_map[i].tpm_id; 429 break; 430 } 431 } 432 433 if (i == ARRAY_SIZE(tpm2_hash_map)) 434 return -EINVAL; 435 436 rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE); 437 if (rc) 438 return rc; 439 440 tpm_buf_append_u32(&buf, options->keyhandle); 441 tpm2_buf_append_auth(&buf, TPM2_RS_PW, 442 NULL /* nonce */, 0, 443 0 /* session_attributes */, 444 options->keyauth /* hmac */, 445 TPM_DIGEST_SIZE); 446 447 /* sensitive */ 448 tpm_buf_append_u16(&buf, 4 + TPM_DIGEST_SIZE + payload->key_len + 1); 449 450 tpm_buf_append_u16(&buf, TPM_DIGEST_SIZE); 451 tpm_buf_append(&buf, options->blobauth, TPM_DIGEST_SIZE); 452 tpm_buf_append_u16(&buf, payload->key_len + 1); 453 tpm_buf_append(&buf, payload->key, payload->key_len); 454 tpm_buf_append_u8(&buf, payload->migratable); 455 456 /* public */ 457 tpm_buf_append_u16(&buf, 14 + options->policydigest_len); 458 tpm_buf_append_u16(&buf, TPM_ALG_KEYEDHASH); 459 tpm_buf_append_u16(&buf, hash); 460 461 /* policy */ 462 if (options->policydigest_len) { 463 tpm_buf_append_u32(&buf, 0); 464 tpm_buf_append_u16(&buf, options->policydigest_len); 465 tpm_buf_append(&buf, options->policydigest, 466 options->policydigest_len); 467 } else { 468 tpm_buf_append_u32(&buf, TPM2_OA_USER_WITH_AUTH); 469 tpm_buf_append_u16(&buf, 0); 470 } 471 472 /* public parameters */ 473 tpm_buf_append_u16(&buf, TPM_ALG_NULL); 474 tpm_buf_append_u16(&buf, 0); 475 476 /* outside info */ 477 tpm_buf_append_u16(&buf, 0); 478 479 /* creation PCR */ 480 tpm_buf_append_u32(&buf, 0); 481 482 if (buf.flags & TPM_BUF_OVERFLOW) { 483 rc = -E2BIG; 484 goto out; 485 } 486 487 rc = tpm_transmit_cmd(chip, &buf, 4, "sealing data"); 488 if (rc) 489 goto out; 490 491 blob_len = be32_to_cpup((__be32 *) &buf.data[TPM_HEADER_SIZE]); 492 if (blob_len > MAX_BLOB_SIZE) { 493 rc = -E2BIG; 494 goto out; 495 } 496 if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 4 + blob_len) { 497 rc = -EFAULT; 498 goto out; 499 } 500 501 memcpy(payload->blob, &buf.data[TPM_HEADER_SIZE + 4], blob_len); 502 payload->blob_len = blob_len; 503 504 out: 505 tpm_buf_destroy(&buf); 506 507 if (rc > 0) { 508 if (tpm2_rc_value(rc) == TPM2_RC_HASH) 509 rc = -EINVAL; 510 else 511 rc = -EPERM; 512 } 513 514 return rc; 515 } 516 517 /** 518 * tpm2_load_cmd() - execute a TPM2_Load command 519 * 520 * @chip: TPM chip to use 521 * @payload: the key data in clear and encrypted form 522 * @options: authentication values and other options 523 * @blob_handle: returned blob handle 524 * 525 * Return: 0 on success. 526 * -E2BIG on wrong payload size. 527 * -EPERM on tpm error status. 528 * < 0 error from tpm_transmit_cmd. 529 */ 530 static int tpm2_load_cmd(struct tpm_chip *chip, 531 struct trusted_key_payload *payload, 532 struct trusted_key_options *options, 533 u32 *blob_handle) 534 { 535 struct tpm_buf buf; 536 unsigned int private_len; 537 unsigned int public_len; 538 unsigned int blob_len; 539 int rc; 540 541 private_len = be16_to_cpup((__be16 *) &payload->blob[0]); 542 if (private_len > (payload->blob_len - 2)) 543 return -E2BIG; 544 545 public_len = be16_to_cpup((__be16 *) &payload->blob[2 + private_len]); 546 blob_len = private_len + public_len + 4; 547 if (blob_len > payload->blob_len) 548 return -E2BIG; 549 550 rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD); 551 if (rc) 552 return rc; 553 554 tpm_buf_append_u32(&buf, options->keyhandle); 555 tpm2_buf_append_auth(&buf, TPM2_RS_PW, 556 NULL /* nonce */, 0, 557 0 /* session_attributes */, 558 options->keyauth /* hmac */, 559 TPM_DIGEST_SIZE); 560 561 tpm_buf_append(&buf, payload->blob, blob_len); 562 563 if (buf.flags & TPM_BUF_OVERFLOW) { 564 rc = -E2BIG; 565 goto out; 566 } 567 568 rc = tpm_transmit_cmd(chip, &buf, 4, "loading blob"); 569 if (!rc) 570 *blob_handle = be32_to_cpup( 571 (__be32 *) &buf.data[TPM_HEADER_SIZE]); 572 573 out: 574 tpm_buf_destroy(&buf); 575 576 if (rc > 0) 577 rc = -EPERM; 578 579 return rc; 580 } 581 582 /** 583 * tpm2_unseal_cmd() - execute a TPM2_Unload command 584 * 585 * @chip: TPM chip to use 586 * @payload: the key data in clear and encrypted form 587 * @options: authentication values and other options 588 * @blob_handle: blob handle 589 * 590 * Return: 0 on success 591 * -EPERM on tpm error status 592 * < 0 error from tpm_transmit_cmd 593 */ 594 static int tpm2_unseal_cmd(struct tpm_chip *chip, 595 struct trusted_key_payload *payload, 596 struct trusted_key_options *options, 597 u32 blob_handle) 598 { 599 struct tpm_buf buf; 600 u16 data_len; 601 u8 *data; 602 int rc; 603 604 rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL); 605 if (rc) 606 return rc; 607 608 tpm_buf_append_u32(&buf, blob_handle); 609 tpm2_buf_append_auth(&buf, 610 options->policyhandle ? 611 options->policyhandle : TPM2_RS_PW, 612 NULL /* nonce */, 0, 613 TPM2_SA_CONTINUE_SESSION, 614 options->blobauth /* hmac */, 615 TPM_DIGEST_SIZE); 616 617 rc = tpm_transmit_cmd(chip, &buf, 6, "unsealing"); 618 if (rc > 0) 619 rc = -EPERM; 620 621 if (!rc) { 622 data_len = be16_to_cpup( 623 (__be16 *) &buf.data[TPM_HEADER_SIZE + 4]); 624 if (data_len < MIN_KEY_SIZE || data_len > MAX_KEY_SIZE + 1) { 625 rc = -EFAULT; 626 goto out; 627 } 628 629 if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 6 + data_len) { 630 rc = -EFAULT; 631 goto out; 632 } 633 data = &buf.data[TPM_HEADER_SIZE + 6]; 634 635 memcpy(payload->key, data, data_len - 1); 636 payload->key_len = data_len - 1; 637 payload->migratable = data[data_len - 1]; 638 } 639 640 out: 641 tpm_buf_destroy(&buf); 642 return rc; 643 } 644 645 /** 646 * tpm2_unseal_trusted() - unseal the payload of a trusted key 647 * 648 * @chip: TPM chip to use 649 * @payload: the key data in clear and encrypted form 650 * @options: authentication values and other options 651 * 652 * Return: Same as with tpm_transmit_cmd. 653 */ 654 int tpm2_unseal_trusted(struct tpm_chip *chip, 655 struct trusted_key_payload *payload, 656 struct trusted_key_options *options) 657 { 658 u32 blob_handle; 659 int rc; 660 661 rc = tpm2_load_cmd(chip, payload, options, &blob_handle); 662 if (rc) 663 return rc; 664 665 rc = tpm2_unseal_cmd(chip, payload, options, blob_handle); 666 tpm2_flush_context(chip, blob_handle); 667 return rc; 668 } 669 670 struct tpm2_get_cap_out { 671 u8 more_data; 672 __be32 subcap_id; 673 __be32 property_cnt; 674 __be32 property_id; 675 __be32 value; 676 } __packed; 677 678 /** 679 * tpm2_get_tpm_pt() - get value of a TPM_CAP_TPM_PROPERTIES type property 680 * @chip: a &tpm_chip instance 681 * @property_id: property ID. 682 * @value: output variable. 683 * @desc: passed to tpm_transmit_cmd() 684 * 685 * Return: 686 * 0 on success, 687 * -errno or a TPM return code otherwise 688 */ 689 ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id, u32 *value, 690 const char *desc) 691 { 692 struct tpm2_get_cap_out *out; 693 struct tpm_buf buf; 694 int rc; 695 696 rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY); 697 if (rc) 698 return rc; 699 tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES); 700 tpm_buf_append_u32(&buf, property_id); 701 tpm_buf_append_u32(&buf, 1); 702 rc = tpm_transmit_cmd(chip, &buf, 0, NULL); 703 if (!rc) { 704 out = (struct tpm2_get_cap_out *) 705 &buf.data[TPM_HEADER_SIZE]; 706 *value = be32_to_cpu(out->value); 707 } 708 tpm_buf_destroy(&buf); 709 return rc; 710 } 711 EXPORT_SYMBOL_GPL(tpm2_get_tpm_pt); 712 713 /** 714 * tpm2_shutdown() - send a TPM shutdown command 715 * 716 * Sends a TPM shutdown command. The shutdown command is used in call 717 * sites where the system is going down. If it fails, there is not much 718 * that can be done except print an error message. 719 * 720 * @chip: a &tpm_chip instance 721 * @shutdown_type: TPM_SU_CLEAR or TPM_SU_STATE. 722 */ 723 void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type) 724 { 725 struct tpm_buf buf; 726 int rc; 727 728 rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SHUTDOWN); 729 if (rc) 730 return; 731 tpm_buf_append_u16(&buf, shutdown_type); 732 tpm_transmit_cmd(chip, &buf, 0, "stopping the TPM"); 733 tpm_buf_destroy(&buf); 734 } 735 736 /** 737 * tpm2_do_selftest() - ensure that all self tests have passed 738 * 739 * @chip: TPM chip to use 740 * 741 * Return: Same as with tpm_transmit_cmd. 742 * 743 * The TPM can either run all self tests synchronously and then return 744 * RC_SUCCESS once all tests were successful. Or it can choose to run the tests 745 * asynchronously and return RC_TESTING immediately while the self tests still 746 * execute in the background. This function handles both cases and waits until 747 * all tests have completed. 748 */ 749 static int tpm2_do_selftest(struct tpm_chip *chip) 750 { 751 struct tpm_buf buf; 752 int full; 753 int rc; 754 755 for (full = 0; full < 2; full++) { 756 rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SELF_TEST); 757 if (rc) 758 return rc; 759 760 tpm_buf_append_u8(&buf, full); 761 rc = tpm_transmit_cmd(chip, &buf, 0, 762 "attempting the self test"); 763 tpm_buf_destroy(&buf); 764 765 if (rc == TPM2_RC_TESTING) 766 rc = TPM2_RC_SUCCESS; 767 if (rc == TPM2_RC_INITIALIZE || rc == TPM2_RC_SUCCESS) 768 return rc; 769 } 770 771 return rc; 772 } 773 774 /** 775 * tpm2_probe() - probe for the TPM 2.0 protocol 776 * @chip: a &tpm_chip instance 777 * 778 * Send an idempotent TPM 2.0 command and see whether there is TPM2 chip in the 779 * other end based on the response tag. The flag TPM_CHIP_FLAG_TPM2 is set by 780 * this function if this is the case. 781 * 782 * Return: 783 * 0 on success, 784 * -errno otherwise 785 */ 786 int tpm2_probe(struct tpm_chip *chip) 787 { 788 struct tpm_header *out; 789 struct tpm_buf buf; 790 int rc; 791 792 rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY); 793 if (rc) 794 return rc; 795 tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES); 796 tpm_buf_append_u32(&buf, TPM_PT_TOTAL_COMMANDS); 797 tpm_buf_append_u32(&buf, 1); 798 rc = tpm_transmit_cmd(chip, &buf, 0, NULL); 799 /* We ignore TPM return codes on purpose. */ 800 if (rc >= 0) { 801 out = (struct tpm_header *)buf.data; 802 if (be16_to_cpu(out->tag) == TPM2_ST_NO_SESSIONS) 803 chip->flags |= TPM_CHIP_FLAG_TPM2; 804 } 805 tpm_buf_destroy(&buf); 806 return 0; 807 } 808 EXPORT_SYMBOL_GPL(tpm2_probe); 809 810 static int tpm2_init_bank_info(struct tpm_chip *chip, u32 bank_index) 811 { 812 struct tpm_bank_info *bank = chip->allocated_banks + bank_index; 813 struct tpm_digest digest = { .alg_id = bank->alg_id }; 814 int i; 815 816 /* 817 * Avoid unnecessary PCR read operations to reduce overhead 818 * and obtain identifiers of the crypto subsystem. 819 */ 820 for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) { 821 enum hash_algo crypto_algo = tpm2_hash_map[i].crypto_id; 822 823 if (bank->alg_id != tpm2_hash_map[i].tpm_id) 824 continue; 825 826 bank->digest_size = hash_digest_size[crypto_algo]; 827 bank->crypto_id = crypto_algo; 828 return 0; 829 } 830 831 return tpm2_pcr_read(chip, 0, &digest, &bank->digest_size); 832 } 833 834 struct tpm2_pcr_selection { 835 __be16 hash_alg; 836 u8 size_of_select; 837 u8 pcr_select[3]; 838 } __packed; 839 840 static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip) 841 { 842 struct tpm2_pcr_selection pcr_selection; 843 struct tpm_buf buf; 844 void *marker; 845 void *end; 846 void *pcr_select_offset; 847 u32 sizeof_pcr_selection; 848 u32 nr_possible_banks; 849 u32 nr_alloc_banks = 0; 850 u16 hash_alg; 851 u32 rsp_len; 852 int rc; 853 int i = 0; 854 855 rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY); 856 if (rc) 857 return rc; 858 859 tpm_buf_append_u32(&buf, TPM2_CAP_PCRS); 860 tpm_buf_append_u32(&buf, 0); 861 tpm_buf_append_u32(&buf, 1); 862 863 rc = tpm_transmit_cmd(chip, &buf, 9, "get tpm pcr allocation"); 864 if (rc) 865 goto out; 866 867 nr_possible_banks = be32_to_cpup( 868 (__be32 *)&buf.data[TPM_HEADER_SIZE + 5]); 869 870 chip->allocated_banks = kcalloc(nr_possible_banks, 871 sizeof(*chip->allocated_banks), 872 GFP_KERNEL); 873 if (!chip->allocated_banks) { 874 rc = -ENOMEM; 875 goto out; 876 } 877 878 marker = &buf.data[TPM_HEADER_SIZE + 9]; 879 880 rsp_len = be32_to_cpup((__be32 *)&buf.data[2]); 881 end = &buf.data[rsp_len]; 882 883 for (i = 0; i < nr_possible_banks; i++) { 884 pcr_select_offset = marker + 885 offsetof(struct tpm2_pcr_selection, size_of_select); 886 if (pcr_select_offset >= end) { 887 rc = -EFAULT; 888 break; 889 } 890 891 memcpy(&pcr_selection, marker, sizeof(pcr_selection)); 892 hash_alg = be16_to_cpu(pcr_selection.hash_alg); 893 894 pcr_select_offset = memchr_inv(pcr_selection.pcr_select, 0, 895 pcr_selection.size_of_select); 896 if (pcr_select_offset) { 897 chip->allocated_banks[nr_alloc_banks].alg_id = hash_alg; 898 899 rc = tpm2_init_bank_info(chip, nr_alloc_banks); 900 if (rc < 0) 901 break; 902 903 nr_alloc_banks++; 904 } 905 906 sizeof_pcr_selection = sizeof(pcr_selection.hash_alg) + 907 sizeof(pcr_selection.size_of_select) + 908 pcr_selection.size_of_select; 909 marker = marker + sizeof_pcr_selection; 910 } 911 912 chip->nr_allocated_banks = nr_alloc_banks; 913 out: 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, &buf, 9 + 4 * nr_commands, NULL); 949 if (rc) { 950 tpm_buf_destroy(&buf); 951 goto out; 952 } 953 954 if (nr_commands != 955 be32_to_cpup((__be32 *)&buf.data[TPM_HEADER_SIZE + 5])) { 956 tpm_buf_destroy(&buf); 957 goto out; 958 } 959 960 chip->nr_commands = nr_commands; 961 962 attrs = (__be32 *)&buf.data[TPM_HEADER_SIZE + 9]; 963 for (i = 0; i < nr_commands; i++, attrs++) { 964 chip->cc_attrs_tbl[i] = be32_to_cpup(attrs); 965 cc = chip->cc_attrs_tbl[i] & 0xFFFF; 966 967 if (cc == TPM2_CC_CONTEXT_SAVE || cc == TPM2_CC_FLUSH_CONTEXT) { 968 chip->cc_attrs_tbl[i] &= 969 ~(GENMASK(2, 0) << TPM2_CC_ATTR_CHANDLES); 970 chip->cc_attrs_tbl[i] |= 1 << TPM2_CC_ATTR_CHANDLES; 971 } 972 } 973 974 tpm_buf_destroy(&buf); 975 976 out: 977 if (rc > 0) 978 rc = -ENODEV; 979 return rc; 980 } 981 982 /** 983 * tpm2_startup - turn on the TPM 984 * @chip: TPM chip to use 985 * 986 * Normally the firmware should start the TPM. This function is provided as a 987 * workaround if this does not happen. A legal case for this could be for 988 * example when a TPM emulator is used. 989 * 990 * Return: same as tpm_transmit_cmd() 991 */ 992 993 static int tpm2_startup(struct tpm_chip *chip) 994 { 995 struct tpm_buf buf; 996 int rc; 997 998 dev_info(&chip->dev, "starting up the TPM manually\n"); 999 1000 rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_STARTUP); 1001 if (rc < 0) 1002 return rc; 1003 1004 tpm_buf_append_u16(&buf, TPM2_SU_CLEAR); 1005 rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to start the TPM"); 1006 tpm_buf_destroy(&buf); 1007 1008 return rc; 1009 } 1010 1011 /** 1012 * tpm2_auto_startup - Perform the standard automatic TPM initialization 1013 * sequence 1014 * @chip: TPM chip to use 1015 * 1016 * Returns 0 on success, < 0 in case of fatal error. 1017 */ 1018 int tpm2_auto_startup(struct tpm_chip *chip) 1019 { 1020 int rc; 1021 1022 rc = tpm2_get_timeouts(chip); 1023 if (rc) 1024 goto out; 1025 1026 rc = tpm2_do_selftest(chip); 1027 if (rc && rc != TPM2_RC_INITIALIZE) 1028 goto out; 1029 1030 if (rc == TPM2_RC_INITIALIZE) { 1031 rc = tpm2_startup(chip); 1032 if (rc) 1033 goto out; 1034 1035 rc = tpm2_do_selftest(chip); 1036 if (rc) 1037 goto out; 1038 } 1039 1040 rc = tpm2_get_pcr_allocation(chip); 1041 if (rc) 1042 goto out; 1043 1044 rc = tpm2_get_cc_attrs_tbl(chip); 1045 1046 out: 1047 if (rc > 0) 1048 rc = -ENODEV; 1049 return rc; 1050 } 1051 1052 int tpm2_find_cc(struct tpm_chip *chip, u32 cc) 1053 { 1054 int i; 1055 1056 for (i = 0; i < chip->nr_commands; i++) 1057 if (cc == (chip->cc_attrs_tbl[i] & GENMASK(15, 0))) 1058 return i; 1059 1060 return -1; 1061 } 1062