drivers/char/tpm/tpm2-cmd.c

   1 /*
   2  * Copyright (C) 2014, 2015 Intel Corporation
   3  *
   4  * Authors:
   5  * Jarkko Sakkinen <[email protected]>
   6  *
   7  * Maintained by: <[email protected]>
   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_startup_in {
  31         __be16  startup_type;
  32 } __packed;
  33
  34 struct tpm2_self_test_in {
  35         u8      full_test;
  36 } __packed;
  37
  38 struct tpm2_pcr_read_in {
  39         __be32  pcr_selects_cnt;
  40         __be16  hash_alg;
  41         u8      pcr_select_size;
  42         u8      pcr_select[TPM2_PCR_SELECT_MIN];
  43 } __packed;
  44
  45 struct tpm2_pcr_read_out {
  46         __be32  update_cnt;
  47         __be32  pcr_selects_cnt;
  48         __be16  hash_alg;
  49         u8      pcr_select_size;
  50         u8      pcr_select[TPM2_PCR_SELECT_MIN];
  51         __be32  digests_cnt;
  52         __be16  digest_size;
  53         u8      digest[TPM_DIGEST_SIZE];
  54 } __packed;
  55
  56 struct tpm2_get_tpm_pt_in {
  57         __be32  cap_id;
  58         __be32  property_id;
  59         __be32  property_cnt;
  60 } __packed;
  61
  62 struct tpm2_get_tpm_pt_out {
  63         u8      more_data;
  64         __be32  subcap_id;
  65         __be32  property_cnt;
  66         __be32  property_id;
  67         __be32  value;
  68 } __packed;
  69
  70 struct tpm2_get_random_in {
  71         __be16  size;
  72 } __packed;
  73
  74 struct tpm2_get_random_out {
  75         __be16  size;
  76         u8      buffer[TPM_MAX_RNG_DATA];
  77 } __packed;
  78
  79 union tpm2_cmd_params {
  80         struct  tpm2_startup_in         startup_in;
  81         struct  tpm2_self_test_in       selftest_in;
  82         struct  tpm2_pcr_read_in        pcrread_in;
  83         struct  tpm2_pcr_read_out       pcrread_out;
  84         struct  tpm2_get_tpm_pt_in      get_tpm_pt_in;
  85         struct  tpm2_get_tpm_pt_out     get_tpm_pt_out;
  86         struct  tpm2_get_random_in      getrandom_in;
  87         struct  tpm2_get_random_out     getrandom_out;
  88 };
  89
  90 struct tpm2_cmd {
  91         tpm_cmd_header          header;
  92         union tpm2_cmd_params   params;
  93 } __packed;
  94
  95 struct tpm2_hash {
  96         unsigned int crypto_id;
  97         unsigned int tpm_id;
  98 };
  99
 100 static struct tpm2_hash tpm2_hash_map[] = {
 101         {HASH_ALGO_SHA1, TPM2_ALG_SHA1},
 102         {HASH_ALGO_SHA256, TPM2_ALG_SHA256},
 103         {HASH_ALGO_SHA384, TPM2_ALG_SHA384},
 104         {HASH_ALGO_SHA512, TPM2_ALG_SHA512},
 105         {HASH_ALGO_SM3_256, TPM2_ALG_SM3_256},
 106 };
 107
 108 /*
 109  * Array with one entry per ordinal defining the maximum amount
 110  * of time the chip could take to return the result. The values
 111  * of the SHORT, MEDIUM, and LONG durations are taken from the
 112  * PC Client Profile (PTP) specification.
 113  */
 114 static const u8 tpm2_ordinal_duration[TPM2_CC_LAST - TPM2_CC_FIRST + 1] = {
 115         TPM_UNDEFINED,          /* 11F */
 116         TPM_UNDEFINED,          /* 120 */
 117         TPM_LONG,               /* 121 */
 118         TPM_UNDEFINED,          /* 122 */
 119         TPM_UNDEFINED,          /* 123 */
 120         TPM_UNDEFINED,          /* 124 */
 121         TPM_UNDEFINED,          /* 125 */
 122         TPM_UNDEFINED,          /* 126 */
 123         TPM_UNDEFINED,          /* 127 */
 124         TPM_UNDEFINED,          /* 128 */
 125         TPM_LONG,               /* 129 */
 126         TPM_UNDEFINED,          /* 12a */
 127         TPM_UNDEFINED,          /* 12b */
 128         TPM_UNDEFINED,          /* 12c */
 129         TPM_UNDEFINED,          /* 12d */
 130         TPM_UNDEFINED,          /* 12e */
 131         TPM_UNDEFINED,          /* 12f */
 132         TPM_UNDEFINED,          /* 130 */
 133         TPM_UNDEFINED,          /* 131 */
 134         TPM_UNDEFINED,          /* 132 */
 135         TPM_UNDEFINED,          /* 133 */
 136         TPM_UNDEFINED,          /* 134 */
 137         TPM_UNDEFINED,          /* 135 */
 138         TPM_UNDEFINED,          /* 136 */
 139         TPM_UNDEFINED,          /* 137 */
 140         TPM_UNDEFINED,          /* 138 */
 141         TPM_UNDEFINED,          /* 139 */
 142         TPM_UNDEFINED,          /* 13a */
 143         TPM_UNDEFINED,          /* 13b */
 144         TPM_UNDEFINED,          /* 13c */
 145         TPM_UNDEFINED,          /* 13d */
 146         TPM_MEDIUM,             /* 13e */
 147         TPM_UNDEFINED,          /* 13f */
 148         TPM_UNDEFINED,          /* 140 */
 149         TPM_UNDEFINED,          /* 141 */
 150         TPM_UNDEFINED,          /* 142 */
 151         TPM_LONG,               /* 143 */
 152         TPM_MEDIUM,             /* 144 */
 153         TPM_UNDEFINED,          /* 145 */
 154         TPM_UNDEFINED,          /* 146 */
 155         TPM_UNDEFINED,          /* 147 */
 156         TPM_UNDEFINED,          /* 148 */
 157         TPM_UNDEFINED,          /* 149 */
 158         TPM_UNDEFINED,          /* 14a */
 159         TPM_UNDEFINED,          /* 14b */
 160         TPM_UNDEFINED,          /* 14c */
 161         TPM_UNDEFINED,          /* 14d */
 162         TPM_LONG,               /* 14e */
 163         TPM_UNDEFINED,          /* 14f */
 164         TPM_UNDEFINED,          /* 150 */
 165         TPM_UNDEFINED,          /* 151 */
 166         TPM_UNDEFINED,          /* 152 */
 167         TPM_UNDEFINED,          /* 153 */
 168         TPM_UNDEFINED,          /* 154 */
 169         TPM_UNDEFINED,          /* 155 */
 170         TPM_UNDEFINED,          /* 156 */
 171         TPM_UNDEFINED,          /* 157 */
 172         TPM_UNDEFINED,          /* 158 */
 173         TPM_UNDEFINED,          /* 159 */
 174         TPM_UNDEFINED,          /* 15a */
 175         TPM_UNDEFINED,          /* 15b */
 176         TPM_MEDIUM,             /* 15c */
 177         TPM_UNDEFINED,          /* 15d */
 178         TPM_UNDEFINED,          /* 15e */
 179         TPM_UNDEFINED,          /* 15f */
 180         TPM_UNDEFINED,          /* 160 */
 181         TPM_UNDEFINED,          /* 161 */
 182         TPM_UNDEFINED,          /* 162 */
 183         TPM_UNDEFINED,          /* 163 */
 184         TPM_UNDEFINED,          /* 164 */
 185         TPM_UNDEFINED,          /* 165 */
 186         TPM_UNDEFINED,          /* 166 */
 187         TPM_UNDEFINED,          /* 167 */
 188         TPM_UNDEFINED,          /* 168 */
 189         TPM_UNDEFINED,          /* 169 */
 190         TPM_UNDEFINED,          /* 16a */
 191         TPM_UNDEFINED,          /* 16b */
 192         TPM_UNDEFINED,          /* 16c */
 193         TPM_UNDEFINED,          /* 16d */
 194         TPM_UNDEFINED,          /* 16e */
 195         TPM_UNDEFINED,          /* 16f */
 196         TPM_UNDEFINED,          /* 170 */
 197         TPM_UNDEFINED,          /* 171 */
 198         TPM_UNDEFINED,          /* 172 */
 199         TPM_UNDEFINED,          /* 173 */
 200         TPM_UNDEFINED,          /* 174 */
 201         TPM_UNDEFINED,          /* 175 */
 202         TPM_UNDEFINED,          /* 176 */
 203         TPM_LONG,               /* 177 */
 204         TPM_UNDEFINED,          /* 178 */
 205         TPM_UNDEFINED,          /* 179 */
 206         TPM_MEDIUM,             /* 17a */
 207         TPM_LONG,               /* 17b */
 208         TPM_UNDEFINED,          /* 17c */
 209         TPM_UNDEFINED,          /* 17d */
 210         TPM_UNDEFINED,          /* 17e */
 211         TPM_UNDEFINED,          /* 17f */
 212         TPM_UNDEFINED,          /* 180 */
 213         TPM_UNDEFINED,          /* 181 */
 214         TPM_MEDIUM,             /* 182 */
 215         TPM_UNDEFINED,          /* 183 */
 216         TPM_UNDEFINED,          /* 184 */
 217         TPM_MEDIUM,             /* 185 */
 218         TPM_MEDIUM,             /* 186 */
 219         TPM_UNDEFINED,          /* 187 */
 220         TPM_UNDEFINED,          /* 188 */
 221         TPM_UNDEFINED,          /* 189 */
 222         TPM_UNDEFINED,          /* 18a */
 223         TPM_UNDEFINED,          /* 18b */
 224         TPM_UNDEFINED,          /* 18c */
 225         TPM_UNDEFINED,          /* 18d */
 226         TPM_UNDEFINED,          /* 18e */
 227         TPM_UNDEFINED           /* 18f */
 228 };
 229
 230 #define TPM2_PCR_READ_IN_SIZE \
 231         (sizeof(struct tpm_input_header) + \
 232          sizeof(struct tpm2_pcr_read_in))
 233
 234 #define TPM2_PCR_READ_RESP_BODY_SIZE \
 235          sizeof(struct tpm2_pcr_read_out)
 236
 237 static const struct tpm_input_header tpm2_pcrread_header = {
 238         .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
 239         .length = cpu_to_be32(TPM2_PCR_READ_IN_SIZE),
 240         .ordinal = cpu_to_be32(TPM2_CC_PCR_READ)
 241 };
 242
 243 /**
 244  * tpm2_pcr_read() - read a PCR value
 245  * @chip:       TPM chip to use.
 246  * @pcr_idx:    index of the PCR to read.
 247  * @res_buf:    buffer to store the resulting hash.
 248  *
 249  * Return: Same as with tpm_transmit_cmd.
 250  */
 251 int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 252 {
 253         int rc;
 254         struct tpm2_cmd cmd;
 255         u8 *buf;
 256
 257         if (pcr_idx >= TPM2_PLATFORM_PCR)
 258                 return -EINVAL;
 259
 260         cmd.header.in = tpm2_pcrread_header;
 261         cmd.params.pcrread_in.pcr_selects_cnt = cpu_to_be32(1);
 262         cmd.params.pcrread_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1);
 263         cmd.params.pcrread_in.pcr_select_size = TPM2_PCR_SELECT_MIN;
 264
 265         memset(cmd.params.pcrread_in.pcr_select, 0,
 266                sizeof(cmd.params.pcrread_in.pcr_select));
 267         cmd.params.pcrread_in.pcr_select[pcr_idx >> 3] = 1 << (pcr_idx & 0x7);
 268
 269         rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
 270                               TPM2_PCR_READ_RESP_BODY_SIZE,
 271                               0, "attempting to read a pcr value");
 272         if (rc == 0) {
 273                 buf = cmd.params.pcrread_out.digest;
 274                 memcpy(res_buf, buf, TPM_DIGEST_SIZE);
 275         }
 276
 277         return rc;
 278 }
 279
 280 struct tpm2_null_auth_area {
 281         __be32  handle;
 282         __be16  nonce_size;
 283         u8  attributes;
 284         __be16  auth_size;
 285 } __packed;
 286
 287 /**
 288  * tpm2_pcr_extend() - extend a PCR value
 289  *
 290  * @chip:       TPM chip to use.
 291  * @pcr_idx:    index of the PCR.
 292  * @count:      number of digests passed.
 293  * @digests:    list of pcr banks and corresponding digest values to extend.
 294  *
 295  * Return: Same as with tpm_transmit_cmd.
 296  */
 297 int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, u32 count,
 298                     struct tpm2_digest *digests)
 299 {
 300         struct tpm_buf buf;
 301         struct tpm2_null_auth_area auth_area;
 302         int rc;
 303         int i;
 304         int j;
 305
 306         if (count > ARRAY_SIZE(chip->active_banks))
 307                 return -EINVAL;
 308
 309         rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND);
 310         if (rc)
 311                 return rc;
 312
 313         tpm_buf_append_u32(&buf, pcr_idx);
 314
 315         auth_area.handle = cpu_to_be32(TPM2_RS_PW);
 316         auth_area.nonce_size = 0;
 317         auth_area.attributes = 0;
 318         auth_area.auth_size = 0;
 319
 320         tpm_buf_append_u32(&buf, sizeof(struct tpm2_null_auth_area));
 321         tpm_buf_append(&buf, (const unsigned char *)&auth_area,
 322                        sizeof(auth_area));
 323         tpm_buf_append_u32(&buf, count);
 324
 325         for (i = 0; i < count; i++) {
 326                 for (j = 0; j < ARRAY_SIZE(tpm2_hash_map); j++) {
 327                         if (digests[i].alg_id != tpm2_hash_map[j].tpm_id)
 328                                 continue;
 329                         tpm_buf_append_u16(&buf, digests[i].alg_id);
 330                         tpm_buf_append(&buf, (const unsigned char
 331                                               *)&digests[i].digest,
 332                                hash_digest_size[tpm2_hash_map[j].crypto_id]);
 333                 }
 334         }
 335
 336         rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, 0, 0,
 337                               "attempting extend a PCR value");
 338
 339         tpm_buf_destroy(&buf);
 340
 341         return rc;
 342 }
 343
 344
 345 #define TPM2_GETRANDOM_IN_SIZE \
 346         (sizeof(struct tpm_input_header) + \
 347          sizeof(struct tpm2_get_random_in))
 348
 349 static const struct tpm_input_header tpm2_getrandom_header = {
 350         .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
 351         .length = cpu_to_be32(TPM2_GETRANDOM_IN_SIZE),
 352         .ordinal = cpu_to_be32(TPM2_CC_GET_RANDOM)
 353 };
 354
 355 /**
 356  * tpm2_get_random() - get random bytes from the TPM RNG
 357  *
 358  * @chip: TPM chip to use
 359  * @out: destination buffer for the random bytes
 360  * @max: the max number of bytes to write to @out
 361  *
 362  * Return:
 363  *    Size of the output buffer, or -EIO on error.
 364  */
 365 int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max)
 366 {
 367         struct tpm2_cmd cmd;
 368         u32 recd, rlength;
 369         u32 num_bytes;
 370         int err;
 371         int total = 0;
 372         int retries = 5;
 373         u8 *dest = out;
 374
 375         num_bytes = min_t(u32, max, sizeof(cmd.params.getrandom_out.buffer));
 376
 377         if (!out || !num_bytes ||
 378             max > sizeof(cmd.params.getrandom_out.buffer))
 379                 return -EINVAL;
 380
 381         do {
 382                 cmd.header.in = tpm2_getrandom_header;
 383                 cmd.params.getrandom_in.size = cpu_to_be16(num_bytes);
 384
 385                 err = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
 386                                        offsetof(struct tpm2_get_random_out,
 387                                                 buffer),
 388                                        0, "attempting get random");
 389                 if (err)
 390                         break;
 391
 392                 recd = min_t(u32, be16_to_cpu(cmd.params.getrandom_out.size),
 393                              num_bytes);
 394                 rlength = be32_to_cpu(cmd.header.out.length);
 395                 if (rlength < offsetof(struct tpm2_get_random_out, buffer) +
 396                               recd)
 397                         return -EFAULT;
 398                 memcpy(dest, cmd.params.getrandom_out.buffer, recd);
 399
 400                 dest += recd;
 401                 total += recd;
 402                 num_bytes -= recd;
 403         } while (retries-- && total < max);
 404
 405         return total ? total : -EIO;
 406 }
 407
 408 #define TPM2_GET_TPM_PT_IN_SIZE \
 409         (sizeof(struct tpm_input_header) + \
 410          sizeof(struct tpm2_get_tpm_pt_in))
 411
 412 #define TPM2_GET_TPM_PT_OUT_BODY_SIZE \
 413          sizeof(struct tpm2_get_tpm_pt_out)
 414
 415 static const struct tpm_input_header tpm2_get_tpm_pt_header = {
 416         .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
 417         .length = cpu_to_be32(TPM2_GET_TPM_PT_IN_SIZE),
 418         .ordinal = cpu_to_be32(TPM2_CC_GET_CAPABILITY)
 419 };
 420
 421 /**
 422  * tpm_buf_append_auth() - append TPMS_AUTH_COMMAND to the buffer.
 423  *
 424  * @buf: an allocated tpm_buf instance
 425  * @session_handle: session handle
 426  * @nonce: the session nonce, may be NULL if not used
 427  * @nonce_len: the session nonce length, may be 0 if not used
 428  * @attributes: the session attributes
 429  * @hmac: the session HMAC or password, may be NULL if not used
 430  * @hmac_len: the session HMAC or password length, maybe 0 if not used
 431  */
 432 static void tpm2_buf_append_auth(struct tpm_buf *buf, u32 session_handle,
 433                                  const u8 *nonce, u16 nonce_len,
 434                                  u8 attributes,
 435                                  const u8 *hmac, u16 hmac_len)
 436 {
 437         tpm_buf_append_u32(buf, 9 + nonce_len + hmac_len);
 438         tpm_buf_append_u32(buf, session_handle);
 439         tpm_buf_append_u16(buf, nonce_len);
 440
 441         if (nonce && nonce_len)
 442                 tpm_buf_append(buf, nonce, nonce_len);
 443
 444         tpm_buf_append_u8(buf, attributes);
 445         tpm_buf_append_u16(buf, hmac_len);
 446
 447         if (hmac && hmac_len)
 448                 tpm_buf_append(buf, hmac, hmac_len);
 449 }
 450
 451 /**
 452  * tpm2_seal_trusted() - seal the payload of a trusted key
 453  *
 454  * @chip: TPM chip to use
 455  * @payload: the key data in clear and encrypted form
 456  * @options: authentication values and other options
 457  *
 458  * Return: < 0 on error and 0 on success.
 459  */
 460 int tpm2_seal_trusted(struct tpm_chip *chip,
 461                       struct trusted_key_payload *payload,
 462                       struct trusted_key_options *options)
 463 {
 464         unsigned int blob_len;
 465         struct tpm_buf buf;
 466         u32 hash, rlength;
 467         int i;
 468         int rc;
 469
 470         for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
 471                 if (options->hash == tpm2_hash_map[i].crypto_id) {
 472                         hash = tpm2_hash_map[i].tpm_id;
 473                         break;
 474                 }
 475         }
 476
 477         if (i == ARRAY_SIZE(tpm2_hash_map))
 478                 return -EINVAL;
 479
 480         rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE);
 481         if (rc)
 482                 return rc;
 483
 484         tpm_buf_append_u32(&buf, options->keyhandle);
 485         tpm2_buf_append_auth(&buf, TPM2_RS_PW,
 486                              NULL /* nonce */, 0,
 487                              0 /* session_attributes */,
 488                              options->keyauth /* hmac */,
 489                              TPM_DIGEST_SIZE);
 490
 491         /* sensitive */
 492         tpm_buf_append_u16(&buf, 4 + TPM_DIGEST_SIZE + payload->key_len + 1);
 493
 494         tpm_buf_append_u16(&buf, TPM_DIGEST_SIZE);
 495         tpm_buf_append(&buf, options->blobauth, TPM_DIGEST_SIZE);
 496         tpm_buf_append_u16(&buf, payload->key_len + 1);
 497         tpm_buf_append(&buf, payload->key, payload->key_len);
 498         tpm_buf_append_u8(&buf, payload->migratable);
 499
 500         /* public */
 501         tpm_buf_append_u16(&buf, 14 + options->policydigest_len);
 502         tpm_buf_append_u16(&buf, TPM2_ALG_KEYEDHASH);
 503         tpm_buf_append_u16(&buf, hash);
 504
 505         /* policy */
 506         if (options->policydigest_len) {
 507                 tpm_buf_append_u32(&buf, 0);
 508                 tpm_buf_append_u16(&buf, options->policydigest_len);
 509                 tpm_buf_append(&buf, options->policydigest,
 510                                options->policydigest_len);
 511         } else {
 512                 tpm_buf_append_u32(&buf, TPM2_OA_USER_WITH_AUTH);
 513                 tpm_buf_append_u16(&buf, 0);
 514         }
 515
 516         /* public parameters */
 517         tpm_buf_append_u16(&buf, TPM2_ALG_NULL);
 518         tpm_buf_append_u16(&buf, 0);
 519
 520         /* outside info */
 521         tpm_buf_append_u16(&buf, 0);
 522
 523         /* creation PCR */
 524         tpm_buf_append_u32(&buf, 0);
 525
 526         if (buf.flags & TPM_BUF_OVERFLOW) {
 527                 rc = -E2BIG;
 528                 goto out;
 529         }
 530
 531         rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, 4, 0,
 532                               "sealing data");
 533         if (rc)
 534                 goto out;
 535
 536         blob_len = be32_to_cpup((__be32 *) &buf.data[TPM_HEADER_SIZE]);
 537         if (blob_len > MAX_BLOB_SIZE) {
 538                 rc = -E2BIG;
 539                 goto out;
 540         }
 541         rlength = be32_to_cpu(((struct tpm2_cmd *)&buf)->header.out.length);
 542         if (rlength < TPM_HEADER_SIZE + 4 + blob_len) {
 543                 rc = -EFAULT;
 544                 goto out;
 545         }
 546
 547         memcpy(payload->blob, &buf.data[TPM_HEADER_SIZE + 4], blob_len);
 548         payload->blob_len = blob_len;
 549
 550 out:
 551         tpm_buf_destroy(&buf);
 552
 553         if (rc > 0) {
 554                 if (tpm2_rc_value(rc) == TPM2_RC_HASH)
 555                         rc = -EINVAL;
 556                 else
 557                         rc = -EPERM;
 558         }
 559
 560         return rc;
 561 }
 562
 563 /**
 564  * tpm2_load_cmd() - execute a TPM2_Load command
 565  *
 566  * @chip: TPM chip to use
 567  * @payload: the key data in clear and encrypted form
 568  * @options: authentication values and other options
 569  * @blob_handle: returned blob handle
 570  * @flags: tpm transmit flags
 571  *
 572  * Return: 0 on success.
 573  *        -E2BIG on wrong payload size.
 574  *        -EPERM on tpm error status.
 575  *        < 0 error from tpm_transmit_cmd.
 576  */
 577 static int tpm2_load_cmd(struct tpm_chip *chip,
 578                          struct trusted_key_payload *payload,
 579                          struct trusted_key_options *options,
 580                          u32 *blob_handle, unsigned int flags)
 581 {
 582         struct tpm_buf buf;
 583         unsigned int private_len;
 584         unsigned int public_len;
 585         unsigned int blob_len;
 586         int rc;
 587
 588         private_len = be16_to_cpup((__be16 *) &payload->blob[0]);
 589         if (private_len > (payload->blob_len - 2))
 590                 return -E2BIG;
 591
 592         public_len = be16_to_cpup((__be16 *) &payload->blob[2 + private_len]);
 593         blob_len = private_len + public_len + 4;
 594         if (blob_len > payload->blob_len)
 595                 return -E2BIG;
 596
 597         rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD);
 598         if (rc)
 599                 return rc;
 600
 601         tpm_buf_append_u32(&buf, options->keyhandle);
 602         tpm2_buf_append_auth(&buf, TPM2_RS_PW,
 603                              NULL /* nonce */, 0,
 604                              0 /* session_attributes */,
 605                              options->keyauth /* hmac */,
 606                              TPM_DIGEST_SIZE);
 607
 608         tpm_buf_append(&buf, payload->blob, blob_len);
 609
 610         if (buf.flags & TPM_BUF_OVERFLOW) {
 611                 rc = -E2BIG;
 612                 goto out;
 613         }
 614
 615         rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, 4, flags,
 616                               "loading blob");
 617         if (!rc)
 618                 *blob_handle = be32_to_cpup(
 619                         (__be32 *) &buf.data[TPM_HEADER_SIZE]);
 620
 621 out:
 622         tpm_buf_destroy(&buf);
 623
 624         if (rc > 0)
 625                 rc = -EPERM;
 626
 627         return rc;
 628 }
 629
 630 /**
 631  * tpm2_flush_context_cmd() - execute a TPM2_FlushContext command
 632  *
 633  * @chip: TPM chip to use
 634  * @handle: the key data in clear and encrypted form
 635  * @flags: tpm transmit flags
 636  *
 637  * Return: Same as with tpm_transmit_cmd.
 638  */
 639 static void tpm2_flush_context_cmd(struct tpm_chip *chip, u32 handle,
 640                                    unsigned int flags)
 641 {
 642         struct tpm_buf buf;
 643         int rc;
 644
 645         rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_FLUSH_CONTEXT);
 646         if (rc) {
 647                 dev_warn(&chip->dev, "0x%08x was not flushed, out of memory\n",
 648                          handle);
 649                 return;
 650         }
 651
 652         tpm_buf_append_u32(&buf, handle);
 653
 654         rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, 0, flags,
 655                               "flushing context");
 656         if (rc)
 657                 dev_warn(&chip->dev, "0x%08x was not flushed, rc=%d\n", handle,
 658                          rc);
 659
 660         tpm_buf_destroy(&buf);
 661 }
 662
 663 /**
 664  * tpm2_unseal_cmd() - execute a TPM2_Unload command
 665  *
 666  * @chip: TPM chip to use
 667  * @payload: the key data in clear and encrypted form
 668  * @options: authentication values and other options
 669  * @blob_handle: blob handle
 670  * @flags: tpm_transmit_cmd flags
 671  *
 672  * Return: 0 on success
 673  *         -EPERM on tpm error status
 674  *         < 0 error from tpm_transmit_cmd
 675  */
 676 static int tpm2_unseal_cmd(struct tpm_chip *chip,
 677                            struct trusted_key_payload *payload,
 678                            struct trusted_key_options *options,
 679                            u32 blob_handle, unsigned int flags)
 680 {
 681         struct tpm_buf buf;
 682         u16 data_len;
 683         u8 *data;
 684         int rc;
 685         u32 rlength;
 686
 687         rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL);
 688         if (rc)
 689                 return rc;
 690
 691         tpm_buf_append_u32(&buf, blob_handle);
 692         tpm2_buf_append_auth(&buf,
 693                              options->policyhandle ?
 694                              options->policyhandle : TPM2_RS_PW,
 695                              NULL /* nonce */, 0,
 696                              TPM2_SA_CONTINUE_SESSION,
 697                              options->blobauth /* hmac */,
 698                              TPM_DIGEST_SIZE);
 699
 700         rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, 6, flags,
 701                               "unsealing");
 702         if (rc > 0)
 703                 rc = -EPERM;
 704
 705         if (!rc) {
 706                 data_len = be16_to_cpup(
 707                         (__be16 *) &buf.data[TPM_HEADER_SIZE + 4]);
 708
 709                 rlength = be32_to_cpu(((struct tpm2_cmd *)&buf)
 710                                         ->header.out.length);
 711                 if (rlength < TPM_HEADER_SIZE + 6 + data_len) {
 712                         rc = -EFAULT;
 713                         goto out;
 714                 }
 715                 data = &buf.data[TPM_HEADER_SIZE + 6];
 716
 717                 memcpy(payload->key, data, data_len - 1);
 718                 payload->key_len = data_len - 1;
 719                 payload->migratable = data[data_len - 1];
 720         }
 721
 722 out:
 723         tpm_buf_destroy(&buf);
 724         return rc;
 725 }
 726
 727 /**
 728  * tpm2_unseal_trusted() - unseal the payload of a trusted key
 729  *
 730  * @chip: TPM chip to use
 731  * @payload: the key data in clear and encrypted form
 732  * @options: authentication values and other options
 733  *
 734  * Return: Same as with tpm_transmit_cmd.
 735  */
 736 int tpm2_unseal_trusted(struct tpm_chip *chip,
 737                         struct trusted_key_payload *payload,
 738                         struct trusted_key_options *options)
 739 {
 740         u32 blob_handle;
 741         int rc;
 742
 743         mutex_lock(&chip->tpm_mutex);
 744         rc = tpm2_load_cmd(chip, payload, options, &blob_handle,
 745                            TPM_TRANSMIT_UNLOCKED);
 746         if (rc)
 747                 goto out;
 748
 749         rc = tpm2_unseal_cmd(chip, payload, options, blob_handle,
 750                              TPM_TRANSMIT_UNLOCKED);
 751         tpm2_flush_context_cmd(chip, blob_handle, TPM_TRANSMIT_UNLOCKED);
 752 out:
 753         mutex_unlock(&chip->tpm_mutex);
 754         return rc;
 755 }
 756
 757 /**
 758  * tpm2_get_tpm_pt() - get value of a TPM_CAP_TPM_PROPERTIES type property
 759  * @chip:               TPM chip to use.
 760  * @property_id:        property ID.
 761  * @value:              output variable.
 762  * @desc:               passed to tpm_transmit_cmd()
 763  *
 764  * Return: Same as with tpm_transmit_cmd.
 765  */
 766 ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id,  u32 *value,
 767                         const char *desc)
 768 {
 769         struct tpm2_cmd cmd;
 770         int rc;
 771
 772         cmd.header.in = tpm2_get_tpm_pt_header;
 773         cmd.params.get_tpm_pt_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES);
 774         cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(property_id);
 775         cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
 776
 777         rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
 778                               TPM2_GET_TPM_PT_OUT_BODY_SIZE, 0, desc);
 779         if (!rc)
 780                 *value = be32_to_cpu(cmd.params.get_tpm_pt_out.value);
 781
 782         return rc;
 783 }
 784 EXPORT_SYMBOL_GPL(tpm2_get_tpm_pt);
 785
 786 #define TPM2_STARTUP_IN_SIZE \
 787         (sizeof(struct tpm_input_header) + \
 788          sizeof(struct tpm2_startup_in))
 789
 790 static const struct tpm_input_header tpm2_startup_header = {
 791         .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
 792         .length = cpu_to_be32(TPM2_STARTUP_IN_SIZE),
 793         .ordinal = cpu_to_be32(TPM2_CC_STARTUP)
 794 };
 795
 796 /**
 797  * tpm2_startup() - send startup command to the TPM chip
 798  *
 799  * @chip:               TPM chip to use.
 800  * @startup_type:       startup type. The value is either
 801  *                      TPM_SU_CLEAR or TPM_SU_STATE.
 802  *
 803  * Return: Same as with tpm_transmit_cmd.
 804  */
 805 static int tpm2_startup(struct tpm_chip *chip, u16 startup_type)
 806 {
 807         struct tpm2_cmd cmd;
 808
 809         cmd.header.in = tpm2_startup_header;
 810
 811         cmd.params.startup_in.startup_type = cpu_to_be16(startup_type);
 812         return tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, 0,
 813                                 "attempting to start the TPM");
 814 }
 815
 816 #define TPM2_SHUTDOWN_IN_SIZE \
 817         (sizeof(struct tpm_input_header) + \
 818          sizeof(struct tpm2_startup_in))
 819
 820 static const struct tpm_input_header tpm2_shutdown_header = {
 821         .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
 822         .length = cpu_to_be32(TPM2_SHUTDOWN_IN_SIZE),
 823         .ordinal = cpu_to_be32(TPM2_CC_SHUTDOWN)
 824 };
 825
 826 /**
 827  * tpm2_shutdown() - send shutdown command to the TPM chip
 828  *
 829  * @chip:               TPM chip to use.
 830  * @shutdown_type:      shutdown type. The value is either
 831  *                      TPM_SU_CLEAR or TPM_SU_STATE.
 832  */
 833 void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
 834 {
 835         struct tpm2_cmd cmd;
 836         int rc;
 837
 838         cmd.header.in = tpm2_shutdown_header;
 839         cmd.params.startup_in.startup_type = cpu_to_be16(shutdown_type);
 840
 841         rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, 0,
 842                               "stopping the TPM");
 843
 844         /* In places where shutdown command is sent there's no much we can do
 845          * except print the error code on a system failure.
 846          */
 847         if (rc < 0)
 848                 dev_warn(&chip->dev, "transmit returned %d while stopping the TPM",
 849                          rc);
 850 }
 851
 852 /*
 853  * tpm2_calc_ordinal_duration() - maximum duration for a command
 854  *
 855  * @chip:       TPM chip to use.
 856  * @ordinal:    command code number.
 857  *
 858  * Return: maximum duration for a command
 859  */
 860 unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
 861 {
 862         int index = TPM_UNDEFINED;
 863         int duration = 0;
 864
 865         if (ordinal >= TPM2_CC_FIRST && ordinal <= TPM2_CC_LAST)
 866                 index = tpm2_ordinal_duration[ordinal - TPM2_CC_FIRST];
 867
 868         if (index != TPM_UNDEFINED)
 869                 duration = chip->duration[index];
 870
 871         if (duration <= 0)
 872                 duration = 2 * 60 * HZ;
 873
 874         return duration;
 875 }
 876 EXPORT_SYMBOL_GPL(tpm2_calc_ordinal_duration);
 877
 878 #define TPM2_SELF_TEST_IN_SIZE \
 879         (sizeof(struct tpm_input_header) + \
 880          sizeof(struct tpm2_self_test_in))
 881
 882 static const struct tpm_input_header tpm2_selftest_header = {
 883         .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
 884         .length = cpu_to_be32(TPM2_SELF_TEST_IN_SIZE),
 885         .ordinal = cpu_to_be32(TPM2_CC_SELF_TEST)
 886 };
 887
 888 /**
 889  * tpm2_continue_selftest() - start a self test
 890  *
 891  * @chip: TPM chip to use
 892  * @full: test all commands instead of testing only those that were not
 893  *        previously tested.
 894  *
 895  * Return: Same as with tpm_transmit_cmd with exception of RC_TESTING.
 896  */
 897 static int tpm2_start_selftest(struct tpm_chip *chip, bool full)
 898 {
 899         int rc;
 900         struct tpm2_cmd cmd;
 901
 902         cmd.header.in = tpm2_selftest_header;
 903         cmd.params.selftest_in.full_test = full;
 904
 905         rc = tpm_transmit_cmd(chip, &cmd, TPM2_SELF_TEST_IN_SIZE, 0, 0,
 906                               "continue selftest");
 907
 908         /* At least some prototype chips seem to give RC_TESTING error
 909          * immediately. This is a workaround for that.
 910          */
 911         if (rc == TPM2_RC_TESTING) {
 912                 dev_warn(&chip->dev, "Got RC_TESTING, ignoring\n");
 913                 rc = 0;
 914         }
 915
 916         return rc;
 917 }
 918
 919 /**
 920  * tpm2_do_selftest() - run a full self test
 921  *
 922  * @chip: TPM chip to use
 923  *
 924  * Return: Same as with tpm_transmit_cmd.
 925  *
 926  * During the self test TPM2 commands return with the error code RC_TESTING.
 927  * Waiting is done by issuing PCR read until it executes successfully.
 928  */
 929 static int tpm2_do_selftest(struct tpm_chip *chip)
 930 {
 931         int rc;
 932         unsigned int loops;
 933         unsigned int delay_msec = 100;
 934         unsigned long duration;
 935         struct tpm2_cmd cmd;
 936         int i;
 937
 938         duration = tpm2_calc_ordinal_duration(chip, TPM2_CC_SELF_TEST);
 939
 940         loops = jiffies_to_msecs(duration) / delay_msec;
 941
 942         rc = tpm2_start_selftest(chip, true);
 943         if (rc)
 944                 return rc;
 945
 946         for (i = 0; i < loops; i++) {
 947                 /* Attempt to read a PCR value */
 948                 cmd.header.in = tpm2_pcrread_header;
 949                 cmd.params.pcrread_in.pcr_selects_cnt = cpu_to_be32(1);
 950                 cmd.params.pcrread_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1);
 951                 cmd.params.pcrread_in.pcr_select_size = TPM2_PCR_SELECT_MIN;
 952                 cmd.params.pcrread_in.pcr_select[0] = 0x01;
 953                 cmd.params.pcrread_in.pcr_select[1] = 0x00;
 954                 cmd.params.pcrread_in.pcr_select[2] = 0x00;
 955
 956                 rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, 0, NULL);
 957                 if (rc < 0)
 958                         break;
 959
 960                 rc = be32_to_cpu(cmd.header.out.return_code);
 961                 if (rc != TPM2_RC_TESTING)
 962                         break;
 963
 964                 msleep(delay_msec);
 965         }
 966
 967         return rc;
 968 }
 969
 970 /**
 971  * tpm2_probe() - probe TPM 2.0
 972  * @chip: TPM chip to use
 973  *
 974  * Return: < 0 error and 0 on success.
 975  *
 976  * Send idempotent TPM 2.0 command and see whether TPM 2.0 chip replied based on
 977  * the reply tag.
 978  */
 979 int tpm2_probe(struct tpm_chip *chip)
 980 {
 981         struct tpm2_cmd cmd;
 982         int rc;
 983
 984         cmd.header.in = tpm2_get_tpm_pt_header;
 985         cmd.params.get_tpm_pt_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES);
 986         cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(0x100);
 987         cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
 988
 989         rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, 0, NULL);
 990         if (rc <  0)
 991                 return rc;
 992
 993         if (be16_to_cpu(cmd.header.out.tag) == TPM2_ST_NO_SESSIONS)
 994                 chip->flags |= TPM_CHIP_FLAG_TPM2;
 995
 996         return 0;
 997 }
 998 EXPORT_SYMBOL_GPL(tpm2_probe);
 999
1000 struct tpm2_pcr_selection {
1001         __be16  hash_alg;
1002         u8  size_of_select;
1003         u8  pcr_select[3];
1004 } __packed;
1005
1006 static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
1007 {
1008         struct tpm2_pcr_selection pcr_selection;
1009         struct tpm_buf buf;
1010         void *marker;
1011         void *end;
1012         void *pcr_select_offset;
1013         unsigned int count;
1014         u32 sizeof_pcr_selection;
1015         u32 rsp_len;
1016         int rc;
1017         int i = 0;
1018
1019         rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
1020         if (rc)
1021                 return rc;
1022
1023         tpm_buf_append_u32(&buf, TPM2_CAP_PCRS);
1024         tpm_buf_append_u32(&buf, 0);
1025         tpm_buf_append_u32(&buf, 1);
1026
1027         rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, 9, 0,
1028                               "get tpm pcr allocation");
1029         if (rc)
1030                 goto out;
1031
1032         count = be32_to_cpup(
1033                 (__be32 *)&buf.data[TPM_HEADER_SIZE + 5]);
1034
1035         if (count > ARRAY_SIZE(chip->active_banks)) {
1036                 rc = -ENODEV;
1037                 goto out;
1038         }
1039
1040         marker = &buf.data[TPM_HEADER_SIZE + 9];
1041
1042         rsp_len = be32_to_cpup((__be32 *)&buf.data[2]);
1043         end = &buf.data[rsp_len];
1044
1045         for (i = 0; i < count; i++) {
1046                 pcr_select_offset = marker +
1047                         offsetof(struct tpm2_pcr_selection, size_of_select);
1048                 if (pcr_select_offset >= end) {
1049                         rc = -EFAULT;
1050                         break;
1051                 }
1052
1053                 memcpy(&pcr_selection, marker, sizeof(pcr_selection));
1054                 chip->active_banks[i] = be16_to_cpu(pcr_selection.hash_alg);
1055                 sizeof_pcr_selection = sizeof(pcr_selection.hash_alg) +
1056                         sizeof(pcr_selection.size_of_select) +
1057                         pcr_selection.size_of_select;
1058                 marker = marker + sizeof_pcr_selection;
1059         }
1060
1061 out:
1062         if (i < ARRAY_SIZE(chip->active_banks))
1063                 chip->active_banks[i] = TPM2_ALG_ERROR;
1064
1065         tpm_buf_destroy(&buf);
1066
1067         return rc;
1068 }
1069
1070 /**
1071  * tpm2_auto_startup - Perform the standard automatic TPM initialization
1072  *                     sequence
1073  * @chip: TPM chip to use
1074  *
1075  * Initializes timeout values for operation and command durations, conducts
1076  * a self-test and reads the list of active PCR banks.
1077  *
1078  * Return: 0 on success. Otherwise, a system error code is returned.
1079  */
1080 int tpm2_auto_startup(struct tpm_chip *chip)
1081 {
1082         int rc;
1083
1084         rc = tpm_get_timeouts(chip);
1085         if (rc)
1086                 goto out;
1087
1088         rc = tpm2_do_selftest(chip);
1089         if (rc != 0 && rc != TPM2_RC_INITIALIZE) {
1090                 dev_err(&chip->dev, "TPM self test failed\n");
1091                 goto out;
1092         }
1093
1094         if (rc == TPM2_RC_INITIALIZE) {
1095                 rc = tpm2_startup(chip, TPM2_SU_CLEAR);
1096                 if (rc)
1097                         goto out;
1098
1099                 rc = tpm2_do_selftest(chip);
1100                 if (rc) {
1101                         dev_err(&chip->dev, "TPM self test failed\n");
1102                         goto out;
1103                 }
1104         }
1105
1106         rc = tpm2_get_pcr_allocation(chip);
1107
1108 out:
1109         if (rc > 0)
1110                 rc = -ENODEV;
1111         return rc;
1112 }