drivers/char/tpm/tpm2-cmd.c

   1 /*
   2  * Copyright (C) 2014, 2015 Intel Corporation
   3  *
   4  * Authors:
   5  * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
   6  *
   7  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
   8  *
   9  * This file contains TPM2 protocol implementations of the commands
  10  * used by the kernel internally.
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; version 2
  15  * of the License.
  16  */
  17
  18 #include "tpm.h"
  19 #include <keys/trusted-type.h>
  20
  21 enum tpm2_object_attributes {
  22         TPM2_ATTR_USER_WITH_AUTH        = BIT(6),
  23 };
  24
  25 struct tpm2_startup_in {
  26         __be16  startup_type;
  27 } __packed;
  28
  29 struct tpm2_self_test_in {
  30         u8      full_test;
  31 } __packed;
  32
  33 struct tpm2_pcr_read_in {
  34         __be32  pcr_selects_cnt;
  35         __be16  hash_alg;
  36         u8      pcr_select_size;
  37         u8      pcr_select[TPM2_PCR_SELECT_MIN];
  38 } __packed;
  39
  40 struct tpm2_pcr_read_out {
  41         __be32  update_cnt;
  42         __be32  pcr_selects_cnt;
  43         __be16  hash_alg;
  44         u8      pcr_select_size;
  45         u8      pcr_select[TPM2_PCR_SELECT_MIN];
  46         __be32  digests_cnt;
  47         __be16  digest_size;
  48         u8      digest[TPM_DIGEST_SIZE];
  49 } __packed;
  50
  51 struct tpm2_null_auth_area {
  52         __be32                  handle;
  53         __be16                  nonce_size;
  54         u8                      attributes;
  55         __be16                  auth_size;
  56 } __packed;
  57
  58 struct tpm2_pcr_extend_in {
  59         __be32                          pcr_idx;
  60         __be32                          auth_area_size;
  61         struct tpm2_null_auth_area      auth_area;
  62         __be32                          digest_cnt;
  63         __be16                          hash_alg;
  64         u8                              digest[TPM_DIGEST_SIZE];
  65 } __packed;
  66
  67 struct tpm2_get_tpm_pt_in {
  68         __be32  cap_id;
  69         __be32  property_id;
  70         __be32  property_cnt;
  71 } __packed;
  72
  73 struct tpm2_get_tpm_pt_out {
  74         u8      more_data;
  75         __be32  subcap_id;
  76         __be32  property_cnt;
  77         __be32  property_id;
  78         __be32  value;
  79 } __packed;
  80
  81 struct tpm2_get_random_in {
  82         __be16  size;
  83 } __packed;
  84
  85 struct tpm2_get_random_out {
  86         __be16  size;
  87         u8      buffer[TPM_MAX_RNG_DATA];
  88 } __packed;
  89
  90 union tpm2_cmd_params {
  91         struct  tpm2_startup_in         startup_in;
  92         struct  tpm2_self_test_in       selftest_in;
  93         struct  tpm2_pcr_read_in        pcrread_in;
  94         struct  tpm2_pcr_read_out       pcrread_out;
  95         struct  tpm2_pcr_extend_in      pcrextend_in;
  96         struct  tpm2_get_tpm_pt_in      get_tpm_pt_in;
  97         struct  tpm2_get_tpm_pt_out     get_tpm_pt_out;
  98         struct  tpm2_get_random_in      getrandom_in;
  99         struct  tpm2_get_random_out     getrandom_out;
 100 };
 101
 102 struct tpm2_cmd {
 103         tpm_cmd_header          header;
 104         union tpm2_cmd_params   params;
 105 } __packed;
 106
 107 /*
 108  * Array with one entry per ordinal defining the maximum amount
 109  * of time the chip could take to return the result. The values
 110  * of the SHORT, MEDIUM, and LONG durations are taken from the
 111  * PC Client Profile (PTP) specification.
 112  */
 113 static const u8 tpm2_ordinal_duration[TPM2_CC_LAST - TPM2_CC_FIRST + 1] = {
 114         TPM_UNDEFINED,          /* 11F */
 115         TPM_UNDEFINED,          /* 120 */
 116         TPM_LONG,               /* 121 */
 117         TPM_UNDEFINED,          /* 122 */
 118         TPM_UNDEFINED,          /* 123 */
 119         TPM_UNDEFINED,          /* 124 */
 120         TPM_UNDEFINED,          /* 125 */
 121         TPM_UNDEFINED,          /* 126 */
 122         TPM_UNDEFINED,          /* 127 */
 123         TPM_UNDEFINED,          /* 128 */
 124         TPM_LONG,               /* 129 */
 125         TPM_UNDEFINED,          /* 12a */
 126         TPM_UNDEFINED,          /* 12b */
 127         TPM_UNDEFINED,          /* 12c */
 128         TPM_UNDEFINED,          /* 12d */
 129         TPM_UNDEFINED,          /* 12e */
 130         TPM_UNDEFINED,          /* 12f */
 131         TPM_UNDEFINED,          /* 130 */
 132         TPM_UNDEFINED,          /* 131 */
 133         TPM_UNDEFINED,          /* 132 */
 134         TPM_UNDEFINED,          /* 133 */
 135         TPM_UNDEFINED,          /* 134 */
 136         TPM_UNDEFINED,          /* 135 */
 137         TPM_UNDEFINED,          /* 136 */
 138         TPM_UNDEFINED,          /* 137 */
 139         TPM_UNDEFINED,          /* 138 */
 140         TPM_UNDEFINED,          /* 139 */
 141         TPM_UNDEFINED,          /* 13a */
 142         TPM_UNDEFINED,          /* 13b */
 143         TPM_UNDEFINED,          /* 13c */
 144         TPM_UNDEFINED,          /* 13d */
 145         TPM_MEDIUM,             /* 13e */
 146         TPM_UNDEFINED,          /* 13f */
 147         TPM_UNDEFINED,          /* 140 */
 148         TPM_UNDEFINED,          /* 141 */
 149         TPM_UNDEFINED,          /* 142 */
 150         TPM_LONG,               /* 143 */
 151         TPM_MEDIUM,             /* 144 */
 152         TPM_UNDEFINED,          /* 145 */
 153         TPM_UNDEFINED,          /* 146 */
 154         TPM_UNDEFINED,          /* 147 */
 155         TPM_UNDEFINED,          /* 148 */
 156         TPM_UNDEFINED,          /* 149 */
 157         TPM_UNDEFINED,          /* 14a */
 158         TPM_UNDEFINED,          /* 14b */
 159         TPM_UNDEFINED,          /* 14c */
 160         TPM_UNDEFINED,          /* 14d */
 161         TPM_LONG,               /* 14e */
 162         TPM_UNDEFINED,          /* 14f */
 163         TPM_UNDEFINED,          /* 150 */
 164         TPM_UNDEFINED,          /* 151 */
 165         TPM_UNDEFINED,          /* 152 */
 166         TPM_UNDEFINED,          /* 153 */
 167         TPM_UNDEFINED,          /* 154 */
 168         TPM_UNDEFINED,          /* 155 */
 169         TPM_UNDEFINED,          /* 156 */
 170         TPM_UNDEFINED,          /* 157 */
 171         TPM_UNDEFINED,          /* 158 */
 172         TPM_UNDEFINED,          /* 159 */
 173         TPM_UNDEFINED,          /* 15a */
 174         TPM_UNDEFINED,          /* 15b */
 175         TPM_MEDIUM,             /* 15c */
 176         TPM_UNDEFINED,          /* 15d */
 177         TPM_UNDEFINED,          /* 15e */
 178         TPM_UNDEFINED,          /* 15f */
 179         TPM_UNDEFINED,          /* 160 */
 180         TPM_UNDEFINED,          /* 161 */
 181         TPM_UNDEFINED,          /* 162 */
 182         TPM_UNDEFINED,          /* 163 */
 183         TPM_UNDEFINED,          /* 164 */
 184         TPM_UNDEFINED,          /* 165 */
 185         TPM_UNDEFINED,          /* 166 */
 186         TPM_UNDEFINED,          /* 167 */
 187         TPM_UNDEFINED,          /* 168 */
 188         TPM_UNDEFINED,          /* 169 */
 189         TPM_UNDEFINED,          /* 16a */
 190         TPM_UNDEFINED,          /* 16b */
 191         TPM_UNDEFINED,          /* 16c */
 192         TPM_UNDEFINED,          /* 16d */
 193         TPM_UNDEFINED,          /* 16e */
 194         TPM_UNDEFINED,          /* 16f */
 195         TPM_UNDEFINED,          /* 170 */
 196         TPM_UNDEFINED,          /* 171 */
 197         TPM_UNDEFINED,          /* 172 */
 198         TPM_UNDEFINED,          /* 173 */
 199         TPM_UNDEFINED,          /* 174 */
 200         TPM_UNDEFINED,          /* 175 */
 201         TPM_UNDEFINED,          /* 176 */
 202         TPM_LONG,               /* 177 */
 203         TPM_UNDEFINED,          /* 178 */
 204         TPM_UNDEFINED,          /* 179 */
 205         TPM_MEDIUM,             /* 17a */
 206         TPM_LONG,               /* 17b */
 207         TPM_UNDEFINED,          /* 17c */
 208         TPM_UNDEFINED,          /* 17d */
 209         TPM_UNDEFINED,          /* 17e */
 210         TPM_UNDEFINED,          /* 17f */
 211         TPM_UNDEFINED,          /* 180 */
 212         TPM_UNDEFINED,          /* 181 */
 213         TPM_MEDIUM,             /* 182 */
 214         TPM_UNDEFINED,          /* 183 */
 215         TPM_UNDEFINED,          /* 184 */
 216         TPM_MEDIUM,             /* 185 */
 217         TPM_MEDIUM,             /* 186 */
 218         TPM_UNDEFINED,          /* 187 */
 219         TPM_UNDEFINED,          /* 188 */
 220         TPM_UNDEFINED,          /* 189 */
 221         TPM_UNDEFINED,          /* 18a */
 222         TPM_UNDEFINED,          /* 18b */
 223         TPM_UNDEFINED,          /* 18c */
 224         TPM_UNDEFINED,          /* 18d */
 225         TPM_UNDEFINED,          /* 18e */
 226         TPM_UNDEFINED           /* 18f */
 227 };
 228
 229 #define TPM2_PCR_READ_IN_SIZE \
 230         (sizeof(struct tpm_input_header) + \
 231          sizeof(struct tpm2_pcr_read_in))
 232
 233 static const struct tpm_input_header tpm2_pcrread_header = {
 234         .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
 235         .length = cpu_to_be32(TPM2_PCR_READ_IN_SIZE),
 236         .ordinal = cpu_to_be32(TPM2_CC_PCR_READ)
 237 };
 238
 239 /**
 240  * tpm2_pcr_read() - read a PCR value
 241  * @chip:       TPM chip to use.
 242  * @pcr_idx:    index of the PCR to read.
 243  * @ref_buf:    buffer to store the resulting hash,
 244  *
 245  * 0 is returned when the operation is successful. If a negative number is
 246  * returned it remarks a POSIX error code. If a positive number is returned
 247  * it remarks a TPM error.
 248  */
 249 int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 250 {
 251         int rc;
 252         struct tpm2_cmd cmd;
 253         u8 *buf;
 254
 255         if (pcr_idx >= TPM2_PLATFORM_PCR)
 256                 return -EINVAL;
 257
 258         cmd.header.in = tpm2_pcrread_header;
 259         cmd.params.pcrread_in.pcr_selects_cnt = cpu_to_be32(1);
 260         cmd.params.pcrread_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1);
 261         cmd.params.pcrread_in.pcr_select_size = TPM2_PCR_SELECT_MIN;
 262
 263         memset(cmd.params.pcrread_in.pcr_select, 0,
 264                sizeof(cmd.params.pcrread_in.pcr_select));
 265         cmd.params.pcrread_in.pcr_select[pcr_idx >> 3] = 1 << (pcr_idx & 0x7);
 266
 267         rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
 268                               "attempting to read a pcr value");
 269         if (rc == 0) {
 270                 buf = cmd.params.pcrread_out.digest;
 271                 memcpy(res_buf, buf, TPM_DIGEST_SIZE);
 272         }
 273
 274         return rc;
 275 }
 276
 277 #define TPM2_GET_PCREXTEND_IN_SIZE \
 278         (sizeof(struct tpm_input_header) + \
 279          sizeof(struct tpm2_pcr_extend_in))
 280
 281 static const struct tpm_input_header tpm2_pcrextend_header = {
 282         .tag = cpu_to_be16(TPM2_ST_SESSIONS),
 283         .length = cpu_to_be32(TPM2_GET_PCREXTEND_IN_SIZE),
 284         .ordinal = cpu_to_be32(TPM2_CC_PCR_EXTEND)
 285 };
 286
 287 /**
 288  * tpm2_pcr_extend() - extend a PCR value
 289  * @chip:       TPM chip to use.
 290  * @pcr_idx:    index of the PCR.
 291  * @hash:       hash value to use for the extend operation.
 292  *
 293  * 0 is returned when the operation is successful. If a negative number is
 294  * returned it remarks a POSIX error code. If a positive number is returned
 295  * it remarks a TPM error.
 296  */
 297 int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash)
 298 {
 299         struct tpm2_cmd cmd;
 300         int rc;
 301
 302         cmd.header.in = tpm2_pcrextend_header;
 303         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 304         cmd.params.pcrextend_in.auth_area_size =
 305                 cpu_to_be32(sizeof(struct tpm2_null_auth_area));
 306         cmd.params.pcrextend_in.auth_area.handle =
 307                 cpu_to_be32(TPM2_RS_PW);
 308         cmd.params.pcrextend_in.auth_area.nonce_size = 0;
 309         cmd.params.pcrextend_in.auth_area.attributes = 0;
 310         cmd.params.pcrextend_in.auth_area.auth_size = 0;
 311         cmd.params.pcrextend_in.digest_cnt = cpu_to_be32(1);
 312         cmd.params.pcrextend_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1);
 313         memcpy(cmd.params.pcrextend_in.digest, hash, TPM_DIGEST_SIZE);
 314
 315         rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
 316                               "attempting extend a PCR value");
 317
 318         return rc;
 319 }
 320
 321 #define TPM2_GETRANDOM_IN_SIZE \
 322         (sizeof(struct tpm_input_header) + \
 323          sizeof(struct tpm2_get_random_in))
 324
 325 static const struct tpm_input_header tpm2_getrandom_header = {
 326         .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
 327         .length = cpu_to_be32(TPM2_GETRANDOM_IN_SIZE),
 328         .ordinal = cpu_to_be32(TPM2_CC_GET_RANDOM)
 329 };
 330
 331 /**
 332  * tpm2_get_random() - get random bytes from the TPM RNG
 333  * @chip: TPM chip to use
 334  * @out: destination buffer for the random bytes
 335  * @max: the max number of bytes to write to @out
 336  *
 337  * 0 is returned when the operation is successful. If a negative number is
 338  * returned it remarks a POSIX error code. If a positive number is returned
 339  * it remarks a TPM error.
 340  */
 341 int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max)
 342 {
 343         struct tpm2_cmd cmd;
 344         u32 recd;
 345         u32 num_bytes;
 346         int err;
 347         int total = 0;
 348         int retries = 5;
 349         u8 *dest = out;
 350
 351         num_bytes = min_t(u32, max, sizeof(cmd.params.getrandom_out.buffer));
 352
 353         if (!out || !num_bytes ||
 354             max > sizeof(cmd.params.getrandom_out.buffer))
 355                 return -EINVAL;
 356
 357         do {
 358                 cmd.header.in = tpm2_getrandom_header;
 359                 cmd.params.getrandom_in.size = cpu_to_be16(num_bytes);
 360
 361                 err = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
 362                                        "attempting get random");
 363                 if (err)
 364                         break;
 365
 366                 recd = min_t(u32, be16_to_cpu(cmd.params.getrandom_out.size),
 367                              num_bytes);
 368                 memcpy(dest, cmd.params.getrandom_out.buffer, recd);
 369
 370                 dest += recd;
 371                 total += recd;
 372                 num_bytes -= recd;
 373         } while (retries-- && total < max);
 374
 375         return total ? total : -EIO;
 376 }
 377
 378 #define TPM2_GET_TPM_PT_IN_SIZE \
 379         (sizeof(struct tpm_input_header) + \
 380          sizeof(struct tpm2_get_tpm_pt_in))
 381
 382 static const struct tpm_input_header tpm2_get_tpm_pt_header = {
 383         .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
 384         .length = cpu_to_be32(TPM2_GET_TPM_PT_IN_SIZE),
 385         .ordinal = cpu_to_be32(TPM2_CC_GET_CAPABILITY)
 386 };
 387
 388 /**
 389  * Append TPMS_AUTH_COMMAND to the buffer. The buffer must be allocated with
 390  * tpm_buf_alloc().
 391  *
 392  * @param buf: an allocated tpm_buf instance
 393  * @param nonce: the session nonce, may be NULL if not used
 394  * @param nonce_len: the session nonce length, may be 0 if not used
 395  * @param attributes: the session attributes
 396  * @param hmac: the session HMAC or password, may be NULL if not used
 397  * @param hmac_len: the session HMAC or password length, maybe 0 if not used
 398  */
 399 static void tpm2_buf_append_auth(struct tpm_buf *buf, u32 session_handle,
 400                                  const u8 *nonce, u16 nonce_len,
 401                                  u8 attributes,
 402                                  const u8 *hmac, u16 hmac_len)
 403 {
 404         tpm_buf_append_u32(buf, 9 + nonce_len + hmac_len);
 405         tpm_buf_append_u32(buf, session_handle);
 406         tpm_buf_append_u16(buf, nonce_len);
 407
 408         if (nonce && nonce_len)
 409                 tpm_buf_append(buf, nonce, nonce_len);
 410
 411         tpm_buf_append_u8(buf, attributes);
 412         tpm_buf_append_u16(buf, hmac_len);
 413
 414         if (hmac && hmac_len)
 415                 tpm_buf_append(buf, hmac, hmac_len);
 416 }
 417
 418 /**
 419  * tpm2_seal_trusted() - seal a trusted key
 420  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
 421  * @options: authentication values and other options
 422  * @payload: the key data in clear and encrypted form
 423  *
 424  * Returns < 0 on error and 0 on success.
 425  */
 426 int tpm2_seal_trusted(struct tpm_chip *chip,
 427                       struct trusted_key_payload *payload,
 428                       struct trusted_key_options *options)
 429 {
 430         unsigned int blob_len;
 431         struct tpm_buf buf;
 432         int rc;
 433
 434         rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE);
 435         if (rc)
 436                 return rc;
 437
 438         tpm_buf_append_u32(&buf, options->keyhandle);
 439         tpm2_buf_append_auth(&buf, TPM2_RS_PW,
 440                              NULL /* nonce */, 0,
 441                              0 /* session_attributes */,
 442                              options->keyauth /* hmac */,
 443                              TPM_DIGEST_SIZE);
 444
 445         /* sensitive */
 446         tpm_buf_append_u16(&buf, 4 + TPM_DIGEST_SIZE + payload->key_len + 1);
 447
 448         tpm_buf_append_u16(&buf, TPM_DIGEST_SIZE);
 449         tpm_buf_append(&buf, options->blobauth, TPM_DIGEST_SIZE);
 450         tpm_buf_append_u16(&buf, payload->key_len + 1);
 451         tpm_buf_append(&buf, payload->key, payload->key_len);
 452         tpm_buf_append_u8(&buf, payload->migratable);
 453
 454         /* public */
 455         tpm_buf_append_u16(&buf, 14);
 456
 457         tpm_buf_append_u16(&buf, TPM2_ALG_KEYEDHASH);
 458         tpm_buf_append_u16(&buf, TPM2_ALG_SHA256);
 459         tpm_buf_append_u32(&buf, TPM2_ATTR_USER_WITH_AUTH);
 460         tpm_buf_append_u16(&buf, 0); /* policy digest size */
 461         tpm_buf_append_u16(&buf, TPM2_ALG_NULL);
 462         tpm_buf_append_u16(&buf, 0);
 463
 464         /* outside info */
 465         tpm_buf_append_u16(&buf, 0);
 466
 467         /* creation PCR */
 468         tpm_buf_append_u32(&buf, 0);
 469
 470         if (buf.flags & TPM_BUF_OVERFLOW) {
 471                 rc = -E2BIG;
 472                 goto out;
 473         }
 474
 475         rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "sealing data");
 476         if (rc)
 477                 goto out;
 478
 479         blob_len = be32_to_cpup((__be32 *) &buf.data[TPM_HEADER_SIZE]);
 480         if (blob_len > MAX_BLOB_SIZE) {
 481                 rc = -E2BIG;
 482                 goto out;
 483         }
 484
 485         memcpy(payload->blob, &buf.data[TPM_HEADER_SIZE + 4], blob_len);
 486         payload->blob_len = blob_len;
 487
 488 out:
 489         tpm_buf_destroy(&buf);
 490
 491         if (rc > 0)
 492                 rc = -EPERM;
 493
 494         return rc;
 495 }
 496
 497 static int tpm2_load(struct tpm_chip *chip,
 498                      struct trusted_key_payload *payload,
 499                      struct trusted_key_options *options,
 500                      u32 *blob_handle)
 501 {
 502         struct tpm_buf buf;
 503         unsigned int private_len;
 504         unsigned int public_len;
 505         unsigned int blob_len;
 506         int rc;
 507
 508         private_len = be16_to_cpup((__be16 *) &payload->blob[0]);
 509         if (private_len > (payload->blob_len - 2))
 510                 return -E2BIG;
 511
 512         public_len = be16_to_cpup((__be16 *) &payload->blob[2 + private_len]);
 513         blob_len = private_len + public_len + 4;
 514         if (blob_len > payload->blob_len)
 515                 return -E2BIG;
 516
 517         rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD);
 518         if (rc)
 519                 return rc;
 520
 521         tpm_buf_append_u32(&buf, options->keyhandle);
 522         tpm2_buf_append_auth(&buf, TPM2_RS_PW,
 523                              NULL /* nonce */, 0,
 524                              0 /* session_attributes */,
 525                              options->keyauth /* hmac */,
 526                              TPM_DIGEST_SIZE);
 527
 528         tpm_buf_append(&buf, payload->blob, blob_len);
 529
 530         if (buf.flags & TPM_BUF_OVERFLOW) {
 531                 rc = -E2BIG;
 532                 goto out;
 533         }
 534
 535         rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "loading blob");
 536         if (!rc)
 537                 *blob_handle = be32_to_cpup(
 538                         (__be32 *) &buf.data[TPM_HEADER_SIZE]);
 539
 540 out:
 541         tpm_buf_destroy(&buf);
 542
 543         if (rc > 0)
 544                 rc = -EPERM;
 545
 546         return rc;
 547 }
 548
 549 static void tpm2_flush_context(struct tpm_chip *chip, u32 handle)
 550 {
 551         struct tpm_buf buf;
 552         int rc;
 553
 554         rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_FLUSH_CONTEXT);
 555         if (rc) {
 556                 dev_warn(chip->pdev, "0x%08x was not flushed, out of memory\n",
 557                          handle);
 558                 return;
 559         }
 560
 561         tpm_buf_append_u32(&buf, handle);
 562
 563         rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "flushing context");
 564         if (rc)
 565                 dev_warn(chip->pdev, "0x%08x was not flushed, rc=%d\n", handle,
 566                          rc);
 567
 568         tpm_buf_destroy(&buf);
 569 }
 570
 571 static int tpm2_unseal(struct tpm_chip *chip,
 572                        struct trusted_key_payload *payload,
 573                        struct trusted_key_options *options,
 574                        u32 blob_handle)
 575 {
 576         struct tpm_buf buf;
 577         u16 data_len;
 578         u8 *data;
 579         int rc;
 580
 581         rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL);
 582         if (rc)
 583                 return rc;
 584
 585         tpm_buf_append_u32(&buf, blob_handle);
 586         tpm2_buf_append_auth(&buf, TPM2_RS_PW,
 587                              NULL /* nonce */, 0,
 588                              0 /* session_attributes */,
 589                              options->blobauth /* hmac */,
 590                              TPM_DIGEST_SIZE);
 591
 592         rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "unsealing");
 593         if (rc > 0)
 594                 rc = -EPERM;
 595
 596         if (!rc) {
 597                 data_len = be16_to_cpup(
 598                         (__be16 *) &buf.data[TPM_HEADER_SIZE + 4]);
 599                 data = &buf.data[TPM_HEADER_SIZE + 6];
 600
 601                 memcpy(payload->key, data, data_len - 1);
 602                 payload->key_len = data_len - 1;
 603                 payload->migratable = data[data_len - 1];
 604         }
 605
 606         tpm_buf_destroy(&buf);
 607         return rc;
 608 }
 609
 610 /**
 611  * tpm_unseal_trusted() - unseal a trusted key
 612  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
 613  * @options: authentication values and other options
 614  * @payload: the key data in clear and encrypted form
 615  *
 616  * Returns < 0 on error and 0 on success.
 617  */
 618 int tpm2_unseal_trusted(struct tpm_chip *chip,
 619                         struct trusted_key_payload *payload,
 620                         struct trusted_key_options *options)
 621 {
 622         u32 blob_handle;
 623         int rc;
 624
 625         rc = tpm2_load(chip, payload, options, &blob_handle);
 626         if (rc)
 627                 return rc;
 628
 629         rc = tpm2_unseal(chip, payload, options, blob_handle);
 630
 631         tpm2_flush_context(chip, blob_handle);
 632
 633         return rc;
 634 }
 635
 636 /**
 637  * tpm2_get_tpm_pt() - get value of a TPM_CAP_TPM_PROPERTIES type property
 638  * @chip:               TPM chip to use.
 639  * @property_id:        property ID.
 640  * @value:              output variable.
 641  * @desc:               passed to tpm_transmit_cmd()
 642  *
 643  * 0 is returned when the operation is successful. If a negative number is
 644  * returned it remarks a POSIX error code. If a positive number is returned
 645  * it remarks a TPM error.
 646  */
 647 ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id,  u32 *value,
 648                         const char *desc)
 649 {
 650         struct tpm2_cmd cmd;
 651         int rc;
 652
 653         cmd.header.in = tpm2_get_tpm_pt_header;
 654         cmd.params.get_tpm_pt_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES);
 655         cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(property_id);
 656         cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
 657
 658         rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), desc);
 659         if (!rc)
 660                 *value = cmd.params.get_tpm_pt_out.value;
 661
 662         return rc;
 663 }
 664
 665 #define TPM2_STARTUP_IN_SIZE \
 666         (sizeof(struct tpm_input_header) + \
 667          sizeof(struct tpm2_startup_in))
 668
 669 static const struct tpm_input_header tpm2_startup_header = {
 670         .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
 671         .length = cpu_to_be32(TPM2_STARTUP_IN_SIZE),
 672         .ordinal = cpu_to_be32(TPM2_CC_STARTUP)
 673 };
 674
 675 /**
 676  * tpm2_startup() - send startup command to the TPM chip
 677  * @chip:               TPM chip to use.
 678  * @startup_type        startup type. The value is either
 679  *                      TPM_SU_CLEAR or TPM_SU_STATE.
 680  *
 681  * 0 is returned when the operation is successful. If a negative number is
 682  * returned it remarks a POSIX error code. If a positive number is returned
 683  * it remarks a TPM error.
 684  */
 685 int tpm2_startup(struct tpm_chip *chip, u16 startup_type)
 686 {
 687         struct tpm2_cmd cmd;
 688
 689         cmd.header.in = tpm2_startup_header;
 690
 691         cmd.params.startup_in.startup_type = cpu_to_be16(startup_type);
 692         return tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
 693                                 "attempting to start the TPM");
 694 }
 695 EXPORT_SYMBOL_GPL(tpm2_startup);
 696
 697 #define TPM2_SHUTDOWN_IN_SIZE \
 698         (sizeof(struct tpm_input_header) + \
 699          sizeof(struct tpm2_startup_in))
 700
 701 static const struct tpm_input_header tpm2_shutdown_header = {
 702         .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
 703         .length = cpu_to_be32(TPM2_SHUTDOWN_IN_SIZE),
 704         .ordinal = cpu_to_be32(TPM2_CC_SHUTDOWN)
 705 };
 706
 707 /**
 708  * tpm2_shutdown() - send shutdown command to the TPM chip
 709  * @chip:               TPM chip to use.
 710  * @shutdown_type       shutdown type. The value is either
 711  *                      TPM_SU_CLEAR or TPM_SU_STATE.
 712  */
 713 void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
 714 {
 715         struct tpm2_cmd cmd;
 716         int rc;
 717
 718         cmd.header.in = tpm2_shutdown_header;
 719         cmd.params.startup_in.startup_type = cpu_to_be16(shutdown_type);
 720
 721         rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), "stopping the TPM");
 722
 723         /* In places where shutdown command is sent there's no much we can do
 724          * except print the error code on a system failure.
 725          */
 726         if (rc < 0)
 727                 dev_warn(chip->pdev, "transmit returned %d while stopping the TPM",
 728                          rc);
 729 }
 730 EXPORT_SYMBOL_GPL(tpm2_shutdown);
 731
 732 /*
 733  * tpm2_calc_ordinal_duration() - maximum duration for a command
 734  * @chip:       TPM chip to use.
 735  * @ordinal:    command code number.
 736  *
 737  * 0 is returned when the operation is successful. If a negative number is
 738  * returned it remarks a POSIX error code. If a positive number is returned
 739  * it remarks a TPM error.
 740  */
 741 unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
 742 {
 743         int index = TPM_UNDEFINED;
 744         int duration = 0;
 745
 746         if (ordinal >= TPM2_CC_FIRST && ordinal <= TPM2_CC_LAST)
 747                 index = tpm2_ordinal_duration[ordinal - TPM2_CC_FIRST];
 748
 749         if (index != TPM_UNDEFINED)
 750                 duration = chip->vendor.duration[index];
 751
 752         if (duration <= 0)
 753                 duration = 2 * 60 * HZ;
 754
 755         return duration;
 756 }
 757 EXPORT_SYMBOL_GPL(tpm2_calc_ordinal_duration);
 758
 759 #define TPM2_SELF_TEST_IN_SIZE \
 760         (sizeof(struct tpm_input_header) + \
 761          sizeof(struct tpm2_self_test_in))
 762
 763 static const struct tpm_input_header tpm2_selftest_header = {
 764         .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
 765         .length = cpu_to_be32(TPM2_SELF_TEST_IN_SIZE),
 766         .ordinal = cpu_to_be32(TPM2_CC_SELF_TEST)
 767 };
 768
 769 /**
 770  * tpm2_continue_selftest() - start a self test
 771  * @chip: TPM chip to use
 772  * @full: test all commands instead of testing only those that were not
 773  *        previously tested.
 774  *
 775  * 0 is returned when the operation is successful. If a negative number is
 776  * returned it remarks a POSIX error code. If a positive number is returned
 777  * it remarks a TPM error.
 778  */
 779 static int tpm2_start_selftest(struct tpm_chip *chip, bool full)
 780 {
 781         int rc;
 782         struct tpm2_cmd cmd;
 783
 784         cmd.header.in = tpm2_selftest_header;
 785         cmd.params.selftest_in.full_test = full;
 786
 787         rc = tpm_transmit_cmd(chip, &cmd, TPM2_SELF_TEST_IN_SIZE,
 788                               "continue selftest");
 789
 790         /* At least some prototype chips seem to give RC_TESTING error
 791          * immediately. This is a workaround for that.
 792          */
 793         if (rc == TPM2_RC_TESTING) {
 794                 dev_warn(chip->pdev, "Got RC_TESTING, ignoring\n");
 795                 rc = 0;
 796         }
 797
 798         return rc;
 799 }
 800
 801 /**
 802  * tpm2_do_selftest() - run a full self test
 803  * @chip: TPM chip to use
 804  *
 805  * During the self test TPM2 commands return with the error code RC_TESTING.
 806  * Waiting is done by issuing PCR read until it executes successfully.
 807  *
 808  * 0 is returned when the operation is successful. If a negative number is
 809  * returned it remarks a POSIX error code. If a positive number is returned
 810  * it remarks a TPM error.
 811  */
 812 int tpm2_do_selftest(struct tpm_chip *chip)
 813 {
 814         int rc;
 815         unsigned int loops;
 816         unsigned int delay_msec = 100;
 817         unsigned long duration;
 818         struct tpm2_cmd cmd;
 819         int i;
 820
 821         duration = tpm2_calc_ordinal_duration(chip, TPM2_CC_SELF_TEST);
 822
 823         loops = jiffies_to_msecs(duration) / delay_msec;
 824
 825         rc = tpm2_start_selftest(chip, true);
 826         if (rc)
 827                 return rc;
 828
 829         for (i = 0; i < loops; i++) {
 830                 /* Attempt to read a PCR value */
 831                 cmd.header.in = tpm2_pcrread_header;
 832                 cmd.params.pcrread_in.pcr_selects_cnt = cpu_to_be32(1);
 833                 cmd.params.pcrread_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1);
 834                 cmd.params.pcrread_in.pcr_select_size = TPM2_PCR_SELECT_MIN;
 835                 cmd.params.pcrread_in.pcr_select[0] = 0x01;
 836                 cmd.params.pcrread_in.pcr_select[1] = 0x00;
 837                 cmd.params.pcrread_in.pcr_select[2] = 0x00;
 838
 839                 rc = tpm_transmit_cmd(chip, (u8 *) &cmd, sizeof(cmd), NULL);
 840                 if (rc < 0)
 841                         break;
 842
 843                 rc = be32_to_cpu(cmd.header.out.return_code);
 844                 if (rc != TPM2_RC_TESTING)
 845                         break;
 846
 847                 msleep(delay_msec);
 848         }
 849
 850         return rc;
 851 }
 852 EXPORT_SYMBOL_GPL(tpm2_do_selftest);
 853
 854 /**
 855  * tpm2_gen_interrupt() - generate an interrupt
 856  * @chip: TPM chip to use
 857  *
 858  * 0 is returned when the operation is successful. If a negative number is
 859  * returned it remarks a POSIX error code. If a positive number is returned
 860  * it remarks a TPM error.
 861  */
 862 int tpm2_gen_interrupt(struct tpm_chip *chip)
 863 {
 864         u32 dummy;
 865
 866         return tpm2_get_tpm_pt(chip, 0x100, &dummy,
 867                                "attempting to generate an interrupt");
 868 }
 869 EXPORT_SYMBOL_GPL(tpm2_gen_interrupt);
 870
 871 /**
 872  * tpm2_probe() - probe TPM 2.0
 873  * @chip: TPM chip to use
 874  *
 875  * Send idempotent TPM 2.0 command and see whether TPM 2.0 chip replied based on
 876  * the reply tag.
 877  */
 878 int tpm2_probe(struct tpm_chip *chip)
 879 {
 880         struct tpm2_cmd cmd;
 881         int rc;
 882
 883         cmd.header.in = tpm2_get_tpm_pt_header;
 884         cmd.params.get_tpm_pt_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES);
 885         cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(0x100);
 886         cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
 887
 888         rc = tpm_transmit(chip, (const char *) &cmd, sizeof(cmd));
 889         if (rc <  0)
 890                 return rc;
 891         else if (rc < TPM_HEADER_SIZE)
 892                 return -EFAULT;
 893
 894         if (be16_to_cpu(cmd.header.out.tag) == TPM2_ST_NO_SESSIONS)
 895                 chip->flags |= TPM_CHIP_FLAG_TPM2;
 896
 897         return 0;
 898 }
 899 EXPORT_SYMBOL_GPL(tpm2_probe);