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 <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_null_auth_area {
  57         __be32                  handle;
  58         __be16                  nonce_size;
  59         u8                      attributes;
  60         __be16                  auth_size;
  61 } __packed;
  62
  63 struct tpm2_pcr_extend_in {
  64         __be32                          pcr_idx;
  65         __be32                          auth_area_size;
  66         struct tpm2_null_auth_area      auth_area;
  67         __be32                          digest_cnt;
  68         __be16                          hash_alg;
  69         u8                              digest[TPM_DIGEST_SIZE];
  70 } __packed;
  71
  72 struct tpm2_get_tpm_pt_in {
  73         __be32  cap_id;
  74         __be32  property_id;
  75         __be32  property_cnt;
  76 } __packed;
  77
  78 struct tpm2_get_tpm_pt_out {
  79         u8      more_data;
  80         __be32  subcap_id;
  81         __be32  property_cnt;
  82         __be32  property_id;
  83         __be32  value;
  84 } __packed;
  85
  86 struct tpm2_get_random_in {
  87         __be16  size;
  88 } __packed;
  89
  90 struct tpm2_get_random_out {
  91         __be16  size;
  92         u8      buffer[TPM_MAX_RNG_DATA];
  93 } __packed;
  94
  95 union tpm2_cmd_params {
  96         struct  tpm2_startup_in         startup_in;
  97         struct  tpm2_self_test_in       selftest_in;
  98         struct  tpm2_pcr_read_in        pcrread_in;
  99         struct  tpm2_pcr_read_out       pcrread_out;
 100         struct  tpm2_pcr_extend_in      pcrextend_in;
 101         struct  tpm2_get_tpm_pt_in      get_tpm_pt_in;
 102         struct  tpm2_get_tpm_pt_out     get_tpm_pt_out;
 103         struct  tpm2_get_random_in      getrandom_in;
 104         struct  tpm2_get_random_out     getrandom_out;
 105 };
 106
 107 struct tpm2_cmd {
 108         tpm_cmd_header          header;
 109         union tpm2_cmd_params   params;
 110 } __packed;
 111
 112 struct tpm2_hash {
 113         unsigned int crypto_id;
 114         unsigned int tpm_id;
 115 };
 116
 117 static struct tpm2_hash tpm2_hash_map[] = {
 118         {HASH_ALGO_SHA1, TPM2_ALG_SHA1},
 119         {HASH_ALGO_SHA256, TPM2_ALG_SHA256},
 120         {HASH_ALGO_SHA384, TPM2_ALG_SHA384},
 121         {HASH_ALGO_SHA512, TPM2_ALG_SHA512},
 122         {HASH_ALGO_SM3_256, TPM2_ALG_SM3_256},
 123 };
 124
 125 /*
 126  * Array with one entry per ordinal defining the maximum amount
 127  * of time the chip could take to return the result. The values
 128  * of the SHORT, MEDIUM, and LONG durations are taken from the
 129  * PC Client Profile (PTP) specification.
 130  */
 131 static const u8 tpm2_ordinal_duration[TPM2_CC_LAST - TPM2_CC_FIRST + 1] = {
 132         TPM_UNDEFINED,          /* 11F */
 133         TPM_UNDEFINED,          /* 120 */
 134         TPM_LONG,               /* 121 */
 135         TPM_UNDEFINED,          /* 122 */
 136         TPM_UNDEFINED,          /* 123 */
 137         TPM_UNDEFINED,          /* 124 */
 138         TPM_UNDEFINED,          /* 125 */
 139         TPM_UNDEFINED,          /* 126 */
 140         TPM_UNDEFINED,          /* 127 */
 141         TPM_UNDEFINED,          /* 128 */
 142         TPM_LONG,               /* 129 */
 143         TPM_UNDEFINED,          /* 12a */
 144         TPM_UNDEFINED,          /* 12b */
 145         TPM_UNDEFINED,          /* 12c */
 146         TPM_UNDEFINED,          /* 12d */
 147         TPM_UNDEFINED,          /* 12e */
 148         TPM_UNDEFINED,          /* 12f */
 149         TPM_UNDEFINED,          /* 130 */
 150         TPM_UNDEFINED,          /* 131 */
 151         TPM_UNDEFINED,          /* 132 */
 152         TPM_UNDEFINED,          /* 133 */
 153         TPM_UNDEFINED,          /* 134 */
 154         TPM_UNDEFINED,          /* 135 */
 155         TPM_UNDEFINED,          /* 136 */
 156         TPM_UNDEFINED,          /* 137 */
 157         TPM_UNDEFINED,          /* 138 */
 158         TPM_UNDEFINED,          /* 139 */
 159         TPM_UNDEFINED,          /* 13a */
 160         TPM_UNDEFINED,          /* 13b */
 161         TPM_UNDEFINED,          /* 13c */
 162         TPM_UNDEFINED,          /* 13d */
 163         TPM_MEDIUM,             /* 13e */
 164         TPM_UNDEFINED,          /* 13f */
 165         TPM_UNDEFINED,          /* 140 */
 166         TPM_UNDEFINED,          /* 141 */
 167         TPM_UNDEFINED,          /* 142 */
 168         TPM_LONG,               /* 143 */
 169         TPM_MEDIUM,             /* 144 */
 170         TPM_UNDEFINED,          /* 145 */
 171         TPM_UNDEFINED,          /* 146 */
 172         TPM_UNDEFINED,          /* 147 */
 173         TPM_UNDEFINED,          /* 148 */
 174         TPM_UNDEFINED,          /* 149 */
 175         TPM_UNDEFINED,          /* 14a */
 176         TPM_UNDEFINED,          /* 14b */
 177         TPM_UNDEFINED,          /* 14c */
 178         TPM_UNDEFINED,          /* 14d */
 179         TPM_LONG,               /* 14e */
 180         TPM_UNDEFINED,          /* 14f */
 181         TPM_UNDEFINED,          /* 150 */
 182         TPM_UNDEFINED,          /* 151 */
 183         TPM_UNDEFINED,          /* 152 */
 184         TPM_UNDEFINED,          /* 153 */
 185         TPM_UNDEFINED,          /* 154 */
 186         TPM_UNDEFINED,          /* 155 */
 187         TPM_UNDEFINED,          /* 156 */
 188         TPM_UNDEFINED,          /* 157 */
 189         TPM_UNDEFINED,          /* 158 */
 190         TPM_UNDEFINED,          /* 159 */
 191         TPM_UNDEFINED,          /* 15a */
 192         TPM_UNDEFINED,          /* 15b */
 193         TPM_MEDIUM,             /* 15c */
 194         TPM_UNDEFINED,          /* 15d */
 195         TPM_UNDEFINED,          /* 15e */
 196         TPM_UNDEFINED,          /* 15f */
 197         TPM_UNDEFINED,          /* 160 */
 198         TPM_UNDEFINED,          /* 161 */
 199         TPM_UNDEFINED,          /* 162 */
 200         TPM_UNDEFINED,          /* 163 */
 201         TPM_UNDEFINED,          /* 164 */
 202         TPM_UNDEFINED,          /* 165 */
 203         TPM_UNDEFINED,          /* 166 */
 204         TPM_UNDEFINED,          /* 167 */
 205         TPM_UNDEFINED,          /* 168 */
 206         TPM_UNDEFINED,          /* 169 */
 207         TPM_UNDEFINED,          /* 16a */
 208         TPM_UNDEFINED,          /* 16b */
 209         TPM_UNDEFINED,          /* 16c */
 210         TPM_UNDEFINED,          /* 16d */
 211         TPM_UNDEFINED,          /* 16e */
 212         TPM_UNDEFINED,          /* 16f */
 213         TPM_UNDEFINED,          /* 170 */
 214         TPM_UNDEFINED,          /* 171 */
 215         TPM_UNDEFINED,          /* 172 */
 216         TPM_UNDEFINED,          /* 173 */
 217         TPM_UNDEFINED,          /* 174 */
 218         TPM_UNDEFINED,          /* 175 */
 219         TPM_UNDEFINED,          /* 176 */
 220         TPM_LONG,               /* 177 */
 221         TPM_UNDEFINED,          /* 178 */
 222         TPM_UNDEFINED,          /* 179 */
 223         TPM_MEDIUM,             /* 17a */
 224         TPM_LONG,               /* 17b */
 225         TPM_UNDEFINED,          /* 17c */
 226         TPM_UNDEFINED,          /* 17d */
 227         TPM_UNDEFINED,          /* 17e */
 228         TPM_UNDEFINED,          /* 17f */
 229         TPM_UNDEFINED,          /* 180 */
 230         TPM_UNDEFINED,          /* 181 */
 231         TPM_MEDIUM,             /* 182 */
 232         TPM_UNDEFINED,          /* 183 */
 233         TPM_UNDEFINED,          /* 184 */
 234         TPM_MEDIUM,             /* 185 */
 235         TPM_MEDIUM,             /* 186 */
 236         TPM_UNDEFINED,          /* 187 */
 237         TPM_UNDEFINED,          /* 188 */
 238         TPM_UNDEFINED,          /* 189 */
 239         TPM_UNDEFINED,          /* 18a */
 240         TPM_UNDEFINED,          /* 18b */
 241         TPM_UNDEFINED,          /* 18c */
 242         TPM_UNDEFINED,          /* 18d */
 243         TPM_UNDEFINED,          /* 18e */
 244         TPM_UNDEFINED           /* 18f */
 245 };
 246
 247 #define TPM2_PCR_READ_IN_SIZE \
 248         (sizeof(struct tpm_input_header) + \
 249          sizeof(struct tpm2_pcr_read_in))
 250
 251 static const struct tpm_input_header tpm2_pcrread_header = {
 252         .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
 253         .length = cpu_to_be32(TPM2_PCR_READ_IN_SIZE),
 254         .ordinal = cpu_to_be32(TPM2_CC_PCR_READ)
 255 };
 256
 257 /**
 258  * tpm2_pcr_read() - read a PCR value
 259  * @chip:       TPM chip to use.
 260  * @pcr_idx:    index of the PCR to read.
 261  * @ref_buf:    buffer to store the resulting hash,
 262  *
 263  * 0 is returned when the operation is successful. If a negative number is
 264  * returned it remarks a POSIX error code. If a positive number is returned
 265  * it remarks a TPM error.
 266  */
 267 int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 268 {
 269         int rc;
 270         struct tpm2_cmd cmd;
 271         u8 *buf;
 272
 273         if (pcr_idx >= TPM2_PLATFORM_PCR)
 274                 return -EINVAL;
 275
 276         cmd.header.in = tpm2_pcrread_header;
 277         cmd.params.pcrread_in.pcr_selects_cnt = cpu_to_be32(1);
 278         cmd.params.pcrread_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1);
 279         cmd.params.pcrread_in.pcr_select_size = TPM2_PCR_SELECT_MIN;
 280
 281         memset(cmd.params.pcrread_in.pcr_select, 0,
 282                sizeof(cmd.params.pcrread_in.pcr_select));
 283         cmd.params.pcrread_in.pcr_select[pcr_idx >> 3] = 1 << (pcr_idx & 0x7);
 284
 285         rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
 286                               "attempting to read a pcr value");
 287         if (rc == 0) {
 288                 buf = cmd.params.pcrread_out.digest;
 289                 memcpy(res_buf, buf, TPM_DIGEST_SIZE);
 290         }
 291
 292         return rc;
 293 }
 294
 295 #define TPM2_GET_PCREXTEND_IN_SIZE \
 296         (sizeof(struct tpm_input_header) + \
 297          sizeof(struct tpm2_pcr_extend_in))
 298
 299 static const struct tpm_input_header tpm2_pcrextend_header = {
 300         .tag = cpu_to_be16(TPM2_ST_SESSIONS),
 301         .length = cpu_to_be32(TPM2_GET_PCREXTEND_IN_SIZE),
 302         .ordinal = cpu_to_be32(TPM2_CC_PCR_EXTEND)
 303 };
 304
 305 /**
 306  * tpm2_pcr_extend() - extend a PCR value
 307  * @chip:       TPM chip to use.
 308  * @pcr_idx:    index of the PCR.
 309  * @hash:       hash value to use for the extend operation.
 310  *
 311  * 0 is returned when the operation is successful. If a negative number is
 312  * returned it remarks a POSIX error code. If a positive number is returned
 313  * it remarks a TPM error.
 314  */
 315 int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash)
 316 {
 317         struct tpm2_cmd cmd;
 318         int rc;
 319
 320         cmd.header.in = tpm2_pcrextend_header;
 321         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 322         cmd.params.pcrextend_in.auth_area_size =
 323                 cpu_to_be32(sizeof(struct tpm2_null_auth_area));
 324         cmd.params.pcrextend_in.auth_area.handle =
 325                 cpu_to_be32(TPM2_RS_PW);
 326         cmd.params.pcrextend_in.auth_area.nonce_size = 0;
 327         cmd.params.pcrextend_in.auth_area.attributes = 0;
 328         cmd.params.pcrextend_in.auth_area.auth_size = 0;
 329         cmd.params.pcrextend_in.digest_cnt = cpu_to_be32(1);
 330         cmd.params.pcrextend_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1);
 331         memcpy(cmd.params.pcrextend_in.digest, hash, TPM_DIGEST_SIZE);
 332
 333         rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
 334                               "attempting extend a PCR value");
 335
 336         return rc;
 337 }
 338
 339 #define TPM2_GETRANDOM_IN_SIZE \
 340         (sizeof(struct tpm_input_header) + \
 341          sizeof(struct tpm2_get_random_in))
 342
 343 static const struct tpm_input_header tpm2_getrandom_header = {
 344         .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
 345         .length = cpu_to_be32(TPM2_GETRANDOM_IN_SIZE),
 346         .ordinal = cpu_to_be32(TPM2_CC_GET_RANDOM)
 347 };
 348
 349 /**
 350  * tpm2_get_random() - get random bytes from the TPM RNG
 351  * @chip: TPM chip to use
 352  * @out: destination buffer for the random bytes
 353  * @max: the max number of bytes to write to @out
 354  *
 355  * 0 is returned when the operation is successful. If a negative number is
 356  * returned it remarks a POSIX error code. If a positive number is returned
 357  * it remarks a TPM error.
 358  */
 359 int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max)
 360 {
 361         struct tpm2_cmd cmd;
 362         u32 recd;
 363         u32 num_bytes;
 364         int err;
 365         int total = 0;
 366         int retries = 5;
 367         u8 *dest = out;
 368
 369         num_bytes = min_t(u32, max, sizeof(cmd.params.getrandom_out.buffer));
 370
 371         if (!out || !num_bytes ||
 372             max > sizeof(cmd.params.getrandom_out.buffer))
 373                 return -EINVAL;
 374
 375         do {
 376                 cmd.header.in = tpm2_getrandom_header;
 377                 cmd.params.getrandom_in.size = cpu_to_be16(num_bytes);
 378
 379                 err = tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
 380                                        "attempting get random");
 381                 if (err)
 382                         break;
 383
 384                 recd = min_t(u32, be16_to_cpu(cmd.params.getrandom_out.size),
 385                              num_bytes);
 386                 memcpy(dest, cmd.params.getrandom_out.buffer, recd);
 387
 388                 dest += recd;
 389                 total += recd;
 390                 num_bytes -= recd;
 391         } while (retries-- && total < max);
 392
 393         return total ? total : -EIO;
 394 }
 395
 396 #define TPM2_GET_TPM_PT_IN_SIZE \
 397         (sizeof(struct tpm_input_header) + \
 398          sizeof(struct tpm2_get_tpm_pt_in))
 399
 400 static const struct tpm_input_header tpm2_get_tpm_pt_header = {
 401         .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
 402         .length = cpu_to_be32(TPM2_GET_TPM_PT_IN_SIZE),
 403         .ordinal = cpu_to_be32(TPM2_CC_GET_CAPABILITY)
 404 };
 405
 406 /**
 407  * Append TPMS_AUTH_COMMAND to the buffer. The buffer must be allocated with
 408  * tpm_buf_alloc().
 409  *
 410  * @param buf: an allocated tpm_buf instance
 411  * @param nonce: the session nonce, may be NULL if not used
 412  * @param nonce_len: the session nonce length, may be 0 if not used
 413  * @param attributes: the session attributes
 414  * @param hmac: the session HMAC or password, may be NULL if not used
 415  * @param hmac_len: the session HMAC or password length, maybe 0 if not used
 416  */
 417 static void tpm2_buf_append_auth(struct tpm_buf *buf, u32 session_handle,
 418                                  const u8 *nonce, u16 nonce_len,
 419                                  u8 attributes,
 420                                  const u8 *hmac, u16 hmac_len)
 421 {
 422         tpm_buf_append_u32(buf, 9 + nonce_len + hmac_len);
 423         tpm_buf_append_u32(buf, session_handle);
 424         tpm_buf_append_u16(buf, nonce_len);
 425
 426         if (nonce && nonce_len)
 427                 tpm_buf_append(buf, nonce, nonce_len);
 428
 429         tpm_buf_append_u8(buf, attributes);
 430         tpm_buf_append_u16(buf, hmac_len);
 431
 432         if (hmac && hmac_len)
 433                 tpm_buf_append(buf, hmac, hmac_len);
 434 }
 435
 436 /**
 437  * tpm2_seal_trusted() - seal a trusted key
 438  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
 439  * @options: authentication values and other options
 440  * @payload: the key data in clear and encrypted form
 441  *
 442  * Returns < 0 on error and 0 on success.
 443  */
 444 int tpm2_seal_trusted(struct tpm_chip *chip,
 445                       struct trusted_key_payload *payload,
 446                       struct trusted_key_options *options)
 447 {
 448         unsigned int blob_len;
 449         struct tpm_buf buf;
 450         u32 hash;
 451         int i;
 452         int rc;
 453
 454         for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
 455                 if (options->hash == tpm2_hash_map[i].crypto_id) {
 456                         hash = tpm2_hash_map[i].tpm_id;
 457                         break;
 458                 }
 459         }
 460
 461         if (i == ARRAY_SIZE(tpm2_hash_map))
 462                 return -EINVAL;
 463
 464         rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE);
 465         if (rc)
 466                 return rc;
 467
 468         tpm_buf_append_u32(&buf, options->keyhandle);
 469         tpm2_buf_append_auth(&buf, TPM2_RS_PW,
 470                              NULL /* nonce */, 0,
 471                              0 /* session_attributes */,
 472                              options->keyauth /* hmac */,
 473                              TPM_DIGEST_SIZE);
 474
 475         /* sensitive */
 476         tpm_buf_append_u16(&buf, 4 + TPM_DIGEST_SIZE + payload->key_len + 1);
 477
 478         tpm_buf_append_u16(&buf, TPM_DIGEST_SIZE);
 479         tpm_buf_append(&buf, options->blobauth, TPM_DIGEST_SIZE);
 480         tpm_buf_append_u16(&buf, payload->key_len + 1);
 481         tpm_buf_append(&buf, payload->key, payload->key_len);
 482         tpm_buf_append_u8(&buf, payload->migratable);
 483
 484         /* public */
 485         tpm_buf_append_u16(&buf, 14 + options->policydigest_len);
 486         tpm_buf_append_u16(&buf, TPM2_ALG_KEYEDHASH);
 487         tpm_buf_append_u16(&buf, hash);
 488
 489         /* policy */
 490         if (options->policydigest_len) {
 491                 tpm_buf_append_u32(&buf, 0);
 492                 tpm_buf_append_u16(&buf, options->policydigest_len);
 493                 tpm_buf_append(&buf, options->policydigest,
 494                                options->policydigest_len);
 495         } else {
 496                 tpm_buf_append_u32(&buf, TPM2_OA_USER_WITH_AUTH);
 497                 tpm_buf_append_u16(&buf, 0);
 498         }
 499
 500         /* public parameters */
 501         tpm_buf_append_u16(&buf, TPM2_ALG_NULL);
 502         tpm_buf_append_u16(&buf, 0);
 503
 504         /* outside info */
 505         tpm_buf_append_u16(&buf, 0);
 506
 507         /* creation PCR */
 508         tpm_buf_append_u32(&buf, 0);
 509
 510         if (buf.flags & TPM_BUF_OVERFLOW) {
 511                 rc = -E2BIG;
 512                 goto out;
 513         }
 514
 515         rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "sealing data");
 516         if (rc)
 517                 goto out;
 518
 519         blob_len = be32_to_cpup((__be32 *) &buf.data[TPM_HEADER_SIZE]);
 520         if (blob_len > MAX_BLOB_SIZE) {
 521                 rc = -E2BIG;
 522                 goto out;
 523         }
 524
 525         memcpy(payload->blob, &buf.data[TPM_HEADER_SIZE + 4], blob_len);
 526         payload->blob_len = blob_len;
 527
 528 out:
 529         tpm_buf_destroy(&buf);
 530
 531         if (rc > 0) {
 532                 if ((rc & TPM2_RC_HASH) == TPM2_RC_HASH)
 533                         rc = -EINVAL;
 534                 else
 535                         rc = -EPERM;
 536         }
 537
 538         return rc;
 539 }
 540
 541 static int tpm2_load(struct tpm_chip *chip,
 542                      struct trusted_key_payload *payload,
 543                      struct trusted_key_options *options,
 544                      u32 *blob_handle)
 545 {
 546         struct tpm_buf buf;
 547         unsigned int private_len;
 548         unsigned int public_len;
 549         unsigned int blob_len;
 550         int rc;
 551
 552         private_len = be16_to_cpup((__be16 *) &payload->blob[0]);
 553         if (private_len > (payload->blob_len - 2))
 554                 return -E2BIG;
 555
 556         public_len = be16_to_cpup((__be16 *) &payload->blob[2 + private_len]);
 557         blob_len = private_len + public_len + 4;
 558         if (blob_len > payload->blob_len)
 559                 return -E2BIG;
 560
 561         rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD);
 562         if (rc)
 563                 return rc;
 564
 565         tpm_buf_append_u32(&buf, options->keyhandle);
 566         tpm2_buf_append_auth(&buf, TPM2_RS_PW,
 567                              NULL /* nonce */, 0,
 568                              0 /* session_attributes */,
 569                              options->keyauth /* hmac */,
 570                              TPM_DIGEST_SIZE);
 571
 572         tpm_buf_append(&buf, payload->blob, blob_len);
 573
 574         if (buf.flags & TPM_BUF_OVERFLOW) {
 575                 rc = -E2BIG;
 576                 goto out;
 577         }
 578
 579         rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "loading blob");
 580         if (!rc)
 581                 *blob_handle = be32_to_cpup(
 582                         (__be32 *) &buf.data[TPM_HEADER_SIZE]);
 583
 584 out:
 585         tpm_buf_destroy(&buf);
 586
 587         if (rc > 0)
 588                 rc = -EPERM;
 589
 590         return rc;
 591 }
 592
 593 static void tpm2_flush_context(struct tpm_chip *chip, u32 handle)
 594 {
 595         struct tpm_buf buf;
 596         int rc;
 597
 598         rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_FLUSH_CONTEXT);
 599         if (rc) {
 600                 dev_warn(&chip->dev, "0x%08x was not flushed, out of memory\n",
 601                          handle);
 602                 return;
 603         }
 604
 605         tpm_buf_append_u32(&buf, handle);
 606
 607         rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "flushing context");
 608         if (rc)
 609                 dev_warn(&chip->dev, "0x%08x was not flushed, rc=%d\n", handle,
 610                          rc);
 611
 612         tpm_buf_destroy(&buf);
 613 }
 614
 615 static int tpm2_unseal(struct tpm_chip *chip,
 616                        struct trusted_key_payload *payload,
 617                        struct trusted_key_options *options,
 618                        u32 blob_handle)
 619 {
 620         struct tpm_buf buf;
 621         u16 data_len;
 622         u8 *data;
 623         int rc;
 624
 625         rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL);
 626         if (rc)
 627                 return rc;
 628
 629         tpm_buf_append_u32(&buf, blob_handle);
 630         tpm2_buf_append_auth(&buf,
 631                              options->policyhandle ?
 632                              options->policyhandle : TPM2_RS_PW,
 633                              NULL /* nonce */, 0,
 634                              TPM2_SA_CONTINUE_SESSION,
 635                              options->blobauth /* hmac */,
 636                              TPM_DIGEST_SIZE);
 637
 638         rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, "unsealing");
 639         if (rc > 0)
 640                 rc = -EPERM;
 641
 642         if (!rc) {
 643                 data_len = be16_to_cpup(
 644                         (__be16 *) &buf.data[TPM_HEADER_SIZE + 4]);
 645                 data = &buf.data[TPM_HEADER_SIZE + 6];
 646
 647                 memcpy(payload->key, data, data_len - 1);
 648                 payload->key_len = data_len - 1;
 649                 payload->migratable = data[data_len - 1];
 650         }
 651
 652         tpm_buf_destroy(&buf);
 653         return rc;
 654 }
 655
 656 /**
 657  * tpm_unseal_trusted() - unseal a trusted key
 658  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
 659  * @options: authentication values and other options
 660  * @payload: the key data in clear and encrypted form
 661  *
 662  * Returns < 0 on error and 0 on success.
 663  */
 664 int tpm2_unseal_trusted(struct tpm_chip *chip,
 665                         struct trusted_key_payload *payload,
 666                         struct trusted_key_options *options)
 667 {
 668         u32 blob_handle;
 669         int rc;
 670
 671         rc = tpm2_load(chip, payload, options, &blob_handle);
 672         if (rc)
 673                 return rc;
 674
 675         rc = tpm2_unseal(chip, payload, options, blob_handle);
 676
 677         tpm2_flush_context(chip, blob_handle);
 678
 679         return rc;
 680 }
 681
 682 /**
 683  * tpm2_get_tpm_pt() - get value of a TPM_CAP_TPM_PROPERTIES type property
 684  * @chip:               TPM chip to use.
 685  * @property_id:        property ID.
 686  * @value:              output variable.
 687  * @desc:               passed to tpm_transmit_cmd()
 688  *
 689  * 0 is returned when the operation is successful. If a negative number is
 690  * returned it remarks a POSIX error code. If a positive number is returned
 691  * it remarks a TPM error.
 692  */
 693 ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id,  u32 *value,
 694                         const char *desc)
 695 {
 696         struct tpm2_cmd cmd;
 697         int rc;
 698
 699         cmd.header.in = tpm2_get_tpm_pt_header;
 700         cmd.params.get_tpm_pt_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES);
 701         cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(property_id);
 702         cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
 703
 704         rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), desc);
 705         if (!rc)
 706                 *value = be32_to_cpu(cmd.params.get_tpm_pt_out.value);
 707
 708         return rc;
 709 }
 710
 711 #define TPM2_STARTUP_IN_SIZE \
 712         (sizeof(struct tpm_input_header) + \
 713          sizeof(struct tpm2_startup_in))
 714
 715 static const struct tpm_input_header tpm2_startup_header = {
 716         .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
 717         .length = cpu_to_be32(TPM2_STARTUP_IN_SIZE),
 718         .ordinal = cpu_to_be32(TPM2_CC_STARTUP)
 719 };
 720
 721 /**
 722  * tpm2_startup() - send startup command to the TPM chip
 723  * @chip:               TPM chip to use.
 724  * @startup_type        startup type. The value is either
 725  *                      TPM_SU_CLEAR or TPM_SU_STATE.
 726  *
 727  * 0 is returned when the operation is successful. If a negative number is
 728  * returned it remarks a POSIX error code. If a positive number is returned
 729  * it remarks a TPM error.
 730  */
 731 static int tpm2_startup(struct tpm_chip *chip, u16 startup_type)
 732 {
 733         struct tpm2_cmd cmd;
 734
 735         cmd.header.in = tpm2_startup_header;
 736
 737         cmd.params.startup_in.startup_type = cpu_to_be16(startup_type);
 738         return tpm_transmit_cmd(chip, &cmd, sizeof(cmd),
 739                                 "attempting to start the TPM");
 740 }
 741
 742 #define TPM2_SHUTDOWN_IN_SIZE \
 743         (sizeof(struct tpm_input_header) + \
 744          sizeof(struct tpm2_startup_in))
 745
 746 static const struct tpm_input_header tpm2_shutdown_header = {
 747         .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
 748         .length = cpu_to_be32(TPM2_SHUTDOWN_IN_SIZE),
 749         .ordinal = cpu_to_be32(TPM2_CC_SHUTDOWN)
 750 };
 751
 752 /**
 753  * tpm2_shutdown() - send shutdown command to the TPM chip
 754  * @chip:               TPM chip to use.
 755  * @shutdown_type       shutdown type. The value is either
 756  *                      TPM_SU_CLEAR or TPM_SU_STATE.
 757  */
 758 void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
 759 {
 760         struct tpm2_cmd cmd;
 761         int rc;
 762
 763         cmd.header.in = tpm2_shutdown_header;
 764         cmd.params.startup_in.startup_type = cpu_to_be16(shutdown_type);
 765
 766         rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), "stopping the TPM");
 767
 768         /* In places where shutdown command is sent there's no much we can do
 769          * except print the error code on a system failure.
 770          */
 771         if (rc < 0)
 772                 dev_warn(&chip->dev, "transmit returned %d while stopping the TPM",
 773                          rc);
 774 }
 775
 776 /*
 777  * tpm2_calc_ordinal_duration() - maximum duration for a command
 778  * @chip:       TPM chip to use.
 779  * @ordinal:    command code number.
 780  *
 781  * 0 is returned when the operation is successful. If a negative number is
 782  * returned it remarks a POSIX error code. If a positive number is returned
 783  * it remarks a TPM error.
 784  */
 785 unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
 786 {
 787         int index = TPM_UNDEFINED;
 788         int duration = 0;
 789
 790         if (ordinal >= TPM2_CC_FIRST && ordinal <= TPM2_CC_LAST)
 791                 index = tpm2_ordinal_duration[ordinal - TPM2_CC_FIRST];
 792
 793         if (index != TPM_UNDEFINED)
 794                 duration = chip->duration[index];
 795
 796         if (duration <= 0)
 797                 duration = 2 * 60 * HZ;
 798
 799         return duration;
 800 }
 801 EXPORT_SYMBOL_GPL(tpm2_calc_ordinal_duration);
 802
 803 #define TPM2_SELF_TEST_IN_SIZE \
 804         (sizeof(struct tpm_input_header) + \
 805          sizeof(struct tpm2_self_test_in))
 806
 807 static const struct tpm_input_header tpm2_selftest_header = {
 808         .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
 809         .length = cpu_to_be32(TPM2_SELF_TEST_IN_SIZE),
 810         .ordinal = cpu_to_be32(TPM2_CC_SELF_TEST)
 811 };
 812
 813 /**
 814  * tpm2_continue_selftest() - start a self test
 815  * @chip: TPM chip to use
 816  * @full: test all commands instead of testing only those that were not
 817  *        previously tested.
 818  *
 819  * 0 is returned when the operation is successful. If a negative number is
 820  * returned it remarks a POSIX error code. If a positive number is returned
 821  * it remarks a TPM error.
 822  */
 823 static int tpm2_start_selftest(struct tpm_chip *chip, bool full)
 824 {
 825         int rc;
 826         struct tpm2_cmd cmd;
 827
 828         cmd.header.in = tpm2_selftest_header;
 829         cmd.params.selftest_in.full_test = full;
 830
 831         rc = tpm_transmit_cmd(chip, &cmd, TPM2_SELF_TEST_IN_SIZE,
 832                               "continue selftest");
 833
 834         /* At least some prototype chips seem to give RC_TESTING error
 835          * immediately. This is a workaround for that.
 836          */
 837         if (rc == TPM2_RC_TESTING) {
 838                 dev_warn(&chip->dev, "Got RC_TESTING, ignoring\n");
 839                 rc = 0;
 840         }
 841
 842         return rc;
 843 }
 844
 845 /**
 846  * tpm2_do_selftest() - run a full self test
 847  * @chip: TPM chip to use
 848  *
 849  * During the self test TPM2 commands return with the error code RC_TESTING.
 850  * Waiting is done by issuing PCR read until it executes successfully.
 851  *
 852  * 0 is returned when the operation is successful. If a negative number is
 853  * returned it remarks a POSIX error code. If a positive number is returned
 854  * it remarks a TPM error.
 855  */
 856 static int tpm2_do_selftest(struct tpm_chip *chip)
 857 {
 858         int rc;
 859         unsigned int loops;
 860         unsigned int delay_msec = 100;
 861         unsigned long duration;
 862         struct tpm2_cmd cmd;
 863         int i;
 864
 865         duration = tpm2_calc_ordinal_duration(chip, TPM2_CC_SELF_TEST);
 866
 867         loops = jiffies_to_msecs(duration) / delay_msec;
 868
 869         rc = tpm2_start_selftest(chip, true);
 870         if (rc)
 871                 return rc;
 872
 873         for (i = 0; i < loops; i++) {
 874                 /* Attempt to read a PCR value */
 875                 cmd.header.in = tpm2_pcrread_header;
 876                 cmd.params.pcrread_in.pcr_selects_cnt = cpu_to_be32(1);
 877                 cmd.params.pcrread_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1);
 878                 cmd.params.pcrread_in.pcr_select_size = TPM2_PCR_SELECT_MIN;
 879                 cmd.params.pcrread_in.pcr_select[0] = 0x01;
 880                 cmd.params.pcrread_in.pcr_select[1] = 0x00;
 881                 cmd.params.pcrread_in.pcr_select[2] = 0x00;
 882
 883                 rc = tpm_transmit_cmd(chip, (u8 *) &cmd, sizeof(cmd), NULL);
 884                 if (rc < 0)
 885                         break;
 886
 887                 rc = be32_to_cpu(cmd.header.out.return_code);
 888                 if (rc != TPM2_RC_TESTING)
 889                         break;
 890
 891                 msleep(delay_msec);
 892         }
 893
 894         return rc;
 895 }
 896
 897 /**
 898  * tpm2_gen_interrupt() - generate an interrupt
 899  * @chip: TPM chip to use
 900  *
 901  * 0 is returned when the operation is successful. If a negative number is
 902  * returned it remarks a POSIX error code. If a positive number is returned
 903  * it remarks a TPM error.
 904  */
 905 int tpm2_gen_interrupt(struct tpm_chip *chip)
 906 {
 907         u32 dummy;
 908
 909         return tpm2_get_tpm_pt(chip, 0x100, &dummy,
 910                                "attempting to generate an interrupt");
 911 }
 912 EXPORT_SYMBOL_GPL(tpm2_gen_interrupt);
 913
 914 /**
 915  * tpm2_probe() - probe TPM 2.0
 916  * @chip: TPM chip to use
 917  *
 918  * Send idempotent TPM 2.0 command and see whether TPM 2.0 chip replied based on
 919  * the reply tag.
 920  */
 921 int tpm2_probe(struct tpm_chip *chip)
 922 {
 923         struct tpm2_cmd cmd;
 924         int rc;
 925
 926         cmd.header.in = tpm2_get_tpm_pt_header;
 927         cmd.params.get_tpm_pt_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES);
 928         cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(0x100);
 929         cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
 930
 931         rc = tpm_transmit(chip, (const char *) &cmd, sizeof(cmd));
 932         if (rc <  0)
 933                 return rc;
 934         else if (rc < TPM_HEADER_SIZE)
 935                 return -EFAULT;
 936
 937         if (be16_to_cpu(cmd.header.out.tag) == TPM2_ST_NO_SESSIONS)
 938                 chip->flags |= TPM_CHIP_FLAG_TPM2;
 939
 940         return 0;
 941 }
 942 EXPORT_SYMBOL_GPL(tpm2_probe);
 943
 944 /**
 945  * tpm2_auto_startup - Perform the standard automatic TPM initialization
 946  *                     sequence
 947  * @chip: TPM chip to use
 948  *
 949  * Returns 0 on success, < 0 in case of fatal error.
 950  */
 951 int tpm2_auto_startup(struct tpm_chip *chip)
 952 {
 953         int rc;
 954
 955         rc = tpm_get_timeouts(chip);
 956         if (rc)
 957                 goto out;
 958
 959         rc = tpm2_do_selftest(chip);
 960         if (rc != TPM2_RC_INITIALIZE) {
 961                 dev_err(&chip->dev, "TPM self test failed\n");
 962                 goto out;
 963         }
 964
 965         if (rc == TPM2_RC_INITIALIZE) {
 966                 rc = tpm2_startup(chip, TPM2_SU_CLEAR);
 967                 if (rc)
 968                         goto out;
 969
 970                 rc = tpm2_do_selftest(chip);
 971                 if (rc) {
 972                         dev_err(&chip->dev, "TPM self test failed\n");
 973                         goto out;
 974                 }
 975         }
 976
 977         return rc;
 978 out:
 979         if (rc > 0)
 980                 rc = -ENODEV;
 981         return rc;
 982 }