drivers/char/tpm/tpm-sysfs.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2004 IBM Corporation
   4  * Authors:
   5  * Leendert van Doorn <leendert@watson.ibm.com>
   6  * Dave Safford <safford@watson.ibm.com>
   7  * Reiner Sailer <sailer@watson.ibm.com>
   8  * Kylene Hall <kjhall@us.ibm.com>
   9  *
  10  * Copyright (C) 2013 Obsidian Research Corp
  11  * Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
  12  *
  13  * sysfs filesystem inspection interface to the TPM
  14  */
  15 #include <linux/device.h>
  16 #include "tpm.h"
  17
  18 struct tpm_readpubek_out {
  19         u8 algorithm[4];
  20         u8 encscheme[2];
  21         u8 sigscheme[2];
  22         __be32 paramsize;
  23         u8 parameters[12];
  24         __be32 keysize;
  25         u8 modulus[256];
  26         u8 checksum[20];
  27 } __packed;
  28
  29 #define READ_PUBEK_RESULT_MIN_BODY_SIZE (28 + 256)
  30 #define TPM_ORD_READPUBEK 124
  31
  32 static ssize_t pubek_show(struct device *dev, struct device_attribute *attr,
  33                           char *buf)
  34 {
  35         struct tpm_buf tpm_buf;
  36         struct tpm_readpubek_out *out;
  37         int i;
  38         char *str = buf;
  39         struct tpm_chip *chip = to_tpm_chip(dev);
  40         char anti_replay[20];
  41
  42         memset(&anti_replay, 0, sizeof(anti_replay));
  43
  44         if (tpm_try_get_ops(chip))
  45                 return 0;
  46
  47         if (tpm_buf_init(&tpm_buf, TPM_TAG_RQU_COMMAND, TPM_ORD_READPUBEK))
  48                 goto out_ops;
  49
  50         tpm_buf_append(&tpm_buf, anti_replay, sizeof(anti_replay));
  51
  52         if (tpm_transmit_cmd(chip, &tpm_buf, READ_PUBEK_RESULT_MIN_BODY_SIZE,
  53                              "attempting to read the PUBEK"))
  54                 goto out_buf;
  55
  56         out = (struct tpm_readpubek_out *)&tpm_buf.data[10];
  57         str +=
  58             sprintf(str,
  59                     "Algorithm: %4ph\n"
  60                     "Encscheme: %2ph\n"
  61                     "Sigscheme: %2ph\n"
  62                     "Parameters: %12ph\n"
  63                     "Modulus length: %d\n"
  64                     "Modulus:\n",
  65                     out->algorithm,
  66                     out->encscheme,
  67                     out->sigscheme,
  68                     out->parameters,
  69                     be32_to_cpu(out->keysize));
  70
  71         for (i = 0; i < 256; i += 16)
  72                 str += sprintf(str, "%16ph\n", &out->modulus[i]);
  73
  74 out_buf:
  75         tpm_buf_destroy(&tpm_buf);
  76 out_ops:
  77         tpm_put_ops(chip);
  78         return str - buf;
  79 }
  80 static DEVICE_ATTR_RO(pubek);
  81
  82 static ssize_t pcrs_show(struct device *dev, struct device_attribute *attr,
  83                          char *buf)
  84 {
  85         cap_t cap;
  86         u8 digest[TPM_DIGEST_SIZE];
  87         u32 i, j, num_pcrs;
  88         char *str = buf;
  89         struct tpm_chip *chip = to_tpm_chip(dev);
  90
  91         if (tpm_try_get_ops(chip))
  92                 return 0;
  93
  94         if (tpm1_getcap(chip, TPM_CAP_PROP_PCR, &cap,
  95                         "attempting to determine the number of PCRS",
  96                         sizeof(cap.num_pcrs))) {
  97                 tpm_put_ops(chip);
  98                 return 0;
  99         }
 100
 101         num_pcrs = be32_to_cpu(cap.num_pcrs);
 102         for (i = 0; i < num_pcrs; i++) {
 103                 if (tpm1_pcr_read(chip, i, digest)) {
 104                         str = buf;
 105                         break;
 106                 }
 107                 str += sprintf(str, "PCR-%02d: ", i);
 108                 for (j = 0; j < TPM_DIGEST_SIZE; j++)
 109                         str += sprintf(str, "%02X ", digest[j]);
 110                 str += sprintf(str, "\n");
 111         }
 112         tpm_put_ops(chip);
 113         return str - buf;
 114 }
 115 static DEVICE_ATTR_RO(pcrs);
 116
 117 static ssize_t enabled_show(struct device *dev, struct device_attribute *attr,
 118                      char *buf)
 119 {
 120         struct tpm_chip *chip = to_tpm_chip(dev);
 121         ssize_t rc = 0;
 122         cap_t cap;
 123
 124         if (tpm_try_get_ops(chip))
 125                 return 0;
 126
 127         if (tpm1_getcap(chip, TPM_CAP_FLAG_PERM, &cap,
 128                         "attempting to determine the permanent enabled state",
 129                         sizeof(cap.perm_flags)))
 130                 goto out_ops;
 131
 132         rc = sprintf(buf, "%d\n", !cap.perm_flags.disable);
 133 out_ops:
 134         tpm_put_ops(chip);
 135         return rc;
 136 }
 137 static DEVICE_ATTR_RO(enabled);
 138
 139 static ssize_t active_show(struct device *dev, struct device_attribute *attr,
 140                     char *buf)
 141 {
 142         struct tpm_chip *chip = to_tpm_chip(dev);
 143         ssize_t rc = 0;
 144         cap_t cap;
 145
 146         if (tpm_try_get_ops(chip))
 147                 return 0;
 148
 149         if (tpm1_getcap(chip, TPM_CAP_FLAG_PERM, &cap,
 150                         "attempting to determine the permanent active state",
 151                         sizeof(cap.perm_flags)))
 152                 goto out_ops;
 153
 154         rc = sprintf(buf, "%d\n", !cap.perm_flags.deactivated);
 155 out_ops:
 156         tpm_put_ops(chip);
 157         return rc;
 158 }
 159 static DEVICE_ATTR_RO(active);
 160
 161 static ssize_t owned_show(struct device *dev, struct device_attribute *attr,
 162                           char *buf)
 163 {
 164         struct tpm_chip *chip = to_tpm_chip(dev);
 165         ssize_t rc = 0;
 166         cap_t cap;
 167
 168         if (tpm_try_get_ops(chip))
 169                 return 0;
 170
 171         if (tpm1_getcap(to_tpm_chip(dev), TPM_CAP_PROP_OWNER, &cap,
 172                         "attempting to determine the owner state",
 173                         sizeof(cap.owned)))
 174                 goto out_ops;
 175
 176         rc = sprintf(buf, "%d\n", cap.owned);
 177 out_ops:
 178         tpm_put_ops(chip);
 179         return rc;
 180 }
 181 static DEVICE_ATTR_RO(owned);
 182
 183 static ssize_t temp_deactivated_show(struct device *dev,
 184                                      struct device_attribute *attr, char *buf)
 185 {
 186         struct tpm_chip *chip = to_tpm_chip(dev);
 187         ssize_t rc = 0;
 188         cap_t cap;
 189
 190         if (tpm_try_get_ops(chip))
 191                 return 0;
 192
 193         if (tpm1_getcap(to_tpm_chip(dev), TPM_CAP_FLAG_VOL, &cap,
 194                         "attempting to determine the temporary state",
 195                         sizeof(cap.stclear_flags)))
 196                 goto out_ops;
 197
 198         rc = sprintf(buf, "%d\n", cap.stclear_flags.deactivated);
 199 out_ops:
 200         tpm_put_ops(chip);
 201         return rc;
 202 }
 203 static DEVICE_ATTR_RO(temp_deactivated);
 204
 205 static ssize_t caps_show(struct device *dev, struct device_attribute *attr,
 206                          char *buf)
 207 {
 208         struct tpm_chip *chip = to_tpm_chip(dev);
 209         struct tpm1_version *version;
 210         ssize_t rc = 0;
 211         char *str = buf;
 212         cap_t cap;
 213
 214         if (tpm_try_get_ops(chip))
 215                 return 0;
 216
 217         if (tpm1_getcap(chip, TPM_CAP_PROP_MANUFACTURER, &cap,
 218                         "attempting to determine the manufacturer",
 219                         sizeof(cap.manufacturer_id)))
 220                 goto out_ops;
 221
 222         str += sprintf(str, "Manufacturer: 0x%x\n",
 223                        be32_to_cpu(cap.manufacturer_id));
 224
 225         /* TPM 1.2 */
 226         if (!tpm1_getcap(chip, TPM_CAP_VERSION_1_2, &cap,
 227                          "attempting to determine the 1.2 version",
 228                          sizeof(cap.version2))) {
 229                 version = &cap.version2.version;
 230                 goto out_print;
 231         }
 232
 233         /* TPM 1.1 */
 234         if (tpm1_getcap(chip, TPM_CAP_VERSION_1_1, &cap,
 235                         "attempting to determine the 1.1 version",
 236                         sizeof(cap.version1))) {
 237                 goto out_ops;
 238         }
 239
 240         version = &cap.version1;
 241
 242 out_print:
 243         str += sprintf(str,
 244                        "TCG version: %d.%d\nFirmware version: %d.%d\n",
 245                        version->major, version->minor,
 246                        version->rev_major, version->rev_minor);
 247
 248         rc = str - buf;
 249
 250 out_ops:
 251         tpm_put_ops(chip);
 252         return rc;
 253 }
 254 static DEVICE_ATTR_RO(caps);
 255
 256 static ssize_t cancel_store(struct device *dev, struct device_attribute *attr,
 257                             const char *buf, size_t count)
 258 {
 259         struct tpm_chip *chip = to_tpm_chip(dev);
 260
 261         if (tpm_try_get_ops(chip))
 262                 return 0;
 263
 264         chip->ops->cancel(chip);
 265         tpm_put_ops(chip);
 266         return count;
 267 }
 268 static DEVICE_ATTR_WO(cancel);
 269
 270 static ssize_t durations_show(struct device *dev, struct device_attribute *attr,
 271                               char *buf)
 272 {
 273         struct tpm_chip *chip = to_tpm_chip(dev);
 274
 275         if (chip->duration[TPM_LONG] == 0)
 276                 return 0;
 277
 278         return sprintf(buf, "%d %d %d [%s]\n",
 279                        jiffies_to_usecs(chip->duration[TPM_SHORT]),
 280                        jiffies_to_usecs(chip->duration[TPM_MEDIUM]),
 281                        jiffies_to_usecs(chip->duration[TPM_LONG]),
 282                        chip->duration_adjusted
 283                        ? "adjusted" : "original");
 284 }
 285 static DEVICE_ATTR_RO(durations);
 286
 287 static ssize_t timeouts_show(struct device *dev, struct device_attribute *attr,
 288                              char *buf)
 289 {
 290         struct tpm_chip *chip = to_tpm_chip(dev);
 291
 292         return sprintf(buf, "%d %d %d %d [%s]\n",
 293                        jiffies_to_usecs(chip->timeout_a),
 294                        jiffies_to_usecs(chip->timeout_b),
 295                        jiffies_to_usecs(chip->timeout_c),
 296                        jiffies_to_usecs(chip->timeout_d),
 297                        chip->timeout_adjusted
 298                        ? "adjusted" : "original");
 299 }
 300 static DEVICE_ATTR_RO(timeouts);
 301
 302 static ssize_t tpm_version_major_show(struct device *dev,
 303                                   struct device_attribute *attr, char *buf)
 304 {
 305         struct tpm_chip *chip = to_tpm_chip(dev);
 306
 307         return sprintf(buf, "%s\n", chip->flags & TPM_CHIP_FLAG_TPM2
 308                        ? "2" : "1");
 309 }
 310 static DEVICE_ATTR_RO(tpm_version_major);
 311
 312 #ifdef CONFIG_TCG_TPM2_HMAC
 313 static ssize_t null_name_show(struct device *dev, struct device_attribute *attr,
 314                               char *buf)
 315 {
 316         struct tpm_chip *chip = to_tpm_chip(dev);
 317         int size = TPM2_NAME_SIZE;
 318
 319         bin2hex(buf, chip->null_key_name, size);
 320         size *= 2;
 321         buf[size++] = '\n';
 322         return size;
 323 }
 324 static DEVICE_ATTR_RO(null_name);
 325 #endif
 326
 327 static struct attribute *tpm1_dev_attrs[] = {
 328         &dev_attr_pubek.attr,
 329         &dev_attr_pcrs.attr,
 330         &dev_attr_enabled.attr,
 331         &dev_attr_active.attr,
 332         &dev_attr_owned.attr,
 333         &dev_attr_temp_deactivated.attr,
 334         &dev_attr_caps.attr,
 335         &dev_attr_cancel.attr,
 336         &dev_attr_durations.attr,
 337         &dev_attr_timeouts.attr,
 338         &dev_attr_tpm_version_major.attr,
 339         NULL,
 340 };
 341
 342 static struct attribute *tpm2_dev_attrs[] = {
 343         &dev_attr_tpm_version_major.attr,
 344 #ifdef CONFIG_TCG_TPM2_HMAC
 345         &dev_attr_null_name.attr,
 346 #endif
 347         NULL
 348 };
 349
 350 static const struct attribute_group tpm1_dev_group = {
 351         .attrs = tpm1_dev_attrs,
 352 };
 353
 354 static const struct attribute_group tpm2_dev_group = {
 355         .attrs = tpm2_dev_attrs,
 356 };
 357
 358 struct tpm_pcr_attr {
 359         int alg_id;
 360         int pcr;
 361         struct device_attribute attr;
 362 };
 363
 364 #define to_tpm_pcr_attr(a) container_of(a, struct tpm_pcr_attr, attr)
 365
 366 static ssize_t pcr_value_show(struct device *dev,
 367                               struct device_attribute *attr,
 368                               char *buf)
 369 {
 370         struct tpm_pcr_attr *ha = to_tpm_pcr_attr(attr);
 371         struct tpm_chip *chip = to_tpm_chip(dev);
 372         struct tpm_digest digest;
 373         int i;
 374         int digest_size = 0;
 375         int rc;
 376         char *str = buf;
 377
 378         for (i = 0; i < chip->nr_allocated_banks; i++)
 379                 if (ha->alg_id == chip->allocated_banks[i].alg_id)
 380                         digest_size = chip->allocated_banks[i].digest_size;
 381         /* should never happen */
 382         if (!digest_size)
 383                 return -EINVAL;
 384
 385         digest.alg_id = ha->alg_id;
 386         rc = tpm_pcr_read(chip, ha->pcr, &digest);
 387         if (rc)
 388                 return rc;
 389         for (i = 0; i < digest_size; i++)
 390                 str += sprintf(str, "%02X", digest.digest[i]);
 391         str += sprintf(str, "\n");
 392
 393         return str - buf;
 394 }
 395
 396 /*
 397  * The following set of defines represents all the magic to build
 398  * the per hash attribute groups for displaying each bank of PCRs.
 399  * The only slight problem with this approach is that every PCR is
 400  * hard coded to be present, so you don't know if an PCR is missing
 401  * until a cat of the file returns -EINVAL
 402  *
 403  * Also note you must ignore checkpatch warnings in this macro
 404  * code. This is deep macro magic that checkpatch.pl doesn't
 405  * understand.
 406  */
 407
 408 /* Note, this must match TPM2_PLATFORM_PCR which is fixed at 24. */
 409 #define _TPM_HELPER(_alg, _hash, F) \
 410         F(_alg, _hash, 0)           \
 411         F(_alg, _hash, 1)           \
 412         F(_alg, _hash, 2)           \
 413         F(_alg, _hash, 3)           \
 414         F(_alg, _hash, 4)           \
 415         F(_alg, _hash, 5)           \
 416         F(_alg, _hash, 6)           \
 417         F(_alg, _hash, 7)           \
 418         F(_alg, _hash, 8)           \
 419         F(_alg, _hash, 9)           \
 420         F(_alg, _hash, 10)          \
 421         F(_alg, _hash, 11)          \
 422         F(_alg, _hash, 12)          \
 423         F(_alg, _hash, 13)          \
 424         F(_alg, _hash, 14)          \
 425         F(_alg, _hash, 15)          \
 426         F(_alg, _hash, 16)          \
 427         F(_alg, _hash, 17)          \
 428         F(_alg, _hash, 18)          \
 429         F(_alg, _hash, 19)          \
 430         F(_alg, _hash, 20)          \
 431         F(_alg, _hash, 21)          \
 432         F(_alg, _hash, 22)          \
 433         F(_alg, _hash, 23)
 434
 435 /* ignore checkpatch warning about trailing ; in macro. */
 436 #define PCR_ATTR(_alg, _hash, _pcr)                                \
 437         static struct tpm_pcr_attr dev_attr_pcr_##_hash##_##_pcr = {    \
 438                 .alg_id = _alg,                                    \
 439                 .pcr = _pcr,                                       \
 440                 .attr = {                                          \
 441                         .attr = {                                  \
 442                                 .name = __stringify(_pcr),         \
 443                                 .mode = 0444                       \
 444                         },                                         \
 445                         .show = pcr_value_show                     \
 446                 }                                                  \
 447         };
 448
 449 #define PCR_ATTRS(_alg, _hash)                  \
 450         _TPM_HELPER(_alg, _hash, PCR_ATTR)
 451
 452 /* ignore checkpatch warning about trailing , in macro. */
 453 #define PCR_ATTR_VAL(_alg, _hash, _pcr)         \
 454         &dev_attr_pcr_##_hash##_##_pcr.attr.attr,
 455
 456 #define PCR_ATTR_GROUP_ARRAY(_alg, _hash)                      \
 457         static struct attribute *pcr_group_attrs_##_hash[] = { \
 458                 _TPM_HELPER(_alg, _hash, PCR_ATTR_VAL)         \
 459                 NULL                                           \
 460         }
 461
 462 #define PCR_ATTR_GROUP(_alg, _hash)                         \
 463         static struct attribute_group pcr_group_##_hash = { \
 464                 .name = "pcr-" __stringify(_hash),          \
 465                 .attrs = pcr_group_attrs_##_hash            \
 466         }
 467
 468 #define PCR_ATTR_BUILD(_alg, _hash)        \
 469         PCR_ATTRS(_alg, _hash)             \
 470         PCR_ATTR_GROUP_ARRAY(_alg, _hash); \
 471         PCR_ATTR_GROUP(_alg, _hash)
 472 /*
 473  * End of macro structure to build an attribute group containing 24
 474  * PCR value files for each supported hash algorithm
 475  */
 476
 477 /*
 478  * The next set of macros implements the cleverness for each hash to
 479  * build a static attribute group called pcr_group_<hash> which can be
 480  * added to chip->groups[].
 481  *
 482  * The first argument is the TPM algorithm id and the second is the
 483  * hash used as both the suffix and the group name.  Note: the group
 484  * name is a directory in the top level tpm class with the name
 485  * pcr-<hash>, so it must not clash with any other names already
 486  * in the sysfs directory.
 487  */
 488 PCR_ATTR_BUILD(TPM_ALG_SHA1, sha1);
 489 PCR_ATTR_BUILD(TPM_ALG_SHA256, sha256);
 490 PCR_ATTR_BUILD(TPM_ALG_SHA384, sha384);
 491 PCR_ATTR_BUILD(TPM_ALG_SHA512, sha512);
 492 PCR_ATTR_BUILD(TPM_ALG_SM3_256, sm3);
 493
 494
 495 void tpm_sysfs_add_device(struct tpm_chip *chip)
 496 {
 497         int i;
 498
 499         WARN_ON(chip->groups_cnt != 0);
 500
 501         if (tpm_is_firmware_upgrade(chip))
 502                 return;
 503
 504         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 505                 chip->groups[chip->groups_cnt++] = &tpm2_dev_group;
 506         else
 507                 chip->groups[chip->groups_cnt++] = &tpm1_dev_group;
 508
 509         /* add one group for each bank hash */
 510         for (i = 0; i < chip->nr_allocated_banks; i++) {
 511                 switch (chip->allocated_banks[i].alg_id) {
 512                 case TPM_ALG_SHA1:
 513                         chip->groups[chip->groups_cnt++] = &pcr_group_sha1;
 514                         break;
 515                 case TPM_ALG_SHA256:
 516                         chip->groups[chip->groups_cnt++] = &pcr_group_sha256;
 517                         break;
 518                 case TPM_ALG_SHA384:
 519                         chip->groups[chip->groups_cnt++] = &pcr_group_sha384;
 520                         break;
 521                 case TPM_ALG_SHA512:
 522                         chip->groups[chip->groups_cnt++] = &pcr_group_sha512;
 523                         break;
 524                 case TPM_ALG_SM3_256:
 525                         chip->groups[chip->groups_cnt++] = &pcr_group_sm3;
 526                         break;
 527                 default:
 528                         /*
 529                          * If triggers, send a patch to add both a
 530                          * PCR_ATTR_BUILD() macro above for the
 531                          * missing algorithm as well as an additional
 532                          * case in this switch statement.
 533                          */
 534                         dev_err(&chip->dev,
 535                                 "TPM with unsupported bank algorithm 0x%04x",
 536                                 chip->allocated_banks[i].alg_id);
 537                         break;
 538                 }
 539         }
 540
 541         /*
 542          * This will only trigger if someone has added an additional
 543          * hash to the tpm_algorithms enum without incrementing
 544          * TPM_MAX_HASHES.
 545          */
 546         WARN_ON(chip->groups_cnt > TPM_MAX_HASHES + 1);
 547 }