security/keys/trusted-keys/trusted_tpm1.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2010 IBM Corporation
   4  *
   5  * Author:
   6  * David Safford <safford@us.ibm.com>
   7  *
   8  * See Documentation/security/keys/trusted-encrypted.rst
   9  */
  10
  11 #include <crypto/hash_info.h>
  12 #include <linux/uaccess.h>
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/slab.h>
  16 #include <linux/parser.h>
  17 #include <linux/string.h>
  18 #include <linux/err.h>
  19 #include <keys/user-type.h>
  20 #include <keys/trusted-type.h>
  21 #include <linux/key-type.h>
  22 #include <linux/rcupdate.h>
  23 #include <linux/crypto.h>
  24 #include <crypto/hash.h>
  25 #include <crypto/sha.h>
  26 #include <linux/capability.h>
  27 #include <linux/tpm.h>
  28 #include <linux/tpm_command.h>
  29
  30 #include <keys/trusted_tpm.h>
  31
  32 static const char hmac_alg[] = "hmac(sha1)";
  33 static const char hash_alg[] = "sha1";
  34 static struct tpm_chip *chip;
  35 static struct tpm_digest *digests;
  36
  37 struct sdesc {
  38         struct shash_desc shash;
  39         char ctx[];
  40 };
  41
  42 static struct crypto_shash *hashalg;
  43 static struct crypto_shash *hmacalg;
  44
  45 static struct sdesc *init_sdesc(struct crypto_shash *alg)
  46 {
  47         struct sdesc *sdesc;
  48         int size;
  49
  50         size = sizeof(struct shash_desc) + crypto_shash_descsize(alg);
  51         sdesc = kmalloc(size, GFP_KERNEL);
  52         if (!sdesc)
  53                 return ERR_PTR(-ENOMEM);
  54         sdesc->shash.tfm = alg;
  55         return sdesc;
  56 }
  57
  58 static int TSS_sha1(const unsigned char *data, unsigned int datalen,
  59                     unsigned char *digest)
  60 {
  61         struct sdesc *sdesc;
  62         int ret;
  63
  64         sdesc = init_sdesc(hashalg);
  65         if (IS_ERR(sdesc)) {
  66                 pr_info("trusted_key: can't alloc %s\n", hash_alg);
  67                 return PTR_ERR(sdesc);
  68         }
  69
  70         ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest);
  71         kfree_sensitive(sdesc);
  72         return ret;
  73 }
  74
  75 static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
  76                        unsigned int keylen, ...)
  77 {
  78         struct sdesc *sdesc;
  79         va_list argp;
  80         unsigned int dlen;
  81         unsigned char *data;
  82         int ret;
  83
  84         sdesc = init_sdesc(hmacalg);
  85         if (IS_ERR(sdesc)) {
  86                 pr_info("trusted_key: can't alloc %s\n", hmac_alg);
  87                 return PTR_ERR(sdesc);
  88         }
  89
  90         ret = crypto_shash_setkey(hmacalg, key, keylen);
  91         if (ret < 0)
  92                 goto out;
  93         ret = crypto_shash_init(&sdesc->shash);
  94         if (ret < 0)
  95                 goto out;
  96
  97         va_start(argp, keylen);
  98         for (;;) {
  99                 dlen = va_arg(argp, unsigned int);
 100                 if (dlen == 0)
 101                         break;
 102                 data = va_arg(argp, unsigned char *);
 103                 if (data == NULL) {
 104                         ret = -EINVAL;
 105                         break;
 106                 }
 107                 ret = crypto_shash_update(&sdesc->shash, data, dlen);
 108                 if (ret < 0)
 109                         break;
 110         }
 111         va_end(argp);
 112         if (!ret)
 113                 ret = crypto_shash_final(&sdesc->shash, digest);
 114 out:
 115         kfree_sensitive(sdesc);
 116         return ret;
 117 }
 118
 119 /*
 120  * calculate authorization info fields to send to TPM
 121  */
 122 int TSS_authhmac(unsigned char *digest, const unsigned char *key,
 123                         unsigned int keylen, unsigned char *h1,
 124                         unsigned char *h2, unsigned int h3, ...)
 125 {
 126         unsigned char paramdigest[SHA1_DIGEST_SIZE];
 127         struct sdesc *sdesc;
 128         unsigned int dlen;
 129         unsigned char *data;
 130         unsigned char c;
 131         int ret;
 132         va_list argp;
 133
 134         if (!chip)
 135                 return -ENODEV;
 136
 137         sdesc = init_sdesc(hashalg);
 138         if (IS_ERR(sdesc)) {
 139                 pr_info("trusted_key: can't alloc %s\n", hash_alg);
 140                 return PTR_ERR(sdesc);
 141         }
 142
 143         c = !!h3;
 144         ret = crypto_shash_init(&sdesc->shash);
 145         if (ret < 0)
 146                 goto out;
 147         va_start(argp, h3);
 148         for (;;) {
 149                 dlen = va_arg(argp, unsigned int);
 150                 if (dlen == 0)
 151                         break;
 152                 data = va_arg(argp, unsigned char *);
 153                 if (!data) {
 154                         ret = -EINVAL;
 155                         break;
 156                 }
 157                 ret = crypto_shash_update(&sdesc->shash, data, dlen);
 158                 if (ret < 0)
 159                         break;
 160         }
 161         va_end(argp);
 162         if (!ret)
 163                 ret = crypto_shash_final(&sdesc->shash, paramdigest);
 164         if (!ret)
 165                 ret = TSS_rawhmac(digest, key, keylen, SHA1_DIGEST_SIZE,
 166                                   paramdigest, TPM_NONCE_SIZE, h1,
 167                                   TPM_NONCE_SIZE, h2, 1, &c, 0, 0);
 168 out:
 169         kfree_sensitive(sdesc);
 170         return ret;
 171 }
 172 EXPORT_SYMBOL_GPL(TSS_authhmac);
 173
 174 /*
 175  * verify the AUTH1_COMMAND (Seal) result from TPM
 176  */
 177 int TSS_checkhmac1(unsigned char *buffer,
 178                           const uint32_t command,
 179                           const unsigned char *ononce,
 180                           const unsigned char *key,
 181                           unsigned int keylen, ...)
 182 {
 183         uint32_t bufsize;
 184         uint16_t tag;
 185         uint32_t ordinal;
 186         uint32_t result;
 187         unsigned char *enonce;
 188         unsigned char *continueflag;
 189         unsigned char *authdata;
 190         unsigned char testhmac[SHA1_DIGEST_SIZE];
 191         unsigned char paramdigest[SHA1_DIGEST_SIZE];
 192         struct sdesc *sdesc;
 193         unsigned int dlen;
 194         unsigned int dpos;
 195         va_list argp;
 196         int ret;
 197
 198         if (!chip)
 199                 return -ENODEV;
 200
 201         bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
 202         tag = LOAD16(buffer, 0);
 203         ordinal = command;
 204         result = LOAD32N(buffer, TPM_RETURN_OFFSET);
 205         if (tag == TPM_TAG_RSP_COMMAND)
 206                 return 0;
 207         if (tag != TPM_TAG_RSP_AUTH1_COMMAND)
 208                 return -EINVAL;
 209         authdata = buffer + bufsize - SHA1_DIGEST_SIZE;
 210         continueflag = authdata - 1;
 211         enonce = continueflag - TPM_NONCE_SIZE;
 212
 213         sdesc = init_sdesc(hashalg);
 214         if (IS_ERR(sdesc)) {
 215                 pr_info("trusted_key: can't alloc %s\n", hash_alg);
 216                 return PTR_ERR(sdesc);
 217         }
 218         ret = crypto_shash_init(&sdesc->shash);
 219         if (ret < 0)
 220                 goto out;
 221         ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
 222                                   sizeof result);
 223         if (ret < 0)
 224                 goto out;
 225         ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
 226                                   sizeof ordinal);
 227         if (ret < 0)
 228                 goto out;
 229         va_start(argp, keylen);
 230         for (;;) {
 231                 dlen = va_arg(argp, unsigned int);
 232                 if (dlen == 0)
 233                         break;
 234                 dpos = va_arg(argp, unsigned int);
 235                 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
 236                 if (ret < 0)
 237                         break;
 238         }
 239         va_end(argp);
 240         if (!ret)
 241                 ret = crypto_shash_final(&sdesc->shash, paramdigest);
 242         if (ret < 0)
 243                 goto out;
 244
 245         ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest,
 246                           TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce,
 247                           1, continueflag, 0, 0);
 248         if (ret < 0)
 249                 goto out;
 250
 251         if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE))
 252                 ret = -EINVAL;
 253 out:
 254         kfree_sensitive(sdesc);
 255         return ret;
 256 }
 257 EXPORT_SYMBOL_GPL(TSS_checkhmac1);
 258
 259 /*
 260  * verify the AUTH2_COMMAND (unseal) result from TPM
 261  */
 262 static int TSS_checkhmac2(unsigned char *buffer,
 263                           const uint32_t command,
 264                           const unsigned char *ononce,
 265                           const unsigned char *key1,
 266                           unsigned int keylen1,
 267                           const unsigned char *key2,
 268                           unsigned int keylen2, ...)
 269 {
 270         uint32_t bufsize;
 271         uint16_t tag;
 272         uint32_t ordinal;
 273         uint32_t result;
 274         unsigned char *enonce1;
 275         unsigned char *continueflag1;
 276         unsigned char *authdata1;
 277         unsigned char *enonce2;
 278         unsigned char *continueflag2;
 279         unsigned char *authdata2;
 280         unsigned char testhmac1[SHA1_DIGEST_SIZE];
 281         unsigned char testhmac2[SHA1_DIGEST_SIZE];
 282         unsigned char paramdigest[SHA1_DIGEST_SIZE];
 283         struct sdesc *sdesc;
 284         unsigned int dlen;
 285         unsigned int dpos;
 286         va_list argp;
 287         int ret;
 288
 289         bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
 290         tag = LOAD16(buffer, 0);
 291         ordinal = command;
 292         result = LOAD32N(buffer, TPM_RETURN_OFFSET);
 293
 294         if (tag == TPM_TAG_RSP_COMMAND)
 295                 return 0;
 296         if (tag != TPM_TAG_RSP_AUTH2_COMMAND)
 297                 return -EINVAL;
 298         authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1
 299                         + SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE);
 300         authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE);
 301         continueflag1 = authdata1 - 1;
 302         continueflag2 = authdata2 - 1;
 303         enonce1 = continueflag1 - TPM_NONCE_SIZE;
 304         enonce2 = continueflag2 - TPM_NONCE_SIZE;
 305
 306         sdesc = init_sdesc(hashalg);
 307         if (IS_ERR(sdesc)) {
 308                 pr_info("trusted_key: can't alloc %s\n", hash_alg);
 309                 return PTR_ERR(sdesc);
 310         }
 311         ret = crypto_shash_init(&sdesc->shash);
 312         if (ret < 0)
 313                 goto out;
 314         ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
 315                                   sizeof result);
 316         if (ret < 0)
 317                 goto out;
 318         ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
 319                                   sizeof ordinal);
 320         if (ret < 0)
 321                 goto out;
 322
 323         va_start(argp, keylen2);
 324         for (;;) {
 325                 dlen = va_arg(argp, unsigned int);
 326                 if (dlen == 0)
 327                         break;
 328                 dpos = va_arg(argp, unsigned int);
 329                 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
 330                 if (ret < 0)
 331                         break;
 332         }
 333         va_end(argp);
 334         if (!ret)
 335                 ret = crypto_shash_final(&sdesc->shash, paramdigest);
 336         if (ret < 0)
 337                 goto out;
 338
 339         ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE,
 340                           paramdigest, TPM_NONCE_SIZE, enonce1,
 341                           TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0);
 342         if (ret < 0)
 343                 goto out;
 344         if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) {
 345                 ret = -EINVAL;
 346                 goto out;
 347         }
 348         ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE,
 349                           paramdigest, TPM_NONCE_SIZE, enonce2,
 350                           TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0);
 351         if (ret < 0)
 352                 goto out;
 353         if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE))
 354                 ret = -EINVAL;
 355 out:
 356         kfree_sensitive(sdesc);
 357         return ret;
 358 }
 359
 360 /*
 361  * For key specific tpm requests, we will generate and send our
 362  * own TPM command packets using the drivers send function.
 363  */
 364 int trusted_tpm_send(unsigned char *cmd, size_t buflen)
 365 {
 366         int rc;
 367
 368         if (!chip)
 369                 return -ENODEV;
 370
 371         dump_tpm_buf(cmd);
 372         rc = tpm_send(chip, cmd, buflen);
 373         dump_tpm_buf(cmd);
 374         if (rc > 0)
 375                 /* Can't return positive return codes values to keyctl */
 376                 rc = -EPERM;
 377         return rc;
 378 }
 379 EXPORT_SYMBOL_GPL(trusted_tpm_send);
 380
 381 /*
 382  * Lock a trusted key, by extending a selected PCR.
 383  *
 384  * Prevents a trusted key that is sealed to PCRs from being accessed.
 385  * This uses the tpm driver's extend function.
 386  */
 387 static int pcrlock(const int pcrnum)
 388 {
 389         if (!capable(CAP_SYS_ADMIN))
 390                 return -EPERM;
 391
 392         return tpm_pcr_extend(chip, pcrnum, digests) ? -EINVAL : 0;
 393 }
 394
 395 /*
 396  * Create an object specific authorisation protocol (OSAP) session
 397  */
 398 static int osap(struct tpm_buf *tb, struct osapsess *s,
 399                 const unsigned char *key, uint16_t type, uint32_t handle)
 400 {
 401         unsigned char enonce[TPM_NONCE_SIZE];
 402         unsigned char ononce[TPM_NONCE_SIZE];
 403         int ret;
 404
 405         ret = tpm_get_random(chip, ononce, TPM_NONCE_SIZE);
 406         if (ret != TPM_NONCE_SIZE)
 407                 return ret;
 408
 409         tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OSAP);
 410         tpm_buf_append_u16(tb, type);
 411         tpm_buf_append_u32(tb, handle);
 412         tpm_buf_append(tb, ononce, TPM_NONCE_SIZE);
 413
 414         ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
 415         if (ret < 0)
 416                 return ret;
 417
 418         s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
 419         memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
 420                TPM_NONCE_SIZE);
 421         memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
 422                                   TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
 423         return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
 424                            enonce, TPM_NONCE_SIZE, ononce, 0, 0);
 425 }
 426
 427 /*
 428  * Create an object independent authorisation protocol (oiap) session
 429  */
 430 int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
 431 {
 432         int ret;
 433
 434         if (!chip)
 435                 return -ENODEV;
 436
 437         tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OIAP);
 438         ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
 439         if (ret < 0)
 440                 return ret;
 441
 442         *handle = LOAD32(tb->data, TPM_DATA_OFFSET);
 443         memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
 444                TPM_NONCE_SIZE);
 445         return 0;
 446 }
 447 EXPORT_SYMBOL_GPL(oiap);
 448
 449 struct tpm_digests {
 450         unsigned char encauth[SHA1_DIGEST_SIZE];
 451         unsigned char pubauth[SHA1_DIGEST_SIZE];
 452         unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
 453         unsigned char xorhash[SHA1_DIGEST_SIZE];
 454         unsigned char nonceodd[TPM_NONCE_SIZE];
 455 };
 456
 457 /*
 458  * Have the TPM seal(encrypt) the trusted key, possibly based on
 459  * Platform Configuration Registers (PCRs). AUTH1 for sealing key.
 460  */
 461 static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
 462                     uint32_t keyhandle, const unsigned char *keyauth,
 463                     const unsigned char *data, uint32_t datalen,
 464                     unsigned char *blob, uint32_t *bloblen,
 465                     const unsigned char *blobauth,
 466                     const unsigned char *pcrinfo, uint32_t pcrinfosize)
 467 {
 468         struct osapsess sess;
 469         struct tpm_digests *td;
 470         unsigned char cont;
 471         uint32_t ordinal;
 472         uint32_t pcrsize;
 473         uint32_t datsize;
 474         int sealinfosize;
 475         int encdatasize;
 476         int storedsize;
 477         int ret;
 478         int i;
 479
 480         /* alloc some work space for all the hashes */
 481         td = kmalloc(sizeof *td, GFP_KERNEL);
 482         if (!td)
 483                 return -ENOMEM;
 484
 485         /* get session for sealing key */
 486         ret = osap(tb, &sess, keyauth, keytype, keyhandle);
 487         if (ret < 0)
 488                 goto out;
 489         dump_sess(&sess);
 490
 491         /* calculate encrypted authorization value */
 492         memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
 493         memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
 494         ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
 495         if (ret < 0)
 496                 goto out;
 497
 498         ret = tpm_get_random(chip, td->nonceodd, TPM_NONCE_SIZE);
 499         if (ret != TPM_NONCE_SIZE)
 500                 goto out;
 501         ordinal = htonl(TPM_ORD_SEAL);
 502         datsize = htonl(datalen);
 503         pcrsize = htonl(pcrinfosize);
 504         cont = 0;
 505
 506         /* encrypt data authorization key */
 507         for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
 508                 td->encauth[i] = td->xorhash[i] ^ blobauth[i];
 509
 510         /* calculate authorization HMAC value */
 511         if (pcrinfosize == 0) {
 512                 /* no pcr info specified */
 513                 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
 514                                    sess.enonce, td->nonceodd, cont,
 515                                    sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
 516                                    td->encauth, sizeof(uint32_t), &pcrsize,
 517                                    sizeof(uint32_t), &datsize, datalen, data, 0,
 518                                    0);
 519         } else {
 520                 /* pcr info specified */
 521                 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
 522                                    sess.enonce, td->nonceodd, cont,
 523                                    sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
 524                                    td->encauth, sizeof(uint32_t), &pcrsize,
 525                                    pcrinfosize, pcrinfo, sizeof(uint32_t),
 526                                    &datsize, datalen, data, 0, 0);
 527         }
 528         if (ret < 0)
 529                 goto out;
 530
 531         /* build and send the TPM request packet */
 532         tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_SEAL);
 533         tpm_buf_append_u32(tb, keyhandle);
 534         tpm_buf_append(tb, td->encauth, SHA1_DIGEST_SIZE);
 535         tpm_buf_append_u32(tb, pcrinfosize);
 536         tpm_buf_append(tb, pcrinfo, pcrinfosize);
 537         tpm_buf_append_u32(tb, datalen);
 538         tpm_buf_append(tb, data, datalen);
 539         tpm_buf_append_u32(tb, sess.handle);
 540         tpm_buf_append(tb, td->nonceodd, TPM_NONCE_SIZE);
 541         tpm_buf_append_u8(tb, cont);
 542         tpm_buf_append(tb, td->pubauth, SHA1_DIGEST_SIZE);
 543
 544         ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
 545         if (ret < 0)
 546                 goto out;
 547
 548         /* calculate the size of the returned Blob */
 549         sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
 550         encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
 551                              sizeof(uint32_t) + sealinfosize);
 552         storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
 553             sizeof(uint32_t) + encdatasize;
 554
 555         /* check the HMAC in the response */
 556         ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
 557                              SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
 558                              0);
 559
 560         /* copy the returned blob to caller */
 561         if (!ret) {
 562                 memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
 563                 *bloblen = storedsize;
 564         }
 565 out:
 566         kfree_sensitive(td);
 567         return ret;
 568 }
 569
 570 /*
 571  * use the AUTH2_COMMAND form of unseal, to authorize both key and blob
 572  */
 573 static int tpm_unseal(struct tpm_buf *tb,
 574                       uint32_t keyhandle, const unsigned char *keyauth,
 575                       const unsigned char *blob, int bloblen,
 576                       const unsigned char *blobauth,
 577                       unsigned char *data, unsigned int *datalen)
 578 {
 579         unsigned char nonceodd[TPM_NONCE_SIZE];
 580         unsigned char enonce1[TPM_NONCE_SIZE];
 581         unsigned char enonce2[TPM_NONCE_SIZE];
 582         unsigned char authdata1[SHA1_DIGEST_SIZE];
 583         unsigned char authdata2[SHA1_DIGEST_SIZE];
 584         uint32_t authhandle1 = 0;
 585         uint32_t authhandle2 = 0;
 586         unsigned char cont = 0;
 587         uint32_t ordinal;
 588         int ret;
 589
 590         /* sessions for unsealing key and data */
 591         ret = oiap(tb, &authhandle1, enonce1);
 592         if (ret < 0) {
 593                 pr_info("trusted_key: oiap failed (%d)\n", ret);
 594                 return ret;
 595         }
 596         ret = oiap(tb, &authhandle2, enonce2);
 597         if (ret < 0) {
 598                 pr_info("trusted_key: oiap failed (%d)\n", ret);
 599                 return ret;
 600         }
 601
 602         ordinal = htonl(TPM_ORD_UNSEAL);
 603         ret = tpm_get_random(chip, nonceodd, TPM_NONCE_SIZE);
 604         if (ret != TPM_NONCE_SIZE) {
 605                 pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
 606                 return ret;
 607         }
 608         ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
 609                            enonce1, nonceodd, cont, sizeof(uint32_t),
 610                            &ordinal, bloblen, blob, 0, 0);
 611         if (ret < 0)
 612                 return ret;
 613         ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
 614                            enonce2, nonceodd, cont, sizeof(uint32_t),
 615                            &ordinal, bloblen, blob, 0, 0);
 616         if (ret < 0)
 617                 return ret;
 618
 619         /* build and send TPM request packet */
 620         tpm_buf_reset(tb, TPM_TAG_RQU_AUTH2_COMMAND, TPM_ORD_UNSEAL);
 621         tpm_buf_append_u32(tb, keyhandle);
 622         tpm_buf_append(tb, blob, bloblen);
 623         tpm_buf_append_u32(tb, authhandle1);
 624         tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
 625         tpm_buf_append_u8(tb, cont);
 626         tpm_buf_append(tb, authdata1, SHA1_DIGEST_SIZE);
 627         tpm_buf_append_u32(tb, authhandle2);
 628         tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
 629         tpm_buf_append_u8(tb, cont);
 630         tpm_buf_append(tb, authdata2, SHA1_DIGEST_SIZE);
 631
 632         ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
 633         if (ret < 0) {
 634                 pr_info("trusted_key: authhmac failed (%d)\n", ret);
 635                 return ret;
 636         }
 637
 638         *datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
 639         ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
 640                              keyauth, SHA1_DIGEST_SIZE,
 641                              blobauth, SHA1_DIGEST_SIZE,
 642                              sizeof(uint32_t), TPM_DATA_OFFSET,
 643                              *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
 644                              0);
 645         if (ret < 0) {
 646                 pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret);
 647                 return ret;
 648         }
 649         memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
 650         return 0;
 651 }
 652
 653 /*
 654  * Have the TPM seal(encrypt) the symmetric key
 655  */
 656 static int key_seal(struct trusted_key_payload *p,
 657                     struct trusted_key_options *o)
 658 {
 659         struct tpm_buf tb;
 660         int ret;
 661
 662         ret = tpm_buf_init(&tb, 0, 0);
 663         if (ret)
 664                 return ret;
 665
 666         /* include migratable flag at end of sealed key */
 667         p->key[p->key_len] = p->migratable;
 668
 669         ret = tpm_seal(&tb, o->keytype, o->keyhandle, o->keyauth,
 670                        p->key, p->key_len + 1, p->blob, &p->blob_len,
 671                        o->blobauth, o->pcrinfo, o->pcrinfo_len);
 672         if (ret < 0)
 673                 pr_info("trusted_key: srkseal failed (%d)\n", ret);
 674
 675         tpm_buf_destroy(&tb);
 676         return ret;
 677 }
 678
 679 /*
 680  * Have the TPM unseal(decrypt) the symmetric key
 681  */
 682 static int key_unseal(struct trusted_key_payload *p,
 683                       struct trusted_key_options *o)
 684 {
 685         struct tpm_buf tb;
 686         int ret;
 687
 688         ret = tpm_buf_init(&tb, 0, 0);
 689         if (ret)
 690                 return ret;
 691
 692         ret = tpm_unseal(&tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
 693                          o->blobauth, p->key, &p->key_len);
 694         if (ret < 0)
 695                 pr_info("trusted_key: srkunseal failed (%d)\n", ret);
 696         else
 697                 /* pull migratable flag out of sealed key */
 698                 p->migratable = p->key[--p->key_len];
 699
 700         tpm_buf_destroy(&tb);
 701         return ret;
 702 }
 703
 704 enum {
 705         Opt_err,
 706         Opt_new, Opt_load, Opt_update,
 707         Opt_keyhandle, Opt_keyauth, Opt_blobauth,
 708         Opt_pcrinfo, Opt_pcrlock, Opt_migratable,
 709         Opt_hash,
 710         Opt_policydigest,
 711         Opt_policyhandle,
 712 };
 713
 714 static const match_table_t key_tokens = {
 715         {Opt_new, "new"},
 716         {Opt_load, "load"},
 717         {Opt_update, "update"},
 718         {Opt_keyhandle, "keyhandle=%s"},
 719         {Opt_keyauth, "keyauth=%s"},
 720         {Opt_blobauth, "blobauth=%s"},
 721         {Opt_pcrinfo, "pcrinfo=%s"},
 722         {Opt_pcrlock, "pcrlock=%s"},
 723         {Opt_migratable, "migratable=%s"},
 724         {Opt_hash, "hash=%s"},
 725         {Opt_policydigest, "policydigest=%s"},
 726         {Opt_policyhandle, "policyhandle=%s"},
 727         {Opt_err, NULL}
 728 };
 729
 730 /* can have zero or more token= options */
 731 static int getoptions(char *c, struct trusted_key_payload *pay,
 732                       struct trusted_key_options *opt)
 733 {
 734         substring_t args[MAX_OPT_ARGS];
 735         char *p = c;
 736         int token;
 737         int res;
 738         unsigned long handle;
 739         unsigned long lock;
 740         unsigned long token_mask = 0;
 741         unsigned int digest_len;
 742         int i;
 743         int tpm2;
 744
 745         tpm2 = tpm_is_tpm2(chip);
 746         if (tpm2 < 0)
 747                 return tpm2;
 748
 749         opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1;
 750
 751         while ((p = strsep(&c, " \t"))) {
 752                 if (*p == '\0' || *p == ' ' || *p == '\t')
 753                         continue;
 754                 token = match_token(p, key_tokens, args);
 755                 if (test_and_set_bit(token, &token_mask))
 756                         return -EINVAL;
 757
 758                 switch (token) {
 759                 case Opt_pcrinfo:
 760                         opt->pcrinfo_len = strlen(args[0].from) / 2;
 761                         if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
 762                                 return -EINVAL;
 763                         res = hex2bin(opt->pcrinfo, args[0].from,
 764                                       opt->pcrinfo_len);
 765                         if (res < 0)
 766                                 return -EINVAL;
 767                         break;
 768                 case Opt_keyhandle:
 769                         res = kstrtoul(args[0].from, 16, &handle);
 770                         if (res < 0)
 771                                 return -EINVAL;
 772                         opt->keytype = SEAL_keytype;
 773                         opt->keyhandle = handle;
 774                         break;
 775                 case Opt_keyauth:
 776                         if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
 777                                 return -EINVAL;
 778                         res = hex2bin(opt->keyauth, args[0].from,
 779                                       SHA1_DIGEST_SIZE);
 780                         if (res < 0)
 781                                 return -EINVAL;
 782                         break;
 783                 case Opt_blobauth:
 784                         if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
 785                                 return -EINVAL;
 786                         res = hex2bin(opt->blobauth, args[0].from,
 787                                       SHA1_DIGEST_SIZE);
 788                         if (res < 0)
 789                                 return -EINVAL;
 790                         break;
 791                 case Opt_migratable:
 792                         if (*args[0].from == '0')
 793                                 pay->migratable = 0;
 794                         else
 795                                 return -EINVAL;
 796                         break;
 797                 case Opt_pcrlock:
 798                         res = kstrtoul(args[0].from, 10, &lock);
 799                         if (res < 0)
 800                                 return -EINVAL;
 801                         opt->pcrlock = lock;
 802                         break;
 803                 case Opt_hash:
 804                         if (test_bit(Opt_policydigest, &token_mask))
 805                                 return -EINVAL;
 806                         for (i = 0; i < HASH_ALGO__LAST; i++) {
 807                                 if (!strcmp(args[0].from, hash_algo_name[i])) {
 808                                         opt->hash = i;
 809                                         break;
 810                                 }
 811                         }
 812                         if (i == HASH_ALGO__LAST)
 813                                 return -EINVAL;
 814                         if  (!tpm2 && i != HASH_ALGO_SHA1) {
 815                                 pr_info("trusted_key: TPM 1.x only supports SHA-1.\n");
 816                                 return -EINVAL;
 817                         }
 818                         break;
 819                 case Opt_policydigest:
 820                         digest_len = hash_digest_size[opt->hash];
 821                         if (!tpm2 || strlen(args[0].from) != (2 * digest_len))
 822                                 return -EINVAL;
 823                         res = hex2bin(opt->policydigest, args[0].from,
 824                                       digest_len);
 825                         if (res < 0)
 826                                 return -EINVAL;
 827                         opt->policydigest_len = digest_len;
 828                         break;
 829                 case Opt_policyhandle:
 830                         if (!tpm2)
 831                                 return -EINVAL;
 832                         res = kstrtoul(args[0].from, 16, &handle);
 833                         if (res < 0)
 834                                 return -EINVAL;
 835                         opt->policyhandle = handle;
 836                         break;
 837                 default:
 838                         return -EINVAL;
 839                 }
 840         }
 841         return 0;
 842 }
 843
 844 /*
 845  * datablob_parse - parse the keyctl data and fill in the
 846  *                  payload and options structures
 847  *
 848  * On success returns 0, otherwise -EINVAL.
 849  */
 850 static int datablob_parse(char *datablob, struct trusted_key_payload *p,
 851                           struct trusted_key_options *o)
 852 {
 853         substring_t args[MAX_OPT_ARGS];
 854         long keylen;
 855         int ret = -EINVAL;
 856         int key_cmd;
 857         char *c;
 858
 859         /* main command */
 860         c = strsep(&datablob, " \t");
 861         if (!c)
 862                 return -EINVAL;
 863         key_cmd = match_token(c, key_tokens, args);
 864         switch (key_cmd) {
 865         case Opt_new:
 866                 /* first argument is key size */
 867                 c = strsep(&datablob, " \t");
 868                 if (!c)
 869                         return -EINVAL;
 870                 ret = kstrtol(c, 10, &keylen);
 871                 if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
 872                         return -EINVAL;
 873                 p->key_len = keylen;
 874                 ret = getoptions(datablob, p, o);
 875                 if (ret < 0)
 876                         return ret;
 877                 ret = Opt_new;
 878                 break;
 879         case Opt_load:
 880                 /* first argument is sealed blob */
 881                 c = strsep(&datablob, " \t");
 882                 if (!c)
 883                         return -EINVAL;
 884                 p->blob_len = strlen(c) / 2;
 885                 if (p->blob_len > MAX_BLOB_SIZE)
 886                         return -EINVAL;
 887                 ret = hex2bin(p->blob, c, p->blob_len);
 888                 if (ret < 0)
 889                         return -EINVAL;
 890                 ret = getoptions(datablob, p, o);
 891                 if (ret < 0)
 892                         return ret;
 893                 ret = Opt_load;
 894                 break;
 895         case Opt_update:
 896                 /* all arguments are options */
 897                 ret = getoptions(datablob, p, o);
 898                 if (ret < 0)
 899                         return ret;
 900                 ret = Opt_update;
 901                 break;
 902         case Opt_err:
 903                 return -EINVAL;
 904                 break;
 905         }
 906         return ret;
 907 }
 908
 909 static struct trusted_key_options *trusted_options_alloc(void)
 910 {
 911         struct trusted_key_options *options;
 912         int tpm2;
 913
 914         tpm2 = tpm_is_tpm2(chip);
 915         if (tpm2 < 0)
 916                 return NULL;
 917
 918         options = kzalloc(sizeof *options, GFP_KERNEL);
 919         if (options) {
 920                 /* set any non-zero defaults */
 921                 options->keytype = SRK_keytype;
 922
 923                 if (!tpm2)
 924                         options->keyhandle = SRKHANDLE;
 925         }
 926         return options;
 927 }
 928
 929 static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
 930 {
 931         struct trusted_key_payload *p = NULL;
 932         int ret;
 933
 934         ret = key_payload_reserve(key, sizeof *p);
 935         if (ret < 0)
 936                 return p;
 937         p = kzalloc(sizeof *p, GFP_KERNEL);
 938         if (p)
 939                 p->migratable = 1; /* migratable by default */
 940         return p;
 941 }
 942
 943 /*
 944  * trusted_instantiate - create a new trusted key
 945  *
 946  * Unseal an existing trusted blob or, for a new key, get a
 947  * random key, then seal and create a trusted key-type key,
 948  * adding it to the specified keyring.
 949  *
 950  * On success, return 0. Otherwise return errno.
 951  */
 952 static int trusted_instantiate(struct key *key,
 953                                struct key_preparsed_payload *prep)
 954 {
 955         struct trusted_key_payload *payload = NULL;
 956         struct trusted_key_options *options = NULL;
 957         size_t datalen = prep->datalen;
 958         char *datablob;
 959         int ret = 0;
 960         int key_cmd;
 961         size_t key_len;
 962         int tpm2;
 963
 964         tpm2 = tpm_is_tpm2(chip);
 965         if (tpm2 < 0)
 966                 return tpm2;
 967
 968         if (datalen <= 0 || datalen > 32767 || !prep->data)
 969                 return -EINVAL;
 970
 971         datablob = kmalloc(datalen + 1, GFP_KERNEL);
 972         if (!datablob)
 973                 return -ENOMEM;
 974         memcpy(datablob, prep->data, datalen);
 975         datablob[datalen] = '\0';
 976
 977         options = trusted_options_alloc();
 978         if (!options) {
 979                 ret = -ENOMEM;
 980                 goto out;
 981         }
 982         payload = trusted_payload_alloc(key);
 983         if (!payload) {
 984                 ret = -ENOMEM;
 985                 goto out;
 986         }
 987
 988         key_cmd = datablob_parse(datablob, payload, options);
 989         if (key_cmd < 0) {
 990                 ret = key_cmd;
 991                 goto out;
 992         }
 993
 994         if (!options->keyhandle) {
 995                 ret = -EINVAL;
 996                 goto out;
 997         }
 998
 999         dump_payload(payload);
1000         dump_options(options);
1001
1002         switch (key_cmd) {
1003         case Opt_load:
1004                 if (tpm2)
1005                         ret = tpm2_unseal_trusted(chip, payload, options);
1006                 else
1007                         ret = key_unseal(payload, options);
1008                 dump_payload(payload);
1009                 dump_options(options);
1010                 if (ret < 0)
1011                         pr_info("trusted_key: key_unseal failed (%d)\n", ret);
1012                 break;
1013         case Opt_new:
1014                 key_len = payload->key_len;
1015                 ret = tpm_get_random(chip, payload->key, key_len);
1016                 if (ret != key_len) {
1017                         pr_info("trusted_key: key_create failed (%d)\n", ret);
1018                         goto out;
1019                 }
1020                 if (tpm2)
1021                         ret = tpm2_seal_trusted(chip, payload, options);
1022                 else
1023                         ret = key_seal(payload, options);
1024                 if (ret < 0)
1025                         pr_info("trusted_key: key_seal failed (%d)\n", ret);
1026                 break;
1027         default:
1028                 ret = -EINVAL;
1029                 goto out;
1030         }
1031         if (!ret && options->pcrlock)
1032                 ret = pcrlock(options->pcrlock);
1033 out:
1034         kfree_sensitive(datablob);
1035         kfree_sensitive(options);
1036         if (!ret)
1037                 rcu_assign_keypointer(key, payload);
1038         else
1039                 kfree_sensitive(payload);
1040         return ret;
1041 }
1042
1043 static void trusted_rcu_free(struct rcu_head *rcu)
1044 {
1045         struct trusted_key_payload *p;
1046
1047         p = container_of(rcu, struct trusted_key_payload, rcu);
1048         kfree_sensitive(p);
1049 }
1050
1051 /*
1052  * trusted_update - reseal an existing key with new PCR values
1053  */
1054 static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
1055 {
1056         struct trusted_key_payload *p;
1057         struct trusted_key_payload *new_p;
1058         struct trusted_key_options *new_o;
1059         size_t datalen = prep->datalen;
1060         char *datablob;
1061         int ret = 0;
1062
1063         if (key_is_negative(key))
1064                 return -ENOKEY;
1065         p = key->payload.data[0];
1066         if (!p->migratable)
1067                 return -EPERM;
1068         if (datalen <= 0 || datalen > 32767 || !prep->data)
1069                 return -EINVAL;
1070
1071         datablob = kmalloc(datalen + 1, GFP_KERNEL);
1072         if (!datablob)
1073                 return -ENOMEM;
1074         new_o = trusted_options_alloc();
1075         if (!new_o) {
1076                 ret = -ENOMEM;
1077                 goto out;
1078         }
1079         new_p = trusted_payload_alloc(key);
1080         if (!new_p) {
1081                 ret = -ENOMEM;
1082                 goto out;
1083         }
1084
1085         memcpy(datablob, prep->data, datalen);
1086         datablob[datalen] = '\0';
1087         ret = datablob_parse(datablob, new_p, new_o);
1088         if (ret != Opt_update) {
1089                 ret = -EINVAL;
1090                 kfree_sensitive(new_p);
1091                 goto out;
1092         }
1093
1094         if (!new_o->keyhandle) {
1095                 ret = -EINVAL;
1096                 kfree_sensitive(new_p);
1097                 goto out;
1098         }
1099
1100         /* copy old key values, and reseal with new pcrs */
1101         new_p->migratable = p->migratable;
1102         new_p->key_len = p->key_len;
1103         memcpy(new_p->key, p->key, p->key_len);
1104         dump_payload(p);
1105         dump_payload(new_p);
1106
1107         ret = key_seal(new_p, new_o);
1108         if (ret < 0) {
1109                 pr_info("trusted_key: key_seal failed (%d)\n", ret);
1110                 kfree_sensitive(new_p);
1111                 goto out;
1112         }
1113         if (new_o->pcrlock) {
1114                 ret = pcrlock(new_o->pcrlock);
1115                 if (ret < 0) {
1116                         pr_info("trusted_key: pcrlock failed (%d)\n", ret);
1117                         kfree_sensitive(new_p);
1118                         goto out;
1119                 }
1120         }
1121         rcu_assign_keypointer(key, new_p);
1122         call_rcu(&p->rcu, trusted_rcu_free);
1123 out:
1124         kfree_sensitive(datablob);
1125         kfree_sensitive(new_o);
1126         return ret;
1127 }
1128
1129 /*
1130  * trusted_read - copy the sealed blob data to userspace in hex.
1131  * On success, return to userspace the trusted key datablob size.
1132  */
1133 static long trusted_read(const struct key *key, char *buffer,
1134                          size_t buflen)
1135 {
1136         const struct trusted_key_payload *p;
1137         char *bufp;
1138         int i;
1139
1140         p = dereference_key_locked(key);
1141         if (!p)
1142                 return -EINVAL;
1143
1144         if (buffer && buflen >= 2 * p->blob_len) {
1145                 bufp = buffer;
1146                 for (i = 0; i < p->blob_len; i++)
1147                         bufp = hex_byte_pack(bufp, p->blob[i]);
1148         }
1149         return 2 * p->blob_len;
1150 }
1151
1152 /*
1153  * trusted_destroy - clear and free the key's payload
1154  */
1155 static void trusted_destroy(struct key *key)
1156 {
1157         kfree_sensitive(key->payload.data[0]);
1158 }
1159
1160 struct key_type key_type_trusted = {
1161         .name = "trusted",
1162         .instantiate = trusted_instantiate,
1163         .update = trusted_update,
1164         .destroy = trusted_destroy,
1165         .describe = user_describe,
1166         .read = trusted_read,
1167 };
1168
1169 EXPORT_SYMBOL_GPL(key_type_trusted);
1170
1171 static void trusted_shash_release(void)
1172 {
1173         if (hashalg)
1174                 crypto_free_shash(hashalg);
1175         if (hmacalg)
1176                 crypto_free_shash(hmacalg);
1177 }
1178
1179 static int __init trusted_shash_alloc(void)
1180 {
1181         int ret;
1182
1183         hmacalg = crypto_alloc_shash(hmac_alg, 0, 0);
1184         if (IS_ERR(hmacalg)) {
1185                 pr_info("trusted_key: could not allocate crypto %s\n",
1186                         hmac_alg);
1187                 return PTR_ERR(hmacalg);
1188         }
1189
1190         hashalg = crypto_alloc_shash(hash_alg, 0, 0);
1191         if (IS_ERR(hashalg)) {
1192                 pr_info("trusted_key: could not allocate crypto %s\n",
1193                         hash_alg);
1194                 ret = PTR_ERR(hashalg);
1195                 goto hashalg_fail;
1196         }
1197
1198         return 0;
1199
1200 hashalg_fail:
1201         crypto_free_shash(hmacalg);
1202         return ret;
1203 }
1204
1205 static int __init init_digests(void)
1206 {
1207         int i;
1208
1209         digests = kcalloc(chip->nr_allocated_banks, sizeof(*digests),
1210                           GFP_KERNEL);
1211         if (!digests)
1212                 return -ENOMEM;
1213
1214         for (i = 0; i < chip->nr_allocated_banks; i++)
1215                 digests[i].alg_id = chip->allocated_banks[i].alg_id;
1216
1217         return 0;
1218 }
1219
1220 static int __init init_trusted(void)
1221 {
1222         int ret;
1223
1224         /* encrypted_keys.ko depends on successful load of this module even if
1225          * TPM is not used.
1226          */
1227         chip = tpm_default_chip();
1228         if (!chip)
1229                 return 0;
1230
1231         ret = init_digests();
1232         if (ret < 0)
1233                 goto err_put;
1234         ret = trusted_shash_alloc();
1235         if (ret < 0)
1236                 goto err_free;
1237         ret = register_key_type(&key_type_trusted);
1238         if (ret < 0)
1239                 goto err_release;
1240         return 0;
1241 err_release:
1242         trusted_shash_release();
1243 err_free:
1244         kfree(digests);
1245 err_put:
1246         put_device(&chip->dev);
1247         return ret;
1248 }
1249
1250 static void __exit cleanup_trusted(void)
1251 {
1252         if (chip) {
1253                 put_device(&chip->dev);
1254                 kfree(digests);
1255                 trusted_shash_release();
1256                 unregister_key_type(&key_type_trusted);
1257         }
1258 }
1259
1260 late_initcall(init_trusted);
1261 module_exit(cleanup_trusted);
1262
1263 MODULE_LICENSE("GPL");