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 < 0)
 407                 return ret;
 408
 409         if (ret != TPM_NONCE_SIZE)
 410                 return -EIO;
 411
 412         tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OSAP);
 413         tpm_buf_append_u16(tb, type);
 414         tpm_buf_append_u32(tb, handle);
 415         tpm_buf_append(tb, ononce, TPM_NONCE_SIZE);
 416
 417         ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
 418         if (ret < 0)
 419                 return ret;
 420
 421         s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
 422         memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
 423                TPM_NONCE_SIZE);
 424         memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
 425                                   TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
 426         return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
 427                            enonce, TPM_NONCE_SIZE, ononce, 0, 0);
 428 }
 429
 430 /*
 431  * Create an object independent authorisation protocol (oiap) session
 432  */
 433 int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
 434 {
 435         int ret;
 436
 437         if (!chip)
 438                 return -ENODEV;
 439
 440         tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OIAP);
 441         ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
 442         if (ret < 0)
 443                 return ret;
 444
 445         *handle = LOAD32(tb->data, TPM_DATA_OFFSET);
 446         memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
 447                TPM_NONCE_SIZE);
 448         return 0;
 449 }
 450 EXPORT_SYMBOL_GPL(oiap);
 451
 452 struct tpm_digests {
 453         unsigned char encauth[SHA1_DIGEST_SIZE];
 454         unsigned char pubauth[SHA1_DIGEST_SIZE];
 455         unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
 456         unsigned char xorhash[SHA1_DIGEST_SIZE];
 457         unsigned char nonceodd[TPM_NONCE_SIZE];
 458 };
 459
 460 /*
 461  * Have the TPM seal(encrypt) the trusted key, possibly based on
 462  * Platform Configuration Registers (PCRs). AUTH1 for sealing key.
 463  */
 464 static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
 465                     uint32_t keyhandle, const unsigned char *keyauth,
 466                     const unsigned char *data, uint32_t datalen,
 467                     unsigned char *blob, uint32_t *bloblen,
 468                     const unsigned char *blobauth,
 469                     const unsigned char *pcrinfo, uint32_t pcrinfosize)
 470 {
 471         struct osapsess sess;
 472         struct tpm_digests *td;
 473         unsigned char cont;
 474         uint32_t ordinal;
 475         uint32_t pcrsize;
 476         uint32_t datsize;
 477         int sealinfosize;
 478         int encdatasize;
 479         int storedsize;
 480         int ret;
 481         int i;
 482
 483         /* alloc some work space for all the hashes */
 484         td = kmalloc(sizeof *td, GFP_KERNEL);
 485         if (!td)
 486                 return -ENOMEM;
 487
 488         /* get session for sealing key */
 489         ret = osap(tb, &sess, keyauth, keytype, keyhandle);
 490         if (ret < 0)
 491                 goto out;
 492         dump_sess(&sess);
 493
 494         /* calculate encrypted authorization value */
 495         memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
 496         memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
 497         ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
 498         if (ret < 0)
 499                 goto out;
 500
 501         ret = tpm_get_random(chip, td->nonceodd, TPM_NONCE_SIZE);
 502         if (ret < 0)
 503                 goto out;
 504
 505         if (ret != TPM_NONCE_SIZE) {
 506                 ret = -EIO;
 507                 goto out;
 508         }
 509
 510         ordinal = htonl(TPM_ORD_SEAL);
 511         datsize = htonl(datalen);
 512         pcrsize = htonl(pcrinfosize);
 513         cont = 0;
 514
 515         /* encrypt data authorization key */
 516         for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
 517                 td->encauth[i] = td->xorhash[i] ^ blobauth[i];
 518
 519         /* calculate authorization HMAC value */
 520         if (pcrinfosize == 0) {
 521                 /* no pcr info specified */
 522                 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
 523                                    sess.enonce, td->nonceodd, cont,
 524                                    sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
 525                                    td->encauth, sizeof(uint32_t), &pcrsize,
 526                                    sizeof(uint32_t), &datsize, datalen, data, 0,
 527                                    0);
 528         } else {
 529                 /* pcr info specified */
 530                 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
 531                                    sess.enonce, td->nonceodd, cont,
 532                                    sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
 533                                    td->encauth, sizeof(uint32_t), &pcrsize,
 534                                    pcrinfosize, pcrinfo, sizeof(uint32_t),
 535                                    &datsize, datalen, data, 0, 0);
 536         }
 537         if (ret < 0)
 538                 goto out;
 539
 540         /* build and send the TPM request packet */
 541         tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_SEAL);
 542         tpm_buf_append_u32(tb, keyhandle);
 543         tpm_buf_append(tb, td->encauth, SHA1_DIGEST_SIZE);
 544         tpm_buf_append_u32(tb, pcrinfosize);
 545         tpm_buf_append(tb, pcrinfo, pcrinfosize);
 546         tpm_buf_append_u32(tb, datalen);
 547         tpm_buf_append(tb, data, datalen);
 548         tpm_buf_append_u32(tb, sess.handle);
 549         tpm_buf_append(tb, td->nonceodd, TPM_NONCE_SIZE);
 550         tpm_buf_append_u8(tb, cont);
 551         tpm_buf_append(tb, td->pubauth, SHA1_DIGEST_SIZE);
 552
 553         ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
 554         if (ret < 0)
 555                 goto out;
 556
 557         /* calculate the size of the returned Blob */
 558         sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
 559         encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
 560                              sizeof(uint32_t) + sealinfosize);
 561         storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
 562             sizeof(uint32_t) + encdatasize;
 563
 564         /* check the HMAC in the response */
 565         ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
 566                              SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
 567                              0);
 568
 569         /* copy the returned blob to caller */
 570         if (!ret) {
 571                 memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
 572                 *bloblen = storedsize;
 573         }
 574 out:
 575         kfree_sensitive(td);
 576         return ret;
 577 }
 578
 579 /*
 580  * use the AUTH2_COMMAND form of unseal, to authorize both key and blob
 581  */
 582 static int tpm_unseal(struct tpm_buf *tb,
 583                       uint32_t keyhandle, const unsigned char *keyauth,
 584                       const unsigned char *blob, int bloblen,
 585                       const unsigned char *blobauth,
 586                       unsigned char *data, unsigned int *datalen)
 587 {
 588         unsigned char nonceodd[TPM_NONCE_SIZE];
 589         unsigned char enonce1[TPM_NONCE_SIZE];
 590         unsigned char enonce2[TPM_NONCE_SIZE];
 591         unsigned char authdata1[SHA1_DIGEST_SIZE];
 592         unsigned char authdata2[SHA1_DIGEST_SIZE];
 593         uint32_t authhandle1 = 0;
 594         uint32_t authhandle2 = 0;
 595         unsigned char cont = 0;
 596         uint32_t ordinal;
 597         int ret;
 598
 599         /* sessions for unsealing key and data */
 600         ret = oiap(tb, &authhandle1, enonce1);
 601         if (ret < 0) {
 602                 pr_info("trusted_key: oiap failed (%d)\n", ret);
 603                 return ret;
 604         }
 605         ret = oiap(tb, &authhandle2, enonce2);
 606         if (ret < 0) {
 607                 pr_info("trusted_key: oiap failed (%d)\n", ret);
 608                 return ret;
 609         }
 610
 611         ordinal = htonl(TPM_ORD_UNSEAL);
 612         ret = tpm_get_random(chip, nonceodd, TPM_NONCE_SIZE);
 613         if (ret < 0)
 614                 return ret;
 615
 616         if (ret != TPM_NONCE_SIZE) {
 617                 pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
 618                 return -EIO;
 619         }
 620         ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
 621                            enonce1, nonceodd, cont, sizeof(uint32_t),
 622                            &ordinal, bloblen, blob, 0, 0);
 623         if (ret < 0)
 624                 return ret;
 625         ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
 626                            enonce2, nonceodd, cont, sizeof(uint32_t),
 627                            &ordinal, bloblen, blob, 0, 0);
 628         if (ret < 0)
 629                 return ret;
 630
 631         /* build and send TPM request packet */
 632         tpm_buf_reset(tb, TPM_TAG_RQU_AUTH2_COMMAND, TPM_ORD_UNSEAL);
 633         tpm_buf_append_u32(tb, keyhandle);
 634         tpm_buf_append(tb, blob, bloblen);
 635         tpm_buf_append_u32(tb, authhandle1);
 636         tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
 637         tpm_buf_append_u8(tb, cont);
 638         tpm_buf_append(tb, authdata1, SHA1_DIGEST_SIZE);
 639         tpm_buf_append_u32(tb, authhandle2);
 640         tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
 641         tpm_buf_append_u8(tb, cont);
 642         tpm_buf_append(tb, authdata2, SHA1_DIGEST_SIZE);
 643
 644         ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
 645         if (ret < 0) {
 646                 pr_info("trusted_key: authhmac failed (%d)\n", ret);
 647                 return ret;
 648         }
 649
 650         *datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
 651         ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
 652                              keyauth, SHA1_DIGEST_SIZE,
 653                              blobauth, SHA1_DIGEST_SIZE,
 654                              sizeof(uint32_t), TPM_DATA_OFFSET,
 655                              *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
 656                              0);
 657         if (ret < 0) {
 658                 pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret);
 659                 return ret;
 660         }
 661         memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
 662         return 0;
 663 }
 664
 665 /*
 666  * Have the TPM seal(encrypt) the symmetric key
 667  */
 668 static int key_seal(struct trusted_key_payload *p,
 669                     struct trusted_key_options *o)
 670 {
 671         struct tpm_buf tb;
 672         int ret;
 673
 674         ret = tpm_buf_init(&tb, 0, 0);
 675         if (ret)
 676                 return ret;
 677
 678         /* include migratable flag at end of sealed key */
 679         p->key[p->key_len] = p->migratable;
 680
 681         ret = tpm_seal(&tb, o->keytype, o->keyhandle, o->keyauth,
 682                        p->key, p->key_len + 1, p->blob, &p->blob_len,
 683                        o->blobauth, o->pcrinfo, o->pcrinfo_len);
 684         if (ret < 0)
 685                 pr_info("trusted_key: srkseal failed (%d)\n", ret);
 686
 687         tpm_buf_destroy(&tb);
 688         return ret;
 689 }
 690
 691 /*
 692  * Have the TPM unseal(decrypt) the symmetric key
 693  */
 694 static int key_unseal(struct trusted_key_payload *p,
 695                       struct trusted_key_options *o)
 696 {
 697         struct tpm_buf tb;
 698         int ret;
 699
 700         ret = tpm_buf_init(&tb, 0, 0);
 701         if (ret)
 702                 return ret;
 703
 704         ret = tpm_unseal(&tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
 705                          o->blobauth, p->key, &p->key_len);
 706         if (ret < 0)
 707                 pr_info("trusted_key: srkunseal failed (%d)\n", ret);
 708         else
 709                 /* pull migratable flag out of sealed key */
 710                 p->migratable = p->key[--p->key_len];
 711
 712         tpm_buf_destroy(&tb);
 713         return ret;
 714 }
 715
 716 enum {
 717         Opt_err,
 718         Opt_new, Opt_load, Opt_update,
 719         Opt_keyhandle, Opt_keyauth, Opt_blobauth,
 720         Opt_pcrinfo, Opt_pcrlock, Opt_migratable,
 721         Opt_hash,
 722         Opt_policydigest,
 723         Opt_policyhandle,
 724 };
 725
 726 static const match_table_t key_tokens = {
 727         {Opt_new, "new"},
 728         {Opt_load, "load"},
 729         {Opt_update, "update"},
 730         {Opt_keyhandle, "keyhandle=%s"},
 731         {Opt_keyauth, "keyauth=%s"},
 732         {Opt_blobauth, "blobauth=%s"},
 733         {Opt_pcrinfo, "pcrinfo=%s"},
 734         {Opt_pcrlock, "pcrlock=%s"},
 735         {Opt_migratable, "migratable=%s"},
 736         {Opt_hash, "hash=%s"},
 737         {Opt_policydigest, "policydigest=%s"},
 738         {Opt_policyhandle, "policyhandle=%s"},
 739         {Opt_err, NULL}
 740 };
 741
 742 /* can have zero or more token= options */
 743 static int getoptions(char *c, struct trusted_key_payload *pay,
 744                       struct trusted_key_options *opt)
 745 {
 746         substring_t args[MAX_OPT_ARGS];
 747         char *p = c;
 748         int token;
 749         int res;
 750         unsigned long handle;
 751         unsigned long lock;
 752         unsigned long token_mask = 0;
 753         unsigned int digest_len;
 754         int i;
 755         int tpm2;
 756
 757         tpm2 = tpm_is_tpm2(chip);
 758         if (tpm2 < 0)
 759                 return tpm2;
 760
 761         opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1;
 762
 763         while ((p = strsep(&c, " \t"))) {
 764                 if (*p == '\0' || *p == ' ' || *p == '\t')
 765                         continue;
 766                 token = match_token(p, key_tokens, args);
 767                 if (test_and_set_bit(token, &token_mask))
 768                         return -EINVAL;
 769
 770                 switch (token) {
 771                 case Opt_pcrinfo:
 772                         opt->pcrinfo_len = strlen(args[0].from) / 2;
 773                         if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
 774                                 return -EINVAL;
 775                         res = hex2bin(opt->pcrinfo, args[0].from,
 776                                       opt->pcrinfo_len);
 777                         if (res < 0)
 778                                 return -EINVAL;
 779                         break;
 780                 case Opt_keyhandle:
 781                         res = kstrtoul(args[0].from, 16, &handle);
 782                         if (res < 0)
 783                                 return -EINVAL;
 784                         opt->keytype = SEAL_keytype;
 785                         opt->keyhandle = handle;
 786                         break;
 787                 case Opt_keyauth:
 788                         if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
 789                                 return -EINVAL;
 790                         res = hex2bin(opt->keyauth, args[0].from,
 791                                       SHA1_DIGEST_SIZE);
 792                         if (res < 0)
 793                                 return -EINVAL;
 794                         break;
 795                 case Opt_blobauth:
 796                         /*
 797                          * TPM 1.2 authorizations are sha1 hashes passed in as
 798                          * hex strings.  TPM 2.0 authorizations are simple
 799                          * passwords (although it can take a hash as well)
 800                          */
 801                         opt->blobauth_len = strlen(args[0].from);
 802
 803                         if (opt->blobauth_len == 2 * TPM_DIGEST_SIZE) {
 804                                 res = hex2bin(opt->blobauth, args[0].from,
 805                                               TPM_DIGEST_SIZE);
 806                                 if (res < 0)
 807                                         return -EINVAL;
 808
 809                                 opt->blobauth_len = TPM_DIGEST_SIZE;
 810                                 break;
 811                         }
 812
 813                         if (tpm2 && opt->blobauth_len <= sizeof(opt->blobauth)) {
 814                                 memcpy(opt->blobauth, args[0].from,
 815                                        opt->blobauth_len);
 816                                 break;
 817                         }
 818
 819                         return -EINVAL;
 820
 821                         break;
 822
 823                 case Opt_migratable:
 824                         if (*args[0].from == '0')
 825                                 pay->migratable = 0;
 826                         else if (*args[0].from != '1')
 827                                 return -EINVAL;
 828                         break;
 829                 case Opt_pcrlock:
 830                         res = kstrtoul(args[0].from, 10, &lock);
 831                         if (res < 0)
 832                                 return -EINVAL;
 833                         opt->pcrlock = lock;
 834                         break;
 835                 case Opt_hash:
 836                         if (test_bit(Opt_policydigest, &token_mask))
 837                                 return -EINVAL;
 838                         for (i = 0; i < HASH_ALGO__LAST; i++) {
 839                                 if (!strcmp(args[0].from, hash_algo_name[i])) {
 840                                         opt->hash = i;
 841                                         break;
 842                                 }
 843                         }
 844                         if (i == HASH_ALGO__LAST)
 845                                 return -EINVAL;
 846                         if  (!tpm2 && i != HASH_ALGO_SHA1) {
 847                                 pr_info("trusted_key: TPM 1.x only supports SHA-1.\n");
 848                                 return -EINVAL;
 849                         }
 850                         break;
 851                 case Opt_policydigest:
 852                         digest_len = hash_digest_size[opt->hash];
 853                         if (!tpm2 || strlen(args[0].from) != (2 * digest_len))
 854                                 return -EINVAL;
 855                         res = hex2bin(opt->policydigest, args[0].from,
 856                                       digest_len);
 857                         if (res < 0)
 858                                 return -EINVAL;
 859                         opt->policydigest_len = digest_len;
 860                         break;
 861                 case Opt_policyhandle:
 862                         if (!tpm2)
 863                                 return -EINVAL;
 864                         res = kstrtoul(args[0].from, 16, &handle);
 865                         if (res < 0)
 866                                 return -EINVAL;
 867                         opt->policyhandle = handle;
 868                         break;
 869                 default:
 870                         return -EINVAL;
 871                 }
 872         }
 873         return 0;
 874 }
 875
 876 /*
 877  * datablob_parse - parse the keyctl data and fill in the
 878  *                  payload and options structures
 879  *
 880  * On success returns 0, otherwise -EINVAL.
 881  */
 882 static int datablob_parse(char *datablob, struct trusted_key_payload *p,
 883                           struct trusted_key_options *o)
 884 {
 885         substring_t args[MAX_OPT_ARGS];
 886         long keylen;
 887         int ret = -EINVAL;
 888         int key_cmd;
 889         char *c;
 890
 891         /* main command */
 892         c = strsep(&datablob, " \t");
 893         if (!c)
 894                 return -EINVAL;
 895         key_cmd = match_token(c, key_tokens, args);
 896         switch (key_cmd) {
 897         case Opt_new:
 898                 /* first argument is key size */
 899                 c = strsep(&datablob, " \t");
 900                 if (!c)
 901                         return -EINVAL;
 902                 ret = kstrtol(c, 10, &keylen);
 903                 if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
 904                         return -EINVAL;
 905                 p->key_len = keylen;
 906                 ret = getoptions(datablob, p, o);
 907                 if (ret < 0)
 908                         return ret;
 909                 ret = Opt_new;
 910                 break;
 911         case Opt_load:
 912                 /* first argument is sealed blob */
 913                 c = strsep(&datablob, " \t");
 914                 if (!c)
 915                         return -EINVAL;
 916                 p->blob_len = strlen(c) / 2;
 917                 if (p->blob_len > MAX_BLOB_SIZE)
 918                         return -EINVAL;
 919                 ret = hex2bin(p->blob, c, p->blob_len);
 920                 if (ret < 0)
 921                         return -EINVAL;
 922                 ret = getoptions(datablob, p, o);
 923                 if (ret < 0)
 924                         return ret;
 925                 ret = Opt_load;
 926                 break;
 927         case Opt_update:
 928                 /* all arguments are options */
 929                 ret = getoptions(datablob, p, o);
 930                 if (ret < 0)
 931                         return ret;
 932                 ret = Opt_update;
 933                 break;
 934         case Opt_err:
 935                 return -EINVAL;
 936                 break;
 937         }
 938         return ret;
 939 }
 940
 941 static struct trusted_key_options *trusted_options_alloc(void)
 942 {
 943         struct trusted_key_options *options;
 944         int tpm2;
 945
 946         tpm2 = tpm_is_tpm2(chip);
 947         if (tpm2 < 0)
 948                 return NULL;
 949
 950         options = kzalloc(sizeof *options, GFP_KERNEL);
 951         if (options) {
 952                 /* set any non-zero defaults */
 953                 options->keytype = SRK_keytype;
 954
 955                 if (!tpm2)
 956                         options->keyhandle = SRKHANDLE;
 957         }
 958         return options;
 959 }
 960
 961 static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
 962 {
 963         struct trusted_key_payload *p = NULL;
 964         int ret;
 965
 966         ret = key_payload_reserve(key, sizeof *p);
 967         if (ret < 0)
 968                 return p;
 969         p = kzalloc(sizeof *p, GFP_KERNEL);
 970         if (p)
 971                 p->migratable = 1; /* migratable by default */
 972         return p;
 973 }
 974
 975 /*
 976  * trusted_instantiate - create a new trusted key
 977  *
 978  * Unseal an existing trusted blob or, for a new key, get a
 979  * random key, then seal and create a trusted key-type key,
 980  * adding it to the specified keyring.
 981  *
 982  * On success, return 0. Otherwise return errno.
 983  */
 984 static int trusted_instantiate(struct key *key,
 985                                struct key_preparsed_payload *prep)
 986 {
 987         struct trusted_key_payload *payload = NULL;
 988         struct trusted_key_options *options = NULL;
 989         size_t datalen = prep->datalen;
 990         char *datablob;
 991         int ret = 0;
 992         int key_cmd;
 993         size_t key_len;
 994         int tpm2;
 995
 996         tpm2 = tpm_is_tpm2(chip);
 997         if (tpm2 < 0)
 998                 return tpm2;
 999
1000         if (datalen <= 0 || datalen > 32767 || !prep->data)
1001                 return -EINVAL;
1002
1003         datablob = kmalloc(datalen + 1, GFP_KERNEL);
1004         if (!datablob)
1005                 return -ENOMEM;
1006         memcpy(datablob, prep->data, datalen);
1007         datablob[datalen] = '\0';
1008
1009         options = trusted_options_alloc();
1010         if (!options) {
1011                 ret = -ENOMEM;
1012                 goto out;
1013         }
1014         payload = trusted_payload_alloc(key);
1015         if (!payload) {
1016                 ret = -ENOMEM;
1017                 goto out;
1018         }
1019
1020         key_cmd = datablob_parse(datablob, payload, options);
1021         if (key_cmd < 0) {
1022                 ret = key_cmd;
1023                 goto out;
1024         }
1025
1026         if (!options->keyhandle) {
1027                 ret = -EINVAL;
1028                 goto out;
1029         }
1030
1031         dump_payload(payload);
1032         dump_options(options);
1033
1034         switch (key_cmd) {
1035         case Opt_load:
1036                 if (tpm2)
1037                         ret = tpm2_unseal_trusted(chip, payload, options);
1038                 else
1039                         ret = key_unseal(payload, options);
1040                 dump_payload(payload);
1041                 dump_options(options);
1042                 if (ret < 0)
1043                         pr_info("trusted_key: key_unseal failed (%d)\n", ret);
1044                 break;
1045         case Opt_new:
1046                 key_len = payload->key_len;
1047                 ret = tpm_get_random(chip, payload->key, key_len);
1048                 if (ret < 0)
1049                         goto out;
1050
1051                 if (ret != key_len) {
1052                         pr_info("trusted_key: key_create failed (%d)\n", ret);
1053                         ret = -EIO;
1054                         goto out;
1055                 }
1056                 if (tpm2)
1057                         ret = tpm2_seal_trusted(chip, payload, options);
1058                 else
1059                         ret = key_seal(payload, options);
1060                 if (ret < 0)
1061                         pr_info("trusted_key: key_seal failed (%d)\n", ret);
1062                 break;
1063         default:
1064                 ret = -EINVAL;
1065                 goto out;
1066         }
1067         if (!ret && options->pcrlock)
1068                 ret = pcrlock(options->pcrlock);
1069 out:
1070         kfree_sensitive(datablob);
1071         kfree_sensitive(options);
1072         if (!ret)
1073                 rcu_assign_keypointer(key, payload);
1074         else
1075                 kfree_sensitive(payload);
1076         return ret;
1077 }
1078
1079 static void trusted_rcu_free(struct rcu_head *rcu)
1080 {
1081         struct trusted_key_payload *p;
1082
1083         p = container_of(rcu, struct trusted_key_payload, rcu);
1084         kfree_sensitive(p);
1085 }
1086
1087 /*
1088  * trusted_update - reseal an existing key with new PCR values
1089  */
1090 static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
1091 {
1092         struct trusted_key_payload *p;
1093         struct trusted_key_payload *new_p;
1094         struct trusted_key_options *new_o;
1095         size_t datalen = prep->datalen;
1096         char *datablob;
1097         int ret = 0;
1098
1099         if (key_is_negative(key))
1100                 return -ENOKEY;
1101         p = key->payload.data[0];
1102         if (!p->migratable)
1103                 return -EPERM;
1104         if (datalen <= 0 || datalen > 32767 || !prep->data)
1105                 return -EINVAL;
1106
1107         datablob = kmalloc(datalen + 1, GFP_KERNEL);
1108         if (!datablob)
1109                 return -ENOMEM;
1110         new_o = trusted_options_alloc();
1111         if (!new_o) {
1112                 ret = -ENOMEM;
1113                 goto out;
1114         }
1115         new_p = trusted_payload_alloc(key);
1116         if (!new_p) {
1117                 ret = -ENOMEM;
1118                 goto out;
1119         }
1120
1121         memcpy(datablob, prep->data, datalen);
1122         datablob[datalen] = '\0';
1123         ret = datablob_parse(datablob, new_p, new_o);
1124         if (ret != Opt_update) {
1125                 ret = -EINVAL;
1126                 kfree_sensitive(new_p);
1127                 goto out;
1128         }
1129
1130         if (!new_o->keyhandle) {
1131                 ret = -EINVAL;
1132                 kfree_sensitive(new_p);
1133                 goto out;
1134         }
1135
1136         /* copy old key values, and reseal with new pcrs */
1137         new_p->migratable = p->migratable;
1138         new_p->key_len = p->key_len;
1139         memcpy(new_p->key, p->key, p->key_len);
1140         dump_payload(p);
1141         dump_payload(new_p);
1142
1143         ret = key_seal(new_p, new_o);
1144         if (ret < 0) {
1145                 pr_info("trusted_key: key_seal failed (%d)\n", ret);
1146                 kfree_sensitive(new_p);
1147                 goto out;
1148         }
1149         if (new_o->pcrlock) {
1150                 ret = pcrlock(new_o->pcrlock);
1151                 if (ret < 0) {
1152                         pr_info("trusted_key: pcrlock failed (%d)\n", ret);
1153                         kfree_sensitive(new_p);
1154                         goto out;
1155                 }
1156         }
1157         rcu_assign_keypointer(key, new_p);
1158         call_rcu(&p->rcu, trusted_rcu_free);
1159 out:
1160         kfree_sensitive(datablob);
1161         kfree_sensitive(new_o);
1162         return ret;
1163 }
1164
1165 /*
1166  * trusted_read - copy the sealed blob data to userspace in hex.
1167  * On success, return to userspace the trusted key datablob size.
1168  */
1169 static long trusted_read(const struct key *key, char *buffer,
1170                          size_t buflen)
1171 {
1172         const struct trusted_key_payload *p;
1173         char *bufp;
1174         int i;
1175
1176         p = dereference_key_locked(key);
1177         if (!p)
1178                 return -EINVAL;
1179
1180         if (buffer && buflen >= 2 * p->blob_len) {
1181                 bufp = buffer;
1182                 for (i = 0; i < p->blob_len; i++)
1183                         bufp = hex_byte_pack(bufp, p->blob[i]);
1184         }
1185         return 2 * p->blob_len;
1186 }
1187
1188 /*
1189  * trusted_destroy - clear and free the key's payload
1190  */
1191 static void trusted_destroy(struct key *key)
1192 {
1193         kfree_sensitive(key->payload.data[0]);
1194 }
1195
1196 struct key_type key_type_trusted = {
1197         .name = "trusted",
1198         .instantiate = trusted_instantiate,
1199         .update = trusted_update,
1200         .destroy = trusted_destroy,
1201         .describe = user_describe,
1202         .read = trusted_read,
1203 };
1204
1205 EXPORT_SYMBOL_GPL(key_type_trusted);
1206
1207 static void trusted_shash_release(void)
1208 {
1209         if (hashalg)
1210                 crypto_free_shash(hashalg);
1211         if (hmacalg)
1212                 crypto_free_shash(hmacalg);
1213 }
1214
1215 static int __init trusted_shash_alloc(void)
1216 {
1217         int ret;
1218
1219         hmacalg = crypto_alloc_shash(hmac_alg, 0, 0);
1220         if (IS_ERR(hmacalg)) {
1221                 pr_info("trusted_key: could not allocate crypto %s\n",
1222                         hmac_alg);
1223                 return PTR_ERR(hmacalg);
1224         }
1225
1226         hashalg = crypto_alloc_shash(hash_alg, 0, 0);
1227         if (IS_ERR(hashalg)) {
1228                 pr_info("trusted_key: could not allocate crypto %s\n",
1229                         hash_alg);
1230                 ret = PTR_ERR(hashalg);
1231                 goto hashalg_fail;
1232         }
1233
1234         return 0;
1235
1236 hashalg_fail:
1237         crypto_free_shash(hmacalg);
1238         return ret;
1239 }
1240
1241 static int __init init_digests(void)
1242 {
1243         int i;
1244
1245         digests = kcalloc(chip->nr_allocated_banks, sizeof(*digests),
1246                           GFP_KERNEL);
1247         if (!digests)
1248                 return -ENOMEM;
1249
1250         for (i = 0; i < chip->nr_allocated_banks; i++)
1251                 digests[i].alg_id = chip->allocated_banks[i].alg_id;
1252
1253         return 0;
1254 }
1255
1256 static int __init init_trusted(void)
1257 {
1258         int ret;
1259
1260         /* encrypted_keys.ko depends on successful load of this module even if
1261          * TPM is not used.
1262          */
1263         chip = tpm_default_chip();
1264         if (!chip)
1265                 return 0;
1266
1267         ret = init_digests();
1268         if (ret < 0)
1269                 goto err_put;
1270         ret = trusted_shash_alloc();
1271         if (ret < 0)
1272                 goto err_free;
1273         ret = register_key_type(&key_type_trusted);
1274         if (ret < 0)
1275                 goto err_release;
1276         return 0;
1277 err_release:
1278         trusted_shash_release();
1279 err_free:
1280         kfree(digests);
1281 err_put:
1282         put_device(&chip->dev);
1283         return ret;
1284 }
1285
1286 static void __exit cleanup_trusted(void)
1287 {
1288         if (chip) {
1289                 put_device(&chip->dev);
1290                 kfree(digests);
1291                 trusted_shash_release();
1292                 unregister_key_type(&key_type_trusted);
1293         }
1294 }
1295
1296 late_initcall(init_trusted);
1297 module_exit(cleanup_trusted);
1298
1299 MODULE_LICENSE("GPL");