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