security/keys/trusted-keys/trusted_tpm1.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2010 IBM Corporation
   4  * Copyright (c) 2019-2021, Linaro Limited
   5  *
   6  * See Documentation/security/keys/trusted-encrypted.rst
   7  */
   8
   9 #include <crypto/hash_info.h>
  10 #include <linux/init.h>
  11 #include <linux/slab.h>
  12 #include <linux/parser.h>
  13 #include <linux/string.h>
  14 #include <linux/err.h>
  15 #include <keys/trusted-type.h>
  16 #include <linux/key-type.h>
  17 #include <linux/crypto.h>
  18 #include <crypto/hash.h>
  19 #include <crypto/sha1.h>
  20 #include <linux/tpm.h>
  21 #include <linux/tpm_command.h>
  22
  23 #include <keys/trusted_tpm.h>
  24
  25 static const char hmac_alg[] = "hmac(sha1)";
  26 static const char hash_alg[] = "sha1";
  27 static struct tpm_chip *chip;
  28 static struct tpm_digest *digests;
  29
  30 struct sdesc {
  31         struct shash_desc shash;
  32         char ctx[];
  33 };
  34
  35 static struct crypto_shash *hashalg;
  36 static struct crypto_shash *hmacalg;
  37
  38 static struct sdesc *init_sdesc(struct crypto_shash *alg)
  39 {
  40         struct sdesc *sdesc;
  41         int size;
  42
  43         size = sizeof(struct shash_desc) + crypto_shash_descsize(alg);
  44         sdesc = kmalloc(size, GFP_KERNEL);
  45         if (!sdesc)
  46                 return ERR_PTR(-ENOMEM);
  47         sdesc->shash.tfm = alg;
  48         return sdesc;
  49 }
  50
  51 static int TSS_sha1(const unsigned char *data, unsigned int datalen,
  52                     unsigned char *digest)
  53 {
  54         struct sdesc *sdesc;
  55         int ret;
  56
  57         sdesc = init_sdesc(hashalg);
  58         if (IS_ERR(sdesc)) {
  59                 pr_info("can't alloc %s\n", hash_alg);
  60                 return PTR_ERR(sdesc);
  61         }
  62
  63         ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest);
  64         kfree_sensitive(sdesc);
  65         return ret;
  66 }
  67
  68 static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
  69                        unsigned int keylen, ...)
  70 {
  71         struct sdesc *sdesc;
  72         va_list argp;
  73         unsigned int dlen;
  74         unsigned char *data;
  75         int ret;
  76
  77         sdesc = init_sdesc(hmacalg);
  78         if (IS_ERR(sdesc)) {
  79                 pr_info("can't alloc %s\n", hmac_alg);
  80                 return PTR_ERR(sdesc);
  81         }
  82
  83         ret = crypto_shash_setkey(hmacalg, key, keylen);
  84         if (ret < 0)
  85                 goto out;
  86         ret = crypto_shash_init(&sdesc->shash);
  87         if (ret < 0)
  88                 goto out;
  89
  90         va_start(argp, keylen);
  91         for (;;) {
  92                 dlen = va_arg(argp, unsigned int);
  93                 if (dlen == 0)
  94                         break;
  95                 data = va_arg(argp, unsigned char *);
  96                 if (data == NULL) {
  97                         ret = -EINVAL;
  98                         break;
  99                 }
 100                 ret = crypto_shash_update(&sdesc->shash, data, dlen);
 101                 if (ret < 0)
 102                         break;
 103         }
 104         va_end(argp);
 105         if (!ret)
 106                 ret = crypto_shash_final(&sdesc->shash, digest);
 107 out:
 108         kfree_sensitive(sdesc);
 109         return ret;
 110 }
 111
 112 /*
 113  * calculate authorization info fields to send to TPM
 114  */
 115 int TSS_authhmac(unsigned char *digest, const unsigned char *key,
 116                         unsigned int keylen, unsigned char *h1,
 117                         unsigned char *h2, unsigned int h3, ...)
 118 {
 119         unsigned char paramdigest[SHA1_DIGEST_SIZE];
 120         struct sdesc *sdesc;
 121         unsigned int dlen;
 122         unsigned char *data;
 123         unsigned char c;
 124         int ret;
 125         va_list argp;
 126
 127         if (!chip)
 128                 return -ENODEV;
 129
 130         sdesc = init_sdesc(hashalg);
 131         if (IS_ERR(sdesc)) {
 132                 pr_info("can't alloc %s\n", hash_alg);
 133                 return PTR_ERR(sdesc);
 134         }
 135
 136         c = !!h3;
 137         ret = crypto_shash_init(&sdesc->shash);
 138         if (ret < 0)
 139                 goto out;
 140         va_start(argp, h3);
 141         for (;;) {
 142                 dlen = va_arg(argp, unsigned int);
 143                 if (dlen == 0)
 144                         break;
 145                 data = va_arg(argp, unsigned char *);
 146                 if (!data) {
 147                         ret = -EINVAL;
 148                         break;
 149                 }
 150                 ret = crypto_shash_update(&sdesc->shash, data, dlen);
 151                 if (ret < 0)
 152                         break;
 153         }
 154         va_end(argp);
 155         if (!ret)
 156                 ret = crypto_shash_final(&sdesc->shash, paramdigest);
 157         if (!ret)
 158                 ret = TSS_rawhmac(digest, key, keylen, SHA1_DIGEST_SIZE,
 159                                   paramdigest, TPM_NONCE_SIZE, h1,
 160                                   TPM_NONCE_SIZE, h2, 1, &c, 0, 0);
 161 out:
 162         kfree_sensitive(sdesc);
 163         return ret;
 164 }
 165 EXPORT_SYMBOL_GPL(TSS_authhmac);
 166
 167 /*
 168  * verify the AUTH1_COMMAND (Seal) result from TPM
 169  */
 170 int TSS_checkhmac1(unsigned char *buffer,
 171                           const uint32_t command,
 172                           const unsigned char *ononce,
 173                           const unsigned char *key,
 174                           unsigned int keylen, ...)
 175 {
 176         uint32_t bufsize;
 177         uint16_t tag;
 178         uint32_t ordinal;
 179         uint32_t result;
 180         unsigned char *enonce;
 181         unsigned char *continueflag;
 182         unsigned char *authdata;
 183         unsigned char testhmac[SHA1_DIGEST_SIZE];
 184         unsigned char paramdigest[SHA1_DIGEST_SIZE];
 185         struct sdesc *sdesc;
 186         unsigned int dlen;
 187         unsigned int dpos;
 188         va_list argp;
 189         int ret;
 190
 191         if (!chip)
 192                 return -ENODEV;
 193
 194         bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
 195         tag = LOAD16(buffer, 0);
 196         ordinal = command;
 197         result = LOAD32N(buffer, TPM_RETURN_OFFSET);
 198         if (tag == TPM_TAG_RSP_COMMAND)
 199                 return 0;
 200         if (tag != TPM_TAG_RSP_AUTH1_COMMAND)
 201                 return -EINVAL;
 202         authdata = buffer + bufsize - SHA1_DIGEST_SIZE;
 203         continueflag = authdata - 1;
 204         enonce = continueflag - TPM_NONCE_SIZE;
 205
 206         sdesc = init_sdesc(hashalg);
 207         if (IS_ERR(sdesc)) {
 208                 pr_info("can't alloc %s\n", hash_alg);
 209                 return PTR_ERR(sdesc);
 210         }
 211         ret = crypto_shash_init(&sdesc->shash);
 212         if (ret < 0)
 213                 goto out;
 214         ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
 215                                   sizeof result);
 216         if (ret < 0)
 217                 goto out;
 218         ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
 219                                   sizeof ordinal);
 220         if (ret < 0)
 221                 goto out;
 222         va_start(argp, keylen);
 223         for (;;) {
 224                 dlen = va_arg(argp, unsigned int);
 225                 if (dlen == 0)
 226                         break;
 227                 dpos = va_arg(argp, unsigned int);
 228                 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
 229                 if (ret < 0)
 230                         break;
 231         }
 232         va_end(argp);
 233         if (!ret)
 234                 ret = crypto_shash_final(&sdesc->shash, paramdigest);
 235         if (ret < 0)
 236                 goto out;
 237
 238         ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest,
 239                           TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce,
 240                           1, continueflag, 0, 0);
 241         if (ret < 0)
 242                 goto out;
 243
 244         if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE))
 245                 ret = -EINVAL;
 246 out:
 247         kfree_sensitive(sdesc);
 248         return ret;
 249 }
 250 EXPORT_SYMBOL_GPL(TSS_checkhmac1);
 251
 252 /*
 253  * verify the AUTH2_COMMAND (unseal) result from TPM
 254  */
 255 static int TSS_checkhmac2(unsigned char *buffer,
 256                           const uint32_t command,
 257                           const unsigned char *ononce,
 258                           const unsigned char *key1,
 259                           unsigned int keylen1,
 260                           const unsigned char *key2,
 261                           unsigned int keylen2, ...)
 262 {
 263         uint32_t bufsize;
 264         uint16_t tag;
 265         uint32_t ordinal;
 266         uint32_t result;
 267         unsigned char *enonce1;
 268         unsigned char *continueflag1;
 269         unsigned char *authdata1;
 270         unsigned char *enonce2;
 271         unsigned char *continueflag2;
 272         unsigned char *authdata2;
 273         unsigned char testhmac1[SHA1_DIGEST_SIZE];
 274         unsigned char testhmac2[SHA1_DIGEST_SIZE];
 275         unsigned char paramdigest[SHA1_DIGEST_SIZE];
 276         struct sdesc *sdesc;
 277         unsigned int dlen;
 278         unsigned int dpos;
 279         va_list argp;
 280         int ret;
 281
 282         bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
 283         tag = LOAD16(buffer, 0);
 284         ordinal = command;
 285         result = LOAD32N(buffer, TPM_RETURN_OFFSET);
 286
 287         if (tag == TPM_TAG_RSP_COMMAND)
 288                 return 0;
 289         if (tag != TPM_TAG_RSP_AUTH2_COMMAND)
 290                 return -EINVAL;
 291         authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1
 292                         + SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE);
 293         authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE);
 294         continueflag1 = authdata1 - 1;
 295         continueflag2 = authdata2 - 1;
 296         enonce1 = continueflag1 - TPM_NONCE_SIZE;
 297         enonce2 = continueflag2 - TPM_NONCE_SIZE;
 298
 299         sdesc = init_sdesc(hashalg);
 300         if (IS_ERR(sdesc)) {
 301                 pr_info("can't alloc %s\n", hash_alg);
 302                 return PTR_ERR(sdesc);
 303         }
 304         ret = crypto_shash_init(&sdesc->shash);
 305         if (ret < 0)
 306                 goto out;
 307         ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
 308                                   sizeof result);
 309         if (ret < 0)
 310                 goto out;
 311         ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
 312                                   sizeof ordinal);
 313         if (ret < 0)
 314                 goto out;
 315
 316         va_start(argp, keylen2);
 317         for (;;) {
 318                 dlen = va_arg(argp, unsigned int);
 319                 if (dlen == 0)
 320                         break;
 321                 dpos = va_arg(argp, unsigned int);
 322                 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
 323                 if (ret < 0)
 324                         break;
 325         }
 326         va_end(argp);
 327         if (!ret)
 328                 ret = crypto_shash_final(&sdesc->shash, paramdigest);
 329         if (ret < 0)
 330                 goto out;
 331
 332         ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE,
 333                           paramdigest, TPM_NONCE_SIZE, enonce1,
 334                           TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0);
 335         if (ret < 0)
 336                 goto out;
 337         if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) {
 338                 ret = -EINVAL;
 339                 goto out;
 340         }
 341         ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE,
 342                           paramdigest, TPM_NONCE_SIZE, enonce2,
 343                           TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0);
 344         if (ret < 0)
 345                 goto out;
 346         if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE))
 347                 ret = -EINVAL;
 348 out:
 349         kfree_sensitive(sdesc);
 350         return ret;
 351 }
 352
 353 /*
 354  * For key specific tpm requests, we will generate and send our
 355  * own TPM command packets using the drivers send function.
 356  */
 357 int trusted_tpm_send(unsigned char *cmd, size_t buflen)
 358 {
 359         int rc;
 360
 361         if (!chip)
 362                 return -ENODEV;
 363
 364         dump_tpm_buf(cmd);
 365         rc = tpm_send(chip, cmd, buflen);
 366         dump_tpm_buf(cmd);
 367         if (rc > 0)
 368                 /* Can't return positive return codes values to keyctl */
 369                 rc = -EPERM;
 370         return rc;
 371 }
 372 EXPORT_SYMBOL_GPL(trusted_tpm_send);
 373
 374 /*
 375  * Lock a trusted key, by extending a selected PCR.
 376  *
 377  * Prevents a trusted key that is sealed to PCRs from being accessed.
 378  * This uses the tpm driver's extend function.
 379  */
 380 static int pcrlock(const int pcrnum)
 381 {
 382         if (!capable(CAP_SYS_ADMIN))
 383                 return -EPERM;
 384
 385         return tpm_pcr_extend(chip, pcrnum, digests) ? -EINVAL : 0;
 386 }
 387
 388 /*
 389  * Create an object specific authorisation protocol (OSAP) session
 390  */
 391 static int osap(struct tpm_buf *tb, struct osapsess *s,
 392                 const unsigned char *key, uint16_t type, uint32_t handle)
 393 {
 394         unsigned char enonce[TPM_NONCE_SIZE];
 395         unsigned char ononce[TPM_NONCE_SIZE];
 396         int ret;
 397
 398         ret = tpm_get_random(chip, ononce, TPM_NONCE_SIZE);
 399         if (ret < 0)
 400                 return ret;
 401
 402         if (ret != TPM_NONCE_SIZE)
 403                 return -EIO;
 404
 405         tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OSAP);
 406         tpm_buf_append_u16(tb, type);
 407         tpm_buf_append_u32(tb, handle);
 408         tpm_buf_append(tb, ononce, TPM_NONCE_SIZE);
 409
 410         ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
 411         if (ret < 0)
 412                 return ret;
 413
 414         s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
 415         memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
 416                TPM_NONCE_SIZE);
 417         memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
 418                                   TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
 419         return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
 420                            enonce, TPM_NONCE_SIZE, ononce, 0, 0);
 421 }
 422
 423 /*
 424  * Create an object independent authorisation protocol (oiap) session
 425  */
 426 int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
 427 {
 428         int ret;
 429
 430         if (!chip)
 431                 return -ENODEV;
 432
 433         tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OIAP);
 434         ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
 435         if (ret < 0)
 436                 return ret;
 437
 438         *handle = LOAD32(tb->data, TPM_DATA_OFFSET);
 439         memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
 440                TPM_NONCE_SIZE);
 441         return 0;
 442 }
 443 EXPORT_SYMBOL_GPL(oiap);
 444
 445 struct tpm_digests {
 446         unsigned char encauth[SHA1_DIGEST_SIZE];
 447         unsigned char pubauth[SHA1_DIGEST_SIZE];
 448         unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
 449         unsigned char xorhash[SHA1_DIGEST_SIZE];
 450         unsigned char nonceodd[TPM_NONCE_SIZE];
 451 };
 452
 453 /*
 454  * Have the TPM seal(encrypt) the trusted key, possibly based on
 455  * Platform Configuration Registers (PCRs). AUTH1 for sealing key.
 456  */
 457 static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
 458                     uint32_t keyhandle, const unsigned char *keyauth,
 459                     const unsigned char *data, uint32_t datalen,
 460                     unsigned char *blob, uint32_t *bloblen,
 461                     const unsigned char *blobauth,
 462                     const unsigned char *pcrinfo, uint32_t pcrinfosize)
 463 {
 464         struct osapsess sess;
 465         struct tpm_digests *td;
 466         unsigned char cont;
 467         uint32_t ordinal;
 468         uint32_t pcrsize;
 469         uint32_t datsize;
 470         int sealinfosize;
 471         int encdatasize;
 472         int storedsize;
 473         int ret;
 474         int i;
 475
 476         /* alloc some work space for all the hashes */
 477         td = kmalloc(sizeof *td, GFP_KERNEL);
 478         if (!td)
 479                 return -ENOMEM;
 480
 481         /* get session for sealing key */
 482         ret = osap(tb, &sess, keyauth, keytype, keyhandle);
 483         if (ret < 0)
 484                 goto out;
 485         dump_sess(&sess);
 486
 487         /* calculate encrypted authorization value */
 488         memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
 489         memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
 490         ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
 491         if (ret < 0)
 492                 goto out;
 493
 494         ret = tpm_get_random(chip, td->nonceodd, TPM_NONCE_SIZE);
 495         if (ret < 0)
 496                 return ret;
 497
 498         if (ret != TPM_NONCE_SIZE)
 499                 return -EIO;
 500
 501         ordinal = htonl(TPM_ORD_SEAL);
 502         datsize = htonl(datalen);
 503         pcrsize = htonl(pcrinfosize);
 504         cont = 0;
 505
 506         /* encrypt data authorization key */
 507         for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
 508                 td->encauth[i] = td->xorhash[i] ^ blobauth[i];
 509
 510         /* calculate authorization HMAC value */
 511         if (pcrinfosize == 0) {
 512                 /* no pcr info specified */
 513                 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
 514                                    sess.enonce, td->nonceodd, cont,
 515                                    sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
 516                                    td->encauth, sizeof(uint32_t), &pcrsize,
 517                                    sizeof(uint32_t), &datsize, datalen, data, 0,
 518                                    0);
 519         } else {
 520                 /* pcr info specified */
 521                 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
 522                                    sess.enonce, td->nonceodd, cont,
 523                                    sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
 524                                    td->encauth, sizeof(uint32_t), &pcrsize,
 525                                    pcrinfosize, pcrinfo, sizeof(uint32_t),
 526                                    &datsize, datalen, data, 0, 0);
 527         }
 528         if (ret < 0)
 529                 goto out;
 530
 531         /* build and send the TPM request packet */
 532         tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_SEAL);
 533         tpm_buf_append_u32(tb, keyhandle);
 534         tpm_buf_append(tb, td->encauth, SHA1_DIGEST_SIZE);
 535         tpm_buf_append_u32(tb, pcrinfosize);
 536         tpm_buf_append(tb, pcrinfo, pcrinfosize);
 537         tpm_buf_append_u32(tb, datalen);
 538         tpm_buf_append(tb, data, datalen);
 539         tpm_buf_append_u32(tb, sess.handle);
 540         tpm_buf_append(tb, td->nonceodd, TPM_NONCE_SIZE);
 541         tpm_buf_append_u8(tb, cont);
 542         tpm_buf_append(tb, td->pubauth, SHA1_DIGEST_SIZE);
 543
 544         ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
 545         if (ret < 0)
 546                 goto out;
 547
 548         /* calculate the size of the returned Blob */
 549         sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
 550         encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
 551                              sizeof(uint32_t) + sealinfosize);
 552         storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
 553             sizeof(uint32_t) + encdatasize;
 554
 555         /* check the HMAC in the response */
 556         ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
 557                              SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
 558                              0);
 559
 560         /* copy the returned blob to caller */
 561         if (!ret) {
 562                 memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
 563                 *bloblen = storedsize;
 564         }
 565 out:
 566         kfree_sensitive(td);
 567         return ret;
 568 }
 569
 570 /*
 571  * use the AUTH2_COMMAND form of unseal, to authorize both key and blob
 572  */
 573 static int tpm_unseal(struct tpm_buf *tb,
 574                       uint32_t keyhandle, const unsigned char *keyauth,
 575                       const unsigned char *blob, int bloblen,
 576                       const unsigned char *blobauth,
 577                       unsigned char *data, unsigned int *datalen)
 578 {
 579         unsigned char nonceodd[TPM_NONCE_SIZE];
 580         unsigned char enonce1[TPM_NONCE_SIZE];
 581         unsigned char enonce2[TPM_NONCE_SIZE];
 582         unsigned char authdata1[SHA1_DIGEST_SIZE];
 583         unsigned char authdata2[SHA1_DIGEST_SIZE];
 584         uint32_t authhandle1 = 0;
 585         uint32_t authhandle2 = 0;
 586         unsigned char cont = 0;
 587         uint32_t ordinal;
 588         int ret;
 589
 590         /* sessions for unsealing key and data */
 591         ret = oiap(tb, &authhandle1, enonce1);
 592         if (ret < 0) {
 593                 pr_info("oiap failed (%d)\n", ret);
 594                 return ret;
 595         }
 596         ret = oiap(tb, &authhandle2, enonce2);
 597         if (ret < 0) {
 598                 pr_info("oiap failed (%d)\n", ret);
 599                 return ret;
 600         }
 601
 602         ordinal = htonl(TPM_ORD_UNSEAL);
 603         ret = tpm_get_random(chip, nonceodd, TPM_NONCE_SIZE);
 604         if (ret < 0)
 605                 return ret;
 606
 607         if (ret != TPM_NONCE_SIZE) {
 608                 pr_info("tpm_get_random failed (%d)\n", ret);
 609                 return -EIO;
 610         }
 611         ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
 612                            enonce1, nonceodd, cont, sizeof(uint32_t),
 613                            &ordinal, bloblen, blob, 0, 0);
 614         if (ret < 0)
 615                 return ret;
 616         ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
 617                            enonce2, nonceodd, cont, sizeof(uint32_t),
 618                            &ordinal, bloblen, blob, 0, 0);
 619         if (ret < 0)
 620                 return ret;
 621
 622         /* build and send TPM request packet */
 623         tpm_buf_reset(tb, TPM_TAG_RQU_AUTH2_COMMAND, TPM_ORD_UNSEAL);
 624         tpm_buf_append_u32(tb, keyhandle);
 625         tpm_buf_append(tb, blob, bloblen);
 626         tpm_buf_append_u32(tb, authhandle1);
 627         tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
 628         tpm_buf_append_u8(tb, cont);
 629         tpm_buf_append(tb, authdata1, SHA1_DIGEST_SIZE);
 630         tpm_buf_append_u32(tb, authhandle2);
 631         tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
 632         tpm_buf_append_u8(tb, cont);
 633         tpm_buf_append(tb, authdata2, SHA1_DIGEST_SIZE);
 634
 635         ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
 636         if (ret < 0) {
 637                 pr_info("authhmac failed (%d)\n", ret);
 638                 return ret;
 639         }
 640
 641         *datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
 642         ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
 643                              keyauth, SHA1_DIGEST_SIZE,
 644                              blobauth, SHA1_DIGEST_SIZE,
 645                              sizeof(uint32_t), TPM_DATA_OFFSET,
 646                              *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
 647                              0);
 648         if (ret < 0) {
 649                 pr_info("TSS_checkhmac2 failed (%d)\n", ret);
 650                 return ret;
 651         }
 652         memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
 653         return 0;
 654 }
 655
 656 /*
 657  * Have the TPM seal(encrypt) the symmetric key
 658  */
 659 static int key_seal(struct trusted_key_payload *p,
 660                     struct trusted_key_options *o)
 661 {
 662         struct tpm_buf tb;
 663         int ret;
 664
 665         ret = tpm_buf_init(&tb, 0, 0);
 666         if (ret)
 667                 return ret;
 668
 669         /* include migratable flag at end of sealed key */
 670         p->key[p->key_len] = p->migratable;
 671
 672         ret = tpm_seal(&tb, o->keytype, o->keyhandle, o->keyauth,
 673                        p->key, p->key_len + 1, p->blob, &p->blob_len,
 674                        o->blobauth, o->pcrinfo, o->pcrinfo_len);
 675         if (ret < 0)
 676                 pr_info("srkseal failed (%d)\n", ret);
 677
 678         tpm_buf_destroy(&tb);
 679         return ret;
 680 }
 681
 682 /*
 683  * Have the TPM unseal(decrypt) the symmetric key
 684  */
 685 static int key_unseal(struct trusted_key_payload *p,
 686                       struct trusted_key_options *o)
 687 {
 688         struct tpm_buf tb;
 689         int ret;
 690
 691         ret = tpm_buf_init(&tb, 0, 0);
 692         if (ret)
 693                 return ret;
 694
 695         ret = tpm_unseal(&tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
 696                          o->blobauth, p->key, &p->key_len);
 697         if (ret < 0)
 698                 pr_info("srkunseal failed (%d)\n", ret);
 699         else
 700                 /* pull migratable flag out of sealed key */
 701                 p->migratable = p->key[--p->key_len];
 702
 703         tpm_buf_destroy(&tb);
 704         return ret;
 705 }
 706
 707 enum {
 708         Opt_err,
 709         Opt_keyhandle, Opt_keyauth, Opt_blobauth,
 710         Opt_pcrinfo, Opt_pcrlock, Opt_migratable,
 711         Opt_hash,
 712         Opt_policydigest,
 713         Opt_policyhandle,
 714 };
 715
 716 static const match_table_t key_tokens = {
 717         {Opt_keyhandle, "keyhandle=%s"},
 718         {Opt_keyauth, "keyauth=%s"},
 719         {Opt_blobauth, "blobauth=%s"},
 720         {Opt_pcrinfo, "pcrinfo=%s"},
 721         {Opt_pcrlock, "pcrlock=%s"},
 722         {Opt_migratable, "migratable=%s"},
 723         {Opt_hash, "hash=%s"},
 724         {Opt_policydigest, "policydigest=%s"},
 725         {Opt_policyhandle, "policyhandle=%s"},
 726         {Opt_err, NULL}
 727 };
 728
 729 /* can have zero or more token= options */
 730 static int getoptions(char *c, struct trusted_key_payload *pay,
 731                       struct trusted_key_options *opt)
 732 {
 733         substring_t args[MAX_OPT_ARGS];
 734         char *p = c;
 735         int token;
 736         int res;
 737         unsigned long handle;
 738         unsigned long lock;
 739         unsigned long token_mask = 0;
 740         unsigned int digest_len;
 741         int i;
 742         int tpm2;
 743
 744         tpm2 = tpm_is_tpm2(chip);
 745         if (tpm2 < 0)
 746                 return tpm2;
 747
 748         opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1;
 749
 750         while ((p = strsep(&c, " \t"))) {
 751                 if (*p == '\0' || *p == ' ' || *p == '\t')
 752                         continue;
 753                 token = match_token(p, key_tokens, args);
 754                 if (test_and_set_bit(token, &token_mask))
 755                         return -EINVAL;
 756
 757                 switch (token) {
 758                 case Opt_pcrinfo:
 759                         opt->pcrinfo_len = strlen(args[0].from) / 2;
 760                         if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
 761                                 return -EINVAL;
 762                         res = hex2bin(opt->pcrinfo, args[0].from,
 763                                       opt->pcrinfo_len);
 764                         if (res < 0)
 765                                 return -EINVAL;
 766                         break;
 767                 case Opt_keyhandle:
 768                         res = kstrtoul(args[0].from, 16, &handle);
 769                         if (res < 0)
 770                                 return -EINVAL;
 771                         opt->keytype = SEAL_keytype;
 772                         opt->keyhandle = handle;
 773                         break;
 774                 case Opt_keyauth:
 775                         if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
 776                                 return -EINVAL;
 777                         res = hex2bin(opt->keyauth, args[0].from,
 778                                       SHA1_DIGEST_SIZE);
 779                         if (res < 0)
 780                                 return -EINVAL;
 781                         break;
 782                 case Opt_blobauth:
 783                         /*
 784                          * TPM 1.2 authorizations are sha1 hashes passed in as
 785                          * hex strings.  TPM 2.0 authorizations are simple
 786                          * passwords (although it can take a hash as well)
 787                          */
 788                         opt->blobauth_len = strlen(args[0].from);
 789
 790                         if (opt->blobauth_len == 2 * TPM_DIGEST_SIZE) {
 791                                 res = hex2bin(opt->blobauth, args[0].from,
 792                                               TPM_DIGEST_SIZE);
 793                                 if (res < 0)
 794                                         return -EINVAL;
 795
 796                                 opt->blobauth_len = TPM_DIGEST_SIZE;
 797                                 break;
 798                         }
 799
 800                         if (tpm2 && opt->blobauth_len <= sizeof(opt->blobauth)) {
 801                                 memcpy(opt->blobauth, args[0].from,
 802                                        opt->blobauth_len);
 803                                 break;
 804                         }
 805
 806                         return -EINVAL;
 807
 808                         break;
 809
 810                 case Opt_migratable:
 811                         if (*args[0].from == '0')
 812                                 pay->migratable = 0;
 813                         else if (*args[0].from != '1')
 814                                 return -EINVAL;
 815                         break;
 816                 case Opt_pcrlock:
 817                         res = kstrtoul(args[0].from, 10, &lock);
 818                         if (res < 0)
 819                                 return -EINVAL;
 820                         opt->pcrlock = lock;
 821                         break;
 822                 case Opt_hash:
 823                         if (test_bit(Opt_policydigest, &token_mask))
 824                                 return -EINVAL;
 825                         for (i = 0; i < HASH_ALGO__LAST; i++) {
 826                                 if (!strcmp(args[0].from, hash_algo_name[i])) {
 827                                         opt->hash = i;
 828                                         break;
 829                                 }
 830                         }
 831                         if (i == HASH_ALGO__LAST)
 832                                 return -EINVAL;
 833                         if  (!tpm2 && i != HASH_ALGO_SHA1) {
 834                                 pr_info("TPM 1.x only supports SHA-1.\n");
 835                                 return -EINVAL;
 836                         }
 837                         break;
 838                 case Opt_policydigest:
 839                         digest_len = hash_digest_size[opt->hash];
 840                         if (!tpm2 || strlen(args[0].from) != (2 * digest_len))
 841                                 return -EINVAL;
 842                         res = hex2bin(opt->policydigest, args[0].from,
 843                                       digest_len);
 844                         if (res < 0)
 845                                 return -EINVAL;
 846                         opt->policydigest_len = digest_len;
 847                         break;
 848                 case Opt_policyhandle:
 849                         if (!tpm2)
 850                                 return -EINVAL;
 851                         res = kstrtoul(args[0].from, 16, &handle);
 852                         if (res < 0)
 853                                 return -EINVAL;
 854                         opt->policyhandle = handle;
 855                         break;
 856                 default:
 857                         return -EINVAL;
 858                 }
 859         }
 860         return 0;
 861 }
 862
 863 static struct trusted_key_options *trusted_options_alloc(void)
 864 {
 865         struct trusted_key_options *options;
 866         int tpm2;
 867
 868         tpm2 = tpm_is_tpm2(chip);
 869         if (tpm2 < 0)
 870                 return NULL;
 871
 872         options = kzalloc(sizeof *options, GFP_KERNEL);
 873         if (options) {
 874                 /* set any non-zero defaults */
 875                 options->keytype = SRK_keytype;
 876
 877                 if (!tpm2)
 878                         options->keyhandle = SRKHANDLE;
 879         }
 880         return options;
 881 }
 882
 883 static int trusted_tpm_seal(struct trusted_key_payload *p, char *datablob)
 884 {
 885         struct trusted_key_options *options = NULL;
 886         int ret = 0;
 887         int tpm2;
 888
 889         tpm2 = tpm_is_tpm2(chip);
 890         if (tpm2 < 0)
 891                 return tpm2;
 892
 893         options = trusted_options_alloc();
 894         if (!options)
 895                 return -ENOMEM;
 896
 897         ret = getoptions(datablob, p, options);
 898         if (ret < 0)
 899                 goto out;
 900         dump_options(options);
 901
 902         if (!options->keyhandle && !tpm2) {
 903                 ret = -EINVAL;
 904                 goto out;
 905         }
 906
 907         if (tpm2)
 908                 ret = tpm2_seal_trusted(chip, p, options);
 909         else
 910                 ret = key_seal(p, options);
 911         if (ret < 0) {
 912                 pr_info("key_seal failed (%d)\n", ret);
 913                 goto out;
 914         }
 915
 916         if (options->pcrlock) {
 917                 ret = pcrlock(options->pcrlock);
 918                 if (ret < 0) {
 919                         pr_info("pcrlock failed (%d)\n", ret);
 920                         goto out;
 921                 }
 922         }
 923 out:
 924         kfree_sensitive(options);
 925         return ret;
 926 }
 927
 928 static int trusted_tpm_unseal(struct trusted_key_payload *p, char *datablob)
 929 {
 930         struct trusted_key_options *options = NULL;
 931         int ret = 0;
 932         int tpm2;
 933
 934         tpm2 = tpm_is_tpm2(chip);
 935         if (tpm2 < 0)
 936                 return tpm2;
 937
 938         options = trusted_options_alloc();
 939         if (!options)
 940                 return -ENOMEM;
 941
 942         ret = getoptions(datablob, p, options);
 943         if (ret < 0)
 944                 goto out;
 945         dump_options(options);
 946
 947         if (!options->keyhandle) {
 948                 ret = -EINVAL;
 949                 goto out;
 950         }
 951
 952         if (tpm2)
 953                 ret = tpm2_unseal_trusted(chip, p, options);
 954         else
 955                 ret = key_unseal(p, options);
 956         if (ret < 0)
 957                 pr_info("key_unseal failed (%d)\n", ret);
 958
 959         if (options->pcrlock) {
 960                 ret = pcrlock(options->pcrlock);
 961                 if (ret < 0) {
 962                         pr_info("pcrlock failed (%d)\n", ret);
 963                         goto out;
 964                 }
 965         }
 966 out:
 967         kfree_sensitive(options);
 968         return ret;
 969 }
 970
 971 static int trusted_tpm_get_random(unsigned char *key, size_t key_len)
 972 {
 973         return tpm_get_random(chip, key, key_len);
 974 }
 975
 976 static void trusted_shash_release(void)
 977 {
 978         if (hashalg)
 979                 crypto_free_shash(hashalg);
 980         if (hmacalg)
 981                 crypto_free_shash(hmacalg);
 982 }
 983
 984 static int __init trusted_shash_alloc(void)
 985 {
 986         int ret;
 987
 988         hmacalg = crypto_alloc_shash(hmac_alg, 0, 0);
 989         if (IS_ERR(hmacalg)) {
 990                 pr_info("could not allocate crypto %s\n",
 991                         hmac_alg);
 992                 return PTR_ERR(hmacalg);
 993         }
 994
 995         hashalg = crypto_alloc_shash(hash_alg, 0, 0);
 996         if (IS_ERR(hashalg)) {
 997                 pr_info("could not allocate crypto %s\n",
 998                         hash_alg);
 999                 ret = PTR_ERR(hashalg);
1000                 goto hashalg_fail;
1001         }
1002
1003         return 0;
1004
1005 hashalg_fail:
1006         crypto_free_shash(hmacalg);
1007         return ret;
1008 }
1009
1010 static int __init init_digests(void)
1011 {
1012         int i;
1013
1014         digests = kcalloc(chip->nr_allocated_banks, sizeof(*digests),
1015                           GFP_KERNEL);
1016         if (!digests)
1017                 return -ENOMEM;
1018
1019         for (i = 0; i < chip->nr_allocated_banks; i++)
1020                 digests[i].alg_id = chip->allocated_banks[i].alg_id;
1021
1022         return 0;
1023 }
1024
1025 static int __init trusted_tpm_init(void)
1026 {
1027         int ret;
1028
1029         chip = tpm_default_chip();
1030         if (!chip)
1031                 return -ENODEV;
1032
1033         ret = init_digests();
1034         if (ret < 0)
1035                 goto err_put;
1036         ret = trusted_shash_alloc();
1037         if (ret < 0)
1038                 goto err_free;
1039         ret = register_key_type(&key_type_trusted);
1040         if (ret < 0)
1041                 goto err_release;
1042         return 0;
1043 err_release:
1044         trusted_shash_release();
1045 err_free:
1046         kfree(digests);
1047 err_put:
1048         put_device(&chip->dev);
1049         return ret;
1050 }
1051
1052 static void trusted_tpm_exit(void)
1053 {
1054         if (chip) {
1055                 put_device(&chip->dev);
1056                 kfree(digests);
1057                 trusted_shash_release();
1058                 unregister_key_type(&key_type_trusted);
1059         }
1060 }
1061
1062 struct trusted_key_ops trusted_key_tpm_ops = {
1063         .migratable = 1, /* migratable by default */
1064         .init = trusted_tpm_init,
1065         .seal = trusted_tpm_seal,
1066         .unseal = trusted_tpm_unseal,
1067         .get_random = trusted_tpm_get_random,
1068         .exit = trusted_tpm_exit,
1069 };