linux/security/keys/trusted-keys/trusted_tpm1.c
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   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
  25static const char hmac_alg[] = "hmac(sha1)";
  26static const char hash_alg[] = "sha1";
  27static struct tpm_chip *chip;
  28static struct tpm_digest *digests;
  29
  30struct sdesc {
  31        struct shash_desc shash;
  32        char ctx[];
  33};
  34
  35static struct crypto_shash *hashalg;
  36static struct crypto_shash *hmacalg;
  37
  38static 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
  51static 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
  68static 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);
 107out:
 108        kfree_sensitive(sdesc);
 109        return ret;
 110}
 111
 112/*
 113 * calculate authorization info fields to send to TPM
 114 */
 115int 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);
 161out:
 162        kfree_sensitive(sdesc);
 163        return ret;
 164}
 165EXPORT_SYMBOL_GPL(TSS_authhmac);
 166
 167/*
 168 * verify the AUTH1_COMMAND (Seal) result from TPM
 169 */
 170int 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;
 246out:
 247        kfree_sensitive(sdesc);
 248        return ret;
 249}
 250EXPORT_SYMBOL_GPL(TSS_checkhmac1);
 251
 252/*
 253 * verify the AUTH2_COMMAND (unseal) result from TPM
 254 */
 255static 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;
 348out:
 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 */
 357int 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}
 372EXPORT_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 */
 380static 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 */
 391static 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 */
 426int 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}
 443EXPORT_SYMBOL_GPL(oiap);
 444
 445struct 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 */
 457static 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                goto out;
 497
 498        if (ret != TPM_NONCE_SIZE) {
 499                ret = -EIO;
 500                goto out;
 501        }
 502
 503        ordinal = htonl(TPM_ORD_SEAL);
 504        datsize = htonl(datalen);
 505        pcrsize = htonl(pcrinfosize);
 506        cont = 0;
 507
 508        /* encrypt data authorization key */
 509        for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
 510                td->encauth[i] = td->xorhash[i] ^ blobauth[i];
 511
 512        /* calculate authorization HMAC value */
 513        if (pcrinfosize == 0) {
 514                /* no pcr info specified */
 515                ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
 516                                   sess.enonce, td->nonceodd, cont,
 517                                   sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
 518                                   td->encauth, sizeof(uint32_t), &pcrsize,
 519                                   sizeof(uint32_t), &datsize, datalen, data, 0,
 520                                   0);
 521        } else {
 522                /* pcr info specified */
 523                ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
 524                                   sess.enonce, td->nonceodd, cont,
 525                                   sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
 526                                   td->encauth, sizeof(uint32_t), &pcrsize,
 527                                   pcrinfosize, pcrinfo, sizeof(uint32_t),
 528                                   &datsize, datalen, data, 0, 0);
 529        }
 530        if (ret < 0)
 531                goto out;
 532
 533        /* build and send the TPM request packet */
 534        tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_SEAL);
 535        tpm_buf_append_u32(tb, keyhandle);
 536        tpm_buf_append(tb, td->encauth, SHA1_DIGEST_SIZE);
 537        tpm_buf_append_u32(tb, pcrinfosize);
 538        tpm_buf_append(tb, pcrinfo, pcrinfosize);
 539        tpm_buf_append_u32(tb, datalen);
 540        tpm_buf_append(tb, data, datalen);
 541        tpm_buf_append_u32(tb, sess.handle);
 542        tpm_buf_append(tb, td->nonceodd, TPM_NONCE_SIZE);
 543        tpm_buf_append_u8(tb, cont);
 544        tpm_buf_append(tb, td->pubauth, SHA1_DIGEST_SIZE);
 545
 546        ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
 547        if (ret < 0)
 548                goto out;
 549
 550        /* calculate the size of the returned Blob */
 551        sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
 552        encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
 553                             sizeof(uint32_t) + sealinfosize);
 554        storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
 555            sizeof(uint32_t) + encdatasize;
 556
 557        /* check the HMAC in the response */
 558        ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
 559                             SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
 560                             0);
 561
 562        /* copy the returned blob to caller */
 563        if (!ret) {
 564                memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
 565                *bloblen = storedsize;
 566        }
 567out:
 568        kfree_sensitive(td);
 569        return ret;
 570}
 571
 572/*
 573 * use the AUTH2_COMMAND form of unseal, to authorize both key and blob
 574 */
 575static int tpm_unseal(struct tpm_buf *tb,
 576                      uint32_t keyhandle, const unsigned char *keyauth,
 577                      const unsigned char *blob, int bloblen,
 578                      const unsigned char *blobauth,
 579                      unsigned char *data, unsigned int *datalen)
 580{
 581        unsigned char nonceodd[TPM_NONCE_SIZE];
 582        unsigned char enonce1[TPM_NONCE_SIZE];
 583        unsigned char enonce2[TPM_NONCE_SIZE];
 584        unsigned char authdata1[SHA1_DIGEST_SIZE];
 585        unsigned char authdata2[SHA1_DIGEST_SIZE];
 586        uint32_t authhandle1 = 0;
 587        uint32_t authhandle2 = 0;
 588        unsigned char cont = 0;
 589        uint32_t ordinal;
 590        int ret;
 591
 592        /* sessions for unsealing key and data */
 593        ret = oiap(tb, &authhandle1, enonce1);
 594        if (ret < 0) {
 595                pr_info("oiap failed (%d)\n", ret);
 596                return ret;
 597        }
 598        ret = oiap(tb, &authhandle2, enonce2);
 599        if (ret < 0) {
 600                pr_info("oiap failed (%d)\n", ret);
 601                return ret;
 602        }
 603
 604        ordinal = htonl(TPM_ORD_UNSEAL);
 605        ret = tpm_get_random(chip, nonceodd, TPM_NONCE_SIZE);
 606        if (ret < 0)
 607                return ret;
 608
 609        if (ret != TPM_NONCE_SIZE) {
 610                pr_info("tpm_get_random failed (%d)\n", ret);
 611                return -EIO;
 612        }
 613        ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
 614                           enonce1, nonceodd, cont, sizeof(uint32_t),
 615                           &ordinal, bloblen, blob, 0, 0);
 616        if (ret < 0)
 617                return ret;
 618        ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
 619                           enonce2, nonceodd, cont, sizeof(uint32_t),
 620                           &ordinal, bloblen, blob, 0, 0);
 621        if (ret < 0)
 622                return ret;
 623
 624        /* build and send TPM request packet */
 625        tpm_buf_reset(tb, TPM_TAG_RQU_AUTH2_COMMAND, TPM_ORD_UNSEAL);
 626        tpm_buf_append_u32(tb, keyhandle);
 627        tpm_buf_append(tb, blob, bloblen);
 628        tpm_buf_append_u32(tb, authhandle1);
 629        tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
 630        tpm_buf_append_u8(tb, cont);
 631        tpm_buf_append(tb, authdata1, SHA1_DIGEST_SIZE);
 632        tpm_buf_append_u32(tb, authhandle2);
 633        tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
 634        tpm_buf_append_u8(tb, cont);
 635        tpm_buf_append(tb, authdata2, SHA1_DIGEST_SIZE);
 636
 637        ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
 638        if (ret < 0) {
 639                pr_info("authhmac failed (%d)\n", ret);
 640                return ret;
 641        }
 642
 643        *datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
 644        ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
 645                             keyauth, SHA1_DIGEST_SIZE,
 646                             blobauth, SHA1_DIGEST_SIZE,
 647                             sizeof(uint32_t), TPM_DATA_OFFSET,
 648                             *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
 649                             0);
 650        if (ret < 0) {
 651                pr_info("TSS_checkhmac2 failed (%d)\n", ret);
 652                return ret;
 653        }
 654        memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
 655        return 0;
 656}
 657
 658/*
 659 * Have the TPM seal(encrypt) the symmetric key
 660 */
 661static int key_seal(struct trusted_key_payload *p,
 662                    struct trusted_key_options *o)
 663{
 664        struct tpm_buf tb;
 665        int ret;
 666
 667        ret = tpm_buf_init(&tb, 0, 0);
 668        if (ret)
 669                return ret;
 670
 671        /* include migratable flag at end of sealed key */
 672        p->key[p->key_len] = p->migratable;
 673
 674        ret = tpm_seal(&tb, o->keytype, o->keyhandle, o->keyauth,
 675                       p->key, p->key_len + 1, p->blob, &p->blob_len,
 676                       o->blobauth, o->pcrinfo, o->pcrinfo_len);
 677        if (ret < 0)
 678                pr_info("srkseal failed (%d)\n", ret);
 679
 680        tpm_buf_destroy(&tb);
 681        return ret;
 682}
 683
 684/*
 685 * Have the TPM unseal(decrypt) the symmetric key
 686 */
 687static int key_unseal(struct trusted_key_payload *p,
 688                      struct trusted_key_options *o)
 689{
 690        struct tpm_buf tb;
 691        int ret;
 692
 693        ret = tpm_buf_init(&tb, 0, 0);
 694        if (ret)
 695                return ret;
 696
 697        ret = tpm_unseal(&tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
 698                         o->blobauth, p->key, &p->key_len);
 699        if (ret < 0)
 700                pr_info("srkunseal failed (%d)\n", ret);
 701        else
 702                /* pull migratable flag out of sealed key */
 703                p->migratable = p->key[--p->key_len];
 704
 705        tpm_buf_destroy(&tb);
 706        return ret;
 707}
 708
 709enum {
 710        Opt_err,
 711        Opt_keyhandle, Opt_keyauth, Opt_blobauth,
 712        Opt_pcrinfo, Opt_pcrlock, Opt_migratable,
 713        Opt_hash,
 714        Opt_policydigest,
 715        Opt_policyhandle,
 716};
 717
 718static const match_table_t key_tokens = {
 719        {Opt_keyhandle, "keyhandle=%s"},
 720        {Opt_keyauth, "keyauth=%s"},
 721        {Opt_blobauth, "blobauth=%s"},
 722        {Opt_pcrinfo, "pcrinfo=%s"},
 723        {Opt_pcrlock, "pcrlock=%s"},
 724        {Opt_migratable, "migratable=%s"},
 725        {Opt_hash, "hash=%s"},
 726        {Opt_policydigest, "policydigest=%s"},
 727        {Opt_policyhandle, "policyhandle=%s"},
 728        {Opt_err, NULL}
 729};
 730
 731/* can have zero or more token= options */
 732static int getoptions(char *c, struct trusted_key_payload *pay,
 733                      struct trusted_key_options *opt)
 734{
 735        substring_t args[MAX_OPT_ARGS];
 736        char *p = c;
 737        int token;
 738        int res;
 739        unsigned long handle;
 740        unsigned long lock;
 741        unsigned long token_mask = 0;
 742        unsigned int digest_len;
 743        int i;
 744        int tpm2;
 745
 746        tpm2 = tpm_is_tpm2(chip);
 747        if (tpm2 < 0)
 748                return tpm2;
 749
 750        opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1;
 751
 752        if (!c)
 753                return 0;
 754
 755        while ((p = strsep(&c, " \t"))) {
 756                if (*p == '\0' || *p == ' ' || *p == '\t')
 757                        continue;
 758                token = match_token(p, key_tokens, args);
 759                if (test_and_set_bit(token, &token_mask))
 760                        return -EINVAL;
 761
 762                switch (token) {
 763                case Opt_pcrinfo:
 764                        opt->pcrinfo_len = strlen(args[0].from) / 2;
 765                        if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
 766                                return -EINVAL;
 767                        res = hex2bin(opt->pcrinfo, args[0].from,
 768                                      opt->pcrinfo_len);
 769                        if (res < 0)
 770                                return -EINVAL;
 771                        break;
 772                case Opt_keyhandle:
 773                        res = kstrtoul(args[0].from, 16, &handle);
 774                        if (res < 0)
 775                                return -EINVAL;
 776                        opt->keytype = SEAL_keytype;
 777                        opt->keyhandle = handle;
 778                        break;
 779                case Opt_keyauth:
 780                        if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
 781                                return -EINVAL;
 782                        res = hex2bin(opt->keyauth, args[0].from,
 783                                      SHA1_DIGEST_SIZE);
 784                        if (res < 0)
 785                                return -EINVAL;
 786                        break;
 787                case Opt_blobauth:
 788                        /*
 789                         * TPM 1.2 authorizations are sha1 hashes passed in as
 790                         * hex strings.  TPM 2.0 authorizations are simple
 791                         * passwords (although it can take a hash as well)
 792                         */
 793                        opt->blobauth_len = strlen(args[0].from);
 794
 795                        if (opt->blobauth_len == 2 * TPM_DIGEST_SIZE) {
 796                                res = hex2bin(opt->blobauth, args[0].from,
 797                                              TPM_DIGEST_SIZE);
 798                                if (res < 0)
 799                                        return -EINVAL;
 800
 801                                opt->blobauth_len = TPM_DIGEST_SIZE;
 802                                break;
 803                        }
 804
 805                        if (tpm2 && opt->blobauth_len <= sizeof(opt->blobauth)) {
 806                                memcpy(opt->blobauth, args[0].from,
 807                                       opt->blobauth_len);
 808                                break;
 809                        }
 810
 811                        return -EINVAL;
 812
 813                        break;
 814
 815                case Opt_migratable:
 816                        if (*args[0].from == '0')
 817                                pay->migratable = 0;
 818                        else if (*args[0].from != '1')
 819                                return -EINVAL;
 820                        break;
 821                case Opt_pcrlock:
 822                        res = kstrtoul(args[0].from, 10, &lock);
 823                        if (res < 0)
 824                                return -EINVAL;
 825                        opt->pcrlock = lock;
 826                        break;
 827                case Opt_hash:
 828                        if (test_bit(Opt_policydigest, &token_mask))
 829                                return -EINVAL;
 830                        for (i = 0; i < HASH_ALGO__LAST; i++) {
 831                                if (!strcmp(args[0].from, hash_algo_name[i])) {
 832                                        opt->hash = i;
 833                                        break;
 834                                }
 835                        }
 836                        if (i == HASH_ALGO__LAST)
 837                                return -EINVAL;
 838                        if  (!tpm2 && i != HASH_ALGO_SHA1) {
 839                                pr_info("TPM 1.x only supports SHA-1.\n");
 840                                return -EINVAL;
 841                        }
 842                        break;
 843                case Opt_policydigest:
 844                        digest_len = hash_digest_size[opt->hash];
 845                        if (!tpm2 || strlen(args[0].from) != (2 * digest_len))
 846                                return -EINVAL;
 847                        res = hex2bin(opt->policydigest, args[0].from,
 848                                      digest_len);
 849                        if (res < 0)
 850                                return -EINVAL;
 851                        opt->policydigest_len = digest_len;
 852                        break;
 853                case Opt_policyhandle:
 854                        if (!tpm2)
 855                                return -EINVAL;
 856                        res = kstrtoul(args[0].from, 16, &handle);
 857                        if (res < 0)
 858                                return -EINVAL;
 859                        opt->policyhandle = handle;
 860                        break;
 861                default:
 862                        return -EINVAL;
 863                }
 864        }
 865        return 0;
 866}
 867
 868static struct trusted_key_options *trusted_options_alloc(void)
 869{
 870        struct trusted_key_options *options;
 871        int tpm2;
 872
 873        tpm2 = tpm_is_tpm2(chip);
 874        if (tpm2 < 0)
 875                return NULL;
 876
 877        options = kzalloc(sizeof *options, GFP_KERNEL);
 878        if (options) {
 879                /* set any non-zero defaults */
 880                options->keytype = SRK_keytype;
 881
 882                if (!tpm2)
 883                        options->keyhandle = SRKHANDLE;
 884        }
 885        return options;
 886}
 887
 888static int trusted_tpm_seal(struct trusted_key_payload *p, char *datablob)
 889{
 890        struct trusted_key_options *options = NULL;
 891        int ret = 0;
 892        int tpm2;
 893
 894        tpm2 = tpm_is_tpm2(chip);
 895        if (tpm2 < 0)
 896                return tpm2;
 897
 898        options = trusted_options_alloc();
 899        if (!options)
 900                return -ENOMEM;
 901
 902        ret = getoptions(datablob, p, options);
 903        if (ret < 0)
 904                goto out;
 905        dump_options(options);
 906
 907        if (!options->keyhandle && !tpm2) {
 908                ret = -EINVAL;
 909                goto out;
 910        }
 911
 912        if (tpm2)
 913                ret = tpm2_seal_trusted(chip, p, options);
 914        else
 915                ret = key_seal(p, options);
 916        if (ret < 0) {
 917                pr_info("key_seal failed (%d)\n", ret);
 918                goto out;
 919        }
 920
 921        if (options->pcrlock) {
 922                ret = pcrlock(options->pcrlock);
 923                if (ret < 0) {
 924                        pr_info("pcrlock failed (%d)\n", ret);
 925                        goto out;
 926                }
 927        }
 928out:
 929        kfree_sensitive(options);
 930        return ret;
 931}
 932
 933static int trusted_tpm_unseal(struct trusted_key_payload *p, char *datablob)
 934{
 935        struct trusted_key_options *options = NULL;
 936        int ret = 0;
 937        int tpm2;
 938
 939        tpm2 = tpm_is_tpm2(chip);
 940        if (tpm2 < 0)
 941                return tpm2;
 942
 943        options = trusted_options_alloc();
 944        if (!options)
 945                return -ENOMEM;
 946
 947        ret = getoptions(datablob, p, options);
 948        if (ret < 0)
 949                goto out;
 950        dump_options(options);
 951
 952        if (!options->keyhandle && !tpm2) {
 953                ret = -EINVAL;
 954                goto out;
 955        }
 956
 957        if (tpm2)
 958                ret = tpm2_unseal_trusted(chip, p, options);
 959        else
 960                ret = key_unseal(p, options);
 961        if (ret < 0)
 962                pr_info("key_unseal failed (%d)\n", ret);
 963
 964        if (options->pcrlock) {
 965                ret = pcrlock(options->pcrlock);
 966                if (ret < 0) {
 967                        pr_info("pcrlock failed (%d)\n", ret);
 968                        goto out;
 969                }
 970        }
 971out:
 972        kfree_sensitive(options);
 973        return ret;
 974}
 975
 976static int trusted_tpm_get_random(unsigned char *key, size_t key_len)
 977{
 978        return tpm_get_random(chip, key, key_len);
 979}
 980
 981static void trusted_shash_release(void)
 982{
 983        if (hashalg)
 984                crypto_free_shash(hashalg);
 985        if (hmacalg)
 986                crypto_free_shash(hmacalg);
 987}
 988
 989static int __init trusted_shash_alloc(void)
 990{
 991        int ret;
 992
 993        hmacalg = crypto_alloc_shash(hmac_alg, 0, 0);
 994        if (IS_ERR(hmacalg)) {
 995                pr_info("could not allocate crypto %s\n",
 996                        hmac_alg);
 997                return PTR_ERR(hmacalg);
 998        }
 999
1000        hashalg = crypto_alloc_shash(hash_alg, 0, 0);
1001        if (IS_ERR(hashalg)) {
1002                pr_info("could not allocate crypto %s\n",
1003                        hash_alg);
1004                ret = PTR_ERR(hashalg);
1005                goto hashalg_fail;
1006        }
1007
1008        return 0;
1009
1010hashalg_fail:
1011        crypto_free_shash(hmacalg);
1012        return ret;
1013}
1014
1015static int __init init_digests(void)
1016{
1017        int i;
1018
1019        digests = kcalloc(chip->nr_allocated_banks, sizeof(*digests),
1020                          GFP_KERNEL);
1021        if (!digests)
1022                return -ENOMEM;
1023
1024        for (i = 0; i < chip->nr_allocated_banks; i++)
1025                digests[i].alg_id = chip->allocated_banks[i].alg_id;
1026
1027        return 0;
1028}
1029
1030static int __init trusted_tpm_init(void)
1031{
1032        int ret;
1033
1034        chip = tpm_default_chip();
1035        if (!chip)
1036                return -ENODEV;
1037
1038        ret = init_digests();
1039        if (ret < 0)
1040                goto err_put;
1041        ret = trusted_shash_alloc();
1042        if (ret < 0)
1043                goto err_free;
1044        ret = register_key_type(&key_type_trusted);
1045        if (ret < 0)
1046                goto err_release;
1047        return 0;
1048err_release:
1049        trusted_shash_release();
1050err_free:
1051        kfree(digests);
1052err_put:
1053        put_device(&chip->dev);
1054        return ret;
1055}
1056
1057static void trusted_tpm_exit(void)
1058{
1059        if (chip) {
1060                put_device(&chip->dev);
1061                kfree(digests);
1062                trusted_shash_release();
1063                unregister_key_type(&key_type_trusted);
1064        }
1065}
1066
1067struct trusted_key_ops trusted_key_tpm_ops = {
1068        .migratable = 1, /* migratable by default */
1069        .init = trusted_tpm_init,
1070        .seal = trusted_tpm_seal,
1071        .unseal = trusted_tpm_unseal,
1072        .get_random = trusted_tpm_get_random,
1073        .exit = trusted_tpm_exit,
1074};
1075