security/keys/trusted.c

   1 /*
   2  * Copyright (C) 2010 IBM Corporation
   3  *
   4  * Author:
   5  * David Safford <safford@us.ibm.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, version 2 of the License.
  10  *
  11  * See Documentation/security/keys-trusted-encrypted.txt
  12  */
  13
  14 #include <crypto/hash_info.h>
  15 #include <linux/uaccess.h>
  16 #include <linux/module.h>
  17 #include <linux/init.h>
  18 #include <linux/slab.h>
  19 #include <linux/parser.h>
  20 #include <linux/string.h>
  21 #include <linux/err.h>
  22 #include <keys/user-type.h>
  23 #include <keys/trusted-type.h>
  24 #include <linux/key-type.h>
  25 #include <linux/rcupdate.h>
  26 #include <linux/crypto.h>
  27 #include <crypto/hash.h>
  28 #include <crypto/sha.h>
  29 #include <linux/capability.h>
  30 #include <linux/tpm.h>
  31 #include <linux/tpm_command.h>
  32
  33 #include "trusted.h"
  34
  35 static const char hmac_alg[] = "hmac(sha1)";
  36 static const char hash_alg[] = "sha1";
  37
  38 struct sdesc {
  39         struct shash_desc shash;
  40         char ctx[];
  41 };
  42
  43 static struct crypto_shash *hashalg;
  44 static struct crypto_shash *hmacalg;
  45
  46 static struct sdesc *init_sdesc(struct crypto_shash *alg)
  47 {
  48         struct sdesc *sdesc;
  49         int size;
  50
  51         size = sizeof(struct shash_desc) + crypto_shash_descsize(alg);
  52         sdesc = kmalloc(size, GFP_KERNEL);
  53         if (!sdesc)
  54                 return ERR_PTR(-ENOMEM);
  55         sdesc->shash.tfm = alg;
  56         sdesc->shash.flags = 0x0;
  57         return sdesc;
  58 }
  59
  60 static int TSS_sha1(const unsigned char *data, unsigned int datalen,
  61                     unsigned char *digest)
  62 {
  63         struct sdesc *sdesc;
  64         int ret;
  65
  66         sdesc = init_sdesc(hashalg);
  67         if (IS_ERR(sdesc)) {
  68                 pr_info("trusted_key: can't alloc %s\n", hash_alg);
  69                 return PTR_ERR(sdesc);
  70         }
  71
  72         ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest);
  73         kfree(sdesc);
  74         return ret;
  75 }
  76
  77 static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
  78                        unsigned int keylen, ...)
  79 {
  80         struct sdesc *sdesc;
  81         va_list argp;
  82         unsigned int dlen;
  83         unsigned char *data;
  84         int ret;
  85
  86         sdesc = init_sdesc(hmacalg);
  87         if (IS_ERR(sdesc)) {
  88                 pr_info("trusted_key: can't alloc %s\n", hmac_alg);
  89                 return PTR_ERR(sdesc);
  90         }
  91
  92         ret = crypto_shash_setkey(hmacalg, key, keylen);
  93         if (ret < 0)
  94                 goto out;
  95         ret = crypto_shash_init(&sdesc->shash);
  96         if (ret < 0)
  97                 goto out;
  98
  99         va_start(argp, keylen);
 100         for (;;) {
 101                 dlen = va_arg(argp, unsigned int);
 102                 if (dlen == 0)
 103                         break;
 104                 data = va_arg(argp, unsigned char *);
 105                 if (data == NULL) {
 106                         ret = -EINVAL;
 107                         break;
 108                 }
 109                 ret = crypto_shash_update(&sdesc->shash, data, dlen);
 110                 if (ret < 0)
 111                         break;
 112         }
 113         va_end(argp);
 114         if (!ret)
 115                 ret = crypto_shash_final(&sdesc->shash, digest);
 116 out:
 117         kfree(sdesc);
 118         return ret;
 119 }
 120
 121 /*
 122  * calculate authorization info fields to send to TPM
 123  */
 124 static int TSS_authhmac(unsigned char *digest, const unsigned char *key,
 125                         unsigned int keylen, unsigned char *h1,
 126                         unsigned char *h2, unsigned char h3, ...)
 127 {
 128         unsigned char paramdigest[SHA1_DIGEST_SIZE];
 129         struct sdesc *sdesc;
 130         unsigned int dlen;
 131         unsigned char *data;
 132         unsigned char c;
 133         int ret;
 134         va_list argp;
 135
 136         sdesc = init_sdesc(hashalg);
 137         if (IS_ERR(sdesc)) {
 138                 pr_info("trusted_key: can't alloc %s\n", hash_alg);
 139                 return PTR_ERR(sdesc);
 140         }
 141
 142         c = h3;
 143         ret = crypto_shash_init(&sdesc->shash);
 144         if (ret < 0)
 145                 goto out;
 146         va_start(argp, h3);
 147         for (;;) {
 148                 dlen = va_arg(argp, unsigned int);
 149                 if (dlen == 0)
 150                         break;
 151                 data = va_arg(argp, unsigned char *);
 152                 if (!data) {
 153                         ret = -EINVAL;
 154                         break;
 155                 }
 156                 ret = crypto_shash_update(&sdesc->shash, data, dlen);
 157                 if (ret < 0)
 158                         break;
 159         }
 160         va_end(argp);
 161         if (!ret)
 162                 ret = crypto_shash_final(&sdesc->shash, paramdigest);
 163         if (!ret)
 164                 ret = TSS_rawhmac(digest, key, keylen, SHA1_DIGEST_SIZE,
 165                                   paramdigest, TPM_NONCE_SIZE, h1,
 166                                   TPM_NONCE_SIZE, h2, 1, &c, 0, 0);
 167 out:
 168         kfree(sdesc);
 169         return ret;
 170 }
 171
 172 /*
 173  * verify the AUTH1_COMMAND (Seal) result from TPM
 174  */
 175 static int TSS_checkhmac1(unsigned char *buffer,
 176                           const uint32_t command,
 177                           const unsigned char *ononce,
 178                           const unsigned char *key,
 179                           unsigned int keylen, ...)
 180 {
 181         uint32_t bufsize;
 182         uint16_t tag;
 183         uint32_t ordinal;
 184         uint32_t result;
 185         unsigned char *enonce;
 186         unsigned char *continueflag;
 187         unsigned char *authdata;
 188         unsigned char testhmac[SHA1_DIGEST_SIZE];
 189         unsigned char paramdigest[SHA1_DIGEST_SIZE];
 190         struct sdesc *sdesc;
 191         unsigned int dlen;
 192         unsigned int dpos;
 193         va_list argp;
 194         int ret;
 195
 196         bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
 197         tag = LOAD16(buffer, 0);
 198         ordinal = command;
 199         result = LOAD32N(buffer, TPM_RETURN_OFFSET);
 200         if (tag == TPM_TAG_RSP_COMMAND)
 201                 return 0;
 202         if (tag != TPM_TAG_RSP_AUTH1_COMMAND)
 203                 return -EINVAL;
 204         authdata = buffer + bufsize - SHA1_DIGEST_SIZE;
 205         continueflag = authdata - 1;
 206         enonce = continueflag - TPM_NONCE_SIZE;
 207
 208         sdesc = init_sdesc(hashalg);
 209         if (IS_ERR(sdesc)) {
 210                 pr_info("trusted_key: can't alloc %s\n", hash_alg);
 211                 return PTR_ERR(sdesc);
 212         }
 213         ret = crypto_shash_init(&sdesc->shash);
 214         if (ret < 0)
 215                 goto out;
 216         ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
 217                                   sizeof result);
 218         if (ret < 0)
 219                 goto out;
 220         ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
 221                                   sizeof ordinal);
 222         if (ret < 0)
 223                 goto out;
 224         va_start(argp, keylen);
 225         for (;;) {
 226                 dlen = va_arg(argp, unsigned int);
 227                 if (dlen == 0)
 228                         break;
 229                 dpos = va_arg(argp, unsigned int);
 230                 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
 231                 if (ret < 0)
 232                         break;
 233         }
 234         va_end(argp);
 235         if (!ret)
 236                 ret = crypto_shash_final(&sdesc->shash, paramdigest);
 237         if (ret < 0)
 238                 goto out;
 239
 240         ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest,
 241                           TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce,
 242                           1, continueflag, 0, 0);
 243         if (ret < 0)
 244                 goto out;
 245
 246         if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE))
 247                 ret = -EINVAL;
 248 out:
 249         kfree(sdesc);
 250         return ret;
 251 }
 252
 253 /*
 254  * verify the AUTH2_COMMAND (unseal) result from TPM
 255  */
 256 static int TSS_checkhmac2(unsigned char *buffer,
 257                           const uint32_t command,
 258                           const unsigned char *ononce,
 259                           const unsigned char *key1,
 260                           unsigned int keylen1,
 261                           const unsigned char *key2,
 262                           unsigned int keylen2, ...)
 263 {
 264         uint32_t bufsize;
 265         uint16_t tag;
 266         uint32_t ordinal;
 267         uint32_t result;
 268         unsigned char *enonce1;
 269         unsigned char *continueflag1;
 270         unsigned char *authdata1;
 271         unsigned char *enonce2;
 272         unsigned char *continueflag2;
 273         unsigned char *authdata2;
 274         unsigned char testhmac1[SHA1_DIGEST_SIZE];
 275         unsigned char testhmac2[SHA1_DIGEST_SIZE];
 276         unsigned char paramdigest[SHA1_DIGEST_SIZE];
 277         struct sdesc *sdesc;
 278         unsigned int dlen;
 279         unsigned int dpos;
 280         va_list argp;
 281         int ret;
 282
 283         bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
 284         tag = LOAD16(buffer, 0);
 285         ordinal = command;
 286         result = LOAD32N(buffer, TPM_RETURN_OFFSET);
 287
 288         if (tag == TPM_TAG_RSP_COMMAND)
 289                 return 0;
 290         if (tag != TPM_TAG_RSP_AUTH2_COMMAND)
 291                 return -EINVAL;
 292         authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1
 293                         + SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE);
 294         authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE);
 295         continueflag1 = authdata1 - 1;
 296         continueflag2 = authdata2 - 1;
 297         enonce1 = continueflag1 - TPM_NONCE_SIZE;
 298         enonce2 = continueflag2 - TPM_NONCE_SIZE;
 299
 300         sdesc = init_sdesc(hashalg);
 301         if (IS_ERR(sdesc)) {
 302                 pr_info("trusted_key: can't alloc %s\n", hash_alg);
 303                 return PTR_ERR(sdesc);
 304         }
 305         ret = crypto_shash_init(&sdesc->shash);
 306         if (ret < 0)
 307                 goto out;
 308         ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
 309                                   sizeof result);
 310         if (ret < 0)
 311                 goto out;
 312         ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
 313                                   sizeof ordinal);
 314         if (ret < 0)
 315                 goto out;
 316
 317         va_start(argp, keylen2);
 318         for (;;) {
 319                 dlen = va_arg(argp, unsigned int);
 320                 if (dlen == 0)
 321                         break;
 322                 dpos = va_arg(argp, unsigned int);
 323                 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
 324                 if (ret < 0)
 325                         break;
 326         }
 327         va_end(argp);
 328         if (!ret)
 329                 ret = crypto_shash_final(&sdesc->shash, paramdigest);
 330         if (ret < 0)
 331                 goto out;
 332
 333         ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE,
 334                           paramdigest, TPM_NONCE_SIZE, enonce1,
 335                           TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0);
 336         if (ret < 0)
 337                 goto out;
 338         if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) {
 339                 ret = -EINVAL;
 340                 goto out;
 341         }
 342         ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE,
 343                           paramdigest, TPM_NONCE_SIZE, enonce2,
 344                           TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0);
 345         if (ret < 0)
 346                 goto out;
 347         if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE))
 348                 ret = -EINVAL;
 349 out:
 350         kfree(sdesc);
 351         return ret;
 352 }
 353
 354 /*
 355  * For key specific tpm requests, we will generate and send our
 356  * own TPM command packets using the drivers send function.
 357  */
 358 static int trusted_tpm_send(const u32 chip_num, unsigned char *cmd,
 359                             size_t buflen)
 360 {
 361         int rc;
 362
 363         dump_tpm_buf(cmd);
 364         rc = tpm_send(chip_num, cmd, buflen);
 365         dump_tpm_buf(cmd);
 366         if (rc > 0)
 367                 /* Can't return positive return codes values to keyctl */
 368                 rc = -EPERM;
 369         return rc;
 370 }
 371
 372 /*
 373  * Lock a trusted key, by extending a selected PCR.
 374  *
 375  * Prevents a trusted key that is sealed to PCRs from being accessed.
 376  * This uses the tpm driver's extend function.
 377  */
 378 static int pcrlock(const int pcrnum)
 379 {
 380         unsigned char hash[SHA1_DIGEST_SIZE];
 381         int ret;
 382
 383         if (!capable(CAP_SYS_ADMIN))
 384                 return -EPERM;
 385         ret = tpm_get_random(TPM_ANY_NUM, hash, SHA1_DIGEST_SIZE);
 386         if (ret != SHA1_DIGEST_SIZE)
 387                 return ret;
 388         return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0;
 389 }
 390
 391 /*
 392  * Create an object specific authorisation protocol (OSAP) session
 393  */
 394 static int osap(struct tpm_buf *tb, struct osapsess *s,
 395                 const unsigned char *key, uint16_t type, uint32_t handle)
 396 {
 397         unsigned char enonce[TPM_NONCE_SIZE];
 398         unsigned char ononce[TPM_NONCE_SIZE];
 399         int ret;
 400
 401         ret = tpm_get_random(TPM_ANY_NUM, ononce, TPM_NONCE_SIZE);
 402         if (ret != TPM_NONCE_SIZE)
 403                 return ret;
 404
 405         INIT_BUF(tb);
 406         store16(tb, TPM_TAG_RQU_COMMAND);
 407         store32(tb, TPM_OSAP_SIZE);
 408         store32(tb, TPM_ORD_OSAP);
 409         store16(tb, type);
 410         store32(tb, handle);
 411         storebytes(tb, ononce, TPM_NONCE_SIZE);
 412
 413         ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
 414         if (ret < 0)
 415                 return ret;
 416
 417         s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
 418         memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
 419                TPM_NONCE_SIZE);
 420         memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
 421                                   TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
 422         return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
 423                            enonce, TPM_NONCE_SIZE, ononce, 0, 0);
 424 }
 425
 426 /*
 427  * Create an object independent authorisation protocol (oiap) session
 428  */
 429 static int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
 430 {
 431         int ret;
 432
 433         INIT_BUF(tb);
 434         store16(tb, TPM_TAG_RQU_COMMAND);
 435         store32(tb, TPM_OIAP_SIZE);
 436         store32(tb, TPM_ORD_OIAP);
 437         ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
 438         if (ret < 0)
 439                 return ret;
 440
 441         *handle = LOAD32(tb->data, TPM_DATA_OFFSET);
 442         memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
 443                TPM_NONCE_SIZE);
 444         return 0;
 445 }
 446
 447 struct tpm_digests {
 448         unsigned char encauth[SHA1_DIGEST_SIZE];
 449         unsigned char pubauth[SHA1_DIGEST_SIZE];
 450         unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
 451         unsigned char xorhash[SHA1_DIGEST_SIZE];
 452         unsigned char nonceodd[TPM_NONCE_SIZE];
 453 };
 454
 455 /*
 456  * Have the TPM seal(encrypt) the trusted key, possibly based on
 457  * Platform Configuration Registers (PCRs). AUTH1 for sealing key.
 458  */
 459 static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
 460                     uint32_t keyhandle, const unsigned char *keyauth,
 461                     const unsigned char *data, uint32_t datalen,
 462                     unsigned char *blob, uint32_t *bloblen,
 463                     const unsigned char *blobauth,
 464                     const unsigned char *pcrinfo, uint32_t pcrinfosize)
 465 {
 466         struct osapsess sess;
 467         struct tpm_digests *td;
 468         unsigned char cont;
 469         uint32_t ordinal;
 470         uint32_t pcrsize;
 471         uint32_t datsize;
 472         int sealinfosize;
 473         int encdatasize;
 474         int storedsize;
 475         int ret;
 476         int i;
 477
 478         /* alloc some work space for all the hashes */
 479         td = kmalloc(sizeof *td, GFP_KERNEL);
 480         if (!td)
 481                 return -ENOMEM;
 482
 483         /* get session for sealing key */
 484         ret = osap(tb, &sess, keyauth, keytype, keyhandle);
 485         if (ret < 0)
 486                 goto out;
 487         dump_sess(&sess);
 488
 489         /* calculate encrypted authorization value */
 490         memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
 491         memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
 492         ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
 493         if (ret < 0)
 494                 goto out;
 495
 496         ret = tpm_get_random(TPM_ANY_NUM, td->nonceodd, TPM_NONCE_SIZE);
 497         if (ret != TPM_NONCE_SIZE)
 498                 goto out;
 499         ordinal = htonl(TPM_ORD_SEAL);
 500         datsize = htonl(datalen);
 501         pcrsize = htonl(pcrinfosize);
 502         cont = 0;
 503
 504         /* encrypt data authorization key */
 505         for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
 506                 td->encauth[i] = td->xorhash[i] ^ blobauth[i];
 507
 508         /* calculate authorization HMAC value */
 509         if (pcrinfosize == 0) {
 510                 /* no pcr info specified */
 511                 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
 512                                    sess.enonce, td->nonceodd, cont,
 513                                    sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
 514                                    td->encauth, sizeof(uint32_t), &pcrsize,
 515                                    sizeof(uint32_t), &datsize, datalen, data, 0,
 516                                    0);
 517         } else {
 518                 /* pcr info specified */
 519                 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
 520                                    sess.enonce, td->nonceodd, cont,
 521                                    sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
 522                                    td->encauth, sizeof(uint32_t), &pcrsize,
 523                                    pcrinfosize, pcrinfo, sizeof(uint32_t),
 524                                    &datsize, datalen, data, 0, 0);
 525         }
 526         if (ret < 0)
 527                 goto out;
 528
 529         /* build and send the TPM request packet */
 530         INIT_BUF(tb);
 531         store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
 532         store32(tb, TPM_SEAL_SIZE + pcrinfosize + datalen);
 533         store32(tb, TPM_ORD_SEAL);
 534         store32(tb, keyhandle);
 535         storebytes(tb, td->encauth, SHA1_DIGEST_SIZE);
 536         store32(tb, pcrinfosize);
 537         storebytes(tb, pcrinfo, pcrinfosize);
 538         store32(tb, datalen);
 539         storebytes(tb, data, datalen);
 540         store32(tb, sess.handle);
 541         storebytes(tb, td->nonceodd, TPM_NONCE_SIZE);
 542         store8(tb, cont);
 543         storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE);
 544
 545         ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
 546         if (ret < 0)
 547                 goto out;
 548
 549         /* calculate the size of the returned Blob */
 550         sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
 551         encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
 552                              sizeof(uint32_t) + sealinfosize);
 553         storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
 554             sizeof(uint32_t) + encdatasize;
 555
 556         /* check the HMAC in the response */
 557         ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
 558                              SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
 559                              0);
 560
 561         /* copy the returned blob to caller */
 562         if (!ret) {
 563                 memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
 564                 *bloblen = storedsize;
 565         }
 566 out:
 567         kfree(td);
 568         return ret;
 569 }
 570
 571 /*
 572  * use the AUTH2_COMMAND form of unseal, to authorize both key and blob
 573  */
 574 static int tpm_unseal(struct tpm_buf *tb,
 575                       uint32_t keyhandle, const unsigned char *keyauth,
 576                       const unsigned char *blob, int bloblen,
 577                       const unsigned char *blobauth,
 578                       unsigned char *data, unsigned int *datalen)
 579 {
 580         unsigned char nonceodd[TPM_NONCE_SIZE];
 581         unsigned char enonce1[TPM_NONCE_SIZE];
 582         unsigned char enonce2[TPM_NONCE_SIZE];
 583         unsigned char authdata1[SHA1_DIGEST_SIZE];
 584         unsigned char authdata2[SHA1_DIGEST_SIZE];
 585         uint32_t authhandle1 = 0;
 586         uint32_t authhandle2 = 0;
 587         unsigned char cont = 0;
 588         uint32_t ordinal;
 589         uint32_t keyhndl;
 590         int ret;
 591
 592         /* sessions for unsealing key and data */
 593         ret = oiap(tb, &authhandle1, enonce1);
 594         if (ret < 0) {
 595                 pr_info("trusted_key: oiap failed (%d)\n", ret);
 596                 return ret;
 597         }
 598         ret = oiap(tb, &authhandle2, enonce2);
 599         if (ret < 0) {
 600                 pr_info("trusted_key: oiap failed (%d)\n", ret);
 601                 return ret;
 602         }
 603
 604         ordinal = htonl(TPM_ORD_UNSEAL);
 605         keyhndl = htonl(SRKHANDLE);
 606         ret = tpm_get_random(TPM_ANY_NUM, nonceodd, TPM_NONCE_SIZE);
 607         if (ret != TPM_NONCE_SIZE) {
 608                 pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
 609                 return ret;
 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         INIT_BUF(tb);
 624         store16(tb, TPM_TAG_RQU_AUTH2_COMMAND);
 625         store32(tb, TPM_UNSEAL_SIZE + bloblen);
 626         store32(tb, TPM_ORD_UNSEAL);
 627         store32(tb, keyhandle);
 628         storebytes(tb, blob, bloblen);
 629         store32(tb, authhandle1);
 630         storebytes(tb, nonceodd, TPM_NONCE_SIZE);
 631         store8(tb, cont);
 632         storebytes(tb, authdata1, SHA1_DIGEST_SIZE);
 633         store32(tb, authhandle2);
 634         storebytes(tb, nonceodd, TPM_NONCE_SIZE);
 635         store8(tb, cont);
 636         storebytes(tb, authdata2, SHA1_DIGEST_SIZE);
 637
 638         ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
 639         if (ret < 0) {
 640                 pr_info("trusted_key: authhmac failed (%d)\n", ret);
 641                 return ret;
 642         }
 643
 644         *datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
 645         ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
 646                              keyauth, SHA1_DIGEST_SIZE,
 647                              blobauth, SHA1_DIGEST_SIZE,
 648                              sizeof(uint32_t), TPM_DATA_OFFSET,
 649                              *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
 650                              0);
 651         if (ret < 0) {
 652                 pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret);
 653                 return ret;
 654         }
 655         memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
 656         return 0;
 657 }
 658
 659 /*
 660  * Have the TPM seal(encrypt) the symmetric key
 661  */
 662 static int key_seal(struct trusted_key_payload *p,
 663                     struct trusted_key_options *o)
 664 {
 665         struct tpm_buf *tb;
 666         int ret;
 667
 668         tb = kzalloc(sizeof *tb, GFP_KERNEL);
 669         if (!tb)
 670                 return -ENOMEM;
 671
 672         /* include migratable flag at end of sealed key */
 673         p->key[p->key_len] = p->migratable;
 674
 675         ret = tpm_seal(tb, o->keytype, o->keyhandle, o->keyauth,
 676                        p->key, p->key_len + 1, p->blob, &p->blob_len,
 677                        o->blobauth, o->pcrinfo, o->pcrinfo_len);
 678         if (ret < 0)
 679                 pr_info("trusted_key: srkseal failed (%d)\n", ret);
 680
 681         kfree(tb);
 682         return ret;
 683 }
 684
 685 /*
 686  * Have the TPM unseal(decrypt) the symmetric key
 687  */
 688 static int key_unseal(struct trusted_key_payload *p,
 689                       struct trusted_key_options *o)
 690 {
 691         struct tpm_buf *tb;
 692         int ret;
 693
 694         tb = kzalloc(sizeof *tb, GFP_KERNEL);
 695         if (!tb)
 696                 return -ENOMEM;
 697
 698         ret = tpm_unseal(tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
 699                          o->blobauth, p->key, &p->key_len);
 700         if (ret < 0)
 701                 pr_info("trusted_key: srkunseal failed (%d)\n", ret);
 702         else
 703                 /* pull migratable flag out of sealed key */
 704                 p->migratable = p->key[--p->key_len];
 705
 706         kfree(tb);
 707         return ret;
 708 }
 709
 710 enum {
 711         Opt_err = -1,
 712         Opt_new, Opt_load, Opt_update,
 713         Opt_keyhandle, Opt_keyauth, Opt_blobauth,
 714         Opt_pcrinfo, Opt_pcrlock, Opt_migratable,
 715         Opt_hash,
 716         Opt_policydigest,
 717         Opt_policyhandle,
 718 };
 719
 720 static const match_table_t key_tokens = {
 721         {Opt_new, "new"},
 722         {Opt_load, "load"},
 723         {Opt_update, "update"},
 724         {Opt_keyhandle, "keyhandle=%s"},
 725         {Opt_keyauth, "keyauth=%s"},
 726         {Opt_blobauth, "blobauth=%s"},
 727         {Opt_pcrinfo, "pcrinfo=%s"},
 728         {Opt_pcrlock, "pcrlock=%s"},
 729         {Opt_migratable, "migratable=%s"},
 730         {Opt_hash, "hash=%s"},
 731         {Opt_policydigest, "policydigest=%s"},
 732         {Opt_policyhandle, "policyhandle=%s"},
 733         {Opt_err, NULL}
 734 };
 735
 736 /* can have zero or more token= options */
 737 static int getoptions(char *c, struct trusted_key_payload *pay,
 738                       struct trusted_key_options *opt)
 739 {
 740         substring_t args[MAX_OPT_ARGS];
 741         char *p = c;
 742         int token;
 743         int res;
 744         unsigned long handle;
 745         unsigned long lock;
 746         unsigned long token_mask = 0;
 747         int i;
 748         int tpm2;
 749
 750         tpm2 = tpm_is_tpm2(TPM_ANY_NUM);
 751         if (tpm2 < 0)
 752                 return tpm2;
 753
 754         opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1;
 755         opt->digest_len = hash_digest_size[opt->hash];
 756
 757         while ((p = strsep(&c, " \t"))) {
 758                 if (*p == '\0' || *p == ' ' || *p == '\t')
 759                         continue;
 760                 token = match_token(p, key_tokens, args);
 761                 if (test_and_set_bit(token, &token_mask))
 762                         return -EINVAL;
 763
 764                 switch (token) {
 765                 case Opt_pcrinfo:
 766                         opt->pcrinfo_len = strlen(args[0].from) / 2;
 767                         if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
 768                                 return -EINVAL;
 769                         res = hex2bin(opt->pcrinfo, args[0].from,
 770                                       opt->pcrinfo_len);
 771                         if (res < 0)
 772                                 return -EINVAL;
 773                         break;
 774                 case Opt_keyhandle:
 775                         res = kstrtoul(args[0].from, 16, &handle);
 776                         if (res < 0)
 777                                 return -EINVAL;
 778                         opt->keytype = SEAL_keytype;
 779                         opt->keyhandle = handle;
 780                         break;
 781                 case Opt_keyauth:
 782                         if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
 783                                 return -EINVAL;
 784                         res = hex2bin(opt->keyauth, args[0].from,
 785                                       SHA1_DIGEST_SIZE);
 786                         if (res < 0)
 787                                 return -EINVAL;
 788                         break;
 789                 case Opt_blobauth:
 790                         if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
 791                                 return -EINVAL;
 792                         res = hex2bin(opt->blobauth, args[0].from,
 793                                       SHA1_DIGEST_SIZE);
 794                         if (res < 0)
 795                                 return -EINVAL;
 796                         break;
 797                 case Opt_migratable:
 798                         if (*args[0].from == '0')
 799                                 pay->migratable = 0;
 800                         else
 801                                 return -EINVAL;
 802                         break;
 803                 case Opt_pcrlock:
 804                         res = kstrtoul(args[0].from, 10, &lock);
 805                         if (res < 0)
 806                                 return -EINVAL;
 807                         opt->pcrlock = lock;
 808                         break;
 809                 case Opt_hash:
 810                         if (test_bit(Opt_policydigest, &token_mask))
 811                                 return -EINVAL;
 812                         for (i = 0; i < HASH_ALGO__LAST; i++) {
 813                                 if (!strcmp(args[0].from, hash_algo_name[i])) {
 814                                         opt->hash = i;
 815                                         opt->digest_len =
 816                                                 hash_digest_size[opt->hash];
 817                                         break;
 818                                 }
 819                         }
 820                         if (i == HASH_ALGO__LAST)
 821                                 return -EINVAL;
 822                         if  (!tpm2 && i != HASH_ALGO_SHA1) {
 823                                 pr_info("trusted_key: TPM 1.x only supports SHA-1.\n");
 824                                 return -EINVAL;
 825                         }
 826                         break;
 827                 case Opt_policydigest:
 828                         if (!tpm2 ||
 829                             strlen(args[0].from) != (2 * opt->digest_len))
 830                                 return -EINVAL;
 831                         res = hex2bin(opt->policydigest, args[0].from,
 832                                       opt->digest_len);
 833                         if (res < 0)
 834                                 return -EINVAL;
 835                         break;
 836                 case Opt_policyhandle:
 837                         if (!tpm2)
 838                                 return -EINVAL;
 839                         res = kstrtoul(args[0].from, 16, &handle);
 840                         if (res < 0)
 841                                 return -EINVAL;
 842                         opt->policyhandle = handle;
 843                         break;
 844                 default:
 845                         return -EINVAL;
 846                 }
 847         }
 848         return 0;
 849 }
 850
 851 /*
 852  * datablob_parse - parse the keyctl data and fill in the
 853  *                  payload and options structures
 854  *
 855  * On success returns 0, otherwise -EINVAL.
 856  */
 857 static int datablob_parse(char *datablob, struct trusted_key_payload *p,
 858                           struct trusted_key_options *o)
 859 {
 860         substring_t args[MAX_OPT_ARGS];
 861         long keylen;
 862         int ret = -EINVAL;
 863         int key_cmd;
 864         char *c;
 865
 866         /* main command */
 867         c = strsep(&datablob, " \t");
 868         if (!c)
 869                 return -EINVAL;
 870         key_cmd = match_token(c, key_tokens, args);
 871         switch (key_cmd) {
 872         case Opt_new:
 873                 /* first argument is key size */
 874                 c = strsep(&datablob, " \t");
 875                 if (!c)
 876                         return -EINVAL;
 877                 ret = kstrtol(c, 10, &keylen);
 878                 if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
 879                         return -EINVAL;
 880                 p->key_len = keylen;
 881                 ret = getoptions(datablob, p, o);
 882                 if (ret < 0)
 883                         return ret;
 884                 ret = Opt_new;
 885                 break;
 886         case Opt_load:
 887                 /* first argument is sealed blob */
 888                 c = strsep(&datablob, " \t");
 889                 if (!c)
 890                         return -EINVAL;
 891                 p->blob_len = strlen(c) / 2;
 892                 if (p->blob_len > MAX_BLOB_SIZE)
 893                         return -EINVAL;
 894                 ret = hex2bin(p->blob, c, p->blob_len);
 895                 if (ret < 0)
 896                         return -EINVAL;
 897                 ret = getoptions(datablob, p, o);
 898                 if (ret < 0)
 899                         return ret;
 900                 ret = Opt_load;
 901                 break;
 902         case Opt_update:
 903                 /* all arguments are options */
 904                 ret = getoptions(datablob, p, o);
 905                 if (ret < 0)
 906                         return ret;
 907                 ret = Opt_update;
 908                 break;
 909         case Opt_err:
 910                 return -EINVAL;
 911                 break;
 912         }
 913         return ret;
 914 }
 915
 916 static struct trusted_key_options *trusted_options_alloc(void)
 917 {
 918         struct trusted_key_options *options;
 919         int tpm2;
 920
 921         tpm2 = tpm_is_tpm2(TPM_ANY_NUM);
 922         if (tpm2 < 0)
 923                 return NULL;
 924
 925         options = kzalloc(sizeof *options, GFP_KERNEL);
 926         if (options) {
 927                 /* set any non-zero defaults */
 928                 options->keytype = SRK_keytype;
 929
 930                 if (!tpm2)
 931                         options->keyhandle = SRKHANDLE;
 932         }
 933         return options;
 934 }
 935
 936 static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
 937 {
 938         struct trusted_key_payload *p = NULL;
 939         int ret;
 940
 941         ret = key_payload_reserve(key, sizeof *p);
 942         if (ret < 0)
 943                 return p;
 944         p = kzalloc(sizeof *p, GFP_KERNEL);
 945         if (p)
 946                 p->migratable = 1; /* migratable by default */
 947         return p;
 948 }
 949
 950 /*
 951  * trusted_instantiate - create a new trusted key
 952  *
 953  * Unseal an existing trusted blob or, for a new key, get a
 954  * random key, then seal and create a trusted key-type key,
 955  * adding it to the specified keyring.
 956  *
 957  * On success, return 0. Otherwise return errno.
 958  */
 959 static int trusted_instantiate(struct key *key,
 960                                struct key_preparsed_payload *prep)
 961 {
 962         struct trusted_key_payload *payload = NULL;
 963         struct trusted_key_options *options = NULL;
 964         size_t datalen = prep->datalen;
 965         char *datablob;
 966         int ret = 0;
 967         int key_cmd;
 968         size_t key_len;
 969         int tpm2;
 970
 971         tpm2 = tpm_is_tpm2(TPM_ANY_NUM);
 972         if (tpm2 < 0)
 973                 return tpm2;
 974
 975         if (datalen <= 0 || datalen > 32767 || !prep->data)
 976                 return -EINVAL;
 977
 978         datablob = kmalloc(datalen + 1, GFP_KERNEL);
 979         if (!datablob)
 980                 return -ENOMEM;
 981         memcpy(datablob, prep->data, datalen);
 982         datablob[datalen] = '\0';
 983
 984         options = trusted_options_alloc();
 985         if (!options) {
 986                 ret = -ENOMEM;
 987                 goto out;
 988         }
 989         payload = trusted_payload_alloc(key);
 990         if (!payload) {
 991                 ret = -ENOMEM;
 992                 goto out;
 993         }
 994
 995         key_cmd = datablob_parse(datablob, payload, options);
 996         if (key_cmd < 0) {
 997                 ret = key_cmd;
 998                 goto out;
 999         }
1000
1001         if (!options->keyhandle) {
1002                 ret = -EINVAL;
1003                 goto out;
1004         }
1005
1006         dump_payload(payload);
1007         dump_options(options);
1008
1009         switch (key_cmd) {
1010         case Opt_load:
1011                 if (tpm2)
1012                         ret = tpm_unseal_trusted(TPM_ANY_NUM, payload, options);
1013                 else
1014                         ret = key_unseal(payload, options);
1015                 dump_payload(payload);
1016                 dump_options(options);
1017                 if (ret < 0)
1018                         pr_info("trusted_key: key_unseal failed (%d)\n", ret);
1019                 break;
1020         case Opt_new:
1021                 key_len = payload->key_len;
1022                 ret = tpm_get_random(TPM_ANY_NUM, payload->key, key_len);
1023                 if (ret != key_len) {
1024                         pr_info("trusted_key: key_create failed (%d)\n", ret);
1025                         goto out;
1026                 }
1027                 if (tpm2)
1028                         ret = tpm_seal_trusted(TPM_ANY_NUM, payload, options);
1029                 else
1030                         ret = key_seal(payload, options);
1031                 if (ret < 0)
1032                         pr_info("trusted_key: key_seal failed (%d)\n", ret);
1033                 break;
1034         default:
1035                 ret = -EINVAL;
1036                 goto out;
1037         }
1038         if (!ret && options->pcrlock)
1039                 ret = pcrlock(options->pcrlock);
1040 out:
1041         kfree(datablob);
1042         kfree(options);
1043         if (!ret)
1044                 rcu_assign_keypointer(key, payload);
1045         else
1046                 kfree(payload);
1047         return ret;
1048 }
1049
1050 static void trusted_rcu_free(struct rcu_head *rcu)
1051 {
1052         struct trusted_key_payload *p;
1053
1054         p = container_of(rcu, struct trusted_key_payload, rcu);
1055         memset(p->key, 0, p->key_len);
1056         kfree(p);
1057 }
1058
1059 /*
1060  * trusted_update - reseal an existing key with new PCR values
1061  */
1062 static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
1063 {
1064         struct trusted_key_payload *p;
1065         struct trusted_key_payload *new_p;
1066         struct trusted_key_options *new_o;
1067         size_t datalen = prep->datalen;
1068         char *datablob;
1069         int ret = 0;
1070
1071         if (test_bit(KEY_FLAG_NEGATIVE, &key->flags))
1072                 return -ENOKEY;
1073         p = key->payload.data[0];
1074         if (!p->migratable)
1075                 return -EPERM;
1076         if (datalen <= 0 || datalen > 32767 || !prep->data)
1077                 return -EINVAL;
1078
1079         datablob = kmalloc(datalen + 1, GFP_KERNEL);
1080         if (!datablob)
1081                 return -ENOMEM;
1082         new_o = trusted_options_alloc();
1083         if (!new_o) {
1084                 ret = -ENOMEM;
1085                 goto out;
1086         }
1087         new_p = trusted_payload_alloc(key);
1088         if (!new_p) {
1089                 ret = -ENOMEM;
1090                 goto out;
1091         }
1092
1093         memcpy(datablob, prep->data, datalen);
1094         datablob[datalen] = '\0';
1095         ret = datablob_parse(datablob, new_p, new_o);
1096         if (ret != Opt_update) {
1097                 ret = -EINVAL;
1098                 kfree(new_p);
1099                 goto out;
1100         }
1101
1102         if (!new_o->keyhandle) {
1103                 ret = -EINVAL;
1104                 kfree(new_p);
1105                 goto out;
1106         }
1107
1108         /* copy old key values, and reseal with new pcrs */
1109         new_p->migratable = p->migratable;
1110         new_p->key_len = p->key_len;
1111         memcpy(new_p->key, p->key, p->key_len);
1112         dump_payload(p);
1113         dump_payload(new_p);
1114
1115         ret = key_seal(new_p, new_o);
1116         if (ret < 0) {
1117                 pr_info("trusted_key: key_seal failed (%d)\n", ret);
1118                 kfree(new_p);
1119                 goto out;
1120         }
1121         if (new_o->pcrlock) {
1122                 ret = pcrlock(new_o->pcrlock);
1123                 if (ret < 0) {
1124                         pr_info("trusted_key: pcrlock failed (%d)\n", ret);
1125                         kfree(new_p);
1126                         goto out;
1127                 }
1128         }
1129         rcu_assign_keypointer(key, new_p);
1130         call_rcu(&p->rcu, trusted_rcu_free);
1131 out:
1132         kfree(datablob);
1133         kfree(new_o);
1134         return ret;
1135 }
1136
1137 /*
1138  * trusted_read - copy the sealed blob data to userspace in hex.
1139  * On success, return to userspace the trusted key datablob size.
1140  */
1141 static long trusted_read(const struct key *key, char __user *buffer,
1142                          size_t buflen)
1143 {
1144         struct trusted_key_payload *p;
1145         char *ascii_buf;
1146         char *bufp;
1147         int i;
1148
1149         p = rcu_dereference_key(key);
1150         if (!p)
1151                 return -EINVAL;
1152         if (!buffer || buflen <= 0)
1153                 return 2 * p->blob_len;
1154         ascii_buf = kmalloc(2 * p->blob_len, GFP_KERNEL);
1155         if (!ascii_buf)
1156                 return -ENOMEM;
1157
1158         bufp = ascii_buf;
1159         for (i = 0; i < p->blob_len; i++)
1160                 bufp = hex_byte_pack(bufp, p->blob[i]);
1161         if ((copy_to_user(buffer, ascii_buf, 2 * p->blob_len)) != 0) {
1162                 kfree(ascii_buf);
1163                 return -EFAULT;
1164         }
1165         kfree(ascii_buf);
1166         return 2 * p->blob_len;
1167 }
1168
1169 /*
1170  * trusted_destroy - before freeing the key, clear the decrypted data
1171  */
1172 static void trusted_destroy(struct key *key)
1173 {
1174         struct trusted_key_payload *p = key->payload.data[0];
1175
1176         if (!p)
1177                 return;
1178         memset(p->key, 0, p->key_len);
1179         kfree(key->payload.data[0]);
1180 }
1181
1182 struct key_type key_type_trusted = {
1183         .name = "trusted",
1184         .instantiate = trusted_instantiate,
1185         .update = trusted_update,
1186         .destroy = trusted_destroy,
1187         .describe = user_describe,
1188         .read = trusted_read,
1189 };
1190
1191 EXPORT_SYMBOL_GPL(key_type_trusted);
1192
1193 static void trusted_shash_release(void)
1194 {
1195         if (hashalg)
1196                 crypto_free_shash(hashalg);
1197         if (hmacalg)
1198                 crypto_free_shash(hmacalg);
1199 }
1200
1201 static int __init trusted_shash_alloc(void)
1202 {
1203         int ret;
1204
1205         hmacalg = crypto_alloc_shash(hmac_alg, 0, CRYPTO_ALG_ASYNC);
1206         if (IS_ERR(hmacalg)) {
1207                 pr_info("trusted_key: could not allocate crypto %s\n",
1208                         hmac_alg);
1209                 return PTR_ERR(hmacalg);
1210         }
1211
1212         hashalg = crypto_alloc_shash(hash_alg, 0, CRYPTO_ALG_ASYNC);
1213         if (IS_ERR(hashalg)) {
1214                 pr_info("trusted_key: could not allocate crypto %s\n",
1215                         hash_alg);
1216                 ret = PTR_ERR(hashalg);
1217                 goto hashalg_fail;
1218         }
1219
1220         return 0;
1221
1222 hashalg_fail:
1223         crypto_free_shash(hmacalg);
1224         return ret;
1225 }
1226
1227 static int __init init_trusted(void)
1228 {
1229         int ret;
1230
1231         ret = trusted_shash_alloc();
1232         if (ret < 0)
1233                 return ret;
1234         ret = register_key_type(&key_type_trusted);
1235         if (ret < 0)
1236                 trusted_shash_release();
1237         return ret;
1238 }
1239
1240 static void __exit cleanup_trusted(void)
1241 {
1242         trusted_shash_release();
1243         unregister_key_type(&key_type_trusted);
1244 }
1245
1246 late_initcall(init_trusted);
1247 module_exit(cleanup_trusted);
1248
1249 MODULE_LICENSE("GPL");