security/keys/trusted_defined.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/keys-trusted-encrypted.txt
  12  */
  13
  14 #include <linux/uaccess.h>
  15 #include <linux/module.h>
  16 #include <linux/init.h>
  17 #include <linux/slab.h>
  18 #include <linux/parser.h>
  19 #include <linux/string.h>
  20 #include <linux/err.h>
  21 #include <keys/user-type.h>
  22 #include <keys/trusted-type.h>
  23 #include <linux/key-type.h>
  24 #include <linux/rcupdate.h>
  25 #include <linux/crypto.h>
  26 #include <crypto/hash.h>
  27 #include <crypto/sha.h>
  28 #include <linux/capability.h>
  29 #include <linux/tpm.h>
  30 #include <linux/tpm_command.h>
  31
  32 #include "trusted_defined.h"
  33
  34 static const char hmac_alg[] = "hmac(sha1)";
  35 static const char hash_alg[] = "sha1";
  36
  37 struct sdesc {
  38         struct shash_desc shash;
  39         char ctx[];
  40 };
  41
  42 static struct crypto_shash *hashalg;
  43 static struct crypto_shash *hmacalg;
  44
  45 static struct sdesc *init_sdesc(struct crypto_shash *alg)
  46 {
  47         struct sdesc *sdesc;
  48         int size;
  49
  50         size = sizeof(struct shash_desc) + crypto_shash_descsize(alg);
  51         sdesc = kmalloc(size, GFP_KERNEL);
  52         if (!sdesc)
  53                 return ERR_PTR(-ENOMEM);
  54         sdesc->shash.tfm = alg;
  55         sdesc->shash.flags = 0x0;
  56         return sdesc;
  57 }
  58
  59 static int TSS_sha1(const unsigned char *data, unsigned int datalen,
  60                     unsigned char *digest)
  61 {
  62         struct sdesc *sdesc;
  63         int ret;
  64
  65         sdesc = init_sdesc(hashalg);
  66         if (IS_ERR(sdesc)) {
  67                 pr_info("trusted_key: can't alloc %s\n", hash_alg);
  68                 return PTR_ERR(sdesc);
  69         }
  70
  71         ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest);
  72         kfree(sdesc);
  73         return ret;
  74 }
  75
  76 static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
  77                        unsigned int keylen, ...)
  78 {
  79         struct sdesc *sdesc;
  80         va_list argp;
  81         unsigned int dlen;
  82         unsigned char *data;
  83         int ret;
  84
  85         sdesc = init_sdesc(hmacalg);
  86         if (IS_ERR(sdesc)) {
  87                 pr_info("trusted_key: can't alloc %s\n", hmac_alg);
  88                 return PTR_ERR(sdesc);
  89         }
  90
  91         ret = crypto_shash_setkey(hmacalg, key, keylen);
  92         if (ret < 0)
  93                 goto out;
  94         ret = crypto_shash_init(&sdesc->shash);
  95         if (ret < 0)
  96                 goto out;
  97
  98         va_start(argp, keylen);
  99         for (;;) {
 100                 dlen = va_arg(argp, unsigned int);
 101                 if (dlen == 0)
 102                         break;
 103                 data = va_arg(argp, unsigned char *);
 104                 if (data == NULL)
 105                         return -EINVAL;
 106                 ret = crypto_shash_update(&sdesc->shash, data, dlen);
 107                 if (ret < 0)
 108                         goto out;
 109         }
 110         va_end(argp);
 111         if (!ret)
 112                 ret = crypto_shash_final(&sdesc->shash, digest);
 113 out:
 114         kfree(sdesc);
 115         return ret;
 116 }
 117
 118 /*
 119  * calculate authorization info fields to send to TPM
 120  */
 121 static int TSS_authhmac(unsigned char *digest, const unsigned char *key,
 122                         unsigned int keylen, unsigned char *h1,
 123                         unsigned char *h2, unsigned char h3, ...)
 124 {
 125         unsigned char paramdigest[SHA1_DIGEST_SIZE];
 126         struct sdesc *sdesc;
 127         unsigned int dlen;
 128         unsigned char *data;
 129         unsigned char c;
 130         int ret;
 131         va_list argp;
 132
 133         sdesc = init_sdesc(hashalg);
 134         if (IS_ERR(sdesc)) {
 135                 pr_info("trusted_key: can't alloc %s\n", hash_alg);
 136                 return PTR_ERR(sdesc);
 137         }
 138
 139         c = h3;
 140         ret = crypto_shash_init(&sdesc->shash);
 141         if (ret < 0)
 142                 goto out;
 143         va_start(argp, h3);
 144         for (;;) {
 145                 dlen = va_arg(argp, unsigned int);
 146                 if (dlen == 0)
 147                         break;
 148                 data = va_arg(argp, unsigned char *);
 149                 ret = crypto_shash_update(&sdesc->shash, data, dlen);
 150                 if (ret < 0) {
 151                         va_end(argp);
 152                         goto out;
 153                 }
 154         }
 155         va_end(argp);
 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(sdesc);
 163         return ret;
 164 }
 165
 166 /*
 167  * verify the AUTH1_COMMAND (Seal) result from TPM
 168  */
 169 static int TSS_checkhmac1(unsigned char *buffer,
 170                           const uint32_t command,
 171                           const unsigned char *ononce,
 172                           const unsigned char *key,
 173                           unsigned int keylen, ...)
 174 {
 175         uint32_t bufsize;
 176         uint16_t tag;
 177         uint32_t ordinal;
 178         uint32_t result;
 179         unsigned char *enonce;
 180         unsigned char *continueflag;
 181         unsigned char *authdata;
 182         unsigned char testhmac[SHA1_DIGEST_SIZE];
 183         unsigned char paramdigest[SHA1_DIGEST_SIZE];
 184         struct sdesc *sdesc;
 185         unsigned int dlen;
 186         unsigned int dpos;
 187         va_list argp;
 188         int ret;
 189
 190         bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
 191         tag = LOAD16(buffer, 0);
 192         ordinal = command;
 193         result = LOAD32N(buffer, TPM_RETURN_OFFSET);
 194         if (tag == TPM_TAG_RSP_COMMAND)
 195                 return 0;
 196         if (tag != TPM_TAG_RSP_AUTH1_COMMAND)
 197                 return -EINVAL;
 198         authdata = buffer + bufsize - SHA1_DIGEST_SIZE;
 199         continueflag = authdata - 1;
 200         enonce = continueflag - TPM_NONCE_SIZE;
 201
 202         sdesc = init_sdesc(hashalg);
 203         if (IS_ERR(sdesc)) {
 204                 pr_info("trusted_key: can't alloc %s\n", hash_alg);
 205                 return PTR_ERR(sdesc);
 206         }
 207         ret = crypto_shash_init(&sdesc->shash);
 208         if (ret < 0)
 209                 goto out;
 210         ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
 211                                   sizeof result);
 212         if (ret < 0)
 213                 goto out;
 214         ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
 215                                   sizeof ordinal);
 216         if (ret < 0)
 217                 goto out;
 218         va_start(argp, keylen);
 219         for (;;) {
 220                 dlen = va_arg(argp, unsigned int);
 221                 if (dlen == 0)
 222                         break;
 223                 dpos = va_arg(argp, unsigned int);
 224                 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
 225                 if (ret < 0) {
 226                         va_end(argp);
 227                         goto out;
 228                 }
 229         }
 230         va_end(argp);
 231         ret = crypto_shash_final(&sdesc->shash, paramdigest);
 232         if (ret < 0)
 233                 goto out;
 234
 235         ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest,
 236                           TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce,
 237                           1, continueflag, 0, 0);
 238         if (ret < 0)
 239                 goto out;
 240
 241         if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE))
 242                 ret = -EINVAL;
 243 out:
 244         kfree(sdesc);
 245         return ret;
 246 }
 247
 248 /*
 249  * verify the AUTH2_COMMAND (unseal) result from TPM
 250  */
 251 static int TSS_checkhmac2(unsigned char *buffer,
 252                           const uint32_t command,
 253                           const unsigned char *ononce,
 254                           const unsigned char *key1,
 255                           unsigned int keylen1,
 256                           const unsigned char *key2,
 257                           unsigned int keylen2, ...)
 258 {
 259         uint32_t bufsize;
 260         uint16_t tag;
 261         uint32_t ordinal;
 262         uint32_t result;
 263         unsigned char *enonce1;
 264         unsigned char *continueflag1;
 265         unsigned char *authdata1;
 266         unsigned char *enonce2;
 267         unsigned char *continueflag2;
 268         unsigned char *authdata2;
 269         unsigned char testhmac1[SHA1_DIGEST_SIZE];
 270         unsigned char testhmac2[SHA1_DIGEST_SIZE];
 271         unsigned char paramdigest[SHA1_DIGEST_SIZE];
 272         struct sdesc *sdesc;
 273         unsigned int dlen;
 274         unsigned int dpos;
 275         va_list argp;
 276         int ret;
 277
 278         bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
 279         tag = LOAD16(buffer, 0);
 280         ordinal = command;
 281         result = LOAD32N(buffer, TPM_RETURN_OFFSET);
 282
 283         if (tag == TPM_TAG_RSP_COMMAND)
 284                 return 0;
 285         if (tag != TPM_TAG_RSP_AUTH2_COMMAND)
 286                 return -EINVAL;
 287         authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1
 288                         + SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE);
 289         authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE);
 290         continueflag1 = authdata1 - 1;
 291         continueflag2 = authdata2 - 1;
 292         enonce1 = continueflag1 - TPM_NONCE_SIZE;
 293         enonce2 = continueflag2 - TPM_NONCE_SIZE;
 294
 295         sdesc = init_sdesc(hashalg);
 296         if (IS_ERR(sdesc)) {
 297                 pr_info("trusted_key: can't alloc %s\n", hash_alg);
 298                 return PTR_ERR(sdesc);
 299         }
 300         ret = crypto_shash_init(&sdesc->shash);
 301         if (ret < 0)
 302                 goto out;
 303         ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
 304                                   sizeof result);
 305         if (ret < 0)
 306                 goto out;
 307         ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
 308                                   sizeof ordinal);
 309         if (ret < 0)
 310                 goto out;
 311
 312         va_start(argp, keylen2);
 313         for (;;) {
 314                 dlen = va_arg(argp, unsigned int);
 315                 if (dlen == 0)
 316                         break;
 317                 dpos = va_arg(argp, unsigned int);
 318                 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
 319                 if (ret < 0) {
 320                         va_end(argp);
 321                         goto out;
 322                 }
 323         }
 324         va_end(argp);
 325         ret = crypto_shash_final(&sdesc->shash, paramdigest);
 326         if (ret < 0)
 327                 goto out;
 328
 329         ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE,
 330                           paramdigest, TPM_NONCE_SIZE, enonce1,
 331                           TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0);
 332         if (ret < 0)
 333                 goto out;
 334         if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) {
 335                 ret = -EINVAL;
 336                 goto out;
 337         }
 338         ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE,
 339                           paramdigest, TPM_NONCE_SIZE, enonce2,
 340                           TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0);
 341         if (ret < 0)
 342                 goto out;
 343         if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE))
 344                 ret = -EINVAL;
 345 out:
 346         kfree(sdesc);
 347         return ret;
 348 }
 349
 350 /*
 351  * For key specific tpm requests, we will generate and send our
 352  * own TPM command packets using the drivers send function.
 353  */
 354 static int trusted_tpm_send(const u32 chip_num, unsigned char *cmd,
 355                             size_t buflen)
 356 {
 357         int rc;
 358
 359         dump_tpm_buf(cmd);
 360         rc = tpm_send(chip_num, cmd, buflen);
 361         dump_tpm_buf(cmd);
 362         if (rc > 0)
 363                 /* Can't return positive return codes values to keyctl */
 364                 rc = -EPERM;
 365         return rc;
 366 }
 367
 368 /*
 369  * get a random value from TPM
 370  */
 371 static int tpm_get_random(struct tpm_buf *tb, unsigned char *buf, uint32_t len)
 372 {
 373         int ret;
 374
 375         INIT_BUF(tb);
 376         store16(tb, TPM_TAG_RQU_COMMAND);
 377         store32(tb, TPM_GETRANDOM_SIZE);
 378         store32(tb, TPM_ORD_GETRANDOM);
 379         store32(tb, len);
 380         ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, sizeof tb->data);
 381         if (!ret)
 382                 memcpy(buf, tb->data + TPM_GETRANDOM_SIZE, len);
 383         return ret;
 384 }
 385
 386 static int my_get_random(unsigned char *buf, int len)
 387 {
 388         struct tpm_buf *tb;
 389         int ret;
 390
 391         tb = kmalloc(sizeof *tb, GFP_KERNEL);
 392         if (!tb)
 393                 return -ENOMEM;
 394         ret = tpm_get_random(tb, buf, len);
 395
 396         kfree(tb);
 397         return ret;
 398 }
 399
 400 /*
 401  * Lock a trusted key, by extending a selected PCR.
 402  *
 403  * Prevents a trusted key that is sealed to PCRs from being accessed.
 404  * This uses the tpm driver's extend function.
 405  */
 406 static int pcrlock(const int pcrnum)
 407 {
 408         unsigned char hash[SHA1_DIGEST_SIZE];
 409         int ret;
 410
 411         if (!capable(CAP_SYS_ADMIN))
 412                 return -EPERM;
 413         ret = my_get_random(hash, SHA1_DIGEST_SIZE);
 414         if (ret < 0)
 415                 return ret;
 416         return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0;
 417 }
 418
 419 /*
 420  * Create an object specific authorisation protocol (OSAP) session
 421  */
 422 static int osap(struct tpm_buf *tb, struct osapsess *s,
 423                 const unsigned char *key, uint16_t type, uint32_t handle)
 424 {
 425         unsigned char enonce[TPM_NONCE_SIZE];
 426         unsigned char ononce[TPM_NONCE_SIZE];
 427         int ret;
 428
 429         ret = tpm_get_random(tb, ononce, TPM_NONCE_SIZE);
 430         if (ret < 0)
 431                 return ret;
 432
 433         INIT_BUF(tb);
 434         store16(tb, TPM_TAG_RQU_COMMAND);
 435         store32(tb, TPM_OSAP_SIZE);
 436         store32(tb, TPM_ORD_OSAP);
 437         store16(tb, type);
 438         store32(tb, handle);
 439         storebytes(tb, ononce, TPM_NONCE_SIZE);
 440
 441         ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
 442         if (ret < 0)
 443                 return ret;
 444
 445         s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
 446         memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
 447                TPM_NONCE_SIZE);
 448         memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
 449                                   TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
 450         return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
 451                            enonce, TPM_NONCE_SIZE, ononce, 0, 0);
 452 }
 453
 454 /*
 455  * Create an object independent authorisation protocol (oiap) session
 456  */
 457 static int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
 458 {
 459         int ret;
 460
 461         INIT_BUF(tb);
 462         store16(tb, TPM_TAG_RQU_COMMAND);
 463         store32(tb, TPM_OIAP_SIZE);
 464         store32(tb, TPM_ORD_OIAP);
 465         ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
 466         if (ret < 0)
 467                 return ret;
 468
 469         *handle = LOAD32(tb->data, TPM_DATA_OFFSET);
 470         memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
 471                TPM_NONCE_SIZE);
 472         return 0;
 473 }
 474
 475 struct tpm_digests {
 476         unsigned char encauth[SHA1_DIGEST_SIZE];
 477         unsigned char pubauth[SHA1_DIGEST_SIZE];
 478         unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
 479         unsigned char xorhash[SHA1_DIGEST_SIZE];
 480         unsigned char nonceodd[TPM_NONCE_SIZE];
 481 };
 482
 483 /*
 484  * Have the TPM seal(encrypt) the trusted key, possibly based on
 485  * Platform Configuration Registers (PCRs). AUTH1 for sealing key.
 486  */
 487 static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
 488                     uint32_t keyhandle, const unsigned char *keyauth,
 489                     const unsigned char *data, uint32_t datalen,
 490                     unsigned char *blob, uint32_t *bloblen,
 491                     const unsigned char *blobauth,
 492                     const unsigned char *pcrinfo, uint32_t pcrinfosize)
 493 {
 494         struct osapsess sess;
 495         struct tpm_digests *td;
 496         unsigned char cont;
 497         uint32_t ordinal;
 498         uint32_t pcrsize;
 499         uint32_t datsize;
 500         int sealinfosize;
 501         int encdatasize;
 502         int storedsize;
 503         int ret;
 504         int i;
 505
 506         /* alloc some work space for all the hashes */
 507         td = kmalloc(sizeof *td, GFP_KERNEL);
 508         if (!td)
 509                 return -ENOMEM;
 510
 511         /* get session for sealing key */
 512         ret = osap(tb, &sess, keyauth, keytype, keyhandle);
 513         if (ret < 0)
 514                 return ret;
 515         dump_sess(&sess);
 516
 517         /* calculate encrypted authorization value */
 518         memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
 519         memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
 520         ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
 521         if (ret < 0)
 522                 return ret;
 523
 524         ret = tpm_get_random(tb, td->nonceodd, TPM_NONCE_SIZE);
 525         if (ret < 0)
 526                 return ret;
 527         ordinal = htonl(TPM_ORD_SEAL);
 528         datsize = htonl(datalen);
 529         pcrsize = htonl(pcrinfosize);
 530         cont = 0;
 531
 532         /* encrypt data authorization key */
 533         for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
 534                 td->encauth[i] = td->xorhash[i] ^ blobauth[i];
 535
 536         /* calculate authorization HMAC value */
 537         if (pcrinfosize == 0) {
 538                 /* no pcr info specified */
 539                 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
 540                                    sess.enonce, td->nonceodd, cont,
 541                                    sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
 542                                    td->encauth, sizeof(uint32_t), &pcrsize,
 543                                    sizeof(uint32_t), &datsize, datalen, data, 0,
 544                                    0);
 545         } else {
 546                 /* pcr info specified */
 547                 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
 548                                    sess.enonce, td->nonceodd, cont,
 549                                    sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
 550                                    td->encauth, sizeof(uint32_t), &pcrsize,
 551                                    pcrinfosize, pcrinfo, sizeof(uint32_t),
 552                                    &datsize, datalen, data, 0, 0);
 553         }
 554         if (ret < 0)
 555                 return ret;
 556
 557         /* build and send the TPM request packet */
 558         INIT_BUF(tb);
 559         store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
 560         store32(tb, TPM_SEAL_SIZE + pcrinfosize + datalen);
 561         store32(tb, TPM_ORD_SEAL);
 562         store32(tb, keyhandle);
 563         storebytes(tb, td->encauth, SHA1_DIGEST_SIZE);
 564         store32(tb, pcrinfosize);
 565         storebytes(tb, pcrinfo, pcrinfosize);
 566         store32(tb, datalen);
 567         storebytes(tb, data, datalen);
 568         store32(tb, sess.handle);
 569         storebytes(tb, td->nonceodd, TPM_NONCE_SIZE);
 570         store8(tb, cont);
 571         storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE);
 572
 573         ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
 574         if (ret < 0)
 575                 return ret;
 576
 577         /* calculate the size of the returned Blob */
 578         sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
 579         encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
 580                              sizeof(uint32_t) + sealinfosize);
 581         storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
 582             sizeof(uint32_t) + encdatasize;
 583
 584         /* check the HMAC in the response */
 585         ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
 586                              SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
 587                              0);
 588
 589         /* copy the returned blob to caller */
 590         if (!ret) {
 591                 memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
 592                 *bloblen = storedsize;
 593         }
 594         return ret;
 595 }
 596
 597 /*
 598  * use the AUTH2_COMMAND form of unseal, to authorize both key and blob
 599  */
 600 static int tpm_unseal(struct tpm_buf *tb,
 601                       uint32_t keyhandle, const unsigned char *keyauth,
 602                       const unsigned char *blob, int bloblen,
 603                       const unsigned char *blobauth,
 604                       unsigned char *data, unsigned int *datalen)
 605 {
 606         unsigned char nonceodd[TPM_NONCE_SIZE];
 607         unsigned char enonce1[TPM_NONCE_SIZE];
 608         unsigned char enonce2[TPM_NONCE_SIZE];
 609         unsigned char authdata1[SHA1_DIGEST_SIZE];
 610         unsigned char authdata2[SHA1_DIGEST_SIZE];
 611         uint32_t authhandle1 = 0;
 612         uint32_t authhandle2 = 0;
 613         unsigned char cont = 0;
 614         uint32_t ordinal;
 615         uint32_t keyhndl;
 616         int ret;
 617
 618         /* sessions for unsealing key and data */
 619         ret = oiap(tb, &authhandle1, enonce1);
 620         if (ret < 0) {
 621                 pr_info("trusted_key: oiap failed (%d)\n", ret);
 622                 return ret;
 623         }
 624         ret = oiap(tb, &authhandle2, enonce2);
 625         if (ret < 0) {
 626                 pr_info("trusted_key: oiap failed (%d)\n", ret);
 627                 return ret;
 628         }
 629
 630         ordinal = htonl(TPM_ORD_UNSEAL);
 631         keyhndl = htonl(SRKHANDLE);
 632         ret = tpm_get_random(tb, nonceodd, TPM_NONCE_SIZE);
 633         if (ret < 0) {
 634                 pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
 635                 return ret;
 636         }
 637         ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
 638                            enonce1, nonceodd, cont, sizeof(uint32_t),
 639                            &ordinal, bloblen, blob, 0, 0);
 640         if (ret < 0)
 641                 return ret;
 642         ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
 643                            enonce2, nonceodd, cont, sizeof(uint32_t),
 644                            &ordinal, bloblen, blob, 0, 0);
 645         if (ret < 0)
 646                 return ret;
 647
 648         /* build and send TPM request packet */
 649         INIT_BUF(tb);
 650         store16(tb, TPM_TAG_RQU_AUTH2_COMMAND);
 651         store32(tb, TPM_UNSEAL_SIZE + bloblen);
 652         store32(tb, TPM_ORD_UNSEAL);
 653         store32(tb, keyhandle);
 654         storebytes(tb, blob, bloblen);
 655         store32(tb, authhandle1);
 656         storebytes(tb, nonceodd, TPM_NONCE_SIZE);
 657         store8(tb, cont);
 658         storebytes(tb, authdata1, SHA1_DIGEST_SIZE);
 659         store32(tb, authhandle2);
 660         storebytes(tb, nonceodd, TPM_NONCE_SIZE);
 661         store8(tb, cont);
 662         storebytes(tb, authdata2, SHA1_DIGEST_SIZE);
 663
 664         ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
 665         if (ret < 0) {
 666                 pr_info("trusted_key: authhmac failed (%d)\n", ret);
 667                 return ret;
 668         }
 669
 670         *datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
 671         ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
 672                              keyauth, SHA1_DIGEST_SIZE,
 673                              blobauth, SHA1_DIGEST_SIZE,
 674                              sizeof(uint32_t), TPM_DATA_OFFSET,
 675                              *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
 676                              0);
 677         if (ret < 0) {
 678                 pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret);
 679                 return ret;
 680         }
 681         memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
 682         return 0;
 683 }
 684
 685 /*
 686  * Have the TPM seal(encrypt) the symmetric key
 687  */
 688 static int key_seal(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         /* include migratable flag at end of sealed key */
 699         p->key[p->key_len] = p->migratable;
 700
 701         ret = tpm_seal(tb, o->keytype, o->keyhandle, o->keyauth,
 702                        p->key, p->key_len + 1, p->blob, &p->blob_len,
 703                        o->blobauth, o->pcrinfo, o->pcrinfo_len);
 704         if (ret < 0)
 705                 pr_info("trusted_key: srkseal failed (%d)\n", ret);
 706
 707         kfree(tb);
 708         return ret;
 709 }
 710
 711 /*
 712  * Have the TPM unseal(decrypt) the symmetric key
 713  */
 714 static int key_unseal(struct trusted_key_payload *p,
 715                       struct trusted_key_options *o)
 716 {
 717         struct tpm_buf *tb;
 718         int ret;
 719
 720         tb = kzalloc(sizeof *tb, GFP_KERNEL);
 721         if (!tb)
 722                 return -ENOMEM;
 723
 724         ret = tpm_unseal(tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
 725                          o->blobauth, p->key, &p->key_len);
 726         if (ret < 0)
 727                 pr_info("trusted_key: srkunseal failed (%d)\n", ret);
 728         else
 729                 /* pull migratable flag out of sealed key */
 730                 p->migratable = p->key[--p->key_len];
 731
 732         kfree(tb);
 733         return ret;
 734 }
 735
 736 enum {
 737         Opt_err = -1,
 738         Opt_new, Opt_load, Opt_update,
 739         Opt_keyhandle, Opt_keyauth, Opt_blobauth,
 740         Opt_pcrinfo, Opt_pcrlock, Opt_migratable
 741 };
 742
 743 static const match_table_t key_tokens = {
 744         {Opt_new, "new"},
 745         {Opt_load, "load"},
 746         {Opt_update, "update"},
 747         {Opt_keyhandle, "keyhandle=%s"},
 748         {Opt_keyauth, "keyauth=%s"},
 749         {Opt_blobauth, "blobauth=%s"},
 750         {Opt_pcrinfo, "pcrinfo=%s"},
 751         {Opt_pcrlock, "pcrlock=%s"},
 752         {Opt_migratable, "migratable=%s"},
 753         {Opt_err, NULL}
 754 };
 755
 756 /* can have zero or more token= options */
 757 static int getoptions(char *c, struct trusted_key_payload *pay,
 758                       struct trusted_key_options *opt)
 759 {
 760         substring_t args[MAX_OPT_ARGS];
 761         char *p = c;
 762         int token;
 763         int res;
 764         unsigned long handle;
 765         unsigned long lock;
 766
 767         while ((p = strsep(&c, " \t"))) {
 768                 if (*p == '\0' || *p == ' ' || *p == '\t')
 769                         continue;
 770                 token = match_token(p, key_tokens, args);
 771
 772                 switch (token) {
 773                 case Opt_pcrinfo:
 774                         opt->pcrinfo_len = strlen(args[0].from) / 2;
 775                         if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
 776                                 return -EINVAL;
 777                         hex2bin(opt->pcrinfo, args[0].from, opt->pcrinfo_len);
 778                         break;
 779                 case Opt_keyhandle:
 780                         res = strict_strtoul(args[0].from, 16, &handle);
 781                         if (res < 0)
 782                                 return -EINVAL;
 783                         opt->keytype = SEAL_keytype;
 784                         opt->keyhandle = handle;
 785                         break;
 786                 case Opt_keyauth:
 787                         if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
 788                                 return -EINVAL;
 789                         hex2bin(opt->keyauth, args[0].from, SHA1_DIGEST_SIZE);
 790                         break;
 791                 case Opt_blobauth:
 792                         if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
 793                                 return -EINVAL;
 794                         hex2bin(opt->blobauth, args[0].from, SHA1_DIGEST_SIZE);
 795                         break;
 796                 case Opt_migratable:
 797                         if (*args[0].from == '0')
 798                                 pay->migratable = 0;
 799                         else
 800                                 return -EINVAL;
 801                         break;
 802                 case Opt_pcrlock:
 803                         res = strict_strtoul(args[0].from, 10, &lock);
 804                         if (res < 0)
 805                                 return -EINVAL;
 806                         opt->pcrlock = lock;
 807                         break;
 808                 default:
 809                         return -EINVAL;
 810                 }
 811         }
 812         return 0;
 813 }
 814
 815 /*
 816  * datablob_parse - parse the keyctl data and fill in the
 817  *                  payload and options structures
 818  *
 819  * On success returns 0, otherwise -EINVAL.
 820  */
 821 static int datablob_parse(char *datablob, struct trusted_key_payload *p,
 822                           struct trusted_key_options *o)
 823 {
 824         substring_t args[MAX_OPT_ARGS];
 825         long keylen;
 826         int ret = -EINVAL;
 827         int key_cmd;
 828         char *c;
 829
 830         /* main command */
 831         c = strsep(&datablob, " \t");
 832         if (!c)
 833                 return -EINVAL;
 834         key_cmd = match_token(c, key_tokens, args);
 835         switch (key_cmd) {
 836         case Opt_new:
 837                 /* first argument is key size */
 838                 c = strsep(&datablob, " \t");
 839                 if (!c)
 840                         return -EINVAL;
 841                 ret = strict_strtol(c, 10, &keylen);
 842                 if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
 843                         return -EINVAL;
 844                 p->key_len = keylen;
 845                 ret = getoptions(datablob, p, o);
 846                 if (ret < 0)
 847                         return ret;
 848                 ret = Opt_new;
 849                 break;
 850         case Opt_load:
 851                 /* first argument is sealed blob */
 852                 c = strsep(&datablob, " \t");
 853                 if (!c)
 854                         return -EINVAL;
 855                 p->blob_len = strlen(c) / 2;
 856                 if (p->blob_len > MAX_BLOB_SIZE)
 857                         return -EINVAL;
 858                 hex2bin(p->blob, c, p->blob_len);
 859                 ret = getoptions(datablob, p, o);
 860                 if (ret < 0)
 861                         return ret;
 862                 ret = Opt_load;
 863                 break;
 864         case Opt_update:
 865                 /* all arguments are options */
 866                 ret = getoptions(datablob, p, o);
 867                 if (ret < 0)
 868                         return ret;
 869                 ret = Opt_update;
 870                 break;
 871         case Opt_err:
 872                 return -EINVAL;
 873                 break;
 874         }
 875         return ret;
 876 }
 877
 878 static struct trusted_key_options *trusted_options_alloc(void)
 879 {
 880         struct trusted_key_options *options;
 881
 882         options = kzalloc(sizeof *options, GFP_KERNEL);
 883         if (options) {
 884                 /* set any non-zero defaults */
 885                 options->keytype = SRK_keytype;
 886                 options->keyhandle = SRKHANDLE;
 887         }
 888         return options;
 889 }
 890
 891 static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
 892 {
 893         struct trusted_key_payload *p = NULL;
 894         int ret;
 895
 896         ret = key_payload_reserve(key, sizeof *p);
 897         if (ret < 0)
 898                 return p;
 899         p = kzalloc(sizeof *p, GFP_KERNEL);
 900         if (p)
 901                 p->migratable = 1; /* migratable by default */
 902         return p;
 903 }
 904
 905 /*
 906  * trusted_instantiate - create a new trusted key
 907  *
 908  * Unseal an existing trusted blob or, for a new key, get a
 909  * random key, then seal and create a trusted key-type key,
 910  * adding it to the specified keyring.
 911  *
 912  * On success, return 0. Otherwise return errno.
 913  */
 914 static int trusted_instantiate(struct key *key, const void *data,
 915                                size_t datalen)
 916 {
 917         struct trusted_key_payload *payload = NULL;
 918         struct trusted_key_options *options = NULL;
 919         char *datablob;
 920         int ret = 0;
 921         int key_cmd;
 922
 923         if (datalen <= 0 || datalen > 32767 || !data)
 924                 return -EINVAL;
 925
 926         datablob = kmalloc(datalen + 1, GFP_KERNEL);
 927         if (!datablob)
 928                 return -ENOMEM;
 929         memcpy(datablob, data, datalen);
 930         datablob[datalen] = '\0';
 931
 932         options = trusted_options_alloc();
 933         if (!options) {
 934                 ret = -ENOMEM;
 935                 goto out;
 936         }
 937         payload = trusted_payload_alloc(key);
 938         if (!payload) {
 939                 ret = -ENOMEM;
 940                 goto out;
 941         }
 942
 943         key_cmd = datablob_parse(datablob, payload, options);
 944         if (key_cmd < 0) {
 945                 ret = key_cmd;
 946                 goto out;
 947         }
 948
 949         dump_payload(payload);
 950         dump_options(options);
 951
 952         switch (key_cmd) {
 953         case Opt_load:
 954                 ret = key_unseal(payload, options);
 955                 dump_payload(payload);
 956                 dump_options(options);
 957                 if (ret < 0)
 958                         pr_info("trusted_key: key_unseal failed (%d)\n", ret);
 959                 break;
 960         case Opt_new:
 961                 ret = my_get_random(payload->key, payload->key_len);
 962                 if (ret < 0) {
 963                         pr_info("trusted_key: key_create failed (%d)\n", ret);
 964                         goto out;
 965                 }
 966                 ret = key_seal(payload, options);
 967                 if (ret < 0)
 968                         pr_info("trusted_key: key_seal failed (%d)\n", ret);
 969                 break;
 970         default:
 971                 ret = -EINVAL;
 972                 goto out;
 973         }
 974         if (!ret && options->pcrlock)
 975                 ret = pcrlock(options->pcrlock);
 976 out:
 977         kfree(datablob);
 978         kfree(options);
 979         if (!ret)
 980                 rcu_assign_pointer(key->payload.data, payload);
 981         else
 982                 kfree(payload);
 983         return ret;
 984 }
 985
 986 static void trusted_rcu_free(struct rcu_head *rcu)
 987 {
 988         struct trusted_key_payload *p;
 989
 990         p = container_of(rcu, struct trusted_key_payload, rcu);
 991         memset(p->key, 0, p->key_len);
 992         kfree(p);
 993 }
 994
 995 /*
 996  * trusted_update - reseal an existing key with new PCR values
 997  */
 998 static int trusted_update(struct key *key, const void *data, size_t datalen)
 999 {
1000         struct trusted_key_payload *p = key->payload.data;
1001         struct trusted_key_payload *new_p;
1002         struct trusted_key_options *new_o;
1003         char *datablob;
1004         int ret = 0;
1005
1006         if (!p->migratable)
1007                 return -EPERM;
1008         if (datalen <= 0 || datalen > 32767 || !data)
1009                 return -EINVAL;
1010
1011         datablob = kmalloc(datalen + 1, GFP_KERNEL);
1012         if (!datablob)
1013                 return -ENOMEM;
1014         new_o = trusted_options_alloc();
1015         if (!new_o) {
1016                 ret = -ENOMEM;
1017                 goto out;
1018         }
1019         new_p = trusted_payload_alloc(key);
1020         if (!new_p) {
1021                 ret = -ENOMEM;
1022                 goto out;
1023         }
1024
1025         memcpy(datablob, data, datalen);
1026         datablob[datalen] = '\0';
1027         ret = datablob_parse(datablob, new_p, new_o);
1028         if (ret != Opt_update) {
1029                 ret = -EINVAL;
1030                 goto out;
1031         }
1032         /* copy old key values, and reseal with new pcrs */
1033         new_p->migratable = p->migratable;
1034         new_p->key_len = p->key_len;
1035         memcpy(new_p->key, p->key, p->key_len);
1036         dump_payload(p);
1037         dump_payload(new_p);
1038
1039         ret = key_seal(new_p, new_o);
1040         if (ret < 0) {
1041                 pr_info("trusted_key: key_seal failed (%d)\n", ret);
1042                 kfree(new_p);
1043                 goto out;
1044         }
1045         if (new_o->pcrlock) {
1046                 ret = pcrlock(new_o->pcrlock);
1047                 if (ret < 0) {
1048                         pr_info("trusted_key: pcrlock failed (%d)\n", ret);
1049                         kfree(new_p);
1050                         goto out;
1051                 }
1052         }
1053         rcu_assign_pointer(key->payload.data, new_p);
1054         call_rcu(&p->rcu, trusted_rcu_free);
1055 out:
1056         kfree(datablob);
1057         kfree(new_o);
1058         return ret;
1059 }
1060
1061 /*
1062  * trusted_read - copy the sealed blob data to userspace in hex.
1063  * On success, return to userspace the trusted key datablob size.
1064  */
1065 static long trusted_read(const struct key *key, char __user *buffer,
1066                          size_t buflen)
1067 {
1068         struct trusted_key_payload *p;
1069         char *ascii_buf;
1070         char *bufp;
1071         int i;
1072
1073         p = rcu_dereference_protected(key->payload.data,
1074                         rwsem_is_locked(&((struct key *)key)->sem));
1075         if (!p)
1076                 return -EINVAL;
1077         if (!buffer || buflen <= 0)
1078                 return 2 * p->blob_len;
1079         ascii_buf = kmalloc(2 * p->blob_len, GFP_KERNEL);
1080         if (!ascii_buf)
1081                 return -ENOMEM;
1082
1083         bufp = ascii_buf;
1084         for (i = 0; i < p->blob_len; i++)
1085                 bufp = pack_hex_byte(bufp, p->blob[i]);
1086         if ((copy_to_user(buffer, ascii_buf, 2 * p->blob_len)) != 0) {
1087                 kfree(ascii_buf);
1088                 return -EFAULT;
1089         }
1090         kfree(ascii_buf);
1091         return 2 * p->blob_len;
1092 }
1093
1094 /*
1095  * trusted_destroy - before freeing the key, clear the decrypted data
1096  */
1097 static void trusted_destroy(struct key *key)
1098 {
1099         struct trusted_key_payload *p = key->payload.data;
1100
1101         if (!p)
1102                 return;
1103         memset(p->key, 0, p->key_len);
1104         kfree(key->payload.data);
1105 }
1106
1107 struct key_type key_type_trusted = {
1108         .name = "trusted",
1109         .instantiate = trusted_instantiate,
1110         .update = trusted_update,
1111         .match = user_match,
1112         .destroy = trusted_destroy,
1113         .describe = user_describe,
1114         .read = trusted_read,
1115 };
1116
1117 EXPORT_SYMBOL_GPL(key_type_trusted);
1118
1119 static void trusted_shash_release(void)
1120 {
1121         if (hashalg)
1122                 crypto_free_shash(hashalg);
1123         if (hmacalg)
1124                 crypto_free_shash(hmacalg);
1125 }
1126
1127 static int __init trusted_shash_alloc(void)
1128 {
1129         int ret;
1130
1131         hmacalg = crypto_alloc_shash(hmac_alg, 0, CRYPTO_ALG_ASYNC);
1132         if (IS_ERR(hmacalg)) {
1133                 pr_info("trusted_key: could not allocate crypto %s\n",
1134                         hmac_alg);
1135                 return PTR_ERR(hmacalg);
1136         }
1137
1138         hashalg = crypto_alloc_shash(hash_alg, 0, CRYPTO_ALG_ASYNC);
1139         if (IS_ERR(hashalg)) {
1140                 pr_info("trusted_key: could not allocate crypto %s\n",
1141                         hash_alg);
1142                 ret = PTR_ERR(hashalg);
1143                 goto hashalg_fail;
1144         }
1145
1146         return 0;
1147
1148 hashalg_fail:
1149         crypto_free_shash(hmacalg);
1150         return ret;
1151 }
1152
1153 static int __init init_trusted(void)
1154 {
1155         int ret;
1156
1157         ret = trusted_shash_alloc();
1158         if (ret < 0)
1159                 return ret;
1160         ret = register_key_type(&key_type_trusted);
1161         if (ret < 0)
1162                 trusted_shash_release();
1163         return ret;
1164 }
1165
1166 static void __exit cleanup_trusted(void)
1167 {
1168         trusted_shash_release();
1169         unregister_key_type(&key_type_trusted);
1170 }
1171
1172 late_initcall(init_trusted);
1173 module_exit(cleanup_trusted);
1174
1175 MODULE_LICENSE("GPL");