1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2010 IBM Corporation
6 * David Safford <safford@us.ibm.com>
8 * See Documentation/security/keys/trusted-encrypted.rst
11 #include <crypto/hash_info.h>
12 #include <linux/uaccess.h>
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/slab.h>
16 #include <linux/parser.h>
17 #include <linux/string.h>
18 #include <linux/err.h>
19 #include <keys/user-type.h>
20 #include <keys/trusted-type.h>
21 #include <linux/key-type.h>
22 #include <linux/rcupdate.h>
23 #include <linux/crypto.h>
24 #include <crypto/hash.h>
25 #include <crypto/sha.h>
26 #include <linux/capability.h>
27 #include <linux/tpm.h>
28 #include <linux/tpm_command.h>
30 #include <keys/trusted_tpm.h>
32 static const char hmac_alg[] = "hmac(sha1)";
33 static const char hash_alg[] = "sha1";
34 static struct tpm_chip *chip;
35 static struct tpm_digest *digests;
38 struct shash_desc shash;
42 static struct crypto_shash *hashalg;
43 static struct crypto_shash *hmacalg;
45 static struct sdesc *init_sdesc(struct crypto_shash *alg)
50 size = sizeof(struct shash_desc) + crypto_shash_descsize(alg);
51 sdesc = kmalloc(size, GFP_KERNEL);
53 return ERR_PTR(-ENOMEM);
54 sdesc->shash.tfm = alg;
58 static int TSS_sha1(const unsigned char *data, unsigned int datalen,
59 unsigned char *digest)
64 sdesc = init_sdesc(hashalg);
66 pr_info("trusted_key: can't alloc %s\n", hash_alg);
67 return PTR_ERR(sdesc);
70 ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest);
71 kfree_sensitive(sdesc);
75 static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
76 unsigned int keylen, ...)
84 sdesc = init_sdesc(hmacalg);
86 pr_info("trusted_key: can't alloc %s\n", hmac_alg);
87 return PTR_ERR(sdesc);
90 ret = crypto_shash_setkey(hmacalg, key, keylen);
93 ret = crypto_shash_init(&sdesc->shash);
97 va_start(argp, keylen);
99 dlen = va_arg(argp, unsigned int);
102 data = va_arg(argp, unsigned char *);
107 ret = crypto_shash_update(&sdesc->shash, data, dlen);
113 ret = crypto_shash_final(&sdesc->shash, digest);
115 kfree_sensitive(sdesc);
120 * calculate authorization info fields to send to TPM
122 int TSS_authhmac(unsigned char *digest, const unsigned char *key,
123 unsigned int keylen, unsigned char *h1,
124 unsigned char *h2, unsigned int h3, ...)
126 unsigned char paramdigest[SHA1_DIGEST_SIZE];
137 sdesc = init_sdesc(hashalg);
139 pr_info("trusted_key: can't alloc %s\n", hash_alg);
140 return PTR_ERR(sdesc);
144 ret = crypto_shash_init(&sdesc->shash);
149 dlen = va_arg(argp, unsigned int);
152 data = va_arg(argp, unsigned char *);
157 ret = crypto_shash_update(&sdesc->shash, data, dlen);
163 ret = crypto_shash_final(&sdesc->shash, paramdigest);
165 ret = TSS_rawhmac(digest, key, keylen, SHA1_DIGEST_SIZE,
166 paramdigest, TPM_NONCE_SIZE, h1,
167 TPM_NONCE_SIZE, h2, 1, &c, 0, 0);
169 kfree_sensitive(sdesc);
172 EXPORT_SYMBOL_GPL(TSS_authhmac);
175 * verify the AUTH1_COMMAND (Seal) result from TPM
177 int TSS_checkhmac1(unsigned char *buffer,
178 const uint32_t command,
179 const unsigned char *ononce,
180 const unsigned char *key,
181 unsigned int keylen, ...)
187 unsigned char *enonce;
188 unsigned char *continueflag;
189 unsigned char *authdata;
190 unsigned char testhmac[SHA1_DIGEST_SIZE];
191 unsigned char paramdigest[SHA1_DIGEST_SIZE];
201 bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
202 tag = LOAD16(buffer, 0);
204 result = LOAD32N(buffer, TPM_RETURN_OFFSET);
205 if (tag == TPM_TAG_RSP_COMMAND)
207 if (tag != TPM_TAG_RSP_AUTH1_COMMAND)
209 authdata = buffer + bufsize - SHA1_DIGEST_SIZE;
210 continueflag = authdata - 1;
211 enonce = continueflag - TPM_NONCE_SIZE;
213 sdesc = init_sdesc(hashalg);
215 pr_info("trusted_key: can't alloc %s\n", hash_alg);
216 return PTR_ERR(sdesc);
218 ret = crypto_shash_init(&sdesc->shash);
221 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
225 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
229 va_start(argp, keylen);
231 dlen = va_arg(argp, unsigned int);
234 dpos = va_arg(argp, unsigned int);
235 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
241 ret = crypto_shash_final(&sdesc->shash, paramdigest);
245 ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest,
246 TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce,
247 1, continueflag, 0, 0);
251 if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE))
254 kfree_sensitive(sdesc);
257 EXPORT_SYMBOL_GPL(TSS_checkhmac1);
260 * verify the AUTH2_COMMAND (unseal) result from TPM
262 static int TSS_checkhmac2(unsigned char *buffer,
263 const uint32_t command,
264 const unsigned char *ononce,
265 const unsigned char *key1,
266 unsigned int keylen1,
267 const unsigned char *key2,
268 unsigned int keylen2, ...)
274 unsigned char *enonce1;
275 unsigned char *continueflag1;
276 unsigned char *authdata1;
277 unsigned char *enonce2;
278 unsigned char *continueflag2;
279 unsigned char *authdata2;
280 unsigned char testhmac1[SHA1_DIGEST_SIZE];
281 unsigned char testhmac2[SHA1_DIGEST_SIZE];
282 unsigned char paramdigest[SHA1_DIGEST_SIZE];
289 bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
290 tag = LOAD16(buffer, 0);
292 result = LOAD32N(buffer, TPM_RETURN_OFFSET);
294 if (tag == TPM_TAG_RSP_COMMAND)
296 if (tag != TPM_TAG_RSP_AUTH2_COMMAND)
298 authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1
299 + SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE);
300 authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE);
301 continueflag1 = authdata1 - 1;
302 continueflag2 = authdata2 - 1;
303 enonce1 = continueflag1 - TPM_NONCE_SIZE;
304 enonce2 = continueflag2 - TPM_NONCE_SIZE;
306 sdesc = init_sdesc(hashalg);
308 pr_info("trusted_key: can't alloc %s\n", hash_alg);
309 return PTR_ERR(sdesc);
311 ret = crypto_shash_init(&sdesc->shash);
314 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
318 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
323 va_start(argp, keylen2);
325 dlen = va_arg(argp, unsigned int);
328 dpos = va_arg(argp, unsigned int);
329 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
335 ret = crypto_shash_final(&sdesc->shash, paramdigest);
339 ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE,
340 paramdigest, TPM_NONCE_SIZE, enonce1,
341 TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0);
344 if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) {
348 ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE,
349 paramdigest, TPM_NONCE_SIZE, enonce2,
350 TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0);
353 if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE))
356 kfree_sensitive(sdesc);
361 * For key specific tpm requests, we will generate and send our
362 * own TPM command packets using the drivers send function.
364 int trusted_tpm_send(unsigned char *cmd, size_t buflen)
372 rc = tpm_send(chip, cmd, buflen);
375 /* Can't return positive return codes values to keyctl */
379 EXPORT_SYMBOL_GPL(trusted_tpm_send);
382 * Lock a trusted key, by extending a selected PCR.
384 * Prevents a trusted key that is sealed to PCRs from being accessed.
385 * This uses the tpm driver's extend function.
387 static int pcrlock(const int pcrnum)
389 if (!capable(CAP_SYS_ADMIN))
392 return tpm_pcr_extend(chip, pcrnum, digests) ? -EINVAL : 0;
396 * Create an object specific authorisation protocol (OSAP) session
398 static int osap(struct tpm_buf *tb, struct osapsess *s,
399 const unsigned char *key, uint16_t type, uint32_t handle)
401 unsigned char enonce[TPM_NONCE_SIZE];
402 unsigned char ononce[TPM_NONCE_SIZE];
405 ret = tpm_get_random(chip, ononce, TPM_NONCE_SIZE);
409 if (ret != TPM_NONCE_SIZE)
412 tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OSAP);
413 tpm_buf_append_u16(tb, type);
414 tpm_buf_append_u32(tb, handle);
415 tpm_buf_append(tb, ononce, TPM_NONCE_SIZE);
417 ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
421 s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
422 memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
424 memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
425 TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
426 return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
427 enonce, TPM_NONCE_SIZE, ononce, 0, 0);
431 * Create an object independent authorisation protocol (oiap) session
433 int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
440 tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OIAP);
441 ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
445 *handle = LOAD32(tb->data, TPM_DATA_OFFSET);
446 memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
450 EXPORT_SYMBOL_GPL(oiap);
453 unsigned char encauth[SHA1_DIGEST_SIZE];
454 unsigned char pubauth[SHA1_DIGEST_SIZE];
455 unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
456 unsigned char xorhash[SHA1_DIGEST_SIZE];
457 unsigned char nonceodd[TPM_NONCE_SIZE];
461 * Have the TPM seal(encrypt) the trusted key, possibly based on
462 * Platform Configuration Registers (PCRs). AUTH1 for sealing key.
464 static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
465 uint32_t keyhandle, const unsigned char *keyauth,
466 const unsigned char *data, uint32_t datalen,
467 unsigned char *blob, uint32_t *bloblen,
468 const unsigned char *blobauth,
469 const unsigned char *pcrinfo, uint32_t pcrinfosize)
471 struct osapsess sess;
472 struct tpm_digests *td;
483 /* alloc some work space for all the hashes */
484 td = kmalloc(sizeof *td, GFP_KERNEL);
488 /* get session for sealing key */
489 ret = osap(tb, &sess, keyauth, keytype, keyhandle);
494 /* calculate encrypted authorization value */
495 memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
496 memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
497 ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
501 ret = tpm_get_random(chip, td->nonceodd, TPM_NONCE_SIZE);
505 if (ret != TPM_NONCE_SIZE) {
510 ordinal = htonl(TPM_ORD_SEAL);
511 datsize = htonl(datalen);
512 pcrsize = htonl(pcrinfosize);
515 /* encrypt data authorization key */
516 for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
517 td->encauth[i] = td->xorhash[i] ^ blobauth[i];
519 /* calculate authorization HMAC value */
520 if (pcrinfosize == 0) {
521 /* no pcr info specified */
522 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
523 sess.enonce, td->nonceodd, cont,
524 sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
525 td->encauth, sizeof(uint32_t), &pcrsize,
526 sizeof(uint32_t), &datsize, datalen, data, 0,
529 /* pcr info specified */
530 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
531 sess.enonce, td->nonceodd, cont,
532 sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
533 td->encauth, sizeof(uint32_t), &pcrsize,
534 pcrinfosize, pcrinfo, sizeof(uint32_t),
535 &datsize, datalen, data, 0, 0);
540 /* build and send the TPM request packet */
541 tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_SEAL);
542 tpm_buf_append_u32(tb, keyhandle);
543 tpm_buf_append(tb, td->encauth, SHA1_DIGEST_SIZE);
544 tpm_buf_append_u32(tb, pcrinfosize);
545 tpm_buf_append(tb, pcrinfo, pcrinfosize);
546 tpm_buf_append_u32(tb, datalen);
547 tpm_buf_append(tb, data, datalen);
548 tpm_buf_append_u32(tb, sess.handle);
549 tpm_buf_append(tb, td->nonceodd, TPM_NONCE_SIZE);
550 tpm_buf_append_u8(tb, cont);
551 tpm_buf_append(tb, td->pubauth, SHA1_DIGEST_SIZE);
553 ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
557 /* calculate the size of the returned Blob */
558 sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
559 encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
560 sizeof(uint32_t) + sealinfosize);
561 storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
562 sizeof(uint32_t) + encdatasize;
564 /* check the HMAC in the response */
565 ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
566 SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
569 /* copy the returned blob to caller */
571 memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
572 *bloblen = storedsize;
580 * use the AUTH2_COMMAND form of unseal, to authorize both key and blob
582 static int tpm_unseal(struct tpm_buf *tb,
583 uint32_t keyhandle, const unsigned char *keyauth,
584 const unsigned char *blob, int bloblen,
585 const unsigned char *blobauth,
586 unsigned char *data, unsigned int *datalen)
588 unsigned char nonceodd[TPM_NONCE_SIZE];
589 unsigned char enonce1[TPM_NONCE_SIZE];
590 unsigned char enonce2[TPM_NONCE_SIZE];
591 unsigned char authdata1[SHA1_DIGEST_SIZE];
592 unsigned char authdata2[SHA1_DIGEST_SIZE];
593 uint32_t authhandle1 = 0;
594 uint32_t authhandle2 = 0;
595 unsigned char cont = 0;
599 /* sessions for unsealing key and data */
600 ret = oiap(tb, &authhandle1, enonce1);
602 pr_info("trusted_key: oiap failed (%d)\n", ret);
605 ret = oiap(tb, &authhandle2, enonce2);
607 pr_info("trusted_key: oiap failed (%d)\n", ret);
611 ordinal = htonl(TPM_ORD_UNSEAL);
612 ret = tpm_get_random(chip, nonceodd, TPM_NONCE_SIZE);
616 if (ret != TPM_NONCE_SIZE) {
617 pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
620 ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
621 enonce1, nonceodd, cont, sizeof(uint32_t),
622 &ordinal, bloblen, blob, 0, 0);
625 ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
626 enonce2, nonceodd, cont, sizeof(uint32_t),
627 &ordinal, bloblen, blob, 0, 0);
631 /* build and send TPM request packet */
632 tpm_buf_reset(tb, TPM_TAG_RQU_AUTH2_COMMAND, TPM_ORD_UNSEAL);
633 tpm_buf_append_u32(tb, keyhandle);
634 tpm_buf_append(tb, blob, bloblen);
635 tpm_buf_append_u32(tb, authhandle1);
636 tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
637 tpm_buf_append_u8(tb, cont);
638 tpm_buf_append(tb, authdata1, SHA1_DIGEST_SIZE);
639 tpm_buf_append_u32(tb, authhandle2);
640 tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
641 tpm_buf_append_u8(tb, cont);
642 tpm_buf_append(tb, authdata2, SHA1_DIGEST_SIZE);
644 ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
646 pr_info("trusted_key: authhmac failed (%d)\n", ret);
650 *datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
651 ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
652 keyauth, SHA1_DIGEST_SIZE,
653 blobauth, SHA1_DIGEST_SIZE,
654 sizeof(uint32_t), TPM_DATA_OFFSET,
655 *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
658 pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret);
661 memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
666 * Have the TPM seal(encrypt) the symmetric key
668 static int key_seal(struct trusted_key_payload *p,
669 struct trusted_key_options *o)
674 ret = tpm_buf_init(&tb, 0, 0);
678 /* include migratable flag at end of sealed key */
679 p->key[p->key_len] = p->migratable;
681 ret = tpm_seal(&tb, o->keytype, o->keyhandle, o->keyauth,
682 p->key, p->key_len + 1, p->blob, &p->blob_len,
683 o->blobauth, o->pcrinfo, o->pcrinfo_len);
685 pr_info("trusted_key: srkseal failed (%d)\n", ret);
687 tpm_buf_destroy(&tb);
692 * Have the TPM unseal(decrypt) the symmetric key
694 static int key_unseal(struct trusted_key_payload *p,
695 struct trusted_key_options *o)
700 ret = tpm_buf_init(&tb, 0, 0);
704 ret = tpm_unseal(&tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
705 o->blobauth, p->key, &p->key_len);
707 pr_info("trusted_key: srkunseal failed (%d)\n", ret);
709 /* pull migratable flag out of sealed key */
710 p->migratable = p->key[--p->key_len];
712 tpm_buf_destroy(&tb);
718 Opt_new, Opt_load, Opt_update,
719 Opt_keyhandle, Opt_keyauth, Opt_blobauth,
720 Opt_pcrinfo, Opt_pcrlock, Opt_migratable,
726 static const match_table_t key_tokens = {
729 {Opt_update, "update"},
730 {Opt_keyhandle, "keyhandle=%s"},
731 {Opt_keyauth, "keyauth=%s"},
732 {Opt_blobauth, "blobauth=%s"},
733 {Opt_pcrinfo, "pcrinfo=%s"},
734 {Opt_pcrlock, "pcrlock=%s"},
735 {Opt_migratable, "migratable=%s"},
736 {Opt_hash, "hash=%s"},
737 {Opt_policydigest, "policydigest=%s"},
738 {Opt_policyhandle, "policyhandle=%s"},
742 /* can have zero or more token= options */
743 static int getoptions(char *c, struct trusted_key_payload *pay,
744 struct trusted_key_options *opt)
746 substring_t args[MAX_OPT_ARGS];
750 unsigned long handle;
752 unsigned long token_mask = 0;
753 unsigned int digest_len;
757 tpm2 = tpm_is_tpm2(chip);
761 opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1;
763 while ((p = strsep(&c, " \t"))) {
764 if (*p == '\0' || *p == ' ' || *p == '\t')
766 token = match_token(p, key_tokens, args);
767 if (test_and_set_bit(token, &token_mask))
772 opt->pcrinfo_len = strlen(args[0].from) / 2;
773 if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
775 res = hex2bin(opt->pcrinfo, args[0].from,
781 res = kstrtoul(args[0].from, 16, &handle);
784 opt->keytype = SEAL_keytype;
785 opt->keyhandle = handle;
788 if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
790 res = hex2bin(opt->keyauth, args[0].from,
797 * TPM 1.2 authorizations are sha1 hashes passed in as
798 * hex strings. TPM 2.0 authorizations are simple
799 * passwords (although it can take a hash as well)
801 opt->blobauth_len = strlen(args[0].from);
803 if (opt->blobauth_len == 2 * TPM_DIGEST_SIZE) {
804 res = hex2bin(opt->blobauth, args[0].from,
809 opt->blobauth_len = TPM_DIGEST_SIZE;
813 if (tpm2 && opt->blobauth_len <= sizeof(opt->blobauth)) {
814 memcpy(opt->blobauth, args[0].from,
824 if (*args[0].from == '0')
826 else if (*args[0].from != '1')
830 res = kstrtoul(args[0].from, 10, &lock);
836 if (test_bit(Opt_policydigest, &token_mask))
838 for (i = 0; i < HASH_ALGO__LAST; i++) {
839 if (!strcmp(args[0].from, hash_algo_name[i])) {
844 if (i == HASH_ALGO__LAST)
846 if (!tpm2 && i != HASH_ALGO_SHA1) {
847 pr_info("trusted_key: TPM 1.x only supports SHA-1.\n");
851 case Opt_policydigest:
852 digest_len = hash_digest_size[opt->hash];
853 if (!tpm2 || strlen(args[0].from) != (2 * digest_len))
855 res = hex2bin(opt->policydigest, args[0].from,
859 opt->policydigest_len = digest_len;
861 case Opt_policyhandle:
864 res = kstrtoul(args[0].from, 16, &handle);
867 opt->policyhandle = handle;
877 * datablob_parse - parse the keyctl data and fill in the
878 * payload and options structures
880 * On success returns 0, otherwise -EINVAL.
882 static int datablob_parse(char *datablob, struct trusted_key_payload *p,
883 struct trusted_key_options *o)
885 substring_t args[MAX_OPT_ARGS];
892 c = strsep(&datablob, " \t");
895 key_cmd = match_token(c, key_tokens, args);
898 /* first argument is key size */
899 c = strsep(&datablob, " \t");
902 ret = kstrtol(c, 10, &keylen);
903 if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
906 ret = getoptions(datablob, p, o);
912 /* first argument is sealed blob */
913 c = strsep(&datablob, " \t");
916 p->blob_len = strlen(c) / 2;
917 if (p->blob_len > MAX_BLOB_SIZE)
919 ret = hex2bin(p->blob, c, p->blob_len);
922 ret = getoptions(datablob, p, o);
928 /* all arguments are options */
929 ret = getoptions(datablob, p, o);
941 static struct trusted_key_options *trusted_options_alloc(void)
943 struct trusted_key_options *options;
946 tpm2 = tpm_is_tpm2(chip);
950 options = kzalloc(sizeof *options, GFP_KERNEL);
952 /* set any non-zero defaults */
953 options->keytype = SRK_keytype;
956 options->keyhandle = SRKHANDLE;
961 static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
963 struct trusted_key_payload *p = NULL;
966 ret = key_payload_reserve(key, sizeof *p);
969 p = kzalloc(sizeof *p, GFP_KERNEL);
971 p->migratable = 1; /* migratable by default */
976 * trusted_instantiate - create a new trusted key
978 * Unseal an existing trusted blob or, for a new key, get a
979 * random key, then seal and create a trusted key-type key,
980 * adding it to the specified keyring.
982 * On success, return 0. Otherwise return errno.
984 static int trusted_instantiate(struct key *key,
985 struct key_preparsed_payload *prep)
987 struct trusted_key_payload *payload = NULL;
988 struct trusted_key_options *options = NULL;
989 size_t datalen = prep->datalen;
996 tpm2 = tpm_is_tpm2(chip);
1000 if (datalen <= 0 || datalen > 32767 || !prep->data)
1003 datablob = kmalloc(datalen + 1, GFP_KERNEL);
1006 memcpy(datablob, prep->data, datalen);
1007 datablob[datalen] = '\0';
1009 options = trusted_options_alloc();
1014 payload = trusted_payload_alloc(key);
1020 key_cmd = datablob_parse(datablob, payload, options);
1026 if (!options->keyhandle) {
1031 dump_payload(payload);
1032 dump_options(options);
1037 ret = tpm2_unseal_trusted(chip, payload, options);
1039 ret = key_unseal(payload, options);
1040 dump_payload(payload);
1041 dump_options(options);
1043 pr_info("trusted_key: key_unseal failed (%d)\n", ret);
1046 key_len = payload->key_len;
1047 ret = tpm_get_random(chip, payload->key, key_len);
1051 if (ret != key_len) {
1052 pr_info("trusted_key: key_create failed (%d)\n", ret);
1057 ret = tpm2_seal_trusted(chip, payload, options);
1059 ret = key_seal(payload, options);
1061 pr_info("trusted_key: key_seal failed (%d)\n", ret);
1067 if (!ret && options->pcrlock)
1068 ret = pcrlock(options->pcrlock);
1070 kfree_sensitive(datablob);
1071 kfree_sensitive(options);
1073 rcu_assign_keypointer(key, payload);
1075 kfree_sensitive(payload);
1079 static void trusted_rcu_free(struct rcu_head *rcu)
1081 struct trusted_key_payload *p;
1083 p = container_of(rcu, struct trusted_key_payload, rcu);
1088 * trusted_update - reseal an existing key with new PCR values
1090 static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
1092 struct trusted_key_payload *p;
1093 struct trusted_key_payload *new_p;
1094 struct trusted_key_options *new_o;
1095 size_t datalen = prep->datalen;
1099 if (key_is_negative(key))
1101 p = key->payload.data[0];
1104 if (datalen <= 0 || datalen > 32767 || !prep->data)
1107 datablob = kmalloc(datalen + 1, GFP_KERNEL);
1110 new_o = trusted_options_alloc();
1115 new_p = trusted_payload_alloc(key);
1121 memcpy(datablob, prep->data, datalen);
1122 datablob[datalen] = '\0';
1123 ret = datablob_parse(datablob, new_p, new_o);
1124 if (ret != Opt_update) {
1126 kfree_sensitive(new_p);
1130 if (!new_o->keyhandle) {
1132 kfree_sensitive(new_p);
1136 /* copy old key values, and reseal with new pcrs */
1137 new_p->migratable = p->migratable;
1138 new_p->key_len = p->key_len;
1139 memcpy(new_p->key, p->key, p->key_len);
1141 dump_payload(new_p);
1143 ret = key_seal(new_p, new_o);
1145 pr_info("trusted_key: key_seal failed (%d)\n", ret);
1146 kfree_sensitive(new_p);
1149 if (new_o->pcrlock) {
1150 ret = pcrlock(new_o->pcrlock);
1152 pr_info("trusted_key: pcrlock failed (%d)\n", ret);
1153 kfree_sensitive(new_p);
1157 rcu_assign_keypointer(key, new_p);
1158 call_rcu(&p->rcu, trusted_rcu_free);
1160 kfree_sensitive(datablob);
1161 kfree_sensitive(new_o);
1166 * trusted_read - copy the sealed blob data to userspace in hex.
1167 * On success, return to userspace the trusted key datablob size.
1169 static long trusted_read(const struct key *key, char *buffer,
1172 const struct trusted_key_payload *p;
1176 p = dereference_key_locked(key);
1180 if (buffer && buflen >= 2 * p->blob_len) {
1182 for (i = 0; i < p->blob_len; i++)
1183 bufp = hex_byte_pack(bufp, p->blob[i]);
1185 return 2 * p->blob_len;
1189 * trusted_destroy - clear and free the key's payload
1191 static void trusted_destroy(struct key *key)
1193 kfree_sensitive(key->payload.data[0]);
1196 struct key_type key_type_trusted = {
1198 .instantiate = trusted_instantiate,
1199 .update = trusted_update,
1200 .destroy = trusted_destroy,
1201 .describe = user_describe,
1202 .read = trusted_read,
1205 EXPORT_SYMBOL_GPL(key_type_trusted);
1207 static void trusted_shash_release(void)
1210 crypto_free_shash(hashalg);
1212 crypto_free_shash(hmacalg);
1215 static int __init trusted_shash_alloc(void)
1219 hmacalg = crypto_alloc_shash(hmac_alg, 0, 0);
1220 if (IS_ERR(hmacalg)) {
1221 pr_info("trusted_key: could not allocate crypto %s\n",
1223 return PTR_ERR(hmacalg);
1226 hashalg = crypto_alloc_shash(hash_alg, 0, 0);
1227 if (IS_ERR(hashalg)) {
1228 pr_info("trusted_key: could not allocate crypto %s\n",
1230 ret = PTR_ERR(hashalg);
1237 crypto_free_shash(hmacalg);
1241 static int __init init_digests(void)
1245 digests = kcalloc(chip->nr_allocated_banks, sizeof(*digests),
1250 for (i = 0; i < chip->nr_allocated_banks; i++)
1251 digests[i].alg_id = chip->allocated_banks[i].alg_id;
1256 static int __init init_trusted(void)
1260 /* encrypted_keys.ko depends on successful load of this module even if
1263 chip = tpm_default_chip();
1267 ret = init_digests();
1270 ret = trusted_shash_alloc();
1273 ret = register_key_type(&key_type_trusted);
1278 trusted_shash_release();
1282 put_device(&chip->dev);
1286 static void __exit cleanup_trusted(void)
1289 put_device(&chip->dev);
1291 trusted_shash_release();
1292 unregister_key_type(&key_type_trusted);
1296 late_initcall(init_trusted);
1297 module_exit(cleanup_trusted);
1299 MODULE_LICENSE("GPL");