2 * Copyright (C) 2010 IBM Corporation
5 * David Safford <safford@us.ibm.com>
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.
11 * See Documentation/keys-trusted-encrypted.txt
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>
32 #include "trusted_defined.h"
34 static const char hmac_alg[] = "hmac(sha1)";
35 static const char hash_alg[] = "sha1";
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;
55 sdesc->shash.flags = 0x0;
59 static int TSS_sha1(const unsigned char *data, const unsigned int datalen,
60 unsigned char *digest)
65 sdesc = init_sdesc(hashalg);
67 pr_info("trusted_key: can't alloc %s\n", hash_alg);
68 return PTR_ERR(sdesc);
71 ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest);
76 static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
77 const unsigned int keylen, ...)
85 sdesc = init_sdesc(hmacalg);
87 pr_info("trusted_key: can't alloc %s\n", hmac_alg);
88 return PTR_ERR(sdesc);
91 ret = crypto_shash_setkey(hmacalg, key, keylen);
94 ret = crypto_shash_init(&sdesc->shash);
98 va_start(argp, keylen);
100 dlen = va_arg(argp, unsigned int);
103 data = va_arg(argp, unsigned char *);
106 ret = crypto_shash_update(&sdesc->shash, data, dlen);
112 ret = crypto_shash_final(&sdesc->shash, digest);
119 * calculate authorization info fields to send to TPM
121 static int TSS_authhmac(unsigned char *digest, const unsigned char *key,
122 const unsigned int keylen, unsigned char *h1,
123 unsigned char *h2, unsigned char h3, ...)
125 unsigned char paramdigest[SHA1_DIGEST_SIZE];
133 sdesc = init_sdesc(hashalg);
135 pr_info("trusted_key: can't alloc %s\n", hash_alg);
136 return PTR_ERR(sdesc);
140 ret = crypto_shash_init(&sdesc->shash);
145 dlen = va_arg(argp, unsigned int);
148 data = va_arg(argp, unsigned char *);
149 ret = crypto_shash_update(&sdesc->shash, data, dlen);
156 ret = crypto_shash_final(&sdesc->shash, paramdigest);
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);
167 * verify the AUTH1_COMMAND (Seal) result from TPM
169 static int TSS_checkhmac1(unsigned char *buffer,
170 const uint32_t command,
171 const unsigned char *ononce,
172 const unsigned char *key,
173 const unsigned int keylen, ...)
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];
190 bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
191 tag = LOAD16(buffer, 0);
193 result = LOAD32N(buffer, TPM_RETURN_OFFSET);
194 if (tag == TPM_TAG_RSP_COMMAND)
196 if (tag != TPM_TAG_RSP_AUTH1_COMMAND)
198 authdata = buffer + bufsize - SHA1_DIGEST_SIZE;
199 continueflag = authdata - 1;
200 enonce = continueflag - TPM_NONCE_SIZE;
202 sdesc = init_sdesc(hashalg);
204 pr_info("trusted_key: can't alloc %s\n", hash_alg);
205 return PTR_ERR(sdesc);
207 ret = crypto_shash_init(&sdesc->shash);
210 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
214 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
218 va_start(argp, keylen);
220 dlen = va_arg(argp, unsigned int);
223 dpos = va_arg(argp, unsigned int);
224 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
231 ret = crypto_shash_final(&sdesc->shash, paramdigest);
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);
241 if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE))
249 * verify the AUTH2_COMMAND (unseal) result from TPM
251 static int TSS_checkhmac2(unsigned char *buffer,
252 const uint32_t command,
253 const unsigned char *ononce,
254 const unsigned char *key1,
255 const unsigned int keylen1,
256 const unsigned char *key2,
257 const unsigned int keylen2, ...)
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];
278 bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
279 tag = LOAD16(buffer, 0);
281 result = LOAD32N(buffer, TPM_RETURN_OFFSET);
283 if (tag == TPM_TAG_RSP_COMMAND)
285 if (tag != TPM_TAG_RSP_AUTH2_COMMAND)
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;
295 sdesc = init_sdesc(hashalg);
297 pr_info("trusted_key: can't alloc %s\n", hash_alg);
298 return PTR_ERR(sdesc);
300 ret = crypto_shash_init(&sdesc->shash);
303 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
307 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
312 va_start(argp, keylen2);
314 dlen = va_arg(argp, unsigned int);
317 dpos = va_arg(argp, unsigned int);
318 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
325 ret = crypto_shash_final(&sdesc->shash, paramdigest);
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);
334 if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) {
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);
343 if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE))
351 * For key specific tpm requests, we will generate and send our
352 * own TPM command packets using the drivers send function.
354 static int trusted_tpm_send(const u32 chip_num, unsigned char *cmd,
360 rc = tpm_send(chip_num, cmd, buflen);
363 /* Can't return positive return codes values to keyctl */
369 * get a random value from TPM
371 static int tpm_get_random(struct tpm_buf *tb, unsigned char *buf, uint32_t len)
376 store16(tb, TPM_TAG_RQU_COMMAND);
377 store32(tb, TPM_GETRANDOM_SIZE);
378 store32(tb, TPM_ORD_GETRANDOM);
380 ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, sizeof tb->data);
382 memcpy(buf, tb->data + TPM_GETRANDOM_SIZE, len);
386 static int my_get_random(unsigned char *buf, int len)
391 tb = kzalloc(sizeof *tb, GFP_KERNEL);
394 ret = tpm_get_random(tb, buf, len);
401 * Lock a trusted key, by extending a selected PCR.
403 * Prevents a trusted key that is sealed to PCRs from being accessed.
404 * This uses the tpm driver's extend function.
406 static int pcrlock(const int pcrnum)
408 unsigned char hash[SHA1_DIGEST_SIZE];
411 if (!capable(CAP_SYS_ADMIN))
413 ret = my_get_random(hash, SHA1_DIGEST_SIZE);
416 return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0;
420 * Create an object specific authorisation protocol (OSAP) session
422 static int osap(struct tpm_buf *tb, struct osapsess *s,
423 const unsigned char *key, const uint16_t type,
424 const uint32_t handle)
426 unsigned char enonce[TPM_NONCE_SIZE];
427 unsigned char ononce[TPM_NONCE_SIZE];
430 ret = tpm_get_random(tb, ononce, TPM_NONCE_SIZE);
435 store16(tb, TPM_TAG_RQU_COMMAND);
436 store32(tb, TPM_OSAP_SIZE);
437 store32(tb, TPM_ORD_OSAP);
440 storebytes(tb, ononce, TPM_NONCE_SIZE);
442 ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
446 s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
447 memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
449 memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
450 TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
451 return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
452 enonce, TPM_NONCE_SIZE, ononce, 0, 0);
456 * Create an object independent authorisation protocol (oiap) session
458 static int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
463 store16(tb, TPM_TAG_RQU_COMMAND);
464 store32(tb, TPM_OIAP_SIZE);
465 store32(tb, TPM_ORD_OIAP);
466 ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
470 *handle = LOAD32(tb->data, TPM_DATA_OFFSET);
471 memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
477 unsigned char encauth[SHA1_DIGEST_SIZE];
478 unsigned char pubauth[SHA1_DIGEST_SIZE];
479 unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
480 unsigned char xorhash[SHA1_DIGEST_SIZE];
481 unsigned char nonceodd[TPM_NONCE_SIZE];
485 * Have the TPM seal(encrypt) the trusted key, possibly based on
486 * Platform Configuration Registers (PCRs). AUTH1 for sealing key.
488 static int tpm_seal(struct tpm_buf *tb, const uint16_t keytype,
489 const uint32_t keyhandle, const unsigned char *keyauth,
490 const unsigned char *data, const uint32_t datalen,
491 unsigned char *blob, uint32_t *bloblen,
492 const unsigned char *blobauth,
493 const unsigned char *pcrinfo, const uint32_t pcrinfosize)
495 struct osapsess sess;
496 struct tpm_digests *td;
507 /* alloc some work space for all the hashes */
508 td = kmalloc(sizeof *td, GFP_KERNEL);
512 /* get session for sealing key */
513 ret = osap(tb, &sess, keyauth, keytype, keyhandle);
518 /* calculate encrypted authorization value */
519 memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
520 memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
521 ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
525 ret = tpm_get_random(tb, td->nonceodd, TPM_NONCE_SIZE);
528 ordinal = htonl(TPM_ORD_SEAL);
529 datsize = htonl(datalen);
530 pcrsize = htonl(pcrinfosize);
533 /* encrypt data authorization key */
534 for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
535 td->encauth[i] = td->xorhash[i] ^ blobauth[i];
537 /* calculate authorization HMAC value */
538 if (pcrinfosize == 0) {
539 /* no pcr info specified */
540 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
541 sess.enonce, td->nonceodd, cont,
542 sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
543 td->encauth, sizeof(uint32_t), &pcrsize,
544 sizeof(uint32_t), &datsize, datalen, data, 0,
547 /* pcr info specified */
548 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
549 sess.enonce, td->nonceodd, cont,
550 sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
551 td->encauth, sizeof(uint32_t), &pcrsize,
552 pcrinfosize, pcrinfo, sizeof(uint32_t),
553 &datsize, datalen, data, 0, 0);
558 /* build and send the TPM request packet */
560 store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
561 store32(tb, TPM_SEAL_SIZE + pcrinfosize + datalen);
562 store32(tb, TPM_ORD_SEAL);
563 store32(tb, keyhandle);
564 storebytes(tb, td->encauth, SHA1_DIGEST_SIZE);
565 store32(tb, pcrinfosize);
566 storebytes(tb, pcrinfo, pcrinfosize);
567 store32(tb, datalen);
568 storebytes(tb, data, datalen);
569 store32(tb, sess.handle);
570 storebytes(tb, td->nonceodd, TPM_NONCE_SIZE);
572 storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE);
574 ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
578 /* calculate the size of the returned Blob */
579 sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
580 encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
581 sizeof(uint32_t) + sealinfosize);
582 storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
583 sizeof(uint32_t) + encdatasize;
585 /* check the HMAC in the response */
586 ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
587 SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
590 /* copy the returned blob to caller */
592 memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
593 *bloblen = storedsize;
599 * use the AUTH2_COMMAND form of unseal, to authorize both key and blob
601 static int tpm_unseal(struct tpm_buf *tb,
602 const uint32_t keyhandle, const unsigned char *keyauth,
603 const unsigned char *blob, const int bloblen,
604 const unsigned char *blobauth,
605 unsigned char *data, unsigned int *datalen)
607 unsigned char nonceodd[TPM_NONCE_SIZE];
608 unsigned char enonce1[TPM_NONCE_SIZE];
609 unsigned char enonce2[TPM_NONCE_SIZE];
610 unsigned char authdata1[SHA1_DIGEST_SIZE];
611 unsigned char authdata2[SHA1_DIGEST_SIZE];
612 uint32_t authhandle1 = 0;
613 uint32_t authhandle2 = 0;
614 unsigned char cont = 0;
619 /* sessions for unsealing key and data */
620 ret = oiap(tb, &authhandle1, enonce1);
622 pr_info("trusted_key: oiap failed (%d)\n", ret);
625 ret = oiap(tb, &authhandle2, enonce2);
627 pr_info("trusted_key: oiap failed (%d)\n", ret);
631 ordinal = htonl(TPM_ORD_UNSEAL);
632 keyhndl = htonl(SRKHANDLE);
633 ret = tpm_get_random(tb, nonceodd, TPM_NONCE_SIZE);
635 pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
638 ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
639 enonce1, nonceodd, cont, sizeof(uint32_t),
640 &ordinal, bloblen, blob, 0, 0);
643 ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
644 enonce2, nonceodd, cont, sizeof(uint32_t),
645 &ordinal, bloblen, blob, 0, 0);
649 /* build and send TPM request packet */
651 store16(tb, TPM_TAG_RQU_AUTH2_COMMAND);
652 store32(tb, TPM_UNSEAL_SIZE + bloblen);
653 store32(tb, TPM_ORD_UNSEAL);
654 store32(tb, keyhandle);
655 storebytes(tb, blob, bloblen);
656 store32(tb, authhandle1);
657 storebytes(tb, nonceodd, TPM_NONCE_SIZE);
659 storebytes(tb, authdata1, SHA1_DIGEST_SIZE);
660 store32(tb, authhandle2);
661 storebytes(tb, nonceodd, TPM_NONCE_SIZE);
663 storebytes(tb, authdata2, SHA1_DIGEST_SIZE);
665 ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
667 pr_info("trusted_key: authhmac failed (%d)\n", ret);
671 *datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
672 ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
673 keyauth, SHA1_DIGEST_SIZE,
674 blobauth, SHA1_DIGEST_SIZE,
675 sizeof(uint32_t), TPM_DATA_OFFSET,
676 *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
679 pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret);
682 memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
687 * Have the TPM seal(encrypt) the symmetric key
689 static int key_seal(struct trusted_key_payload *p,
690 struct trusted_key_options *o)
695 tb = kzalloc(sizeof *tb, GFP_KERNEL);
699 /* include migratable flag at end of sealed key */
700 p->key[p->key_len] = p->migratable;
702 ret = tpm_seal(tb, o->keytype, o->keyhandle, o->keyauth,
703 p->key, p->key_len + 1, p->blob, &p->blob_len,
704 o->blobauth, o->pcrinfo, o->pcrinfo_len);
706 pr_info("trusted_key: srkseal failed (%d)\n", ret);
713 * Have the TPM unseal(decrypt) the symmetric key
715 static int key_unseal(struct trusted_key_payload *p,
716 struct trusted_key_options *o)
721 tb = kzalloc(sizeof *tb, GFP_KERNEL);
725 ret = tpm_unseal(tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
726 o->blobauth, p->key, &p->key_len);
728 pr_info("trusted_key: srkunseal failed (%d)\n", ret);
730 /* pull migratable flag out of sealed key */
731 p->migratable = p->key[--p->key_len];
739 Opt_new, Opt_load, Opt_update,
740 Opt_keyhandle, Opt_keyauth, Opt_blobauth,
741 Opt_pcrinfo, Opt_pcrlock, Opt_migratable
744 static const match_table_t key_tokens = {
747 {Opt_update, "update"},
748 {Opt_keyhandle, "keyhandle=%s"},
749 {Opt_keyauth, "keyauth=%s"},
750 {Opt_blobauth, "blobauth=%s"},
751 {Opt_pcrinfo, "pcrinfo=%s"},
752 {Opt_pcrlock, "pcrlock=%s"},
753 {Opt_migratable, "migratable=%s"},
757 /* can have zero or more token= options */
758 static int getoptions(char *c, struct trusted_key_payload *pay,
759 struct trusted_key_options *opt)
761 substring_t args[MAX_OPT_ARGS];
765 unsigned long handle;
768 while ((p = strsep(&c, " \t"))) {
769 if (*p == '\0' || *p == ' ' || *p == '\t')
771 token = match_token(p, key_tokens, args);
775 opt->pcrinfo_len = strlen(args[0].from) / 2;
776 if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
778 hex2bin(opt->pcrinfo, args[0].from, opt->pcrinfo_len);
781 res = strict_strtoul(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 hex2bin(opt->keyauth, args[0].from, SHA1_DIGEST_SIZE);
793 if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
795 hex2bin(opt->blobauth, args[0].from, SHA1_DIGEST_SIZE);
798 if (*args[0].from == '0')
804 res = strict_strtoul(args[0].from, 10, &lock);
817 * datablob_parse - parse the keyctl data and fill in the
818 * payload and options structures
820 * On success returns 0, otherwise -EINVAL.
822 static int datablob_parse(char *datablob, struct trusted_key_payload *p,
823 struct trusted_key_options *o)
825 substring_t args[MAX_OPT_ARGS];
832 c = strsep(&datablob, " \t");
835 key_cmd = match_token(c, key_tokens, args);
838 /* first argument is key size */
839 c = strsep(&datablob, " \t");
842 ret = strict_strtol(c, 10, &keylen);
843 if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
846 ret = getoptions(datablob, p, o);
852 /* first argument is sealed blob */
853 c = strsep(&datablob, " \t");
856 p->blob_len = strlen(c) / 2;
857 if (p->blob_len > MAX_BLOB_SIZE)
859 hex2bin(p->blob, c, p->blob_len);
860 ret = getoptions(datablob, p, o);
866 /* all arguments are options */
867 ret = getoptions(datablob, p, o);
879 static struct trusted_key_options *trusted_options_alloc(void)
881 struct trusted_key_options *options;
883 options = kzalloc(sizeof *options, GFP_KERNEL);
885 /* set any non-zero defaults */
886 options->keytype = SRK_keytype;
887 options->keyhandle = SRKHANDLE;
892 static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
894 struct trusted_key_payload *p = NULL;
897 ret = key_payload_reserve(key, sizeof *p);
900 p = kzalloc(sizeof *p, GFP_KERNEL);
902 p->migratable = 1; /* migratable by default */
907 * trusted_instantiate - create a new trusted key
909 * Unseal an existing trusted blob or, for a new key, get a
910 * random key, then seal and create a trusted key-type key,
911 * adding it to the specified keyring.
913 * On success, return 0. Otherwise return errno.
915 static int trusted_instantiate(struct key *key, const void *data,
916 const size_t datalen)
918 struct trusted_key_payload *payload = NULL;
919 struct trusted_key_options *options = NULL;
924 if (datalen <= 0 || datalen > 32767 || !data)
927 datablob = kmalloc(datalen + 1, GFP_KERNEL);
930 memcpy(datablob, data, datalen);
931 datablob[datalen] = '\0';
933 options = trusted_options_alloc();
938 payload = trusted_payload_alloc(key);
944 key_cmd = datablob_parse(datablob, payload, options);
950 dump_payload(payload);
951 dump_options(options);
955 ret = key_unseal(payload, options);
956 dump_payload(payload);
957 dump_options(options);
959 pr_info("trusted_key: key_unseal failed (%d)\n", ret);
962 ret = my_get_random(payload->key, payload->key_len);
964 pr_info("trusted_key: key_create failed (%d)\n", ret);
967 ret = key_seal(payload, options);
969 pr_info("trusted_key: key_seal failed (%d)\n", ret);
975 if (!ret && options->pcrlock)
976 ret = pcrlock(options->pcrlock);
981 rcu_assign_pointer(key->payload.data, payload);
987 static void trusted_rcu_free(struct rcu_head *rcu)
989 struct trusted_key_payload *p;
991 p = container_of(rcu, struct trusted_key_payload, rcu);
992 memset(p->key, 0, p->key_len);
997 * trusted_update - reseal an existing key with new PCR values
999 static int trusted_update(struct key *key, const void *data,
1000 const size_t datalen)
1002 struct trusted_key_payload *p = key->payload.data;
1003 struct trusted_key_payload *new_p;
1004 struct trusted_key_options *new_o;
1010 if (datalen <= 0 || datalen > 32767 || !data)
1013 datablob = kmalloc(datalen + 1, GFP_KERNEL);
1016 new_o = trusted_options_alloc();
1021 new_p = trusted_payload_alloc(key);
1027 memcpy(datablob, data, datalen);
1028 datablob[datalen] = '\0';
1029 ret = datablob_parse(datablob, new_p, new_o);
1030 if (ret != Opt_update) {
1034 /* copy old key values, and reseal with new pcrs */
1035 new_p->migratable = p->migratable;
1036 new_p->key_len = p->key_len;
1037 memcpy(new_p->key, p->key, p->key_len);
1039 dump_payload(new_p);
1041 ret = key_seal(new_p, new_o);
1043 pr_info("trusted_key: key_seal failed (%d)\n", ret);
1047 if (new_o->pcrlock) {
1048 ret = pcrlock(new_o->pcrlock);
1050 pr_info("trusted_key: pcrlock failed (%d)\n", ret);
1055 rcu_assign_pointer(key->payload.data, new_p);
1056 call_rcu(&p->rcu, trusted_rcu_free);
1064 * trusted_read - copy the sealed blob data to userspace in hex.
1065 * On success, return to userspace the trusted key datablob size.
1067 static long trusted_read(const struct key *key, char __user *buffer,
1070 struct trusted_key_payload *p;
1075 p = rcu_dereference_protected(key->payload.data,
1076 rwsem_is_locked(&((struct key *)key)->sem));
1079 if (!buffer || buflen <= 0)
1080 return 2 * p->blob_len;
1081 ascii_buf = kmalloc(2 * p->blob_len, GFP_KERNEL);
1086 for (i = 0; i < p->blob_len; i++)
1087 bufp = pack_hex_byte(bufp, p->blob[i]);
1088 if ((copy_to_user(buffer, ascii_buf, 2 * p->blob_len)) != 0) {
1093 return 2 * p->blob_len;
1097 * trusted_destroy - before freeing the key, clear the decrypted data
1099 static void trusted_destroy(struct key *key)
1101 struct trusted_key_payload *p = key->payload.data;
1105 memset(p->key, 0, p->key_len);
1106 kfree(key->payload.data);
1109 struct key_type key_type_trusted = {
1111 .instantiate = trusted_instantiate,
1112 .update = trusted_update,
1113 .match = user_match,
1114 .destroy = trusted_destroy,
1115 .describe = user_describe,
1116 .read = trusted_read,
1119 EXPORT_SYMBOL_GPL(key_type_trusted);
1121 static void trusted_shash_release(void)
1124 crypto_free_shash(hashalg);
1126 crypto_free_shash(hmacalg);
1129 static int __init trusted_shash_alloc(void)
1133 hmacalg = crypto_alloc_shash(hmac_alg, 0, CRYPTO_ALG_ASYNC);
1134 if (IS_ERR(hmacalg)) {
1135 pr_info("trusted_key: could not allocate crypto %s\n",
1137 return PTR_ERR(hmacalg);
1140 hashalg = crypto_alloc_shash(hash_alg, 0, CRYPTO_ALG_ASYNC);
1141 if (IS_ERR(hashalg)) {
1142 pr_info("trusted_key: could not allocate crypto %s\n",
1144 ret = PTR_ERR(hashalg);
1151 crypto_free_shash(hmacalg);
1155 static int __init init_trusted(void)
1159 ret = trusted_shash_alloc();
1162 ret = register_key_type(&key_type_trusted);
1164 trusted_shash_release();
1168 static void __exit cleanup_trusted(void)
1170 trusted_shash_release();
1171 unregister_key_type(&key_type_trusted);
1174 late_initcall(init_trusted);
1175 module_exit(cleanup_trusted);
1177 MODULE_LICENSE("GPL");