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, 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 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 *);
108 ret = crypto_shash_update(&sdesc->shash, data, dlen);
114 ret = crypto_shash_final(&sdesc->shash, digest);
121 * calculate authorization info fields to send to TPM
123 static int TSS_authhmac(unsigned char *digest, const unsigned char *key,
124 unsigned int keylen, unsigned char *h1,
125 unsigned char *h2, unsigned char h3, ...)
127 unsigned char paramdigest[SHA1_DIGEST_SIZE];
135 sdesc = init_sdesc(hashalg);
137 pr_info("trusted_key: can't alloc %s\n", hash_alg);
138 return PTR_ERR(sdesc);
142 ret = crypto_shash_init(&sdesc->shash);
147 dlen = va_arg(argp, unsigned int);
150 data = va_arg(argp, unsigned char *);
156 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);
174 * verify the AUTH1_COMMAND (Seal) result from TPM
176 static int TSS_checkhmac1(unsigned char *buffer,
177 const uint32_t command,
178 const unsigned char *ononce,
179 const unsigned char *key,
180 unsigned int keylen, ...)
186 unsigned char *enonce;
187 unsigned char *continueflag;
188 unsigned char *authdata;
189 unsigned char testhmac[SHA1_DIGEST_SIZE];
190 unsigned char paramdigest[SHA1_DIGEST_SIZE];
197 bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
198 tag = LOAD16(buffer, 0);
200 result = LOAD32N(buffer, TPM_RETURN_OFFSET);
201 if (tag == TPM_TAG_RSP_COMMAND)
203 if (tag != TPM_TAG_RSP_AUTH1_COMMAND)
205 authdata = buffer + bufsize - SHA1_DIGEST_SIZE;
206 continueflag = authdata - 1;
207 enonce = continueflag - TPM_NONCE_SIZE;
209 sdesc = init_sdesc(hashalg);
211 pr_info("trusted_key: can't alloc %s\n", hash_alg);
212 return PTR_ERR(sdesc);
214 ret = crypto_shash_init(&sdesc->shash);
217 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
221 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
225 va_start(argp, keylen);
227 dlen = va_arg(argp, unsigned int);
230 dpos = va_arg(argp, unsigned int);
231 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
238 ret = crypto_shash_final(&sdesc->shash, paramdigest);
242 ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest,
243 TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce,
244 1, continueflag, 0, 0);
248 if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE))
256 * verify the AUTH2_COMMAND (unseal) result from TPM
258 static int TSS_checkhmac2(unsigned char *buffer,
259 const uint32_t command,
260 const unsigned char *ononce,
261 const unsigned char *key1,
262 unsigned int keylen1,
263 const unsigned char *key2,
264 unsigned int keylen2, ...)
270 unsigned char *enonce1;
271 unsigned char *continueflag1;
272 unsigned char *authdata1;
273 unsigned char *enonce2;
274 unsigned char *continueflag2;
275 unsigned char *authdata2;
276 unsigned char testhmac1[SHA1_DIGEST_SIZE];
277 unsigned char testhmac2[SHA1_DIGEST_SIZE];
278 unsigned char paramdigest[SHA1_DIGEST_SIZE];
285 bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
286 tag = LOAD16(buffer, 0);
288 result = LOAD32N(buffer, TPM_RETURN_OFFSET);
290 if (tag == TPM_TAG_RSP_COMMAND)
292 if (tag != TPM_TAG_RSP_AUTH2_COMMAND)
294 authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1
295 + SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE);
296 authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE);
297 continueflag1 = authdata1 - 1;
298 continueflag2 = authdata2 - 1;
299 enonce1 = continueflag1 - TPM_NONCE_SIZE;
300 enonce2 = continueflag2 - TPM_NONCE_SIZE;
302 sdesc = init_sdesc(hashalg);
304 pr_info("trusted_key: can't alloc %s\n", hash_alg);
305 return PTR_ERR(sdesc);
307 ret = crypto_shash_init(&sdesc->shash);
310 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
314 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
319 va_start(argp, keylen2);
321 dlen = va_arg(argp, unsigned int);
324 dpos = va_arg(argp, unsigned int);
325 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
332 ret = crypto_shash_final(&sdesc->shash, paramdigest);
336 ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE,
337 paramdigest, TPM_NONCE_SIZE, enonce1,
338 TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0);
341 if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) {
345 ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE,
346 paramdigest, TPM_NONCE_SIZE, enonce2,
347 TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0);
350 if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE))
358 * For key specific tpm requests, we will generate and send our
359 * own TPM command packets using the drivers send function.
361 static int trusted_tpm_send(const u32 chip_num, unsigned char *cmd,
367 rc = tpm_send(chip_num, cmd, buflen);
370 /* Can't return positive return codes values to keyctl */
376 * get a random value from TPM
378 static int tpm_get_random(struct tpm_buf *tb, unsigned char *buf, uint32_t len)
383 store16(tb, TPM_TAG_RQU_COMMAND);
384 store32(tb, TPM_GETRANDOM_SIZE);
385 store32(tb, TPM_ORD_GETRANDOM);
387 ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, sizeof tb->data);
389 memcpy(buf, tb->data + TPM_GETRANDOM_SIZE, len);
393 static int my_get_random(unsigned char *buf, int len)
398 tb = kmalloc(sizeof *tb, GFP_KERNEL);
401 ret = tpm_get_random(tb, buf, len);
408 * Lock a trusted key, by extending a selected PCR.
410 * Prevents a trusted key that is sealed to PCRs from being accessed.
411 * This uses the tpm driver's extend function.
413 static int pcrlock(const int pcrnum)
415 unsigned char hash[SHA1_DIGEST_SIZE];
418 if (!capable(CAP_SYS_ADMIN))
420 ret = my_get_random(hash, SHA1_DIGEST_SIZE);
423 return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0;
427 * Create an object specific authorisation protocol (OSAP) session
429 static int osap(struct tpm_buf *tb, struct osapsess *s,
430 const unsigned char *key, uint16_t type, uint32_t handle)
432 unsigned char enonce[TPM_NONCE_SIZE];
433 unsigned char ononce[TPM_NONCE_SIZE];
436 ret = tpm_get_random(tb, ononce, TPM_NONCE_SIZE);
441 store16(tb, TPM_TAG_RQU_COMMAND);
442 store32(tb, TPM_OSAP_SIZE);
443 store32(tb, TPM_ORD_OSAP);
446 storebytes(tb, ononce, TPM_NONCE_SIZE);
448 ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
452 s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
453 memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
455 memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
456 TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
457 return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
458 enonce, TPM_NONCE_SIZE, ononce, 0, 0);
462 * Create an object independent authorisation protocol (oiap) session
464 static int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
469 store16(tb, TPM_TAG_RQU_COMMAND);
470 store32(tb, TPM_OIAP_SIZE);
471 store32(tb, TPM_ORD_OIAP);
472 ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
476 *handle = LOAD32(tb->data, TPM_DATA_OFFSET);
477 memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
483 unsigned char encauth[SHA1_DIGEST_SIZE];
484 unsigned char pubauth[SHA1_DIGEST_SIZE];
485 unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
486 unsigned char xorhash[SHA1_DIGEST_SIZE];
487 unsigned char nonceodd[TPM_NONCE_SIZE];
491 * Have the TPM seal(encrypt) the trusted key, possibly based on
492 * Platform Configuration Registers (PCRs). AUTH1 for sealing key.
494 static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
495 uint32_t keyhandle, const unsigned char *keyauth,
496 const unsigned char *data, uint32_t datalen,
497 unsigned char *blob, uint32_t *bloblen,
498 const unsigned char *blobauth,
499 const unsigned char *pcrinfo, uint32_t pcrinfosize)
501 struct osapsess sess;
502 struct tpm_digests *td;
513 /* alloc some work space for all the hashes */
514 td = kmalloc(sizeof *td, GFP_KERNEL);
518 /* get session for sealing key */
519 ret = osap(tb, &sess, keyauth, keytype, keyhandle);
524 /* calculate encrypted authorization value */
525 memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
526 memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
527 ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
531 ret = tpm_get_random(tb, td->nonceodd, TPM_NONCE_SIZE);
534 ordinal = htonl(TPM_ORD_SEAL);
535 datsize = htonl(datalen);
536 pcrsize = htonl(pcrinfosize);
539 /* encrypt data authorization key */
540 for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
541 td->encauth[i] = td->xorhash[i] ^ blobauth[i];
543 /* calculate authorization HMAC value */
544 if (pcrinfosize == 0) {
545 /* no pcr info specified */
546 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
547 sess.enonce, td->nonceodd, cont,
548 sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
549 td->encauth, sizeof(uint32_t), &pcrsize,
550 sizeof(uint32_t), &datsize, datalen, data, 0,
553 /* pcr info specified */
554 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
555 sess.enonce, td->nonceodd, cont,
556 sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
557 td->encauth, sizeof(uint32_t), &pcrsize,
558 pcrinfosize, pcrinfo, sizeof(uint32_t),
559 &datsize, datalen, data, 0, 0);
564 /* build and send the TPM request packet */
566 store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
567 store32(tb, TPM_SEAL_SIZE + pcrinfosize + datalen);
568 store32(tb, TPM_ORD_SEAL);
569 store32(tb, keyhandle);
570 storebytes(tb, td->encauth, SHA1_DIGEST_SIZE);
571 store32(tb, pcrinfosize);
572 storebytes(tb, pcrinfo, pcrinfosize);
573 store32(tb, datalen);
574 storebytes(tb, data, datalen);
575 store32(tb, sess.handle);
576 storebytes(tb, td->nonceodd, TPM_NONCE_SIZE);
578 storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE);
580 ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
584 /* calculate the size of the returned Blob */
585 sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
586 encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
587 sizeof(uint32_t) + sealinfosize);
588 storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
589 sizeof(uint32_t) + encdatasize;
591 /* check the HMAC in the response */
592 ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
593 SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
596 /* copy the returned blob to caller */
598 memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
599 *bloblen = storedsize;
607 * use the AUTH2_COMMAND form of unseal, to authorize both key and blob
609 static int tpm_unseal(struct tpm_buf *tb,
610 uint32_t keyhandle, const unsigned char *keyauth,
611 const unsigned char *blob, int bloblen,
612 const unsigned char *blobauth,
613 unsigned char *data, unsigned int *datalen)
615 unsigned char nonceodd[TPM_NONCE_SIZE];
616 unsigned char enonce1[TPM_NONCE_SIZE];
617 unsigned char enonce2[TPM_NONCE_SIZE];
618 unsigned char authdata1[SHA1_DIGEST_SIZE];
619 unsigned char authdata2[SHA1_DIGEST_SIZE];
620 uint32_t authhandle1 = 0;
621 uint32_t authhandle2 = 0;
622 unsigned char cont = 0;
627 /* sessions for unsealing key and data */
628 ret = oiap(tb, &authhandle1, enonce1);
630 pr_info("trusted_key: oiap failed (%d)\n", ret);
633 ret = oiap(tb, &authhandle2, enonce2);
635 pr_info("trusted_key: oiap failed (%d)\n", ret);
639 ordinal = htonl(TPM_ORD_UNSEAL);
640 keyhndl = htonl(SRKHANDLE);
641 ret = tpm_get_random(tb, nonceodd, TPM_NONCE_SIZE);
643 pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
646 ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
647 enonce1, nonceodd, cont, sizeof(uint32_t),
648 &ordinal, bloblen, blob, 0, 0);
651 ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
652 enonce2, nonceodd, cont, sizeof(uint32_t),
653 &ordinal, bloblen, blob, 0, 0);
657 /* build and send TPM request packet */
659 store16(tb, TPM_TAG_RQU_AUTH2_COMMAND);
660 store32(tb, TPM_UNSEAL_SIZE + bloblen);
661 store32(tb, TPM_ORD_UNSEAL);
662 store32(tb, keyhandle);
663 storebytes(tb, blob, bloblen);
664 store32(tb, authhandle1);
665 storebytes(tb, nonceodd, TPM_NONCE_SIZE);
667 storebytes(tb, authdata1, SHA1_DIGEST_SIZE);
668 store32(tb, authhandle2);
669 storebytes(tb, nonceodd, TPM_NONCE_SIZE);
671 storebytes(tb, authdata2, SHA1_DIGEST_SIZE);
673 ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
675 pr_info("trusted_key: authhmac failed (%d)\n", ret);
679 *datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
680 ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
681 keyauth, SHA1_DIGEST_SIZE,
682 blobauth, SHA1_DIGEST_SIZE,
683 sizeof(uint32_t), TPM_DATA_OFFSET,
684 *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
687 pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret);
690 memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
695 * Have the TPM seal(encrypt) the symmetric key
697 static int key_seal(struct trusted_key_payload *p,
698 struct trusted_key_options *o)
703 tb = kzalloc(sizeof *tb, GFP_KERNEL);
707 /* include migratable flag at end of sealed key */
708 p->key[p->key_len] = p->migratable;
710 ret = tpm_seal(tb, o->keytype, o->keyhandle, o->keyauth,
711 p->key, p->key_len + 1, p->blob, &p->blob_len,
712 o->blobauth, o->pcrinfo, o->pcrinfo_len);
714 pr_info("trusted_key: srkseal failed (%d)\n", ret);
721 * Have the TPM unseal(decrypt) the symmetric key
723 static int key_unseal(struct trusted_key_payload *p,
724 struct trusted_key_options *o)
729 tb = kzalloc(sizeof *tb, GFP_KERNEL);
733 ret = tpm_unseal(tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
734 o->blobauth, p->key, &p->key_len);
736 pr_info("trusted_key: srkunseal failed (%d)\n", ret);
738 /* pull migratable flag out of sealed key */
739 p->migratable = p->key[--p->key_len];
747 Opt_new, Opt_load, Opt_update,
748 Opt_keyhandle, Opt_keyauth, Opt_blobauth,
749 Opt_pcrinfo, Opt_pcrlock, Opt_migratable
752 static const match_table_t key_tokens = {
755 {Opt_update, "update"},
756 {Opt_keyhandle, "keyhandle=%s"},
757 {Opt_keyauth, "keyauth=%s"},
758 {Opt_blobauth, "blobauth=%s"},
759 {Opt_pcrinfo, "pcrinfo=%s"},
760 {Opt_pcrlock, "pcrlock=%s"},
761 {Opt_migratable, "migratable=%s"},
765 /* can have zero or more token= options */
766 static int getoptions(char *c, struct trusted_key_payload *pay,
767 struct trusted_key_options *opt)
769 substring_t args[MAX_OPT_ARGS];
773 unsigned long handle;
776 while ((p = strsep(&c, " \t"))) {
777 if (*p == '\0' || *p == ' ' || *p == '\t')
779 token = match_token(p, key_tokens, args);
783 opt->pcrinfo_len = strlen(args[0].from) / 2;
784 if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
786 hex2bin(opt->pcrinfo, args[0].from, opt->pcrinfo_len);
789 res = strict_strtoul(args[0].from, 16, &handle);
792 opt->keytype = SEAL_keytype;
793 opt->keyhandle = handle;
796 if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
798 hex2bin(opt->keyauth, args[0].from, SHA1_DIGEST_SIZE);
801 if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
803 hex2bin(opt->blobauth, args[0].from, SHA1_DIGEST_SIZE);
806 if (*args[0].from == '0')
812 res = strict_strtoul(args[0].from, 10, &lock);
825 * datablob_parse - parse the keyctl data and fill in the
826 * payload and options structures
828 * On success returns 0, otherwise -EINVAL.
830 static int datablob_parse(char *datablob, struct trusted_key_payload *p,
831 struct trusted_key_options *o)
833 substring_t args[MAX_OPT_ARGS];
840 c = strsep(&datablob, " \t");
843 key_cmd = match_token(c, key_tokens, args);
846 /* first argument is key size */
847 c = strsep(&datablob, " \t");
850 ret = strict_strtol(c, 10, &keylen);
851 if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
854 ret = getoptions(datablob, p, o);
860 /* first argument is sealed blob */
861 c = strsep(&datablob, " \t");
864 p->blob_len = strlen(c) / 2;
865 if (p->blob_len > MAX_BLOB_SIZE)
867 hex2bin(p->blob, c, p->blob_len);
868 ret = getoptions(datablob, p, o);
874 /* all arguments are options */
875 ret = getoptions(datablob, p, o);
887 static struct trusted_key_options *trusted_options_alloc(void)
889 struct trusted_key_options *options;
891 options = kzalloc(sizeof *options, GFP_KERNEL);
893 /* set any non-zero defaults */
894 options->keytype = SRK_keytype;
895 options->keyhandle = SRKHANDLE;
900 static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
902 struct trusted_key_payload *p = NULL;
905 ret = key_payload_reserve(key, sizeof *p);
908 p = kzalloc(sizeof *p, GFP_KERNEL);
910 p->migratable = 1; /* migratable by default */
915 * trusted_instantiate - create a new trusted key
917 * Unseal an existing trusted blob or, for a new key, get a
918 * random key, then seal and create a trusted key-type key,
919 * adding it to the specified keyring.
921 * On success, return 0. Otherwise return errno.
923 static int trusted_instantiate(struct key *key, const void *data,
926 struct trusted_key_payload *payload = NULL;
927 struct trusted_key_options *options = NULL;
932 if (datalen <= 0 || datalen > 32767 || !data)
935 datablob = kmalloc(datalen + 1, GFP_KERNEL);
938 memcpy(datablob, data, datalen);
939 datablob[datalen] = '\0';
941 options = trusted_options_alloc();
946 payload = trusted_payload_alloc(key);
952 key_cmd = datablob_parse(datablob, payload, options);
958 dump_payload(payload);
959 dump_options(options);
963 ret = key_unseal(payload, options);
964 dump_payload(payload);
965 dump_options(options);
967 pr_info("trusted_key: key_unseal failed (%d)\n", ret);
970 ret = my_get_random(payload->key, payload->key_len);
972 pr_info("trusted_key: key_create failed (%d)\n", ret);
975 ret = key_seal(payload, options);
977 pr_info("trusted_key: key_seal failed (%d)\n", ret);
983 if (!ret && options->pcrlock)
984 ret = pcrlock(options->pcrlock);
989 rcu_assign_pointer(key->payload.data, payload);
995 static void trusted_rcu_free(struct rcu_head *rcu)
997 struct trusted_key_payload *p;
999 p = container_of(rcu, struct trusted_key_payload, rcu);
1000 memset(p->key, 0, p->key_len);
1005 * trusted_update - reseal an existing key with new PCR values
1007 static int trusted_update(struct key *key, const void *data, size_t datalen)
1009 struct trusted_key_payload *p = key->payload.data;
1010 struct trusted_key_payload *new_p;
1011 struct trusted_key_options *new_o;
1017 if (datalen <= 0 || datalen > 32767 || !data)
1020 datablob = kmalloc(datalen + 1, GFP_KERNEL);
1023 new_o = trusted_options_alloc();
1028 new_p = trusted_payload_alloc(key);
1034 memcpy(datablob, data, datalen);
1035 datablob[datalen] = '\0';
1036 ret = datablob_parse(datablob, new_p, new_o);
1037 if (ret != Opt_update) {
1041 /* copy old key values, and reseal with new pcrs */
1042 new_p->migratable = p->migratable;
1043 new_p->key_len = p->key_len;
1044 memcpy(new_p->key, p->key, p->key_len);
1046 dump_payload(new_p);
1048 ret = key_seal(new_p, new_o);
1050 pr_info("trusted_key: key_seal failed (%d)\n", ret);
1054 if (new_o->pcrlock) {
1055 ret = pcrlock(new_o->pcrlock);
1057 pr_info("trusted_key: pcrlock failed (%d)\n", ret);
1062 rcu_assign_pointer(key->payload.data, new_p);
1063 call_rcu(&p->rcu, trusted_rcu_free);
1071 * trusted_read - copy the sealed blob data to userspace in hex.
1072 * On success, return to userspace the trusted key datablob size.
1074 static long trusted_read(const struct key *key, char __user *buffer,
1077 struct trusted_key_payload *p;
1082 p = rcu_dereference_protected(key->payload.data,
1083 rwsem_is_locked(&((struct key *)key)->sem));
1086 if (!buffer || buflen <= 0)
1087 return 2 * p->blob_len;
1088 ascii_buf = kmalloc(2 * p->blob_len, GFP_KERNEL);
1093 for (i = 0; i < p->blob_len; i++)
1094 bufp = pack_hex_byte(bufp, p->blob[i]);
1095 if ((copy_to_user(buffer, ascii_buf, 2 * p->blob_len)) != 0) {
1100 return 2 * p->blob_len;
1104 * trusted_destroy - before freeing the key, clear the decrypted data
1106 static void trusted_destroy(struct key *key)
1108 struct trusted_key_payload *p = key->payload.data;
1112 memset(p->key, 0, p->key_len);
1113 kfree(key->payload.data);
1116 struct key_type key_type_trusted = {
1118 .instantiate = trusted_instantiate,
1119 .update = trusted_update,
1120 .match = user_match,
1121 .destroy = trusted_destroy,
1122 .describe = user_describe,
1123 .read = trusted_read,
1126 EXPORT_SYMBOL_GPL(key_type_trusted);
1128 static void trusted_shash_release(void)
1131 crypto_free_shash(hashalg);
1133 crypto_free_shash(hmacalg);
1136 static int __init trusted_shash_alloc(void)
1140 hmacalg = crypto_alloc_shash(hmac_alg, 0, CRYPTO_ALG_ASYNC);
1141 if (IS_ERR(hmacalg)) {
1142 pr_info("trusted_key: could not allocate crypto %s\n",
1144 return PTR_ERR(hmacalg);
1147 hashalg = crypto_alloc_shash(hash_alg, 0, CRYPTO_ALG_ASYNC);
1148 if (IS_ERR(hashalg)) {
1149 pr_info("trusted_key: could not allocate crypto %s\n",
1151 ret = PTR_ERR(hashalg);
1158 crypto_free_shash(hmacalg);
1162 static int __init init_trusted(void)
1166 ret = trusted_shash_alloc();
1169 ret = register_key_type(&key_type_trusted);
1171 trusted_shash_release();
1175 static void __exit cleanup_trusted(void)
1177 trusted_shash_release();
1178 unregister_key_type(&key_type_trusted);
1181 late_initcall(init_trusted);
1182 module_exit(cleanup_trusted);
1184 MODULE_LICENSE("GPL");