tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Copyright (C) 2010 IBM Corporation
3 *
4 * Author:
5 * David Safford <safford@us.ibm.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation, version 2 of the License.
10 *
11 * See Documentation/security/keys/trusted-encrypted.rst
12 */
13
14#include <crypto/hash_info.h>
15#include <linux/uaccess.h>
16#include <linux/module.h>
17#include <linux/init.h>
18#include <linux/slab.h>
19#include <linux/parser.h>
20#include <linux/string.h>
21#include <linux/err.h>
22#include <keys/user-type.h>
23#include <keys/trusted-type.h>
24#include <linux/key-type.h>
25#include <linux/rcupdate.h>
26#include <linux/crypto.h>
27#include <crypto/hash.h>
28#include <crypto/sha.h>
29#include <linux/capability.h>
30#include <linux/tpm.h>
31#include <linux/tpm_command.h>
32
33#include <keys/trusted.h>
34
35static const char hmac_alg[] = "hmac(sha1)";
36static const char hash_alg[] = "sha1";
37static struct tpm_chip *chip;
38static struct tpm_digest *digests;
39
40struct sdesc {
41 struct shash_desc shash;
42 char ctx[];
43};
44
45static struct crypto_shash *hashalg;
46static struct crypto_shash *hmacalg;
47
48static struct sdesc *init_sdesc(struct crypto_shash *alg)
49{
50 struct sdesc *sdesc;
51 int size;
52
53 size = sizeof(struct shash_desc) + crypto_shash_descsize(alg);
54 sdesc = kmalloc(size, GFP_KERNEL);
55 if (!sdesc)
56 return ERR_PTR(-ENOMEM);
57 sdesc->shash.tfm = alg;
58 sdesc->shash.flags = 0x0;
59 return sdesc;
60}
61
62static int TSS_sha1(const unsigned char *data, unsigned int datalen,
63 unsigned char *digest)
64{
65 struct sdesc *sdesc;
66 int ret;
67
68 sdesc = init_sdesc(hashalg);
69 if (IS_ERR(sdesc)) {
70 pr_info("trusted_key: can't alloc %s\n", hash_alg);
71 return PTR_ERR(sdesc);
72 }
73
74 ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest);
75 kzfree(sdesc);
76 return ret;
77}
78
79static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
80 unsigned int keylen, ...)
81{
82 struct sdesc *sdesc;
83 va_list argp;
84 unsigned int dlen;
85 unsigned char *data;
86 int ret;
87
88 sdesc = init_sdesc(hmacalg);
89 if (IS_ERR(sdesc)) {
90 pr_info("trusted_key: can't alloc %s\n", hmac_alg);
91 return PTR_ERR(sdesc);
92 }
93
94 ret = crypto_shash_setkey(hmacalg, key, keylen);
95 if (ret < 0)
96 goto out;
97 ret = crypto_shash_init(&sdesc->shash);
98 if (ret < 0)
99 goto out;
100
101 va_start(argp, keylen);
102 for (;;) {
103 dlen = va_arg(argp, unsigned int);
104 if (dlen == 0)
105 break;
106 data = va_arg(argp, unsigned char *);
107 if (data == NULL) {
108 ret = -EINVAL;
109 break;
110 }
111 ret = crypto_shash_update(&sdesc->shash, data, dlen);
112 if (ret < 0)
113 break;
114 }
115 va_end(argp);
116 if (!ret)
117 ret = crypto_shash_final(&sdesc->shash, digest);
118out:
119 kzfree(sdesc);
120 return ret;
121}
122
123/*
124 * calculate authorization info fields to send to TPM
125 */
126int TSS_authhmac(unsigned char *digest, const unsigned char *key,
127 unsigned int keylen, unsigned char *h1,
128 unsigned char *h2, unsigned char h3, ...)
129{
130 unsigned char paramdigest[SHA1_DIGEST_SIZE];
131 struct sdesc *sdesc;
132 unsigned int dlen;
133 unsigned char *data;
134 unsigned char c;
135 int ret;
136 va_list argp;
137
138 sdesc = init_sdesc(hashalg);
139 if (IS_ERR(sdesc)) {
140 pr_info("trusted_key: can't alloc %s\n", hash_alg);
141 return PTR_ERR(sdesc);
142 }
143
144 c = h3;
145 ret = crypto_shash_init(&sdesc->shash);
146 if (ret < 0)
147 goto out;
148 va_start(argp, h3);
149 for (;;) {
150 dlen = va_arg(argp, unsigned int);
151 if (dlen == 0)
152 break;
153 data = va_arg(argp, unsigned char *);
154 if (!data) {
155 ret = -EINVAL;
156 break;
157 }
158 ret = crypto_shash_update(&sdesc->shash, data, dlen);
159 if (ret < 0)
160 break;
161 }
162 va_end(argp);
163 if (!ret)
164 ret = crypto_shash_final(&sdesc->shash, paramdigest);
165 if (!ret)
166 ret = TSS_rawhmac(digest, key, keylen, SHA1_DIGEST_SIZE,
167 paramdigest, TPM_NONCE_SIZE, h1,
168 TPM_NONCE_SIZE, h2, 1, &c, 0, 0);
169out:
170 kzfree(sdesc);
171 return ret;
172}
173EXPORT_SYMBOL_GPL(TSS_authhmac);
174
175/*
176 * verify the AUTH1_COMMAND (Seal) result from TPM
177 */
178int TSS_checkhmac1(unsigned char *buffer,
179 const uint32_t command,
180 const unsigned char *ononce,
181 const unsigned char *key,
182 unsigned int keylen, ...)
183{
184 uint32_t bufsize;
185 uint16_t tag;
186 uint32_t ordinal;
187 uint32_t result;
188 unsigned char *enonce;
189 unsigned char *continueflag;
190 unsigned char *authdata;
191 unsigned char testhmac[SHA1_DIGEST_SIZE];
192 unsigned char paramdigest[SHA1_DIGEST_SIZE];
193 struct sdesc *sdesc;
194 unsigned int dlen;
195 unsigned int dpos;
196 va_list argp;
197 int ret;
198
199 bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
200 tag = LOAD16(buffer, 0);
201 ordinal = command;
202 result = LOAD32N(buffer, TPM_RETURN_OFFSET);
203 if (tag == TPM_TAG_RSP_COMMAND)
204 return 0;
205 if (tag != TPM_TAG_RSP_AUTH1_COMMAND)
206 return -EINVAL;
207 authdata = buffer + bufsize - SHA1_DIGEST_SIZE;
208 continueflag = authdata - 1;
209 enonce = continueflag - TPM_NONCE_SIZE;
210
211 sdesc = init_sdesc(hashalg);
212 if (IS_ERR(sdesc)) {
213 pr_info("trusted_key: can't alloc %s\n", hash_alg);
214 return PTR_ERR(sdesc);
215 }
216 ret = crypto_shash_init(&sdesc->shash);
217 if (ret < 0)
218 goto out;
219 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
220 sizeof result);
221 if (ret < 0)
222 goto out;
223 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
224 sizeof ordinal);
225 if (ret < 0)
226 goto out;
227 va_start(argp, keylen);
228 for (;;) {
229 dlen = va_arg(argp, unsigned int);
230 if (dlen == 0)
231 break;
232 dpos = va_arg(argp, unsigned int);
233 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
234 if (ret < 0)
235 break;
236 }
237 va_end(argp);
238 if (!ret)
239 ret = crypto_shash_final(&sdesc->shash, paramdigest);
240 if (ret < 0)
241 goto out;
242
243 ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest,
244 TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce,
245 1, continueflag, 0, 0);
246 if (ret < 0)
247 goto out;
248
249 if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE))
250 ret = -EINVAL;
251out:
252 kzfree(sdesc);
253 return ret;
254}
255EXPORT_SYMBOL_GPL(TSS_checkhmac1);
256
257/*
258 * verify the AUTH2_COMMAND (unseal) result from TPM
259 */
260static int TSS_checkhmac2(unsigned char *buffer,
261 const uint32_t command,
262 const unsigned char *ononce,
263 const unsigned char *key1,
264 unsigned int keylen1,
265 const unsigned char *key2,
266 unsigned int keylen2, ...)
267{
268 uint32_t bufsize;
269 uint16_t tag;
270 uint32_t ordinal;
271 uint32_t result;
272 unsigned char *enonce1;
273 unsigned char *continueflag1;
274 unsigned char *authdata1;
275 unsigned char *enonce2;
276 unsigned char *continueflag2;
277 unsigned char *authdata2;
278 unsigned char testhmac1[SHA1_DIGEST_SIZE];
279 unsigned char testhmac2[SHA1_DIGEST_SIZE];
280 unsigned char paramdigest[SHA1_DIGEST_SIZE];
281 struct sdesc *sdesc;
282 unsigned int dlen;
283 unsigned int dpos;
284 va_list argp;
285 int ret;
286
287 bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
288 tag = LOAD16(buffer, 0);
289 ordinal = command;
290 result = LOAD32N(buffer, TPM_RETURN_OFFSET);
291
292 if (tag == TPM_TAG_RSP_COMMAND)
293 return 0;
294 if (tag != TPM_TAG_RSP_AUTH2_COMMAND)
295 return -EINVAL;
296 authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1
297 + SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE);
298 authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE);
299 continueflag1 = authdata1 - 1;
300 continueflag2 = authdata2 - 1;
301 enonce1 = continueflag1 - TPM_NONCE_SIZE;
302 enonce2 = continueflag2 - TPM_NONCE_SIZE;
303
304 sdesc = init_sdesc(hashalg);
305 if (IS_ERR(sdesc)) {
306 pr_info("trusted_key: can't alloc %s\n", hash_alg);
307 return PTR_ERR(sdesc);
308 }
309 ret = crypto_shash_init(&sdesc->shash);
310 if (ret < 0)
311 goto out;
312 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
313 sizeof result);
314 if (ret < 0)
315 goto out;
316 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
317 sizeof ordinal);
318 if (ret < 0)
319 goto out;
320
321 va_start(argp, keylen2);
322 for (;;) {
323 dlen = va_arg(argp, unsigned int);
324 if (dlen == 0)
325 break;
326 dpos = va_arg(argp, unsigned int);
327 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
328 if (ret < 0)
329 break;
330 }
331 va_end(argp);
332 if (!ret)
333 ret = crypto_shash_final(&sdesc->shash, paramdigest);
334 if (ret < 0)
335 goto out;
336
337 ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE,
338 paramdigest, TPM_NONCE_SIZE, enonce1,
339 TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0);
340 if (ret < 0)
341 goto out;
342 if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) {
343 ret = -EINVAL;
344 goto out;
345 }
346 ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE,
347 paramdigest, TPM_NONCE_SIZE, enonce2,
348 TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0);
349 if (ret < 0)
350 goto out;
351 if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE))
352 ret = -EINVAL;
353out:
354 kzfree(sdesc);
355 return ret;
356}
357
358/*
359 * For key specific tpm requests, we will generate and send our
360 * own TPM command packets using the drivers send function.
361 */
362int trusted_tpm_send(unsigned char *cmd, size_t buflen)
363{
364 int rc;
365
366 dump_tpm_buf(cmd);
367 rc = tpm_send(chip, cmd, buflen);
368 dump_tpm_buf(cmd);
369 if (rc > 0)
370 /* Can't return positive return codes values to keyctl */
371 rc = -EPERM;
372 return rc;
373}
374EXPORT_SYMBOL_GPL(trusted_tpm_send);
375
376/*
377 * Lock a trusted key, by extending a selected PCR.
378 *
379 * Prevents a trusted key that is sealed to PCRs from being accessed.
380 * This uses the tpm driver's extend function.
381 */
382static int pcrlock(const int pcrnum)
383{
384 if (!capable(CAP_SYS_ADMIN))
385 return -EPERM;
386
387 return tpm_pcr_extend(chip, pcrnum, digests) ? -EINVAL : 0;
388}
389
390/*
391 * Create an object specific authorisation protocol (OSAP) session
392 */
393static int osap(struct tpm_buf *tb, struct osapsess *s,
394 const unsigned char *key, uint16_t type, uint32_t handle)
395{
396 unsigned char enonce[TPM_NONCE_SIZE];
397 unsigned char ononce[TPM_NONCE_SIZE];
398 int ret;
399
400 ret = tpm_get_random(chip, ononce, TPM_NONCE_SIZE);
401 if (ret != TPM_NONCE_SIZE)
402 return ret;
403
404 INIT_BUF(tb);
405 store16(tb, TPM_TAG_RQU_COMMAND);
406 store32(tb, TPM_OSAP_SIZE);
407 store32(tb, TPM_ORD_OSAP);
408 store16(tb, type);
409 store32(tb, handle);
410 storebytes(tb, ononce, TPM_NONCE_SIZE);
411
412 ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
413 if (ret < 0)
414 return ret;
415
416 s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
417 memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
418 TPM_NONCE_SIZE);
419 memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
420 TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
421 return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
422 enonce, TPM_NONCE_SIZE, ononce, 0, 0);
423}
424
425/*
426 * Create an object independent authorisation protocol (oiap) session
427 */
428int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
429{
430 int ret;
431
432 INIT_BUF(tb);
433 store16(tb, TPM_TAG_RQU_COMMAND);
434 store32(tb, TPM_OIAP_SIZE);
435 store32(tb, TPM_ORD_OIAP);
436 ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
437 if (ret < 0)
438 return ret;
439
440 *handle = LOAD32(tb->data, TPM_DATA_OFFSET);
441 memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
442 TPM_NONCE_SIZE);
443 return 0;
444}
445EXPORT_SYMBOL_GPL(oiap);
446
447struct tpm_digests {
448 unsigned char encauth[SHA1_DIGEST_SIZE];
449 unsigned char pubauth[SHA1_DIGEST_SIZE];
450 unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
451 unsigned char xorhash[SHA1_DIGEST_SIZE];
452 unsigned char nonceodd[TPM_NONCE_SIZE];
453};
454
455/*
456 * Have the TPM seal(encrypt) the trusted key, possibly based on
457 * Platform Configuration Registers (PCRs). AUTH1 for sealing key.
458 */
459static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
460 uint32_t keyhandle, const unsigned char *keyauth,
461 const unsigned char *data, uint32_t datalen,
462 unsigned char *blob, uint32_t *bloblen,
463 const unsigned char *blobauth,
464 const unsigned char *pcrinfo, uint32_t pcrinfosize)
465{
466 struct osapsess sess;
467 struct tpm_digests *td;
468 unsigned char cont;
469 uint32_t ordinal;
470 uint32_t pcrsize;
471 uint32_t datsize;
472 int sealinfosize;
473 int encdatasize;
474 int storedsize;
475 int ret;
476 int i;
477
478 /* alloc some work space for all the hashes */
479 td = kmalloc(sizeof *td, GFP_KERNEL);
480 if (!td)
481 return -ENOMEM;
482
483 /* get session for sealing key */
484 ret = osap(tb, &sess, keyauth, keytype, keyhandle);
485 if (ret < 0)
486 goto out;
487 dump_sess(&sess);
488
489 /* calculate encrypted authorization value */
490 memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
491 memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
492 ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
493 if (ret < 0)
494 goto out;
495
496 ret = tpm_get_random(chip, td->nonceodd, TPM_NONCE_SIZE);
497 if (ret != TPM_NONCE_SIZE)
498 goto out;
499 ordinal = htonl(TPM_ORD_SEAL);
500 datsize = htonl(datalen);
501 pcrsize = htonl(pcrinfosize);
502 cont = 0;
503
504 /* encrypt data authorization key */
505 for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
506 td->encauth[i] = td->xorhash[i] ^ blobauth[i];
507
508 /* calculate authorization HMAC value */
509 if (pcrinfosize == 0) {
510 /* no pcr info specified */
511 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
512 sess.enonce, td->nonceodd, cont,
513 sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
514 td->encauth, sizeof(uint32_t), &pcrsize,
515 sizeof(uint32_t), &datsize, datalen, data, 0,
516 0);
517 } else {
518 /* pcr info specified */
519 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
520 sess.enonce, td->nonceodd, cont,
521 sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
522 td->encauth, sizeof(uint32_t), &pcrsize,
523 pcrinfosize, pcrinfo, sizeof(uint32_t),
524 &datsize, datalen, data, 0, 0);
525 }
526 if (ret < 0)
527 goto out;
528
529 /* build and send the TPM request packet */
530 INIT_BUF(tb);
531 store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
532 store32(tb, TPM_SEAL_SIZE + pcrinfosize + datalen);
533 store32(tb, TPM_ORD_SEAL);
534 store32(tb, keyhandle);
535 storebytes(tb, td->encauth, SHA1_DIGEST_SIZE);
536 store32(tb, pcrinfosize);
537 storebytes(tb, pcrinfo, pcrinfosize);
538 store32(tb, datalen);
539 storebytes(tb, data, datalen);
540 store32(tb, sess.handle);
541 storebytes(tb, td->nonceodd, TPM_NONCE_SIZE);
542 store8(tb, cont);
543 storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE);
544
545 ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
546 if (ret < 0)
547 goto out;
548
549 /* calculate the size of the returned Blob */
550 sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
551 encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
552 sizeof(uint32_t) + sealinfosize);
553 storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
554 sizeof(uint32_t) + encdatasize;
555
556 /* check the HMAC in the response */
557 ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
558 SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
559 0);
560
561 /* copy the returned blob to caller */
562 if (!ret) {
563 memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
564 *bloblen = storedsize;
565 }
566out:
567 kzfree(td);
568 return ret;
569}
570
571/*
572 * use the AUTH2_COMMAND form of unseal, to authorize both key and blob
573 */
574static int tpm_unseal(struct tpm_buf *tb,
575 uint32_t keyhandle, const unsigned char *keyauth,
576 const unsigned char *blob, int bloblen,
577 const unsigned char *blobauth,
578 unsigned char *data, unsigned int *datalen)
579{
580 unsigned char nonceodd[TPM_NONCE_SIZE];
581 unsigned char enonce1[TPM_NONCE_SIZE];
582 unsigned char enonce2[TPM_NONCE_SIZE];
583 unsigned char authdata1[SHA1_DIGEST_SIZE];
584 unsigned char authdata2[SHA1_DIGEST_SIZE];
585 uint32_t authhandle1 = 0;
586 uint32_t authhandle2 = 0;
587 unsigned char cont = 0;
588 uint32_t ordinal;
589 uint32_t keyhndl;
590 int ret;
591
592 /* sessions for unsealing key and data */
593 ret = oiap(tb, &authhandle1, enonce1);
594 if (ret < 0) {
595 pr_info("trusted_key: oiap failed (%d)\n", ret);
596 return ret;
597 }
598 ret = oiap(tb, &authhandle2, enonce2);
599 if (ret < 0) {
600 pr_info("trusted_key: oiap failed (%d)\n", ret);
601 return ret;
602 }
603
604 ordinal = htonl(TPM_ORD_UNSEAL);
605 keyhndl = htonl(SRKHANDLE);
606 ret = tpm_get_random(chip, nonceodd, TPM_NONCE_SIZE);
607 if (ret != TPM_NONCE_SIZE) {
608 pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
609 return ret;
610 }
611 ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
612 enonce1, nonceodd, cont, sizeof(uint32_t),
613 &ordinal, bloblen, blob, 0, 0);
614 if (ret < 0)
615 return ret;
616 ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
617 enonce2, nonceodd, cont, sizeof(uint32_t),
618 &ordinal, bloblen, blob, 0, 0);
619 if (ret < 0)
620 return ret;
621
622 /* build and send TPM request packet */
623 INIT_BUF(tb);
624 store16(tb, TPM_TAG_RQU_AUTH2_COMMAND);
625 store32(tb, TPM_UNSEAL_SIZE + bloblen);
626 store32(tb, TPM_ORD_UNSEAL);
627 store32(tb, keyhandle);
628 storebytes(tb, blob, bloblen);
629 store32(tb, authhandle1);
630 storebytes(tb, nonceodd, TPM_NONCE_SIZE);
631 store8(tb, cont);
632 storebytes(tb, authdata1, SHA1_DIGEST_SIZE);
633 store32(tb, authhandle2);
634 storebytes(tb, nonceodd, TPM_NONCE_SIZE);
635 store8(tb, cont);
636 storebytes(tb, authdata2, SHA1_DIGEST_SIZE);
637
638 ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
639 if (ret < 0) {
640 pr_info("trusted_key: authhmac failed (%d)\n", ret);
641 return ret;
642 }
643
644 *datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
645 ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
646 keyauth, SHA1_DIGEST_SIZE,
647 blobauth, SHA1_DIGEST_SIZE,
648 sizeof(uint32_t), TPM_DATA_OFFSET,
649 *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
650 0);
651 if (ret < 0) {
652 pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret);
653 return ret;
654 }
655 memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
656 return 0;
657}
658
659/*
660 * Have the TPM seal(encrypt) the symmetric key
661 */
662static int key_seal(struct trusted_key_payload *p,
663 struct trusted_key_options *o)
664{
665 struct tpm_buf *tb;
666 int ret;
667
668 tb = kzalloc(sizeof *tb, GFP_KERNEL);
669 if (!tb)
670 return -ENOMEM;
671
672 /* include migratable flag at end of sealed key */
673 p->key[p->key_len] = p->migratable;
674
675 ret = tpm_seal(tb, o->keytype, o->keyhandle, o->keyauth,
676 p->key, p->key_len + 1, p->blob, &p->blob_len,
677 o->blobauth, o->pcrinfo, o->pcrinfo_len);
678 if (ret < 0)
679 pr_info("trusted_key: srkseal failed (%d)\n", ret);
680
681 kzfree(tb);
682 return ret;
683}
684
685/*
686 * Have the TPM unseal(decrypt) the symmetric key
687 */
688static int key_unseal(struct trusted_key_payload *p,
689 struct trusted_key_options *o)
690{
691 struct tpm_buf *tb;
692 int ret;
693
694 tb = kzalloc(sizeof *tb, GFP_KERNEL);
695 if (!tb)
696 return -ENOMEM;
697
698 ret = tpm_unseal(tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
699 o->blobauth, p->key, &p->key_len);
700 if (ret < 0)
701 pr_info("trusted_key: srkunseal failed (%d)\n", ret);
702 else
703 /* pull migratable flag out of sealed key */
704 p->migratable = p->key[--p->key_len];
705
706 kzfree(tb);
707 return ret;
708}
709
710enum {
711 Opt_err,
712 Opt_new, Opt_load, Opt_update,
713 Opt_keyhandle, Opt_keyauth, Opt_blobauth,
714 Opt_pcrinfo, Opt_pcrlock, Opt_migratable,
715 Opt_hash,
716 Opt_policydigest,
717 Opt_policyhandle,
718};
719
720static const match_table_t key_tokens = {
721 {Opt_new, "new"},
722 {Opt_load, "load"},
723 {Opt_update, "update"},
724 {Opt_keyhandle, "keyhandle=%s"},
725 {Opt_keyauth, "keyauth=%s"},
726 {Opt_blobauth, "blobauth=%s"},
727 {Opt_pcrinfo, "pcrinfo=%s"},
728 {Opt_pcrlock, "pcrlock=%s"},
729 {Opt_migratable, "migratable=%s"},
730 {Opt_hash, "hash=%s"},
731 {Opt_policydigest, "policydigest=%s"},
732 {Opt_policyhandle, "policyhandle=%s"},
733 {Opt_err, NULL}
734};
735
736/* can have zero or more token= options */
737static int getoptions(char *c, struct trusted_key_payload *pay,
738 struct trusted_key_options *opt)
739{
740 substring_t args[MAX_OPT_ARGS];
741 char *p = c;
742 int token;
743 int res;
744 unsigned long handle;
745 unsigned long lock;
746 unsigned long token_mask = 0;
747 unsigned int digest_len;
748 int i;
749 int tpm2;
750
751 tpm2 = tpm_is_tpm2(chip);
752 if (tpm2 < 0)
753 return tpm2;
754
755 opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1;
756
757 while ((p = strsep(&c, " \t"))) {
758 if (*p == '\0' || *p == ' ' || *p == '\t')
759 continue;
760 token = match_token(p, key_tokens, args);
761 if (test_and_set_bit(token, &token_mask))
762 return -EINVAL;
763
764 switch (token) {
765 case Opt_pcrinfo:
766 opt->pcrinfo_len = strlen(args[0].from) / 2;
767 if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
768 return -EINVAL;
769 res = hex2bin(opt->pcrinfo, args[0].from,
770 opt->pcrinfo_len);
771 if (res < 0)
772 return -EINVAL;
773 break;
774 case Opt_keyhandle:
775 res = kstrtoul(args[0].from, 16, &handle);
776 if (res < 0)
777 return -EINVAL;
778 opt->keytype = SEAL_keytype;
779 opt->keyhandle = handle;
780 break;
781 case Opt_keyauth:
782 if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
783 return -EINVAL;
784 res = hex2bin(opt->keyauth, args[0].from,
785 SHA1_DIGEST_SIZE);
786 if (res < 0)
787 return -EINVAL;
788 break;
789 case Opt_blobauth:
790 if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
791 return -EINVAL;
792 res = hex2bin(opt->blobauth, args[0].from,
793 SHA1_DIGEST_SIZE);
794 if (res < 0)
795 return -EINVAL;
796 break;
797 case Opt_migratable:
798 if (*args[0].from == '0')
799 pay->migratable = 0;
800 else
801 return -EINVAL;
802 break;
803 case Opt_pcrlock:
804 res = kstrtoul(args[0].from, 10, &lock);
805 if (res < 0)
806 return -EINVAL;
807 opt->pcrlock = lock;
808 break;
809 case Opt_hash:
810 if (test_bit(Opt_policydigest, &token_mask))
811 return -EINVAL;
812 for (i = 0; i < HASH_ALGO__LAST; i++) {
813 if (!strcmp(args[0].from, hash_algo_name[i])) {
814 opt->hash = i;
815 break;
816 }
817 }
818 if (i == HASH_ALGO__LAST)
819 return -EINVAL;
820 if (!tpm2 && i != HASH_ALGO_SHA1) {
821 pr_info("trusted_key: TPM 1.x only supports SHA-1.\n");
822 return -EINVAL;
823 }
824 break;
825 case Opt_policydigest:
826 digest_len = hash_digest_size[opt->hash];
827 if (!tpm2 || strlen(args[0].from) != (2 * digest_len))
828 return -EINVAL;
829 res = hex2bin(opt->policydigest, args[0].from,
830 digest_len);
831 if (res < 0)
832 return -EINVAL;
833 opt->policydigest_len = digest_len;
834 break;
835 case Opt_policyhandle:
836 if (!tpm2)
837 return -EINVAL;
838 res = kstrtoul(args[0].from, 16, &handle);
839 if (res < 0)
840 return -EINVAL;
841 opt->policyhandle = handle;
842 break;
843 default:
844 return -EINVAL;
845 }
846 }
847 return 0;
848}
849
850/*
851 * datablob_parse - parse the keyctl data and fill in the
852 * payload and options structures
853 *
854 * On success returns 0, otherwise -EINVAL.
855 */
856static int datablob_parse(char *datablob, struct trusted_key_payload *p,
857 struct trusted_key_options *o)
858{
859 substring_t args[MAX_OPT_ARGS];
860 long keylen;
861 int ret = -EINVAL;
862 int key_cmd;
863 char *c;
864
865 /* main command */
866 c = strsep(&datablob, " \t");
867 if (!c)
868 return -EINVAL;
869 key_cmd = match_token(c, key_tokens, args);
870 switch (key_cmd) {
871 case Opt_new:
872 /* first argument is key size */
873 c = strsep(&datablob, " \t");
874 if (!c)
875 return -EINVAL;
876 ret = kstrtol(c, 10, &keylen);
877 if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
878 return -EINVAL;
879 p->key_len = keylen;
880 ret = getoptions(datablob, p, o);
881 if (ret < 0)
882 return ret;
883 ret = Opt_new;
884 break;
885 case Opt_load:
886 /* first argument is sealed blob */
887 c = strsep(&datablob, " \t");
888 if (!c)
889 return -EINVAL;
890 p->blob_len = strlen(c) / 2;
891 if (p->blob_len > MAX_BLOB_SIZE)
892 return -EINVAL;
893 ret = hex2bin(p->blob, c, p->blob_len);
894 if (ret < 0)
895 return -EINVAL;
896 ret = getoptions(datablob, p, o);
897 if (ret < 0)
898 return ret;
899 ret = Opt_load;
900 break;
901 case Opt_update:
902 /* all arguments are options */
903 ret = getoptions(datablob, p, o);
904 if (ret < 0)
905 return ret;
906 ret = Opt_update;
907 break;
908 case Opt_err:
909 return -EINVAL;
910 break;
911 }
912 return ret;
913}
914
915static struct trusted_key_options *trusted_options_alloc(void)
916{
917 struct trusted_key_options *options;
918 int tpm2;
919
920 tpm2 = tpm_is_tpm2(chip);
921 if (tpm2 < 0)
922 return NULL;
923
924 options = kzalloc(sizeof *options, GFP_KERNEL);
925 if (options) {
926 /* set any non-zero defaults */
927 options->keytype = SRK_keytype;
928
929 if (!tpm2)
930 options->keyhandle = SRKHANDLE;
931 }
932 return options;
933}
934
935static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
936{
937 struct trusted_key_payload *p = NULL;
938 int ret;
939
940 ret = key_payload_reserve(key, sizeof *p);
941 if (ret < 0)
942 return p;
943 p = kzalloc(sizeof *p, GFP_KERNEL);
944 if (p)
945 p->migratable = 1; /* migratable by default */
946 return p;
947}
948
949/*
950 * trusted_instantiate - create a new trusted key
951 *
952 * Unseal an existing trusted blob or, for a new key, get a
953 * random key, then seal and create a trusted key-type key,
954 * adding it to the specified keyring.
955 *
956 * On success, return 0. Otherwise return errno.
957 */
958static int trusted_instantiate(struct key *key,
959 struct key_preparsed_payload *prep)
960{
961 struct trusted_key_payload *payload = NULL;
962 struct trusted_key_options *options = NULL;
963 size_t datalen = prep->datalen;
964 char *datablob;
965 int ret = 0;
966 int key_cmd;
967 size_t key_len;
968 int tpm2;
969
970 tpm2 = tpm_is_tpm2(chip);
971 if (tpm2 < 0)
972 return tpm2;
973
974 if (datalen <= 0 || datalen > 32767 || !prep->data)
975 return -EINVAL;
976
977 datablob = kmalloc(datalen + 1, GFP_KERNEL);
978 if (!datablob)
979 return -ENOMEM;
980 memcpy(datablob, prep->data, datalen);
981 datablob[datalen] = '\0';
982
983 options = trusted_options_alloc();
984 if (!options) {
985 ret = -ENOMEM;
986 goto out;
987 }
988 payload = trusted_payload_alloc(key);
989 if (!payload) {
990 ret = -ENOMEM;
991 goto out;
992 }
993
994 key_cmd = datablob_parse(datablob, payload, options);
995 if (key_cmd < 0) {
996 ret = key_cmd;
997 goto out;
998 }
999
1000 if (!options->keyhandle) {
1001 ret = -EINVAL;
1002 goto out;
1003 }
1004
1005 dump_payload(payload);
1006 dump_options(options);
1007
1008 switch (key_cmd) {
1009 case Opt_load:
1010 if (tpm2)
1011 ret = tpm_unseal_trusted(chip, payload, options);
1012 else
1013 ret = key_unseal(payload, options);
1014 dump_payload(payload);
1015 dump_options(options);
1016 if (ret < 0)
1017 pr_info("trusted_key: key_unseal failed (%d)\n", ret);
1018 break;
1019 case Opt_new:
1020 key_len = payload->key_len;
1021 ret = tpm_get_random(chip, payload->key, key_len);
1022 if (ret != key_len) {
1023 pr_info("trusted_key: key_create failed (%d)\n", ret);
1024 goto out;
1025 }
1026 if (tpm2)
1027 ret = tpm_seal_trusted(chip, payload, options);
1028 else
1029 ret = key_seal(payload, options);
1030 if (ret < 0)
1031 pr_info("trusted_key: key_seal failed (%d)\n", ret);
1032 break;
1033 default:
1034 ret = -EINVAL;
1035 goto out;
1036 }
1037 if (!ret && options->pcrlock)
1038 ret = pcrlock(options->pcrlock);
1039out:
1040 kzfree(datablob);
1041 kzfree(options);
1042 if (!ret)
1043 rcu_assign_keypointer(key, payload);
1044 else
1045 kzfree(payload);
1046 return ret;
1047}
1048
1049static void trusted_rcu_free(struct rcu_head *rcu)
1050{
1051 struct trusted_key_payload *p;
1052
1053 p = container_of(rcu, struct trusted_key_payload, rcu);
1054 kzfree(p);
1055}
1056
1057/*
1058 * trusted_update - reseal an existing key with new PCR values
1059 */
1060static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
1061{
1062 struct trusted_key_payload *p;
1063 struct trusted_key_payload *new_p;
1064 struct trusted_key_options *new_o;
1065 size_t datalen = prep->datalen;
1066 char *datablob;
1067 int ret = 0;
1068
1069 if (key_is_negative(key))
1070 return -ENOKEY;
1071 p = key->payload.data[0];
1072 if (!p->migratable)
1073 return -EPERM;
1074 if (datalen <= 0 || datalen > 32767 || !prep->data)
1075 return -EINVAL;
1076
1077 datablob = kmalloc(datalen + 1, GFP_KERNEL);
1078 if (!datablob)
1079 return -ENOMEM;
1080 new_o = trusted_options_alloc();
1081 if (!new_o) {
1082 ret = -ENOMEM;
1083 goto out;
1084 }
1085 new_p = trusted_payload_alloc(key);
1086 if (!new_p) {
1087 ret = -ENOMEM;
1088 goto out;
1089 }
1090
1091 memcpy(datablob, prep->data, datalen);
1092 datablob[datalen] = '\0';
1093 ret = datablob_parse(datablob, new_p, new_o);
1094 if (ret != Opt_update) {
1095 ret = -EINVAL;
1096 kzfree(new_p);
1097 goto out;
1098 }
1099
1100 if (!new_o->keyhandle) {
1101 ret = -EINVAL;
1102 kzfree(new_p);
1103 goto out;
1104 }
1105
1106 /* copy old key values, and reseal with new pcrs */
1107 new_p->migratable = p->migratable;
1108 new_p->key_len = p->key_len;
1109 memcpy(new_p->key, p->key, p->key_len);
1110 dump_payload(p);
1111 dump_payload(new_p);
1112
1113 ret = key_seal(new_p, new_o);
1114 if (ret < 0) {
1115 pr_info("trusted_key: key_seal failed (%d)\n", ret);
1116 kzfree(new_p);
1117 goto out;
1118 }
1119 if (new_o->pcrlock) {
1120 ret = pcrlock(new_o->pcrlock);
1121 if (ret < 0) {
1122 pr_info("trusted_key: pcrlock failed (%d)\n", ret);
1123 kzfree(new_p);
1124 goto out;
1125 }
1126 }
1127 rcu_assign_keypointer(key, new_p);
1128 call_rcu(&p->rcu, trusted_rcu_free);
1129out:
1130 kzfree(datablob);
1131 kzfree(new_o);
1132 return ret;
1133}
1134
1135/*
1136 * trusted_read - copy the sealed blob data to userspace in hex.
1137 * On success, return to userspace the trusted key datablob size.
1138 */
1139static long trusted_read(const struct key *key, char __user *buffer,
1140 size_t buflen)
1141{
1142 const struct trusted_key_payload *p;
1143 char *ascii_buf;
1144 char *bufp;
1145 int i;
1146
1147 p = dereference_key_locked(key);
1148 if (!p)
1149 return -EINVAL;
1150
1151 if (buffer && buflen >= 2 * p->blob_len) {
1152 ascii_buf = kmalloc_array(2, p->blob_len, GFP_KERNEL);
1153 if (!ascii_buf)
1154 return -ENOMEM;
1155
1156 bufp = ascii_buf;
1157 for (i = 0; i < p->blob_len; i++)
1158 bufp = hex_byte_pack(bufp, p->blob[i]);
1159 if (copy_to_user(buffer, ascii_buf, 2 * p->blob_len) != 0) {
1160 kzfree(ascii_buf);
1161 return -EFAULT;
1162 }
1163 kzfree(ascii_buf);
1164 }
1165 return 2 * p->blob_len;
1166}
1167
1168/*
1169 * trusted_destroy - clear and free the key's payload
1170 */
1171static void trusted_destroy(struct key *key)
1172{
1173 kzfree(key->payload.data[0]);
1174}
1175
1176struct key_type key_type_trusted = {
1177 .name = "trusted",
1178 .instantiate = trusted_instantiate,
1179 .update = trusted_update,
1180 .destroy = trusted_destroy,
1181 .describe = user_describe,
1182 .read = trusted_read,
1183};
1184
1185EXPORT_SYMBOL_GPL(key_type_trusted);
1186
1187static void trusted_shash_release(void)
1188{
1189 if (hashalg)
1190 crypto_free_shash(hashalg);
1191 if (hmacalg)
1192 crypto_free_shash(hmacalg);
1193}
1194
1195static int __init trusted_shash_alloc(void)
1196{
1197 int ret;
1198
1199 hmacalg = crypto_alloc_shash(hmac_alg, 0, 0);
1200 if (IS_ERR(hmacalg)) {
1201 pr_info("trusted_key: could not allocate crypto %s\n",
1202 hmac_alg);
1203 return PTR_ERR(hmacalg);
1204 }
1205
1206 hashalg = crypto_alloc_shash(hash_alg, 0, 0);
1207 if (IS_ERR(hashalg)) {
1208 pr_info("trusted_key: could not allocate crypto %s\n",
1209 hash_alg);
1210 ret = PTR_ERR(hashalg);
1211 goto hashalg_fail;
1212 }
1213
1214 return 0;
1215
1216hashalg_fail:
1217 crypto_free_shash(hmacalg);
1218 return ret;
1219}
1220
1221static int __init init_digests(void)
1222{
1223 u8 digest[TPM_MAX_DIGEST_SIZE];
1224 int ret;
1225 int i;
1226
1227 ret = tpm_get_random(chip, digest, TPM_MAX_DIGEST_SIZE);
1228 if (ret < 0)
1229 return ret;
1230 if (ret < TPM_MAX_DIGEST_SIZE)
1231 return -EFAULT;
1232
1233 digests = kcalloc(chip->nr_allocated_banks, sizeof(*digests),
1234 GFP_KERNEL);
1235 if (!digests)
1236 return -ENOMEM;
1237
1238 for (i = 0; i < chip->nr_allocated_banks; i++)
1239 memcpy(digests[i].digest, digest, TPM_MAX_DIGEST_SIZE);
1240
1241 return 0;
1242}
1243
1244static int __init init_trusted(void)
1245{
1246 int ret;
1247
1248 chip = tpm_default_chip();
1249 if (!chip)
1250 return -ENOENT;
1251 ret = init_digests();
1252 if (ret < 0)
1253 goto err_put;
1254 ret = trusted_shash_alloc();
1255 if (ret < 0)
1256 goto err_free;
1257 ret = register_key_type(&key_type_trusted);
1258 if (ret < 0)
1259 goto err_release;
1260 return 0;
1261err_release:
1262 trusted_shash_release();
1263err_free:
1264 kfree(digests);
1265err_put:
1266 put_device(&chip->dev);
1267 return ret;
1268}
1269
1270static void __exit cleanup_trusted(void)
1271{
1272 put_device(&chip->dev);
1273 kfree(digests);
1274 trusted_shash_release();
1275 unregister_key_type(&key_type_trusted);
1276}
1277
1278late_initcall(init_trusted);
1279module_exit(cleanup_trusted);
1280
1281MODULE_LICENSE("GPL");