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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2010 IBM Corporation
4 * Copyright (c) 2019-2021, Linaro Limited
5 *
6 * See Documentation/security/keys/trusted-encrypted.rst
7 */
8
9#include <crypto/hash_info.h>
10#include <linux/init.h>
11#include <linux/slab.h>
12#include <linux/parser.h>
13#include <linux/string.h>
14#include <linux/err.h>
15#include <keys/trusted-type.h>
16#include <linux/key-type.h>
17#include <linux/crypto.h>
18#include <crypto/hash.h>
19#include <crypto/sha1.h>
20#include <linux/tpm.h>
21#include <linux/tpm_command.h>
22
23#include <keys/trusted_tpm.h>
24
25static const char hmac_alg[] = "hmac(sha1)";
26static const char hash_alg[] = "sha1";
27static struct tpm_chip *chip;
28static struct tpm_digest *digests;
29
30struct sdesc {
31 struct shash_desc shash;
32 char ctx[];
33};
34
35static struct crypto_shash *hashalg;
36static struct crypto_shash *hmacalg;
37
38static struct sdesc *init_sdesc(struct crypto_shash *alg)
39{
40 struct sdesc *sdesc;
41 int size;
42
43 size = sizeof(struct shash_desc) + crypto_shash_descsize(alg);
44 sdesc = kmalloc(size, GFP_KERNEL);
45 if (!sdesc)
46 return ERR_PTR(-ENOMEM);
47 sdesc->shash.tfm = alg;
48 return sdesc;
49}
50
51static int TSS_sha1(const unsigned char *data, unsigned int datalen,
52 unsigned char *digest)
53{
54 struct sdesc *sdesc;
55 int ret;
56
57 sdesc = init_sdesc(hashalg);
58 if (IS_ERR(sdesc)) {
59 pr_info("can't alloc %s\n", hash_alg);
60 return PTR_ERR(sdesc);
61 }
62
63 ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest);
64 kfree_sensitive(sdesc);
65 return ret;
66}
67
68static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
69 unsigned int keylen, ...)
70{
71 struct sdesc *sdesc;
72 va_list argp;
73 unsigned int dlen;
74 unsigned char *data;
75 int ret;
76
77 sdesc = init_sdesc(hmacalg);
78 if (IS_ERR(sdesc)) {
79 pr_info("can't alloc %s\n", hmac_alg);
80 return PTR_ERR(sdesc);
81 }
82
83 ret = crypto_shash_setkey(hmacalg, key, keylen);
84 if (ret < 0)
85 goto out;
86 ret = crypto_shash_init(&sdesc->shash);
87 if (ret < 0)
88 goto out;
89
90 va_start(argp, keylen);
91 for (;;) {
92 dlen = va_arg(argp, unsigned int);
93 if (dlen == 0)
94 break;
95 data = va_arg(argp, unsigned char *);
96 if (data == NULL) {
97 ret = -EINVAL;
98 break;
99 }
100 ret = crypto_shash_update(&sdesc->shash, data, dlen);
101 if (ret < 0)
102 break;
103 }
104 va_end(argp);
105 if (!ret)
106 ret = crypto_shash_final(&sdesc->shash, digest);
107out:
108 kfree_sensitive(sdesc);
109 return ret;
110}
111
112/*
113 * calculate authorization info fields to send to TPM
114 */
115int TSS_authhmac(unsigned char *digest, const unsigned char *key,
116 unsigned int keylen, unsigned char *h1,
117 unsigned char *h2, unsigned int h3, ...)
118{
119 unsigned char paramdigest[SHA1_DIGEST_SIZE];
120 struct sdesc *sdesc;
121 unsigned int dlen;
122 unsigned char *data;
123 unsigned char c;
124 int ret;
125 va_list argp;
126
127 if (!chip)
128 return -ENODEV;
129
130 sdesc = init_sdesc(hashalg);
131 if (IS_ERR(sdesc)) {
132 pr_info("can't alloc %s\n", hash_alg);
133 return PTR_ERR(sdesc);
134 }
135
136 c = !!h3;
137 ret = crypto_shash_init(&sdesc->shash);
138 if (ret < 0)
139 goto out;
140 va_start(argp, h3);
141 for (;;) {
142 dlen = va_arg(argp, unsigned int);
143 if (dlen == 0)
144 break;
145 data = va_arg(argp, unsigned char *);
146 if (!data) {
147 ret = -EINVAL;
148 break;
149 }
150 ret = crypto_shash_update(&sdesc->shash, data, dlen);
151 if (ret < 0)
152 break;
153 }
154 va_end(argp);
155 if (!ret)
156 ret = crypto_shash_final(&sdesc->shash, paramdigest);
157 if (!ret)
158 ret = TSS_rawhmac(digest, key, keylen, SHA1_DIGEST_SIZE,
159 paramdigest, TPM_NONCE_SIZE, h1,
160 TPM_NONCE_SIZE, h2, 1, &c, 0, 0);
161out:
162 kfree_sensitive(sdesc);
163 return ret;
164}
165EXPORT_SYMBOL_GPL(TSS_authhmac);
166
167/*
168 * verify the AUTH1_COMMAND (Seal) result from TPM
169 */
170int TSS_checkhmac1(unsigned char *buffer,
171 const uint32_t command,
172 const unsigned char *ononce,
173 const unsigned char *key,
174 unsigned int keylen, ...)
175{
176 uint32_t bufsize;
177 uint16_t tag;
178 uint32_t ordinal;
179 uint32_t result;
180 unsigned char *enonce;
181 unsigned char *continueflag;
182 unsigned char *authdata;
183 unsigned char testhmac[SHA1_DIGEST_SIZE];
184 unsigned char paramdigest[SHA1_DIGEST_SIZE];
185 struct sdesc *sdesc;
186 unsigned int dlen;
187 unsigned int dpos;
188 va_list argp;
189 int ret;
190
191 if (!chip)
192 return -ENODEV;
193
194 bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
195 tag = LOAD16(buffer, 0);
196 ordinal = command;
197 result = LOAD32N(buffer, TPM_RETURN_OFFSET);
198 if (tag == TPM_TAG_RSP_COMMAND)
199 return 0;
200 if (tag != TPM_TAG_RSP_AUTH1_COMMAND)
201 return -EINVAL;
202 authdata = buffer + bufsize - SHA1_DIGEST_SIZE;
203 continueflag = authdata - 1;
204 enonce = continueflag - TPM_NONCE_SIZE;
205
206 sdesc = init_sdesc(hashalg);
207 if (IS_ERR(sdesc)) {
208 pr_info("can't alloc %s\n", hash_alg);
209 return PTR_ERR(sdesc);
210 }
211 ret = crypto_shash_init(&sdesc->shash);
212 if (ret < 0)
213 goto out;
214 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
215 sizeof result);
216 if (ret < 0)
217 goto out;
218 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
219 sizeof ordinal);
220 if (ret < 0)
221 goto out;
222 va_start(argp, keylen);
223 for (;;) {
224 dlen = va_arg(argp, unsigned int);
225 if (dlen == 0)
226 break;
227 dpos = va_arg(argp, unsigned int);
228 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
229 if (ret < 0)
230 break;
231 }
232 va_end(argp);
233 if (!ret)
234 ret = crypto_shash_final(&sdesc->shash, paramdigest);
235 if (ret < 0)
236 goto out;
237
238 ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest,
239 TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce,
240 1, continueflag, 0, 0);
241 if (ret < 0)
242 goto out;
243
244 if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE))
245 ret = -EINVAL;
246out:
247 kfree_sensitive(sdesc);
248 return ret;
249}
250EXPORT_SYMBOL_GPL(TSS_checkhmac1);
251
252/*
253 * verify the AUTH2_COMMAND (unseal) result from TPM
254 */
255static int TSS_checkhmac2(unsigned char *buffer,
256 const uint32_t command,
257 const unsigned char *ononce,
258 const unsigned char *key1,
259 unsigned int keylen1,
260 const unsigned char *key2,
261 unsigned int keylen2, ...)
262{
263 uint32_t bufsize;
264 uint16_t tag;
265 uint32_t ordinal;
266 uint32_t result;
267 unsigned char *enonce1;
268 unsigned char *continueflag1;
269 unsigned char *authdata1;
270 unsigned char *enonce2;
271 unsigned char *continueflag2;
272 unsigned char *authdata2;
273 unsigned char testhmac1[SHA1_DIGEST_SIZE];
274 unsigned char testhmac2[SHA1_DIGEST_SIZE];
275 unsigned char paramdigest[SHA1_DIGEST_SIZE];
276 struct sdesc *sdesc;
277 unsigned int dlen;
278 unsigned int dpos;
279 va_list argp;
280 int ret;
281
282 bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
283 tag = LOAD16(buffer, 0);
284 ordinal = command;
285 result = LOAD32N(buffer, TPM_RETURN_OFFSET);
286
287 if (tag == TPM_TAG_RSP_COMMAND)
288 return 0;
289 if (tag != TPM_TAG_RSP_AUTH2_COMMAND)
290 return -EINVAL;
291 authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1
292 + SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE);
293 authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE);
294 continueflag1 = authdata1 - 1;
295 continueflag2 = authdata2 - 1;
296 enonce1 = continueflag1 - TPM_NONCE_SIZE;
297 enonce2 = continueflag2 - TPM_NONCE_SIZE;
298
299 sdesc = init_sdesc(hashalg);
300 if (IS_ERR(sdesc)) {
301 pr_info("can't alloc %s\n", hash_alg);
302 return PTR_ERR(sdesc);
303 }
304 ret = crypto_shash_init(&sdesc->shash);
305 if (ret < 0)
306 goto out;
307 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
308 sizeof result);
309 if (ret < 0)
310 goto out;
311 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
312 sizeof ordinal);
313 if (ret < 0)
314 goto out;
315
316 va_start(argp, keylen2);
317 for (;;) {
318 dlen = va_arg(argp, unsigned int);
319 if (dlen == 0)
320 break;
321 dpos = va_arg(argp, unsigned int);
322 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
323 if (ret < 0)
324 break;
325 }
326 va_end(argp);
327 if (!ret)
328 ret = crypto_shash_final(&sdesc->shash, paramdigest);
329 if (ret < 0)
330 goto out;
331
332 ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE,
333 paramdigest, TPM_NONCE_SIZE, enonce1,
334 TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0);
335 if (ret < 0)
336 goto out;
337 if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) {
338 ret = -EINVAL;
339 goto out;
340 }
341 ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE,
342 paramdigest, TPM_NONCE_SIZE, enonce2,
343 TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0);
344 if (ret < 0)
345 goto out;
346 if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE))
347 ret = -EINVAL;
348out:
349 kfree_sensitive(sdesc);
350 return ret;
351}
352
353/*
354 * For key specific tpm requests, we will generate and send our
355 * own TPM command packets using the drivers send function.
356 */
357int trusted_tpm_send(unsigned char *cmd, size_t buflen)
358{
359 int rc;
360
361 if (!chip)
362 return -ENODEV;
363
364 dump_tpm_buf(cmd);
365 rc = tpm_send(chip, cmd, buflen);
366 dump_tpm_buf(cmd);
367 if (rc > 0)
368 /* Can't return positive return codes values to keyctl */
369 rc = -EPERM;
370 return rc;
371}
372EXPORT_SYMBOL_GPL(trusted_tpm_send);
373
374/*
375 * Lock a trusted key, by extending a selected PCR.
376 *
377 * Prevents a trusted key that is sealed to PCRs from being accessed.
378 * This uses the tpm driver's extend function.
379 */
380static int pcrlock(const int pcrnum)
381{
382 if (!capable(CAP_SYS_ADMIN))
383 return -EPERM;
384
385 return tpm_pcr_extend(chip, pcrnum, digests) ? -EINVAL : 0;
386}
387
388/*
389 * Create an object specific authorisation protocol (OSAP) session
390 */
391static int osap(struct tpm_buf *tb, struct osapsess *s,
392 const unsigned char *key, uint16_t type, uint32_t handle)
393{
394 unsigned char enonce[TPM_NONCE_SIZE];
395 unsigned char ononce[TPM_NONCE_SIZE];
396 int ret;
397
398 ret = tpm_get_random(chip, ononce, TPM_NONCE_SIZE);
399 if (ret < 0)
400 return ret;
401
402 if (ret != TPM_NONCE_SIZE)
403 return -EIO;
404
405 tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OSAP);
406 tpm_buf_append_u16(tb, type);
407 tpm_buf_append_u32(tb, handle);
408 tpm_buf_append(tb, ononce, TPM_NONCE_SIZE);
409
410 ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
411 if (ret < 0)
412 return ret;
413
414 s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
415 memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
416 TPM_NONCE_SIZE);
417 memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
418 TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
419 return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
420 enonce, TPM_NONCE_SIZE, ononce, 0, 0);
421}
422
423/*
424 * Create an object independent authorisation protocol (oiap) session
425 */
426int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
427{
428 int ret;
429
430 if (!chip)
431 return -ENODEV;
432
433 tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OIAP);
434 ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
435 if (ret < 0)
436 return ret;
437
438 *handle = LOAD32(tb->data, TPM_DATA_OFFSET);
439 memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
440 TPM_NONCE_SIZE);
441 return 0;
442}
443EXPORT_SYMBOL_GPL(oiap);
444
445struct tpm_digests {
446 unsigned char encauth[SHA1_DIGEST_SIZE];
447 unsigned char pubauth[SHA1_DIGEST_SIZE];
448 unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
449 unsigned char xorhash[SHA1_DIGEST_SIZE];
450 unsigned char nonceodd[TPM_NONCE_SIZE];
451};
452
453/*
454 * Have the TPM seal(encrypt) the trusted key, possibly based on
455 * Platform Configuration Registers (PCRs). AUTH1 for sealing key.
456 */
457static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
458 uint32_t keyhandle, const unsigned char *keyauth,
459 const unsigned char *data, uint32_t datalen,
460 unsigned char *blob, uint32_t *bloblen,
461 const unsigned char *blobauth,
462 const unsigned char *pcrinfo, uint32_t pcrinfosize)
463{
464 struct osapsess sess;
465 struct tpm_digests *td;
466 unsigned char cont;
467 uint32_t ordinal;
468 uint32_t pcrsize;
469 uint32_t datsize;
470 int sealinfosize;
471 int encdatasize;
472 int storedsize;
473 int ret;
474 int i;
475
476 /* alloc some work space for all the hashes */
477 td = kmalloc(sizeof *td, GFP_KERNEL);
478 if (!td)
479 return -ENOMEM;
480
481 /* get session for sealing key */
482 ret = osap(tb, &sess, keyauth, keytype, keyhandle);
483 if (ret < 0)
484 goto out;
485 dump_sess(&sess);
486
487 /* calculate encrypted authorization value */
488 memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
489 memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
490 ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
491 if (ret < 0)
492 goto out;
493
494 ret = tpm_get_random(chip, td->nonceodd, TPM_NONCE_SIZE);
495 if (ret < 0)
496 goto out;
497
498 if (ret != TPM_NONCE_SIZE) {
499 ret = -EIO;
500 goto out;
501 }
502
503 ordinal = htonl(TPM_ORD_SEAL);
504 datsize = htonl(datalen);
505 pcrsize = htonl(pcrinfosize);
506 cont = 0;
507
508 /* encrypt data authorization key */
509 for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
510 td->encauth[i] = td->xorhash[i] ^ blobauth[i];
511
512 /* calculate authorization HMAC value */
513 if (pcrinfosize == 0) {
514 /* no pcr info specified */
515 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
516 sess.enonce, td->nonceodd, cont,
517 sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
518 td->encauth, sizeof(uint32_t), &pcrsize,
519 sizeof(uint32_t), &datsize, datalen, data, 0,
520 0);
521 } else {
522 /* pcr info specified */
523 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
524 sess.enonce, td->nonceodd, cont,
525 sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
526 td->encauth, sizeof(uint32_t), &pcrsize,
527 pcrinfosize, pcrinfo, sizeof(uint32_t),
528 &datsize, datalen, data, 0, 0);
529 }
530 if (ret < 0)
531 goto out;
532
533 /* build and send the TPM request packet */
534 tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_SEAL);
535 tpm_buf_append_u32(tb, keyhandle);
536 tpm_buf_append(tb, td->encauth, SHA1_DIGEST_SIZE);
537 tpm_buf_append_u32(tb, pcrinfosize);
538 tpm_buf_append(tb, pcrinfo, pcrinfosize);
539 tpm_buf_append_u32(tb, datalen);
540 tpm_buf_append(tb, data, datalen);
541 tpm_buf_append_u32(tb, sess.handle);
542 tpm_buf_append(tb, td->nonceodd, TPM_NONCE_SIZE);
543 tpm_buf_append_u8(tb, cont);
544 tpm_buf_append(tb, td->pubauth, SHA1_DIGEST_SIZE);
545
546 ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
547 if (ret < 0)
548 goto out;
549
550 /* calculate the size of the returned Blob */
551 sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
552 encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
553 sizeof(uint32_t) + sealinfosize);
554 storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
555 sizeof(uint32_t) + encdatasize;
556
557 /* check the HMAC in the response */
558 ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
559 SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
560 0);
561
562 /* copy the returned blob to caller */
563 if (!ret) {
564 memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
565 *bloblen = storedsize;
566 }
567out:
568 kfree_sensitive(td);
569 return ret;
570}
571
572/*
573 * use the AUTH2_COMMAND form of unseal, to authorize both key and blob
574 */
575static int tpm_unseal(struct tpm_buf *tb,
576 uint32_t keyhandle, const unsigned char *keyauth,
577 const unsigned char *blob, int bloblen,
578 const unsigned char *blobauth,
579 unsigned char *data, unsigned int *datalen)
580{
581 unsigned char nonceodd[TPM_NONCE_SIZE];
582 unsigned char enonce1[TPM_NONCE_SIZE];
583 unsigned char enonce2[TPM_NONCE_SIZE];
584 unsigned char authdata1[SHA1_DIGEST_SIZE];
585 unsigned char authdata2[SHA1_DIGEST_SIZE];
586 uint32_t authhandle1 = 0;
587 uint32_t authhandle2 = 0;
588 unsigned char cont = 0;
589 uint32_t ordinal;
590 int ret;
591
592 /* sessions for unsealing key and data */
593 ret = oiap(tb, &authhandle1, enonce1);
594 if (ret < 0) {
595 pr_info("oiap failed (%d)\n", ret);
596 return ret;
597 }
598 ret = oiap(tb, &authhandle2, enonce2);
599 if (ret < 0) {
600 pr_info("oiap failed (%d)\n", ret);
601 return ret;
602 }
603
604 ordinal = htonl(TPM_ORD_UNSEAL);
605 ret = tpm_get_random(chip, nonceodd, TPM_NONCE_SIZE);
606 if (ret < 0)
607 return ret;
608
609 if (ret != TPM_NONCE_SIZE) {
610 pr_info("tpm_get_random failed (%d)\n", ret);
611 return -EIO;
612 }
613 ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
614 enonce1, nonceodd, cont, sizeof(uint32_t),
615 &ordinal, bloblen, blob, 0, 0);
616 if (ret < 0)
617 return ret;
618 ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
619 enonce2, nonceodd, cont, sizeof(uint32_t),
620 &ordinal, bloblen, blob, 0, 0);
621 if (ret < 0)
622 return ret;
623
624 /* build and send TPM request packet */
625 tpm_buf_reset(tb, TPM_TAG_RQU_AUTH2_COMMAND, TPM_ORD_UNSEAL);
626 tpm_buf_append_u32(tb, keyhandle);
627 tpm_buf_append(tb, blob, bloblen);
628 tpm_buf_append_u32(tb, authhandle1);
629 tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
630 tpm_buf_append_u8(tb, cont);
631 tpm_buf_append(tb, authdata1, SHA1_DIGEST_SIZE);
632 tpm_buf_append_u32(tb, authhandle2);
633 tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
634 tpm_buf_append_u8(tb, cont);
635 tpm_buf_append(tb, authdata2, SHA1_DIGEST_SIZE);
636
637 ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
638 if (ret < 0) {
639 pr_info("authhmac failed (%d)\n", ret);
640 return ret;
641 }
642
643 *datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
644 ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
645 keyauth, SHA1_DIGEST_SIZE,
646 blobauth, SHA1_DIGEST_SIZE,
647 sizeof(uint32_t), TPM_DATA_OFFSET,
648 *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
649 0);
650 if (ret < 0) {
651 pr_info("TSS_checkhmac2 failed (%d)\n", ret);
652 return ret;
653 }
654 memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
655 return 0;
656}
657
658/*
659 * Have the TPM seal(encrypt) the symmetric key
660 */
661static int key_seal(struct trusted_key_payload *p,
662 struct trusted_key_options *o)
663{
664 struct tpm_buf tb;
665 int ret;
666
667 ret = tpm_buf_init(&tb, 0, 0);
668 if (ret)
669 return ret;
670
671 /* include migratable flag at end of sealed key */
672 p->key[p->key_len] = p->migratable;
673
674 ret = tpm_seal(&tb, o->keytype, o->keyhandle, o->keyauth,
675 p->key, p->key_len + 1, p->blob, &p->blob_len,
676 o->blobauth, o->pcrinfo, o->pcrinfo_len);
677 if (ret < 0)
678 pr_info("srkseal failed (%d)\n", ret);
679
680 tpm_buf_destroy(&tb);
681 return ret;
682}
683
684/*
685 * Have the TPM unseal(decrypt) the symmetric key
686 */
687static int key_unseal(struct trusted_key_payload *p,
688 struct trusted_key_options *o)
689{
690 struct tpm_buf tb;
691 int ret;
692
693 ret = tpm_buf_init(&tb, 0, 0);
694 if (ret)
695 return ret;
696
697 ret = tpm_unseal(&tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
698 o->blobauth, p->key, &p->key_len);
699 if (ret < 0)
700 pr_info("srkunseal failed (%d)\n", ret);
701 else
702 /* pull migratable flag out of sealed key */
703 p->migratable = p->key[--p->key_len];
704
705 tpm_buf_destroy(&tb);
706 return ret;
707}
708
709enum {
710 Opt_err,
711 Opt_keyhandle, Opt_keyauth, Opt_blobauth,
712 Opt_pcrinfo, Opt_pcrlock, Opt_migratable,
713 Opt_hash,
714 Opt_policydigest,
715 Opt_policyhandle,
716};
717
718static const match_table_t key_tokens = {
719 {Opt_keyhandle, "keyhandle=%s"},
720 {Opt_keyauth, "keyauth=%s"},
721 {Opt_blobauth, "blobauth=%s"},
722 {Opt_pcrinfo, "pcrinfo=%s"},
723 {Opt_pcrlock, "pcrlock=%s"},
724 {Opt_migratable, "migratable=%s"},
725 {Opt_hash, "hash=%s"},
726 {Opt_policydigest, "policydigest=%s"},
727 {Opt_policyhandle, "policyhandle=%s"},
728 {Opt_err, NULL}
729};
730
731/* can have zero or more token= options */
732static int getoptions(char *c, struct trusted_key_payload *pay,
733 struct trusted_key_options *opt)
734{
735 substring_t args[MAX_OPT_ARGS];
736 char *p = c;
737 int token;
738 int res;
739 unsigned long handle;
740 unsigned long lock;
741 unsigned long token_mask = 0;
742 unsigned int digest_len;
743 int i;
744 int tpm2;
745
746 tpm2 = tpm_is_tpm2(chip);
747 if (tpm2 < 0)
748 return tpm2;
749
750 opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1;
751
752 if (!c)
753 return 0;
754
755 while ((p = strsep(&c, " \t"))) {
756 if (*p == '\0' || *p == ' ' || *p == '\t')
757 continue;
758 token = match_token(p, key_tokens, args);
759 if (test_and_set_bit(token, &token_mask))
760 return -EINVAL;
761
762 switch (token) {
763 case Opt_pcrinfo:
764 opt->pcrinfo_len = strlen(args[0].from) / 2;
765 if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
766 return -EINVAL;
767 res = hex2bin(opt->pcrinfo, args[0].from,
768 opt->pcrinfo_len);
769 if (res < 0)
770 return -EINVAL;
771 break;
772 case Opt_keyhandle:
773 res = kstrtoul(args[0].from, 16, &handle);
774 if (res < 0)
775 return -EINVAL;
776 opt->keytype = SEAL_keytype;
777 opt->keyhandle = handle;
778 break;
779 case Opt_keyauth:
780 if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
781 return -EINVAL;
782 res = hex2bin(opt->keyauth, args[0].from,
783 SHA1_DIGEST_SIZE);
784 if (res < 0)
785 return -EINVAL;
786 break;
787 case Opt_blobauth:
788 /*
789 * TPM 1.2 authorizations are sha1 hashes passed in as
790 * hex strings. TPM 2.0 authorizations are simple
791 * passwords (although it can take a hash as well)
792 */
793 opt->blobauth_len = strlen(args[0].from);
794
795 if (opt->blobauth_len == 2 * TPM_DIGEST_SIZE) {
796 res = hex2bin(opt->blobauth, args[0].from,
797 TPM_DIGEST_SIZE);
798 if (res < 0)
799 return -EINVAL;
800
801 opt->blobauth_len = TPM_DIGEST_SIZE;
802 break;
803 }
804
805 if (tpm2 && opt->blobauth_len <= sizeof(opt->blobauth)) {
806 memcpy(opt->blobauth, args[0].from,
807 opt->blobauth_len);
808 break;
809 }
810
811 return -EINVAL;
812
813 break;
814
815 case Opt_migratable:
816 if (*args[0].from == '0')
817 pay->migratable = 0;
818 else if (*args[0].from != '1')
819 return -EINVAL;
820 break;
821 case Opt_pcrlock:
822 res = kstrtoul(args[0].from, 10, &lock);
823 if (res < 0)
824 return -EINVAL;
825 opt->pcrlock = lock;
826 break;
827 case Opt_hash:
828 if (test_bit(Opt_policydigest, &token_mask))
829 return -EINVAL;
830 for (i = 0; i < HASH_ALGO__LAST; i++) {
831 if (!strcmp(args[0].from, hash_algo_name[i])) {
832 opt->hash = i;
833 break;
834 }
835 }
836 if (i == HASH_ALGO__LAST)
837 return -EINVAL;
838 if (!tpm2 && i != HASH_ALGO_SHA1) {
839 pr_info("TPM 1.x only supports SHA-1.\n");
840 return -EINVAL;
841 }
842 break;
843 case Opt_policydigest:
844 digest_len = hash_digest_size[opt->hash];
845 if (!tpm2 || strlen(args[0].from) != (2 * digest_len))
846 return -EINVAL;
847 res = hex2bin(opt->policydigest, args[0].from,
848 digest_len);
849 if (res < 0)
850 return -EINVAL;
851 opt->policydigest_len = digest_len;
852 break;
853 case Opt_policyhandle:
854 if (!tpm2)
855 return -EINVAL;
856 res = kstrtoul(args[0].from, 16, &handle);
857 if (res < 0)
858 return -EINVAL;
859 opt->policyhandle = handle;
860 break;
861 default:
862 return -EINVAL;
863 }
864 }
865 return 0;
866}
867
868static struct trusted_key_options *trusted_options_alloc(void)
869{
870 struct trusted_key_options *options;
871 int tpm2;
872
873 tpm2 = tpm_is_tpm2(chip);
874 if (tpm2 < 0)
875 return NULL;
876
877 options = kzalloc(sizeof *options, GFP_KERNEL);
878 if (options) {
879 /* set any non-zero defaults */
880 options->keytype = SRK_keytype;
881
882 if (!tpm2)
883 options->keyhandle = SRKHANDLE;
884 }
885 return options;
886}
887
888static int trusted_tpm_seal(struct trusted_key_payload *p, char *datablob)
889{
890 struct trusted_key_options *options = NULL;
891 int ret = 0;
892 int tpm2;
893
894 tpm2 = tpm_is_tpm2(chip);
895 if (tpm2 < 0)
896 return tpm2;
897
898 options = trusted_options_alloc();
899 if (!options)
900 return -ENOMEM;
901
902 ret = getoptions(datablob, p, options);
903 if (ret < 0)
904 goto out;
905 dump_options(options);
906
907 if (!options->keyhandle && !tpm2) {
908 ret = -EINVAL;
909 goto out;
910 }
911
912 if (tpm2)
913 ret = tpm2_seal_trusted(chip, p, options);
914 else
915 ret = key_seal(p, options);
916 if (ret < 0) {
917 pr_info("key_seal failed (%d)\n", ret);
918 goto out;
919 }
920
921 if (options->pcrlock) {
922 ret = pcrlock(options->pcrlock);
923 if (ret < 0) {
924 pr_info("pcrlock failed (%d)\n", ret);
925 goto out;
926 }
927 }
928out:
929 kfree_sensitive(options);
930 return ret;
931}
932
933static int trusted_tpm_unseal(struct trusted_key_payload *p, char *datablob)
934{
935 struct trusted_key_options *options = NULL;
936 int ret = 0;
937 int tpm2;
938
939 tpm2 = tpm_is_tpm2(chip);
940 if (tpm2 < 0)
941 return tpm2;
942
943 options = trusted_options_alloc();
944 if (!options)
945 return -ENOMEM;
946
947 ret = getoptions(datablob, p, options);
948 if (ret < 0)
949 goto out;
950 dump_options(options);
951
952 if (!options->keyhandle && !tpm2) {
953 ret = -EINVAL;
954 goto out;
955 }
956
957 if (tpm2)
958 ret = tpm2_unseal_trusted(chip, p, options);
959 else
960 ret = key_unseal(p, options);
961 if (ret < 0)
962 pr_info("key_unseal failed (%d)\n", ret);
963
964 if (options->pcrlock) {
965 ret = pcrlock(options->pcrlock);
966 if (ret < 0) {
967 pr_info("pcrlock failed (%d)\n", ret);
968 goto out;
969 }
970 }
971out:
972 kfree_sensitive(options);
973 return ret;
974}
975
976static int trusted_tpm_get_random(unsigned char *key, size_t key_len)
977{
978 return tpm_get_random(chip, key, key_len);
979}
980
981static void trusted_shash_release(void)
982{
983 if (hashalg)
984 crypto_free_shash(hashalg);
985 if (hmacalg)
986 crypto_free_shash(hmacalg);
987}
988
989static int __init trusted_shash_alloc(void)
990{
991 int ret;
992
993 hmacalg = crypto_alloc_shash(hmac_alg, 0, 0);
994 if (IS_ERR(hmacalg)) {
995 pr_info("could not allocate crypto %s\n",
996 hmac_alg);
997 return PTR_ERR(hmacalg);
998 }
999
1000 hashalg = crypto_alloc_shash(hash_alg, 0, 0);
1001 if (IS_ERR(hashalg)) {
1002 pr_info("could not allocate crypto %s\n",
1003 hash_alg);
1004 ret = PTR_ERR(hashalg);
1005 goto hashalg_fail;
1006 }
1007
1008 return 0;
1009
1010hashalg_fail:
1011 crypto_free_shash(hmacalg);
1012 return ret;
1013}
1014
1015static int __init init_digests(void)
1016{
1017 int i;
1018
1019 digests = kcalloc(chip->nr_allocated_banks, sizeof(*digests),
1020 GFP_KERNEL);
1021 if (!digests)
1022 return -ENOMEM;
1023
1024 for (i = 0; i < chip->nr_allocated_banks; i++)
1025 digests[i].alg_id = chip->allocated_banks[i].alg_id;
1026
1027 return 0;
1028}
1029
1030static int __init trusted_tpm_init(void)
1031{
1032 int ret;
1033
1034 chip = tpm_default_chip();
1035 if (!chip)
1036 return -ENODEV;
1037
1038 ret = init_digests();
1039 if (ret < 0)
1040 goto err_put;
1041 ret = trusted_shash_alloc();
1042 if (ret < 0)
1043 goto err_free;
1044 ret = register_key_type(&key_type_trusted);
1045 if (ret < 0)
1046 goto err_release;
1047 return 0;
1048err_release:
1049 trusted_shash_release();
1050err_free:
1051 kfree(digests);
1052err_put:
1053 put_device(&chip->dev);
1054 return ret;
1055}
1056
1057static void trusted_tpm_exit(void)
1058{
1059 if (chip) {
1060 put_device(&chip->dev);
1061 kfree(digests);
1062 trusted_shash_release();
1063 unregister_key_type(&key_type_trusted);
1064 }
1065}
1066
1067struct trusted_key_ops trusted_key_tpm_ops = {
1068 .migratable = 1, /* migratable by default */
1069 .init = trusted_tpm_init,
1070 .seal = trusted_tpm_seal,
1071 .unseal = trusted_tpm_unseal,
1072 .get_random = trusted_tpm_get_random,
1073 .exit = trusted_tpm_exit,
1074};