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
25 static const char hmac_alg[] = "hmac(sha1)";
26 static const char hash_alg[] = "sha1";
27 static struct tpm_chip *chip;
28 static struct tpm_digest *digests;
29
30 struct sdesc {
31 struct shash_desc shash;
32 char ctx[];
33 };
34
35 static struct crypto_shash *hashalg;
36 static struct crypto_shash *hmacalg;
37
38 static 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
51 static 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
68 static 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);
107 out:
108 kfree_sensitive(sdesc);
109 return ret;
110 }
111
112 /*
113 * calculate authorization info fields to send to TPM
114 */
115 int 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);
161 out:
162 kfree_sensitive(sdesc);
163 return ret;
164 }
165 EXPORT_SYMBOL_GPL(TSS_authhmac);
166
167 /*
168 * verify the AUTH1_COMMAND (Seal) result from TPM
169 */
170 int 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;
246 out:
247 kfree_sensitive(sdesc);
248 return ret;
249 }
250 EXPORT_SYMBOL_GPL(TSS_checkhmac1);
251
252 /*
253 * verify the AUTH2_COMMAND (unseal) result from TPM
254 */
255 static 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;
348 out:
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 */
357 int trusted_tpm_send(unsigned char *cmd, size_t buflen)
358 {
359 struct tpm_buf buf;
360 int rc;
361
362 if (!chip)
363 return -ENODEV;
364
365 rc = tpm_try_get_ops(chip);
366 if (rc)
367 return rc;
368
369 buf.flags = 0;
370 buf.length = buflen;
371 buf.data = cmd;
372 dump_tpm_buf(cmd);
373 rc = tpm_transmit_cmd(chip, &buf, 4, "sending data");
374 dump_tpm_buf(cmd);
375
376 if (rc > 0)
377 /* TPM error */
378 rc = -EPERM;
379
380 tpm_put_ops(chip);
381 return rc;
382 }
383 EXPORT_SYMBOL_GPL(trusted_tpm_send);
384
385 /*
386 * Lock a trusted key, by extending a selected PCR.
387 *
388 * Prevents a trusted key that is sealed to PCRs from being accessed.
389 * This uses the tpm driver's extend function.
390 */
391 static int pcrlock(const int pcrnum)
392 {
393 if (!capable(CAP_SYS_ADMIN))
394 return -EPERM;
395
396 return tpm_pcr_extend(chip, pcrnum, digests) ? -EINVAL : 0;
397 }
398
399 /*
400 * Create an object specific authorisation protocol (OSAP) session
401 */
402 static int osap(struct tpm_buf *tb, struct osapsess *s,
403 const unsigned char *key, uint16_t type, uint32_t handle)
404 {
405 unsigned char enonce[TPM_NONCE_SIZE];
406 unsigned char ononce[TPM_NONCE_SIZE];
407 int ret;
408
409 ret = tpm_get_random(chip, ononce, TPM_NONCE_SIZE);
410 if (ret < 0)
411 return ret;
412
413 if (ret != TPM_NONCE_SIZE)
414 return -EIO;
415
416 tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OSAP);
417 tpm_buf_append_u16(tb, type);
418 tpm_buf_append_u32(tb, handle);
419 tpm_buf_append(tb, ononce, TPM_NONCE_SIZE);
420
421 ret = trusted_tpm_send(tb->data, tb->length);
422 if (ret < 0)
423 return ret;
424
425 s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
426 memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
427 TPM_NONCE_SIZE);
428 memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
429 TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
430 return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
431 enonce, TPM_NONCE_SIZE, ononce, 0, 0);
432 }
433
434 /*
435 * Create an object independent authorisation protocol (oiap) session
436 */
437 int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
438 {
439 int ret;
440
441 if (!chip)
442 return -ENODEV;
443
444 tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OIAP);
445 ret = trusted_tpm_send(tb->data, tb->length);
446 if (ret < 0)
447 return ret;
448
449 *handle = LOAD32(tb->data, TPM_DATA_OFFSET);
450 memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
451 TPM_NONCE_SIZE);
452 return 0;
453 }
454 EXPORT_SYMBOL_GPL(oiap);
455
456 struct tpm_digests {
457 unsigned char encauth[SHA1_DIGEST_SIZE];
458 unsigned char pubauth[SHA1_DIGEST_SIZE];
459 unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
460 unsigned char xorhash[SHA1_DIGEST_SIZE];
461 unsigned char nonceodd[TPM_NONCE_SIZE];
462 };
463
464 /*
465 * Have the TPM seal(encrypt) the trusted key, possibly based on
466 * Platform Configuration Registers (PCRs). AUTH1 for sealing key.
467 */
468 static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
469 uint32_t keyhandle, const unsigned char *keyauth,
470 const unsigned char *data, uint32_t datalen,
471 unsigned char *blob, uint32_t *bloblen,
472 const unsigned char *blobauth,
473 const unsigned char *pcrinfo, uint32_t pcrinfosize)
474 {
475 struct osapsess sess;
476 struct tpm_digests *td;
477 unsigned char cont;
478 uint32_t ordinal;
479 uint32_t pcrsize;
480 uint32_t datsize;
481 int sealinfosize;
482 int encdatasize;
483 int storedsize;
484 int ret;
485 int i;
486
487 /* alloc some work space for all the hashes */
488 td = kmalloc(sizeof *td, GFP_KERNEL);
489 if (!td)
490 return -ENOMEM;
491
492 /* get session for sealing key */
493 ret = osap(tb, &sess, keyauth, keytype, keyhandle);
494 if (ret < 0)
495 goto out;
496 dump_sess(&sess);
497
498 /* calculate encrypted authorization value */
499 memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
500 memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
501 ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
502 if (ret < 0)
503 goto out;
504
505 ret = tpm_get_random(chip, td->nonceodd, TPM_NONCE_SIZE);
506 if (ret < 0)
507 goto out;
508
509 if (ret != TPM_NONCE_SIZE) {
510 ret = -EIO;
511 goto out;
512 }
513
514 ordinal = htonl(TPM_ORD_SEAL);
515 datsize = htonl(datalen);
516 pcrsize = htonl(pcrinfosize);
517 cont = 0;
518
519 /* encrypt data authorization key */
520 for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
521 td->encauth[i] = td->xorhash[i] ^ blobauth[i];
522
523 /* calculate authorization HMAC value */
524 if (pcrinfosize == 0) {
525 /* no pcr info specified */
526 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
527 sess.enonce, td->nonceodd, cont,
528 sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
529 td->encauth, sizeof(uint32_t), &pcrsize,
530 sizeof(uint32_t), &datsize, datalen, data, 0,
531 0);
532 } else {
533 /* pcr info specified */
534 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
535 sess.enonce, td->nonceodd, cont,
536 sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
537 td->encauth, sizeof(uint32_t), &pcrsize,
538 pcrinfosize, pcrinfo, sizeof(uint32_t),
539 &datsize, datalen, data, 0, 0);
540 }
541 if (ret < 0)
542 goto out;
543
544 /* build and send the TPM request packet */
545 tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_SEAL);
546 tpm_buf_append_u32(tb, keyhandle);
547 tpm_buf_append(tb, td->encauth, SHA1_DIGEST_SIZE);
548 tpm_buf_append_u32(tb, pcrinfosize);
549 tpm_buf_append(tb, pcrinfo, pcrinfosize);
550 tpm_buf_append_u32(tb, datalen);
551 tpm_buf_append(tb, data, datalen);
552 tpm_buf_append_u32(tb, sess.handle);
553 tpm_buf_append(tb, td->nonceodd, TPM_NONCE_SIZE);
554 tpm_buf_append_u8(tb, cont);
555 tpm_buf_append(tb, td->pubauth, SHA1_DIGEST_SIZE);
556
557 ret = trusted_tpm_send(tb->data, tb->length);
558 if (ret < 0)
559 goto out;
560
561 /* calculate the size of the returned Blob */
562 sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
563 encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
564 sizeof(uint32_t) + sealinfosize);
565 storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
566 sizeof(uint32_t) + encdatasize;
567
568 /* check the HMAC in the response */
569 ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
570 SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
571 0);
572
573 /* copy the returned blob to caller */
574 if (!ret) {
575 memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
576 *bloblen = storedsize;
577 }
578 out:
579 kfree_sensitive(td);
580 return ret;
581 }
582
583 /*
584 * use the AUTH2_COMMAND form of unseal, to authorize both key and blob
585 */
586 static int tpm_unseal(struct tpm_buf *tb,
587 uint32_t keyhandle, const unsigned char *keyauth,
588 const unsigned char *blob, int bloblen,
589 const unsigned char *blobauth,
590 unsigned char *data, unsigned int *datalen)
591 {
592 unsigned char nonceodd[TPM_NONCE_SIZE];
593 unsigned char enonce1[TPM_NONCE_SIZE];
594 unsigned char enonce2[TPM_NONCE_SIZE];
595 unsigned char authdata1[SHA1_DIGEST_SIZE];
596 unsigned char authdata2[SHA1_DIGEST_SIZE];
597 uint32_t authhandle1 = 0;
598 uint32_t authhandle2 = 0;
599 unsigned char cont = 0;
600 uint32_t ordinal;
601 int ret;
602
603 /* sessions for unsealing key and data */
604 ret = oiap(tb, &authhandle1, enonce1);
605 if (ret < 0) {
606 pr_info("oiap failed (%d)\n", ret);
607 return ret;
608 }
609 ret = oiap(tb, &authhandle2, enonce2);
610 if (ret < 0) {
611 pr_info("oiap failed (%d)\n", ret);
612 return ret;
613 }
614
615 ordinal = htonl(TPM_ORD_UNSEAL);
616 ret = tpm_get_random(chip, nonceodd, TPM_NONCE_SIZE);
617 if (ret < 0)
618 return ret;
619
620 if (ret != TPM_NONCE_SIZE) {
621 pr_info("tpm_get_random failed (%d)\n", ret);
622 return -EIO;
623 }
624 ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
625 enonce1, nonceodd, cont, sizeof(uint32_t),
626 &ordinal, bloblen, blob, 0, 0);
627 if (ret < 0)
628 return ret;
629 ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
630 enonce2, nonceodd, cont, sizeof(uint32_t),
631 &ordinal, bloblen, blob, 0, 0);
632 if (ret < 0)
633 return ret;
634
635 /* build and send TPM request packet */
636 tpm_buf_reset(tb, TPM_TAG_RQU_AUTH2_COMMAND, TPM_ORD_UNSEAL);
637 tpm_buf_append_u32(tb, keyhandle);
638 tpm_buf_append(tb, blob, bloblen);
639 tpm_buf_append_u32(tb, authhandle1);
640 tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
641 tpm_buf_append_u8(tb, cont);
642 tpm_buf_append(tb, authdata1, SHA1_DIGEST_SIZE);
643 tpm_buf_append_u32(tb, authhandle2);
644 tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
645 tpm_buf_append_u8(tb, cont);
646 tpm_buf_append(tb, authdata2, SHA1_DIGEST_SIZE);
647
648 ret = trusted_tpm_send(tb->data, tb->length);
649 if (ret < 0) {
650 pr_info("authhmac failed (%d)\n", ret);
651 return ret;
652 }
653
654 *datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
655 ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
656 keyauth, SHA1_DIGEST_SIZE,
657 blobauth, SHA1_DIGEST_SIZE,
658 sizeof(uint32_t), TPM_DATA_OFFSET,
659 *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
660 0);
661 if (ret < 0) {
662 pr_info("TSS_checkhmac2 failed (%d)\n", ret);
663 return ret;
664 }
665 memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
666 return 0;
667 }
668
669 /*
670 * Have the TPM seal(encrypt) the symmetric key
671 */
672 static int key_seal(struct trusted_key_payload *p,
673 struct trusted_key_options *o)
674 {
675 struct tpm_buf tb;
676 int ret;
677
678 ret = tpm_buf_init(&tb, 0, 0);
679 if (ret)
680 return ret;
681
682 /* include migratable flag at end of sealed key */
683 p->key[p->key_len] = p->migratable;
684
685 ret = tpm_seal(&tb, o->keytype, o->keyhandle, o->keyauth,
686 p->key, p->key_len + 1, p->blob, &p->blob_len,
687 o->blobauth, o->pcrinfo, o->pcrinfo_len);
688 if (ret < 0)
689 pr_info("srkseal failed (%d)\n", ret);
690
691 tpm_buf_destroy(&tb);
692 return ret;
693 }
694
695 /*
696 * Have the TPM unseal(decrypt) the symmetric key
697 */
698 static int key_unseal(struct trusted_key_payload *p,
699 struct trusted_key_options *o)
700 {
701 struct tpm_buf tb;
702 int ret;
703
704 ret = tpm_buf_init(&tb, 0, 0);
705 if (ret)
706 return ret;
707
708 ret = tpm_unseal(&tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
709 o->blobauth, p->key, &p->key_len);
710 if (ret < 0)
711 pr_info("srkunseal failed (%d)\n", ret);
712 else
713 /* pull migratable flag out of sealed key */
714 p->migratable = p->key[--p->key_len];
715
716 tpm_buf_destroy(&tb);
717 return ret;
718 }
719
720 enum {
721 Opt_err,
722 Opt_keyhandle, Opt_keyauth, Opt_blobauth,
723 Opt_pcrinfo, Opt_pcrlock, Opt_migratable,
724 Opt_hash,
725 Opt_policydigest,
726 Opt_policyhandle,
727 };
728
729 static const match_table_t key_tokens = {
730 {Opt_keyhandle, "keyhandle=%s"},
731 {Opt_keyauth, "keyauth=%s"},
732 {Opt_blobauth, "blobauth=%s"},
733 {Opt_pcrinfo, "pcrinfo=%s"},
734 {Opt_pcrlock, "pcrlock=%s"},
735 {Opt_migratable, "migratable=%s"},
736 {Opt_hash, "hash=%s"},
737 {Opt_policydigest, "policydigest=%s"},
738 {Opt_policyhandle, "policyhandle=%s"},
739 {Opt_err, NULL}
740 };
741
742 /* can have zero or more token= options */
743 static int getoptions(char *c, struct trusted_key_payload *pay,
744 struct trusted_key_options *opt)
745 {
746 substring_t args[MAX_OPT_ARGS];
747 char *p = c;
748 int token;
749 int res;
750 unsigned long handle;
751 unsigned long lock;
752 unsigned long token_mask = 0;
753 unsigned int digest_len;
754 int i;
755 int tpm2;
756
757 tpm2 = tpm_is_tpm2(chip);
758 if (tpm2 < 0)
759 return tpm2;
760
761 opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1;
762
763 if (!c)
764 return 0;
765
766 while ((p = strsep(&c, " \t"))) {
767 if (*p == '\0' || *p == ' ' || *p == '\t')
768 continue;
769 token = match_token(p, key_tokens, args);
770 if (test_and_set_bit(token, &token_mask))
771 return -EINVAL;
772
773 switch (token) {
774 case Opt_pcrinfo:
775 opt->pcrinfo_len = strlen(args[0].from) / 2;
776 if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
777 return -EINVAL;
778 res = hex2bin(opt->pcrinfo, args[0].from,
779 opt->pcrinfo_len);
780 if (res < 0)
781 return -EINVAL;
782 break;
783 case Opt_keyhandle:
784 res = kstrtoul(args[0].from, 16, &handle);
785 if (res < 0)
786 return -EINVAL;
787 opt->keytype = SEAL_keytype;
788 opt->keyhandle = handle;
789 break;
790 case Opt_keyauth:
791 if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
792 return -EINVAL;
793 res = hex2bin(opt->keyauth, args[0].from,
794 SHA1_DIGEST_SIZE);
795 if (res < 0)
796 return -EINVAL;
797 break;
798 case Opt_blobauth:
799 /*
800 * TPM 1.2 authorizations are sha1 hashes passed in as
801 * hex strings. TPM 2.0 authorizations are simple
802 * passwords (although it can take a hash as well)
803 */
804 opt->blobauth_len = strlen(args[0].from);
805
806 if (opt->blobauth_len == 2 * TPM_DIGEST_SIZE) {
807 res = hex2bin(opt->blobauth, args[0].from,
808 TPM_DIGEST_SIZE);
809 if (res < 0)
810 return -EINVAL;
811
812 opt->blobauth_len = TPM_DIGEST_SIZE;
813 break;
814 }
815
816 if (tpm2 && opt->blobauth_len <= sizeof(opt->blobauth)) {
817 memcpy(opt->blobauth, args[0].from,
818 opt->blobauth_len);
819 break;
820 }
821
822 return -EINVAL;
823
824 break;
825
826 case Opt_migratable:
827 if (*args[0].from == '')
828 pay->migratable = 0;
829 else if (*args[0].from != '1')
830 return -EINVAL;
831 break;
832 case Opt_pcrlock:
833 res = kstrtoul(args[0].from, 10, &lock);
834 if (res < 0)
835 return -EINVAL;
836 opt->pcrlock = lock;
837 break;
838 case Opt_hash:
839 if (test_bit(Opt_policydigest, &token_mask))
840 return -EINVAL;
841 for (i = 0; i < HASH_ALGO__LAST; i++) {
842 if (!strcmp(args[0].from, hash_algo_name[i])) {
843 opt->hash = i;
844 break;
845 }
846 }
847 if (i == HASH_ALGO__LAST)
848 return -EINVAL;
849 if (!tpm2 && i != HASH_ALGO_SHA1) {
850 pr_info("TPM 1.x only supports SHA-1.\n");
851 return -EINVAL;
852 }
853 break;
854 case Opt_policydigest:
855 digest_len = hash_digest_size[opt->hash];
856 if (!tpm2 || strlen(args[0].from) != (2 * digest_len))
857 return -EINVAL;
858 res = hex2bin(opt->policydigest, args[0].from,
859 digest_len);
860 if (res < 0)
861 return -EINVAL;
862 opt->policydigest_len = digest_len;
863 break;
864 case Opt_policyhandle:
865 if (!tpm2)
866 return -EINVAL;
867 res = kstrtoul(args[0].from, 16, &handle);
868 if (res < 0)
869 return -EINVAL;
870 opt->policyhandle = handle;
871 break;
872 default:
873 return -EINVAL;
874 }
875 }
876 return 0;
877 }
878
879 static struct trusted_key_options *trusted_options_alloc(void)
880 {
881 struct trusted_key_options *options;
882 int tpm2;
883
884 tpm2 = tpm_is_tpm2(chip);
885 if (tpm2 < 0)
886 return NULL;
887
888 options = kzalloc(sizeof *options, GFP_KERNEL);
889 if (options) {
890 /* set any non-zero defaults */
891 options->keytype = SRK_keytype;
892
893 if (!tpm2)
894 options->keyhandle = SRKHANDLE;
895 }
896 return options;
897 }
898
899 static int trusted_tpm_seal(struct trusted_key_payload *p, char *datablob)
900 {
901 struct trusted_key_options *options = NULL;
902 int ret = 0;
903 int tpm2;
904
905 tpm2 = tpm_is_tpm2(chip);
906 if (tpm2 < 0)
907 return tpm2;
908
909 options = trusted_options_alloc();
910 if (!options)
911 return -ENOMEM;
912
913 ret = getoptions(datablob, p, options);
914 if (ret < 0)
915 goto out;
916 dump_options(options);
917
918 if (!options->keyhandle && !tpm2) {
919 ret = -EINVAL;
920 goto out;
921 }
922
923 if (tpm2)
924 ret = tpm2_seal_trusted(chip, p, options);
925 else
926 ret = key_seal(p, options);
927 if (ret < 0) {
928 pr_info("key_seal failed (%d)\n", ret);
929 goto out;
930 }
931
932 if (options->pcrlock) {
933 ret = pcrlock(options->pcrlock);
934 if (ret < 0) {
935 pr_info("pcrlock failed (%d)\n", ret);
936 goto out;
937 }
938 }
939 out:
940 kfree_sensitive(options);
941 return ret;
942 }
943
944 static int trusted_tpm_unseal(struct trusted_key_payload *p, char *datablob)
945 {
946 struct trusted_key_options *options = NULL;
947 int ret = 0;
948 int tpm2;
949
950 tpm2 = tpm_is_tpm2(chip);
951 if (tpm2 < 0)
952 return tpm2;
953
954 options = trusted_options_alloc();
955 if (!options)
956 return -ENOMEM;
957
958 ret = getoptions(datablob, p, options);
959 if (ret < 0)
960 goto out;
961 dump_options(options);
962
963 if (!options->keyhandle && !tpm2) {
964 ret = -EINVAL;
965 goto out;
966 }
967
968 if (tpm2)
969 ret = tpm2_unseal_trusted(chip, p, options);
970 else
971 ret = key_unseal(p, options);
972 if (ret < 0)
973 pr_info("key_unseal failed (%d)\n", ret);
974
975 if (options->pcrlock) {
976 ret = pcrlock(options->pcrlock);
977 if (ret < 0) {
978 pr_info("pcrlock failed (%d)\n", ret);
979 goto out;
980 }
981 }
982 out:
983 kfree_sensitive(options);
984 return ret;
985 }
986
987 static int trusted_tpm_get_random(unsigned char *key, size_t key_len)
988 {
989 return tpm_get_random(chip, key, key_len);
990 }
991
992 static void trusted_shash_release(void)
993 {
994 if (hashalg)
995 crypto_free_shash(hashalg);
996 if (hmacalg)
997 crypto_free_shash(hmacalg);
998 }
999
1000 static int __init trusted_shash_alloc(void)
1001 {
1002 int ret;
1003
1004 hmacalg = crypto_alloc_shash(hmac_alg, 0, 0);
1005 if (IS_ERR(hmacalg)) {
1006 pr_info("could not allocate crypto %s\n",
1007 hmac_alg);
1008 return PTR_ERR(hmacalg);
1009 }
1010
1011 hashalg = crypto_alloc_shash(hash_alg, 0, 0);
1012 if (IS_ERR(hashalg)) {
1013 pr_info("could not allocate crypto %s\n",
1014 hash_alg);
1015 ret = PTR_ERR(hashalg);
1016 goto hashalg_fail;
1017 }
1018
1019 return 0;
1020
1021 hashalg_fail:
1022 crypto_free_shash(hmacalg);
1023 return ret;
1024 }
1025
1026 static int __init init_digests(void)
1027 {
1028 int i;
1029
1030 digests = kcalloc(chip->nr_allocated_banks, sizeof(*digests),
1031 GFP_KERNEL);
1032 if (!digests)
1033 return -ENOMEM;
1034
1035 for (i = 0; i < chip->nr_allocated_banks; i++)
1036 digests[i].alg_id = chip->allocated_banks[i].alg_id;
1037
1038 return 0;
1039 }
1040
1041 static int __init trusted_tpm_init(void)
1042 {
1043 int ret;
1044
1045 chip = tpm_default_chip();
1046 if (!chip)
1047 return -ENODEV;
1048
1049 ret = init_digests();
1050 if (ret < 0)
1051 goto err_put;
1052 ret = trusted_shash_alloc();
1053 if (ret < 0)
1054 goto err_free;
1055 ret = register_key_type(&key_type_trusted);
1056 if (ret < 0)
1057 goto err_release;
1058 return 0;
1059 err_release:
1060 trusted_shash_release();
1061 err_free:
1062 kfree(digests);
1063 err_put:
1064 put_device(&chip->dev);
1065 return ret;
1066 }
1067
1068 static void trusted_tpm_exit(void)
1069 {
1070 if (chip) {
1071 put_device(&chip->dev);
1072 kfree(digests);
1073 trusted_shash_release();
1074 unregister_key_type(&key_type_trusted);
1075 }
1076 }
1077
1078 struct trusted_key_ops trusted_key_tpm_ops = {
1079 .migratable = 1, /* migratable by default */
1080 .init = trusted_tpm_init,
1081 .seal = trusted_tpm_seal,
1082 .unseal = trusted_tpm_unseal,
1083 .get_random = trusted_tpm_get_random,
1084 .exit = trusted_tpm_exit,
1085 };
1086
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