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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2010 IBM Corporation
4 *
5 * Author:
6 * David Safford <safford@us.ibm.com>
7 *
8 * See Documentation/security/keys/trusted-encrypted.rst
9 */
10
11#include <crypto/hash_info.h>
12#include <linux/uaccess.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/slab.h>
16#include <linux/parser.h>
17#include <linux/string.h>
18#include <linux/err.h>
19#include <keys/user-type.h>
20#include <keys/trusted-type.h>
21#include <linux/key-type.h>
22#include <linux/rcupdate.h>
23#include <linux/crypto.h>
24#include <crypto/hash.h>
25#include <crypto/sha.h>
26#include <linux/capability.h>
27#include <linux/tpm.h>
28#include <linux/tpm_command.h>
29
30#include <keys/trusted.h>
31
32static const char hmac_alg[] = "hmac(sha1)";
33static const char hash_alg[] = "sha1";
34static struct tpm_chip *chip;
35static struct tpm_digest *digests;
36
37struct sdesc {
38 struct shash_desc shash;
39 char ctx[];
40};
41
42static struct crypto_shash *hashalg;
43static struct crypto_shash *hmacalg;
44
45static struct sdesc *init_sdesc(struct crypto_shash *alg)
46{
47 struct sdesc *sdesc;
48 int size;
49
50 size = sizeof(struct shash_desc) + crypto_shash_descsize(alg);
51 sdesc = kmalloc(size, GFP_KERNEL);
52 if (!sdesc)
53 return ERR_PTR(-ENOMEM);
54 sdesc->shash.tfm = alg;
55 return sdesc;
56}
57
58static int TSS_sha1(const unsigned char *data, unsigned int datalen,
59 unsigned char *digest)
60{
61 struct sdesc *sdesc;
62 int ret;
63
64 sdesc = init_sdesc(hashalg);
65 if (IS_ERR(sdesc)) {
66 pr_info("trusted_key: can't alloc %s\n", hash_alg);
67 return PTR_ERR(sdesc);
68 }
69
70 ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest);
71 kzfree(sdesc);
72 return ret;
73}
74
75static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
76 unsigned int keylen, ...)
77{
78 struct sdesc *sdesc;
79 va_list argp;
80 unsigned int dlen;
81 unsigned char *data;
82 int ret;
83
84 sdesc = init_sdesc(hmacalg);
85 if (IS_ERR(sdesc)) {
86 pr_info("trusted_key: can't alloc %s\n", hmac_alg);
87 return PTR_ERR(sdesc);
88 }
89
90 ret = crypto_shash_setkey(hmacalg, key, keylen);
91 if (ret < 0)
92 goto out;
93 ret = crypto_shash_init(&sdesc->shash);
94 if (ret < 0)
95 goto out;
96
97 va_start(argp, keylen);
98 for (;;) {
99 dlen = va_arg(argp, unsigned int);
100 if (dlen == 0)
101 break;
102 data = va_arg(argp, unsigned char *);
103 if (data == NULL) {
104 ret = -EINVAL;
105 break;
106 }
107 ret = crypto_shash_update(&sdesc->shash, data, dlen);
108 if (ret < 0)
109 break;
110 }
111 va_end(argp);
112 if (!ret)
113 ret = crypto_shash_final(&sdesc->shash, digest);
114out:
115 kzfree(sdesc);
116 return ret;
117}
118
119/*
120 * calculate authorization info fields to send to TPM
121 */
122int TSS_authhmac(unsigned char *digest, const unsigned char *key,
123 unsigned int keylen, unsigned char *h1,
124 unsigned char *h2, unsigned int h3, ...)
125{
126 unsigned char paramdigest[SHA1_DIGEST_SIZE];
127 struct sdesc *sdesc;
128 unsigned int dlen;
129 unsigned char *data;
130 unsigned char c;
131 int ret;
132 va_list argp;
133
134 if (!chip)
135 return -ENODEV;
136
137 sdesc = init_sdesc(hashalg);
138 if (IS_ERR(sdesc)) {
139 pr_info("trusted_key: can't alloc %s\n", hash_alg);
140 return PTR_ERR(sdesc);
141 }
142
143 c = !!h3;
144 ret = crypto_shash_init(&sdesc->shash);
145 if (ret < 0)
146 goto out;
147 va_start(argp, h3);
148 for (;;) {
149 dlen = va_arg(argp, unsigned int);
150 if (dlen == 0)
151 break;
152 data = va_arg(argp, unsigned char *);
153 if (!data) {
154 ret = -EINVAL;
155 break;
156 }
157 ret = crypto_shash_update(&sdesc->shash, data, dlen);
158 if (ret < 0)
159 break;
160 }
161 va_end(argp);
162 if (!ret)
163 ret = crypto_shash_final(&sdesc->shash, paramdigest);
164 if (!ret)
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);
168out:
169 kzfree(sdesc);
170 return ret;
171}
172EXPORT_SYMBOL_GPL(TSS_authhmac);
173
174/*
175 * verify the AUTH1_COMMAND (Seal) result from TPM
176 */
177int TSS_checkhmac1(unsigned char *buffer,
178 const uint32_t command,
179 const unsigned char *ononce,
180 const unsigned char *key,
181 unsigned int keylen, ...)
182{
183 uint32_t bufsize;
184 uint16_t tag;
185 uint32_t ordinal;
186 uint32_t result;
187 unsigned char *enonce;
188 unsigned char *continueflag;
189 unsigned char *authdata;
190 unsigned char testhmac[SHA1_DIGEST_SIZE];
191 unsigned char paramdigest[SHA1_DIGEST_SIZE];
192 struct sdesc *sdesc;
193 unsigned int dlen;
194 unsigned int dpos;
195 va_list argp;
196 int ret;
197
198 if (!chip)
199 return -ENODEV;
200
201 bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
202 tag = LOAD16(buffer, 0);
203 ordinal = command;
204 result = LOAD32N(buffer, TPM_RETURN_OFFSET);
205 if (tag == TPM_TAG_RSP_COMMAND)
206 return 0;
207 if (tag != TPM_TAG_RSP_AUTH1_COMMAND)
208 return -EINVAL;
209 authdata = buffer + bufsize - SHA1_DIGEST_SIZE;
210 continueflag = authdata - 1;
211 enonce = continueflag - TPM_NONCE_SIZE;
212
213 sdesc = init_sdesc(hashalg);
214 if (IS_ERR(sdesc)) {
215 pr_info("trusted_key: can't alloc %s\n", hash_alg);
216 return PTR_ERR(sdesc);
217 }
218 ret = crypto_shash_init(&sdesc->shash);
219 if (ret < 0)
220 goto out;
221 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
222 sizeof result);
223 if (ret < 0)
224 goto out;
225 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
226 sizeof ordinal);
227 if (ret < 0)
228 goto out;
229 va_start(argp, keylen);
230 for (;;) {
231 dlen = va_arg(argp, unsigned int);
232 if (dlen == 0)
233 break;
234 dpos = va_arg(argp, unsigned int);
235 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
236 if (ret < 0)
237 break;
238 }
239 va_end(argp);
240 if (!ret)
241 ret = crypto_shash_final(&sdesc->shash, paramdigest);
242 if (ret < 0)
243 goto out;
244
245 ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest,
246 TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce,
247 1, continueflag, 0, 0);
248 if (ret < 0)
249 goto out;
250
251 if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE))
252 ret = -EINVAL;
253out:
254 kzfree(sdesc);
255 return ret;
256}
257EXPORT_SYMBOL_GPL(TSS_checkhmac1);
258
259/*
260 * verify the AUTH2_COMMAND (unseal) result from TPM
261 */
262static int TSS_checkhmac2(unsigned char *buffer,
263 const uint32_t command,
264 const unsigned char *ononce,
265 const unsigned char *key1,
266 unsigned int keylen1,
267 const unsigned char *key2,
268 unsigned int keylen2, ...)
269{
270 uint32_t bufsize;
271 uint16_t tag;
272 uint32_t ordinal;
273 uint32_t result;
274 unsigned char *enonce1;
275 unsigned char *continueflag1;
276 unsigned char *authdata1;
277 unsigned char *enonce2;
278 unsigned char *continueflag2;
279 unsigned char *authdata2;
280 unsigned char testhmac1[SHA1_DIGEST_SIZE];
281 unsigned char testhmac2[SHA1_DIGEST_SIZE];
282 unsigned char paramdigest[SHA1_DIGEST_SIZE];
283 struct sdesc *sdesc;
284 unsigned int dlen;
285 unsigned int dpos;
286 va_list argp;
287 int ret;
288
289 bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
290 tag = LOAD16(buffer, 0);
291 ordinal = command;
292 result = LOAD32N(buffer, TPM_RETURN_OFFSET);
293
294 if (tag == TPM_TAG_RSP_COMMAND)
295 return 0;
296 if (tag != TPM_TAG_RSP_AUTH2_COMMAND)
297 return -EINVAL;
298 authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1
299 + SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE);
300 authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE);
301 continueflag1 = authdata1 - 1;
302 continueflag2 = authdata2 - 1;
303 enonce1 = continueflag1 - TPM_NONCE_SIZE;
304 enonce2 = continueflag2 - TPM_NONCE_SIZE;
305
306 sdesc = init_sdesc(hashalg);
307 if (IS_ERR(sdesc)) {
308 pr_info("trusted_key: can't alloc %s\n", hash_alg);
309 return PTR_ERR(sdesc);
310 }
311 ret = crypto_shash_init(&sdesc->shash);
312 if (ret < 0)
313 goto out;
314 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
315 sizeof result);
316 if (ret < 0)
317 goto out;
318 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
319 sizeof ordinal);
320 if (ret < 0)
321 goto out;
322
323 va_start(argp, keylen2);
324 for (;;) {
325 dlen = va_arg(argp, unsigned int);
326 if (dlen == 0)
327 break;
328 dpos = va_arg(argp, unsigned int);
329 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
330 if (ret < 0)
331 break;
332 }
333 va_end(argp);
334 if (!ret)
335 ret = crypto_shash_final(&sdesc->shash, paramdigest);
336 if (ret < 0)
337 goto out;
338
339 ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE,
340 paramdigest, TPM_NONCE_SIZE, enonce1,
341 TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0);
342 if (ret < 0)
343 goto out;
344 if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) {
345 ret = -EINVAL;
346 goto out;
347 }
348 ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE,
349 paramdigest, TPM_NONCE_SIZE, enonce2,
350 TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0);
351 if (ret < 0)
352 goto out;
353 if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE))
354 ret = -EINVAL;
355out:
356 kzfree(sdesc);
357 return ret;
358}
359
360/*
361 * For key specific tpm requests, we will generate and send our
362 * own TPM command packets using the drivers send function.
363 */
364int trusted_tpm_send(unsigned char *cmd, size_t buflen)
365{
366 int rc;
367
368 if (!chip)
369 return -ENODEV;
370
371 dump_tpm_buf(cmd);
372 rc = tpm_send(chip, cmd, buflen);
373 dump_tpm_buf(cmd);
374 if (rc > 0)
375 /* Can't return positive return codes values to keyctl */
376 rc = -EPERM;
377 return rc;
378}
379EXPORT_SYMBOL_GPL(trusted_tpm_send);
380
381/*
382 * Lock a trusted key, by extending a selected PCR.
383 *
384 * Prevents a trusted key that is sealed to PCRs from being accessed.
385 * This uses the tpm driver's extend function.
386 */
387static int pcrlock(const int pcrnum)
388{
389 if (!capable(CAP_SYS_ADMIN))
390 return -EPERM;
391
392 return tpm_pcr_extend(chip, pcrnum, digests) ? -EINVAL : 0;
393}
394
395/*
396 * Create an object specific authorisation protocol (OSAP) session
397 */
398static int osap(struct tpm_buf *tb, struct osapsess *s,
399 const unsigned char *key, uint16_t type, uint32_t handle)
400{
401 unsigned char enonce[TPM_NONCE_SIZE];
402 unsigned char ononce[TPM_NONCE_SIZE];
403 int ret;
404
405 ret = tpm_get_random(chip, ononce, TPM_NONCE_SIZE);
406 if (ret != TPM_NONCE_SIZE)
407 return ret;
408
409 INIT_BUF(tb);
410 store16(tb, TPM_TAG_RQU_COMMAND);
411 store32(tb, TPM_OSAP_SIZE);
412 store32(tb, TPM_ORD_OSAP);
413 store16(tb, type);
414 store32(tb, handle);
415 storebytes(tb, ononce, TPM_NONCE_SIZE);
416
417 ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
418 if (ret < 0)
419 return ret;
420
421 s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
422 memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
423 TPM_NONCE_SIZE);
424 memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
425 TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
426 return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
427 enonce, TPM_NONCE_SIZE, ononce, 0, 0);
428}
429
430/*
431 * Create an object independent authorisation protocol (oiap) session
432 */
433int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
434{
435 int ret;
436
437 if (!chip)
438 return -ENODEV;
439
440 INIT_BUF(tb);
441 store16(tb, TPM_TAG_RQU_COMMAND);
442 store32(tb, TPM_OIAP_SIZE);
443 store32(tb, TPM_ORD_OIAP);
444 ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
445 if (ret < 0)
446 return ret;
447
448 *handle = LOAD32(tb->data, TPM_DATA_OFFSET);
449 memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
450 TPM_NONCE_SIZE);
451 return 0;
452}
453EXPORT_SYMBOL_GPL(oiap);
454
455struct tpm_digests {
456 unsigned char encauth[SHA1_DIGEST_SIZE];
457 unsigned char pubauth[SHA1_DIGEST_SIZE];
458 unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
459 unsigned char xorhash[SHA1_DIGEST_SIZE];
460 unsigned char nonceodd[TPM_NONCE_SIZE];
461};
462
463/*
464 * Have the TPM seal(encrypt) the trusted key, possibly based on
465 * Platform Configuration Registers (PCRs). AUTH1 for sealing key.
466 */
467static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
468 uint32_t keyhandle, const unsigned char *keyauth,
469 const unsigned char *data, uint32_t datalen,
470 unsigned char *blob, uint32_t *bloblen,
471 const unsigned char *blobauth,
472 const unsigned char *pcrinfo, uint32_t pcrinfosize)
473{
474 struct osapsess sess;
475 struct tpm_digests *td;
476 unsigned char cont;
477 uint32_t ordinal;
478 uint32_t pcrsize;
479 uint32_t datsize;
480 int sealinfosize;
481 int encdatasize;
482 int storedsize;
483 int ret;
484 int i;
485
486 /* alloc some work space for all the hashes */
487 td = kmalloc(sizeof *td, GFP_KERNEL);
488 if (!td)
489 return -ENOMEM;
490
491 /* get session for sealing key */
492 ret = osap(tb, &sess, keyauth, keytype, keyhandle);
493 if (ret < 0)
494 goto out;
495 dump_sess(&sess);
496
497 /* calculate encrypted authorization value */
498 memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
499 memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
500 ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
501 if (ret < 0)
502 goto out;
503
504 ret = tpm_get_random(chip, td->nonceodd, TPM_NONCE_SIZE);
505 if (ret != TPM_NONCE_SIZE)
506 goto out;
507 ordinal = htonl(TPM_ORD_SEAL);
508 datsize = htonl(datalen);
509 pcrsize = htonl(pcrinfosize);
510 cont = 0;
511
512 /* encrypt data authorization key */
513 for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
514 td->encauth[i] = td->xorhash[i] ^ blobauth[i];
515
516 /* calculate authorization HMAC value */
517 if (pcrinfosize == 0) {
518 /* no 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 sizeof(uint32_t), &datsize, datalen, data, 0,
524 0);
525 } else {
526 /* pcr info specified */
527 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
528 sess.enonce, td->nonceodd, cont,
529 sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
530 td->encauth, sizeof(uint32_t), &pcrsize,
531 pcrinfosize, pcrinfo, sizeof(uint32_t),
532 &datsize, datalen, data, 0, 0);
533 }
534 if (ret < 0)
535 goto out;
536
537 /* build and send the TPM request packet */
538 INIT_BUF(tb);
539 store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
540 store32(tb, TPM_SEAL_SIZE + pcrinfosize + datalen);
541 store32(tb, TPM_ORD_SEAL);
542 store32(tb, keyhandle);
543 storebytes(tb, td->encauth, SHA1_DIGEST_SIZE);
544 store32(tb, pcrinfosize);
545 storebytes(tb, pcrinfo, pcrinfosize);
546 store32(tb, datalen);
547 storebytes(tb, data, datalen);
548 store32(tb, sess.handle);
549 storebytes(tb, td->nonceodd, TPM_NONCE_SIZE);
550 store8(tb, cont);
551 storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE);
552
553 ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
554 if (ret < 0)
555 goto out;
556
557 /* calculate the size of the returned Blob */
558 sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
559 encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
560 sizeof(uint32_t) + sealinfosize);
561 storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
562 sizeof(uint32_t) + encdatasize;
563
564 /* check the HMAC in the response */
565 ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
566 SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
567 0);
568
569 /* copy the returned blob to caller */
570 if (!ret) {
571 memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
572 *bloblen = storedsize;
573 }
574out:
575 kzfree(td);
576 return ret;
577}
578
579/*
580 * use the AUTH2_COMMAND form of unseal, to authorize both key and blob
581 */
582static int tpm_unseal(struct tpm_buf *tb,
583 uint32_t keyhandle, const unsigned char *keyauth,
584 const unsigned char *blob, int bloblen,
585 const unsigned char *blobauth,
586 unsigned char *data, unsigned int *datalen)
587{
588 unsigned char nonceodd[TPM_NONCE_SIZE];
589 unsigned char enonce1[TPM_NONCE_SIZE];
590 unsigned char enonce2[TPM_NONCE_SIZE];
591 unsigned char authdata1[SHA1_DIGEST_SIZE];
592 unsigned char authdata2[SHA1_DIGEST_SIZE];
593 uint32_t authhandle1 = 0;
594 uint32_t authhandle2 = 0;
595 unsigned char cont = 0;
596 uint32_t ordinal;
597 uint32_t keyhndl;
598 int ret;
599
600 /* sessions for unsealing key and data */
601 ret = oiap(tb, &authhandle1, enonce1);
602 if (ret < 0) {
603 pr_info("trusted_key: oiap failed (%d)\n", ret);
604 return ret;
605 }
606 ret = oiap(tb, &authhandle2, enonce2);
607 if (ret < 0) {
608 pr_info("trusted_key: oiap failed (%d)\n", ret);
609 return ret;
610 }
611
612 ordinal = htonl(TPM_ORD_UNSEAL);
613 keyhndl = htonl(SRKHANDLE);
614 ret = tpm_get_random(chip, nonceodd, TPM_NONCE_SIZE);
615 if (ret != TPM_NONCE_SIZE) {
616 pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
617 return ret;
618 }
619 ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
620 enonce1, nonceodd, cont, sizeof(uint32_t),
621 &ordinal, bloblen, blob, 0, 0);
622 if (ret < 0)
623 return ret;
624 ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
625 enonce2, nonceodd, cont, sizeof(uint32_t),
626 &ordinal, bloblen, blob, 0, 0);
627 if (ret < 0)
628 return ret;
629
630 /* build and send TPM request packet */
631 INIT_BUF(tb);
632 store16(tb, TPM_TAG_RQU_AUTH2_COMMAND);
633 store32(tb, TPM_UNSEAL_SIZE + bloblen);
634 store32(tb, TPM_ORD_UNSEAL);
635 store32(tb, keyhandle);
636 storebytes(tb, blob, bloblen);
637 store32(tb, authhandle1);
638 storebytes(tb, nonceodd, TPM_NONCE_SIZE);
639 store8(tb, cont);
640 storebytes(tb, authdata1, SHA1_DIGEST_SIZE);
641 store32(tb, authhandle2);
642 storebytes(tb, nonceodd, TPM_NONCE_SIZE);
643 store8(tb, cont);
644 storebytes(tb, authdata2, SHA1_DIGEST_SIZE);
645
646 ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
647 if (ret < 0) {
648 pr_info("trusted_key: authhmac failed (%d)\n", ret);
649 return ret;
650 }
651
652 *datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
653 ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
654 keyauth, SHA1_DIGEST_SIZE,
655 blobauth, SHA1_DIGEST_SIZE,
656 sizeof(uint32_t), TPM_DATA_OFFSET,
657 *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
658 0);
659 if (ret < 0) {
660 pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret);
661 return ret;
662 }
663 memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
664 return 0;
665}
666
667/*
668 * Have the TPM seal(encrypt) the symmetric key
669 */
670static int key_seal(struct trusted_key_payload *p,
671 struct trusted_key_options *o)
672{
673 struct tpm_buf *tb;
674 int ret;
675
676 tb = kzalloc(sizeof *tb, GFP_KERNEL);
677 if (!tb)
678 return -ENOMEM;
679
680 /* include migratable flag at end of sealed key */
681 p->key[p->key_len] = p->migratable;
682
683 ret = tpm_seal(tb, o->keytype, o->keyhandle, o->keyauth,
684 p->key, p->key_len + 1, p->blob, &p->blob_len,
685 o->blobauth, o->pcrinfo, o->pcrinfo_len);
686 if (ret < 0)
687 pr_info("trusted_key: srkseal failed (%d)\n", ret);
688
689 kzfree(tb);
690 return ret;
691}
692
693/*
694 * Have the TPM unseal(decrypt) the symmetric key
695 */
696static int key_unseal(struct trusted_key_payload *p,
697 struct trusted_key_options *o)
698{
699 struct tpm_buf *tb;
700 int ret;
701
702 tb = kzalloc(sizeof *tb, GFP_KERNEL);
703 if (!tb)
704 return -ENOMEM;
705
706 ret = tpm_unseal(tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
707 o->blobauth, p->key, &p->key_len);
708 if (ret < 0)
709 pr_info("trusted_key: srkunseal failed (%d)\n", ret);
710 else
711 /* pull migratable flag out of sealed key */
712 p->migratable = p->key[--p->key_len];
713
714 kzfree(tb);
715 return ret;
716}
717
718enum {
719 Opt_err,
720 Opt_new, Opt_load, Opt_update,
721 Opt_keyhandle, Opt_keyauth, Opt_blobauth,
722 Opt_pcrinfo, Opt_pcrlock, Opt_migratable,
723 Opt_hash,
724 Opt_policydigest,
725 Opt_policyhandle,
726};
727
728static const match_table_t key_tokens = {
729 {Opt_new, "new"},
730 {Opt_load, "load"},
731 {Opt_update, "update"},
732 {Opt_keyhandle, "keyhandle=%s"},
733 {Opt_keyauth, "keyauth=%s"},
734 {Opt_blobauth, "blobauth=%s"},
735 {Opt_pcrinfo, "pcrinfo=%s"},
736 {Opt_pcrlock, "pcrlock=%s"},
737 {Opt_migratable, "migratable=%s"},
738 {Opt_hash, "hash=%s"},
739 {Opt_policydigest, "policydigest=%s"},
740 {Opt_policyhandle, "policyhandle=%s"},
741 {Opt_err, NULL}
742};
743
744/* can have zero or more token= options */
745static int getoptions(char *c, struct trusted_key_payload *pay,
746 struct trusted_key_options *opt)
747{
748 substring_t args[MAX_OPT_ARGS];
749 char *p = c;
750 int token;
751 int res;
752 unsigned long handle;
753 unsigned long lock;
754 unsigned long token_mask = 0;
755 unsigned int digest_len;
756 int i;
757 int tpm2;
758
759 tpm2 = tpm_is_tpm2(chip);
760 if (tpm2 < 0)
761 return tpm2;
762
763 opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1;
764
765 while ((p = strsep(&c, " \t"))) {
766 if (*p == '\0' || *p == ' ' || *p == '\t')
767 continue;
768 token = match_token(p, key_tokens, args);
769 if (test_and_set_bit(token, &token_mask))
770 return -EINVAL;
771
772 switch (token) {
773 case Opt_pcrinfo:
774 opt->pcrinfo_len = strlen(args[0].from) / 2;
775 if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
776 return -EINVAL;
777 res = hex2bin(opt->pcrinfo, args[0].from,
778 opt->pcrinfo_len);
779 if (res < 0)
780 return -EINVAL;
781 break;
782 case Opt_keyhandle:
783 res = kstrtoul(args[0].from, 16, &handle);
784 if (res < 0)
785 return -EINVAL;
786 opt->keytype = SEAL_keytype;
787 opt->keyhandle = handle;
788 break;
789 case Opt_keyauth:
790 if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
791 return -EINVAL;
792 res = hex2bin(opt->keyauth, args[0].from,
793 SHA1_DIGEST_SIZE);
794 if (res < 0)
795 return -EINVAL;
796 break;
797 case Opt_blobauth:
798 if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
799 return -EINVAL;
800 res = hex2bin(opt->blobauth, args[0].from,
801 SHA1_DIGEST_SIZE);
802 if (res < 0)
803 return -EINVAL;
804 break;
805 case Opt_migratable:
806 if (*args[0].from == '0')
807 pay->migratable = 0;
808 else
809 return -EINVAL;
810 break;
811 case Opt_pcrlock:
812 res = kstrtoul(args[0].from, 10, &lock);
813 if (res < 0)
814 return -EINVAL;
815 opt->pcrlock = lock;
816 break;
817 case Opt_hash:
818 if (test_bit(Opt_policydigest, &token_mask))
819 return -EINVAL;
820 for (i = 0; i < HASH_ALGO__LAST; i++) {
821 if (!strcmp(args[0].from, hash_algo_name[i])) {
822 opt->hash = i;
823 break;
824 }
825 }
826 if (i == HASH_ALGO__LAST)
827 return -EINVAL;
828 if (!tpm2 && i != HASH_ALGO_SHA1) {
829 pr_info("trusted_key: TPM 1.x only supports SHA-1.\n");
830 return -EINVAL;
831 }
832 break;
833 case Opt_policydigest:
834 digest_len = hash_digest_size[opt->hash];
835 if (!tpm2 || strlen(args[0].from) != (2 * digest_len))
836 return -EINVAL;
837 res = hex2bin(opt->policydigest, args[0].from,
838 digest_len);
839 if (res < 0)
840 return -EINVAL;
841 opt->policydigest_len = digest_len;
842 break;
843 case Opt_policyhandle:
844 if (!tpm2)
845 return -EINVAL;
846 res = kstrtoul(args[0].from, 16, &handle);
847 if (res < 0)
848 return -EINVAL;
849 opt->policyhandle = handle;
850 break;
851 default:
852 return -EINVAL;
853 }
854 }
855 return 0;
856}
857
858/*
859 * datablob_parse - parse the keyctl data and fill in the
860 * payload and options structures
861 *
862 * On success returns 0, otherwise -EINVAL.
863 */
864static int datablob_parse(char *datablob, struct trusted_key_payload *p,
865 struct trusted_key_options *o)
866{
867 substring_t args[MAX_OPT_ARGS];
868 long keylen;
869 int ret = -EINVAL;
870 int key_cmd;
871 char *c;
872
873 /* main command */
874 c = strsep(&datablob, " \t");
875 if (!c)
876 return -EINVAL;
877 key_cmd = match_token(c, key_tokens, args);
878 switch (key_cmd) {
879 case Opt_new:
880 /* first argument is key size */
881 c = strsep(&datablob, " \t");
882 if (!c)
883 return -EINVAL;
884 ret = kstrtol(c, 10, &keylen);
885 if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
886 return -EINVAL;
887 p->key_len = keylen;
888 ret = getoptions(datablob, p, o);
889 if (ret < 0)
890 return ret;
891 ret = Opt_new;
892 break;
893 case Opt_load:
894 /* first argument is sealed blob */
895 c = strsep(&datablob, " \t");
896 if (!c)
897 return -EINVAL;
898 p->blob_len = strlen(c) / 2;
899 if (p->blob_len > MAX_BLOB_SIZE)
900 return -EINVAL;
901 ret = hex2bin(p->blob, c, p->blob_len);
902 if (ret < 0)
903 return -EINVAL;
904 ret = getoptions(datablob, p, o);
905 if (ret < 0)
906 return ret;
907 ret = Opt_load;
908 break;
909 case Opt_update:
910 /* all arguments are options */
911 ret = getoptions(datablob, p, o);
912 if (ret < 0)
913 return ret;
914 ret = Opt_update;
915 break;
916 case Opt_err:
917 return -EINVAL;
918 break;
919 }
920 return ret;
921}
922
923static struct trusted_key_options *trusted_options_alloc(void)
924{
925 struct trusted_key_options *options;
926 int tpm2;
927
928 tpm2 = tpm_is_tpm2(chip);
929 if (tpm2 < 0)
930 return NULL;
931
932 options = kzalloc(sizeof *options, GFP_KERNEL);
933 if (options) {
934 /* set any non-zero defaults */
935 options->keytype = SRK_keytype;
936
937 if (!tpm2)
938 options->keyhandle = SRKHANDLE;
939 }
940 return options;
941}
942
943static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
944{
945 struct trusted_key_payload *p = NULL;
946 int ret;
947
948 ret = key_payload_reserve(key, sizeof *p);
949 if (ret < 0)
950 return p;
951 p = kzalloc(sizeof *p, GFP_KERNEL);
952 if (p)
953 p->migratable = 1; /* migratable by default */
954 return p;
955}
956
957/*
958 * trusted_instantiate - create a new trusted key
959 *
960 * Unseal an existing trusted blob or, for a new key, get a
961 * random key, then seal and create a trusted key-type key,
962 * adding it to the specified keyring.
963 *
964 * On success, return 0. Otherwise return errno.
965 */
966static int trusted_instantiate(struct key *key,
967 struct key_preparsed_payload *prep)
968{
969 struct trusted_key_payload *payload = NULL;
970 struct trusted_key_options *options = NULL;
971 size_t datalen = prep->datalen;
972 char *datablob;
973 int ret = 0;
974 int key_cmd;
975 size_t key_len;
976 int tpm2;
977
978 tpm2 = tpm_is_tpm2(chip);
979 if (tpm2 < 0)
980 return tpm2;
981
982 if (datalen <= 0 || datalen > 32767 || !prep->data)
983 return -EINVAL;
984
985 datablob = kmalloc(datalen + 1, GFP_KERNEL);
986 if (!datablob)
987 return -ENOMEM;
988 memcpy(datablob, prep->data, datalen);
989 datablob[datalen] = '\0';
990
991 options = trusted_options_alloc();
992 if (!options) {
993 ret = -ENOMEM;
994 goto out;
995 }
996 payload = trusted_payload_alloc(key);
997 if (!payload) {
998 ret = -ENOMEM;
999 goto out;
1000 }
1001
1002 key_cmd = datablob_parse(datablob, payload, options);
1003 if (key_cmd < 0) {
1004 ret = key_cmd;
1005 goto out;
1006 }
1007
1008 if (!options->keyhandle) {
1009 ret = -EINVAL;
1010 goto out;
1011 }
1012
1013 dump_payload(payload);
1014 dump_options(options);
1015
1016 switch (key_cmd) {
1017 case Opt_load:
1018 if (tpm2)
1019 ret = tpm_unseal_trusted(chip, payload, options);
1020 else
1021 ret = key_unseal(payload, options);
1022 dump_payload(payload);
1023 dump_options(options);
1024 if (ret < 0)
1025 pr_info("trusted_key: key_unseal failed (%d)\n", ret);
1026 break;
1027 case Opt_new:
1028 key_len = payload->key_len;
1029 ret = tpm_get_random(chip, payload->key, key_len);
1030 if (ret != key_len) {
1031 pr_info("trusted_key: key_create failed (%d)\n", ret);
1032 goto out;
1033 }
1034 if (tpm2)
1035 ret = tpm_seal_trusted(chip, payload, options);
1036 else
1037 ret = key_seal(payload, options);
1038 if (ret < 0)
1039 pr_info("trusted_key: key_seal failed (%d)\n", ret);
1040 break;
1041 default:
1042 ret = -EINVAL;
1043 goto out;
1044 }
1045 if (!ret && options->pcrlock)
1046 ret = pcrlock(options->pcrlock);
1047out:
1048 kzfree(datablob);
1049 kzfree(options);
1050 if (!ret)
1051 rcu_assign_keypointer(key, payload);
1052 else
1053 kzfree(payload);
1054 return ret;
1055}
1056
1057static void trusted_rcu_free(struct rcu_head *rcu)
1058{
1059 struct trusted_key_payload *p;
1060
1061 p = container_of(rcu, struct trusted_key_payload, rcu);
1062 kzfree(p);
1063}
1064
1065/*
1066 * trusted_update - reseal an existing key with new PCR values
1067 */
1068static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
1069{
1070 struct trusted_key_payload *p;
1071 struct trusted_key_payload *new_p;
1072 struct trusted_key_options *new_o;
1073 size_t datalen = prep->datalen;
1074 char *datablob;
1075 int ret = 0;
1076
1077 if (key_is_negative(key))
1078 return -ENOKEY;
1079 p = key->payload.data[0];
1080 if (!p->migratable)
1081 return -EPERM;
1082 if (datalen <= 0 || datalen > 32767 || !prep->data)
1083 return -EINVAL;
1084
1085 datablob = kmalloc(datalen + 1, GFP_KERNEL);
1086 if (!datablob)
1087 return -ENOMEM;
1088 new_o = trusted_options_alloc();
1089 if (!new_o) {
1090 ret = -ENOMEM;
1091 goto out;
1092 }
1093 new_p = trusted_payload_alloc(key);
1094 if (!new_p) {
1095 ret = -ENOMEM;
1096 goto out;
1097 }
1098
1099 memcpy(datablob, prep->data, datalen);
1100 datablob[datalen] = '\0';
1101 ret = datablob_parse(datablob, new_p, new_o);
1102 if (ret != Opt_update) {
1103 ret = -EINVAL;
1104 kzfree(new_p);
1105 goto out;
1106 }
1107
1108 if (!new_o->keyhandle) {
1109 ret = -EINVAL;
1110 kzfree(new_p);
1111 goto out;
1112 }
1113
1114 /* copy old key values, and reseal with new pcrs */
1115 new_p->migratable = p->migratable;
1116 new_p->key_len = p->key_len;
1117 memcpy(new_p->key, p->key, p->key_len);
1118 dump_payload(p);
1119 dump_payload(new_p);
1120
1121 ret = key_seal(new_p, new_o);
1122 if (ret < 0) {
1123 pr_info("trusted_key: key_seal failed (%d)\n", ret);
1124 kzfree(new_p);
1125 goto out;
1126 }
1127 if (new_o->pcrlock) {
1128 ret = pcrlock(new_o->pcrlock);
1129 if (ret < 0) {
1130 pr_info("trusted_key: pcrlock failed (%d)\n", ret);
1131 kzfree(new_p);
1132 goto out;
1133 }
1134 }
1135 rcu_assign_keypointer(key, new_p);
1136 call_rcu(&p->rcu, trusted_rcu_free);
1137out:
1138 kzfree(datablob);
1139 kzfree(new_o);
1140 return ret;
1141}
1142
1143/*
1144 * trusted_read - copy the sealed blob data to userspace in hex.
1145 * On success, return to userspace the trusted key datablob size.
1146 */
1147static long trusted_read(const struct key *key, char __user *buffer,
1148 size_t buflen)
1149{
1150 const struct trusted_key_payload *p;
1151 char *ascii_buf;
1152 char *bufp;
1153 int i;
1154
1155 p = dereference_key_locked(key);
1156 if (!p)
1157 return -EINVAL;
1158
1159 if (buffer && buflen >= 2 * p->blob_len) {
1160 ascii_buf = kmalloc_array(2, p->blob_len, GFP_KERNEL);
1161 if (!ascii_buf)
1162 return -ENOMEM;
1163
1164 bufp = ascii_buf;
1165 for (i = 0; i < p->blob_len; i++)
1166 bufp = hex_byte_pack(bufp, p->blob[i]);
1167 if (copy_to_user(buffer, ascii_buf, 2 * p->blob_len) != 0) {
1168 kzfree(ascii_buf);
1169 return -EFAULT;
1170 }
1171 kzfree(ascii_buf);
1172 }
1173 return 2 * p->blob_len;
1174}
1175
1176/*
1177 * trusted_destroy - clear and free the key's payload
1178 */
1179static void trusted_destroy(struct key *key)
1180{
1181 kzfree(key->payload.data[0]);
1182}
1183
1184struct key_type key_type_trusted = {
1185 .name = "trusted",
1186 .instantiate = trusted_instantiate,
1187 .update = trusted_update,
1188 .destroy = trusted_destroy,
1189 .describe = user_describe,
1190 .read = trusted_read,
1191};
1192
1193EXPORT_SYMBOL_GPL(key_type_trusted);
1194
1195static void trusted_shash_release(void)
1196{
1197 if (hashalg)
1198 crypto_free_shash(hashalg);
1199 if (hmacalg)
1200 crypto_free_shash(hmacalg);
1201}
1202
1203static int __init trusted_shash_alloc(void)
1204{
1205 int ret;
1206
1207 hmacalg = crypto_alloc_shash(hmac_alg, 0, 0);
1208 if (IS_ERR(hmacalg)) {
1209 pr_info("trusted_key: could not allocate crypto %s\n",
1210 hmac_alg);
1211 return PTR_ERR(hmacalg);
1212 }
1213
1214 hashalg = crypto_alloc_shash(hash_alg, 0, 0);
1215 if (IS_ERR(hashalg)) {
1216 pr_info("trusted_key: could not allocate crypto %s\n",
1217 hash_alg);
1218 ret = PTR_ERR(hashalg);
1219 goto hashalg_fail;
1220 }
1221
1222 return 0;
1223
1224hashalg_fail:
1225 crypto_free_shash(hmacalg);
1226 return ret;
1227}
1228
1229static int __init init_digests(void)
1230{
1231 int i;
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 digests[i].alg_id = chip->allocated_banks[i].alg_id;
1240
1241 return 0;
1242}
1243
1244static int __init init_trusted(void)
1245{
1246 int ret;
1247
1248 /* encrypted_keys.ko depends on successful load of this module even if
1249 * TPM is not used.
1250 */
1251 chip = tpm_default_chip();
1252 if (!chip)
1253 return 0;
1254
1255 ret = init_digests();
1256 if (ret < 0)
1257 goto err_put;
1258 ret = trusted_shash_alloc();
1259 if (ret < 0)
1260 goto err_free;
1261 ret = register_key_type(&key_type_trusted);
1262 if (ret < 0)
1263 goto err_release;
1264 return 0;
1265err_release:
1266 trusted_shash_release();
1267err_free:
1268 kfree(digests);
1269err_put:
1270 put_device(&chip->dev);
1271 return ret;
1272}
1273
1274static void __exit cleanup_trusted(void)
1275{
1276 if (chip) {
1277 put_device(&chip->dev);
1278 kfree(digests);
1279 trusted_shash_release();
1280 unregister_key_type(&key_type_trusted);
1281 }
1282}
1283
1284late_initcall(init_trusted);
1285module_exit(cleanup_trusted);
1286
1287MODULE_LICENSE("GPL");
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.txt
12 */
13
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>
31
32#include "trusted.h"
33
34static const char hmac_alg[] = "hmac(sha1)";
35static const char hash_alg[] = "sha1";
36
37struct sdesc {
38 struct shash_desc shash;
39 char ctx[];
40};
41
42static struct crypto_shash *hashalg;
43static struct crypto_shash *hmacalg;
44
45static struct sdesc *init_sdesc(struct crypto_shash *alg)
46{
47 struct sdesc *sdesc;
48 int size;
49
50 size = sizeof(struct shash_desc) + crypto_shash_descsize(alg);
51 sdesc = kmalloc(size, GFP_KERNEL);
52 if (!sdesc)
53 return ERR_PTR(-ENOMEM);
54 sdesc->shash.tfm = alg;
55 sdesc->shash.flags = 0x0;
56 return sdesc;
57}
58
59static int TSS_sha1(const unsigned char *data, unsigned int datalen,
60 unsigned char *digest)
61{
62 struct sdesc *sdesc;
63 int ret;
64
65 sdesc = init_sdesc(hashalg);
66 if (IS_ERR(sdesc)) {
67 pr_info("trusted_key: can't alloc %s\n", hash_alg);
68 return PTR_ERR(sdesc);
69 }
70
71 ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest);
72 kfree(sdesc);
73 return ret;
74}
75
76static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
77 unsigned int keylen, ...)
78{
79 struct sdesc *sdesc;
80 va_list argp;
81 unsigned int dlen;
82 unsigned char *data;
83 int ret;
84
85 sdesc = init_sdesc(hmacalg);
86 if (IS_ERR(sdesc)) {
87 pr_info("trusted_key: can't alloc %s\n", hmac_alg);
88 return PTR_ERR(sdesc);
89 }
90
91 ret = crypto_shash_setkey(hmacalg, key, keylen);
92 if (ret < 0)
93 goto out;
94 ret = crypto_shash_init(&sdesc->shash);
95 if (ret < 0)
96 goto out;
97
98 va_start(argp, keylen);
99 for (;;) {
100 dlen = va_arg(argp, unsigned int);
101 if (dlen == 0)
102 break;
103 data = va_arg(argp, unsigned char *);
104 if (data == NULL) {
105 ret = -EINVAL;
106 break;
107 }
108 ret = crypto_shash_update(&sdesc->shash, data, dlen);
109 if (ret < 0)
110 break;
111 }
112 va_end(argp);
113 if (!ret)
114 ret = crypto_shash_final(&sdesc->shash, digest);
115out:
116 kfree(sdesc);
117 return ret;
118}
119
120/*
121 * calculate authorization info fields to send to TPM
122 */
123static int TSS_authhmac(unsigned char *digest, const unsigned char *key,
124 unsigned int keylen, unsigned char *h1,
125 unsigned char *h2, unsigned char h3, ...)
126{
127 unsigned char paramdigest[SHA1_DIGEST_SIZE];
128 struct sdesc *sdesc;
129 unsigned int dlen;
130 unsigned char *data;
131 unsigned char c;
132 int ret;
133 va_list argp;
134
135 sdesc = init_sdesc(hashalg);
136 if (IS_ERR(sdesc)) {
137 pr_info("trusted_key: can't alloc %s\n", hash_alg);
138 return PTR_ERR(sdesc);
139 }
140
141 c = h3;
142 ret = crypto_shash_init(&sdesc->shash);
143 if (ret < 0)
144 goto out;
145 va_start(argp, h3);
146 for (;;) {
147 dlen = va_arg(argp, unsigned int);
148 if (dlen == 0)
149 break;
150 data = va_arg(argp, unsigned char *);
151 if (!data) {
152 ret = -EINVAL;
153 break;
154 }
155 ret = crypto_shash_update(&sdesc->shash, data, dlen);
156 if (ret < 0)
157 break;
158 }
159 va_end(argp);
160 if (!ret)
161 ret = crypto_shash_final(&sdesc->shash, paramdigest);
162 if (!ret)
163 ret = TSS_rawhmac(digest, key, keylen, SHA1_DIGEST_SIZE,
164 paramdigest, TPM_NONCE_SIZE, h1,
165 TPM_NONCE_SIZE, h2, 1, &c, 0, 0);
166out:
167 kfree(sdesc);
168 return ret;
169}
170
171/*
172 * verify the AUTH1_COMMAND (Seal) result from TPM
173 */
174static int TSS_checkhmac1(unsigned char *buffer,
175 const uint32_t command,
176 const unsigned char *ononce,
177 const unsigned char *key,
178 unsigned int keylen, ...)
179{
180 uint32_t bufsize;
181 uint16_t tag;
182 uint32_t ordinal;
183 uint32_t result;
184 unsigned char *enonce;
185 unsigned char *continueflag;
186 unsigned char *authdata;
187 unsigned char testhmac[SHA1_DIGEST_SIZE];
188 unsigned char paramdigest[SHA1_DIGEST_SIZE];
189 struct sdesc *sdesc;
190 unsigned int dlen;
191 unsigned int dpos;
192 va_list argp;
193 int ret;
194
195 bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
196 tag = LOAD16(buffer, 0);
197 ordinal = command;
198 result = LOAD32N(buffer, TPM_RETURN_OFFSET);
199 if (tag == TPM_TAG_RSP_COMMAND)
200 return 0;
201 if (tag != TPM_TAG_RSP_AUTH1_COMMAND)
202 return -EINVAL;
203 authdata = buffer + bufsize - SHA1_DIGEST_SIZE;
204 continueflag = authdata - 1;
205 enonce = continueflag - TPM_NONCE_SIZE;
206
207 sdesc = init_sdesc(hashalg);
208 if (IS_ERR(sdesc)) {
209 pr_info("trusted_key: can't alloc %s\n", hash_alg);
210 return PTR_ERR(sdesc);
211 }
212 ret = crypto_shash_init(&sdesc->shash);
213 if (ret < 0)
214 goto out;
215 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
216 sizeof result);
217 if (ret < 0)
218 goto out;
219 ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
220 sizeof ordinal);
221 if (ret < 0)
222 goto out;
223 va_start(argp, keylen);
224 for (;;) {
225 dlen = va_arg(argp, unsigned int);
226 if (dlen == 0)
227 break;
228 dpos = va_arg(argp, unsigned int);
229 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
230 if (ret < 0)
231 break;
232 }
233 va_end(argp);
234 if (!ret)
235 ret = crypto_shash_final(&sdesc->shash, paramdigest);
236 if (ret < 0)
237 goto out;
238
239 ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest,
240 TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce,
241 1, continueflag, 0, 0);
242 if (ret < 0)
243 goto out;
244
245 if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE))
246 ret = -EINVAL;
247out:
248 kfree(sdesc);
249 return ret;
250}
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("trusted_key: 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(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 */
357static int trusted_tpm_send(const u32 chip_num, unsigned char *cmd,
358 size_t buflen)
359{
360 int rc;
361
362 dump_tpm_buf(cmd);
363 rc = tpm_send(chip_num, cmd, buflen);
364 dump_tpm_buf(cmd);
365 if (rc > 0)
366 /* Can't return positive return codes values to keyctl */
367 rc = -EPERM;
368 return rc;
369}
370
371/*
372 * get a random value from TPM
373 */
374static int tpm_get_random(struct tpm_buf *tb, unsigned char *buf, uint32_t len)
375{
376 int ret;
377
378 INIT_BUF(tb);
379 store16(tb, TPM_TAG_RQU_COMMAND);
380 store32(tb, TPM_GETRANDOM_SIZE);
381 store32(tb, TPM_ORD_GETRANDOM);
382 store32(tb, len);
383 ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, sizeof tb->data);
384 if (!ret)
385 memcpy(buf, tb->data + TPM_GETRANDOM_SIZE, len);
386 return ret;
387}
388
389static int my_get_random(unsigned char *buf, int len)
390{
391 struct tpm_buf *tb;
392 int ret;
393
394 tb = kmalloc(sizeof *tb, GFP_KERNEL);
395 if (!tb)
396 return -ENOMEM;
397 ret = tpm_get_random(tb, buf, len);
398
399 kfree(tb);
400 return ret;
401}
402
403/*
404 * Lock a trusted key, by extending a selected PCR.
405 *
406 * Prevents a trusted key that is sealed to PCRs from being accessed.
407 * This uses the tpm driver's extend function.
408 */
409static int pcrlock(const int pcrnum)
410{
411 unsigned char hash[SHA1_DIGEST_SIZE];
412 int ret;
413
414 if (!capable(CAP_SYS_ADMIN))
415 return -EPERM;
416 ret = my_get_random(hash, SHA1_DIGEST_SIZE);
417 if (ret < 0)
418 return ret;
419 return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0;
420}
421
422/*
423 * Create an object specific authorisation protocol (OSAP) session
424 */
425static int osap(struct tpm_buf *tb, struct osapsess *s,
426 const unsigned char *key, uint16_t type, uint32_t handle)
427{
428 unsigned char enonce[TPM_NONCE_SIZE];
429 unsigned char ononce[TPM_NONCE_SIZE];
430 int ret;
431
432 ret = tpm_get_random(tb, ononce, TPM_NONCE_SIZE);
433 if (ret < 0)
434 return ret;
435
436 INIT_BUF(tb);
437 store16(tb, TPM_TAG_RQU_COMMAND);
438 store32(tb, TPM_OSAP_SIZE);
439 store32(tb, TPM_ORD_OSAP);
440 store16(tb, type);
441 store32(tb, handle);
442 storebytes(tb, ononce, TPM_NONCE_SIZE);
443
444 ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
445 if (ret < 0)
446 return ret;
447
448 s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
449 memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
450 TPM_NONCE_SIZE);
451 memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
452 TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
453 return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
454 enonce, TPM_NONCE_SIZE, ononce, 0, 0);
455}
456
457/*
458 * Create an object independent authorisation protocol (oiap) session
459 */
460static int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
461{
462 int ret;
463
464 INIT_BUF(tb);
465 store16(tb, TPM_TAG_RQU_COMMAND);
466 store32(tb, TPM_OIAP_SIZE);
467 store32(tb, TPM_ORD_OIAP);
468 ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
469 if (ret < 0)
470 return ret;
471
472 *handle = LOAD32(tb->data, TPM_DATA_OFFSET);
473 memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
474 TPM_NONCE_SIZE);
475 return 0;
476}
477
478struct tpm_digests {
479 unsigned char encauth[SHA1_DIGEST_SIZE];
480 unsigned char pubauth[SHA1_DIGEST_SIZE];
481 unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
482 unsigned char xorhash[SHA1_DIGEST_SIZE];
483 unsigned char nonceodd[TPM_NONCE_SIZE];
484};
485
486/*
487 * Have the TPM seal(encrypt) the trusted key, possibly based on
488 * Platform Configuration Registers (PCRs). AUTH1 for sealing key.
489 */
490static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
491 uint32_t keyhandle, const unsigned char *keyauth,
492 const unsigned char *data, uint32_t datalen,
493 unsigned char *blob, uint32_t *bloblen,
494 const unsigned char *blobauth,
495 const unsigned char *pcrinfo, uint32_t pcrinfosize)
496{
497 struct osapsess sess;
498 struct tpm_digests *td;
499 unsigned char cont;
500 uint32_t ordinal;
501 uint32_t pcrsize;
502 uint32_t datsize;
503 int sealinfosize;
504 int encdatasize;
505 int storedsize;
506 int ret;
507 int i;
508
509 /* alloc some work space for all the hashes */
510 td = kmalloc(sizeof *td, GFP_KERNEL);
511 if (!td)
512 return -ENOMEM;
513
514 /* get session for sealing key */
515 ret = osap(tb, &sess, keyauth, keytype, keyhandle);
516 if (ret < 0)
517 goto out;
518 dump_sess(&sess);
519
520 /* calculate encrypted authorization value */
521 memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
522 memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
523 ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
524 if (ret < 0)
525 goto out;
526
527 ret = tpm_get_random(tb, td->nonceodd, TPM_NONCE_SIZE);
528 if (ret < 0)
529 goto out;
530 ordinal = htonl(TPM_ORD_SEAL);
531 datsize = htonl(datalen);
532 pcrsize = htonl(pcrinfosize);
533 cont = 0;
534
535 /* encrypt data authorization key */
536 for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
537 td->encauth[i] = td->xorhash[i] ^ blobauth[i];
538
539 /* calculate authorization HMAC value */
540 if (pcrinfosize == 0) {
541 /* no pcr info specified */
542 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
543 sess.enonce, td->nonceodd, cont,
544 sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
545 td->encauth, sizeof(uint32_t), &pcrsize,
546 sizeof(uint32_t), &datsize, datalen, data, 0,
547 0);
548 } else {
549 /* pcr info specified */
550 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
551 sess.enonce, td->nonceodd, cont,
552 sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
553 td->encauth, sizeof(uint32_t), &pcrsize,
554 pcrinfosize, pcrinfo, sizeof(uint32_t),
555 &datsize, datalen, data, 0, 0);
556 }
557 if (ret < 0)
558 goto out;
559
560 /* build and send the TPM request packet */
561 INIT_BUF(tb);
562 store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
563 store32(tb, TPM_SEAL_SIZE + pcrinfosize + datalen);
564 store32(tb, TPM_ORD_SEAL);
565 store32(tb, keyhandle);
566 storebytes(tb, td->encauth, SHA1_DIGEST_SIZE);
567 store32(tb, pcrinfosize);
568 storebytes(tb, pcrinfo, pcrinfosize);
569 store32(tb, datalen);
570 storebytes(tb, data, datalen);
571 store32(tb, sess.handle);
572 storebytes(tb, td->nonceodd, TPM_NONCE_SIZE);
573 store8(tb, cont);
574 storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE);
575
576 ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
577 if (ret < 0)
578 goto out;
579
580 /* calculate the size of the returned Blob */
581 sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
582 encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
583 sizeof(uint32_t) + sealinfosize);
584 storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
585 sizeof(uint32_t) + encdatasize;
586
587 /* check the HMAC in the response */
588 ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
589 SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
590 0);
591
592 /* copy the returned blob to caller */
593 if (!ret) {
594 memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
595 *bloblen = storedsize;
596 }
597out:
598 kfree(td);
599 return ret;
600}
601
602/*
603 * use the AUTH2_COMMAND form of unseal, to authorize both key and blob
604 */
605static int tpm_unseal(struct tpm_buf *tb,
606 uint32_t keyhandle, const unsigned char *keyauth,
607 const unsigned char *blob, int bloblen,
608 const unsigned char *blobauth,
609 unsigned char *data, unsigned int *datalen)
610{
611 unsigned char nonceodd[TPM_NONCE_SIZE];
612 unsigned char enonce1[TPM_NONCE_SIZE];
613 unsigned char enonce2[TPM_NONCE_SIZE];
614 unsigned char authdata1[SHA1_DIGEST_SIZE];
615 unsigned char authdata2[SHA1_DIGEST_SIZE];
616 uint32_t authhandle1 = 0;
617 uint32_t authhandle2 = 0;
618 unsigned char cont = 0;
619 uint32_t ordinal;
620 uint32_t keyhndl;
621 int ret;
622
623 /* sessions for unsealing key and data */
624 ret = oiap(tb, &authhandle1, enonce1);
625 if (ret < 0) {
626 pr_info("trusted_key: oiap failed (%d)\n", ret);
627 return ret;
628 }
629 ret = oiap(tb, &authhandle2, enonce2);
630 if (ret < 0) {
631 pr_info("trusted_key: oiap failed (%d)\n", ret);
632 return ret;
633 }
634
635 ordinal = htonl(TPM_ORD_UNSEAL);
636 keyhndl = htonl(SRKHANDLE);
637 ret = tpm_get_random(tb, nonceodd, TPM_NONCE_SIZE);
638 if (ret < 0) {
639 pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
640 return ret;
641 }
642 ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
643 enonce1, nonceodd, cont, sizeof(uint32_t),
644 &ordinal, bloblen, blob, 0, 0);
645 if (ret < 0)
646 return ret;
647 ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
648 enonce2, nonceodd, cont, sizeof(uint32_t),
649 &ordinal, bloblen, blob, 0, 0);
650 if (ret < 0)
651 return ret;
652
653 /* build and send TPM request packet */
654 INIT_BUF(tb);
655 store16(tb, TPM_TAG_RQU_AUTH2_COMMAND);
656 store32(tb, TPM_UNSEAL_SIZE + bloblen);
657 store32(tb, TPM_ORD_UNSEAL);
658 store32(tb, keyhandle);
659 storebytes(tb, blob, bloblen);
660 store32(tb, authhandle1);
661 storebytes(tb, nonceodd, TPM_NONCE_SIZE);
662 store8(tb, cont);
663 storebytes(tb, authdata1, SHA1_DIGEST_SIZE);
664 store32(tb, authhandle2);
665 storebytes(tb, nonceodd, TPM_NONCE_SIZE);
666 store8(tb, cont);
667 storebytes(tb, authdata2, SHA1_DIGEST_SIZE);
668
669 ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
670 if (ret < 0) {
671 pr_info("trusted_key: authhmac failed (%d)\n", ret);
672 return ret;
673 }
674
675 *datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
676 ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
677 keyauth, SHA1_DIGEST_SIZE,
678 blobauth, SHA1_DIGEST_SIZE,
679 sizeof(uint32_t), TPM_DATA_OFFSET,
680 *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
681 0);
682 if (ret < 0) {
683 pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret);
684 return ret;
685 }
686 memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
687 return 0;
688}
689
690/*
691 * Have the TPM seal(encrypt) the symmetric key
692 */
693static int key_seal(struct trusted_key_payload *p,
694 struct trusted_key_options *o)
695{
696 struct tpm_buf *tb;
697 int ret;
698
699 tb = kzalloc(sizeof *tb, GFP_KERNEL);
700 if (!tb)
701 return -ENOMEM;
702
703 /* include migratable flag at end of sealed key */
704 p->key[p->key_len] = p->migratable;
705
706 ret = tpm_seal(tb, o->keytype, o->keyhandle, o->keyauth,
707 p->key, p->key_len + 1, p->blob, &p->blob_len,
708 o->blobauth, o->pcrinfo, o->pcrinfo_len);
709 if (ret < 0)
710 pr_info("trusted_key: srkseal failed (%d)\n", ret);
711
712 kfree(tb);
713 return ret;
714}
715
716/*
717 * Have the TPM unseal(decrypt) the symmetric key
718 */
719static int key_unseal(struct trusted_key_payload *p,
720 struct trusted_key_options *o)
721{
722 struct tpm_buf *tb;
723 int ret;
724
725 tb = kzalloc(sizeof *tb, GFP_KERNEL);
726 if (!tb)
727 return -ENOMEM;
728
729 ret = tpm_unseal(tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
730 o->blobauth, p->key, &p->key_len);
731 if (ret < 0)
732 pr_info("trusted_key: srkunseal failed (%d)\n", ret);
733 else
734 /* pull migratable flag out of sealed key */
735 p->migratable = p->key[--p->key_len];
736
737 kfree(tb);
738 return ret;
739}
740
741enum {
742 Opt_err = -1,
743 Opt_new, Opt_load, Opt_update,
744 Opt_keyhandle, Opt_keyauth, Opt_blobauth,
745 Opt_pcrinfo, Opt_pcrlock, Opt_migratable
746};
747
748static const match_table_t key_tokens = {
749 {Opt_new, "new"},
750 {Opt_load, "load"},
751 {Opt_update, "update"},
752 {Opt_keyhandle, "keyhandle=%s"},
753 {Opt_keyauth, "keyauth=%s"},
754 {Opt_blobauth, "blobauth=%s"},
755 {Opt_pcrinfo, "pcrinfo=%s"},
756 {Opt_pcrlock, "pcrlock=%s"},
757 {Opt_migratable, "migratable=%s"},
758 {Opt_err, NULL}
759};
760
761/* can have zero or more token= options */
762static int getoptions(char *c, struct trusted_key_payload *pay,
763 struct trusted_key_options *opt)
764{
765 substring_t args[MAX_OPT_ARGS];
766 char *p = c;
767 int token;
768 int res;
769 unsigned long handle;
770 unsigned long lock;
771
772 while ((p = strsep(&c, " \t"))) {
773 if (*p == '\0' || *p == ' ' || *p == '\t')
774 continue;
775 token = match_token(p, key_tokens, args);
776
777 switch (token) {
778 case Opt_pcrinfo:
779 opt->pcrinfo_len = strlen(args[0].from) / 2;
780 if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
781 return -EINVAL;
782 res = hex2bin(opt->pcrinfo, args[0].from,
783 opt->pcrinfo_len);
784 if (res < 0)
785 return -EINVAL;
786 break;
787 case Opt_keyhandle:
788 res = strict_strtoul(args[0].from, 16, &handle);
789 if (res < 0)
790 return -EINVAL;
791 opt->keytype = SEAL_keytype;
792 opt->keyhandle = handle;
793 break;
794 case Opt_keyauth:
795 if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
796 return -EINVAL;
797 res = hex2bin(opt->keyauth, args[0].from,
798 SHA1_DIGEST_SIZE);
799 if (res < 0)
800 return -EINVAL;
801 break;
802 case Opt_blobauth:
803 if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
804 return -EINVAL;
805 res = hex2bin(opt->blobauth, args[0].from,
806 SHA1_DIGEST_SIZE);
807 if (res < 0)
808 return -EINVAL;
809 break;
810 case Opt_migratable:
811 if (*args[0].from == '0')
812 pay->migratable = 0;
813 else
814 return -EINVAL;
815 break;
816 case Opt_pcrlock:
817 res = strict_strtoul(args[0].from, 10, &lock);
818 if (res < 0)
819 return -EINVAL;
820 opt->pcrlock = lock;
821 break;
822 default:
823 return -EINVAL;
824 }
825 }
826 return 0;
827}
828
829/*
830 * datablob_parse - parse the keyctl data and fill in the
831 * payload and options structures
832 *
833 * On success returns 0, otherwise -EINVAL.
834 */
835static int datablob_parse(char *datablob, struct trusted_key_payload *p,
836 struct trusted_key_options *o)
837{
838 substring_t args[MAX_OPT_ARGS];
839 long keylen;
840 int ret = -EINVAL;
841 int key_cmd;
842 char *c;
843
844 /* main command */
845 c = strsep(&datablob, " \t");
846 if (!c)
847 return -EINVAL;
848 key_cmd = match_token(c, key_tokens, args);
849 switch (key_cmd) {
850 case Opt_new:
851 /* first argument is key size */
852 c = strsep(&datablob, " \t");
853 if (!c)
854 return -EINVAL;
855 ret = strict_strtol(c, 10, &keylen);
856 if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
857 return -EINVAL;
858 p->key_len = keylen;
859 ret = getoptions(datablob, p, o);
860 if (ret < 0)
861 return ret;
862 ret = Opt_new;
863 break;
864 case Opt_load:
865 /* first argument is sealed blob */
866 c = strsep(&datablob, " \t");
867 if (!c)
868 return -EINVAL;
869 p->blob_len = strlen(c) / 2;
870 if (p->blob_len > MAX_BLOB_SIZE)
871 return -EINVAL;
872 ret = hex2bin(p->blob, c, p->blob_len);
873 if (ret < 0)
874 return -EINVAL;
875 ret = getoptions(datablob, p, o);
876 if (ret < 0)
877 return ret;
878 ret = Opt_load;
879 break;
880 case Opt_update:
881 /* all arguments are options */
882 ret = getoptions(datablob, p, o);
883 if (ret < 0)
884 return ret;
885 ret = Opt_update;
886 break;
887 case Opt_err:
888 return -EINVAL;
889 break;
890 }
891 return ret;
892}
893
894static struct trusted_key_options *trusted_options_alloc(void)
895{
896 struct trusted_key_options *options;
897
898 options = kzalloc(sizeof *options, GFP_KERNEL);
899 if (options) {
900 /* set any non-zero defaults */
901 options->keytype = SRK_keytype;
902 options->keyhandle = SRKHANDLE;
903 }
904 return options;
905}
906
907static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
908{
909 struct trusted_key_payload *p = NULL;
910 int ret;
911
912 ret = key_payload_reserve(key, sizeof *p);
913 if (ret < 0)
914 return p;
915 p = kzalloc(sizeof *p, GFP_KERNEL);
916 if (p)
917 p->migratable = 1; /* migratable by default */
918 return p;
919}
920
921/*
922 * trusted_instantiate - create a new trusted key
923 *
924 * Unseal an existing trusted blob or, for a new key, get a
925 * random key, then seal and create a trusted key-type key,
926 * adding it to the specified keyring.
927 *
928 * On success, return 0. Otherwise return errno.
929 */
930static int trusted_instantiate(struct key *key, const void *data,
931 size_t datalen)
932{
933 struct trusted_key_payload *payload = NULL;
934 struct trusted_key_options *options = NULL;
935 char *datablob;
936 int ret = 0;
937 int key_cmd;
938
939 if (datalen <= 0 || datalen > 32767 || !data)
940 return -EINVAL;
941
942 datablob = kmalloc(datalen + 1, GFP_KERNEL);
943 if (!datablob)
944 return -ENOMEM;
945 memcpy(datablob, data, datalen);
946 datablob[datalen] = '\0';
947
948 options = trusted_options_alloc();
949 if (!options) {
950 ret = -ENOMEM;
951 goto out;
952 }
953 payload = trusted_payload_alloc(key);
954 if (!payload) {
955 ret = -ENOMEM;
956 goto out;
957 }
958
959 key_cmd = datablob_parse(datablob, payload, options);
960 if (key_cmd < 0) {
961 ret = key_cmd;
962 goto out;
963 }
964
965 dump_payload(payload);
966 dump_options(options);
967
968 switch (key_cmd) {
969 case Opt_load:
970 ret = key_unseal(payload, options);
971 dump_payload(payload);
972 dump_options(options);
973 if (ret < 0)
974 pr_info("trusted_key: key_unseal failed (%d)\n", ret);
975 break;
976 case Opt_new:
977 ret = my_get_random(payload->key, payload->key_len);
978 if (ret < 0) {
979 pr_info("trusted_key: key_create failed (%d)\n", ret);
980 goto out;
981 }
982 ret = key_seal(payload, options);
983 if (ret < 0)
984 pr_info("trusted_key: key_seal failed (%d)\n", ret);
985 break;
986 default:
987 ret = -EINVAL;
988 goto out;
989 }
990 if (!ret && options->pcrlock)
991 ret = pcrlock(options->pcrlock);
992out:
993 kfree(datablob);
994 kfree(options);
995 if (!ret)
996 rcu_assign_keypointer(key, payload);
997 else
998 kfree(payload);
999 return ret;
1000}
1001
1002static void trusted_rcu_free(struct rcu_head *rcu)
1003{
1004 struct trusted_key_payload *p;
1005
1006 p = container_of(rcu, struct trusted_key_payload, rcu);
1007 memset(p->key, 0, p->key_len);
1008 kfree(p);
1009}
1010
1011/*
1012 * trusted_update - reseal an existing key with new PCR values
1013 */
1014static int trusted_update(struct key *key, const void *data, size_t datalen)
1015{
1016 struct trusted_key_payload *p = key->payload.data;
1017 struct trusted_key_payload *new_p;
1018 struct trusted_key_options *new_o;
1019 char *datablob;
1020 int ret = 0;
1021
1022 if (!p->migratable)
1023 return -EPERM;
1024 if (datalen <= 0 || datalen > 32767 || !data)
1025 return -EINVAL;
1026
1027 datablob = kmalloc(datalen + 1, GFP_KERNEL);
1028 if (!datablob)
1029 return -ENOMEM;
1030 new_o = trusted_options_alloc();
1031 if (!new_o) {
1032 ret = -ENOMEM;
1033 goto out;
1034 }
1035 new_p = trusted_payload_alloc(key);
1036 if (!new_p) {
1037 ret = -ENOMEM;
1038 goto out;
1039 }
1040
1041 memcpy(datablob, data, datalen);
1042 datablob[datalen] = '\0';
1043 ret = datablob_parse(datablob, new_p, new_o);
1044 if (ret != Opt_update) {
1045 ret = -EINVAL;
1046 kfree(new_p);
1047 goto out;
1048 }
1049 /* copy old key values, and reseal with new pcrs */
1050 new_p->migratable = p->migratable;
1051 new_p->key_len = p->key_len;
1052 memcpy(new_p->key, p->key, p->key_len);
1053 dump_payload(p);
1054 dump_payload(new_p);
1055
1056 ret = key_seal(new_p, new_o);
1057 if (ret < 0) {
1058 pr_info("trusted_key: key_seal failed (%d)\n", ret);
1059 kfree(new_p);
1060 goto out;
1061 }
1062 if (new_o->pcrlock) {
1063 ret = pcrlock(new_o->pcrlock);
1064 if (ret < 0) {
1065 pr_info("trusted_key: pcrlock failed (%d)\n", ret);
1066 kfree(new_p);
1067 goto out;
1068 }
1069 }
1070 rcu_assign_keypointer(key, new_p);
1071 call_rcu(&p->rcu, trusted_rcu_free);
1072out:
1073 kfree(datablob);
1074 kfree(new_o);
1075 return ret;
1076}
1077
1078/*
1079 * trusted_read - copy the sealed blob data to userspace in hex.
1080 * On success, return to userspace the trusted key datablob size.
1081 */
1082static long trusted_read(const struct key *key, char __user *buffer,
1083 size_t buflen)
1084{
1085 struct trusted_key_payload *p;
1086 char *ascii_buf;
1087 char *bufp;
1088 int i;
1089
1090 p = rcu_dereference_key(key);
1091 if (!p)
1092 return -EINVAL;
1093 if (!buffer || buflen <= 0)
1094 return 2 * p->blob_len;
1095 ascii_buf = kmalloc(2 * p->blob_len, GFP_KERNEL);
1096 if (!ascii_buf)
1097 return -ENOMEM;
1098
1099 bufp = ascii_buf;
1100 for (i = 0; i < p->blob_len; i++)
1101 bufp = hex_byte_pack(bufp, p->blob[i]);
1102 if ((copy_to_user(buffer, ascii_buf, 2 * p->blob_len)) != 0) {
1103 kfree(ascii_buf);
1104 return -EFAULT;
1105 }
1106 kfree(ascii_buf);
1107 return 2 * p->blob_len;
1108}
1109
1110/*
1111 * trusted_destroy - before freeing the key, clear the decrypted data
1112 */
1113static void trusted_destroy(struct key *key)
1114{
1115 struct trusted_key_payload *p = key->payload.data;
1116
1117 if (!p)
1118 return;
1119 memset(p->key, 0, p->key_len);
1120 kfree(key->payload.data);
1121}
1122
1123struct key_type key_type_trusted = {
1124 .name = "trusted",
1125 .instantiate = trusted_instantiate,
1126 .update = trusted_update,
1127 .match = user_match,
1128 .destroy = trusted_destroy,
1129 .describe = user_describe,
1130 .read = trusted_read,
1131};
1132
1133EXPORT_SYMBOL_GPL(key_type_trusted);
1134
1135static void trusted_shash_release(void)
1136{
1137 if (hashalg)
1138 crypto_free_shash(hashalg);
1139 if (hmacalg)
1140 crypto_free_shash(hmacalg);
1141}
1142
1143static int __init trusted_shash_alloc(void)
1144{
1145 int ret;
1146
1147 hmacalg = crypto_alloc_shash(hmac_alg, 0, CRYPTO_ALG_ASYNC);
1148 if (IS_ERR(hmacalg)) {
1149 pr_info("trusted_key: could not allocate crypto %s\n",
1150 hmac_alg);
1151 return PTR_ERR(hmacalg);
1152 }
1153
1154 hashalg = crypto_alloc_shash(hash_alg, 0, CRYPTO_ALG_ASYNC);
1155 if (IS_ERR(hashalg)) {
1156 pr_info("trusted_key: could not allocate crypto %s\n",
1157 hash_alg);
1158 ret = PTR_ERR(hashalg);
1159 goto hashalg_fail;
1160 }
1161
1162 return 0;
1163
1164hashalg_fail:
1165 crypto_free_shash(hmacalg);
1166 return ret;
1167}
1168
1169static int __init init_trusted(void)
1170{
1171 int ret;
1172
1173 ret = trusted_shash_alloc();
1174 if (ret < 0)
1175 return ret;
1176 ret = register_key_type(&key_type_trusted);
1177 if (ret < 0)
1178 trusted_shash_release();
1179 return ret;
1180}
1181
1182static void __exit cleanup_trusted(void)
1183{
1184 trusted_shash_release();
1185 unregister_key_type(&key_type_trusted);
1186}
1187
1188late_initcall(init_trusted);
1189module_exit(cleanup_trusted);
1190
1191MODULE_LICENSE("GPL");