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_tpm.h>
31 
32 static const char hmac_alg[] = "hmac(sha1)";
33 static const char hash_alg[] = "sha1";
34 static struct tpm_chip *chip;
35 static struct tpm_digest *digests;
36 
37 struct sdesc {
38 	struct shash_desc shash;
39 	char ctx[];
40 };
41 
42 static struct crypto_shash *hashalg;
43 static struct crypto_shash *hmacalg;
44 
45 static 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 
58 static 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 
75 static 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);
114 out:
115 	kzfree(sdesc);
116 	return ret;
117 }
118 
119 /*
120  * calculate authorization info fields to send to TPM
121  */
122 int 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);
168 out:
169 	kzfree(sdesc);
170 	return ret;
171 }
172 EXPORT_SYMBOL_GPL(TSS_authhmac);
173 
174 /*
175  * verify the AUTH1_COMMAND (Seal) result from TPM
176  */
177 int 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;
253 out:
254 	kzfree(sdesc);
255 	return ret;
256 }
257 EXPORT_SYMBOL_GPL(TSS_checkhmac1);
258 
259 /*
260  * verify the AUTH2_COMMAND (unseal) result from TPM
261  */
262 static 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;
355 out:
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  */
364 int 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 }
379 EXPORT_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  */
387 static 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  */
398 static 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 	tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OSAP);
410 	tpm_buf_append_u16(tb, type);
411 	tpm_buf_append_u32(tb, handle);
412 	tpm_buf_append(tb, ononce, TPM_NONCE_SIZE);
413 
414 	ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
415 	if (ret < 0)
416 		return ret;
417 
418 	s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
419 	memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
420 	       TPM_NONCE_SIZE);
421 	memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
422 				  TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
423 	return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
424 			   enonce, TPM_NONCE_SIZE, ononce, 0, 0);
425 }
426 
427 /*
428  * Create an object independent authorisation protocol (oiap) session
429  */
430 int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
431 {
432 	int ret;
433 
434 	if (!chip)
435 		return -ENODEV;
436 
437 	tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OIAP);
438 	ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
439 	if (ret < 0)
440 		return ret;
441 
442 	*handle = LOAD32(tb->data, TPM_DATA_OFFSET);
443 	memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
444 	       TPM_NONCE_SIZE);
445 	return 0;
446 }
447 EXPORT_SYMBOL_GPL(oiap);
448 
449 struct tpm_digests {
450 	unsigned char encauth[SHA1_DIGEST_SIZE];
451 	unsigned char pubauth[SHA1_DIGEST_SIZE];
452 	unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
453 	unsigned char xorhash[SHA1_DIGEST_SIZE];
454 	unsigned char nonceodd[TPM_NONCE_SIZE];
455 };
456 
457 /*
458  * Have the TPM seal(encrypt) the trusted key, possibly based on
459  * Platform Configuration Registers (PCRs). AUTH1 for sealing key.
460  */
461 static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
462 		    uint32_t keyhandle, const unsigned char *keyauth,
463 		    const unsigned char *data, uint32_t datalen,
464 		    unsigned char *blob, uint32_t *bloblen,
465 		    const unsigned char *blobauth,
466 		    const unsigned char *pcrinfo, uint32_t pcrinfosize)
467 {
468 	struct osapsess sess;
469 	struct tpm_digests *td;
470 	unsigned char cont;
471 	uint32_t ordinal;
472 	uint32_t pcrsize;
473 	uint32_t datsize;
474 	int sealinfosize;
475 	int encdatasize;
476 	int storedsize;
477 	int ret;
478 	int i;
479 
480 	/* alloc some work space for all the hashes */
481 	td = kmalloc(sizeof *td, GFP_KERNEL);
482 	if (!td)
483 		return -ENOMEM;
484 
485 	/* get session for sealing key */
486 	ret = osap(tb, &sess, keyauth, keytype, keyhandle);
487 	if (ret < 0)
488 		goto out;
489 	dump_sess(&sess);
490 
491 	/* calculate encrypted authorization value */
492 	memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
493 	memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
494 	ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
495 	if (ret < 0)
496 		goto out;
497 
498 	ret = tpm_get_random(chip, td->nonceodd, TPM_NONCE_SIZE);
499 	if (ret != TPM_NONCE_SIZE)
500 		goto out;
501 	ordinal = htonl(TPM_ORD_SEAL);
502 	datsize = htonl(datalen);
503 	pcrsize = htonl(pcrinfosize);
504 	cont = 0;
505 
506 	/* encrypt data authorization key */
507 	for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
508 		td->encauth[i] = td->xorhash[i] ^ blobauth[i];
509 
510 	/* calculate authorization HMAC value */
511 	if (pcrinfosize == 0) {
512 		/* no pcr info specified */
513 		ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
514 				   sess.enonce, td->nonceodd, cont,
515 				   sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
516 				   td->encauth, sizeof(uint32_t), &pcrsize,
517 				   sizeof(uint32_t), &datsize, datalen, data, 0,
518 				   0);
519 	} else {
520 		/* pcr info specified */
521 		ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
522 				   sess.enonce, td->nonceodd, cont,
523 				   sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
524 				   td->encauth, sizeof(uint32_t), &pcrsize,
525 				   pcrinfosize, pcrinfo, sizeof(uint32_t),
526 				   &datsize, datalen, data, 0, 0);
527 	}
528 	if (ret < 0)
529 		goto out;
530 
531 	/* build and send the TPM request packet */
532 	tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_SEAL);
533 	tpm_buf_append_u32(tb, keyhandle);
534 	tpm_buf_append(tb, td->encauth, SHA1_DIGEST_SIZE);
535 	tpm_buf_append_u32(tb, pcrinfosize);
536 	tpm_buf_append(tb, pcrinfo, pcrinfosize);
537 	tpm_buf_append_u32(tb, datalen);
538 	tpm_buf_append(tb, data, datalen);
539 	tpm_buf_append_u32(tb, sess.handle);
540 	tpm_buf_append(tb, td->nonceodd, TPM_NONCE_SIZE);
541 	tpm_buf_append_u8(tb, cont);
542 	tpm_buf_append(tb, td->pubauth, SHA1_DIGEST_SIZE);
543 
544 	ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
545 	if (ret < 0)
546 		goto out;
547 
548 	/* calculate the size of the returned Blob */
549 	sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
550 	encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
551 			     sizeof(uint32_t) + sealinfosize);
552 	storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
553 	    sizeof(uint32_t) + encdatasize;
554 
555 	/* check the HMAC in the response */
556 	ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
557 			     SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
558 			     0);
559 
560 	/* copy the returned blob to caller */
561 	if (!ret) {
562 		memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
563 		*bloblen = storedsize;
564 	}
565 out:
566 	kzfree(td);
567 	return ret;
568 }
569 
570 /*
571  * use the AUTH2_COMMAND form of unseal, to authorize both key and blob
572  */
573 static int tpm_unseal(struct tpm_buf *tb,
574 		      uint32_t keyhandle, const unsigned char *keyauth,
575 		      const unsigned char *blob, int bloblen,
576 		      const unsigned char *blobauth,
577 		      unsigned char *data, unsigned int *datalen)
578 {
579 	unsigned char nonceodd[TPM_NONCE_SIZE];
580 	unsigned char enonce1[TPM_NONCE_SIZE];
581 	unsigned char enonce2[TPM_NONCE_SIZE];
582 	unsigned char authdata1[SHA1_DIGEST_SIZE];
583 	unsigned char authdata2[SHA1_DIGEST_SIZE];
584 	uint32_t authhandle1 = 0;
585 	uint32_t authhandle2 = 0;
586 	unsigned char cont = 0;
587 	uint32_t ordinal;
588 	int ret;
589 
590 	/* sessions for unsealing key and data */
591 	ret = oiap(tb, &authhandle1, enonce1);
592 	if (ret < 0) {
593 		pr_info("trusted_key: oiap failed (%d)\n", ret);
594 		return ret;
595 	}
596 	ret = oiap(tb, &authhandle2, enonce2);
597 	if (ret < 0) {
598 		pr_info("trusted_key: oiap failed (%d)\n", ret);
599 		return ret;
600 	}
601 
602 	ordinal = htonl(TPM_ORD_UNSEAL);
603 	ret = tpm_get_random(chip, nonceodd, TPM_NONCE_SIZE);
604 	if (ret != TPM_NONCE_SIZE) {
605 		pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
606 		return ret;
607 	}
608 	ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
609 			   enonce1, nonceodd, cont, sizeof(uint32_t),
610 			   &ordinal, bloblen, blob, 0, 0);
611 	if (ret < 0)
612 		return ret;
613 	ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
614 			   enonce2, nonceodd, cont, sizeof(uint32_t),
615 			   &ordinal, bloblen, blob, 0, 0);
616 	if (ret < 0)
617 		return ret;
618 
619 	/* build and send TPM request packet */
620 	tpm_buf_reset(tb, TPM_TAG_RQU_AUTH2_COMMAND, TPM_ORD_UNSEAL);
621 	tpm_buf_append_u32(tb, keyhandle);
622 	tpm_buf_append(tb, blob, bloblen);
623 	tpm_buf_append_u32(tb, authhandle1);
624 	tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
625 	tpm_buf_append_u8(tb, cont);
626 	tpm_buf_append(tb, authdata1, SHA1_DIGEST_SIZE);
627 	tpm_buf_append_u32(tb, authhandle2);
628 	tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE);
629 	tpm_buf_append_u8(tb, cont);
630 	tpm_buf_append(tb, authdata2, SHA1_DIGEST_SIZE);
631 
632 	ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
633 	if (ret < 0) {
634 		pr_info("trusted_key: authhmac failed (%d)\n", ret);
635 		return ret;
636 	}
637 
638 	*datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
639 	ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
640 			     keyauth, SHA1_DIGEST_SIZE,
641 			     blobauth, SHA1_DIGEST_SIZE,
642 			     sizeof(uint32_t), TPM_DATA_OFFSET,
643 			     *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
644 			     0);
645 	if (ret < 0) {
646 		pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret);
647 		return ret;
648 	}
649 	memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
650 	return 0;
651 }
652 
653 /*
654  * Have the TPM seal(encrypt) the symmetric key
655  */
656 static int key_seal(struct trusted_key_payload *p,
657 		    struct trusted_key_options *o)
658 {
659 	struct tpm_buf tb;
660 	int ret;
661 
662 	ret = tpm_buf_init(&tb, 0, 0);
663 	if (ret)
664 		return ret;
665 
666 	/* include migratable flag at end of sealed key */
667 	p->key[p->key_len] = p->migratable;
668 
669 	ret = tpm_seal(&tb, o->keytype, o->keyhandle, o->keyauth,
670 		       p->key, p->key_len + 1, p->blob, &p->blob_len,
671 		       o->blobauth, o->pcrinfo, o->pcrinfo_len);
672 	if (ret < 0)
673 		pr_info("trusted_key: srkseal failed (%d)\n", ret);
674 
675 	tpm_buf_destroy(&tb);
676 	return ret;
677 }
678 
679 /*
680  * Have the TPM unseal(decrypt) the symmetric key
681  */
682 static int key_unseal(struct trusted_key_payload *p,
683 		      struct trusted_key_options *o)
684 {
685 	struct tpm_buf tb;
686 	int ret;
687 
688 	ret = tpm_buf_init(&tb, 0, 0);
689 	if (ret)
690 		return ret;
691 
692 	ret = tpm_unseal(&tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
693 			 o->blobauth, p->key, &p->key_len);
694 	if (ret < 0)
695 		pr_info("trusted_key: srkunseal failed (%d)\n", ret);
696 	else
697 		/* pull migratable flag out of sealed key */
698 		p->migratable = p->key[--p->key_len];
699 
700 	tpm_buf_destroy(&tb);
701 	return ret;
702 }
703 
704 enum {
705 	Opt_err,
706 	Opt_new, Opt_load, Opt_update,
707 	Opt_keyhandle, Opt_keyauth, Opt_blobauth,
708 	Opt_pcrinfo, Opt_pcrlock, Opt_migratable,
709 	Opt_hash,
710 	Opt_policydigest,
711 	Opt_policyhandle,
712 };
713 
714 static const match_table_t key_tokens = {
715 	{Opt_new, "new"},
716 	{Opt_load, "load"},
717 	{Opt_update, "update"},
718 	{Opt_keyhandle, "keyhandle=%s"},
719 	{Opt_keyauth, "keyauth=%s"},
720 	{Opt_blobauth, "blobauth=%s"},
721 	{Opt_pcrinfo, "pcrinfo=%s"},
722 	{Opt_pcrlock, "pcrlock=%s"},
723 	{Opt_migratable, "migratable=%s"},
724 	{Opt_hash, "hash=%s"},
725 	{Opt_policydigest, "policydigest=%s"},
726 	{Opt_policyhandle, "policyhandle=%s"},
727 	{Opt_err, NULL}
728 };
729 
730 /* can have zero or more token= options */
731 static int getoptions(char *c, struct trusted_key_payload *pay,
732 		      struct trusted_key_options *opt)
733 {
734 	substring_t args[MAX_OPT_ARGS];
735 	char *p = c;
736 	int token;
737 	int res;
738 	unsigned long handle;
739 	unsigned long lock;
740 	unsigned long token_mask = 0;
741 	unsigned int digest_len;
742 	int i;
743 	int tpm2;
744 
745 	tpm2 = tpm_is_tpm2(chip);
746 	if (tpm2 < 0)
747 		return tpm2;
748 
749 	opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1;
750 
751 	while ((p = strsep(&c, " \t"))) {
752 		if (*p == '\0' || *p == ' ' || *p == '\t')
753 			continue;
754 		token = match_token(p, key_tokens, args);
755 		if (test_and_set_bit(token, &token_mask))
756 			return -EINVAL;
757 
758 		switch (token) {
759 		case Opt_pcrinfo:
760 			opt->pcrinfo_len = strlen(args[0].from) / 2;
761 			if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
762 				return -EINVAL;
763 			res = hex2bin(opt->pcrinfo, args[0].from,
764 				      opt->pcrinfo_len);
765 			if (res < 0)
766 				return -EINVAL;
767 			break;
768 		case Opt_keyhandle:
769 			res = kstrtoul(args[0].from, 16, &handle);
770 			if (res < 0)
771 				return -EINVAL;
772 			opt->keytype = SEAL_keytype;
773 			opt->keyhandle = handle;
774 			break;
775 		case Opt_keyauth:
776 			if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
777 				return -EINVAL;
778 			res = hex2bin(opt->keyauth, args[0].from,
779 				      SHA1_DIGEST_SIZE);
780 			if (res < 0)
781 				return -EINVAL;
782 			break;
783 		case Opt_blobauth:
784 			if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
785 				return -EINVAL;
786 			res = hex2bin(opt->blobauth, args[0].from,
787 				      SHA1_DIGEST_SIZE);
788 			if (res < 0)
789 				return -EINVAL;
790 			break;
791 		case Opt_migratable:
792 			if (*args[0].from == '0')
793 				pay->migratable = 0;
794 			else
795 				return -EINVAL;
796 			break;
797 		case Opt_pcrlock:
798 			res = kstrtoul(args[0].from, 10, &lock);
799 			if (res < 0)
800 				return -EINVAL;
801 			opt->pcrlock = lock;
802 			break;
803 		case Opt_hash:
804 			if (test_bit(Opt_policydigest, &token_mask))
805 				return -EINVAL;
806 			for (i = 0; i < HASH_ALGO__LAST; i++) {
807 				if (!strcmp(args[0].from, hash_algo_name[i])) {
808 					opt->hash = i;
809 					break;
810 				}
811 			}
812 			if (i == HASH_ALGO__LAST)
813 				return -EINVAL;
814 			if  (!tpm2 && i != HASH_ALGO_SHA1) {
815 				pr_info("trusted_key: TPM 1.x only supports SHA-1.\n");
816 				return -EINVAL;
817 			}
818 			break;
819 		case Opt_policydigest:
820 			digest_len = hash_digest_size[opt->hash];
821 			if (!tpm2 || strlen(args[0].from) != (2 * digest_len))
822 				return -EINVAL;
823 			res = hex2bin(opt->policydigest, args[0].from,
824 				      digest_len);
825 			if (res < 0)
826 				return -EINVAL;
827 			opt->policydigest_len = digest_len;
828 			break;
829 		case Opt_policyhandle:
830 			if (!tpm2)
831 				return -EINVAL;
832 			res = kstrtoul(args[0].from, 16, &handle);
833 			if (res < 0)
834 				return -EINVAL;
835 			opt->policyhandle = handle;
836 			break;
837 		default:
838 			return -EINVAL;
839 		}
840 	}
841 	return 0;
842 }
843 
844 /*
845  * datablob_parse - parse the keyctl data and fill in the
846  * 		    payload and options structures
847  *
848  * On success returns 0, otherwise -EINVAL.
849  */
850 static int datablob_parse(char *datablob, struct trusted_key_payload *p,
851 			  struct trusted_key_options *o)
852 {
853 	substring_t args[MAX_OPT_ARGS];
854 	long keylen;
855 	int ret = -EINVAL;
856 	int key_cmd;
857 	char *c;
858 
859 	/* main command */
860 	c = strsep(&datablob, " \t");
861 	if (!c)
862 		return -EINVAL;
863 	key_cmd = match_token(c, key_tokens, args);
864 	switch (key_cmd) {
865 	case Opt_new:
866 		/* first argument is key size */
867 		c = strsep(&datablob, " \t");
868 		if (!c)
869 			return -EINVAL;
870 		ret = kstrtol(c, 10, &keylen);
871 		if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
872 			return -EINVAL;
873 		p->key_len = keylen;
874 		ret = getoptions(datablob, p, o);
875 		if (ret < 0)
876 			return ret;
877 		ret = Opt_new;
878 		break;
879 	case Opt_load:
880 		/* first argument is sealed blob */
881 		c = strsep(&datablob, " \t");
882 		if (!c)
883 			return -EINVAL;
884 		p->blob_len = strlen(c) / 2;
885 		if (p->blob_len > MAX_BLOB_SIZE)
886 			return -EINVAL;
887 		ret = hex2bin(p->blob, c, p->blob_len);
888 		if (ret < 0)
889 			return -EINVAL;
890 		ret = getoptions(datablob, p, o);
891 		if (ret < 0)
892 			return ret;
893 		ret = Opt_load;
894 		break;
895 	case Opt_update:
896 		/* all arguments are options */
897 		ret = getoptions(datablob, p, o);
898 		if (ret < 0)
899 			return ret;
900 		ret = Opt_update;
901 		break;
902 	case Opt_err:
903 		return -EINVAL;
904 		break;
905 	}
906 	return ret;
907 }
908 
909 static struct trusted_key_options *trusted_options_alloc(void)
910 {
911 	struct trusted_key_options *options;
912 	int tpm2;
913 
914 	tpm2 = tpm_is_tpm2(chip);
915 	if (tpm2 < 0)
916 		return NULL;
917 
918 	options = kzalloc(sizeof *options, GFP_KERNEL);
919 	if (options) {
920 		/* set any non-zero defaults */
921 		options->keytype = SRK_keytype;
922 
923 		if (!tpm2)
924 			options->keyhandle = SRKHANDLE;
925 	}
926 	return options;
927 }
928 
929 static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
930 {
931 	struct trusted_key_payload *p = NULL;
932 	int ret;
933 
934 	ret = key_payload_reserve(key, sizeof *p);
935 	if (ret < 0)
936 		return p;
937 	p = kzalloc(sizeof *p, GFP_KERNEL);
938 	if (p)
939 		p->migratable = 1; /* migratable by default */
940 	return p;
941 }
942 
943 /*
944  * trusted_instantiate - create a new trusted key
945  *
946  * Unseal an existing trusted blob or, for a new key, get a
947  * random key, then seal and create a trusted key-type key,
948  * adding it to the specified keyring.
949  *
950  * On success, return 0. Otherwise return errno.
951  */
952 static int trusted_instantiate(struct key *key,
953 			       struct key_preparsed_payload *prep)
954 {
955 	struct trusted_key_payload *payload = NULL;
956 	struct trusted_key_options *options = NULL;
957 	size_t datalen = prep->datalen;
958 	char *datablob;
959 	int ret = 0;
960 	int key_cmd;
961 	size_t key_len;
962 	int tpm2;
963 
964 	tpm2 = tpm_is_tpm2(chip);
965 	if (tpm2 < 0)
966 		return tpm2;
967 
968 	if (datalen <= 0 || datalen > 32767 || !prep->data)
969 		return -EINVAL;
970 
971 	datablob = kmalloc(datalen + 1, GFP_KERNEL);
972 	if (!datablob)
973 		return -ENOMEM;
974 	memcpy(datablob, prep->data, datalen);
975 	datablob[datalen] = '\0';
976 
977 	options = trusted_options_alloc();
978 	if (!options) {
979 		ret = -ENOMEM;
980 		goto out;
981 	}
982 	payload = trusted_payload_alloc(key);
983 	if (!payload) {
984 		ret = -ENOMEM;
985 		goto out;
986 	}
987 
988 	key_cmd = datablob_parse(datablob, payload, options);
989 	if (key_cmd < 0) {
990 		ret = key_cmd;
991 		goto out;
992 	}
993 
994 	if (!options->keyhandle) {
995 		ret = -EINVAL;
996 		goto out;
997 	}
998 
999 	dump_payload(payload);
1000 	dump_options(options);
1001 
1002 	switch (key_cmd) {
1003 	case Opt_load:
1004 		if (tpm2)
1005 			ret = tpm2_unseal_trusted(chip, payload, options);
1006 		else
1007 			ret = key_unseal(payload, options);
1008 		dump_payload(payload);
1009 		dump_options(options);
1010 		if (ret < 0)
1011 			pr_info("trusted_key: key_unseal failed (%d)\n", ret);
1012 		break;
1013 	case Opt_new:
1014 		key_len = payload->key_len;
1015 		ret = tpm_get_random(chip, payload->key, key_len);
1016 		if (ret != key_len) {
1017 			pr_info("trusted_key: key_create failed (%d)\n", ret);
1018 			goto out;
1019 		}
1020 		if (tpm2)
1021 			ret = tpm2_seal_trusted(chip, payload, options);
1022 		else
1023 			ret = key_seal(payload, options);
1024 		if (ret < 0)
1025 			pr_info("trusted_key: key_seal failed (%d)\n", ret);
1026 		break;
1027 	default:
1028 		ret = -EINVAL;
1029 		goto out;
1030 	}
1031 	if (!ret && options->pcrlock)
1032 		ret = pcrlock(options->pcrlock);
1033 out:
1034 	kzfree(datablob);
1035 	kzfree(options);
1036 	if (!ret)
1037 		rcu_assign_keypointer(key, payload);
1038 	else
1039 		kzfree(payload);
1040 	return ret;
1041 }
1042 
1043 static void trusted_rcu_free(struct rcu_head *rcu)
1044 {
1045 	struct trusted_key_payload *p;
1046 
1047 	p = container_of(rcu, struct trusted_key_payload, rcu);
1048 	kzfree(p);
1049 }
1050 
1051 /*
1052  * trusted_update - reseal an existing key with new PCR values
1053  */
1054 static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
1055 {
1056 	struct trusted_key_payload *p;
1057 	struct trusted_key_payload *new_p;
1058 	struct trusted_key_options *new_o;
1059 	size_t datalen = prep->datalen;
1060 	char *datablob;
1061 	int ret = 0;
1062 
1063 	if (key_is_negative(key))
1064 		return -ENOKEY;
1065 	p = key->payload.data[0];
1066 	if (!p->migratable)
1067 		return -EPERM;
1068 	if (datalen <= 0 || datalen > 32767 || !prep->data)
1069 		return -EINVAL;
1070 
1071 	datablob = kmalloc(datalen + 1, GFP_KERNEL);
1072 	if (!datablob)
1073 		return -ENOMEM;
1074 	new_o = trusted_options_alloc();
1075 	if (!new_o) {
1076 		ret = -ENOMEM;
1077 		goto out;
1078 	}
1079 	new_p = trusted_payload_alloc(key);
1080 	if (!new_p) {
1081 		ret = -ENOMEM;
1082 		goto out;
1083 	}
1084 
1085 	memcpy(datablob, prep->data, datalen);
1086 	datablob[datalen] = '\0';
1087 	ret = datablob_parse(datablob, new_p, new_o);
1088 	if (ret != Opt_update) {
1089 		ret = -EINVAL;
1090 		kzfree(new_p);
1091 		goto out;
1092 	}
1093 
1094 	if (!new_o->keyhandle) {
1095 		ret = -EINVAL;
1096 		kzfree(new_p);
1097 		goto out;
1098 	}
1099 
1100 	/* copy old key values, and reseal with new pcrs */
1101 	new_p->migratable = p->migratable;
1102 	new_p->key_len = p->key_len;
1103 	memcpy(new_p->key, p->key, p->key_len);
1104 	dump_payload(p);
1105 	dump_payload(new_p);
1106 
1107 	ret = key_seal(new_p, new_o);
1108 	if (ret < 0) {
1109 		pr_info("trusted_key: key_seal failed (%d)\n", ret);
1110 		kzfree(new_p);
1111 		goto out;
1112 	}
1113 	if (new_o->pcrlock) {
1114 		ret = pcrlock(new_o->pcrlock);
1115 		if (ret < 0) {
1116 			pr_info("trusted_key: pcrlock failed (%d)\n", ret);
1117 			kzfree(new_p);
1118 			goto out;
1119 		}
1120 	}
1121 	rcu_assign_keypointer(key, new_p);
1122 	call_rcu(&p->rcu, trusted_rcu_free);
1123 out:
1124 	kzfree(datablob);
1125 	kzfree(new_o);
1126 	return ret;
1127 }
1128 
1129 /*
1130  * trusted_read - copy the sealed blob data to userspace in hex.
1131  * On success, return to userspace the trusted key datablob size.
1132  */
1133 static long trusted_read(const struct key *key, char *buffer,
1134 			 size_t buflen)
1135 {
1136 	const struct trusted_key_payload *p;
1137 	char *bufp;
1138 	int i;
1139 
1140 	p = dereference_key_locked(key);
1141 	if (!p)
1142 		return -EINVAL;
1143 
1144 	if (buffer && buflen >= 2 * p->blob_len) {
1145 		bufp = buffer;
1146 		for (i = 0; i < p->blob_len; i++)
1147 			bufp = hex_byte_pack(bufp, p->blob[i]);
1148 	}
1149 	return 2 * p->blob_len;
1150 }
1151 
1152 /*
1153  * trusted_destroy - clear and free the key's payload
1154  */
1155 static void trusted_destroy(struct key *key)
1156 {
1157 	kzfree(key->payload.data[0]);
1158 }
1159 
1160 struct key_type key_type_trusted = {
1161 	.name = "trusted",
1162 	.instantiate = trusted_instantiate,
1163 	.update = trusted_update,
1164 	.destroy = trusted_destroy,
1165 	.describe = user_describe,
1166 	.read = trusted_read,
1167 };
1168 
1169 EXPORT_SYMBOL_GPL(key_type_trusted);
1170 
1171 static void trusted_shash_release(void)
1172 {
1173 	if (hashalg)
1174 		crypto_free_shash(hashalg);
1175 	if (hmacalg)
1176 		crypto_free_shash(hmacalg);
1177 }
1178 
1179 static int __init trusted_shash_alloc(void)
1180 {
1181 	int ret;
1182 
1183 	hmacalg = crypto_alloc_shash(hmac_alg, 0, 0);
1184 	if (IS_ERR(hmacalg)) {
1185 		pr_info("trusted_key: could not allocate crypto %s\n",
1186 			hmac_alg);
1187 		return PTR_ERR(hmacalg);
1188 	}
1189 
1190 	hashalg = crypto_alloc_shash(hash_alg, 0, 0);
1191 	if (IS_ERR(hashalg)) {
1192 		pr_info("trusted_key: could not allocate crypto %s\n",
1193 			hash_alg);
1194 		ret = PTR_ERR(hashalg);
1195 		goto hashalg_fail;
1196 	}
1197 
1198 	return 0;
1199 
1200 hashalg_fail:
1201 	crypto_free_shash(hmacalg);
1202 	return ret;
1203 }
1204 
1205 static int __init init_digests(void)
1206 {
1207 	int i;
1208 
1209 	digests = kcalloc(chip->nr_allocated_banks, sizeof(*digests),
1210 			  GFP_KERNEL);
1211 	if (!digests)
1212 		return -ENOMEM;
1213 
1214 	for (i = 0; i < chip->nr_allocated_banks; i++)
1215 		digests[i].alg_id = chip->allocated_banks[i].alg_id;
1216 
1217 	return 0;
1218 }
1219 
1220 static int __init init_trusted(void)
1221 {
1222 	int ret;
1223 
1224 	/* encrypted_keys.ko depends on successful load of this module even if
1225 	 * TPM is not used.
1226 	 */
1227 	chip = tpm_default_chip();
1228 	if (!chip)
1229 		return 0;
1230 
1231 	ret = init_digests();
1232 	if (ret < 0)
1233 		goto err_put;
1234 	ret = trusted_shash_alloc();
1235 	if (ret < 0)
1236 		goto err_free;
1237 	ret = register_key_type(&key_type_trusted);
1238 	if (ret < 0)
1239 		goto err_release;
1240 	return 0;
1241 err_release:
1242 	trusted_shash_release();
1243 err_free:
1244 	kfree(digests);
1245 err_put:
1246 	put_device(&chip->dev);
1247 	return ret;
1248 }
1249 
1250 static void __exit cleanup_trusted(void)
1251 {
1252 	if (chip) {
1253 		put_device(&chip->dev);
1254 		kfree(digests);
1255 		trusted_shash_release();
1256 		unregister_key_type(&key_type_trusted);
1257 	}
1258 }
1259 
1260 late_initcall(init_trusted);
1261 module_exit(cleanup_trusted);
1262 
1263 MODULE_LICENSE("GPL");
1264