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d00a1c72 MZ |
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 | * | |
d410fa4e | 11 | * See Documentation/security/keys-trusted-encrypted.txt |
d00a1c72 MZ |
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> | |
93ae86e7 | 20 | #include <linux/err.h> |
d00a1c72 MZ |
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 | ||
4b174b6d | 32 | #include "trusted.h" |
d00a1c72 MZ |
33 | |
34 | static const char hmac_alg[] = "hmac(sha1)"; | |
35 | static const char hash_alg[] = "sha1"; | |
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 | sdesc->shash.flags = 0x0; | |
56 | return sdesc; | |
57 | } | |
58 | ||
1bdbb402 | 59 | static int TSS_sha1(const unsigned char *data, unsigned int datalen, |
d00a1c72 MZ |
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 | ||
76 | static int TSS_rawhmac(unsigned char *digest, const unsigned char *key, | |
1bdbb402 | 77 | unsigned int keylen, ...) |
d00a1c72 MZ |
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 *); | |
35576eab TH |
104 | if (data == NULL) { |
105 | ret = -EINVAL; | |
106 | break; | |
107 | } | |
d00a1c72 MZ |
108 | ret = crypto_shash_update(&sdesc->shash, data, dlen); |
109 | if (ret < 0) | |
35576eab | 110 | break; |
d00a1c72 MZ |
111 | } |
112 | va_end(argp); | |
bc5e0af0 MZ |
113 | if (!ret) |
114 | ret = crypto_shash_final(&sdesc->shash, digest); | |
d00a1c72 MZ |
115 | out: |
116 | kfree(sdesc); | |
117 | return ret; | |
118 | } | |
119 | ||
120 | /* | |
121 | * calculate authorization info fields to send to TPM | |
122 | */ | |
bc5e0af0 | 123 | static int TSS_authhmac(unsigned char *digest, const unsigned char *key, |
1bdbb402 | 124 | unsigned int keylen, unsigned char *h1, |
bc5e0af0 | 125 | unsigned char *h2, unsigned char h3, ...) |
d00a1c72 MZ |
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 *); | |
0e7491f6 TH |
151 | if (!data) { |
152 | ret = -EINVAL; | |
154a96bf | 153 | break; |
0e7491f6 | 154 | } |
d00a1c72 | 155 | ret = crypto_shash_update(&sdesc->shash, data, dlen); |
154a96bf TH |
156 | if (ret < 0) |
157 | break; | |
d00a1c72 MZ |
158 | } |
159 | va_end(argp); | |
154a96bf TH |
160 | if (!ret) |
161 | ret = crypto_shash_final(&sdesc->shash, paramdigest); | |
d00a1c72 | 162 | if (!ret) |
bc5e0af0 MZ |
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); | |
d00a1c72 MZ |
166 | out: |
167 | kfree(sdesc); | |
168 | return ret; | |
169 | } | |
170 | ||
171 | /* | |
172 | * verify the AUTH1_COMMAND (Seal) result from TPM | |
173 | */ | |
bc5e0af0 MZ |
174 | static int TSS_checkhmac1(unsigned char *buffer, |
175 | const uint32_t command, | |
176 | const unsigned char *ononce, | |
177 | const unsigned char *key, | |
1bdbb402 | 178 | unsigned int keylen, ...) |
d00a1c72 MZ |
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); | |
154a96bf TH |
230 | if (ret < 0) |
231 | break; | |
d00a1c72 MZ |
232 | } |
233 | va_end(argp); | |
154a96bf TH |
234 | if (!ret) |
235 | ret = crypto_shash_final(&sdesc->shash, paramdigest); | |
d00a1c72 MZ |
236 | if (ret < 0) |
237 | goto out; | |
bc5e0af0 | 238 | |
d00a1c72 MZ |
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; | |
bc5e0af0 | 244 | |
d00a1c72 MZ |
245 | if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE)) |
246 | ret = -EINVAL; | |
247 | out: | |
248 | kfree(sdesc); | |
249 | return ret; | |
250 | } | |
251 | ||
252 | /* | |
253 | * verify the AUTH2_COMMAND (unseal) result from TPM | |
254 | */ | |
bc5e0af0 MZ |
255 | static int TSS_checkhmac2(unsigned char *buffer, |
256 | const uint32_t command, | |
257 | const unsigned char *ononce, | |
258 | const unsigned char *key1, | |
1bdbb402 | 259 | unsigned int keylen1, |
bc5e0af0 | 260 | const unsigned char *key2, |
1bdbb402 | 261 | unsigned int keylen2, ...) |
d00a1c72 MZ |
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); | |
154a96bf TH |
323 | if (ret < 0) |
324 | break; | |
d00a1c72 | 325 | } |
bc5e0af0 | 326 | va_end(argp); |
154a96bf TH |
327 | if (!ret) |
328 | ret = crypto_shash_final(&sdesc->shash, paramdigest); | |
d00a1c72 MZ |
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); | |
bc5e0af0 MZ |
335 | if (ret < 0) |
336 | goto out; | |
d00a1c72 MZ |
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); | |
bc5e0af0 MZ |
344 | if (ret < 0) |
345 | goto out; | |
d00a1c72 MZ |
346 | if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE)) |
347 | ret = -EINVAL; | |
348 | out: | |
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 | */ | |
357 | static 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 | ||
d00a1c72 MZ |
371 | /* |
372 | * Lock a trusted key, by extending a selected PCR. | |
373 | * | |
374 | * Prevents a trusted key that is sealed to PCRs from being accessed. | |
375 | * This uses the tpm driver's extend function. | |
376 | */ | |
377 | static int pcrlock(const int pcrnum) | |
378 | { | |
379 | unsigned char hash[SHA1_DIGEST_SIZE]; | |
bc5e0af0 | 380 | int ret; |
d00a1c72 MZ |
381 | |
382 | if (!capable(CAP_SYS_ADMIN)) | |
383 | return -EPERM; | |
41ab999c KY |
384 | ret = tpm_get_random(TPM_ANY_NUM, hash, SHA1_DIGEST_SIZE); |
385 | if (ret != SHA1_DIGEST_SIZE) | |
bc5e0af0 | 386 | return ret; |
d00a1c72 MZ |
387 | return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0; |
388 | } | |
389 | ||
390 | /* | |
391 | * Create an object specific authorisation protocol (OSAP) session | |
392 | */ | |
393 | static int osap(struct tpm_buf *tb, struct osapsess *s, | |
1bdbb402 | 394 | const unsigned char *key, uint16_t type, uint32_t handle) |
d00a1c72 MZ |
395 | { |
396 | unsigned char enonce[TPM_NONCE_SIZE]; | |
397 | unsigned char ononce[TPM_NONCE_SIZE]; | |
398 | int ret; | |
399 | ||
41ab999c KY |
400 | ret = tpm_get_random(TPM_ANY_NUM, ononce, TPM_NONCE_SIZE); |
401 | if (ret != TPM_NONCE_SIZE) | |
d00a1c72 MZ |
402 | return ret; |
403 | ||
404 | INIT_BUF(tb); | |
405 | store16(tb, TPM_TAG_RQU_COMMAND); | |
406 | store32(tb, TPM_OSAP_SIZE); | |
407 | store32(tb, TPM_ORD_OSAP); | |
408 | store16(tb, type); | |
409 | store32(tb, handle); | |
410 | storebytes(tb, ononce, TPM_NONCE_SIZE); | |
411 | ||
412 | ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); | |
413 | if (ret < 0) | |
414 | return ret; | |
415 | ||
416 | s->handle = LOAD32(tb->data, TPM_DATA_OFFSET); | |
417 | memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]), | |
418 | TPM_NONCE_SIZE); | |
419 | memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) + | |
420 | TPM_NONCE_SIZE]), TPM_NONCE_SIZE); | |
bc5e0af0 MZ |
421 | return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE, |
422 | enonce, TPM_NONCE_SIZE, ononce, 0, 0); | |
d00a1c72 MZ |
423 | } |
424 | ||
425 | /* | |
426 | * Create an object independent authorisation protocol (oiap) session | |
427 | */ | |
428 | static int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce) | |
429 | { | |
430 | int ret; | |
431 | ||
432 | INIT_BUF(tb); | |
433 | store16(tb, TPM_TAG_RQU_COMMAND); | |
434 | store32(tb, TPM_OIAP_SIZE); | |
435 | store32(tb, TPM_ORD_OIAP); | |
436 | ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); | |
437 | if (ret < 0) | |
438 | return ret; | |
439 | ||
440 | *handle = LOAD32(tb->data, TPM_DATA_OFFSET); | |
441 | memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)], | |
442 | TPM_NONCE_SIZE); | |
bc5e0af0 | 443 | return 0; |
d00a1c72 MZ |
444 | } |
445 | ||
446 | struct tpm_digests { | |
447 | unsigned char encauth[SHA1_DIGEST_SIZE]; | |
448 | unsigned char pubauth[SHA1_DIGEST_SIZE]; | |
449 | unsigned char xorwork[SHA1_DIGEST_SIZE * 2]; | |
450 | unsigned char xorhash[SHA1_DIGEST_SIZE]; | |
451 | unsigned char nonceodd[TPM_NONCE_SIZE]; | |
452 | }; | |
453 | ||
454 | /* | |
455 | * Have the TPM seal(encrypt) the trusted key, possibly based on | |
456 | * Platform Configuration Registers (PCRs). AUTH1 for sealing key. | |
457 | */ | |
1bdbb402 MZ |
458 | static int tpm_seal(struct tpm_buf *tb, uint16_t keytype, |
459 | uint32_t keyhandle, const unsigned char *keyauth, | |
460 | const unsigned char *data, uint32_t datalen, | |
d00a1c72 MZ |
461 | unsigned char *blob, uint32_t *bloblen, |
462 | const unsigned char *blobauth, | |
1bdbb402 | 463 | const unsigned char *pcrinfo, uint32_t pcrinfosize) |
d00a1c72 MZ |
464 | { |
465 | struct osapsess sess; | |
466 | struct tpm_digests *td; | |
467 | unsigned char cont; | |
468 | uint32_t ordinal; | |
469 | uint32_t pcrsize; | |
470 | uint32_t datsize; | |
471 | int sealinfosize; | |
472 | int encdatasize; | |
473 | int storedsize; | |
474 | int ret; | |
475 | int i; | |
476 | ||
477 | /* alloc some work space for all the hashes */ | |
478 | td = kmalloc(sizeof *td, GFP_KERNEL); | |
479 | if (!td) | |
480 | return -ENOMEM; | |
481 | ||
482 | /* get session for sealing key */ | |
483 | ret = osap(tb, &sess, keyauth, keytype, keyhandle); | |
484 | if (ret < 0) | |
40c10017 | 485 | goto out; |
d00a1c72 MZ |
486 | dump_sess(&sess); |
487 | ||
488 | /* calculate encrypted authorization value */ | |
489 | memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE); | |
490 | memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE); | |
491 | ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash); | |
492 | if (ret < 0) | |
40c10017 | 493 | goto out; |
d00a1c72 | 494 | |
41ab999c KY |
495 | ret = tpm_get_random(TPM_ANY_NUM, td->nonceodd, TPM_NONCE_SIZE); |
496 | if (ret != TPM_NONCE_SIZE) | |
40c10017 | 497 | goto out; |
d00a1c72 MZ |
498 | ordinal = htonl(TPM_ORD_SEAL); |
499 | datsize = htonl(datalen); | |
500 | pcrsize = htonl(pcrinfosize); | |
501 | cont = 0; | |
502 | ||
503 | /* encrypt data authorization key */ | |
504 | for (i = 0; i < SHA1_DIGEST_SIZE; ++i) | |
505 | td->encauth[i] = td->xorhash[i] ^ blobauth[i]; | |
506 | ||
507 | /* calculate authorization HMAC value */ | |
508 | if (pcrinfosize == 0) { | |
509 | /* no pcr info specified */ | |
bc5e0af0 MZ |
510 | ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE, |
511 | sess.enonce, td->nonceodd, cont, | |
512 | sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE, | |
513 | td->encauth, sizeof(uint32_t), &pcrsize, | |
514 | sizeof(uint32_t), &datsize, datalen, data, 0, | |
515 | 0); | |
d00a1c72 MZ |
516 | } else { |
517 | /* pcr info specified */ | |
bc5e0af0 MZ |
518 | ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE, |
519 | sess.enonce, td->nonceodd, cont, | |
520 | sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE, | |
521 | td->encauth, sizeof(uint32_t), &pcrsize, | |
522 | pcrinfosize, pcrinfo, sizeof(uint32_t), | |
523 | &datsize, datalen, data, 0, 0); | |
d00a1c72 | 524 | } |
bc5e0af0 | 525 | if (ret < 0) |
40c10017 | 526 | goto out; |
d00a1c72 MZ |
527 | |
528 | /* build and send the TPM request packet */ | |
529 | INIT_BUF(tb); | |
530 | store16(tb, TPM_TAG_RQU_AUTH1_COMMAND); | |
531 | store32(tb, TPM_SEAL_SIZE + pcrinfosize + datalen); | |
532 | store32(tb, TPM_ORD_SEAL); | |
533 | store32(tb, keyhandle); | |
534 | storebytes(tb, td->encauth, SHA1_DIGEST_SIZE); | |
535 | store32(tb, pcrinfosize); | |
536 | storebytes(tb, pcrinfo, pcrinfosize); | |
537 | store32(tb, datalen); | |
538 | storebytes(tb, data, datalen); | |
539 | store32(tb, sess.handle); | |
540 | storebytes(tb, td->nonceodd, TPM_NONCE_SIZE); | |
541 | store8(tb, cont); | |
542 | storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE); | |
543 | ||
544 | ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); | |
545 | if (ret < 0) | |
40c10017 | 546 | goto out; |
d00a1c72 MZ |
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 */ | |
bc5e0af0 MZ |
561 | if (!ret) { |
562 | memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize); | |
563 | *bloblen = storedsize; | |
564 | } | |
40c10017 MZ |
565 | out: |
566 | kfree(td); | |
d00a1c72 MZ |
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, | |
1bdbb402 MZ |
574 | uint32_t keyhandle, const unsigned char *keyauth, |
575 | const unsigned char *blob, int bloblen, | |
d00a1c72 MZ |
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 | uint32_t keyhndl; | |
589 | int ret; | |
590 | ||
591 | /* sessions for unsealing key and data */ | |
592 | ret = oiap(tb, &authhandle1, enonce1); | |
593 | if (ret < 0) { | |
594 | pr_info("trusted_key: oiap failed (%d)\n", ret); | |
595 | return ret; | |
596 | } | |
597 | ret = oiap(tb, &authhandle2, enonce2); | |
598 | if (ret < 0) { | |
599 | pr_info("trusted_key: oiap failed (%d)\n", ret); | |
600 | return ret; | |
601 | } | |
602 | ||
603 | ordinal = htonl(TPM_ORD_UNSEAL); | |
604 | keyhndl = htonl(SRKHANDLE); | |
41ab999c KY |
605 | ret = tpm_get_random(TPM_ANY_NUM, nonceodd, TPM_NONCE_SIZE); |
606 | if (ret != TPM_NONCE_SIZE) { | |
d00a1c72 MZ |
607 | pr_info("trusted_key: tpm_get_random failed (%d)\n", ret); |
608 | return ret; | |
609 | } | |
bc5e0af0 MZ |
610 | ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE, |
611 | enonce1, nonceodd, cont, sizeof(uint32_t), | |
612 | &ordinal, bloblen, blob, 0, 0); | |
613 | if (ret < 0) | |
614 | return ret; | |
615 | ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE, | |
616 | enonce2, nonceodd, cont, sizeof(uint32_t), | |
617 | &ordinal, bloblen, blob, 0, 0); | |
618 | if (ret < 0) | |
619 | return ret; | |
d00a1c72 MZ |
620 | |
621 | /* build and send TPM request packet */ | |
622 | INIT_BUF(tb); | |
623 | store16(tb, TPM_TAG_RQU_AUTH2_COMMAND); | |
624 | store32(tb, TPM_UNSEAL_SIZE + bloblen); | |
625 | store32(tb, TPM_ORD_UNSEAL); | |
626 | store32(tb, keyhandle); | |
627 | storebytes(tb, blob, bloblen); | |
628 | store32(tb, authhandle1); | |
629 | storebytes(tb, nonceodd, TPM_NONCE_SIZE); | |
630 | store8(tb, cont); | |
631 | storebytes(tb, authdata1, SHA1_DIGEST_SIZE); | |
632 | store32(tb, authhandle2); | |
633 | storebytes(tb, nonceodd, TPM_NONCE_SIZE); | |
634 | store8(tb, cont); | |
635 | storebytes(tb, authdata2, SHA1_DIGEST_SIZE); | |
636 | ||
637 | ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); | |
638 | if (ret < 0) { | |
639 | pr_info("trusted_key: authhmac failed (%d)\n", ret); | |
640 | return ret; | |
641 | } | |
642 | ||
643 | *datalen = LOAD32(tb->data, TPM_DATA_OFFSET); | |
644 | ret = TSS_checkhmac2(tb->data, ordinal, nonceodd, | |
645 | keyauth, SHA1_DIGEST_SIZE, | |
646 | blobauth, SHA1_DIGEST_SIZE, | |
647 | sizeof(uint32_t), TPM_DATA_OFFSET, | |
648 | *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0, | |
649 | 0); | |
bc5e0af0 | 650 | if (ret < 0) { |
d00a1c72 | 651 | pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret); |
bc5e0af0 MZ |
652 | return ret; |
653 | } | |
d00a1c72 | 654 | memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen); |
bc5e0af0 | 655 | return 0; |
d00a1c72 MZ |
656 | } |
657 | ||
658 | /* | |
659 | * Have the TPM seal(encrypt) the symmetric key | |
660 | */ | |
661 | static int key_seal(struct trusted_key_payload *p, | |
662 | struct trusted_key_options *o) | |
663 | { | |
664 | struct tpm_buf *tb; | |
665 | int ret; | |
666 | ||
667 | tb = kzalloc(sizeof *tb, GFP_KERNEL); | |
668 | if (!tb) | |
669 | return -ENOMEM; | |
670 | ||
671 | /* include migratable flag at end of sealed key */ | |
672 | p->key[p->key_len] = p->migratable; | |
673 | ||
674 | ret = tpm_seal(tb, o->keytype, o->keyhandle, o->keyauth, | |
675 | p->key, p->key_len + 1, p->blob, &p->blob_len, | |
676 | o->blobauth, o->pcrinfo, o->pcrinfo_len); | |
677 | if (ret < 0) | |
678 | pr_info("trusted_key: srkseal failed (%d)\n", ret); | |
679 | ||
680 | kfree(tb); | |
681 | return ret; | |
682 | } | |
683 | ||
684 | /* | |
685 | * Have the TPM unseal(decrypt) the symmetric key | |
686 | */ | |
687 | static int key_unseal(struct trusted_key_payload *p, | |
688 | struct trusted_key_options *o) | |
689 | { | |
690 | struct tpm_buf *tb; | |
691 | int ret; | |
692 | ||
693 | tb = kzalloc(sizeof *tb, GFP_KERNEL); | |
694 | if (!tb) | |
695 | return -ENOMEM; | |
696 | ||
697 | ret = tpm_unseal(tb, o->keyhandle, o->keyauth, p->blob, p->blob_len, | |
698 | o->blobauth, p->key, &p->key_len); | |
d00a1c72 MZ |
699 | if (ret < 0) |
700 | pr_info("trusted_key: srkunseal failed (%d)\n", ret); | |
bc5e0af0 MZ |
701 | else |
702 | /* pull migratable flag out of sealed key */ | |
703 | p->migratable = p->key[--p->key_len]; | |
d00a1c72 MZ |
704 | |
705 | kfree(tb); | |
706 | return ret; | |
707 | } | |
708 | ||
709 | enum { | |
710 | Opt_err = -1, | |
711 | Opt_new, Opt_load, Opt_update, | |
712 | Opt_keyhandle, Opt_keyauth, Opt_blobauth, | |
713 | Opt_pcrinfo, Opt_pcrlock, Opt_migratable | |
714 | }; | |
715 | ||
716 | static const match_table_t key_tokens = { | |
717 | {Opt_new, "new"}, | |
718 | {Opt_load, "load"}, | |
719 | {Opt_update, "update"}, | |
720 | {Opt_keyhandle, "keyhandle=%s"}, | |
721 | {Opt_keyauth, "keyauth=%s"}, | |
722 | {Opt_blobauth, "blobauth=%s"}, | |
723 | {Opt_pcrinfo, "pcrinfo=%s"}, | |
724 | {Opt_pcrlock, "pcrlock=%s"}, | |
725 | {Opt_migratable, "migratable=%s"}, | |
726 | {Opt_err, NULL} | |
727 | }; | |
728 | ||
729 | /* can have zero or more token= options */ | |
730 | static int getoptions(char *c, struct trusted_key_payload *pay, | |
731 | struct trusted_key_options *opt) | |
732 | { | |
733 | substring_t args[MAX_OPT_ARGS]; | |
734 | char *p = c; | |
735 | int token; | |
736 | int res; | |
737 | unsigned long handle; | |
738 | unsigned long lock; | |
739 | ||
740 | while ((p = strsep(&c, " \t"))) { | |
741 | if (*p == '\0' || *p == ' ' || *p == '\t') | |
742 | continue; | |
743 | token = match_token(p, key_tokens, args); | |
744 | ||
745 | switch (token) { | |
746 | case Opt_pcrinfo: | |
747 | opt->pcrinfo_len = strlen(args[0].from) / 2; | |
748 | if (opt->pcrinfo_len > MAX_PCRINFO_SIZE) | |
749 | return -EINVAL; | |
2684bf7f MZ |
750 | res = hex2bin(opt->pcrinfo, args[0].from, |
751 | opt->pcrinfo_len); | |
752 | if (res < 0) | |
753 | return -EINVAL; | |
d00a1c72 MZ |
754 | break; |
755 | case Opt_keyhandle: | |
756 | res = strict_strtoul(args[0].from, 16, &handle); | |
757 | if (res < 0) | |
758 | return -EINVAL; | |
759 | opt->keytype = SEAL_keytype; | |
760 | opt->keyhandle = handle; | |
761 | break; | |
762 | case Opt_keyauth: | |
763 | if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE) | |
764 | return -EINVAL; | |
2684bf7f MZ |
765 | res = hex2bin(opt->keyauth, args[0].from, |
766 | SHA1_DIGEST_SIZE); | |
767 | if (res < 0) | |
768 | return -EINVAL; | |
d00a1c72 MZ |
769 | break; |
770 | case Opt_blobauth: | |
771 | if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE) | |
772 | return -EINVAL; | |
2684bf7f MZ |
773 | res = hex2bin(opt->blobauth, args[0].from, |
774 | SHA1_DIGEST_SIZE); | |
775 | if (res < 0) | |
776 | return -EINVAL; | |
d00a1c72 MZ |
777 | break; |
778 | case Opt_migratable: | |
779 | if (*args[0].from == '0') | |
780 | pay->migratable = 0; | |
781 | else | |
782 | return -EINVAL; | |
783 | break; | |
784 | case Opt_pcrlock: | |
785 | res = strict_strtoul(args[0].from, 10, &lock); | |
786 | if (res < 0) | |
787 | return -EINVAL; | |
788 | opt->pcrlock = lock; | |
789 | break; | |
790 | default: | |
791 | return -EINVAL; | |
792 | } | |
793 | } | |
794 | return 0; | |
795 | } | |
796 | ||
797 | /* | |
798 | * datablob_parse - parse the keyctl data and fill in the | |
799 | * payload and options structures | |
800 | * | |
801 | * On success returns 0, otherwise -EINVAL. | |
802 | */ | |
803 | static int datablob_parse(char *datablob, struct trusted_key_payload *p, | |
804 | struct trusted_key_options *o) | |
805 | { | |
806 | substring_t args[MAX_OPT_ARGS]; | |
807 | long keylen; | |
808 | int ret = -EINVAL; | |
809 | int key_cmd; | |
810 | char *c; | |
811 | ||
812 | /* main command */ | |
813 | c = strsep(&datablob, " \t"); | |
814 | if (!c) | |
815 | return -EINVAL; | |
816 | key_cmd = match_token(c, key_tokens, args); | |
817 | switch (key_cmd) { | |
818 | case Opt_new: | |
819 | /* first argument is key size */ | |
820 | c = strsep(&datablob, " \t"); | |
821 | if (!c) | |
822 | return -EINVAL; | |
823 | ret = strict_strtol(c, 10, &keylen); | |
824 | if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE) | |
825 | return -EINVAL; | |
826 | p->key_len = keylen; | |
827 | ret = getoptions(datablob, p, o); | |
828 | if (ret < 0) | |
829 | return ret; | |
830 | ret = Opt_new; | |
831 | break; | |
832 | case Opt_load: | |
833 | /* first argument is sealed blob */ | |
834 | c = strsep(&datablob, " \t"); | |
835 | if (!c) | |
836 | return -EINVAL; | |
837 | p->blob_len = strlen(c) / 2; | |
838 | if (p->blob_len > MAX_BLOB_SIZE) | |
839 | return -EINVAL; | |
2684bf7f MZ |
840 | ret = hex2bin(p->blob, c, p->blob_len); |
841 | if (ret < 0) | |
842 | return -EINVAL; | |
d00a1c72 MZ |
843 | ret = getoptions(datablob, p, o); |
844 | if (ret < 0) | |
845 | return ret; | |
846 | ret = Opt_load; | |
847 | break; | |
848 | case Opt_update: | |
849 | /* all arguments are options */ | |
850 | ret = getoptions(datablob, p, o); | |
851 | if (ret < 0) | |
852 | return ret; | |
853 | ret = Opt_update; | |
854 | break; | |
855 | case Opt_err: | |
856 | return -EINVAL; | |
857 | break; | |
858 | } | |
859 | return ret; | |
860 | } | |
861 | ||
862 | static struct trusted_key_options *trusted_options_alloc(void) | |
863 | { | |
864 | struct trusted_key_options *options; | |
865 | ||
866 | options = kzalloc(sizeof *options, GFP_KERNEL); | |
bc5e0af0 MZ |
867 | if (options) { |
868 | /* set any non-zero defaults */ | |
869 | options->keytype = SRK_keytype; | |
870 | options->keyhandle = SRKHANDLE; | |
871 | } | |
d00a1c72 MZ |
872 | return options; |
873 | } | |
874 | ||
875 | static struct trusted_key_payload *trusted_payload_alloc(struct key *key) | |
876 | { | |
877 | struct trusted_key_payload *p = NULL; | |
878 | int ret; | |
879 | ||
880 | ret = key_payload_reserve(key, sizeof *p); | |
881 | if (ret < 0) | |
882 | return p; | |
883 | p = kzalloc(sizeof *p, GFP_KERNEL); | |
bc5e0af0 MZ |
884 | if (p) |
885 | p->migratable = 1; /* migratable by default */ | |
d00a1c72 MZ |
886 | return p; |
887 | } | |
888 | ||
889 | /* | |
890 | * trusted_instantiate - create a new trusted key | |
891 | * | |
892 | * Unseal an existing trusted blob or, for a new key, get a | |
893 | * random key, then seal and create a trusted key-type key, | |
894 | * adding it to the specified keyring. | |
895 | * | |
896 | * On success, return 0. Otherwise return errno. | |
897 | */ | |
cf7f601c DH |
898 | static int trusted_instantiate(struct key *key, |
899 | struct key_preparsed_payload *prep) | |
d00a1c72 MZ |
900 | { |
901 | struct trusted_key_payload *payload = NULL; | |
902 | struct trusted_key_options *options = NULL; | |
cf7f601c | 903 | size_t datalen = prep->datalen; |
d00a1c72 MZ |
904 | char *datablob; |
905 | int ret = 0; | |
906 | int key_cmd; | |
41ab999c | 907 | size_t key_len; |
d00a1c72 | 908 | |
cf7f601c | 909 | if (datalen <= 0 || datalen > 32767 || !prep->data) |
d00a1c72 MZ |
910 | return -EINVAL; |
911 | ||
912 | datablob = kmalloc(datalen + 1, GFP_KERNEL); | |
913 | if (!datablob) | |
914 | return -ENOMEM; | |
cf7f601c | 915 | memcpy(datablob, prep->data, datalen); |
d00a1c72 MZ |
916 | datablob[datalen] = '\0'; |
917 | ||
918 | options = trusted_options_alloc(); | |
919 | if (!options) { | |
920 | ret = -ENOMEM; | |
921 | goto out; | |
922 | } | |
923 | payload = trusted_payload_alloc(key); | |
924 | if (!payload) { | |
925 | ret = -ENOMEM; | |
926 | goto out; | |
927 | } | |
928 | ||
929 | key_cmd = datablob_parse(datablob, payload, options); | |
930 | if (key_cmd < 0) { | |
931 | ret = key_cmd; | |
932 | goto out; | |
933 | } | |
934 | ||
935 | dump_payload(payload); | |
936 | dump_options(options); | |
937 | ||
938 | switch (key_cmd) { | |
939 | case Opt_load: | |
940 | ret = key_unseal(payload, options); | |
941 | dump_payload(payload); | |
942 | dump_options(options); | |
943 | if (ret < 0) | |
944 | pr_info("trusted_key: key_unseal failed (%d)\n", ret); | |
945 | break; | |
946 | case Opt_new: | |
41ab999c KY |
947 | key_len = payload->key_len; |
948 | ret = tpm_get_random(TPM_ANY_NUM, payload->key, key_len); | |
949 | if (ret != key_len) { | |
d00a1c72 MZ |
950 | pr_info("trusted_key: key_create failed (%d)\n", ret); |
951 | goto out; | |
952 | } | |
953 | ret = key_seal(payload, options); | |
954 | if (ret < 0) | |
955 | pr_info("trusted_key: key_seal failed (%d)\n", ret); | |
956 | break; | |
957 | default: | |
958 | ret = -EINVAL; | |
959 | goto out; | |
960 | } | |
961 | if (!ret && options->pcrlock) | |
962 | ret = pcrlock(options->pcrlock); | |
963 | out: | |
964 | kfree(datablob); | |
965 | kfree(options); | |
966 | if (!ret) | |
ee0b31a2 | 967 | rcu_assign_keypointer(key, payload); |
d00a1c72 MZ |
968 | else |
969 | kfree(payload); | |
970 | return ret; | |
971 | } | |
972 | ||
973 | static void trusted_rcu_free(struct rcu_head *rcu) | |
974 | { | |
975 | struct trusted_key_payload *p; | |
976 | ||
977 | p = container_of(rcu, struct trusted_key_payload, rcu); | |
978 | memset(p->key, 0, p->key_len); | |
979 | kfree(p); | |
980 | } | |
981 | ||
982 | /* | |
983 | * trusted_update - reseal an existing key with new PCR values | |
984 | */ | |
cf7f601c | 985 | static int trusted_update(struct key *key, struct key_preparsed_payload *prep) |
d00a1c72 MZ |
986 | { |
987 | struct trusted_key_payload *p = key->payload.data; | |
988 | struct trusted_key_payload *new_p; | |
989 | struct trusted_key_options *new_o; | |
cf7f601c | 990 | size_t datalen = prep->datalen; |
d00a1c72 MZ |
991 | char *datablob; |
992 | int ret = 0; | |
993 | ||
994 | if (!p->migratable) | |
995 | return -EPERM; | |
cf7f601c | 996 | if (datalen <= 0 || datalen > 32767 || !prep->data) |
d00a1c72 MZ |
997 | return -EINVAL; |
998 | ||
999 | datablob = kmalloc(datalen + 1, GFP_KERNEL); | |
1000 | if (!datablob) | |
1001 | return -ENOMEM; | |
1002 | new_o = trusted_options_alloc(); | |
1003 | if (!new_o) { | |
1004 | ret = -ENOMEM; | |
1005 | goto out; | |
1006 | } | |
1007 | new_p = trusted_payload_alloc(key); | |
1008 | if (!new_p) { | |
1009 | ret = -ENOMEM; | |
1010 | goto out; | |
1011 | } | |
1012 | ||
cf7f601c | 1013 | memcpy(datablob, prep->data, datalen); |
d00a1c72 MZ |
1014 | datablob[datalen] = '\0'; |
1015 | ret = datablob_parse(datablob, new_p, new_o); | |
1016 | if (ret != Opt_update) { | |
1017 | ret = -EINVAL; | |
54031109 | 1018 | kfree(new_p); |
d00a1c72 MZ |
1019 | goto out; |
1020 | } | |
1021 | /* copy old key values, and reseal with new pcrs */ | |
1022 | new_p->migratable = p->migratable; | |
1023 | new_p->key_len = p->key_len; | |
1024 | memcpy(new_p->key, p->key, p->key_len); | |
1025 | dump_payload(p); | |
1026 | dump_payload(new_p); | |
1027 | ||
1028 | ret = key_seal(new_p, new_o); | |
1029 | if (ret < 0) { | |
1030 | pr_info("trusted_key: key_seal failed (%d)\n", ret); | |
1031 | kfree(new_p); | |
1032 | goto out; | |
1033 | } | |
1034 | if (new_o->pcrlock) { | |
1035 | ret = pcrlock(new_o->pcrlock); | |
1036 | if (ret < 0) { | |
1037 | pr_info("trusted_key: pcrlock failed (%d)\n", ret); | |
1038 | kfree(new_p); | |
1039 | goto out; | |
1040 | } | |
1041 | } | |
ee0b31a2 | 1042 | rcu_assign_keypointer(key, new_p); |
d00a1c72 MZ |
1043 | call_rcu(&p->rcu, trusted_rcu_free); |
1044 | out: | |
1045 | kfree(datablob); | |
1046 | kfree(new_o); | |
1047 | return ret; | |
1048 | } | |
1049 | ||
1050 | /* | |
1051 | * trusted_read - copy the sealed blob data to userspace in hex. | |
1052 | * On success, return to userspace the trusted key datablob size. | |
1053 | */ | |
1054 | static long trusted_read(const struct key *key, char __user *buffer, | |
1055 | size_t buflen) | |
1056 | { | |
1057 | struct trusted_key_payload *p; | |
1058 | char *ascii_buf; | |
1059 | char *bufp; | |
1060 | int i; | |
1061 | ||
633e804e | 1062 | p = rcu_dereference_key(key); |
d00a1c72 MZ |
1063 | if (!p) |
1064 | return -EINVAL; | |
1065 | if (!buffer || buflen <= 0) | |
1066 | return 2 * p->blob_len; | |
1067 | ascii_buf = kmalloc(2 * p->blob_len, GFP_KERNEL); | |
1068 | if (!ascii_buf) | |
1069 | return -ENOMEM; | |
1070 | ||
1071 | bufp = ascii_buf; | |
1072 | for (i = 0; i < p->blob_len; i++) | |
02473119 | 1073 | bufp = hex_byte_pack(bufp, p->blob[i]); |
d00a1c72 MZ |
1074 | if ((copy_to_user(buffer, ascii_buf, 2 * p->blob_len)) != 0) { |
1075 | kfree(ascii_buf); | |
1076 | return -EFAULT; | |
1077 | } | |
1078 | kfree(ascii_buf); | |
1079 | return 2 * p->blob_len; | |
1080 | } | |
1081 | ||
1082 | /* | |
1083 | * trusted_destroy - before freeing the key, clear the decrypted data | |
1084 | */ | |
1085 | static void trusted_destroy(struct key *key) | |
1086 | { | |
1087 | struct trusted_key_payload *p = key->payload.data; | |
1088 | ||
1089 | if (!p) | |
1090 | return; | |
1091 | memset(p->key, 0, p->key_len); | |
1092 | kfree(key->payload.data); | |
1093 | } | |
1094 | ||
1095 | struct key_type key_type_trusted = { | |
1096 | .name = "trusted", | |
1097 | .instantiate = trusted_instantiate, | |
1098 | .update = trusted_update, | |
1099 | .match = user_match, | |
1100 | .destroy = trusted_destroy, | |
1101 | .describe = user_describe, | |
1102 | .read = trusted_read, | |
1103 | }; | |
1104 | ||
1105 | EXPORT_SYMBOL_GPL(key_type_trusted); | |
1106 | ||
1107 | static void trusted_shash_release(void) | |
1108 | { | |
1109 | if (hashalg) | |
1110 | crypto_free_shash(hashalg); | |
1111 | if (hmacalg) | |
1112 | crypto_free_shash(hmacalg); | |
1113 | } | |
1114 | ||
1115 | static int __init trusted_shash_alloc(void) | |
1116 | { | |
1117 | int ret; | |
1118 | ||
1119 | hmacalg = crypto_alloc_shash(hmac_alg, 0, CRYPTO_ALG_ASYNC); | |
1120 | if (IS_ERR(hmacalg)) { | |
1121 | pr_info("trusted_key: could not allocate crypto %s\n", | |
1122 | hmac_alg); | |
1123 | return PTR_ERR(hmacalg); | |
1124 | } | |
1125 | ||
1126 | hashalg = crypto_alloc_shash(hash_alg, 0, CRYPTO_ALG_ASYNC); | |
1127 | if (IS_ERR(hashalg)) { | |
1128 | pr_info("trusted_key: could not allocate crypto %s\n", | |
1129 | hash_alg); | |
1130 | ret = PTR_ERR(hashalg); | |
1131 | goto hashalg_fail; | |
1132 | } | |
1133 | ||
1134 | return 0; | |
1135 | ||
1136 | hashalg_fail: | |
1137 | crypto_free_shash(hmacalg); | |
1138 | return ret; | |
1139 | } | |
1140 | ||
1141 | static int __init init_trusted(void) | |
1142 | { | |
1143 | int ret; | |
1144 | ||
1145 | ret = trusted_shash_alloc(); | |
1146 | if (ret < 0) | |
1147 | return ret; | |
1148 | ret = register_key_type(&key_type_trusted); | |
1149 | if (ret < 0) | |
1150 | trusted_shash_release(); | |
1151 | return ret; | |
1152 | } | |
1153 | ||
1154 | static void __exit cleanup_trusted(void) | |
1155 | { | |
1156 | trusted_shash_release(); | |
1157 | unregister_key_type(&key_type_trusted); | |
1158 | } | |
1159 | ||
1160 | late_initcall(init_trusted); | |
1161 | module_exit(cleanup_trusted); | |
1162 | ||
1163 | MODULE_LICENSE("GPL"); |