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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 | * | |
11 | * See Documentation/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> | |
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 | ||
32 | #include "trusted_defined.h" | |
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; | |
153 | va_end(argp); | |
154 | goto out; | |
155 | } | |
d00a1c72 | 156 | ret = crypto_shash_update(&sdesc->shash, data, dlen); |
bc5e0af0 MZ |
157 | if (ret < 0) { |
158 | va_end(argp); | |
d00a1c72 | 159 | goto out; |
bc5e0af0 | 160 | } |
d00a1c72 MZ |
161 | } |
162 | va_end(argp); | |
163 | ret = crypto_shash_final(&sdesc->shash, paramdigest); | |
164 | if (!ret) | |
bc5e0af0 MZ |
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); | |
d00a1c72 MZ |
168 | out: |
169 | kfree(sdesc); | |
170 | return ret; | |
171 | } | |
172 | ||
173 | /* | |
174 | * verify the AUTH1_COMMAND (Seal) result from TPM | |
175 | */ | |
bc5e0af0 MZ |
176 | static int TSS_checkhmac1(unsigned char *buffer, |
177 | const uint32_t command, | |
178 | const unsigned char *ononce, | |
179 | const unsigned char *key, | |
1bdbb402 | 180 | unsigned int keylen, ...) |
d00a1c72 MZ |
181 | { |
182 | uint32_t bufsize; | |
183 | uint16_t tag; | |
184 | uint32_t ordinal; | |
185 | uint32_t result; | |
186 | unsigned char *enonce; | |
187 | unsigned char *continueflag; | |
188 | unsigned char *authdata; | |
189 | unsigned char testhmac[SHA1_DIGEST_SIZE]; | |
190 | unsigned char paramdigest[SHA1_DIGEST_SIZE]; | |
191 | struct sdesc *sdesc; | |
192 | unsigned int dlen; | |
193 | unsigned int dpos; | |
194 | va_list argp; | |
195 | int ret; | |
196 | ||
197 | bufsize = LOAD32(buffer, TPM_SIZE_OFFSET); | |
198 | tag = LOAD16(buffer, 0); | |
199 | ordinal = command; | |
200 | result = LOAD32N(buffer, TPM_RETURN_OFFSET); | |
201 | if (tag == TPM_TAG_RSP_COMMAND) | |
202 | return 0; | |
203 | if (tag != TPM_TAG_RSP_AUTH1_COMMAND) | |
204 | return -EINVAL; | |
205 | authdata = buffer + bufsize - SHA1_DIGEST_SIZE; | |
206 | continueflag = authdata - 1; | |
207 | enonce = continueflag - TPM_NONCE_SIZE; | |
208 | ||
209 | sdesc = init_sdesc(hashalg); | |
210 | if (IS_ERR(sdesc)) { | |
211 | pr_info("trusted_key: can't alloc %s\n", hash_alg); | |
212 | return PTR_ERR(sdesc); | |
213 | } | |
214 | ret = crypto_shash_init(&sdesc->shash); | |
215 | if (ret < 0) | |
216 | goto out; | |
217 | ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result, | |
218 | sizeof result); | |
219 | if (ret < 0) | |
220 | goto out; | |
221 | ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal, | |
222 | sizeof ordinal); | |
223 | if (ret < 0) | |
224 | goto out; | |
225 | va_start(argp, keylen); | |
226 | for (;;) { | |
227 | dlen = va_arg(argp, unsigned int); | |
228 | if (dlen == 0) | |
229 | break; | |
230 | dpos = va_arg(argp, unsigned int); | |
231 | ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen); | |
bc5e0af0 MZ |
232 | if (ret < 0) { |
233 | va_end(argp); | |
d00a1c72 | 234 | goto out; |
bc5e0af0 | 235 | } |
d00a1c72 MZ |
236 | } |
237 | va_end(argp); | |
238 | ret = crypto_shash_final(&sdesc->shash, paramdigest); | |
239 | if (ret < 0) | |
240 | goto out; | |
bc5e0af0 | 241 | |
d00a1c72 MZ |
242 | ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest, |
243 | TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce, | |
244 | 1, continueflag, 0, 0); | |
245 | if (ret < 0) | |
246 | goto out; | |
bc5e0af0 | 247 | |
d00a1c72 MZ |
248 | if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE)) |
249 | ret = -EINVAL; | |
250 | out: | |
251 | kfree(sdesc); | |
252 | return ret; | |
253 | } | |
254 | ||
255 | /* | |
256 | * verify the AUTH2_COMMAND (unseal) result from TPM | |
257 | */ | |
bc5e0af0 MZ |
258 | static int TSS_checkhmac2(unsigned char *buffer, |
259 | const uint32_t command, | |
260 | const unsigned char *ononce, | |
261 | const unsigned char *key1, | |
1bdbb402 | 262 | unsigned int keylen1, |
bc5e0af0 | 263 | const unsigned char *key2, |
1bdbb402 | 264 | unsigned int keylen2, ...) |
d00a1c72 MZ |
265 | { |
266 | uint32_t bufsize; | |
267 | uint16_t tag; | |
268 | uint32_t ordinal; | |
269 | uint32_t result; | |
270 | unsigned char *enonce1; | |
271 | unsigned char *continueflag1; | |
272 | unsigned char *authdata1; | |
273 | unsigned char *enonce2; | |
274 | unsigned char *continueflag2; | |
275 | unsigned char *authdata2; | |
276 | unsigned char testhmac1[SHA1_DIGEST_SIZE]; | |
277 | unsigned char testhmac2[SHA1_DIGEST_SIZE]; | |
278 | unsigned char paramdigest[SHA1_DIGEST_SIZE]; | |
279 | struct sdesc *sdesc; | |
280 | unsigned int dlen; | |
281 | unsigned int dpos; | |
282 | va_list argp; | |
283 | int ret; | |
284 | ||
285 | bufsize = LOAD32(buffer, TPM_SIZE_OFFSET); | |
286 | tag = LOAD16(buffer, 0); | |
287 | ordinal = command; | |
288 | result = LOAD32N(buffer, TPM_RETURN_OFFSET); | |
289 | ||
290 | if (tag == TPM_TAG_RSP_COMMAND) | |
291 | return 0; | |
292 | if (tag != TPM_TAG_RSP_AUTH2_COMMAND) | |
293 | return -EINVAL; | |
294 | authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1 | |
295 | + SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE); | |
296 | authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE); | |
297 | continueflag1 = authdata1 - 1; | |
298 | continueflag2 = authdata2 - 1; | |
299 | enonce1 = continueflag1 - TPM_NONCE_SIZE; | |
300 | enonce2 = continueflag2 - TPM_NONCE_SIZE; | |
301 | ||
302 | sdesc = init_sdesc(hashalg); | |
303 | if (IS_ERR(sdesc)) { | |
304 | pr_info("trusted_key: can't alloc %s\n", hash_alg); | |
305 | return PTR_ERR(sdesc); | |
306 | } | |
307 | ret = crypto_shash_init(&sdesc->shash); | |
308 | if (ret < 0) | |
309 | goto out; | |
310 | ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result, | |
311 | sizeof result); | |
312 | if (ret < 0) | |
313 | goto out; | |
314 | ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal, | |
315 | sizeof ordinal); | |
316 | if (ret < 0) | |
317 | goto out; | |
318 | ||
319 | va_start(argp, keylen2); | |
320 | for (;;) { | |
321 | dlen = va_arg(argp, unsigned int); | |
322 | if (dlen == 0) | |
323 | break; | |
324 | dpos = va_arg(argp, unsigned int); | |
325 | ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen); | |
bc5e0af0 MZ |
326 | if (ret < 0) { |
327 | va_end(argp); | |
d00a1c72 | 328 | goto out; |
bc5e0af0 | 329 | } |
d00a1c72 | 330 | } |
bc5e0af0 | 331 | va_end(argp); |
d00a1c72 MZ |
332 | ret = crypto_shash_final(&sdesc->shash, paramdigest); |
333 | if (ret < 0) | |
334 | goto out; | |
335 | ||
336 | ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE, | |
337 | paramdigest, TPM_NONCE_SIZE, enonce1, | |
338 | TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0); | |
bc5e0af0 MZ |
339 | if (ret < 0) |
340 | goto out; | |
d00a1c72 MZ |
341 | if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) { |
342 | ret = -EINVAL; | |
343 | goto out; | |
344 | } | |
345 | ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE, | |
346 | paramdigest, TPM_NONCE_SIZE, enonce2, | |
347 | TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0); | |
bc5e0af0 MZ |
348 | if (ret < 0) |
349 | goto out; | |
d00a1c72 MZ |
350 | if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE)) |
351 | ret = -EINVAL; | |
352 | out: | |
353 | kfree(sdesc); | |
354 | return ret; | |
355 | } | |
356 | ||
357 | /* | |
358 | * For key specific tpm requests, we will generate and send our | |
359 | * own TPM command packets using the drivers send function. | |
360 | */ | |
361 | static int trusted_tpm_send(const u32 chip_num, unsigned char *cmd, | |
362 | size_t buflen) | |
363 | { | |
364 | int rc; | |
365 | ||
366 | dump_tpm_buf(cmd); | |
367 | rc = tpm_send(chip_num, cmd, buflen); | |
368 | dump_tpm_buf(cmd); | |
369 | if (rc > 0) | |
370 | /* Can't return positive return codes values to keyctl */ | |
371 | rc = -EPERM; | |
372 | return rc; | |
373 | } | |
374 | ||
375 | /* | |
376 | * get a random value from TPM | |
377 | */ | |
378 | static int tpm_get_random(struct tpm_buf *tb, unsigned char *buf, uint32_t len) | |
379 | { | |
380 | int ret; | |
381 | ||
382 | INIT_BUF(tb); | |
383 | store16(tb, TPM_TAG_RQU_COMMAND); | |
384 | store32(tb, TPM_GETRANDOM_SIZE); | |
385 | store32(tb, TPM_ORD_GETRANDOM); | |
386 | store32(tb, len); | |
387 | ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, sizeof tb->data); | |
bc5e0af0 MZ |
388 | if (!ret) |
389 | memcpy(buf, tb->data + TPM_GETRANDOM_SIZE, len); | |
d00a1c72 MZ |
390 | return ret; |
391 | } | |
392 | ||
393 | static int my_get_random(unsigned char *buf, int len) | |
394 | { | |
395 | struct tpm_buf *tb; | |
396 | int ret; | |
397 | ||
1bdbb402 | 398 | tb = kmalloc(sizeof *tb, GFP_KERNEL); |
d00a1c72 MZ |
399 | if (!tb) |
400 | return -ENOMEM; | |
401 | ret = tpm_get_random(tb, buf, len); | |
402 | ||
403 | kfree(tb); | |
404 | return ret; | |
405 | } | |
406 | ||
407 | /* | |
408 | * Lock a trusted key, by extending a selected PCR. | |
409 | * | |
410 | * Prevents a trusted key that is sealed to PCRs from being accessed. | |
411 | * This uses the tpm driver's extend function. | |
412 | */ | |
413 | static int pcrlock(const int pcrnum) | |
414 | { | |
415 | unsigned char hash[SHA1_DIGEST_SIZE]; | |
bc5e0af0 | 416 | int ret; |
d00a1c72 MZ |
417 | |
418 | if (!capable(CAP_SYS_ADMIN)) | |
419 | return -EPERM; | |
bc5e0af0 MZ |
420 | ret = my_get_random(hash, SHA1_DIGEST_SIZE); |
421 | if (ret < 0) | |
422 | return ret; | |
d00a1c72 MZ |
423 | return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0; |
424 | } | |
425 | ||
426 | /* | |
427 | * Create an object specific authorisation protocol (OSAP) session | |
428 | */ | |
429 | static int osap(struct tpm_buf *tb, struct osapsess *s, | |
1bdbb402 | 430 | const unsigned char *key, uint16_t type, uint32_t handle) |
d00a1c72 MZ |
431 | { |
432 | unsigned char enonce[TPM_NONCE_SIZE]; | |
433 | unsigned char ononce[TPM_NONCE_SIZE]; | |
434 | int ret; | |
435 | ||
436 | ret = tpm_get_random(tb, ononce, TPM_NONCE_SIZE); | |
437 | if (ret < 0) | |
438 | return ret; | |
439 | ||
440 | INIT_BUF(tb); | |
441 | store16(tb, TPM_TAG_RQU_COMMAND); | |
442 | store32(tb, TPM_OSAP_SIZE); | |
443 | store32(tb, TPM_ORD_OSAP); | |
444 | store16(tb, type); | |
445 | store32(tb, handle); | |
446 | storebytes(tb, ononce, TPM_NONCE_SIZE); | |
447 | ||
448 | ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); | |
449 | if (ret < 0) | |
450 | return ret; | |
451 | ||
452 | s->handle = LOAD32(tb->data, TPM_DATA_OFFSET); | |
453 | memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]), | |
454 | TPM_NONCE_SIZE); | |
455 | memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) + | |
456 | TPM_NONCE_SIZE]), TPM_NONCE_SIZE); | |
bc5e0af0 MZ |
457 | return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE, |
458 | enonce, TPM_NONCE_SIZE, ononce, 0, 0); | |
d00a1c72 MZ |
459 | } |
460 | ||
461 | /* | |
462 | * Create an object independent authorisation protocol (oiap) session | |
463 | */ | |
464 | static int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce) | |
465 | { | |
466 | int ret; | |
467 | ||
468 | INIT_BUF(tb); | |
469 | store16(tb, TPM_TAG_RQU_COMMAND); | |
470 | store32(tb, TPM_OIAP_SIZE); | |
471 | store32(tb, TPM_ORD_OIAP); | |
472 | ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); | |
473 | if (ret < 0) | |
474 | return ret; | |
475 | ||
476 | *handle = LOAD32(tb->data, TPM_DATA_OFFSET); | |
477 | memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)], | |
478 | TPM_NONCE_SIZE); | |
bc5e0af0 | 479 | return 0; |
d00a1c72 MZ |
480 | } |
481 | ||
482 | struct tpm_digests { | |
483 | unsigned char encauth[SHA1_DIGEST_SIZE]; | |
484 | unsigned char pubauth[SHA1_DIGEST_SIZE]; | |
485 | unsigned char xorwork[SHA1_DIGEST_SIZE * 2]; | |
486 | unsigned char xorhash[SHA1_DIGEST_SIZE]; | |
487 | unsigned char nonceodd[TPM_NONCE_SIZE]; | |
488 | }; | |
489 | ||
490 | /* | |
491 | * Have the TPM seal(encrypt) the trusted key, possibly based on | |
492 | * Platform Configuration Registers (PCRs). AUTH1 for sealing key. | |
493 | */ | |
1bdbb402 MZ |
494 | static int tpm_seal(struct tpm_buf *tb, uint16_t keytype, |
495 | uint32_t keyhandle, const unsigned char *keyauth, | |
496 | const unsigned char *data, uint32_t datalen, | |
d00a1c72 MZ |
497 | unsigned char *blob, uint32_t *bloblen, |
498 | const unsigned char *blobauth, | |
1bdbb402 | 499 | const unsigned char *pcrinfo, uint32_t pcrinfosize) |
d00a1c72 MZ |
500 | { |
501 | struct osapsess sess; | |
502 | struct tpm_digests *td; | |
503 | unsigned char cont; | |
504 | uint32_t ordinal; | |
505 | uint32_t pcrsize; | |
506 | uint32_t datsize; | |
507 | int sealinfosize; | |
508 | int encdatasize; | |
509 | int storedsize; | |
510 | int ret; | |
511 | int i; | |
512 | ||
513 | /* alloc some work space for all the hashes */ | |
514 | td = kmalloc(sizeof *td, GFP_KERNEL); | |
515 | if (!td) | |
516 | return -ENOMEM; | |
517 | ||
518 | /* get session for sealing key */ | |
519 | ret = osap(tb, &sess, keyauth, keytype, keyhandle); | |
520 | if (ret < 0) | |
40c10017 | 521 | goto out; |
d00a1c72 MZ |
522 | dump_sess(&sess); |
523 | ||
524 | /* calculate encrypted authorization value */ | |
525 | memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE); | |
526 | memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE); | |
527 | ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash); | |
528 | if (ret < 0) | |
40c10017 | 529 | goto out; |
d00a1c72 MZ |
530 | |
531 | ret = tpm_get_random(tb, td->nonceodd, TPM_NONCE_SIZE); | |
532 | if (ret < 0) | |
40c10017 | 533 | goto out; |
d00a1c72 MZ |
534 | ordinal = htonl(TPM_ORD_SEAL); |
535 | datsize = htonl(datalen); | |
536 | pcrsize = htonl(pcrinfosize); | |
537 | cont = 0; | |
538 | ||
539 | /* encrypt data authorization key */ | |
540 | for (i = 0; i < SHA1_DIGEST_SIZE; ++i) | |
541 | td->encauth[i] = td->xorhash[i] ^ blobauth[i]; | |
542 | ||
543 | /* calculate authorization HMAC value */ | |
544 | if (pcrinfosize == 0) { | |
545 | /* no pcr info specified */ | |
bc5e0af0 MZ |
546 | ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE, |
547 | sess.enonce, td->nonceodd, cont, | |
548 | sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE, | |
549 | td->encauth, sizeof(uint32_t), &pcrsize, | |
550 | sizeof(uint32_t), &datsize, datalen, data, 0, | |
551 | 0); | |
d00a1c72 MZ |
552 | } else { |
553 | /* pcr info specified */ | |
bc5e0af0 MZ |
554 | ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE, |
555 | sess.enonce, td->nonceodd, cont, | |
556 | sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE, | |
557 | td->encauth, sizeof(uint32_t), &pcrsize, | |
558 | pcrinfosize, pcrinfo, sizeof(uint32_t), | |
559 | &datsize, datalen, data, 0, 0); | |
d00a1c72 | 560 | } |
bc5e0af0 | 561 | if (ret < 0) |
40c10017 | 562 | goto out; |
d00a1c72 MZ |
563 | |
564 | /* build and send the TPM request packet */ | |
565 | INIT_BUF(tb); | |
566 | store16(tb, TPM_TAG_RQU_AUTH1_COMMAND); | |
567 | store32(tb, TPM_SEAL_SIZE + pcrinfosize + datalen); | |
568 | store32(tb, TPM_ORD_SEAL); | |
569 | store32(tb, keyhandle); | |
570 | storebytes(tb, td->encauth, SHA1_DIGEST_SIZE); | |
571 | store32(tb, pcrinfosize); | |
572 | storebytes(tb, pcrinfo, pcrinfosize); | |
573 | store32(tb, datalen); | |
574 | storebytes(tb, data, datalen); | |
575 | store32(tb, sess.handle); | |
576 | storebytes(tb, td->nonceodd, TPM_NONCE_SIZE); | |
577 | store8(tb, cont); | |
578 | storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE); | |
579 | ||
580 | ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); | |
581 | if (ret < 0) | |
40c10017 | 582 | goto out; |
d00a1c72 MZ |
583 | |
584 | /* calculate the size of the returned Blob */ | |
585 | sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t)); | |
586 | encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) + | |
587 | sizeof(uint32_t) + sealinfosize); | |
588 | storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize + | |
589 | sizeof(uint32_t) + encdatasize; | |
590 | ||
591 | /* check the HMAC in the response */ | |
592 | ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret, | |
593 | SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0, | |
594 | 0); | |
595 | ||
596 | /* copy the returned blob to caller */ | |
bc5e0af0 MZ |
597 | if (!ret) { |
598 | memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize); | |
599 | *bloblen = storedsize; | |
600 | } | |
40c10017 MZ |
601 | out: |
602 | kfree(td); | |
d00a1c72 MZ |
603 | return ret; |
604 | } | |
605 | ||
606 | /* | |
607 | * use the AUTH2_COMMAND form of unseal, to authorize both key and blob | |
608 | */ | |
609 | static int tpm_unseal(struct tpm_buf *tb, | |
1bdbb402 MZ |
610 | uint32_t keyhandle, const unsigned char *keyauth, |
611 | const unsigned char *blob, int bloblen, | |
d00a1c72 MZ |
612 | const unsigned char *blobauth, |
613 | unsigned char *data, unsigned int *datalen) | |
614 | { | |
615 | unsigned char nonceodd[TPM_NONCE_SIZE]; | |
616 | unsigned char enonce1[TPM_NONCE_SIZE]; | |
617 | unsigned char enonce2[TPM_NONCE_SIZE]; | |
618 | unsigned char authdata1[SHA1_DIGEST_SIZE]; | |
619 | unsigned char authdata2[SHA1_DIGEST_SIZE]; | |
620 | uint32_t authhandle1 = 0; | |
621 | uint32_t authhandle2 = 0; | |
622 | unsigned char cont = 0; | |
623 | uint32_t ordinal; | |
624 | uint32_t keyhndl; | |
625 | int ret; | |
626 | ||
627 | /* sessions for unsealing key and data */ | |
628 | ret = oiap(tb, &authhandle1, enonce1); | |
629 | if (ret < 0) { | |
630 | pr_info("trusted_key: oiap failed (%d)\n", ret); | |
631 | return ret; | |
632 | } | |
633 | ret = oiap(tb, &authhandle2, enonce2); | |
634 | if (ret < 0) { | |
635 | pr_info("trusted_key: oiap failed (%d)\n", ret); | |
636 | return ret; | |
637 | } | |
638 | ||
639 | ordinal = htonl(TPM_ORD_UNSEAL); | |
640 | keyhndl = htonl(SRKHANDLE); | |
641 | ret = tpm_get_random(tb, nonceodd, TPM_NONCE_SIZE); | |
642 | if (ret < 0) { | |
643 | pr_info("trusted_key: tpm_get_random failed (%d)\n", ret); | |
644 | return ret; | |
645 | } | |
bc5e0af0 MZ |
646 | ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE, |
647 | enonce1, nonceodd, cont, sizeof(uint32_t), | |
648 | &ordinal, bloblen, blob, 0, 0); | |
649 | if (ret < 0) | |
650 | return ret; | |
651 | ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE, | |
652 | enonce2, nonceodd, cont, sizeof(uint32_t), | |
653 | &ordinal, bloblen, blob, 0, 0); | |
654 | if (ret < 0) | |
655 | return ret; | |
d00a1c72 MZ |
656 | |
657 | /* build and send TPM request packet */ | |
658 | INIT_BUF(tb); | |
659 | store16(tb, TPM_TAG_RQU_AUTH2_COMMAND); | |
660 | store32(tb, TPM_UNSEAL_SIZE + bloblen); | |
661 | store32(tb, TPM_ORD_UNSEAL); | |
662 | store32(tb, keyhandle); | |
663 | storebytes(tb, blob, bloblen); | |
664 | store32(tb, authhandle1); | |
665 | storebytes(tb, nonceodd, TPM_NONCE_SIZE); | |
666 | store8(tb, cont); | |
667 | storebytes(tb, authdata1, SHA1_DIGEST_SIZE); | |
668 | store32(tb, authhandle2); | |
669 | storebytes(tb, nonceodd, TPM_NONCE_SIZE); | |
670 | store8(tb, cont); | |
671 | storebytes(tb, authdata2, SHA1_DIGEST_SIZE); | |
672 | ||
673 | ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); | |
674 | if (ret < 0) { | |
675 | pr_info("trusted_key: authhmac failed (%d)\n", ret); | |
676 | return ret; | |
677 | } | |
678 | ||
679 | *datalen = LOAD32(tb->data, TPM_DATA_OFFSET); | |
680 | ret = TSS_checkhmac2(tb->data, ordinal, nonceodd, | |
681 | keyauth, SHA1_DIGEST_SIZE, | |
682 | blobauth, SHA1_DIGEST_SIZE, | |
683 | sizeof(uint32_t), TPM_DATA_OFFSET, | |
684 | *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0, | |
685 | 0); | |
bc5e0af0 | 686 | if (ret < 0) { |
d00a1c72 | 687 | pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret); |
bc5e0af0 MZ |
688 | return ret; |
689 | } | |
d00a1c72 | 690 | memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen); |
bc5e0af0 | 691 | return 0; |
d00a1c72 MZ |
692 | } |
693 | ||
694 | /* | |
695 | * Have the TPM seal(encrypt) the symmetric key | |
696 | */ | |
697 | static int key_seal(struct trusted_key_payload *p, | |
698 | struct trusted_key_options *o) | |
699 | { | |
700 | struct tpm_buf *tb; | |
701 | int ret; | |
702 | ||
703 | tb = kzalloc(sizeof *tb, GFP_KERNEL); | |
704 | if (!tb) | |
705 | return -ENOMEM; | |
706 | ||
707 | /* include migratable flag at end of sealed key */ | |
708 | p->key[p->key_len] = p->migratable; | |
709 | ||
710 | ret = tpm_seal(tb, o->keytype, o->keyhandle, o->keyauth, | |
711 | p->key, p->key_len + 1, p->blob, &p->blob_len, | |
712 | o->blobauth, o->pcrinfo, o->pcrinfo_len); | |
713 | if (ret < 0) | |
714 | pr_info("trusted_key: srkseal failed (%d)\n", ret); | |
715 | ||
716 | kfree(tb); | |
717 | return ret; | |
718 | } | |
719 | ||
720 | /* | |
721 | * Have the TPM unseal(decrypt) the symmetric key | |
722 | */ | |
723 | static int key_unseal(struct trusted_key_payload *p, | |
724 | struct trusted_key_options *o) | |
725 | { | |
726 | struct tpm_buf *tb; | |
727 | int ret; | |
728 | ||
729 | tb = kzalloc(sizeof *tb, GFP_KERNEL); | |
730 | if (!tb) | |
731 | return -ENOMEM; | |
732 | ||
733 | ret = tpm_unseal(tb, o->keyhandle, o->keyauth, p->blob, p->blob_len, | |
734 | o->blobauth, p->key, &p->key_len); | |
d00a1c72 MZ |
735 | if (ret < 0) |
736 | pr_info("trusted_key: srkunseal failed (%d)\n", ret); | |
bc5e0af0 MZ |
737 | else |
738 | /* pull migratable flag out of sealed key */ | |
739 | p->migratable = p->key[--p->key_len]; | |
d00a1c72 MZ |
740 | |
741 | kfree(tb); | |
742 | return ret; | |
743 | } | |
744 | ||
745 | enum { | |
746 | Opt_err = -1, | |
747 | Opt_new, Opt_load, Opt_update, | |
748 | Opt_keyhandle, Opt_keyauth, Opt_blobauth, | |
749 | Opt_pcrinfo, Opt_pcrlock, Opt_migratable | |
750 | }; | |
751 | ||
752 | static const match_table_t key_tokens = { | |
753 | {Opt_new, "new"}, | |
754 | {Opt_load, "load"}, | |
755 | {Opt_update, "update"}, | |
756 | {Opt_keyhandle, "keyhandle=%s"}, | |
757 | {Opt_keyauth, "keyauth=%s"}, | |
758 | {Opt_blobauth, "blobauth=%s"}, | |
759 | {Opt_pcrinfo, "pcrinfo=%s"}, | |
760 | {Opt_pcrlock, "pcrlock=%s"}, | |
761 | {Opt_migratable, "migratable=%s"}, | |
762 | {Opt_err, NULL} | |
763 | }; | |
764 | ||
765 | /* can have zero or more token= options */ | |
766 | static int getoptions(char *c, struct trusted_key_payload *pay, | |
767 | struct trusted_key_options *opt) | |
768 | { | |
769 | substring_t args[MAX_OPT_ARGS]; | |
770 | char *p = c; | |
771 | int token; | |
772 | int res; | |
773 | unsigned long handle; | |
774 | unsigned long lock; | |
775 | ||
776 | while ((p = strsep(&c, " \t"))) { | |
777 | if (*p == '\0' || *p == ' ' || *p == '\t') | |
778 | continue; | |
779 | token = match_token(p, key_tokens, args); | |
780 | ||
781 | switch (token) { | |
782 | case Opt_pcrinfo: | |
783 | opt->pcrinfo_len = strlen(args[0].from) / 2; | |
784 | if (opt->pcrinfo_len > MAX_PCRINFO_SIZE) | |
785 | return -EINVAL; | |
786 | hex2bin(opt->pcrinfo, args[0].from, opt->pcrinfo_len); | |
787 | break; | |
788 | case Opt_keyhandle: | |
789 | res = strict_strtoul(args[0].from, 16, &handle); | |
790 | if (res < 0) | |
791 | return -EINVAL; | |
792 | opt->keytype = SEAL_keytype; | |
793 | opt->keyhandle = handle; | |
794 | break; | |
795 | case Opt_keyauth: | |
796 | if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE) | |
797 | return -EINVAL; | |
798 | hex2bin(opt->keyauth, args[0].from, SHA1_DIGEST_SIZE); | |
799 | break; | |
800 | case Opt_blobauth: | |
801 | if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE) | |
802 | return -EINVAL; | |
803 | hex2bin(opt->blobauth, args[0].from, SHA1_DIGEST_SIZE); | |
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 = strict_strtoul(args[0].from, 10, &lock); | |
813 | if (res < 0) | |
814 | return -EINVAL; | |
815 | opt->pcrlock = lock; | |
816 | break; | |
817 | default: | |
818 | return -EINVAL; | |
819 | } | |
820 | } | |
821 | return 0; | |
822 | } | |
823 | ||
824 | /* | |
825 | * datablob_parse - parse the keyctl data and fill in the | |
826 | * payload and options structures | |
827 | * | |
828 | * On success returns 0, otherwise -EINVAL. | |
829 | */ | |
830 | static int datablob_parse(char *datablob, struct trusted_key_payload *p, | |
831 | struct trusted_key_options *o) | |
832 | { | |
833 | substring_t args[MAX_OPT_ARGS]; | |
834 | long keylen; | |
835 | int ret = -EINVAL; | |
836 | int key_cmd; | |
837 | char *c; | |
838 | ||
839 | /* main command */ | |
840 | c = strsep(&datablob, " \t"); | |
841 | if (!c) | |
842 | return -EINVAL; | |
843 | key_cmd = match_token(c, key_tokens, args); | |
844 | switch (key_cmd) { | |
845 | case Opt_new: | |
846 | /* first argument is key size */ | |
847 | c = strsep(&datablob, " \t"); | |
848 | if (!c) | |
849 | return -EINVAL; | |
850 | ret = strict_strtol(c, 10, &keylen); | |
851 | if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE) | |
852 | return -EINVAL; | |
853 | p->key_len = keylen; | |
854 | ret = getoptions(datablob, p, o); | |
855 | if (ret < 0) | |
856 | return ret; | |
857 | ret = Opt_new; | |
858 | break; | |
859 | case Opt_load: | |
860 | /* first argument is sealed blob */ | |
861 | c = strsep(&datablob, " \t"); | |
862 | if (!c) | |
863 | return -EINVAL; | |
864 | p->blob_len = strlen(c) / 2; | |
865 | if (p->blob_len > MAX_BLOB_SIZE) | |
866 | return -EINVAL; | |
867 | hex2bin(p->blob, c, p->blob_len); | |
868 | ret = getoptions(datablob, p, o); | |
869 | if (ret < 0) | |
870 | return ret; | |
871 | ret = Opt_load; | |
872 | break; | |
873 | case Opt_update: | |
874 | /* all arguments are options */ | |
875 | ret = getoptions(datablob, p, o); | |
876 | if (ret < 0) | |
877 | return ret; | |
878 | ret = Opt_update; | |
879 | break; | |
880 | case Opt_err: | |
881 | return -EINVAL; | |
882 | break; | |
883 | } | |
884 | return ret; | |
885 | } | |
886 | ||
887 | static struct trusted_key_options *trusted_options_alloc(void) | |
888 | { | |
889 | struct trusted_key_options *options; | |
890 | ||
891 | options = kzalloc(sizeof *options, GFP_KERNEL); | |
bc5e0af0 MZ |
892 | if (options) { |
893 | /* set any non-zero defaults */ | |
894 | options->keytype = SRK_keytype; | |
895 | options->keyhandle = SRKHANDLE; | |
896 | } | |
d00a1c72 MZ |
897 | return options; |
898 | } | |
899 | ||
900 | static struct trusted_key_payload *trusted_payload_alloc(struct key *key) | |
901 | { | |
902 | struct trusted_key_payload *p = NULL; | |
903 | int ret; | |
904 | ||
905 | ret = key_payload_reserve(key, sizeof *p); | |
906 | if (ret < 0) | |
907 | return p; | |
908 | p = kzalloc(sizeof *p, GFP_KERNEL); | |
bc5e0af0 MZ |
909 | if (p) |
910 | p->migratable = 1; /* migratable by default */ | |
d00a1c72 MZ |
911 | return p; |
912 | } | |
913 | ||
914 | /* | |
915 | * trusted_instantiate - create a new trusted key | |
916 | * | |
917 | * Unseal an existing trusted blob or, for a new key, get a | |
918 | * random key, then seal and create a trusted key-type key, | |
919 | * adding it to the specified keyring. | |
920 | * | |
921 | * On success, return 0. Otherwise return errno. | |
922 | */ | |
923 | static int trusted_instantiate(struct key *key, const void *data, | |
1bdbb402 | 924 | size_t datalen) |
d00a1c72 MZ |
925 | { |
926 | struct trusted_key_payload *payload = NULL; | |
927 | struct trusted_key_options *options = NULL; | |
928 | char *datablob; | |
929 | int ret = 0; | |
930 | int key_cmd; | |
931 | ||
932 | if (datalen <= 0 || datalen > 32767 || !data) | |
933 | return -EINVAL; | |
934 | ||
935 | datablob = kmalloc(datalen + 1, GFP_KERNEL); | |
936 | if (!datablob) | |
937 | return -ENOMEM; | |
938 | memcpy(datablob, data, datalen); | |
939 | datablob[datalen] = '\0'; | |
940 | ||
941 | options = trusted_options_alloc(); | |
942 | if (!options) { | |
943 | ret = -ENOMEM; | |
944 | goto out; | |
945 | } | |
946 | payload = trusted_payload_alloc(key); | |
947 | if (!payload) { | |
948 | ret = -ENOMEM; | |
949 | goto out; | |
950 | } | |
951 | ||
952 | key_cmd = datablob_parse(datablob, payload, options); | |
953 | if (key_cmd < 0) { | |
954 | ret = key_cmd; | |
955 | goto out; | |
956 | } | |
957 | ||
958 | dump_payload(payload); | |
959 | dump_options(options); | |
960 | ||
961 | switch (key_cmd) { | |
962 | case Opt_load: | |
963 | ret = key_unseal(payload, options); | |
964 | dump_payload(payload); | |
965 | dump_options(options); | |
966 | if (ret < 0) | |
967 | pr_info("trusted_key: key_unseal failed (%d)\n", ret); | |
968 | break; | |
969 | case Opt_new: | |
970 | ret = my_get_random(payload->key, payload->key_len); | |
971 | if (ret < 0) { | |
972 | pr_info("trusted_key: key_create failed (%d)\n", ret); | |
973 | goto out; | |
974 | } | |
975 | ret = key_seal(payload, options); | |
976 | if (ret < 0) | |
977 | pr_info("trusted_key: key_seal failed (%d)\n", ret); | |
978 | break; | |
979 | default: | |
980 | ret = -EINVAL; | |
981 | goto out; | |
982 | } | |
983 | if (!ret && options->pcrlock) | |
984 | ret = pcrlock(options->pcrlock); | |
985 | out: | |
986 | kfree(datablob); | |
987 | kfree(options); | |
988 | if (!ret) | |
989 | rcu_assign_pointer(key->payload.data, payload); | |
990 | else | |
991 | kfree(payload); | |
992 | return ret; | |
993 | } | |
994 | ||
995 | static void trusted_rcu_free(struct rcu_head *rcu) | |
996 | { | |
997 | struct trusted_key_payload *p; | |
998 | ||
999 | p = container_of(rcu, struct trusted_key_payload, rcu); | |
1000 | memset(p->key, 0, p->key_len); | |
1001 | kfree(p); | |
1002 | } | |
1003 | ||
1004 | /* | |
1005 | * trusted_update - reseal an existing key with new PCR values | |
1006 | */ | |
1bdbb402 | 1007 | static int trusted_update(struct key *key, const void *data, size_t datalen) |
d00a1c72 MZ |
1008 | { |
1009 | struct trusted_key_payload *p = key->payload.data; | |
1010 | struct trusted_key_payload *new_p; | |
1011 | struct trusted_key_options *new_o; | |
1012 | char *datablob; | |
1013 | int ret = 0; | |
1014 | ||
1015 | if (!p->migratable) | |
1016 | return -EPERM; | |
1017 | if (datalen <= 0 || datalen > 32767 || !data) | |
1018 | return -EINVAL; | |
1019 | ||
1020 | datablob = kmalloc(datalen + 1, GFP_KERNEL); | |
1021 | if (!datablob) | |
1022 | return -ENOMEM; | |
1023 | new_o = trusted_options_alloc(); | |
1024 | if (!new_o) { | |
1025 | ret = -ENOMEM; | |
1026 | goto out; | |
1027 | } | |
1028 | new_p = trusted_payload_alloc(key); | |
1029 | if (!new_p) { | |
1030 | ret = -ENOMEM; | |
1031 | goto out; | |
1032 | } | |
1033 | ||
1034 | memcpy(datablob, data, datalen); | |
1035 | datablob[datalen] = '\0'; | |
1036 | ret = datablob_parse(datablob, new_p, new_o); | |
1037 | if (ret != Opt_update) { | |
1038 | ret = -EINVAL; | |
1039 | goto out; | |
1040 | } | |
1041 | /* copy old key values, and reseal with new pcrs */ | |
1042 | new_p->migratable = p->migratable; | |
1043 | new_p->key_len = p->key_len; | |
1044 | memcpy(new_p->key, p->key, p->key_len); | |
1045 | dump_payload(p); | |
1046 | dump_payload(new_p); | |
1047 | ||
1048 | ret = key_seal(new_p, new_o); | |
1049 | if (ret < 0) { | |
1050 | pr_info("trusted_key: key_seal failed (%d)\n", ret); | |
1051 | kfree(new_p); | |
1052 | goto out; | |
1053 | } | |
1054 | if (new_o->pcrlock) { | |
1055 | ret = pcrlock(new_o->pcrlock); | |
1056 | if (ret < 0) { | |
1057 | pr_info("trusted_key: pcrlock failed (%d)\n", ret); | |
1058 | kfree(new_p); | |
1059 | goto out; | |
1060 | } | |
1061 | } | |
1062 | rcu_assign_pointer(key->payload.data, new_p); | |
1063 | call_rcu(&p->rcu, trusted_rcu_free); | |
1064 | out: | |
1065 | kfree(datablob); | |
1066 | kfree(new_o); | |
1067 | return ret; | |
1068 | } | |
1069 | ||
1070 | /* | |
1071 | * trusted_read - copy the sealed blob data to userspace in hex. | |
1072 | * On success, return to userspace the trusted key datablob size. | |
1073 | */ | |
1074 | static long trusted_read(const struct key *key, char __user *buffer, | |
1075 | size_t buflen) | |
1076 | { | |
1077 | struct trusted_key_payload *p; | |
1078 | char *ascii_buf; | |
1079 | char *bufp; | |
1080 | int i; | |
1081 | ||
1082 | p = rcu_dereference_protected(key->payload.data, | |
1083 | rwsem_is_locked(&((struct key *)key)->sem)); | |
1084 | if (!p) | |
1085 | return -EINVAL; | |
1086 | if (!buffer || buflen <= 0) | |
1087 | return 2 * p->blob_len; | |
1088 | ascii_buf = kmalloc(2 * p->blob_len, GFP_KERNEL); | |
1089 | if (!ascii_buf) | |
1090 | return -ENOMEM; | |
1091 | ||
1092 | bufp = ascii_buf; | |
1093 | for (i = 0; i < p->blob_len; i++) | |
1094 | bufp = pack_hex_byte(bufp, p->blob[i]); | |
1095 | if ((copy_to_user(buffer, ascii_buf, 2 * p->blob_len)) != 0) { | |
1096 | kfree(ascii_buf); | |
1097 | return -EFAULT; | |
1098 | } | |
1099 | kfree(ascii_buf); | |
1100 | return 2 * p->blob_len; | |
1101 | } | |
1102 | ||
1103 | /* | |
1104 | * trusted_destroy - before freeing the key, clear the decrypted data | |
1105 | */ | |
1106 | static void trusted_destroy(struct key *key) | |
1107 | { | |
1108 | struct trusted_key_payload *p = key->payload.data; | |
1109 | ||
1110 | if (!p) | |
1111 | return; | |
1112 | memset(p->key, 0, p->key_len); | |
1113 | kfree(key->payload.data); | |
1114 | } | |
1115 | ||
1116 | struct key_type key_type_trusted = { | |
1117 | .name = "trusted", | |
1118 | .instantiate = trusted_instantiate, | |
1119 | .update = trusted_update, | |
1120 | .match = user_match, | |
1121 | .destroy = trusted_destroy, | |
1122 | .describe = user_describe, | |
1123 | .read = trusted_read, | |
1124 | }; | |
1125 | ||
1126 | EXPORT_SYMBOL_GPL(key_type_trusted); | |
1127 | ||
1128 | static void trusted_shash_release(void) | |
1129 | { | |
1130 | if (hashalg) | |
1131 | crypto_free_shash(hashalg); | |
1132 | if (hmacalg) | |
1133 | crypto_free_shash(hmacalg); | |
1134 | } | |
1135 | ||
1136 | static int __init trusted_shash_alloc(void) | |
1137 | { | |
1138 | int ret; | |
1139 | ||
1140 | hmacalg = crypto_alloc_shash(hmac_alg, 0, CRYPTO_ALG_ASYNC); | |
1141 | if (IS_ERR(hmacalg)) { | |
1142 | pr_info("trusted_key: could not allocate crypto %s\n", | |
1143 | hmac_alg); | |
1144 | return PTR_ERR(hmacalg); | |
1145 | } | |
1146 | ||
1147 | hashalg = crypto_alloc_shash(hash_alg, 0, CRYPTO_ALG_ASYNC); | |
1148 | if (IS_ERR(hashalg)) { | |
1149 | pr_info("trusted_key: could not allocate crypto %s\n", | |
1150 | hash_alg); | |
1151 | ret = PTR_ERR(hashalg); | |
1152 | goto hashalg_fail; | |
1153 | } | |
1154 | ||
1155 | return 0; | |
1156 | ||
1157 | hashalg_fail: | |
1158 | crypto_free_shash(hmacalg); | |
1159 | return ret; | |
1160 | } | |
1161 | ||
1162 | static int __init init_trusted(void) | |
1163 | { | |
1164 | int ret; | |
1165 | ||
1166 | ret = trusted_shash_alloc(); | |
1167 | if (ret < 0) | |
1168 | return ret; | |
1169 | ret = register_key_type(&key_type_trusted); | |
1170 | if (ret < 0) | |
1171 | trusted_shash_release(); | |
1172 | return ret; | |
1173 | } | |
1174 | ||
1175 | static void __exit cleanup_trusted(void) | |
1176 | { | |
1177 | trusted_shash_release(); | |
1178 | unregister_key_type(&key_type_trusted); | |
1179 | } | |
1180 | ||
1181 | late_initcall(init_trusted); | |
1182 | module_exit(cleanup_trusted); | |
1183 | ||
1184 | MODULE_LICENSE("GPL"); |