Commit | Line | Data |
---|---|---|
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 *); | |
151 | ret = crypto_shash_update(&sdesc->shash, data, dlen); | |
bc5e0af0 MZ |
152 | if (ret < 0) { |
153 | va_end(argp); | |
d00a1c72 | 154 | goto out; |
bc5e0af0 | 155 | } |
d00a1c72 MZ |
156 | } |
157 | va_end(argp); | |
158 | ret = crypto_shash_final(&sdesc->shash, paramdigest); | |
159 | if (!ret) | |
bc5e0af0 MZ |
160 | ret = TSS_rawhmac(digest, key, keylen, SHA1_DIGEST_SIZE, |
161 | paramdigest, TPM_NONCE_SIZE, h1, | |
162 | TPM_NONCE_SIZE, h2, 1, &c, 0, 0); | |
d00a1c72 MZ |
163 | out: |
164 | kfree(sdesc); | |
165 | return ret; | |
166 | } | |
167 | ||
168 | /* | |
169 | * verify the AUTH1_COMMAND (Seal) result from TPM | |
170 | */ | |
bc5e0af0 MZ |
171 | static int TSS_checkhmac1(unsigned char *buffer, |
172 | const uint32_t command, | |
173 | const unsigned char *ononce, | |
174 | const unsigned char *key, | |
1bdbb402 | 175 | unsigned int keylen, ...) |
d00a1c72 MZ |
176 | { |
177 | uint32_t bufsize; | |
178 | uint16_t tag; | |
179 | uint32_t ordinal; | |
180 | uint32_t result; | |
181 | unsigned char *enonce; | |
182 | unsigned char *continueflag; | |
183 | unsigned char *authdata; | |
184 | unsigned char testhmac[SHA1_DIGEST_SIZE]; | |
185 | unsigned char paramdigest[SHA1_DIGEST_SIZE]; | |
186 | struct sdesc *sdesc; | |
187 | unsigned int dlen; | |
188 | unsigned int dpos; | |
189 | va_list argp; | |
190 | int ret; | |
191 | ||
192 | bufsize = LOAD32(buffer, TPM_SIZE_OFFSET); | |
193 | tag = LOAD16(buffer, 0); | |
194 | ordinal = command; | |
195 | result = LOAD32N(buffer, TPM_RETURN_OFFSET); | |
196 | if (tag == TPM_TAG_RSP_COMMAND) | |
197 | return 0; | |
198 | if (tag != TPM_TAG_RSP_AUTH1_COMMAND) | |
199 | return -EINVAL; | |
200 | authdata = buffer + bufsize - SHA1_DIGEST_SIZE; | |
201 | continueflag = authdata - 1; | |
202 | enonce = continueflag - TPM_NONCE_SIZE; | |
203 | ||
204 | sdesc = init_sdesc(hashalg); | |
205 | if (IS_ERR(sdesc)) { | |
206 | pr_info("trusted_key: can't alloc %s\n", hash_alg); | |
207 | return PTR_ERR(sdesc); | |
208 | } | |
209 | ret = crypto_shash_init(&sdesc->shash); | |
210 | if (ret < 0) | |
211 | goto out; | |
212 | ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result, | |
213 | sizeof result); | |
214 | if (ret < 0) | |
215 | goto out; | |
216 | ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal, | |
217 | sizeof ordinal); | |
218 | if (ret < 0) | |
219 | goto out; | |
220 | va_start(argp, keylen); | |
221 | for (;;) { | |
222 | dlen = va_arg(argp, unsigned int); | |
223 | if (dlen == 0) | |
224 | break; | |
225 | dpos = va_arg(argp, unsigned int); | |
226 | ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen); | |
bc5e0af0 MZ |
227 | if (ret < 0) { |
228 | va_end(argp); | |
d00a1c72 | 229 | goto out; |
bc5e0af0 | 230 | } |
d00a1c72 MZ |
231 | } |
232 | va_end(argp); | |
233 | ret = crypto_shash_final(&sdesc->shash, paramdigest); | |
234 | if (ret < 0) | |
235 | goto out; | |
bc5e0af0 | 236 | |
d00a1c72 MZ |
237 | ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest, |
238 | TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce, | |
239 | 1, continueflag, 0, 0); | |
240 | if (ret < 0) | |
241 | goto out; | |
bc5e0af0 | 242 | |
d00a1c72 MZ |
243 | if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE)) |
244 | ret = -EINVAL; | |
245 | out: | |
246 | kfree(sdesc); | |
247 | return ret; | |
248 | } | |
249 | ||
250 | /* | |
251 | * verify the AUTH2_COMMAND (unseal) result from TPM | |
252 | */ | |
bc5e0af0 MZ |
253 | static int TSS_checkhmac2(unsigned char *buffer, |
254 | const uint32_t command, | |
255 | const unsigned char *ononce, | |
256 | const unsigned char *key1, | |
1bdbb402 | 257 | unsigned int keylen1, |
bc5e0af0 | 258 | const unsigned char *key2, |
1bdbb402 | 259 | unsigned int keylen2, ...) |
d00a1c72 MZ |
260 | { |
261 | uint32_t bufsize; | |
262 | uint16_t tag; | |
263 | uint32_t ordinal; | |
264 | uint32_t result; | |
265 | unsigned char *enonce1; | |
266 | unsigned char *continueflag1; | |
267 | unsigned char *authdata1; | |
268 | unsigned char *enonce2; | |
269 | unsigned char *continueflag2; | |
270 | unsigned char *authdata2; | |
271 | unsigned char testhmac1[SHA1_DIGEST_SIZE]; | |
272 | unsigned char testhmac2[SHA1_DIGEST_SIZE]; | |
273 | unsigned char paramdigest[SHA1_DIGEST_SIZE]; | |
274 | struct sdesc *sdesc; | |
275 | unsigned int dlen; | |
276 | unsigned int dpos; | |
277 | va_list argp; | |
278 | int ret; | |
279 | ||
280 | bufsize = LOAD32(buffer, TPM_SIZE_OFFSET); | |
281 | tag = LOAD16(buffer, 0); | |
282 | ordinal = command; | |
283 | result = LOAD32N(buffer, TPM_RETURN_OFFSET); | |
284 | ||
285 | if (tag == TPM_TAG_RSP_COMMAND) | |
286 | return 0; | |
287 | if (tag != TPM_TAG_RSP_AUTH2_COMMAND) | |
288 | return -EINVAL; | |
289 | authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1 | |
290 | + SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE); | |
291 | authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE); | |
292 | continueflag1 = authdata1 - 1; | |
293 | continueflag2 = authdata2 - 1; | |
294 | enonce1 = continueflag1 - TPM_NONCE_SIZE; | |
295 | enonce2 = continueflag2 - TPM_NONCE_SIZE; | |
296 | ||
297 | sdesc = init_sdesc(hashalg); | |
298 | if (IS_ERR(sdesc)) { | |
299 | pr_info("trusted_key: can't alloc %s\n", hash_alg); | |
300 | return PTR_ERR(sdesc); | |
301 | } | |
302 | ret = crypto_shash_init(&sdesc->shash); | |
303 | if (ret < 0) | |
304 | goto out; | |
305 | ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result, | |
306 | sizeof result); | |
307 | if (ret < 0) | |
308 | goto out; | |
309 | ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal, | |
310 | sizeof ordinal); | |
311 | if (ret < 0) | |
312 | goto out; | |
313 | ||
314 | va_start(argp, keylen2); | |
315 | for (;;) { | |
316 | dlen = va_arg(argp, unsigned int); | |
317 | if (dlen == 0) | |
318 | break; | |
319 | dpos = va_arg(argp, unsigned int); | |
320 | ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen); | |
bc5e0af0 MZ |
321 | if (ret < 0) { |
322 | va_end(argp); | |
d00a1c72 | 323 | goto out; |
bc5e0af0 | 324 | } |
d00a1c72 | 325 | } |
bc5e0af0 | 326 | va_end(argp); |
d00a1c72 MZ |
327 | ret = crypto_shash_final(&sdesc->shash, paramdigest); |
328 | if (ret < 0) | |
329 | goto out; | |
330 | ||
331 | ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE, | |
332 | paramdigest, TPM_NONCE_SIZE, enonce1, | |
333 | TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0); | |
bc5e0af0 MZ |
334 | if (ret < 0) |
335 | goto out; | |
d00a1c72 MZ |
336 | if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) { |
337 | ret = -EINVAL; | |
338 | goto out; | |
339 | } | |
340 | ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE, | |
341 | paramdigest, TPM_NONCE_SIZE, enonce2, | |
342 | TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0); | |
bc5e0af0 MZ |
343 | if (ret < 0) |
344 | goto out; | |
d00a1c72 MZ |
345 | if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE)) |
346 | ret = -EINVAL; | |
347 | out: | |
348 | kfree(sdesc); | |
349 | return ret; | |
350 | } | |
351 | ||
352 | /* | |
353 | * For key specific tpm requests, we will generate and send our | |
354 | * own TPM command packets using the drivers send function. | |
355 | */ | |
356 | static int trusted_tpm_send(const u32 chip_num, unsigned char *cmd, | |
357 | size_t buflen) | |
358 | { | |
359 | int rc; | |
360 | ||
361 | dump_tpm_buf(cmd); | |
362 | rc = tpm_send(chip_num, cmd, buflen); | |
363 | dump_tpm_buf(cmd); | |
364 | if (rc > 0) | |
365 | /* Can't return positive return codes values to keyctl */ | |
366 | rc = -EPERM; | |
367 | return rc; | |
368 | } | |
369 | ||
370 | /* | |
371 | * get a random value from TPM | |
372 | */ | |
373 | static int tpm_get_random(struct tpm_buf *tb, unsigned char *buf, uint32_t len) | |
374 | { | |
375 | int ret; | |
376 | ||
377 | INIT_BUF(tb); | |
378 | store16(tb, TPM_TAG_RQU_COMMAND); | |
379 | store32(tb, TPM_GETRANDOM_SIZE); | |
380 | store32(tb, TPM_ORD_GETRANDOM); | |
381 | store32(tb, len); | |
382 | ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, sizeof tb->data); | |
bc5e0af0 MZ |
383 | if (!ret) |
384 | memcpy(buf, tb->data + TPM_GETRANDOM_SIZE, len); | |
d00a1c72 MZ |
385 | return ret; |
386 | } | |
387 | ||
388 | static int my_get_random(unsigned char *buf, int len) | |
389 | { | |
390 | struct tpm_buf *tb; | |
391 | int ret; | |
392 | ||
1bdbb402 | 393 | tb = kmalloc(sizeof *tb, GFP_KERNEL); |
d00a1c72 MZ |
394 | if (!tb) |
395 | return -ENOMEM; | |
396 | ret = tpm_get_random(tb, buf, len); | |
397 | ||
398 | kfree(tb); | |
399 | return ret; | |
400 | } | |
401 | ||
402 | /* | |
403 | * Lock a trusted key, by extending a selected PCR. | |
404 | * | |
405 | * Prevents a trusted key that is sealed to PCRs from being accessed. | |
406 | * This uses the tpm driver's extend function. | |
407 | */ | |
408 | static int pcrlock(const int pcrnum) | |
409 | { | |
410 | unsigned char hash[SHA1_DIGEST_SIZE]; | |
bc5e0af0 | 411 | int ret; |
d00a1c72 MZ |
412 | |
413 | if (!capable(CAP_SYS_ADMIN)) | |
414 | return -EPERM; | |
bc5e0af0 MZ |
415 | ret = my_get_random(hash, SHA1_DIGEST_SIZE); |
416 | if (ret < 0) | |
417 | return ret; | |
d00a1c72 MZ |
418 | return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0; |
419 | } | |
420 | ||
421 | /* | |
422 | * Create an object specific authorisation protocol (OSAP) session | |
423 | */ | |
424 | static int osap(struct tpm_buf *tb, struct osapsess *s, | |
1bdbb402 | 425 | const unsigned char *key, uint16_t type, uint32_t handle) |
d00a1c72 MZ |
426 | { |
427 | unsigned char enonce[TPM_NONCE_SIZE]; | |
428 | unsigned char ononce[TPM_NONCE_SIZE]; | |
429 | int ret; | |
430 | ||
431 | ret = tpm_get_random(tb, ononce, TPM_NONCE_SIZE); | |
432 | if (ret < 0) | |
433 | return ret; | |
434 | ||
435 | INIT_BUF(tb); | |
436 | store16(tb, TPM_TAG_RQU_COMMAND); | |
437 | store32(tb, TPM_OSAP_SIZE); | |
438 | store32(tb, TPM_ORD_OSAP); | |
439 | store16(tb, type); | |
440 | store32(tb, handle); | |
441 | storebytes(tb, ononce, TPM_NONCE_SIZE); | |
442 | ||
443 | ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); | |
444 | if (ret < 0) | |
445 | return ret; | |
446 | ||
447 | s->handle = LOAD32(tb->data, TPM_DATA_OFFSET); | |
448 | memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]), | |
449 | TPM_NONCE_SIZE); | |
450 | memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) + | |
451 | TPM_NONCE_SIZE]), TPM_NONCE_SIZE); | |
bc5e0af0 MZ |
452 | return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE, |
453 | enonce, TPM_NONCE_SIZE, ononce, 0, 0); | |
d00a1c72 MZ |
454 | } |
455 | ||
456 | /* | |
457 | * Create an object independent authorisation protocol (oiap) session | |
458 | */ | |
459 | static int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce) | |
460 | { | |
461 | int ret; | |
462 | ||
463 | INIT_BUF(tb); | |
464 | store16(tb, TPM_TAG_RQU_COMMAND); | |
465 | store32(tb, TPM_OIAP_SIZE); | |
466 | store32(tb, TPM_ORD_OIAP); | |
467 | ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); | |
468 | if (ret < 0) | |
469 | return ret; | |
470 | ||
471 | *handle = LOAD32(tb->data, TPM_DATA_OFFSET); | |
472 | memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)], | |
473 | TPM_NONCE_SIZE); | |
bc5e0af0 | 474 | return 0; |
d00a1c72 MZ |
475 | } |
476 | ||
477 | struct tpm_digests { | |
478 | unsigned char encauth[SHA1_DIGEST_SIZE]; | |
479 | unsigned char pubauth[SHA1_DIGEST_SIZE]; | |
480 | unsigned char xorwork[SHA1_DIGEST_SIZE * 2]; | |
481 | unsigned char xorhash[SHA1_DIGEST_SIZE]; | |
482 | unsigned char nonceodd[TPM_NONCE_SIZE]; | |
483 | }; | |
484 | ||
485 | /* | |
486 | * Have the TPM seal(encrypt) the trusted key, possibly based on | |
487 | * Platform Configuration Registers (PCRs). AUTH1 for sealing key. | |
488 | */ | |
1bdbb402 MZ |
489 | static int tpm_seal(struct tpm_buf *tb, uint16_t keytype, |
490 | uint32_t keyhandle, const unsigned char *keyauth, | |
491 | const unsigned char *data, uint32_t datalen, | |
d00a1c72 MZ |
492 | unsigned char *blob, uint32_t *bloblen, |
493 | const unsigned char *blobauth, | |
1bdbb402 | 494 | const unsigned char *pcrinfo, uint32_t pcrinfosize) |
d00a1c72 MZ |
495 | { |
496 | struct osapsess sess; | |
497 | struct tpm_digests *td; | |
498 | unsigned char cont; | |
499 | uint32_t ordinal; | |
500 | uint32_t pcrsize; | |
501 | uint32_t datsize; | |
502 | int sealinfosize; | |
503 | int encdatasize; | |
504 | int storedsize; | |
505 | int ret; | |
506 | int i; | |
507 | ||
508 | /* alloc some work space for all the hashes */ | |
509 | td = kmalloc(sizeof *td, GFP_KERNEL); | |
510 | if (!td) | |
511 | return -ENOMEM; | |
512 | ||
513 | /* get session for sealing key */ | |
514 | ret = osap(tb, &sess, keyauth, keytype, keyhandle); | |
515 | if (ret < 0) | |
40c10017 | 516 | goto out; |
d00a1c72 MZ |
517 | dump_sess(&sess); |
518 | ||
519 | /* calculate encrypted authorization value */ | |
520 | memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE); | |
521 | memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE); | |
522 | ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash); | |
523 | if (ret < 0) | |
40c10017 | 524 | goto out; |
d00a1c72 MZ |
525 | |
526 | ret = tpm_get_random(tb, td->nonceodd, TPM_NONCE_SIZE); | |
527 | if (ret < 0) | |
40c10017 | 528 | goto out; |
d00a1c72 MZ |
529 | ordinal = htonl(TPM_ORD_SEAL); |
530 | datsize = htonl(datalen); | |
531 | pcrsize = htonl(pcrinfosize); | |
532 | cont = 0; | |
533 | ||
534 | /* encrypt data authorization key */ | |
535 | for (i = 0; i < SHA1_DIGEST_SIZE; ++i) | |
536 | td->encauth[i] = td->xorhash[i] ^ blobauth[i]; | |
537 | ||
538 | /* calculate authorization HMAC value */ | |
539 | if (pcrinfosize == 0) { | |
540 | /* no pcr info specified */ | |
bc5e0af0 MZ |
541 | ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE, |
542 | sess.enonce, td->nonceodd, cont, | |
543 | sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE, | |
544 | td->encauth, sizeof(uint32_t), &pcrsize, | |
545 | sizeof(uint32_t), &datsize, datalen, data, 0, | |
546 | 0); | |
d00a1c72 MZ |
547 | } else { |
548 | /* pcr info specified */ | |
bc5e0af0 MZ |
549 | ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE, |
550 | sess.enonce, td->nonceodd, cont, | |
551 | sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE, | |
552 | td->encauth, sizeof(uint32_t), &pcrsize, | |
553 | pcrinfosize, pcrinfo, sizeof(uint32_t), | |
554 | &datsize, datalen, data, 0, 0); | |
d00a1c72 | 555 | } |
bc5e0af0 | 556 | if (ret < 0) |
40c10017 | 557 | goto out; |
d00a1c72 MZ |
558 | |
559 | /* build and send the TPM request packet */ | |
560 | INIT_BUF(tb); | |
561 | store16(tb, TPM_TAG_RQU_AUTH1_COMMAND); | |
562 | store32(tb, TPM_SEAL_SIZE + pcrinfosize + datalen); | |
563 | store32(tb, TPM_ORD_SEAL); | |
564 | store32(tb, keyhandle); | |
565 | storebytes(tb, td->encauth, SHA1_DIGEST_SIZE); | |
566 | store32(tb, pcrinfosize); | |
567 | storebytes(tb, pcrinfo, pcrinfosize); | |
568 | store32(tb, datalen); | |
569 | storebytes(tb, data, datalen); | |
570 | store32(tb, sess.handle); | |
571 | storebytes(tb, td->nonceodd, TPM_NONCE_SIZE); | |
572 | store8(tb, cont); | |
573 | storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE); | |
574 | ||
575 | ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); | |
576 | if (ret < 0) | |
40c10017 | 577 | goto out; |
d00a1c72 MZ |
578 | |
579 | /* calculate the size of the returned Blob */ | |
580 | sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t)); | |
581 | encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) + | |
582 | sizeof(uint32_t) + sealinfosize); | |
583 | storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize + | |
584 | sizeof(uint32_t) + encdatasize; | |
585 | ||
586 | /* check the HMAC in the response */ | |
587 | ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret, | |
588 | SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0, | |
589 | 0); | |
590 | ||
591 | /* copy the returned blob to caller */ | |
bc5e0af0 MZ |
592 | if (!ret) { |
593 | memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize); | |
594 | *bloblen = storedsize; | |
595 | } | |
40c10017 MZ |
596 | out: |
597 | kfree(td); | |
d00a1c72 MZ |
598 | return ret; |
599 | } | |
600 | ||
601 | /* | |
602 | * use the AUTH2_COMMAND form of unseal, to authorize both key and blob | |
603 | */ | |
604 | static int tpm_unseal(struct tpm_buf *tb, | |
1bdbb402 MZ |
605 | uint32_t keyhandle, const unsigned char *keyauth, |
606 | const unsigned char *blob, int bloblen, | |
d00a1c72 MZ |
607 | const unsigned char *blobauth, |
608 | unsigned char *data, unsigned int *datalen) | |
609 | { | |
610 | unsigned char nonceodd[TPM_NONCE_SIZE]; | |
611 | unsigned char enonce1[TPM_NONCE_SIZE]; | |
612 | unsigned char enonce2[TPM_NONCE_SIZE]; | |
613 | unsigned char authdata1[SHA1_DIGEST_SIZE]; | |
614 | unsigned char authdata2[SHA1_DIGEST_SIZE]; | |
615 | uint32_t authhandle1 = 0; | |
616 | uint32_t authhandle2 = 0; | |
617 | unsigned char cont = 0; | |
618 | uint32_t ordinal; | |
619 | uint32_t keyhndl; | |
620 | int ret; | |
621 | ||
622 | /* sessions for unsealing key and data */ | |
623 | ret = oiap(tb, &authhandle1, enonce1); | |
624 | if (ret < 0) { | |
625 | pr_info("trusted_key: oiap failed (%d)\n", ret); | |
626 | return ret; | |
627 | } | |
628 | ret = oiap(tb, &authhandle2, enonce2); | |
629 | if (ret < 0) { | |
630 | pr_info("trusted_key: oiap failed (%d)\n", ret); | |
631 | return ret; | |
632 | } | |
633 | ||
634 | ordinal = htonl(TPM_ORD_UNSEAL); | |
635 | keyhndl = htonl(SRKHANDLE); | |
636 | ret = tpm_get_random(tb, nonceodd, TPM_NONCE_SIZE); | |
637 | if (ret < 0) { | |
638 | pr_info("trusted_key: tpm_get_random failed (%d)\n", ret); | |
639 | return ret; | |
640 | } | |
bc5e0af0 MZ |
641 | ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE, |
642 | enonce1, nonceodd, cont, sizeof(uint32_t), | |
643 | &ordinal, bloblen, blob, 0, 0); | |
644 | if (ret < 0) | |
645 | return ret; | |
646 | ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE, | |
647 | enonce2, nonceodd, cont, sizeof(uint32_t), | |
648 | &ordinal, bloblen, blob, 0, 0); | |
649 | if (ret < 0) | |
650 | return ret; | |
d00a1c72 MZ |
651 | |
652 | /* build and send TPM request packet */ | |
653 | INIT_BUF(tb); | |
654 | store16(tb, TPM_TAG_RQU_AUTH2_COMMAND); | |
655 | store32(tb, TPM_UNSEAL_SIZE + bloblen); | |
656 | store32(tb, TPM_ORD_UNSEAL); | |
657 | store32(tb, keyhandle); | |
658 | storebytes(tb, blob, bloblen); | |
659 | store32(tb, authhandle1); | |
660 | storebytes(tb, nonceodd, TPM_NONCE_SIZE); | |
661 | store8(tb, cont); | |
662 | storebytes(tb, authdata1, SHA1_DIGEST_SIZE); | |
663 | store32(tb, authhandle2); | |
664 | storebytes(tb, nonceodd, TPM_NONCE_SIZE); | |
665 | store8(tb, cont); | |
666 | storebytes(tb, authdata2, SHA1_DIGEST_SIZE); | |
667 | ||
668 | ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); | |
669 | if (ret < 0) { | |
670 | pr_info("trusted_key: authhmac failed (%d)\n", ret); | |
671 | return ret; | |
672 | } | |
673 | ||
674 | *datalen = LOAD32(tb->data, TPM_DATA_OFFSET); | |
675 | ret = TSS_checkhmac2(tb->data, ordinal, nonceodd, | |
676 | keyauth, SHA1_DIGEST_SIZE, | |
677 | blobauth, SHA1_DIGEST_SIZE, | |
678 | sizeof(uint32_t), TPM_DATA_OFFSET, | |
679 | *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0, | |
680 | 0); | |
bc5e0af0 | 681 | if (ret < 0) { |
d00a1c72 | 682 | pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret); |
bc5e0af0 MZ |
683 | return ret; |
684 | } | |
d00a1c72 | 685 | memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen); |
bc5e0af0 | 686 | return 0; |
d00a1c72 MZ |
687 | } |
688 | ||
689 | /* | |
690 | * Have the TPM seal(encrypt) the symmetric key | |
691 | */ | |
692 | static int key_seal(struct trusted_key_payload *p, | |
693 | struct trusted_key_options *o) | |
694 | { | |
695 | struct tpm_buf *tb; | |
696 | int ret; | |
697 | ||
698 | tb = kzalloc(sizeof *tb, GFP_KERNEL); | |
699 | if (!tb) | |
700 | return -ENOMEM; | |
701 | ||
702 | /* include migratable flag at end of sealed key */ | |
703 | p->key[p->key_len] = p->migratable; | |
704 | ||
705 | ret = tpm_seal(tb, o->keytype, o->keyhandle, o->keyauth, | |
706 | p->key, p->key_len + 1, p->blob, &p->blob_len, | |
707 | o->blobauth, o->pcrinfo, o->pcrinfo_len); | |
708 | if (ret < 0) | |
709 | pr_info("trusted_key: srkseal failed (%d)\n", ret); | |
710 | ||
711 | kfree(tb); | |
712 | return ret; | |
713 | } | |
714 | ||
715 | /* | |
716 | * Have the TPM unseal(decrypt) the symmetric key | |
717 | */ | |
718 | static int key_unseal(struct trusted_key_payload *p, | |
719 | struct trusted_key_options *o) | |
720 | { | |
721 | struct tpm_buf *tb; | |
722 | int ret; | |
723 | ||
724 | tb = kzalloc(sizeof *tb, GFP_KERNEL); | |
725 | if (!tb) | |
726 | return -ENOMEM; | |
727 | ||
728 | ret = tpm_unseal(tb, o->keyhandle, o->keyauth, p->blob, p->blob_len, | |
729 | o->blobauth, p->key, &p->key_len); | |
d00a1c72 MZ |
730 | if (ret < 0) |
731 | pr_info("trusted_key: srkunseal failed (%d)\n", ret); | |
bc5e0af0 MZ |
732 | else |
733 | /* pull migratable flag out of sealed key */ | |
734 | p->migratable = p->key[--p->key_len]; | |
d00a1c72 MZ |
735 | |
736 | kfree(tb); | |
737 | return ret; | |
738 | } | |
739 | ||
740 | enum { | |
741 | Opt_err = -1, | |
742 | Opt_new, Opt_load, Opt_update, | |
743 | Opt_keyhandle, Opt_keyauth, Opt_blobauth, | |
744 | Opt_pcrinfo, Opt_pcrlock, Opt_migratable | |
745 | }; | |
746 | ||
747 | static const match_table_t key_tokens = { | |
748 | {Opt_new, "new"}, | |
749 | {Opt_load, "load"}, | |
750 | {Opt_update, "update"}, | |
751 | {Opt_keyhandle, "keyhandle=%s"}, | |
752 | {Opt_keyauth, "keyauth=%s"}, | |
753 | {Opt_blobauth, "blobauth=%s"}, | |
754 | {Opt_pcrinfo, "pcrinfo=%s"}, | |
755 | {Opt_pcrlock, "pcrlock=%s"}, | |
756 | {Opt_migratable, "migratable=%s"}, | |
757 | {Opt_err, NULL} | |
758 | }; | |
759 | ||
760 | /* can have zero or more token= options */ | |
761 | static int getoptions(char *c, struct trusted_key_payload *pay, | |
762 | struct trusted_key_options *opt) | |
763 | { | |
764 | substring_t args[MAX_OPT_ARGS]; | |
765 | char *p = c; | |
766 | int token; | |
767 | int res; | |
768 | unsigned long handle; | |
769 | unsigned long lock; | |
770 | ||
771 | while ((p = strsep(&c, " \t"))) { | |
772 | if (*p == '\0' || *p == ' ' || *p == '\t') | |
773 | continue; | |
774 | token = match_token(p, key_tokens, args); | |
775 | ||
776 | switch (token) { | |
777 | case Opt_pcrinfo: | |
778 | opt->pcrinfo_len = strlen(args[0].from) / 2; | |
779 | if (opt->pcrinfo_len > MAX_PCRINFO_SIZE) | |
780 | return -EINVAL; | |
781 | hex2bin(opt->pcrinfo, args[0].from, opt->pcrinfo_len); | |
782 | break; | |
783 | case Opt_keyhandle: | |
784 | res = strict_strtoul(args[0].from, 16, &handle); | |
785 | if (res < 0) | |
786 | return -EINVAL; | |
787 | opt->keytype = SEAL_keytype; | |
788 | opt->keyhandle = handle; | |
789 | break; | |
790 | case Opt_keyauth: | |
791 | if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE) | |
792 | return -EINVAL; | |
793 | hex2bin(opt->keyauth, args[0].from, SHA1_DIGEST_SIZE); | |
794 | break; | |
795 | case Opt_blobauth: | |
796 | if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE) | |
797 | return -EINVAL; | |
798 | hex2bin(opt->blobauth, args[0].from, SHA1_DIGEST_SIZE); | |
799 | break; | |
800 | case Opt_migratable: | |
801 | if (*args[0].from == '0') | |
802 | pay->migratable = 0; | |
803 | else | |
804 | return -EINVAL; | |
805 | break; | |
806 | case Opt_pcrlock: | |
807 | res = strict_strtoul(args[0].from, 10, &lock); | |
808 | if (res < 0) | |
809 | return -EINVAL; | |
810 | opt->pcrlock = lock; | |
811 | break; | |
812 | default: | |
813 | return -EINVAL; | |
814 | } | |
815 | } | |
816 | return 0; | |
817 | } | |
818 | ||
819 | /* | |
820 | * datablob_parse - parse the keyctl data and fill in the | |
821 | * payload and options structures | |
822 | * | |
823 | * On success returns 0, otherwise -EINVAL. | |
824 | */ | |
825 | static int datablob_parse(char *datablob, struct trusted_key_payload *p, | |
826 | struct trusted_key_options *o) | |
827 | { | |
828 | substring_t args[MAX_OPT_ARGS]; | |
829 | long keylen; | |
830 | int ret = -EINVAL; | |
831 | int key_cmd; | |
832 | char *c; | |
833 | ||
834 | /* main command */ | |
835 | c = strsep(&datablob, " \t"); | |
836 | if (!c) | |
837 | return -EINVAL; | |
838 | key_cmd = match_token(c, key_tokens, args); | |
839 | switch (key_cmd) { | |
840 | case Opt_new: | |
841 | /* first argument is key size */ | |
842 | c = strsep(&datablob, " \t"); | |
843 | if (!c) | |
844 | return -EINVAL; | |
845 | ret = strict_strtol(c, 10, &keylen); | |
846 | if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE) | |
847 | return -EINVAL; | |
848 | p->key_len = keylen; | |
849 | ret = getoptions(datablob, p, o); | |
850 | if (ret < 0) | |
851 | return ret; | |
852 | ret = Opt_new; | |
853 | break; | |
854 | case Opt_load: | |
855 | /* first argument is sealed blob */ | |
856 | c = strsep(&datablob, " \t"); | |
857 | if (!c) | |
858 | return -EINVAL; | |
859 | p->blob_len = strlen(c) / 2; | |
860 | if (p->blob_len > MAX_BLOB_SIZE) | |
861 | return -EINVAL; | |
862 | hex2bin(p->blob, c, p->blob_len); | |
863 | ret = getoptions(datablob, p, o); | |
864 | if (ret < 0) | |
865 | return ret; | |
866 | ret = Opt_load; | |
867 | break; | |
868 | case Opt_update: | |
869 | /* all arguments are options */ | |
870 | ret = getoptions(datablob, p, o); | |
871 | if (ret < 0) | |
872 | return ret; | |
873 | ret = Opt_update; | |
874 | break; | |
875 | case Opt_err: | |
876 | return -EINVAL; | |
877 | break; | |
878 | } | |
879 | return ret; | |
880 | } | |
881 | ||
882 | static struct trusted_key_options *trusted_options_alloc(void) | |
883 | { | |
884 | struct trusted_key_options *options; | |
885 | ||
886 | options = kzalloc(sizeof *options, GFP_KERNEL); | |
bc5e0af0 MZ |
887 | if (options) { |
888 | /* set any non-zero defaults */ | |
889 | options->keytype = SRK_keytype; | |
890 | options->keyhandle = SRKHANDLE; | |
891 | } | |
d00a1c72 MZ |
892 | return options; |
893 | } | |
894 | ||
895 | static struct trusted_key_payload *trusted_payload_alloc(struct key *key) | |
896 | { | |
897 | struct trusted_key_payload *p = NULL; | |
898 | int ret; | |
899 | ||
900 | ret = key_payload_reserve(key, sizeof *p); | |
901 | if (ret < 0) | |
902 | return p; | |
903 | p = kzalloc(sizeof *p, GFP_KERNEL); | |
bc5e0af0 MZ |
904 | if (p) |
905 | p->migratable = 1; /* migratable by default */ | |
d00a1c72 MZ |
906 | return p; |
907 | } | |
908 | ||
909 | /* | |
910 | * trusted_instantiate - create a new trusted key | |
911 | * | |
912 | * Unseal an existing trusted blob or, for a new key, get a | |
913 | * random key, then seal and create a trusted key-type key, | |
914 | * adding it to the specified keyring. | |
915 | * | |
916 | * On success, return 0. Otherwise return errno. | |
917 | */ | |
918 | static int trusted_instantiate(struct key *key, const void *data, | |
1bdbb402 | 919 | size_t datalen) |
d00a1c72 MZ |
920 | { |
921 | struct trusted_key_payload *payload = NULL; | |
922 | struct trusted_key_options *options = NULL; | |
923 | char *datablob; | |
924 | int ret = 0; | |
925 | int key_cmd; | |
926 | ||
927 | if (datalen <= 0 || datalen > 32767 || !data) | |
928 | return -EINVAL; | |
929 | ||
930 | datablob = kmalloc(datalen + 1, GFP_KERNEL); | |
931 | if (!datablob) | |
932 | return -ENOMEM; | |
933 | memcpy(datablob, data, datalen); | |
934 | datablob[datalen] = '\0'; | |
935 | ||
936 | options = trusted_options_alloc(); | |
937 | if (!options) { | |
938 | ret = -ENOMEM; | |
939 | goto out; | |
940 | } | |
941 | payload = trusted_payload_alloc(key); | |
942 | if (!payload) { | |
943 | ret = -ENOMEM; | |
944 | goto out; | |
945 | } | |
946 | ||
947 | key_cmd = datablob_parse(datablob, payload, options); | |
948 | if (key_cmd < 0) { | |
949 | ret = key_cmd; | |
950 | goto out; | |
951 | } | |
952 | ||
953 | dump_payload(payload); | |
954 | dump_options(options); | |
955 | ||
956 | switch (key_cmd) { | |
957 | case Opt_load: | |
958 | ret = key_unseal(payload, options); | |
959 | dump_payload(payload); | |
960 | dump_options(options); | |
961 | if (ret < 0) | |
962 | pr_info("trusted_key: key_unseal failed (%d)\n", ret); | |
963 | break; | |
964 | case Opt_new: | |
965 | ret = my_get_random(payload->key, payload->key_len); | |
966 | if (ret < 0) { | |
967 | pr_info("trusted_key: key_create failed (%d)\n", ret); | |
968 | goto out; | |
969 | } | |
970 | ret = key_seal(payload, options); | |
971 | if (ret < 0) | |
972 | pr_info("trusted_key: key_seal failed (%d)\n", ret); | |
973 | break; | |
974 | default: | |
975 | ret = -EINVAL; | |
976 | goto out; | |
977 | } | |
978 | if (!ret && options->pcrlock) | |
979 | ret = pcrlock(options->pcrlock); | |
980 | out: | |
981 | kfree(datablob); | |
982 | kfree(options); | |
983 | if (!ret) | |
984 | rcu_assign_pointer(key->payload.data, payload); | |
985 | else | |
986 | kfree(payload); | |
987 | return ret; | |
988 | } | |
989 | ||
990 | static void trusted_rcu_free(struct rcu_head *rcu) | |
991 | { | |
992 | struct trusted_key_payload *p; | |
993 | ||
994 | p = container_of(rcu, struct trusted_key_payload, rcu); | |
995 | memset(p->key, 0, p->key_len); | |
996 | kfree(p); | |
997 | } | |
998 | ||
999 | /* | |
1000 | * trusted_update - reseal an existing key with new PCR values | |
1001 | */ | |
1bdbb402 | 1002 | static int trusted_update(struct key *key, const void *data, size_t datalen) |
d00a1c72 MZ |
1003 | { |
1004 | struct trusted_key_payload *p = key->payload.data; | |
1005 | struct trusted_key_payload *new_p; | |
1006 | struct trusted_key_options *new_o; | |
1007 | char *datablob; | |
1008 | int ret = 0; | |
1009 | ||
1010 | if (!p->migratable) | |
1011 | return -EPERM; | |
1012 | if (datalen <= 0 || datalen > 32767 || !data) | |
1013 | return -EINVAL; | |
1014 | ||
1015 | datablob = kmalloc(datalen + 1, GFP_KERNEL); | |
1016 | if (!datablob) | |
1017 | return -ENOMEM; | |
1018 | new_o = trusted_options_alloc(); | |
1019 | if (!new_o) { | |
1020 | ret = -ENOMEM; | |
1021 | goto out; | |
1022 | } | |
1023 | new_p = trusted_payload_alloc(key); | |
1024 | if (!new_p) { | |
1025 | ret = -ENOMEM; | |
1026 | goto out; | |
1027 | } | |
1028 | ||
1029 | memcpy(datablob, data, datalen); | |
1030 | datablob[datalen] = '\0'; | |
1031 | ret = datablob_parse(datablob, new_p, new_o); | |
1032 | if (ret != Opt_update) { | |
1033 | ret = -EINVAL; | |
1034 | goto out; | |
1035 | } | |
1036 | /* copy old key values, and reseal with new pcrs */ | |
1037 | new_p->migratable = p->migratable; | |
1038 | new_p->key_len = p->key_len; | |
1039 | memcpy(new_p->key, p->key, p->key_len); | |
1040 | dump_payload(p); | |
1041 | dump_payload(new_p); | |
1042 | ||
1043 | ret = key_seal(new_p, new_o); | |
1044 | if (ret < 0) { | |
1045 | pr_info("trusted_key: key_seal failed (%d)\n", ret); | |
1046 | kfree(new_p); | |
1047 | goto out; | |
1048 | } | |
1049 | if (new_o->pcrlock) { | |
1050 | ret = pcrlock(new_o->pcrlock); | |
1051 | if (ret < 0) { | |
1052 | pr_info("trusted_key: pcrlock failed (%d)\n", ret); | |
1053 | kfree(new_p); | |
1054 | goto out; | |
1055 | } | |
1056 | } | |
1057 | rcu_assign_pointer(key->payload.data, new_p); | |
1058 | call_rcu(&p->rcu, trusted_rcu_free); | |
1059 | out: | |
1060 | kfree(datablob); | |
1061 | kfree(new_o); | |
1062 | return ret; | |
1063 | } | |
1064 | ||
1065 | /* | |
1066 | * trusted_read - copy the sealed blob data to userspace in hex. | |
1067 | * On success, return to userspace the trusted key datablob size. | |
1068 | */ | |
1069 | static long trusted_read(const struct key *key, char __user *buffer, | |
1070 | size_t buflen) | |
1071 | { | |
1072 | struct trusted_key_payload *p; | |
1073 | char *ascii_buf; | |
1074 | char *bufp; | |
1075 | int i; | |
1076 | ||
1077 | p = rcu_dereference_protected(key->payload.data, | |
1078 | rwsem_is_locked(&((struct key *)key)->sem)); | |
1079 | if (!p) | |
1080 | return -EINVAL; | |
1081 | if (!buffer || buflen <= 0) | |
1082 | return 2 * p->blob_len; | |
1083 | ascii_buf = kmalloc(2 * p->blob_len, GFP_KERNEL); | |
1084 | if (!ascii_buf) | |
1085 | return -ENOMEM; | |
1086 | ||
1087 | bufp = ascii_buf; | |
1088 | for (i = 0; i < p->blob_len; i++) | |
1089 | bufp = pack_hex_byte(bufp, p->blob[i]); | |
1090 | if ((copy_to_user(buffer, ascii_buf, 2 * p->blob_len)) != 0) { | |
1091 | kfree(ascii_buf); | |
1092 | return -EFAULT; | |
1093 | } | |
1094 | kfree(ascii_buf); | |
1095 | return 2 * p->blob_len; | |
1096 | } | |
1097 | ||
1098 | /* | |
1099 | * trusted_destroy - before freeing the key, clear the decrypted data | |
1100 | */ | |
1101 | static void trusted_destroy(struct key *key) | |
1102 | { | |
1103 | struct trusted_key_payload *p = key->payload.data; | |
1104 | ||
1105 | if (!p) | |
1106 | return; | |
1107 | memset(p->key, 0, p->key_len); | |
1108 | kfree(key->payload.data); | |
1109 | } | |
1110 | ||
1111 | struct key_type key_type_trusted = { | |
1112 | .name = "trusted", | |
1113 | .instantiate = trusted_instantiate, | |
1114 | .update = trusted_update, | |
1115 | .match = user_match, | |
1116 | .destroy = trusted_destroy, | |
1117 | .describe = user_describe, | |
1118 | .read = trusted_read, | |
1119 | }; | |
1120 | ||
1121 | EXPORT_SYMBOL_GPL(key_type_trusted); | |
1122 | ||
1123 | static void trusted_shash_release(void) | |
1124 | { | |
1125 | if (hashalg) | |
1126 | crypto_free_shash(hashalg); | |
1127 | if (hmacalg) | |
1128 | crypto_free_shash(hmacalg); | |
1129 | } | |
1130 | ||
1131 | static int __init trusted_shash_alloc(void) | |
1132 | { | |
1133 | int ret; | |
1134 | ||
1135 | hmacalg = crypto_alloc_shash(hmac_alg, 0, CRYPTO_ALG_ASYNC); | |
1136 | if (IS_ERR(hmacalg)) { | |
1137 | pr_info("trusted_key: could not allocate crypto %s\n", | |
1138 | hmac_alg); | |
1139 | return PTR_ERR(hmacalg); | |
1140 | } | |
1141 | ||
1142 | hashalg = crypto_alloc_shash(hash_alg, 0, CRYPTO_ALG_ASYNC); | |
1143 | if (IS_ERR(hashalg)) { | |
1144 | pr_info("trusted_key: could not allocate crypto %s\n", | |
1145 | hash_alg); | |
1146 | ret = PTR_ERR(hashalg); | |
1147 | goto hashalg_fail; | |
1148 | } | |
1149 | ||
1150 | return 0; | |
1151 | ||
1152 | hashalg_fail: | |
1153 | crypto_free_shash(hmacalg); | |
1154 | return ret; | |
1155 | } | |
1156 | ||
1157 | static int __init init_trusted(void) | |
1158 | { | |
1159 | int ret; | |
1160 | ||
1161 | ret = trusted_shash_alloc(); | |
1162 | if (ret < 0) | |
1163 | return ret; | |
1164 | ret = register_key_type(&key_type_trusted); | |
1165 | if (ret < 0) | |
1166 | trusted_shash_release(); | |
1167 | return ret; | |
1168 | } | |
1169 | ||
1170 | static void __exit cleanup_trusted(void) | |
1171 | { | |
1172 | trusted_shash_release(); | |
1173 | unregister_key_type(&key_type_trusted); | |
1174 | } | |
1175 | ||
1176 | late_initcall(init_trusted); | |
1177 | module_exit(cleanup_trusted); | |
1178 | ||
1179 | MODULE_LICENSE("GPL"); |