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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 | ||
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 | ||
371 | /* | |
372 | * get a random value from TPM | |
373 | */ | |
374 | static int tpm_get_random(struct tpm_buf *tb, unsigned char *buf, uint32_t len) | |
375 | { | |
376 | int ret; | |
377 | ||
378 | INIT_BUF(tb); | |
379 | store16(tb, TPM_TAG_RQU_COMMAND); | |
380 | store32(tb, TPM_GETRANDOM_SIZE); | |
381 | store32(tb, TPM_ORD_GETRANDOM); | |
382 | store32(tb, len); | |
383 | ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, sizeof tb->data); | |
bc5e0af0 MZ |
384 | if (!ret) |
385 | memcpy(buf, tb->data + TPM_GETRANDOM_SIZE, len); | |
d00a1c72 MZ |
386 | return ret; |
387 | } | |
388 | ||
389 | static int my_get_random(unsigned char *buf, int len) | |
390 | { | |
391 | struct tpm_buf *tb; | |
392 | int ret; | |
393 | ||
1bdbb402 | 394 | tb = kmalloc(sizeof *tb, GFP_KERNEL); |
d00a1c72 MZ |
395 | if (!tb) |
396 | return -ENOMEM; | |
397 | ret = tpm_get_random(tb, buf, len); | |
398 | ||
399 | kfree(tb); | |
400 | return ret; | |
401 | } | |
402 | ||
403 | /* | |
404 | * Lock a trusted key, by extending a selected PCR. | |
405 | * | |
406 | * Prevents a trusted key that is sealed to PCRs from being accessed. | |
407 | * This uses the tpm driver's extend function. | |
408 | */ | |
409 | static int pcrlock(const int pcrnum) | |
410 | { | |
411 | unsigned char hash[SHA1_DIGEST_SIZE]; | |
bc5e0af0 | 412 | int ret; |
d00a1c72 MZ |
413 | |
414 | if (!capable(CAP_SYS_ADMIN)) | |
415 | return -EPERM; | |
bc5e0af0 MZ |
416 | ret = my_get_random(hash, SHA1_DIGEST_SIZE); |
417 | if (ret < 0) | |
418 | return ret; | |
d00a1c72 MZ |
419 | return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0; |
420 | } | |
421 | ||
422 | /* | |
423 | * Create an object specific authorisation protocol (OSAP) session | |
424 | */ | |
425 | static int osap(struct tpm_buf *tb, struct osapsess *s, | |
1bdbb402 | 426 | const unsigned char *key, uint16_t type, uint32_t handle) |
d00a1c72 MZ |
427 | { |
428 | unsigned char enonce[TPM_NONCE_SIZE]; | |
429 | unsigned char ononce[TPM_NONCE_SIZE]; | |
430 | int ret; | |
431 | ||
432 | ret = tpm_get_random(tb, ononce, TPM_NONCE_SIZE); | |
433 | if (ret < 0) | |
434 | return ret; | |
435 | ||
436 | INIT_BUF(tb); | |
437 | store16(tb, TPM_TAG_RQU_COMMAND); | |
438 | store32(tb, TPM_OSAP_SIZE); | |
439 | store32(tb, TPM_ORD_OSAP); | |
440 | store16(tb, type); | |
441 | store32(tb, handle); | |
442 | storebytes(tb, ononce, TPM_NONCE_SIZE); | |
443 | ||
444 | ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); | |
445 | if (ret < 0) | |
446 | return ret; | |
447 | ||
448 | s->handle = LOAD32(tb->data, TPM_DATA_OFFSET); | |
449 | memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]), | |
450 | TPM_NONCE_SIZE); | |
451 | memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) + | |
452 | TPM_NONCE_SIZE]), TPM_NONCE_SIZE); | |
bc5e0af0 MZ |
453 | return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE, |
454 | enonce, TPM_NONCE_SIZE, ononce, 0, 0); | |
d00a1c72 MZ |
455 | } |
456 | ||
457 | /* | |
458 | * Create an object independent authorisation protocol (oiap) session | |
459 | */ | |
460 | static int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce) | |
461 | { | |
462 | int ret; | |
463 | ||
464 | INIT_BUF(tb); | |
465 | store16(tb, TPM_TAG_RQU_COMMAND); | |
466 | store32(tb, TPM_OIAP_SIZE); | |
467 | store32(tb, TPM_ORD_OIAP); | |
468 | ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); | |
469 | if (ret < 0) | |
470 | return ret; | |
471 | ||
472 | *handle = LOAD32(tb->data, TPM_DATA_OFFSET); | |
473 | memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)], | |
474 | TPM_NONCE_SIZE); | |
bc5e0af0 | 475 | return 0; |
d00a1c72 MZ |
476 | } |
477 | ||
478 | struct tpm_digests { | |
479 | unsigned char encauth[SHA1_DIGEST_SIZE]; | |
480 | unsigned char pubauth[SHA1_DIGEST_SIZE]; | |
481 | unsigned char xorwork[SHA1_DIGEST_SIZE * 2]; | |
482 | unsigned char xorhash[SHA1_DIGEST_SIZE]; | |
483 | unsigned char nonceodd[TPM_NONCE_SIZE]; | |
484 | }; | |
485 | ||
486 | /* | |
487 | * Have the TPM seal(encrypt) the trusted key, possibly based on | |
488 | * Platform Configuration Registers (PCRs). AUTH1 for sealing key. | |
489 | */ | |
1bdbb402 MZ |
490 | static int tpm_seal(struct tpm_buf *tb, uint16_t keytype, |
491 | uint32_t keyhandle, const unsigned char *keyauth, | |
492 | const unsigned char *data, uint32_t datalen, | |
d00a1c72 MZ |
493 | unsigned char *blob, uint32_t *bloblen, |
494 | const unsigned char *blobauth, | |
1bdbb402 | 495 | const unsigned char *pcrinfo, uint32_t pcrinfosize) |
d00a1c72 MZ |
496 | { |
497 | struct osapsess sess; | |
498 | struct tpm_digests *td; | |
499 | unsigned char cont; | |
500 | uint32_t ordinal; | |
501 | uint32_t pcrsize; | |
502 | uint32_t datsize; | |
503 | int sealinfosize; | |
504 | int encdatasize; | |
505 | int storedsize; | |
506 | int ret; | |
507 | int i; | |
508 | ||
509 | /* alloc some work space for all the hashes */ | |
510 | td = kmalloc(sizeof *td, GFP_KERNEL); | |
511 | if (!td) | |
512 | return -ENOMEM; | |
513 | ||
514 | /* get session for sealing key */ | |
515 | ret = osap(tb, &sess, keyauth, keytype, keyhandle); | |
516 | if (ret < 0) | |
40c10017 | 517 | goto out; |
d00a1c72 MZ |
518 | dump_sess(&sess); |
519 | ||
520 | /* calculate encrypted authorization value */ | |
521 | memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE); | |
522 | memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE); | |
523 | ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash); | |
524 | if (ret < 0) | |
40c10017 | 525 | goto out; |
d00a1c72 MZ |
526 | |
527 | ret = tpm_get_random(tb, td->nonceodd, TPM_NONCE_SIZE); | |
528 | if (ret < 0) | |
40c10017 | 529 | goto out; |
d00a1c72 MZ |
530 | ordinal = htonl(TPM_ORD_SEAL); |
531 | datsize = htonl(datalen); | |
532 | pcrsize = htonl(pcrinfosize); | |
533 | cont = 0; | |
534 | ||
535 | /* encrypt data authorization key */ | |
536 | for (i = 0; i < SHA1_DIGEST_SIZE; ++i) | |
537 | td->encauth[i] = td->xorhash[i] ^ blobauth[i]; | |
538 | ||
539 | /* calculate authorization HMAC value */ | |
540 | if (pcrinfosize == 0) { | |
541 | /* no pcr info specified */ | |
bc5e0af0 MZ |
542 | ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE, |
543 | sess.enonce, td->nonceodd, cont, | |
544 | sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE, | |
545 | td->encauth, sizeof(uint32_t), &pcrsize, | |
546 | sizeof(uint32_t), &datsize, datalen, data, 0, | |
547 | 0); | |
d00a1c72 MZ |
548 | } else { |
549 | /* pcr info specified */ | |
bc5e0af0 MZ |
550 | ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE, |
551 | sess.enonce, td->nonceodd, cont, | |
552 | sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE, | |
553 | td->encauth, sizeof(uint32_t), &pcrsize, | |
554 | pcrinfosize, pcrinfo, sizeof(uint32_t), | |
555 | &datsize, datalen, data, 0, 0); | |
d00a1c72 | 556 | } |
bc5e0af0 | 557 | if (ret < 0) |
40c10017 | 558 | goto out; |
d00a1c72 MZ |
559 | |
560 | /* build and send the TPM request packet */ | |
561 | INIT_BUF(tb); | |
562 | store16(tb, TPM_TAG_RQU_AUTH1_COMMAND); | |
563 | store32(tb, TPM_SEAL_SIZE + pcrinfosize + datalen); | |
564 | store32(tb, TPM_ORD_SEAL); | |
565 | store32(tb, keyhandle); | |
566 | storebytes(tb, td->encauth, SHA1_DIGEST_SIZE); | |
567 | store32(tb, pcrinfosize); | |
568 | storebytes(tb, pcrinfo, pcrinfosize); | |
569 | store32(tb, datalen); | |
570 | storebytes(tb, data, datalen); | |
571 | store32(tb, sess.handle); | |
572 | storebytes(tb, td->nonceodd, TPM_NONCE_SIZE); | |
573 | store8(tb, cont); | |
574 | storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE); | |
575 | ||
576 | ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); | |
577 | if (ret < 0) | |
40c10017 | 578 | goto out; |
d00a1c72 MZ |
579 | |
580 | /* calculate the size of the returned Blob */ | |
581 | sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t)); | |
582 | encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) + | |
583 | sizeof(uint32_t) + sealinfosize); | |
584 | storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize + | |
585 | sizeof(uint32_t) + encdatasize; | |
586 | ||
587 | /* check the HMAC in the response */ | |
588 | ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret, | |
589 | SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0, | |
590 | 0); | |
591 | ||
592 | /* copy the returned blob to caller */ | |
bc5e0af0 MZ |
593 | if (!ret) { |
594 | memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize); | |
595 | *bloblen = storedsize; | |
596 | } | |
40c10017 MZ |
597 | out: |
598 | kfree(td); | |
d00a1c72 MZ |
599 | return ret; |
600 | } | |
601 | ||
602 | /* | |
603 | * use the AUTH2_COMMAND form of unseal, to authorize both key and blob | |
604 | */ | |
605 | static int tpm_unseal(struct tpm_buf *tb, | |
1bdbb402 MZ |
606 | uint32_t keyhandle, const unsigned char *keyauth, |
607 | const unsigned char *blob, int bloblen, | |
d00a1c72 MZ |
608 | const unsigned char *blobauth, |
609 | unsigned char *data, unsigned int *datalen) | |
610 | { | |
611 | unsigned char nonceodd[TPM_NONCE_SIZE]; | |
612 | unsigned char enonce1[TPM_NONCE_SIZE]; | |
613 | unsigned char enonce2[TPM_NONCE_SIZE]; | |
614 | unsigned char authdata1[SHA1_DIGEST_SIZE]; | |
615 | unsigned char authdata2[SHA1_DIGEST_SIZE]; | |
616 | uint32_t authhandle1 = 0; | |
617 | uint32_t authhandle2 = 0; | |
618 | unsigned char cont = 0; | |
619 | uint32_t ordinal; | |
620 | uint32_t keyhndl; | |
621 | int ret; | |
622 | ||
623 | /* sessions for unsealing key and data */ | |
624 | ret = oiap(tb, &authhandle1, enonce1); | |
625 | if (ret < 0) { | |
626 | pr_info("trusted_key: oiap failed (%d)\n", ret); | |
627 | return ret; | |
628 | } | |
629 | ret = oiap(tb, &authhandle2, enonce2); | |
630 | if (ret < 0) { | |
631 | pr_info("trusted_key: oiap failed (%d)\n", ret); | |
632 | return ret; | |
633 | } | |
634 | ||
635 | ordinal = htonl(TPM_ORD_UNSEAL); | |
636 | keyhndl = htonl(SRKHANDLE); | |
637 | ret = tpm_get_random(tb, nonceodd, TPM_NONCE_SIZE); | |
638 | if (ret < 0) { | |
639 | pr_info("trusted_key: tpm_get_random failed (%d)\n", ret); | |
640 | return ret; | |
641 | } | |
bc5e0af0 MZ |
642 | ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE, |
643 | enonce1, nonceodd, cont, sizeof(uint32_t), | |
644 | &ordinal, bloblen, blob, 0, 0); | |
645 | if (ret < 0) | |
646 | return ret; | |
647 | ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE, | |
648 | enonce2, nonceodd, cont, sizeof(uint32_t), | |
649 | &ordinal, bloblen, blob, 0, 0); | |
650 | if (ret < 0) | |
651 | return ret; | |
d00a1c72 MZ |
652 | |
653 | /* build and send TPM request packet */ | |
654 | INIT_BUF(tb); | |
655 | store16(tb, TPM_TAG_RQU_AUTH2_COMMAND); | |
656 | store32(tb, TPM_UNSEAL_SIZE + bloblen); | |
657 | store32(tb, TPM_ORD_UNSEAL); | |
658 | store32(tb, keyhandle); | |
659 | storebytes(tb, blob, bloblen); | |
660 | store32(tb, authhandle1); | |
661 | storebytes(tb, nonceodd, TPM_NONCE_SIZE); | |
662 | store8(tb, cont); | |
663 | storebytes(tb, authdata1, SHA1_DIGEST_SIZE); | |
664 | store32(tb, authhandle2); | |
665 | storebytes(tb, nonceodd, TPM_NONCE_SIZE); | |
666 | store8(tb, cont); | |
667 | storebytes(tb, authdata2, SHA1_DIGEST_SIZE); | |
668 | ||
669 | ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); | |
670 | if (ret < 0) { | |
671 | pr_info("trusted_key: authhmac failed (%d)\n", ret); | |
672 | return ret; | |
673 | } | |
674 | ||
675 | *datalen = LOAD32(tb->data, TPM_DATA_OFFSET); | |
676 | ret = TSS_checkhmac2(tb->data, ordinal, nonceodd, | |
677 | keyauth, SHA1_DIGEST_SIZE, | |
678 | blobauth, SHA1_DIGEST_SIZE, | |
679 | sizeof(uint32_t), TPM_DATA_OFFSET, | |
680 | *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0, | |
681 | 0); | |
bc5e0af0 | 682 | if (ret < 0) { |
d00a1c72 | 683 | pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret); |
bc5e0af0 MZ |
684 | return ret; |
685 | } | |
d00a1c72 | 686 | memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen); |
bc5e0af0 | 687 | return 0; |
d00a1c72 MZ |
688 | } |
689 | ||
690 | /* | |
691 | * Have the TPM seal(encrypt) the symmetric key | |
692 | */ | |
693 | static int key_seal(struct trusted_key_payload *p, | |
694 | struct trusted_key_options *o) | |
695 | { | |
696 | struct tpm_buf *tb; | |
697 | int ret; | |
698 | ||
699 | tb = kzalloc(sizeof *tb, GFP_KERNEL); | |
700 | if (!tb) | |
701 | return -ENOMEM; | |
702 | ||
703 | /* include migratable flag at end of sealed key */ | |
704 | p->key[p->key_len] = p->migratable; | |
705 | ||
706 | ret = tpm_seal(tb, o->keytype, o->keyhandle, o->keyauth, | |
707 | p->key, p->key_len + 1, p->blob, &p->blob_len, | |
708 | o->blobauth, o->pcrinfo, o->pcrinfo_len); | |
709 | if (ret < 0) | |
710 | pr_info("trusted_key: srkseal failed (%d)\n", ret); | |
711 | ||
712 | kfree(tb); | |
713 | return ret; | |
714 | } | |
715 | ||
716 | /* | |
717 | * Have the TPM unseal(decrypt) the symmetric key | |
718 | */ | |
719 | static int key_unseal(struct trusted_key_payload *p, | |
720 | struct trusted_key_options *o) | |
721 | { | |
722 | struct tpm_buf *tb; | |
723 | int ret; | |
724 | ||
725 | tb = kzalloc(sizeof *tb, GFP_KERNEL); | |
726 | if (!tb) | |
727 | return -ENOMEM; | |
728 | ||
729 | ret = tpm_unseal(tb, o->keyhandle, o->keyauth, p->blob, p->blob_len, | |
730 | o->blobauth, p->key, &p->key_len); | |
d00a1c72 MZ |
731 | if (ret < 0) |
732 | pr_info("trusted_key: srkunseal failed (%d)\n", ret); | |
bc5e0af0 MZ |
733 | else |
734 | /* pull migratable flag out of sealed key */ | |
735 | p->migratable = p->key[--p->key_len]; | |
d00a1c72 MZ |
736 | |
737 | kfree(tb); | |
738 | return ret; | |
739 | } | |
740 | ||
741 | enum { | |
742 | Opt_err = -1, | |
743 | Opt_new, Opt_load, Opt_update, | |
744 | Opt_keyhandle, Opt_keyauth, Opt_blobauth, | |
745 | Opt_pcrinfo, Opt_pcrlock, Opt_migratable | |
746 | }; | |
747 | ||
748 | static const match_table_t key_tokens = { | |
749 | {Opt_new, "new"}, | |
750 | {Opt_load, "load"}, | |
751 | {Opt_update, "update"}, | |
752 | {Opt_keyhandle, "keyhandle=%s"}, | |
753 | {Opt_keyauth, "keyauth=%s"}, | |
754 | {Opt_blobauth, "blobauth=%s"}, | |
755 | {Opt_pcrinfo, "pcrinfo=%s"}, | |
756 | {Opt_pcrlock, "pcrlock=%s"}, | |
757 | {Opt_migratable, "migratable=%s"}, | |
758 | {Opt_err, NULL} | |
759 | }; | |
760 | ||
761 | /* can have zero or more token= options */ | |
762 | static int getoptions(char *c, struct trusted_key_payload *pay, | |
763 | struct trusted_key_options *opt) | |
764 | { | |
765 | substring_t args[MAX_OPT_ARGS]; | |
766 | char *p = c; | |
767 | int token; | |
768 | int res; | |
769 | unsigned long handle; | |
770 | unsigned long lock; | |
771 | ||
772 | while ((p = strsep(&c, " \t"))) { | |
773 | if (*p == '\0' || *p == ' ' || *p == '\t') | |
774 | continue; | |
775 | token = match_token(p, key_tokens, args); | |
776 | ||
777 | switch (token) { | |
778 | case Opt_pcrinfo: | |
779 | opt->pcrinfo_len = strlen(args[0].from) / 2; | |
780 | if (opt->pcrinfo_len > MAX_PCRINFO_SIZE) | |
781 | return -EINVAL; | |
782 | hex2bin(opt->pcrinfo, args[0].from, opt->pcrinfo_len); | |
783 | break; | |
784 | case Opt_keyhandle: | |
785 | res = strict_strtoul(args[0].from, 16, &handle); | |
786 | if (res < 0) | |
787 | return -EINVAL; | |
788 | opt->keytype = SEAL_keytype; | |
789 | opt->keyhandle = handle; | |
790 | break; | |
791 | case Opt_keyauth: | |
792 | if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE) | |
793 | return -EINVAL; | |
794 | hex2bin(opt->keyauth, args[0].from, SHA1_DIGEST_SIZE); | |
795 | break; | |
796 | case Opt_blobauth: | |
797 | if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE) | |
798 | return -EINVAL; | |
799 | hex2bin(opt->blobauth, args[0].from, SHA1_DIGEST_SIZE); | |
800 | break; | |
801 | case Opt_migratable: | |
802 | if (*args[0].from == '0') | |
803 | pay->migratable = 0; | |
804 | else | |
805 | return -EINVAL; | |
806 | break; | |
807 | case Opt_pcrlock: | |
808 | res = strict_strtoul(args[0].from, 10, &lock); | |
809 | if (res < 0) | |
810 | return -EINVAL; | |
811 | opt->pcrlock = lock; | |
812 | break; | |
813 | default: | |
814 | return -EINVAL; | |
815 | } | |
816 | } | |
817 | return 0; | |
818 | } | |
819 | ||
820 | /* | |
821 | * datablob_parse - parse the keyctl data and fill in the | |
822 | * payload and options structures | |
823 | * | |
824 | * On success returns 0, otherwise -EINVAL. | |
825 | */ | |
826 | static int datablob_parse(char *datablob, struct trusted_key_payload *p, | |
827 | struct trusted_key_options *o) | |
828 | { | |
829 | substring_t args[MAX_OPT_ARGS]; | |
830 | long keylen; | |
831 | int ret = -EINVAL; | |
832 | int key_cmd; | |
833 | char *c; | |
834 | ||
835 | /* main command */ | |
836 | c = strsep(&datablob, " \t"); | |
837 | if (!c) | |
838 | return -EINVAL; | |
839 | key_cmd = match_token(c, key_tokens, args); | |
840 | switch (key_cmd) { | |
841 | case Opt_new: | |
842 | /* first argument is key size */ | |
843 | c = strsep(&datablob, " \t"); | |
844 | if (!c) | |
845 | return -EINVAL; | |
846 | ret = strict_strtol(c, 10, &keylen); | |
847 | if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE) | |
848 | return -EINVAL; | |
849 | p->key_len = keylen; | |
850 | ret = getoptions(datablob, p, o); | |
851 | if (ret < 0) | |
852 | return ret; | |
853 | ret = Opt_new; | |
854 | break; | |
855 | case Opt_load: | |
856 | /* first argument is sealed blob */ | |
857 | c = strsep(&datablob, " \t"); | |
858 | if (!c) | |
859 | return -EINVAL; | |
860 | p->blob_len = strlen(c) / 2; | |
861 | if (p->blob_len > MAX_BLOB_SIZE) | |
862 | return -EINVAL; | |
863 | hex2bin(p->blob, c, p->blob_len); | |
864 | ret = getoptions(datablob, p, o); | |
865 | if (ret < 0) | |
866 | return ret; | |
867 | ret = Opt_load; | |
868 | break; | |
869 | case Opt_update: | |
870 | /* all arguments are options */ | |
871 | ret = getoptions(datablob, p, o); | |
872 | if (ret < 0) | |
873 | return ret; | |
874 | ret = Opt_update; | |
875 | break; | |
876 | case Opt_err: | |
877 | return -EINVAL; | |
878 | break; | |
879 | } | |
880 | return ret; | |
881 | } | |
882 | ||
883 | static struct trusted_key_options *trusted_options_alloc(void) | |
884 | { | |
885 | struct trusted_key_options *options; | |
886 | ||
887 | options = kzalloc(sizeof *options, GFP_KERNEL); | |
bc5e0af0 MZ |
888 | if (options) { |
889 | /* set any non-zero defaults */ | |
890 | options->keytype = SRK_keytype; | |
891 | options->keyhandle = SRKHANDLE; | |
892 | } | |
d00a1c72 MZ |
893 | return options; |
894 | } | |
895 | ||
896 | static struct trusted_key_payload *trusted_payload_alloc(struct key *key) | |
897 | { | |
898 | struct trusted_key_payload *p = NULL; | |
899 | int ret; | |
900 | ||
901 | ret = key_payload_reserve(key, sizeof *p); | |
902 | if (ret < 0) | |
903 | return p; | |
904 | p = kzalloc(sizeof *p, GFP_KERNEL); | |
bc5e0af0 MZ |
905 | if (p) |
906 | p->migratable = 1; /* migratable by default */ | |
d00a1c72 MZ |
907 | return p; |
908 | } | |
909 | ||
910 | /* | |
911 | * trusted_instantiate - create a new trusted key | |
912 | * | |
913 | * Unseal an existing trusted blob or, for a new key, get a | |
914 | * random key, then seal and create a trusted key-type key, | |
915 | * adding it to the specified keyring. | |
916 | * | |
917 | * On success, return 0. Otherwise return errno. | |
918 | */ | |
919 | static int trusted_instantiate(struct key *key, const void *data, | |
1bdbb402 | 920 | size_t datalen) |
d00a1c72 MZ |
921 | { |
922 | struct trusted_key_payload *payload = NULL; | |
923 | struct trusted_key_options *options = NULL; | |
924 | char *datablob; | |
925 | int ret = 0; | |
926 | int key_cmd; | |
927 | ||
928 | if (datalen <= 0 || datalen > 32767 || !data) | |
929 | return -EINVAL; | |
930 | ||
931 | datablob = kmalloc(datalen + 1, GFP_KERNEL); | |
932 | if (!datablob) | |
933 | return -ENOMEM; | |
934 | memcpy(datablob, data, datalen); | |
935 | datablob[datalen] = '\0'; | |
936 | ||
937 | options = trusted_options_alloc(); | |
938 | if (!options) { | |
939 | ret = -ENOMEM; | |
940 | goto out; | |
941 | } | |
942 | payload = trusted_payload_alloc(key); | |
943 | if (!payload) { | |
944 | ret = -ENOMEM; | |
945 | goto out; | |
946 | } | |
947 | ||
948 | key_cmd = datablob_parse(datablob, payload, options); | |
949 | if (key_cmd < 0) { | |
950 | ret = key_cmd; | |
951 | goto out; | |
952 | } | |
953 | ||
954 | dump_payload(payload); | |
955 | dump_options(options); | |
956 | ||
957 | switch (key_cmd) { | |
958 | case Opt_load: | |
959 | ret = key_unseal(payload, options); | |
960 | dump_payload(payload); | |
961 | dump_options(options); | |
962 | if (ret < 0) | |
963 | pr_info("trusted_key: key_unseal failed (%d)\n", ret); | |
964 | break; | |
965 | case Opt_new: | |
966 | ret = my_get_random(payload->key, payload->key_len); | |
967 | if (ret < 0) { | |
968 | pr_info("trusted_key: key_create failed (%d)\n", ret); | |
969 | goto out; | |
970 | } | |
971 | ret = key_seal(payload, options); | |
972 | if (ret < 0) | |
973 | pr_info("trusted_key: key_seal failed (%d)\n", ret); | |
974 | break; | |
975 | default: | |
976 | ret = -EINVAL; | |
977 | goto out; | |
978 | } | |
979 | if (!ret && options->pcrlock) | |
980 | ret = pcrlock(options->pcrlock); | |
981 | out: | |
982 | kfree(datablob); | |
983 | kfree(options); | |
984 | if (!ret) | |
985 | rcu_assign_pointer(key->payload.data, payload); | |
986 | else | |
987 | kfree(payload); | |
988 | return ret; | |
989 | } | |
990 | ||
991 | static void trusted_rcu_free(struct rcu_head *rcu) | |
992 | { | |
993 | struct trusted_key_payload *p; | |
994 | ||
995 | p = container_of(rcu, struct trusted_key_payload, rcu); | |
996 | memset(p->key, 0, p->key_len); | |
997 | kfree(p); | |
998 | } | |
999 | ||
1000 | /* | |
1001 | * trusted_update - reseal an existing key with new PCR values | |
1002 | */ | |
1bdbb402 | 1003 | static int trusted_update(struct key *key, const void *data, size_t datalen) |
d00a1c72 MZ |
1004 | { |
1005 | struct trusted_key_payload *p = key->payload.data; | |
1006 | struct trusted_key_payload *new_p; | |
1007 | struct trusted_key_options *new_o; | |
1008 | char *datablob; | |
1009 | int ret = 0; | |
1010 | ||
1011 | if (!p->migratable) | |
1012 | return -EPERM; | |
1013 | if (datalen <= 0 || datalen > 32767 || !data) | |
1014 | return -EINVAL; | |
1015 | ||
1016 | datablob = kmalloc(datalen + 1, GFP_KERNEL); | |
1017 | if (!datablob) | |
1018 | return -ENOMEM; | |
1019 | new_o = trusted_options_alloc(); | |
1020 | if (!new_o) { | |
1021 | ret = -ENOMEM; | |
1022 | goto out; | |
1023 | } | |
1024 | new_p = trusted_payload_alloc(key); | |
1025 | if (!new_p) { | |
1026 | ret = -ENOMEM; | |
1027 | goto out; | |
1028 | } | |
1029 | ||
1030 | memcpy(datablob, data, datalen); | |
1031 | datablob[datalen] = '\0'; | |
1032 | ret = datablob_parse(datablob, new_p, new_o); | |
1033 | if (ret != Opt_update) { | |
1034 | ret = -EINVAL; | |
54031109 | 1035 | kfree(new_p); |
d00a1c72 MZ |
1036 | goto out; |
1037 | } | |
1038 | /* copy old key values, and reseal with new pcrs */ | |
1039 | new_p->migratable = p->migratable; | |
1040 | new_p->key_len = p->key_len; | |
1041 | memcpy(new_p->key, p->key, p->key_len); | |
1042 | dump_payload(p); | |
1043 | dump_payload(new_p); | |
1044 | ||
1045 | ret = key_seal(new_p, new_o); | |
1046 | if (ret < 0) { | |
1047 | pr_info("trusted_key: key_seal failed (%d)\n", ret); | |
1048 | kfree(new_p); | |
1049 | goto out; | |
1050 | } | |
1051 | if (new_o->pcrlock) { | |
1052 | ret = pcrlock(new_o->pcrlock); | |
1053 | if (ret < 0) { | |
1054 | pr_info("trusted_key: pcrlock failed (%d)\n", ret); | |
1055 | kfree(new_p); | |
1056 | goto out; | |
1057 | } | |
1058 | } | |
1059 | rcu_assign_pointer(key->payload.data, new_p); | |
1060 | call_rcu(&p->rcu, trusted_rcu_free); | |
1061 | out: | |
1062 | kfree(datablob); | |
1063 | kfree(new_o); | |
1064 | return ret; | |
1065 | } | |
1066 | ||
1067 | /* | |
1068 | * trusted_read - copy the sealed blob data to userspace in hex. | |
1069 | * On success, return to userspace the trusted key datablob size. | |
1070 | */ | |
1071 | static long trusted_read(const struct key *key, char __user *buffer, | |
1072 | size_t buflen) | |
1073 | { | |
1074 | struct trusted_key_payload *p; | |
1075 | char *ascii_buf; | |
1076 | char *bufp; | |
1077 | int i; | |
1078 | ||
1079 | p = rcu_dereference_protected(key->payload.data, | |
1080 | rwsem_is_locked(&((struct key *)key)->sem)); | |
1081 | if (!p) | |
1082 | return -EINVAL; | |
1083 | if (!buffer || buflen <= 0) | |
1084 | return 2 * p->blob_len; | |
1085 | ascii_buf = kmalloc(2 * p->blob_len, GFP_KERNEL); | |
1086 | if (!ascii_buf) | |
1087 | return -ENOMEM; | |
1088 | ||
1089 | bufp = ascii_buf; | |
1090 | for (i = 0; i < p->blob_len; i++) | |
1091 | bufp = pack_hex_byte(bufp, p->blob[i]); | |
1092 | if ((copy_to_user(buffer, ascii_buf, 2 * p->blob_len)) != 0) { | |
1093 | kfree(ascii_buf); | |
1094 | return -EFAULT; | |
1095 | } | |
1096 | kfree(ascii_buf); | |
1097 | return 2 * p->blob_len; | |
1098 | } | |
1099 | ||
1100 | /* | |
1101 | * trusted_destroy - before freeing the key, clear the decrypted data | |
1102 | */ | |
1103 | static void trusted_destroy(struct key *key) | |
1104 | { | |
1105 | struct trusted_key_payload *p = key->payload.data; | |
1106 | ||
1107 | if (!p) | |
1108 | return; | |
1109 | memset(p->key, 0, p->key_len); | |
1110 | kfree(key->payload.data); | |
1111 | } | |
1112 | ||
1113 | struct key_type key_type_trusted = { | |
1114 | .name = "trusted", | |
1115 | .instantiate = trusted_instantiate, | |
1116 | .update = trusted_update, | |
1117 | .match = user_match, | |
1118 | .destroy = trusted_destroy, | |
1119 | .describe = user_describe, | |
1120 | .read = trusted_read, | |
1121 | }; | |
1122 | ||
1123 | EXPORT_SYMBOL_GPL(key_type_trusted); | |
1124 | ||
1125 | static void trusted_shash_release(void) | |
1126 | { | |
1127 | if (hashalg) | |
1128 | crypto_free_shash(hashalg); | |
1129 | if (hmacalg) | |
1130 | crypto_free_shash(hmacalg); | |
1131 | } | |
1132 | ||
1133 | static int __init trusted_shash_alloc(void) | |
1134 | { | |
1135 | int ret; | |
1136 | ||
1137 | hmacalg = crypto_alloc_shash(hmac_alg, 0, CRYPTO_ALG_ASYNC); | |
1138 | if (IS_ERR(hmacalg)) { | |
1139 | pr_info("trusted_key: could not allocate crypto %s\n", | |
1140 | hmac_alg); | |
1141 | return PTR_ERR(hmacalg); | |
1142 | } | |
1143 | ||
1144 | hashalg = crypto_alloc_shash(hash_alg, 0, CRYPTO_ALG_ASYNC); | |
1145 | if (IS_ERR(hashalg)) { | |
1146 | pr_info("trusted_key: could not allocate crypto %s\n", | |
1147 | hash_alg); | |
1148 | ret = PTR_ERR(hashalg); | |
1149 | goto hashalg_fail; | |
1150 | } | |
1151 | ||
1152 | return 0; | |
1153 | ||
1154 | hashalg_fail: | |
1155 | crypto_free_shash(hmacalg); | |
1156 | return ret; | |
1157 | } | |
1158 | ||
1159 | static int __init init_trusted(void) | |
1160 | { | |
1161 | int ret; | |
1162 | ||
1163 | ret = trusted_shash_alloc(); | |
1164 | if (ret < 0) | |
1165 | return ret; | |
1166 | ret = register_key_type(&key_type_trusted); | |
1167 | if (ret < 0) | |
1168 | trusted_shash_release(); | |
1169 | return ret; | |
1170 | } | |
1171 | ||
1172 | static void __exit cleanup_trusted(void) | |
1173 | { | |
1174 | trusted_shash_release(); | |
1175 | unregister_key_type(&key_type_trusted); | |
1176 | } | |
1177 | ||
1178 | late_initcall(init_trusted); | |
1179 | module_exit(cleanup_trusted); | |
1180 | ||
1181 | MODULE_LICENSE("GPL"); |