Commit | Line | Data |
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3323eec9 MZ |
1 | /* |
2 | * Copyright (C) 2005,2006,2007,2008 IBM Corporation | |
3 | * | |
4 | * Authors: | |
5 | * Mimi Zohar <zohar@us.ibm.com> | |
6 | * Kylene Hall <kjhall@us.ibm.com> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation, version 2 of the License. | |
11 | * | |
12 | * File: ima_crypto.c | |
2bb930ab | 13 | * Calculates md5/sha1 file hash, template hash, boot-aggreate hash |
3323eec9 MZ |
14 | */ |
15 | ||
20ee451f JP |
16 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
17 | ||
3323eec9 | 18 | #include <linux/kernel.h> |
3bcced39 DK |
19 | #include <linux/moduleparam.h> |
20 | #include <linux/ratelimit.h> | |
3323eec9 MZ |
21 | #include <linux/file.h> |
22 | #include <linux/crypto.h> | |
23 | #include <linux/scatterlist.h> | |
24 | #include <linux/err.h> | |
5a0e3ad6 | 25 | #include <linux/slab.h> |
76bb28f6 | 26 | #include <crypto/hash.h> |
c7c8bb23 | 27 | #include <crypto/hash_info.h> |
3323eec9 MZ |
28 | #include "ima.h" |
29 | ||
3bcced39 DK |
30 | struct ahash_completion { |
31 | struct completion completion; | |
32 | int err; | |
33 | }; | |
34 | ||
35 | /* minimum file size for ahash use */ | |
36 | static unsigned long ima_ahash_minsize; | |
37 | module_param_named(ahash_minsize, ima_ahash_minsize, ulong, 0644); | |
38 | MODULE_PARM_DESC(ahash_minsize, "Minimum file size for ahash use"); | |
39 | ||
6edf7a89 DK |
40 | /* default is 0 - 1 page. */ |
41 | static int ima_maxorder; | |
42 | static unsigned int ima_bufsize = PAGE_SIZE; | |
43 | ||
44 | static int param_set_bufsize(const char *val, const struct kernel_param *kp) | |
45 | { | |
46 | unsigned long long size; | |
47 | int order; | |
48 | ||
49 | size = memparse(val, NULL); | |
50 | order = get_order(size); | |
51 | if (order >= MAX_ORDER) | |
52 | return -EINVAL; | |
53 | ima_maxorder = order; | |
54 | ima_bufsize = PAGE_SIZE << order; | |
55 | return 0; | |
56 | } | |
57 | ||
58 | static struct kernel_param_ops param_ops_bufsize = { | |
59 | .set = param_set_bufsize, | |
60 | .get = param_get_uint, | |
61 | }; | |
62 | #define param_check_bufsize(name, p) __param_check(name, p, unsigned int) | |
63 | ||
64 | module_param_named(ahash_bufsize, ima_bufsize, bufsize, 0644); | |
65 | MODULE_PARM_DESC(ahash_bufsize, "Maximum ahash buffer size"); | |
66 | ||
76bb28f6 | 67 | static struct crypto_shash *ima_shash_tfm; |
3bcced39 | 68 | static struct crypto_ahash *ima_ahash_tfm; |
76bb28f6 | 69 | |
0430e49b DK |
70 | /** |
71 | * ima_kernel_read - read file content | |
72 | * | |
73 | * This is a function for reading file content instead of kernel_read(). | |
74 | * It does not perform locking checks to ensure it cannot be blocked. | |
75 | * It does not perform security checks because it is irrelevant for IMA. | |
76 | * | |
77 | */ | |
78 | static int ima_kernel_read(struct file *file, loff_t offset, | |
79 | char *addr, unsigned long count) | |
80 | { | |
81 | mm_segment_t old_fs; | |
82 | char __user *buf = addr; | |
27cd1fc3 | 83 | ssize_t ret = -EINVAL; |
0430e49b DK |
84 | |
85 | if (!(file->f_mode & FMODE_READ)) | |
86 | return -EBADF; | |
0430e49b DK |
87 | |
88 | old_fs = get_fs(); | |
89 | set_fs(get_ds()); | |
90 | if (file->f_op->read) | |
91 | ret = file->f_op->read(file, buf, count, &offset); | |
27cd1fc3 | 92 | else if (file->f_op->aio_read) |
0430e49b | 93 | ret = do_sync_read(file, buf, count, &offset); |
27cd1fc3 DK |
94 | else if (file->f_op->read_iter) |
95 | ret = new_sync_read(file, buf, count, &offset); | |
0430e49b DK |
96 | set_fs(old_fs); |
97 | return ret; | |
98 | } | |
99 | ||
e4a9c519 | 100 | int __init ima_init_crypto(void) |
3323eec9 | 101 | { |
76bb28f6 | 102 | long rc; |
3323eec9 | 103 | |
c7c8bb23 | 104 | ima_shash_tfm = crypto_alloc_shash(hash_algo_name[ima_hash_algo], 0, 0); |
76bb28f6 DK |
105 | if (IS_ERR(ima_shash_tfm)) { |
106 | rc = PTR_ERR(ima_shash_tfm); | |
c7c8bb23 DK |
107 | pr_err("Can not allocate %s (reason: %ld)\n", |
108 | hash_algo_name[ima_hash_algo], rc); | |
3323eec9 MZ |
109 | return rc; |
110 | } | |
76bb28f6 | 111 | return 0; |
3323eec9 MZ |
112 | } |
113 | ||
723326b9 DK |
114 | static struct crypto_shash *ima_alloc_tfm(enum hash_algo algo) |
115 | { | |
116 | struct crypto_shash *tfm = ima_shash_tfm; | |
117 | int rc; | |
118 | ||
23c19e2c DK |
119 | if (algo < 0 || algo >= HASH_ALGO__LAST) |
120 | algo = ima_hash_algo; | |
121 | ||
122 | if (algo != ima_hash_algo) { | |
723326b9 DK |
123 | tfm = crypto_alloc_shash(hash_algo_name[algo], 0, 0); |
124 | if (IS_ERR(tfm)) { | |
125 | rc = PTR_ERR(tfm); | |
126 | pr_err("Can not allocate %s (reason: %d)\n", | |
127 | hash_algo_name[algo], rc); | |
128 | } | |
129 | } | |
130 | return tfm; | |
131 | } | |
132 | ||
133 | static void ima_free_tfm(struct crypto_shash *tfm) | |
134 | { | |
135 | if (tfm != ima_shash_tfm) | |
136 | crypto_free_shash(tfm); | |
137 | } | |
138 | ||
6edf7a89 DK |
139 | /** |
140 | * ima_alloc_pages() - Allocate contiguous pages. | |
141 | * @max_size: Maximum amount of memory to allocate. | |
142 | * @allocated_size: Returned size of actual allocation. | |
143 | * @last_warn: Should the min_size allocation warn or not. | |
144 | * | |
145 | * Tries to do opportunistic allocation for memory first trying to allocate | |
146 | * max_size amount of memory and then splitting that until zero order is | |
147 | * reached. Allocation is tried without generating allocation warnings unless | |
148 | * last_warn is set. Last_warn set affects only last allocation of zero order. | |
149 | * | |
150 | * By default, ima_maxorder is 0 and it is equivalent to kmalloc(GFP_KERNEL) | |
151 | * | |
152 | * Return pointer to allocated memory, or NULL on failure. | |
153 | */ | |
154 | static void *ima_alloc_pages(loff_t max_size, size_t *allocated_size, | |
155 | int last_warn) | |
156 | { | |
157 | void *ptr; | |
158 | int order = ima_maxorder; | |
159 | gfp_t gfp_mask = __GFP_WAIT | __GFP_NOWARN | __GFP_NORETRY; | |
160 | ||
161 | if (order) | |
162 | order = min(get_order(max_size), order); | |
163 | ||
164 | for (; order; order--) { | |
165 | ptr = (void *)__get_free_pages(gfp_mask, order); | |
166 | if (ptr) { | |
167 | *allocated_size = PAGE_SIZE << order; | |
168 | return ptr; | |
169 | } | |
170 | } | |
171 | ||
172 | /* order is zero - one page */ | |
173 | ||
174 | gfp_mask = GFP_KERNEL; | |
175 | ||
176 | if (!last_warn) | |
177 | gfp_mask |= __GFP_NOWARN; | |
178 | ||
179 | ptr = (void *)__get_free_pages(gfp_mask, 0); | |
180 | if (ptr) { | |
181 | *allocated_size = PAGE_SIZE; | |
182 | return ptr; | |
183 | } | |
184 | ||
185 | *allocated_size = 0; | |
186 | return NULL; | |
187 | } | |
188 | ||
189 | /** | |
190 | * ima_free_pages() - Free pages allocated by ima_alloc_pages(). | |
191 | * @ptr: Pointer to allocated pages. | |
192 | * @size: Size of allocated buffer. | |
193 | */ | |
194 | static void ima_free_pages(void *ptr, size_t size) | |
195 | { | |
196 | if (!ptr) | |
197 | return; | |
198 | free_pages((unsigned long)ptr, get_order(size)); | |
199 | } | |
200 | ||
3bcced39 DK |
201 | static struct crypto_ahash *ima_alloc_atfm(enum hash_algo algo) |
202 | { | |
203 | struct crypto_ahash *tfm = ima_ahash_tfm; | |
204 | int rc; | |
205 | ||
9a8d289f MZ |
206 | if (algo < 0 || algo >= HASH_ALGO__LAST) |
207 | algo = ima_hash_algo; | |
208 | ||
209 | if (algo != ima_hash_algo || !tfm) { | |
3bcced39 DK |
210 | tfm = crypto_alloc_ahash(hash_algo_name[algo], 0, 0); |
211 | if (!IS_ERR(tfm)) { | |
212 | if (algo == ima_hash_algo) | |
213 | ima_ahash_tfm = tfm; | |
214 | } else { | |
215 | rc = PTR_ERR(tfm); | |
216 | pr_err("Can not allocate %s (reason: %d)\n", | |
217 | hash_algo_name[algo], rc); | |
218 | } | |
219 | } | |
220 | return tfm; | |
221 | } | |
222 | ||
223 | static void ima_free_atfm(struct crypto_ahash *tfm) | |
224 | { | |
225 | if (tfm != ima_ahash_tfm) | |
226 | crypto_free_ahash(tfm); | |
227 | } | |
228 | ||
229 | static void ahash_complete(struct crypto_async_request *req, int err) | |
230 | { | |
231 | struct ahash_completion *res = req->data; | |
232 | ||
233 | if (err == -EINPROGRESS) | |
234 | return; | |
235 | res->err = err; | |
236 | complete(&res->completion); | |
237 | } | |
238 | ||
239 | static int ahash_wait(int err, struct ahash_completion *res) | |
240 | { | |
241 | switch (err) { | |
242 | case 0: | |
243 | break; | |
244 | case -EINPROGRESS: | |
245 | case -EBUSY: | |
246 | wait_for_completion(&res->completion); | |
247 | reinit_completion(&res->completion); | |
248 | err = res->err; | |
249 | /* fall through */ | |
250 | default: | |
251 | pr_crit_ratelimited("ahash calculation failed: err: %d\n", err); | |
252 | } | |
253 | ||
254 | return err; | |
255 | } | |
256 | ||
257 | static int ima_calc_file_hash_atfm(struct file *file, | |
258 | struct ima_digest_data *hash, | |
259 | struct crypto_ahash *tfm) | |
260 | { | |
261 | loff_t i_size, offset; | |
32c2e675 DK |
262 | char *rbuf[2] = { NULL, }; |
263 | int rc, read = 0, rbuf_len, active = 0, ahash_rc = 0; | |
3bcced39 DK |
264 | struct ahash_request *req; |
265 | struct scatterlist sg[1]; | |
266 | struct ahash_completion res; | |
32c2e675 | 267 | size_t rbuf_size[2]; |
3bcced39 DK |
268 | |
269 | hash->length = crypto_ahash_digestsize(tfm); | |
270 | ||
271 | req = ahash_request_alloc(tfm, GFP_KERNEL); | |
272 | if (!req) | |
273 | return -ENOMEM; | |
274 | ||
275 | init_completion(&res.completion); | |
276 | ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG | | |
277 | CRYPTO_TFM_REQ_MAY_SLEEP, | |
278 | ahash_complete, &res); | |
279 | ||
280 | rc = ahash_wait(crypto_ahash_init(req), &res); | |
281 | if (rc) | |
282 | goto out1; | |
283 | ||
284 | i_size = i_size_read(file_inode(file)); | |
285 | ||
286 | if (i_size == 0) | |
287 | goto out2; | |
288 | ||
6edf7a89 DK |
289 | /* |
290 | * Try to allocate maximum size of memory. | |
291 | * Fail if even a single page cannot be allocated. | |
292 | */ | |
32c2e675 DK |
293 | rbuf[0] = ima_alloc_pages(i_size, &rbuf_size[0], 1); |
294 | if (!rbuf[0]) { | |
3bcced39 DK |
295 | rc = -ENOMEM; |
296 | goto out1; | |
297 | } | |
298 | ||
32c2e675 DK |
299 | /* Only allocate one buffer if that is enough. */ |
300 | if (i_size > rbuf_size[0]) { | |
301 | /* | |
302 | * Try to allocate secondary buffer. If that fails fallback to | |
303 | * using single buffering. Use previous memory allocation size | |
304 | * as baseline for possible allocation size. | |
305 | */ | |
306 | rbuf[1] = ima_alloc_pages(i_size - rbuf_size[0], | |
307 | &rbuf_size[1], 0); | |
308 | } | |
309 | ||
3bcced39 DK |
310 | if (!(file->f_mode & FMODE_READ)) { |
311 | file->f_mode |= FMODE_READ; | |
312 | read = 1; | |
313 | } | |
314 | ||
315 | for (offset = 0; offset < i_size; offset += rbuf_len) { | |
32c2e675 DK |
316 | if (!rbuf[1] && offset) { |
317 | /* Not using two buffers, and it is not the first | |
318 | * read/request, wait for the completion of the | |
319 | * previous ahash_update() request. | |
320 | */ | |
321 | rc = ahash_wait(ahash_rc, &res); | |
322 | if (rc) | |
323 | goto out3; | |
324 | } | |
325 | /* read buffer */ | |
326 | rbuf_len = min_t(loff_t, i_size - offset, rbuf_size[active]); | |
327 | rc = ima_kernel_read(file, offset, rbuf[active], rbuf_len); | |
328 | if (rc != rbuf_len) | |
329 | goto out3; | |
330 | ||
331 | if (rbuf[1] && offset) { | |
332 | /* Using two buffers, and it is not the first | |
333 | * read/request, wait for the completion of the | |
334 | * previous ahash_update() request. | |
335 | */ | |
336 | rc = ahash_wait(ahash_rc, &res); | |
337 | if (rc) | |
338 | goto out3; | |
3bcced39 | 339 | } |
3bcced39 | 340 | |
32c2e675 | 341 | sg_init_one(&sg[0], rbuf[active], rbuf_len); |
3bcced39 DK |
342 | ahash_request_set_crypt(req, sg, NULL, rbuf_len); |
343 | ||
32c2e675 DK |
344 | ahash_rc = crypto_ahash_update(req); |
345 | ||
346 | if (rbuf[1]) | |
347 | active = !active; /* swap buffers, if we use two */ | |
3bcced39 | 348 | } |
32c2e675 DK |
349 | /* wait for the last update request to complete */ |
350 | rc = ahash_wait(ahash_rc, &res); | |
351 | out3: | |
3bcced39 DK |
352 | if (read) |
353 | file->f_mode &= ~FMODE_READ; | |
32c2e675 DK |
354 | ima_free_pages(rbuf[0], rbuf_size[0]); |
355 | ima_free_pages(rbuf[1], rbuf_size[1]); | |
3bcced39 DK |
356 | out2: |
357 | if (!rc) { | |
358 | ahash_request_set_crypt(req, NULL, hash->digest, 0); | |
359 | rc = ahash_wait(crypto_ahash_final(req), &res); | |
360 | } | |
361 | out1: | |
362 | ahash_request_free(req); | |
363 | return rc; | |
364 | } | |
365 | ||
366 | static int ima_calc_file_ahash(struct file *file, struct ima_digest_data *hash) | |
367 | { | |
368 | struct crypto_ahash *tfm; | |
369 | int rc; | |
370 | ||
371 | tfm = ima_alloc_atfm(hash->algo); | |
372 | if (IS_ERR(tfm)) | |
373 | return PTR_ERR(tfm); | |
374 | ||
375 | rc = ima_calc_file_hash_atfm(file, hash, tfm); | |
376 | ||
377 | ima_free_atfm(tfm); | |
378 | ||
379 | return rc; | |
380 | } | |
381 | ||
c7c8bb23 DK |
382 | static int ima_calc_file_hash_tfm(struct file *file, |
383 | struct ima_digest_data *hash, | |
384 | struct crypto_shash *tfm) | |
3323eec9 | 385 | { |
16bfa38b | 386 | loff_t i_size, offset = 0; |
3323eec9 | 387 | char *rbuf; |
2fe5d6de | 388 | int rc, read = 0; |
76bb28f6 DK |
389 | struct { |
390 | struct shash_desc shash; | |
c7c8bb23 | 391 | char ctx[crypto_shash_descsize(tfm)]; |
76bb28f6 | 392 | } desc; |
3323eec9 | 393 | |
c7c8bb23 | 394 | desc.shash.tfm = tfm; |
76bb28f6 DK |
395 | desc.shash.flags = 0; |
396 | ||
723326b9 DK |
397 | hash->length = crypto_shash_digestsize(tfm); |
398 | ||
76bb28f6 | 399 | rc = crypto_shash_init(&desc.shash); |
3323eec9 MZ |
400 | if (rc != 0) |
401 | return rc; | |
402 | ||
1d91ac62 DK |
403 | i_size = i_size_read(file_inode(file)); |
404 | ||
405 | if (i_size == 0) | |
3323eec9 | 406 | goto out; |
1d91ac62 DK |
407 | |
408 | rbuf = kzalloc(PAGE_SIZE, GFP_KERNEL); | |
409 | if (!rbuf) | |
410 | return -ENOMEM; | |
411 | ||
2fe5d6de MZ |
412 | if (!(file->f_mode & FMODE_READ)) { |
413 | file->f_mode |= FMODE_READ; | |
414 | read = 1; | |
415 | } | |
1d91ac62 | 416 | |
3323eec9 MZ |
417 | while (offset < i_size) { |
418 | int rbuf_len; | |
419 | ||
0430e49b | 420 | rbuf_len = ima_kernel_read(file, offset, rbuf, PAGE_SIZE); |
3323eec9 MZ |
421 | if (rbuf_len < 0) { |
422 | rc = rbuf_len; | |
423 | break; | |
424 | } | |
16bfa38b MZ |
425 | if (rbuf_len == 0) |
426 | break; | |
3323eec9 | 427 | offset += rbuf_len; |
3323eec9 | 428 | |
76bb28f6 | 429 | rc = crypto_shash_update(&desc.shash, rbuf, rbuf_len); |
3323eec9 MZ |
430 | if (rc) |
431 | break; | |
432 | } | |
2fe5d6de MZ |
433 | if (read) |
434 | file->f_mode &= ~FMODE_READ; | |
1d91ac62 | 435 | kfree(rbuf); |
3323eec9 | 436 | out: |
1d91ac62 DK |
437 | if (!rc) |
438 | rc = crypto_shash_final(&desc.shash, hash->digest); | |
3323eec9 MZ |
439 | return rc; |
440 | } | |
441 | ||
3bcced39 | 442 | static int ima_calc_file_shash(struct file *file, struct ima_digest_data *hash) |
c7c8bb23 | 443 | { |
723326b9 | 444 | struct crypto_shash *tfm; |
c7c8bb23 DK |
445 | int rc; |
446 | ||
723326b9 DK |
447 | tfm = ima_alloc_tfm(hash->algo); |
448 | if (IS_ERR(tfm)) | |
449 | return PTR_ERR(tfm); | |
c7c8bb23 DK |
450 | |
451 | rc = ima_calc_file_hash_tfm(file, hash, tfm); | |
452 | ||
723326b9 | 453 | ima_free_tfm(tfm); |
c7c8bb23 DK |
454 | |
455 | return rc; | |
456 | } | |
457 | ||
3bcced39 DK |
458 | /* |
459 | * ima_calc_file_hash - calculate file hash | |
460 | * | |
461 | * Asynchronous hash (ahash) allows using HW acceleration for calculating | |
462 | * a hash. ahash performance varies for different data sizes on different | |
463 | * crypto accelerators. shash performance might be better for smaller files. | |
464 | * The 'ima.ahash_minsize' module parameter allows specifying the best | |
465 | * minimum file size for using ahash on the system. | |
466 | * | |
467 | * If the ima.ahash_minsize parameter is not specified, this function uses | |
468 | * shash for the hash calculation. If ahash fails, it falls back to using | |
469 | * shash. | |
470 | */ | |
471 | int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash) | |
472 | { | |
473 | loff_t i_size; | |
474 | int rc; | |
475 | ||
476 | i_size = i_size_read(file_inode(file)); | |
477 | ||
478 | if (ima_ahash_minsize && i_size >= ima_ahash_minsize) { | |
479 | rc = ima_calc_file_ahash(file, hash); | |
480 | if (!rc) | |
481 | return 0; | |
482 | } | |
483 | ||
484 | return ima_calc_file_shash(file, hash); | |
485 | } | |
486 | ||
3323eec9 | 487 | /* |
a71dc65d | 488 | * Calculate the hash of template data |
3323eec9 | 489 | */ |
a71dc65d | 490 | static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data, |
b6f8f16f | 491 | struct ima_template_desc *td, |
a71dc65d RS |
492 | int num_fields, |
493 | struct ima_digest_data *hash, | |
494 | struct crypto_shash *tfm) | |
3323eec9 | 495 | { |
76bb28f6 DK |
496 | struct { |
497 | struct shash_desc shash; | |
ea593993 | 498 | char ctx[crypto_shash_descsize(tfm)]; |
76bb28f6 | 499 | } desc; |
a71dc65d | 500 | int rc, i; |
3323eec9 | 501 | |
ea593993 | 502 | desc.shash.tfm = tfm; |
76bb28f6 | 503 | desc.shash.flags = 0; |
3323eec9 | 504 | |
ea593993 | 505 | hash->length = crypto_shash_digestsize(tfm); |
c7c8bb23 | 506 | |
a71dc65d RS |
507 | rc = crypto_shash_init(&desc.shash); |
508 | if (rc != 0) | |
509 | return rc; | |
510 | ||
511 | for (i = 0; i < num_fields; i++) { | |
e3b64c26 RS |
512 | u8 buffer[IMA_EVENT_NAME_LEN_MAX + 1] = { 0 }; |
513 | u8 *data_to_hash = field_data[i].data; | |
514 | u32 datalen = field_data[i].len; | |
515 | ||
b6f8f16f RS |
516 | if (strcmp(td->name, IMA_TEMPLATE_IMA_NAME) != 0) { |
517 | rc = crypto_shash_update(&desc.shash, | |
518 | (const u8 *) &field_data[i].len, | |
519 | sizeof(field_data[i].len)); | |
520 | if (rc) | |
521 | break; | |
e3b64c26 RS |
522 | } else if (strcmp(td->fields[i]->field_id, "n") == 0) { |
523 | memcpy(buffer, data_to_hash, datalen); | |
524 | data_to_hash = buffer; | |
525 | datalen = IMA_EVENT_NAME_LEN_MAX + 1; | |
b6f8f16f | 526 | } |
e3b64c26 | 527 | rc = crypto_shash_update(&desc.shash, data_to_hash, datalen); |
a71dc65d RS |
528 | if (rc) |
529 | break; | |
530 | } | |
531 | ||
532 | if (!rc) | |
533 | rc = crypto_shash_final(&desc.shash, hash->digest); | |
534 | ||
535 | return rc; | |
3323eec9 MZ |
536 | } |
537 | ||
b6f8f16f RS |
538 | int ima_calc_field_array_hash(struct ima_field_data *field_data, |
539 | struct ima_template_desc *desc, int num_fields, | |
a71dc65d | 540 | struct ima_digest_data *hash) |
ea593993 DK |
541 | { |
542 | struct crypto_shash *tfm; | |
543 | int rc; | |
544 | ||
545 | tfm = ima_alloc_tfm(hash->algo); | |
546 | if (IS_ERR(tfm)) | |
547 | return PTR_ERR(tfm); | |
548 | ||
b6f8f16f RS |
549 | rc = ima_calc_field_array_hash_tfm(field_data, desc, num_fields, |
550 | hash, tfm); | |
ea593993 DK |
551 | |
552 | ima_free_tfm(tfm); | |
553 | ||
554 | return rc; | |
555 | } | |
556 | ||
932995f0 | 557 | static void __init ima_pcrread(int idx, u8 *pcr) |
3323eec9 MZ |
558 | { |
559 | if (!ima_used_chip) | |
560 | return; | |
561 | ||
562 | if (tpm_pcr_read(TPM_ANY_NUM, idx, pcr) != 0) | |
20ee451f | 563 | pr_err("Error Communicating to TPM chip\n"); |
3323eec9 MZ |
564 | } |
565 | ||
566 | /* | |
567 | * Calculate the boot aggregate hash | |
568 | */ | |
09ef5435 DK |
569 | static int __init ima_calc_boot_aggregate_tfm(char *digest, |
570 | struct crypto_shash *tfm) | |
3323eec9 | 571 | { |
140d8022 | 572 | u8 pcr_i[TPM_DIGEST_SIZE]; |
3323eec9 | 573 | int rc, i; |
76bb28f6 DK |
574 | struct { |
575 | struct shash_desc shash; | |
09ef5435 | 576 | char ctx[crypto_shash_descsize(tfm)]; |
76bb28f6 DK |
577 | } desc; |
578 | ||
09ef5435 | 579 | desc.shash.tfm = tfm; |
76bb28f6 | 580 | desc.shash.flags = 0; |
3323eec9 | 581 | |
76bb28f6 | 582 | rc = crypto_shash_init(&desc.shash); |
3323eec9 MZ |
583 | if (rc != 0) |
584 | return rc; | |
585 | ||
586 | /* cumulative sha1 over tpm registers 0-7 */ | |
587 | for (i = TPM_PCR0; i < TPM_PCR8; i++) { | |
588 | ima_pcrread(i, pcr_i); | |
589 | /* now accumulate with current aggregate */ | |
140d8022 | 590 | rc = crypto_shash_update(&desc.shash, pcr_i, TPM_DIGEST_SIZE); |
3323eec9 MZ |
591 | } |
592 | if (!rc) | |
76bb28f6 | 593 | crypto_shash_final(&desc.shash, digest); |
3323eec9 MZ |
594 | return rc; |
595 | } | |
09ef5435 DK |
596 | |
597 | int __init ima_calc_boot_aggregate(struct ima_digest_data *hash) | |
598 | { | |
599 | struct crypto_shash *tfm; | |
600 | int rc; | |
601 | ||
602 | tfm = ima_alloc_tfm(hash->algo); | |
603 | if (IS_ERR(tfm)) | |
604 | return PTR_ERR(tfm); | |
605 | ||
606 | hash->length = crypto_shash_digestsize(tfm); | |
607 | rc = ima_calc_boot_aggregate_tfm(hash->digest, tfm); | |
608 | ||
609 | ima_free_tfm(tfm); | |
610 | ||
611 | return rc; | |
612 | } |