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16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18#include <linux/kernel.h>
19#include <linux/moduleparam.h>
20#include <linux/ratelimit.h>
21#include <linux/file.h>
22#include <linux/crypto.h>
23#include <linux/scatterlist.h>
24#include <linux/err.h>
25#include <linux/slab.h>
26#include <crypto/hash.h>
27
28#include "ima.h"
29
30
31static unsigned long ima_ahash_minsize;
32module_param_named(ahash_minsize, ima_ahash_minsize, ulong, 0644);
33MODULE_PARM_DESC(ahash_minsize, "Minimum file size for ahash use");
34
35
36static int ima_maxorder;
37static unsigned int ima_bufsize = PAGE_SIZE;
38
39static int param_set_bufsize(const char *val, const struct kernel_param *kp)
40{
41 unsigned long long size;
42 int order;
43
44 size = memparse(val, NULL);
45 order = get_order(size);
46 if (order >= MAX_ORDER)
47 return -EINVAL;
48 ima_maxorder = order;
49 ima_bufsize = PAGE_SIZE << order;
50 return 0;
51}
52
53static const struct kernel_param_ops param_ops_bufsize = {
54 .set = param_set_bufsize,
55 .get = param_get_uint,
56};
57#define param_check_bufsize(name, p) __param_check(name, p, unsigned int)
58
59module_param_named(ahash_bufsize, ima_bufsize, bufsize, 0644);
60MODULE_PARM_DESC(ahash_bufsize, "Maximum ahash buffer size");
61
62static struct crypto_shash *ima_shash_tfm;
63static struct crypto_ahash *ima_ahash_tfm;
64
65int __init ima_init_crypto(void)
66{
67 long rc;
68
69 ima_shash_tfm = crypto_alloc_shash(hash_algo_name[ima_hash_algo], 0, 0);
70 if (IS_ERR(ima_shash_tfm)) {
71 rc = PTR_ERR(ima_shash_tfm);
72 pr_err("Can not allocate %s (reason: %ld)\n",
73 hash_algo_name[ima_hash_algo], rc);
74 return rc;
75 }
76 pr_info("Allocated hash algorithm: %s\n",
77 hash_algo_name[ima_hash_algo]);
78 return 0;
79}
80
81static struct crypto_shash *ima_alloc_tfm(enum hash_algo algo)
82{
83 struct crypto_shash *tfm = ima_shash_tfm;
84 int rc;
85
86 if (algo < 0 || algo >= HASH_ALGO__LAST)
87 algo = ima_hash_algo;
88
89 if (algo != ima_hash_algo) {
90 tfm = crypto_alloc_shash(hash_algo_name[algo], 0, 0);
91 if (IS_ERR(tfm)) {
92 rc = PTR_ERR(tfm);
93 pr_err("Can not allocate %s (reason: %d)\n",
94 hash_algo_name[algo], rc);
95 }
96 }
97 return tfm;
98}
99
100static void ima_free_tfm(struct crypto_shash *tfm)
101{
102 if (tfm != ima_shash_tfm)
103 crypto_free_shash(tfm);
104}
105
106
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112
113
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115
116
117
118
119
120
121static void *ima_alloc_pages(loff_t max_size, size_t *allocated_size,
122 int last_warn)
123{
124 void *ptr;
125 int order = ima_maxorder;
126 gfp_t gfp_mask = __GFP_RECLAIM | __GFP_NOWARN | __GFP_NORETRY;
127
128 if (order)
129 order = min(get_order(max_size), order);
130
131 for (; order; order--) {
132 ptr = (void *)__get_free_pages(gfp_mask, order);
133 if (ptr) {
134 *allocated_size = PAGE_SIZE << order;
135 return ptr;
136 }
137 }
138
139
140
141 gfp_mask = GFP_KERNEL;
142
143 if (!last_warn)
144 gfp_mask |= __GFP_NOWARN;
145
146 ptr = (void *)__get_free_pages(gfp_mask, 0);
147 if (ptr) {
148 *allocated_size = PAGE_SIZE;
149 return ptr;
150 }
151
152 *allocated_size = 0;
153 return NULL;
154}
155
156
157
158
159
160
161static void ima_free_pages(void *ptr, size_t size)
162{
163 if (!ptr)
164 return;
165 free_pages((unsigned long)ptr, get_order(size));
166}
167
168static struct crypto_ahash *ima_alloc_atfm(enum hash_algo algo)
169{
170 struct crypto_ahash *tfm = ima_ahash_tfm;
171 int rc;
172
173 if (algo < 0 || algo >= HASH_ALGO__LAST)
174 algo = ima_hash_algo;
175
176 if (algo != ima_hash_algo || !tfm) {
177 tfm = crypto_alloc_ahash(hash_algo_name[algo], 0, 0);
178 if (!IS_ERR(tfm)) {
179 if (algo == ima_hash_algo)
180 ima_ahash_tfm = tfm;
181 } else {
182 rc = PTR_ERR(tfm);
183 pr_err("Can not allocate %s (reason: %d)\n",
184 hash_algo_name[algo], rc);
185 }
186 }
187 return tfm;
188}
189
190static void ima_free_atfm(struct crypto_ahash *tfm)
191{
192 if (tfm != ima_ahash_tfm)
193 crypto_free_ahash(tfm);
194}
195
196static inline int ahash_wait(int err, struct crypto_wait *wait)
197{
198
199 err = crypto_wait_req(err, wait);
200
201 if (err)
202 pr_crit_ratelimited("ahash calculation failed: err: %d\n", err);
203
204 return err;
205}
206
207static int ima_calc_file_hash_atfm(struct file *file,
208 struct ima_digest_data *hash,
209 struct crypto_ahash *tfm)
210{
211 loff_t i_size, offset;
212 char *rbuf[2] = { NULL, };
213 int rc, read = 0, rbuf_len, active = 0, ahash_rc = 0;
214 struct ahash_request *req;
215 struct scatterlist sg[1];
216 struct crypto_wait wait;
217 size_t rbuf_size[2];
218
219 hash->length = crypto_ahash_digestsize(tfm);
220
221 req = ahash_request_alloc(tfm, GFP_KERNEL);
222 if (!req)
223 return -ENOMEM;
224
225 crypto_init_wait(&wait);
226 ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
227 CRYPTO_TFM_REQ_MAY_SLEEP,
228 crypto_req_done, &wait);
229
230 rc = ahash_wait(crypto_ahash_init(req), &wait);
231 if (rc)
232 goto out1;
233
234 i_size = i_size_read(file_inode(file));
235
236 if (i_size == 0)
237 goto out2;
238
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240
241
242
243 rbuf[0] = ima_alloc_pages(i_size, &rbuf_size[0], 1);
244 if (!rbuf[0]) {
245 rc = -ENOMEM;
246 goto out1;
247 }
248
249
250 if (i_size > rbuf_size[0]) {
251
252
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254
255
256 rbuf[1] = ima_alloc_pages(i_size - rbuf_size[0],
257 &rbuf_size[1], 0);
258 }
259
260 if (!(file->f_mode & FMODE_READ)) {
261 file->f_mode |= FMODE_READ;
262 read = 1;
263 }
264
265 for (offset = 0; offset < i_size; offset += rbuf_len) {
266 if (!rbuf[1] && offset) {
267
268
269
270
271 rc = ahash_wait(ahash_rc, &wait);
272 if (rc)
273 goto out3;
274 }
275
276 rbuf_len = min_t(loff_t, i_size - offset, rbuf_size[active]);
277 rc = integrity_kernel_read(file, offset, rbuf[active],
278 rbuf_len);
279 if (rc != rbuf_len)
280 goto out3;
281
282 if (rbuf[1] && offset) {
283
284
285
286
287 rc = ahash_wait(ahash_rc, &wait);
288 if (rc)
289 goto out3;
290 }
291
292 sg_init_one(&sg[0], rbuf[active], rbuf_len);
293 ahash_request_set_crypt(req, sg, NULL, rbuf_len);
294
295 ahash_rc = crypto_ahash_update(req);
296
297 if (rbuf[1])
298 active = !active;
299 }
300
301 rc = ahash_wait(ahash_rc, &wait);
302out3:
303 if (read)
304 file->f_mode &= ~FMODE_READ;
305 ima_free_pages(rbuf[0], rbuf_size[0]);
306 ima_free_pages(rbuf[1], rbuf_size[1]);
307out2:
308 if (!rc) {
309 ahash_request_set_crypt(req, NULL, hash->digest, 0);
310 rc = ahash_wait(crypto_ahash_final(req), &wait);
311 }
312out1:
313 ahash_request_free(req);
314 return rc;
315}
316
317static int ima_calc_file_ahash(struct file *file, struct ima_digest_data *hash)
318{
319 struct crypto_ahash *tfm;
320 int rc;
321
322 tfm = ima_alloc_atfm(hash->algo);
323 if (IS_ERR(tfm))
324 return PTR_ERR(tfm);
325
326 rc = ima_calc_file_hash_atfm(file, hash, tfm);
327
328 ima_free_atfm(tfm);
329
330 return rc;
331}
332
333static int ima_calc_file_hash_tfm(struct file *file,
334 struct ima_digest_data *hash,
335 struct crypto_shash *tfm)
336{
337 loff_t i_size, offset = 0;
338 char *rbuf;
339 int rc, read = 0;
340 SHASH_DESC_ON_STACK(shash, tfm);
341
342 shash->tfm = tfm;
343 shash->flags = 0;
344
345 hash->length = crypto_shash_digestsize(tfm);
346
347 rc = crypto_shash_init(shash);
348 if (rc != 0)
349 return rc;
350
351 i_size = i_size_read(file_inode(file));
352
353 if (i_size == 0)
354 goto out;
355
356 rbuf = kzalloc(PAGE_SIZE, GFP_KERNEL);
357 if (!rbuf)
358 return -ENOMEM;
359
360 if (!(file->f_mode & FMODE_READ)) {
361 file->f_mode |= FMODE_READ;
362 read = 1;
363 }
364
365 while (offset < i_size) {
366 int rbuf_len;
367
368 rbuf_len = integrity_kernel_read(file, offset, rbuf, PAGE_SIZE);
369 if (rbuf_len < 0) {
370 rc = rbuf_len;
371 break;
372 }
373 if (rbuf_len == 0)
374 break;
375 offset += rbuf_len;
376
377 rc = crypto_shash_update(shash, rbuf, rbuf_len);
378 if (rc)
379 break;
380 }
381 if (read)
382 file->f_mode &= ~FMODE_READ;
383 kfree(rbuf);
384out:
385 if (!rc)
386 rc = crypto_shash_final(shash, hash->digest);
387 return rc;
388}
389
390static int ima_calc_file_shash(struct file *file, struct ima_digest_data *hash)
391{
392 struct crypto_shash *tfm;
393 int rc;
394
395 tfm = ima_alloc_tfm(hash->algo);
396 if (IS_ERR(tfm))
397 return PTR_ERR(tfm);
398
399 rc = ima_calc_file_hash_tfm(file, hash, tfm);
400
401 ima_free_tfm(tfm);
402
403 return rc;
404}
405
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417
418
419int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash)
420{
421 loff_t i_size;
422 int rc;
423
424
425
426
427
428 if (file->f_flags & O_DIRECT) {
429 hash->length = hash_digest_size[ima_hash_algo];
430 hash->algo = ima_hash_algo;
431 return -EINVAL;
432 }
433
434 i_size = i_size_read(file_inode(file));
435
436 if (ima_ahash_minsize && i_size >= ima_ahash_minsize) {
437 rc = ima_calc_file_ahash(file, hash);
438 if (!rc)
439 return 0;
440 }
441
442 return ima_calc_file_shash(file, hash);
443}
444
445
446
447
448static int ima_calc_field_array_hash_tfm(struct ima_field_data *field_data,
449 struct ima_template_desc *td,
450 int num_fields,
451 struct ima_digest_data *hash,
452 struct crypto_shash *tfm)
453{
454 SHASH_DESC_ON_STACK(shash, tfm);
455 int rc, i;
456
457 shash->tfm = tfm;
458 shash->flags = 0;
459
460 hash->length = crypto_shash_digestsize(tfm);
461
462 rc = crypto_shash_init(shash);
463 if (rc != 0)
464 return rc;
465
466 for (i = 0; i < num_fields; i++) {
467 u8 buffer[IMA_EVENT_NAME_LEN_MAX + 1] = { 0 };
468 u8 *data_to_hash = field_data[i].data;
469 u32 datalen = field_data[i].len;
470 u32 datalen_to_hash =
471 !ima_canonical_fmt ? datalen : cpu_to_le32(datalen);
472
473 if (strcmp(td->name, IMA_TEMPLATE_IMA_NAME) != 0) {
474 rc = crypto_shash_update(shash,
475 (const u8 *) &datalen_to_hash,
476 sizeof(datalen_to_hash));
477 if (rc)
478 break;
479 } else if (strcmp(td->fields[i]->field_id, "n") == 0) {
480 memcpy(buffer, data_to_hash, datalen);
481 data_to_hash = buffer;
482 datalen = IMA_EVENT_NAME_LEN_MAX + 1;
483 }
484 rc = crypto_shash_update(shash, data_to_hash, datalen);
485 if (rc)
486 break;
487 }
488
489 if (!rc)
490 rc = crypto_shash_final(shash, hash->digest);
491
492 return rc;
493}
494
495int ima_calc_field_array_hash(struct ima_field_data *field_data,
496 struct ima_template_desc *desc, int num_fields,
497 struct ima_digest_data *hash)
498{
499 struct crypto_shash *tfm;
500 int rc;
501
502 tfm = ima_alloc_tfm(hash->algo);
503 if (IS_ERR(tfm))
504 return PTR_ERR(tfm);
505
506 rc = ima_calc_field_array_hash_tfm(field_data, desc, num_fields,
507 hash, tfm);
508
509 ima_free_tfm(tfm);
510
511 return rc;
512}
513
514static int calc_buffer_ahash_atfm(const void *buf, loff_t len,
515 struct ima_digest_data *hash,
516 struct crypto_ahash *tfm)
517{
518 struct ahash_request *req;
519 struct scatterlist sg;
520 struct crypto_wait wait;
521 int rc, ahash_rc = 0;
522
523 hash->length = crypto_ahash_digestsize(tfm);
524
525 req = ahash_request_alloc(tfm, GFP_KERNEL);
526 if (!req)
527 return -ENOMEM;
528
529 crypto_init_wait(&wait);
530 ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
531 CRYPTO_TFM_REQ_MAY_SLEEP,
532 crypto_req_done, &wait);
533
534 rc = ahash_wait(crypto_ahash_init(req), &wait);
535 if (rc)
536 goto out;
537
538 sg_init_one(&sg, buf, len);
539 ahash_request_set_crypt(req, &sg, NULL, len);
540
541 ahash_rc = crypto_ahash_update(req);
542
543
544 rc = ahash_wait(ahash_rc, &wait);
545 if (!rc) {
546 ahash_request_set_crypt(req, NULL, hash->digest, 0);
547 rc = ahash_wait(crypto_ahash_final(req), &wait);
548 }
549out:
550 ahash_request_free(req);
551 return rc;
552}
553
554static int calc_buffer_ahash(const void *buf, loff_t len,
555 struct ima_digest_data *hash)
556{
557 struct crypto_ahash *tfm;
558 int rc;
559
560 tfm = ima_alloc_atfm(hash->algo);
561 if (IS_ERR(tfm))
562 return PTR_ERR(tfm);
563
564 rc = calc_buffer_ahash_atfm(buf, len, hash, tfm);
565
566 ima_free_atfm(tfm);
567
568 return rc;
569}
570
571static int calc_buffer_shash_tfm(const void *buf, loff_t size,
572 struct ima_digest_data *hash,
573 struct crypto_shash *tfm)
574{
575 SHASH_DESC_ON_STACK(shash, tfm);
576 unsigned int len;
577 int rc;
578
579 shash->tfm = tfm;
580 shash->flags = 0;
581
582 hash->length = crypto_shash_digestsize(tfm);
583
584 rc = crypto_shash_init(shash);
585 if (rc != 0)
586 return rc;
587
588 while (size) {
589 len = size < PAGE_SIZE ? size : PAGE_SIZE;
590 rc = crypto_shash_update(shash, buf, len);
591 if (rc)
592 break;
593 buf += len;
594 size -= len;
595 }
596
597 if (!rc)
598 rc = crypto_shash_final(shash, hash->digest);
599 return rc;
600}
601
602static int calc_buffer_shash(const void *buf, loff_t len,
603 struct ima_digest_data *hash)
604{
605 struct crypto_shash *tfm;
606 int rc;
607
608 tfm = ima_alloc_tfm(hash->algo);
609 if (IS_ERR(tfm))
610 return PTR_ERR(tfm);
611
612 rc = calc_buffer_shash_tfm(buf, len, hash, tfm);
613
614 ima_free_tfm(tfm);
615 return rc;
616}
617
618int ima_calc_buffer_hash(const void *buf, loff_t len,
619 struct ima_digest_data *hash)
620{
621 int rc;
622
623 if (ima_ahash_minsize && len >= ima_ahash_minsize) {
624 rc = calc_buffer_ahash(buf, len, hash);
625 if (!rc)
626 return 0;
627 }
628
629 return calc_buffer_shash(buf, len, hash);
630}
631
632static void __init ima_pcrread(int idx, u8 *pcr)
633{
634 if (!ima_used_chip)
635 return;
636
637 if (tpm_pcr_read(NULL, idx, pcr) != 0)
638 pr_err("Error Communicating to TPM chip\n");
639}
640
641
642
643
644static int __init ima_calc_boot_aggregate_tfm(char *digest,
645 struct crypto_shash *tfm)
646{
647 u8 pcr_i[TPM_DIGEST_SIZE];
648 int rc, i;
649 SHASH_DESC_ON_STACK(shash, tfm);
650
651 shash->tfm = tfm;
652 shash->flags = 0;
653
654 rc = crypto_shash_init(shash);
655 if (rc != 0)
656 return rc;
657
658
659 for (i = TPM_PCR0; i < TPM_PCR8; i++) {
660 ima_pcrread(i, pcr_i);
661
662 rc = crypto_shash_update(shash, pcr_i, TPM_DIGEST_SIZE);
663 }
664 if (!rc)
665 crypto_shash_final(shash, digest);
666 return rc;
667}
668
669int __init ima_calc_boot_aggregate(struct ima_digest_data *hash)
670{
671 struct crypto_shash *tfm;
672 int rc;
673
674 tfm = ima_alloc_tfm(hash->algo);
675 if (IS_ERR(tfm))
676 return PTR_ERR(tfm);
677
678 hash->length = crypto_shash_digestsize(tfm);
679 rc = ima_calc_boot_aggregate_tfm(hash->digest, tfm);
680
681 ima_free_tfm(tfm);
682
683 return rc;
684}
685