summaryrefslogtreecommitdiff
path: root/crypto/shash.c
blob: 0a0a50cb694f0ebb1fa7a27cca5ec6225f86ec60 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Synchronous Cryptographic Hash operations.
 *
 * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
 */

#include <crypto/scatterwalk.h>
#include <crypto/internal/hash.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <linux/cryptouser.h>
#include <net/netlink.h>
#include <linux/compiler.h>

#include "internal.h"

static const struct crypto_type crypto_shash_type;

static int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
			   unsigned int keylen)
{
	return -ENOSYS;
}

/*
 * Check whether an shash algorithm has a setkey function.
 *
 * For CFI compatibility, this must not be an inline function.  This is because
 * when CFI is enabled, modules won't get the same address for shash_no_setkey
 * (if it were exported, which inlining would require) as the core kernel will.
 */
bool crypto_shash_alg_has_setkey(struct shash_alg *alg)
{
	return alg->setkey != shash_no_setkey;
}
EXPORT_SYMBOL_GPL(crypto_shash_alg_has_setkey);

static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
				  unsigned int keylen)
{
	struct shash_alg *shash = crypto_shash_alg(tfm);
	unsigned long alignmask = crypto_shash_alignmask(tfm);
	unsigned long absize;
	u8 *buffer, *alignbuffer;
	int err;

	absize = keylen + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
	buffer = kmalloc(absize, GFP_ATOMIC);
	if (!buffer)
		return -ENOMEM;

	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
	memcpy(alignbuffer, key, keylen);
	err = shash->setkey(tfm, alignbuffer, keylen);
	kfree_sensitive(buffer);
	return err;
}

static void shash_set_needkey(struct crypto_shash *tfm, struct shash_alg *alg)
{
	if (crypto_shash_alg_needs_key(alg))
		crypto_shash_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
}

int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
			unsigned int keylen)
{
	struct shash_alg *shash = crypto_shash_alg(tfm);
	unsigned long alignmask = crypto_shash_alignmask(tfm);
	int err;

	if ((unsigned long)key & alignmask)
		err = shash_setkey_unaligned(tfm, key, keylen);
	else
		err = shash->setkey(tfm, key, keylen);

	if (unlikely(err)) {
		shash_set_needkey(tfm, shash);
		return err;
	}

	crypto_shash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
	return 0;
}
EXPORT_SYMBOL_GPL(crypto_shash_setkey);

static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
				  unsigned int len)
{
	struct crypto_shash *tfm = desc->tfm;
	struct shash_alg *shash = crypto_shash_alg(tfm);
	unsigned long alignmask = crypto_shash_alignmask(tfm);
	unsigned int unaligned_len = alignmask + 1 -
				     ((unsigned long)data & alignmask);
	/*
	 * We cannot count on __aligned() working for large values:
	 * https://patchwork.kernel.org/patch/9507697/
	 */
	u8 ubuf[MAX_ALGAPI_ALIGNMASK * 2];
	u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
	int err;

	if (WARN_ON(buf + unaligned_len > ubuf + sizeof(ubuf)))
		return -EINVAL;

	if (unaligned_len > len)
		unaligned_len = len;

	memcpy(buf, data, unaligned_len);
	err = shash->update(desc, buf, unaligned_len);
	memset(buf, 0, unaligned_len);

	return err ?:
	       shash->update(desc, data + unaligned_len, len - unaligned_len);
}

int crypto_shash_update(struct shash_desc *desc, const u8 *data,
			unsigned int len)
{
	struct crypto_shash *tfm = desc->tfm;
	struct shash_alg *shash = crypto_shash_alg(tfm);
	unsigned long alignmask = crypto_shash_alignmask(tfm);

	if ((unsigned long)data & alignmask)
		return shash_update_unaligned(desc, data, len);

	return shash->update(desc, data, len);
}
EXPORT_SYMBOL_GPL(crypto_shash_update);

static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
{
	struct crypto_shash *tfm = desc->tfm;
	unsigned long alignmask = crypto_shash_alignmask(tfm);
	struct shash_alg *shash = crypto_shash_alg(tfm);
	unsigned int ds = crypto_shash_digestsize(tfm);
	/*
	 * We cannot count on __aligned() working for large values:
	 * https://patchwork.kernel.org/patch/9507697/
	 */
	u8 ubuf[MAX_ALGAPI_ALIGNMASK + HASH_MAX_DIGESTSIZE];
	u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
	int err;

	if (WARN_ON(buf + ds > ubuf + sizeof(ubuf)))
		return -EINVAL;

	err = shash->final(desc, buf);
	if (err)
		goto out;

	memcpy(out, buf, ds);

out:
	memset(buf, 0, ds);
	return err;
}

int crypto_shash_final(struct shash_desc *desc, u8 *out)
{
	struct crypto_shash *tfm = desc->tfm;
	struct shash_alg *shash = crypto_shash_alg(tfm);
	unsigned long alignmask = crypto_shash_alignmask(tfm);

	if ((unsigned long)out & alignmask)
		return shash_final_unaligned(desc, out);

	return shash->final(desc, out);
}
EXPORT_SYMBOL_GPL(crypto_shash_final);

static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
				 unsigned int len, u8 *out)
{
	return crypto_shash_update(desc, data, len) ?:
	       crypto_shash_final(desc, out);
}

int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
		       unsigned int len, u8 *out)
{
	struct crypto_shash *tfm = desc->tfm;
	struct shash_alg *shash = crypto_shash_alg(tfm);
	unsigned long alignmask = crypto_shash_alignmask(tfm);

	if (((unsigned long)data | (unsigned long)out) & alignmask)
		return shash_finup_unaligned(desc, data, len, out);

	return shash->finup(desc, data, len, out);
}
EXPORT_SYMBOL_GPL(crypto_shash_finup);

static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
				  unsigned int len, u8 *out)
{
	return crypto_shash_init(desc) ?:
	       crypto_shash_finup(desc, data, len, out);
}

int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
			unsigned int len, u8 *out)
{
	struct crypto_shash *tfm = desc->tfm;
	struct shash_alg *shash = crypto_shash_alg(tfm);
	unsigned long alignmask = crypto_shash_alignmask(tfm);

	if (crypto_shash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
		return -ENOKEY;

	if (((unsigned long)data | (unsigned long)out) & alignmask)
		return shash_digest_unaligned(desc, data, len, out);

	return shash->digest(desc, data, len, out);
}
EXPORT_SYMBOL_GPL(crypto_shash_digest);

int crypto_shash_tfm_digest(struct crypto_shash *tfm, const u8 *data,
			    unsigned int len, u8 *out)
{
	SHASH_DESC_ON_STACK(desc, tfm);
	int err;

	desc->tfm = tfm;

	err = crypto_shash_digest(desc, data, len, out);

	shash_desc_zero(desc);

	return err;
}
EXPORT_SYMBOL_GPL(crypto_shash_tfm_digest);

static int shash_default_export(struct shash_desc *desc, void *out)
{
	memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
	return 0;
}

static int shash_default_import(struct shash_desc *desc, const void *in)
{
	memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
	return 0;
}

static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
			      unsigned int keylen)
{
	struct crypto_shash **ctx = crypto_ahash_ctx(tfm);

	return crypto_shash_setkey(*ctx, key, keylen);
}

static int shash_async_init(struct ahash_request *req)
{
	struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
	struct shash_desc *desc = ahash_request_ctx(req);

	desc->tfm = *ctx;

	return crypto_shash_init(desc);
}

int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
{
	struct crypto_hash_walk walk;
	int nbytes;

	for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
	     nbytes = crypto_hash_walk_done(&walk, nbytes))
		nbytes = crypto_shash_update(desc, walk.data, nbytes);

	return nbytes;
}
EXPORT_SYMBOL_GPL(shash_ahash_update);

static int shash_async_update(struct ahash_request *req)
{
	return shash_ahash_update(req, ahash_request_ctx(req));
}

static int shash_async_final(struct ahash_request *req)
{
	return crypto_shash_final(ahash_request_ctx(req), req->result);
}

int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
{
	struct crypto_hash_walk walk;
	int nbytes;

	nbytes = crypto_hash_walk_first(req, &walk);
	if (!nbytes)
		return crypto_shash_final(desc, req->result);

	do {
		nbytes = crypto_hash_walk_last(&walk) ?
			 crypto_shash_finup(desc, walk.data, nbytes,
					    req->result) :
			 crypto_shash_update(desc, walk.data, nbytes);
		nbytes = crypto_hash_walk_done(&walk, nbytes);
	} while (nbytes > 0);

	return nbytes;
}
EXPORT_SYMBOL_GPL(shash_ahash_finup);

static int shash_async_finup(struct ahash_request *req)
{
	struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
	struct shash_desc *desc = ahash_request_ctx(req);

	desc->tfm = *ctx;

	return shash_ahash_finup(req, desc);
}

int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
{
	unsigned int nbytes = req->nbytes;
	struct scatterlist *sg;
	unsigned int offset;
	int err;

	if (nbytes &&
	    (sg = req->src, offset = sg->offset,
	     nbytes <= min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
		void *data;

		data = kmap_atomic(sg_page(sg));
		err = crypto_shash_digest(desc, data + offset, nbytes,
					  req->result);
		kunmap_atomic(data);
	} else
		err = crypto_shash_init(desc) ?:
		      shash_ahash_finup(req, desc);

	return err;
}
EXPORT_SYMBOL_GPL(shash_ahash_digest);

static int shash_async_digest(struct ahash_request *req)
{
	struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
	struct shash_desc *desc = ahash_request_ctx(req);

	desc->tfm = *ctx;

	return shash_ahash_digest(req, desc);
}

static int shash_async_export(struct ahash_request *req, void *out)
{
	return crypto_shash_export(ahash_request_ctx(req), out);
}

static int shash_async_import(struct ahash_request *req, const void *in)
{
	struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
	struct shash_desc *desc = ahash_request_ctx(req);

	desc->tfm = *ctx;

	return crypto_shash_import(desc, in);
}

static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
{
	struct crypto_shash **ctx = crypto_tfm_ctx(tfm);

	crypto_free_shash(*ctx);
}

int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
{
	struct crypto_alg *calg = tfm->__crt_alg;
	struct shash_alg *alg = __crypto_shash_alg(calg);
	struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
	struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
	struct crypto_shash *shash;

	if (!crypto_mod_get(calg))
		return -EAGAIN;

	shash = crypto_create_tfm(calg, &crypto_shash_type);
	if (IS_ERR(shash)) {
		crypto_mod_put(calg);
		return PTR_ERR(shash);
	}

	*ctx = shash;
	tfm->exit = crypto_exit_shash_ops_async;

	crt->init = shash_async_init;
	crt->update = shash_async_update;
	crt->final = shash_async_final;
	crt->finup = shash_async_finup;
	crt->digest = shash_async_digest;
	if (crypto_shash_alg_has_setkey(alg))
		crt->setkey = shash_async_setkey;

	crypto_ahash_set_flags(crt, crypto_shash_get_flags(shash) &
				    CRYPTO_TFM_NEED_KEY);

	crt->export = shash_async_export;
	crt->import = shash_async_import;

	crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);

	return 0;
}

static void crypto_shash_exit_tfm(struct crypto_tfm *tfm)
{
	struct crypto_shash *hash = __crypto_shash_cast(tfm);
	struct shash_alg *alg = crypto_shash_alg(hash);

	alg->exit_tfm(hash);
}

static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
{
	struct crypto_shash *hash = __crypto_shash_cast(tfm);
	struct shash_alg *alg = crypto_shash_alg(hash);
	int err;

	hash->descsize = alg->descsize;

	shash_set_needkey(hash, alg);

	if (alg->exit_tfm)
		tfm->exit = crypto_shash_exit_tfm;

	if (!alg->init_tfm)
		return 0;

	err = alg->init_tfm(hash);
	if (err)
		return err;

	/* ->init_tfm() may have increased the descsize. */
	if (WARN_ON_ONCE(hash->descsize > HASH_MAX_DESCSIZE)) {
		if (alg->exit_tfm)
			alg->exit_tfm(hash);
		return -EINVAL;
	}

	return 0;
}

static void crypto_shash_free_instance(struct crypto_instance *inst)
{
	struct shash_instance *shash = shash_instance(inst);

	shash->free(shash);
}

#ifdef CONFIG_NET
static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
{
	struct crypto_report_hash rhash;
	struct shash_alg *salg = __crypto_shash_alg(alg);

	memset(&rhash, 0, sizeof(rhash));

	strscpy(rhash.type, "shash", sizeof(rhash.type));

	rhash.blocksize = alg->cra_blocksize;
	rhash.digestsize = salg->digestsize;

	return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash);
}
#else
static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
{
	return -ENOSYS;
}
#endif

static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
	__maybe_unused;
static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
{
	struct shash_alg *salg = __crypto_shash_alg(alg);

	seq_printf(m, "type         : shash\n");
	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
	seq_printf(m, "digestsize   : %u\n", salg->digestsize);
}

static const struct crypto_type crypto_shash_type = {
	.extsize = crypto_alg_extsize,
	.init_tfm = crypto_shash_init_tfm,
	.free = crypto_shash_free_instance,
#ifdef CONFIG_PROC_FS
	.show = crypto_shash_show,
#endif
	.report = crypto_shash_report,
	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
	.maskset = CRYPTO_ALG_TYPE_MASK,
	.type = CRYPTO_ALG_TYPE_SHASH,
	.tfmsize = offsetof(struct crypto_shash, base),
};

int crypto_grab_shash(struct crypto_shash_spawn *spawn,
		      struct crypto_instance *inst,
		      const char *name, u32 type, u32 mask)
{
	spawn->base.frontend = &crypto_shash_type;
	return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_grab_shash);

struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
					u32 mask)
{
	return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_alloc_shash);

static int shash_prepare_alg(struct shash_alg *alg)
{
	struct crypto_alg *base = &alg->base;

	if (alg->digestsize > HASH_MAX_DIGESTSIZE ||
	    alg->descsize > HASH_MAX_DESCSIZE ||
	    alg->statesize > HASH_MAX_STATESIZE)
		return -EINVAL;

	if ((alg->export && !alg->import) || (alg->import && !alg->export))
		return -EINVAL;

	base->cra_type = &crypto_shash_type;
	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
	base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;

	if (!alg->finup)
		alg->finup = shash_finup_unaligned;
	if (!alg->digest)
		alg->digest = shash_digest_unaligned;
	if (!alg->export) {
		alg->export = shash_default_export;
		alg->import = shash_default_import;
		alg->statesize = alg->descsize;
	}
	if (!alg->setkey)
		alg->setkey = shash_no_setkey;

	return 0;
}

int crypto_register_shash(struct shash_alg *alg)
{
	struct crypto_alg *base = &alg->base;
	int err;

	err = shash_prepare_alg(alg);
	if (err)
		return err;

	return crypto_register_alg(base);
}
EXPORT_SYMBOL_GPL(crypto_register_shash);

void crypto_unregister_shash(struct shash_alg *alg)
{
	crypto_unregister_alg(&alg->base);
}
EXPORT_SYMBOL_GPL(crypto_unregister_shash);

int crypto_register_shashes(struct shash_alg *algs, int count)
{
	int i, ret;

	for (i = 0; i < count; i++) {
		ret = crypto_register_shash(&algs[i]);
		if (ret)
			goto err;
	}

	return 0;

err:
	for (--i; i >= 0; --i)
		crypto_unregister_shash(&algs[i]);

	return ret;
}
EXPORT_SYMBOL_GPL(crypto_register_shashes);

void crypto_unregister_shashes(struct shash_alg *algs, int count)
{
	int i;

	for (i = count - 1; i >= 0; --i)
		crypto_unregister_shash(&algs[i]);
}
EXPORT_SYMBOL_GPL(crypto_unregister_shashes);

int shash_register_instance(struct crypto_template *tmpl,
			    struct shash_instance *inst)
{
	int err;

	if (WARN_ON(!inst->free))
		return -EINVAL;

	err = shash_prepare_alg(&inst->alg);
	if (err)
		return err;

	return crypto_register_instance(tmpl, shash_crypto_instance(inst));
}
EXPORT_SYMBOL_GPL(shash_register_instance);

void shash_free_singlespawn_instance(struct shash_instance *inst)
{
	crypto_drop_spawn(shash_instance_ctx(inst));
	kfree(inst);
}
EXPORT_SYMBOL_GPL(shash_free_singlespawn_instance);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Synchronous cryptographic hash type");