summaryrefslogtreecommitdiffstats
path: root/crypto/aead.c
blob: f5b1add31976fe65d345e024f0bbf2c062bd2fc9 (plain)
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
/*
 * AEAD: Authenticated Encryption with Associated Data
 * 
 * This file provides API support for AEAD algorithms.
 *
 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option) 
 * any later version.
 *
 */

#include <crypto/internal/aead.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include <linux/seq_file.h>

#include "internal.h"

static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
			    unsigned int keylen)
{
	struct aead_alg *aead = crypto_aead_alg(tfm);
	unsigned long alignmask = crypto_aead_alignmask(tfm);
	int ret;
	u8 *buffer, *alignbuffer;
	unsigned long absize;

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

	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
	memcpy(alignbuffer, key, keylen);
	ret = aead->setkey(tfm, alignbuffer, keylen);
	memset(alignbuffer, 0, keylen);
	kfree(buffer);
	return ret;
}

static int setkey(struct crypto_aead *tfm, const u8 *key, unsigned int keylen)
{
	struct aead_alg *aead = crypto_aead_alg(tfm);
	unsigned long alignmask = crypto_aead_alignmask(tfm);

	if ((unsigned long)key & alignmask)
		return setkey_unaligned(tfm, key, keylen);

	return aead->setkey(tfm, key, keylen);
}

int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
{
	struct aead_tfm *crt = crypto_aead_crt(tfm);
	int err;

	if (authsize > crypto_aead_alg(tfm)->maxauthsize)
		return -EINVAL;

	if (crypto_aead_alg(tfm)->setauthsize) {
		err = crypto_aead_alg(tfm)->setauthsize(crt->base, authsize);
		if (err)
			return err;
	}

	crypto_aead_crt(crt->base)->authsize = authsize;
	crt->authsize = authsize;
	return 0;
}
EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);

static unsigned int crypto_aead_ctxsize(struct crypto_alg *alg, u32 type,
					u32 mask)
{
	return alg->cra_ctxsize;
}

static int no_givcrypt(struct aead_givcrypt_request *req)
{
	return -ENOSYS;
}

static int crypto_init_aead_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
{
	struct aead_alg *alg = &tfm->__crt_alg->cra_aead;
	struct aead_tfm *crt = &tfm->crt_aead;

	if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8)
		return -EINVAL;

	crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
		      alg->setkey : setkey;
	crt->encrypt = alg->encrypt;
	crt->decrypt = alg->decrypt;
	crt->givencrypt = alg->givencrypt ?: no_givcrypt;
	crt->givdecrypt = alg->givdecrypt ?: no_givcrypt;
	crt->base = __crypto_aead_cast(tfm);
	crt->ivsize = alg->ivsize;
	crt->authsize = alg->maxauthsize;

	return 0;
}

static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
	__attribute__ ((unused));
static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
{
	struct aead_alg *aead = &alg->cra_aead;

	seq_printf(m, "type         : aead\n");
	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
	seq_printf(m, "ivsize       : %u\n", aead->ivsize);
	seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
	seq_printf(m, "geniv        : %s\n", aead->geniv ?: "<built-in>");
}

const struct crypto_type crypto_aead_type = {
	.ctxsize = crypto_aead_ctxsize,
	.init = crypto_init_aead_ops,
#ifdef CONFIG_PROC_FS
	.show = crypto_aead_show,
#endif
};
EXPORT_SYMBOL_GPL(crypto_aead_type);

static int aead_null_givencrypt(struct aead_givcrypt_request *req)
{
	return crypto_aead_encrypt(&req->areq);
}

static int aead_null_givdecrypt(struct aead_givcrypt_request *req)
{
	return crypto_aead_decrypt(&req->areq);
}

static int crypto_init_nivaead_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
{
	struct aead_alg *alg = &tfm->__crt_alg->cra_aead;
	struct aead_tfm *crt = &tfm->crt_aead;

	if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8)
		return -EINVAL;

	crt->setkey = setkey;
	crt->encrypt = alg->encrypt;
	crt->decrypt = alg->decrypt;
	if (!alg->ivsize) {
		crt->givencrypt = aead_null_givencrypt;
		crt->givdecrypt = aead_null_givdecrypt;
	}
	crt->base = __crypto_aead_cast(tfm);
	crt->ivsize = alg->ivsize;
	crt->authsize = alg->maxauthsize;

	return 0;
}

static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
	__attribute__ ((unused));
static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
{
	struct aead_alg *aead = &alg->cra_aead;

	seq_printf(m, "type         : nivaead\n");
	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
	seq_printf(m, "ivsize       : %u\n", aead->ivsize);
	seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
	seq_printf(m, "geniv        : %s\n", aead->geniv);
}

const struct crypto_type crypto_nivaead_type = {
	.ctxsize = crypto_aead_ctxsize,
	.init = crypto_init_nivaead_ops,
#ifdef CONFIG_PROC_FS
	.show = crypto_nivaead_show,
#endif
};
EXPORT_SYMBOL_GPL(crypto_nivaead_type);

static int crypto_grab_nivaead(struct crypto_aead_spawn *spawn,
			       const char *name, u32 type, u32 mask)
{
	struct crypto_alg *alg;
	int err;

	type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
	type |= CRYPTO_ALG_TYPE_AEAD;
	mask |= CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV;

	alg = crypto_alg_mod_lookup(name, type, mask);
	if (IS_ERR(alg))
		return PTR_ERR(alg);

	err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
	crypto_mod_put(alg);
	return err;
}

struct crypto_instance *aead_geniv_alloc(struct crypto_template *tmpl,
					 struct rtattr **tb, u32 type,
					 u32 mask)
{
	const char *name;
	struct crypto_aead_spawn *spawn;
	struct crypto_attr_type *algt;
	struct crypto_instance *inst;
	struct crypto_alg *alg;
	int err;

	algt = crypto_get_attr_type(tb);
	err = PTR_ERR(algt);
	if (IS_ERR(algt))
		return ERR_PTR(err);

	if ((algt->type ^ (CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV)) &
	    algt->mask)
		return ERR_PTR(-EINVAL);

	name = crypto_attr_alg_name(tb[1]);
	err = PTR_ERR(name);
	if (IS_ERR(name))
		return ERR_PTR(err);

	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
	if (!inst)
		return ERR_PTR(-ENOMEM);

	spawn = crypto_instance_ctx(inst);

	/* Ignore async algorithms if necessary. */
	mask |= crypto_requires_sync(algt->type, algt->mask);

	crypto_set_aead_spawn(spawn, inst);
	err = crypto_grab_nivaead(spawn, name, type, mask);
	if (err)
		goto err_free_inst;

	alg = crypto_aead_spawn_alg(spawn);

	err = -EINVAL;
	if (!alg->cra_aead.ivsize)
		goto err_drop_alg;

	/*
	 * This is only true if we're constructing an algorithm with its
	 * default IV generator.  For the default generator we elide the
	 * template name and double-check the IV generator.
	 */
	if (algt->mask & CRYPTO_ALG_GENIV) {
		if (strcmp(tmpl->name, alg->cra_aead.geniv))
			goto err_drop_alg;

		memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
		memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
		       CRYPTO_MAX_ALG_NAME);
	} else {
		err = -ENAMETOOLONG;
		if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
			     "%s(%s)", tmpl->name, alg->cra_name) >=
		    CRYPTO_MAX_ALG_NAME)
			goto err_drop_alg;
		if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
			     "%s(%s)", tmpl->name, alg->cra_driver_name) >=
		    CRYPTO_MAX_ALG_NAME)
			goto err_drop_alg;
	}

	inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV;
	inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
	inst->alg.cra_priority = alg->cra_priority;
	inst->alg.cra_blocksize = alg->cra_blocksize;
	inst->alg.cra_alignmask = alg->cra_alignmask;
	inst->alg.cra_type = &crypto_aead_type;

	inst->alg.cra_aead.ivsize = alg->cra_aead.ivsize;
	inst->alg.cra_aead.maxauthsize = alg->cra_aead.maxauthsize;
	inst->alg.cra_aead.geniv = alg->cra_aead.geniv;

	inst->alg.cra_aead.setkey = alg->cra_aead.setkey;
	inst->alg.cra_aead.setauthsize = alg->cra_aead.setauthsize;
	inst->alg.cra_aead.encrypt = alg->cra_aead.encrypt;
	inst->alg.cra_aead.decrypt = alg->cra_aead.decrypt;

out:
	return inst;

err_drop_alg:
	crypto_drop_aead(spawn);
err_free_inst:
	kfree(inst);
	inst = ERR_PTR(err);
	goto out;
}
EXPORT_SYMBOL_GPL(aead_geniv_alloc);

void aead_geniv_free(struct crypto_instance *inst)
{
	crypto_drop_aead(crypto_instance_ctx(inst));
	kfree(inst);
}
EXPORT_SYMBOL_GPL(aead_geniv_free);

int aead_geniv_init(struct crypto_tfm *tfm)
{
	struct crypto_instance *inst = (void *)tfm->__crt_alg;
	struct crypto_aead *aead;

	aead = crypto_spawn_aead(crypto_instance_ctx(inst));
	if (IS_ERR(aead))
		return PTR_ERR(aead);

	tfm->crt_aead.base = aead;
	tfm->crt_aead.reqsize += crypto_aead_reqsize(aead);

	return 0;
}
EXPORT_SYMBOL_GPL(aead_geniv_init);

void aead_geniv_exit(struct crypto_tfm *tfm)
{
	crypto_free_aead(tfm->crt_aead.base);
}
EXPORT_SYMBOL_GPL(aead_geniv_exit);

static int crypto_nivaead_default(struct crypto_alg *alg, u32 type, u32 mask)
{
	struct rtattr *tb[3];
	struct {
		struct rtattr attr;
		struct crypto_attr_type data;
	} ptype;
	struct {
		struct rtattr attr;
		struct crypto_attr_alg data;
	} palg;
	struct crypto_template *tmpl;
	struct crypto_instance *inst;
	struct crypto_alg *larval;
	const char *geniv;
	int err;

	larval = crypto_larval_lookup(alg->cra_driver_name,
				      CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV,
				      CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
	err = PTR_ERR(larval);
	if (IS_ERR(larval))
		goto out;

	err = -EAGAIN;
	if (!crypto_is_larval(larval))
		goto drop_larval;

	ptype.attr.rta_len = sizeof(ptype);
	ptype.attr.rta_type = CRYPTOA_TYPE;
	ptype.data.type = type | CRYPTO_ALG_GENIV;
	/* GENIV tells the template that we're making a default geniv. */
	ptype.data.mask = mask | CRYPTO_ALG_GENIV;
	tb[0] = &ptype.attr;

	palg.attr.rta_len = sizeof(palg);
	palg.attr.rta_type = CRYPTOA_ALG;
	/* Must use the exact name to locate ourselves. */
	memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
	tb[1] = &palg.attr;

	tb[2] = NULL;

	geniv = alg->cra_aead.geniv;

	tmpl = crypto_lookup_template(geniv);
	err = -ENOENT;
	if (!tmpl)
		goto kill_larval;

	inst = tmpl->alloc(tb);
	err = PTR_ERR(inst);
	if (IS_ERR(inst))
		goto put_tmpl;

	if ((err = crypto_register_instance(tmpl, inst))) {
		tmpl->free(inst);
		goto put_tmpl;
	}

	/* Redo the lookup to use the instance we just registered. */
	err = -EAGAIN;

put_tmpl:
	crypto_tmpl_put(tmpl);
kill_larval:
	crypto_larval_kill(larval);
drop_larval:
	crypto_mod_put(larval);
out:
	crypto_mod_put(alg);
	return err;
}

static struct crypto_alg *crypto_lookup_aead(const char *name, u32 type,
					     u32 mask)
{
	struct crypto_alg *alg;

	alg = crypto_alg_mod_lookup(name, type, mask);
	if (IS_ERR(alg))
		return alg;

	if (alg->cra_type == &crypto_aead_type)
		return alg;

	if (!alg->cra_aead.ivsize)
		return alg;

	return ERR_PTR(crypto_nivaead_default(alg, type, mask));
}

int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
		     u32 type, u32 mask)
{
	struct crypto_alg *alg;
	int err;

	type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
	type |= CRYPTO_ALG_TYPE_AEAD;
	mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
	mask |= CRYPTO_ALG_TYPE_MASK;

	alg = crypto_lookup_aead(name, type, mask);
	if (IS_ERR(alg))
		return PTR_ERR(alg);

	err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
	crypto_mod_put(alg);
	return err;
}
EXPORT_SYMBOL_GPL(crypto_grab_aead);

struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
{
	struct crypto_tfm *tfm;
	int err;

	type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
	type |= CRYPTO_ALG_TYPE_AEAD;
	mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
	mask |= CRYPTO_ALG_TYPE_MASK;

	for (;;) {
		struct crypto_alg *alg;

		alg = crypto_lookup_aead(alg_name, type, mask);
		if (IS_ERR(alg)) {
			err = PTR_ERR(alg);
			goto err;
		}

		tfm = __crypto_alloc_tfm(alg, type, mask);
		if (!IS_ERR(tfm))
			return __crypto_aead_cast(tfm);

		crypto_mod_put(alg);
		err = PTR_ERR(tfm);

err:
		if (err != -EAGAIN)
			break;
		if (signal_pending(current)) {
			err = -EINTR;
			break;
		}
	}

	return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(crypto_alloc_aead);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");
OpenPOWER on IntegriCloud