rsa-pkcs1pad.c 17.6 KB
Newer Older
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
/*
 * RSA padding templates.
 *
 * Copyright (c) 2015  Intel Corporation
 *
 * 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/algapi.h>
#include <crypto/akcipher.h>
#include <crypto/internal/akcipher.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/random.h>

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
/*
 * Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2].
 */
static const u8 rsa_digest_info_md5[] = {
	0x30, 0x20, 0x30, 0x0c, 0x06, 0x08,
	0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x02, 0x05, /* OID */
	0x05, 0x00, 0x04, 0x10
};

static const u8 rsa_digest_info_sha1[] = {
	0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
	0x2b, 0x0e, 0x03, 0x02, 0x1a,
	0x05, 0x00, 0x04, 0x14
};

static const u8 rsa_digest_info_rmd160[] = {
	0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
	0x2b, 0x24, 0x03, 0x02, 0x01,
	0x05, 0x00, 0x04, 0x14
};

static const u8 rsa_digest_info_sha224[] = {
	0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09,
	0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04,
	0x05, 0x00, 0x04, 0x1c
};

static const u8 rsa_digest_info_sha256[] = {
	0x30, 0x31, 0x30, 0x0d, 0x06, 0x09,
	0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01,
	0x05, 0x00, 0x04, 0x20
};

static const u8 rsa_digest_info_sha384[] = {
	0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
	0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02,
	0x05, 0x00, 0x04, 0x30
};

static const u8 rsa_digest_info_sha512[] = {
	0x30, 0x51, 0x30, 0x0d, 0x06, 0x09,
	0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03,
	0x05, 0x00, 0x04, 0x40
};

static const struct rsa_asn1_template {
	const char	*name;
	const u8	*data;
	size_t		size;
} rsa_asn1_templates[] = {
#define _(X) { #X, rsa_digest_info_##X, sizeof(rsa_digest_info_##X) }
	_(md5),
	_(sha1),
	_(rmd160),
	_(sha256),
	_(sha384),
	_(sha512),
	_(sha224),
	{ NULL }
#undef _
};

static const struct rsa_asn1_template *rsa_lookup_asn1(const char *name)
{
	const struct rsa_asn1_template *p;

	for (p = rsa_asn1_templates; p->name; p++)
		if (strcmp(name, p->name) == 0)
			return p;
	return NULL;
}

93
94
95
96
97
struct pkcs1pad_ctx {
	struct crypto_akcipher *child;
	unsigned int key_size;
};

98
99
struct pkcs1pad_inst_ctx {
	struct crypto_akcipher_spawn spawn;
100
	const struct rsa_asn1_template *digest_info;
101
102
};

103
104
105
struct pkcs1pad_request {
	struct akcipher_request child_req;

106
	struct scatterlist in_sg[2], out_sg[1];
107
108
109
110
111
112
113
	uint8_t *in_buf, *out_buf;
};

static int pkcs1pad_set_pub_key(struct crypto_akcipher *tfm, const void *key,
		unsigned int keylen)
{
	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
114
115
116
	int err;

	ctx->key_size = 0;
117
118

	err = crypto_akcipher_set_pub_key(ctx->child, key, keylen);
119
120
	if (err)
		return err;
121

122
123
124
125
	/* Find out new modulus size from rsa implementation */
	err = crypto_akcipher_maxsize(ctx->child);
	if (err < 0)
		return err;
126

127
128
	if (err > PAGE_SIZE)
		return -ENOTSUPP;
129

130
131
	ctx->key_size = err;
	return 0;
132
133
134
135
136
137
}

static int pkcs1pad_set_priv_key(struct crypto_akcipher *tfm, const void *key,
		unsigned int keylen)
{
	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
138
139
140
	int err;

	ctx->key_size = 0;
141
142

	err = crypto_akcipher_set_priv_key(ctx->child, key, keylen);
143
144
	if (err)
		return err;
145

146
147
148
149
	/* Find out new modulus size from rsa implementation */
	err = crypto_akcipher_maxsize(ctx->child);
	if (err < 0)
		return err;
150

151
152
	if (err > PAGE_SIZE)
		return -ENOTSUPP;
153

154
155
	ctx->key_size = err;
	return 0;
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
}

static int pkcs1pad_get_max_size(struct crypto_akcipher *tfm)
{
	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);

	/*
	 * The maximum destination buffer size for the encrypt/sign operations
	 * will be the same as for RSA, even though it's smaller for
	 * decrypt/verify.
	 */

	return ctx->key_size ?: -EINVAL;
}

static void pkcs1pad_sg_set_buf(struct scatterlist *sg, void *buf, size_t len,
		struct scatterlist *next)
{
174
175
176
177
	int nsegs = next ? 2 : 1;

	sg_init_table(sg, nsegs);
	sg_set_buf(sg, buf, len);
178
179
180
181
182
183
184
185
186
187

	if (next)
		sg_chain(sg, nsegs, next);
}

static int pkcs1pad_encrypt_sign_complete(struct akcipher_request *req, int err)
{
	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
	struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
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
	unsigned int pad_len;
	unsigned int len;
	u8 *out_buf;

	if (err)
		goto out;

	len = req_ctx->child_req.dst_len;
	pad_len = ctx->key_size - len;

	/* Four billion to one */
	if (likely(!pad_len))
		goto out;

	out_buf = kzalloc(ctx->key_size, GFP_ATOMIC);
	err = -ENOMEM;
	if (!out_buf)
		goto out;

	sg_copy_to_buffer(req->dst, sg_nents_for_len(req->dst, len),
			  out_buf + pad_len, len);
	sg_copy_from_buffer(req->dst,
			    sg_nents_for_len(req->dst, ctx->key_size),
			    out_buf, ctx->key_size);
	kzfree(out_buf);

out:
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
	req->dst_len = ctx->key_size;

	kfree(req_ctx->in_buf);

	return err;
}

static void pkcs1pad_encrypt_sign_complete_cb(
		struct crypto_async_request *child_async_req, int err)
{
	struct akcipher_request *req = child_async_req->data;
	struct crypto_async_request async_req;

	if (err == -EINPROGRESS)
		return;

	async_req.data = req->base.data;
	async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
	async_req.flags = child_async_req->flags;
	req->base.complete(&async_req,
			pkcs1pad_encrypt_sign_complete(req, err));
}

static int pkcs1pad_encrypt(struct akcipher_request *req)
{
	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
	struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
	int err;
	unsigned int i, ps_end;

	if (!ctx->key_size)
		return -EINVAL;

	if (req->src_len > ctx->key_size - 11)
		return -EOVERFLOW;

	if (req->dst_len < ctx->key_size) {
		req->dst_len = ctx->key_size;
		return -EOVERFLOW;
	}

	req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
258
				  GFP_KERNEL);
259
260
261
262
263
264
265
266
267
268
269
270
	if (!req_ctx->in_buf)
		return -ENOMEM;

	ps_end = ctx->key_size - req->src_len - 2;
	req_ctx->in_buf[0] = 0x02;
	for (i = 1; i < ps_end; i++)
		req_ctx->in_buf[i] = 1 + prandom_u32_max(255);
	req_ctx->in_buf[ps_end] = 0x00;

	pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
			ctx->key_size - 1 - req->src_len, req->src);

271
	req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL);
272
273
274
275
276
277
278
279
280
281
282
283
	if (!req_ctx->out_buf) {
		kfree(req_ctx->in_buf);
		return -ENOMEM;
	}

	pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
			ctx->key_size, NULL);

	akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
	akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
			pkcs1pad_encrypt_sign_complete_cb, req);

284
285
286
287
	/* Reuse output buffer */
	akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg,
				   req->dst, ctx->key_size - 1, req->dst_len);

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
	err = crypto_akcipher_encrypt(&req_ctx->child_req);
	if (err != -EINPROGRESS &&
			(err != -EBUSY ||
			 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
		return pkcs1pad_encrypt_sign_complete(req, err);

	return err;
}

static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err)
{
	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
	struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
	unsigned int pos;

	if (err == -EOVERFLOW)
		/* Decrypted value had no leading 0 byte */
		err = -EINVAL;

	if (err)
		goto done;

	if (req_ctx->child_req.dst_len != ctx->key_size - 1) {
		err = -EINVAL;
		goto done;
	}

	if (req_ctx->out_buf[0] != 0x02) {
		err = -EINVAL;
		goto done;
	}
	for (pos = 1; pos < req_ctx->child_req.dst_len; pos++)
		if (req_ctx->out_buf[pos] == 0x00)
			break;
	if (pos < 9 || pos == req_ctx->child_req.dst_len) {
		err = -EINVAL;
		goto done;
	}
	pos++;

	if (req->dst_len < req_ctx->child_req.dst_len - pos)
		err = -EOVERFLOW;
	req->dst_len = req_ctx->child_req.dst_len - pos;

	if (!err)
		sg_copy_from_buffer(req->dst,
				sg_nents_for_len(req->dst, req->dst_len),
				req_ctx->out_buf + pos, req->dst_len);

done:
	kzfree(req_ctx->out_buf);

	return err;
}

static void pkcs1pad_decrypt_complete_cb(
		struct crypto_async_request *child_async_req, int err)
{
	struct akcipher_request *req = child_async_req->data;
	struct crypto_async_request async_req;

	if (err == -EINPROGRESS)
		return;

	async_req.data = req->base.data;
	async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
	async_req.flags = child_async_req->flags;
	req->base.complete(&async_req, pkcs1pad_decrypt_complete(req, err));
}

static int pkcs1pad_decrypt(struct akcipher_request *req)
{
	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
	struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
	int err;

	if (!ctx->key_size || req->src_len != ctx->key_size)
		return -EINVAL;

369
	req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL);
370
371
372
373
	if (!req_ctx->out_buf)
		return -ENOMEM;

	pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
374
			    ctx->key_size, NULL);
375
376
377
378
379

	akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
	akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
			pkcs1pad_decrypt_complete_cb, req);

380
381
382
383
384
	/* Reuse input buffer, output to a new buffer */
	akcipher_request_set_crypt(&req_ctx->child_req, req->src,
				   req_ctx->out_sg, req->src_len,
				   ctx->key_size);

385
386
387
388
389
390
391
392
393
394
395
396
397
398
	err = crypto_akcipher_decrypt(&req_ctx->child_req);
	if (err != -EINPROGRESS &&
			(err != -EBUSY ||
			 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
		return pkcs1pad_decrypt_complete(req, err);

	return err;
}

static int pkcs1pad_sign(struct akcipher_request *req)
{
	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
	struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
399
400
401
	struct akcipher_instance *inst = akcipher_alg_instance(tfm);
	struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
	const struct rsa_asn1_template *digest_info = ictx->digest_info;
402
	int err;
403
	unsigned int ps_end, digest_size = 0;
404
405
406
407

	if (!ctx->key_size)
		return -EINVAL;

408
	digest_size = digest_info->size;
409
410

	if (req->src_len + digest_size > ctx->key_size - 11)
411
412
413
414
415
416
417
418
		return -EOVERFLOW;

	if (req->dst_len < ctx->key_size) {
		req->dst_len = ctx->key_size;
		return -EOVERFLOW;
	}

	req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
419
				  GFP_KERNEL);
420
421
422
	if (!req_ctx->in_buf)
		return -ENOMEM;

423
	ps_end = ctx->key_size - digest_size - req->src_len - 2;
424
425
426
427
	req_ctx->in_buf[0] = 0x01;
	memset(req_ctx->in_buf + 1, 0xff, ps_end - 1);
	req_ctx->in_buf[ps_end] = 0x00;

428
429
	memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data,
	       digest_info->size);
430

431
432
433
434
435
436
437
	pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
			ctx->key_size - 1 - req->src_len, req->src);

	akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
	akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
			pkcs1pad_encrypt_sign_complete_cb, req);

438
439
440
441
	/* Reuse output buffer */
	akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg,
				   req->dst, ctx->key_size - 1, req->dst_len);

442
443
444
445
446
447
448
449
450
451
452
453
454
455
	err = crypto_akcipher_sign(&req_ctx->child_req);
	if (err != -EINPROGRESS &&
			(err != -EBUSY ||
			 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
		return pkcs1pad_encrypt_sign_complete(req, err);

	return err;
}

static int pkcs1pad_verify_complete(struct akcipher_request *req, int err)
{
	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
	struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
456
457
458
	struct akcipher_instance *inst = akcipher_alg_instance(tfm);
	struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
	const struct rsa_asn1_template *digest_info = ictx->digest_info;
459
460
461
462
463
464
465
466
467
468
469
470
471
472
	unsigned int pos;

	if (err == -EOVERFLOW)
		/* Decrypted value had no leading 0 byte */
		err = -EINVAL;

	if (err)
		goto done;

	if (req_ctx->child_req.dst_len != ctx->key_size - 1) {
		err = -EINVAL;
		goto done;
	}

473
474
	err = -EBADMSG;
	if (req_ctx->out_buf[0] != 0x01)
475
		goto done;
476

477
478
479
	for (pos = 1; pos < req_ctx->child_req.dst_len; pos++)
		if (req_ctx->out_buf[pos] != 0xff)
			break;
480

481
	if (pos < 9 || pos == req_ctx->child_req.dst_len ||
482
	    req_ctx->out_buf[pos] != 0x00)
483
484
485
		goto done;
	pos++;

486
487
488
	if (memcmp(req_ctx->out_buf + pos, digest_info->data,
		   digest_info->size))
		goto done;
489

490
	pos += digest_info->size;
491
492
493

	err = 0;

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
	if (req->dst_len < req_ctx->child_req.dst_len - pos)
		err = -EOVERFLOW;
	req->dst_len = req_ctx->child_req.dst_len - pos;

	if (!err)
		sg_copy_from_buffer(req->dst,
				sg_nents_for_len(req->dst, req->dst_len),
				req_ctx->out_buf + pos, req->dst_len);
done:
	kzfree(req_ctx->out_buf);

	return err;
}

static void pkcs1pad_verify_complete_cb(
		struct crypto_async_request *child_async_req, int err)
{
	struct akcipher_request *req = child_async_req->data;
	struct crypto_async_request async_req;

	if (err == -EINPROGRESS)
		return;

	async_req.data = req->base.data;
	async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
	async_req.flags = child_async_req->flags;
	req->base.complete(&async_req, pkcs1pad_verify_complete(req, err));
}

/*
 * The verify operation is here for completeness similar to the verification
 * defined in RFC2313 section 10.2 except that block type 0 is not accepted,
 * as in RFC2437.  RFC2437 section 9.2 doesn't define any operation to
 * retrieve the DigestInfo from a signature, instead the user is expected
 * to call the sign operation to generate the expected signature and compare
 * signatures instead of the message-digests.
 */
static int pkcs1pad_verify(struct akcipher_request *req)
{
	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
	struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
	int err;

538
	if (!ctx->key_size || req->src_len < ctx->key_size)
539
540
		return -EINVAL;

541
	req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL);
542
543
544
545
	if (!req_ctx->out_buf)
		return -ENOMEM;

	pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
546
			    ctx->key_size, NULL);
547
548
549
550
551

	akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
	akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
			pkcs1pad_verify_complete_cb, req);

552
553
554
555
556
	/* Reuse input buffer, output to a new buffer */
	akcipher_request_set_crypt(&req_ctx->child_req, req->src,
				   req_ctx->out_sg, req->src_len,
				   ctx->key_size);

557
558
559
560
561
562
563
564
565
566
567
568
	err = crypto_akcipher_verify(&req_ctx->child_req);
	if (err != -EINPROGRESS &&
			(err != -EBUSY ||
			 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
		return pkcs1pad_verify_complete(req, err);

	return err;
}

static int pkcs1pad_init_tfm(struct crypto_akcipher *tfm)
{
	struct akcipher_instance *inst = akcipher_alg_instance(tfm);
569
	struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
570
571
572
	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
	struct crypto_akcipher *child_tfm;

573
	child_tfm = crypto_spawn_akcipher(&ictx->spawn);
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
	if (IS_ERR(child_tfm))
		return PTR_ERR(child_tfm);

	ctx->child = child_tfm;
	return 0;
}

static void pkcs1pad_exit_tfm(struct crypto_akcipher *tfm)
{
	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);

	crypto_free_akcipher(ctx->child);
}

static void pkcs1pad_free(struct akcipher_instance *inst)
{
590
591
	struct pkcs1pad_inst_ctx *ctx = akcipher_instance_ctx(inst);
	struct crypto_akcipher_spawn *spawn = &ctx->spawn;
592
593
594
595
596
597
598

	crypto_drop_akcipher(spawn);
	kfree(inst);
}

static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
{
599
	const struct rsa_asn1_template *digest_info;
600
601
	struct crypto_attr_type *algt;
	struct akcipher_instance *inst;
602
	struct pkcs1pad_inst_ctx *ctx;
603
604
605
	struct crypto_akcipher_spawn *spawn;
	struct akcipher_alg *rsa_alg;
	const char *rsa_alg_name;
606
	const char *hash_name;
607
608
609
610
611
612
613
614
615
616
617
618
619
	int err;

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

	if ((algt->type ^ CRYPTO_ALG_TYPE_AKCIPHER) & algt->mask)
		return -EINVAL;

	rsa_alg_name = crypto_attr_alg_name(tb[1]);
	if (IS_ERR(rsa_alg_name))
		return PTR_ERR(rsa_alg_name);

620
621
	hash_name = crypto_attr_alg_name(tb[2]);
	if (IS_ERR(hash_name))
622
623
624
625
626
		return PTR_ERR(hash_name);

	digest_info = rsa_lookup_asn1(hash_name);
	if (!digest_info)
		return -EINVAL;
627
628

	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
629
630
631
	if (!inst)
		return -ENOMEM;

632
633
	ctx = akcipher_instance_ctx(inst);
	spawn = &ctx->spawn;
634
	ctx->digest_info = digest_info;
635

636
637
638
639
640
641
642
643
644
	crypto_set_spawn(&spawn->base, akcipher_crypto_instance(inst));
	err = crypto_grab_akcipher(spawn, rsa_alg_name, 0,
			crypto_requires_sync(algt->type, algt->mask));
	if (err)
		goto out_free_inst;

	rsa_alg = crypto_spawn_akcipher_alg(spawn);

	err = -ENAMETOOLONG;
645

646
647
648
649
650
651
652
	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
		     "pkcs1pad(%s,%s)", rsa_alg->base.cra_name, hash_name) >=
	    CRYPTO_MAX_ALG_NAME ||
	    snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
		     "pkcs1pad(%s,%s)",
		     rsa_alg->base.cra_driver_name, hash_name) >=
	    CRYPTO_MAX_ALG_NAME)
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
		goto out_drop_alg;

	inst->alg.base.cra_flags = rsa_alg->base.cra_flags & CRYPTO_ALG_ASYNC;
	inst->alg.base.cra_priority = rsa_alg->base.cra_priority;
	inst->alg.base.cra_ctxsize = sizeof(struct pkcs1pad_ctx);

	inst->alg.init = pkcs1pad_init_tfm;
	inst->alg.exit = pkcs1pad_exit_tfm;

	inst->alg.encrypt = pkcs1pad_encrypt;
	inst->alg.decrypt = pkcs1pad_decrypt;
	inst->alg.sign = pkcs1pad_sign;
	inst->alg.verify = pkcs1pad_verify;
	inst->alg.set_pub_key = pkcs1pad_set_pub_key;
	inst->alg.set_priv_key = pkcs1pad_set_priv_key;
	inst->alg.max_size = pkcs1pad_get_max_size;
	inst->alg.reqsize = sizeof(struct pkcs1pad_request) + rsa_alg->reqsize;

	inst->free = pkcs1pad_free;

	err = akcipher_register_instance(tmpl, inst);
	if (err)
675
		goto out_drop_alg;
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690

	return 0;

out_drop_alg:
	crypto_drop_akcipher(spawn);
out_free_inst:
	kfree(inst);
	return err;
}

struct crypto_template rsa_pkcs1pad_tmpl = {
	.name = "pkcs1pad",
	.create = pkcs1pad_create,
	.module = THIS_MODULE,
};