xref: /openbmc/linux/crypto/rsa-pkcs1pad.c (revision 6391503b) 
1 /*
2  * RSA padding templates.
3  *
4  * Copyright (c) 2015  Intel Corporation
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License as published by the Free
8  * Software Foundation; either version 2 of the License, or (at your option)
9  * any later version.
10  */
11 
12 #include <crypto/algapi.h>
13 #include <crypto/akcipher.h>
14 #include <crypto/internal/akcipher.h>
15 #include <linux/err.h>
16 #include <linux/init.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/random.h>
20 
21 struct pkcs1pad_ctx {
22 	struct crypto_akcipher *child;
23 
24 	unsigned int key_size;
25 };
26 
27 struct pkcs1pad_request {
28 	struct akcipher_request child_req;
29 
30 	struct scatterlist in_sg[3], out_sg[2];
31 	uint8_t *in_buf, *out_buf;
32 };
33 
34 static int pkcs1pad_set_pub_key(struct crypto_akcipher *tfm, const void *key,
35 		unsigned int keylen)
36 {
37 	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
38 	int err, size;
39 
40 	err = crypto_akcipher_set_pub_key(ctx->child, key, keylen);
41 
42 	if (!err) {
43 		/* Find out new modulus size from rsa implementation */
44 		size = crypto_akcipher_maxsize(ctx->child);
45 
46 		ctx->key_size = size > 0 ? size : 0;
47 		if (size <= 0)
48 			err = size;
49 	}
50 
51 	return err;
52 }
53 
54 static int pkcs1pad_set_priv_key(struct crypto_akcipher *tfm, const void *key,
55 		unsigned int keylen)
56 {
57 	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
58 	int err, size;
59 
60 	err = crypto_akcipher_set_priv_key(ctx->child, key, keylen);
61 
62 	if (!err) {
63 		/* Find out new modulus size from rsa implementation */
64 		size = crypto_akcipher_maxsize(ctx->child);
65 
66 		ctx->key_size = size > 0 ? size : 0;
67 		if (size <= 0)
68 			err = size;
69 	}
70 
71 	return err;
72 }
73 
74 static int pkcs1pad_get_max_size(struct crypto_akcipher *tfm)
75 {
76 	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
77 
78 	/*
79 	 * The maximum destination buffer size for the encrypt/sign operations
80 	 * will be the same as for RSA, even though it's smaller for
81 	 * decrypt/verify.
82 	 */
83 
84 	return ctx->key_size ?: -EINVAL;
85 }
86 
87 static void pkcs1pad_sg_set_buf(struct scatterlist *sg, void *buf, size_t len,
88 		struct scatterlist *next)
89 {
90 	int nsegs = next ? 1 : 0;
91 
92 	if (offset_in_page(buf) + len <= PAGE_SIZE) {
93 		nsegs += 1;
94 		sg_init_table(sg, nsegs);
95 		sg_set_buf(sg, buf, len);
96 	} else {
97 		nsegs += 2;
98 		sg_init_table(sg, nsegs);
99 		sg_set_buf(sg + 0, buf, PAGE_SIZE - offset_in_page(buf));
100 		sg_set_buf(sg + 1, buf + PAGE_SIZE - offset_in_page(buf),
101 				offset_in_page(buf) + len - PAGE_SIZE);
102 	}
103 
104 	if (next)
105 		sg_chain(sg, nsegs, next);
106 }
107 
108 static int pkcs1pad_encrypt_sign_complete(struct akcipher_request *req, int err)
109 {
110 	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
111 	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
112 	struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
113 	size_t pad_len = ctx->key_size - req_ctx->child_req.dst_len;
114 	size_t chunk_len, pad_left;
115 	struct sg_mapping_iter miter;
116 
117 	if (!err) {
118 		if (pad_len) {
119 			sg_miter_start(&miter, req->dst,
120 					sg_nents_for_len(req->dst, pad_len),
121 					SG_MITER_ATOMIC | SG_MITER_TO_SG);
122 
123 			pad_left = pad_len;
124 			while (pad_left) {
125 				sg_miter_next(&miter);
126 
127 				chunk_len = min(miter.length, pad_left);
128 				memset(miter.addr, 0, chunk_len);
129 				pad_left -= chunk_len;
130 			}
131 
132 			sg_miter_stop(&miter);
133 		}
134 
135 		sg_pcopy_from_buffer(req->dst,
136 				sg_nents_for_len(req->dst, ctx->key_size),
137 				req_ctx->out_buf, req_ctx->child_req.dst_len,
138 				pad_len);
139 	}
140 	req->dst_len = ctx->key_size;
141 
142 	kfree(req_ctx->in_buf);
143 	kzfree(req_ctx->out_buf);
144 
145 	return err;
146 }
147 
148 static void pkcs1pad_encrypt_sign_complete_cb(
149 		struct crypto_async_request *child_async_req, int err)
150 {
151 	struct akcipher_request *req = child_async_req->data;
152 	struct crypto_async_request async_req;
153 
154 	if (err == -EINPROGRESS)
155 		return;
156 
157 	async_req.data = req->base.data;
158 	async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
159 	async_req.flags = child_async_req->flags;
160 	req->base.complete(&async_req,
161 			pkcs1pad_encrypt_sign_complete(req, err));
162 }
163 
164 static int pkcs1pad_encrypt(struct akcipher_request *req)
165 {
166 	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
167 	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
168 	struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
169 	int err;
170 	unsigned int i, ps_end;
171 
172 	if (!ctx->key_size)
173 		return -EINVAL;
174 
175 	if (req->src_len > ctx->key_size - 11)
176 		return -EOVERFLOW;
177 
178 	if (req->dst_len < ctx->key_size) {
179 		req->dst_len = ctx->key_size;
180 		return -EOVERFLOW;
181 	}
182 
183 	if (ctx->key_size > PAGE_SIZE)
184 		return -ENOTSUPP;
185 
186 	/*
187 	 * Replace both input and output to add the padding in the input and
188 	 * the potential missing leading zeros in the output.
189 	 */
190 	req_ctx->child_req.src = req_ctx->in_sg;
191 	req_ctx->child_req.src_len = ctx->key_size - 1;
192 	req_ctx->child_req.dst = req_ctx->out_sg;
193 	req_ctx->child_req.dst_len = ctx->key_size;
194 
195 	req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
196 			(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
197 			GFP_KERNEL : GFP_ATOMIC);
198 	if (!req_ctx->in_buf)
199 		return -ENOMEM;
200 
201 	ps_end = ctx->key_size - req->src_len - 2;
202 	req_ctx->in_buf[0] = 0x02;
203 	for (i = 1; i < ps_end; i++)
204 		req_ctx->in_buf[i] = 1 + prandom_u32_max(255);
205 	req_ctx->in_buf[ps_end] = 0x00;
206 
207 	pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
208 			ctx->key_size - 1 - req->src_len, req->src);
209 
210 	req_ctx->out_buf = kmalloc(ctx->key_size,
211 			(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
212 			GFP_KERNEL : GFP_ATOMIC);
213 	if (!req_ctx->out_buf) {
214 		kfree(req_ctx->in_buf);
215 		return -ENOMEM;
216 	}
217 
218 	pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
219 			ctx->key_size, NULL);
220 
221 	akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
222 	akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
223 			pkcs1pad_encrypt_sign_complete_cb, req);
224 
225 	err = crypto_akcipher_encrypt(&req_ctx->child_req);
226 	if (err != -EINPROGRESS &&
227 			(err != -EBUSY ||
228 			 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
229 		return pkcs1pad_encrypt_sign_complete(req, err);
230 
231 	return err;
232 }
233 
234 static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err)
235 {
236 	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
237 	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
238 	struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
239 	unsigned int pos;
240 
241 	if (err == -EOVERFLOW)
242 		/* Decrypted value had no leading 0 byte */
243 		err = -EINVAL;
244 
245 	if (err)
246 		goto done;
247 
248 	if (req_ctx->child_req.dst_len != ctx->key_size - 1) {
249 		err = -EINVAL;
250 		goto done;
251 	}
252 
253 	if (req_ctx->out_buf[0] != 0x02) {
254 		err = -EINVAL;
255 		goto done;
256 	}
257 	for (pos = 1; pos < req_ctx->child_req.dst_len; pos++)
258 		if (req_ctx->out_buf[pos] == 0x00)
259 			break;
260 	if (pos < 9 || pos == req_ctx->child_req.dst_len) {
261 		err = -EINVAL;
262 		goto done;
263 	}
264 	pos++;
265 
266 	if (req->dst_len < req_ctx->child_req.dst_len - pos)
267 		err = -EOVERFLOW;
268 	req->dst_len = req_ctx->child_req.dst_len - pos;
269 
270 	if (!err)
271 		sg_copy_from_buffer(req->dst,
272 				sg_nents_for_len(req->dst, req->dst_len),
273 				req_ctx->out_buf + pos, req->dst_len);
274 
275 done:
276 	kzfree(req_ctx->out_buf);
277 
278 	return err;
279 }
280 
281 static void pkcs1pad_decrypt_complete_cb(
282 		struct crypto_async_request *child_async_req, int err)
283 {
284 	struct akcipher_request *req = child_async_req->data;
285 	struct crypto_async_request async_req;
286 
287 	if (err == -EINPROGRESS)
288 		return;
289 
290 	async_req.data = req->base.data;
291 	async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
292 	async_req.flags = child_async_req->flags;
293 	req->base.complete(&async_req, pkcs1pad_decrypt_complete(req, err));
294 }
295 
296 static int pkcs1pad_decrypt(struct akcipher_request *req)
297 {
298 	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
299 	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
300 	struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
301 	int err;
302 
303 	if (!ctx->key_size || req->src_len != ctx->key_size)
304 		return -EINVAL;
305 
306 	if (ctx->key_size > PAGE_SIZE)
307 		return -ENOTSUPP;
308 
309 	/* Reuse input buffer, output to a new buffer */
310 	req_ctx->child_req.src = req->src;
311 	req_ctx->child_req.src_len = req->src_len;
312 	req_ctx->child_req.dst = req_ctx->out_sg;
313 	req_ctx->child_req.dst_len = ctx->key_size - 1;
314 
315 	req_ctx->out_buf = kmalloc(ctx->key_size - 1,
316 			(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
317 			GFP_KERNEL : GFP_ATOMIC);
318 	if (!req_ctx->out_buf)
319 		return -ENOMEM;
320 
321 	pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
322 			ctx->key_size - 1, NULL);
323 
324 	akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
325 	akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
326 			pkcs1pad_decrypt_complete_cb, req);
327 
328 	err = crypto_akcipher_decrypt(&req_ctx->child_req);
329 	if (err != -EINPROGRESS &&
330 			(err != -EBUSY ||
331 			 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
332 		return pkcs1pad_decrypt_complete(req, err);
333 
334 	return err;
335 }
336 
337 static int pkcs1pad_sign(struct akcipher_request *req)
338 {
339 	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
340 	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
341 	struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
342 	int err;
343 	unsigned int ps_end;
344 
345 	if (!ctx->key_size)
346 		return -EINVAL;
347 
348 	if (req->src_len > ctx->key_size - 11)
349 		return -EOVERFLOW;
350 
351 	if (req->dst_len < ctx->key_size) {
352 		req->dst_len = ctx->key_size;
353 		return -EOVERFLOW;
354 	}
355 
356 	if (ctx->key_size > PAGE_SIZE)
357 		return -ENOTSUPP;
358 
359 	/*
360 	 * Replace both input and output to add the padding in the input and
361 	 * the potential missing leading zeros in the output.
362 	 */
363 	req_ctx->child_req.src = req_ctx->in_sg;
364 	req_ctx->child_req.src_len = ctx->key_size - 1;
365 	req_ctx->child_req.dst = req_ctx->out_sg;
366 	req_ctx->child_req.dst_len = ctx->key_size;
367 
368 	req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
369 			(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
370 			GFP_KERNEL : GFP_ATOMIC);
371 	if (!req_ctx->in_buf)
372 		return -ENOMEM;
373 
374 	ps_end = ctx->key_size - req->src_len - 2;
375 	req_ctx->in_buf[0] = 0x01;
376 	memset(req_ctx->in_buf + 1, 0xff, ps_end - 1);
377 	req_ctx->in_buf[ps_end] = 0x00;
378 
379 	pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
380 			ctx->key_size - 1 - req->src_len, req->src);
381 
382 	req_ctx->out_buf = kmalloc(ctx->key_size,
383 			(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
384 			GFP_KERNEL : GFP_ATOMIC);
385 	if (!req_ctx->out_buf) {
386 		kfree(req_ctx->in_buf);
387 		return -ENOMEM;
388 	}
389 
390 	pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
391 			ctx->key_size, NULL);
392 
393 	akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
394 	akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
395 			pkcs1pad_encrypt_sign_complete_cb, req);
396 
397 	err = crypto_akcipher_sign(&req_ctx->child_req);
398 	if (err != -EINPROGRESS &&
399 			(err != -EBUSY ||
400 			 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
401 		return pkcs1pad_encrypt_sign_complete(req, err);
402 
403 	return err;
404 }
405 
406 static int pkcs1pad_verify_complete(struct akcipher_request *req, int err)
407 {
408 	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
409 	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
410 	struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
411 	unsigned int pos;
412 
413 	if (err == -EOVERFLOW)
414 		/* Decrypted value had no leading 0 byte */
415 		err = -EINVAL;
416 
417 	if (err)
418 		goto done;
419 
420 	if (req_ctx->child_req.dst_len != ctx->key_size - 1) {
421 		err = -EINVAL;
422 		goto done;
423 	}
424 
425 	if (req_ctx->out_buf[0] != 0x01) {
426 		err = -EINVAL;
427 		goto done;
428 	}
429 	for (pos = 1; pos < req_ctx->child_req.dst_len; pos++)
430 		if (req_ctx->out_buf[pos] != 0xff)
431 			break;
432 	if (pos < 9 || pos == req_ctx->child_req.dst_len ||
433 			req_ctx->out_buf[pos] != 0x00) {
434 		err = -EINVAL;
435 		goto done;
436 	}
437 	pos++;
438 
439 	if (req->dst_len < req_ctx->child_req.dst_len - pos)
440 		err = -EOVERFLOW;
441 	req->dst_len = req_ctx->child_req.dst_len - pos;
442 
443 	if (!err)
444 		sg_copy_from_buffer(req->dst,
445 				sg_nents_for_len(req->dst, req->dst_len),
446 				req_ctx->out_buf + pos, req->dst_len);
447 
448 done:
449 	kzfree(req_ctx->out_buf);
450 
451 	return err;
452 }
453 
454 static void pkcs1pad_verify_complete_cb(
455 		struct crypto_async_request *child_async_req, int err)
456 {
457 	struct akcipher_request *req = child_async_req->data;
458 	struct crypto_async_request async_req;
459 
460 	if (err == -EINPROGRESS)
461 		return;
462 
463 	async_req.data = req->base.data;
464 	async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
465 	async_req.flags = child_async_req->flags;
466 	req->base.complete(&async_req, pkcs1pad_verify_complete(req, err));
467 }
468 
469 /*
470  * The verify operation is here for completeness similar to the verification
471  * defined in RFC2313 section 10.2 except that block type 0 is not accepted,
472  * as in RFC2437.  RFC2437 section 9.2 doesn't define any operation to
473  * retrieve the DigestInfo from a signature, instead the user is expected
474  * to call the sign operation to generate the expected signature and compare
475  * signatures instead of the message-digests.
476  */
477 static int pkcs1pad_verify(struct akcipher_request *req)
478 {
479 	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
480 	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
481 	struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
482 	int err;
483 
484 	if (!ctx->key_size || req->src_len != ctx->key_size)
485 		return -EINVAL;
486 
487 	if (ctx->key_size > PAGE_SIZE)
488 		return -ENOTSUPP;
489 
490 	/* Reuse input buffer, output to a new buffer */
491 	req_ctx->child_req.src = req->src;
492 	req_ctx->child_req.src_len = req->src_len;
493 	req_ctx->child_req.dst = req_ctx->out_sg;
494 	req_ctx->child_req.dst_len = ctx->key_size - 1;
495 
496 	req_ctx->out_buf = kmalloc(ctx->key_size - 1,
497 			(req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
498 			GFP_KERNEL : GFP_ATOMIC);
499 	if (!req_ctx->out_buf)
500 		return -ENOMEM;
501 
502 	pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
503 			ctx->key_size - 1, NULL);
504 
505 	akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
506 	akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
507 			pkcs1pad_verify_complete_cb, req);
508 
509 	err = crypto_akcipher_verify(&req_ctx->child_req);
510 	if (err != -EINPROGRESS &&
511 			(err != -EBUSY ||
512 			 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
513 		return pkcs1pad_verify_complete(req, err);
514 
515 	return err;
516 }
517 
518 static int pkcs1pad_init_tfm(struct crypto_akcipher *tfm)
519 {
520 	struct akcipher_instance *inst = akcipher_alg_instance(tfm);
521 	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
522 	struct crypto_akcipher *child_tfm;
523 
524 	child_tfm = crypto_spawn_akcipher(akcipher_instance_ctx(inst));
525 	if (IS_ERR(child_tfm))
526 		return PTR_ERR(child_tfm);
527 
528 	ctx->child = child_tfm;
529 
530 	return 0;
531 }
532 
533 static void pkcs1pad_exit_tfm(struct crypto_akcipher *tfm)
534 {
535 	struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
536 
537 	crypto_free_akcipher(ctx->child);
538 }
539 
540 static void pkcs1pad_free(struct akcipher_instance *inst)
541 {
542 	struct crypto_akcipher_spawn *spawn = akcipher_instance_ctx(inst);
543 
544 	crypto_drop_akcipher(spawn);
545 
546 	kfree(inst);
547 }
548 
549 static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
550 {
551 	struct crypto_attr_type *algt;
552 	struct akcipher_instance *inst;
553 	struct crypto_akcipher_spawn *spawn;
554 	struct akcipher_alg *rsa_alg;
555 	const char *rsa_alg_name;
556 	int err;
557 
558 	algt = crypto_get_attr_type(tb);
559 	if (IS_ERR(algt))
560 		return PTR_ERR(algt);
561 
562 	if ((algt->type ^ CRYPTO_ALG_TYPE_AKCIPHER) & algt->mask)
563 		return -EINVAL;
564 
565 	rsa_alg_name = crypto_attr_alg_name(tb[1]);
566 	if (IS_ERR(rsa_alg_name))
567 		return PTR_ERR(rsa_alg_name);
568 
569 	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
570 	if (!inst)
571 		return -ENOMEM;
572 
573 	spawn = akcipher_instance_ctx(inst);
574 	crypto_set_spawn(&spawn->base, akcipher_crypto_instance(inst));
575 	err = crypto_grab_akcipher(spawn, rsa_alg_name, 0,
576 			crypto_requires_sync(algt->type, algt->mask));
577 	if (err)
578 		goto out_free_inst;
579 
580 	rsa_alg = crypto_spawn_akcipher_alg(spawn);
581 
582 	err = -ENAMETOOLONG;
583 	if (snprintf(inst->alg.base.cra_name,
584 				CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
585 				rsa_alg->base.cra_name) >=
586 			CRYPTO_MAX_ALG_NAME ||
587 			snprintf(inst->alg.base.cra_driver_name,
588 				CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
589 				rsa_alg->base.cra_driver_name) >=
590 			CRYPTO_MAX_ALG_NAME)
591 		goto out_drop_alg;
592 
593 	inst->alg.base.cra_flags = rsa_alg->base.cra_flags & CRYPTO_ALG_ASYNC;
594 	inst->alg.base.cra_priority = rsa_alg->base.cra_priority;
595 	inst->alg.base.cra_ctxsize = sizeof(struct pkcs1pad_ctx);
596 
597 	inst->alg.init = pkcs1pad_init_tfm;
598 	inst->alg.exit = pkcs1pad_exit_tfm;
599 
600 	inst->alg.encrypt = pkcs1pad_encrypt;
601 	inst->alg.decrypt = pkcs1pad_decrypt;
602 	inst->alg.sign = pkcs1pad_sign;
603 	inst->alg.verify = pkcs1pad_verify;
604 	inst->alg.set_pub_key = pkcs1pad_set_pub_key;
605 	inst->alg.set_priv_key = pkcs1pad_set_priv_key;
606 	inst->alg.max_size = pkcs1pad_get_max_size;
607 	inst->alg.reqsize = sizeof(struct pkcs1pad_request) + rsa_alg->reqsize;
608 
609 	inst->free = pkcs1pad_free;
610 
611 	err = akcipher_register_instance(tmpl, inst);
612 	if (err)
613 		goto out_drop_alg;
614 
615 	return 0;
616 
617 out_drop_alg:
618 	crypto_drop_akcipher(spawn);
619 out_free_inst:
620 	kfree(inst);
621 	return err;
622 }
623 
624 struct crypto_template rsa_pkcs1pad_tmpl = {
625 	.name = "pkcs1pad",
626 	.create = pkcs1pad_create,
627 	.module = THIS_MODULE,
628 };
629