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 /*
22 * Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2].
23 */
24 static const u8 rsa_digest_info_md5[] = {
25 0x30, 0x20, 0x30, 0x0c, 0x06, 0x08,
26 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x02, 0x05, /* OID */
27 0x05, 0x00, 0x04, 0x10
28 };
29
30 static const u8 rsa_digest_info_sha1[] = {
31 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
32 0x2b, 0x0e, 0x03, 0x02, 0x1a,
33 0x05, 0x00, 0x04, 0x14
34 };
35
36 static const u8 rsa_digest_info_rmd160[] = {
37 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
38 0x2b, 0x24, 0x03, 0x02, 0x01,
39 0x05, 0x00, 0x04, 0x14
40 };
41
42 static const u8 rsa_digest_info_sha224[] = {
43 0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09,
44 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04,
45 0x05, 0x00, 0x04, 0x1c
46 };
47
48 static const u8 rsa_digest_info_sha256[] = {
49 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09,
50 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01,
51 0x05, 0x00, 0x04, 0x20
52 };
53
54 static const u8 rsa_digest_info_sha384[] = {
55 0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
56 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02,
57 0x05, 0x00, 0x04, 0x30
58 };
59
60 static const u8 rsa_digest_info_sha512[] = {
61 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09,
62 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03,
63 0x05, 0x00, 0x04, 0x40
64 };
65
66 static const struct rsa_asn1_template {
67 const char *name;
68 const u8 *data;
69 size_t size;
70 } rsa_asn1_templates[] = {
71 #define _(X) { #X, rsa_digest_info_##X, sizeof(rsa_digest_info_##X) }
72 _(md5),
73 _(sha1),
74 _(rmd160),
75 _(sha256),
76 _(sha384),
77 _(sha512),
78 _(sha224),
79 { NULL }
80 #undef _
81 };
82
rsa_lookup_asn1(const char * name)83 static const struct rsa_asn1_template *rsa_lookup_asn1(const char *name)
84 {
85 const struct rsa_asn1_template *p;
86
87 for (p = rsa_asn1_templates; p->name; p++)
88 if (strcmp(name, p->name) == 0)
89 return p;
90 return NULL;
91 }
92
93 struct pkcs1pad_ctx {
94 struct crypto_akcipher *child;
95 unsigned int key_size;
96 };
97
98 struct pkcs1pad_inst_ctx {
99 struct crypto_akcipher_spawn spawn;
100 const struct rsa_asn1_template *digest_info;
101 };
102
103 struct pkcs1pad_request {
104 struct scatterlist in_sg[2], out_sg[1];
105 uint8_t *in_buf, *out_buf;
106 struct akcipher_request child_req;
107 };
108
pkcs1pad_set_pub_key(struct crypto_akcipher * tfm,const void * key,unsigned int keylen)109 static int pkcs1pad_set_pub_key(struct crypto_akcipher *tfm, const void *key,
110 unsigned int keylen)
111 {
112 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
113 int err;
114
115 ctx->key_size = 0;
116
117 err = crypto_akcipher_set_pub_key(ctx->child, key, keylen);
118 if (err)
119 return err;
120
121 /* Find out new modulus size from rsa implementation */
122 err = crypto_akcipher_maxsize(ctx->child);
123 if (err > PAGE_SIZE)
124 return -ENOTSUPP;
125
126 ctx->key_size = err;
127 return 0;
128 }
129
pkcs1pad_set_priv_key(struct crypto_akcipher * tfm,const void * key,unsigned int keylen)130 static int pkcs1pad_set_priv_key(struct crypto_akcipher *tfm, const void *key,
131 unsigned int keylen)
132 {
133 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
134 int err;
135
136 ctx->key_size = 0;
137
138 err = crypto_akcipher_set_priv_key(ctx->child, key, keylen);
139 if (err)
140 return err;
141
142 /* Find out new modulus size from rsa implementation */
143 err = crypto_akcipher_maxsize(ctx->child);
144 if (err > PAGE_SIZE)
145 return -ENOTSUPP;
146
147 ctx->key_size = err;
148 return 0;
149 }
150
pkcs1pad_get_max_size(struct crypto_akcipher * tfm)151 static unsigned int pkcs1pad_get_max_size(struct crypto_akcipher *tfm)
152 {
153 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
154
155 /*
156 * The maximum destination buffer size for the encrypt/sign operations
157 * will be the same as for RSA, even though it's smaller for
158 * decrypt/verify.
159 */
160
161 return ctx->key_size;
162 }
163
pkcs1pad_sg_set_buf(struct scatterlist * sg,void * buf,size_t len,struct scatterlist * next)164 static void pkcs1pad_sg_set_buf(struct scatterlist *sg, void *buf, size_t len,
165 struct scatterlist *next)
166 {
167 int nsegs = next ? 2 : 1;
168
169 sg_init_table(sg, nsegs);
170 sg_set_buf(sg, buf, len);
171
172 if (next)
173 sg_chain(sg, nsegs, next);
174 }
175
pkcs1pad_encrypt_sign_complete(struct akcipher_request * req,int err)176 static int pkcs1pad_encrypt_sign_complete(struct akcipher_request *req, int err)
177 {
178 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
179 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
180 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
181 unsigned int pad_len;
182 unsigned int len;
183 u8 *out_buf;
184
185 if (err)
186 goto out;
187
188 len = req_ctx->child_req.dst_len;
189 pad_len = ctx->key_size - len;
190
191 /* Four billion to one */
192 if (likely(!pad_len))
193 goto out;
194
195 out_buf = kzalloc(ctx->key_size, GFP_ATOMIC);
196 err = -ENOMEM;
197 if (!out_buf)
198 goto out;
199
200 sg_copy_to_buffer(req->dst, sg_nents_for_len(req->dst, len),
201 out_buf + pad_len, len);
202 sg_copy_from_buffer(req->dst,
203 sg_nents_for_len(req->dst, ctx->key_size),
204 out_buf, ctx->key_size);
205 kzfree(out_buf);
206
207 out:
208 req->dst_len = ctx->key_size;
209
210 kfree(req_ctx->in_buf);
211
212 return err;
213 }
214
pkcs1pad_encrypt_sign_complete_cb(struct crypto_async_request * child_async_req,int err)215 static void pkcs1pad_encrypt_sign_complete_cb(
216 struct crypto_async_request *child_async_req, int err)
217 {
218 struct akcipher_request *req = child_async_req->data;
219 struct crypto_async_request async_req;
220
221 if (err == -EINPROGRESS)
222 return;
223
224 async_req.data = req->base.data;
225 async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
226 async_req.flags = child_async_req->flags;
227 req->base.complete(&async_req,
228 pkcs1pad_encrypt_sign_complete(req, err));
229 }
230
pkcs1pad_encrypt(struct akcipher_request * req)231 static int pkcs1pad_encrypt(struct akcipher_request *req)
232 {
233 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
234 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
235 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
236 int err;
237 unsigned int i, ps_end;
238
239 if (!ctx->key_size)
240 return -EINVAL;
241
242 if (req->src_len > ctx->key_size - 11)
243 return -EOVERFLOW;
244
245 if (req->dst_len < ctx->key_size) {
246 req->dst_len = ctx->key_size;
247 return -EOVERFLOW;
248 }
249
250 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
251 GFP_KERNEL);
252 if (!req_ctx->in_buf)
253 return -ENOMEM;
254
255 ps_end = ctx->key_size - req->src_len - 2;
256 req_ctx->in_buf[0] = 0x02;
257 for (i = 1; i < ps_end; i++)
258 req_ctx->in_buf[i] = 1 + prandom_u32_max(255);
259 req_ctx->in_buf[ps_end] = 0x00;
260
261 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
262 ctx->key_size - 1 - req->src_len, req->src);
263
264 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
265 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
266 pkcs1pad_encrypt_sign_complete_cb, req);
267
268 /* Reuse output buffer */
269 akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg,
270 req->dst, ctx->key_size - 1, req->dst_len);
271
272 err = crypto_akcipher_encrypt(&req_ctx->child_req);
273 if (err != -EINPROGRESS &&
274 (err != -EBUSY ||
275 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
276 return pkcs1pad_encrypt_sign_complete(req, err);
277
278 return err;
279 }
280
pkcs1pad_decrypt_complete(struct akcipher_request * req,int err)281 static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err)
282 {
283 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
284 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
285 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
286 unsigned int dst_len;
287 unsigned int pos;
288 u8 *out_buf;
289
290 if (err)
291 goto done;
292
293 err = -EINVAL;
294 dst_len = req_ctx->child_req.dst_len;
295 if (dst_len < ctx->key_size - 1)
296 goto done;
297
298 out_buf = req_ctx->out_buf;
299 if (dst_len == ctx->key_size) {
300 if (out_buf[0] != 0x00)
301 /* Decrypted value had no leading 0 byte */
302 goto done;
303
304 dst_len--;
305 out_buf++;
306 }
307
308 if (out_buf[0] != 0x02)
309 goto done;
310
311 for (pos = 1; pos < dst_len; pos++)
312 if (out_buf[pos] == 0x00)
313 break;
314 if (pos < 9 || pos == dst_len)
315 goto done;
316 pos++;
317
318 err = 0;
319
320 if (req->dst_len < dst_len - pos)
321 err = -EOVERFLOW;
322 req->dst_len = dst_len - pos;
323
324 if (!err)
325 sg_copy_from_buffer(req->dst,
326 sg_nents_for_len(req->dst, req->dst_len),
327 out_buf + pos, req->dst_len);
328
329 done:
330 kzfree(req_ctx->out_buf);
331
332 return err;
333 }
334
pkcs1pad_decrypt_complete_cb(struct crypto_async_request * child_async_req,int err)335 static void pkcs1pad_decrypt_complete_cb(
336 struct crypto_async_request *child_async_req, int err)
337 {
338 struct akcipher_request *req = child_async_req->data;
339 struct crypto_async_request async_req;
340
341 if (err == -EINPROGRESS)
342 return;
343
344 async_req.data = req->base.data;
345 async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
346 async_req.flags = child_async_req->flags;
347 req->base.complete(&async_req, pkcs1pad_decrypt_complete(req, err));
348 }
349
pkcs1pad_decrypt(struct akcipher_request * req)350 static int pkcs1pad_decrypt(struct akcipher_request *req)
351 {
352 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
353 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
354 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
355 int err;
356
357 if (!ctx->key_size || req->src_len != ctx->key_size)
358 return -EINVAL;
359
360 req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL);
361 if (!req_ctx->out_buf)
362 return -ENOMEM;
363
364 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
365 ctx->key_size, NULL);
366
367 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
368 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
369 pkcs1pad_decrypt_complete_cb, req);
370
371 /* Reuse input buffer, output to a new buffer */
372 akcipher_request_set_crypt(&req_ctx->child_req, req->src,
373 req_ctx->out_sg, req->src_len,
374 ctx->key_size);
375
376 err = crypto_akcipher_decrypt(&req_ctx->child_req);
377 if (err != -EINPROGRESS &&
378 (err != -EBUSY ||
379 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
380 return pkcs1pad_decrypt_complete(req, err);
381
382 return err;
383 }
384
pkcs1pad_sign(struct akcipher_request * req)385 static int pkcs1pad_sign(struct akcipher_request *req)
386 {
387 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
388 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
389 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
390 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
391 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
392 const struct rsa_asn1_template *digest_info = ictx->digest_info;
393 int err;
394 unsigned int ps_end, digest_size = 0;
395
396 if (!ctx->key_size)
397 return -EINVAL;
398
399 digest_size = digest_info->size;
400
401 if (req->src_len + digest_size > ctx->key_size - 11)
402 return -EOVERFLOW;
403
404 if (req->dst_len < ctx->key_size) {
405 req->dst_len = ctx->key_size;
406 return -EOVERFLOW;
407 }
408
409 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
410 GFP_KERNEL);
411 if (!req_ctx->in_buf)
412 return -ENOMEM;
413
414 ps_end = ctx->key_size - digest_size - req->src_len - 2;
415 req_ctx->in_buf[0] = 0x01;
416 memset(req_ctx->in_buf + 1, 0xff, ps_end - 1);
417 req_ctx->in_buf[ps_end] = 0x00;
418
419 memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data,
420 digest_info->size);
421
422 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
423 ctx->key_size - 1 - req->src_len, req->src);
424
425 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
426 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
427 pkcs1pad_encrypt_sign_complete_cb, req);
428
429 /* Reuse output buffer */
430 akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg,
431 req->dst, ctx->key_size - 1, req->dst_len);
432
433 err = crypto_akcipher_sign(&req_ctx->child_req);
434 if (err != -EINPROGRESS &&
435 (err != -EBUSY ||
436 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
437 return pkcs1pad_encrypt_sign_complete(req, err);
438
439 return err;
440 }
441
pkcs1pad_verify_complete(struct akcipher_request * req,int err)442 static int pkcs1pad_verify_complete(struct akcipher_request *req, int err)
443 {
444 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
445 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
446 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
447 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
448 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
449 const struct rsa_asn1_template *digest_info = ictx->digest_info;
450 unsigned int dst_len;
451 unsigned int pos;
452 u8 *out_buf;
453
454 if (err)
455 goto done;
456
457 err = -EINVAL;
458 dst_len = req_ctx->child_req.dst_len;
459 if (dst_len < ctx->key_size - 1)
460 goto done;
461
462 out_buf = req_ctx->out_buf;
463 if (dst_len == ctx->key_size) {
464 if (out_buf[0] != 0x00)
465 /* Decrypted value had no leading 0 byte */
466 goto done;
467
468 dst_len--;
469 out_buf++;
470 }
471
472 err = -EBADMSG;
473 if (out_buf[0] != 0x01)
474 goto done;
475
476 for (pos = 1; pos < dst_len; pos++)
477 if (out_buf[pos] != 0xff)
478 break;
479
480 if (pos < 9 || pos == dst_len || out_buf[pos] != 0x00)
481 goto done;
482 pos++;
483
484 if (crypto_memneq(out_buf + pos, digest_info->data, digest_info->size))
485 goto done;
486
487 pos += digest_info->size;
488
489 err = 0;
490
491 if (req->dst_len < dst_len - pos)
492 err = -EOVERFLOW;
493 req->dst_len = dst_len - pos;
494
495 if (!err)
496 sg_copy_from_buffer(req->dst,
497 sg_nents_for_len(req->dst, req->dst_len),
498 out_buf + pos, req->dst_len);
499 done:
500 kzfree(req_ctx->out_buf);
501
502 return err;
503 }
504
pkcs1pad_verify_complete_cb(struct crypto_async_request * child_async_req,int err)505 static void pkcs1pad_verify_complete_cb(
506 struct crypto_async_request *child_async_req, int err)
507 {
508 struct akcipher_request *req = child_async_req->data;
509 struct crypto_async_request async_req;
510
511 if (err == -EINPROGRESS)
512 return;
513
514 async_req.data = req->base.data;
515 async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
516 async_req.flags = child_async_req->flags;
517 req->base.complete(&async_req, pkcs1pad_verify_complete(req, err));
518 }
519
520 /*
521 * The verify operation is here for completeness similar to the verification
522 * defined in RFC2313 section 10.2 except that block type 0 is not accepted,
523 * as in RFC2437. RFC2437 section 9.2 doesn't define any operation to
524 * retrieve the DigestInfo from a signature, instead the user is expected
525 * to call the sign operation to generate the expected signature and compare
526 * signatures instead of the message-digests.
527 */
pkcs1pad_verify(struct akcipher_request * req)528 static int pkcs1pad_verify(struct akcipher_request *req)
529 {
530 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
531 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
532 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
533 int err;
534
535 if (!ctx->key_size || req->src_len < ctx->key_size)
536 return -EINVAL;
537
538 req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL);
539 if (!req_ctx->out_buf)
540 return -ENOMEM;
541
542 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
543 ctx->key_size, NULL);
544
545 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
546 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
547 pkcs1pad_verify_complete_cb, req);
548
549 /* Reuse input buffer, output to a new buffer */
550 akcipher_request_set_crypt(&req_ctx->child_req, req->src,
551 req_ctx->out_sg, req->src_len,
552 ctx->key_size);
553
554 err = crypto_akcipher_verify(&req_ctx->child_req);
555 if (err != -EINPROGRESS &&
556 (err != -EBUSY ||
557 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
558 return pkcs1pad_verify_complete(req, err);
559
560 return err;
561 }
562
pkcs1pad_init_tfm(struct crypto_akcipher * tfm)563 static int pkcs1pad_init_tfm(struct crypto_akcipher *tfm)
564 {
565 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
566 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
567 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
568 struct crypto_akcipher *child_tfm;
569
570 child_tfm = crypto_spawn_akcipher(&ictx->spawn);
571 if (IS_ERR(child_tfm))
572 return PTR_ERR(child_tfm);
573
574 ctx->child = child_tfm;
575 return 0;
576 }
577
pkcs1pad_exit_tfm(struct crypto_akcipher * tfm)578 static void pkcs1pad_exit_tfm(struct crypto_akcipher *tfm)
579 {
580 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
581
582 crypto_free_akcipher(ctx->child);
583 }
584
pkcs1pad_free(struct akcipher_instance * inst)585 static void pkcs1pad_free(struct akcipher_instance *inst)
586 {
587 struct pkcs1pad_inst_ctx *ctx = akcipher_instance_ctx(inst);
588 struct crypto_akcipher_spawn *spawn = &ctx->spawn;
589
590 crypto_drop_akcipher(spawn);
591 kfree(inst);
592 }
593
pkcs1pad_create(struct crypto_template * tmpl,struct rtattr ** tb)594 static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
595 {
596 const struct rsa_asn1_template *digest_info;
597 struct crypto_attr_type *algt;
598 struct akcipher_instance *inst;
599 struct pkcs1pad_inst_ctx *ctx;
600 struct crypto_akcipher_spawn *spawn;
601 struct akcipher_alg *rsa_alg;
602 const char *rsa_alg_name;
603 const char *hash_name;
604 int err;
605
606 algt = crypto_get_attr_type(tb);
607 if (IS_ERR(algt))
608 return PTR_ERR(algt);
609
610 if ((algt->type ^ CRYPTO_ALG_TYPE_AKCIPHER) & algt->mask)
611 return -EINVAL;
612
613 rsa_alg_name = crypto_attr_alg_name(tb[1]);
614 if (IS_ERR(rsa_alg_name))
615 return PTR_ERR(rsa_alg_name);
616
617 hash_name = crypto_attr_alg_name(tb[2]);
618 if (IS_ERR(hash_name))
619 return PTR_ERR(hash_name);
620
621 digest_info = rsa_lookup_asn1(hash_name);
622 if (!digest_info)
623 return -EINVAL;
624
625 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
626 if (!inst)
627 return -ENOMEM;
628
629 ctx = akcipher_instance_ctx(inst);
630 spawn = &ctx->spawn;
631 ctx->digest_info = digest_info;
632
633 crypto_set_spawn(&spawn->base, akcipher_crypto_instance(inst));
634 err = crypto_grab_akcipher(spawn, rsa_alg_name, 0,
635 crypto_requires_sync(algt->type, algt->mask));
636 if (err)
637 goto out_free_inst;
638
639 rsa_alg = crypto_spawn_akcipher_alg(spawn);
640
641 err = -ENAMETOOLONG;
642
643 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
644 "pkcs1pad(%s,%s)", rsa_alg->base.cra_name, hash_name) >=
645 CRYPTO_MAX_ALG_NAME ||
646 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
647 "pkcs1pad(%s,%s)",
648 rsa_alg->base.cra_driver_name, hash_name) >=
649 CRYPTO_MAX_ALG_NAME)
650 goto out_drop_alg;
651
652 inst->alg.base.cra_flags = rsa_alg->base.cra_flags & CRYPTO_ALG_ASYNC;
653 inst->alg.base.cra_priority = rsa_alg->base.cra_priority;
654 inst->alg.base.cra_ctxsize = sizeof(struct pkcs1pad_ctx);
655
656 inst->alg.init = pkcs1pad_init_tfm;
657 inst->alg.exit = pkcs1pad_exit_tfm;
658
659 inst->alg.encrypt = pkcs1pad_encrypt;
660 inst->alg.decrypt = pkcs1pad_decrypt;
661 inst->alg.sign = pkcs1pad_sign;
662 inst->alg.verify = pkcs1pad_verify;
663 inst->alg.set_pub_key = pkcs1pad_set_pub_key;
664 inst->alg.set_priv_key = pkcs1pad_set_priv_key;
665 inst->alg.max_size = pkcs1pad_get_max_size;
666 inst->alg.reqsize = sizeof(struct pkcs1pad_request) + rsa_alg->reqsize;
667
668 inst->free = pkcs1pad_free;
669
670 err = akcipher_register_instance(tmpl, inst);
671 if (err)
672 goto out_drop_alg;
673
674 return 0;
675
676 out_drop_alg:
677 crypto_drop_akcipher(spawn);
678 out_free_inst:
679 kfree(inst);
680 return err;
681 }
682
683 struct crypto_template rsa_pkcs1pad_tmpl = {
684 .name = "pkcs1pad",
685 .create = pkcs1pad_create,
686 .module = THIS_MODULE,
687 };
688