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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 */
24static 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
30static 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
36static 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
42static 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
48static 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
54static 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
60static 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
66static 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
83static 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
93struct pkcs1pad_ctx {
94 struct crypto_akcipher *child;
95 const char *hash_name;
96 unsigned int key_size;
97};
98
99struct pkcs1pad_inst_ctx {
100 struct crypto_akcipher_spawn spawn;
101 const char *hash_name;
102};
103
104struct pkcs1pad_request {
105 struct akcipher_request child_req;
106
107 struct scatterlist in_sg[3], out_sg[2];
108 uint8_t *in_buf, *out_buf;
109};
110
111static int pkcs1pad_set_pub_key(struct crypto_akcipher *tfm, const void *key,
112 unsigned int keylen)
113{
114 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
115 int err, size;
116
117 err = crypto_akcipher_set_pub_key(ctx->child, key, keylen);
118
119 if (!err) {
120 /* Find out new modulus size from rsa implementation */
121 size = crypto_akcipher_maxsize(ctx->child);
122
123 ctx->key_size = size > 0 ? size : 0;
124 if (size <= 0)
125 err = size;
126 }
127
128 return err;
129}
130
131static int pkcs1pad_set_priv_key(struct crypto_akcipher *tfm, const void *key,
132 unsigned int keylen)
133{
134 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
135 int err, size;
136
137 err = crypto_akcipher_set_priv_key(ctx->child, key, keylen);
138
139 if (!err) {
140 /* Find out new modulus size from rsa implementation */
141 size = crypto_akcipher_maxsize(ctx->child);
142
143 ctx->key_size = size > 0 ? size : 0;
144 if (size <= 0)
145 err = size;
146 }
147
148 return err;
149}
150
151static 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 ?: -EINVAL;
162}
163
164static void pkcs1pad_sg_set_buf(struct scatterlist *sg, void *buf, size_t len,
165 struct scatterlist *next)
166{
167 int nsegs = next ? 1 : 0;
168
169 if (offset_in_page(buf) + len <= PAGE_SIZE) {
170 nsegs += 1;
171 sg_init_table(sg, nsegs);
172 sg_set_buf(sg, buf, len);
173 } else {
174 nsegs += 2;
175 sg_init_table(sg, nsegs);
176 sg_set_buf(sg + 0, buf, PAGE_SIZE - offset_in_page(buf));
177 sg_set_buf(sg + 1, buf + PAGE_SIZE - offset_in_page(buf),
178 offset_in_page(buf) + len - PAGE_SIZE);
179 }
180
181 if (next)
182 sg_chain(sg, nsegs, next);
183}
184
185static int pkcs1pad_encrypt_sign_complete(struct akcipher_request *req, int err)
186{
187 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
188 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
189 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
190 size_t pad_len = ctx->key_size - req_ctx->child_req.dst_len;
191 size_t chunk_len, pad_left;
192 struct sg_mapping_iter miter;
193
194 if (!err) {
195 if (pad_len) {
196 sg_miter_start(&miter, req->dst,
197 sg_nents_for_len(req->dst, pad_len),
198 SG_MITER_ATOMIC | SG_MITER_TO_SG);
199
200 pad_left = pad_len;
201 while (pad_left) {
202 sg_miter_next(&miter);
203
204 chunk_len = min(miter.length, pad_left);
205 memset(miter.addr, 0, chunk_len);
206 pad_left -= chunk_len;
207 }
208
209 sg_miter_stop(&miter);
210 }
211
212 sg_pcopy_from_buffer(req->dst,
213 sg_nents_for_len(req->dst, ctx->key_size),
214 req_ctx->out_buf, req_ctx->child_req.dst_len,
215 pad_len);
216 }
217 req->dst_len = ctx->key_size;
218
219 kfree(req_ctx->in_buf);
220 kzfree(req_ctx->out_buf);
221
222 return err;
223}
224
225static void pkcs1pad_encrypt_sign_complete_cb(
226 struct crypto_async_request *child_async_req, int err)
227{
228 struct akcipher_request *req = child_async_req->data;
229 struct crypto_async_request async_req;
230
231 if (err == -EINPROGRESS)
232 return;
233
234 async_req.data = req->base.data;
235 async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
236 async_req.flags = child_async_req->flags;
237 req->base.complete(&async_req,
238 pkcs1pad_encrypt_sign_complete(req, err));
239}
240
241static int pkcs1pad_encrypt(struct akcipher_request *req)
242{
243 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
244 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
245 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
246 int err;
247 unsigned int i, ps_end;
248
249 if (!ctx->key_size)
250 return -EINVAL;
251
252 if (req->src_len > ctx->key_size - 11)
253 return -EOVERFLOW;
254
255 if (req->dst_len < ctx->key_size) {
256 req->dst_len = ctx->key_size;
257 return -EOVERFLOW;
258 }
259
260 if (ctx->key_size > PAGE_SIZE)
261 return -ENOTSUPP;
262
263 /*
264 * Replace both input and output to add the padding in the input and
265 * the potential missing leading zeros in the output.
266 */
267 req_ctx->child_req.src = req_ctx->in_sg;
268 req_ctx->child_req.src_len = ctx->key_size - 1;
269 req_ctx->child_req.dst = req_ctx->out_sg;
270 req_ctx->child_req.dst_len = ctx->key_size;
271
272 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
273 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
274 GFP_KERNEL : GFP_ATOMIC);
275 if (!req_ctx->in_buf)
276 return -ENOMEM;
277
278 ps_end = ctx->key_size - req->src_len - 2;
279 req_ctx->in_buf[0] = 0x02;
280 for (i = 1; i < ps_end; i++)
281 req_ctx->in_buf[i] = 1 + prandom_u32_max(255);
282 req_ctx->in_buf[ps_end] = 0x00;
283
284 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
285 ctx->key_size - 1 - req->src_len, req->src);
286
287 req_ctx->out_buf = kmalloc(ctx->key_size,
288 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
289 GFP_KERNEL : GFP_ATOMIC);
290 if (!req_ctx->out_buf) {
291 kfree(req_ctx->in_buf);
292 return -ENOMEM;
293 }
294
295 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
296 ctx->key_size, NULL);
297
298 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
299 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
300 pkcs1pad_encrypt_sign_complete_cb, req);
301
302 err = crypto_akcipher_encrypt(&req_ctx->child_req);
303 if (err != -EINPROGRESS &&
304 (err != -EBUSY ||
305 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
306 return pkcs1pad_encrypt_sign_complete(req, err);
307
308 return err;
309}
310
311static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err)
312{
313 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
314 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
315 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
316 unsigned int pos;
317
318 if (err == -EOVERFLOW)
319 /* Decrypted value had no leading 0 byte */
320 err = -EINVAL;
321
322 if (err)
323 goto done;
324
325 if (req_ctx->child_req.dst_len != ctx->key_size - 1) {
326 err = -EINVAL;
327 goto done;
328 }
329
330 if (req_ctx->out_buf[0] != 0x02) {
331 err = -EINVAL;
332 goto done;
333 }
334 for (pos = 1; pos < req_ctx->child_req.dst_len; pos++)
335 if (req_ctx->out_buf[pos] == 0x00)
336 break;
337 if (pos < 9 || pos == req_ctx->child_req.dst_len) {
338 err = -EINVAL;
339 goto done;
340 }
341 pos++;
342
343 if (req->dst_len < req_ctx->child_req.dst_len - pos)
344 err = -EOVERFLOW;
345 req->dst_len = req_ctx->child_req.dst_len - pos;
346
347 if (!err)
348 sg_copy_from_buffer(req->dst,
349 sg_nents_for_len(req->dst, req->dst_len),
350 req_ctx->out_buf + pos, req->dst_len);
351
352done:
353 kzfree(req_ctx->out_buf);
354
355 return err;
356}
357
358static void pkcs1pad_decrypt_complete_cb(
359 struct crypto_async_request *child_async_req, int err)
360{
361 struct akcipher_request *req = child_async_req->data;
362 struct crypto_async_request async_req;
363
364 if (err == -EINPROGRESS)
365 return;
366
367 async_req.data = req->base.data;
368 async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
369 async_req.flags = child_async_req->flags;
370 req->base.complete(&async_req, pkcs1pad_decrypt_complete(req, err));
371}
372
373static int pkcs1pad_decrypt(struct akcipher_request *req)
374{
375 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
376 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
377 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
378 int err;
379
380 if (!ctx->key_size || req->src_len != ctx->key_size)
381 return -EINVAL;
382
383 if (ctx->key_size > PAGE_SIZE)
384 return -ENOTSUPP;
385
386 /* Reuse input buffer, output to a new buffer */
387 req_ctx->child_req.src = req->src;
388 req_ctx->child_req.src_len = req->src_len;
389 req_ctx->child_req.dst = req_ctx->out_sg;
390 req_ctx->child_req.dst_len = ctx->key_size ;
391
392 req_ctx->out_buf = kmalloc(ctx->key_size,
393 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
394 GFP_KERNEL : GFP_ATOMIC);
395 if (!req_ctx->out_buf)
396 return -ENOMEM;
397
398 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
399 ctx->key_size, NULL);
400
401 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
402 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
403 pkcs1pad_decrypt_complete_cb, req);
404
405 err = crypto_akcipher_decrypt(&req_ctx->child_req);
406 if (err != -EINPROGRESS &&
407 (err != -EBUSY ||
408 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
409 return pkcs1pad_decrypt_complete(req, err);
410
411 return err;
412}
413
414static int pkcs1pad_sign(struct akcipher_request *req)
415{
416 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
417 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
418 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
419 const struct rsa_asn1_template *digest_info = NULL;
420 int err;
421 unsigned int ps_end, digest_size = 0;
422
423 if (!ctx->key_size)
424 return -EINVAL;
425
426 if (ctx->hash_name) {
427 digest_info = rsa_lookup_asn1(ctx->hash_name);
428 if (!digest_info)
429 return -EINVAL;
430
431 digest_size = digest_info->size;
432 }
433
434 if (req->src_len + digest_size > ctx->key_size - 11)
435 return -EOVERFLOW;
436
437 if (req->dst_len < ctx->key_size) {
438 req->dst_len = ctx->key_size;
439 return -EOVERFLOW;
440 }
441
442 if (ctx->key_size > PAGE_SIZE)
443 return -ENOTSUPP;
444
445 /*
446 * Replace both input and output to add the padding in the input and
447 * the potential missing leading zeros in the output.
448 */
449 req_ctx->child_req.src = req_ctx->in_sg;
450 req_ctx->child_req.src_len = ctx->key_size - 1;
451 req_ctx->child_req.dst = req_ctx->out_sg;
452 req_ctx->child_req.dst_len = ctx->key_size;
453
454 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
455 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
456 GFP_KERNEL : GFP_ATOMIC);
457 if (!req_ctx->in_buf)
458 return -ENOMEM;
459
460 ps_end = ctx->key_size - digest_size - req->src_len - 2;
461 req_ctx->in_buf[0] = 0x01;
462 memset(req_ctx->in_buf + 1, 0xff, ps_end - 1);
463 req_ctx->in_buf[ps_end] = 0x00;
464
465 if (digest_info) {
466 memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data,
467 digest_info->size);
468 }
469
470 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
471 ctx->key_size - 1 - req->src_len, req->src);
472
473 req_ctx->out_buf = kmalloc(ctx->key_size,
474 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
475 GFP_KERNEL : GFP_ATOMIC);
476 if (!req_ctx->out_buf) {
477 kfree(req_ctx->in_buf);
478 return -ENOMEM;
479 }
480
481 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
482 ctx->key_size, NULL);
483
484 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
485 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
486 pkcs1pad_encrypt_sign_complete_cb, req);
487
488 err = crypto_akcipher_sign(&req_ctx->child_req);
489 if (err != -EINPROGRESS &&
490 (err != -EBUSY ||
491 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
492 return pkcs1pad_encrypt_sign_complete(req, err);
493
494 return err;
495}
496
497static int pkcs1pad_verify_complete(struct akcipher_request *req, int err)
498{
499 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
500 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
501 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
502 const struct rsa_asn1_template *digest_info;
503 unsigned int pos;
504
505 if (err == -EOVERFLOW)
506 /* Decrypted value had no leading 0 byte */
507 err = -EINVAL;
508
509 if (err)
510 goto done;
511
512 if (req_ctx->child_req.dst_len != ctx->key_size - 1) {
513 err = -EINVAL;
514 goto done;
515 }
516
517 err = -EBADMSG;
518 if (req_ctx->out_buf[0] != 0x01)
519 goto done;
520
521 for (pos = 1; pos < req_ctx->child_req.dst_len; pos++)
522 if (req_ctx->out_buf[pos] != 0xff)
523 break;
524
525 if (pos < 9 || pos == req_ctx->child_req.dst_len ||
526 req_ctx->out_buf[pos] != 0x00)
527 goto done;
528 pos++;
529
530 if (ctx->hash_name) {
531 digest_info = rsa_lookup_asn1(ctx->hash_name);
532 if (!digest_info)
533 goto done;
534
535 if (memcmp(req_ctx->out_buf + pos, digest_info->data,
536 digest_info->size))
537 goto done;
538
539 pos += digest_info->size;
540 }
541
542 err = 0;
543
544 if (req->dst_len < req_ctx->child_req.dst_len - pos)
545 err = -EOVERFLOW;
546 req->dst_len = req_ctx->child_req.dst_len - pos;
547
548 if (!err)
549 sg_copy_from_buffer(req->dst,
550 sg_nents_for_len(req->dst, req->dst_len),
551 req_ctx->out_buf + pos, req->dst_len);
552done:
553 kzfree(req_ctx->out_buf);
554
555 return err;
556}
557
558static void pkcs1pad_verify_complete_cb(
559 struct crypto_async_request *child_async_req, int err)
560{
561 struct akcipher_request *req = child_async_req->data;
562 struct crypto_async_request async_req;
563
564 if (err == -EINPROGRESS)
565 return;
566
567 async_req.data = req->base.data;
568 async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
569 async_req.flags = child_async_req->flags;
570 req->base.complete(&async_req, pkcs1pad_verify_complete(req, err));
571}
572
573/*
574 * The verify operation is here for completeness similar to the verification
575 * defined in RFC2313 section 10.2 except that block type 0 is not accepted,
576 * as in RFC2437. RFC2437 section 9.2 doesn't define any operation to
577 * retrieve the DigestInfo from a signature, instead the user is expected
578 * to call the sign operation to generate the expected signature and compare
579 * signatures instead of the message-digests.
580 */
581static int pkcs1pad_verify(struct akcipher_request *req)
582{
583 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
584 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
585 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
586 int err;
587
588 if (!ctx->key_size || req->src_len < ctx->key_size)
589 return -EINVAL;
590
591 if (ctx->key_size > PAGE_SIZE)
592 return -ENOTSUPP;
593
594 /* Reuse input buffer, output to a new buffer */
595 req_ctx->child_req.src = req->src;
596 req_ctx->child_req.src_len = req->src_len;
597 req_ctx->child_req.dst = req_ctx->out_sg;
598 req_ctx->child_req.dst_len = ctx->key_size;
599
600 req_ctx->out_buf = kmalloc(ctx->key_size,
601 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
602 GFP_KERNEL : GFP_ATOMIC);
603 if (!req_ctx->out_buf)
604 return -ENOMEM;
605
606 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
607 ctx->key_size, NULL);
608
609 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
610 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
611 pkcs1pad_verify_complete_cb, req);
612
613 err = crypto_akcipher_verify(&req_ctx->child_req);
614 if (err != -EINPROGRESS &&
615 (err != -EBUSY ||
616 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
617 return pkcs1pad_verify_complete(req, err);
618
619 return err;
620}
621
622static int pkcs1pad_init_tfm(struct crypto_akcipher *tfm)
623{
624 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
625 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
626 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
627 struct crypto_akcipher *child_tfm;
628
629 child_tfm = crypto_spawn_akcipher(akcipher_instance_ctx(inst));
630 if (IS_ERR(child_tfm))
631 return PTR_ERR(child_tfm);
632
633 ctx->child = child_tfm;
634 ctx->hash_name = ictx->hash_name;
635 return 0;
636}
637
638static void pkcs1pad_exit_tfm(struct crypto_akcipher *tfm)
639{
640 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
641
642 crypto_free_akcipher(ctx->child);
643}
644
645static void pkcs1pad_free(struct akcipher_instance *inst)
646{
647 struct pkcs1pad_inst_ctx *ctx = akcipher_instance_ctx(inst);
648 struct crypto_akcipher_spawn *spawn = &ctx->spawn;
649
650 crypto_drop_akcipher(spawn);
651 kfree(ctx->hash_name);
652 kfree(inst);
653}
654
655static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
656{
657 struct crypto_attr_type *algt;
658 struct akcipher_instance *inst;
659 struct pkcs1pad_inst_ctx *ctx;
660 struct crypto_akcipher_spawn *spawn;
661 struct akcipher_alg *rsa_alg;
662 const char *rsa_alg_name;
663 const char *hash_name;
664 int err;
665
666 algt = crypto_get_attr_type(tb);
667 if (IS_ERR(algt))
668 return PTR_ERR(algt);
669
670 if ((algt->type ^ CRYPTO_ALG_TYPE_AKCIPHER) & algt->mask)
671 return -EINVAL;
672
673 rsa_alg_name = crypto_attr_alg_name(tb[1]);
674 if (IS_ERR(rsa_alg_name))
675 return PTR_ERR(rsa_alg_name);
676
677 hash_name = crypto_attr_alg_name(tb[2]);
678 if (IS_ERR(hash_name))
679 hash_name = NULL;
680
681 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
682 if (!inst)
683 return -ENOMEM;
684
685 ctx = akcipher_instance_ctx(inst);
686 spawn = &ctx->spawn;
687 ctx->hash_name = hash_name ? kstrdup(hash_name, GFP_KERNEL) : NULL;
688
689 crypto_set_spawn(&spawn->base, akcipher_crypto_instance(inst));
690 err = crypto_grab_akcipher(spawn, rsa_alg_name, 0,
691 crypto_requires_sync(algt->type, algt->mask));
692 if (err)
693 goto out_free_inst;
694
695 rsa_alg = crypto_spawn_akcipher_alg(spawn);
696
697 err = -ENAMETOOLONG;
698
699 if (!hash_name) {
700 if (snprintf(inst->alg.base.cra_name,
701 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
702 rsa_alg->base.cra_name) >=
703 CRYPTO_MAX_ALG_NAME ||
704 snprintf(inst->alg.base.cra_driver_name,
705 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
706 rsa_alg->base.cra_driver_name) >=
707 CRYPTO_MAX_ALG_NAME)
708 goto out_drop_alg;
709 } else {
710 if (snprintf(inst->alg.base.cra_name,
711 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s,%s)",
712 rsa_alg->base.cra_name, hash_name) >=
713 CRYPTO_MAX_ALG_NAME ||
714 snprintf(inst->alg.base.cra_driver_name,
715 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s,%s)",
716 rsa_alg->base.cra_driver_name, hash_name) >=
717 CRYPTO_MAX_ALG_NAME)
718 goto out_free_hash;
719 }
720
721 inst->alg.base.cra_flags = rsa_alg->base.cra_flags & CRYPTO_ALG_ASYNC;
722 inst->alg.base.cra_priority = rsa_alg->base.cra_priority;
723 inst->alg.base.cra_ctxsize = sizeof(struct pkcs1pad_ctx);
724
725 inst->alg.init = pkcs1pad_init_tfm;
726 inst->alg.exit = pkcs1pad_exit_tfm;
727
728 inst->alg.encrypt = pkcs1pad_encrypt;
729 inst->alg.decrypt = pkcs1pad_decrypt;
730 inst->alg.sign = pkcs1pad_sign;
731 inst->alg.verify = pkcs1pad_verify;
732 inst->alg.set_pub_key = pkcs1pad_set_pub_key;
733 inst->alg.set_priv_key = pkcs1pad_set_priv_key;
734 inst->alg.max_size = pkcs1pad_get_max_size;
735 inst->alg.reqsize = sizeof(struct pkcs1pad_request) + rsa_alg->reqsize;
736
737 inst->free = pkcs1pad_free;
738
739 err = akcipher_register_instance(tmpl, inst);
740 if (err)
741 goto out_free_hash;
742
743 return 0;
744
745out_free_hash:
746 kfree(ctx->hash_name);
747out_drop_alg:
748 crypto_drop_akcipher(spawn);
749out_free_inst:
750 kfree(inst);
751 return err;
752}
753
754struct crypto_template rsa_pkcs1pad_tmpl = {
755 .name = "pkcs1pad",
756 .create = pkcs1pad_create,
757 .module = THIS_MODULE,
758};
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * RSA padding templates.
4 *
5 * Copyright (c) 2015 Intel Corporation
6 */
7
8#include <crypto/algapi.h>
9#include <crypto/akcipher.h>
10#include <crypto/internal/akcipher.h>
11#include <crypto/internal/rsa.h>
12#include <linux/err.h>
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/random.h>
17#include <linux/scatterlist.h>
18
19/*
20 * Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2].
21 */
22static const u8 rsa_digest_info_md5[] = {
23 0x30, 0x20, 0x30, 0x0c, 0x06, 0x08,
24 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x02, 0x05, /* OID */
25 0x05, 0x00, 0x04, 0x10
26};
27
28static const u8 rsa_digest_info_sha1[] = {
29 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
30 0x2b, 0x0e, 0x03, 0x02, 0x1a,
31 0x05, 0x00, 0x04, 0x14
32};
33
34static const u8 rsa_digest_info_rmd160[] = {
35 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
36 0x2b, 0x24, 0x03, 0x02, 0x01,
37 0x05, 0x00, 0x04, 0x14
38};
39
40static const u8 rsa_digest_info_sha224[] = {
41 0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09,
42 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04,
43 0x05, 0x00, 0x04, 0x1c
44};
45
46static const u8 rsa_digest_info_sha256[] = {
47 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09,
48 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01,
49 0x05, 0x00, 0x04, 0x20
50};
51
52static const u8 rsa_digest_info_sha384[] = {
53 0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
54 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02,
55 0x05, 0x00, 0x04, 0x30
56};
57
58static const u8 rsa_digest_info_sha512[] = {
59 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09,
60 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03,
61 0x05, 0x00, 0x04, 0x40
62};
63
64static const u8 rsa_digest_info_sha3_256[] = {
65 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09,
66 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x08,
67 0x05, 0x00, 0x04, 0x20
68};
69
70static const u8 rsa_digest_info_sha3_384[] = {
71 0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
72 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x09,
73 0x05, 0x00, 0x04, 0x30
74};
75
76static const u8 rsa_digest_info_sha3_512[] = {
77 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09,
78 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x0A,
79 0x05, 0x00, 0x04, 0x40
80};
81
82static const struct rsa_asn1_template {
83 const char *name;
84 const u8 *data;
85 size_t size;
86} rsa_asn1_templates[] = {
87#define _(X) { #X, rsa_digest_info_##X, sizeof(rsa_digest_info_##X) }
88 _(md5),
89 _(sha1),
90 _(rmd160),
91 _(sha256),
92 _(sha384),
93 _(sha512),
94 _(sha224),
95#undef _
96#define _(X) { "sha3-" #X, rsa_digest_info_sha3_##X, sizeof(rsa_digest_info_sha3_##X) }
97 _(256),
98 _(384),
99 _(512),
100#undef _
101 { NULL }
102};
103
104static const struct rsa_asn1_template *rsa_lookup_asn1(const char *name)
105{
106 const struct rsa_asn1_template *p;
107
108 for (p = rsa_asn1_templates; p->name; p++)
109 if (strcmp(name, p->name) == 0)
110 return p;
111 return NULL;
112}
113
114struct pkcs1pad_ctx {
115 struct crypto_akcipher *child;
116 unsigned int key_size;
117};
118
119struct pkcs1pad_inst_ctx {
120 struct crypto_akcipher_spawn spawn;
121 const struct rsa_asn1_template *digest_info;
122};
123
124struct pkcs1pad_request {
125 struct scatterlist in_sg[2], out_sg[1];
126 uint8_t *in_buf, *out_buf;
127 struct akcipher_request child_req;
128};
129
130static int pkcs1pad_set_pub_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_pub_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
151static int pkcs1pad_set_priv_key(struct crypto_akcipher *tfm, const void *key,
152 unsigned int keylen)
153{
154 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
155 int err;
156
157 ctx->key_size = 0;
158
159 err = crypto_akcipher_set_priv_key(ctx->child, key, keylen);
160 if (err)
161 return err;
162
163 /* Find out new modulus size from rsa implementation */
164 err = crypto_akcipher_maxsize(ctx->child);
165 if (err > PAGE_SIZE)
166 return -ENOTSUPP;
167
168 ctx->key_size = err;
169 return 0;
170}
171
172static unsigned int pkcs1pad_get_max_size(struct crypto_akcipher *tfm)
173{
174 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
175
176 /*
177 * The maximum destination buffer size for the encrypt/sign operations
178 * will be the same as for RSA, even though it's smaller for
179 * decrypt/verify.
180 */
181
182 return ctx->key_size;
183}
184
185static void pkcs1pad_sg_set_buf(struct scatterlist *sg, void *buf, size_t len,
186 struct scatterlist *next)
187{
188 int nsegs = next ? 2 : 1;
189
190 sg_init_table(sg, nsegs);
191 sg_set_buf(sg, buf, len);
192
193 if (next)
194 sg_chain(sg, nsegs, next);
195}
196
197static int pkcs1pad_encrypt_sign_complete(struct akcipher_request *req, int err)
198{
199 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
200 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
201 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
202 unsigned int pad_len;
203 unsigned int len;
204 u8 *out_buf;
205
206 if (err)
207 goto out;
208
209 len = req_ctx->child_req.dst_len;
210 pad_len = ctx->key_size - len;
211
212 /* Four billion to one */
213 if (likely(!pad_len))
214 goto out;
215
216 out_buf = kzalloc(ctx->key_size, GFP_ATOMIC);
217 err = -ENOMEM;
218 if (!out_buf)
219 goto out;
220
221 sg_copy_to_buffer(req->dst, sg_nents_for_len(req->dst, len),
222 out_buf + pad_len, len);
223 sg_copy_from_buffer(req->dst,
224 sg_nents_for_len(req->dst, ctx->key_size),
225 out_buf, ctx->key_size);
226 kfree_sensitive(out_buf);
227
228out:
229 req->dst_len = ctx->key_size;
230
231 kfree(req_ctx->in_buf);
232
233 return err;
234}
235
236static void pkcs1pad_encrypt_sign_complete_cb(void *data, int err)
237{
238 struct akcipher_request *req = data;
239
240 if (err == -EINPROGRESS)
241 goto out;
242
243 err = pkcs1pad_encrypt_sign_complete(req, err);
244
245out:
246 akcipher_request_complete(req, err);
247}
248
249static int pkcs1pad_encrypt(struct akcipher_request *req)
250{
251 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
252 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
253 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
254 int err;
255 unsigned int i, ps_end;
256
257 if (!ctx->key_size)
258 return -EINVAL;
259
260 if (req->src_len > ctx->key_size - 11)
261 return -EOVERFLOW;
262
263 if (req->dst_len < ctx->key_size) {
264 req->dst_len = ctx->key_size;
265 return -EOVERFLOW;
266 }
267
268 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
269 GFP_KERNEL);
270 if (!req_ctx->in_buf)
271 return -ENOMEM;
272
273 ps_end = ctx->key_size - req->src_len - 2;
274 req_ctx->in_buf[0] = 0x02;
275 for (i = 1; i < ps_end; i++)
276 req_ctx->in_buf[i] = get_random_u32_inclusive(1, 255);
277 req_ctx->in_buf[ps_end] = 0x00;
278
279 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
280 ctx->key_size - 1 - req->src_len, req->src);
281
282 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
283 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
284 pkcs1pad_encrypt_sign_complete_cb, req);
285
286 /* Reuse output buffer */
287 akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg,
288 req->dst, ctx->key_size - 1, req->dst_len);
289
290 err = crypto_akcipher_encrypt(&req_ctx->child_req);
291 if (err != -EINPROGRESS && err != -EBUSY)
292 return pkcs1pad_encrypt_sign_complete(req, err);
293
294 return err;
295}
296
297static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err)
298{
299 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
300 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
301 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
302 unsigned int dst_len;
303 unsigned int pos;
304 u8 *out_buf;
305
306 if (err)
307 goto done;
308
309 err = -EINVAL;
310 dst_len = req_ctx->child_req.dst_len;
311 if (dst_len < ctx->key_size - 1)
312 goto done;
313
314 out_buf = req_ctx->out_buf;
315 if (dst_len == ctx->key_size) {
316 if (out_buf[0] != 0x00)
317 /* Decrypted value had no leading 0 byte */
318 goto done;
319
320 dst_len--;
321 out_buf++;
322 }
323
324 if (out_buf[0] != 0x02)
325 goto done;
326
327 for (pos = 1; pos < dst_len; pos++)
328 if (out_buf[pos] == 0x00)
329 break;
330 if (pos < 9 || pos == dst_len)
331 goto done;
332 pos++;
333
334 err = 0;
335
336 if (req->dst_len < dst_len - pos)
337 err = -EOVERFLOW;
338 req->dst_len = dst_len - pos;
339
340 if (!err)
341 sg_copy_from_buffer(req->dst,
342 sg_nents_for_len(req->dst, req->dst_len),
343 out_buf + pos, req->dst_len);
344
345done:
346 kfree_sensitive(req_ctx->out_buf);
347
348 return err;
349}
350
351static void pkcs1pad_decrypt_complete_cb(void *data, int err)
352{
353 struct akcipher_request *req = data;
354
355 if (err == -EINPROGRESS)
356 goto out;
357
358 err = pkcs1pad_decrypt_complete(req, err);
359
360out:
361 akcipher_request_complete(req, err);
362}
363
364static int pkcs1pad_decrypt(struct akcipher_request *req)
365{
366 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
367 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
368 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
369 int err;
370
371 if (!ctx->key_size || req->src_len != ctx->key_size)
372 return -EINVAL;
373
374 req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL);
375 if (!req_ctx->out_buf)
376 return -ENOMEM;
377
378 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
379 ctx->key_size, NULL);
380
381 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
382 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
383 pkcs1pad_decrypt_complete_cb, req);
384
385 /* Reuse input buffer, output to a new buffer */
386 akcipher_request_set_crypt(&req_ctx->child_req, req->src,
387 req_ctx->out_sg, req->src_len,
388 ctx->key_size);
389
390 err = crypto_akcipher_decrypt(&req_ctx->child_req);
391 if (err != -EINPROGRESS && err != -EBUSY)
392 return pkcs1pad_decrypt_complete(req, err);
393
394 return err;
395}
396
397static int pkcs1pad_sign(struct akcipher_request *req)
398{
399 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
400 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
401 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
402 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
403 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
404 const struct rsa_asn1_template *digest_info = ictx->digest_info;
405 int err;
406 unsigned int ps_end, digest_info_size = 0;
407
408 if (!ctx->key_size)
409 return -EINVAL;
410
411 if (digest_info)
412 digest_info_size = digest_info->size;
413
414 if (req->src_len + digest_info_size > ctx->key_size - 11)
415 return -EOVERFLOW;
416
417 if (req->dst_len < ctx->key_size) {
418 req->dst_len = ctx->key_size;
419 return -EOVERFLOW;
420 }
421
422 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
423 GFP_KERNEL);
424 if (!req_ctx->in_buf)
425 return -ENOMEM;
426
427 ps_end = ctx->key_size - digest_info_size - req->src_len - 2;
428 req_ctx->in_buf[0] = 0x01;
429 memset(req_ctx->in_buf + 1, 0xff, ps_end - 1);
430 req_ctx->in_buf[ps_end] = 0x00;
431
432 if (digest_info)
433 memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data,
434 digest_info->size);
435
436 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
437 ctx->key_size - 1 - req->src_len, req->src);
438
439 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
440 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
441 pkcs1pad_encrypt_sign_complete_cb, req);
442
443 /* Reuse output buffer */
444 akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg,
445 req->dst, ctx->key_size - 1, req->dst_len);
446
447 err = crypto_akcipher_decrypt(&req_ctx->child_req);
448 if (err != -EINPROGRESS && err != -EBUSY)
449 return pkcs1pad_encrypt_sign_complete(req, err);
450
451 return err;
452}
453
454static int pkcs1pad_verify_complete(struct akcipher_request *req, int err)
455{
456 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
457 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
458 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
459 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
460 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
461 const struct rsa_asn1_template *digest_info = ictx->digest_info;
462 const unsigned int sig_size = req->src_len;
463 const unsigned int digest_size = req->dst_len;
464 unsigned int dst_len;
465 unsigned int pos;
466 u8 *out_buf;
467
468 if (err)
469 goto done;
470
471 err = -EINVAL;
472 dst_len = req_ctx->child_req.dst_len;
473 if (dst_len < ctx->key_size - 1)
474 goto done;
475
476 out_buf = req_ctx->out_buf;
477 if (dst_len == ctx->key_size) {
478 if (out_buf[0] != 0x00)
479 /* Decrypted value had no leading 0 byte */
480 goto done;
481
482 dst_len--;
483 out_buf++;
484 }
485
486 err = -EBADMSG;
487 if (out_buf[0] != 0x01)
488 goto done;
489
490 for (pos = 1; pos < dst_len; pos++)
491 if (out_buf[pos] != 0xff)
492 break;
493
494 if (pos < 9 || pos == dst_len || out_buf[pos] != 0x00)
495 goto done;
496 pos++;
497
498 if (digest_info) {
499 if (digest_info->size > dst_len - pos)
500 goto done;
501 if (crypto_memneq(out_buf + pos, digest_info->data,
502 digest_info->size))
503 goto done;
504
505 pos += digest_info->size;
506 }
507
508 err = 0;
509
510 if (digest_size != dst_len - pos) {
511 err = -EKEYREJECTED;
512 req->dst_len = dst_len - pos;
513 goto done;
514 }
515 /* Extract appended digest. */
516 sg_pcopy_to_buffer(req->src,
517 sg_nents_for_len(req->src, sig_size + digest_size),
518 req_ctx->out_buf + ctx->key_size,
519 digest_size, sig_size);
520 /* Do the actual verification step. */
521 if (memcmp(req_ctx->out_buf + ctx->key_size, out_buf + pos,
522 digest_size) != 0)
523 err = -EKEYREJECTED;
524done:
525 kfree_sensitive(req_ctx->out_buf);
526
527 return err;
528}
529
530static void pkcs1pad_verify_complete_cb(void *data, int err)
531{
532 struct akcipher_request *req = data;
533
534 if (err == -EINPROGRESS)
535 goto out;
536
537 err = pkcs1pad_verify_complete(req, err);
538
539out:
540 akcipher_request_complete(req, err);
541}
542
543/*
544 * The verify operation is here for completeness similar to the verification
545 * defined in RFC2313 section 10.2 except that block type 0 is not accepted,
546 * as in RFC2437. RFC2437 section 9.2 doesn't define any operation to
547 * retrieve the DigestInfo from a signature, instead the user is expected
548 * to call the sign operation to generate the expected signature and compare
549 * signatures instead of the message-digests.
550 */
551static int pkcs1pad_verify(struct akcipher_request *req)
552{
553 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
554 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
555 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
556 const unsigned int sig_size = req->src_len;
557 const unsigned int digest_size = req->dst_len;
558 int err;
559
560 if (WARN_ON(req->dst) || WARN_ON(!digest_size) ||
561 !ctx->key_size || sig_size != ctx->key_size)
562 return -EINVAL;
563
564 req_ctx->out_buf = kmalloc(ctx->key_size + digest_size, GFP_KERNEL);
565 if (!req_ctx->out_buf)
566 return -ENOMEM;
567
568 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
569 ctx->key_size, NULL);
570
571 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
572 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
573 pkcs1pad_verify_complete_cb, req);
574
575 /* Reuse input buffer, output to a new buffer */
576 akcipher_request_set_crypt(&req_ctx->child_req, req->src,
577 req_ctx->out_sg, sig_size, ctx->key_size);
578
579 err = crypto_akcipher_encrypt(&req_ctx->child_req);
580 if (err != -EINPROGRESS && err != -EBUSY)
581 return pkcs1pad_verify_complete(req, err);
582
583 return err;
584}
585
586static int pkcs1pad_init_tfm(struct crypto_akcipher *tfm)
587{
588 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
589 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
590 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
591 struct crypto_akcipher *child_tfm;
592
593 child_tfm = crypto_spawn_akcipher(&ictx->spawn);
594 if (IS_ERR(child_tfm))
595 return PTR_ERR(child_tfm);
596
597 ctx->child = child_tfm;
598
599 akcipher_set_reqsize(tfm, sizeof(struct pkcs1pad_request) +
600 crypto_akcipher_reqsize(child_tfm));
601
602 return 0;
603}
604
605static void pkcs1pad_exit_tfm(struct crypto_akcipher *tfm)
606{
607 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
608
609 crypto_free_akcipher(ctx->child);
610}
611
612static void pkcs1pad_free(struct akcipher_instance *inst)
613{
614 struct pkcs1pad_inst_ctx *ctx = akcipher_instance_ctx(inst);
615 struct crypto_akcipher_spawn *spawn = &ctx->spawn;
616
617 crypto_drop_akcipher(spawn);
618 kfree(inst);
619}
620
621static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
622{
623 u32 mask;
624 struct akcipher_instance *inst;
625 struct pkcs1pad_inst_ctx *ctx;
626 struct akcipher_alg *rsa_alg;
627 const char *hash_name;
628 int err;
629
630 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AKCIPHER, &mask);
631 if (err)
632 return err;
633
634 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
635 if (!inst)
636 return -ENOMEM;
637
638 ctx = akcipher_instance_ctx(inst);
639
640 err = crypto_grab_akcipher(&ctx->spawn, akcipher_crypto_instance(inst),
641 crypto_attr_alg_name(tb[1]), 0, mask);
642 if (err)
643 goto err_free_inst;
644
645 rsa_alg = crypto_spawn_akcipher_alg(&ctx->spawn);
646
647 if (strcmp(rsa_alg->base.cra_name, "rsa") != 0) {
648 err = -EINVAL;
649 goto err_free_inst;
650 }
651
652 err = -ENAMETOOLONG;
653 hash_name = crypto_attr_alg_name(tb[2]);
654 if (IS_ERR(hash_name)) {
655 if (snprintf(inst->alg.base.cra_name,
656 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
657 rsa_alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
658 goto err_free_inst;
659
660 if (snprintf(inst->alg.base.cra_driver_name,
661 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
662 rsa_alg->base.cra_driver_name) >=
663 CRYPTO_MAX_ALG_NAME)
664 goto err_free_inst;
665 } else {
666 ctx->digest_info = rsa_lookup_asn1(hash_name);
667 if (!ctx->digest_info) {
668 err = -EINVAL;
669 goto err_free_inst;
670 }
671
672 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
673 "pkcs1pad(%s,%s)", rsa_alg->base.cra_name,
674 hash_name) >= CRYPTO_MAX_ALG_NAME)
675 goto err_free_inst;
676
677 if (snprintf(inst->alg.base.cra_driver_name,
678 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s,%s)",
679 rsa_alg->base.cra_driver_name,
680 hash_name) >= CRYPTO_MAX_ALG_NAME)
681 goto err_free_inst;
682 }
683
684 inst->alg.base.cra_priority = rsa_alg->base.cra_priority;
685 inst->alg.base.cra_ctxsize = sizeof(struct pkcs1pad_ctx);
686
687 inst->alg.init = pkcs1pad_init_tfm;
688 inst->alg.exit = pkcs1pad_exit_tfm;
689
690 inst->alg.encrypt = pkcs1pad_encrypt;
691 inst->alg.decrypt = pkcs1pad_decrypt;
692 inst->alg.sign = pkcs1pad_sign;
693 inst->alg.verify = pkcs1pad_verify;
694 inst->alg.set_pub_key = pkcs1pad_set_pub_key;
695 inst->alg.set_priv_key = pkcs1pad_set_priv_key;
696 inst->alg.max_size = pkcs1pad_get_max_size;
697
698 inst->free = pkcs1pad_free;
699
700 err = akcipher_register_instance(tmpl, inst);
701 if (err) {
702err_free_inst:
703 pkcs1pad_free(inst);
704 }
705 return err;
706}
707
708struct crypto_template rsa_pkcs1pad_tmpl = {
709 .name = "pkcs1pad",
710 .create = pkcs1pad_create,
711 .module = THIS_MODULE,
712};
713
714MODULE_ALIAS_CRYPTO("pkcs1pad");