2 * RSA padding templates.
4 * Copyright (c) 2015 Intel Corporation
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)
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>
22 * Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2].
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
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
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
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
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
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
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
66 static const struct rsa_asn1_template
{
70 } rsa_asn1_templates
[] = {
71 #define _(X) { #X, rsa_digest_info_##X, sizeof(rsa_digest_info_##X) }
83 static const struct rsa_asn1_template
*rsa_lookup_asn1(const char *name
)
85 const struct rsa_asn1_template
*p
;
87 for (p
= rsa_asn1_templates
; p
->name
; p
++)
88 if (strcmp(name
, p
->name
) == 0)
94 struct crypto_akcipher
*child
;
95 unsigned int key_size
;
98 struct pkcs1pad_inst_ctx
{
99 struct crypto_akcipher_spawn spawn
;
100 const struct rsa_asn1_template
*digest_info
;
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
;
109 static int pkcs1pad_set_pub_key(struct crypto_akcipher
*tfm
, const void *key
,
112 struct pkcs1pad_ctx
*ctx
= akcipher_tfm_ctx(tfm
);
117 err
= crypto_akcipher_set_pub_key(ctx
->child
, key
, keylen
);
121 /* Find out new modulus size from rsa implementation */
122 err
= crypto_akcipher_maxsize(ctx
->child
);
130 static int pkcs1pad_set_priv_key(struct crypto_akcipher
*tfm
, const void *key
,
133 struct pkcs1pad_ctx
*ctx
= akcipher_tfm_ctx(tfm
);
138 err
= crypto_akcipher_set_priv_key(ctx
->child
, key
, keylen
);
142 /* Find out new modulus size from rsa implementation */
143 err
= crypto_akcipher_maxsize(ctx
->child
);
151 static unsigned int pkcs1pad_get_max_size(struct crypto_akcipher
*tfm
)
153 struct pkcs1pad_ctx
*ctx
= akcipher_tfm_ctx(tfm
);
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
161 return ctx
->key_size
;
164 static void pkcs1pad_sg_set_buf(struct scatterlist
*sg
, void *buf
, size_t len
,
165 struct scatterlist
*next
)
167 int nsegs
= next
? 2 : 1;
169 sg_init_table(sg
, nsegs
);
170 sg_set_buf(sg
, buf
, len
);
173 sg_chain(sg
, nsegs
, next
);
176 static int pkcs1pad_encrypt_sign_complete(struct akcipher_request
*req
, int err
)
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
;
188 len
= req_ctx
->child_req
.dst_len
;
189 pad_len
= ctx
->key_size
- len
;
191 /* Four billion to one */
192 if (likely(!pad_len
))
195 out_buf
= kzalloc(ctx
->key_size
, GFP_KERNEL
);
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
);
208 req
->dst_len
= ctx
->key_size
;
210 kfree(req_ctx
->in_buf
);
215 static void pkcs1pad_encrypt_sign_complete_cb(
216 struct crypto_async_request
*child_async_req
, int err
)
218 struct akcipher_request
*req
= child_async_req
->data
;
219 struct crypto_async_request async_req
;
221 if (err
== -EINPROGRESS
)
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
));
231 static int pkcs1pad_encrypt(struct akcipher_request
*req
)
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
);
237 unsigned int i
, ps_end
;
242 if (req
->src_len
> ctx
->key_size
- 11)
245 if (req
->dst_len
< ctx
->key_size
) {
246 req
->dst_len
= ctx
->key_size
;
250 req_ctx
->in_buf
= kmalloc(ctx
->key_size
- 1 - req
->src_len
,
252 if (!req_ctx
->in_buf
)
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;
261 pkcs1pad_sg_set_buf(req_ctx
->in_sg
, req_ctx
->in_buf
,
262 ctx
->key_size
- 1 - req
->src_len
, req
->src
);
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
);
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
);
272 err
= crypto_akcipher_encrypt(&req_ctx
->child_req
);
273 if (err
!= -EINPROGRESS
&& err
!= -EBUSY
)
274 return pkcs1pad_encrypt_sign_complete(req
, err
);
279 static int pkcs1pad_decrypt_complete(struct akcipher_request
*req
, int err
)
281 struct crypto_akcipher
*tfm
= crypto_akcipher_reqtfm(req
);
282 struct pkcs1pad_ctx
*ctx
= akcipher_tfm_ctx(tfm
);
283 struct pkcs1pad_request
*req_ctx
= akcipher_request_ctx(req
);
284 unsigned int dst_len
;
292 dst_len
= req_ctx
->child_req
.dst_len
;
293 if (dst_len
< ctx
->key_size
- 1)
296 out_buf
= req_ctx
->out_buf
;
297 if (dst_len
== ctx
->key_size
) {
298 if (out_buf
[0] != 0x00)
299 /* Decrypted value had no leading 0 byte */
306 if (out_buf
[0] != 0x02)
309 for (pos
= 1; pos
< dst_len
; pos
++)
310 if (out_buf
[pos
] == 0x00)
312 if (pos
< 9 || pos
== dst_len
)
318 if (req
->dst_len
< dst_len
- pos
)
320 req
->dst_len
= dst_len
- pos
;
323 sg_copy_from_buffer(req
->dst
,
324 sg_nents_for_len(req
->dst
, req
->dst_len
),
325 out_buf
+ pos
, req
->dst_len
);
328 kzfree(req_ctx
->out_buf
);
333 static void pkcs1pad_decrypt_complete_cb(
334 struct crypto_async_request
*child_async_req
, int err
)
336 struct akcipher_request
*req
= child_async_req
->data
;
337 struct crypto_async_request async_req
;
339 if (err
== -EINPROGRESS
)
342 async_req
.data
= req
->base
.data
;
343 async_req
.tfm
= crypto_akcipher_tfm(crypto_akcipher_reqtfm(req
));
344 async_req
.flags
= child_async_req
->flags
;
345 req
->base
.complete(&async_req
, pkcs1pad_decrypt_complete(req
, err
));
348 static int pkcs1pad_decrypt(struct akcipher_request
*req
)
350 struct crypto_akcipher
*tfm
= crypto_akcipher_reqtfm(req
);
351 struct pkcs1pad_ctx
*ctx
= akcipher_tfm_ctx(tfm
);
352 struct pkcs1pad_request
*req_ctx
= akcipher_request_ctx(req
);
355 if (!ctx
->key_size
|| req
->src_len
!= ctx
->key_size
)
358 req_ctx
->out_buf
= kmalloc(ctx
->key_size
, GFP_KERNEL
);
359 if (!req_ctx
->out_buf
)
362 pkcs1pad_sg_set_buf(req_ctx
->out_sg
, req_ctx
->out_buf
,
363 ctx
->key_size
, NULL
);
365 akcipher_request_set_tfm(&req_ctx
->child_req
, ctx
->child
);
366 akcipher_request_set_callback(&req_ctx
->child_req
, req
->base
.flags
,
367 pkcs1pad_decrypt_complete_cb
, req
);
369 /* Reuse input buffer, output to a new buffer */
370 akcipher_request_set_crypt(&req_ctx
->child_req
, req
->src
,
371 req_ctx
->out_sg
, req
->src_len
,
374 err
= crypto_akcipher_decrypt(&req_ctx
->child_req
);
375 if (err
!= -EINPROGRESS
&& err
!= -EBUSY
)
376 return pkcs1pad_decrypt_complete(req
, err
);
381 static int pkcs1pad_sign(struct akcipher_request
*req
)
383 struct crypto_akcipher
*tfm
= crypto_akcipher_reqtfm(req
);
384 struct pkcs1pad_ctx
*ctx
= akcipher_tfm_ctx(tfm
);
385 struct pkcs1pad_request
*req_ctx
= akcipher_request_ctx(req
);
386 struct akcipher_instance
*inst
= akcipher_alg_instance(tfm
);
387 struct pkcs1pad_inst_ctx
*ictx
= akcipher_instance_ctx(inst
);
388 const struct rsa_asn1_template
*digest_info
= ictx
->digest_info
;
390 unsigned int ps_end
, digest_size
= 0;
396 digest_size
= digest_info
->size
;
398 if (req
->src_len
+ digest_size
> ctx
->key_size
- 11)
401 if (req
->dst_len
< ctx
->key_size
) {
402 req
->dst_len
= ctx
->key_size
;
406 req_ctx
->in_buf
= kmalloc(ctx
->key_size
- 1 - req
->src_len
,
408 if (!req_ctx
->in_buf
)
411 ps_end
= ctx
->key_size
- digest_size
- req
->src_len
- 2;
412 req_ctx
->in_buf
[0] = 0x01;
413 memset(req_ctx
->in_buf
+ 1, 0xff, ps_end
- 1);
414 req_ctx
->in_buf
[ps_end
] = 0x00;
417 memcpy(req_ctx
->in_buf
+ ps_end
+ 1, digest_info
->data
,
420 pkcs1pad_sg_set_buf(req_ctx
->in_sg
, req_ctx
->in_buf
,
421 ctx
->key_size
- 1 - req
->src_len
, req
->src
);
423 akcipher_request_set_tfm(&req_ctx
->child_req
, ctx
->child
);
424 akcipher_request_set_callback(&req_ctx
->child_req
, req
->base
.flags
,
425 pkcs1pad_encrypt_sign_complete_cb
, req
);
427 /* Reuse output buffer */
428 akcipher_request_set_crypt(&req_ctx
->child_req
, req_ctx
->in_sg
,
429 req
->dst
, ctx
->key_size
- 1, req
->dst_len
);
431 err
= crypto_akcipher_sign(&req_ctx
->child_req
);
432 if (err
!= -EINPROGRESS
&& err
!= -EBUSY
)
433 return pkcs1pad_encrypt_sign_complete(req
, err
);
438 static int pkcs1pad_verify_complete(struct akcipher_request
*req
, int err
)
440 struct crypto_akcipher
*tfm
= crypto_akcipher_reqtfm(req
);
441 struct pkcs1pad_ctx
*ctx
= akcipher_tfm_ctx(tfm
);
442 struct pkcs1pad_request
*req_ctx
= akcipher_request_ctx(req
);
443 struct akcipher_instance
*inst
= akcipher_alg_instance(tfm
);
444 struct pkcs1pad_inst_ctx
*ictx
= akcipher_instance_ctx(inst
);
445 const struct rsa_asn1_template
*digest_info
= ictx
->digest_info
;
446 unsigned int dst_len
;
454 dst_len
= req_ctx
->child_req
.dst_len
;
455 if (dst_len
< ctx
->key_size
- 1)
458 out_buf
= req_ctx
->out_buf
;
459 if (dst_len
== ctx
->key_size
) {
460 if (out_buf
[0] != 0x00)
461 /* Decrypted value had no leading 0 byte */
469 if (out_buf
[0] != 0x01)
472 for (pos
= 1; pos
< dst_len
; pos
++)
473 if (out_buf
[pos
] != 0xff)
476 if (pos
< 9 || pos
== dst_len
|| out_buf
[pos
] != 0x00)
481 if (crypto_memneq(out_buf
+ pos
, digest_info
->data
,
485 pos
+= digest_info
->size
;
490 if (req
->dst_len
< dst_len
- pos
)
492 req
->dst_len
= dst_len
- pos
;
495 sg_copy_from_buffer(req
->dst
,
496 sg_nents_for_len(req
->dst
, req
->dst_len
),
497 out_buf
+ pos
, req
->dst_len
);
499 kzfree(req_ctx
->out_buf
);
504 static void pkcs1pad_verify_complete_cb(
505 struct crypto_async_request
*child_async_req
, int err
)
507 struct akcipher_request
*req
= child_async_req
->data
;
508 struct crypto_async_request async_req
;
510 if (err
== -EINPROGRESS
)
513 async_req
.data
= req
->base
.data
;
514 async_req
.tfm
= crypto_akcipher_tfm(crypto_akcipher_reqtfm(req
));
515 async_req
.flags
= child_async_req
->flags
;
516 req
->base
.complete(&async_req
, pkcs1pad_verify_complete(req
, err
));
520 * The verify operation is here for completeness similar to the verification
521 * defined in RFC2313 section 10.2 except that block type 0 is not accepted,
522 * as in RFC2437. RFC2437 section 9.2 doesn't define any operation to
523 * retrieve the DigestInfo from a signature, instead the user is expected
524 * to call the sign operation to generate the expected signature and compare
525 * signatures instead of the message-digests.
527 static int pkcs1pad_verify(struct akcipher_request
*req
)
529 struct crypto_akcipher
*tfm
= crypto_akcipher_reqtfm(req
);
530 struct pkcs1pad_ctx
*ctx
= akcipher_tfm_ctx(tfm
);
531 struct pkcs1pad_request
*req_ctx
= akcipher_request_ctx(req
);
534 if (!ctx
->key_size
|| req
->src_len
< ctx
->key_size
)
537 req_ctx
->out_buf
= kmalloc(ctx
->key_size
, GFP_KERNEL
);
538 if (!req_ctx
->out_buf
)
541 pkcs1pad_sg_set_buf(req_ctx
->out_sg
, req_ctx
->out_buf
,
542 ctx
->key_size
, NULL
);
544 akcipher_request_set_tfm(&req_ctx
->child_req
, ctx
->child
);
545 akcipher_request_set_callback(&req_ctx
->child_req
, req
->base
.flags
,
546 pkcs1pad_verify_complete_cb
, req
);
548 /* Reuse input buffer, output to a new buffer */
549 akcipher_request_set_crypt(&req_ctx
->child_req
, req
->src
,
550 req_ctx
->out_sg
, req
->src_len
,
553 err
= crypto_akcipher_verify(&req_ctx
->child_req
);
554 if (err
!= -EINPROGRESS
&& err
!= -EBUSY
)
555 return pkcs1pad_verify_complete(req
, err
);
560 static int pkcs1pad_init_tfm(struct crypto_akcipher
*tfm
)
562 struct akcipher_instance
*inst
= akcipher_alg_instance(tfm
);
563 struct pkcs1pad_inst_ctx
*ictx
= akcipher_instance_ctx(inst
);
564 struct pkcs1pad_ctx
*ctx
= akcipher_tfm_ctx(tfm
);
565 struct crypto_akcipher
*child_tfm
;
567 child_tfm
= crypto_spawn_akcipher(&ictx
->spawn
);
568 if (IS_ERR(child_tfm
))
569 return PTR_ERR(child_tfm
);
571 ctx
->child
= child_tfm
;
575 static void pkcs1pad_exit_tfm(struct crypto_akcipher
*tfm
)
577 struct pkcs1pad_ctx
*ctx
= akcipher_tfm_ctx(tfm
);
579 crypto_free_akcipher(ctx
->child
);
582 static void pkcs1pad_free(struct akcipher_instance
*inst
)
584 struct pkcs1pad_inst_ctx
*ctx
= akcipher_instance_ctx(inst
);
585 struct crypto_akcipher_spawn
*spawn
= &ctx
->spawn
;
587 crypto_drop_akcipher(spawn
);
591 static int pkcs1pad_create(struct crypto_template
*tmpl
, struct rtattr
**tb
)
593 const struct rsa_asn1_template
*digest_info
;
594 struct crypto_attr_type
*algt
;
595 struct akcipher_instance
*inst
;
596 struct pkcs1pad_inst_ctx
*ctx
;
597 struct crypto_akcipher_spawn
*spawn
;
598 struct akcipher_alg
*rsa_alg
;
599 const char *rsa_alg_name
;
600 const char *hash_name
;
603 algt
= crypto_get_attr_type(tb
);
605 return PTR_ERR(algt
);
607 if ((algt
->type
^ CRYPTO_ALG_TYPE_AKCIPHER
) & algt
->mask
)
610 rsa_alg_name
= crypto_attr_alg_name(tb
[1]);
611 if (IS_ERR(rsa_alg_name
))
612 return PTR_ERR(rsa_alg_name
);
614 hash_name
= crypto_attr_alg_name(tb
[2]);
615 if (IS_ERR(hash_name
))
619 digest_info
= rsa_lookup_asn1(hash_name
);
625 inst
= kzalloc(sizeof(*inst
) + sizeof(*ctx
), GFP_KERNEL
);
629 ctx
= akcipher_instance_ctx(inst
);
631 ctx
->digest_info
= digest_info
;
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
));
639 rsa_alg
= crypto_spawn_akcipher_alg(spawn
);
644 if (snprintf(inst
->alg
.base
.cra_name
,
645 CRYPTO_MAX_ALG_NAME
, "pkcs1pad(%s)",
646 rsa_alg
->base
.cra_name
) >= CRYPTO_MAX_ALG_NAME
)
649 if (snprintf(inst
->alg
.base
.cra_driver_name
,
650 CRYPTO_MAX_ALG_NAME
, "pkcs1pad(%s)",
651 rsa_alg
->base
.cra_driver_name
) >=
655 if (snprintf(inst
->alg
.base
.cra_name
, CRYPTO_MAX_ALG_NAME
,
656 "pkcs1pad(%s,%s)", rsa_alg
->base
.cra_name
,
657 hash_name
) >= CRYPTO_MAX_ALG_NAME
)
660 if (snprintf(inst
->alg
.base
.cra_driver_name
,
661 CRYPTO_MAX_ALG_NAME
, "pkcs1pad(%s,%s)",
662 rsa_alg
->base
.cra_driver_name
,
663 hash_name
) >= CRYPTO_MAX_ALG_NAME
)
667 inst
->alg
.base
.cra_flags
= rsa_alg
->base
.cra_flags
& CRYPTO_ALG_ASYNC
;
668 inst
->alg
.base
.cra_priority
= rsa_alg
->base
.cra_priority
;
669 inst
->alg
.base
.cra_ctxsize
= sizeof(struct pkcs1pad_ctx
);
671 inst
->alg
.init
= pkcs1pad_init_tfm
;
672 inst
->alg
.exit
= pkcs1pad_exit_tfm
;
674 inst
->alg
.encrypt
= pkcs1pad_encrypt
;
675 inst
->alg
.decrypt
= pkcs1pad_decrypt
;
676 inst
->alg
.sign
= pkcs1pad_sign
;
677 inst
->alg
.verify
= pkcs1pad_verify
;
678 inst
->alg
.set_pub_key
= pkcs1pad_set_pub_key
;
679 inst
->alg
.set_priv_key
= pkcs1pad_set_priv_key
;
680 inst
->alg
.max_size
= pkcs1pad_get_max_size
;
681 inst
->alg
.reqsize
= sizeof(struct pkcs1pad_request
) + rsa_alg
->reqsize
;
683 inst
->free
= pkcs1pad_free
;
685 err
= akcipher_register_instance(tmpl
, inst
);
692 crypto_drop_akcipher(spawn
);
698 struct crypto_template rsa_pkcs1pad_tmpl
= {
700 .create
= pkcs1pad_create
,
701 .module
= THIS_MODULE
,