xref: /freebsd/contrib/bearssl/src/rsa/rsa_i31_oaep_decrypt.c (revision b18a4ccab954b694b9ed6dcc83773f615c430d33)
1 /*
2  * Copyright (c) 2018 Thomas Pornin <pornin@bolet.org>
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining
5  * a copy of this software and associated documentation files (the
6  * "Software"), to deal in the Software without restriction, including
7  * without limitation the rights to use, copy, modify, merge, publish,
8  * distribute, sublicense, and/or sell copies of the Software, and to
9  * permit persons to whom the Software is furnished to do so, subject to
10  * the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be
13  * included in all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22  * SOFTWARE.
23  */
24 
25 #include "inner.h"
26 
27 /* see bearssl_rsa.h */
28 uint32_t
29 br_rsa_i31_oaep_decrypt(const br_hash_class *dig,
30 	const void *label, size_t label_len,
31 	const br_rsa_private_key *sk, void *data, size_t *len)
32 {
33 	uint32_t r;
34 
35 	if (*len != ((sk->n_bitlen + 7) >> 3)) {
36 		return 0;
37 	}
38 	r = br_rsa_i31_private(data, sk);
39 	r &= br_rsa_oaep_unpad(dig, label, label_len, data, len);
40 	return r;
41 }
42