3 * PKCS stuff for rsa-sha256.
6 /* nettle, low-level cryptographics library
8 * Copyright (C) 2001, 2003, 2006 Niels Möller
10 * The nettle library is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU Lesser General Public License as published by
12 * the Free Software Foundation; either version 2.1 of the License, or (at your
13 * option) any later version.
15 * The nettle library is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
17 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
18 * License for more details.
20 * You should have received a copy of the GNU Lesser General Public License
21 * along with the nettle library; see the file COPYING.LIB. If not, write to
22 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
41 /* From RFC 3447, Public-Key Cryptography Standards (PKCS) #1: RSA
42 * Cryptography Specifications Version 2.1.
44 * id-sha256 OBJECT IDENTIFIER ::=
45 * {joint-iso-itu-t(2) country(16) us(840) organization(1)
46 * gov(101) csor(3) nistalgorithm(4) hashalgs(2) 1}
52 /* 19 octets prefix, 32 octets hash, total 51 */
53 0x30, 49, /* SEQUENCE */
54 0x30, 13, /* SEQUENCE */
55 0x06, 9, /* OBJECT IDENTIFIER */
56 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01,
58 0x04, 32 /* OCTET STRING */
59 /* Here comes the raw hash value */
63 pkcs1_rsa_sha256_encode(mpz_t m, size_t key_size, struct sha256_ctx *hash)
66 TMP_GMP_DECL(em, uint8_t);
68 TMP_GMP_ALLOC(em, key_size);
70 p = _pkcs1_signature_prefix(key_size, em,
71 sizeof(sha256_prefix),
76 sha256_digest(hash, SHA256_DIGEST_SIZE, p);
77 nettle_mpz_set_str_256_u(m, key_size, em);
89 pkcs1_rsa_sha256_encode_digest(mpz_t m, size_t key_size, const uint8_t *digest)
92 TMP_GMP_DECL(em, uint8_t);
94 TMP_GMP_ALLOC(em, key_size);
96 p = _pkcs1_signature_prefix(key_size, em,
97 sizeof(sha256_prefix),
102 memcpy(p, digest, SHA256_DIGEST_SIZE);
103 nettle_mpz_set_str_256_u(m, key_size, em);