3 This file is part of the AVR-Crypto-Lib.
4 Copyright (C) 2010 Daniel Otte (daniel.otte@rub.de)
6 This program is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
23 #include "hfal-basic.h"
26 * MGF1 as defined in PKCS #1 v2.1 B.2.1
30 void mgf1_short_seed(void* dest, const void* seed, uint8_t seed_len_B, uint16_t out_length_B, const mgf1_parameter_t* p){
31 uint8_t buffer[seed_len_B+4];
33 uint8_t hv_len = hfal_hash_getHashsize(p->hashfunction)/8;
34 memcpy(buffer, seed, seed_len_B);
35 memset(buffer + seed_len_B, 0, 4);
36 while(out_length_B >= hv_len){
37 hfal_hash_mem(p->hashfunction, dest, buffer, (seed_len_B + 4) * 8);
38 dest = (uint8_t*)dest + hv_len;
39 out_length_B -= hv_len;
40 buffer[seed_len_B + 3] = counter & 0xff;
41 buffer[seed_len_B + 2] = (counter>>8) & 0xff;
42 buffer[seed_len_B + 1] = (counter>>16) & 0xff;
43 buffer[seed_len_B + 0] = (counter>>24) & 0xff;
47 uint8_t hash_buffer[hv_len];
48 hfal_hash_mem(p->hashfunction, hash_buffer, buffer, (seed_len_B + 4) * 8);
49 memcpy(dest, hash_buffer, out_length_B);
53 void mgf1(void* dest, const void* seed, uint16_t seed_len_B, uint16_t out_length_B, const mgf1_parameter_t* p){
54 mgf1_short_seed(dest, seed, seed_len_B, out_length_B, p);