Commit e69f1207 authored by bg's avatar bg

adding mgf1 source

parent 566eed83
/* mgf1.c */
/*
This file is part of the AVR-Crypto-Lib.
Copyright (C) 2010 Daniel Otte (daniel.otte@rub.de)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdint.h>
#include <string.h>
#include "mgf1.h"
#include "hfal-basic.h"
/*
* MGF1 as defined in PKCS #1 v2.1 B.2.1
*/
void mgf1_short_seed(void* dest, const void* seed, uint8_t seed_len_B, uint16_t out_length_B, const mgf1_parameter_t* p){
uint8_t buffer[seed_len_B+4];
uint32_t counter=1;
uint8_t hv_len = hfal_hash_getHashsize(p->hashfunction)/8;
memcpy(buffer, seed, seed_len_B);
memset(buffer + seed_len_B, 0, 4);
while(out_length_B >= hv_len){
hfal_hash_mem(p->hashfunction, dest, buffer, (seed_len_B + 4) * 8);
dest = (uint8_t*)dest + hv_len;
out_length_B -= hv_len;
buffer[seed_len_B + 3] = counter & 0xff;
buffer[seed_len_B + 2] = (counter>>8) & 0xff;
buffer[seed_len_B + 1] = (counter>>16) & 0xff;
buffer[seed_len_B + 0] = (counter>>24) & 0xff;
++counter;
}
if(out_length_B){
uint8_t hash_buffer[hv_len];
hfal_hash_mem(p->hashfunction, hash_buffer, buffer, (seed_len_B + 4) * 8);
memcpy(dest, hash_buffer, out_length_B);
}
}
void mgf1(void* dest, const void* seed, uint16_t seed_len_B, uint16_t out_length_B, const mgf1_parameter_t* p){
mgf1_short_seed(dest, seed, seed_len_B, out_length_B, p);
}
/* mgf1.h */
/*
This file is part of the AVR-Crypto-Lib.
Copyright (C) 2010 Daniel Otte (daniel.otte@rub.de)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef MGF1_H_
#define MGF1_H_
#include <stdint.h>
#include "hfal-basic.h"
typedef struct {
const hfdesc_t* hashfunction;
} mgf1_parameter_t;
/*
* MGF1 as defined in PKCS #1 v2.1 B.2.1
*/
void mgf1(void* dest, const void* seed, uint16_t seed_len_B, uint16_t out_length_B, const mgf1_parameter_t* p);
#endif /* MGF1_H_ */
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